microRNA involvement in the regulation of survivin in peripheral blood mononuclear cells from rheumatoid arthritis patients

Aim: Impaired regulation of immune tolerance results in autoimmune diseases, such as rheumatoid arthritis (RA). Survivin is an anti-apoptotic protein and can induce cellular mitosis. In the current study, we assessed the transcript level of total survivin (survivin-TS) and its three major variants and evaluated the expression level of important micro RNAs (miRNAs) involved in survivin expression regulation in RA patients.

Method: Peripheral blood mononuclear cells (PBMCs) were isolated from 50 healthy controls and 50 RA-active patients. RNA extraction was performed and then single-strand complementary DNA was synthesized. Quantitative real-time polymerase chain reaction was used to assess the expression level of survivin-TS and its variants with effective miRNAs in PBMCs.

Results: Overexpression of survivin-2B (fold change = 1.57, P = 0.005), survivn-ΔEx3 (fold change = 1.93, P = 0.009) and downregulation of survivin-WT (fold change = 0.64, P = 0.0002) were found in PBMCs of patients, while messenger RNA (mRNA) expression of survivin-TS had no significant difference between RA patients and controls. Expression levels of miR-335-5p, miR-485-5p, miR-16-5p, miR-150-5p, miR-34a-5p, and miR-203a-3p were significantly increased in PBMCs from patients compared with healthy controls. In a correlation study, dysregulation of these miRNAs were not correlated with mRNA expression level of survivin.

Conclusion: While survivin-TS was not differently expressed in RA patients, its variants had altered expression. Although miRNAs were aberrantly expressed in PBMCs from RA subjects, they did not regulate survivin-TS. miRNAs might be involved in RA pathogenesis, but not through controlling survivin.