Pharmacological inhibition of histone deacetylase reduces NADPH oxidase expression, oxidative stress and the progression of atherosclerotic lesions in hypercholesterolemic apolipoprotein E-deficient mice; potential implications for human atherosclerosis

Abstract

NADPH oxidase (Nox)-derived reactive oxygen species (ROS) are instrumental in all inflammatory phases of atherosclerosis. Dysregulated histone deacetylase (HDAC)-related epigenetic pathways have been mechanistically linked to alterations in gene expression in experimental models of cardiovascular disorders. Hitherto, the relation between HDAC and Nox in atherosclerosis is not known. We aimed at uncovering whether HDAC plays a role in mediating Nox up-regulation, oxidative stress, inflammation, and atherosclerotic lesion progression. Human non-atherosclerotic and atherosclerotic arterial samples, ApoE−/− mice, and in vitro polarized monocyte-derived M1/M2-macrophages (Mac) were examined. Male ApoE−/− mice, maintained on normal or high-fat, cholesterol-rich diet, were randomized to receive 10 mg/kg suberoylanilide hydroxamic acid (SAHA), a pan-HDAC inhibitor, or its vehicle, for 4 weeks. In the human/animal studies, real-time PCR, Western blot, lipid staining, lucigenin-enhanced chemiluminescence assay, and enzyme-linked immunosorbent assay were employed. The protein levels of class I, class IIa, class IIb, and class IV HDAC isoenzymes were significantly elevated both in human atherosclerotic tissue samples and in atherosclerotic aorta of ApoE−/− mice. Treatment of ApoE−/− mice with SAHA reduced significantly the extent of atherosclerotic lesions, and the aortic expression of Nox subtypes, NADPH-stimulated ROS production, oxidative stress and pro-inflammatory markers. Significantly up-regulated HDAC and Nox subtypes were detected in inflammatory M1-Mac. In these cells, SAHA reduced the Nox1/2/4 transcript levels. Collectively, HDAC inhibition reduced atherosclerotic lesion progression in ApoE−/− mice, possibly by intertwined mechanisms involving negative regulation of Nox expression and inflammation. The data propose that HDAC-oriented pharmacological interventions could represent an effective therapeutic strategy in atherosclerosis.

Detection of Vascular Reactive Oxygen Species in Experimental Atherosclerosis by High-Resolution Near-Infrared Fluorescence Imaging Using VCAM-1-Targeted Liposomes Entrapping a Fluorogenic Redox-Sensitive Probe

“…Others and we have demonstrated that augmented formation of ROS is instrumental in all phases of atherosclerosis [3], and it is a hallmark of CVD, in general [4]. A strong correlation between upregulated ROS and the severity of atherosclerotic lesions has been demonstrated in humans and atherosclerotic mice [3][4][5][6]. Notably, early atherosclerotic lesions can be barely detected using standard imaging procedures (e.g., echography and angiography) due to the fact that several parameters such as luminal diameter and vessel wall thickness are not essentially modified as compared to normal conditions.…”

Histone Deacetylases (HDACs) and Atherosclerosis: A Mechanistic and Pharmacological Review

“…It was reported that the pan-HDACi varinostat (SAHA) reduced expression of Nox1/2/4 in the aorta of ApoE –/– mice, which contributed to its anti-AS effect ( Manea et al, 2020 ). Recruitment of HDAC abolishes the interaction of RNA polymerase II and p300 to the promoter sites of Nox2/4/5, respectively, which inhibited the activation at those promoter regions and resulted in a decline of ROS ( Chen et al, 2016 ; Hakami et al, 2016 ).…”

“…On the contrary, it was demonstrated that reduced expression of HDAC9 induced by miR-182 was implicated in increased levels of cholesterol, lipoprotein lipase, and proinflammatory cytokines in oxLDL-treated human THP-1 macrophages, which the author suggested might mediate the lipid accumulation in atherosclerotic lesions and thus promoted atherogenesis in ApoE –/– mice administered with miR-182 agomir ( Cheng et al, 2017 ). Moreover, it was found that HDAC1/2/3/4/6/11 were all upregulated in atherosclerotic carotid arteries and aortas from human and ApoE –/– mice, respectively ( Manea et al, 2020 ). By using aortic isografted model, Zampetaki et al (2010) found that endothelial-specific knockdown of HDAC3 in aortas from ApoE –/– mice robustly promoted atherosclerotic lesion formation.…”

“…In ox-LDL-treated HAECs and aortas from ApoE –/– mice, HDAC6 was upregulated, and its selective inhibitor tubacin prevented endothelial dysfunction and the development of AS ( Leucker et al, 2017 ). Several HDACi such as TSA ( Gao et al, 2020 ), metacept-1 ( Vinh et al, 2008 ), BuA ( He and Moreau, 2019 ), and SAHA ( Ye et al, 2018 ; Manea et al, 2020 ) have been demonstrated to inhibit the development of AS.…”

Targeting epigenetics as atherosclerosis treatment: an updated view

“…Although in vitro HDAC inhibition has anti-inflammatory properties in immune cells such as macrophages [ 5 ] and T cells [ 6 ], the first in vivo mice study using HDAC inhibitors for atherosclerosis surprisingly showed that treatment with the pan-HDAC inhibitor trichostatin A (TSA) enhanced atherosclerotic lesion formation in a Ldlr −/− mice model for atherosclerosis [ 7 ]. On the contrary, treatment with the more specific class I HDAC inhibitor valproate attenuated atherosclerosis development in a hyperglycaemic ApoE -deficient mouse model [ 8 ], and recently, it was shown that also treatment with the pan-HDAC inhibitor vorinostat (SAHA) decreased atherosclerotic lesion size in an ApoE-deficient mice [ 9 ]. Differences in outcomes might not only be explained by the specificity and selectivity of the compounds, but also by the type of cells that are affected by the HDAC inhibitors.…”