Fig. 7.

VPO1-derived HOCl activates Smad2/3 to regulate cardiac fibroblasts differentiation, and collagen I synthesis and ERK1/2 to regulate cardiac fibroblasts proliferation. (A–B) 3-Cl Tyr levels in MI mice injected with si-NC and si-VPO1(A), or cultured cardiac fibroblasts transfected with siRNA and incubated with or without TGF-β1(B) were measured by western blot. (C) 1 × 10⁽⁶⁾ cardiac fibroblasts were seeded in 6 cm plates and incubated with HOCl (100 μmoL/L, diluted in PBS solution) for 2 h, and then changed to normal DMEM and incubated for 24 h before harvesting. α-SMA, Collagen I, Smad2/3 and ERK1/2 were measured by western blot and quantified by Image Lab. n = 4. (D) Cultured cardiac fibroblasts were stimulated with HOCl, then incubated with U0126 (10 μmoL/l). Proliferation was assessed by CCK-8 assay. n = 6. (E) Cultured cardiac fibroblasts were stimulated with HOCl, then incubated with SIS3 (10 μmoL/l). Cardiac fibroblasts were co-stained with α-SMA (red) and phalloidin (green). (F) The expression of α-SMA and collagen I was measured by western blot. n = 4. Data are presented as mean ± SEM. In C, Student's t-test was used in comparison with control group. In D and F, One-way ANOVA test was used. *P < 0.05, **P < 0.01, ***P < 0.001. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)