MicroRNA expression changes during interferon-beta treatment in the peripheral blood of multiple sclerosis patients

Stem Cell-Derived Exosomal MicroRNAs as Novel Potential Approach for Multiple Sclerosis Treatment

Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by inflammation and demyelination of CNS neurons. Up to now, there are many therapeutic strategies for MS but they are only being able to reduce progression of diseases and have not got any effect on repair and remyelination. Stem cell therapy is an appropriate method for regeneration but has limitations and problems. So recently, researches were used of exosomes that facilitate intercellular communication and transfer cell-to-cell biological information. MicroRNAs (miRNAs) are a class of short non-coding RNAs that we can used to their dysregulation in order to diseases diagnosis. The miRNAs of microvesicles obtained stem cells may change the fate of transplanted cells based on received signals of injured regions. The miRNAs existing in MSCs may be displayed the cell type and their biological activities. Current studies show also that the miRNAs create communication between stem cells and tissue-injured cells. In the present review, firstly we discuss the role of miRNAs dysregulation in MS patients and miRNAs expression by stem cells. Finally, in this study was confirmed the relationship of microRNAs involved in MS and miRNAs expressed by stem cells and interaction between them in order to find appropriate treatment methods in future for limit to disability progression.

Twenty Years of Subcutaneous Interferon-Beta-1a for Multiple Sclerosis: Contemporary Perspectives

Multiple sclerosis (MS) is a chronic, progressive, inflammatory disorder of the central nervous system. Relapsing-remitting MS (RRMS), the most common form of the disease, is characterized by transient neurological dysfunction with concurrent accumulation of disability. Over the past three decades, disease-modifying therapies (DMTs) capable of reducing the frequency of relapses and slowing disability worsening have been studied and approved for use in patients with RRMS. The first DMTs were interferon-betas (IFN-βs), which were approved in the 1990s. Among them was IFN-β-1a for subcutaneous (sc) injection (Rebif®), which was approved for the treatment of MS in Europe and Canada in 1998 and in the USA in 2002. Twenty years of clinical data and experience have supported the efficacy and safety of IFN-β-1a sc in the treatment of RRMS, including pivotal trials, real-world data, and extension studies lasting up to 15 years past initial treatment. Today, IFN-β-1a sc remains an important therapeutic option in clinical use, especially around pregnancy planning and lactation, and may also be considered for aging patients, in which MS activity declines and long-term immunosuppression associated with some alternative therapies is a concern. In addition, IFN-β-1a sc is used as a comparator in many clinical studies and provides a framework for research into the mechanisms by which MS begins and progresses.

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 microRNAs involved in the disorder of blood-brain barrier in the pathogenesis of multiple sclerosis

miRNAs are involved in various vital processes, including cell growth, development, apoptosis, cellular differentiation, and pathological cellular activities. Circulating miRNAs can be detected in various body fluids including serum, plasma, saliva, and urine. It is worth mentioning that miRNAs remain stable in the circulation in biological fluids and are released from membrane-bound vesicles called exosomes, which protect them from RNase activity. It has been shown that miRNAs regulate blood-brain barrier integrity by targeting both tight junction and adherens junction molecules and can also influence the expression of inflammatory cytokines. Some recent studies have examined the impact of certain commonly used drugs in Multiple Sclerosis on miRNA levels. In this review, we will focus on the recent findings on the role of miRNAs in multiple sclerosis, including their role in the cause of MS and molecular mechanisms of the disease, utilizing miRNAs as diagnostic and clinical biomarkers, using miRNAs as a therapeutic modality or target for Multiple Sclerosis and drug responses in patients, elucidating their importance as prognosticators of disease progression, and highlighting their potential as a future treatment for MS.

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.

Multi-omics reveals aspirin eugenol ester alleviates neurological disease

BACKGROUND

Exosomes play an essential role in maintaining normal brain function due to their ability to cross the blood-brain barrier. Aspirin eugenol ester (AEE) is a new medicinal compound synthesized by the esterification of aspirin with eugenol using the prodrug principle. Aspirin has been reported to have neuroprotective effects and may be effective against neurodegenerative diseases.

PURPOSE

This study wanted to investigate how AEE affected neurological diseases in vivo and in vitro.

EXPERIMENTAL APPROACH

A multi-omics approach was used to explore the effects of AEE on the nervous system. Gene and protein expression changes of BDNF and NEFM in SY5Y cells after AEE treatment were detected using RT-qPCR and Western Blot.

KEY RESULTS

The multi-omics results showed that AEE could regulate neuronal synapses, neuronal axons, neuronal migration, and neuropeptide signaling by affecting transport, inflammatory response, and regulating apoptosis. Exosomes secreted by AEE-treated Caco-2 cells could promote the growth of neurofilaments in SY5Y cells and increased the expression of BDNF and NEFM proteins in SY5Y cells. miRNAs in the exosomes of AEE-treated Caco-2 cells may play an important role in the activation of SY5Y neuronal cells.

CONCLUSIONS

In conclusion, AEE could play positive effects on neurological-related diseases.

Integrated co-expression analysis of regulatory elements (miRNA, lncRNA, and TFs) in bovine monocytes induced by Str. uberis

Non-coding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), together with transcription factors, are critical pre-, co-, and post-transcriptional regulators. In addition to their criteria as ideal biomarkers, they have great potential in disease prognosis, diagnosis, and treatment of complex diseases. Investigation of regulatory mechanisms in the context of bovine mastitis, as most common and economic disease in the dairy industry, to identify elements influencing the expression of candidate genes as key regulators of the mammary immune response is not yet fully understood. Transcriptome profiles (50 RNA-Seq and 50 miRNA-Seq samples) of bovine monocytes induced by Str. uberis were used for co-expression module detection and preservation analysis using the weighted gene co-expression network analysis (WGCNA) approach. Assigned mi-, lnc-, and m-modules used to construct the integrated regulatory networks and miRNA-lncRNA-mRNA regulatory sub-networks. Remarkably, we have identified 18 miRNAs, five lncRNAs, and seven TFs as key regulators of str. uberis-induced mastitis. Most of the genes introduced here, mainly involved in immune response, inflammation, and apoptosis, were new to mastitis. These findings may help to further elucidate the underlying mechanisms of bovine mastitis, and the discovered genes may serve as signatures for early diagnosis and treatment of the disease.

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.

