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Relapsing-remitting (RR) Multiple Sclerosis (MS) is the most common form of the disease; RRMS patients can maintain their clinical phenotype throughout life or can develop a secondary progressive (SP) course over time. We investigated whether circulating miRNAs can predict RR-to-SPMS conversion. A serum miRNAs profile was initially analyzed in a cross-sectional study by qPCR in 16 patients (8 RRMS and 8 SPMS) (Discovery cohort). Three miRNAs, i.e. miR-34a-5p, miR-103a-3p and miR-376a-3p, were significantly up-regulated in SPMS compared to RRMS patients (p < 0.0 5). Serum concentration of the same miRNAs was subsequently analyzed in a retrospective study by ddPCR at baseline in 69 RRMS patients who did (N = 36 cSPMS) or did not (N = 33) convert into SPMS over a 10-year observation period (Study cohort). The results showed that these miRNAs were significantly increased at baseline only in those RRMS patients who converted to SPMS over time. miR-34a-5p and miR-376a-3p alone were significantly increased in cSPMS sera at the end of the 10-years period too. Serum concentration of miR-34a-5p, miR-103a-3p and miR-376a-3p is increased in RRMS patients several years before their conversion to SPMS. These miRNAs might be useful biomarkers to predict the conversion from RRMS to SPMS., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The incidence of Alzheimer's disease (AD)-the most frequent cause of dementia-is expected to increase as life expectancies rise across the globe. While sex-based differences in AD have previously been described, there remain uncertainties regarding any association between sex and disease-associated molecular mechanisms. Studying sex-specific expression profiles of regulatory factors such as microRNAs (miRNAs) could contribute to more accurate disease diagnosis and treatment., Methods: A systematic review identified six studies of microRNA expression in AD patients that incorporated information regarding the biological sex of samples in the Gene Expression Omnibus repository. A differential microRNA expression analysis was performed, considering disease status and patient sex. Subsequently, results were integrated within a meta-analysis methodology, with a functional enrichment of meta-analysis results establishing an association between altered miRNA expression and relevant Gene Ontology terms., Results: Meta-analyses of miRNA expression profiles in blood samples revealed the alteration of sixteen miRNAs in female and 22 miRNAs in male AD patients. We discovered nine miRNAs commonly overexpressed in both sexes, suggesting a shared miRNA dysregulation profile. Functional enrichment results based on miRNA profiles revealed sex-based differences in biological processes; most affected processes related to ubiquitination, regulation of different kinase activities, and apoptotic processes in males, but RNA splicing and translation in females. Meta-analyses of miRNA expression profiles in brain samples revealed the alteration of six miRNAs in female and four miRNAs in male AD patients. We observed a single underexpressed miRNA in female and male AD patients (hsa-miR-767-5p); however, the functional enrichment analysis for brain samples did not reveal any specifically affected biological process., Conclusions: Sex-specific meta-analyses supported the detection of differentially expressed miRNAs in female and male AD patients, highlighting the relevance of sex-based information in biomedical data. Further studies on miRNA regulation in AD patients should meet the criteria for comparability and standardization of information., (© 2024. The Author(s).)

The etiology of Parkinson's disease (PD) is poorly understood, and is strongly suspected to include both genetic and environmental factors. In this context, it is essential to investigate possible biomarkers for both prognostic and diagnostic purposes. Several studies reported dysregulated microRNA expression in neurodegenerative disorders, including PD. Using ddPCR, we investigated the concentrations of miR-7-1-5p, miR-499-3p, miR-223-3p and miR-223-5p-miRNAs involved in the α-synuclein pathway and in inflammation-in the serum and serum-isolated exosomes of 45 PD patients and 49 age- and sex-matched healthy controls (HC). While miR-499-3p and miR-223-5p showed no differences (1), serum concentration of miR-7-1-5p was significantly increased ( p = 0.0007 vs. HC) and (2) miR-223-3p serum ( p = 0.0006) and exosome ( p = 0.0002) concentrations were significantly increased. ROC curve analysis showed that miR-223-3p and miR-7-1-5p serum concentration discriminates between PD and HC ( p = 0.0001, in both cases). Notably, in PD patients, both miR-223-3p serum ( p = 0.0008) and exosome ( p = 0.006) concentrations correlated with levodopa equivalent daily dosage (LEDD). Finally, serum α-synuclein was increased in PD patients compared to HC ( p = 0.025), and in patients correlated with serum miR-7-1-5p in ( p = 0.05). Our results suggest that both miR-7-1-5p and miR-223-3p, distinguishing PD from HC, have the potential to be useful and non-invasive biomarkers in Parkinson's disease.

