DDR2-dependent integrin-β1 expression is a determinant of α-SMA and collagen type I expression in Ang II–treated cardiac fibroblasts.
A–C, cardiac fibroblasts were transiently co-transfected with DDR2 siRNA and integrin-β1 (ITGB1) plasmid overexpression vector. Following revival and serum deprivation, the transfected cells were exposed to Ang II for 12 h. Collagen α1(I) protein expression was examined by Western blot analysis and normalized to β-actin. **, p < 0.01 versus control; ##, p < 0.01 versus Ang II; ††, p < 0.01 versus Ang II + DDR2 siRNA. α-SMA protein expression was examined by Western blot analysis and normalized to β-actin. **, p < 0.01 versus control; ##, p < 0.01 versus Ang II; †, p < 0.05 versus Ang II + DDR2 siRNA. D–F, cardiac fibroblasts were transiently co-transfected with integrin-β1 (ITGB1) siRNA and DDR2 overexpression vector. Following revival and serum deprivation, the transfected cells were exposed to Ang II for 12 h. Collagen α1(I) protein expression was examined by Western blot analysis and normalized to GAPDH. ***, p < 0.001 versus control; ###, p < 0.001 versus Ang II; **, p < 0.01 versus Ang II. α-SMA protein expression was examined by Western blot analysis and normalized to GAPDH. **, p < 0.01 versus control; ***, p < 0.001 versus Ang II; ###, p < 0.001 versus Ang II. Data are representative of three independent experiments (n = 3). Error bars, S.D.