miR-27a and miR-214 exert opposite regulatory roles in Th17 differentiation via mediating different signaling pathways in peripheral blood CD4+ T lymphocytes of patients with relapsing-remitting multiple sclerosis.

Multiple sclerosis (MS) is one of the most prevalent autoimmune diseases, which involves the central nervous system. In this illness, Treg/Th17 cell imbalance causes the defect. Several studies revealed that T helper 17 (Th17) cells play a crucial role in pathogenesis, inflammation, and autoimmunity of several autoimmune diseases such as MS. In the present study, we assessed transcript levels of miR-27a and miR-214, in purified CD4+ T cells of MS patients, during relapsing and remitting phases in inducing differentiation of T naïve cells to Th17 cells. Forty RR-MS patient samples including those in relapsing (n=20) and remitting (n=20) phases were participated in this study. In addition, transcript levels of IL-17A, RORγt, IL-23R, Foxp3, and TGF-β in purified CD4+ T cells of patients in relapsing and remitting phases of RRMS patients were compared to healthy controls. Expression levels of miR-27a and miR-214 were measured by RT-qPCR and compared to healthy control group (n=10). Data indicated upregulation of miR27a in relapsing phase of multiple sclerosis compared to remitting phase and healthy volunteers while miR-214 downregulated in relapsing phase of MS compared to remitting phase and healthy volunteers. In silico studies demonstrated pathways which miR-27a and miR-214 could effect on CD4+ T cell lineage fate including TGF-β and mTOR signaling, respectively. Our data suggest that miR-27a may probably inhibit negative regulators of Th17 cell differentiation, thus promoting its differentiation while miR-214 has an adverse effect.