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Dab H, Ben Hamed S, Hodroj W, Zourgui L. Combined diabetes and chronic stress exacerbates cytokine production and oxidative stress in rat liver and kidney. BIOTECHNOL BIOTEC EQ 2023. [DOI: 10.1080/13102818.2023.2182137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Affiliation(s)
- Houcine Dab
- Research Unit of Valorization of Active Biomolecules, Higher Institute of Applied Biology Medenine, University of Gabes, Medenine, Tunisia
| | - Said Ben Hamed
- Laboratory of Epidemiology and Veterinary Microbiology (LEMV), Institut Pasteur de Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Wassim Hodroj
- Académie de Versailles, University of Versailles, Athis-Mons, France
| | - Lazhar Zourgui
- Research Unit of Valorization of Active Biomolecules, Higher Institute of Applied Biology Medenine, University of Gabes, Medenine, Tunisia
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Coronary Microvascular Dysfunction in Diabetes Mellitus: Pathogenetic Mechanisms and Potential Therapeutic Options. Biomedicines 2022; 10:biomedicines10092274. [PMID: 36140374 PMCID: PMC9496134 DOI: 10.3390/biomedicines10092274] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Diabetic patients are frequently affected by coronary microvascular dysfunction (CMD), a condition consisting of a combination of altered vasomotion and long-term structural change to coronary arterioles leading to impaired regulation of blood flow in response to changing cardiomyocyte oxygen requirements. The pathogenesis of this microvascular complication is complex and not completely known, involving several alterations among which hyperglycemia and insulin resistance play particularly central roles leading to oxidative stress, inflammatory activation and altered barrier function of endothelium. CMD significantly contributes to cardiac events such as angina or infarction without obstructive coronary artery disease, as well as heart failure, especially the phenotype associated with preserved ejection fraction, which greatly impact cardiovascular (CV) prognosis. To date, no treatments specifically target this vascular damage, but recent experimental studies and some clinical investigations have produced data in favor of potential beneficial effects on coronary micro vessels caused by two classes of glucose-lowering drugs: glucagon-like peptide 1 (GLP-1)-based therapy and inhibitors of sodium-glucose cotransporter-2 (SGLT2). The purpose of this review is to describe pathophysiological mechanisms, clinical manifestations of CMD with particular reference to diabetes, and to summarize the protective effects of antidiabetic drugs on the myocardial microvascular compartment.
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Sabe SA, Feng J, Sellke FW, Abid MR. Mechanisms and clinical implications of endothelium-dependent vasomotor dysfunction in coronary microvasculature. Am J Physiol Heart Circ Physiol 2022; 322:H819-H841. [PMID: 35333122 PMCID: PMC9018047 DOI: 10.1152/ajpheart.00603.2021] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 03/21/2022] [Accepted: 03/21/2022] [Indexed: 12/16/2022]
Abstract
Coronary microvascular disease (CMD), which affects the arterioles and capillary endothelium that regulate myocardial perfusion, is an increasingly recognized source of morbidity and mortality, particularly in the setting of metabolic syndrome. The coronary endothelium plays a pivotal role in maintaining homeostasis, though factors such as diabetes, hypertension, hyperlipidemia, and obesity can contribute to endothelial injury and consequently arteriolar vasomotor dysfunction. These disturbances in the coronary microvasculature clinically manifest as diminished coronary flow reserve, which is a known independent risk factor for cardiac death, even in the absence of macrovascular atherosclerotic disease. Therefore, a growing body of literature has examined the molecular mechanisms by which coronary microvascular injury occurs at the level of the endothelium and the consequences on arteriolar vasomotor responses. This review will begin with an overview of normal coronary microvascular physiology, modalities of measuring coronary microvascular function, and clinical implications of CMD. These introductory topics will be followed by a discussion of recent advances in the understanding of the mechanisms by which inflammation, oxidative stress, insulin resistance, hyperlipidemia, hypertension, shear stress, endothelial cell senescence, and tissue ischemia dysregulate coronary endothelial homeostasis and arteriolar vasomotor function.
