Fig. 9. Role of ET-1 in TGF--mediated endothelial cell migration and proliferation. (A) Effect of exogenous ET-1 on endothelial cell migration. BAEC were seeded on Transwell inserts and cell-migration capacity analyzed for the indicated experimental conditions (basal, TGF- alone, TGF- plus SB-431542 and TGF- plus SB-431542 in the presence of 100 nM ET-1). A control experiment with ET-1 alone is also shown. Cell-migration capacity is shown as the ratio of migrating versus non-migrating cells expressed as a percentage of basal (mean ± s.d., n=3, ^*P<0.05 versus basal, ^#P<0.05 versus TGF- alone). (B) Effect of TGF--induced ET-1 on endothelial cell proliferation. BrdU incorporation: BAEC seeded on six-well plates were treated with TGF-, TGF- plus SB431542 or TGF- plus bosentan in the presence of 10 µM BrdU for 24 hours. They were then fixed, treated with pepsin/HCl, washed with PBS and incubated with anti-BrdU FITC-conjugated antibody. Estimation of cell proliferation was obtained by measurement of the mean fluorescence intensity from the FITC signal expressed as a percentage of basal (mean ± s.d., n=3, ^*P<0.05 versus basal, ^#P<0.05 versus TGF- alone).