HDAC5 inhibition reduces angiotensin II-induced vascular contraction, hypertrophy, and oxidative stress in a mouse model

Abstract

Non-specific histone deacetylase (HDAC) inhibition reduces high blood pressure in essential hypertensive animal models. However, the exact HDAC isoforms that play a critical role in controlling hypertension are not known. Here, we investigated the role of HDAC5 in vascular contraction, hypertrophy, and oxidative stress in the context of angiotensin II (Ang II)-induced hypertension. Genetic deletion of HDAC5 and treatment with class IIa HDAC inhibitors (TMP269 and TMP195) prevented Ang II-induced increases in blood pressure and arterial wall thickness. Hdac5-knockout mice were also resistant to the thromboxane A2 agonist (U46619)-induced vascular contractile response. Furthermore, the expression of Rho-associated protein kinase (ROCK) 2 was downregulated in the aortas of Ang II-treated Hdac5-knockout mice. Knockdown of HDAC5, RhoA, or ROCK2 reduced collagen gel contraction, whereas silencing of ROCK1 increased it. VSMC hypertrophy reduced on knocking down HDAC5, ROCK1, and ROCK2. Here we showed that genetic deletion of HDAC5 and pharmacological inhibition of class IIa HDACs ameliorated Ang II-induced ROS generation. Moreover, ROCK1 and ROCK2, the downstream targets of HDAC5, influenced ROS generation. The relative protein levels of HDAC5, ROCK1, and ROCK2 were increased both in the cytoplasm and nuclear fraction in response to Ang II stimulation in vascular smooth muscle cells. Inhibition of HDAC5 expression or activity reduced vascular hypertrophy, vasoconstriction, and oxidative stress in the Ang II-induced hypertension model. These findings indicate that HDAC5 may serve as a potential target in the treatment of hypertension.

Keywords: HDAC5; Hypertension; Oxidative stress; Rho-associated protein kinase; Vascular contraction; Vascular hypertrophy.