MicroRNAs associated with the pathogenesis of multiple sclerosis

Unveiling the Potential of Cannabinoids in Multiple Sclerosis and the Dawn of Nano-Cannabinoid Medicine

Multiple sclerosis is the predominant autoimmune disorder affecting the central nervous system in adolescents and adults. Specific treatments are categorized as disease-modifying, whereas others are symptomatic treatments to alleviate painful symptoms. Currently, no singular conventional therapy is universally effective for all patients across all stages of the illness. Nevertheless, cannabinoids exhibit significant promise in their capacity for neuroprotection, anti-inflammation, and immunosuppression. This review will examine the traditional treatment for multiple sclerosis, the increasing interest in using cannabis as a treatment method, its role in protecting the nervous system and regulating the immune system, commercially available therapeutic cannabinoids, and the emerging use of cannabis in nanomedicine. In conclusion, cannabinoids exhibit potential as a disease-modifying treatment rather than merely symptomatic relief. However, further research is necessary to unveil their role and establish the safety and advancements in nano-cannabinoid medicine, offering the potential for reduced toxicity and fewer adverse effects, thereby maximizing the benefits of cannabinoids.

MicroRNAs are dysregulated in peripheral blood mononuclear cells in multiple sclerosis and correlate with T cell mediators

T cell mediators and microRNAs are involved in the pathogenesis of multiple sclerosis (MS), but their interaction largely remains undetermined. We investigated by RT-qPCR the dysregulation of microRNAs in peripheral blood mononuclear cells of MS patients versus healthy controls, according to radiological disease activity or treatment. Several microRNAs correlated positively/negatively with IL21/FOXP3 mRNA expression, but not with serum neurofilament light chain levels. Cytokine expression is conceivably balanced by several regulators, whereas microRNAs possibly target upstream transcription factors rather than directly cytokine mRNAs. Functional studies are needed to investigate their interaction, notably for the predicted targeting of FOXP3 by miR-34c-5p.

The role of miRNAs in multiple sclerosis pathogenesis, diagnosis, and therapeutic resistance

In recent years, microRNAs (miRNAs) have gained increased attention from researchers around the globe. Although it is twenty nucleotides long, it can modulate several gene targets simultaneously. Their mal expression is a signature of various pathologies, and they provide the foundation to elucidate the molecular mechanisms of each pathology. Among the debilitating central nervous system (CNS) disorders with a growing prevalence globally is the multiple sclerosis (MS). Moreover, the diagnosis of MS is challenging due to the lack of disease-specific biomarkers, and the diagnosis mainly depends on ruling out other disabilities. MS could adversely affect patients' lives through its progression, and only symptomatic treatments are available as therapeutic options, but an exact cure is yet unavailable. Consequently, this review hopes to further the study of the biological features of miRNAs in MS and explore their potential as a therapeutic target.

Multiplex Analysis of Cerebrospinal Fluid and Serum Exosomes MicroRNAs of Untreated Relapsing Remitting Multiple Sclerosis (RRMS) and Proposing Noninvasive Diagnostic Biomarkers

Exosomal microRNAs (miRNAs) are emerging diagnostic biomarkers for neurodegenerative diseases. In this study, we aimed to detect relapsing-remitting multiple sclerosis (RRMS)-specific miRNAs in cerebrospinal fluid (CSF) and serum exosomes with diagnostic potential. One ml of CSF and serum sample were collected from each of the 30 untreated RRMS patients and healthy controls (HCs). A panel of 18 miRNAs affecting inflammatory responses was applied, and qRT-PCR was conducted to detect differentially expressed exosomal miRNAs in CSF and serum of RRMS patients. We identified that 17 out of 18 miRNAs displayed different patterns in RRMS patients compared to HCs. Let-7 g-5p, miR-18a-5p, miR-145-5p, and miR-374a-5p with dual pro-inflammatory and anti-inflammatory actions and miR-150-5p and miR-342-3p with anti-inflammatory action were significantly upregulated in both CSF and serum-derived exosomes of RRMS patients compared to corresponding HCs. Additionally, anti-inflammatory miR-132-5p and pro-inflammatory miR-320a-5p were significantly downregulated in both CSF and serum-derived exosomes of RRMS patients compared to HCs. Ten of 18 miRNAs were differentially expressed in CSF and serum exosomes of the patients. Furthermore, miR-15a-5p, miR-19b-3p, and miR-432-5p were upregulated, and miR-17-5p was downregulated only in CSF exosomes. Interestingly, U6 housekeeping gene was differentially expressed in CSF and serum exosomes, in both RRMS and HCs. As the first report describing CSF exosomal miRNAs expression profile compared to that of serum exosomes in untreated RRMS patients, we showed that CSF and serum exosomes are not identical in terms of biological compounds and display different patterns in miRNAs and U6 expression.

Whole blood miRNAs in relapsing MS patients treated with dimethyl fumarate in the phase 4 TREMEND trial

We investigated the impact of dimethyl fumarate (DMF), an oral therapy for relapsing multiple sclerosis (MS), on blood microRNA (miRNA) signatures and neurofilament light (NFL) levels. DMF normalized miR-660-5p and modulated various miRNAs associated with the NF-kB pathway. These alterations reached a peak 4-7 months after treatment. Notably, particular miRNAs correlated with high or low NFL levels, implying their potential role as markers of treatment efficacy. Our findings broaden the understanding of DMF's immunomodulatory effects and may aid in predicting treatment responses.

Exploring the impact of miR-128 in inflammatory diseases: A comprehensive study on autoimmune diseases

microRNAs (miRNAs) play a crucial role in various biological processes, including immune system regulation, such as cell proliferation, tolerance (central and peripheral), and T helper cell development. Dysregulation of miRNA expression and activity can disrupt immune responses and increase susceptibility to neuroimmune disorders. Conversely, miRNAs have been shown to have a protective role in modulating immune responses and preventing autoimmunity. Specifically, reducing the expression of miRNA-128 (miR-128) in an Alzheimer's disease (AD) mouse model has been found to improve cognitive deficits and reduce neuropathology. This comprehensive review focuses on the significance of miR-128 in the pathogenesis of neuroautoimmune disorders, including multiple sclerosis (MS), AD, Parkinson's disease (PD), Huntington's disease (HD), epilepsy, as well as other immune-mediated diseases such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). Additionally, we present compelling evidence supporting the potential use of miR-128 as a diagnostic or therapeutic biomarker for neuroimmune disorders. Collectively, the available literature suggests that targeting miR-128 could be a promising strategy to alleviate the behavioral symptoms associated with neuroimmune diseases. Furthermore, further research in this area may uncover new insights into the molecular mechanisms underlying these disorders and potentially lead to the development of novel therapeutic approaches.

