[Differential expressed proteins of knee osteoarthritic chondrocytes]

To investigate the molecular mechanism of osteoarthritis (OA) through the differential expressed proteins of advanced osteoarthritic chondrocytes.

Normal articular cartilage (NAC, n = 22) were obtained from knee cartilage of donors without knee diseases and osteoarthritic cartilage (OAC, n = 17) from OA patients undergoing knee arthroplasty. Total protein was extracted from chondrocytes and loaded directly for two-dimensional gel electrophoresis (2-DE). Gel images were analyzed with the software Imagemaster 2-D platinum3.0 to screen the differential expression protein spots. Target spots were excised and digested and the resulting peptides submitted for mass spectrometry analysis. Identities of differential expressed proteins were recognized through matching the peptide mass finger printing of each spot with NCBI protein database by MASCOT.

About 1000 protein spots were presented in the 2-DE gels for each group. Thirty-five NAC spots and 31 OAC spots were confirmed to be differential expression protein spots. Among these spots, 19 proteins were identified by MASCOT, including type VI collagen, enzymes involved in collagen synthesis, shock related proteins and some novel proteins with unknown functions.

The differential expressed proteins isolated and identified by the present study provide valuable information on various aspects of OA pathology. It may help us to gain new insights into the molecular mechanism of OA.