[Osteoclastogenesis Inhibitory Factor (OCIF) /Osteoprotegerin (OPG) as a new therapeutic agent for osteoporosis]

Abstract

Osteoclastogenesis inhibitory factor (OCIF) is a novel member of the Tumor Necrosis Factor Receptor superfamily and identical with Osteoprotegerin (OPG) discovered by Amgen researchers. OCIF/OPG is a decoy receptor (a soluble receptor that acts as an antagonist) that binds to osteoblast cells via Receptor Activator of NF-kappa B Ligand (RANKL) involved in the signal transduction between osteoblast cells and osteoclastic progenitor cells, eventually suppressing differentiation of the progenitor cells into osteoclasts. The balance between the OCIF/OPG and RANKL is regulated by cytokines and hormones. Studies on OCIF/OPG-RANKL system have provided important insights into the pathogenesis of human metabolic bone diseases, leading to the expectation of OCIF/OPG as a novel candidate for a therapeutic agent for metabolic bone diseases.