Figure 2.

Knockdown of p300 and p300-HAT inhibitor suppressed histone acetylation. Primary cultured neonatal rat cardiomyocytes were transfected with p300 si-RNA or si-control as a control (50 nM, respectively). (A and B) Immunostaining was performed on primary cultured cardiomyocytes with anti-MHC antibody. The areas of 50 randomly chosen cells were measured using ImageJ v4.16. (A) is a photograph of representative cardiomyocytes, and (B) is a quantification of (A). Scale bar: 20 μm. (C–D) mRNA was extracted from the cardiomyocytes, and mRNA levels of ANF (C), BNP (D), and β-MHC (E) were measured by qRT-PCR assay. (F–H) Nuclear proteins (nuclear extract) and histone fraction (histone extract) were extracted from the cardiomyocytes. (F) is a photograph of a representative Western blot, and (G and H) are quantifications of (F). (I–K) Primary cultured cardiomyocytes were treated with 10 μM of curcumin (Cur), a p300 specific HAT inhibitor, and were stimulated with 30 μM of PE. Nuclear proteins and histone fraction were extracted from primary cardiomyocytes after 48 h of PE stimulation. (I) is a photograph of a representative Western blot, and (J) and (K) are quantifications of (I). (B–E,G,H,J, and K), N = 3; one-way ANOVA followed by Tukey test. * p < 0.05.