Fig. 3. TGF1 induction of collagen expression on pLL. (A) Mesangial cells serum-deprived for 24 hours were trypsinized and re-plated on either gelatin-or pLL-coated plates. After 3 hours, these cells and two additional plates that were not trypsinized (retained on plate, two left-most lanes) were treated with TGF1 (1.0 ng/ml, 8 hours) and were analyzed for 1(I) collagen mRNA and 28S expression. Representative blots from one of six independent experiments are shown. (B) Cells transiently transfected with a luciferase construct of–0.42(I) collagen promoter and a plasmid expressing -galactosidase were trypsinized and re-plated on either gelatin-or pLL-coated plates. After 20 hours of treatment with TGF1 (1.0 ng/ml), cells were harvested and analyzed for luciferase activity. Relative luciferase activity (mean ± s.e.m., n=3) corrected for -galactosidase expression of a representative experiment out of five independent experiments is shown. White bars, vehicle; black bars, TGF1. *P<0.05 compared to values on gelatin without TGF1. Numbers in the graph represent fold induction by TGF1 over control.