Figure 4. Nrf2 negatively regulated CSE-induced ROS level. (A–F) RT-PCR on mRNA level of Nrf2, HO-1 and NQO1 and western blotting on protein level of HO-1 and NQO1 was performed. (G, H) Cellular ROS level was measured with flow cytometry, and CSE-induced ROS level was negatively regulated by Nrf2 pathway. *p < 0.05, **p < 0.01, ns, not significant, compared with CSE group. The data are represented as mean ± SD (n = 3).