Extracellular vesicles as contributors in the pathogenesis of multiple sclerosis

Extracellular vesicles (EVs) are a heterogeneous family of extracellular structures bounded by a phospholipid bilayer, released by all cell types in various biological fluids, such as blood and cerebrospinal fluid (CSF), playing important roles in intercellular communication, both locally and systemically. EVs carry and deliver a variety of bioactive molecules (proteins, nucleic acids, lipids and metabolites), conferring epigenetic and phenotypic changes to the recipient cells and thus resulting as important mediators of both homeostasis and pathogenesis. In neurological diseases, such as multiple sclerosis (MS), the EV ability to cross Blood-Brain Barrier (BBB), moving from central nervous system (CNS) to the peripheral circulation and vice versa, has increased the interest in EV study in the neurological field. In the present review, we will provide an overview of the recent advances made in understanding the pathogenic role of EVs regarding the immune response, the BBB dysfunction and the CNS inflammatory processes.

Evaluation of the expressed miR-129 and miR-549a in patients with multiple sclerosis

Background:

The expression of microRNAs (miRNAs) as circulating biomarkers has been underlined in multiple sclerosis (MS) in the last decade. Due to the presence of a possible relationship between expressed miRNAs and heterogeneous appearances of the pathological processes in MS, the present study attempts to evaluate the expression of miR-129 and miR-549a in patients with MS in comparison with healthy control (HC) group.

Materials and Methods:

Peripheral blood mononuclear cells were separated from fifty patients with MS (subtypes including relapsing–remitting MS and secondary progressive MS) in the Kashani Hospital, Isfahan, Iran, and fifty people as HC group. After RNA extraction and complementary DNA synthesis, the expression of miR-129 and miR-549a was evaluated in patients with MS in comparison with the HC group using a quantitative real-time polymerase chain reaction assay. The data were analyzed using the Kolmogorov–Smirnov and Mann–Whitney tests. Spearman's correlation coefficient was used to examine the relationship between miR-129 and miR-549a with age.

Results:

The results showed that the expression of miR-129 and miR-549a was not significant in patients with MS in comparison with the HC group. Furthermore, the relationship between such miRNAs and age and gender was not significant.

Conclusion:

We suggest the expression of miR-129 and miR-549a as circulating miRNAs in peripheral blood mononuclear cells could not be considered a biomarker for diagnosis and Para clinical.

Non-coding RNAs in the Pathogenesis of Multiple Sclerosis

Multiple sclerosis (MS) is an early onset chronic neurological condition in adults characterized by inflammation, demyelination, gliosis, and axonal loss in the central nervous system. The pathological cause of MS is complex and includes both genetic and environmental factors. Non-protein-coding RNAs (ncRNAs), specifically miRNAs and lncRNAs, are important regulators of various biological processes. Over the past decade, many studies have investigated both miRNAs and lncRNAs in patients with MS. Since then, insightful knowledge has been gained in this field. Here, we review the role of miRNAs and lncRNAs in MS pathogenesis and discuss their implications for diagnosis and treatment.

MiR-142-3p regulates synaptopathy-driven disease progression in multiple sclerosis

Aim

We recently proposed miR‐142‐3p as a molecular player in inflammatory synaptopathy, a new pathogenic hallmark of multiple sclerosis (MS) and of its mouse model experimental autoimmune encephalomyelitis (EAE), that leads to neuronal loss independently of demyelination. MiR‐142‐3p seems to be unique among potential biomarker candidates in MS, since it is an inflammatory miRNA playing a dual role in the immune and central nervous systems. Here, we aimed to verify the impact of miR‐142‐3p circulating in the cerebrospinal fluid (CSF) of MS patients on clinical parameters, neuronal excitability and its potential interaction with disease modifying therapies (DMTs).

Methods and Results

In a cohort of 151 MS patients, we found positive correlations between CSF miR‐142‐3p levels and clinical progression, IL‐1β signalling as well as synaptic excitability measured by transcranial magnetic stimulation. Furthermore, therapy response of patients with ‘low miR‐142‐3p’ to dimethyl fumarate (DMF), an established disease‐modifying treatment (DMT), was superior to that of patients with ‘high miR‐142‐3p’ levels. Accordingly, the EAE clinical course of heterozygous miR‐142 mice was ameliorated by peripheral DMF treatment with a greater impact relative to their wild type littermates. In addition, a central protective effect of this drug was observed following intracerebroventricular and ex vivo acute treatments of EAE wild type mice, showing a rescue of miR‐142‐3p‐dependent glutamatergic alterations. By means of electrophysiology, molecular and biochemical analysis, we suggest miR‐142‐3p as a molecular target of DMF.

Conclusion

MiR‐142‐3p is a novel and potential negative prognostic CSF marker of MS and a promising tool for identifying personalised therapies.

The microRNA let-7b-5p Is Negatively Associated with Inflammation and Disease Severity in Multiple Sclerosis

The identification of microRNAs in biological fluids for diagnosis and prognosis is receiving great attention in the field of multiple sclerosis (MS) research but it is still in its infancy. In the present study, we observed in a large sample of MS patients that let-7b-5p levels in the cerebrospinal fluid (CSF) were highly correlated with a number of microRNAs implicated in MS, as well as with a variety of inflammation-related protein factors, showing specific expression patterns coherent with let-7b-5p-mediated regulation. Additionally, we found that the CSF let-7b-5p levels were significantly reduced in patients with the progressive MS compared to patients with relapsing-remitting MS and were negatively correlated with characteristic hallmark processes of the two phases of the disease. Indeed, in the non-progressive phase, let-7b-5p inversely associated with both central and peripheral inflammation; whereas, in progressive MS, the CSF levels of let-7b-5p negatively correlated with clinical disability at disease onset and after a follow-up period. Overall, our results uncovered, by the means of a multidisciplinary approach and multiple statistical analyses, a new possible pleiotropic action of let-7b-5p in MS, with potential utility as a biomarker of MS course.

A literature review of biosensors for multiple sclerosis: Towards personalized medicine and point-of-care testing

Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the central nervous system that leads to severe motor and sensory deficits in patients. Although some biomolecules in serum or cerebrospinal fluid have been suggested as biomarkers for MS diagnosis, following disease activity and monitoring treatment response, most of these potential biomarkers are not currently in clinical use and available for all patients. The reasons behind this are generally related to insufficient robustness of biomarker or technical difficulties, high prices, and requirements for technical personnel for their detection. Point-of-care testing (POCT) is an emerging field of healthcare that can be applied at the hospital as well as at home without the need for a centralized laboratory. Biosensor devices offer a convenient means for POCT. A biosensor is a compact analytical device that uses a bioreceptor, such as an antibody, enzyme, or oligonucleotide, to capture the analyte of interest. The interaction between the analyte and the bioreceptor is sensed and transduced into a suitable signal by the signal transducer. The advantages of using a biosensor for detecting the biomolecule of interest include speed, simplicity, accuracy, relatively lower cost, and lack of requirements for highly qualified personnel to perform the testing. Owing to these advantages and with the help of innovations in biosensor development technologies, there has been a great interest in developing biosensor devices for MS in recent years. Hence, the purpose of this review was to provide researchers with an up-to-date summary of the literature as well as to highlight the challenges and opportunities in this translational research field. In addition, because this is a highly interdisciplinary field of study, potentially concerning MS specialists, neurologists, biomedical researchers, and engineers, another aim of this review was to bridge the gap between these disciplines.

