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Ahn SJ, Fancher IS, Granados ST, Do Couto NF, Hwang CL, Phillips SA, Levitan I. Cholesterol-Induced Suppression of Endothelial Kir Channels Is a Driver of Impairment of Arteriolar Flow-Induced Vasodilation in Humans. Hypertension 2022; 79:126-138. [PMID: 34784737 PMCID: PMC8845492 DOI: 10.1161/hypertensionaha.121.17672] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Dyslipidemia-induced endothelial dysfunction is an important factor in the progression of cardiovascular disease; however, the underlying mechanisms are unclear. Our recent studies demonstrated that flow-induced vasodilation (FIV) is regulated by inwardly rectifying K+ channels (Kir2.1) in resistance arteries. Furthermore, we showed that hypercholesterolemia inhibits Kir2.1-dependent vasodilation. In this study, we introduced 2 new mouse models: (1) endothelial-specific deletion of Kir2.1 to demonstrate the role of endothelial Kir2.1 in FIV and (2) cholesterol-insensitive Kir2.1 mutant to determine the Kir2.1 regulation in FIV under hypercholesterolemia. FIV was significantly reduced in endothelial-specific Kir2.1 knock-out mouse mesenteric arteries compared with control groups. In cholesterol-insensitive Kir2.1 mutant mice, Kir2.1 currents were not affected by cyclodextrin and FIV was restored in cells and arteries, respectively, with a hypercholesterolemic background. To extend our observations to humans, 16 healthy subjects were recruited with LDL (low-density lipoprotein)-cholesterol ranging from 51 to 153 mg/dL and FIV was assessed in resistance arteries isolated from gluteal adipose. Resistance arteries from participants with >100 mg/dL LDL (high-LDL) exhibited reduced FIV as compared with those participants with <100 mg/dL LDL (low-LDL). A significant negative correlation was observed between LDL cholesterol and FIV in high-LDL. Expressing dominant-negative Kir2.1 in endothelium blunted FIV in arteries from low-LDL but had no further effect on FIV in arteries from high-LDL. The Kir2.1-dependent vasodilation more negatively correlated to LDL cholesterol in high-LDL. Overexpressing wild-type Kir2.1 in endothelium fully recovered FIV in arteries from participants with high-LDL. Our data suggest that cholesterol-induced suppression of Kir2.1 is a major mechanism underlying endothelial dysfunction in hypercholesterolemia.
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Affiliation(s)
- Sang Joon Ahn
- Department of Medicine, Division of Pulmonary, Critical Care, Allergy and Sleep, College of Medicine, University of Illinois at Chicago
| | - Ibra S. Fancher
- Department of Medicine, Division of Pulmonary, Critical Care, Allergy and Sleep, College of Medicine, University of Illinois at Chicago,Department of Kinesiology and Applied Physiology, University of Delaware
| | - Sara T. Granados
- Department of Medicine, Division of Pulmonary, Critical Care, Allergy and Sleep, College of Medicine, University of Illinois at Chicago
| | - Natalia F. Do Couto
- Department of Medicine, Division of Pulmonary, Critical Care, Allergy and Sleep, College of Medicine, University of Illinois at Chicago,Department of Physical Therapy, College of Applied Health Science, University of Illinois at Chicago
| | - Chueh-Lung Hwang
- Department of Physical Therapy, College of Applied Health Science, University of Illinois at Chicago
| | - Shane A. Phillips
- Department of Physical Therapy, College of Applied Health Science, University of Illinois at Chicago
| | - Irena Levitan
- Department of Medicine, Division of Pulmonary, Critical Care, Allergy and Sleep, College of Medicine, University of Illinois at Chicago
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Horseradish (Moringa oleifera) seed and leaf inclusive diets modulates activities of enzymes linked with hypertension, and lipid metabolites in high-fat fed rats. PHARMANUTRITION 2019. [DOI: 10.1016/j.phanu.2018.100141] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Liao HY, Chien CC, Tang P, Chen CC, Chen CY, Chen SC. The integrated analysis of transcriptome and proteome for exploring the biodegradation mechanism of 2, 4, 6-trinitrotoluene by Citrobacter sp. JOURNAL OF HAZARDOUS MATERIALS 2018; 349:79-90. [PMID: 29414755 DOI: 10.1016/j.jhazmat.2018.01.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 06/08/2023]
Abstract
Citrobacter sp. has been shown to degrade 2,4,6-trinitrotoluene (TNT). However, the mechanism of its TNT biodegradation is poorly understood. An integrated proteome and transcriptome analysis was performed for investigating the differential genes and differential proteins in bacterial growth at the onset of experiments and after 12 h treatment with TNT. With the RNA sequencing, we found a total of 3792 transcripts and 569 differentially expressed genes (≥2 fold, P < 0.05) by. Genes for amino acid transport, cellular metabolism and stress-shock proteins were up-regulated, while carbohydrate transport and metabolism were down-regulated. A total of 42 protein spots (≥1.5 fold, P < 0.05) showed differential expression on two-dimensional gel electrophoresis and these proteins were identified by mass spectrometry. The most prominent proteins up-regulated were involved in energy production and conversion, amino acid transport and metabolism, posttranslational modification, protein turnover and chaperones. Proteins involved in carbohydrate transport and metabolism were down-regulated. Most notably, we observed that nemA encoding N-ethylmaleimide reductase was the most up-regulated gene involved in TNT degradation, and further proved that it can transform TNT to 4-amino-2,6-dinitrotoluene (4-ADNT) and 2-amino-4,6-dinitrotoluene (2-ADNT). This study highlights the molecular mechanisms of Citrobacter sp. for TNT removal.
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Affiliation(s)
- Hung-Yu Liao
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan
| | - Chih-Ching Chien
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, No. 135, Yuantung Rd., Jhongli City, Taoyuan, 32003, Taiwan
| | - Petrus Tang
- Department of Parasitology, Chang Gung University, No.259, Wenhua 1st Rd., Guishan Dis., Taoyuan City, 33302, Taiwan
| | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, No.116, Heping 1st Rd., Lingya District, Kaohsiung City, 80201, Taiwan
| | - Chin-Yu Chen
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan
| | - Ssu-Ching Chen
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan.
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Fancher IS, Ahn SJ, Adamos C, Osborn C, Oh MJ, Fang Y, Reardon CA, Getz GS, Phillips SA, Levitan I. Hypercholesterolemia-Induced Loss of Flow-Induced Vasodilation and Lesion Formation in Apolipoprotein E-Deficient Mice Critically Depend on Inwardly Rectifying K + Channels. J Am Heart Assoc 2018; 7:e007430. [PMID: 29502106 PMCID: PMC5866319 DOI: 10.1161/jaha.117.007430] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 01/17/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Hypercholesterolemia-induced decreased availability of nitric oxide (NO) is a major factor in cardiovascular disease. We previously established that cholesterol suppresses endothelial inwardly rectifying K+ (Kir) channels and that Kir2.1 is an upstream mediator of flow-induced NO production. Therefore, we tested the hypothesis that suppression of Kir2.1 is responsible for hypercholesterolemia-induced inhibition of flow-induced NO production and flow-induced vasodilation (FIV). We also tested the role of Kir2.1 in the development of atherosclerotic lesions. METHODS AND RESULTS Kir2.1 currents are significantly suppressed in microvascular endothelial cells exposed to acetylated-low-density lipoprotein or isolated from apolipoprotein E-deficient (Apoe-/- ) mice and rescued by cholesterol depletion. Genetic deficiency of Kir2.1 on the background of hypercholesterolemic Apoe-/- mice, Kir2.1+/-/Apoe-/- exhibit the same blunted FIV and flow-induced NO response as Apoe-/- or Kir2.1+/- alone, but while FIV in Apoe-/- mice can be rescued by cholesterol depletion, in Kir2.1+/-/Apoe-/- mice cholesterol depletion has no effect on FIV. Endothelial-specific overexpression of Kir2.1 in arteries from Apoe-/- and Kir2.1+/-/Apoe-/- mice results in full rescue of FIV and NO production in Apoe-/- mice with and without the addition of a high-fat diet. Conversely, endothelial-specific expression of dominant-negative Kir2.1 results in the opposite effect. Kir2.1+/-/Apoe-/- mice also show increased lesion formation, particularly in the atheroresistant area of descending aorta. CONCLUSIONS We conclude that hypercholesterolemia-induced reduction in FIV is largely attributable to cholesterol suppression of Kir2.1 function via the loss of flow-induced NO production, whereas the stages downstream of flow-induced Kir2.1 activation appear to be mostly intact. Kir2.1 channels also have an atheroprotective role.
