The putative cannabinoid receptor GPR55 affects osteoclast function in vitro and bone mass in vivo.

ABSTRACT: GPR55 is a G protein-coupled receptor recently shown to be activated by certain cannabinoids and by lysophosphatidylinositol (LPI). However, the physiological role of GPR55 remains unknown. Given the recent finding that the cannabinoid receptors CB(1) and CB(2) affect bone metabolism, we examined the role of GPR55 in bone biology. GPR55 was expressed in human and mouse osteoclasts and osteoblasts; expression was higher in human osteoclasts than in macrophage progenitors. Although the GPR55 agonists O-1602 and LPI inhibited mouse osteoclast formation in vitro, these ligands stimulated mouse and human osteoclast polarization and resorption in vitro and caused activation of Rho and ERK1/2. These stimulatory effects on osteoclast function were attenuated in osteoclasts generated from GPR55(-/-

SUBMITTER: Whyte LS 

PROVIDER: S-EPMC2737440 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature