Epigenetic regulation of vascular NADPH oxidase expression and reactive oxygen species production by histone deacetylase-dependent mechanisms in experimental diabetes

Abstract

Reactive oxygen species (ROS) generated by up-regulated NADPH oxidase (Nox) contribute to structural-functional alterations of the vascular wall in diabetes. Epigenetic mechanisms, such as histone acetylation, emerged as important regulators of gene expression in cardiovascular disorders. Since their role in diabetes is still elusive we hypothesized that histone deacetylase (HDAC)-dependent mechanisms could mediate vascular Nox overexpression in diabetic conditions. Non-diabetic and streptozotocin-induced diabetic C57BL/6J mice were randomized to receive vehicle or suberoylanilide hydroxamic acid (SAHA), a pan-HDAC inhibitor. In vitro studies were performed on a human aortic smooth muscle cell (SMC) line. Aortic SMCs typically express Nox1, Nox4, and Nox5 subtypes. HDAC1 and HDAC2 proteins along with Nox1, Nox2, and Nox4 levels were found significantly elevated in the aortas of diabetic mice compared to non-diabetic animals. Treatment of diabetic mice with SAHA mitigated the aortic expression of Nox1, Nox2, and Nox4 subtypes and NADPH-stimulated ROS production. High concentrations of glucose increased HDAC1 and HDAC2 protein levels in cultured SMCs. SAHA significantly reduced the high glucose-induced Nox1/4/5 expression, ROS production, and the formation malondialdehyde-protein adducts in SMCs. Overexpression of HDAC2 up-regulated the Nox1/4/5 gene promoter activities in SMCs. Physical interactions of HDAC1/2 and p300 proteins with Nox1/4/5 promoters were detected at the sites of active transcription. High glucose induced histone H3K27 acetylation enrichment at the promoters of Nox1/4/5 genes in SMCs. The novel data of this study indicate that HDACs mediate vascular Nox up-regulation in diabetes. HDAC inhibition reduces vascular ROS production in experimental diabetes, possibly by a mechanism involving negative regulation of Nox expression.

Magnesium Lithospermate B Derived from Salvia miltiorrhiza Ameliorates Right Ventricle Remodeling in Pulmonary Hypertensive Rats via Inhibition of NOX/VPO1 Pathway

“…Although NOX1, NOX2, and NOX4 are expressed in cardiovascular systems including the pulmonary vasculature, only NOX2 and NOX4 are considered the major sources for ROS production in the cardiovascular system under pathological con-ditions [27]. Under normal conditions, NOX constitutively generates low levels of ROS, but it can be activated acutely under condition of ischemia [28], hypoxia [29], hyperlipidemia [30], high glucose [31], or high blood pressure [32]. Consistent with the reports, NOX2 and NOX4 protein levels were evidently elevated in the RV of hypoxic PAH rats or in hypoxia-treated H9c2 cells.…”

NOX5: Molecular biology and pathophysiology

“…In human atherosclerosis, oxidative and inflammatory processes involve increased expression and activation of NOX5 in vascular cells and resident macrophages (Chen et al., ; Hahn et al., ). In in vitro studies, exposure of monocytes and monocyte‐derived macrophages to increasing concentrations of interferon‐γ or oxidized low‐density lipoprotein, conditions that recapitulate atherogenesis, induced a dose‐dependent increase in NOX5 expression and ROS production (Manea et al., ). However, not all models of vascular inflammation and remodelling are associated with NOX5, as demonstrated in a primate model of atherosclerosis, where NOX2, but not NOX5, was involved in vascular injury (Stanic, Pandey, Fulton, & Miller, ).…”

“…In human atherosclerosis, oxidative and inflammatory processes involve increased expression and activation of NOX5 in vascular cells and resident macrophages Hahn et al, 2012). In in vitro studies, exposure of monocytes and monocyte-derived macrophages to increasing concentrations of interferon-or oxidized low-density lipoprotein, conditions that recapitulate atherogenesis, induced a dose-dependent increase in NOX5 expression and ROS production (Manea et al, 2018).…”

A positive feedback loop between EZH2 and NOX4 regulates nucleus pulposus cell senescence in age-related intervertebral disc degeneration

“…Rabbit polyclonal antibodies against H3K27me3 (#9733, 1:50 dilution) and H3K27ac (#4353, 1:25 dilution) were applied for the assay. PCR was performed with three primer sets [57] spanning the region of the NOX4 proximal promotor (≈ 800 bp). 'Input' (DNA purified by sonication), rabbit IgG antibody, and negative controls (no antibody) were used.…”