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MESH Headings
- Animals
- Aorta/metabolism
- Aorta/pathology
- Aortic Diseases/genetics
- Aortic Diseases/metabolism
- Aortic Diseases/pathology
- Aortic Diseases/physiopathology
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Atherosclerosis/physiopathology
- Cells, Cultured
- Cholesterol/blood
- Disease Models, Animal
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Hypercholesterolemia/genetics
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/pathology
- Hypercholesterolemia/physiopathology
- Male
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mice, Inbred C57BL
- Mice, Knockout, ApoE
- Nitric Oxide/metabolism
- Plaque, Atherosclerotic
- Potassium Channels, Inwardly Rectifying/deficiency
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/metabolism
- Signal Transduction
- Vasodilation
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Affiliation(s)
- Ibra S Fancher
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Sang Joon Ahn
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
| | - Crystal Adamos
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Catherine Osborn
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
| | - Myung-Jin Oh
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, IL
| | - Yun Fang
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, IL
| | | | | | - Shane A Phillips
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Irena Levitan
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
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Violi F, Loffredo L, Carnevale R, Pignatelli P, Pastori D. Atherothrombosis and Oxidative Stress: Mechanisms and Management in Elderly. Antioxid Redox Signal 2017; 27:1083-1124. [PMID: 28816059 DOI: 10.1089/ars.2016.6963] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
SIGNIFICANCE The incidence of cardiovascular events (CVEs) increases with age, representing the main cause of death in an elderly population. Aging is associated with overproduction of reactive oxygen species (ROS), which may affect clotting and platelet activation, and impair endothelial function, thus predisposing elderly patients to thrombotic complications. Recent Advances: There is increasing evidence to suggest that aging is associated with an imbalance between oxidative stress and antioxidant status. Thus, upregulation of ROS-producing enzymes such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and myeloperoxidase, along with downregulation of antioxidant enzymes, such as superoxide dismutase and glutathione peroxidase, occurs during aging. This imbalance may predispose to thrombosis by enhancing platelet and clotting activation and eliciting endothelial dysfunction. Recently, gut-derived products, such as trimethylamine N-oxide (TMAO) and lipopolysaccharide, are emerging as novel atherosclerotic risk factors, and gut microbiota composition has been shown to change by aging, and may concur with the increased cardiovascular risk in the elderly. CRITICAL ISSUES Antioxidant treatment is ineffective in patients at risk or with cardiovascular disease. Further, anti-thrombotic treatment seems to work less in the elderly population. FUTURE DIRECTIONS Interventional trials with antioxidants targeting enzymes implicated in aging-related atherothrombosis are warranted to explore whether modulation of redox status is effective in lowering CVEs in the elderly. Antioxid. Redox Signal. 27, 1083-1124.
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Affiliation(s)
- Francesco Violi
- 1 I Clinica Medica, Department of Internal Medicine and Medical Specialties, Sapienza University of Rome , Roma, Italy
| | - Lorenzo Loffredo
- 1 I Clinica Medica, Department of Internal Medicine and Medical Specialties, Sapienza University of Rome , Roma, Italy
| | - Roberto Carnevale
- 1 I Clinica Medica, Department of Internal Medicine and Medical Specialties, Sapienza University of Rome , Roma, Italy .,2 Department of Medical-Surgical Sciences and Biotechnologies, Sapienza University of Rome , Latina, Italy
| | - Pasquale Pignatelli
- 1 I Clinica Medica, Department of Internal Medicine and Medical Specialties, Sapienza University of Rome , Roma, Italy
| | - Daniele Pastori
- 1 I Clinica Medica, Department of Internal Medicine and Medical Specialties, Sapienza University of Rome , Roma, Italy
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6
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Edwards M, Czank C, Woodward GM, Cassidy A, Kay CD. Phenolic metabolites of anthocyanins modulate mechanisms of endothelial function. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:2423-2431. [PMID: 25686009 DOI: 10.1021/jf5041993] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Anthocyanins are reported to have vascular bioactivity, however their mechanisms of action are largely unknown. Evidence suggests that anthocyanins modulate endothelial function, potentially by increasing nitric oxide (NO) synthesis, or enhancing NO bioavailability. This study compared the activity of cyanidin-3-glucoside, its degradation product protocatechuic acid, and phase II metabolite, vanillic acid. Production of NO and superoxide and expression of endothelial NO synthase (eNOS), NADPH oxidase (NOX), and heme oxygenase-1 (HO-1) were established in human vascular cell models. Nitric oxide levels were not modulated by the treatments, although eNOS was upregulated by cyanidin-3-glucoside, and superoxide production was decreased by both phenolic acids. Vanillic acid upregulated p22(phox) mRNA but did not alter NOX protein expression, although trends were observed for p47(phox) downregulation and HO-1 upregulation. Anthocyanin metabolites may therefore modulate vascular reactivity by inducing HO-1 and modulating NOX activity, resulting in reduced superoxide production and improved NO bioavailability.
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Affiliation(s)
- Michael Edwards
- Department of Nutrition, Norwich Medical School, University of East Anglia , Norwich NR4 7TJ, United Kingdom
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7
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Heo JH, Hyon-Lee, Lee KM. The possible role of antioxidant vitamin C in Alzheimer's disease treatment and prevention. Am J Alzheimers Dis Other Demen 2013; 28:120-5. [PMID: 23307795 PMCID: PMC10852723 DOI: 10.1177/1533317512473193] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Oxidative stress is suggested to play a major role in the pathogenesis of Alzheimer's disease (AD). Among the antioxidants, vitamin C has been regarded as the most important one in neural tissue. It also decreases β-amyloid generation and acetylcholinesterase activity and prevents endothelial dysfunction by regulating nitric oxide, a newly discovered factor in the pathogenesis and progression of AD. However, clinical trials using antioxidants, including vitamin C, in patients with AD yielded equivocal results. The current article discusses the relevance of vitamin C in the cellular and molecular pathogenesis of AD and explores its therapeutic potential against this neurodegenerative disorder.