Omics approaches to understanding the efficacy and safety of disease-modifying treatments in multiple sclerosis

From the perspective of precision medicine, the challenge for the future is to improve the accuracy of diagnosis, prognosis, and prediction of therapeutic responses through the identification of biomarkers. In this framework, the omics sciences (genomics, transcriptomics, proteomics, and metabolomics) and their combined use represent innovative approaches for the exploration of the complexity and heterogeneity of multiple sclerosis (MS). This review examines the evidence currently available on the application of omics sciences to MS, analyses the methods, their limitations, the samples used, and their characteristics, with a particular focus on biomarkers associated with the disease state, exposure to disease-modifying treatments (DMTs), and drug efficacies and safety profiles.

miRNA Signature in CSF From Patients With Primary Progressive Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Primary progressive multiple sclerosis (PPMS) displays a highly variable disease progression with a characteristic accumulation of disability, what makes difficult its diagnosis and efficient treatment. The identification of microRNAs (miRNAs)-based signature for the early detection in biological fluids could reveal promising biomarkers to provide new insights into defining MS clinical subtypes and potential therapeutic strategies. The objective of this cross-sectional study was to describe PPMS miRNA profiles in CSF and serum samples compared with other neurologic disease individuals (OND) and relapsing-remitting MS (RRMS).

METHODS

First, a screening stage analyzing multiple miRNAs in few samples using OpenArray plates was performed. Second, individual quantitative polymerase chain reactions (qPCRs) were used to validate specific miRNAs in a greater number of samples.

RESULTS

A specific profile of dysregulated circulating miRNAs (let-7b-5p and miR-143-3p) was found downregulated in PPMS CSF samples compared with OND. In addition, in serum samples, miR-20a-5p and miR-320b were dysregulated in PPMS against RRMS and OND, miR-26a-5p and miR-485-3p were downregulated in PPMS vs RRMS, and miR-142-5p was upregulated in RRMS compared with OND.

DISCUSSION

We described a 2-miRNA signature in CSF of PPMS individuals and several dysregulated miRNAs in serum from patients with MS, which could be considered valuable candidates to be further studied to unravel their actual role in MS.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that specific miRNA profiles accurately distinguish PPMS from RRMS and other neurologic disorders.

Temporal variability of serum miR-191, miR-223, miR-128, and miR-24 in multiple sclerosis: A 4-year follow-up study

BACKGROUND

Circulating microRNAs (miRNA) are suggested to be a promising biomarker for multiple sclerosis (MS). Previously, miR-128-3p, miR-24-3p, miR-191-5p and miR-223-3p have been reported to associate with MS pathology. However, their longitudinal changes and association with the disease activity have not been studied.

OBJECTIVES

To evaluate the serum temporal variability of miR-128-3p, miR-191-5p, miR-24-3p, and miR-223-3p and their association with disability and disease activity in MS.

METHODS

The expression of four miRNAs in serum was studied in 57 MS patients, 18 clinically isolated syndrome patients, and 32 healthy controls over the four-year follow-up.

RESULTS

At the baseline, miR-191-5p was overexpressed in RRMS in comparison to controls, and its levels correlated positively with EDSS and progression index (PI) in RRMS. Increased levels of miR-128-3p were detected in PPMS in comparison to controls, and increased levels correlated with EDSS and PI in RRMS. The expression of miR-24-3p and miR-223-3p did not differ between the subtypes, but miR-223-3p correlated negatively with T1 lesions volumes in SPMS and PPMS. Over the four-years follow-up period, the expression of miR-128-3p and miR-24-3p was stable longitudinally, while temporal changes of miR-191-5p and miR-223-3p were observed in MS. Temporal changes in miR-191-5p were observed to be associated with an increase of EDSS or MRI activity, while the variability of miR-223-3p was associated with relapses.

CONCLUSION

Temporal variability of miR-191-5p and miR-223-3p are associated with changes in disability accumulation and disease activity. While, miR-128-3p was stably expressed and associated with the PPMS subtype and correlated with disability accumulation.

The role of microRNAs in neurodegenerative diseases: a review

MicroRNAs (miRNAs) are non-coding RNAs which are essential post-transcriptional gene regulators in various neuronal degenerative diseases and playact a key role in these physiological progresses. Neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, multiple sclerosis, and, stroke, are seriously threats to the life and health of all human health and life kind. Recently, various studies have reported that some various miRNAs can regulate the development of neurodegenerative diseases as well as act as biomarkers to predict these neuronal diseases conditions. Endogenic miRNAs such as miR-9, the miR-29 family, miR-15, and the miR-34 family are generally dysregulated in animal and cell models. They are involved in regulating the physiological and biochemical processes in the nervous system by targeting regulating different molecular targets and influencing a variety of pathways. Additionally, exogenous miRNAs derived from homologous plants and defined as botanmin, such as miR2911 and miR168, can be taken up and transferred by other species to be and then act analogously to endogenic miRNAs to regulate the physiological and biochemical processes. This review summarizes the mechanism and principle of miRNAs in the treatment of some neurodegenerative diseases, as well as discusses several types of miRNAs which were the most commonly reported in diseases. These miRNAs could serve as a study provided some potential biomarkers in neurodegenerative diseases might be an ideal and/or therapeutic targets for neurodegenerative diseases. Finally, the role accounted of the prospective exogenous miRNAs involved in mammalian diseases is described.

Current Advancement of Immunomodulatory Drugs as Potential Pharmacotherapies for Autoimmunity Based Neurological Diseases

Dramatic advancement has been made in recent decades to understand the basis of autoimmunity-mediated neurological diseases. These diseases create a strong influence on the central nervous system (CNS) and the peripheral nervous system (PNS), leading to various clinical manifestations and numerous symptoms. Multiple sclerosis (MS) is the most prevalent autoimmune neurological disease while NMO spectrum disorder (NMOSD) is less common. Furthermore, evidence supports the presence of autoimmune mechanisms contributing to the pathogenesis of amyotrophic lateral sclerosis (ALS), which is a neurodegenerative disorder characterized by the progressive death of motor neurons. Additionally, autoimmunity is believed to be involved in the basis of Alzheimer’s and Parkinson’s diseases. In recent years, the prevalence of autoimmune-based neurological disorders has been elevated and current findings strongly suggest the role of pharmacotherapies in controlling the progression of autoimmune diseases. Therefore, this review focused on the current advancement of immunomodulatory drugs as novel approaches in the management of autoimmune neurological diseases and their future outlook.

Discovering miRNAs Associated With Multiple Sclerosis Based on Network Representation Learning and Deep Learning Methods

Identifying biomarkers of Multiple Sclerosis is important for the diagnosis and treatment of Multiple Sclerosis. The existing study has shown that miRNA is one of the most important biomarkers for diseases. However, few existing methods are designed for predicting Multiple Sclerosis-related miRNAs. To fill this gap, we proposed a novel computation framework for predicting Multiple Sclerosis-associated miRNAs. The proposed framework uses a network representation model to learn the feature representation of miRNA and uses a deep learning-based model to predict the miRNAs associated with Multiple Sclerosis. The evaluation result shows that the proposed model can predict the miRNAs associated with Multiple Sclerosis precisely. In addition, the proposed model can outperform several existing methods in a large margin.

