Mechanism of miRNA-31 Regulating Wnt/β-catenin Signaling Pathway by Targeting Satb2 in the Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells.

Objective: To explore the expression of miR-31 and Satb2 gene in the serum of postmenopausal women with osteoporosis (OP).

Methods: 97 postmenopausal women with OP and 100 healthy women were selected as research subjects. MSCs were purchased from Shanghai Zhong Qiao Xin Zhou Biotechnology Co., Ltd. Bone marrow-derived mesenchymal stem cells (BMSCs) were isolated, identified and transfected, and then quantified by alkaline phosphatase (ALP) levels. The expression levels of miR-31 and Satb2 gene mRNA were determined by qRT-PCR. The proteins of RUNX2, OCN and BMP and Wnt/β-catenin pathway-related proteins (GSK-3, Frizzled 1, Lrp5, Lrp6 and β-catenin) were tested by Western blotting.

Results: In the OP group, the relative expression of miR-31 was 3.61±0.54, significantly higher than that (1.75±0.27) in the healthy control group (t=9.422, P<0.001). The relative expression of mRNA of Satb2 gene was 0.86±0.12, significantly lower than that (1.35±0.21) in the healthy control group (t=5.897, P<0.001).

Conclusions: The increase in miR-31 expression can down-regulate the Wnt/β-catenin pathway by targeting the expression of Satb2 gene, thereby inhibiting the osteogenic differentiation of BMSCs. This provides an important reference for further understanding the mechanism of OP and identifying targets for early diagnosis and treatment.