DECREASED COLLAGENASE EXPRESSION IN CULTURED SYSTEMIC-SCLEROSIS FIBROBLASTS

One cause of the excessive deposition of collagen in systemic sclerosi s is thought to be abnormal functioning of fibroblasts. The purpose of this study is to determine whether there is decreased expression of c ollagenase in systemic sclerosis fibroblasts. In this study, we analyz ed collagen and collagenase expression in dermal fibroblasts derived f rom eight patients with systemic sclerosis and compared the findings w ith those from nine sex- and age-matched healthy subjects. Increased c ollagen synthesis accompanying enhanced mRNA levels was observed in tw o of eight strains, whereas all eight strains showed remarkable decrea ses in collagenase activity and production. There were no differences in the levels of collagenase mRNA between the systemic sclerosis strai ns and the normal strains. Results suggest that decreased collagenase expression is a characteristic of systemic sclerosis fibroblasts, and both increased collagen expression and decreased collagenase expressio n in systemic sclerosis fibroblasts may result in the excessive accumu lation of collagen in patients with systemic sclerosis. It is also sug gested that decreased collagenase expression is altered at translation al and/or post-translational levels.