Abstract:Objective To investigate the effect of miRNA-140-5p on the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) and its possible mechanisms. Methods The miRNA-140-5p mimic, inhibitor, recombinant plasmid pcDNA3.1-Wnt1 and its corresponding negative control were constructed and transfected into hBMSCs，which were divided into corresponding groups according to the different transfectants. CCK8, alizarin red staining, ELISA, qRT-PCR, Western blot and other molecular biological techniques were applied to detect the cell viability and osteogenic differentiation of hBMSCs, and the dual-luciferase reporter gene system was used to identify the target gene of miRNA-140-5p. Results After transfection, the expression level of miRNA-140-5p was significantly increased in Mimic group and was significantly decreased in Inhibitor group（P＜0.05）, while the cell viability of hBMSCs had no significant change in both groups（P>0.05）. Alizarin red staining and the detection of osteogenic differentiation markers Runt-related transcription factor 2（RUNX2） and alkaline phosphatase （ALP） protein showed that the osteogenic differentiation of hBMSCs was significantly increased in Inhibitor group and was inhibited in Mimic group（P＜0.05）. The results of the dual-luciferase reporter gene system showed that Wnt1 was the target gene of miRNA-140-5p. Western blot analysis showed that the expression levels of Wnt1 and β-catenin decreased in Mimic group and increased in Inhibitor group（P＜0.05）. High expression of Wnt1 in hBMSCs significantly increased their osteogenic differentiation（P＜0.05）. Conclusion Low expression of miRNA-140-5p can promote the osteogenic differentiation of hBMSCs by targeting the Wnt1/β-catenin signaling pathway.