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Affiliation(s)
- Sharif A Sabe
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
- Division of Cardiothoracic Surgery, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
| | - Jun Feng
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
- Division of Cardiothoracic Surgery, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
| | - Frank W Sellke
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
- Division of Cardiothoracic Surgery, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
| | - M Ruhul Abid
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
- Division of Cardiothoracic Surgery, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
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Metabolic regulation and dysregulation of endothelial small conductance calcium activated potassium channels. Eur J Cell Biol 2022; 101:151208. [DOI: 10.1016/j.ejcb.2022.151208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022] Open
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Taylor MS, Lowery J, Choi CS, Francis M. Restricted Intimal Ca 2+ Signaling Associated With Cardiovascular Disease. Front Physiol 2022; 13:848681. [PMID: 35492608 PMCID: PMC9040708 DOI: 10.3389/fphys.2022.848681] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Endothelial dysfunction is a key feature of cardiovascular disease (CVD) including atherosclerosis. Impaired endothelial signaling leads to plaque formation, vascular wall remodeling and widespread cardiovascular dysregulation. The specific changes along the vascular intima associated with atherosclerosis, including the vulnerable circulation downstream of the flow obstruction, remain poorly understood. Previous findings from animal models suggest that preservation of a distinct Ca2+ signaling profile along the arterial endothelial network is crucial for maintaining vasculature homeostasis and preventing arterial disease. Ca2+ signaling in the intact human artery intima has not been well characterized. Here, we employed confocal imaging and a custom analysis algorithm to assess the spatially and temporally dynamic Ca2+ signaling profiles of human peripheral arteries isolated from the amputated legs of patients with advanced CVD (peripheral artery disease and/or diabetes) or patients who had lost limbs due to non-cardiovascular trauma. In all tibial artery branches (0.5-5 mm diameter) assessed, the intima consistently elicited a broad range of basal Ca2+ signals ranging from isolated focal transients to broad waves. Arteries from patients with existing CVD displayed a restricted intimal Ca2+ signaling pattern characterized by diminished event amplitude and area. Stimulation of type-4 vanilloid transient receptor potential channels (TRPV4) amplified endothelial Ca2+ signals; however, these signals remained smaller and spatially confined in arteries from patients with CVD verses those without CVD. Our findings reveal a characteristic underlying basal Ca2+ signaling pattern within the intima of human peripheral arteries and suggest a distinct truncation of the inherent Ca2+ profile with CVD.
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Affiliation(s)
- Mark S. Taylor
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, United States
| | - Jordan Lowery
- Department of Pathology, University of South Alabama College of Medicine, Mobile, AL, United States
| | - Chung-Sik Choi
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, United States
| | - Michael Francis
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, United States
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Miklankova D, Markova I, Hüttl M, Stankova B, Malinska H. The Different Insulin-Sensitising and Anti-Inflammatory Effects of Palmitoleic Acid and Oleic Acid in a Prediabetes Model. J Diabetes Res 2022; 2022:4587907. [PMID: 36147256 PMCID: PMC9489414 DOI: 10.1155/2022/4587907] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/01/2022] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Monounsaturated fatty acids (MUFA) are understood to have therapeutic and preventive effects on chronic complications associated with type 2 diabetes mellitus (T2DM); however, there are differences between individual MUFAs. Although the effects of palmitoleic acid (POA) are still debated, POA can regulate glucose homeostasis, lipid metabolism, and cytokine production, thus improving metabolic disorders. In this study, we investigated and compared the metabolic effects of POA and oleic acid (OA) supplementation on glucose and lipid metabolism, insulin sensitivity, and inflammation in a prediabetic model, the hereditary hypertriglyceridemic rat (HHTg). HHTg rats exhibiting genetically determined hypertriglyceridemia, insulin resistance, and impaired glucose tolerance were fed a standard diet. POA and OA were each administered intragastrically at a dose of 100 mg/kg b.wt. for four weeks. RESULTS Supplementation with both MUFAs significantly elevated insulin and glucagon levels, but only POA decreased nonfasting glucose. POA-treated rats showed elevated circulating NEFA associated with increased lipolysis, lipoprotein lipase gene expression, and fatty acid reesterification in visceral adipose tissue (VAT). The mechanism of improved insulin sensitivity of peripheral tissues (measured as insulin-stimulated lipogenesis and glycogenesis) in POA-treated HHTg rats could contribute increased circulating adiponectin and omentin levels together with elevated FADS1 gene expression in VAT. POA-supplemented rats exhibited markedly decreased proinflammatory cytokine production by VAT, which can alleviate chronic inflammation. OA-supplemented rats exhibited decreased arachidonic acid (AA) profiles and decreased proinflammatory AA-derived metabolites (20-HETE) in membrane phospholipids of peripheral tissues. Slightly increased FADS1 gene expression after OA along with increased adiponectin production by VAT was reflected in slightly ameliorated adipose tissue insulin sensitivity (increased insulin-stimulated lipogenesis). CONCLUSIONS Our results show that POA served as a lipokine, ameliorating insulin sensitivity in peripheral tissue and markedly modulating the metabolic activity of VAT including cytokine secretion. OA had a beneficial effect on lipid metabolism and improved inflammation by modulating AA metabolism.
