BIRC3 facilitates osteogenic differentiation of bone marrow mesenchymal stem cells via NGFR/β-catenin signalling axis

Aims: Osteoporosis primarily results from age-related declines in bone marrow mesenchymal stem cell (BMSC) differentiation into osteoblasts; however, the regulatory mechanisms remain unclear. Methods: Integrated analysis of Gene Expression Omnibus (GEO) and RNA sequencing (RNA-seq) data identified a key osteogenic regulator. Western blot, reverse transcription quantitative polymerase chain reaction (RT-qPCR), RNA-seq, immunohistochemistry (IHC), alkaline phosphatase (ALP), and alizarin red S (ARS) staining were employed to elucidate the functional and mechanistic aspects of modulating osteogenic differentiation. A C57 mouse tibial drill-hole model was used to evaluate therapeutic potential. Results: RNA-seq identified baculoviral inhibitor of apoptosis (IAP) repeat-containing protein 3 (BIRC3) as a potential regulator of BMSC osteogenesis, showing significant upregulation during BMSC osteogenic differentiation and upon monocyte stimulation. BIRC3 positively correlated with ALP and ARS staining intensity and significantly enhanced the expression of (runt-related transcription factor 2) RUNX2 and ALP proteins. RNA-seq, RT-qPCR, and western blot data indicated that BIRC3 positively regulates the expression of nerve growth factor receptor (NGFR). NGFR also promoted the osteogenic differentiation of BMSCs. Further experiments demonstrated that BIRC3 regulates BMSC osteogenesis through NGFR. Through XAV939 treatment, we demonstrated that both BIRC3 and NGFR promoted BMSC osteogenesis by enhancing β-catenin expression and nuclear translocation, thereby defining the functional role of the BIRC3/NGFR/β-catenin axis in BMSCs. In C57 mouse tibial bone defect models, BIRC3 overexpression group exhibited significantly enhanced callus formation and ossification compared to the control group. Conclusion: BIRC3 regulates BMSC osteogenic differentiation via NGFR/β-catenin signalling in vitro and promotes bone healing in vivo, suggesting therapeutic potential for osteoporosis and bone defects.