Anacardic acid protects against phenylephrine-induced mouse cardiac hypertrophy through JNK signaling-dependent regulation of histone acetylation

Cardiac hypertrophy is a complex process induced by the activation of multiple signaling pathways. We previously reported that anacardic acid (AA), a histone acetylase (HAT) inhibitor, attenuates phenylephrine (PE)-induced cardiac hypertrophy by downregulating histone H3 acetylation at lysine 9 (H3K9ac). Unfortunately, the upstream signaling events remained unknown. The mitogen-activated protein kinase (MAPK) pathway is an important regulator of cardiac hypertrophy. In this study, we explored the role of JNK/MAPK signaling in cardiac hypertrophy. A mouse model of cardiomyocyte hypertrophy was successfully established in vitro using PE. This study showed that p-JNK directly interacts with HATs (P300 and P300/CBP-associated factor, PCAF) and alters H3K9ac. In addition, both the JNK inhibitor SP600125 and the HAT inhibitor AA attenuated p-JNK overexpression and H3K9 hyperacetylation by inhibiting P300 and PCAF during PE-induced cardiomyocyte hypertrophy. Moreover, we demonstrated that both SP600125 and AA attenuate the overexpression of cardiac hypertrophy-related genes (MEF2A, ANP, BNP, and {beta}-MHC), preventing cardiomyocyte hypertrophy and dysfunction. These results revealed a novel mechanism through which AA might protect mice from PE-induced cardiac hypertrophy. In particular, AA inhibits the effects of JNK signaling on HAT-mediated histone acetylation, and could therefore be used to prevent and treat hypertrophic cardiomyopathy.