Fig. 7. RNAi-induced loss of BMPR1A, by reducing MMP9 and MMP2 expression, impairs directed migration of human vascular smooth muscle cells. (A) Gelatin zymography in response to PDGF-BB. Gelatin zymography performed on conditioned media (left) and densitometric analysis (right) show MMP9 and pro and active MMP2 activities in SiBMPR1A-treated (SiBR1A) versus SiControl-treated (SiC) cells in response to PDGF-BB (20 ng/ml) stimulation for 6 hours. Bars indicate mean±s.e.m. of densitometric values of SiBR1A MMP forms normalized to the corresponding SiC values. (n=4). ^**P<0.01, ^***P<0.001. (B) Migration in response to PDGF-BB as assessed by modified Boyden Chamber assay. SiC- or SiBR1A-transfected HPASMCs were stimulated with 20 ng/ml of PDGF-BB for 6 hours. Bars represent mean±s.e.m. of migrating cells in 5-6 different microscopic fields. (n=4). P<0.05 for stimulated versus unstimulated comparisons for each Si; ^***P<0.001 for comparisons between SiBR1A and SiC. Representative micrographs show the number of migrating cells under each condition. Scale bar: 100 µm.