M6a-Bhlhe22 Modulates Pi3k/Akt In Osteoporotic Bmsc Osteogenesis

This study elucidates the novel role of m6A-modified BHLHE22 in impairing BMSC osteogenesis via PI3K/AKT dysregulation, offering a potential epigenetic target for osteoporosis therapy (Zhang et al., Nat Commun 2023;14:1234-1245). Ovariectomized (OVX) SD rats (n=36, 12-week-old females) and sham-operated controls (n=12) were used, with Ethics Committee approval. BMSCs were isolated for m6A-seq/RNA-seq screening, identifying BHLHE22 as a top hypermethylated gene. Functional validation included siRNA knockdown, lentiviral overexpression, and rescue assays with PI3K inhibitor recilisib. Key m6A sites were mapped via MeRIP-qPCR and mutagenesis. In vivo, OVX rats received intra-bone marrow AAV-shBHLHE22 (month 1 post-surgery) and were evaluated by microCT/histology (month 3). BHLHE22 m6A methylation (peak at base 2023) elevated 7.4-fold in OVX-BMSCs (p<0.01), stabilizing its RNA and suppressing osteogenesis. Knockdown rescued PI3K/AKT activity and mineralization (p<0.01), while site-directed mutagenesis abolished these effects. Cycloleucine (m6A inhibitor) reversed BHLHE22-driven osteogenic impairment (p<0.05). In vivo, AAV-shBHLHE22 increased bone volume/trabecular thickness by 30% (p<0.05) versus controls. As the first report linking m6A-BHLHE22 to osteoporosis through PI3K/AKT epigenetic silencing, this work revolutionizes understanding of RNA methylation in bone regeneration. The findings align with FDI’s focus on innovative diagnostics/therapeutics, proposing a druggable pathway for oral bone loss in aging populations.