Longevity & AgingAPJ Receptor Activation Clears Damaged Mitochondria to Halt Inflammation-Driven Bone Loss
Chronic inflammation drives bone loss by pushing macrophages into a destructive M1 state that activates osteoclasts. Researchers found that activating APJ, a G-protein-coupled receptor, counteracts this by ramping up mitophagy — the cellular process that clears damaged mitochondria. In a mouse model of LPS-induced systemic inflammatory bone loss, treatment with Apelin-13 (the APJ ligand) reduced osteoclast activity and preserved bone density. Lab studies traced the mechanism through the AMPK/BNIP3/PINK1/PARKIN pathway: APJ activation improved mitochondrial quality, lowered reactive oxygen species, and blocked NLRP3 inflammasome assembly, ultimately suppressing M1 macrophage polarization. The findings position APJ as a promising therapeutic target for inflammation-associated osteoporosis.
