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Background Risdiplam has been approved for Compassionate Use (CUP) since 2019, for SMA type 1 and type 2 who could not receive the approved treatment for the disease. It’s an orally administered drug targeting SMN2 gene. More than 200 patients have had access to this program in Italy, up to June 2021. Aims To describe the clinical and demographic features of patients included in CUP amongst the iSMAc’ Italian centers. Methods This is a retrospective study including demographic, neuromotor, respiratory and nutritional data, shifts, adverse events and dropouts. Results 44 out of 576 Italian iSMAc patients (7.6%) are on risdiplam (8 SMA1, 36 SMA2). Age ranges: 0-10 yrs (n = 1, SMA2); 11-17 yrs (n = 13, 4 SMA1, 9 SMA2); 18-25 yrs (n = 15, 3 SMA1, 12 SMA2); 18-25 yrs (n = 15.3 SMA1, 12 SMA2) and older than 25 yrs (n=14 SMA2). The majority (73%) are non-sitters. Concerning respiratory status, 6 patients are in invasive-ventilation, 26 use NIV and 8 patients do not require respiratory support. Regarding the nutritional status, 11 have a PEG and 12 have dysphagia. About 20% of patients switched from nusinersen for difficulties in intrathecal administration. 3 dropped-out respectively for side-effects, subjective inefficacy, shift to gene therapy. Conclusions Considering the criteria to access risdiplam so far, all but one are older than 11 yrs, have severe motor, nutritional and respiratory conditions and are naive due to inaccessibility to nusinersen for technical difficulties. After open clinical use, further follow-up data will provide information on additional reasons and number of patients accessing risdiplam., Spinal muscular atrophy (SMA) is an autosomal recessive disease where a deficient amount of SMN protein leads to progressive degeneration of bulbar and spinal motor neurons. Therapies for the restoration of SMN production are now available. Yet, fatigue and signs of impaired neuromuscular junction (NMJ) transmission have been documented as possible contributors to SMA phenotype. Amifampridine (3,4-diaminopyridine, AP), a voltage-dependent K+ channel blocker, prolongs depolarization of the presynaptic NMJ terminal, enhancing neuromuscular transmission. Here, we evaluated the safety and efficacy of AP in ambulatory patients with SMA type 3, in a 1:1 randomized, double-blind, placebo-controlled, 2-period, 2-treatment, crossover study. Type 3 SMA, able to walk unaided for 30m, entered the run-in phase during which AP was titrated up to an optimized stable dose. Then, patients with at least 3-points improvement in Hammersmith Functional Motor Score Extended (HFMSE) were randomized to receive either AP or placebo for 2 weeks, alternatively, for a total of 28 days of double-blind treatment. Efficacy was evaluated by changes from randomization of HFMSE, quality of life, 6-minute walk test. Descriptive analyses and a mixed effects linear model were used for statistic. Six patients for each sequence of treatment were randomized. Transient paresthesias (33,3%) were the only AP-related AEs reported. AP treatment led to a statistically significant improvement in HFMSE (LS Mean Difference 0.792 (0.22 to 1.37), p = 0.0083), compared to placebo, but not in the secondary endpoints. SMA-001 study provided evidence that AP was safe and effective in treating ambulatory patients affected by SMA type 3. IND/EUDRACT number: 106263 /2017-004600-22, Objective To determine the efficacy and safety of risdiplam in infants with type 1 spinal muscular atrophy (SMA) after 24 months of treatment. Background SMA is a severe, progressive neuromuscular disease caused by reduced levels of survival of motor neuron (SMN) protein due to deletions and/or mutations of the SMN1 gene. A second SMN gene, SMN2, produces only low levels of functional SMN protein. Risdiplam (EVRYSDI™) is a centrally and peripherally distributed oral SMN2 pre-mRNA splicing modifier that increases the levels of functional SMN protein. Design/methods FIREFISH (NCT02913482) is a multicenter, open-label, two-part study of risdiplam in infants with type 1 SMA and two SMN2 gene copies, aged 1-7 months at enrollment. Part 1 (n = 21) assesses the safety, tolerability and pharmacokinetics/pharmacodynamics of different risdiplam doses. Part 2 (n = 41) assesses the efficacy and safety of the Part 1-selected dose. Results The primary endpoint of Part 2 at 12 months was met (data-cut: 14th November 2019); 29% (p < 0.0001, performance criterion = 5%) of infants were able to sit without support for ≥ 5 seconds, as measured by the Bayley Scales of Infant and Toddler Development, Third Edition. This milestone was never achieved in natural history cohorts. No treatment-related safety findings leading to withdrawal were reported in Part 2. Efficacy and safety data from infants in Part 2 who have received risdiplam treatment for 24 months will be presented. Conclusions Part 2 is ongoing and will provide important data on the long-term efficacy and safety of risdiplam in infants with Type 1 SMA., Objective To retrospectively investigate long-term safety and efficacy of nusinersen in a large cohort of adult Italian SMA patients. Methods Inclusion criteria were: 1) clinical and molecular diagnosis of SMA2 or SMA3; 2) nusinersen treatment started in adult age (> 18 years); 3) clinical data available at least at baseline (beginning of treatment) and 14 months. Results We included 112 patients (15 SMA2 and 97 SMA3) with median age at first administration of 35 years (range 18-74). Median period of treatment was 30 months (range 14-38). The Hammersmith Functional Rating Scale Expanded (HFMSE) in SMA3 patients increased significantly from baseline to the end of the follow-up (p = 0.0013), with higher improvement in walkers (median +2, p = 0.0147) than in sitters (median 0, p = 0.0384). The Revised Upper Limb Module (RULM) in SMA3 significantly improved between baseline and the end of the follow-up (p = 0.0002), with higher effect in sitters (median +2, p = 0.0024) than in walkers (median 0, p = 0.0281). Conversely, SMA2 patients had no significant changes of median HFMSE and RULM over the observational period. Furthermore, six-minute walking test distance significantly increased in SMA3 walkers during the follow-up (mean +35 m, p = 0.0003). Conclusions: Our data provide the first evidence of prolonged nusinersen safety and efficacy in a large cohort of adult SMA2 and SMA3., Type 1 spinal muscular atrophy (SMA1) is the most severe and common form of SMA. Its poor life expectancy has been drastically improved after the advent of gene therapy. In our centre, we have recently treated four patients with Onasemnogene abeparvovec (Zolgensma). Two were novel diagnoses (one female, one male), the other two were already being treated with antisense oligonucleotides (males). The median age of diagnosis was 5.5 months; the median age of treatment was 25 months. Gene therapy was administered by a neurologist and the pediatric palliative care (PPC) team specialists provided the following interventions: 1) communication of diagnosis, helping the parents to choose the treatment for their baby in line with their values and beliefs; 2) training the parents to administer respiratory, nutritional and physical therapies 3) training the family paediatrician, the home care nurses, and local hospital personnel 4) performing regular visits at home to monitor the patients and further train the parents 5) guaranteeing psychological and social support. Families’ main issues were daily managing the long-term disease burden and accepting a possible variability in the therapy outcome. From the medical perspective, communication with families, verifying their global comprehension, and mediating their expectations and attitudes (especially when switching from oligonucleotides), was additionally demanding. Neurological follow-up with periodic assessments is currently ongoing. To conclude, in the growing panorama of innovative SMA therapies, PPC supportive approaches based on continuous multidisciplinary and comprehensive clinical, rehabilitative, and social strategies maintain an essential role., Background COVID-19 is caused by SARS-CoV-2 virus and in many cases lead to a pneumonia. However a number of neumuscular manifestations have been associated to SARS-CoV-2 infection. Furthermore, multiorgan symptoms after COVID-19 are being reported by increasing numbers of patients, ranging from cough to fatigue and muscle pain. However, the long-term health consequences of COVID-19 remain largely unclear. Methods We evaluated 124 patients hospitalized between march and May 2020 for SARS-COV-2 associated pneumonia at 6 and 12 months. We retrospectively collected clinical, laboratory and radiological information available. for each patient, cognitive tests, scales for depression and anxiety and a specific Fatigue Severity Scale (FSS) were performed. Results Twenty-five patients died during hospitalization. At 12 months follow up 85 patient were evaluated. Eighty-seven (70%) patiens were male and mean age was 67.3 years. During hospitalization 43 (36.5%) of patients complain of myalgia. This patients had higher CK levels than patients who did not (534 U/L vs 93 U/l, p < 0.001). At 12 months 42% of patients complain about myalgia while 34% about fatigue. Mean FSS value were 32.93, and were significatively higher in patiets who complain about fatigue (41.52 vs 27.08 p < 0.001) and Muscle pain (40.84 vs 26.80, p < 0.001) compared to who did not. Conclusions During hospitalization for COVID-19 myalgia was associated with an higher level of CK, suggesting a possible muscle involvement. At 12 month myalgia and fatigue were present in a more than a third of patient suggesting that this manifestation could be one of the main COVID-19 sequelae., Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a rare childhood autosomal recessive motor neuron disease, due to recessively inherited IGHMBP2 gene mutations. The main hallmarks of the disease are diaphragmatic palsy and progressive distal muscular atrophy and paralysis. In few cases mutations in the same gene leaded to Charcot-Marie Tooth disease type 2S (CMT2S). There is no treatment and very little data are available on the disease progression. We present the data of a European patients’ cohort composed of 15 patients with SMARD1, aged between 5 months and 21 years and 2 patients with CMT2S respectively 16 and 63 years old. Clinical data have been collected retrospectively and prospectively. For SMARD1 patients the disease onset was before 5 months, manifesting with weak crying, feeding difficulties, hypotonia, club foot and acute respiratory distress. All patients need continuous ventilatory support (12 via tracheostomy while 3 with NIV) and G-tube was necessary in 12 cases. Head control was reached only by 60% of the patients, independent sitting only by 27%. Autonomic dysfunction and scoliosis were observed in all patients. The two CMT2S patients manifested with distal motor neuropathy respectively at 8 and 10 years, both of them are still ambulant. Diseases related to IGHMBP2 mutations are very rare and with heterogeneous clinical manifestations. Our case studies broaden the knowledge relating to the phenotype and natural course of these disorders, providing useful data for the evaluation of possible future therapeutic strategies., We present updated results from ASPIRO (NCT03199469), investigating gene replacement therapy with AT132 for XLMTM patients. XLMTM, an ultra-rare, life-threatening myopathy caused by mutations in the MTM1 gene, leads to impaired neuromuscular and respiratory function, and early death. Patients enrolled required ventilator support and had no clinically significant underlying liver disease at baseline, defined as > 5x ULN ALT or AST, or hepatic peliosis by imaging. As of July 2020, efficacy data were analysed for 16 patients (n = 6, 1 x 1014 vg/kg (age 0.8-4.1 years at dosing); n = 10, 3 x 1014 vg/kg (age 1.3-6.8 years at dosing). At baseline, all patients required ventilator support (mean [SD] 22.4 [3.34] hours/day), and missed critical motor milestones. Treated patients had significant reductions in daily hours of ventilator dependence vs control (p < 0.0001 for both doses); seven achieved ventilator independence. Treated patients showed significant improvements in motor function vs control, and acquired and maintained several major motor milestones. Muscle biopsies demonstrated durable myotubularin expression with improved pathology scores at 48 weeks. Three patients treated at 3x1014 vg/kg, experienced fatal sepsis or gastrointestinal bleeding with ongoing severe cholestatic liver dysfunction. As of September 2021, the ASPIRO program is placed on a clinical hold by the FDA following the death of a newly dosed participant at 1 x 1014 vg/kg; the cause of death is still pending. Present understanding is that these events are related to a combination of gene therapy and underlying XLMTM disease process. Safety of AT132 is being closely monitored as the four patient deaths are being thoroughly investigated., Objective Limb-girdle muscular dystrophy type 2E/R4 (LGMD2E/R4) is caused by mutations in the beta-sarcoglycan gene (SGCB), resulting in loss of SGCB protein and other components of the dystrophin-associated protein complex (DAPC). LGMD 2E/R4 manifests as progressive hip/shoulder muscle weakness. This first-in-human, phase 1/2 trial (NCT03652259) evaluated SRP-9003, a self-complementary rAAVrh74.MHCK7.hSGCB construct restoring SGCB. Methods Patients aged 4-15 years with SGCB mutation (both alleles) received 1 SRP-9003 IV infusion: Cohort 1 (n = 3), 1.85 × 1013 vg/kg; Cohort 2 (n = 3), 7.41 × 1013 vg/kg. Endpoints included safety (primary), SGCB expression (secondary), and function (North Star Assessment for Limb-girdle Type Muscular Dystrophies [NSAD], time to rise [TTR], 4-stair climb [4-sc], 100-meter timed test [100 m], 10-meter timed test [10 m]). Results We report Year 2 (Y2; Cohort 1) and Year 1 (Y1; Cohort 2) results. As of January 2021, SRP-9003 was well tolerated with no new safety signals since the previous data cut (July 2020); adverse events occurred early and were manageable. Immunofluorescence showed robust SGCB expression post treatment, leading to DAPC reconstitution, maintained to Y2 (Cohort 1). SRP-9003-treated patients showed functional improvements, maintained at Y2 in Cohort 1 (NSAD, +5.7 points; TTR, -0.6 s; 4-sc, -0.3 s; 100 m, -2.8 s; 10 m, -0.2 s) and Y1 in Cohort 2 (NSAD, +4 points; TTR, -1.1 s; 4-sc, -0.4 s; 100 m, -7.9 s; 10 m, -0.6 s). Post hoc analysis showed improved NSAD outcomes versus untreated natural history cohort (9.2-point difference, Y2; 95% CI, 3.2-15.1). Conclusions Results suggest long-term efficacy of SRP-9003, supporting advancement of the clinical development program. Study Support Sarepta Therapeutics, Inc. Disclosures LRR-K, ERP, SL, DAG, ASM, EK, SN, XL, and LP are or have been employees of Sarepta Therapeutics, Inc, and may own stock in the company. LNA and LPL received fees from Sarepta Therapeutics, Inc, for licensure of the LGMD natural history data set. JRM received financial support from Sarepta Therapeutics, Inc, for travel to meetings to present any products sponsored by Sarepta. KJL, KC, NFR, MAI, and BP have no conflicts to disclose. Product is investigational only., We are working on an integrated, multiparametric approach in diagnosis and management of neuromuscular diseases (NMDs) by using a single support software platform, potentially useful in implementing diagnosis and taking care towards trials readiness. Promising preliminary results have been obtained to date with the Health360 platform under the umbrella of the InGene 2.0 project. Health360, a platform developed under the Software-as-a-Service (SaaS) principles, merges all that, with sections dedicated to the collection of personal data (under the premises of the EU 2016/679 GDPR Regulation), as well as modules devoted to biomedical images storage and interpretation. In particular, further modules, including neurological examination and functional motor tests, muscular MRI, genetic data, muscle biopsies, are under development and optimization. The possibility to upload such images in a common, user-friendly software platform, where data and image storage, as well as the analysis of images and loops can be performed in an intelligent manner, would be of extreme aid to the clinician. If confirmed on larger cohorts and with robust statistical approach, such results could drive the present tool to be used for diagnostic aims, phenotypic characterization and clinical follow-up., Objectives To collect creatinine and CK plasma concentration in a cohort of BMD patients, in order to explore their role as biomarkers and correlation with age and muscular function. Materials and methods We collected 110 CK values in a cohort of BMD patients whose muscular function was assessed by NSAA score; for 27 patients (26.5%) we had more than one value. We also collected 61 serum creatinine values. We correlated CK (log10 transformed) and creatinine values with age and muscular function of patients. Results The mean value of CK levels in our cohort was 2090 U/L (± SD 3596 U/L), while the median was 903 U/L. We expected a decrease in CK values during years; in fact, the negative association between CK values and age was strongly significant (r = -0.63, p < 0.0001). CK decrease was loosely correlated with the reduction of NSAA score (r = 0.19, p = 0.043). The mean value of creatinine levels in our cohort was 0.59 mg/dL (± SD 0.27 mg/dL), while the median was 0.49 mg/dL. The relationship between creatinine and muscular function was statistically significant, with normal creatinine values in patients with preserved muscular function, and low creatinine values in patients with deteriorated muscular function (r = 0.61, p < 0.0001). Creatinine tended to decrease with age, but in our cohort this association was not statically significant (r = 0.2, p = 0.115). Discussion and conclusions Creatine and CK plasma concentrations seem to correlate well with muscle mass and function in BMD, as observed also in other neuromuscular diseases. Future perspectives include the evaluation of potential changes of these biomarkers with novel therapeutic interventions., Titin truncating variants (TTNtv) have been associated with a dominant cardiomyopathy showing a reduced, age dependent, penetrance but they also cause recessive skeletal muscle diseases. The mechanisms explaining the TTNtv role in dominant cardiomyopathies and in recessive skeletal muscle titinopathies are still unclear. We analysed by RNA sequencing 44 skeletal muscle samples from patients with a confirmed or a suspected titinopathy, proving variants causing a premature stop codon out of the M-band to result in a nonsense mediated decay (NMD) of titin transcripts. Vice versa, stop codons in the M-band escape NMD and still result in a ‘quasi-full-length’ protein. Although most TTNtv cause splicing defects, their effect on the transcripts is highly variable. Most of the splice variants we have characterized cause in-frame losses or gains, still resulting in a near–full length protein. Moreover, some of them affect only a reduced number of transcripts and a significant amount of normal protein is still produced. A direct analysis of RNA, cDNA and protein is crucial to characterize the effect of truncating variants. These second-tier studies are mandatory to support the variant classification of DNA changes and to clarify the pathomechanisms of rare diseases., Background In order to ease diagnosis and treatment of rare diseases afflicting 30 million people in Europe, the EU had created the European Reference Networks (ERNs), connecting cross-border healthcare providers. Among the ERN features is the Clinical Patients Management System (CPMS), a digital web-based software where clinicians can discuss about patients through virtual panels, sharing patients’ data securely. The CPMS requires carefull training for its correct use, hence a twelve-month project funded by Sarepta Therapeutics was set up to improve the use of the CPMS among Euro-NMD ERN Italian members. Methods In the first two months, two medical doctors (MD) underwent a teaching course with a CPMS expert. Afterwards, the two MDs organized and managed a training course across four months with a flexible schedule to ease the course attendance. In a further phase lasting five months, the trainers focused on panels’ progression so to ease the moving forward across the panel timeline and ease panel closure by attendees. Several new panels were opened. Results At the end of the course, participants had opened 98 panels (approximately 80% of the total in the whole Euro-NMD ERN). The participants managed to access the platform and became acquainted in using it, and the course strengthened the Italian network overall. Conclusions Cross-border virtual consulting is an outstanding tool to improve the quality of health care provision. Our results show that a training course tailored to healthcare professionals might boost the usability of the CPMS, increasing its impact to European health system., Perturbation of glycolytic enzymes results in glycogen storage disorders such as Pompe disease (PD), which is an autosomal recessive metabolic pathology due to a defect of the lysosomal enzyme acid α-glucosidase (GAA), necessary for glycogen degradation. PD was the first glycogen storage disorder linked to autophagy, a key molecular mechanism that maintains cellular homeostasis and ensures correct macromolecule turnover in the cell. Despite the significant results achieved in this disease comprehension, it remains unclear how autophagy is disrupted in PD, since it is yet unknown if an excessive acceleration or reduction of this process is present. The importance of understanding autophagy dysfunction relies in the fact that this could explain the difficulties of current therapies in restoring muscle function, in particular in late onset patients. Moreover, could explain the presence of secondary symptoms in PD patients, in particular related to neuromuscular junction (NMJ) malfunctioning. Taking advantage of the zebrafish transgenic line Tg(CMV:EGFP-map1Lc3b), characterized by fluorescent autophagosomes, we generated a new zebrafish PD model, useful for the deep study of autophagic pathway. Exploiting different drugs known to have effects on autophagy, we are investigating this pathway at immunohistochemistry, biochemistry, electron microscopy and behavioral level. We believe that our findings will trigger a reassessment of the PD pathogenic mechanisms, as well as the research of new therapeutic targets addressing both glycogen accumulation and autophagy. Furthermore, this investigation will be essential to explore if the secondary symptoms of PD could be reversible., Objective In this study we applied next generation sequencing (NGS) in undiagnosed patients with suspected neuromuscular disease to investigate the prevalence of variants in collagen VI and collected clinical and instrumental data to verify the real pathogenicity of these variants. Methods As part of InGene project, we screened 241 neuromuscular genes of which COL6A1, COL6A2, COL6A3 by NGS in 580 patients with neuromuscular disorders referred to Molecular Medicine Lab of IRCCS FSM in the last five years. Variants in collagen VI were classified according to reference literature and were collected independently by clinical picture. Clinical data available were collected in a CRF and missing data were updated with referred clinician. Results We identified “probable” or “likely pathogenetic” disease-related mutations in COLVI-related genes in 47 patients (26 male and 21 female). 