Background: Frailty, defined as physical performance impairment, is a common condition in older adults and can anticipate the development of sarcopenia, a geriatric syndrome characterized by loss of muscle strength and mass. microRNAs (miRNAs) are short molecules of RNA endowed with the ability to modulate gene expression; miRNAs are present in serum and are considered potential biomarkers for several diseases. Serum concentration of miR-451a, miR-93-5p, miR-155-5p, miR-421-3p, miR-425-5p, miR-495-3p and miR-744-5p was recently shown to be altered in sarcopenic patients., Methods: We verified if a particular miRNAs pattern could be detected in frailty as well by analyzing these molecules in 50 frail and 136 robust subjects. Additionally, a subgroup of these subjects (15 frail and 30 robust) underwent a 12-week program based on a multicomponent exercise protocol (VIVIFRAIL) consisting of resistance training, gait retraining, and balance training. After the program, serum miRNAs concentration was measured again, to verify whether the physical activity had an effect on their concentration. Moreover, clinical characteristics and indicators of physical performance of all subjects were compared before and after intervention to verify the effect of the VIVIFRAIL program., Results: At the end of the multicomponent exercise program, Short Physical Performance Battery (SPPB) score as well right and left handgrip (p < 0.05) were significantly increased in frail subjects; right and left handgrip significantly were increased also in robust subjects (p < 0.05). Interestingly, the variation of SPPB was significantly higher in frail compared to robust subjects (p < 0.0001). Moreover, at the end of the program, in frail compared to robust subjects: miR-451a serum concentration was significantly increased (frail: 6.59 × 10 4 ; 1.12 × 10 4 -2.5 × 10 5 c/ng; robust: 2.31 × 10 4 ; 1.94 × 10 3 -2.01 × 10 5 c/ng) (p < 0.05); and 2) miR-93-5p and miR-495-3p serum concentration was reduced, whereas that of miR-155-5p was significantly increased (p < 0.05 in both cases). Serum concentration of miR-93-5p and miR-495-3p was decreased, and that of miR-155-5p was increased at the end of the program in robust subjects alone, statistical significance being reached for miR-93-5p alone (p = 0.02)., Conclusion: These results suggest that serum miR-451a should be investigated as a potential biomarker for frailty and show that the VIVIFRAIL multicomponent program modulates circulatory miRNAs expression, at least in older adults., (© 2023. The Author(s).)

SNAP-25 protein is a key protein of the SNARE complex that is involved in synaptic vesicles fusion with plasma membranes and neurotransmitter release, playing a fundamental role in neural plasticity. Recently the concentration of three specific miRNAs-miR-27b-3p, miR-181a-5p and miR-23a-3p -was found to be associated with a specific SNAP-25 polymorphism (rs363050). in silico analysis showed that all the three miRNAs target SNAP-25, but the effect of the interaction between these miRNAs and the 3'UTR of SNAP-25 mRNA is currently unknown. For this reason, we verified in vitro whether miR-27b-3p, miR-181a-5p and miR-23a-3p modulate SNAP-25 gene and protein expression. Initial experiments using miRNAs-co-transfected Vero cells and SNAP-25 3'UTR luciferase reporter plasmids showed that miR-181a-5p (p≤0.01) and miR-23a-3p (p<0.05), but not miR-27b-3p, modulate the luciferase signal, indicating that these two miRNAs bind the SNAP-25 3'UTR. Results obtained using human oligodendroglial cell line (MO3.13) transfected with miR-181a-5p or miR-27b-3p confirmed that miR-181a-5p and miR-23a-3p regulate SNAP-25 gene and protein expression. Interestingly, the two miRNAs modulate in an opposite way SNAP-25, as miR-181a-5p significantly increases (p<0.0005), whereas miR-23a-3p decreases (p<0.0005) its expression. These results for the first time describe the ability of miR-181a-5p and miR-23a-3p to modulate SNAP-25 expression, suggesting their possible use as biomarkers or as therapeutical targets for diseases in which SNAP-25 expression is altered., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Agostini et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Sarcopenia is a loss of muscle mass and strength causing disability, morbidity, and mortality in older adults, which is characterized by alterations of the neuromuscular junctions (NMJs). SNAP-25 is essential for the maintenance of NMJ integrity, and the expression of this protein was shown to be modulated by the SNAP-25 rs363050 polymorphism and by a number of miRNAs., Methods: We analysed these parameters in a cohort of sarcopenic patients undergoing structured rehabilitation. The rs363050 genotype frequency distribution was analyzed in 177 sarcopenic patients and 181 healthy controls (HC). The concentration of seven miRNAs (miR-451a, miR-425-5p, miR155-5p, miR-421-3p, miR-495-3p, miR-744-5p and miR-93-5p), identified by mouse brain miRNome analysis to be differentially expressed in wild type compared to SNAP-25 ± heterozygous mice, was analyzed as well by droplet digital PCR (ddPCR) in a subgroup of severe sarcopenic patients undergoing rehabilitation., Results: The SNAP-25 rs363050 AA genotype was significantly more common in sarcopenic patients compared to HC (p c  = 0.01); miR-451a was significantly up-regulated in these patients before rehabilitation. Rehabilitation modified miRNAs expression, as miR-155-5p, miR-421-3p, miR-451a, miR-425-5p, miR-744-5p and miR-93-5p expression was significantly up-regulated (p < 0.01), whereas that of miR-495-3p was significantly down-regulated (p < 0.001) by rehabilitation. Notably, rehabilitation-associated improvement of the muscle-skeletal SPPB score was significantly associated with the reduction of miR-451a expression., Conclusion: These results support the hypothesis of a role for SNAP-25 in sarcopenia and suggest SNAP-25-associated miRNAs as circulatory biomarkers of rehabilitative outcome for sarcopenia., (© 2021. The Author(s).)