[Role of circular RNAs in immune-related diseases]

Objective Circular RNAs (circRNAs) are non-coding RNAs (ncRNA) circularized without a 3′ polyadenylation [poly-(A)] tail or a 5′ cap, resulting in a covalently closed loop structure. circRNAs were first discovered in RNA viruses in the 1970s, but only a small number of circRNAs were discovered at that time due to limitations in traditional polyadenylated transcriptome analyses. With the development of specific biochemical and computational methods, recent studies have shown the presence of abundant circRNAs in eukaryotic transcriptomes. circRNAs play vital roles in many physiological and pathological processes, such as acting as miRNA sponges, binding to RNA-binding proteins (RBPs), acting as transcriptional regulatory factors, and even serving as translation templates. Current evidence has shown that circRNAs can be potentially used as excellent biomarkers for diagnosis, therapeutic effect evaluation, and prognostic assessment of a variety of diseases, and they may also provide effective therapeutic targets due to their stability and tissue and development-stage specificity. This review focuses on the properties of circRNAs and their immune relationship to disease, and explores the role of circRNAs in immune-related diseases and the directions of future research.

The Effect of Interferon-Beta Therapy on T-Helper 17/miR-326 and T-Helper 1/miR-29b-3p Axis in Relapsing-Remitting Multiple Sclerosis Patients

BACKGROUND

We aimed to evaluate the therapeutic effects of interferon-beta (IFN-β) on hsa-miR29b-3p and hsa-miR326 in isolated T-helper (Th)1 and Th17 cells expressed by relapsing-remitting multiple sclerosis (RRMS) patients before and after 1 year of treatment with IFN-β.

METHODS

The study was done on 19 RRMS patients pre- and posttreatment with IFN-β to evaluate the frequency of Th1 and Th17 cells by flow cytometry. The expression level of hsa-miR-29b-3p and hsa-miR-326 in isolated Th1 and Th17 cells was assessed by quantitative polymerase chain reaction. Enzyme-linked immunosorbent assay was also used to measure the plasma levels of I interferon -gamma and interleukin (IL)-17A.

RESULTS

Th17 cells and plasma levels of IL-17A decreased in RRMS patients after IFN-β therapy but hsa-miR-29b-3p and hsa-miR-326 expression had no significant change in treated RRMS patients versus baseline. MxA gene expression was significantly induced upon IFN-β therapy in patients with RRMS.

CONCLUSION

IFN-β therapy is more effective on Th17 than Th1, but it does not reform altered expression of hsa-miR-326 and hsa-miR-29b-3p in Th17 and Th1, respectively.

The Role of microRNAs in the Mammary Gland Development, Health, and Function of Cattle, Goats, and Sheep

Milk is an integral and therefore complex structural element of mammalian nutrition. Therefore, it is simple to conclude that lactation, the process of producing milk, is as complex as the mammary gland, the organ responsible for this biochemical activity. Nutrition, genetics, epigenetics, disease pathogens, climatic conditions, and other environmental variables all impact breast productivity. In the last decade, the number of studies devoted to epigenetics has increased dramatically. Reports are increasingly describing the direct participation of microRNAs (miRNAs), small noncoding RNAs that regulate gene expression post-transcriptionally, in the regulation of mammary gland development and function. This paper presents a summary of the current state of knowledge about the roles of miRNAs in mammary gland development, health, and functions, particularly during lactation. The significance of miRNAs in signaling pathways, cellular proliferation, and the lipid metabolism in agricultural ruminants, which are crucial in light of their role in the nutrition of humans as consumers of dairy products, is discussed.

The expression and prognostic value of miR-146a and miR-155 in Turkish patients with multiple sclerosis

Multiple sclerosis (MS) is an inflammatory, autoimmune demyelinating, and neurodegenerative disorder of the central nervous system. Interactions between environmental factors, predisposition genes, and determining genes appear to be involved in its etiology. Epigenetic mechanisms such as microRNA-mediated gene regulation can determine the susceptibility and severity of autoimmune diseases. Therefore, to determine the role of miR-146a and miR-155 in MS and its developmental stages, the expression levels in the serum of MS and clinically isolated syndrome (CIS) patients were compared with those of healthy controls. In the present study, the expression levels of miR-146a and miR-155 were assessed using quantitative Real-Time PCR in blood samples of 15 CIS patients and 61 relapsing-remitting multiple sclerosis (RRMS) patients alongside 32 healthy patients as controls. Furthermore, any associations with the clinicopathologic variables of the patients were also evaluated. Dysregulations were found only in the miR-146a and miR-155 expressions in the RRMS-Control group. When the RRMS patients were evaluated in terms of the characteristics of sex, annual attack rate, age of diagnosis, duration of follow-up, and immunomodulatory treatments used, no significant differences were observed. However, significant dysregulations were identified in miRNA expression in the vitamin D level, EDSS values, and the number of attacks. ROC curve analysis showed that miR-146a and miR-155 were significant in the RRMS-Control group for the area under the curve (AUC). It is possible that miR-146a may be associated with vitamin D deficiency and disease disability, while miR-155 may be associated with the number of attacks.

Expression Profiling of microRNA From Peripheral Blood of Dairy Cows in Response to Staphylococcus aureus-Infected Mastitis

As the main pathogen causing dairy cow mastitis, Staphylococcus aureus can cause subclinical mastitis, which is difficult to be diagnosed. It seriously affects milk quality and the economic benefits of the dairy industry. Therefore, it is very necessary to find biomarkers for early diagnosis of S. aureus-infected mastitis in peripheral blood of dairy cows. In this study, S. aureus was used to infect the mammary gland tissues of dairy cows, and a mastitis model was successfully constructed. The RNAseq technology was used to determine the expression profiles of microRNA (miRNA) from peripheral blood of dairy cows infected with S. aureus at 0, 1, 3, 5, and 7 days. A total of 288 differentially expressed miRNAs (DIE-miRNAs) were found, of which 108 were known miRNAs and 180 were novel predicted miRNAs. Bioinformatics analysis results showed that the above DIE-miRNAs might be involved in 10 immune system-related signaling pathways (i.e., chemokine signaling pathway, leukocyte transendothelial migration, natural killer cell-mediated cytotoxicity, toll-like receptor signaling pathway, Jak-STAT signaling pathway, MAPK signaling pathway, Wnt signaling pathway, cell adhesion molecules, cytokine-cytokine receptor interaction, and ECM-receptor interaction), thus regulating the process of S. aureus mastitis. It was also found that the expression variation of up-regulated expression of miR-320a, miR-19a, and miR-19b as well as down-regulated expression of miR-143, miR-205, and miR-24 reached a significant level on the 5th and 7th day of infection, suggesting that they might play an important biological role in mastitis and provide a direction for the research and development of molecular therapy technology for mastitis. However, at different times after S. aureus infection, miR-1301 was significantly up-regulated in peripheral blood. miR-2284r was significantly down-regulated, suggesting that these two miRNAs might be the new blood biomarkers for S. aureus-infected dairy cow mastitis. The above results laid a new foundation for the research and development of molecular diagnosis and biological therapy technology for S. aureus-infected mastitis in dairy cow.

