Abstract
The role of circulating, systemic TGF-beta levels in endothelial function is not clear. TGF-beta(1) may cause endothelial dysfunction in apolipoprotein E-deficient (apoE(-/-)) mice via stimulation of reactive oxygen species (ROS) production by the NADPH oxidase (NOX) system and aggravate aortic and heart remodeling and hypertension. Thoracic aorta (TA) were isolated from 4-mo-old control (C57Bl/6), apoE(-/-), TGF-beta(1)-overexpressing (TGFbeta(1)), and crossbred apoE(-/-) x TGFbeta(1) mice. Endothelium-dependent relaxation was measured before and after incubation with apocynin (NOX inhibitor) or superoxide dismutase (SOD; ROS scavenger). Superoxide production within the vessel wall was determined by dihydroethidine staining under confocal microscope. In 8-mo-old mice, aortic and myocardial morphometric changes, plaque formation by en face fat staining, and blood pressure were determined. Serum TGF-beta(1) levels (ELISA) were elevated in TGFbeta(1) mice without downregulation of TGF-beta-I receptor (immunohistochemistry). In the aortic wall, superoxide production was enhanced and NO-dependent relaxation diminished in apoE(-/-) x TGFbeta(1) mice but improved significantly after apocynin or SOD. Myocardial capillary density was reduced, fibrocyte density increased, aortic wall was thicker, combined lesion area was greater, and blood pressure was higher in the apoE(-/-) x TGFbeta vs. C57Bl/6 mice. Our results demonstrate that elevated circulating TGF-beta(1) causes endothelial dysfunction through NOX activation-induced oxidative stress, accelerating atherosclerosis and hypertension in apoE(-/-) mice. These findings may provide a mechanism explaining accelerated atherosclerosis in patients with elevated plasma TGFbeta(1).
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Acetophenones / pharmacology
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Animals
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Aorta / drug effects
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Aorta / enzymology*
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Aorta / pathology
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Aorta / physiopathology
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Apolipoproteins E / deficiency*
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Apolipoproteins E / genetics
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Atherosclerosis / enzymology*
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Atherosclerosis / genetics
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Atherosclerosis / pathology
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Atherosclerosis / physiopathology
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Blood Pressure
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Body Weight
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Cardiomegaly / enzymology
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Cardiomegaly / pathology
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Cardiomegaly / physiopathology
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Disease Models, Animal
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Disease Progression
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Enzyme Activation
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Enzyme Inhibitors / pharmacology
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Female
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Free Radical Scavengers / pharmacology
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Heart Diseases / enzymology*
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Heart Diseases / genetics
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Heart Diseases / pathology
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Heart Diseases / physiopathology
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Humans
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Hypertension / enzymology*
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Hypertension / genetics
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Hypertension / pathology
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Hypertension / physiopathology
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Lipid Metabolism
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Male
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Mice
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Mice, Inbred C57BL
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Mice, Inbred CBA
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Mice, Knockout
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Mice, Transgenic
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Myocardium / pathology
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NADPH Oxidases / antagonists & inhibitors
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NADPH Oxidases / metabolism*
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Nitric Oxide / metabolism
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Oxidative Stress
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Protein Serine-Threonine Kinases / metabolism
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Receptor, Transforming Growth Factor-beta Type I
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Receptors, Transforming Growth Factor beta / metabolism
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Superoxide Dismutase / pharmacology
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Superoxides / metabolism*
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Swine
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Transforming Growth Factor beta1 / blood*
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Transforming Growth Factor beta1 / genetics
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Up-Regulation
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Vasodilation* / drug effects
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Ventricular Remodeling*
Substances
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Acetophenones
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Apolipoproteins E
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Enzyme Inhibitors
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Free Radical Scavengers
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Receptors, Transforming Growth Factor beta
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Transforming Growth Factor beta1
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Superoxides
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Nitric Oxide
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acetovanillone
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Superoxide Dismutase
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NADPH Oxidases
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Protein Serine-Threonine Kinases
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Receptor, Transforming Growth Factor-beta Type I