MiR-376a-3p inhibits bone repair by regulating osteoblastic differentiation

Nonunion occurs in about 10% of fracture cases, which leads to secondary surgical injury and economic burden for patients.

Our study aimed to confirm the effects of miR-376a-3p/WWTR1 on fracture healing.

Through bioinformatics analysis, we found that miR-376a-3p was highly expressed in patients with fracture nonunion. We confirmed the interaction of miR-376a-3p and WWTR1 by using RT-qPCR, RNA immunoprecipitation, and Dual-Luciferase assay. Rescue experiment was used to explore the effects of miR-376a-3p/WWTR1 on human bone marrow mesenchymal stem cells (hBMSCs) differentiation into osteoblasts.

We confirmed that miR-376a-3p was up-regulated in fracture nonunion patients by a retrospective study of clinical data of fracture patients. In vitro experiments showed that inhibiting the miR-376a-3p would increase the expression of WWTR1. It was found in the induction of the hBMSCs differentiation assay that inhibition of miR-376a-3p or overexpression of WWTR1 could increase the level of ALP, Runx2, and OSX in cell supernatant, which reflected the increased differentiation of hBMSCs into osteoblasts. And rescue experiment confirmed that miR-376a-3p inhibits differentiation of hBMSCs through targeted regulating WWTR1.

We revealed the regulatory role of miR-376a-3p/WWTR1 in fracture nonunion by inhibiting osteogenic induction, which provides the possibility that miR-376a-3p may be a new underlying target for fracture nonunion prediction and therapy.