Identifying miRNAs in multiple sclerosis gray matter lesions that correlate with atrophy measures

OBJECTIVE

Multiple sclerosis (MS) is an inflammatory, demyelinating and neurodegenerative disease of the central nervous system (CNS). Though MS was initially considered to be a white matter demyelinating disease, myelin loss in cortical gray matter has been reported in all disease stages. We previously identified microRNAs (miRNAs) in white matter lesions (WMLs) that are detected in serum from MS patients. However, miRNA expression profiles in gray matter lesions (GMLs) from progressive MS brains are understudied.

METHODS

We used a combination of global miRNAs and gene expression profiling of GMLs and independent validation using real-time quantitative polymerase chain reaction (RT-qPCR), immuno-in situ hybridization, and immunohistochemistry.

RESULTS

Compared to matched myelinated gray matter (GM) regions, we identified 82 miRNAs in GMLs, of which 10 were significantly upregulated and 17 were significantly downregulated. Among these 82 miRNAs, 13 were also detected in serum and importantly were associated with brain atrophy in MS patients. The predicted target mRNAs of these miRNAs belonged to pathways associated with axonal guidance, TGF-β signaling, and FOXO signaling. Further, using state-of-the-art human protein-protein interactome network analysis, we mapped the four key GM atrophy-associated miRNAs (hsa-miR-149*, hsa-miR-20a, hsa-miR-29c, and hsa-miR-25) to their target mRNAs that were also changed in GMLs.

INTERPRETATION

Our study identifies miRNAs altered in GMLs in progressive MS brains that correlate with atrophy measures. As these miRNAs were also detected in sera of MS patients, these could act as markers of GML demyelination in MS.

The role of miR-29 family in disease

MicroRNAs are small noncoding RNAs that can bind to the target sites in the 3’‐untranslated region of messenger RNA to regulate posttranscriptional gene expression. Increasing evidence has identified the miR‐29 family, consisting of miR‐29a, miR‐29b‐1, miR‐29b‐2, and miR‐29c, as key regulators of a number of biological processes. Moreover, their abnormal expression contributes to the etiology of numerous diseases. In the current review, we aimed to summarize the differential expression patterns and functional roles of the miR‐29 family in the etiology of diseases including osteoarthritis, osteoporosis, cardiorenal, and immune disease. Furthermore, we highlight the therapeutic potential of targeting members of miR‐29 family in these diseases. We present miR‐29s as promoters of osteoblast differentiation and apoptosis but suppressors of chondrogenic and osteoclast differentiation, fibrosis, and T cell differentiation, with clear avenues for therapeutic manipulation. Further research will be crucial to identify the precise mechanism of miR‐29 family in these diseases and their full potential in therapeutics.

MicroRNA in multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system (CNS). Despite a complex pathogenesis, it appears that an imbalanced immune system plays an important role in the disease process. MicroRNAs (miRNAs) are comprised of short non-coding single-stranded molecules mainly involved in regulating gene expression through the inhibition of transcription and translation. miRNAs are key regulatory molecules in the nucleus and participate in the proliferation, differentiation, and apoptosis of various cells throughout the body. Recent studies, however, have found that miRNAs are also involved in MS pathogenesis, mainly affecting glial cells and peripheral immune cells. Fortunately, miRNAs are highly stable and have high specificity in peripheral body fluids. Accordingly, these molecules have become new diagnostic and therapeutic targets. The present review discusses the role of miRNAs in the pathogenesis of MS. We highlight the potential of miRNAs as new biomarkers of MS and potential therapeutic agents.

Effects of therapeutic probiotics on modulation of microRNAs

Probiotics are beneficial bacteria that exist within the human gut, and which are also present in different food products and supplements. They have been investigated for some decades, due to their potential beneficial impact on human health. Probiotics compete with pathogenic microorganisms for adhesion sites within the gut, to antagonize them or to regulate the host immune response resulting in preventive and therapeutic effects. Therefore, dysbiosis, defined as an impairment in the gut microbiota, could play a role in various pathological conditions, such as lactose intolerance, gastrointestinal and urogenital infections, various cancers, cystic fibrosis, allergies, inflammatory bowel disease, and can also be caused by antibiotic side effects. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate gene expression in a post-transcriptional manner. miRNAs are biochemical biomarkers that play an important role in almost all cellular signaling pathways in many healthy and disease states. For the first time, the present review summarizes current evidence suggesting that the beneficial properties of probiotics could be explained based on the pivotal role of miRNAs.

Competing Endogenous RNA Networks as Biomarkers in Neurodegenerative Diseases

Protein aggregation is classically considered the main cause of neuronal death in neurodegenerative diseases (NDDs). However, increasing evidence suggests that alteration of RNA metabolism is a key factor in the etiopathogenesis of these complex disorders. Non-coding RNAs are the major contributor to the human transcriptome and are particularly abundant in the central nervous system, where they have been proposed to be involved in the onset and development of NDDs. Interestingly, some ncRNAs (such as lncRNAs, circRNAs and pseudogenes) share a common functionality in their ability to regulate gene expression by modulating miRNAs in a phenomenon known as the competing endogenous RNA mechanism. Moreover, ncRNAs are found in body fluids where their presence and concentration could serve as potential non-invasive biomarkers of NDDs. In this review, we summarize the ceRNA networks described in Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and spinocerebellar ataxia type 7, and discuss their potential as biomarkers of these NDDs. Although numerous studies have been carried out, further research is needed to validate these complex interactions between RNAs and the alterations in RNA editing that could provide specific ceRNET profiles for neurodegenerative disorders, paving the way to a better understanding of these diseases.

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.

