Growth factor inhibition: potential role in the etiopathogenesis of osteoarthritis.

Growth factors are small proteins that regulate cellular function. Some growth factors, including insulin like growth factor-1 and transforming growth factor-beta play an anabolic role in articular cartilage. The loss of articular cartilage that occurs in osteoarthritis may reflect, in part, an insufficiency of such factors. Recent evidence suggests that inhibition of these growth factors may contribute to the disease process in osteoarthritis. Inhibitors identified to date include binding proteins, cytokines, mechanical factors, and nutritional status. The mechanisms underlying the actions and interactions of these regulatory factors are beginning to be elucidated and may have implications for the development of new approaches to the treatment of osteoarthritis.