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Affiliation(s)
- Jae-Hyeok Heo
- Department of Neurology, Seoul Medical Center, Seoul, Korea
| | - Hyon-Lee
- Department of Neurology, Seoul National University Hospital, Seoul, Korea
| | - Kyoung-Min Lee
- Department of Neurology, Seoul National University Hospital, Seoul, Korea
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8
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Lee W, Xu M, Li Y, Gu Y, Chen J, Wong D, Fung PCW, Shen J. Free cholesterol accumulation impairs antioxidant activities and aggravates apoptotic cell death in menadione-induced oxidative injury. Arch Biochem Biophys 2011; 514:57-67. [PMID: 21843500 DOI: 10.1016/j.abb.2011.07.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 07/26/2011] [Accepted: 07/26/2011] [Indexed: 10/17/2022]
Abstract
Although the relationship between hypercholesterolemia and oxidative stress has been extensively investigated, direct evidence regarding to the roles of cholesterol accumulation in the generations of reactive oxygen species (ROS) and apoptotic cell death under oxidative stress is lack. In this study, we investigated productions of superoxide anions (O(2)(-)) and nitric oxide (NO), and apoptotic cell death in wild type Chinese hamster ovary (CHO) cells and cholesterol accumulated CHO cells genetically and chemically. Oxidative stress was induced by menadione challenge. The results revealed that abundance of free cholesterol (FC) promoted menadione-induced O(2)(-) and NO productions. FC accumulation down-regulated eNOS expression but up-regulated NADPH oxidases, and inhibited the activities of superoxide dismutase (SOD) and catalase. Treatment of menadione increased the expressions of iNOS and qp91 phox, enhanced the activities of SOD and catalase in the wild-type CHO cells but inhibited the activity of glutathione peroxidase in the cholesterol accumulated CHO cells. Moreover, FC abundance promoted apoptotic cell death in these cells. Taken together, those results suggest that free cholesterol accumulation aggravates menadione-induced oxidative stress and exacerbates apoptotic cell death.
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Affiliation(s)
- Waisin Lee
- School of Chinese Medicine, The University of Hong Kong, China
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9
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Weng Y, Dang Y, Ye X, Liu N, Zhang Z, Ren Q. Investigation of irradiation by different nonablative lasers on primary cultured skin fibroblasts. Clin Exp Dermatol 2011; 36:655-60. [PMID: 21457156 DOI: 10.1111/j.1365-2230.2011.04043.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND A variety of lasers with different wavelengths and biological effects are widely used for nonablative skin rejuvenation, but the underlying mechanisms have not been fully investigated. AIM To investigate the effects of irradiation by different nonablative lasers on collagen synthesis and the antioxidant status of cultured fibroblasts to identify a possible mechanism for laser photorejuvenation. METHODS Cultured skin fibroblasts were irradiated with three different lasers: 532 nm potassium-titanyl phosphate (KTP), 1064 nm Q-switched neodymium:yttrium-aluminium-garnet (Nd:Yag) and 1064 nm long-pulse Nd:YAG, and production of collagen and changes in lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were assayed. RESULTS Irradiation by all three lasers led to a marked increase in collagen production. Two major antioxidant enzymes, SOD and GSH, were significantly increased, whereas MDA was markedly reduced after laser irradiation. No change in LDH activity was found between nonirradiated and irradiated fibroblasts. CONCLUSION This study indicates that the increased collagen synthesis by fibroblasts after laser treatment may be partly due to improved antioxidant capacity, which reduces oxidative stress and thus stimulates new collagen production.
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Affiliation(s)
- Y Weng
- School of Life Science, East China Normal University, Shanghai, China
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10
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Terasaka N, Westerterp M, Koetsveld J, Fernández-Hernando C, Yvan-Charvet L, Wang N, Sessa WC, Tall AR. ATP-binding cassette transporter G1 and high-density lipoprotein promote endothelial NO synthesis through a decrease in the interaction of caveolin-1 and endothelial NO synthase. Arterioscler Thromb Vasc Biol 2010; 30:2219-25. [PMID: 20798376 DOI: 10.1161/atvbaha.110.213215] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To investigate whether cholesterol efflux to high-density lipoprotein (HDL) via ATP-binding cassette transporter G1 (ABCG1) modulates the interaction of caveolin (Cav) 1 and endothelial NO synthase (eNOS). METHODS AND RESULTS ABCG1 promotes cholesterol and 7-oxysterol efflux from endothelial cells (ECs) to HDL. It was previously reported that ABCG1 protects against dietary cholesterol-induced endothelial dysfunction by promoting the efflux of 7-oxysterols to HDL. Increased cholesterol loading in ECs is known to cause an inhibitory interaction between Cav-1 and eNOS and impaired NO release. In human aortic ECs, free cholesterol loading promoted the interaction of Cav-1 with eNOS, reducing eNOS activity. These effects of cholesterol loading were reversed by HDL in an ABCG1-dependent manner. HDL also reversed the inhibition of eNOS by cholesterol loading in murine lung ECs, but this effect of HDL was abolished in Cav-1-deficient murine lung ECs. Increased interaction of Cav-1 with eNOS was also detected in aortic homogenates of high-cholesterol diet-fed Abcg1(-/-) mice, paralleling a decrease in eNOS activity and impaired endothelial function. CONCLUSIONS The promotion of cholesterol efflux via ABCG1 results in a reduced inhibitory interaction of eNOS with Cav-1.
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Affiliation(s)
- Naoki Terasaka
- Division of Molecular Medicine, Department of Medicine, Columbia University, 630 W 168 St, New York, NY 10032, USA
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11
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Nonneuronal Cholinergic System in Human Erythrocytes: Biological Role and Clinical Relevance. J Membr Biol 2010; 234:227-34. [DOI: 10.1007/s00232-010-9250-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2010] [Accepted: 03/13/2010] [Indexed: 10/19/2022]
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Abstract
The results of five large-scale, randomized, placebo-controlled trials, involving nearly 31,000 subjects, attest to the benefits of statins in the prevention of coronary events. Several key observations can be made on the basis of the evidence from these investigations. Of primary importance is the fact that statins reduce coronary event rates in patients with or without coronary heart disease. The percentage reduction in risk increases with each successive year of statin therapy. Moreover, the risk reduction is proportional to the reduction in low-density lipoprotein cholesterol. Subgroup analyses have demonstrated that the efficacy of statins extends to specific subgroups of patients, including women, people with diabetes, and older individuals. These agents also reduce the risk of stroke and transient ischemic attacks in patients with coronary disease. Both the randomized trials and widespread clinical experience have confirmed that statins are safe and do not increase the risk of cancer or mortality. Several markers of atherosclerotic risk are ameliorated by statins, although the clinical significance of this observation remains under investigation. The broad range of the therapeutic effects of statins yields safe, effective management of hypercholesterolemia in current practice while also providing a foundation for additional therapeutic refinements in the future.
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Affiliation(s)
- D D Waters
- Division of Cardiology, San Francisco General Hospital, University of California at San Francisco, 94110, USA.