Upregulated serum miR-128-3p in progressive and relapse-free multiple sclerosis patients

BACKGROUND

Circulating microRNAs have emerged as novel multiple sclerosis (MS) biomarkers.

AIMS

To assess the association between candidate miR expression in serum samples of patients with MS and the disease course.

METHODS

Serum levels of ten microRNAs (ie, miR-199, miR-128-3p, miR-20a-5p, miR-27a-3p, miR-15b-5p, miR-325, miR-92a1-5p, miR-223-5p, miR-22-5p, and miR-23a-5p) were measured in 74 MS cases and 17 non-MS controls consecutively enrolled at Verona University Hospital. The association of microRNA expression with patients' clinical and MRI features was analyzed. Candidate microRNAs were detected by real-time PCR and expressed as ratio of each microRNA level to a normalizer.

RESULTS

Serum miR-128-3p levels were higher in progressive than relapsing MS (median ratio 2.86 vs 0.73, P = .036). In addition, miR-128-3p was upregulated in patients without relapses after sample collection compared to cases who relapsed (1.64 vs 0.82; P = .014). miR-128-3p levels and relapse rate were inversely correlated (r = -.44, P = .008).

CONCLUSIONS

Serum levels of mir-128-3p could be related to biological mechanisms underlying MS activity and progression.

A hypothesis-generating scoping review of miRs identified in both multiple sclerosis and dementia, their protein targets, and miR signaling pathways

Cognitive impairment (CI) is a frequent complication affecting people with multiple sclerosis (MS). The causes of CI in MS are not fully understood. Besides MRI measures, few other biomarkers exist to help us predict the development of CI and understand its biology. MicroRNAs (miRs) are relatively stable, non-coding RNA molecules about 22 nucleotides in length that can serve as biomarkers and possible therapeutic targets in several autoimmune and neurodegenerative diseases, including the dementias. In this review, we identify dysregulated miRs in MS that overlap with dysregulated miRs in cognitive disorders and dementia and explore how these overlapping miRs play a role in CI in MS. MiR-15, miR-21, miR-128, miR-132, miR-138, miR-142, miR-146a, miR-155, miR-181, miR-572, and let-7 are known to contribute to various forms of dementia and show abnormal expression in MS. These overlapping miRs are involved in pathways related to apoptosis, neuroinflammation, glutamate toxicity, astrocyte activation, microglial burst activity, synaptic dysfunction, and remyelination. The mechanisms of action suggest that these miRs may be related to CI in MS. From our review, we also delineated miRs that could be neuroprotective in MS, namely miR-23a, miR-219, miR-214, and miR-22. Further studies can help clarify if these miRs are responsible for CI in MS, leading to potential therapeutic targets.

Colorectal cancer-derived exosomal miR-106b-3p promotes metastasis by down-regulating DLC-1 expression

Cancer-derived exosomal miRNAs play an important role in the development of metastasis, but the effects and underlying mechanisms remain unclear. In the present study, we investigated the miRNA expression profiles of 5 paired serum exosomal samples from metastatic colorectal cancer (mCRC) and non-mCRC patients via RNA sequencing. After we evaluated the differentially expressed miRNAs in 80 CRC patients, miR-106b-3p was selected as a metastasis-associated miRNA of CRC. We showed that the expression level of serum exosomal miR-106b-3p was significantly higher in CRC patients with metastasis than those without metastasis. Additionally, high serum exosomal miR-106b-3p expression in patients was correlated with a poor prognosis. Coculture of low-metastatic CRC cells with high-metastatic CRC cell-derived exosomes promoted cell migration, invasion, and epithelial-to-mesenchymal transition (EMT), which was caused by the transport and transduction of miR-106b-3p in vitro. Moreover, exosomal miR-106b-3p promoted lung metastasis of CRC cells in vivo. In addition, we demonstrated that miR-106b-3p regulated metastasis by targeting deleted in liver cancer-1 (DLC-1). A negative correlation was also identified between miR-106b-3p and DLC-1 expression in human CRC tumour tissues and in mouse lung metastatic lesions. Collectively, our study indicated that metastasis-associated miR-106b-3p from serum exosomes could be used as a potential prognostic biomarker and therapeutic target for CRC patients.

Protective effect of microRNA-134-3p on multiple sclerosis through inhibiting PRSS57 and promotion of CD34+ cell proliferation in rats

MicroRNAs (miRs) have been extensively studied for their involvement in multiple sclerosis (MS). We investigated the involvement of miR-134-3p on MS. The MS rat model was established, and positive expression of interleukin-17 (IL-17) was detected using the immunohistochemical method while the expression of miR-134-3p and serine protease 57 (PRSS57) was determined by means of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. Second, the miR-134-3p overexpression or short hairpin RNA against PRSS57 was introduced into the CD34⁺ cells to investigate the levels of proliferation and apoptosis-related genes by RT-qPCR and Western blot analysis. In addition, analysis of the targeting relations of miR-134-3p and PRSS57 was conducted using online software and dual-luciferase reporter gene assay. Furthermore, neuronal functions, inflammatory response, proliferation, and apoptosis of CD34⁺ cells were assayed by flow cytometry, enzyme-linked immunosorbent assay, and methyl thiazolyl tetrazolium. IL-17 and PRSS57 expression increased while miR-134-3p expression decreased in the spinal cord from MS rats. miR-134-3p could target PRSS57. miR-134-3p overexpression or PRSS57 silencing enhanced mitochondrial activity of neurons, mitochondrial membrane potential content, CD34⁺ cell proliferation, while decreasing Cyt C content, inflammatory response, and cell apoptosis. Collectively, overexpression of miR-134-3p promotes CD34⁺ cell proliferation via inhibition of PRSS57 in MS, which may serve as a promising target for MS intervention.

