Lysine deacetylase inhibition attenuates hypertension and is accompanied by acetylation of mineralocorticoid receptor instead of histone acetylation in spontaneously hypertensive rats

Inhibition of lysine deacetylase (KDAC) attenuated development of hypertension in spontaneously hypertensive rats (SHRs). We hypothesized that KDAC inhibition attenuates hypertension and is accompanied by acetylation of mineralocorticoid receptors (MR) instead of histone acetylation in SHRs. Valproate (VPA, 0.71 % wt/vol), an inhibitor of class I KDACs, was administered in drinking water to 7-week-old SHRs and Wistar Kyoto rats for 11 weeks. MR acetylation was determined by immunoprecipitation with anti-MR antibody followed by western blot with anti-acetyl-lysine antibody. Expression levels of acetylated histone H3, KDACs, MR target genes, or MR corepressors in the kidney cortex were measured by using western blot analysis or real-time PCR. Recruitment of MR and RNA polymerase II (Pol II) and histone modifications on promoters of target genes were analyzed by performing a chromatin immunoprecipitation (ChIP) assay. Treatment of SHR with VPA increased MR acetylation without affecting MR expression, which attenuated development of hypertension in SHR VPA decreased expression of KDAC class I but globally increased acetylated histone H3. Although VPA treatment increased histone 3 acetylation (H3Ac) and trimethylation of the fourth lysine (H3K4me3) in the promoter regions of MR target genes, it decreased the expression of target genes as well as recruitment of MR and Pol II. These results suggest that KDAC inhibition attenuates the development of hypertension in SHRs and is accompanied by acetylation of MR that is independent of histone acetylation.