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13
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Kanbay M, Yildirir A, Bozbas H, Ulus T, Bilgi M, Muderrisoglu H, Akcay A, Ozdemir FN. Statin Therapy Helps to Control Blood Pressure Levels in Hypertensive Dyslipidemic Patients. Ren Fail 2009. [DOI: 10.1081/jdi-56610] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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14
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Schmid W, Lee A, Son J, Koller E, Volf I. Hypochlorite-oxidized low density lipoproteins reduce production and bioavailability of nitric oxide in RAW 264.7 macrophages by distinct mechanisms. Life Sci 2008; 83:50-8. [PMID: 18558412 DOI: 10.1016/j.lfs.2008.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2007] [Revised: 05/04/2008] [Accepted: 05/04/2008] [Indexed: 10/22/2022]
Abstract
Oxidative modification of low density lipoproteins is thought to play a pivotal role in the development and exacerbation of atherosclerosis and atherogenesis, and is believed to be closely associated with alterations in the vascular production of nitric oxide (NO). Previous work has shown that several products emerging from lipid peroxidation (e.g. lipid hydroperoxides, lysophospholipids, oxidized cholesterol) are able to reduce NO production in macrophages. The naturally occurring oxidant hypochlorite has been shown to be responsible for the in vivo formation of hypochlorite-oxidized LDL and such OxLDL are known to lack lipid peroxidation products. In this work we demonstrate that hypochlorite-oxidized LDL mediate profound effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages. By means of the membrane-permeable NO indicator 4,5-diaminofluorescein diacetate, we are able to show decreased levels of intracellular authentic nitric oxide following incubation with hypochlorite-oxidized LDL. The observed effects are dose-dependent and comparable to results obtained in the presence of the NOS inhibitor NG-monomethyl-L-arginine. This marked reduction of intracellular NO is accompanied by a dose-dependent inhibition of inducible nitric oxide synthase (iNOS) protein and mRNA expression. Furthermore, hyp-OxLDL lead to the generation of peroxynitrite, thereby also reducing bioavailability of NO. By mediating these effects on production and bioavailability of NO, hyp-OxLDL might also contribute to atherogenesis by reducing the antiatherogenic effects of nitric oxide.
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Affiliation(s)
- Werner Schmid
- Center for Physiology and Pathophysiology, Institute of Physiology, Medical University of Vienna, and Department of Urology, Rudolfstiftung Hospital, Vienna, Austria.
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15
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Perségol L, Vergès B, Gambert P, Duvillard L. Inability of HDL from abdominally obese subjects to counteract the inhibitory effect of oxidized LDL on vasorelaxation. J Lipid Res 2007; 48:1396-401. [PMID: 17329618 DOI: 10.1194/jlr.m600309-jlr200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abdominal obesity is associated with a decreased plasma concentration of HDL cholesterol and with qualitative modifications of HDL, such as triglyceride enrichment. Our aim was to determine, in isolated aorta rings, whether HDL from obese subjects can counteract the inhibitory effect of oxidized low density lipoprotein (OxLDL) on endothelium-dependent vasodilation as efficiently as HDL from normolipidemic, lean subjects. Plasma triglycerides were 74% higher (P < 0.005) in obese subjects compared with controls, and apolipoprotein A-I (apoA-I) and HDL cholesterol concentrations were 12% and 17% lower (P < 0.05), respectively. HDL from control subjects significantly reduced the inhibitory effect of OxLDL on vasodilation [maximal relaxation (E(max)) = 82.1 +/- 8.6% vs. 54.1 +/- 8.1%; P < 0.0001], but HDL from obese subjects had no effect (E(max) = 47.2 +/- 12.5% vs. 54.1 +/- 8.1%; NS). In HDL from abdominally obese subjects compared with HDL from controls, the apoA-I content was 12% lower (P < 0.05) and the triglyceride-to-cholesteryl ester ratio was 36% higher (P = 0.08)). E(max)(OxLDL + HDL) was correlated with HDL apoA-I content and triglyceride-to-cholesteryl ester ratio (r = 0.36 and r = -0.38, respectively; P < 0.05). We conclude that in abdominally obese subjects, the ability of HDL to counteract the inhibitory effect of OxLDL on vascular relaxation is impaired. This could contribute to the increased cardiovascular risk observed in these subjects.
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Affiliation(s)
- Laurence Perségol
- Institut National de la Santé et de la Recherche Médicale U866, Dijon F-21000, France
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Perségol L, Vergès B, Foissac M, Gambert P, Duvillard L. Inability of HDL from type 2 diabetic patients to counteract the inhibitory effect of oxidised LDL on endothelium-dependent vasorelaxation. Diabetologia 2006; 49:1380-6. [PMID: 16596357 DOI: 10.1007/s00125-006-0244-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Accepted: 02/23/2006] [Indexed: 02/05/2023]
Abstract
AIMS/HYPOTHESIS In healthy normolipidaemic and normoglycaemic control subjects, HDL are able to reverse the inhibition of vasodilation that is induced by oxidised LDL. In type 2 diabetic patients, HDL are glycated and more triglyceride-rich than in control subjects. These alterations are likely to modify the capacity of HDL to reverse the inhibition of vasodilation induced by oxidised LDL. SUBJECTS AND METHODS Using rabbit aorta rings, we compared the ability of HDL from 16 type 2 diabetic patients and 13 control subjects to suppress the inhibition of vasodilation that is induced by oxidised LDL. RESULTS Oxidised LDL inhibited endothelium-dependent vasodilation (maximal relaxation [Emax] = 58.2+/-14.6 vs 99.3+/-5.2% for incubation without any lipoprotein, p < 0.0001). HDL from control subjects significantly reduced the inhibitory effect of oxidised LDL on vasodilatation (Emax = 77.6+/-12.9 vs 59.5+/-7.7%, p < 0.001), whereas HDL from type 2 diabetic patients had no effect (Emax = 52.4+/-20.4 vs 57.2+/-18.7%, NS). HDL triglyceride content was significantly higher in type 2 diabetic patients than in control subjects (5.3+/-2.2 vs 3.1+/-1.4%, p < 0.01) and was highly inversely correlated to Emax for oxidised LDL+HDL in type 2 diabetic patients (r = -0.71, p < 0.005). CONCLUSIONS/INTERPRETATION In type 2 diabetes mellitus, the ability of HDL to counteract the inhibition of endothelium-dependent vasorelaxation induced by oxidised LDL is impaired and is inversely correlated with HDL triglyceride content. These findings suggest that HDL are less atheroprotective in type 2 diabetic patients than in control subjects.
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Affiliation(s)
- L Perségol
- INSERM U498, Hôpital du Bocage, 21079 Dijon, Cédex, France
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17
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Dudzinski DM, Igarashi J, Greif D, Michel T. The regulation and pharmacology of endothelial nitric oxide synthase. Annu Rev Pharmacol Toxicol 2006; 46:235-76. [PMID: 16402905 DOI: 10.1146/annurev.pharmtox.44.101802.121844] [Citation(s) in RCA: 283] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Nitric oxide (NO) is a small, diffusible, lipophilic free radical gas that mediates significant and diverse signaling functions in nearly every organ system in the body. The endothelial isoform of nitric oxide synthase (eNOS) is a key source of NO found in the cardiovascular system. This review summarizes the pharmacology of NO and the cellular regulation of endothelial NOS (eNOS). The molecular intricacies of the chemistry of NO and the enzymology of NOSs are discussed, followed by a review of the biological activities of NO. This information is then used to develop a more global picture of the pharmacological control of NO synthesis by NOSs in both physiologic conditions and pathophysiologic states.
