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Introduction Bone consolidation defects represent a real orthopedic challenge because of the absence of validated treatment guidelines that can assist the surgeon in his choices. The aim of this study is to evaluate the appropriateness of the Non-Union Scoring System NUSS treatment protocol in the management of long bone non-unions by comparing it to the experience-based therapeutic approach carried out in our facility. Materials and Methods We conducted a comparative outcome study of a retrospective series of 89 patients surgically treated for long bone non-union in our facility vs. clinical results reported by Calori et al. obtained following the NUSS treatment protocol. Results Radiographic healing was reached in 13/13 non-unions (100%) in group NUSS 1, in 58/62 (93.5%) in group NUSS 2, and in 13/14 (92.9%) in group NUSS 3. The mean time to radiographic healing was 5.69 ± 2.09 months in group 1, 7.38 ± 3.81 months in group 2 and 9.23 ± 2.31 months in group 3. 91% of patients in group I, 69% in group II and 48% in group III received what would be considered by the NUSS treatment protocol an “overtreatment”, especially from a biological stand point. The comparative outcome analysis shows that our case series achieved significantly higher global healing rates (p value = 0.017) and shorter radiological healing times in groups NUSS 1 and 2 (p value Conclusion From the results obtained, we can assume that the NUSS treatment protocol might underestimate the necessary therapies, particularly from a biological point of view.

Cell therapy, gene therapy, and tissue engineering have the potential to revolutionize the field of regenerative medicine. In particular, gene therapy is understood as the therapeutical correction of mutated genes by addition of a correct copy of the gene or site-specific gene modifications. Gene correction of somatic stem cells sustaining renewing tissues is critical to ensure long-term clinical success of ex vivo gene therapy. To date, remarkable clinical outcomes arose from combined ex vivo cell and gene therapy of different genetic diseases, such as immunodeficiencies and genodermatoses. Despite the efforts of researchers around the world, only a few of these advanced approaches have yet made it to routine therapy. In fact, gene therapy poses one of the greatest technical challenges in modern medicine, spanning safety and efficacy issues, regulatory constraints, registration and market access, all of which need to be addressed to make the therapy available to patients with rare disease. In this review, we survey some of the main challenges in the development of combined cell and gene therapy of genetic skin diseases.

Treatment of chronic leg ulcers remains a major challenge and it is a substantial financial burden on individuals, families, caregivers, and health care system. There is increasing evidence on using of autologous Platelet-rich-plasma in wound repair but limited clinical data are available on the efficacy and safety of the use of umbilical cord blood platelet gel (CBPG). In our pilot study, for the first time, we aimed to evaluated the safety and efficacy of the use of umbilical CBPG combined with a hydrogel dressing in 10 patients with chronic venous ulcers (VU). The protocol consisted of application of umbilical cord blood platelet-rich plasma (PRP) combined with a Carboxymethyl cellulose (CMC)-based hydrogel dressing once a week for 4 weeks. The 80% of patients after 4 weeks of treatment had a significantly decrease in wound size. Moreover, we obtained an improvement in terms of mean Wound Bed Score (WBS), numeric rating scale (NRS) value and the EQ-5D index score. This pilot study showed that the topically therapeutic administration of umbilical CBPG associated with a CMC-based hydrogel dressing has the potential to accelerate the healing of chronic lesions without adverse reaction. However, additional studies with larger sample size and longer follow-up periods are required to confirm our findings.