11 patients harboured variants in COL6A1 gene, 18 patients had a variant in COL6A2 gene, 21 patients had a variant in COL6A3 gene. Collected clinical and instrumental data partially reflect the phenotype described in literature. Conclusions This study shows both the prevalence of collagen VI variants in patients with weak muscular symptoms and highlights the advantages of NGS used as a first level diagnostic approach especially for complex genes that are difficult to study routinely. Anyhow, it also demonstrates the difficulty of considering these variants as pathogenetic without clinical and instrumental data. It may therefore be useful to outline a flow chart to verify the real pathogenicity of found variants., We evaluated bone mass acquisition and fragility fractures determinants in 26 ambulant prepubertal DMD patients treated with deflazacort. DXA measurements of total body less head (TB-BMD Z-score), lumbar spine bone mineral density (LS-BMD Z-score) and body fat (TBF%) were obtained at baseline (T0) and every year up to 3 years (T3). A delta-TBZ-score/year [(T3_TB-BMD Z-score - T0_TB-BMD Z-score)/years] was used for a better interpretation of bone changes. On day of DXA, subjects underwent antrophometric measurements and dosage of serum bone turnover biomarkers. Median age was 7.7 years (IQR 6/9,2) at T0 and 11.4 years (IQR 9.8/13.4) at T3. At T3, the incidence of fractures was 23.1%, at a median age 12.3 years (IQR 10.7/14.3). Between T0 and T4 we observed a decline of HtSD (p = 0.001) and TB-BMD Z-score (p = 0.004), an increase in TBF% (p = 0.04), while BMI SD, LS-BMD Z-score and serum biomarkers did not change significantly. Multiple regression analysis identified TBF% as the only negative predictor of TB-BMD Z-score, and higher BMI SD at T0 was associated to greater negative delta-TBZ-score/year (r -0.63; p < 0.001). Compared to fracture-free-DMD, fractured-DMD showed 2 times greater delta-TBZ-score/year (p < 0.05) and 2,3 times increased TBF%/year (p < 0.05). Fractures were predicted independently by delta-TBZ-score/year, BMI SDS and TBF% at T3. In conclusion, we demonstrated for the first time a detrimental effect of the fat tissue on bone fragility, and we showed that TB-BMD Z-score represents a reliable tool to detect bone changes in ambulant DMD, suggesting its inclusion in trials assessing the efficacy of bone treatments in DMD., Background One of the most challenging hurdles that clinical researchers face in the Duchenne muscular dystrophy (DMD) field is the considerable inter-patient variability in age at presentation and weakness progression: that is, the relevant phenotypic variability of DMD. Increasingly, it is recognized that the genetic background, i.e genetic variation in genes different from disease gene, may modulate Mendelian disease phenotype. These trans-acting variants are called genetic modifiers. Several modifiers of DMD have been identified through candidate gene studies, while genome-wide association studies have only been initially attempted. Aim This work represents a preliminary analysis of a genome-wide association study (GWAS) looking for DMD modifier loci, that plans to collect clinical data and DNA samples from ~700 DMD patients followed by Consortium of Italian Centers, that in the last decade have collaborated to studies of DMD natural history. Materials The GWAS was carried out using the high-density Illumina Infinium Omni2.5Exome-8 genotyping chip, version 1.5, and implemented a pipeline for data interpretation based on ad-hoc scripts. The association test was a regression test of age at loss of ambulation, with the following covariates: glucocorticoid treatment (at least 1 year while ambulatory) and DMD mutation type. Results So far, we genotyped about 50% of the planned total cohort. The algorithm identified an association signal with a p value of 4,2*10-8 in an intronic region at chromosome 6q22.1, whose functional meaning needs to be further elucidated. Conclusions Identified SNPs represent putative modifiers of the phenotype of DMD. We plan to validate these findings by expanding sample size, and validating top association signals in independent cohorts., Introduction and aims Mutations amenable to skipping of specific exons have been associated with different motor progression in Duchenne muscular dystrophy (DMD). Less is known about their association with long-term respiratory function. We aimed to investigate the features of respiratory progression in four DMD genotypes relevant for ongoing exon skipping therapeutic strategies. Methods This was a retrospective longitudinal study including DMD children followed by the UK North Star network and international AFM network centres (May 2003-October 2020). We included boys amenable to skip exons 44, 45, 51 or 53, older than 5 years and ambulant at first recorded visit. Subjects who were corticosteroid-naïve or enrolled in interventional clinical trials were excluded. The progression of respiratory function (absolute forced vital capacity, FVC, and calculated as percentage of predicted, FVC%) was compared across the four subgroups (skip44, skip45, skip51, skip53). Results We included 142 boys. Mean (SD) age at first visit was 8.6 (2.5) years. Median follow-up was 3(0.3-8.3) years. In skip45 and skip51 FVC% declined linearly from first recorded visit. From the age of 9 years FVC% linearly declined in all genotypes. Skip44 had the slowest (2.7%/year) and skip51 the fastest (5.9%/year) annual FVC% decline. The absolute FVC progressively increased in skip44, skip45, skip51. In skip53 FVC started declining from 14 years of age. Discussion The progression of respiratory dysfunction follows different patterns for specific genotype categories. This information is valuable for prognosis and for the evaluation of exon skipping therapies., Objective To assess the clinical course and genotype-phenotype correlations in patients with neuromuscular disorders due to LMNA/C gene mutations. Methods We analysed clinical and genetic data in a cohort of Italian paediatric patients with a neuromuscular disorder and a pathogenetic or likely pathogenetic mutation in LMNA/C. Clinical data included motor function, scoliosis, respiratory and heart function, laboratory and imaging data. Results Nine patients aged 1-20 years were included in our retrospective study. The mean age at onset was 23 ± 25 months, ranging from birth to 6 years. The patients in the cohort ranged from those with congenital muscular dystrophy (CMD) to patients with myopathic features. All the patients with myopathic features remained independently ambulant and presented a mild phenotype. None of the patients developed conduction system defects or arrythmia but merely minor heart problems (mild tricuspid insufficiency). In our CMD patients, mutations were mainly present in the first part of the coding region (IF domain), and the two patients, whose mutations were in exon 1, presented the worst phenotype. One of them lost ambulation at the age of 2 while the other never acquired it; both needed nocturnal non-invasive ventilation. Conclusions Our findings are consistent with literature, showing an evident correlation between the severity of the muscle phenotype and the protein domain affected. Half of our paediatric patients had a CMD phenotype while the others presented myopathic features highlightening, yet again, that a mutation in LMNA/C in paediatric aged patients may be associated with mild phenotypes., Introduction Defining the natural history of a disease is an essential requisite to any therapeutic intervention. Slow progression, different pathogenic mechanisms and small number of patients have been the most relevant factors interfering with definition of markers of disease progression in LGMD2A and 2B. Patients and methods Patients with LGMDR1/LGMD2A and LGMDR2/LGMD2B attending the IRCCS “E. Medea” in the last 30 years were recruited. Demographic data, muscular strength in at least 14 muscles (Medical Research Council grading); motor function (Motor Function Measures scale, 6 min walk test and Performance of Upper Limb scale); cardiopulmonary function and swallowing capability data were collected. A previously developed regression model was used to reconstruct the evolution over time of each measurements. Results 428 visits of nineteen 2A and twenty 2B patients were retrospectively analysed through the regression model to create the curves of evolution with disease duration of muscle strength, motor and cardio-pulmonary function tests. Relevant muscular and motor function alterations occurred after the first decade of disease, while mild respiratory function alterations started after the second, with preserved cardiac function. Although type 2A showed relatively stronger distal lower limb muscles, while type 2B started with relatively stronger upper limb muscles, the corresponding motor functions were similar, becoming severely compromised after 25 years of disease. Conclusions This was the longest retrospective study in types 2A and 2B. It defined muscular, motor, cardiac and respiratory function curves of disease evolution that could be used to evaluate how the natural progression is changed by therapies., Background Congenital myasthenic syndromes (CMS) are genetic diseases characterized by impairment of neuromuscular junction structure or function. CMS natural history has been poorly investigated and has not been clarified yet. Aim of this study is to longitudinally assess the disease progression of CMS in an Italian cohort of patients. Methods We included patients with a clinical and molecular diagnosis of CMS, followed in three Italian neuromuscular centres. Patients were evaluated at baseline and then once per year, with a minimum follow-up of 1 year. Neurological examination included the Myasthenia Gravis-specific Activities of Daily Living scale (MG-ADL) and the MG-composite scale (MGC). Results A total of 33 patients, including 13 males and 20 females, were enrolled. The most common mutated gene was CHRNE (n = 13 pts), followed by DOK7 (n = 4 pts) and COLQ (n = 3 pts). Mean age at first evaluation was 41.8 ± 14.4 years (range = 10-71) and mean follow-up period was 2.1 ± 0.4 years (range = 1-3). Mean MG-ADL and MGC scores at baseline were 5.9 ± 4.0 and 14.9 ± 8.2, respectively. At the end of follow-up period, a mean reduction of 1 point for MG-ADL and 2.9 points for MGC were found, with improvement usually related to treatment modifications. MG-ADL did not change between first and last evaluation in around half of the patients (n = 19), while MGC resulted stable in 11 (33.3%) patients. Conclusions Our preliminary data suggest a disease stability according to MG-ADL and MGC in most of the CMS patients over the follow-up period., Background and aims Myasthenia Gravis (MG) is an autoimmune disorder with fluctuating weakness of the scheletric muscles causing significant disability and morbidity. The development of specialized care centers for MG patients as well as the employment of new effective treatments improved the survival in MG. The most common MG therapies may worse preexisting patients’ comorbidities or they may be controindicated in such situation. We explored the frequency of comorbidities in MG compared to healthy controls (HCs) and how they are distribuited in MG according to age at disease onset, gender, and disease severity. Materials and methods Patients with MG attending to Neuromuscular Clinic of University Hospital “Paolo Giaccone” of Palermo and “SS Annunziata” Hospital of Chieti were enrolled to study whereas HCs living in Sicily and Abruzzo were collected using a web-available questionnaire. The Chi-squared test was used to compare qualitative variables and the distribution of comorbidities between groups with level of significance set to p < 0.05. Results N = 178 patients with MG (mean age 59 years, 55% male) and 178 sex- and age matched healthy controls were enrolled. The 87% of MG patients and the 76% of HCs from comorbidities (p = 0.006). Comorbidities in MG were differently distribuited according to age at disease onset and gender. In patients with MGFA class III-IV-V respiratory disorders (p = 0.009) and thymoma (p = 0.003) were more common. Conclusions MG patients showed higher prevalence of comorbidities than HCs. Assessing of MG comorbidities may allow the clinicians to optimize the MG management., Background Refractory myasthenia gravis (MG) has been poorly investigated to date. Aim To describe the clinical features of drug-refractory patients with MG in a large Italian cohort. Methods We included 756 ocular and generalized MG patients from 2 Italian Neuromuscular Centers, with MG onset between 2000 and 2018 and at least one year of follow-up. Patients were classified as refractory when remained unchanged or worsened, according to MG Foundation of America post-Interventional Status (MGFA-PIS), with persistent symptoms or drug-related side effects, after treatment with steroids and at 2 least steroid-sparing immunosuppressive agents, administered in adequate doses for an appropriate period, as established by literature. Results Mean disease duration of the whole cohort patients was 11.2 ± 5.16 years (range 1-44). Fifty-nine (7.8%) patients were identified as refractory. The mean age at onset of refractory MG was 44 ± 17.2 years (range 16-83), slightly lower than in non-refractory subgroup, although not significant. Females were predominant in both refractory and non-refractory MG patients, but females were significantly more frequent among the former subgroup (67.8%, p < 0.0001). Similarly, thymoma was more frequently observed in the refractory MG patients (18/59; p-value: 0.002). Conversely, antibodies to MuSK (7/59) were not significantly associated to refractory MG. Recurrent need of rescue therapy as intravenous immunoglobulin or plasma exchange, were significantly more frequently observed in the refractory subgroup (p-value: 0.029). Conclusions Our study emphasises that the drug-refractory patients represent a small but considerable MG subgroup with specific features, needing an adequate management and new emerging treatment options., Although gene panels, WES or WGS analysis have changed our approach to molecular diagnosis, many genetic conditions remain unsolved. To define the large rearrangements in the DMD gene which are the most common cause of dystrophinopathies including Duchenne (DMD) and Becker (BMD) muscular dystrophy, we have applied the linked-read sequencing technology developed by 10x Genomics. The distinction between alleles along the genome through phasing is the main advantage of 10x linked-read technology. As an exemplary case, we studied a DMD carrier with an unsolved genetic status, linked to a 6-year-old boy affected by an X-linked muscular dystrophy. Despite a deletion of exons 16-29 in DMD gene was responsible for BMD phenotype in male of her family, MLPA and array-CGH analysis in the carrier showed a normal dosage of these exons and an increased dosage of flanking exons 1-15 and 30-34. The linked-read WGS was able to phase both X chromosomes, showing two different rearrangements: a deletion of exons 16-29 on one allele and a de novo duplication of exons 1-34 on the other one in the DMD gene. By data analysis, this duplication not only restores the normal dosage of exons 16-29 but involves a region of 1.52 Mb spanning the DMD gene and the 5’ upstream region. In conclusion, our results demonstrate that linked-read WGS can be a useful tool for improving our understanding of unsolved genetic conditions in a very feasible way., Sarcoglycanopathies diagnosis is genetically determined but muscle analysis, by immunohistochemistry and western blot, is still mandatory for a correct diagnostic process. In sarcoglycanopathies, clinical severity is usually correlated with the quantity of residual protein even if a deficiency in a single component of the sarcoglycan protein complex generally leads to concomitant reduction or loss of other sarcoglycans. There is no current therapy for sarcoglycanopathies, one of the most innovative therapeutic approaches is based on the use of adenoviral vectors for restoring protein expression, so the availability of a method that allow objective quantification of the membrane protein, faster than western blot, could be useful in evaluating the efficacy of pharmacological treatment. Morever immunofluorescence provides the opportunity to a simultaneous evaluation of protein quantity and sarcolemma positioning, not achievable by western blot. Muscle biopsies of 13 patients affected with genetically defined sarcoglycanopathy (8 LGMD-R3, 3 LGMD-R4 and 2 LGMD-R5), were analysed histologically and for immunofluorescence and western blot expression of each of the sarcoglycans. Laminin-α2, was used as sarcolemmal reference for membrane integrity and as internal standard of fluorescent reaction. Quantification of integrated density of fluorescent signal was performed using ImageJ software. Further analysis of immunoflourescence and western blot data obtained from these patients by Bland-Altman plot, to evaluate the level of agreement of two methods, suggested that the difference was acceptable. Preliminary results show that this semi-quantitative tool could contribute to better define patient’s prognosis and could be useful to evaluate the efficacy of potential pharmacological treatments during clinical trails., Introduction The diagnosis of FacioScapuloHumeral Dystrophy (FSHD) is complicated the high clinical variability and incomplete penetrance. Therefore, the availability of reliable (epi)genetic biomarkers is desirable for providing patients with more accurate molecular diagnoses and genotype-phenotype correlations. Aim of the study The study aimed at assessing the methylation status of the D4Z4 locus with the purpose of enhancing the molecular diagnosis of FSHD. Materials and methods The study involved 307 subjects (137 with clinical diagnosis of FSHD, 20 with LGMD and 150 controls). DNA methylation levels of the DR1 region (1kb upstream of the DUX4-ORF within the D4Z4 array), the DUX4-PAS (the distal part of the array) and its CpG6 site were assessed on genomic DNA by means of Bisulfite Sequencing and Capillary Electrophoresis. Results FSHD subjects showed significantly (p < 0.01) hypomethylation levels (0.30 ± 0.09, 0.49 ± 0.13 and 0.69 ± 0.18) compared to LGMD and controls subjects (0.38 ±0.05, 0.60 ± 0.07 and 0.88 ± 0.06) for DR1, DUX4-PAS and CpG6, respectively. Interestingly, patients carrying pathogenic mutations in FSHD-associated genes displayed lower DR1 methylation (0.15 ± 0.08 vs 0.31 ± 0.05) compared to wild-type patients. These results suggested that the methylation profile of the D4Z4 represents a useful biomarker for discriminating FSHD subjects from controls or patients with other myopathies. Conclusion The present study showed that the analysis of the methylation levels of D4Z4 region could support the molecular diagnosis of FSHD, by enhancing the genotype-phenotype correlation; orienting the specialist towards a deeper genomic analysis addressed to detect pathogenic variants in causative/modifier genes or perform differential diagnosis (LGMD, other myopathies)., AIGkit is an easy-to-use mobile application, created with the aim of allowing a telematic interaction between adult patient with Pompe disease and clinicians that can be downloaded for free on smartphone. After a first phase, whose results were presented as oral communication at AIM congress in 2018 and 2019, and published as original article in Neuromuscolar Disorders, the second operational phase of the project has been activated for its use in real life and clinical practice. The pre-established goal has been therefore to create an informatic platform for the collection of clinical data where each patient can access through the personal app on their smartphone, in order to allow the registration of their data and facilitate interaction with their clinicians. The design activity and procedures, despite the difficulties encountered in the various phases also caused by the Sars-COVID-19 emergency, were carried out to meet the requirements of the privacy guarantor, in order to activate the use of the platform and the real-time sharing of the data collected remotely on the app of each patients. We are now planning the dissemination of the initiative at national level and the implementation of this project in collaboration with other clinical centers that will be able to use the servers of the Azienda Ospedaliera Universitaria Pisana (AOUP) as coordinating center, thus improving value and utility for users, both patients and clinicians., Teleosts are commonly used in biomedical research to investigate the molecular mechanisms underlying human diseases. The medaka fish (Oryzias latipes) is a well-established vertebrate model used in developmental biology and genetic studies involving fast genetic manipulation, real-time images of developing pathologies and drug efficacy tests. We explored the possibility to use it to determine the performance of intact skeletal muscle at sarcomere level. Optically transparent tails of nine days-old medaka fish larvae were mounted in a thermoregulated trough containing physiological solution between the lever arms of a strain gauge force transducer and a loudspeaker motor at a sarcomere length (SL0) of 2.0 ± 0.1μm. Tetanic contractions were elicited by trains of stimuli (200Hz for fused tetanus) at 10°C. A striation follower (Huxley et al. J Physiol 1981;317:12-13P) was used to record sarcomere length changes during contraction in a 0.8-1.0 mm long segment selected along the central region of the sample. The force-velocity (T-V) relation was determined in afterloaded contractions and the power output at each load was calculated as the product between the imposed load and the steady shortening velocity. In fixed end conditions the plateau tetanic force (62 ± 8 kPa, mean ± SEM, n = 3) was attained with a half-sarcomere shortening against the end compliances of about 8% SL0. The unloaded shortening velocity, determined by fitting Hill equation to the T-V data, and the maximum power output are 5.9 ± 0.3 L0/s and 70 mW/g, respectively. These preliminary results make the medaka fish a promising model to investigate the genotype/phenotype correlation in skeletal muscle diseases. Supported by the EJP-RD., Alpha-sarcoglycan (SGC) deficient muscular dystrophy, also called Limb Girdle muscular disease R3, is an inherited disorder resulting from mutations in the a-sarcoglycan gene and aggravated by chronic inflammation that is finely modulated by the extracellular (e)ATP/purinoreceptors axis. Genetic ablation of P2X7 and pharmacological inhibition of the eATP-P2X7 axis by the broad-spectrum antagonist oxidized-ATP alleviated dystrophic phenotypes and dampened the local inflammatory response in mice affected by Duchenne muscular dystrophy and α-sarcoglycanopathy. Aim of this study is to evaluate the therapeutic effectiveness and to characterize the underlying mechanism of A438079, a potent and selective P2X7 antagonist, in a-sarcoglycan-deficient mice (Sgca mice). Our results show that treatment of Sgca mice with A438079 ameliorated the dystrophic phenotype without any detectable side effects. Recovery was evident in the key functional and biochemical parameters such as improved muscle performance and decreased serum creatine kinase levels. The benefits of A438079 treatment were also reflected by the muscle morphology where we observed a drastic reduction of the extent of local fibrosis and inflammation. A detailed characterization of muscle inflammatory infiltrates indicated that A438079 significantly decreased the percentage of neutrophils, activated monocytes, macrophages and dendritic cells in comparison to untreated dystrophic mice (Sgca control). In contrast, immunosuppressive regulatory T cells were significantly increased in Sgca A438079-treated mice in comparison to Sgca control animals. In conclusion, the pharmacological inhibition of P2X7 by the selective antagonist A438079 might provide a safe therapeutic approach to ameliorate the dystrophic phenotype in a-sarcoglycanopathy by decreasing local fibrosis, inflammation and muscle degeneration., Pompe disease is a lysosomal storage disorder caused by acid alpha-1,4-glucosidase deficiency due to GAA mutations. Late-onset form (LOPD) displays progressive muscle weakness with respiratory involvement often leading to premature death. ERT is the only approved therapy, but this treatment is expensive and requires lifelong biweekly infusion. Some patients are non-responders, and the appearance of autoantibodies lead to therapy suspension. Additional therapies must be investigated. Antisense oligonucleotides (ASO) have been previously used to rescue the GAA leaky splicing mutation IVS1-32-13T > G (resulting in exon 2 skipping), the most frequent molecular defect found in LOPD patients worldwide. We administered modified ASO (MOE1 and MOE2, 50 nM) targeting a GAA transcriptional repressor (MOE1) and a regulator element promoting exon 2 skipping (MOE2) into fibroblasts of 4 LOPD patients. Three days after delivery both MOE1 and MOE2 increased GAA transcript levels (from +60% to +140% versus untreated), accompanied by the restoration of physiological exon 2 splicing by MOE2 (from +49% to +180% versus untreated). The efficacy of the molecular approach was validated by biochemical and immunocytochemical methods. We did observe a significant increase of GAA stability (up to 30% of control cells) and activity as well as a reduction of intracellular glycogen content. MOE2 provided superior results compared to MOE1. The effect was maintained up to 6 days after transfection. Our findings confirm and expands previous data on the efficacy of antisense strategy aiming to increase GAA activity and support the development of ASO-based therapeutic approaches in LOPD., Solve-RD is a Horizon 2020-supported project that aims to solve a large number of unsolved rare diseases. As part of the European Reference Network for Neuromuscular Disease (ERN-EURO-NMD), we have contributed to this effort by sharing WES data from a large cohort of unsolved neuromuscular patients and their affected and unaffected relatives. The fastq files from 362 individuals (204 males and 157 females), corresponding to 223 families, were uploaded into the Genome-Phenome Analysis Platform (https://platform.rd-connect.eu/) together with a comprehensive HPO-based description of the phenotype, and processed using the RD-Connect bioinformatics pipeline. Using automated data filtering for SNV-Indels variants, the reanalysis identified the causative variant in three previously unsolved cases. A missense mutation in CASQ1 (Asp244Gly) caused asymmetrical limb myopathy in a family with autosomal dominant inheritance. A de novo mutation occurred in the other two families: the first with a missense mutation in ACTA1 (Pro334Ser) that caused a congenital myopathy, the second one with a missense mutation in SYT1 (Ile368Thr) in a pediatric patient affected by severe developmental delay and hypotonia. To date, about 1.3% of our shared cases have been solved, in line with the performance obtained from the other ERNs, which altogether account for about 3% of solved cases. Additionally, shared data from all Solve-RD participants can be searched for genes, variants, and phenotypes sub-groups, helping in further investigations, as well as the definition of novel genotype-phenotype correlations and indentifying new genes involved in neuromuscular disorders., Thyrotoxic hypokalemic periodic paralysis (THPP) is an uncommon emergency mainly affecting Asian men. The classic triad for diagnosis is: paralysis, thyrotoxicosis and hypokalemia. The typical presentation consists of symmetrical proximal muscle weakness (with legs more affected than arms, with extensor muscle more involved than flexors). We present the case of a 56-years-old Asian male who was hospitalized because of sudden onset of weakness and pain of lower limbs. He reported six months history of palpitations and hands tremors. Neurological examination showed mild symmetrical paraparesis, hyporeflexia, hands tremors, no sensory or cranial nerve deficits. He had fever (body temperature 37.4°C), profuse sweating and atrial fibrillation. Magnetic resonance imaging of spine and nerve conduction studies were normal. Laboratory data revealed potassium 2.7 mmol/l (3.4-4.5), thyroid stimulating hormone < 0.005 mIU/L (0.270-4.200), thyroxine 65.3 ng/L (9.3-17.0), and triiodothyronine 16.0 ng/L (2.0-4.4), TSH receptor antibody 11.1 IU/L (< 1.8) and anti thyroperoxidase > 600.0 kIU/L (< 34.0). He was treated with potassium supplementation, Propranolol, Methimazole and Propylthiouracil with prompt improvement of symptoms. TPP is the most common form of acquired periodic paralysis, yet diagnosis may be challenging in case of new-onset thyroid disorder. Hypokaliemia linked due to hyperactivity of NaK-ATPase stimulated by thyroid hormones is the key of pathophysiology of TPP. Diagnosis is based on clinical and biochemical elements. Management of THPP includes nonselective beta-blockers, achievement of euthyroid state and eventually potassium supplementation. In conclusion, acute paralysis with hypokalemia should prompt physicians to evaluate thyroid function., Objective To describe the first Italian patient affected by “vocal cord and