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Affiliation(s)
- Denisa Miklankova
- Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Irena Markova
- Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Martina Hüttl
- Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Barbora Stankova
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Hana Malinska
- Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
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Waldeck-Weiermair M, Yadav S, Spyropoulos F, Krüger C, Pandey AK, Michel T. Dissecting in vivo and in vitro redox responses using chemogenetics. Free Radic Biol Med 2021; 177:360-369. [PMID: 34752919 PMCID: PMC8639655 DOI: 10.1016/j.freeradbiomed.2021.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/08/2021] [Accepted: 11/04/2021] [Indexed: 02/03/2023]
Abstract
Hydrogen peroxide (H2O2) is the most abundant reactive oxygen species (ROS) within mammalian cells. At low concentrations, H2O2 serves as a versatile cell signaling molecule that mediates vital physiological functions. Yet at higher concentrations, H2O2 can be a toxic molecule by promoting pathological oxidative stress in cells and tissues. Within normal cells, H2O2 is differentially distributed in a variety of subcellular locales. Moreover, many redox-active enzymes and their substrates are themselves differentially distributed within cells. Numerous reports have described the biological and biochemical consequences of adding exogenous H2O2 to cultured cells and tissues, but many of these observations are difficult to interpret: the effects of exogenous H2O2 do not necessarily replicate the cellular responses to endogenous H2O2. In recent years, chemogenetic approaches have been developed to dynamically regulate the abundance of H2O2 in specific subcellular locales. Chemogenetic approaches have been applied in multiple experimental systems, ranging from in vitro studies on the intracellular transport and metabolism of H2O2, all the way to in vivo studies that generate oxidative stress in specific organs in living animals. These chemogenetic approaches have exploited a yeast-derived d-amino acid oxidase (DAAO) that synthesizes H2O2 only in the presence of its d-amino acid substrate. DAAO can be targeted to various subcellular locales, and can be dynamically activated by the addition or withdrawal of its d-amino acid substrate. In addition, recent advances in the development of highly sensitive genetically encoded H2O2 biosensors are providing a better understanding of both physiological and pathological oxidative pathways. This review highlights several applications of DAAO as a chemogenetic tool across a wide range of biological systems, from analyses of subcellular H2O2 metabolism in cells to the development of new disease models caused by oxidative stress in vivo.
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Affiliation(s)
- Markus Waldeck-Weiermair
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA; Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010, Graz, Austria
| | - Shambhu Yadav
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Fotios Spyropoulos
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA; Department of Pediatric Newborn Medicine, Harvard Medical School, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, USA
| | - Christina Krüger
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Arvind K Pandey
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Thomas Michel
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
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Heo R, Seo MS, An JR, Kang M, Park H, Han ET, Han JH, Chun W, Park WS. The anti-diabetic drug trelagliptin induces vasodilation via activation of Kv channels and SERCA pumps. Life Sci 2021; 283:119868. [PMID: 34358551 DOI: 10.1016/j.lfs.2021.119868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/25/2021] [Accepted: 07/27/2021] [Indexed: 12/29/2022]
Abstract
AIMS In this study, we investigated the vasodilatory effects of trelagliptin (a dipeptidyl peptidase-4 inhibitor) and its related mechanisms using rabbit aortic rings. MAIN METHODS Arterial tone measurement was performed in rabbit thoracic aortic rings. KEY FINDINGS Trelagliptin induced vasodilation in a dose-dependent manner. Pretreatment with the ATP-sensitive K+ channel inhibitor glibenclamide, large-conductance Ca2+-activated K+ channel inhibitor paxilline, and inwardly rectifying K+ channel inhibitor Ba2+ did not affect the vasodilatory effect of trelagliptin. However, pretreatment with the voltage-dependent K+ (Kv) channel inhibitors 4-aminopyridine and tetraethylammonium significantly attenuated the vasodilatory effect of trelagliptin, suggesting that the vasodilatory effect of trelagliptin is associated with Kv channel activation. Although pretreatment with Kv1.5 and Kv2.1 subtype inhibitors did not affect the response to trelagliptin, pretreatment with a Kv7.X subtype inhibitor effectively reduced the vasodilatory effect of trelagliptin. Furthermore, sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitors also significantly attenuated the vasodilatory effect of trelagliptin. These effects, however, were not affected by pretreatment with Ca2+ channel inhibitors, adenylyl cyclase/PKA inhibitors, guanylyl cyclase/PKG inhibitors, or removal of the endothelium. SIGNIFICANCE From these results, we concluded that the vasodilatory effect of trelagliptin was associated with the activation of Kv channels (primary the Kv7.X subtype) and SERCA pump regardless of other K+ channels, Ca2+ channels, cAMP/PKA-related or cGMP/PKG-related signaling pathways, and the endothelium. Therefore, caution is required when prescribing trelagliptin to the patients with hypotension and diabetes.
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Affiliation(s)
- Ryeon Heo
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Mi Seon Seo
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Jin Ryeol An
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Minji Kang
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Hongzoo Park
- Department of Urology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Wanjoo Chun
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea.