MicroRNA Alteration in Developing Rat Oligodendrocyte Precursor Cells Induced by Hypoxia-Ischemia

microRNAs (miRNAs) are involved in the pathogenesis of white matter injury (WMI). However, their roles in developing rat brains under hypoxia-ischemia (HI) insult remain unknown. Here, we examined the expression profiles of miRNAs in oligodendrocyte precursor cells using microarray analysis. We identified 162 miRNAs and only 6 were differentially regulated in HI compared with sham. Next, we used these 6 miRNAs and 525 extensively changed coding genes (fold change absolute: FC(abs) ≥2, p < 0.05) to establish the coexpression network, the result revealed that only 3 miRNAs (miR-142-3p, miR-466b-5p, and miR-146a-5p) have differentially expressed targeted mRNAs. RT-PCR analysis showed that the expression of the miRNAs was consistent with the microarray analysis. Further gene ontology and KEGG pathway analysis of the targets of these 3 miRNAs indicated that they were largely associated with neural activity. Furthermore, we found that 2 of the 3 miRNAs, miR-142-3p, and miR-466b-5p, have the same target gene, Capn6, an antiapoptotic gene that is tightly regulated in the pathogenesis of neurological diseases. Collectively, we have shown that a number of miRNAs change in oligodendrocyte precursor cells in response to HI insult in developing brains, and miR-142-3p/miR-466b-5p/Capn6 pathway might affect the pathogenesis of WMI, providing us new clues for the diagnosis and therapy for WMI.

Animal models for human disease

This chapter introduces some types of animal models which are used for better understanding the disease mechanisms and its treatment. These experimental models fall into two categories: spontaneous models and induced models. Among the diseases, rheumatoid arthritis (RA) as an autoimmune disease was considered. To study the pathogenesis of RA, we explained collagen-induced arthritis as an animal model that reflects a characteristic feature of RA patients. In addition, experimental allergic encephalomyelitis (EAE) as an experimental model for multiple sclerosis (MS) was explained in detail to represent a standard method to investigate in its mechanism, finding the way for the amelioration of this incurable neurological disorder.

MicroRNAs in blood and cerebrospinal fluid as diagnostic biomarkers of multiple sclerosis and to monitor disease progression

Multiple sclerosis is a chronic autoimmune disease of the central nervous system. It is the main cause of non-traumatic neurological disability in young adults. Multiple sclerosis mostly affects people aged 20-50 years; however, it can occur in young children and much older adults. Factors identified in the distribution of MS include age, gender, genetics, environment, and ethnic background. Multiple sclerosis is usually associated with progressive degrees of disability. The disease involves demyelination of axons of the central nervous system and causes brain and spinal cord neuronal loss and atrophy. Diagnosing multiple sclerosis is based on a patient's medical history including symptoms, physical examination, and various tests such as magnetic resonance imaging, cerebrospinal fluid and blood tests, and electrophysiology. The disease course of multiple sclerosis is not well correlated with the biomarkers presently used in clinical practice. Blood-derived biomarkers that can detect and distinguish the different phenotypes in multiple sclerosis may be advantageous in personalized treatment with disease-modifying drugs and to predict response to treatment. The studies reviewed have shown that the expression levels of a large number of miRNAs in peripheral blood, serum, exosomes isolated from serum, and cerebrospinal fluid are altered in multiple sclerosis and can distinguish the disease phenotypes from each other. Further studies are warranted to independently validate these findings so that individual or pairs of miRNAs in serum or cerebrospinal fluid can be used as potential diagnostic markers for adult and pediatric multiple sclerosis and for monitoring disease progression and response to therapy.

Short and Long Term Clinical and Immunologic Follow up after Bone Marrow Mesenchymal Stromal Cell Therapy in Progressive Multiple Sclerosis-A Phase I Study

Bone marrow derived mesenchymal stromal cells (BM-MSCs) have emerged as a possible new therapy for Multiple Sclerosis (MS), however studies regarding efficacy and in vivo immune response have been limited and inconclusive. We conducted a phase I clinical study assessing safety and clinical and peripheral immune responses after MSC therapy in MS. Seven patients with progressive MS were intravenously infused with a single dose of autologous MSC (1–2 × 10⁶ MSCs/kg body weight). The infusions were safe and well tolerated when given during clinical remission. Five out of seven patients completed the follow up of 48 weeks post-infusion. Brain magnetic resonance imaging (MRI) showed the absence of new T2 lesions at 12 weeks in 5/6 patients, while 3/5 had accumulated new T2 lesions at 48 weeks. Patient expanded disability status scales (EDSS) were stable in 6/6 at 12 weeks but declined in 3/5 patients at 48 weeks. Early changes of circulating microRNA levels (2 h) and increased proportion of FOXP3⁺ Tregs were detected at 7 days post-infusion compared to baseline levels. In conclusion, MSC therapy was safe and well tolerated and is associated with possible transient beneficial clinical and peripheral immunotolerogenic effects.

Astrocytes in the Pathogenesis of Multiple Sclerosis: An In Situ MicroRNA Study

Astrocytes are increasingly recognized as active contributors to the disease process in multiple sclerosis (MS), rather than being merely reactive. We investigated the expression of a selected microRNA (miRNA) panel that could contribute both to the injury and to the recovery phases of the disease. Individual astrocytes were laser microdissected from brain sections. We then compared the miRNAs’ expressions in MS and control brain samples at different lesional stages in white versus grey matter regions. In active MS lesions, we found upregulation of ischemia-related miRNAs in white but not grey matter, often with reversion to the normal state in inactive lesions. In contrast to our previous findings on MS macrophages, expression of 2 classical inflammatory-related miRNAs, miRNA-155 and miRNA-146a, was reduced in astrocytes from active and chronic active MS lesions in white and grey matter, suggesting a lesser direct pathogenetic role for these miRNAs in astrocytes. miRNAs within the categories regulating aquaporin4 (-100, -145, -320) and glutamate transport/apoptosis/neuroprotection (-124a, -181a, and -29a) showed some contrasting responses. The regional and lesion-stage differences of expression of these miRNAs indicate the remarkable ability of astrocytes to show a wide range of selective responses in the face of differing insults and phases of resolution.

miRNA contributions to pediatric-onset multiple sclerosis inferred from GWAS

OBJECTIVE

Onset of multiple sclerosis (MS) occurs in childhood for approximately 5% of cases (pediatric MS, or ped-MS). Epigenetic influences are strongly implicated in MS pathogenesis in adults, including the contribution from microRNAs (miRNAs), small noncoding RNAs that affect gene expression by binding target gene mRNAs. Few studies have specifically examined miRNAs in ped-MS, but individuals developing MS at an early age may carry a relatively high burden of genetic risk factors, and miRNA dysregulation may therefore play a larger role in the development of ped-MS than in adult-onset MS. This study aimed to look for evidence of miRNA involvement in ped-MS pathogenesis.

METHODS

GWAS results from 486 ped-MS cases and 1362 controls from the U.S. Pediatric MS Network and Kaiser Permanente Northern California membership were investigated for miRNA-specific signals. First, enrichment of miRNA-target gene network signals was evaluated using MIGWAS software. Second, SNPs in miRNA genes and in target gene binding sites (miR-SNPs) were tested for association with ped-MS, and pathway analysis was performed on associated target genes.

