Targeting osteoblast fatty acid metabolism attenuates skeletal and cardiovascular complications in chronic kidney disease models

Chronic kidney disease (CKD) disrupts mineral homeostasis, leading to impaired skeletal mineralization and cardiovascular pathology, yet the mechanism linking these processes remains undefined. Here we identify glycerol-3-phosphate acyltransferase 2 (GPAT2) as a regulator that couples free fatty acid (FFA) partitioning in osteoblasts to systemic phosphate balance. In mouse and human CKD, elevated osteoblast GPAT2 routes FFA away from mitochondrial oxidation, limiting phosphate incorporation into bone, and toward lysophosphatidic acid synthesis, increasing production of the phosphaturic hormone fibroblast growth factor 23 (FGF23). By contrast, osteoblast-specific Gpat2 deletion restores osteoblast FFA oxidation and skeletal phosphate incorporation, lowers circulating phosphate and FGF23, and attenuates vascular calcification and cardiac hypertrophy in CKD. Further, a bone-targeted GPAT inhibitor recapitulates most of these beneficial effects. These findings establish a fundamental role for osteoblast lipid metabolism in mineral homeostasis and identify GPAT2 in bone as a promising therapeutic target for both skeletal and cardiovascular complications of CKD.