ZM-306416 prevents ovariectomy-induced bone loss by promoting osteoblastogenesis and inhibiting osteoclastogenesis - bone marrow-derived macrophages

Osteoporosis affects millions of people worldwide, and current medications like bisphosphonates and denosumab are not effective enough in reversing bone loss. Moreover, these treatments have drawbacks, including jaw osteonecrosis and skin eczema. Hence, there is an urgent need for new drugs to treat osteoporosis. Drug library screening was performed by alkaline phosphatase (ALP) staining in osteoblasts to identify potential candidates for osteoporosis. qPCR, Western blot, ALP staining, alizarin red staining, and TRAP staining were conducted to assess the impact of ZM-306416 (ZM) on osteoblast and osteoclast differentiation in vitro. Additionally, RNA sequencing and pathway analysis were carried out to explore molecular mechanisms. Micro-CT scan and immunostaining were used to determine bone phenotypes in vivo. Drug library screening demonstrated that ZM enhances ALP activity in osteoblasts, indicating its potential as a pro-osteogenic agent. ZM exerts dual effects by promoting osteoblast differentiation through the Wnt/β-catenin signaling pathway and simultaneously inhibiting osteoclast differentiation by the NF-κB and MAPK signaling pathways. In an OVX mouse model, ZM effectively prevents bone loss by stimulating osteoblast formation and inhibiting osteoclast development. Our study revealed that ZM has a dual anti-osteoporosis effect by promoting osteoblastogenesis and inhibiting osteoclastogenesis, mediated via activation of Wnt/β-catenin signaling and suppression of NF-κB/MAPK cascades. These findings suggest that ZM could be a promising therapeutic strategy for alleviating osteoporosis.