pharyngeal weakness with distal myopathy” (VCPDM) due to MATR3 c.254C > G (p.S85C) mutation, and to expand VCPDM phenotypic spectrum. Methods The proband underwent neurological evaluation, personal and family history investigation, lower limbs muscular magnetic resonance imaging, neurophysiological assessment, and muscle biopsy. Genetic analysis was performed by Next Generation Sequencing analysis of a panel of genes associated with distal myopathy and hereditary neuropathy. Results We detected the heterozygous c.254C > G, p.S85C MATR3 mutation in a patient affected by progressive distal muscle weakness and hypotrophy, myalgias, dysphonia, dysphagia, respiratory impairment, and sensory abnormalities. Neurophysiological assessment revealed a severe sensorimotor polyneuropathy. Variation of fiber size, central nuclei, and non-rimmed vacuoles were evident at muscle biopsy. Conclusions This finding extends MATR3-associated VCPDM phenotypic spectrum and suggests considering MATR3 analysis in suspected congenital polyneuropathies with odd features, including dysphonia, dysphagia, and respiratory insufficiency., Background The histopathological diagnosis of sporadic inclusion body myositis (sIBM) represents a challenge because the pathology can be easily missed. The presenting case is of interest because the diagnostic alterations were detected after the re-orientation of the original muscle biopsy. Case description A 75-year-old male patient underwent a forceps muscle biopsy of gastrocnemius muscle to confirm the clinical diagnosis of sIBM based on the typical distribution of muscle weakness and muscle atrophy, which developed slowly, over the course of 5 years, were asymmetric, of proximal-distal type in the lower limbs and predominant distal in the upper limbs. At the time of the last examination, the patient was unable to flex interphalangeal joints and had severe muscle weakness in hand extensors and flexors as well. He was previously surgically treated for stenosis of the lumbal part of the spinal canal without any relief. EMG was myopathic, creatine kinase was normal. Muscle biopsy demonstrated relatively few muscle fibers (cc. 50), longitudinally oriented and occasional mononuclear inflammatory cells. Rimmed vacuoles were not found. The specimen was cut in a different plane: rimmed vacuoles, with p62 positive inclusions, CD8+ lymphocytes invading non-necrotic muscle fibers and hypertrophic and atrophic muscle fibers were found, most of them cut perpendicularly. Electron microscopy revealed filamentous inclusions in occasional nuclei and in the cytoplasm. Conclusions A diagnostic yield of a single muscle biopsy may be increased by simple maneuver- reorientation of muscle biopsy. The presented case also illustrates the importance of muscle biopsy in avoiding unnecessary surgical interventions., Apoptosis Inducing Factor Mitochondria Associated 1 (AIFM1) is a mitochondrial oxidoreductase with different role in cell pathways, ranging from respiratory chain assembly, to cell death programmes. Pathogenic variants in the AIFM1 gene have been associated with four neurological diseases such as the Cowchock syndrome (CMTX4), the X-linked deafness-5 (DFNX5), the combined oxidative phosphorylation deficiency 6 (COXPD6), and the spondyloepimetaphyseal dysplasia with hypomyelinating leukodystrophy (SEMDHL). Here we report a 17-year-old boy with a mild form of DFNX5 associated with clinical and histological myopathic features, harbouring a novel missense variant in AIFM1. He presented exercise intolerance since early childhood, and at age 7 he was diagnosed with a bilateral auditory neuropathy (deafness), treated with hearing aids. Laboratory investigations, including serum CK and lactic acid were normal. Brain MRI at age 7 and muscle MRI at age 16 did not show any abnormality. An extensive electrophysiological study at age 17 ruled out a peripheral neuropathy. Muscle biopsy performed at age 11, showed myofibrillar texture abnormalities, such as moth eaten fibres and wiped out areas. Activities of the OXPHOS enzymes were normal, while further studies on apoptosis on muscle tissue are ongoing. Whole-exome sequencing (WES) revealed a missense hemizygous mutation in AIFM1, c.1552A > G (p.Lys518Glu), not previously reported in public databases. In conclusion, this case further expands the clinical phenotype associated with AIFM1 gene mutations., Megaconial congenital muscular dystrophy (CMD) is a rare form of congenital muscular dystrophy due to recessive mutations in CHKB gene, encoding Choline Kinase Beta. Since now only few cases have been described, mainly in Asian population. We described a 6-year-old boy who came to our attention for cognitive impairment and slowly progressive muscular weakness. He was the first son of non-consanguineous healthy parents coming from Sri Lanka. Neurological examination showed proximal weakness at four limbs, weak osteotendinous reflexes, Gowers’ manoeuvre and waddling gate. Creatine kinase levels were mildly increased. EMG and brain MRI were normal. Muscle biopsy on quadriceps showed a dystrophic pattern with nuclear centralization and connective tissue increase. Histological and histochemical staining were suggestive for subsarcolemmal localization and dimensional increase of mitochondria. Ultrastructural analysis confirmed the presence of enlarged (“megaconial”) mitochondria. Direct sequencing of CHKB identified two novel defects: the c.1060G > C (p.Gly354Arg) substitution and the c.448-56_29del intronic deletion, segregating from father and mother, respectively. Interestingly, subcloning of RT-PCR amplicons from muscle RNA showed that c.448-56_29del results in the partial retention (14 nucleotides) of intron 3, altering physiological splicing and transcript stability. This report confirms the importance of considering CHKB mutations in the differential diagnosis of patients presenting with muscular dystrophy and mental retardation. Molecular analysis and muscle biopsy were fundamental for the diagnostic process., Adults with DMD are a highly vulnerable population. They are living longer thanks to the improvements of the standard of care but they also experience increasingly complex health issues. To date, there is a paucity of published natural history data and a lack of evidence for managing such complex patients, as recently highlighted by a Consensus document from the UK Adult North Star Network. We present a single centre cross-sectional study on adults with DMD aged > 30 years who are being followed at our Neuromuscular Centre in Turin. Currently, we are following 14 patients with DMD over their thirties (age range: 30 years 4 months - 47 years 10 months). Seven/14 patients are 30-35 years old, and 7/14 are older than 35 years, with 3 out of 7 aged > 45 years. All patients are living with their parent(s) but three who are living in a residential facility and one who is living independently (supported by a caregiver). Data on musculoskeletal, cardiac, respiratory, nutritional/gastrointestinal function will be presented. Data on concomitant neurological (in particular epileptic) and psychiatric aspects will be presented alongside, as well as related management issues in terms of pharmacological treatments. Discussion. Our data confirm the complexity of the multidisciplinary care of patients living with DMD in adulthood. Concomitant psychiatric conditions are frequent, and their pharmacological treatment challenging, especially considering cardiac comorbidities. Management is often based on personal clinical experience. Larger natural history studies and evidence based guidelines on this topic are strongly required., Becker muscular dystrophy (BMD) is a genetic disorder with X-linked recessive inheritance, caused by mutations of Dystrophin gene located at Xp21.2. It typically presents with gradually progressive muscle weakness. Developmental delay can be a manifestation of dystrophinopathies, and the etiology is a debated and investigated topic. 7q11.23 microduplication syndrome is a is a rare syndrome resulting from the partial duplication of the long arm of chromosome 7 characterized by a highly variable phenotype with mild to moderate intellectual delay, speech disorders, and distinctive craniofacial features. We describe a 7-year-old boy with BMD, who presented with developmental delay, bicuspid aorta and interatrial septum defect. At the presentation the serum creatine kinase level was markedly elevated (1046 U/L). Multiplex ligation-dependent probe amplification revealed an exons 48-deletion in the DMD gene. The presence of additional features prompted us to request a cgh array test that revealed a paternal 1.1 Mbp duplication in 7q11.23 region (72.856,430-73.985,812). The father has an intellectual disability too which has never been evaluated by neuropsychiatrist. To our knowledge this is the first case described with the association of BMD and 7q11.23 microduplication syndrome. The case highlights the diagnostic importance of cgh array test in individuals with developmental delay and congenital anomalies and its essential role in excluding other genetic causes of developmental delay/intellectual disability in dystrophinopathies., Introduction Cognitive and behavioral difficulties (i.e. Autism spectrum Disorder, ASD) are described in DMD patients. Different expression of dystrophin isoforms in specific brain areas may play a role in these comorbidities but few imaging data are reported in literature. The aim of this study is to identify DMD specific brain abnormalities through a machine learning approach. Materials and methods 18 boys with DMD (age = 11.0 ± 3.6 yo; IQ = 72.3 ± 16.6; ASD diagnosis n = 5) and 18 controls (age = 9.5 ± 4.1 yo; IQ = 72.1 ± 22.3; ASD n = 5) underwent a Magnetic Resonance (RM) scan session with T1 and diffusion (DTI) sequences. Thickness of 360 cortical regions, volume of 40 brain structures, fractional anisotropy (FA) and mean diffusivity (MD) of 48 regions in the middle of the main fibre bundles were extracted from images. All features were corrected for age, IQ and ASD diagnosis using a linear model. Group classification was performed using a linear SVM algorithm using a balanced leave-one-out cross validation procedure. Feature analysis was performed on the basis of the corresponding forward model weights. Results the linear classifier significantly discriminates between DMD patients and controls with accuracy = 97.2% (p < 0.0005) and AUC = 99.7% (p < 0.0002). The feature weights analysis shows that the discriminative information concentrates in the DTI derived measures (23 /25 ROI weights) and usually report a reduction (in FA/TR/thickness/volume) in DMD patients with respect to the control group (22/25 ROI weights). Moreover, the most selected ROIs refer to the cerebellum (cerebellar peduncles), the brain stem (medial lemniscus, inferior part of the corticospinal tract), the cingulum, the fornix and the superior fronto-occipital fasciculus. Discussion Machine Learning approach allows to identify brain abnormalities specifically associated with DMD, i.e. not caused by a comorbid condition., Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease due to pathogenic variants in the DMD gene. DMD often is associated with cognitive and neuro-behavioural co-morbidities, which pathogenesis and genotype-phenotype relationship are only partially understood. Multiple DMD isoforms, differentially affected based on the mutation site, play a role in these co-morbidities, based on their moderate (Dp427, mainly muscle), prominent (Dp71) or exclusive (Dp140) brain expression. We used two RNAscope® ZZ probes which recognize either the full-length Dp427 transcripts (exons 37-42) or all the DMD transcripts (exons 63-75). BaseScope® ZZ probes were also designed to specifically detect and localize the Dp427b, Dp427p2, Dp140, and Dp71 DMD isoforms. Real-time PCR was performed to validate the results. Sections from normal adult human formalin-fixed cerebellum and temporal lobe were used for the analysis. Both RNAscope probes clearly showed the expression of DMD transcripts in cerebellum (molecular, granular, Purkinje, white matter) and temporal lobe (molecular, granular, pyramidal) tissue layers, including blood vessels. BaseScope® assay allowed discrimination of DMD isoforms and visualization of Dp427b, Dp427p2, Dp140, and Dp71 transcripts in both brain areas. Here we demonstrate that the in-situ RNA hybridization approach has high sensitivity in detecting both full length and short dystrophin isoforms, and low abundant transcripts in fixed brain tissues. The human brain expression map of the multiple dystrophin isoforms will help to define the regional and cellular pattern of DMD expression and may contribute to the understanding of the DMD brain co-morbidities., Background Becker muscular dystrophy (BMD) is a dystrophinopathy caused by mutations in DMD gene which allow production of a partially functional protein, thus justifying the milder phenotype typical of the disease. The molecular diagnostic process starts with the search of large gene deletions or duplications, and, when negative, it proceeds with the sequence of the entire DMD gene. Case description We studied a 26 years-old patient diagnosed at the age of 5 years-old with BMD. At the first evaluation, proximal muscular weakness at lower limbs, mild hypotrophy of pectoralis muscles and calf muscles pseudohypertrophy were detected. Current neuromotor assessment remained stable, however patient developed hypokinetic cardiomyopathy. Diagnosis was supported by immunohistochemical analysis showing fainth dystrophin expression in muscle tissue. MLPA analysis did not show any major rearrangement on DMD. Results NGS analysis revealed a novel nucleotide intronic substitution DMD:NM_004006:exon15:c.[1705-11A>G]:p.[?] which affects a splice site. RNA analysis performed on muscle tissue showed expression of two different splice isoforms. The first one uses the splice site variant as a new acceptor site and generates an aberrant mRNA encoding a truncated protein. The second one consists in an “in-frame” splice of the exon 15. Segregation analysis confirmed the carrier condition of the mother. Conclusions Our study confirms the pathogenicity of the novel intronic variant DMD:NM_004006:exon15:c.[1705-11A>G]:p.[?] in DMD gene by demonstrating its direct effect at RNA level, and defines the genotype/phenotype correlation. We also stress that the exon boundary should always be included in molecular analysis for an exhaustive diagnosis., We report a 13 years-old patient presenting one year ago with incidental finding of high creatine-kinase levels (8413 IU/L). The patient played soccer at a competitive level and was completely asymptomatic, complaining only cramps after strenuous exercise. He did not show weakness, fatigability, myalgias, myoglobinuria. Neurological examination wan normal with exception for mild sural pseudohypertrophy. Cardiological evaluation was normal. Muscle MRI showed fibroadipose substitution of glutei, paraspinal muscles, serratum and teres major. Muscle biopsy displayed mild myopathic signs and moderate reduction of alpha-sarcoglycan levels at immunohistochemistry. A severe reduction of alpha- and beta-sarcoglycan was also confirmed by Western blot analysis. NGS panel sequencing identified two mutations in the gene encoding for beta-sarcoglycan (SGCB): the previously reported known c.377_384dup microduplication and a novel T > C transition located within a putative pseudoexon. The latter variant activated the inclusion of a cryptic sequence between Exons 2 and 3 in SGCB transcript. Interestingly we detected the same variant in a previously reported Italian LGMDR4 patient in which molecular testing had only detected the c.377_384dup insertion. Molecular studies in patient’s tissues, including autoptic heart specimen, showed global reduction of SGCB mRNA and altered splicing at transcript level. The in vitro administration of an antisense morpholino sequence targeting the pseudoexon restored physiological splicing in patient’s myoblasts. Our findings prompt the analysis of a novel variant in suspected LGMDR4 patients with monoallelic SGCB variants and provides a further example of the efficacy of morpholino antisense technology for the correction of splicing molecular defects., Ullrich congenital muscular dystrophy (UCMD) is caused by mutations in COL6A1, COL6A2 or COL6A3 gene, leading to collagen VI deficiency. Either recessive (more frequent) or dominant inheritance is reported. Clinical-pathological hallmarks of UCMD include distal hyperlaxity, proximal joint contractures, early-onset rapidly progressive scoliosis, and respiratory failure. Muscle pathology is characterized by prominent interstitial fibrosis. We describe a patient who came to our observation at the age of 11.5 years, for a picture characterized by early tendon retractions, kyphoscoliosis, respiratory insufficiency (FVC 52%). Symptoms started at the age of 7-9 months; the child could not maintain the sitting position and never walked alone so the patient underwent a muscle biopsy, which showed a severe pattern of interstitial fibrosis. CK values were normal. There was no cardiac involvement. COL6A1 and COL6A2 gene analysis was negative. Over the years, muscle condition remained stable, while the vital capacity has progressively deteriorated. He died at 25 years 9 months of acute respiratory failure. Trio whole exome sequencing identified a de novo variant c.6210+1G>A at the 5’ splice site of intron 16 of the COL6A3 gene. This LoF variant, classified as pathogenic (VCV0000949S6.5), has already been reported in literature. We identified an additional case in a 4-year boy with decreased fetal movement, neonatal respiratory distress, bilateral cryptorchidism. Muscle-skeletal symptoms are present as scoliosis, adducted thumb, kyphoscoliosis, hip dysplasia hyperextensibility at wrists, central hypotonia and no cardiac involvement. These cases expands the number of patients with autosomal dominant UCMD, due to de novo mutation., Oculo-pharyngeal muscular dystrophy (OPMD) is a late-onset, inherited muscle disorder, characterized by progressive ptosis, dysphagia and variable proximal limb weakness. The highest prevalence is reported in French Canadians (1:1000) and Bukhara Jews (1:600). Few Italian cases have also been reported. OPMD is caused by short (GCN)11-17 expansions in the polyadenylate-binding protein nuclear 1 gene (PABPN1). We summarized the neurophysiological and genetic findings of 17 OPMD patients born in Abruzzo, belonging to 11 unrelated families. In our cohort, age at onset was between 42 and 74 years (mean 57.5). The M/F ratio was 1.125:1. Family history was positive in 15 patients. As expected, ptosis was the most common initial complaint. There was a 5.8-year mean delay before the onset of a second symptom, which was dysphagia in 82.4% of cases. External ophthalmoplegia was present in 64.7% of patients. Two siblings presented cognitive impairment. Genetically, we identified four genotypes, including two GCN11 homozygous patients. Mean age at first evaluation was 67.4 and mean age at genetic screening was 69.4. Creatine kinase levels were mildly elevated in seven patients. Electromyography, performed in seven patients, showed myopathic features in four cases. Five patients had ptosis surgery and one patient reported cricopharyngeal myotomy. According to our results, OPMD has an estimated minimal prevalence of 1.32 per 100.000 persons in Abruzzo. A disease cluster can be hypothesized in Caramanico, where OPMD prevalence is about 0.42%. Despite rapid diagnosis through PABPN1 gene screening, OPMD is yet under-recognized and confirmed after several years from symptoms onset., Becker muscular dystrophy (BMD) is characterized by variable disease severity and progression, prompting the identification of biomarkers for clinical trials. We used data from a recently completed Phase II study to provide a comprehensive evaluation of a cohort of patients with BMD, and assessed correlations between histological and magnetic resonance imaging (MRI) markers with muscle function and strength. Eligible patients were ambulatory males with BMD aged 18-65 years (200-450 m on 6 minute walk test). The following were measured: function tests, strength, fat-fraction quantification using chemical shift-encoded MRI (whole thigh and quadriceps), and fibrosis and muscle fiber area (MFA) of the brachial biceps. Of 70 patients screened, 51 entered the study. There was substantial heterogeneity between patients in muscle morphology (histology and MRI), with high fat replacement. Total fibrosis correlated significantly and mostly moderately with all functional endpoints, including both upper arm strength assessments (left and right elbow flexion Rho -0.574 and -0.588, respectively [both p < 0.0001]), as did MRI fat fraction (whole thigh and quadriceps), e.g., with four stair climb velocity -0.554 and -0.550, respectively (both p < 0.0001). Total fibrosis correlated significantly and moderately with both MRI fat fraction assessments (0.500 [p = 0.0003] and 0.423 [0.0024], respectively). In this BMD cohort, micro- and macroscopic morphological muscles parameters correlated (albeit moderately) with each other and with functional parameters, potentially supporting the use of MRI fat fraction and histology as surrogate outcome measures in patients with BMD, although additional research to validate this is required., Aim of the study To describe and analyse long term functional changes in Becker muscular dystrophy (BMD) through a commonly used outcome measure in neuromuscular diseases, the 6-minute walk test (6MWT). Materials and methods We selected patients coming from “Azienda Ospedale-Università di Padova” who have a molecular confirmed diagnosis of BMD. Our patients were followed up for at least 1 year by evaluating motor function through 6MWT and also North Star Ambulatory assessment (NSAA). We used a modified version of 6MWT specifically validated for DMD. Results Our cohort was composed of 105 subjects, of whom 99 patients could perform 6MWT at baseline. We divided patients according to mutational groups. The shortest distances were registered in the “del 45-48” group, (mean distance was 330.8 m ± SD 178.8 m), and the “del 45-47” group, (mean distance was 324.8 m ± SD 142.9 m). The longitudinal study included a mean number of 5.25 (± 2.95) clinical examinations for each patient and the mean follow up was 4.66 years (± 3.0 years). Longitudinal data showed a statistically significant yearly decrease in walked distance in “del 45-48”, “del 45-47”, and “del 48-49” groups. This decrease is larger if we only consider patients with a worst baseline muscular function (NSAA < 33). We considered the comparison between the distances covered between the first and last 3 minutes of 6MWT as an indicator of fatigability. In the overall BMD cohort there was a significant decrease in distance between the two halves of the test, of -3.0 ± 18.5 m (p = 0.0005). This difference was larger in patients with baseline NSAA, Deep intronic single nucleotide variants (SNVs) are the most elusive DNA variants for NGS. Thus, defining their pathogenic role remains challenging and many genetic conditions remain unsolved. Some of deep intronic variants could lead to aberrant splicing, resulting in partial or full pseudo-exon (PEs) inclusion, mainly due to the activation of cryptic intronic acceptor and/or donor splice sites and the alteration of sequence motifs recognized by enhancer or silencer splicing factors. Here, we tested a computational approach to evaluate splicing involvement of DMD deep intronic SNVs annotated in the Leiden Open Variation Database (LOVD). To prioritize our set of variants based on their probability to be involved in PEs formation, we sequentially applied four different prediction tools (SpliceAI, NNSplice Predictor, HSF and SFMap). We divided the collected LOVD variants into two groups, TRAINING (variants with known RNA effect) and TESTING (variants with unknown RNA effect), which were used respectively to validate and test our pipeline. For TRAINING group, we confirmed involvement of 77% of variants in PEs inclusion. Interestingly, we found that 72% of TESTING variants are involved in alternative splicing leading to PEs inclusion. Overall, we believe that this pipeline could be useful to confidently predict the effect of specific SNVs on alternative splicing and PEs formation, thus providing good indication for NGS variants prioritization and transcriptomic studies in muscular biopsy., The etiology of dermatomyositis is unknown but immune dysregulation plays a key role. A 68-year-old man presented with a 1-month history of skin rash, myalgia and symmetrical proximal limb weakness. He developed these symptoms about three weeks after the second dose of Vaxzevria. On examination, he showed a diffuse facial, scalp, arm and trunk rash with periorbital edema. No Gottron papules were detected. Creatine kinase levels were markedly increased. Electromyography was normal, whereas muscle biopsy revealed a perivascular mixed cell infiltrate. Based on clinical features, elevated muscle enzymes and muscle biopsy, a diagnosis of dermatomyositis was established. A full-body CT scan, performed in order to exclude a connection with malignancies, appeared unremarkable. The patient showed a gradual improvement of symptoms after treatment with intravenous methylprednisolone 80 mg for three days, then transitioned to oral prednisolone 50 mg. To the best of our knowledge, this is the first case of new-onset dermatomyositis after COVID-19 vaccination. Dermatomyositis occurring after vaccination is a well-recognized phenomenon and may be attributable to homology between vaccine components and muscle antigens, triggering an autoimmune response. Moreover, dermatomyositis has been recognized as a manifestation of COVID-19-induced muscle disease. It has been hypothesized that SARS-CoV-2 may transfer its genetic material into the muscle fibers, thus triggering a T cell-mediated viral response leading to muscle damage. In addition, three different T cell receptor epitopes “highly specific” for SARS-CoV-2 have been detected in dermatomyositis patients, reinforcing the hypothesis of molecular mimicry., In this work, we studied a novel mutation in SCN4A gene (p. N1180I), identified in two Italian families showing a peculiar phenotype characterized by the association of myopathy and myotonia (Fusco et al., Brain Dev. 2015; Rigamonti et al., Neurol Sci. 2021). The mutation N1180I