PS-BPB02-8: CURCUMIN, AN INHIBITOR OF P300-HAT ACTIVITY, PREVENTS HYPERTENSION-INDUCED CARDIAC HYPERTROPHY WITH PRESERVED SYSTOLIC FUNCTION IN DAHL RATS

Abstract

Background: Hypertension causes left ventricular hypertrophy (LVH) with a preserved systolic function. While LVH might be a compensatory process, its presence of LVH is associated with an increased incidence of cardiovascular events and heart failure. Recently, we found that curcumin, a major curcuminoid isolated from Curcuma longa, inhibits the histone acetyltransferase (HAT) activity of p300 as well as the p300-induced acetylation of histones and a hypertrophy-responsive transcription factor, GATA-4, in cultured cardiomyocytes. Furthermore, curcumin prevents deterioration of the systolic function in rat heart failure models in vivo. However, whether curcumin prevents the development of hypertension-induced LVH at an early stage of hypertension is unclear. Objective: To solve this problem, we have utilized a salt-sensitive Dahl rat (DS) model of hypertension. Methods: We randomized 6-week-old DS (n = 19) and control salt-resistant Dahl rats (DR, n = 10) to curcumin or the vehicle group. Then, these rats were given a high-salt diet and subjected to daily oral treatment with 50 mg/kg/day of curcumin or its vehicle (1% Gum arabic) for 6 weeks. Results: There were no differences between curcumin and vehicle in any data examined before treatment (6 weeks of age). The high-salt diet-induced a similar degree of hypertension in these two groups of DS compared with DR. At 12 weeks of age, transthoracic echocardiography in the vehicle group showed that the LV wall thickness, LV mass, and LV fractional shortening were significantly higher in DS compared with DR, and the LV systolic and diastolic dimensions were significantly smaller in DS than DR. Curcumin treatment significantly (p < 0.01) decreased the LV wall thickness in DS but not DR. Curcumin also significantly (p < 0.01) decreased the LV mass in DS, but not in DR. However, LV fractional shortening in DS was similar between the two groups. Curcumin also prevented the increases in hypertension-induced myocardial cell hypertrophy and perivascular fibrosis. Furthermore, curcumin significantly attenuated the up-regulation of hypertrophy-response gene transcriptions as well as acetylation of GATA4 but not phosphorylation of ERK1/2 and GATA4 in the heart. Conclusions: The natural compound, curcumin, inhibits the development of hypertension-induced concentric LVH without affecting the systolic function through inhibition of GATA4-acetylation. Thus, this compound might be applicable to patients with early-stages hypertensive heart diseases.