Mir-149 Promotes Survival and Differentiation of Bone Marrow Mesenchymal Stem Cells by Regulating Interleukin-6/Signal Transducer and Activator of Transcription 3 Signaling Pathway

Abstract

Bone marrow mesenchymal stem cells (BMSCs) can self-renew with multi-directional differentiation. Mir-149 is involved in various diseases, but whether Mir-149 regulates the survival and differentiation of BMSCs and related mechanisms remains unclear. BMSCs were isolated and randomly divided into Si-NC group, Mir-149 siRNA group, and Mir-149 siRNA + STAT3 inhibitor WP1066 group followed by analysis of the expression of Mir-149, RUNX2 and OPN mRNA by real time PCR, BMSCs proliferation by MTT assay, Caspase 3 activity, ALP activity, formation of type II collagen and IL-6 level by ELISA, as well as STAT3 signaling pathway expression by Western blot. Mir-149 expression was reduced in BMSCs of Mir-149 siRNA group, with promoted survival of BMSCs, decreased Caspase 3 activity, increased expression of RUNX2 and OPN, type II collagen formation, ALP activity, IL-6 secretion, as well as elevated pSTAT3 phosphorylation. The differences were statistically significant compared to Si-NC group (P < 0.05). Mir-149 siRNA + WP1066 inhibited pSTAT3 phosphorylation, reduced BMSCs survival, increased Caspase 3 activity, decreased RUNX2 and OPN expression, type II collagen production, ALP activity, as well as reduced IL-6 secretion. Compared with Mir-149 siRNA group, there were significant differences (P < 0.05). Down-regulation of Mir-149 in BMSCs can promote BMSCs survival and osteogenic differentiation by regulating IL-6/STAT3 signaling pathway.