Decreased expression of miR-29 family associated with autoimmune myasthenia gravis

Background

Myasthenia gravis (MG) is a rare autoimmune disease mainly mediated by autoantibodies against the acetylcholine receptor (AChR) at the neuromuscular junction. The thymus is the effector organ, and its removal alleviates the symptoms of the disease. In the early-onset form of MG, the thymus displays functional and morphological abnormalities such as B cell infiltration leading to follicular hyperplasia, and the production of AChR antibodies. Type-I interferon (IFN-I), especially IFN-β, is the orchestrator of thymic changes observed in MG. As Dicer and miR-29 subtypes play a role in modulating the IFN-I signalization in mouse thymus, we investigated their expression in MG thymus.

Methods

The expression of DICER and miR-29 subtypes were thoroughly investigated by RT-PCR in human control and MG thymuses, and in thymic epithelial cells (TECs). Using miR-29a/b-1-deficient mice, with lower miR-29a/b-1 expression, we investigated their susceptibility to experimental autoimmune MG (EAMG) as compared to wild-type mice.

Results

DICER mRNA and all miR-29 subtypes were down-regulated in the thymus of MG patients and DICER expression was correlated with the lower expression of miR-29a-3p. A decreased expression of miR-29 subtypes was similarly observed in MG TECs; a decrease also induced in TECs upon IFN-β treatment. We demonstrated that miR-29a/b-1-deficient mice were more susceptible to EAMG without higher levels of anti-AChR IgG subtypes. In the thymus, if no B cell infiltration was observed, an increased expression of Ifn-β associated with Baff expression and the differentiation of Th17 cells associated with increased expression of Il-6, Il-17a and Il-21 and decreased Tgf-β1 mRNA were demonstrated in miR-29a/b-1-deficient EAMG mice.

Conclusions

It is not clear if the decreased expression of miR-29 subtypes in human MG is a consequence or a causative factor of thymic inflammation. However, our results from the EAMG mouse model indicated that a reduction in miR-29a/b1 may contribute to the pathophysiological process involved in MG by favoring the increased expression of IFN-β and the emergence of pro-inflammatory Th17 cells.

The role of microRNAs in multiple sclerosis

Despite numerous studies on multiple sclerosis (MS) and understanding many aspects of this disease, researchers still struggle to find proper biomarkers that facilitate diagnosis; prognosis and monitoring of treatment efficacy in MS. MicroRNAs (miRNAs) are considered as endogenous, comparatively stable and small non-coding RNAs involved in various biological and pathological signaling pathways. Interestingly, miRNAs have been emerged as a potential biomarker for monitoring novel therapies in MS patients. In this review, we described the miRNAs alteration in the MS patients as well as their altered expression in patients under common MS therapies.

miRNAs in drug response variability: potential utility as biomarkers for personalized medicine

MicroRNAs (miRNAs) are 18-22 nucleotide RNA molecules that modulate the expression of multiple protein-encoding genes at the post-transcriptional level. Almost all physiological conditions are probably modulated by miRNAs, including pharmacological response. Indeed, acting on the regulation of numerous genes involved in the pharmacokinetics and pharmacodynamics of drugs, differences in the levels of circulating miRNAs or genetic variants in the sequences of the miRNA genes can contribute to interindividual variability in drug response, both in terms of toxicity and efficacy. For their stability in body fluids and the easy availability and accurate quantification, miRNAs could be ideal biomarkers of individual response to drugs. This review aims to give an overview on the available studies that have investigated the relationship between miRNAs and response to drugs in different classes of diseases and considered their possible clinical application as therapy response predictive biomarkers. A comprehensive search was conducted from the international web database PubMed. We included papers that investigated the relationship between miRNAs and response to drugs, published before January 2019.

microRNAs: key modulators of disease-modifying therapies in multiple sclerosis

There is a high level of heterogeneity in symptom manifestations and response to disease-modifying therapies (DMTs) in multiple sclerosis (MS), an immune-based neurodegenerative disease with ever-increasing prevalence in recent decades. Because of unknown aspects of the etiopathology of MS and mechanism of action of DMTs, the reason for this variability is undetermined, and much remains to be understood. Traditionally, physicians consider switching to other DMTs based on the exacerbation of symptoms and/or change in the results of magnetic resonance imaging and biochemical factors. Therefore, identifying biological treatment response markers that help us recognizing non-responders rapidly and subsequently choosing another DMTs is necessary. microRNAs (miRNAs) are micromanagers of gene expression which have been profiled in different samples of MS patients, highlighting their role in pathogenetic of MS. Recent studies have investigated expression profiling of miRNAs after treatment with DMTs to clarify possible DMTs-mediated mechanism and obtaining response to therapy biomarkers. In this review, we will discuss the modulation of miRNAs by DMTs in cells and pathways involved in MS.

Connection of miR-185 and miR-320a expression levels with response to interferon-beta in multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) is an inflammatory autoimmune disease characterized by neurodegeneration in the CNS. Interferon-beta (IFN-β) is an FDA-approved drug used as the first-line treatment for relapse-remitting multiple sclerosis (RRMS). The exact mechanism of IFN-β during the treatment of RRMS still remains unknown. Recently, many studies have shifted towards the role of miRNAs in the treatment of MS patients.

METHODS

Herein, the expression level of miR-185-5p and miR-320a has been evaluated in order to candidate them as novel biomarkers for monitoring the response to IFN-β therapy. For this purpose, one-hundred whole blood samples from patients with RRMS were collected, consisting of 50 responders and 50 non-responders to IFN-β therapy. To predict the possible molecular mechanisms of IFN-β and highlight the role of these miRNAs, in silico analysis was applied to enrich the signaling pathways which may be involved based on the target genes of miR-185-5p and miR-320a.

RESULTS

It is identified that the differentially expressed miR-185-5p was statistically significant between the two treated groups with IFN-β. Furthermore, MAPK signaling pathway was suggested as the main non-canonical pathway involved in IFN-β therapy.

CONCLUSION

miR-185-5p could be considered as a novel biomarker for monitoring the response to IFN-β therapy.

miR-504 expression level is increased in multiple sclerosis patients responder to interferon-beta

Multiple sclerosis is immune-mediated disease of the central nervous system characterized by demyelination in axons. IFN-β is first-line treatment of MS. Biomarkers are needed for early prediction of responders and non-responders to therapy in the first month of treatment to avoid further disabilities. In this study, we analyzed the expression level of miR-504 and miR-711 in 52 IFN-β responder patients in comparison to 53 non-responders. In the next step, the in-silico analysis was used to enrich related signaling pathways. The expression level of miR-504 was significantly higher in patients who respond to IFN-β therapy, compared with non-responders and we obtain related statistically significant KEGG molecular signaling pathways. Our findings suggest that miR-504 can be considered as a novel biomarker for response to IFN-b therapy.

