EGFR signaling is critical for maintaining the superficial layer of articular cartilage and preventing osteoarthritis initiation

• DOI: 10.1016/j.joca.2017.02.112
• Publication Date: 2017-04-18T01:20:32Z
• Authors: H. Jia; X. Ma; W. Tong; B. Doyran; Z. Sun; L. Wang; X. Zhang; Y. Zhou; F. Badar; A. Chandra; X. Lu; Y. Xia; L. Han; M. Enomoto-Iwamoto; L. Qin
• Keywords: Cartilage, Articular; Male; Mice, Knockout; 0301 basic medicine; Arthritis, Experimental; ErbB Receptors; Mice; 03 medical and health sciences; Chondrocytes; Osteoarthritis; Animals; Humans; Proteoglycans; Chondrogenesis; Cells, Cultured; Signal Transduction

SignificanceThe uppermost superficial zone of articular cartilage plays multifaceted roles in maintaining cartilage structure, function, and mechanical properties and in preventing cartilage degeneration during osteoarthritis initiation. However, its regulation by growth factors and hormones is still largely unknown. Here we report that EGFR signaling is an important growth factor pathway that maintains superficial chondrocyte number, promotes boundary lubricant secretion and cartilage surface lubrication, and stimulates mechanical strength of articular cartilage. Reduction in EGFR activity leads to structurally, functionally, and mechanically compromised articular cartilage during development and drastically accelerates cartilage degeneration under normal and surgically induced osteoarthritis conditions. Thus, our studies strongly suggest that targeting cartilage surface EGFR signaling should be considered as a novel direction for osteoarthritis treatment.