Increased procollagen mRNA levels in scleroderma skin fibroblasts.

Procollagen messenger RNA activity in scleroderma and normal skin fibroblasts was measured using a cell-free translation assay. Radioactive translation products were fractionated by electrophoresis and the ratio of procollagen to total incorporation was determined from densitometric scans of gel fluorograms. In 4 scleroderma cell lines 1.78% (+/- 0.10) of incorporated [35S]-methionine was in procollagen, compared to 1.00% (+/- 0.20) in 5 normal controls. These values are consistent with previously reported increases in the rates of collagen synthesis obtained with intact cells and show that most if not all of the increase can be explained on the basis of elevated translatable procollagen messenger RNA in scleroderma fibroblasts.