miR-431 inhibits adipogenic differentiation of human bone marrow-derived mesenchymal stem cells via targeting insulin receptor substance 2

BACKGROUND: An understanding of the mechanism underlying adipogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs) will provide new therapeutic approaches for many diseases, including osteoporosis. This study aimed to investigate the role of miR-431 in adipogenic differentiation of hMSCs. METHODS: hMSCs were induced for adipogenic differentiation and miR-431 was detected by polymerase chain reaction (PCR). hMSCs were transfected by miR-431 or small interfering RNA (siRNA) for insulin receptor substance 2 (IRS2). The expression of IRS2 was detected by PCR and Western blot analysis. The targeting of the 3′-untranslated region (UTR) of IRS2 by miR-431 was examined by luciferase assay. RESULTS: miR-431 expression was decreased during adipogenesis of hMSCs. Overexpression of miR-431 inhibited adipogenic differentiation, accompanied by the downregulation of CCAAT/enhancer binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ), two key regulators of adipogenesis. Moreover, miR-431 decreased both protein and mRNA levels of IRS2. The expression of IRS2 was increased during adipogenic differentiation of hMSCs in conjunction with decreased levels of miR-431, and knockdown of IRS2 in hMSCs inhibited adipogenic differentiation. Luciferase assay confirmed that miR-431 targeted the 3′-UTR of IRS2 in hMSCs. CONCLUSIONS: This is the first study to show that miR-431 inhibits adipogenic differentiation of hMSCs via targeting IRS2.