The use of Natalizumab in Multiple Sclerosis (MS) can cause the reactivation of the polyomavirus JC (JCPyV); this may result in the development of progressive multifocal leukoencephalopathy (PML), a rare and usually lethal disease. JCPyV infection is highly prevalent in worldwide population, but the detection of anti-JCPyV antibodies is not sufficient to identify JCPyV infection, as PML can develop even in patients with negative JCPyV serology. Better comprehension of the JCPyV biology could allow a better understanding of JCPyV infection and reactivation, possibly reducing the risk of developing PML. Here, we investigated whether JCPyV miR-J1-5p-a miRNA that down-regulates the early phase viral protein T-antigen and promotes viral latency-could be detected and quantified by digital droplet PCR (ddPCR) in urine of 25 Natalizumab-treated MS patients. A 24-month study was designed: baseline, before the first dose of Natalizumab, and after 1 (T1), 12 (T12) and 24 months (T24) of therapy. miR-J1-5p was detected in urine of 7/25 MS patients (28%); detection was possible in three cases at T24, in two cases at T12, in one case at T1 and T12, and in the last case at baseline and T1. Two of these patients were seronegative for JCPyV Ab, and viral DNA was never found in either urine or blood. To note, only in one case miR-J1-5p was detected before initiation of Natalizumab. These results suggest that the measurement of miR-J1-5p in urine, could be a biomarker to monitor JCPyV infection and to better identify the possible risk of developing PML in Natalizumab-treated MS patients.

Polyomavirus JC (JCPyV) is a ubiquitous human neurotropic virus that can cause progressive multifocal leukoencephalopathy (PML), sometimes as a consequence of drug treatment for disabling diseases, including Multiple Sclerosis. JCPyV expresses microRNAs (miRNAs), and in particular miR-J1-5p, but at now we have limited knowledge regarding this aspect. In the present study the expression of JCPyV miR-J1-5p was measured in infected COS-7, to verify if and when this miRNA is expressed in a cell model of JCPyV-MAD-4 strain infection. Results showed that miR-J1-5p expression was relatively constant inside the cells from 11 days to 35 days after infection (mean: 4.13 × 10 5 copies/μg), and became measurable in supernatants 18 days after infection (mean: 7.20 × 10 4 copies/μl). miR-J1-5p expression in supernatants peaked (3.76 × 10 5 copies/μl) 25 days after infection and started to decrease 32 days after infection (7.20 × 10 4 copies/μl). These data show that COS-7 cells, already used as model for JCPyV replication cycle, can be also utilized to study JCPyV miRNAs expression, potentially opening new research avenues for diseases in which current therapeutic approaches could result in severe adverse effects (e.g. Natalizumab-associated JCPyV reactivation in Multiple Sclerosis patients). In these situations monitoring of miR-J1-5p may shed light on the mechanisms of virus reactivation and may help the clarification of the mechanisms responsible for such severe side effects.

