Fig. 7

ASK1/p38 signaling is activated in cultured HCECs in vitro. a The protein level of ASK1 or phosphorylated ASK1 was measured by Western blot and then the activation of p38 MAPK was also compared with or without H₂O₂ treatment of HCECs in vitro. Top panel: shows the representative data from the gels; bottom panel: the results normalized to GAPDH. GAPDH served as the loading control. The HCECs with no H₂O₂ treatment was used as control. Three more additional experiments achieved equivalent results. Data are means ± SD (n = 3). All means marked with * (t-test, P < 0.05) are significantly different from the control. b siRNA ASK1 decreased H₂O₂-induced p38 activation. HCECs were transfected with 150 nM ASK1 siRNA and control siRNA, and 24 h later, cells were treated with 100 μM H₂O₂ for 4 h. The protein expression was measured by Western Blot. Top panel: shows the representative data from the gels; bottom panel: the results normalized to GAPDH. GAPDH served as the loading control. Three more additional experiments achieved equivalent results. Data are means ± SD (n = 3). All means marked with * (P < 0.05) are significantly different from the control. c p38 signaling is required for the response to ROS in cultured HCECs in vitro. HCECs were pretreated with or without SB203580 (10 μM) for 2 h and then coincubated with 100 μM H₂O₂ for 4 h. The protein levels were measured by Western blot assays. Top panel: shows the representative data from the gels; bottom panel: the results normalized to GAPDH. GAPDH served as the loading control. HCECs treated without SB203580 was used as control. Three more additional experiments achieved equivalent results. Data are means ± SD (n = 3). All means marked with * (P < 0.05) are significantly different from the control