Environmental Influencers, MicroRNA, and Multiple Sclerosis

Multiple sclerosis (MS) is a complex neurological disorder characterized by an aberrant immune system that affects patients' quality of life. Several environmental factors have previously been proposed to associate with MS pathophysiology, including vitamin D deficiency, Epstein-Barr virus (EBV) infection, and cigarette smoking. These factors may influence cellular molecularity, interfering with cellular proliferation, differentiation, and apoptosis. This review argues that small noncoding RNA named microRNA (miRNA) influences these factors' mode of action. Dysregulation in the miRNAs network may deeply impact cellular hemostasis, thereby possibly resulting in MS pathogenicity. This article represents a literature review and an author's theory of how environmental factors may induce dysregulations in the miRNAs network, which could ultimately affect MS pathogenicity.

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.

Precision Medicine in Neurodegenerative Diseases: Some Promising Tips Coming from the microRNAs' World

: Novel insights in the development of a precision medicine approach for treating the neurodegenerative diseases (NDDs) are provided by emerging advances in the field of pharmacoepigenomics. In this context, microRNAs (miRNAs) have been extensively studied because of their implication in several disorders related to the central nervous system, as well as for their potential role as biomarkers of diagnosis, prognosis, and response to treatment. Recent studies in the field of neurodegeneration reported evidence that drug response and efficacy can be modulated by miRNA-mediated mechanisms. In fact, miRNAs seem to regulate the expression of pharmacology target genes, while approved (conventional and non-conventional) therapies can restore altered miRNAs observed in NDDs. The knowledge of miRNA pharmacoepigenomics may offers new clues to develop more effective treatments by providing novel insights into interindividual variability in drug disposition and response. Recently, the therapeutic potential of miRNAs is gaining increasing attention, and miRNA-based drugs (for cancer) have been under observation in clinical trials. However, the effective use of miRNAs as therapeutic target still needs to be investigated. Here, we report a brief review of representative studies in which miRNAs related to therapeutic effects have been investigated in NDDs, providing exciting potential prospects of miRNAs in pharmacoepigenomics and translational medicine.

Dysregulation of Inflammasome Priming and Activation by MicroRNAs in Human Immune-Mediated Diseases

Inflammasomes are protein complexes that respond to a wide range of pathogens and cellular damage signals. Their activation prompts the caspase-1-mediated cleavage of the proinflammatory cytokines IL-1β and IL-18. Inflammasome dysregulation has been demonstrated to play a role in a range of diseases involving the adaptive immune system like multiple sclerosis, rheumatic diseases, and type 1 diabetes. Priming and activation of inflammasomes can be modulated by microRNAs (miRNAs), small noncoding RNAs that regulate gene expression posttranscriptionally. miRNAs, such as miR-223-3p, have been demonstrated to directly target the inflammasome components NLRP3, caspase-1, and caspase-8. Other miRNAs like miR-155-5p modulate TLR-, IL-1R-, TNFR-, and IFNAR-mediated signaling pathways upstream of the inflammasomes. In this study, we discuss how a more detailed elucidation of miRNA-driven inflammasome regulation helps in understanding the molecular processes underlying immune-mediated human diseases, holds potential for the identification of biomarkers and may offer novel targets for the development of future therapeutics.

Serum Exosome MicroRNAs Predict Multiple Sclerosis Disease Activity after Fingolimod Treatment

We and others have previously demonstrated the potential for circulating exosome microRNAs to aid in disease diagnosis. In this study, we sought the possible utility of serum exosome microRNAs as biomarkers for disease activity in multiple sclerosis patients in response to fingolimod therapy. We studied patients with relapsing-remitting multiple sclerosis prior to and 6 months after treatment with fingolimod. Disease activity was determined using gadolinium-enhanced magnetic resonance imaging. Serum exosome microRNAs were profiled using next-generation sequencing. Data were analysed using univariate/multivariate modelling and machine learning to determine microRNA signatures with predictive utility. Accordingly, we identified 15 individual miRNAs that were differentially expressed in serum exosomes from post-treatment patients with active versus quiescent disease. The targets of these microRNAs clustered in ontologies related to the immune and nervous systems and signal transduction. While the power of individual microRNAs to predict disease status post-fingolimod was modest (average 77%, range 65 to 91%), several combinations of 2 or 3 miRNAs were able to distinguish active from quiescent disease with greater than 90% accuracy. Further stratification of patients identified additional microRNAs associated with stable remission, and a positive response to fingolimod in patients with active disease prior to treatment. Overall, these data underscore the value of serum exosome microRNA signatures as non-invasive biomarkers of disease in multiple sclerosis and suggest they may be used to predict response to fingolimod in future clinical practice. Additionally, these data suggest that fingolimod may have mechanisms of action beyond its known functions.

Comparison of The Expression of miR-326 between Interferon beta Responders and Non-Responders in Relapsing-Remitting Multiple Sclerosis

Objective

Multiple sclerosis (MS) is an inflammatory disease resulting in demyelination of the central nervous system (CNS). T helper 17 (Th17) subset protects the human body against pathogens and induces neuroinflammation, which leads to neurodegeneration. MicroRNAs (miRNAs) are a specific class of small (~22 nt) non-coding RNAs that act as post-transcriptional regulators. The expression of the miR-326 is highly associated with the pathogenesis of MS disease in patients through the promotion of Th17 development. Recently, studies showed that disease-modifying therapies (DMTs) could balance the dysregulation of miRNAs in the immune cells of patients with relapsing-remitting MS (RRMS). Interferon-beta (IFN-β) has emerged as one of the most common drugs for the treatment of RR-MS patients. The purpose of this study was to evaluate the expression of the miR-326 in RRMS patients who were responders and non- responders to IFN-β treatment.

Materials and Methods

In this cross-sectional study, a total of 70 patients (35 responders and 35 non-responders) were enrolled. We analyzed the expression of the miR-326 in peripheral blood mononuclear cells (PBMCs) of RRMS patients at least one year after the initiation of IFN-β therapy. Real-time polymerase chain reaction (RT-PCR) was applied to measure the expression of the miR-326.

Results

The results showed no substantial change in the expression of the miR-326 between responders and non- responders concerning the treatment with IFN-β. Although the expression of the miR-326 was slightly reduced in IFN-β-responders compared with IFN-β-non-responders; however, the reduction of the miR-326 was not statistically significant.

