Impaired inflammasome activation and bacterial clearance in G6PD deficiency due to defective NOX/p38 MAPK/AP-1 redox signaling

Yen, Wei-Chen; Wu, Yi-Hsuan; Wu, Chih-Ching; Lin, Hsin-Ru; Stern, Arnold; Chen, Shih-Hsiang; Shu, Jwu-Ching; Tsun-Yee Chiu, Daniel

The treatment of differentiated control and G6PD-kd THP-1 cells with LPS and nigericin increased ROS production, which was less than that in G6PD-kd THP-1 cells (Fig. 6A) . The production of superoxide was lower in G6PD-kd THP-1 cells than that in control cells upon LPS incubation for 20 min (Fig. 6B) . The pretreatment of G6PD-kd and control THP-1 cells with DPI, an inhibitor of NADPH oxidase, decreased the expression of p-p38 and pro-IL-1β in both cells (Fig. 6C and E) . The quantitative intensity of p-p38 and pro-IL-1β is shown in Fig. 6D and F, respectively. G6PD-kd THP-1 cells treated with H 2 O 2 (100 μM) and NADPH (100 μM) increased the expression of p-p38 and pro-IL-1β ( Fig. 6G and I) . The quantitative intensity of p-p38 and pro-IL-1β is shown in Fig. 6H and J, respectively. The expression of IL-1β was improved by overexpress IDH1 in THP-1-LG and G6PD-kd cells (Fig. S2 ). Variable ROS level has different effects on cellular physiology. In Fig. S3 , the expression of IL-1β was only induced in high concentrated H 2 O 2 -treated THP-1 cells. This suggests that G6PD deficiency decreases ROS level by only affecting inflammasome signal 1 pathway but not signal 2. and pro-IL-1β. PMA-differentiated control and G6PDkd THP-1 cells were treated with SB203580 for 30 min prior LPS treatment for 30 min for p38 detection or 180 min for pro-IL-1β detection. (E), (F) p-p38, p38 and pro-IL-1β quantitative levels of (C) and (D). β-Actin was used as a normalized loading control. The results are representative of three independent experiments (n = 3, *p < 0.05).