Cannabinoid receptor 1 regulates ERK and GSK-3β-dependent glucocorticoid inhibition of osteoblast differentiation in murine MC3T3-E1 cells

► Cannabinoid receptor 1 (CB1) mediates the deleterious effects of glucocorticoid on MC3T3-E1 osteoblastic cell survival and differentiation. ► ERK and GSK-3β signaling transduction contributes to CB1 regulation of osteoblastic activities. ► The osteogenic transcription factor Runx2 reciprocally regulates CB1 signaling in glucocorticoid-stressed osteoblastic cells. ► CB1 blockade is an alternative strategy for alleviating the adverse actions of glucocorticoid on osteoblastic activities.