Expression of cartilage oligomeric matrix protein in articular cartilage in response to bone morphogenetic protein-7 and tumour necrosis factor : peer reviewed original article

Introduction: The extracellular matrix of articular cartilage consists of collagens, proteoglycans and noncollageneous proteins. Cartilage oligomeric matrix protein (COMP) is a non-collagenous protein isolated from articular cartilage. It is localised in articular cartilage and the proliferative and hypertrophic zones of the epiphyseal growth plate. Aim: The aim of the study was to investigate the role of bone morphogenetic proteins (BMP-7) and tumour necrosis factor (TNF-α) on expression of COMP in articular cartilage. Methods: Stifle joints (n=12) from three month-old calves were obtained from a local abattoir. Articular chondrocytes were isolated from three distinct zones of cartilage and cultured as monolayers in a serum-free chemically defined medium. Results: BMP-7 increased COMP accumulation in dose and time dependent manner. TNF-α was however found to significantly reduce COMP accumulation Conclusion: BMP-7 was shown to be important regulators of the COMP gene in different zones of articular cartilage