ZC3H13 Regulates Ferroptosis to Enhance Osteogenic Differentiation in Osteoporotic BMSCs

<b><i>Objectives:</i></b> N6-methyladenosine (m⁶A) modification is critical in the regulation of osteoporosis (OP). Although ZC3H13 is an important m⁶A methyltransferase, its specific regulatory effects and mechanisms in osteoporosis are not yet fully understood. Therefore, we investigated the impact of ZC3H13 on the osteogenic potential of bone marrow-derived mesenchymal stem cells (BMSCs) in osteoporosis and attempted to elucidate its underlying mechanism. <b><i>Materials and Methods:</i></b> Western blotting, quantitative reverse transcription polymerase chain reaction, and immunohistochemical staining were used to identify changes in ZC3H13 and osteogenic factor (RUNX2 and OPN) expression in osteoporosis. Gain- and loss-of-function experiments were conducted to study the impact of ZC3H13 on the osteogenic differentiation of osteoporotic BMSCs (OP-BMSCs). Transcriptomic sequencing, transmission electron microscopy, and intraperitoneal injection of the ferroptosis inhibitor ferrostatin-1 (Fer-1) were used to elucidate the downstream mechanisms regulated by ZC3H13 in osteoporosis. In addition, rescue assays were performed to elucidate the underlying molecular mechanisms involved. <b><i>Results:</i></b> Here, we revealed that ZC3H13 was downregulated in OP-BMSCs and osteoporotic rat femurs, which correlated with the reduced osteogenic differentiation of OP-BMSCs. Functionally, ZC3H13 knockdown resulted in decreased osteogenic differentiation of the BMSCs, whereas ZC3H13 overexpression promoted the osteogenic differentiation of the OP-BMSCs. Furthermore, ZC3H13 knockdown was closely related to metal ion binding, reduced cell proliferation, and altered mitochondrial morphology. Treatment with the ferroptosis inhibitor Fer-1 partially reversed osteoporotic phenotypes <i>in vivo</i>. Mechanistically, ZC3H13 was shown to promote osteogenic differentiation in OP-BMSCs by inhibiting ferroptosis. <b><i>Conclusions:</i></b> Our study revealed that ZC3H13 promoted the osteogenic differentiation of BMSCs by inhibiting ferroptosis in osteoporosis. This research offers a reliable theoretical foundation for predicting and treating osteoporosis.