Conclusion

Overall, since IFN-β doesn’t normalize abnormal expression of miR-326, this might suggest that IFN-β affects Th17 development through epigenetic mechanisms other than miR-326 regulation.

An Overview of Circular RNAs and Their Implications in Myotonic Dystrophy

Circular RNAs (circRNAs) are a class of single-stranded covalently closed RNA rings. Biogenesis of circRNAs, which may occur co-transcriptionally and post-transcriptionally via a back-splicing mechanism, requires the presence of complementary and/or inverted repeat sequences in introns flanking back-spliced exons and is facilitated by RNA-binding proteins. CircRNAs are abundant across eukaryotes; however, their biological functions remain largely speculative. Recently, they have been emerging as new members of a gene regulatory network and contributing factors in various human diseases including cancer, neurological, muscular and cardiovascular disorders. In this review, we present an overview of the current knowledge about circRNAs biogenesis and their aberrant expression in various human disorders. In particular, we focus on the latest discovery of circRNAs global upregulation in myotonic dystrophy type 1 (DM1) skeletal muscles and the role these prospective biomarkers might have for prognosis and therapeutic response in DM1.

MicroRNA-29b variants and MxA expression change during interferon beta therapy in patients with relapsing-remitting multiple sclerosis

BACKGROUND

Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system (CNS) characterized by immune-mediated demyelination and axonal injury. Myelin-reactive IFN-γ-producing Th1 cells has been shown to play an important role in the development of MS. MicroRNAs (miRNAs) are a new class of small non-coding RNA molecules about 22 nucleotides long which regulate gene expression post-transcriptionally by binding to 3' UTR of their mRNA targets, and resulting in degradation or transcriptional repression of the targeted mRNA. Accumulating evidence supports that miRNA dysregulation is linked to the pathogenesis of autoimmune diseases that include MS. miR-29b expression has been shown to be upregulated in memory CD4+T cells from relapsing-remitting MS (RR-MS) patients, which may reflect chronic Th1 inflammation. Interferon beta (IFN-β) benefits patients with MS and reduces symptoms of the RR-MS. MxA is induced by type I interferon and predicts IFN-β response in MS patients. The aim of this study was to evaluate miR-29b variants and MxA expression and serum IFN-γ level in responders and non-responders to IFN-β treatment.

METHODS

A total of 70 IFN-β treated RR-MS patients including 35 responders and 35 non-responders were enrolled. We analyzed the expression level of miR-29b variants and MxA using the peripheral blood of MS patients treated with IFN-β for more than one year. Real-time RT-PCR was performed to analyze miR-29b variants and MxA expression one year after initiation of IFN-β therapy. Serum cytokine level was measured by ELISA.

RESULTS

The results indicated that the expression level of miR-29b-3p changed related to IFN-β response. Moreover, miR-29b-5p was downregulated under IFN-β treatment in responders versus non-responders. MxA level was significantly decreased in the responders. There was no change in IFN-γ level following treatment with IFN-β in the MS patients.

CONCLUSIONS

Our results might provide fundamentals for the development of new markers of the biological effects of IFN-β therapy.

microRNA dysregulation in neurodegenerative diseases: A systematic review

While the root causes for individual neurodegenerative diseases are distinct, many shared pathological features and mechanisms contribute to neurodegeneration across diseases. Altered levels of microRNAs, small non-coding RNAs involved in post transcriptional regulation of gene expression, are reported for numerous neurodegenerative diseases. Yet, comparison between diseases to uncover commonly dysregulated microRNAs during neurodegeneration in general is lagging. We performed a systematic review of peer-reviewed publications describing differential microRNA expression in neurodegenerative diseases and related animal models. We compiled the results from studies covering the prevalent neurodegenerative diseases in the literature: Alzheimer's disease, amyotrophic lateral sclerosis, age-related macular degeneration, ataxia, dementia, myotonic dystrophy, epilepsy, glaucoma, Huntington's disease, multiple sclerosis, Parkinson's disease, and prion disorders. MicroRNAs which were dysregulated most often in these diseases and their models included miR-9-5p, miR-21-5p, the miR-29 family, miR-132-3p, miR-124-3p, miR-146a-5p, miR-155-5p, and miR-223-3p. Common pathways targeted by these predominant miRNAs were identified and revealed great functional overlap across diseases. We also identified a strong role for each microRNA in both the neural and immune components of diseases. microRNAs regulate broad networks of genes and identifying microRNAs commonly dysregulated across neurodegenerative diseases could cultivate novel hypotheses related to common molecular mechanisms underlying neurodegeneration.

MicroRNAs change the games in central nervous system pharmacology

MicroRNAs (miRNAs) represent a class of important post-transcriptional regulators of gene expression, enabling cells to follow their intrinsic developmental program. By directly binding to their targets, miRNAs can both promote transcriptional patterns in crucial steps of cell growth, and act as powerful buffering system that titrate protein content in case of aberrant gene expression. The literature of the last decade showed that the presence of tissue-enriched miRNAs in body fluids could be reminiscent of disease state. This is particularly relevant in neurodegenerative disorders, in which peripheral biomarkers could be helpful means to detect disease onset. However, dysregulation of miRNAs is not merely a consequence of disease, but directly contributes to pathological outcomes. On this basis, increasing interest is growing in the development of pharmacological agents targeting specific miRNAs. Actually, this apparently futuristic approach is already part of the current therapies. In fact, several drugs approved for CNS disorders, such as L-Dopa or valproic acid, were also demonstrated to restore some miRNAs. Moreover, ongoing clinical trials demonstrated that miRNA-based drugs are effective against tumors, suggesting that miRNAs also represent a promising class of therapeutic molecules. However, several issues still need to be addressed, particularly in case of CNS diseases, in which stability and delivery are crucial aspects of the therapy. In this commentary, we highlighted potential advantages and limitations of miRNAs as next generation targets in CNS pharmacology, focusing on multiple sclerosis, a chronic demyelinating disease lacking specific therapeutic targets and bona-fide biomarkers.

