👤 A P Davel

Cholesteryl ester transfer protein (CETP) increases the atherosclerosis risk by lowering HDL-cholesterol levels. It also exhibits tissue-specific effects independent of HDL. However, sexual dimorphism of CETP effects remains largely unexplored. Here, we hypothesized that CETP impacts the perivascular adipose tissue (PVAT) phenotype and function in a sex-specific manner. PVAT function, gene and protein expression, and morphology were examined in male and female transgenic mice expressing human or simian CETP and their non-transgenic counterparts (NTg). PVAT exerted its anticontractile effect in aortas from NTg males, NTg females, and CETP females, but not in CETP males. CETP male PVAT had reduced NO levels, decreased eNOS and phospho-eNOS levels, oxidative stress, increased NOX1 and 2, and decreased SOD2 and 3 expressions. In contrast, CETP-expressing female PVAT displayed increased NO and phospho-eNOS levels with unchanged NOX expression. NOX inhibition and the antioxidant tempol restored PVAT anticontractile function in CETP males. Ex vivo estrogen treatment also restored PVAT function in CETP males. Moreover, CETP males, but not female PVAT, show increased inflammatory markers. PVAT lipid content increased in CETP males but decreased in CETP females, while PVAT cholesterol content increased in CETP females. CETP male PVAT exhibited elevated leptin and reduced Prdm16 (brown adipocyte marker) expression. These findings highlight CETP sex-specific impact on PVAT. In males, CETP impaired PVAT anticontractile function, accompanied by oxidative stress, inflammation, and whitening. Conversely, in females, CETP expression increased NO levels, induced an anti-inflammatory phenotype, and preserved the anticontractile function. This study reveals sex-specific vascular dysfunction mediated by CETP. Show less

Endothelial dysfunction is an early manifestation of atherosclerosis. The cholesteryl ester transfer protein (CETP) has been considered proatherogenic by reducing plasma HDL levels. However, CETP may exhibit cell- or tissue-specific effects. We have previously reported that male mice expressing the human CETP gene show impaired endothelium-mediated vascular relaxation associated with oxidative stress. Although sexual dimorphisms on the metabolic role of CETP have been proposed, possible sex differences in the vascular effects of CETP were not previously studied. Thus, here we investigated the endothelial function of female CETP transgenic mice as compared with nontransgenic controls (NTg). Aortas from CETP females presented preserved endothelium-dependent relaxation to acetylcholine and an endothelium-dependent reduction of phenylephrine-induced contraction. eNOS phosphorylation (Ser1177) and calcium-induced NO levels were enhanced, whereas reactive oxygen species (ROS) production and NOX2 and SOD2 expression were reduced in the CETP female aortas. Furthermore, CETP females exhibited increased aortic relaxation to 17β-estradiol (E Show less

Endothelial dysfunction precedes atherosclerosis and is an independent predictor of cardiovascular events. Cholesterol levels and oxidative stress are key contributors to endothelial damage, whereas high levels of plasma high-density lipoproteins (HDL) could prevent it. Cholesteryl ester transfer protein (CETP) is one of the most potent endogenous negative regulators of HDL-cholesterol. However, whether and to what degree CETP expression impacts endothelial function, and the molecular mechanisms underlying the vascular effects of CETP on endothelial cells, have not been addressed. Acetylcholine-induced endothelium-dependent relaxation of aortic rings was impaired in human CETP-expressing transgenic mice, compared to their non-transgenic littermates. However, endothelial nitric oxide synthase (eNOS) activation was enhanced. The generation of superoxide and hydrogen peroxide was increased in aortas from CETP transgenic mice, while silencing CETP in cultured human aortic endothelial cells effectively decreased oxidative stress promoted by all major sources of ROS: mitochondria and NOX2. The endoplasmic reticulum stress markers, known as GADD153, PERK, and ARF6, and unfolded protein response effectors, were also diminished. Silencing CETP reduced endothelial tumor necrosis factor (TNF) α levels, intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) expression, diminishing monocyte adhesion. These results support the notion that CETP expression negatively impacts endothelial cell function, revealing a new mechanism that might contribute to atherosclerosis. Show less