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Affiliation(s)
- David M Dudzinski
- Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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18
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Kawano H, Yano K. Pravastatin Decreases Blood Pressure in Hypertensive and Hypercholesterolemic Patients Receiving Antihypertensive Treatment. Circ J 2006; 70:1116-21. [PMID: 16936421 DOI: 10.1253/circj.70.1116] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Previous studies have suggested that the lipid-lowering agents, statins, may help reduce blood pressure (BP). The goal of the present study was to characterize the effect of pravastatin on BP in hypercholesterolemic and hypertensive patients already receiving antihypertensive drugs. METHODS AND RESULTS Eighty-two patients with hypercholesterolemia were retrospectively studied before and after 3 months of treatment with pravastatin. Forty-four patients had hypertension (HT group) and were receiving antihypertensive treatment, while the remaining 38 patients were normotensive (NT group). Patients in the HT group were further subdivided into those with uncontrolled or controlled BP. Pravastatin treatment significantly reduced systolic BP (SBP) in the HT group (134+/-16 to 130+/-13 mmHg, p<0.005) but not in the NT group (124+/-10 to 123+/-9 mmHg, p=0.52), despite the fact that treatment significantly reduced low-density lipoprotein cholesterol in both groups (HT group 178+/-27 to 132+/-17 mg/dl, p<0.0001; NT group 169+/-27 to 125+/-21 mg/dl, p<0.0001). Further, pravastatin significantly decreased SBP in the uncontrolled BP group (148+/-7 to 138+/-12 mmHg, p<0.005) but not in the controlled BP group (122+/-10 to 123+/-9 mmHg, p=0.72). CONCLUSION Concomitant use of statins and antihypertensive drugs could result in improved BP control in hypertensive patients with hypercholesterolemia.
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Affiliation(s)
- Hiroaki Kawano
- Department of Cardiovascular Medicine, Course of Medical and Dental Science, Graduate School of Biomedical Science, Nagasaki University, Japan.
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19
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Abstract
Oxidative stress contributes to the initiation and the development of atherosclerotic plaques and adversely influences myocardial integrity. Statins interfere with oxidation in several ways that may contribute to reducing the atherogenic process. In addition to direct antioxidant effects, statins reduce circulating oxidized low-density lipoproteins (oxLDL) and inhibit their uptake by macrophages. They also reduce circulating markers of oxidation such as F2-isoprostane and nitrotyrosine. Statins inhibit oxidant enzymes activity such as that of reduced nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase and myeloperoxidase and up-regulate the activity of antioxidant enzymes such as catalase and paraoxonase. They reduce endothelial dysfunction mainly by their ability to enhance endothelial nitric oxide bioavailability, which is achieved by several mechanisms. The antioxidant properties of statins extend to organ protection especially the myocardium and the lungs.
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Affiliation(s)
- Jean Davignon
- Hyperlipidemia and Atherosclerosis Research Group, Clinical Research Institute of Montreal, and University of Montreal Hospital Medical Centre, Montreal, QC, Canada.
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20
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Abstract
Endothelial cells are exposed to potentially damaging reactive oxygen species generated both within the cells and in the bloodstream and underlying vessel wall. In this work, we studied the ability of ascorbic acid to protect cultured human-derived endothelial cells (EA.hy926) from oxidant stress generated by the redox cycling agent menadione. Menadione caused intracellular oxidation of dihydrofluorescein, which required the presence of D-glucose in the incubation medium, and was inhibited by intracellular ascorbate and desferrioxamine. At concentrations of 100 microM and higher, menadione depleted the cells of both GSH and ascorbate, and ascorbate loading partially prevented the decrease in GSH due to menadione. Menadione increased L-arginine uptake by the cells, but inhibited endothelial nitric oxide synthase, an effect that was prevented by acute loading with ascorbate. Ascorbate blunts menadione-induced oxidant stress in EA.hy926 cells, which may help to preserve nitric oxide synthase activity under conditions of excessive oxidant stress.
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Affiliation(s)
- James M May
- Department of Medicine, Vanderbilt University School of Medicine, 715 Preston Research Building, Nashville, TN 37232-6303, USA.
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21
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Cachofeiro Ramos V, Vázquez-Pérez S, de las Heras Jiménez N, Cediel Gil E, Sanz-Rosa D, Olivares E, Lahera Juliá V. Hipercolesterolemia y disfunción endotelial: mecanismos implicados. HIPERTENSION Y RIESGO VASCULAR 2003. [DOI: 10.1016/s1889-1837(03)71363-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Moriel P, Sevanian A, Ajzen S, Zanella MT, Plavnik FL, Rubbo H, Abdalla DSP. Nitric oxide, cholesterol oxides and endothelium-dependent vasodilation in plasma of patients with essential hypertension. Braz J Med Biol Res 2002; 35:1301-9. [PMID: 12426629 DOI: 10.1590/s0100-879x2002001100007] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The objective of the present study was to identify disturbances of nitric oxide radical (.NO) metabolism and the formation of cholesterol oxidation products in human essential hypertension. The concentrations of.NO derivatives (nitrite, nitrate, S-nitrosothiols and nitrotyrosine), water and lipid-soluble antioxidants and cholesterol oxides were measured in plasma of 11 patients with mild essential hypertension (H: 57.8 +/- 9.7 years; blood pressure, 148.3 +/- 24.8/90.8 +/- 10.2 mmHg) and in 11 healthy subjects (N: 48.4 +/- 7.0 years; blood pressure, 119.4 +/- 9.4/75.0 +/- 8.0 mmHg). Nitrite, nitrate and S-nitrosothiols were measured by chemiluminescence and nitrotyrosine was determined by ELISA. Antioxidants were determined by reverse-phase HPLC and cholesterol oxides by gas chromatography. Hypertensive patients had reduced endothelium-dependent vasodilation in response to reactive hyperemia (H: 9.3 and N: 15.1% increase of diameter 90 s after hyperemia), and lower levels of ascorbate (H: 29.2 +/- 26.0, N: 54.2 +/- 24.9 micro M), urate (H: 108.5 +/- 18.9, N: 156.4 +/- 26.3 micro M), beta-carotene (H: 1.1 +/- 0.8, N: 2.5 +/- 1.2 nmol/mg cholesterol), and lycopene (H: 0.4 +/- 0.2, N: 0.7 +/- 0.2 nmol/mg cholesterol), in plasma, compared to normotensive subjects. The content of 7-ketocholesterol, 5alpha-cholestane-3beta,5,6beta-triol and 5,6alpha-epoxy-5alpha-cholestan-3alpha-ol in LDL, and the concentration of endothelin-1 (H: 0.9 +/- 0.2, N: 0.7 +/- 0.1 ng/ml) in plasma were increased in hypertensive patients. No differences were found for.NO derivatives between groups. These data suggest that an increase in cholesterol oxidation is associated with endothelium dysfunction in essential hypertension and oxidative stress, although.NO metabolite levels in plasma are not modified in the presence of elevated cholesterol oxides.
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Affiliation(s)
- P Moriel
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brasil
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23
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Rubbo H, Trostchansky A, Botti H, Batthyány C. Interactions of nitric oxide and peroxynitrite with low-density lipoprotein. Biol Chem 2002; 383:547-52. [PMID: 12033442 DOI: 10.1515/bc.2002.055] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Nitric oxide (*NO) is a free radical species that diffuses and concentrates in the hydrophobic core of low-density lipoprotein (LDL) to serve as a potent inhibitor of lipid oxidation processes. Peroxynitrite (PN), the product of the diffusion-limited reaction between *NO and superoxide (O2*-) represents a relevant mediator of oxidative modifications in LDL. The focus of this review is the analysis of interactions between *NO and PN and its secondary reactions with oxygen radicals on LDL oxidation, which are relevant in the development of the early steps as well as progression of atherosclerosis. We propose that the balance between rates of PN and *NO production, which greatly depends on oxidative stress processes within the vascular wall, will critically determine the final extent of oxidative LDL modifications leading or not to scavenger receptor-mediated LDL uptake and foam cell formation.