limb-sparing surgery is the mainstream treatment for primary extremity soft tissue sarcoma (ESTS) at referral centers, following advances in surgical reconstructions and multimodal management. However, amputation is still needed in selected patients and has not yet been described for a ESTS cohort in a contemporary scenario.consecutive patients who underwent surgery for primary ESTS from 2006 to 2018 were extracted from a prospectively collected database at our reference center. Patients receiving amputation for either primary tumor or local recurrence (LR) after limb-sparing surgery were selected for analysis.Among 1628 primary ESTS, 29 patients underwent primary amputation (1.8%), 22/1159 (1.9%) for upper limb and 7/469 (1.5%) for lower limb ESTS. Patients were mainly affected by grade III FNCLCC (89.6%) of notable dimension (median size 16 cm, IQR 10-24). 65.5% of patients received preoperative treatments (systemic or regional chemotherapy, radiotherapy or chemo-radiation). Secondary amputation for LR was performed after a median of 23 months in 16/1599 patients (1%). Median survival time was 16.2 and 29.6 months after primary or secondary amputation respectively. Factors prompting the need for a primary amputation were most often a combination of multifocal disease, bone invasion and pain or neurovascular bundle involvement and relevant comorbidities, mainly for grade III tumors in elderly patients.Contemporary rate of amputation for ESTS at a reference center is extremely low. Still, amputation is required in selected cases with advanced presentations, especially in elderly, frail patients.

Continuous exposure of the skin to environmental, mechanical and chemical stress necessitates constant self‐renewal of the epidermis to maintain its barrier function. This self‐renewal ability is attributed to epidermal stem cells (EPSCs), which are long‐lived, multipotent cells located in the basal layer of the epidermis. Epidermal homeostasis – coordinated proliferation and differentiation of EPSCs – relies on fine‐tuned adaptations in gene expression which in turn are tightly associated with specific epigenetic signatures and metabolic requirements. In this review, we will briefly summarize basic concepts of EPSC biology and epigenetic regulation with relevance to epidermal homeostasis. We will highlight the intricate interplay between mitochondrial energy metabolism and epigenetic events – including miRNA‐mediated mechanisms – and discuss how the loss of epigenetic regulation and epidermal homeostasis manifests in skin disease. Discussion of inherited epidermolysis bullosa (EB) and disorders of cornification will focus on evidence for epigenetic deregulation and failure in epidermal homeostasis, including stem cell exhaustion and signs of premature ageing. We reason that the epigenetic and metabolic component of epidermal homeostasis is significant and warrants close attention. Charting epigenetic and metabolic complexities also represents an important step in the development of future systemic interventions aimed at restoring epidermal homeostasis and ameliorating disease burden in severe skin conditions.

Background Solitary fibrous tumor (SFT) is a rare mesenchymal malignancy. Although surgery is potentially curative, the local relapse risk is high after marginal resections. Given the lack of prospective clinical trial data, the objective of the current study was to better define the role of perioperative radiotherapy (RT) in various SFT presentations by location. Methods This was retrospective study performed across 7 sarcoma centers. Clinical information was retrieved from all adult patients with extrameningeal, primary, localized SFT who were treated between 1990 and 2018 with surgery alone (S) compared with those who also received perioperative RT (S+RT). Differences in treatment characteristics between subgroups were tested using analysis of variance statistics and propensity score matching. Local control and overall survival rates were calculated from the start of treatment until progression or death from any cause. Results Of all 549 patients, 428 (78%) underwent S, and 121 (22%) underwent S+RT. The median follow‐up was 52 months. After correction for mitotic count and surgical margins, S+RT was significantly associated with a lower risk of local progression (hazard ratio, 0.19: P = .029), an observation further confirmed by propensity score matching (P = .012); however, this association did not translate into an overall survival benefit. Conclusions The results from this retrospective study investigating perioperative RT in patients with primary extrameningeal SFT suggest that combining RT with surgery in the management of this patient population is significantly associated with a reduced risk of local failures, especially in patients who have less favorable resection margins and in those who have tumors with a high mitotic count., This retrospective study of perioperative radiotherapy in patients with primary extrameningeal solitary fibrous tumors suggests that combining radiotherapy with surgery in the management of this population significantly reduces the risk of local failures, especially in patients who have less favorable resection margins or tumors with a high mitotic count.

