Figure 6. Circadian oscillation of PARP1 activity in normal fibroblasts.

(A, B) Protein levels from forskolin-induced circadian-synchronized WT-MEF and CRY^DKO-MEF were analyzed by western blotting with the indicated antibodies. (C) Quantitative analysis of poly-ADP-ribose (PAR) levels measured in (B). Data points represent averages from three independent experiments. (D) Immunofluorescence of poly-ADP-ribose (PAR) after plasma treatment in forskolin-induced circadian-synchronized WT-MEF and CRY^DKO-MEF. Nuclei were counterstained with Hoechst dye and depicted as dotted lines. Bars and error bars represent the mean ± SD from three independent experiments (* = p < 0.05; ** = p < 0.01).