Fig. 4

Expression of activated caspase-3 according to phase of the circadian cycle. a: Percentage of apoptotic cell counts at 45, 57, and 69 h after adding 5 μM CUR. The relative changes in the percent cell death agreed with the peaks and trough in the circadian rhythm of death rate for cells treated with 5 μM CUR (red line, from Fig. 3e, shown here for comparison). b: Immunostaining cleaved caspase-3 in apoptotic cells (green) at two circadian phases, the peak at 45 h (i) and the trough at 57 h (iii), after 5 μM CUR treatment; ii and iv: The same cells merged with Hoechst nuclear staining (red). Scale bar = 10 μm