Figure 4

Dominant negative form of p38 MAPK significantly decreases SMC migration in response to PDGF. A) Photomicrograph of mouse aortic SMCs showing the morphology and GFP expression at 36 hours following transfection. Sub-confluent SMCs were infected with adenoviral vector at the multiplicity of infection of 100. Note the high level of GFP expression as well as the normal phenotype of Ad-GFP-transfected SMCs. Original magnification, ×200. B) Over-expression of a dominant negative form of p38 MAPK markedly increased total p38 MAPK expression while blocking p38 MAPK phosphorylation in response to serum treatment in SMCs (serum is used as a strong activator for p38 MAPK). Also, note the considerable increase in ILK expression level in SMCs transfected with adenoviral ILK constructs. C) For migration assay, transfected SMCs were cultured in Transwell Boyden Chambers in the presence or absence of 25 ng/ml of PDGF-BB and cell migration was measured 12 hours post culture. Dominant negative p38 MAPK significantly decreases SMC migration in response to PDGF-BB treatment while expression of a wild type form of p38 MAPK increases SMC migration in response to PDGF-BB. In addition, over-expression of a wild type mutant of p38 MAPK subverted the inhibitory effect of p38 inhibition on SMC migration. Data represents three independent experiments (n = 3 cell cultures for each independent experiments).