A comparative proteomic study of chondral chondrocytes in osteoarthritis patients with normal chondrocytes

Osteoarthritis (OA) is a common degenerative disease of joints and the main cause of elder patient's disability. Cartilage damage is a major problem in OA. To investigate the pathogenesis of OA, this study aimed to analyze the differential proteomics of chondrocytes in OA patients compared to normal chondrocytes. Protein extracts of cartilages prepared from 7 patients with end-stage OA, who were candidates for arthroplasty, were compared to 7 samples from normal cartilages. Proteins were analyzed by fluorescent gel electrophoresis (2D-DIGE) method and the differentially expressed proteins were identified by mass spectrometry (MS). Two samples were lost because of tissue insufficiency and the other because of mistransportation. Among the 25 analyzed proteins, difference was seen for the 8 following proteins: osteonectine, cathepsin, chondroadherin, HSP, clustrine and collagen II, Activin A and carbonic Anhydrase. The levels of osteonectine, cathepsin, clustrine and collagen II were decreased in the OA samples compared to normal chondrocytes. Moreover, the levels of chondroadherin and Activin A were increased in the OA samples compared to normal chondrocytes. The findings demonstrate the ability of the 2D-DIGE/MS platform to identify proteins with altered expression in chondrocytes of patients with OA. The identification of these proteins may open new lines of research for the pathogenesis of OA.