was introduced into the pRc/CMV plasmid containing the cDNA encoding wild-type (WT) human Nav1.4 channels. Whole-cell sodium currents were recorded with patch-clamp technique in HEK293 cells transfected with WT or N1180I. Cells transfected with 0.5 μg/ml cDNA of N1180I did not express any current (n = 15), in contrast to 100% of WT-transfected cells. Increasing N1180I cDNA to 1 μg/ml allowed recording of sodium currents in 15 out of 98 patched-cells. Maximum current amplitude from I-V curves was reduced for N1180I (-229 ± 38.5 pA, n = 5), compared to WT (-3959 ± 615 pA, n = 17, p < 0.005). Decay of N1180I currents was significantly slowed. The voltage-dependences of activation and fast inactivation were significantly positively shifted by about 14 mV and 9 mV, respectively. The fast inactivation impairment by N1180I suggests a gain of function of Nav1.4 channels, in accord with occurrence of myotonia in the patients. However, the reduction of expression efficiency and maximum current amplitude, together with the positive shift of activation, suggest a loss of function more compatible with the presence of myopathic traits in the patients. More studies are needed to better understand the mechanisms allowing occurrence of both myotonia and myopathy in the same patient (Supported by Grant 2017-2018 from the University of Bari)., Background Familial periodic paralyses (PPs) are inherited disorders of skeletal muscle characterized by recurrent episodes of flaccid muscle weakness. PPs are classified as hypokalemic (HypoPP), normokaliemic (NormoPP) or hyperkalemic (HyperPP) according to the potassium level during the paralytic attacks. HypoPP is an autosomal dominant disease caused by mutations in the CACNA1S gene, encoding for Cav1.1 channel, (HypoPP-1), or SCN4A gene, encoding for Nav1.4 channel, (HypoPP-2). Methods In the present study, we included 60 patients with a clinical diagnosis of HypoPP. Fifty-one (85%) patients were tested using the direct sequencing (Sanger method) of all reported HypoPP mutations in CACNA1S and SCN4A genes; the remaining 9 (15%) patients were analyzed through a next-generation sequencing (NGS) panel, including the whole CACNA1S and SCN4A genes, plus other genes rarely associated to PPs. Results Fifty patients resulted mutated: 38 (76%) cases showed p.R528H and p.R1239G/H CACNA1S mutations and 12 (24%) displayed p.R669H, p.R672C/H, p.R1132G/Q and p.R1135H SCN4A mutations. Forty-one mutated cases were identified among the 51 patients managed with Sanger sequencing, while all the 9 cases directly analyzed with the NGS panel showed mutations in the hotspot regions of SCN4A and CACNA1S. Ten out of the 51 patients unresolved through the Sanger sequencing were further analyzed with the NGS panel, without the detection of any mutation. Conclusions Hence, our data suggest that in HypoPP patients the extension of genetic analysis from the hotspot regions using the Sanger method to the NGS sequencing of the entire CACNA1S and SCN4A genes does not lead to the identification of new pathological mutations., AChR and MuSK double positive myasthenia gravis has been rarely reported. Generally, it occurs in children and adults after thymectomy or immunotherapy, two young female patients has been described as double positive since the onset of the disease. We report herein a man with a very late onset myasthenia gravis (86-year-old) and coexistence of both antibodies at the time of the diagnosis with a favourable clinical outcome. Despite the presence of MuSK antibodies, he manifested no bulbar symptoms but side effects related to low dose pyridostigmine were evident. Hence, double positivity should be considered also in elderly. We suggest to detect AChR and MuSK antibodies at the time of diagnosis. Other cases of AChR and MuSK double positive myasthenia gravis could allow a better definition of this condition., Congenital myasthenic syndromes (CMS) are genetic disorders characterized by impaired transmission at the motor endplate. Clinically, these forms present with prevalent weakness of the axial muscles (hypotonia at onset) and bulbar muscles (ptosis, ophthalmoplegia, dysphagia, facial weakness). Fluctuations of symptoms, facial dimorphisms and distal weakness are other common features. CMS may respond to treatment with drugs enhancing the neuromuscular transmission and differential diagnosis with congenital myopathies is fundamental. The PREPL gene, responsible for the autosomal recessive form of CMS22, belongs to the prolyl-oligopeptidase subfamily of serine peptidases. PREPL is localized in the cytosol where it is involved in exocytosis processes. We report an 11-year-old patient with CMS, harboring a novel homozygous variant in PREPL. At onset, the patient presented with neonatal hypotonia followed by rhinolalia, bilateral ptosis and dysphagia. Muscle biopsy revealed myopathic changes with selective hypotrophy of type II fibers, in absence of specific characteristics. We performed a custom NGS panel for congenital myopathies/myasthenic syndromes which revealed the homozygous (NM_001374276.1): c.950dup (p.Glu318Argfs*6) variant in PREPL. This insertion determines a premature stop codon, likely leading to nonsense-mediated mRNA decay. The variant is not reported in GnomAD and ClinVar, and is predicted pathogenetic by in silico tools. The repetitive stimulation confirmed an alteration of the neuromuscular transmission. The patient started a treatment with pyridostigmine, which was stopped due to allergic reaction and replaced by salbutamol. This resulted in a global improvement of the generalized hypotonia and dysphagia. However, ptosis and rhinolalia remained severe, with perturbation of speech. This case underlines the importance of genetic characterization for proper clinical management and specific therapeutic strategies., Myasthenia Gravis (MG) is characterized by muscle fatigue, determined by autoantibodies against components of neuromuscular junction, like Acetylcholine Receptor (AchR) and Muscle Specific Kinase (MuSK). Therapies differ according to clinical severity, including symptomatic treatment, immunomodulant approaches and immunosuppressants. Rituximab (RTX) is a “target” immunosuppressant agent against CD20 antigen, determining selective depletion of B lymphocytes with a long-lasting reduction of humoral immune response. It is increasingly used in clinical practice as an off-label treatment of refractory MG. High efficacy has been demonstrated in anti-MuSK MG, though there is also evidence of efficacy in anti-AchR and seronegative MG. Between 2009 and 2020, 12 patients with generalized refractory MG referring to our Unit have been treated with RTX (cycles of 1000 mg IV repeated after two weeks). Among them (9 females and 3 males) 6 had anti-MuSK MG and 6 anti-AchR MG; 3 of these patients had thymoma surgically removed. Efficacy duration of a single cycle ranged from 6 months to 9 years. About 70% of patients substantially reduced dosages of immunosuppressive treatments within one year. At most recent follow up (2021) 6 patients were in Complete Stable Remission, 1 in Pharmacological Remission and 5 in Minimal Manifestation-3 status, according to MGFA Post Interventional scale. None of our patients developed myasthenic crisis or required rescue therapies since the introduction of RTX. Only one severe drug-related, but reversible, adverse event (hypertensive crisis) was observed. Our experience confirmed RTX as a safe and effective treatment for both anti-MusK and anti-AchR MG patients., Background and aims Since COVID-19 infection became a global public health problem, finding a treatment has been an emergency and vaccines are considered the only solution. In the last months, a big amount of data has been published on COVID-19 and vaccines and are currently available for the general population, but little is still known regarding patients with myasthenia gravis. Methods We performed a cross-sectional study among a cohort of patients with Myasthenia gravis attending to the Neuromuscular Clinic of the University Hospital “Paolo Giaccone” of Palermo. Patients underwent a telephonic interview through a dedicated questionary about COVID-19 infection, vaccinations, and their effects on MG. Results In our cohort 9 patients resulted positive to SARS-COV2 infection, 4 patients died for COVID-19, a patient worsened for MG, requiring respiratory support, whereas 3 patients were asymptomatic. Fifty-three patients completed the vaccination with minor side effects in 24 cases. Seventeen patients presented a worsening of symptoms. Conclusions The reduced number of adverse events in our population suggests that vaccines for SARS-cov2 are safe in myasthenic patients that could take advantage of vaccination avoiding life-threatening complications such as myasthenic crisis and COVID-19 pneumonia. The continuation of the regular and periodic clinical follow-up will provide us data on the real effectiveness of vaccine prevention in the myasthenic population., Background Congenital myasthenic syndromes (CMS) are hereditary neuromuscular junction disorders, due to defects of proteins involved in endplate development and function. Different CMS have no clear genetic cause yet, therefore many other genes will have to be discovered. Cases description We describe herein a 52-year-old woman, whose first faticability symptoms manifested at the age of 43 years old. She complained of left fingers weakness, that progressively involved the other hand and pelvic girdle muscles, with difficulty to raising from a chair and climbing stairs. Besides, she presented sporadic episodes of double vision. Clinical examination revealed waddling gait, not possible on heels, positive Gowers sign, severe weakness of flexors and extensors finger muscles, mild weakness of bilateral iliopsoas muscle and pes cavus. Results Blood investigations, including serum CK, were normal. Electromyography evidenced a myopathic pattern. Ulnar nerve repetitive stimulation recorded no alteration, but single fiber electromyography showed increased jitter and blockings. AChR-Abs and MuSK-Abs were negative. Sequence analysis of CMS-related genes resulted surprisingly normal, while it was found a stop codon mutation of Leucine Rich Repeat And Sterile Alpha Motif Containing 1 (LRSAM1) gene (c.1279C > T; p.Arg427Ter), encoding for an axonal membrane protein. Despite that, therapy with ephedrine was started with subsequent and progressive improvement of clinical manifestations. Discussion and conclusions To date, mutations of LRSAM1 gene have been reported in Charcot-Marie-Tooth type 2P. Our patient presented clinical and neurophysiological features of CMS. This case highlights the opportunity to find new molecular basis for these disorders in order to better define their pathophysiology., Objective Neuromuscular diseases (NMD) may represent a risk factor causing a more severe course and outcome of SARS-CoV-2 infection. Interestingly, we observed several cases of SARS-CoV-2 infection in Ligurian patients affected by Myasthenia Gravis from March 2020 to April 2021. Methods We collected data from 13 patients affected by Myasthenia Gravis, followed in different Ligurian hospitals. While eight patients had a mild course of SARS-CoV-2 infection, 5 patients had an unfavorable course causing the death of 4 patients and a prolonged life threating hospitalization in one patient. We analyzed their MGFA class at the moment of the infection, the maximum MGFA class reached during their clinical history, and the previous number of myasthenic crisis. We also evaluated the age at the infection, the BMI and the number of comorbidities as independent risk factors for infection severity. Results As expected, age and elevated BMI are independent risk factors for poor outcome of Covid-19 in myasthenic patients (mean age 68,3 range 47-87 years; comorbidity rate overall 53.8%). Also having 1 or more comorbidities predicts a higher hospitalization rate (7/8 patients, 85.7%). Interestingly, the five patients with an unfavorable SARS-CoV-2 infection course had a moderate MGFA class at the moment of the infection, but almost all (80%) had previous myasthenic crisis and the average maximum MGFA class reached during the clinical history was significantly higher (MGFA = 4), compared with the group with a prompt recover (MGFA = 2); p : 0.01. Conclusions Among our neuromuscular patients, SARS-CoV-2 infection had a significant impact in particular in myasthenic patients causing the death of four of them and a long hospitalization in one. Despite Myasthenia was well compensated at the moment of the infection, patients with previous myasthenic crisis and a higher MGFA maximum tended to have an unfavorable course. This correlation, already described in a large French study (Solé G et al. Impact of Coronavirus Disease 2019 in a French Cohort of Myasthenia Gravis. Neurology 2021) supports the hypothesis that autoimmune neurological diseases may be a risk factor for a severe course of SARS-Cov-2 infection., A 29-year-old woman with Neutral Lipid Storage Myopathy (NLSDM) is presented. Until 2015, she was asymptomatic except for elevated CPK. At 18 years, hyperCkemia suggested NLSDM diagnosis and sequencing analysis revealed a retrotransposal insertion in PNPLA2 gene. PNPLA2 encodes the lipase ATGL, which mutations cause NLSDM onset. In the following years, the patient has been experiencing muscle weakness in both arms, shoulders, and hands, then extended to lower extremities. Calves MRI showed lipid accumulation. At 27 years, she was put on a diet with 30 grams per day of MCT oil and 15 grams of natural fat. After beginning MCT diet, the CPK lowered, from 2640 U/l to 1424 U/l. Nevertheless, muscle weakness did not improve, as showed by GSGC score performed in 2020: Walking 10 Meters = 10 seconds; Climbing Stairs = 13 steps up = 8.10 seconds. 13 step down = 6.40 seconds; Raising from seated floor position with no hands = 2.76 seconds; Getting out of chair = .61 seconds (< less than 1 second). Following parents’ request, we planned a recruiting study for NLSDM, as previously described. We suggested performing a new MRI and skin biopsy. While the skin biopsy showed only a slight oedema, muscle MRI highlighted advanced fat substitution in both upper and lower extremities. In this patient, no beneficial effects on myopathy progression were observed after MCT diet, probably due to complete loss of ATGL production. We reported several cases in a NLSDM registry and this patient represents an NLSDM spectrum severe example., Background Muscle biopsy is considered to be the gold standard test for diagnosis of muscle disease. It is usually indicated to evaluate abnormal clinical and/ or laboratory findings suggestive of myopathy, such as HyperCKemia, myalgia, exercise intolerance, family history of myopathy, muscle weakness, and abnormal electromyography (EMG). Methods We restropectivly reviewed 889 consequential muscle biopsies performed at Center for Neuromuscular disease between 2005 and 2020. We collected several patient information including laboratory data, neurological examination, genetic and byochemical test. Results The clinical reason for performing the muscle biopsy was myalgia in 32% of cases, muscle weakness in 50.4%, muscle atrophy in 4.1% and at least 1 episode of Rhabdomyolysis in 5.1%, while 9.1% of patients had chronic CK serum elevation and 4.4% had a past diagnosis of myopathy. Mucle biopsy led to a unique diagnosis in 42.2% of cases, which the most frequent were inflammatory disease and dystrophic forms. The Area Under the Curve (AUC) for prediction of a specific bioptic diagnosis was 0.63 (0.59-0.68) for patient with weakness, 0.57 (0.53-0.61) for patients with Hyperckemia and 0.63 (0.59-0.68) for patient with myopathic EMG. The association of these 3 element results in an increase of the AUC (0.73, 0.68-0.77). A definitive diagnosis was obtained in only 21.5% of patients without specific a priori clinical suspicion. Conclusions Muscle biopsy remains a fundamental diagnostic test for the study of muscle pathologies, especially in patients with specific clinical signs. However, its role is less clear in patients with more subtle clinical elements., Introduction Respiratory insufficiency is one of the main causes of death in myotonic dystrophy type 1 (DM1). Predictive factors, rate of decline and the effects of ventilator support need to be further explored. Objectives To analyze respiratory function over time. Methods. 175 adult patients with DM1 were subjected to arterial blood gas analysis, spirometry, cough measurements, nocturnal oximetry and respiratory muscle strength testing. Results were correlated with neuromotor function and coping strategies. Results At baseline 84 of 175 had normal respiratory function (median age 38 years, median BMI 23.9, median disease duration: 11 years); 24 were already on NIV (median age: 49 years, median BMI: 26.1, median disease duration: 21.5 years) and 67 received an indication to use NIV (median age: 49 years, median BMI: 25,8, median disease duration: 14 years). After a median time of 3.85 years, 43 patients were lost to follow-up; 9 of 84 required NIV; 16 patients initially on NIV kept using NIV; only 17 of 67 with the new NIV prescription were compliant. Conclusions Respiratory involvement affects almost 50% of patients with DM1 although typical respiratory symptoms may not be present. The majority required NIV and these were the most severely affected patients and having the longest disease durations and higher BMIs than the cohort having normal respiratory function. A minority (11%) required NIV during our observational period. Only 25% was NIV compliant and this was unrelated to the patients’ coping strategies or to specific demographic or respiratory distinctive features., Background Myotonic dystrophy type 1 (DM1) is characterized by a wide phenotypic variety. There is consensus about the need for multidisciplinary management of this disease, but there is still a need to harmonize procedures of assessment and to define the best outcome measures. END-DM1 is a multicenter, international, observational and prospective study proposed by DMCRN. The NeMO Clinical Center in Milan is the Italian representative for this network. Aims to describe the NeMO’s experience in screening, evaluating and collecting data along with difficulties and strengths in following END-DM1 procedures. Methods The protocol includes: clinical assessments (medical history, physical exam, vital signs and EKG), mobility and functional measures (10MWT, 6MWT, TUG, 4 stairs, timed supine-to-sit, step test, vHOT, pick-up coins, 9NHPT), measures of strengths (QMA, MMT, IOPI) and pulmonary function, PROMs (MDHI, EAT-10, Domain Delta questionnaire, WPAI:SHP, EQ-5D-SF, Walking Scale-12, DM1-Activ), cognitive function (Cogstate), biomarker and genetic assessments (blood and urine samples and muscle biopsy). Results We recruited 65 adult onset patients (44 females, age: 44 ± 13.57): 2 were wheel-chair bound, 7 had PM/ICD, 26 cataracts and 21 NIV. Age of first symptom: 22.66 ± 13.57; age at diagnosis 31.54 ± 12.45; grip myotonia was the most frequent symptom at onset (61/65) and hand weakness often preceded limb weakness. Only 4 patients reported cognitive symptoms. Conclusions This academic registry highlights the importance of providing appropriate evaluations by trained and dedicated staff in order to guarantee quality control of data entry in preparation for clinical trials while providing care according to patients’ needs., Heart disease is a determinant of prognosis in type 1 myotonic dystrophy (DM1). Cardiac imaging, possibly including cardiac magnetic resonance (CMR), is recommended, but there is limited information on CMR findings and their prognostic significance. All DM1 patients referred to our CMR laboratory between 2009-2020 (n = 34, 21 males, aged 45 ± 12) were retrieved. At the time of CMR, 90% had neuromuscular symptoms (duration 17 ± 13 years), 13(38%) had previous reports of atrioventricular block, 30(88%) of intraventricular conduction disturbances, 4(12%) of atrial fibrillation/flutter. At CMR, 5(15%) patients had left ventricular (LV) systolic dysfunction (LVEF < 50%) and 4(12%) a depressed right ventricular (RV) function (RVEF < 50%). Compared to age- and sex-specific reference values, 12(35%) showed a decreased LV end-diastolic volume index (LVEDVi), 7(21%) a decreased LV mass index (LVMi), and 29(85%) a decreased LVMi/LVEDVi. Nine(26%) patients had mid-wall late gadolinium enhancement (LGE), and 14(41%) some areas of fatty infiltration. Native T1 in the interventricular septum (1.041 ± 53 ms) approached the upper reference limit (1.089 ms), and the extracellular volume was increased (33 ± 2%, reference < 30%). Over a median follow-up of 2.5(1.5-4.0) years, 2(6%) patients died for infectious and respiratory complications, 5(15%) underwent PM/ICD implantation and 4(12%) presented high-risk (Lown ≥ 4) ventricular ectopic beats (VEBs). Among CMR variables, high LVMi/LVEDVi emerged as univariate predictor of all-cause death (p = 0.044). At logistic regression, anteroseptal wall thickness was associated with PM/ICD implantation (p = 0.028), LGE mass with high-risk VEBs (p = 0.026). In conclusion, DM1 patients display cardiac muscle hypotrophy, fibrosis and fatty infiltration at CMR. Such changes may anticipate the worsening of electrical disturbances., We formerly reported an Italian kindred with adult-onset autosomal dominant vacuolar myopathy with 19 affected individuals over four generations. Myopathology was characterized by rimmed autophagic vacuolation and distinctive immunohistochemical features including involvement of the ubiquitin-proteasome pathway. More recently, we identified the protein accumulating within the vacuoles and pinpoint, with the use of long-read sequencing, a large coding expansion in the PLIN4 gene, member of the perilipins’ family. The accumulation of this protein within the vacuoles and in the subsarcolemmal region of the affected fibers, coincides with the immunohistological activation of the key players of the aggrephagy pathway, notably p62/SQSTM1, NBR1 and WDFY3. We present here clinical, histological and muscle imaging data of 15 affected patients carrying the PLIN4 gene expansion. Mean age at onset was 47.3 ± 10 years (range 30-66), with upper or lower limb distal muscle weakness as presenting symptoms in most of the patients. Disease progression was slow over the years, with around half of the patients developing a predominant scapulo-humeral-peroneal pattern of weakness. Five out of 15 (33.3%) patients were wheelchair-bound after a mean disease duration of 14 ± 6.6 years. No relevant heart involvement was observed. Rimmed values were detected in all muscle biopsies taken from the patients. The extent of the histopathological changes varied between patients correlating with disease severity and PLIN4 expansion entity. In conclusion, we clinically and histologically characterized a new vacuolar distal myopathy presenting in adult age, linked to a pathological expansion of the PLIN4 gene., Glycogen Storage Disease type III (GSDIII) is a rare autosomal recessive disease caused by deficiency of the glycogen debranching enzyme (AGL). Consequently, glycogen accumulates in the affected tissues, mainly damaging liver, muscles and heart (GSD IIIa); in a minority only liver (GSD IIIb). The onset is in infancy. However, the risk of hypoglycemia usually decreases with age, with progressive reduction in liver volume, during pubertal age. In adulthood, cirrhosis of the liver and/or hepatomas may appear, as well as the involvement of skeletal muscles and myocardium. We describe two siblings, male and female, with GSDIII presenting with an early skeletal muscle involvement. Male: onset in the second decade, with difficulties in walking, climbing stairs and getting up from the floor, progressively worsening, associated to muscle weakness. Severe kyphoscoliosis. CK values up to 16 times the maximum normal values. Episodes of hypoglycaemia at 30 years; hepatosplenomegaly. Hypertrophic cardiomyopathy diagnosed at 43 years. LoA at 54 years. Over the years, worsening of general conditions, and increased functional limitation in daily activities. Female: onset of muscle symptoms at the same age; LoA at 43 years. No cardiomyopathy. CK values up to 17 times the maximum. Vacuoles at muscle biopsy, with modest glycogen accumulation; debranching enzyme deficiency causing the disease. Death at 49 years, for causes unrelated to the disease. NGS analysis showed the homozygous variant c.1283G > A p.R428K in exon 10 of the AGL gene, which modifies the last nucleotide of the exon. This variant most likely affect the splicing, as SpliceAI assigns it a score of 0.72 for donor loss. The cases here reported broaden the spectrum of GSDIII clinical presentation, confirming its clinical heterogeneity and intra-familial variability., Mutations in LMNA lead to skeletal muscle laminopathies (SMLs), a group of rare disorders characterized by skeletal and cardiac muscle involvement. To date, natural history of SMLs is not clarified yet, being mainly described by retrospective studies, reporting only major events. We aimed to investigate the natural history of SMLs through a 2-year prospective study, including several clinical outcome measures. Methods Twenty-six SML patients were enrolled in the present study and assessed with the following tests: North Star Ambulatory Assessment scale (NSAA), timed tests, manual muscle testing, joint range of motion, six-minutes walking test (6MWT); respiratory evaluation including forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV1); individualized neuromuscular quality of life (INQoL) questionnaires; cardiac evaluation collecting standard 12-derivations electrocardiogram, 24-hours Holter ECG monitoring and heart echo scan. Results At the baseline, clinical assessments significantly (p value < 0.05) correlated with SMLs phenotypes, showing a worst performance in Emery-Dreifuss muscular dystrophy 2 patients. The NSAA score significantly deteriorated (p value = 0.0005, mean change: 2.9 ± 0.4) during the 2-years follow up. The respiratory function through FVC (p value: 0.0086, mean change: 6.9% ± 1.4%) and FEV1 (p value: 0.0290, mean change: 6.7% ± 1.8%) significantly declined. Conversely, 6MWT and timed tests, did not significantly change. Similarly, elbow, knee and ankle joint range of motion resulted unchanged. Conclusions Disease progression of SMLs was shown with NSAA, FVC and FEV1 in a 2-year period, suggesting a slow