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

Construction of ceRNA network mediated by circRNAs screening from microarray and identification of novel biomarkers for myasthenia gravis

BACKGROUND

Recent studies have revealed that circRNA can serve as ceRNA to participate in multiple autoimmune diseases. Our study aims to explore the key circRNA as ceRNA and biomarker for MG.

METHODS

We used circRNA microarray to explore differentially expressed circRNAs (DECs) from MG and compare with control. Then, we predicted the target miRNA associated with DECs and screened miRNAs by the algorithm of random walk with restart (RWR). Next, we constructed the circRNA-miRNA-mRNA ceRNA regulated network (CMMC) to identify the hub objects. Following, we detected the expression of hub-circRNAs by RT-PCR. We verify has_circ_0004183 (circFRMD4) sponging miR-145-5p regulate cells proliferation using luciferase assay and CCK-8.

RESULTS

We found that the expression level of circFRMD4 and has_circ_0035381 (circPIGB) were upregulated and has_circ_0089153(circ NUP214) had the lowest expression level in MG. Finally, we proved circFRMD4 sponging miR-145-5p regulate Jurkat cells proliferation. CircFRMD4 take part in the genesis and development of MG via circFRMD4/miR145-5p axis.

CONCLUSIONS

We found that circFRMD4, circPIGB and circNUP214 can be considered as valuable potential novel biomarkers for AchR + MG. CircFRMD4 participate in the development of AchR + MG via targeting binding with miR-145-5p.

miR-24-3p and miR-484 are potential biomarkers for neurodegeneration in multiple sclerosis

Multiple sclerosis (MS) is a complex, neurodegenerative chronic disorder. Circulating diagnostic biomarkers for MS have remained elusive, and those proposed so far have limited sensitivity and specificity to MS. Plasma-circulating microRNAs (miRNAs) have advantageous biochemical and physiological attributes that can be utilized in clinical testing and disease monitoring. MS miRNA expression microarray datasets analysis resulted in four candidate miRNAs that were assessed for their expression in a separate MS case-control study. Only miR-24-3p was downregulated in all MS patients compared to healthy controls. MiR-484 was significantly upregulated in relapsing-remitting MS (RRMS) patients compared to healthy controls. Mir-146-5p and miR-484 were significantly downregulated in secondary-progressive MS (SPMS) compared to RRMS. MiR-484 downregulation was associated with worsening disability and increased lipocalin-2 levels. Mir-342-3p and miR-24-3p downregulation were associated with increased semaphorin-3A levels in MS and RRMS patients. In conclusion, mir-24-3p downregulation is diagnostic of MS, and mir-484 upregulation and downregulation are potential biomarkers for RRMS and SPMS conversion, respectively. The differential expression of miR-146a-3p in MS subtypes suggests its potential as an SPMS transition biomarker. The association of downregulated mir-24-3p and mir-484 with increased neurodegeneration biomarkers suggests they play a role in MS pathogenesis and neurodegeneration.

Potential therapeutic and diagnostic approaches of exosomes in multiple sclerosis pathophysiology

Exosomes are bilayer lipid vesicles that are released by cells and contain proteins, nucleic acids, and lipids. They can be internalized by other cells, inducing inflammatory responses and instigating toxicities in the recipient cells. Exosomes can also serve as therapeutic vehicles by transporting protective cargo to maintain homeostasis. Multiple studies have shown that exosomes can initiate and participate in the regulation of neuroinflammation, improve neurogenesis, and are closely related to the pathogenesis of central nervous system (CNS) diseases, including multiple sclerosis (MS). Exosomes can be secreted by both neurons and glial cells in the CNS, and their contents change with disease occurrence. Due to their ability to penetrate the blood-brain barrier and their stability in peripheral fluids, exosomes are attractive biomarkers of CNS diseases. In recent years, exosomes have emerged as potential therapeutic agents for CNS diseases, including MS. However, the molecular pathways in the pathogenesis of MS are still unknown, and further research is needed to fully understand the role of exosomes in the occurrence or improvement of MS disease. Thereby, in this review, we intend to provide a more complete understanding of the pathways in which exosomes are involved and affect the occurrence or improvement of MS disease.

