BICC1 attenuates oxidative stress-induced osteogenic injury via regulation of the PDK/PDH axis in MC3T3-E1 cells.

Oxidative stress-mediated impairment of osteoblast function is a critical pathological basis for the development and progression of various bone metabolic diseases. BicC family RNA binding protein 1 (BICC1) plays important roles in osteoblast function, however, the underlying mechanism remains unclear. This study aimed to investigate the protective role of BICC1 in oxidative stress-induced osteogenic injury and the underlying mechanism. An oxidative injury model was established in MC3T3-E1 cells using 300 µM hydrogen peroxide (H2O2). Bicc1 over-expressing lentivirus and the pyruvate dehydrogenase kinase isozyme (PDK) inhibitor dichloroacetate (DCA) were used for intervention. The osteoblast differentiation and mitochondrial membrane potential and apoptosis were measured by biochemical analysis and Alizarin Red S staining. RT-qPCR and Western blot were used to detect mRNA and protein levels of key molecules. RNA sequencing was performed to identify core targets and signaling pathways. H₂O₂ treatment significantly suppressed MC3T3-E1 cell viability and osteogenic differentiation, enhanced apoptosis, and up-regulated PDK1 expression as well as pyruvate dehydrogenase complex (PDH) phosphorylation. Bicc1 over-expression markedly alleviated H₂O₂-induced mitochondrial dysfunction and apoptosis, restored osteogenic differentiation, and inhibited the activation of the PDK1/PDH axis. Transcriptomic analysis showed that PDK1 was a key target molecule in Bicc1-regulated apoptosis and oxidative stress responses. Inhibition of PDK1 recapitulates the protective effect of BICC1 to oxidative stress injury in MC3T3-E1 cells. Bicc1 attenuates oxidative stress injury and promotes osteogenic differentiation in MC3T3-E1 cells, and may serve as a potential therapeutic target for osteoporosis.