Expression of cartilage specific genes by human capsular cartilaginous cells

The amount of proteoglycan production in tissue that was considered to have cartilaginously differentiated due to mechanical stress and cartilage specific gene expression were investigated. The inner layer of the joint capsule which forms a sliding surface with the femoral head in the case of dislocated hip arthoropathy showed higher proteoglycan production compared to that in the surrounding non-cartilaginous tissue. On examining gene expression, although large cartilaginous proteoglycan is originally absent in this region, gene expression of aggrecan and versican which are able to bind to hyaluronan was observed. Further, gene expression of decorin and link protein was also examined. These findings in the inner layer of joint capsule forming sliding surface with the femoral head suggested the importance of mechanical stress in cartilaginous differentiatiog of mesenchymal tissue.