Enhancing Osteoblast Activity and Accelerating Fracture Healing via miR-656-3p Downregulation: A Novel Targeting Strategy Focused on BMP-2 Expression.

Delayed fracture healing (DFH), a common complication of post-fracture surgery, exhibits an incompletely understood pathogenesis. The present study endeavors to investigate the roles and underlying mechanisms of miR-656-3p and Bone Morphogenetic Protein-2 (BMP-2) in DFH. It was recruited 94 patients with normal fracture healing (NFH) and 88 patients with DFH of the femoral neck. Serum miR-656-3p and BMP-2 expressions were quantified using RT-qPCR and the diagnostic potential of them for DFH was evaluated using ROC analysis. Factors influencing fracture healing were identified through logistic regression analysis. Osteogenic differentiation of MC3T3-E1 cells was induced, followed by evaluations of cell proliferation, apoptosis, and differentiation capabilities utilizing CCK-8, flow cytometry, and mRNA expression analysis of osteogenic markers. The targeting relationship between miR-656-3p and BMP-2 was validated through luciferase reporter assays. The levels of miR-656-3p were significantly elevated in DFH patients compared to those with NFH, whereas BMP-2 levels exhibited a decrease, a negative correlation between their expression patterns. Logistic regression analysis revealed that miR-656-3p and BMP-2 serve as influential factors in fracture healing, with their combined assessment exhibiting enhanced predictive value for DFH. Downregulation of miR-656-3p promoted proliferation and differentiation of MC3T3-E1 cells while inhibiting apoptosis. BMP-2, identified as a target of miR-656-3p, negated the effects of miR-656-3p downregulation when BMP-2 expression was inhibited. miR-656-3p modulates osteoblast function by targeting BMP-2, offering novel therapeutic and diagnostic targets for the management of DFH.