Osteoarthritis cellular pathophysiology: The articular chondrocyte as a central player

Abstract

Worldwide, osteoarthritis is one of the most prevalent diseases. It causes high disability rates and represents a heavy burden to patients and society. In recent years, important findings about the normal function of the chondrocyte, the only cell in articular cartilage and responsible for matrix metabolism, have been made. Chondrocytes respond to the fluctuant conditions of their environment, generated by mechanical pressure changes, by modifying their ionic composition and altering solute and water membrane transport. This characteristic is a key factor to extracellular matrix maintenance, necessary for a functional cartilage. A number of factors related to chronic metabolic diseases initiate a cascade of events that lead to an inadequate response of chondrocytes to mechanical load; this ends in a preponderance of matrix catabolism and impairement of the cartilage, which is the basis for the development of osteoarthritis. Several cytokines and hormones are involved in this process and they may become promising therapeutic targets.