RESULTS

MIGWAS analysis showed that miRNA-target gene signals were enriched in GWAS (P = 0.038) and identified 39 candidate biomarker miRNA-target gene pairs, including immune and neuronal signaling genes. The miR-SNP analysis implicated dysregulation of miRNA binding to target genes in five pathways, mainly involved in immune signaling.

INTERPRETATION

Evidence from GWAS suggests that miRNAs play a role in ped-MS pathogenesis by affecting immune signaling and other pathways. Candidate biomarker miRNA-target gene pairs should be further studied for diagnostic, prognostic, and/or therapeutic utility.

Epstein-Barr Virus and miRNAs: Partners in Crime in the Pathogenesis of Multiple Sclerosis?

MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression post transcriptionally. In healthy individuals, miRNAs contribute to maintaining gene expression homeostasis. However, the level of miRNAs expressed is markedly altered in different diseases, including multiple sclerosis (MS). The impact of such changes is being investigated, and thought to shape the immune system into the inflammatory autoimmune phenotype. Much is yet to be learned about the contribution of miRNAs in the molecular pathology of MS. Epstein-Barr virus (EBV) infection is a major risk factor for the development of MS. EBV encodes more than 40 miRNAs, most of which have been studied in the context of EBV associated cancers. These viral miRNAs regulate genes involved in cell apoptosis, antigen presentation and recognition, as well as B cell transformation. If EBV infection contributes to the pathology of MS, it is plausible that EBV miRNAs may be involved. Unfortunately, there are limited studies addressing how EBV miRNAs are involved in the pathogenesis of MS. This review summarizes what has been reported regarding cellular and viral miRNA profiles in MS and proposes possible interactions between the two in the development of MS.

A genetic variant associated with multiple sclerosis inversely affects the expression of CD58 and microRNA-548ac from the same gene

Genome-wide association studies have identified more than 200 genetic variants to be associated with an increased risk of developing multiple sclerosis (MS). Still, little is known about the causal molecular mechanisms that underlie the genetic contribution to disease susceptibility. In this study, we investigated the role of the single-nucleotide polymorphism (SNP) rs1414273, which is located within the microRNA-548ac stem-loop sequence in the first intron of the CD58 gene. We conducted an expression quantitative trait locus (eQTL) analysis based on public RNA-sequencing and microarray data of blood-derived cells of more than 1000 subjects. Additionally, CD58 transcripts and mature hsa-miR-548ac molecules were measured using real-time PCR in peripheral blood samples of 32 MS patients. Cell culture experiments were performed to evaluate the efficiency of Drosha-mediated stem-loop processing dependent on genotype and to determine the target genes of this underexplored microRNA. Across different global populations and data sets, carriers of the MS risk allele showed reduced CD58 mRNA levels but increased hsa-miR-548ac levels. We provide evidence that the SNP rs1414273 might alter Drosha cleavage activity, thereby provoking partial uncoupling of CD58 gene expression and microRNA-548ac production from the shared primary transcript in immune cells. Moreover, the microRNA was found to regulate genes, which participate in inflammatory processes and in controlling the balance of protein folding and degradation. We thus uncovered new regulatory implications of the MS-associated haplotype of the CD58 gene locus, and we remind that paradoxical findings can be encountered in the analysis of eQTLs upon data aggregation. Our study illustrates that a better understanding of RNA processing events might help to establish the functional nature of genetic variants, which predispose to inflammatory and neurological diseases.

Combined microRNA and mRNA expression analysis in pediatric multiple sclerosis: an integrated approach to uncover novel pathogenic mechanisms of the disease

Multiple sclerosis (MS) is a complex disease of the CNS that usually affects young adults, although 3-5% of cases are diagnosed in childhood and adolescence (hence called pediatric MS, PedMS). Genetic predisposition, among other factors, seems to contribute to the risk of the onset, in pediatric as in adult ages, but few studies have investigated the genetic 'environmentally naïve' load of PedMS. The main goal of this study was to identify circulating markers (miRNAs), target genes (mRNAs) and functional pathways associated with PedMS; we also verified the impact of miRNAs on clinical features, i.e. disability and cognitive performances. The investigation was performed in 19 PedMS and 20 pediatric controls (PCs) using a High-Throughput Next-generation Sequencing (HT-NGS) approach followed by an integrated bioinformatics/biostatistics analysis. Twelve miRNAs were significantly upregulated (let-7a-5p, let-7b-5p, miR-25-3p, miR-125a-5p, miR-942-5p, miR-221-3p, miR-652-3p, miR-182-5p, miR-185-5p, miR-181a-5p, miR-320a, miR-99b-5p) and 1 miRNA was downregulated (miR-148b-3p) in PedMS compared with PCs. The interactions between the significant miRNAs and their targets uncovered predicted genes (i.e. TNFSF13B, TLR2, BACH2, KLF4) related to immunological functions, as well as genes involved in autophagy-related processes (i.e. ATG16L1, SORT1, LAMP2) and ATPase activity (i.e. ABCA1, GPX3). No significant molecular profiles were associated with any PedMS demographic/clinical features. Both miRNAs and mRNA expressions predicted the phenotypes (PedMS-PC) with an accuracy of 92% and 91%, respectively. In our view, this original strategy of contemporary miRNA/mRNA analysis may help to shed light in the genetic background of the disease, suggesting further molecular investigations in novel pathogenic mechanisms.

Increased expression of mir-301a in PBMCs of patients with relapsing-remitting multiple sclerosis is associated with reduced NKRF and PIAS3 expression levels and disease activity

Most of the multiple sclerosis (MS) patients are initially diagnosed with relapsing remitting multiple sclerosis (RRMS). Th17 cells and macrophages have been shown to play critical roles in pathogenesis of MS and initiation of CNS tissue damage. MiR-301a have recently been exposed as an activator of STAT3 in Th17 cells as well as an activator of NF-κB in macrophages by targeting PIAS3 and NKRF correspondingly. However, the possible role of miR-301a in RRMS has not yet been elucidated. Herewith, for the first time, we have studied the expression of miR-301a, NKRF and PIAS3 by quantitative real-time PCR and western blotting method in peripheral blood mononuclear cells (PBMCs) of 71 RRMS patients, including two groups of patients in relapse phase (n = 44) and a group of remitting phase patients (n = 28) in comparison to healthy volunteers (n = 28). In this work, we demonstrate a significant upregulation of miR-301a in relapse phase of MS patients compared to healthy controls and remitting phase patients (P < .05). Our findings also showed a striking decrease of NKRF and PIAS3 expression in relapse phase patients, in contrast to miR-301a and, NF-κB and STAT3 downstream genes (SKA2 and RORc) (P < .05). Subsequently, using luciferase reporter system we confirmed that miR-301a directly targets the mRNA encoding PIAS3 and NKRF proteins. We also showed that miR-301a increasing expression is correlated with down-regulation of PIAS3 and NKRF expression in RRMS patients. Our findings suggest that miR-301a, PIAS3 and NKRF play crucial roles in RRMS and could be considered as promising therapeutic targets.

