MicroRNAs as biomarkers of multiple sclerosis progression

Abstract

Multiple sclerosis (MS) is an autoimmune inflammatory neurodegenerative disease of the central nervous system. The disease is characterized by a heterogeneous clinical course, which is reflected in the fact that there are various types, such as relapsing-remitting MS (RRMS), primary and secondary progressive MS (PPMS and SPMS, respectively). Currently, there is an active search for MS biomarkers capable of predicting and assessing disease progression with high sensitivity and specificity, which would be of great benefit in determining treatment tactics and evaluating their efficacy. MicroRNAs (miRNAs) are short (21–25 nucleotides) non-coding RNA molecules that are primarily involved in post-transcriptional regulation of gene expression. miRNAs play an essential role in tissue development, homeostasis, immune system regulation, and immune cell maturation; they are also involved in the pathophysiology of MS. In addition, high hopes are pinned on miRNAs as disease biomarkers, mainly due to their stability and ability to be released from cells into the extracellular space and circulate there for a long time. The review considers published data on miRNAs in different types of MS. In the future, changes in their levels may be used to create a panel of prognostic markers for disease progression. Studies of miRNAs levels in both circulating fluids (plasma, serum, cerebrospinal fluid) and brain tissue of MS patients were reviewed. Based on the aggregated data from the studies reviewed, it can be confirmed that the accumulated data are quite sufficient to recognize that regulatory miRNAs molecules are involved in the pathophysiological mechanisms of MS progression. However, there is still a long way to go to establish a panel of circulating miRNAs that predict the rate of progression of MS.