Fig. 4: PARP1 promotes FoxO3a activation by excluding histone H1 from its target promoter.

a and b Primary neonatal rat cardiomyocytes were pre-treated with 3AB (10 mM,) or PJ34 (10 µM), or transfected with PARP1 shRNA or an unrelated shRNA for 24 h followed by starvation (24 h). Soluble chromatin was then prepared for ChIP assays with antibodies against the indicated proteins. After infection with Histone H1 shRNA for 24 h, cardiomyocytes were treated with the PARP1 shRNA or PJ34 and were then exposed to starvation for 24 h. c and d Soluble chromatin was then prepared for ChIP assays with antibodies against Foxo3a for amplification of LC3 promoters. N = 5 for each group. ^**P < 0.01 vs. control; ^##P < 0.01 vs. starve; ^$$P < 0.01 vs. starve + PJ34 or starve + PARP1 shRNA. e and f Western blot assay was used to detect the expression of Gabarapl1, ATG12 and LC3 in different treated groups