THE ACCUMULATION OF TYPE-I COLLAGEN MESSENGER-RNAS IN HUMAN EMBRYONIC LUNG FIBROBLASTS STIMULATED BY TRANSFORMING GROWTH-FACTOR-BETA

We examined the expression of type I collagen mRNAs (α1(I) and α2(I)) by embryonic lung fibroblasts in cultures treated with transforming growth factor-β (TGF-β TGF-β caused a concentration dependent increase in the expression of α1(I) mRNA for type I collagen. TGF-β at low concentration (0.1 ng/ml) slightly increased the level of α1(I) mRNA. Higher concentrations of TGF-β (1.0 and 5.0 ng/ml) further increased the amount of α1(I) mRNA. The increase in α1(I) mRNA was associated with a marked increase in production of intact type I collagen molecules. TGF-β did not increase expression of α2(I) mRNA. The α2(I) mRNA levels in human lung fibroblast cultures were not affected by varying the duration of exposure to TGF-β nor the concentration of TGF-β In contrast, TGF-β increased the amount of both α1(I) and α2(I) mRNA in NIH3T3 cells. These data suggest that the amount of α2(I) mRNA is not rate limiting with respect to type I collagen production during TGF-β stimulation in human lung fibroblast cultures. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.