ABSTRACT
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.
Subject(s)
Adipose Tissue , Cholesterol Ester Transfer Proteins , Mice, Transgenic , Oxidative Stress , Cholesterol Ester Transfer Proteins/metabolism , Cholesterol Ester Transfer Proteins/genetics , Animals , Male , Female , Mice , Adipose Tissue/metabolism , Humans , Sex Characteristics , Nitric Oxide/metabolismABSTRACT
BACKGROUND: Although skeletal muscle atrophy and changes in myosin heavy chain (MyHC) isoforms have often been observed during heart failure, their pathophysiological mechanisms are not completely defined. In this study we tested the hypothesis that skeletal muscle phenotype changes are related to myogenic regulatory factors and myostatin/follistatin expression in spontaneously hypertensive rats (SHR) with heart failure. METHODS: After developing tachypnea, SHR were subjected to transthoracic echocardiogram. Pathological evidence of heart failure was assessed during euthanasia. Age-matched Wistar-Kyoto (WKY) rats were used as controls. Soleus muscle morphometry was analyzed in histological sections, and MyHC isoforms evaluated by electrophoresis. Protein levels were assessed by Western blotting. STATISTICAL ANALYSIS: Student'st test and Pearson correlation. RESULTS: All SHR presented right ventricular hypertrophy and seven had pleuropericardial effusion. Echocardiographic evaluation showed dilation in the left chambers and left ventricular hypertrophy with systolic and diastolic dysfunction in SHR. Soleus weight and fiber cross sectional areas were lower (WKY 3615 ± 412; SHR 2035 ± 224 µm(2); P<0.001), and collagen fractional volume was higher in SHR. The relative amount of type I MyHC isoform was increased in SHR. Myogenin, myostatin, and follistatin expression was lower and MRF4 levels higher in SHR. Myogenin and follistatin expression positively correlated with fiber cross sectional areas and MRF4 levels positively correlated with I MyHC isoform. CONCLUSION: Reduced myogenin and follistatin expression seems to participate in muscle atrophy while increased MRF4 protein levels can modulate myosin heavy chain isoform shift in skeletal muscle of spontaneously hypertensive rats with heart failure.
