Figure 1.

DDR2 mediates Ang II-stimulated fibronectin protein expression in cardiac fibroblasts. (A) Sub-confluent quiescent cultures of cardiac fibroblasts were stimulated with Angiotensin II (Ang II) (1 µM). Protein was isolated at 12 h of Ang II treatment and subjected to Western blot analysis for the detection of fibronectin and DDR2, with β-actin as loading control. * p < 0.05 and ** p < 0.01 vs. control. (B) Cardiac fibroblasts were transiently transfected with DDR2 siRNA (5 pmol) or control (scrambled) siRNA prior to treatment with Ang II for 12 h. Fibronectin protein expression was examined with β-actin as loading control. Validation of DDR2 silencing is also shown. * p < 0.05, ** p < 0.01 (comparisons as depicted in the figure). (C) Cardiac fibroblasts were treated with WRG-28 (2 µM) for 1 h prior to Ang II treatment. Cells were collected at 12 h post-Ang II treatment and fibronectin protein levels were examined, with β-actin as loading control. * p < 0.05 and ** p < 0.01 (comparisons as depicted in the Figure). (D) Cardiac fibroblasts were transfected with DDR2 cDNA overexpression plasmid (DDR2 OE) (with empty vector control, Control OE), as described under Materials and Methods, and fibronectin protein expression was examined, with β-actin as loading control. ** p < 0.01 vs. Control OE. Validation of DDR2 overexpression is also shown. Data are representative of three independent experiments, n = 3, Mean ± SEM.