Epidermolysis bullosa (EB) is a devastating genetic skin disease typified by a plethora of different phenotypes and ranking from severe, early lethal, to mild localized forms. Although there is no cure for EB, recent progress in pharmacology and molecular and cellular biology is boosting the development of new advanced therapeutic strategies. Here we will focus on two main categories of such therapies: (1) those aimed at controlling inflammation and inducing reepithelialization of the wounds, and (2) those, perhaps more challenging and ambitious, that aim to permanently regenerate a fully functional epidermis, which requires targeting of epidermal stem cells. In both cases, the genetic variants underlying the different EB forms and factors, such as genetic background, modifier genes, comorbidities, and lifestyle, all of which impinge on EB genotype-phenotype correlation, need to be defined.

Non-alcoholic fatty liver disease (NAFLD) is becoming a global public health issue and the identification of the steatosis severity is very important for the patients’ health. Ultrasound (US) images of 214 patients were acquired in two different scan views (subcostal and intercostal). A classification of the level of steatosis was made by a qualitative evaluation of the liver ultrasound images. Furthermore, an US image processing algorithm provided quantitative parameters (hepatic–renal ratio (HR) and Steato-score) designed to quantifying the fatty liver content. The aim of the study is to evaluate the differences in the assessment of hepatic steatosis acquiring and processing different US scan views. No significant differences were obtained calculating the HR and the Steato-score parameters, not even with the classification of patients on the basis of body mass index (BMI) and of different classes of steatosis severity. Significant differences between the two parameters were found only for patients with absence or mild level of steatosis. These results show that the two different scan projections do not greatly affect HR and the Steato-score assessment. Accordingly, the US-based steatosis assessment is independent from the view of the acquisitions, thus making the subcostal and intercostal scans interchangeable, especially for patients with moderate and severe steatosis.

This paper proposes a simple convolutional neural model as a novel method to predict the level of hepatic steatosis from ultrasound data. Hepatic steatosis is the major histologic feature of non-alcoholic fatty liver disease (NAFLD), which has become a major global health challenge. Recently a new definition for FLD, that take into account the risk factors and clinical characteristics of subjects, has been suggested; the proposed criteria for Metabolic Disfunction-Associated Fatty Liver Disease (MAFLD) are based on histological (biopsy), imaging or blood biomarker evidence of fat accumulation in the liver (hepatic steatosis), in subjects with overweight/obesity or presence of type 2 diabetes mellitus. In lean or normal weight, non-diabetic individuals with steatosis, MAFLD is diagnosed when at least two metabolic abnormalities are present. Ultrasound examinations are the most used technique to non-invasively identify liver steatosis in a screening settings. However, the diagnosis is operator dependent, as accurate image processing techniques have not entered yet in the diagnostic routine. In this paper, we discuss the adoption of simple convolutional neural models to estimate the degree of steatosis from echographic images in accordance with the state-of-the-art magnetic resonance spectroscopy measurements (expressed as percentage of the estimated liver fat). More than 22,000 ultrasound images were used to train three networks, and results show promising performances in our study (150 subjects).

BACKGROUND: Inguinal and/or inguino-scrotal swellings, such as hernia and hydrocele, are among the commonest anomalies in childhood. Hydrocele of the canal of Nuck is an uncommon diagnosis and a rare cause of swelling in women that occurs due to a patent vaginal process. METHODS: From January 2001 to January 2016, 353 female patients 1-14 years of age were admitted to our university hospital division for inguinal swelling. We have performed 403 inguinal approaches, and of these, 399 (99%) had inguinal hernias, 3 (0,74 %) had a cyst of the canal of Nuck, and 1 (0,24%) had a lipoma. All of the patients with Nuck cysts underwent surgical exploration of the swelling through a right inguinal skin crease incision. RESULTS: The patients were between the ages of 1 and 8 years. The cyst sizes varied between 25 and 40 mm. All the patients exhibited right, tender, painless, non-reducible masses. In all patients, ultrasound confirmed the suspected diagnosis. The histological findings revealed fibrous-walled cystic formations with mild chronic inflammatory infiltrate that were covered by mesothelial epithelium. The patients’ postoperative follow-ups at 1, 6 and 12 months revealed normally healed incisions with no recurrences. CONCLUSIONS: The surgical findings and the histological demonstrations of serous epithelium seemed to validate the hypothesis that the patency of the inguinal canal combined with fluid secretion of the peritoneal serosa participated in the formation of the cysts. Surgery with high ligature of the vaginal process is considered the therapy of choice for this pathology.