decline of the motor and respiratory function in these patients., Introduction Progressive external ophthalmoplegia (PEO) represents the most common feature of mitochondrial disorders. When it occurs in isolation, it is defined “chronic progressive external ophthalmoplegia”(CPEO) while the combination of PEO and other features of neuromuscular and multisystem involvement (excluding CNS) is named “CPEO plus syndrome”. Clinical variability is broad even in individuals harbouring the same genotype. Recently, some studies focused the attention on muscle weakness, exercise intolerance, and muscular pain as features of mitochondrial diseases. However, fewer studies focused the attention on severity and distribution of muscle wasting and damage in PEO patients. Our aim is to analyse systemic muscles involvement with the use of muscle MRI. Materials and methods We enrolled patients diagnosed with CPEO or CPEO plus by clinical, biological and genetic tests, at Neuromuscular Centre of Careggi University Hospital, Florence. We analyzed T1-weighted sequences of the neck, shoulder girdle, paraspinal muscles, lumbar girdle, thighs, and legs, evaluating the severity of wasting and the grade of fatty tissue substitution. Results MRI images were taken from 7 patients (3 men); their age ranged between 23 and 72 years. Three patients (2 men, age 56-72yrs) had CPEO-plus; 2 harboured pathogenetic variants in POLG. In those individuals, MRI showed similar involvement of the axial, tight, and leg muscles. Studies of the remaining 4 patients, who are still awaiting molecular definition, were unremarkable. Conclusions MRI could be a useful and informative tool in the clinical evaluation of the general muscle involvement of CPEO patients. This research project is funded by Tuscany Region., Objective To verify the change in the emotional and behavioural conditions of neuromuscular disorders patients’ before and during the COVID-19 pandemic and to evaluate if the change was predicted by coping strategies. Methods We analyzed 43 participants – age range at first assessment 4-52 - out of 112 subjects recruited in the study. The emotional and behavioural conditions were assessed through standardized questionnaires: Youth Self Report (YSR), Adult Self Report (ASR), Child Behaviour Checklist (CBCL), Adult Behaviour Checklist (ABCL). The pre-pandemic coping strategies of both parents and patients were assessed through the New Italian Version of the Coping Orientation to the Problems Experienced questionnaire. The relationship between coping strategies and psychopathological profiles was investigated through correlations, while the change in the patient’s psychopathological profile was observed with repeated measures ANOVA. The predictivity of coping strategies on adaptation during pandemic was analyzed through linear regression’s analysis. Results Patients’ coping strategies are correlated with psychopathological level reported by caregivers pre pandemic. ABCL and CBCL scores reported a significant worsening in patients’ general emotional-behavioral conditions during COVID-19, even though it’s under clinical cut-off; whilst patients didn’t perceive any variation in their well-being status. The change has no causal relationship with the patients’ coping strategies. Conclusions Pre pandemic, parents’ perception of the patient’s psychopathological level depends on the coping strategies used by the subject. Caregivers perceive a worsening of the patient’s psychopathological level during the pandemic, but this is not predicted by the patient’s pre-pandemic coping strategies., We present the case of a 52 years old male patient that came to our attention for widespread myalgia, progressive thinning of muscles and muscle cramps mainly localized at the lower limbs, without significant weakness, beginning two years ago. A positive family history for myotonic dystrophy type 2 (father) was reported. He had also previously performed a brain MRI for recurrent cephalalgia, revealing multiple, large, mainly temporo-occipitally localized subharachnoid cysts along with diffuse leukodystrophyc involvement of both supra and infratentorial white matter. Based on clinical, anamnestic and imaging data, both analysis of expansions of the CCTG repeat in the CNBP gene for DM2 and an NGS analysis panel for leukodystrophies were performed; the patient tested positive for DM2 and a rare variant of unknown significance (allelic frequence 0.00026) associated with autosomal dominant microangiopathy and leukoencephalopathy was identified in the COL4A1 gene (c.2126C > T)., Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder characterized by loss of bulbar and spinal motor neurons due to defective production of SMN protein. Nusinersen, able to restore SMN transcription levels, had recently revolutionized the approach to SMA determining motor function improvement and prolonged survival. Here, we retrospectively evaluated quality of life (QoL) in a large multicenter cohort of adult SMA patients during nusinersen treatment. We included adult patients who started nusinersen treatment in adulthood. QoL was rated by the Individualized Neuromuscular Quality of Life (INQoL) questionnaire. Concurrent motor function evaluation included the Hammersmith Functional Motor Scale Expanded (HFMSE), the Revised Upper Limb Module (RULM), the six minutes walking test (6MWT). 189 completed questionnaires were collected during a 14 months’ treatment period. 78 patients were included (7 SMA2 and 69 SMA3 and 2 SMA4) with mean disease duration at first nusinersen administration of 33.2 years (± 12.5 years). All the scores for each INQoL domain (weakness, fatigue, activities, indipendence, social relationship, emotions, body images) and the derived QoL total score, significantly improved during the observation period, except the muscle locking and pain items. Changes in emotions and social relationships were more relevant in females compared to males. Social relationships were affected also by a longer disease duration (> 30 years). In SMA3 non-walker patients, activities ameliorate better compared to walkers. In our cohort, adult SMA patients showed a global improvement at the INQoL assessment over 14 months of nusinersen treatment. QoL assessment is relevant to SMA multidisciplinary evaluation., Background Patients involved in the Expanded Access Program experience with nusinersen in spinal muscular atrophy (SMA) reported variable degrees of changes in the oro-facial district with treatment, but there are no data about facial mobility and general consensus for testing it. Aims to investigate new quantitative non-invasive measures of facial mobility in SMA. Methods We assessed facial mobility through an easy-to-interpret index based on a face tracking algorithm that exploits Facial Action Coding System (FACS) in patients with SMA at rest and while performing 7 specific tasks: frowning, eye closure without exertion, eye closure with exertion, tight-lipped smile, smile, kiss, cheeks inflation. Based on the FACS encoding system, a set of 56 facial landmarks was defined and tracked in the 2D image space per each expression, using a self-developed software (TrackOnField, BBSoF S.r.l.). These landmarks defined 40 distances that were normalized to the corresponding quantities of the neutral expression. Then, a face mobility index (FMI) was calculated per each subject task. Results 62 patients were recruited: 28 females, 34 males; 8 pts SMA1, 26 SMA2, 27 SMA3, 1 SMA4; mean age 27.16 (± 18.62) years old. Preliminary data from 34 patients showed that the task involving a greater FMI was smile (17.97), followed by eye closure with exertion (15.96) as expected. Conclusions Our preliminary data suggest that this may be a potential measure to track possible alterations on facial muscles’ mobility associated to the disease and to investigate the impact of treatments aiming at improving facial mobility., Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive cortical, bulbar and spinal, motor neuron (MN) death, leading to muscle wasting. Although it is generally accepted that ALS is primarily due to MN degeneration, upcoming evidences show an early involvement of skeletal muscles too. Different causative genes associated to ALS are involved in RNA metabolism; among non-coding RNAs, long-non coding RNAs (lncRNAs) are emerging as molecular contributors to ALS pathophysiology because of their role in regulating gene expression. Here, we analyzed the expression levels of HOTTIP, MALAT1 and NEAT1 lncRNAs, known to be involved in the development and homeostasis of the skeletal muscle, in a human induced pluripotent stem cell (hiPSC) model differentiated towards a myogenic destiny through a small molecule-based protocol, obtained from ALS patients and healthy controls. The expression of key markers of skeletal muscle development was analyzed by qPCR. Further, mRNA targets for the lncRNAs were predicted in silico, and validated by qPCR. We reported a differential lncRNA and mRNA target expression pattern in ALS-mutant cell lines compared to controls, particularly at the mesodermal progenitor, early myocyte and myotube stages. Specifically, through hierarchical clustering analysis we identified specific clusters of lncRNAs/mRNA targets characterizing ALS cell lines, suggesting that an altered expression of these molecules might contribute to the disease pathogenesis. These data highlight the role of HOTTIP, MALAT1 and NEAT1 as potential important players in muscle dysregulation in ALS. Thus, they could represent possible targets for new therapeutic strategies., Spinal muscular atrophy (SMA) is an autosomal-recessive motor neuron disease causing progressive muscular atrophy and weakness. Nusinersen, an antisense oligonucleotide able to increase functional SMN protein modifying the SMN2 pre-mRNA splicing, is proven to significantly modify the natural course SMA type 1 in infants and provides benefit even in adult SMA patients. Since fatigue represents an additional dimension of impaired motor function in SMA type 3 patients, hence we aimed to investigate the impact of nusinersen on fatigability (an objective measure of fatigue) through the 6-minute-walking-test (6MWT) in SMA type 3 patients. From a large Italian cohort of patients, we selected 58 ambulant adult SMA type 3 patients being treated with nusinersen and we analyzed data on 6MWT from baseline (T0, beginning of treatment) to 14 months of treatment (T14). Mean age at baseline was 39.6 ± 16 years. No significant reduction in the meters walked from minute 1 to minute 6 was found at T0 (60.6 ± 20.9 vs 56.38 ± 27 m) and T14 (64.0 ± 19.0 vs 54.16 ± 22.8 m). The analysis of variance for repeated measures for the distance walked at every single minute of the 6MWT during follow-up did not show statistically significant differences. Moreover, we found an average trend of improvement of the total 6MWT over a period of 14-month treatment (329.2 ± 129 vs 310.3 ± 136.3 m). In conclusion, although no relevant fatigability was found in our cohort at baseline and no effect of nusinersen on fatigability through the follow-up period, our data broaden the knowledge of nusinersen effect in adult ambulant SMA patients., Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disorder characterized by a progressive degeneration of motor neurons (MNs). A dysregulation of microRNA (miRNA) expression in ALS has been already described, although downstream pathological events associated with MN degeneration have not been clarified yet. miRNAs are highly expressed in central nervous system thus they may play important roles in the etiology or progression of neurodegenerative diseases. In this study, we aimed at investigating whether alteration of miRNAs expression patterns in ALS-MNs may represent a common molecular feature among the different forms of the disease. We performed differential expression profile analysis of miRNAs isolated from ALS-MN and healthy subjects and we identified a small group of downregulated miRNAs in ALS-MNs. Interestingly, a dysregulation of the same subset of miRNAs has been detected in exosomes released from the same ALS-MN cultures. Since bioinformatic analysis showed that these miRNAs regulate several pathways related to MN degeneration, we investigated their potential as disease biomarkers assessing their expression level in cerebrospinal fluid (CSF) of ALS patients. We confirmed a dysregulation of these miRNAs in CSF suggesting their potential clinical relevance. Taken together our results demonstrate that the neurodegenerative phenotype in ALS can be associated with a dysregulation of miRNAs involved in the control of disease-relevant molecular pathways. The possibility of tuning entire gene networks with a specific subset of miRNAs may provide significant insights on the development of effective new miRNA-based therapies and could be useful as disease biomarkers., As an update of our study in 30 adult SMA type 3 patients we tested as potential biomarkers Neurofilament light chain (NfL) and Profilin-1 (PFN-1) during a 26 months follow-up (timepoint M6). PFN-1 is a small actin-binding protein required in both the presynaptic and the postsynaptic compartment with a role in regulating cytoskeletal architecture and dynamics of neurons (Witke, 2004). CSF NfL was tested with an enzyme-linked immunosorbent assay (ELISA) kit (UmanDiagnostics, Sweden). PFN-1 was measured with a commercial manual ELISA kit (Cusabio, China) in CSF samples of 6 patients (3 sitters 3 walkers) at time points L1, L3 and M2 and in every available serum sample from time point L1 to time point M6; 19 serum samples of healthy donors as a control group. Mean NfL at M6 was 381.83 ± 455.71 ng/l, slightly higher than baseline but not significantly different from M3. PFN-1 concentration in all 18 CSF samples was below the lower limit of quantification (< 31.25 ng/l). Serum PFN-1 at baseline was higher in SMA group than in healthy controls (mean 1016 vs 608 ng/l, p = 0.001 Student’s t test). PFN-1 showed a complex dynamic during loading phase, with a significant reduction at L4 compared to baseline. No correlation was found with NfL and motor scores at each time point. PFN-1 as an exploratory cytoskeletal biomarker changed significantly during the first two months of treatment. To our knowledge this is the first report of PFN-1 determination in serum of SMA patients., Hereditary neuropathies represent the most common inherited neurological conditions and show wide clinical and genetic heterogeneity. To date, more than 100 genes have been described to cause Charcot Marie Tooth Disease (CMT) and the related disorders, as distal hereditary motor neuropathy (dHMN) and hereditary sensory neuropathy (HSN). Next generation sequencing (NGS) has speeded up the diagnosis of hereditary diseases and customized targeted NGS panels of disease relevant genes have been developed and used in clinical practice. We describe a 45 years old patient with distal lower limb predominant sensorimotor neuropathy clinically manifested from the age of 30 and characterized by axonal disfunction with associated demyelination. NGS custom panel analysis of 77 genes associated with CMT and related conditions was performed with an Illumina custom Nextera Rapid Capture panel and sequencing on Illumina MiSeq. The analysis revealed in the AARS1 gene (OMIM * 601065) the c.986 G > A (p.Arg329His) heterozygous missense variation, a known and recurrent mutation described worldwide. Segregation analysis through Sanger sequencing in the healthy parents showed the absence of the variation in the father and an ambiguous nucleotide annotation by Sanger in the mother. Indeed the NGS analysis demonstrated in the mother DNA a clear mosaicism for the variant. NGS analysis is very sensitive in detecting mosaicisms, which should be always analysed by family segregation in order to identify the heterozygous parent and to define the risk or recurrence in the family., Biomarkers of disease progression and outcome measures still lack for ALS. Muscle MRI can play a role to track longitudinal changes and to predict response to treatment in clinical trials. We applied quantitative muscle MRI to evaluate disease progression and explore any clinical correlation in ALS. A cohort of newly-diagnosed ALS patients, longitudinally scored using the leg subscores of ALS Functional Rating Scale Revised (ALSFSr), was enrolled. The muscle MRI protocol (6-point Dixon GRE and multi-echo TSE T2w) was implemented for quantification of fat fraction (FF) and water T2 (wT2). Twelve thigh muscles six leg muscles were manually drawn for each side. Eleven age-matched healthy controls were enrolled for comparison. Fifteen patients (M/F 8/7; average age 62.2, range 29-79) diagnosed with possible (n = 2), probable (12) or definite (1) ALS were enrolled (11 spinal onset, 4 initial bulbar envolvement). All patients performed muscle MRI at T0, nine at T1 (6 mo), and seven at T2 (12 mo). At baseline wT2 was significantly elevated in ALS subjects compared to controls for several thigh and mainly for leg muscles; FF was only elevated in a few thigh muscles. wT2 decreased over time in line with worsening in the leg subscores of ALSFRSr (mainly at the leg level and in the anterior and medial compartment of the thigh); FF increased significantly in the leg muscles over time (mainly in the triceps surae). In ALS quantitative muscle MRI represents a non-invasive tool capable of describing the trajectory of pathogenic modifications in the muscle., Background Villa Rosa RehabLab, Trento Italy, aims to design 3D printed personalized Assistive Devices (AD) to facilitate and promote participation through a user-centred co-design process.; direct involvement of the user in the design process ensures a correspondence of the AD to his/her needs, aiming to empower the person in the therapeutic strategy, ensuring the AD’s continuous use and avoiding stigmatization. The use of 3D printer is increasingly popular in the medical world, particularly in rehabilitation and occupational therapy for the manufacture of personalized adaptations and assistive devices. M.A. 58 y.o., diagnosed with radiation-induced brachial plexopathy since 2012, at the initial occupational therapy interview reported difficulty in cutting hard foods, reporting pain when he presses the knife with his left arm. Patient’s quality of performance was observed and self-perception of performance and satisfaction scored using the Canadian Occupational Performance Measure (COPM). Objective Improve quality of performance and decrease pain when performing this task. Methods After ascertaining that no commercial AD was available, an AD dedicated to this function was designed by the user on paper, and afterwards the occupational therapist created a wood prototype. Once the functionality of the prototype was ascertained, the user, guided by the therapist, drew the object with desired shape and sizes using FUSION360, which was then fabricated with the 3D printer. Result The client’s quality of performance improved using the fabricated AD, as did his COPM scores. Conclusions The RehabLab and use of 3D printer can improve independence and participation with individuals with radiation-induced brachial plexopathy., Spinal muscular atrophy (SMA) is a motor neuron disease and the first known genetic cause of infant mortality. Recently approved therapies have shown efficient results only if administrated during the pre-symptomatic phase, that seldom corresponds to the period when the disease is diagnosed in patients. Therefore, the issue of a symptomatic-suitable treatment, efficient across different clinical phenotypes, is strongly present in a clinical perspective. We have already demonstrated that the ASO variant Morpholino (MO) is able to increase the production of a functional SMN protein and rescue the murine phenotype in pre-symptomatic phase, after intracerebroventricular administration. However, this treatment resulted almost ineffective if administered during the symptomatic phase. The conjugation with Cell-Penetrating Peptides (CPPs) may represent a promising therapeutic strategy to address this issue, allowing the MO to overcome the blood-brain barrier by a systemic administration thus expanding the therapeutic window. We investigated the efficacy of CPPs in delivering MO to the central nervous system in symptomatic mice through an intraperitoneal injection, demonstrating that the conjugation with r6 peptide can improve MO biodistribution and increase SMN levels, rescuing the pathological phenotype. Histological examination on SMA treated mice showed a significant increase in the number of motor neurons and innervation of neuromuscular junctions. These data were supported by a striking increase in survival and motor functions, confirming the safety and efficacy of this approach which has never been observed with other compounds in a symptomatic phase of the disease, laying the ground for the development of future clinical trials for SMA., Background While there is general consensus on the motor function scales to be used in muscle strength and functional assessment, little is available for testing of oro-facial muscles and function, yet the pre-swallowing phase of feeding is affected not only in SMA1, but also in the other types of SMA. Aims To investigate strength and function of the oro-facial and brainstem muscles in a cohort of SMA patients treated with nusinersen and in a cohort of naive patients. Methods This is a 20-months observational, multicenter parallel study involving 120 patients with all types of SMA either on treatment or not subjected to lip and tongue strength assessments, swallowing and mastication functional tests and clinical nutritional assessments. Results 140 patients have been enrolled to date. 65%are on treatment while 35% are not (48% SMA2, 31% SMA3, 21% SMA1). 95% of SMA1, 50% of SMA2 and 27% of SMA3 are underweight. 17% of SMA2 and 33% of SMA3 are overweght. IOPI lip and tongue strength (KPa) and mouth opening (cm) was 2.6 and 2 KPa and 2.5 cm for SMA1; 12.9 and 16.2 KPa and 2.6 cm for SMA2; 19 and 42.5 Ka and 4,2 cm for SMA3. SMAHI subscores referring to swallowing and bulbar functions correlated to the nutrional and swallowing abilities of the patients including PEG tubes. Conclusions Our preliminary data suggest that IOPI and SMA-HI swallowing and bulbar subscores may be potential tools to track possible changes on orofacial and orobulbar functions related to the disease itself or to treatment., Nusinersen (Spinraza) is the first drug approved in Italy in 2017 for the treatment of SMA patients. Since its approval, the drug has been administered in several authorized Italian Centers. In the Emilia-Romagna (ER) region we started to treat SMA patients in 3 Centers authorized to prescribe and administer the drug (Bologna, Reggio-Emilia, Parma), and in 2 Centers authorized for administration (Ravenna and Rimini) in collaboration with the Bologna Centre. After the consent of the Ethics Committee we collected data regarding type of SMA, age of onset and of diagnosis in a cohort of 26 patiens treated with Spinraza, in order to study a possible correlation between these variables and the response to treatment. Moreover, procedural aspects were considered: type of hospitalization, type of anesthesia and management of the post-procedural phase. The response to therapy has been periodically measured by clinical evaluations with motor function scales and systematic collection of quality of life improvements. Instrumental investigations (muscle MRI and CMAP evaluation) were performed in collaborating patients before the start of treatment and again during the follow up. Light chain neurofilaments (NFL) levels were also studied in 17 patients. The creation of a regional network among all the Centers made it possible to share the same operative procedure for the treatment with Spinraza, to get real world data on all treated patients and to reduce the burden for the families related to the procedure and to the travel, allowing patients to be treated close to home.

In many countries, first-generation protease inhibitors (PIs)/peginterferon/ribavirin (P/R) still represent the only treatment option for HCV-infected patients. Subjects with advanced disease and previous failure to P/R urgently need therapy, but they are under-represented in clinical trials. All treatment-experienced F3/4 Metavir patients who received boceprevir (BOC)+P/R in the Italian-Spanish Name Patient Program have been included in this study. Multivariate logistic regression analysis (MLR) was used to identify baseline and on-treatment predictors of SVR and adverse events (AEs). Four hundred and sixteen patients, mean age 57.7 (range 25-78 years), 70% males, 69.5% (289/416) F4, 14% (41/289) Child-Pugh class A6, 24% (70/289) with varices and 42% (173/416) prior null responders to P/R, were analysed. Overall, SVR rate (all 381 patients who received one dose of BOC) was 49%, (58% in F3, 45% in F4, 61% in relapsers, 51% in partial, 38% in null responders, and 72% in subjects with undetectable HCV-RNA at treatment-week (TW)8. Among patients with TW8 HCV-RNA ≥ 1000 IU/L, SVR was 8% (negative predictive value = 92%). Death occurred in 3 (0.8%) patients, while decompensation and infections were observed in 2.9% and 11%, respectively. At MLR, SVR predictors were TW4 HCV-RNA ≥ 1log10 -decline from baseline, undetectable TW8 HCV-RNA, prior relapse, albumin levels ≥3.5 g/dL and platelet counts ≥100 000/μL. Metavir F4, Child-Pugh A6, albumin, platelets, age and female gender were associated with serious and haematological AEs. Among treatment-experienced patients with advanced liver disease eligible for IFN-based therapy, TW8 HCV-RNA characterised the subset with either high or poor likelihood of achieving SVR. Using TW8 HCV-RNA as a futility rule, BOC/P/R appears to have a favourable benefit-risk profile.

It is increasingly clear that a tailored therapeutic approach to patients with hepatitis C virus infection is needed. Success rates in difficult to treat and low-responsive hepatitis C virus patients are not completely satisfactory, and there is the need to optimise treatment duration and intensity in patients with the highest likelihood of response. In addition, the management of special patient categories originally excluded from phase III registration trials needs to be critically re-evaluated. This article reports the recommendations for the treatment of hepatitis C virus infection on an individual basis, drafted by experts of three scientific societies.

