Drosophila DJ-1 Decreases Neural Sensitivity to Stress by Negatively Regulating Daxx-Like Protein through dFOXO
Figure 5
DLP deficiency reduces acute sensitivity to oxidative stress and UV, and improves locomotive dysfunction in DJ-1β mutant.
(A) Comparison of the survival rates of DLP and DJ-1β double mutants (DLP1; DJ-1βex54 and DLP2; DJ-1βex54) with wild-type (WT) and DJ-1βex54 flies under oxidative stress conditions (log-rank test: WT, n = 250; DJ-1βex54, n = 250; DLP1; DJ-1βex54, n = 250; DLP2; DJ-1βex54, n = 250, p<0.01, groups with the same letter do not differ significantly). (B) Reduced oxidative stress-induced apoptosis was noted in the larval brain of the DLP and DJ-1β double mutant (DLP1; DJ-1βex54) compared to DJ-1βex54. The larval brains were treated with 0.1% H2O2 for 24 h and cell death was detected via acridine orange staining. (C) Sensitized DA neuronal death of DJ-1βex54 under oxidative stress conditions was rescued by DLP deficiency. The flies were fed with 1% H2O2 for 3 days. (n = 10, Student's t-test: DM, ** p<0.01, *** p<0.001; DL1, ** p<0.01; PM, ** p<0.01). (D) Survival rates of WT, DJ-1βex54, and double mutant of DLP and DJ-1β (DLP1; DJ-1βex54 and DLP2; DJ-1βex54) pupae after exposure to UV irradiation (10 mJ/cm2; black bars) as described in the Materials and Methods (Kruskal-Wallis test: CTL, n≥6, p>0.1; UV, n≥5, p<0.01, groups with the same letter do not differ significantly). CTL, UV-untreated control pupae; UV, UV-treated pupae. (E) Comparison of climbing abilities of WT, DLP1, DJ-1βex54, and double mutants of DLP and DJ-1β (DLP1; DJ-1βex54). The climbing abilities of 5-day-old flies for each group were tested as described in the Materials and Methods (ANOVA and Tukey's HSD analysis: n≥12, p<0.01, groups with the same letter do not differ significantly). All data are expressed as means ± s.e. values.