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Affiliation(s)
- Homero Rubbo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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24
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Rooyakkers TM, Stroes ESG, Kooistra MP, van Faassen EE, Hider RC, Rabelink TJ, Marx JJM. Ferric saccharate induces oxygen radical stress and endothelial dysfunction in vivo. Eur J Clin Invest 2002; 32 Suppl 1:9-16. [PMID: 11886426 DOI: 10.1046/j.1365-2362.2002.0320s1009.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Intravenous iron supplementation is used widely in haemodialysis patients. However, nontransferrin-bound iron (NTBI), which increases after intravenous supplementation of ferric saccharate, has been suggested to act as a catalytic agent in oxygen radical formation in vitro and may thus contribute to endothelial impairment in vivo. MATERIALS AND METHODS In 20 healthy volunteers the effect of 100 mg ferric saccharate infusion was investigated. Vascular ultrasound was used to assess endothelium-dependent vasodilatation at baseline, and 10 and 240 min after ferric saccharate infusion. Whole blood was collected to measure NTBI and in vivo radical formation was assessed by electron spin resonance. A time-control study was performed using saline infusion. RESULTS Infusion of ferric saccharate induces a greater than fourfold increase in NTBI, as well as a transient, significant (P < 0.01) reduction of flow-mediated dilatation 10 min after infusion of ferric saccharate, when compared with saline. The generation of superoxide in whole blood increased significantly 10 and 240 min after infusion of ferric saccharate by, respectively, 70 and 53%. CONCLUSIONS Iron infusion at a currently used therapeutic dose for intravenous iron supplementation leads to increased oxygen radical stress and acute endothelial dysfunction.
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Affiliation(s)
- T M Rooyakkers
- Department of Internal Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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25
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Trostchansky A, Batthyány C, Botti H, Radi R, Denicola A, Rubbo H. Formation of lipid-protein adducts in low-density lipoprotein by fluxes of peroxynitrite and its inhibition by nitric oxide. Arch Biochem Biophys 2001; 395:225-32. [PMID: 11697860 DOI: 10.1006/abbi.2001.2583] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peroxynitrite (PN), the product of the diffusion-limited reaction between nitric oxide (*NO) and superoxide (O*-(2)), represents a relevant mediator of oxidative modifications in low-density lipoprotein (LDL). This work shows for the first time the simultaneous action of low-controlled fluxes of PN and *NO on LDL oxidation in terms of lipid and protein modifications as well as oxidized lipid-protein adduct formation. Fluxes of PN (e.g., 1 microM min(-1)) initiated lipid oxidation in LDL as measured by conjugated dienes and cholesteryl ester hydroperoxides formation. Oxidized-LDL exhibited a characteristic fluorescent emission spectra (lambda(exc) = 365 nm, lambda(max) = 417 nm) in parallel with changes in both the free amino groups content and the relative electrophoretic mobility of the particle. Physiologically relevant fluxes of *NO (80-300 nM min(-1)) potently inhibited these PN-dependent oxidative processes. These results are consistent with PN-induced adduct formation between lipid oxidation products and free amino groups of LDL in a process prevented by the simultaneous presence of *NO. The balance between rates of PN and *NO production in the vascular wall will critically determine the final extent of LDL oxidative modifications leading or not to scavenger receptor-mediated LDL uptake and foam cell formation.
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Affiliation(s)
- A Trostchansky
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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26
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Martínez-González J, Alfón J, Berrozpe M, Badimon L. HMG-CoA reductase inhibitors reduce vascular monocyte chemotactic protein-1 expression in early lesions from hypercholesterolemic swine independently of their effect on plasma cholesterol levels. Atherosclerosis 2001; 159:27-33. [PMID: 11689203 DOI: 10.1016/s0021-9150(01)00469-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase are widely used in the treatment of dyslipemias and have shown beneficial effects in primary and secondary prevention of cardiovascular diseases. There is new information that seems to suggest that the beneficial effects observed may not be solely attributable to plasma cholesterol reduction. Our objective has been to evaluate the effect of two statins at similar dose, although unequivalent plasma lipid lowering potential, on vessel wall expression of two proteins involved in atherosclerotic lesion progression. We have studied the effects of treatment on vessel wall expression of monocyte chemotactic protein-1 (MCP-1) and the inducible form of nitric oxide synthase (NOS II). Atherosclerosis was induced in pigs by feeding a high cholesterol and saturated fatty acid diet for 50 days. Mild atherosclerotic lesions were found at this early stage of induction. Animals were simultaneously treated with atorvastatin (3 mg/kg/day), pravastatin (3 mg/kg/day) or placebo. Non-HDL-cholesterol levels induced by diet were reduced in the atorvastatin-treated group (63+/-8%, P=0.03) and not as much in the pravastatin treated group (44+/-3, P=0.08). The average MCP-1 expression in carotid, femoral and thoracic aorta was significantly reduced with both statins by 37% (P<0.05), while NOS II expression was unaffected. Therefore, vascular MCP-1 expression was downregulated by statins regardless of their lipid lowering potential and lipo/hydrophilic characteristics. Early downregulation of MCP-1 could attenuate the inflammation within the vascular wall and prevent the development of atherosclerotic lesions.
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Affiliation(s)
- J Martínez-González
- Cardiovascular Research Center, IIBB/CSIC-Institut de Recerca del Hospital de la Santa Creu i Sant Pau-UAB, Barcelona, Spain
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27
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Abstract
Ascorbic acid may be involved in the defense against oxidant stress in endothelial cells. Such a role requires that the cells effectively recycle the vitamin from its oxidized forms. In this work, we studied the ability of cultured bovine aortic endothelial cells (BAECs) to take up and reduce dehydroascorbic acid (DHA) to ascorbate, as well as the dependence of ascorbate recycling on intracellular GSH. BAECs took up and reduced DHA to ascorbate much more readily than they took up ascorbate. Although BAECs in culture did not contain ascorbate, ascorbate accumulated to concentrations of 2-3 mM in BAECs following incubation with 400 microM DHA. Extracellular ferricyanide oxidized intracellular ascorbate, which was recycled by the cells. Reduction of DHA, either when added to the cells or when generated in response to ferricyanide, caused significant decreases in intracellular GSH concentrations. Depletion of intracellular GSH with 1-chloro-2,4-dinitrobenzene, diethylmaleate, and diamide almost abolished the ability of the cells to reduce DHA to ascorbate. DHA reduction by thioredoxin reductase was evident in dialyzed cell extracts, but occurred at rates far lower than direct GSH reduction of DHA. These results suggest that maximal rates of DHA reduction, and thus recycling of ascorbate from DHA, are dependent upon GSH in these cells.
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Affiliation(s)
- J M May
- Department of Medicine, Vanderbilt University School of Medicine, 715 Medical Research Building II, Nashville, TN 37232-6303, USA.
