mPQ-induced epigenetic modification. (A) Western blot analyses of histone marks in cell extract and isolated nucleus, and (B) quantification of western blot data. (C) Histone acetyltransferase/p300 activity was measured in isolated nucleus, as described in Materials and Methods, and C646 was used as a p300-specific inhibitor. Data points are presented as the mean +/− SD of three individual samples. Statistical significance is indicated by asterisks: *, p ≤ 0.05 and **, p ≤ 0.01.