Figure 6.

Que prevents age-related hyperproliferation of ISC through scavenging ROS and inhibiting insulin signaling pathway. (A–E) Representative immunofluorescence images of posterior midguts of flies carrying esg^ts-Gal4-driven UAS-lacZ (A), UAS-Cat; UAS-InR-DN + DMSO (B), UAS-Cat; UAS-InR-DN + Que (C), Keap1 RNAi; UAS-InR-DN + DMSO (D), and Keap1 RNAi; UAS-InR-DN + Que (E) stained with DAPI, GFP, and Dl. The top panels represent the merged images, whereas the bottom panels represent Dl. Scale bars represent 25 µm. (F) The ratio of esg-GFP⁺ cells and Dl⁺ cells to DAPI⁺ cells per ROI in the posterior midguts of flies in experiments (A–E). n: number of ROI counted. (G) The number of pH3⁺ cells in the whole gut of flies in experiments (A–E). n: number of gut counted. (H,I) The percentage of acid-base balanced intestines (H) and eating intestines (I) of flies in experiments (A–E). N ≥ 50 flies per group. Three independent experiments were conducted. (J) Quantifying the excretion deposits of flies in experiments (A–E). Each group included 30 flies and three independent experiments were conducted. n: number of field counted. (K) The percentage of the smurf (+) flies in experiments (A–E). Each group included 15 flies and three independent experiments were conducted. (L) Survival percentage of indicated genotypes of female flies. Each group included 100 flies. Three independent experiments were conducted. (M) Schematic model of the mechanism of quercetin action. Que prevents the hyperproliferation of ISCs via attenuating oxidative stress and inhibiting the insulin signaling pathway. Error bars represent SDs. Log-rank test was used for lifespan analysis. Student’s t-tests, *** p < 0.001, **** p < 0.0001, and non-significance (ns) represents p > 0.05.