MicroRNA-543 promotes ovariectomy-induced osteoporosis through inhibition of AKT/p38 MAPK signaling pathway by targeting YAF2

The present study aimed to determine the roles of miRNA-543 in osteoporosis in rats induced by ovariectomy. The osteoporosis rat model was established by ovariectomy induction. MiRNA-543 expression in osteoblasts was measured by quantitative real-time polymerase chain reaction. The cell proliferation and Apoptosis were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry assays, respectively. Western blot analysis was conducted to examine the expression of YAF-2 and Akt signaling. TargetScan analysis and dual-luciferase reporter assay were performed to determine the target gene of miRNA-543. MiRNA-543 was significantly upregulated in osteoporosis rat model. Overexpression of miRNA-543 significantly suppressed cell growth and promoted Apoptosis in osteoblasts, whereas downregulation of miRNA-543 significantly enhanced cell growth and inhibited Apoptosis. MiRNA-543 upregulation significantly inhibited YAF-2 expression and suppressed the phosphorylation and expression of Akt and p38 mitogen-activated protein kinases (MAPK) in osteoblasts. Furthermore, YAF-2 knockdown enhanced the effects of miRNA-543 on Apoptosis in osteoblasts. Akt Inhibitor MK2206 and p38 MAPK Inhibitor SB203580 also enhanced the effects of miRNA-543 on Apoptosis in osteoblasts. Our findings revealed that inhibition of miRNA-543 could protect osteoblasts against ovariectomy-induced osteoporosis through Akt/p38 MAPK signaling pathway by targeting YAF2.