POSSIBLE FUNCTION OF PACAP SIGNALING IN AGING OF HUMAN KNEE JOINT ARTICULAR CARTILAGE

Purpose: Pituitary adenylate cyclase activating polypeptide (PACAP) is a multifunctional polypeptide that can regulate diverse physiological and developmental processes. PACAP is a neurotrophic and anti-inflammatory substance in the CNS and it is reported to prevent harmful effects of oxidative and mechanical stress in hyaline cartilage. Furthermore, articular cartilage of PACAP KO mice showed signs of early osteoarthritis during aging. Its most potent receptor is PAC1 which activation leads to enhanced Sox9 expression subsequently, increases the expression of collagen type II, glucose aminogylcans and aggrecan.