MiR-223-3p is involved in the regulation of a broad range of cellular processes and in many types of pathological processes as cancer, autoimmune and inflammatory diseases. MiR-223-3p has been indicated as negative regulator of NLRP3 protein, a key protein of inflammasome. The chronic inflammasome activation, an underlying feature of neurodegenerative disorders, is induced by misfolded protein aggregates, including amyloid-beta and alpha-synuclein, resulting in pro-inflammatory cytokines secretion and propagating of neuroinflammation. The aim of the study was to analyze whether circulatory miR-223-3p could be used as biomarker in neurodegeneration and to clarify its possible relationship with inflammasome activation. miR-223-3p concentration was evaluated in serum of Alzheimer's (AD) and Parkinson's disease (PD) or mild cognitive impairment (MCI) patients and healthy controls (HC). Compared to HC, miR-223-3p serum concentration was reduced in MCI and AD, but up-regulated in PD (p < 0.0001), and it decreased progressively from MCI to moderate (p < 0.0001) to severe AD (p = 0.0016). Receiver operating characteristic analysis showed that miR-223-3p concentration discriminates between AD, PD and MCI vs. HC, as well as between AD and PD. miR-223-3p serum concentration discriminates between AD/MCI and PD, suggesting that this molecule could be a potential non-invasive biomarker for differential diagnosis and prognosis of these neurodegenerative conditions.

Here we describe a simple approach for the simultaneous detection of multiple microRNAs (miRNAs) using a single nanostructured reagent as surface plasmon resonance imaging (SPRi) enhancer and without using enzymatic reactions, sequence specific enhancers or multiple enhancing steps as normally reported in similar studies. The strategy involves the preparation and optimisation of neutravidin-coated gold nanospheres (nGNSs) functionalised with a previously biotinylated antibody (Ab) against DNA/RNA hybrids. The Ab guarantees the recognition of any miRNA sequence adsorbed on a surface properly functionalised with different DNA probes; at the same time, gold nanoparticles permit to detect this interaction, thus producing enough SPRi signal even at a low ligand concentration. After a careful optimisation of the nanoenhancer and after its characterisation, the final assay allowed the simultaneous detection of four miRNAs with a limit of detection (LOD) of up to 0.5 pM (equal to 275 attomoles in 500 μL) by performing a single enhancing injection. The proposed strategy shows good signal specificity and permits to discriminate wild-type, single- and triple-mutated sequences much better than non-enhanced SPRi. Finally, the method works properly in complex samples (total RNA extracted from blood) as demonstrated by the detection of four miRNAs potentially related to multiple sclerosis used as case study. This proof-of-concept study confirms that the approach provides the possibility to detect a theoretically unlimited number of miRNAs using a simple protocol and an easily prepared enhancing reagent, and may further facilitate the development of affordable multiplexing miRNA screening for clinical purposes.

The neural cell adhesion molecule 1 (NCAM1) is a fundamental protein in cell-cell interaction and in cellular developmental processes, and its dysregulation is involved in a number of diseases including multiple sclerosis. Studies in rats suggest that the modulation of NCAM1 expression is regulated by miRNA-572, but no data are available confirming such interaction in the human system. We analyzed whether this is the case using a human oligodendroglial cell line (MO3.13). MO3.13 cells were transfected with miRNA-572 mimic and inhibitor separately; NCAM1 mRNA and protein expression levels were analyzed at different time points after transfection. Results indicated that NCAM1 expression is increased after transfection with miRNA-572 inhibitor, whereas it is decreased after transfection with the mimic (p < 0.005). The interaction between NCAM1 and miRNA-572 was subsequently confirmed in a Vero cell line that does not express NCAM1, by luciferase assay after transfection with NCAM1. These results confirm that miRNA-572 regulates NCAM1 and for the first time demonstrate that this interaction regulates NCAM1 expression in human cells. Data herein also support the hypothesis that miRNA-572 is involved in diseases associated with NCAM1 deregulation, suggesting its possible use as a biomarker in these diseases.

Background: Demyelination and failure of remyelination are core mechanisms in the pathogenesis of multiple sclerosis (MS); the factor(s) modulating these processes are still mostly unknown. MicroRNA 572 (miR-572) is deregulated in MS and is suggested to targets neural cell adhesion molecule (NCAM), a glycoprotein involved in CNS reparative mechanisms. The aim of this study is to analyze miR-572 in patients with different clinical phenotypes of MS., Methods: qPCR quantification of miR-572 isolated from serum was performed in 16 primary progressive (PP), 15 secondary progressive (SP), 31 relapsing remitting (RR) MS patients and 15 sex-and age-matched healthy controls., Results: miR-572 expression was reduced overall in MS patients (p < 0.05) compared to HC; this miRNA was significantly upregulated in SPMS and in RRMS during disease relapse, whereas it was downregulated in PPMS and in quiescent phases of RRMS. miR-572 expression correlated with EDSS scores (RSp = 0.491; p < 0.05) independently of the clinical phenotype. The results suggest that this miRNA might be a tool that helps distinguishing between PPMS and SPMS and between relapsing and remitting phases in RRMS., Conclusions: Evaluation of miR-572 may serve as a non-invasive biomarker for remyelination.