Fowler-Stephens Laparoscopic Orchiopexy (FSLO) permits the mobilization of Intra-Abdominal Testis (IAT) to the scrotal position after spermatic vessel ligation. We reported our experience of FSLO for IAT. The charts of all boys who underwent a FSLO were retrospectively reviewed. Data were analysed for demographic data, procedure, complications and follow-up results. From January 2008 to June 2016, 160 laparoscopies for Non Palpable Testis (NPT) were performed at a mean age of 3,2 years. 61% of patients had a right NPT, while 6% were bilateral. In 64 cases, an IAT was found: 20 were managed by FSLO with a two-stage procedure in 11 patients. There were no differences in hospitalisations; one patient had a prolonged ileus. Follow-up ranged from 1 to 8 years. Of the 20 patients who underwent FSLO, testicular atrophy developed in three; the remaining testes were in the scrotal position, with normal consistency. FSLO was applied in 31% of IAT. The overall success rate of the technique was 85 %. The percentage of atrophy associated after spermatic vessels interruption appears to provide a good chance of testicular survival.

To date, more than 200 monogenic, often devastating, skin diseases have been described. Because of unmet medical needs, development of long-lasting and curative therapies has been consistently attempted, with the aim of correcting the underlying molecular defect. In this review, we will specifically address the few combined cell and gene therapy strategies that made it to the clinics. Based on these studies, what can be envisioned for the future is a patient-oriented strategy, built on the specific features of the individual in need. Most likely, a combination of different strategies, approaches, and advanced therapies will be required to reach the finish line at the end of the long and winding road hampering the achievement of definitive treatments for genodermatoses.

Introduction: The treatment of borderline personality disorder (BPD) remains an open question for clinicians. There is scarce evidence available and the guidelines' conclusions diverge. Together with these factors, the complexity of BPD generates uncertainty in day-to-day practice. This narrative review aims to provide an overview of advances in BPD treatment and posit a critical opinion based on clinical evidence and practice.Areas covered: The authors review the clinical trials concerning the efficacy of the main classes of drugs in BPD: antidepressants, mood stabilizers, first-, second-, and third-generation antipsychotics, and other agents (opiate antagonists, clonidine, oxytocin, omega-3 fatty acids). They also include in this review studies on combinations of drugs and psychotherapies.Expert opinion: An individualized, tailored pharmacotherapy for BPD that targets the prominent symptom clusters can improve relevant aspects of the clinical picture. However, no medication is indicated to treat the global psychopathology of BPD. Polypharmacy should be avoided or strictly limited. To date, pharmacotherapy alone does not suffice to manage the complexity of BPD. Combining medication with psychotherapy may improve specific BPD symptom dimensions. In particular, it may help those aspects that respond slowly or not at all to monotherapy.

We report our experience with a sutureless technique for laparoscopic inguinal hernia repair in children. Twenty-eight children, 12 girls and 16 boys, aged 3 months to 7 years, underwent sutureless laparoscopic inguinal hernia repair. In girls, we utilized simple cauterization of the internal inguinal ring with a single trocar technique. In boys denudation of the peritoneum was obtained utilizing a three-trocar technique. The peritoneum around the internal inguinal ring was peeled off and detached from the vas and the vessels, and then wrapped around the grasper, resulting in a large area of denudation. No perioperative complications were observed. No recurrences nor testicular damage were noted after a mean follow-up of 18 months (range 6-35 months). The mean operative time was 12 min (range 7-20 min) for girls and 19 min (range 15-30 min) for boys. A 6-year-old girl exhibited a lymphocele. The sutureless technique appears to be easy, safe, and effective, provided that the patients are carefully selected. In boys, special attention needs to be paid to preservation of the vas and the testicular vessels.