Noncoding RNAs in multiple sclerosis

Multiple sclerosis (MS), a chronic inflammatory demyelinating disease of the central nervous system, is characterized by axonal degeneration and gliosis. Although the causes of MS remain unknown, gene dysregulation in the central nervous system has been associated with the disease pathogenesis. As such, the various regulators of gene expression may be contributing factors. The noncoding (nc) RNAs have piqued the interest of MS researchers due to their known functions in human physiology and various pathological processes, despite being generally characterized as transcripts without apparent protein-coding capacity. Accumulating evidence has indicated that ncRNAs participate in the regulation of MS by acting as epigenetic factors, especially the long (l) ncRNAs and the micro (mi) RNAs, and they are now recognized as key regulatory molecules in MS. In this review, we summarize the most current studies on the contribution of ncRNAs in MS pathogenic processes and discuss their potential applications in the diagnosis and treatment of MS.

Machine-learning based lipid mediator serum concentration patterns allow identification of multiple sclerosis patients with high accuracy

Based on increasing evidence suggesting that MS pathology involves alterations in bioactive lipid metabolism, the present analysis was aimed at generating a complex serum lipid-biomarker. Using unsupervised machine-learning, implemented as emergent self-organizing maps of neuronal networks, swarm intelligence and Minimum Curvilinear Embedding, a cluster structure was found in the input data space comprising serum concentrations of d = 43 different lipid-markers of various classes. The structure coincided largely with the clinical diagnosis, indicating that the data provide a basis for the creation of a biomarker (classifier). This was subsequently assessed using supervised machine-learning, implemented as random forests and computed ABC analysis-based feature selection. Bayesian statistics-based biomarker creation was used to map the diagnostic classes of either MS patients (n = 102) or healthy subjects (n = 301). Eight lipid-markers passed the feature selection and comprised GluCerC16, LPA20:4, HETE15S, LacCerC24:1, C16Sphinganine, biopterin and the endocannabinoids PEA and OEA. A complex classifier or biomarker was developed that predicted MS at a sensitivity, specificity and accuracy of approximately 95% in training and test data sets, respectively. The present successful application of serum lipid marker concentrations to MS data is encouraging for further efforts to establish an MS biomarker based on serum lipidomics.

Analysis of coding and non-coding transcriptome of peripheral B cells reveals an altered interferon response factor (IRF)-1 pathway in multiple sclerosis patients

Several evidences emphasize B-cell pathogenic roles in multiple sclerosis (MS). We performed transcriptome analyses on peripheral B cells from therapy-free patients and age/sex-matched controls. Down-regulation of two transcripts (interferon response factor 1-IRF1, and C-X-C motif chemokine 10-CXCL10), belonging to the same pathway, was validated by RT-PCR in 26 patients and 21 controls. IRF1 and CXCL10 transcripts share potential seeding sequences for hsa-miR-424, that resulted up-regulated in MS patients. We confirmed this interaction and its functional effect by transfection experiments. Consistent findings indicate down-regulation of IRF1/CXCL10 axis, that may plausibly contribute to a pro-survival status of B cells in MS.

The MicroRNA-326: Autoimmune diseases, diagnostic biomarker, and therapeutic target

MicroRNAs (miRNAs) are uniquely regulated in healthy, inflamed, activated, cancerous, or other cells and tissues of a pathological state. Many studies confirm that immune dysregulation and autoimmune diseases with inflammation are correlated with various miRNA expression changes in targeted tissues and cells in innate or adaptive immunity. In this review, we will explain the history and classification of epigenetic changes. Next, we will describe the role of miRNAs changes, especially mir-326 in autoimmunity, autoinflammatory, and other pathological conditions. A systematic search of MEDLINE, Embase, and Cochrane Library was presented for all related studies from 1899 to 2017 with restrictions in the English language. In recent years, researchers have concentrated on mostly those roles of miRNA that are correlated with the inflammatory and anti-inflammatory process. Latest studies have proposed a fundamental pathogenic role in cancers and autoinflammatory diseases. Studies have described the role of microRNAs in autoimmunity and autoinflammatory diseases, cancers, and so on. The miRNA-326 expression plays a significant role in autoimmune and other types of diseases.

Evaluation of serum miR-191-5p, miR-24-3p, miR-128-3p, and miR-376c-3 in multiple sclerosis patients

BACKGROUND

Biomarkers that could be used in early diagnosis of multiple sclerosis (MS), segregation of disease subtypes, and discrimination of the aggressive disease course from the benign one are urgently needed.

OBJECTIVE

The aim of this study was to investigate the specificity of circulating microRNAs: miR-191-5p, miR-128-3p, miR-24-3p, and miR-376c-3p in MS and evaluate their association with disease activity and disability progression.

METHODS

The expressions of circulating miRNAs were studied in serum of 100 subjects (53 relapsing-remitting (RRMS), 20 primary progressive (PPMS), and 27 controls), using miScript serum miRNA RT-PCR assay techniques.

RESULTS

In comparison with controls, miR-191-5p and miR-24-3p were overexpressed in RRMS and PPMS, with no differences between the subtypes. miR-24-3p correlated positively with the disability progression index in the combined group of all patients with MS. miR-128-3p showed tendency toward the predominant expression in PPMS and correlated positively with the annual relapse rate in RRMS. miR-376c-3p expression levels did not differ between the groups, and no associations were found to clinical parameters.

CONCLUSION

This study highlighted the connection of circulating miRNAs to MS. miR-24-3p and miR-128-3p showed a tendency of association with disability accumulation and disease activity, respectively. Further studies should evaluate their suitability for clinical use.

MicroRNA-150 targets PU.1 and regulates macrophage differentiation and function in experimental autoimmune encephalomyelitis

PU.1 is a transcription factor which is expressed in myeloid cells. Herein, we investigated the expression of PU.1 and its potentially targeting miRNAs in the central nervous system (CNS) of mice with experimental autoimmune encephalitis (EAE) and in cultured primary macrophages. PU.1 levels where highly induced in EAE spinal cords and in activated macrophages; this was associated with a significant reduction in miR-150-5p levels at chronic phase of disease and in activated cells. Luciferase assays confirmed the PU.1-miR-150-5p interaction. Overexpression of miR-150-5p in macrophages decreased the expression of proinflammatory cytokines and shifted the polarization of macrophages away from the M1-like phenotype.

