Endoglin effect on PDGF-BB signalling.

<p>(<b>A</b>) Cells were transiently transfected using Lipofectamine 2000 with a cDNA encoding rat endoglin. Thereafter, cells were stimulated with or without BMP-7 (25 ng/ml) for one hour or with PDGF-BB (25 ng/ml) for 10 min. Cellular proteins were prepared and analyzed in Western blot using specific antibodies to endoglin (PPabE2), PDGFRβ, phosphorylated Smad1/5/8 (pSmad1/5/8), phosphorylated ERK1/2 (pERK1/2) and GFP. (<b>B</b>) Cells were transiently transfected as described in (<b>A</b>) and stimulated or not with PDGF-BB (25 ng/ml) in the presence or absence of SB431542 (5 µM). Thereafter, cellular proteins were prepared and analyzed in Western blot using specific antibodies to endoglin (PPabE2), PDGFRβ, phosphorylated ATF-2 (pATF-2), phosphorylated ERK1/2 (pERK1/2) and GFP. All membranes were incubated with an antibody to β-actin to demonstrate equal protein loading. For densitometric analysis bands of β-actin and p-p42 were scanned and the latter one normalized to β-actin. Results are expressed as fold induction relative to the pcDNA control. Results show representative images of one of three independent experiments.