Premature termination codons (PTCs) generated by nonsense mutations produce abnormal, short, or diminished proteins. Eighty-three percent of patients with Herlitz junctional epidermolysis bullosa (H-JEB), an inherited, incurable skin disease, harbor nonsense mutation(s) in genes encoding a structural protein (laminin 332) responsible for skin adherence. Gentamicin, a common antibiotic, was shown to induce readthrough of PTCs in various disease models. Using in vitro assays and 3D skin models, we found that H-JEB cells harboring nonsense mutations exposed to gentamicin produce full-length structural protein, deposit it correctly between skin layers, and exhibit reversal of other H-JEB–associated cellular abnormalities. Our findings indicate that gentamicin may present an immediate therapy for this otherwise fatal disease and other skin disorders caused by nonsense mutations.

Introduction: Epidermolysis bullosa is a severe genodermatosis in which pain and wound management dominate patients’ lives leaving a high demand for more effective treatments. At present, gene therapy is the only treatment with the potential to cure inherited diseases. A small number of individuals with junctional and dystrophic forms of epidermolysis bullosa have received gene replacement therapies involving ex vivo viral transduction of intact transgenes into skin stem cells followed by autologous grafting of corrected epidermal sheets. Corrected stem cells ensure permanent regeneration of stable skin at the graft sites.Areas covered: Alternative therapeutic options are either RNA-based or involve the latest preclinical developments in the area of gene editing using designer nucleases such as TALEN or CRISPR/Cas9, which enable precise targeting of any desired locus and a potential traceless repair of mutations. Due to low targeting efficiencies and safety considerations regarding off-target effe...

Herlitz junctional epidermolysis bullosa (H-JEB) is an incurable, devastating, and mostly fatal inherited skin disease for which there is only supportive care. H-JEB is caused by loss-of-function mutations in LAMA3, LAMB3, or LAMC2, leading to complete loss of laminin 332, the major component of anchoring filaments, which mediate epidermal-dermal adherence. LAMB3 (laminin β3) mutations account for 80% of patients with H-JEB, and ∼95% of H-JEB-associated LAMB3 mutations are nonsense mutations leading to premature termination codons (PTCs). In this study, we evaluated the ability of gentamicin to induce PTC readthrough in H-JEB laminin β3-null keratinocytes transfected with expression vectors encoding eight different LAMB3 nonsense mutations. We found that gentamicin induced PTC readthrough in all eight nonsense mutations tested. We next used lentiviral vectors to generate stably transduced H-JEB cells with the R635X and C290X nonsense mutations. Incubation of these cell lines with various concentrations of gentamicin resulted in the synthesis and secretion of full-length laminin β3 in a dose-dependent and sustained manner. Importantly, the gentamicin-induced laminin β3 led to the restoration of laminin 332 assembly, secretion, and deposition within the dermal/epidermal junction, as well as proper polarization of α6β4 integrin in basal keratinocytes, as assessed by immunoblot analysis, immunofluorescent microscopy, and an in vitro 3D skin equivalent model. Finally, newly restored laminin 332 corrected the abnormal cellular phenotype of H-JEB cells by reversing abnormal cell morphology, poor growth potential, poor cell-substratum adhesion, and hypermotility. Therefore, gentamicin may offer a therapy for H-JEB and other inherited skin diseases caused by PTC mutations.

Contains fulltext : 98388.pdf (Publisher’s version ) (Open Access) p63, a member of the p53 family, is essential for skin morphogenesis and epithelial stem cell maintenance. Here, we report an unexpected role of TAp63 in cardiogenesis. p63 null mice exhibit severe defects in embryonic cardiac development, including dilation of both ventricles, a defect in trabeculation and abnormal septation. This was accompanied by myofibrillar disarray, mitochondrial disorganization, and reduction in spontaneous calcium spikes. By the use of embryonic stem cells (ESCs), we show that TAp63 deficiency prevents expression of pivotal cardiac genes and production of cardiomyocytes. TAp63 is expressed by endodermal cells. Coculture of p63-knockdown ESCs with wild-type ESCs, supplementation with Activin A, or overexpression of GATA-6 rescue cardiogenesis. Therefore, TAp63 acts in a non-cell-autonomous manner by modulating expression of endodermal factors. Our findings uncover a critical role for p63 in cardiogenesis that could be related to human heart disease.

