OBJECTIVE: Although multiple sclerosis (MS) is known to be an immune-mediated disease, very little is known about its etiopathogenesis. MicroRNAs (miRNAs) are small non-coding proteins involved in the regulation of gene expression. T-cell activation potential in neurodegenerative diseases has been a research topic of interest in recent years Cytokines play an important role in the course and pathogenesis of MS, The aim of the present study was to analyze expression levels of miR-20, miR-21, miR-26, miR-155, and Let-7, which target the cytokines interleukin IL-17 and IL-23, in order to evaluate the relationship between MS and miRNAs that modulate the expression of cytokines involved in the autoimmune pathway.MATERIALS and METHODS: The study included 20 relapsing-remitting multiple sclerosis (MS) patients who were at least 18 years of age and were undergoing outpatient immunomodulatory therapy and 20 healthy, unrelated individuals who had no systemic disease and were not taking any medication as a control group. Peripheral blood samples were collected from all participants into EDTA-containing tubes and plasma was isolated for cDNA synthesis. From these cDNA samples, miRNA expression levels were quantitatively analyzed via melting curve analysis using the miScript SYBR Green kit in a Rotor-Gene Q real-time PCR device. RESULTS: Comparison of miRNA expression levels in the peripheral blood samples and MS patients and healthy subjects revealed that the MS patients had significant upregulation of miR-20 and downregulation of miR-26 and miR-155 compared to the control group (p<0.005).CONCLUSION: Dysregulation of miRNA expression may play a role in the pathogenesis of MS.
Keywords: Cytokine; expression; microRNA; patients; relapsing-remitting multiple sclerosis.