Possible Roles of Extracellular Vesicles in the Pathogenesis and Interventions of Immune-Mediated Central Demyelinating Diseases

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are two of the most devastating immune-mediated central demyelinating disorders. NMOSD was once considered as a variant of MS until the discovery of an antibody specific to the condition. Despite both MS and NMOSD being considered central demyelinating disorders, their pathogenesis and clinical manifestations are distinct, however the exact mechanisms associated with each disease remain unclear. Extracellular vesicles (EVs) are nano-sized vesicles originating in various cells which serve as intercellular communicators. There is a large body of evidence to show the possible roles of EVs in the pathogenesis of several diseases, including the immune-mediated central demyelinating disorders. Various types of EVs are found across disease stages and could potentially be used as a surrogate marker, as well as acting by carrying a cargo of biochemical molecules. The possibility for EVs to be used as a next-generation targeted treatment for the immune-mediated central demyelinating disorders has been investigated. The aim of this review was to comprehensively identify, compile and discuss key findings from in vitro, in vivo and clinical studies. A summary of all findings shows that: 1) the EV profiles of MS and NMOSD differ from those of healthy individuals, 2) the use of EV markers as liquid biopsy diagnostic tools appears to be promising biomarkers for both MS and NMOSD, and 3) EVs are being studied as a potential targeted therapy for MS and NMOSD. Any controversial findings are also discussed in this review.

Multiple Sclerosis: Roles of miRNA, lcnRNA, and circRNA and Their Implications in Cellular Pathways

Multiple sclerosis (MS) is a degenerative condition characterized by axonal damage and demyelination induced by autoreactive immune cells that occur in the Central Nervous System (CNS). The interaction between epigenetic changes and genetic factors can be widely involved in the onset, development, and progression of the disease. Although numerous efforts were made to discover new therapies able to prevent and improve the course of MS, definitive curative treatments have not been found yet. However, in recent years, it has been reported that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), acting as gene expression regulators, could be used as potential therapeutic targets or biomarkers to diagnose and fight MS. In this review, we discussed the role of miRNAs, lncRNAs, and circRNAs, as well as their expression level changes and signaling pathways that are related to preclinical and human MS studies. Hence, the investigation of ncRNAs could be important to provide additional information regarding MS pathogenesis as well as promote the discovery of new therapeutic strategies or biomarkers.

Exosome Content-Mediated Signaling Pathways in Multiple Sclerosis

Exosomes are small extracellular vesicles with a complex lipid-bilayer surface and 30-150 nm diameter. These vesicles play a critical role in intercellular signaling networks during physiopathological processes through data trafficking and cell reprogramming. It has been demonstrated that exosomes are involved in a variety of central nervous system (CNS) disorders such as multiple sclerosis (MS). Exosome mediators' cell-to-cell communication is possibly by delivering their contents such as proteins, RNAs (coding and non-coding), DNAs (mitochondrial and genomic), and transposable elements to the target cells. Exosomal microRNAs (miRNAs) differ in their expression patterns in MS disease, thereby providing novel diagnostic and prognostic biomarkers and therapeutic options for better treatment of MS disease. Furthermore, these microvesicles are non-immunogenic and non-toxic therapeutic tools for transferring miRNAs across the blood-brain barrier (BBB). Collectively, exosomes could be used as novel drug delivery devices for the treatment of MS patients. This review summarized research regarding the exosomes from serum, plasma, PBMC, and other cells in MS patients and experimental models. We also provide a critical view of exosome content-mediated signaling pathways in MS, including TNF-α, TGF-β, NF-κB, and Wnt pathways. The use of exosomes as a therapeutic potential in MS has also been discussed.

Mechanisms of microRNA-132 in central neurodegenerative diseases: A comprehensive review

MicroRNA-132 (miR-132) is a highly conserved molecule that plays a crucial regulatory role in central nervous system (CNS) disorders. The expression levels of miR-132 exhibit variability in various neurological disorders and have been closely linked to disease onset and progression. The expression level of miR-132 in the CNS is regulated by a diverse range of stimuli and signaling pathways, including neuronal migration and integration, dendritic outgrowth, and complexity, synaptogenesis, synaptic plasticity, as well as inflammation and apoptosis activation. The aberrant expression of miR-132 in various central neurodegenerative diseases has garnered widespread attention. Clinical studies have revealed altered miR-132 expression levels in both chronic and acute CNS diseases, positioning miR-132 as a potential biomarker or therapeutic target. An in-depth exploration of miR-132 holds the promise of enhancing our understanding of the mechanisms underlying CNS diseases, thereby offering novel insights and strategies for disease diagnosis and treatment. It is anticipated that this review will assist researchers in recognizing the potential value of miR-132 and in generating innovative ideas for clinical trials related to CNS degenerative diseases.