Fig. 1. TGF--mediated induction of the ET-1 gene. BAEC were incubated with or without 5 ng/ml TGF- for different time periods as indicated, and changes in the expression of ET-1 at the level of mRNA, peptide and promoter activity were determined as described in the Materials and Methods. (A) ET-1 mRNA levels were detected and analyzed by RT-qPCR. Values are represented as fold induction (mean ± s.d., n=4, ^*P<0.05 versus zero time). (B) ET-1 peptide levels were detected by specific ELISA and expressed as fmol/well (mean ± s.d., n=3, ^*P<0.05 versus zero time, #P<0.05 versus treated cells). (C) Transcriptional activation of the human ET-1 promoter was estimated from cells transfected with a -650/+172-bp fragment of the human ET-1 promoter, compared with empty vector pGL3-Basic. Basal and TGF--induced luciferase activity was measured by luminometry and expressed as fold induction with respect to the activity of human ET-1 promoter under basal conditions (mean ± s.d., n=4, ^*P<0.05 versus zero time, ^#P<0.001 versus human ET-1 promoter for the indicated times).