MiR-920 promotes osteogenic differentiation of human bone mesenchymal stem cells by targeting HOXA7.

BACKGROUND

To explore the effect of miR-920 on osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs) and the possible mechanism.

METHODS

Osteoporosis (OP) and healthy control bone tissues were collected, and the relative expression of miR-920 and HOXA7 was measured. hBMSCs were isolated and cultured in vitro. Alkaline phosphatase activity and miR-920 and HOXA7 relative expression were measured during osteogenic differentiation of hBMSCs. Then, bioinformatic analysis was performed to assess the potential mechanism of miR-920. MiR-920 mimic and inhibitor were introduced into hBMSCs by lipofection transfection and were used to investigate the effect of miR-920 on the osteogenic differentiation of hBMSCs. A dual luciferase reporter assay was used to identify whether the 3'UTR of HOXA7 mRNA was a direct target of miR-920. Western blotting was performed to assess whether miR-920 affected the MAPK signaling pathway.

RESULTS

We found that miR-920 was downregulated in OP patients compared with controls, while HOXA7 was upregulated, and miR-920 had a negative correlation with HOXA7 (r = - 0.859, P = 0.001). Moreover, miR-920 was increased during osteogenic differentiation of hBMSCs, while HOXA7 had the opposite tendency. Bioinformatic analysis revealed that there were a total of 207 target genes, and MAPK was a potential targeted signaling pathway. MiR-920 mimic significantly increased ALP activity, calcium deposition, osteoblastic protein expression (ALP and OSX), and p-p38 and p-JNK protein levels.

CONCLUSION

Overall, miR-920 promotes osteogenic differentiation of hBMSCs by targeting HOXA7 through the MAPK signaling pathway.