The Role for Exosomal microRNAs in Disruption of Regulatory T Cell Homeostasis in Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, in which myelin and oligodendrocytes are the main targets recognized by inflammatory CD4⁺ T cells reactive to myelin peptides. Regulatory CD4⁺ T (Treg) cells normally keep homeostasis of the immune system by inhibiting detrimental effects of inflammatory T cells. However, Treg cells are reduced in patients with MS for unknown reason. This commentary highlights a novel function of circulating exosomes to inhibit the differentiation of Treg cells in MS. Our recent work has demonstrated that the circulating exosomes, a member of extracellular vesicles, of patients with MS exert this effect by transferring let-7i to naive CD4⁺ T cells. The transferred let-7i subsequently causes a decreased expression of insulin like growth factor 1 receptor (IGF1R) and transforming growth factor β receptor 1 (TGFBR1), leading to the inhibition of Treg cell differentiation. Thus, extrinsic microRNAs transferred by exosomes might have an active role in triggering autoimmune diseases. We hypothesize that extracellular vesicles including exosomes can be a communication tool between the gut microbiota and the host immune system. Further research in this area will expand the knowledge about the precise mechanism of autoimmune diseases and can lead to a new therapeutic approach.

Circulating exosomes suppress the induction of regulatory T cells via let-7i in multiple sclerosis

Multiple sclerosis (MS) is a T cell-mediated autoimmune disease of the central nervous system. Foxp3⁺ regulatory T (Treg) cells are reduced in frequency and dysfunctional in patients with MS, but the underlying mechanisms of this deficiency are unclear. Here, we show that induction of human IFN-γ⁻IL-17A⁻Foxp3⁺CD4⁺ T cells is inhibited in the presence of circulating exosomes from patients with MS. The exosomal miRNA profile of patients with MS differs from that of healthy controls, and let-7i, which is markedly increased in patients with MS, suppresses induction of Treg cells by targeting insulin like growth factor 1 receptor (IGF1R) and transforming growth factor beta receptor 1 (TGFBR1). Consistently, the expression of IGF1R and TGFBR1 on circulating naive CD4⁺ T cells is reduced in patients with MS. Thus, our study shows that exosomal let-7i regulates MS pathogenesis by blocking the IGF1R/TGFBR1 pathway.

MiRNAs are small RNA molecules that can regulate gene expression. Here the authors show that expression of several exosomal miRNAs are altered in patients with multiple sclerosis, and that let-7i modulates regulatory T cell homeostasis to contribute to pathogenesis.

Human miR-26a-5p regulates the glutamate transporter SLC1A1 (EAAT3) expression. Relevance in multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, characterized by chronic inflammation, demyelination and scarring as well as a broad spectrum of signs and symptoms. MicroRNA plays pivotal roles in cellular and developmental processes by regulating gene expression at the post-transcriptional level. Increasing evidence suggests the involvement of microRNAs in the pathogenesis of neurodegenerative diseases, including MS. We have already found that the expression of a specific miRNA, hsa-mir-26a-5p (miR-26a), changed during INF-β treatment in responder Relapsing-Remitting MS patients. Functional annotations of mir-26a targets revealed that a number of genes were implicated in Glutamate Receptor Signaling pathway, which is notoriously altered in neurodegenerative diseases as MS. In this study, the different potential targets were subjected to a validation test based on luciferase reporter constructs transfected in an oligodendroglial cell line. In this functional screening, miR-26a was able to interact with SLC1A1 3' UTR suppressing the reporter activity. Transfection of a miR-26a mimic was then shown to decrease the endogenous SLC1A1 mRNA. Afterward, we have evaluated in blood platelets from interferon-β treated Multiple Sclerosis patients the expression of miR-26a and SLC1A1, finding not only their converse expression, but also a responsiveness to interferon-β therapy. Overall, these data suggest that mir-26a and SLC1A1 may play a role in the MS pathogenesis, and may be potential targets for the development of new biomarkers and/or therapeutic tools.

MicroRNAs: Roles in Regulating Neuroinflammation

MicroRNAs (miRNAs) are small noncoding RNAs that broadly affect cellular and physiological function in all multicellular organisms. Here, the role of miRNAs in neuroinflammation is considered. miRNAs are 21- to 23-oligonucleotide RNAs that regulate translation of specific RNAs by binding to complementary regulatory RNA sequences, thereby causing mRNA degradation or sequestration. More than 5000 miRNAs likely exist in humans, and each miRNA binds an average of 200 RNAs. Specific immunomodulatory miRNAs can regulate a set of RNAs in a coordinated manner, suggesting that effective miRNA-based therapeutic manipulations for neuroinflammatory conditions may be revealed. For instance, miRNAs that preferentially inhibit translation of many cellular anti-inflammatory proteins could drive a pro-inflammatory response. Key pro-inflammatory ( miR-155, miR-27b, miR-326), anti-inflammatory ( miR-124, miR-146a, miR-21, miR-223), and mixed immunomodulatory ( let-7 family) miRNAs regulate neuroinflammation in various pathologies, including spinal cord injury, multiple sclerosis, ischemic stroke, and Alzheimer's disease. miRNAs represent a newly revealed layer of physiological complexity, the therapeutic benefits of which remain to be fully explored and exploited. In this review, we discuss the role of miRNAs in neuroinflammatory regulation and discuss how controlling miRNAs could alter cellular machinery to improve neuroinflammatory dynamics.

MicroRNA in glutamate receptor-dependent neurological diseases

Glutamate-mediated excitotoxicity is the major neuropathological process contributing to numerous neurological diseases. Recently, emerging evidence indicates that microRNAs (miRNAs) play essential roles in the pathophysiology of a wide range of neurological diseases. Notably, there have been significant developments in understanding the biogenesis of miRNAs, their regulatory mechanisms, and their potential as effective biomarkers and therapies. In the present review, we summarize the recent literature that highlights the versatile roles played by miRNAs in glutamate receptor (GluR)-dependent neurological diseases. Based on the reported studies to date, modulation of miRNAs could emerge as a promising therapeutic target for a variety of neurological diseases that were discussed in this review.

MicroRNA-661 promotes non-small cell lung cancer progression by directly targeting RUNX3

Lung cancer is the primary cause of cancer‑associated mortality in men and women worldwide. Increasing evidence indicates that abnormal microRNA (miRNA) expression contributes to the carcinogenesis and progression of multiple human cancers, including non‑small cell lung cancer (NSCLC). Therefore, miRNAs exhibit the potential to act as biomarkers for the diagnosis, treatment and prognosis of human malignancies. miRNA‑661 (miR‑661) has previously been demonstrated to be important in the development of various human cancer types. However, the expression levels, functions and underlying mechanisms of miR‑661 in NSCLC remain to be elucidated. The present study demonstrated that miR‑661 was upregulated in NSCLC tissues and cell lines. In addition, miR‑661 expression levels were significantly correlated with differentiation and tumor stage lymph node metastasis of NSCLC patients. Functional experiments demonstrated that miR-661 downregulation inhibited NSCLC cell proliferation and invasion in vitro. Furthermore, runt‑related transcription factor 3 (RUNX3) was identified as a direct target of miR‑661 in NSCLC. RUNX3 was expressed at a low level in NSCLC tissues and was negatively correlated with the miR‑661 expression level. Further experiments revealed that RUNX3 knockdown significantly rescued the effects of miR‑661 underexpression on NSCLC cell proliferation and invasion. In conclusion, the present findings indicated a role for miR‑661 as an oncogene in NSCLC via direct targeting of RUNX3, thus suggesting that miR‑661 may be used to develop novel therapies for NSCLC patients.

