TRANSFORMING GROWTH-FACTOR-BETA UP-REGULATES HUMAN ELASTIN PROMOTER ACTIVITY IN TRANSGENIC MICE

We have recently developed transgenic mice which express similar to 5. 2 kb of the human elastin promoter linked to the chloramphenicol acety l transferase (CAT) reporter gene (J. Biol. Chem. 269:18072-18075, 199 4). Previously, transforming growth factor-beta (TGF-beta) has been sh own to enhance elastin gene expression, as determined at the mRNA and protein levels. To examine whether this enhancement could be explained by upregulation of the elastin promoter, TGF-beta 1 (100 ng) was inje cted subcutaneously into the transgenic animals. CAT activity in the s kin of treated animals was elevated in a time-dependent manner up to s imilar to 10-fold after a single injection. These results suggest that the 5.2-kb up-stream segment of the human elastin gene contains cis-e lements responsive to TGF-beta 1 in vivo. (C) 1994 Academic Press, Inc .