Muscle regeneration is a multistep process that is regulated by a restricted number of transcription factors whose activity is modulated at multiple levels. However, how different layers of regulation are coordinated to promote adult myogenesis is not yet understood. Here we show that the MEF2C transcription factor controls multiple steps of muscle regeneration, including myogenic progression of satellite cells and muscle maturation of newly generated myofibers, exhibiting multiple functions that depend on alternative splicing and post-translational modifications. Inclusion of the α1 exon in Mef2c transcripts is upregulated in proliferating mouse satellite cells and in the early phases of muscle regeneration. The encoded MEF2Cα1 isoform stimulates expansion of primary myoblasts ex vivo and in vivo. The pro-proliferative activity of MEF2C is mediated by phosphorylation of two phosphoserines located in exon α1. Subsequent terminal differentiation and growth of newly formed myofibers are promoted by dephosphorylated MEF2Cα1 and MEF2Cα2. Our results thus reveal an important role for regulatory interactions between alternative splicing and post translational modifications of a single transcription factor in the control of the multilayered regulatory programs required for adult myogenesis., Skeletal muscle exhibits a high capacity to regenerate, mainly due to the ability of satellite cells to replicate and differentiate in response to stimuli. Epigenetic control is effective at multiple steps of this process. The chromatin remodeling factor, HDAC4, is up-regulated in skeletal muscle upon injury, suggesting a role for this protein in muscle regeneration. With the aim to elucidate the role of HDAC4 in satellite cells and skeletal muscle regeneration, we generated inducible mice lacking HDAC4 in Pax7+ cells (HDAC4 KO mice). Despite having similar amount of satellite cells, HDAC4 KO mice show impaired muscle regeneration in vivo, and compromised satellite cell proliferation and differentiation in vitro. HDAC4 deletion in satellite cells is sufficient to block their differentiation, not acting via soluble factors, and possibly through the inhibition of Pax7 expression. The molecular mechanisms underling compromised muscle regeneration in HDAC4 KO mice are currently under investigation. All together, these data delineate the importance of HDAC4 in satellite cell differentiation and suggest a protective role of HDAC4 in response to muscle damage., The adult skeletal muscle has the ability to self-renew and repair in response to increased workload, stress conditions or limited damage. These properties rely on an array of different progenitor cell populations. While satellite cells play a central role in muscle regeneration, a variety of other mononuclear progenitor cells, either resident in the muscle or recruited from the blood stream, contribute to the complex crosstalk leading to muscle repair. In pathological conditions or with aging, the relative abundance and the activation stage of the different cell populations in the myogenic stem cell compartment vary. The ability to probe the heterogeneity and the dynamic of the muscle tissue is fundamental to achieve a complete understanding of muscle regeneration. To this end we have invested in a novel approach exploiting mass cytometry technology (CyTOF2 platform). CyTOF technology enables probing single cell events, by labelling intracellular and cell surface markers with up to 40 antibodies tagged with stable heavy metal isotopes. The sharp mass peaks obtained by TOF inductively coupled plasma mass spectrometry eliminates the problems of spectra overlap typical of fluorescence based flow cytometry. I will describe the panel of tagged antibodies that I have developed to characterize the heterogeneous muscle mononuclear cell populations and the advantages and limitations of mass cytometry. In addition I will present preliminary data on the dynamic of cell populations under different conditions and stimuli., The mechanisms that regulate skeletal muscle development involve the coordinated activity of transcription factors (TFs) and a precise timing of gene expression patterns. NF-Y is a heterotrimeric TF with a pioneer role in the transcriptional and epigenetic regulation of promoters containing the CCAAT-box. NF-Y activates the expression of various genes related to the cell cycle, particularly genes of the G2/M phase. NF-YA, the regulatory DNA-binding subunit of the complex, is expressed in proliferating myoblasts and down-regulated during terminal differentiation. The NF-YA gene encodes for two alternatively spliced isoforms, namely NF-YAs and NF-YAl, which are not functionally identical. Using mouse C2C12 cells, we provide evidence of a different role for NF-YA variants in the myogenic program. While NF-YAs enhances myoblasts proliferation, NF-YAl boosts their differentiation by up-regulating the transcription of novel target genes, among which Mef2D, Sixs and Cdkn1C, which are known to be involved in the differentiation program. We further demonstrate that NF-YA is expressed in resident stem cells (SCs) and the two isoforms are transcribed at different levels during SCs activation and differentiation. The inhibition of NF-Y activity impairs both proliferation and differentiation of SCs and the overexpression of the two NF-YA isoforms differentially affects their fate., Sarcopenia is the age-related loss of muscle leading to loss of muscle power, which in the end results in frailty and disability. At molecular level, sarcopenia is characterized by insufficient antioxidant defense mechanism, increased oxidative stress and altered function of respiratory chain. It has been hypothesized that the accumulation of oxidative stress is also related to an impaired regeneration cooperating to the atrophic state that characterizes muscle ageing. To the purpose, we investigated the myogenic process in satellite cells, the skeletal muscle stem cells, as myoblasts and myotubes collected by human Vastus Lateralis skeletal muscle of young and old subjects through needle-biopsies. To measure both the O2- and ROS level we used NBT and H2DCF-DA assays revealing higher concentration in elderly myoblasts compared to young ones. To evaluate if mitochondria are damaged by ROS we measured mitochondrial transmembrane potential after an oxidant insult as H2O2. We found that in elderly myoblasts mitochondrial transmembrane potential decreases much more than in young ones probably due to their lower endogenous antioxidant abilities. Specifically, MitoSOX™ Red reagent for direct measurements of O2- in mitochondria revealed that in elderly myoblasts O2- production is increased respect to young ones and the result is worsened in myotubes. Furthermore, the upregulation of the atrophic and ubiquitin-proteasome pathways together with a dysregulation of the proliferative one revealed an alteration at gene expression level in elderly myoblasts vs young ones. Overall our data confirm that oxidative stress impairs muscle regeneration in elderly subjects., Skeletal muscle is a complex structure endowed with extreme regenerative capability; this ability relies on the orchestrated interplay between different muscle populations that reside within the tissue. Functional changes occurring at the microenvironmental level during aging or pathological conditions however interfere with this ability leading to fibrosis and fat infiltration. Despite a large body of work still we are far from completely understanding these changes; even when genetic cause is known (e.g. Duchenne muscular Dystrophy) we are still unable to pin-point the steps that lead from the molecular cause to the outcome of the disease. The main reason for this bottleneck is that our knowledge has been limited so far by the lack of technical tools to dissect the heterogeneity of these populations. The use of bulk-scale methods able only to provide averaged information has frustrated our effort to characterize those pathological changes leaving those dysfunctional, disease-specific subpopulation to remain hidden within the bulk. Here we present a novel approach based on single cell mass spectrometry to study the populations that reside in the muscle. Using Cytof technology we would profile at single cell resolution the muscle resident populations during aging and in diseased state. This would allow us to identify dysfunctional subsets involved in the regeneration defect. This study would not only shed light on the mechanisms underpinning muscle regeneration but would provide a solid ground for the future identification of diagnostic biomarkers through the study of disease specific subpopulations., Hypertrophy and dystrophy are distinct, yet linked processes that remodel both skeletal and cardiac muscles in physiological or pathological settings. Not only is hypertrophy important during development, but it also plays major role upon acute or chronic damage. Muscular dystrophies (MDs) cause progressive degeneration and loss of functionality in both striated muscle types. In MD patients and animal models, an initial hypertrophic response occurs, with contrasting effects on skeletal and cardiac muscle. Recently it has been established that muscle fibers secrete exosomes, whose cargo acts as endocrine signals during myogenesis. We aim at deciphering the exosomal information guiding hypertrophy/dystrophy in both muscle in order to establish a new strategy based on miRNA modulation for novel myogenic regeneration. We performed ex vivo exosome analysis comparing age-matched WT, Sgcb-null (dystrophic), and MAGIC-F1+/+ (hypertrophic) mice. We detected several differentially regulated miRNAs, virtually relevant for striated muscle remodeling and de-/re-generation. We have preliminary results on the effects of ex vivo exosomes on cell types relevant for skeletal and cardiac muscle analysis. Moreover we are currently investigating the uptake routes of exosomes in both muscle types. In the future we will rely on miRNA-sequencing of ex vivo exosomes, to identify key mRNA/miRNA distinctive signatures by means of an high-throughput approach and place our ongoing results into a genome-wide setting. As a final goal, the hypertrophic/dystrophic signatures and tissue-specific information will further be integrated to establish skeletal- and cardiac-enhancing cocktails to selectively improve the regenerative outcome of patient-specific progenitors in vivo, into a xenograft-permissive murine model., Duchenne muscular dystrophy (DMD) is the most common, lethal, inherited myopathy, which results in muscle degeneration. In this work, we aimed at developing an innovative 3D satellite cell niche derived from human induced pluripotent stem cells (hiPSC) within their native sublaminal position in an engineered human skeletal muscle myofiber. One of the main limitations of cell therapy for DMD is the high number of myogenic cells required and the efficiency of engraftment in vivo. hiPSC ensure large amount of cells and the possibility of derive patient-specific cells, but obtaining myogenic cells in vitro from hiPSC is difficult and the yield is low. In this work, we induced the myogenic differentiation of hiPSC through multiple transfection of modified mRNA of the master transcription factors MYOD, PAX3 and PAX7. To this aim, we exploited a microfluidic platform that allows the downscaling of the process for performing cost-effective, multiparametric and highthroughput experimental investigations. We optimized the protocol for transfecting hiPSC colonies leading to a transfection efficiency of 60% per single transfection. After multiple transfections, exogenous MyoD is expressed in 95% of the cells and endogenous expression of desmin and myosin heavy chain was observed (4 days after the last transfection). Ongoing experiments are extending these results to Pax3 and Pax7. Another key factor for a successful cell therapy is the cell delivery. In this sight, we developed a 3D poly-acrilammide/hyaluronic acid hydrogel (HY) scaffold and optimized its biochemical and mechanical properties in order to sustain the myogenic differentiation of human primary myoblasts and to reproduce the protective microenvironment of the satellite cell niche. The scaffold was designed in order to control the cell topology: 3D parallel micro-channels (80-160 μm in diameter, 10-15 mm long) were produced inside the scaffold and functionalized with ECM proteins. To reproduce the physiological mechanobiology, HY chemical composition was optimized in order to obtain a soft scaffold with physiological elastic modulus, E≈12±4kPa. Human primary myoblasts were used to optimize the seeding, culture and differentiation protocols. At 10 days, we observed tightly packed myotubes bundles, expressing myosin heavy chain, α-actinin and dystrophin. We are now integrating hESC-derived myoblast and we observed differentiation into myoubes and expression of myosin heavy chai, α-actinin and desmin.We hypothesize that such engineered niche will provide, upon in vivo implantation, satellite cells able to regenerate the damaged muscle of DMD patients, and reconstitute the stem cell pool for future muscle damages. On the other hand, our 3D niche could be exploited as an in vitro tool to study the biology of the niche itself, the mechanism of the pathology or as a tool for testing new drugs and therapies in a personalized manner., Skeletal muscle regeneration is mediated by a complex crosstalk between various resident mononucleated cell populations. These cell interactions after fiber damage or stress are finely regulated in time and space. Satellite cells, skeletal muscle stem cells, play a pivotal role during regeneration being the main source of new myoblasts. However, their activation, proliferation and differentiation relies on environmental cues shaped by cell populations such as macrophages, pericytes, and fibro-adipogenic progenitors (FAPs). FAPs have a leading role in the regeneration process since they promote myotube formation by positively regulating satellite cell differentiation. However, in pathological conditions, such as muscular dystropies, these cells play a negative role since they are responsible for fibrosis and fatty tissue accumulation. In in vitro experiments we have observed an improvement in the maturation of myotubes derived from satellite cells, when co-cultured with FAPs. Furthermore, we have also observed that direct contact of these two cell populations inhibits adipogenic differentiation of FAPs while in the transwell system this inhibition does not occur. Even though there is a clear interaction between these two populations, it has not been thoroughly characterized yet. Thus exploiting Luminex technology we are aiming at identifying molecules affecting the differentiation process of these two cell types focusing on cytokines, chemokines and growth factors. In addition we are planning to include in these studies macrophages and pericytes in order to obtain a more complete picture of molecular networks involved in myogenesis and finally build a cell-cell interaction model of skeletal muscle regeneration., Electrical stimulation (ES) of skeletal muscle has been proposed to mimic the beneficial effects of physical training and to counteract the muscle atrophy associated with reduced motor activity. If properly used, it can be a potent tool to increase strength and endurance in patients affected by muscle weakness due to ageing or prolonged debilitating illness. However, classical ES exhibits several limitations, such as the unpleasant symptoms due to pulse strength and the occurrence of muscle fatigue. The most appropriate parameters of stimulation, such as intensity, frequency and pulse duration, are still under debate. Field ESs were given to mouse skeletal myotubes in culture. Changes in membrane potential were detected by perforated patch recordings and calcium dynamics was followed using fluorescent indicators. Different patterns of ES were tested. Tetanic high frequency stimulation at 45 Hz induced voltage changes invariably characterized by failures, and discontinuous firing preceding the complete disappearance of the electrical activity, whereas low-frequency stimulations at 1 Hz more efficiently elicited single action potentials. An innovative “noisy” waveform ES pattern was tested, obtained from a segment of electromyogram recording, sampled from a limb muscle of adult volunteers during the execution of a rhythmic motor activity. Using half of the intensity of stimulation employed for more stereotyped ES patterns, it was found to be more efficient in inducing repetitive cell firing, calcium transients and cell twitching. We suggest this approach as a new strategy for the design of new electrical devices able to provide a therapy option for injured muscles in human patients., Muscle contraction is generated by cyclical interactions of myosin heads with actin filaments to form the actomyosin complex. The stable configurations of the actomyosin complex have been described in detail, but whether in vivo, at physiological temperatures, these configurations are fixed to the ones observed in cryomicroscopy (at low temperature) or undergo thermal oscillations is unknown and not generally considered in mathematical modeling. By comparing three mathematical models, we analyze how this intrinsic property of the actomyosin complex affects muscle contraction at three level; namely, single cross-bridge, single fiber and organ levels, in a ceteris paribus analysis. We observed that state fluctuations allow the lever arm of myosin to easily and dynamically explore all possible minima in the energy landscape, generating several backward and forward jumps between states during the lifetime of the actomyosin complex, whereas the rigid case is characterized by fewer force generating events. Therefore, dynamical oscillations enable an efficient contraction mechanism, in which a higher force is sustained by fewer attached cross-bridges., Mammalian neuromuscular junctions (NMJs) undergo a postnatal topological transformation from a simple oval plaque to a complex branch-shaped structure often called a “pretzel”. Although abnormalities in NMJ maturation and/or maintenance are frequently observed in neuromuscular disorders, such as congenital myasthenic syndromes (CMSs), the mechanisms that govern synaptic developmental remodeling are poorly understood. It was reported that myotubes, when cultured aneurally on laminin-coated surfaces, form complex postsynaptic machinery, which resembles that at the NMJ. Interestingly, these assemblies of postsynaptic machinery undergo similar stages in developmental remodeling from “plaques” to “pretzels” as those formed in vivo. We have recently demonstrated that podosomes, actin-rich adhesive organelles, promote the remodeling process in cultured myotubes and showed a key role of one podosome component, Amotl2. We now provide evidence that several other known podosome-associated proteins are present at the NMJ in vivo and are located to the sites of synaptic remodeling. Additionally, we identified proteins that interact with Amotl2 in muscle cells. We show that two of them: Rassf8 and Homer1, together with other podosome components, are concentrated at postsynaptic areas of NMJs in the indentations between the AChR-rich branches. Our results provide further support for the hypothesis that podosome-like organelles are involved in synapse remodeling and that Rassf8 and Homer1 may regulate this process., Depletion of calcium (Ca2+) from intracellular stores (endoplasmic reticulum, ER), triggers Ca2+ entry across the plasma membrane, a process known as store-operated Ca2+ entry (SOCE). SOCE is mediated by the interaction between STIM1 (stromal interaction molecule 1), which functions as the Ca2+ sensor in the ER, and Ca2+ permeable Orai1 channels in the external membrane. In skeletal muscle, SOCE is the primary mechanism of Ca2+ entry during repetitive activity, a crucial step that prevents/delays fatigue. Despite the importance of this mechanism for proper muscle function during sustained activity, the subcellular sites for SOCE in skeletal fibers have not been identified. Here we show that prolonged muscle activity (treadmill running in mice) drives the formation of previously unidentified intracellular junctions between the sarcoplasmic reticulum (SR) and extensions of the external transverse tubule (TT) membrane. The activity-dependent formation of these unique SR-TT junctions reflects a striking and unexpected remodeling of the existing sarcotubular system at the I band of the sarcomere. Using immunochemistry and immuno-gold labeling we also demonstrate that these newly formed, activity-driven junctions contain the molecular machinery known to mediate SOCE in muscle: STIM1 Ca2+ sensor proteins in the SR, already present in the I band in control conditions, and Ca2+- permeable Orai1 channels, which move into the I band with TTs during prolonged muscle activity. Thus, we refer to these junctions as Ca2+ Entry Units, the first new, molecularly defined subcellular structure in skeletal muscle in over 30 years., The loss of connection between muscle and nerve is a crucial biological mechanism involved in Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative disease associated with motor neuron degeneration, muscle atrophy and paralysis [1]. Recent studies showed the primary role of the skeletal muscle in the pathogenesis of the disease, pointing out the key role of the communication between muscle and nerve. In this context, we developed a protocol to measure, ex vivo, the neuromuscular junction (NMJ) functionality [2]. The experimental technique is based on the comparison between the muscle contractile response elicited by membrane stimulation and the response evoked by nerve stimulation. Since this latter stimulation bypasses the neuronal signalling, any difference between the two responses may be related to NMJ alterations. In particular, we started studying the Soleus-sciatic nerve preparation of one of the most studied ALS animal models, the SOD1G93A mouse [3], with the particular aim of following the pathology’s progress. We observed that the first functional alterations begin at 90 days of age, with an intrinsic damage of the muscle and defects in NMJ functionality who increase until the end-stage of the disease. Subsequently, we approached the study of the MLC/SOD1G93A mouse model, in which superoxyde dismutase-1 mutated gene is expressed exclusively in the skeletal muscle [4]. Our preliminary results highlighted defects in soleus muscle and NMJs functionality in MLC/SOD1G93A mouse model, compared to the wild type, suggesting a direct muscle impairment. Further analysis on this model will provide useful information about the NMJ alterations directly related to oxidative stress on skeletal muscles., Myosin is an abundant ATPase protein. It is estimated that 10% of muscle tissue weight is myosin. Due to its abundance, myosin can be a good target to raise basal metabolic rate in animals. A new low-ATP-consumption state of myosin has recently been proposed (1, 2). This new state has been called the “Super Relaxed State (SRX)” of Myosin. Structural evidence for the SRX state have recently been published showing a close complex formed by the two-myosin heads (3). It is characterized by an ATPase time constant in the order of 300 seconds versus the 15 seconds for the so-called “Disordered Relax State” (DRX)(1,2). The idea is that behind that large number of “dormant” ATPases, there is the key to raise basal metabolism in a physiological way. The amount of myosin in the SRX state is estimated to be approximately 60% of the total. Switching of the myosin heads from the SRX state to the DRX state is regulated by phosphorylation in a cooperativeness-driven-equilibrium. Controlling this equilibrium may lead to an increase in basal metabolism that would consume an additional energy of up to 1000 Kcal/day. We studied the effect of several Regulatory Light Chain mutants on the SRX state and we applied this information to the development of a high throughput screen. We are searching a molecule that is able to destabilize the SRX state in skeletal muscle fibers. We screened 2000 compound of an FDA approved library. Potential lead compounds will be discussed, The muscle cell is a biological machine where steady force and shortening are generated by arrays of the motor protein myosin II pulling the actin filament towards the centre of the sarcomere (the ~2 μm long structural unit of muscle) during cyclical ATP-driven interactions. The fraction of the time of the ATP hydrolysis cycle that myosin II spends attached to actin depends on the sarcomere load and at low load can be as small as 0.02. The array-type arrangement of the motors enhances and makes steady the production of force and shortening, but has so far limited the investigation of mechanics, energetics and structural dynamics of this collective motor to top-down approaches, such as single-cell mechanics and X-ray diffraction (Piazzesi et al. Cell 131:784-795, 2007). The laser trap technique in the Three Bead Assay (TBA) configuration allowed the recording of single actin-myosin interaction in vitro, but only when the duration of attachment was increased by reducing the ATP concentration to a few tens of micromolar (two orders of magnitude lower than that in situ in physiological conditions). In this project we use an alternative approach consisting in assembling molecular motor proteins on a nanostructured support to generate a synthetic sarcomere-scale machine, the mechanical output of which is measured with a double laser optical tweezers apparatus (Bianco et al. Biophys. J. 101:866-874, 2011). The shape, the material and the coating of the support carrying the motor array have been optimised using a preliminary version of the machine consisting of an ensemble of motor proteins randomly adsorbed on a flat surface and brought to interact with an actin filament attached to the trapped bead with the correct polarity. Tests on the density and the disposition of the myosin motors on the surface have been done using AFM. The most reproducible results have been obtained when the support for the motor ensemble is the lateral surface of a chemically etched single mode optical fibre (diameter 4 µm). In solution with physiological [ATP] (2 mM), the ensemble drives 350 nm of actin filament sliding developing a steady force of 50 pN. Supported by Italian Institute of Technology-SEED, project MYOMAC (Genova) and PRIN-MIUR, Italy., Skeletal muscle atrophy is caused by several and heterogeneous conditions, such as cancer (cachexia), neuromuscular disorders and aging. In most types of skeletal muscle atrophy overall rates of protein synthesis are suppressed, protein degradation is consistently elevated and atrogenes, such as the ubiquitin ligase Atrogin-1/MAFbx, are up-regulated. Sphingolipids represent a class of bioactive molecules capable of modulating the destiny of many cell types, including skeletal muscle cells. In particular, we and others have shown that sphingosine 1-phosphate (S1P), formed by sphingosine kinase (SphK), is able to act as trophic and morphogenic factor in myoblasts. Here, we report that the inhibition of SphK1 by specific gene silencing or pharmacological inhibition drastically reduced myotube size and myonuclei number, and increased Atrogin-1/MAFbx expression. Notably, the atrophic phenotype of C2C12 myotubes treated with dexamethasone and of muscle fibers obtained from cachectic mice inoculated with C26 adenocarcinoma, was characterized by increased expression of Atrogin-1/MAFbx and reduced levels of active SphK1. In addition, we found that C2C12 muscle cell atrophy was accomplished by changes in the pattern of expression of S1P receptor subtypes (S1PRs) and treatment of myotubes with S1P was able to prevent Dexa-induced atrophic marker expression. Finally, by using specific S1PR agonists and antagonists, we extended the investigation on the role played by S1PRs in the control of Atrogin-1/MAFbx expression. Altogether, these findings provide the first evidence that S1P/SphK1/S1PR axis acts as a molecular regulator of skeletal muscle atrophy, thereby representing a new possible target for therapy in many physiological and pathological conditions., Skeletal muscle is a dynamic tissue that can respond to external stimuli through both anabolic and catabolic processes. In a variety of conditions, including immobilization, AIDS and neuromuscular disorders, skeletal muscle mass is decreased (atrophy). Upon denervation or disuse, skeletal muscle undergoes atrophy, leading to reduced size of myofibers, impaired contractile and metabolic activities. Previous studies have identified key molecular pathways leading to protein breakdown and degradation of sarcomeric proteins; yet, it remains a gap of knowledge on whether muscle resident cell populations can regulate the response of muscle to atrophic stimuli. Indeed, the recent identification of muscle-derived interstitial cells, named fibro-adipogenic progenitors, that can adopt multiple lineages and contribute, either directly o indirectly, to muscle regeneration (Joe et al,2010; Uezumi et al,2010) indicates a previously unrecognized complexity in the regulation of muscle homeostasis (Saccone et al,2014). We have discovered an unexpected key role of specific muscle-derived mononuclear cells in the pathogenesis of muscle atrophy. The characterization of the mechanism by which these cells contribute to the loss of muscle mass may lead to the identification of new therapeutic targets to counteract muscolar atrophy., PGC-1α overexpression is able to protect skeletal muscle from fasting or denervation-induced atrophy (1) and to improve sarcopenia in old mice (2). Consistently, in the skeletal muscle of cachectic tumor-bearing mice, PGC-1α expression is reduced (3), in Association with the accumulation of PAX7+ cells, which is suggestive of an impairment of myogenesis (4). Preliminary observations obtained in mice overexpressing PGC-1α specifically in the skeletal muscle show that the number of CD34+/Sca1+ cells, both integrin-α7 positive (satellite cells) and negative (other myogenic precursors), was higher in the muscle of transgenic (TG) mice than in those of wild-type (wt) animals. Not only, myotubes originating from TG-derived myogenic precursors were increased in both number and size in comparison to those obtained from wt progenitors. Aim of the present study was to investigate if PGC-1α overexpression can improve the regenerative capacity in the muscle of tumor (C26)-bearing animals after chemically-induced injury. BaCl2 (30 μl, 1.2% w/v) was injected in the tibialis anterior muscle the day after tumor implantation. Thirteen days after injury, both wt and TG controls almost completely recovered the initial myofiber cross sectional area (CSA; 70% of uninjured muscle). By contrast, CSA recovery was markedly delayed in wt or TG tumor-bearing mice (30% of uninjured muscle). Such a lack of CSA rescue in TG C26 hosts occurred despite TG mice constitutively possess a number of myogenic precursors higher than wt animals. As an estimate of mitochondria number, cytochrome c expression was evaluated. The results show that cytochrome c levels were significantly reduced in the regenerating muscle of wt C26 hosts, while remained comparable to those of uninjured muscle in BaCl2-treated TG tumor bearers. Previous observations showed that inhibition of ERK