Association Between Serum MicroRNAs and Magnetic Resonance Imaging Measures of Multiple Sclerosis Severity

Importance

MicroRNAs (miRNAs) are promising multiple sclerosis (MS) biomarkers. Establishing the association between miRNAs and magnetic resonance imaging (MRI) measures of disease severity will help define their significance and potential impact.

Objective

To correlate circulating miRNAs in the serum of patients with MS to brain and spinal MRI.

Design, Setting, and Participants

A cross-sectional study comparing serum miRNA samples with MRI metrics was conducted at a tertiary MS referral center. Two independent cohorts (41 and 79 patients) were retrospectively identified from the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital. Expression of miRNA was determined by locked nucleic acid-based quantitative real-time polymerase chain reaction. Spearman correlation coefficients were used to test the association between miRNA and brain lesions (T2 hyperintense lesion volume [T2LV]), the ratio of T1 hypointense lesion volume [T1LV] to T2LV [T1:T2]), brain atrophy (whole brain and gray matter), and cervical spinal cord lesions (T2LV) and atrophy. The study was conducted from December 2013 to April 2016.

Main Outcomes and Measures

miRNA expression.

Results

Of the 120 patients included in the study, cohort 1 included 41 participants (7 [17.1%] men), with mean (SD) age of 47.7 (9.5) years; cohort 2 had 79 participants (26 [32.9%] men) with a mean (SD) age of 43.0 (7.5) years. Associations between miRNAs and MRIs were both protective and pathogenic. Regarding miRNA signatures, a topographic specificity differed for the brain vs the spinal cord, and the signature differed between T2LV and atrophy/destructive measures. Four miRNAs showed similar significant protective correlations with T1:T2 in both cohorts, with the highest for hsa.miR.143.3p (cohort 1: Spearman correlation coefficient rs = -0.452, P = .003; cohort 2: rs = -0.225, P = .046); the others included hsa.miR.142.5p (cohort 1: rs = -0.424, P = .006; cohort 2: rs = -0.226, P = .045), hsa.miR.181c.3p (cohort 1: rs = -0.383, P = .01; cohort 2: rs = -0.222, P = .049), and hsa.miR.181c.5p (cohort 1: rs = -0.433, P = .005; cohort 2: rs = -0.231, P = .04). In the 2 cohorts, hsa.miR.486.5p (cohort 1: rs = 0.348, P = .03; cohort 2: rs = 0.254, P = .02) and hsa.miR.92a.3p (cohort 1: rs = 0.392, P = .01; cohort 2: rs = 0.222, P = .049) showed similar significant pathogenic correlations with T1:T2; hsa.miR.375 (cohort 1: rs = -0.345, P = .03; cohort 2: rs = -0.257, P = .022) and hsa.miR.629.5p (cohort 1: rs = -0.350, P = .03; cohort 2: rs = -0.269, P = .02) showed significant pathogenic correlations with brain atrophy. Although we found several miRNAs associated with MRI outcomes, none of these associations remained significant when correcting for multiple comparisons, suggesting that further validation of our findings is needed.

Conclusions and Relevance

Serum miRNAs may serve as MS biomarkers for monitoring disease progression and act as surrogate markers to identify underlying disease processes.

microRNA-761 induces aggressive phenotypes in triple-negative breast cancer cells by repressing TRIM29 expression

PURPOSE

Despite advances that have been made in systemic chemotherapy, the prognosis of advanced triple-negative breast cancer (TNBC) patients is still poor. The identification of key factors governing TNBC development is considered imperative for the development of novel effective therapeutic approaches. Previously, it has been reported that microRNA (miR)-761 may act as either a tumor suppressor or as an oncogene in different types of cancer. Here, we aimed at assessing the biological role of this miRNA in TNBC.

METHODS

First, we measured the expression of miR-761 in primary breast cancer tissues and breast cancer-derived cell lines using qRT-PCR. Subsequently, over-expression and silencing experiments were performed to determine the role of miR-761 in TNBC cell proliferation, colony formation, migration and invasion in vitro. The in vivo role of miR-761 in TNBC growth and metastasis was determined in mouse models. Bioinformatics analyses, dual-luciferase reporter assays, Western blot analyses and rescue experiments were performed to identify miR-761 target gene(s).

RESULTS

We found that miR-761 was up-regulated in primary breast cancer tissues and its derived cell lines and, particularly, in TNBC tissues and cell lines. We also found that exogenous miR-761 over-expression augmented in vitro TNBC cell proliferation, colony formation, migration and invasion, whereas miR-761 down-regulation impaired these features. In vivo, we found that miR-761 over-expression facilitated TNBC growth and lung metastasis. Mechanistically, miR-761 was found to negatively regulate the expression of tripartite motif-containing 29 (TRIM29) in TNBC cells by binding to the 3'-untranslated region of its mRNA. In conformity with these results, a significant negative correlation between miR-761 expression and TRIM29 protein expression was noted in primary TNBC tissues (r = -0.452, p = 0.0126). We also found that exogenous TRIM29 over-expression reversed the proliferative and invasive capacities of TNBC cells.

CONCLUSIONS

Our data indicate that miR-761 acts as an oncogene in TNBC. This mode of action can, at least partially, be ascribed to the down-regulation of its target TRIM29. We suggest that miR-761 may serve as a promising therapeutic target for TNBC.

A Personalized Approach in Progressive Multiple Sclerosis: The Current Status of Disease Modifying Therapies (DMTs) and Future Perspectives

Using the term of progressive multiple sclerosis (PMS), we considered a combined population of persons with secondary progressive MS (SPMS) and primary progressive MS (PPMS). These forms of MS cannot be challenged with efficacy by the licensed therapy. In the last years, several measures of risk estimation were developed for predicting clinical course in MS, but none is specific for the PMS forms. Personalized medicine is a therapeutic approach, based on identifying what might be the best therapy for an individual patient, taking into account the risk profile. We need to achieve more accurate estimates of useful predictors in PMS, including unconventional and qualitative markers which are not yet currently available or practicable routine diagnostics. The evaluation of an individual patient is based on the profile of disease activity.Within the neurology field, PMS is one of the fastest-moving going into the future.