Fig. 5

Role of ROS in HK-Spn and light induction of clock genes. (a) Relative expression of per2, cry1a, per3, and per1b of Z3 cells exposed to HK-Spn and incubated in dark and low-intensity light conditions for 4 h. A 2-hour pre-treatment of 6 mM of N-acetyl cysteine (NAC) was used to suppress ROS production. Means ± SEM are shown. Asterisks (*) indicate statistically significant differences *p < 0.05, ***p < 0.001, ****p < 0.0001, Two-way ANOVA with Tukey’s multiple comparisons. Five to eight experiments, three replicates per group. (b) Dichlorodihydrofluorescein (DCF) fluorescence was measured after 2 h of PBS or HK-Spn exposure in dark and low-intensity light conditions. A 2-hour pre-treatment of 6 mM of N-acetyl cysteine (NAC) was used to suppress ROS production. Fold induction of relative fluorescent units was calculated against the dark PBS-treated cells. Means ± SEM are shown. Asterisks (*) indicate statistically significant differences ***p < 0.001,****p < 0.0001, Two-way ANOVA with Tukey’s multiple comparisons test. Four experiments, three replicates per group.