Small non-coding RNAs as important players, biomarkers and therapeutic targets in multiple sclerosis: A comprehensive overview

Multiple sclerosis (MS) is a leading cause of progressive disability among young adults caused by inflammation, demyelination and axonal loss in the central nervous system. Small non-coding RNAs (sncRNAs) are important regulators of various biological processes and could therefore play important roles in MS. Over the past decade, a large number of studies investigated sncRNAs in MS patients, focusing primarily on microRNAs (miRNAs). Overwhelming 500 miRNAs have been reported as dysregulated in MS. Nevertheless, owing to a large heterogeneity between studies it is challenging to evaluate the reproducibility of findings, in turn hampering our knowledge about the functional roles of miRNAs in disease. We systematically searched main databases and evaluated results from all studies that examined sncRNAs in MS to date (n = 61) and provided a detailed overview of experimental design and findings of these studies. We focused on the mechanisms of the most dysregulated sncRNAs and used predicted targets of the most dysregulated sncRNAs as input for functional enrichment analysis to highlight affected pathways. The prime affected pathway was TGF-β signaling. This multifunctional cytokine is important in the differentiation and function of T helper type 17 (Th17) and regulatory T (Treg) cells, with opposing functions in the disease. Recent studies demonstrate the importance of miRNAs in controlling the balance between Th17/Th1 cells and Tregs and, importantly, the potential to exploit this paradigm for therapeutic purposes. Additionally, some of the discussed miRNAs could potentially serve as biomarkers of disease. In order to assist researchers in evaluating the evidence of a particular sncRNA in the pathogenesis of MS, we provide a detailed overview of experimental design and findings of these studies to date.

Roles of CircRNAs in Autoimmune Diseases

Circular RNAs (circRNAs) are covalently linked single-stranded RNAs, compared to linear counterparts that are relatively abundant, conserved, stable, and specific. Previously, most studies have revealed that circRNAs function in gene expression processes and participate in the pathogenesis of cancers, cardiovascular diseases, and neurological diseases. With advances in biotechnology, more biological functions of circRNAs have been found in several signaling pathways that are related to tumorigenesis, immunity, and metabolism. Recently, many circRNAs have been reported to be expressed abnormally and play important roles in the progression of autoimmune diseases. Thus, circRNAs may not only serve as potential biomarkers but also act as immune regulators and offer potential opportunities for therapy. This review briefly introduces the properties as well as the functions of circRNAs in different stages of gene expression. In addition, this article summarizes the available knowledge about abnormally expressed circRNAs in different autoimmune diseases and discusses their potential roles in these diseases, which helps us understand their regulatory mechanisms and provides future research perspectives.

Expression Profile of Selected MicroRNAs in the Peripheral Blood of Multiple Sclerosis Patients: a Multivariate Statistical Analysis with ROC Curve to Find New Biomarkers for Fingolimod

Multiple sclerosis (MS) as a chronic autoimmune disease of the central nervous system (CNS) has been associated with dysregulation of several genes including miRNAs. In the present study, we assessed transcript levels of seven miRNAs (miR-96-5p, miR-211-5p, miR-15a, miR-34a-5p, miR-204-5p, miR-501-5p, and miR-524-5p) in the peripheral blood of MS patients compared with healthy subjects in association with response to fingolimod treatment. Expression levels of miR-211-5p and miR-34a-5p were significantly decreased in MS patients compared with healthy subjects (P values of 0.002 and 0.47). While subgroup analysis showed downregulation of miR-211-5p in both fingolimod responders and non-responders, miR-34a-5p expression was only decreased in responders. Moreover, miR-204-5p was downregulated in non-responder male patients compared with male controls. The current study underscores the role of miRNAs in determination of response to fingolimod in MS patients.

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.

Expression profiling of peripheral blood miRNA using RNAseq technology in dairy cows with Escherichia coli-induced mastitis

E. coli is the main causative agent of mastitis in dairy cows, but the mechanism of molecular regulation underlying the occurrence and development of mastitis has not yet been fully elucidated. In this study, an E. coli-induced mastitis model was created and RNASeq technology was used to measure the miRNA expression profiles at different times post-infection (0, 1, 3, 5, 7 dpi), as well as to screen for differentially expressed miRNA. The results show detection of 2416 miRNAs, including 628 known miRNAs and 1788 newly discovered miRNAs. A total of 200 differentially expressed miRNAs were found at different time points. Bioinformatics analysis showed that these differentially expressed miRNAs may regulate the occurrence and development of mastitis in dairy cows through seven signal transduction pathways, namely cytokine-cytokine receptor interaction, MAPK signaling pathway, chemokine signaling pathway, leukocyte transendothelial migration, T cell receptor signaling pathway, Toll-like receptor signaling pathway, and cell adhesion molecules. In addition, bta-miR-200a, bta-miR-205, bta-miR-122, bta-miR-182 and the newly discovered conservative_15_7229 might be involved in immune process in late stage of E. coli-induced mastitis. The results of this study lay the foundation for molecular network analysis of mastitis and molecular breeding of dairy cows.

Dysregulated MicroRNA Involvement in Multiple Sclerosis by Induction of T Helper 17 Cell Differentiation

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system. Growing evidence has proven that T helper 17 (Th17) cells are one of the regulators of neuroinflammation mechanisms in MS disease. Researchers have demonstrated that some microRNAs (miRNAs) are associated with disease activity and duration, even with different MS patterns. miRNAs regulate CD4⁺ T cells to differentiate toward various T cell subtypes including Th17 cells. In this review, we discuss the possible mechanisms of miRNAs in MS pathophysiology by regulating CD4⁺ T cell differentiation into Th17 cells, and potential miRNA targets for current disease-modifying treatments.

Exosome-associated miRNA profile as a prognostic tool for therapy response monitoring in multiple sclerosis patients

Multiple sclerosis (MS) is an autoimmune pathology leading to neurodegeneration. Because of the complexity and heterogenic etiology of this disease, diagnosis and treatment for individual patients are challenging. Exosome-associated microRNAs (miRNAs) have recently emerged as a new class of diagnostic biomarkers involved in both autoimmune and neurologic disorders. Interesting new evidence has emerged showing that circulating miRNAs are dysregulated in MS body fluids, including serum, plasma, and cerebrospinal fluid. We hypothesized that exosome-associated miRNAs could present a readily accessible blood-based assay for MS disease. We detected expression of miRNAs by quantitative PCR on a small cohort of MS patients. We analyzed circulating exosome-associated miRNAs of MS patients before and after therapy and found that 14 exosome-associated miRNAs were significantly down-regulated, while 2 exosome-associated miRNAs were significantly up-regulated in IFN-β-treated relapsing-remitting MS patients with response to therapy compared to those without response. We identified a serum miRNA panel that could be used to monitor the response to IFN-β therapy. Overall, these data suggest that circulating exosome-associated miRNA profiling could represent an easily detectable biomarker of disease and treatment response.-Manna, I., Iaccino, E., Dattilo, V., Barone, S., Vecchio, E., Mimmi, S., Filippelli, E., Demonte, G., Polidoro, S., Granata, A., Scannapieco, S., Quinto, I., Valentino, P., Quattrone, A. Exosome-associated miRNA profile as a prognostic tool for therapy response monitoring in multiple sclerosis patients.