activity improved muscle wasting and myogenesis in the C26 hosts (4). In this regard, muscle pERK levels were significantly lower in TG tumor bearers than in wt C26 hosts. In conclusion, the present study shows that PGC-1α overexpression in the regenerating muscle of tumor hosts resulted in improved mitochondrial mass, and likely, oxidative capacity, and in reduced pERK levels, however without obtaining a significant CSA rescue. These observations suggest that while PGC1α overexpression exerts positive effects on tumor-induced derangements at the molecular level, it does not appear able to impinge on the multifactorial nature of muscle wasting., Cancer cachexia is a life-threatening syndrome that affects most patients with advanced cancers and involves severe body weight loss, with rapid depletion of skeletal muscle. No effective treatment is available. We analyzed microarray datasets to identify a subset of genes whose expression is specifically altered in cachectic muscles of Yoshida hepatoma-bearing rodents, but not in those with diabetes, disuse, uremia or fasting. By Ingenuity Pathways Analysis, we found three genes belonging to the CXCR4 pathway downregulated only in muscles atrophying because of cancer: SDF1, PAK1 and ADCY7. Consistently, we show that the expression of all SDF1 isoforms declines also in Tibialis Anterior from cachectic mice bearing colon adenocarcinoma or renal cancer and anti-cachexia drugs such as sunitinib restore it. Overexpressing genes of this pathway (i.e. SDF1 or CXCR4) in cachectic muscles increases the fiber area by 20%, partially protecting them from wasting. The mechanisms behind this muscle preservation during cachexia include both reduced degradation of long-lived proteins, by either SDF1α or SDF1β on atrophying myotubes, and increased protein synthesis, mainly by SDF1α. However, inhibiting CXCR4 signaling with the antagonist AMD3100 does not affect protein homeostasis in atrophying myotubes at all, whereas normal myotubes treated with AMD3100 display decreased diameter in a time- and dose-dependent manner, until a plateau. This further confirms the involvement of a saturable pathway (i.e. CXCR4). Overall, these findings support the idea that activating the CXCR4 pathway in muscle suppresses the deleterious wasting associated with cancer., Cancer cachexia is a systemic syndrome that consists of a dramatic weight loss with rapid muscle depletion due to enhanced protein degradation, irrespective of food intake. Remarkably, 50% of advanced cancer patients are affected by cachexia, which accounts for approximately 20% of cancer deaths. No therapy is available. Interestingly, females are more resistant to cancer cachexia than males. We analyzed previous microarray datasets to identify genes whose expression is specifically altered in cachectic muscles of Yoshida hepatoma-bearing male rodents. Among these genes, we found that apelin was drastically downregulated to 8% of controls in cachectic gastrocnemius muscles (with 14% of weight loss) from male rats bearing Yoshida hepatoma for 5 days. We confirmed by Q-PCR that apelin was downregulated to 45% and 2% of controls also in Tibialis Anterior (TA) muscles in Lewis Lung Carcinoma and in Colon Adenocarcinoma 26 (C26)-bearing mice, respectively. Moreover, in TA from C26-bearing mice also the expression of apelin receptor (APJ), a member of G-protein coupled receptors, was reduced to 16%. Q-PCR analysis further confirmed that apelin downregulation occurred at all stages of cancer cachexia of C26-bearing male mice, while the expression of APJ was significantly reduced to 30% of controls only in early cachectic mice with less than 14% of body weight loss. Since apelin is expressed on X chromosome both in humans and mice and it is not downregulated in muscles from C26-bearing female mice, we believe that apelin could be a good candidate to explain the gender difference of cancer cachexia., Cachexia is a syndrome frequently occurring in cancer patients. It is characterized by body and skeletal muscle wasting and by metabolic abnormalities. These latter are mediated, partially at least, by humoral factors. Energy balance perturbations also contribute to the onset of cachexia. In this regard, impaired mitochondrial functions and altered energy expenditure likely play a role. Recent observations suggest that in addition to classical humoral factors such as hormones or cytokines, also tumor-derived microvesicles (MVs), circulating particles containing different molecules such as proteins, mRNAs and microRNAs, may contribute to derangements associated with cachexia (1). MVs were isolated by differential ultracentrifugation from the conditioned medium of LLC (Lewis Lung Carcinoma) cells and were quantified by a NanoSight apparatus. After five day culture in differentiation medium, C2C12 myotubes were treated for 24 h with LLC-derived MVs. In C2C12 myotubes tumor-derived MVs induce a reduction of PGC-1α, the master regulator of oxidative metabolisms and mitochondrial biogenesis, as well as of Cyt-c mRNA expression. These results are in agreement with previous observations showing decreased PGC1α expression in the skeletal muscle of cachectic mice. In myotubes oxygen consumption is significantly decreased while lactate levels in the culture medium are increased after treatment with MVs. BNIP3 mRNA expression is significantly increased, while no differences can be observed as for myotube size and mRNA expression of both Atrogin1 and MuRF-1, two muscle-specific ubiquitin ligases. These results suggest that tumor-derived MVs affect mitochondria in C2C12 cultures. The reduction of mitochondrial mass (decreased Cyt-c mRNA expression) and function is associated with down-regulation of PGC-1α expression and enhancement of selective autophagy (mitophagy). On the whole, MV-induced alterations could contribute to muscle wasting during cancer cachexia., High mobility group box 1 (HMGB1) is a nuclear protein that acts extracellularly as an alarmin to modulate inflammation and tissue repair by recruiting cells and promoting their migration and activation. Recently, we showed that HMGB1 orchestrates both processes by switching among mutually exclusive redox states. Fully reduced HMGB1 acts as a chemoattractant, whereas a disulfide bond makes it a proinflammatory cytokine and further cysteine oxidation by reactive oxygen species (ROS) abrogates both activities. The fully reduced HMGB1 is prevalent in the extracellular environment immediately after acute muscle injury, and disulfide- HMGB1 appears a few hours later. Thus, the generation of ROS during muscle damage might modulate the redox status of the protein and eventually limit its lifespan and functions. We created a mutant (3S-HMGB1) not susceptible to redox modifications and we evaluated its regenerative activity in a model of acute muscle injury induced by cardiotoxin. We demonstrated so far that HMGB1 has beneficial effects in skeletal muscle regeneration after acute injury by dramatically increasing the number of healthy fibers and the number of satellite cells and M2c macrophages, two cell types essential for muscle repair. Moreover, HMGB1 acts directly on primary myoblasts by inducing their migration and their fusion to form large myotubes. Remarkably, 3S-HMGB1 behaves as a superagonist of HMGB1 in vivo, suggesting that it is a promising candidate for muscle repair therapies. Our study will be extended to other models of muscle damage, in particular dystrophies, in order to evaluate the therapeutic potential of 3S-HMGB1 in chronic conditions., Atrophy is an active process controlled by specific signaling pathways and transcriptional programs. The identification of the precise signaling cascades that regulate muscle wasting remains poorly understood. The Ubiquitin Proteasome System (UPS) is one of the major systems that control protein breakdown during muscle wasting. The specificity of ubiquitin-dependent degradation derives from many E3s that recognize specific substrates. This work is focus on a novel muscle-specific circadian-rhythm dependent ubiquitin ligase named Asb2β. To dissect its role, we have generated muscle specific and tamoxifen-inducible muscle specific knock-out mice. We have characterized these knockout mice in physiological and in catabolic conditions. Asb2β defective muscles show normal muscle morphology and mitochondrial content but muscles display a fiber type switch and glycogen accumulation. Glucose tolerance test revealed an improved glucose uptake in knockout mice. Moreover, glycogen content dramatically decreased in Asb2β knockout mice during fasting. The changes in glucose homeostasis are Akt independent but TBC1D1and AS160 dependent. However, absence of nutrients triggers necrotic degeneration and appearance of abnormal mitochondria in Asb2β-null muscles. We have also started to characterize the tamoxifen-inducible knockout mice. Preliminary data show that acute inhibition of Asb2β induces a time dependent muscle growth. In conclusion, we have identified a novel muscle specific ubiquitin ligase, Asb2β, that plays an important role in glucose homeostasis and muscle hypertrophy., Aging is characterized by loss of skeletal muscle mass and function, condition known as sarcopenia. The mechanisms underlying sarcopenia are not completely understood, however a role for ectopic fat accumulation has been proposed. Skeletal muscle accumulates lipid in form of triglycerides within lipid droplets (LDs). LDs are characterized by the presence of Perilipins (Plins), that control lipid accumulation and metabolism under physiological and pathological conditions. In skeletal muscle one of the most representative is Plin2, particularly involved in lipid storage. However, the exact role of Plin2 is not still clear. We found that in human muscle the expression of Plin2 increases with aging and it is inversely associated with muscle mass and strength. Moreover, Plin2 expression is associated with atrophy-related genes, MuRF-1 and Atrogin, suggesting a role for Plin2 in muscle aging and atrophy. We also analysed the expression of Plin2 in adult mice where muscle atrophy was induced by denervation. Denervation of tibialis anterior muscle was compared with the contralateral intact side. After denervation, beside the expected increase of MuRF-1 and Atrogin, also Plin2 expression actually increases. This suggested that Plin2 expression is somehow associated with muscle atrophy. To support this hypothesis, we performed muscle-specific in vivo silencing experiments of Plin2. After 7 days from injection, a decrease of Plin2 was observed, and most interestingly the cross-sectional area (CSA) of Plin2-negative fibres resulted increased of about 30% with respect to Plin2-positive ones. As a whole, these data suggest that in skeletal muscle Plin2 is involved not only in muscle atrophy, but also in hypertrophy. Further studies are ongoing to better clarify this new role of Plin2 in skeletal muscle., The rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in people under 20 years of age. It can commonly arise anywhere in the body but the head and neck, the extremities and the genitourinary tract are predominant sites. Based on histology, RMS tumors are classified into two major subtypes, embryonal and alveolar, which also differ in the molecular pathogenesis of development. Despite these differences, the origin of aRMS and eRMS seems to be the same but the precise cell type that triggers RMS is still unclear. Some evidence supports the notion that skeletal muscle precursors, probably satellite cells, may initiate RMS. Alternative theories propose mesenchymal stem cells, or even cells belonging to the adipocyte lineage, as possible tumor-initiating cells. In order to shed light on the origin of eRMS, we adopted the KrasG12D/+Trp53Fl/Fl conditional mouse model. This model allows us to generate eRMS in the hind limb of mice by infecting them with an adenovirus vector carrying the CRE recombinase. In a first approach we want to describe and rationalize the changes in the tumor mass cell populations by analyzing the tumor at different stages of development by using flow and mass cytometry techniques. In a second approach we aim at identifying the cell population(s) that are responsible for initiating the tumor. To this end we induce the gene mutations that are responsible for rhabdomyosarcoma development by infecting, with the CRE recombinase adenovirus, isolated muscle mononucleate cell populations and monitor their ability to develop rhabdomyosarcoma tumorigenic properties in vitro., The purpose of this study was to investigate whether MURC/cavin-4, a plasma membrane and Z-line associated protein exhibiting an overlapping distribution with Caveolin-3 (Cav-3) in heart and muscle tissues, may be expressed and play a role in rhabdomyosarcoma (RMS), an aggressive myogenic tumor affecting childhood. We found MURC/cavin-4 to be expressed, often concurrently with Cav3, in mouse and human RMS, as demonstrated through in silico analysis of gene datasets and immunohistochemical analysis of tumor samples. In vitro expression studies carried out using human cell lines and primary mouse tumor cultures showed that expression levels of both MURC/cavin-4 and Cav-3, while being low or undetectable during cell proliferation, became robustly increased during myogenic differentiation, as detected via semi-quantitative RT-PCR and immunoblotting analysis. Furthermore, confocal microscopy analysis performed on human RD and RH30 cell lines confirmed that MURC/cavin-4 mostly marks differentiated cell elements, colocalizing at the cell surface with Cav-3 and labeling myosin heavy chain (MHC) expressing cells. Finally, MURC/cavin-4 silencing prevented the differentiation in the RD cell line, leading to morphological cell impairment characterized by depletion of myogenin, Cav-3 and MHC protein levels. Overall, our data suggest that MURC/cavin-4, especially in combination with Cav-3, may play a consistent role in the differentiation process of RMS., Rhabdomyosarcoma (RMS) is a childhood soft tissue tumor with broad expression of markers that are typically found in skeletal muscle. Cavin-1 is a recently discovered protein actively cooperating with Caveolin-1 (Cav-1) in the morphogenesis of caveolae and whose role in cancer is drawing increasing attention. Using a combined in silico and in vitro analysis here we show that Cavin-1 is expressed in myogenic RMS tumors as well as in human and primary mouse RMS cultures, exhibiting a broad subcellular localization, ranging from nuclei and cytosol to plasma membrane. In particular, the coexpression and plasma membrane interaction between Cavin-1 and Cav-1 characterized the proliferation of human and mouse RMS cell cultures, while a downregulation of their expression levels was observed during the myogenic differentiation. Knockdown of Cavin-1 or Cav-1 in the human RD and RH30 cells led to impairment of cell proliferation and migration. Moreover, loss of Cavin-1 in RD cells impaired the anchorage-independent cell growth in soft agar. While the loss of Cavin-1 did not affect the Cav-1 protein levels in RMS cells, Cav-1 overexpression and knockdown triggered a rise or depletion of Cavin-1 protein levels in RD cells, respectively, in turn reflecting on increased or decreased cell proliferation, migration and anchorage-independent cell growth. Collectively, these data indicate that the interaction between Cavin-1 and Cav-1 underlies the cell growth, migration and differentiation grade in myogenic tumors., Recently, it was shown that in yeast CK2-dependent phosphorylation of the mitochondrial import receptor Tom22 promotes biogenesis of the TOM translocase and is required for import of mitochondrial proteins. We asked whether CK2-dependent phosphorylation of TOM proteins also occurs in mammals. Using CK2β-deficient skeletal muscle lysates, we observed less phosphorylation of Tom22. Moreover, we confirmed CK2 phosphorylating residues serine 15 and threonine 43 of murine Tom22. Further, CK2-dependent phosphorylation of Tom22 changes its binding affinity for proteins need to be imported into mitochondria. In the absence of CK2 mitochondrial protein import is impaired in muscle fibers and mitochondria are dysfunctional. Pink1, a mitochondria health sensor and involved in Parkinson s disease, accumulates within mutant muscle cells, and labels removal of dysfunctional mitochondria by mitophagy and involvement of autophagic adaptor protein p62/SQSTM1. Consequently, the metabolism of oxidative muscle fibers in mutant muscles shifted towards glycolytic. As proof of concept, removal of aggregated p62/SQSTM1 by muscular in vivo electroporation of phosphomimetic Tom22 was successful. This is the first evidence for both, regulated protein import into mammalian mitochondria, and muscle weaknes due to a mitochondrial protein import defect., Canonical Wnt/β-catenin signaling plays a role in myogenic differentiation, but its role in adult muscle fibers is completely unknown. We approached canonical Wnt signaling in adult myofibers by well-known reporter Axin2-lacZ mice, monitoring X-Gal staining in muscle stem cells, in adult muscle fibers and at their neuromuscular synapse. In muscle stem cells, canonical Wnt signalling is absent in quiescent cells and 72 h proliferating cells. In adult muscle fibers, canonical Wnt signaling is strongly detectable by Axin2- and β-catenin-positive skeletal muscle fibers, where it is expressed only in fast fiber types with small cross-sectional areas. In these fibers, canonical Wnt signaling is active together with Hippo signaling members, YAP/TAZ and TEAD1. During differentiation of C2C12 cells, Axin2 increases together with the expression of TEAD1-target genes: CTGF, Ankrd1 and Cyr61. In cultured primary muscle cells, we observed Axin1 and Axin2 being involved in proliferation and myotube formation in a Wnt1 and Wnt3a dependent manner. We present a model how canonical Wnt/β-catenin signaling, together with YAP/TAZ and TEAD1, influences muscle fiber diameter in fiber-type specific manner., Muscle atrophy contributes to the poor prognosis of many pathophysiological conditions, but pharmacological therapies are still limited. Muscle activity leads to major swings in mitochondrial [Ca2+] which control aerobic metabolism, cell death and survival pathways. We have investigated in vivo the effects of mitochondrial Ca2+ homeostasis in skeletal muscle function and trophism, by overexpressing or silencing the Mitochondrial Calcium Uniporter (MCU). The results demonstrate that both in developing and in adult muscles MCU-dependent mitochondrial Ca2+ uptake has a marked trophic effect that does not depend on aerobic control, but impinges on two major hypertrophic pathways of skeletal muscle, PGC-1α4 and IGF1-AKT/PKB. In addition, MCU overexpression protects from denervation-induced atrophy. These data reveal a novel Ca2+-dependent organelle-to-nucleus signaling route, which links mitochondrial function to the control of muscle mass and may represent a possible pharmacological target in conditions of muscle loss., PKC (protein kinase C) family is composed by 3 subgroups: conventional, novel and atypical PKC. These kinases are involved in a large number of biological processes (such as protein synthesis, glucose metabolism, apoptosis). PKCzeta and PKClambda/iota belong to the atypical PKC subgroup and differ from conventional and novel PKCs for their activation mechanism. Indeed atypical PKCs are calcium and diacylglycerol (DAG) insensitive, while classical PKCs are activated by calcium and DAG, and novel PKCs are activated by DAG but not by calcium (1,2). Little is known on the role of PKCzeta on skeletal muscle homeostasis. Thus, we overexpressed this kinase by in vivo transient transfection. We observed a marked hypertrophy in PKCzeta positive myofibers compared to surrounding not transfected fibers. In addition PKCzeta overexpression protected muscle from denervation-induced atrophy. Next, we studied the effects of 3 different PKCzeta mutants on fiber size: 1) PKCzeta-DN (a dominant negative isoform carrying a point mutation on the ATP-binding site); 2) PKCzeta-ΔNPS (a costitutive active mutant); 3) PKCzeta-InLoop (a dominant negative isoform mutated in the activation loop). Surprisingly all these mutants cause muscle hypertrophy and protect from denervation-induced atrophy suggesting a possible kinase-independent mechanism of PKCzeta on skeletal muscle trophism., P38 mitogen activated protein kinases (MAPKs) are required at several stages during differentiation of muscle progenitor cells. P38 phosphorylation initially accompanies satellite cells activation and triggers asymmetric division. At a later stage, it orchestrates myoblast differentiation promoting myotube formation. The signals that trigger or modulate p38 activation during the differentiation process are still debated. Both cellJtoJcell contact and TNFα prime p38α/β phosphorylation and activation during myogenesis. Cdo, a multifunctional surface protein has been implicated in myogenesis. Following cellJtoJcell contact and ligation to cadherin, Cdo binds JLP and BnipJ2 which act as scaffolds for recruitment of p38α/β and Cdc42. The formation of the complex leads to activation of Cdc42, which is fundamental to promote p38α/β phosphorylation and myogenic differentiation. However, the phosphorylation cascade leading to p38α/β activation has not been elucidated. We focused on Pak1, a member of the p21 activated kinase family, which is activated by Cdc42. We have observed that treatment of differentiating myogenic progenitors (mesoangioblasts) with the Pak1 inhibitor IPAJ3 negatively modulates p38α/β phosphorylation and myogenin expression without affecting cell proliferation. This inhibition of the myogenic differentiation program results in a lower efficiency of myotube formation. We followed these observations in vivo by monitoring regeneration efficiency in mice treated with IPA-3 and we observed that mice treated with IPA-3 displayed a delayed recovery after cardiotoxin injury. These results suggest the Pak1 contributes to myogenic differentiation of progenitor cells in vitro and participates in muscle regeneration in vivo., Ambra1 (activating molecule in Beclin 1-regulated autophagy) is an adaptor protein involved in a plethora of cellular processes. Studies in mice with a randomly mutated Ambra1 locus (Ambra1gt/gt) showed that this gene is essential for the development of the central nervous system. A recently published work by our team suggests that Ambra1 may also play a key role for muscle development in zebrafish and mouse. Indeed, Ambra1gt/gt E13.5 mouse embryos display severe defects of neck, tongue, dorsal and limb muscles, being characterized by increased cellularity and a marked disorganization of myofibers. To better clarify the role of Ambra1 in skeletal muscles, we generated mice with a floxed Ambra1 allele (Ambra1flox/flox). Ambra1flox/flox mice were then crossed with a CAG-Cre transgenic line, which express Cre recombinase in the oocytes, thus obtaining Ambra1+/- mice. Here we show that Ambra1–/– mice die at late developmental stages and display severe morphological defects, similar to Ambra1gt/gt embryos. Adult Ambra1+/- mice show an increased percentage of centrally nucleated fibers and a decreased proportion of oxidative fibers. Ambra1flox/flox mice were then bred with MLC-1f-Cre transgenic animals, which only express Cre recombinase in mature myofibers. Our preliminary data in adult Ambra1flox/flox;MLC-1f-Cre mice show a significant increase of centrally nucleated fibers, although we did not observe any overt defect of oxidative fibers. Altogether, our data suggest that Ambra1 is important for the development of skeletal muscle. Further studies in different muscles of Ambra1flox/flox;MLC-1f-Cre mice under different stress conditions will allow elucidating the role of this adaptor protein in myofiber homeostasis, Myopalladin (MYPN) is a striated muscle-specific sarcomeric protein belonging to a small family of actin-associated immunoglobulin-containing proteins. MYPN mutations have been identified in patients with dilated (DCM), hypertrophic, and restrictive cardiomyopathy. Furthermore, we identified three MYPN mutations in limb girdle muscular dystrophy (LGMD) patients with associated DCM. Within the sarcomeric Z-line, myopalladin binds to α-actinin, nebulin, and PDZ-LIM proteins. Furthermore, it is present in the nucleus and the I-band where it binds to the stress-inducible transcriptional cofactor CARP/Ankrd1, which, in turn, binds to the I-band region of titin, suggesting a role of MYPN in mechanosensing. In our preliminary studies, we found that MYPN can bind to and bundle filamentous actin, thereby promoting actin polymerization. Moreover, MYPN interacts with MRTF-A and strongly increases MRTF-A-mediated activation of serum response factor (SRF) signaling. In studies of MYPN knockout (MKO) mice, we found that MKO mice are significantly smaller compared to wildtype (WT) mice and have an about 30% reduction in skeletal muscle cross-sectional area (CSA) at all ages. Consistently, reduced differentiation rate and myotube width was observed in primary skeletal muscle cultures derived from MKO mice. Furthermore, studies of muscle performance in 2-month-old MKO mice showed reduced isometric force and power during isotonic shortening at any loads as a result of the reduced cross sectional area, whereas the force developed by each myosin molecular motor was unaffected. By up- and downhill treadmill running, MKO and WT mice performed similarly. However, while the performance of WT mice was unaffected following four consecutive days of downhill running, the performance of MKO mice decreased progressively and signs of muscle regeneration following muscle damage were observed. Consistent with a higher susceptibility to muscle damage, progressive Z-line widening was observed in MKO skeletal muscle from about 8 months of age. RNAseq revealed downregulation of actin isoforms and other SRF-target genes in MKO muscle both at 2 and 4 weeks of age, suggesting altered SRF signaling as a possible explanation for the reduced CSA in MKO mice., Impairment of autophagy in muscle leads to precocious ageing1. In particular, autophagy deficient mice are characterized by weakness are atrophy that are associated with alteration in Neuro Muscular Junction (NMJ) and loss of innervation. In order to investigate the cross-talk between muscle and nerve, we found that the expression of FGFBP1, a neurotrophic factor that is critical to preserve muscle-nerve interaction, is suppressed in muscle of autophagy deficient mice. FGFBP1 has been found to be regulated by miRNA206, the muscle-specific miRNA2. When we checked the level of miRNA206 expression, we found higher level of miRNA206 in serum of muscle specific autophagy deficient mice than in controls. Importantly, miRNA206 was detected in the heart of those mice. To understand whether autophagy deficient muscles released vesicles containing microRNAs, we analysed exosomes Quantitative RT-PCR analyses confirmed an increased expression of miRNA206 in purified exosomes from both denervated and autophagy deficient fibers. Moreover expression of BDNF in neurons treated with purified exosomes containing miRNA206 was down-regulated. This finding suggests a potential role of exosomes and miRNA206 in modulating synaptic plasticity. In order to mimic autophagy deficient mice condition, we systemically injected exosomes transfected with miRNA206 in wild-type animals. MiRNA206 was found in several tissues, in particular liver and heart. Moreover the treatment was sufficient to induce skeletal muscle atrophy and changes in the expression of several neurotrophic factors. These data support the role of exosome as a signaling mechanism that connects muscle with different tissues including motorneuron, heart and liver., Duchenne muscular dystrophy (DMD) is a genetic disease in which loss of functional dystrophin protein results in progressive skeletal muscle degeneration. Although the genetic defect is widely known, the mechanisms by which the absence of dystrophin leads to the complex pathophisiology of the disease is not completely understood. MiRNAs are small non coding RNA that are important regulatory elements for muscle development and function [1]. Altered levels of specific miRNAs were found in several muscular disorders, including DMD [2, 3]. In particular it has been identified a specific DMD-signature miRNAs that may serve as a marker for therapeutic purposes [4]. Moreover, in a recent work it has been defined a specific group of miRNAs strictly correlated to dystrophin levels and whose deregulated expression could explain several pathogenetic features of DMD [5]. Previously we have demonstrated that the local expression of mIGF-1 in mdx mice ameliorates the dystrophic phenotype reducing myonecrosis and upregulating survival pathways such as AKT pathway [6]. In this work, we show that a specific group of miRNAs, dystrophin-indipendent, are modulated by mIGF-1 expression. In particular, local expression of mIGF-1 promotes the modulation of miR-206 and miR-24 as well as muscle specific genes associated with maturation of regenerating muscle fibers and differentiation. These results indicates that local overexpression of the anabolic factor mIGF-1 in mdx mice ameliorates the dystrophic microenviroment modulating the expression of a specific group of miRNAs and inducing a partial rescue of the characteristic DMD-signature., Circular RNAs have been recently re-discovered as a large class of putative non-coding RNAs with a peculiar structure and poorly understood functions. Although their biogenesis, which proceeds via a back-splicing reaction, has been studied and dissected in the last years, their role in biologically relevant processes is still uncharacterized. Here, we performed expression profiling of circRNAs during in vitro differentiation of murine and human myoblasts, we selected and validated the expression of a subset of highly expressed, conserved circular RNAs and applied a high-content functional genomic screen in order to identify molecules that were able to impact on the differentiation process. We focused on three circRNAs whose down-regulation resulted in important phenotypes and further scrutinized one of them, named circ-ZNF609, with the aim of undestanding its molecular function. We found that circ-ZNF609 contains an open reading frame spanning from the native start codon of its host transcript and terminating at an in-frame stop codon that is created upon circularization. Circ-ZNF609 is associated to heavy polysomes and is translated into a 30-KDa peptide that is able to promote human myoblasts proliferation., Stem cells and regenerative medicine have greatly increased the expectations of the scientific community and the public for their potential in applications that aim at recovering or replacing injured, aged and diseased tissues. Nevertheless their clinical application is currently hindered by cell survival, inflammatory response, tissue engraftment, vascularization and efficient differentiation. Tissue engineering exploits biomaterials to improve stem cell engraftment and differentiation by mimicking organogenesis. Skeletal muscle tissue engineering is an up-and-coming biotechnology that could offer great potential, in the near future, for muscle repair. Reconstructing the skeletal muscle architecture and function is still a challenge