Figure 7. Nrf2-regulated ROS production and RIPK3 expression is involved in PM2.5-induced oxidative stress, fibrosis and inflammation in vitro. (A) Cardiomyocytes isolated from Nrf2+/+ or Nrf2-/- mice were treated with the indicated concentrations (0, 5, 12.5, 25, 50, 100 and 200 μg/ml) of PM2.5 for 24 h. Then, all cells were harvested for cell viability measurement using MTT analysis. n = 8 in each group. (B–G) Cardiomyocytes isolated from Nrf2+/+ or Nrf2-/- mice were pre-treated with NAC (5 mM) or CoPPIX (15 μM) for 2 h, or transfected with si-RIPK3 for 24 h. Then, all cells were incubated with PM2.5 (100 μg/ml) for another 24 h. After treatments above, all cells were collected for further calculation. (B) Intracellular calculation of ROS production, SOD activity, GSH and GPX levels. n = 8 in each group. (C) Western blot analysis of HO1, NQO1, GCLM and Keap1 protein expression in cells. n = 6 in each group. (D) Western blot analysis of TGFβ1 and α-SMA in cells. n = 6 in each group. (E) RT-qPCR analysis of TNF-α and IL-1β in cells. (F) Western blot analysis of p-IκBα and p-NF-κB in cells. n = 6 in each group. (G) LDH release in cells. n = 8 in each group. Data were expressed as the mean ± SEM. *P < 0.05 and **P < 0.01.