El diagnóstico ortodóncico requiere un examen minucioso de los tejidos de soporte periodontal; alteraciones como dehiscencias, fenestraciones y otros defectos óseos deberían ser incluidos tanto dentro del diagnóstico como dentro del plan de tratamiento.El propósito de este estudio fue investigar la prevalencia y distribución de defectos óseos en un grupo de potenciales pacientes ortodóncicos no tratados, utilizando Tomografías Computarizadas Cone Beam (TCCB), con el objetivo de evaluar su posible incorporación a los estudios diagnósticos básicos previos al tratamiento ortodóncico.Se analizaron 33 TCCB y un total de 792 dientes en busca de dehiscencias y fenestraciones y posteriormente se midió el grosor del hueso alveolar vestibular y palatino o lingual en el tercio medio radicular de 528 dientes. Los datos obtenidos fueron utilizados para realizar un análisis estadístico descriptivo e inferencial que arrojó los siguientes resultados: un 36% de la muestra presentó algún tipo de defectos óseos; las dehiscencias fueron más comunes que las fenestraciones y fueron más comunes en la arcada inferior, mientras que las fenestraciones lo fueron en la superior; la cortical más gruesa se encontró en la superficie lingual de molares inferiores y la más delgada en la superficie vestibular de caninos inferiores.Las TCCB poseen el potencial de reemplazar las radiografías convencionales y permitir realizar decisiones diagnósticas acertadas en base a la arquitectura ósea de cada paciente, por lo que se recomienda su uso como auxiliar diagnóstico, especialmente en pacientes de alto riesgo.

Recessive dystrophic epidermolysis bullosa (RDEB) is caused by defects in type-VII collagen (C7), a protein encoded by the COL7A1 gene and essential for anchoring fibril formation at the dermal-epidermal junction. Gene therapy of RDEB is based on transplantation of autologous epidermal grafts generated from gene-corrected keratinocytes sustaining C7 deposition at the dermal-epidermal junction. Transfer of the COL7A1 gene is complicated by its very large size and repetitive sequence. This article reports a gene delivery approach based on the Sleeping beauty transposon, which allows integration of a full-length COL7A1 cDNA and secretion of C7 at physiological levels in RDEB keratinocytes without rearrangements or detrimental effects on their clonogenic potential. Skin equivalents derived from gene-corrected RDEB keratinocytes were tested in a validated preclinical model of xenotransplantation on immunodeficient mice, where they showed normal deposition of C7 at the dermal-epidermal junction and restoration of skin adhesion properties. These results indicate the feasibility and efficacy of a transposon-based gene therapy approach to RDEB.

p63 and p73 are highly homologous members of the p53 family that originated by gene duplication at the invertebrate-to-vertebrate transition. We characterize here a previously unreported gene, Transformation-related protein 63 regulated (Tprg), located upstream of the p63 gene in the vertebrate genome, with striking similarity to Transformation related protein 63 regulated like (Tprgl), an uncharacterized gene located upstream of p73, suggesting that p63/Tprg and p73/Tprgl are embedded in a paralogue region originated from a single duplication event. Tprg is predominantly expressed in the epithelial compartment of the skin, more abundantly in differentiated cells. Consistent with its relative higher expression in differentiated keratinocytes, finely tuned p63 expression levels are required for optimal Tprg expression in primary keratinocytes. p63 is essential for Tprg expression as shown in p63-knockdown keratinocytes; however, high levels of p63 result in Tprg downregulation. p63 directly binds in vivo to a canonical p63-binding site in an evolutionary conserved genomic region located in Tprg intron 4. This genomic region is sufficient to function as a p63-inducible enhancer in promoter studies. Thus, we demonstrate that the Tprg gene is predominantly expressed in skin, is physically associated with the p63 gene during evolution, and directly regulated by p63 through a long-distance enhancer located within the Tprg locus.

