Figure 5.

LDN193189 inhibited signalling pathways induced by bone morphogenetic protein (BMP)6 but not those induced by vascular endothelial growth factor-a (VEGF). Human pulmonary artery endothelial cells were pretreated with 0.1% fetal bovine serum (FBS), 1 µM dimethylsulphoxide (DMSO) (vehicle control) or 1 µM LDN193189 (LDN) and then with 0.1% FBS or 25 ng·mL⁻¹ VEGF (A, B) or 0.1% FBS or 50 ng·mL⁻¹ BMP6 (C, D). VEGF induced phosphorylation of extracellular regulated kinase (ERK) 1/2 (A), VEGF target genes Nor1 and Nur77 (B) when cells were pretreated with 0.1% FBS, 1 µM DMSO and 1 µM LDN193189. BMP6 induced phosphorylation of Smad 1/5 (C) and Id1 (D) when cells were pretreated with 0.1% FBS and 1 µM DMSO, but this was completely inhibited when cells were treated with LDN193189. A and C are representative blots and B and D show mean ± SD, all n= 3. *P < 0.05, **P < 0.01, compared with 0.1%/0.1% serum control.