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28
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Moriel P, Pereira IR, Bertolami MC, Abdalla DS. Is ceruloplasmin an important catalyst for S-nitrosothiol generation in hypercholesterolemia? Free Radic Biol Med 2001; 30:318-26. [PMID: 11165878 DOI: 10.1016/s0891-5849(00)00467-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Nitric oxide (NO) reacts with thiol-containing biomolecules to form S-nitrosothiols (RSNOs). RSNOs are considered as NO reservoirs as they generate NO by homolytic cleavage. Ceruloplasmin has recently been suggested to have a potent catalytic activity towards RSNO production. Considering that NO activity is impaired in hypercholesterolemia and that RSNOs may act as important NO donors, we investigated the relation between concentrations of ceruloplasmin and RSNOs in plasma of hypercholesterolemic (HC) patients compared to normolipidemic (N) controls. Concentrations of ceruloplasmin (0.36 +/- 0.07 x 0.49 +/- 0.11 mg/dl, N x HC), nitrate (19.10 +/- 12.03 x 40.19 +/- 18.70 microM, N x HC), RSNOs (0.25 +/- 0.20 x 0.54 +/- 0.26 microM, N x HC), nitrated LDL (19.51 +/- 6.98 x 35.29 +/- 17.57 nM nitro-BSA equivalents, N x HC), and cholesteryl ester-derived hydroxy/hydroperoxides (CEOOH, 0.19 +/- 0.06 x 1.46 +/- 0.97 microM) were increased in plasma of HC as compared to N. No difference was found for nitrite levels between the two groups (1.01 +/- 0.53 x 1.02 +/- 0.33 microM, N x HC). The concentrations of RSNOs, nitrate, and nitrated LDL were positively correlated to those of total cholesterol, LDL cholesterol, and apoB. Ceruloplasmin levels were directly correlated to apoB and apoE concentrations. Data suggest that: (i) ceruloplasmin may have a role in the enhancement of RSNOs found in hypercholesterolemia; (ii) the lower NO bioactivity associated with hypercholesterolemia is not related to a RSNOs paucity or a defective NO release from RSNOs; and (iii) the increased nitrotyrosine levels found in hypercholesterolemia indicate that superoxide radicals contribute to inactivation of NO, directly generated by NO synthase or originated by RSNO decomposition.
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Affiliation(s)
- P Moriel
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, Av. Prof. Lineu Prestes, 580, Cidade Universitária-Butantã, 05508-900 São Paulo, Brazil
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29
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Abstract
Human coronary and peripheral arteries show endothelial dysfunction in a variety of conditions, including atherosclerosis, hypercholesterolemia, smoking, and hypertension. This dysfunction manifests as a loss of endothelium-dependent vasodilation to acetylcholine infusion or sheer stress, and is typically associated with decreased generation of nitric oxide (NO) by the endothelium. Vitamin C, or ascorbic acid, when acutely infused or chronically ingested, improves the defective endothelium-dependent vasodilation present in these clinical conditions. The mechanism of the ascorbic acid effect is unknown, although it has been attributed to an antioxidant function of the vitamin to enhance the synthesis or prevent the breakdown of NO. In this review, multiple mechanisms are considered that might account for the ability of ascorbate to preserve NO. These include ascorbate-induced decreases in low-density lipoprotein (LDL) oxidation, scavenging of intracellular superoxide, release of NO from circulating or tissue S-nitrosothiols, direct reduction of nitrite to NO, and activation of either endothelial NO synthase or smooth muscle guanylate cyclase. The ability of ascorbic acid supplements to enhance defective endothelial function in human diseases provides a rationale for use of such supplements in these conditions. However, it is first necessary to determine which of the many plausible mechanisms account for the effect, and to ensure that undesirable toxic effects are not present.
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Affiliation(s)
- J M May
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-6303, USA.
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30
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Borghi C, Prandin MG, Costa FV, Bacchelli S, Degli Esposti D, Ambrosioni E. Use of statins and blood pressure control in treated hypertensive patients with hypercholesterolemia. J Cardiovasc Pharmacol 2000; 35:549-55. [PMID: 10774784 DOI: 10.1097/00005344-200004000-00006] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
High serum cholesterol has been frequently reported in patients with arterial hypertension in whom it might influence the blood pressure control. The aim of this study was to compare the extent of blood pressure changes in 41 patients with hypertension and hypercholesterolemia, taking antihypertensive drugs and treated for 3 months with statins (HC-S; pravastatin or simvastatin) and compared with matched controls with high (HC-D; 44) or normal serum cholesterol (NC-D; 45) undergoing antihypertensive treatment combined with dietary treatment alone. After 3 months of follow-up, a greater reduction of systolic (SBP) and diastolic (DBP) blood pressure values was observed in HC-S patients (ASBP/DBP, -11.3 +/-3/-10.6 +/- 2%) when compared with both HC-D (deltaSBP/DBP, -6.6 +/- 2/-6.1 +/- 2%; p < 0.05) and NC-D (deltaSBP/DBP, -6.9 +/- 2/-6.8 +/- 1.5%; p < 0.05). In statin-treated patients, a slight linear relation has been found between the percentage changes in DBP and those in plasma total cholesterol (R = 0.37, p = 0.043), whereas no relation was found with SBP changes (R =0.11; p = 0.35). In conclusion, the results of this study demonstrate that the use of statins in combination with antihypertensive drugs can improve blood pressure control in patients with uncontrolled hypertension and high serum cholesterol levels. The additional blood pressure reduction observed in patients treated with statins is clinically relevant and only partially related to the lipid-lowering effect.
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Affiliation(s)
- C Borghi
- Department of Internal Medicine, University of Bologna, Italy.
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31
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Wilmink HW, Stroes ES, Erkelens WD, Gerritsen WB, Wever R, Banga JD, Rabelink TJ. Influence of folic acid on postprandial endothelial dysfunction. Arterioscler Thromb Vasc Biol 2000; 20:185-8. [PMID: 10634816 DOI: 10.1161/01.atv.20.1.185] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Triglyceride-rich lipoproteins that circulate postprandially are increasingly being recognized as potentially atherogenic. These particles also have been shown to cause endothelial dysfunction. We recently demonstrated that acute parenteral administration of folic acid restores endothelial function in vivo in patients with increased LDL cholesterol levels. In vitro data suggested that this effect could be mediated by a reduction of radical stress. In the present study, therefore, we evaluated the effect of an acute oral fat load on both endothelial function and oxygen radical production. Next, we studied whether 2 weeks of pretreatment with 10 mg folic acid PO could prevent these fat-induced changes. We conducted a prospective, randomized, placebo-controlled study to evaluate the effect of oral folic acid administration (10 mg/d for 2 weeks) on basal endothelial function as well as endothelial function on an acute fat load in 20 healthy volunteers 18 to 33 years old. Endothelial function was assessed as flow-mediated dilatation (FMD). Endothelium-independent dilatation was measured after sublingual nitroglycerin spray. Oxygen radical stress was assessed by measurement of the urinary excretion of the stable radical-damage end product malondialdehyde. During administration of placebo, FMD decreased significantly after an acute oral fat load, with a median from 10.6% (8.3% to 12.2%) to 5.8% (3.0% to 10.2%), P<0.05. During folic acid administration, FMD was unaffected by a fat load, with a median from 9.6% (7.1% to 12.8%) to 9.9% (7.5% to 14.1%), P=NS. The increase in malondialdehyde excretion in the urine after fat loading was also prevented during folic acid administration (absolute increase after an acute fat load during placebo, 0.11+/-0.1 micromol/L versus folic acid, 0.02+/-0.1 micromol/L, P<0.05). The response to the endothelium-independent vasodilator nitroglycerin remained unaltered throughout the study. Pretreatment with oral folic acid prevents the lipid-induced decrease in FMD as well as the lipid-induced increase in urinary radical-damage end products. Because these observations were made in healthy volunteers with normal folate and homocysteine levels, it is suggested that a higher folate intake in the general population may have vasculoprotective effects.
