The Contributive Role of IGFBP-3 and Mitochondria in Synoviocyte-Induced Osteoarthritis through Hypoxia/Reoxygenation Injury: A Pathogenesis-Focused Literature Review

Figure 4

Schematic diagram of the IGF system. The IGF system is composed of several constituents including IGF-I, IGF-II, their respective receptors, and insulin receptor. In addition, there are 6 high-affinity binding proteins. IGFBP-3 binds to IGF-1 in complex with acid labile subunit. Abbreviations: IGF: insulin-like growth factor; IGFBP: insulin-like growth factor binding protein (reused with permission from Garza [59], author of the dissertation entitled “Insulin-like growth factor binding protein-3 (IGFBP-3) plays an essential role in cellular senescence: molecular and clinical implications”).