Summary: Laminin 332-deficient junctional epidermolysis bullosa (JEB) is a severe genetic skin disease. JEB is marked by epidermal stem cell depletion, the origin of which is unknown. We show that dysregulation of the YAP and TAZ pathway underpins such stem cell depletion. Laminin 332-mediated YAP activity sustains human epidermal stem cells, detected as holoclones. Ablation of YAP selectively depletes holoclones, while enforced YAP blocks conversion of stem cells into progenitors and indefinitely extends the keratinocyte lifespan. YAP is dramatically decreased in JEB keratinocytes, which contain only phosphorylated, inactive YAP. In normal keratinocytes, laminin 332 and α6β4 ablation abolish YAP activity and recapitulate the JEB phenotype. In JEB keratinocytes, laminin 332-gene therapy rescues YAP activity and epidermal stem cells in vitro and in vivo. In JEB cells, enforced YAP recapitulates laminin 332-gene therapy, thus uncoupling adhesion from proliferation in epidermal stem cells. This work has important clinical implication for ex vivo gene therapy of JEB. : Gene therapy of junctional epidermolysis bullosa is hampered by the epidermal stem cell loss marking this disease. De Rosa et al. find that YAP dysregulation underpins such loss, which is recapitulated by laminin 332 and α6β4 integrin ablation. Combined cell and gene therapy rescues adhesion, YAP function, and stem cells. Keywords: epidermal stem cells, epidermolysis bullosa, YAP, cell and gene therapy

Contains fulltext : 118008.pdf (Publisher’s version ) (Open Access) Ankyloblepharon, ectodermal defects, cleft lip/palate (AEC) syndrome is a rare autosomal dominant disorder caused by mutations in the p63 gene, essential for embryonic development of stratified epithelia. The most severe cutaneous manifestation of this disorder is the long-lasting skin fragility associated with severe skin erosions after birth. Using a knock-in mouse model for AEC syndrome, we found that skin fragility was associated with microscopic blistering between the basal and suprabasal compartments of the epidermis and reduced desmosomal contacts. Expression of desmosomal cadherins and desmoplakin was strongly reduced in AEC mutant keratinocytes and in newborn epidermis. A similar impairment in desmosome gene expression was observed in human keratinocytes isolated from AEC patients, in p63-depleted keratinocytes and in p63 null embryonic skin, indicating that p63 mutations causative of AEC syndrome have a dominant-negative effect on the wild-type p63 protein. Among the desmosomal components, desmocollin 3, desmoplakin and desmoglein 1 were the most significantly reduced by mutant p63 both at the RNA and protein levels. Chromatin immunoprecipitation experiments and transactivation assays revealed that p63 controls these genes at the transcriptional level. Consistent with reduced desmosome function, AEC mutant and p63-deficient keratinocytes had an impaired ability to withstand mechanical stress, which was alleviated by epidermal growth factor receptor inhibitors known to stabilize desmosomes. Our study reveals that p63 is a crucial regulator of a subset of desmosomal genes and that this function is impaired in AEC syndrome. Reduced mechanical strength resulting from p63 mutations can be alleviated pharmacologically by increasing desmosome adhesion with possible therapeutic implications.

p63, a p53 family member, is highly expressed in the basal proliferative compartment of the epidermis and its expression has been correlated with the growth ability and regenerative capacity of keratinocytes. In this study we report a mechanism through which p63 maintains cell cycle progression by directly repressing miR-34a and miR-34c. In the absence of p63, increased levels of miR-34a and miR-34c were observed in primary keratinocytes and in embryonic skin, with concomitant G1-phase arrest and inhibition of the cell cycle regulators cyclin D1 and cyclin-dependent kinase 4 (Cdk4). p63 directly bound to p53-consensus sites in both miR-34a and miR-34c regulatory regions and inhibited their activity. Concomitant downregulation of miR-34a and miR-34c substantially restored cell cycle progression and expression of cyclin D1 and Cdk4. Our data indicate that specific miR-34 family members have a significant role downstream of p63 in controlling epidermal cell proliferation.

