Figure 1. Overview of the mechanisms of glucocorticoid-induced osteoporosis (GCOP). Osteoporosis results from an imbalance between osteoblast and osteoclast activity. BMP-2: bone morphogenic protein-2; Cbfa1: core binding factor a1; Bcl-2: B-cell leukemia/lymphoma-2 apoptosis regulator; Bax: BCL-2-associated X protein; IGF-I: insulin-like growth factor-I; IGFBP: IGF binding protein; IGFBP-rPs: IGFBP-related proteins; HGF: hepatocyte growth factor; RANKL: receptor activator of the nuclear factor-κB ligand; CSF-1: colony-stimulating factor-1; OPG: osteoprotegerin; PGE2: Prostaglandin E 2; PGHS-2 prostaglandin synthase-2