Dabigatran Attenuates Osteoporosis by Balancing Osteoblastogenesis and Osteoclastogenesis by Targeting PRKAB1 and RELA.

Imbalances between osteoblastogenesis and osteoclastogenesis represent the fundamental pathological feature of primary osteoporosis; however, safe and cost-effective therapies that simultaneously promote bone formation and suppress bone resorption are lacking. Given the central roles of runt-related transcription factor 2 and the nuclear factor κB pathway in bone remodeling, we performed a phenotypic screen of a Food and Drug Administration-approved drug library to identify dual-acting regulators of bone homeostasis and identified the orally approved anticoagulant dabigatran (DAB) as a novel candidate. In vivo, DAB administration markedly attenuated bone loss and preserved bone microarchitecture in both ovariectomized and aged mouse models of osteoporosis. In vitro, DAB not only inhibited receptor activator of nuclear factor κB ligand-induced osteoclastogenesis from bone-marrow-derived macrophages but also directly enhanced the osteogenic differentiation of bone marrow mesenchymal stem cells. Mechanistically, using limited proteolysis-coupled mass spectrometry, we identified protein kinase adenosine-monophosphate-activated noncatalytic subunit β1 and v-Rel reticuloendotheliosis viral oncogene homolog A as direct targets of DAB. In bone marrow mesenchymal stem cells, DAB binds to protein kinase adenosine-monophosphate-activated noncatalytic subunit β1 via the alanine-77 residue, leading to adenosine-monophosphate-activated protein kinase activation, subsequent mechanistic target of rapamycin complex 1 inhibition, enhanced autophagic flux, and ultimately promoted osteogenesis; in osteoclast precursors, DAB interacts with v-Rel reticuloendotheliosis viral oncogene homolog A at arginine-50, resulting in suppression of the nuclear factor κB pathway and attenuated osteoclast differentiation. Collectively, our findings reposition DAB as a promising therapeutic candidate for restoring osteoblast-osteoclast balance and maintaining skeletal homeostasis while establishing a novel single-molecule, dual-target pharmacological strategy and providing novel mechanistic insights for bone metabolic disease treatment.