requiring parallel alignment of myofibrils arranged into organized sarcomeres. We show that an “anatomical bioreactor-like” represented by the surface of mouse tibialis anterior muscle (TA), positively influences maturation and alignment of fibers derived from adult muscle stem/progenitor cells embedded into a poly-ethylene-glycol-fibrinogen (PF) hydrogel. This approach leads to the generation of an artificial normal muscle. Furthermore by the same approach we succeeded in replacing a complete mouse TA after massive muscle ablation, recovering morphology and function of the substituting artificial TA. Starting from these observations, we are now developing a novel approach for regeneration and/or reconstruction of skeletal muscle tissue segments human-like size in order to translate this technique to clinical application. For this purpose human derived muscle pericytes have been isolated from muscle biopsies and have been investigated for their myogenic potential. Moreover by exploiting the PF properties, we demonstrated the noteworthy potential of this cell population for human skeletal muscle tissue engineering., Histone deacetylases (HDACs) control the transcriptional networks underlying both muscle differentiation and progression of dystrophy. Considering that, HDAC inhibitors (HDACi) are important candidate drugs for pharmacological interventions in muscular dystrophies. Although the beneficial effects of HDACi in the treatment of muscular dystrophy are known, it remains to dissect the mechanism of action and the cellular mediators of these drugs. The goal of this project is to analyze the molecular mechanisms underlying the role of resident satellite cells and infiltrating macrophages in mediating the activity of HDACi ITF2357 (also referred to as Givinostat) in dystrophic muscle of mdx mice, the best animal model of Duchenne Muscular Dystrophy (DMD). We analyzed the dystrophic phenotype of mdx mice treated with Givinostat at different stages of disease, specifically 6, 12 and 36 weeks, corresponding to necrotic/inflammatory, regenerative and fibrotic stage, respectively. The histopathological and morphometric analyses show an amelioration of dystrophic phenotype with a significant increase of muscle fiber cross-sectional area and a consistent reduction of intramuscular fibrosis, surprisingly also at late stage of disease, suggest a positive outcome also in old mdx mice. Moreover, gene expression analysis of whole skeletal muscle and purified cell populations pointed out a modulation of fibrosis and inflammatory markers and fibroadipogenic differentiation. Overall, these data confirm the beneficial effects of Givinostat on dystrophic muscle and identify the involvement of macrophages in mediating Givinostat activity., Central Core Disease (CCD) and Malignant Hyperthermia (MH) are related disorders linked to mutations in the ryanodine receptopr-1 (RYR1) gene, encoding for the sarcoplasmic reticulum (SR) Ca2+ release channel. CCD is a congenital myopathy characterized by amorphous regions lacking mitochondrial activity (cores) in skeletal fibers. In humans, the RYR1-Y522S mutation is associated with MH and formation of structural cores. Skeletal fibers of knock-in RYR1Y522S/WT mice develop mitochondrial damage and cores, caused by excessive oxidative stress (Boncompagni et al. 2009 PNAS). We treated RYR1Y522S/WT mice with an antioxidant, N-acetylcysteine (NAC), provided ad-libitum in drinking water (1%w/v) for 2 months and verified reduction of oxidative stress: indeed, level of 3-nitrotyrosine was increased by 1.44-folds in RYR1Y522S/WT mice, but reduced to control levels after NAC treatment. Electron microscopy was used to assess mitochondrial integrity following NAC-treatment: a) mitochondria swelling and frequency of damaged mitochondria were both decreased (-24% and -10%, respectively); b) the number/100 µm2 of mitochondria (25.9 ± 0.7 vs 29.1 ± 0.6) and their proper association with the SR (+22%) were both increased. Using histological analysis, we also verified that NAC was effective in reducing the frequency of cores (-20% contracture cores; -30% unstructured cores). Finally, we evaluated muscle function in treated mice by grip strength test: NAC was able to improve muscle strength of about 80%. This work provides the bases for clinical trial as it demonstrate that NAC-administration prevents mitochondrial damage, development of cores, and improves muscle function in a mouse model of CCD., In humans, lethal hyperthermic episodes can be trigger by anesthetics (a disorder known as Malignant Hyperthermia, Susceptibility, MHS) and by high temperature and/or strenuous exercise (crises identified as Environmental/Exertional Heat Strokes, EHSs). The correlation between MHS and EHS is strongly supported by extensive work in animal models: indeed, both RYR1Y522S/WT knock-in and CASQ-1 knockout mice trigger similar lethal crises when exposed to both halothane and heat. Here we tested the following hypotheses: a) strenuous exercise is a stimulus capable to trigger EHS-lethal episodes; b) MHS and EHS share common molecular mechanisms underlying crises. When RYR1Y522S/WT and CASQ1-null mice were subjected to an exertional-stress (ES) protocol (executed on a treadmill placed in an environmental chamber), which was well tolerated by WT animals (0% of deaths), the mortality rate was dramatically increased (80% and 75%, respectively), with a rise in core temperature (hyperthermia) significantly higher than in WT at the end of the stimulus. During exertional-crises, most fibers from RYR1 Y522S/WT and CASQ1-null mice suffer severe structural damage (~99% and ~64% of fibers, respectively), indication of rhabdomyolysis. Importantly, pre-treatment of animals with azumolene (a more water soluble dantrolene analog, the only drug approved for treatment of MH crises in humans) almost completely abolished mortality rate in RYR1 Y522S/WT and CASQ1-null animals, by reducing hyperthermia, rhabdomyolysis, and Ca2+leak from the SR. All these results strongly suggest that EHS share common molecular mechanisms with anesthetic-induced MH episodes and that drugs used to treat classic MH should be considered for treatment of EHS., Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder characterized by progressive muscle degeneration due to lack of dystrophin, a protein essential for the integrity of sarcolemma during contraction. In DMD compensative degeneration/regeneration cycles determine a condition of chronic inflammation contributing to progressive muscle wasting. RAGE (receptor for advanced glycation end-products) is a multiligand receptor belonging to the immunoglobulin superfamily involved in physiological and pathological processes including inflammation and myogenesis [1]. RAGE is not expressed in adult muscle tissue, whereas it is expressed in regenerating myofibers during muscle regeneration [2,3], in dystrophic muscles and activated immune cells. To have information about the role of RAGE in the pathophysiology of DMD we generated a double mutant mdx/Ager–/– mouse lacking dystrophin and RAGE (Ager). We analyzed diaphragms and hind-limb muscles (i.e., tibialis anterior and quadriceps femoris) of mdx, mdx/Ager–/–, Ager–/– and WT mice at different ages (i.e., 2, 3, 4 and 5 weeks, and 3 and 6 months of age). We found that although the absence of RAGE in dystrophic mice did not affect the onset of the pathology, muscles of 5 week- and 6 month-old mdx/Ager–/– mice showed significantly reduced numbers of necrotic myofibers, and reduced areas of immune cell infiltrate compared with age-matched mdx mice. Also, muscles of mdx/Ager–/–mice showed strongly reduced expression of the marker of activated macrophages, MAC3, compared with mdx mice. Moreover, muscles of mdx/Ager–/– mice exhibited significantly reduced PAX7+ve and myogenin+ve cell numbers, pointing to a reduced recruitment of muscle precursor cells and a more efficient regeneration in dystrophic mice lacking RAGE. Our results suggest that RAGE has an important role in sustaining inflammatory and degenerative processes in dystrophic muscles, and that inhibition of RAGE expression/activity might represent a potential therapeutic approach in DMD patients., Ageing is associated to a dramatic increase in the incidence of heart failure, even if the existence of a real age-related cardiomyopathy remains controversial. As effective contraction and relaxation of cardiomyocytes also depends on Ca2+ supply to myofibrils (handled by calcium release units, CRUs) and on efficient ATP production (provided by mitochondria), in this study we performed a morphological study of cardiac cells in hearts from adult and old mice (4 months vs. ≥ 24 months of age) using confocal and electron microscopy. The analysis of CRUs indicates that couplons become shorter with age and that the number of CRUs/50 µm2 is decreased of about 24% (adults: 5.1±0.32; old: 3.9±0.19). Also mitochondria present structural modifications, with a significant increase in the percentage of organelles presenting severe alterations (3.5% vs. 16.5%). Importantly, both CRUs and mitochondria undergo a spatial re-organization with respect to sarcomeres/myofibrils: CRUs may be miss-oriented (longitudinal) or miss-placed (found at the A band instead of being correctly placed in proximity of Z-lines), while mitochondria are often grouped in an abnormal fashion. In addition, WB analysis shows that in aged mice, there is a significant reduced expression of junctophilin-2 (JP-2), a membrane protein involved in maintaining stability and morphometry of dyads. These age-related ultra-structural changes may underlie an inefficient supply of Ca2+ and ATP to contractile elements, providing a possible explanation for heart dysfunction associate to age., Progressive muscle degeneration followed by dilated cardiomyopathy is a hallmark of muscular dystrophy. Stem cell therapy is suggested to replace diseased by healthy myofibers, although so far we are faced by low efficiencies of migration, engraftment and differentiation of stem cells. Chemokines are signalling proteins guiding cell migration and have been shown to tightly regulate cardiac repair. We sought to determine which chemokines are expressed in a dystrophic heart that is undergoing cardiac remodelling. Therefor we analysed chemokine expression of Sarcoglycan-α (Sgcα) null, Sarcoglycan-β (Sgcβ) null and immunodeficient Sgcβ-null mice. High expression of all three monocyte-chemotactic proteins was observed, especially Ccl8 in both Sgcβ-null models and to a greater extent in Sgcα-null mice. Additionally, Fractalkine (Cx3cl1) was upregulated in both the immunocompetent and immunodeficient Sgcβ-null mice. In addition, we aim to evaluate the migration potential of cardiovascular progenitors derived from pluripotent stem cells in vitro, that have the potential to differentiate with high efficiency towards cardiomyocytes, smooth muscle cells and endothelial cells in vitro. We plan to test these cells for their in vivo differentiation and migration capacity towards the previously mentioned chemokines. This sheds perspective for an approachable mechanism, which could potentially improve stem cell homing towards the dystrophic myocardium., Cardiac dysfunction from cardiomyopathy is a frequent manifestation of muscular dystrophy. The primary defect common to most dystrophies involves the disruption of the dystrophin-glycoprotein complex (DGC) with subsequent sarcolemma instability and Ca2+ influx, inducing cellular necrosis. Defective Ca2+ uptake resulting from decreased expression and reduced activity of calcium-transporting ATPase (SERCA2a) and, recently, SERCA2a gene therapy has been demonstrated to mitigate dystrophic diseases. Our previous studies have demonstrated that the dystrophic phenotype observed in δ-sarcoglycan–null hamster is dramatically improved by a long-term dietary supplementation with flaxseeds (FS) (rich in n3-PUFAs), but the molecular mechanisms have not yet been fully understood. The present study was designed to test the hypothesis that FS enriched diet could regulate DGC and SERCA2a proteins that play an important structural and functional role in cardiomyocytes. Therefore, the levels of these proteins and mRNAs were analyzed in heart dystrophic hamsters fed with FS diet for long (five months) or short time (48 hours). Results showed that α- distroglycan, α-, β, γ-sarcoglycan and SERCA2a proteins were down-regulated in dystrophic hearts and FS-diet restored their normal expression pattern. The RT-PCR analysis showed that α-distroglycan, α-sarcoglycan and SERCA2a were up-regulated at the transcriptional level. Interestingly, the mRNAs increase was observed even when FS was administered for short periods suggesting the involvement of an epigenetic mechanism. Therefore, it seems plausible to consider the administration of plant-originated n-3 PUFAs as an adjuvant strategy for attenuating sarcolemma instability and defective Ca2+ uptake that represent major damages associated with dystrophic cardiomyopathies., Oxidative stress (OS) is an imbalance between the production of free radicals, in particular reactive oxygen species (ROS), and the ability of the cells to counteract them by antioxidant responses. ROS production in skeletal muscle occurs mainly in mitochondria, both following physiological stimuli (e.g. aging, physical exercise, or at birth) (1-3) and in response to pathological events, such as denervation (4). In all cases, high levels of ROS actively influence the maintenance of muscle homeostasis. Histone deacetylase 4 (HDAC4) is a member the class II of the HDAC superfamily that regulates many cellular processes (5-7). Following denervation, HDAC4 is upregulated in skeletal muscle: it induces muscle atrophy and represses reinnervation (8-9). Increased levels of ROS cause HDAC4 translocation from the nucleus to the cytoplasm, thus inducing the release of genes transcriptionally repressed by HDAC4(10). However, HDAC4 targets in skeletal muscle have not been discovered yet. In order to investigate the role of HDAC4 in response to OS in skeletal muscle, we use a mouse model with the selective deletion of HDAC4 in myogenin positive cells (HDAC4 mKO mice). HDAC4 mKO mice are viable and do not show gross abnormalities in skeletal muscle. We analyzed mice in two different conditions characterized by elevated OS: at birth and in adult mice following denervation. Molecular responses to oxidative stress are blunted in both newborn and adult HDAC4 mKO compared to control mice. Since elevated ROS contribute to mitochondrial damage and are important in redox signaling from the organelle to the rest of the cell, we analyzed mitochondrial ultrastructure. Both newborn and adult HDAC4 mKO muscles presented damaged mitochondria, altered mitochondrial dynamics and defects in myofiber organization. Our results indicate that HDAC4 is important in skeletal muscle to maintain muscle integrity and a proper response upon OS. Current studies are focused on the identification of HDAC4 targets in the OS response in skeletal muscle, Collagen VI (ColVI) is a major extracellular matrix component made of three genetically distinct α chains and abundantly deposited in the basement membrane of both skeletal muscles and peripheral nerves. Mutations in COL6A1, COL6A2 and COL6A3 genes are known to cause different forms of muscle diseases, including Bethlem myopathy, Ullrich congenital muscular dystrophy and myosclerosis myopathy. ColVI null (Col6a1–/–) mice display a myopathic phenotype characterized by latent mitochondrial dysfunction, spontaneous apoptosis, defective autophagy regulation and compromised muscle regeneration. We recently demonstrated that the absence of ColVI in peripheral nerves leads to hypermyelination, altered Remak bundles, sensory-motor functional deficits and decreased nerve conduction velocities, thus pointing at ColVI as a crucial molecule for peripheral nerve structure and function. Given the muscle and nerve defects displayed by Col6a1 null mice, we decided to explore the role of ColVI in the neuromuscular junction (NMJ). Our unpublished studies revealed that ColVI is indeed deposited at the synapse. Immunofluorescence analysis showed ColVI deposition in NMJs. Preliminary results revealed altered expression of synaptic genes and abnormal electrophysiological parameters in Col6a1–/– mice. These findings suggest a potential role for ColVI at the NMJ, and further studies will allow shedding new light on the roles of this extracellular matrix component in the nerve/muscle axis., Muscular dystrophies are non curable diseases. Recently, new strategies shed light to an increase of muscle regeneration. These strategies focus on epigenetic drugs. TSA (HDACi) achieve to enhance the regeneration rate in both mice and humans. However, new challenges stay on the horizon. Monitoring and controlling the changes of the treatment in muscle without invasive techniques are one of that’s. In our research we identified seven microRNAs differential expressed in FAPs population. FAPs are Key players of muscle regeneration under HDACi treatment. From these seven microRNA, miR-143 has been validated with qRT-PCR, and Chip techniques. This miR-143 form part of a cluster with miR-145 that locates into a long non coding RNA non characterized until that moment. The overexpression of this miR-143 turns FAPs into a non adipogenic phenotype, whereas the inhibition of it recovershe adipogenic behavior. Thus, in this work we are trying to characterize the role of this microRNA and their host gene to understand if it could be a good candidate to be used as marker during the treatment., The central dogma of gene expression is that DNA is transcribed into messenger RNAs, which in turn serve as the template for protein synthesis. In recent years, it has been discovered that genomes of multicellular organisms are characterized by the pervasive expression of different types of non-coding RNAs (ncRNA) and, among them, long non-coding RNAs (IncRNAs). In particular the mammalian genome contains many thousands of lncRNAs, which have been proposed to be fundamental in the regulation of many biological processes such as cellular differentiation and show an aberrant regulation in a variety of diseases. A transcriptome analysis performed during in vitro murine muscle differentiation allowed us to identify a subset of new lncRNAs differentially expressed during myogenesis (1). These transcripts were classified on the basis of their expression in proliferating versus differentiated conditions, muscle-restricted activation and subcellular localization. We are now focusing on the characterization of a nuclear lncRNA conserved in human, lnc-405, up-regulated during differentiation, whose expression is cardiac and skeletal muscle restricted. To dissect its role in myogenesis, we performed loss of function experiments using LNA-Gapmers followed by a transcriptome analysis. This approach revealed a strong down-regulation of a subset of genes involved in fiber contraction, cell fusion and related to several cardiomyopathies. With the idea to better explain its crucial role during myogenesis, we are now focusing on the molecular mechanism by which lnc-405 exerts its function in the nucleus by RIP, ChIRP and RNA pull-down assays that are on going., The functional connection between muscle and nerve is affected in several neuromuscular diseases, including Amyotrophic Lateral Sclerosis (ALS) whose major pathological processes are motor neuron degeneration. However, other cells may be involved in the pathogenesis of ALS and open the possibility that alteration in skeletal muscle homeostasis represents one of the principal mediators of motor neuron degeneration. We have evidences that indicate that muscle selective expression of SOD1G93A mutant gene modulates, at the level of spinal cord of MLC/SOD1G93A mice, relevant mRNA and microRNA associated with myelin homeostasis. Our study provided insights into the pathophysiological interplay between muscle and nerve and supports the hypothesis that skeletal muscle is a source of signals that can affect the nervous system., Calsequestrin (CASQ) is the major protein of the sarcoplasmic reticulum of striated muscle that binds Ca2+ with high capacity and moderate affinity. CASQ exist as a monomer and polymers, depending on Ca2+ concentration. CASQ switches from an unfolded state to a folded monomer when the ionic strength increases allowing the formation of front-to-front first and then back-to-back interactions in higher Ca2+ concentrations. In humans, mutations in the cardiac isoform CASQ2 lead to catecholamine-induced polymorphic ventricular tachycardia. Recently we reported one mutation in the skeletal CASQ1 gene in a group of patients with a vacuolar myopathy characterized by the presence of inclusions containing CASQ1 and other SR proteins. The CASQ1 mutation (CASQ1D244G) affects one of the high-affinity Ca2+-binding sites of the protein and alters the kinetics of Ca2+ release in muscle fibers from patients. Expression of the CASQ1D244G in myotubes and in mouse fibers causes the appearance of SR vacuoles containing aggregates of the mutant CASQ1 protein that resemble those observed in patients. Studies of Ca2+ release showed an increase in Ca2+ storage in CASQ1WT COS-7 transfected cells whereas no increase was observed in CASQ1D244G. Moreover both CASQ1WT and CASQ1D244G were expressed in bacteria, purified and analysed for their ability to polymerize at increasing Ca2+ concentrations. The results obtained indicate that the CASQ1D244G protein polymerizes at lower Ca2+ levels and more rapidly than CASQ1WT. These results suggest that the CASQ1D244G mutation interferes with the correct process of Ca2+ -dependent protein polymerization causing altered intracellular calcium storage and the formation of protein aggregates., Muscle regeneration is dependent upon a complex interplay of different cell types in the muscle stem cell niche. In particular, the recently described population of interstitial fibro-adipogenic progenitors (FAPs) and satellite cells (MuSCs) establish a complex network of interactions to coordinate muscle regeneration. FAPs are able to promote satellite cell differentiation and compensate for muscle necrosis. In our recent studies, we demonstrated that FAPs are the key cellular mediators of the beneficial effect of HDAC inhibitors at early stages of Duchenne Muscular Dystrophy (DMD). Indeed, FAPs, from young mdx mice HDACi, induce myogenesis at expense of adipogenesis and enhance their ability to support MuSCs differentiation. Conversely, FAPs from old mdx mice are resistant to HDACi and repress MuSCs differentiation (Mozzetta et al., 2013; Saccone et al., 2014). Given the importance of the cross-talk between FAPs and MuSCs in DMD progression, we are currently deciphering the role of FAP-released extracellular vesicles (and in particular the exosomes - endosome derived vesicles) as mediators of the functional interactions between mononuclear cell types that contribute to muscle regeneration., Limb Girdle Muscular Dystrophies are rare genetic diseases, characterized by weakness and progressive muscular atrophy. A subfamily of LGMD2 regroups sarcoglycanopathies caused by mutations in genes coding for sarcoglycans. These transmembrane proteins are part of the dystrophin complex that protects muscle fibers against mechanical stress due to contraction. There is no treatment available for these diseases.In order to understand the molecular mechanisms implicated in sarcoglycanopathies and to identify new therapeutic targets, we are conducting two studies: 1 - SG mutants are not present at the muscle fiber membrane because they are retained in the endoplasmic reticulum by the quality control (ERQC) and they are prematurely degraded by the proteasome. To study the ERCQ pathways responsible for sarcoglycan disposal at molecular level, we first generated cell lines expressing clonally one SG mutant. Those clones are now used to investigate the SGs cellular trafficking mechanisms and then to test pharmacological compounds modulating ERCQ pathways. 2 – In these diseases, muscular atrophy affects limb muscles and infrequently head muscles. To investigate mechanisms underlying the fact that some muscles are more affected than other, we analyzed different muscles to search for molecular differences that may sign their relative sensitivity to the genetic defects. The content in micro-RNA of muscles from the limbs and face of Macaca fascicularis was explored. Experiments are in progress to analyze the function of identified micro-RNAs and to evaluate their therapeutic potential for sarcoglycanopathies. These projects will improve the knowledge on physio-pathological mechanisms of sarcoglycanopathies in order to identify new therapies for patients., Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common human myopathies and arises with progressive wasting of facial mimic muscles as well as upper arms and shoulder girdle muscles. In 95% of the cases, FSHD is associated with the copy number reduction of D4Z4 macrosatellite repeats at the subtelomeric region of chromosome 4 (4q35). This change is associated with an epigenetic deregulation of the region that ultimately leads to the de-repression of nearby genes, such as DUX4 and FRG1 that have been reported to contribute to the muscular dystrophic phenotype observed in FSHD patients. The chromatin-associated lncRNA DBE-T, encoded by the FSHD locus, has been shown to be one of the main players of such event, though the molecular mechanism has not been yet fully elucidated. DBE-T is preferentially expressed in FSHD patients where it favors the transcription of the 4q35 genes thanks to the recruitment of the histone methyl transferase of the Trithorax group of epigenetic activators ASH1L. Interestingly, through a structural/functional analysis, we have recognized several DBE-T functional domains that can be exploited as new molecular targets for therapeutic purposes. Specifically, we have identified a region and the molecular mechanism required for DBE-T tethering to the chromatin. In addition, we have mapped the minimal binding domains in ASH1L and DBE-T. Finally, we have highlighted a portion of DBE-T required to positively promote transcription. In agreement, a DBE-T mutant lacking this region is unable to trigger transcription. Currently, through proteomic approaches, we are investigating DBE-T protein partners that are specific for each DBE-T functional domain. Our goal is to identify unknown molecular players that, similarly to ASH1L, are recruited by DBE-T to the FSHD locus and can play a role in the disease. Overall, our study elucidates the molecular mechanism of DBE-T in FSHD and might unveil new therapeutic targets for the treatment of the disease.

a b s t r a c t Background: Data on the efficacy of Peg-interferon/ribavirin therapy for chronic hepatitis C are mostly derived from treatment of selected patients enrolled in clinical trials. This study aimed to assess the effectiveness of Peg-interferon/ribavirin therapy in “real world” chronic hepatitis C patients in Italy. Methods: Independent observational multicentre study including consecutive patients receiving Peginterferon/ribavirin in the 18 months before (retrospective phase) and after (prospective phase) the start of the study. Results: 4176 patients were eligible. The final study population consisted of 2051 patients in the retrospective and 2073 in the prospective phase. Sustained virological response was achieved by 1036 patients (50.5%) during the retrospective phase: 325 were genotypes 1/4 (34.1%) and 684 were genotypes 2/3 (67.2%) and by 800 patients (38.6%) during the prospective phase: 300 were genotypes 1/4 (28.4%) and 473 were genotypes 2/3 (51.5%). During multivariate analysis genotypes 2/3 were significantly associated with higher sustained virological response rates; cirrhosis and -glutamil-transpeptidase >2 times the normal limit were associated with poorer response. Conclusions: The response to Peg-interferon/ribavirin therapy in “real world” clinical practice is distinctly lower than in registration trials. The difference in response rates was more pronounced among easy-totreat than among difficult-to-treat hepatitis C virus genotypes.

Background: Factors influencing the outcome of structured treatment interruptions (STIs) in HIV chronic infection are not fully elucidated. Methods: In ISS-PART, 273 subjects were randomly assigned to arm A (137 assigned to continuous highly active antiretroviral therapy [HAART]) and arm B (136 assigned to 5 STIs of 1, 1, 2, 2, and 3 months'duration, each followed by 3 months of therapy). Main outcome measures were the proportion of subjects with a CD4 count >500 cells/mm 3 , the rate of virologic failure, and the emergence of resistance at 24 months. Results: The proportion of subjects with a CD4 count >500 cells/mm 3 was higher in arm A than in arm B (86.5% vs. 69.1%; P = 0.0075). Pre-HAART CD4 cell count and male gender were independent predictors of a CD4 count >500 cells/mm 3 in arm B. The overall risk of virologic failure was not increased in arm B; however, it was higher in the 38 subjects who had resistance mutations in the rebounding virus. Archived mutations at baseline and the use of a regimen that included an unboosted protease inhibitor (PI), compared with nonnucleoside reverse transcriptase inhibitor-based HAART, independently predicted the emergence of plasma mutations during STI (P = 0.002 for DNA mutations and P = 0.048 for PI-based HAART). Conclusions: Our results suggest that patients with preexisting mutations and treated with unboosted PI-based HAART should not be enrolled in studies of time-fixed treatment interruptions, being at higher risk of developing plasma mutations during STI and virologic failure at therapy reinstitution.

The aim of the present retrospective study was to assess the incidence of adverse events (AE) of a second-generation ultrasound contrast agent in real clinical practice. A total of 28 Italian Centres provided data on the postmarketing use of SonoVue (Bracco Spa, Milan, Italy) in abdominal examination performed between December 2001 and December 2004. A total of 23 188 investigations were reported. No fatal event occurred. AEs were reported in 29 cases, of which only two were graded as serious; the rest, 27, were nonserious (23 mild, three moderate and one severe). The overall reporting rate of serious AE was 0.0086%. Overall, only four AEs required treatment (two serious, two nonserious including one moderate and one severe AEs). In conclusion, the present large-scale retrospective analysis showed that SonoVue has a good safety profile in abdominal applications, with an AE reporting rate lower than or similar to that reported for radiologic and magnetic resonance contrast agents.

Background and Aims: To maximize cost/efficay of boceprevirbased triple therapy (BOC) in patients with HCV-related advanced fibrosis/cirrhosis. Methods: ITT SVR12, safety and futility rules value were evaluated in the multicenter national Italian and Spanish early access Name- Patient-Program which includes treatment-experienced patients with HCVG1-related advanced fibrosis/cirrhosis (Metavir F3/4) treated with BOC in both countries. Results: 402 patients (mean age 55 years; range 22–75), 316 (78.6%) G1b, 255 (63.4%) F4, 60 (30.9%) with oesophageal varices, 137 (34.1%) relapsers, 95 (23.6%) partial and 168 (41.8%) null responders were enrolled. Platelets count