p63, a p53 family member, plays an essential role in epidermal development by regulating its transcriptional program. Here we report a previously uncovered role of p63 in controlling bone morphogenetic protein (BMP) signaling, which is required for maintaining low expression levels of several non-epidermal genes. p63 represses transcription of the inhibitory Smad7 and activates Bmp7, thereby sustaining BMP signaling. In the absence of p63, compromised BMP signaling leads to inappropriate non-epidermal gene expression in postnatal mouse keratinocytes and in embryonic epidermis. Reactivation of BMP signaling by Smad7 knockdown and/or, to a lesser extent, by BMP treatment suppresses expression of non-epidermal genes in the absence of p63. Canonical BMP/Smad signaling is essential for control of non-epidermal genes as use of a specific inhibitor, or simultaneous knockdown of Smad1 and Smad5 counteract suppression of non-epidermal genes. Our data indicate that p63 prevents ectopic expression of non-epidermal genes by a mechanism involving Smad7 repression and, to a lesser extent, Bmp7 induction, with consequent enhancement of BMP/Smad signaling.

Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome, which is characterized by cleft palate and severe defects of the skin, is an autosomal dominant disorder caused by mutations in the gene encoding transcription factor p63. Here, we report the generation of a knock-in mouse model for AEC syndrome (p63(+/L514F) ) that recapitulates the human disorder. The AEC mutation exerts a selective dominant-negative function on wild-type p63 by affecting progenitor cell expansion during ectodermal development leading to a defective epidermal stem cell compartment. These phenotypes are associated with impairment of fibroblast growth factor (FGF) signalling resulting from reduced expression of Fgfr2 and Fgfr3, direct p63 target genes. In parallel, a defective stem cell compartment is observed in humans affected by AEC syndrome and in Fgfr2b(-/-) mice. Restoring Fgfr2b expression in p63(+/L514F) epithelial cells by treatment with FGF7 reactivates downstream mitogen-activated protein kinase signalling and cell proliferation. These findings establish a functional link between FGF signalling and p63 in the expansion of epithelial progenitor cells and provide mechanistic insights into the pathogenesis of AEC syndrome.

It has been unclear whether a uniform group of stem cells gives rise to most cells in the epidermis. A study reveals the presence of at least two stem-cell populations that have different proliferative abilities. See Article p.257 Skin epidermis consists of a basal layer of proliferative cells and several suprabasal layers of terminally differentiated cells that are progressively enucleated and shed from the skin surface. The cells that maintain this important barrier to infection and injury are generated in the interfollicular epidermis, but whether this involves a single group of stem cells or multiple populations is controversial. Cedric Blanpain and colleagues use lineage tracing and mathematical modelling to show that there are two classes of stem cell in mouse tail skin: a previously reported population of committed progenitors, and slow-cycling stem cells that divide asymmetrically only about four to six times a year. During homeostasis, asymmetric divisions of slow-cycling and committed progenitors give rise to transient amplifying cells and differentiated cells, respectively. But during wound healing, the slow-cycling stem cells make a significantly larger and more sustained contribution to tissue repair and regeneration.

Inherited epidermolysis bullosa (EB) is a family of rare genetic skin disorders characterized by structural and mechanical fragility of skin and mucosal membranes. The main feature of EB is the presence of recurrent skin blistering or erosions, which have a profound impact in the quality of life of EB patients and, in the most severe forms, cause early lethality. During the past two decades, it became possible to identify mutations in genes responsible for different types of EB and characterize the abnormalities of the related proteins. Nowadays, there is no cure for EB; all the treatments are palliative and focused on the relief of the devastating EB clinical picture. Recent advancements in molecular biology, stem cell biology and regenerative medicine have fostered new therapeutic approaches for EB. This review is focused on recent developments in gene therapy, protein replacement and cell-based therapy for EB, all aimed at finding a cure for this devastating disease.