ABCG1 Attenuates Oxidative Stress Induced by H₂O₂ through the Inhibition of NADPH Oxidase and the Upregulation of Nrf2-Mediated Antioxidant Defense in Endothelial Cells

Figure 1

Effect of ABCG1 on H₂O₂-induced oxidative stress in HUAECs. HUAECs were transfected with the specific ABCG1 siRNA or ABCG1 overexpression plasmid or preincubated with the liver X receptor (LXR) agonist T0901317 and incubated with 200 μM H₂O₂ for 12 h or not. ABCG1 protein levels were determined using(a) western blot assays. The generation of oxidative stress was assessed by the production of (b, c) ROS and (d) MDA. In (b), intracellular ROS production was measured using CDCFHDA-AM fluorescence in different conditions. (A) HUAECs were cultured in medium as normal controls, (B) HUAECs were transfected with the ABCG1 overexpression plasmid, (C) HUAECs were treated with T0901307, (D) HUAECs were transfected with ABCG1 siRNA, (E) HUAECs were exposed for 12 h to 200 μM H₂O₂, (F) HUAECs were transfected with the ABCG1 overexpression plasmid and then cultured with H₂O₂, (G) HUAECs were pretreated with T0901307 and then cultured with H₂O₂, and (H) HUAECs were transfected with ABCG1 siRNA and then cultured with H₂O₂. Representative images are shown for three independent experiments (magnification ×100). Data shown are (). , vs. normal controls; ^## vs. HUAECs treated with H₂O₂ alone.

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