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Affiliation(s)
- H W Wilmink
- Divisions of Internal Medicine , University Hospital Utrecht, The Netherlands
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32
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Abstract
Statins have pleiotropic properties that complement their cholesterol-lowering effects. These properties may partly account for their established benefit in the prevention of coronary artery disease beyond the reduction of LDL-cholesterol levels. The most widely recognized properties are reviewed here. They include: (i) nitric oxide-mediated improvement of endothelial dysfunction and upregulation of endothelin-1 expression; (ii) antioxidant effects; (iii) anti-inflammatory properties; (iv) inhibition of cell proliferation with anticarcinogenic actions in animals; (v) stabilization of atherosclerotic plaques; (vi) anticoagulant effects; and (vii) inhibition of graft rejection after heart and kidney transplantation. As advances are made in our knowledge, new properties are steadily being uncovered. Pleiotropic effects are currently being given consideration when instituting combination therapy for patients at high cardiovascular risk. Some pleiotropic effects are negative, and may account for occasional untoward drug interactions. For many of these new properties, the clinical relevance has not been established. The challenge for the future will be to design and carry out appropriate clinical trials to establish their relative importance in the prevention of coronary artery disease.
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Affiliation(s)
- J Davignon
- Hyperlipidemia and Atherosclerosis Research Group, Clinical Research Institute of Montreal, Quebec, Canada.
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Barnes SE, Weinberg PD. Two patterns of lipid deposition in the cholesterol-fed rabbit. Arterioscler Thromb Vasc Biol 1999; 19:2376-86. [PMID: 10521367 DOI: 10.1161/01.atv.19.10.2376] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A central feature of arterial lipid deposition is its nonuniform and variable distribution. In immature human and rabbit aortas, spontaneous lesions occur most frequently downstream of branch points, but they tend to occur upstream of the same branches at later ages. In cholesterol-fed rabbits, the juvenile pattern has been seen regardless of age. These distributions may be determined by transport properties of the arterial wall, because uptake of plasma macromolecules is elevated downstream of aortic branches in immature rabbits and upstream in mature ones, except during cholesterol feeding, when the juvenile pattern is seen in adult vessels. The effect of cholesterol could reflect its inhibitory influence on the nitric oxide (NO) pathway because the adult transport pattern is NO dependent. Using protocols expected to preserve NO function and the mature pattern of transport during hypercholesterolemia, we made 2 attempts to induce upstream disease in rabbits. In trial I, plasma concentrations of cholesterol were kept within the normal human range for 15 weeks by using dietary levels of 0.05% to 0.2%. Although disease patterns reverse with age in human vessels exposed to these concentrations, lesions in both immature and mature rabbits occurred downstream of intercostal branch ostia. Trial II used older rabbits, a different base diet containing more vitamin E (96 mg/kg rather than 57 mg/kg), and higher levels of cholesterol (1%, administered for 8 weeks). For some animals, extra vitamin E (2000 mg/kg) was added to the diet. The mature pattern of lipid deposition was apparent around intercostal branches in the first group and was accentuated by the additional vitamin E, a change that was associated with a significant increase in the plasma concentration of NO metabolites. Spontaneous lesions, assessed on the base diet, were too rare to have influenced these distributions. This is the first report of upstream disease in the cholesterol-fed rabbit. The results support but do not prove the view that NO and transport are important in atherogenesis.
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Affiliation(s)
- S E Barnes
- School of Animal and Microbial Sciences, University of Reading, UK
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Coppinger RJ, Baum CL. Cholesterol-dependent regulation of nitric oxide production: potential role in atherosclerosis. Nutr Rev 1999; 57:279-82. [PMID: 10568338 DOI: 10.1111/j.1753-4887.1999.tb01812.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Atherosclerosis is preceded by cholesterol-induced diminution in vascular nitric oxide (NO) production and proatherogenic changes in endothelial cell function. Careful dissection of the steps involved in regulating endothelial nitric oxide synthase (eNOS) activity has revealed that cholesterol-induced caveolin expression reduces NO production by stimulating the production of inhibitory caveolin eNOS complexes.
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Affiliation(s)
- R J Coppinger
- Department of Human Nutrition and Dietetics, University of Illinois, Chicago 60612, USA
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Affiliation(s)
- M C Verhaar
- Department of Nephrology and Hypertension, University Hospital Utrecht, The Netherlands
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Feron O, Dessy C, Moniotte S, Desager JP, Balligand JL. Hypercholesterolemia decreases nitric oxide production by promoting the interaction of caveolin and endothelial nitric oxide synthase. J Clin Invest 1999; 103:897-905. [PMID: 10079111 PMCID: PMC408139 DOI: 10.1172/jci4829] [Citation(s) in RCA: 288] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Hypercholesterolemia is a central pathogenic factor of endothelial dysfunction caused in part by an impairment of endothelial nitric oxide (NO) production through mechanisms that remain poorly characterized. The activity of the endothelial isoform of NO synthase (eNOS) was recently shown to be modulated by its reciprocal interactions with the stimulatory Ca2+-calmodulin complex and the inhibitory protein caveolin. We examined whether hypercholesterolemia may reduce NO production through alteration of this regulatory equilibrium. Bovine aortic endothelial cells were cultured in the presence of serum obtained from normocholesterolemic (NC) or hypercholesterolemic (HC) human volunteers. Exposure of endothelial cells to the HC serum upregulated caveolin abundance without any measurable effect on eNOS protein levels. This effect of HC serum was associated with an impairment of basal NO release paralleled by an increase in inhibitory caveolin-eNOS complex formation. Similar treatment with HC serum significantly attenuated the NO production stimulated by the calcium ionophore A23187. Accordingly, higher calmodulin levels were required to disrupt the enhanced caveolin-eNOS heterocomplex from HC serum-treated cells. Finally, cell exposure to the low-density lipoprotein (LDL) fraction alone dose-dependently reproduced the inhibition of basal and stimulated NO release, as well as the upregulation of caveolin expression and its heterocomplex formation with eNOS, which were unaffected by cotreatment with antioxidants. Together, our data establish a new mechanism for the cholesterol-induced impairment of NO production through the modulation of caveolin abundance in endothelial cells, a mechanism that may participate in the pathogenesis of endothelial dysfunction and the proatherogenic effects of hypercholesterolemia.
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Affiliation(s)
- O Feron
- Department of Medicine, Unit of Pharmacology and Therapeutics, Université catholique de Louvain, B-1200 Brussels, Belgium
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Stroes E, Hijmering M, van Zandvoort M, Wever R, Rabelink TJ, van Faassen EE. Origin of superoxide production by endothelial nitric oxide synthase. FEBS Lett 1998; 438:161-4. [PMID: 9827538 DOI: 10.1016/s0014-5793(98)01292-7] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Using fluorescence optical and electron spin resonance spectroscopy, we have investigated the production of superoxide by bovine endothelial nitric oxide synthase (NOS). In contrast to neuronal NOS, the heme moiety is identified as the exclusive source of superoxide production by endothelial NOS. Thus, calmodulin-mediated enzyme regulation affects production of nitric oxide and superoxide simultaneously and inseparably. The balance between the nitric oxide/superoxide reaction pathways may be shifted by addition of exogenous heme-specific agents, such as tetrahydrobiopterin. Our results have direct relevance for the pathophysiology of atherosclerosis.
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Affiliation(s)
- E Stroes
- Department of Nephrology and Vascular Medicine, F 03.226, University Hospital Utrecht, The Netherlands.
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Affiliation(s)
- E S Stroes
- University Hospital Utrecht, Utrecht, The Netherlands.
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