Research on miRNAs Involved in the Remyelination Process in Patients with Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system that leads to progressive neurodegeneration and diverse neurological symptoms, most commonly affecting young and middle-aged women. MicroRNAs play key regulatory roles in immune function and myelin repair, making them potential markers of disease mechanisms and treatment response. MS is managed with disease-modifying therapies classified as first-line agents (e.g., interferon beta, glatiramer acetate) and second-line agents (e.g., natalizumab, fingolimod). However, reliable biomarkers capable of objectively assessing treatment effectiveness in individual patients are still lacking, underscoring the need to identify molecular indicators of therapeutic response. RNA was extracted from blood using the “MirVana™ miRNA Isolation Kit”. Nucleic acid concentration and purity were determined using a NanoDrop 2000 spectrophotometer. Complementary DNA was synthesized with “TaqMan® Advanced miRNA Assays”, and miRNA expression was quantified by real-time PCR. Resulting data were processed using “QuantStudio™ Design & Analysis Software”, and statistical analyses were performed in SPSS. Significant differences in the expression of both examined microRNAs were observed between treatment groups, with the highest levels detected in patients receiving secondline therapy (p < 0.05). A significant positive correlation between miR-204-5p and miR17-5p expression was also identified, most pronounced in the second-line treatment group (p < 0.05). MiR-204-5p and miR-17-5p showed distinct expression patterns across treatment groups, with both microRNAs most highly expressed in patients receiving second-line therapy. When comparing expression levels before and after both first-line and secondline treatment, miR-204-5p showed a slight increase, while miR-17-5p showed a slight decrease. However, these changes were not statistically significant. It was found that the interaction between the two microRNAs involved in the remyelination process was significant in patients treated with second-line therapies.