Expression of microRNA‑27a in a rat model of osteonecrosis of the femoral head and its association with TGF‑β/Smad7 signalling in osteoblasts

• Published in: International journal of molecular medicine 2019-02, Vol.43 (2), p.850-860
• Main Authors: Bai, Yuming, Liu, Ying, Jin, Shengli, Su, Ke, Zhang, Haisen, Ma, Shiyun
• Format: Article
• Language: English
• Subjects: Bones; Cell growth; Gene expression; Laboratory animals; Protein expression; Proteins; Roles; Studies; Wound healing
• ISSN: 1107-3756; 1791-244X
• DOI: 10.3892/ijmm.2018.4007

The present study assessed whether microRNA (miR)-27a is an influential factor in steroid-induced osteonecrosis of the femoral head (ONFH) and investigated the underlying mechanism of action. The results indicated that serum miR-27a was decreased in a rat model of ONFH compared with that in control rats. It was also observed that increased miR-27a expression promoted osteogenic differentiation and cell proliferation, inhibited caspase-3/9 and B-cell lymphoma-2-associated X protein expression and induced alkaline phosphatase (ALP) activity and bone morphogenetic protein (BMP)-2, runt-related transcription factor (Runx)2 and osteonectin mRNA expression in osteoblastic MC3T3-E1 cells. miR-27a mimics also induced transforming growth factor (TGF)-β and Smad7 protein expression in MC3T3-E1 cells. Furthermore, transfection with TGF-β expression plasmid was able to enhance the effects of miR-27a mimics on osteoblastic differentiation, cell proliferation, ALP activity, BMP-2, Runx2 and osteonectin mRNA expression, and Smad7 protein expression in the MC3T3-E1 cells. Transfection with a TGF-β or Smad7 expression plasmid also enhanced the effects of miR-27a mimics on osteoblastic differentiation, cell proliferation, ALP activity and osteonectin mRNA expression in the MC3T3-E1 cells. Taken together, the results of the present study suggested that the induction of TGF-β/Smad7 signaling in osteoblasts may be a potential mechanism by which miR-27a regulates steroid-induced ONFH.