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Li JC, Velagic A, Qin CX, Li M, Leo CH, Kemp-Harper BK, Ritchie RH, Woodman OL. Diabetes Attenuates the Contribution of Endogenous Nitric Oxide but Not Nitroxyl to Endothelium Dependent Relaxation of Rat Carotid Arteries. Front Pharmacol 2021; 11:585740. [PMID: 33716721 PMCID: PMC7944142 DOI: 10.3389/fphar.2020.585740] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/16/2020] [Indexed: 12/27/2022] Open
Abstract
Endothelial dysfunction is a major risk factor for several of the vascular complications of diabetes, including ischemic stroke. Nitroxyl (HNO), the one electron reduced and protonated form of nitric oxide (NO•), is resistant to scavenging by superoxide, but the role of HNO in diabetes mellitus associated endothelial dysfunction in the carotid artery remains unknown. Aim: To assess how diabetes affects the role of endogenous NO• and HNO in endothelium-dependent relaxation in rat isolated carotid arteries. Methods: Male Sprague Dawley rats were fed a high-fat-diet (HFD) for 2 weeks prior to administration of low dose streptozotocin (STZ; 35 mg/kg i. p./day) for 2 days. The HFD was continued for a further 12 weeks. Sham rats were fed standard chow and administered with citrate vehicle. After 14 weeks total, rats were anesthetized and carotid arteries collected to assess responses to the endothelium-dependent vasodilator, acetylcholine (ACh) by myography. The combination of calcium-activated potassium channel blockers, TRAM-34 (1 μmol/L) and apamin (1 μmol/L) was used to assess the contribution of endothelium-dependent hyperpolarization to relaxation. The corresponding contribution of NOS-derived nitrogen oxide species to relaxation was assessed using the combination of the NO• synthase inhibitor, L-NAME (200 μmol/L) and the soluble guanylate cyclase inhibitor ODQ (10 μmol/L). Lastly, L-cysteine (3 mmol/L), a selective HNO scavenger, and hydroxocobalamin (HXC; 100 μmol/L), a NO• scavenger, were used to distinguish between NO• and HNO-mediated relaxation. Results: At study end, diabetic rats exhibited significantly retarded body weight gain and elevated blood glucose levels compared to sham rats. The sensitivity and the maximal relaxation response to ACh was significantly impaired in carotid arteries from diabetic rats, indicating endothelial dysfunction. The vasorelaxation evoked by ACh was abolished by L-NAME plus ODQ, but not affected by the apamin plus TRAM-34 combination, indicating that NOS-derived nitrogen oxide species are the predominant endothelium-derived vasodilators in sham and diabetic rat carotid arteries. The maximum relaxation to ACh was significantly decreased by L-cysteine in both sham and diabetic rats, whereas HXC attenuated ACh-induced relaxation only in sham rats, suggesting that diabetes impaired the contribution of NO•, whereas HNO-mediated vasorelaxation remained intact. Conclusion: Both NO• and HNO contribute to endothelium-dependent relaxation in carotid arteries. In diabetes, NO•-mediated relaxation is impaired, whereas HNO-mediated relaxation was preserved. The potential for preserved HNO activity under pathological conditions that are associated with oxidative stress indicates that HNO donors may represent a viable therapeutic approach to the treatment of vascular dysfunction.
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Affiliation(s)
- Jasmin Chendi Li
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Anida Velagic
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Cheng Xue Qin
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Mandy Li
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Chen Huei Leo
- Science, Maths and Technology Cluster, Singapore University of Technology & Design, Singapore, Singapore
| | - Barbara K. Kemp-Harper
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Rebecca H. Ritchie
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Owen L. Woodman
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
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Electrical Propagation of Vasodilatory Signals in Capillary Networks. Bull Math Biol 2020; 82:128. [PMID: 32968879 DOI: 10.1007/s11538-020-00806-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 09/09/2020] [Indexed: 10/23/2022]
Abstract
We have developed a computational model to study electrical propagation of vasodilatory signals and arteriolar regulation of blood flow depending on the oxygen tension and agonist distribution in the capillary network. The involving key parameters of endothelial cell-to-cell electrical conductivity and plasma membrane area per unit volume were calibrated with the experimental data on an isolated endothelial tube of mouse skeletal feeding arteries. We have estimated the oxygen saturation parameters in terms of erythrocyte ATP release from the data of a left anterior descending coronary blood perfusion of dog. Regarding the acetylcholine-induced upstream conduction, our model shows that spatially uniform superfusion of acetylcholine attenuates the electrical signal propagation, and blocking calcium-activated potassium channels suppresses that attenuation. On the other hand, a local infusion of acetylcholine induces enhanced electrical propagation that corresponds to physiological relevance. Integrating the electrophysiology of endothelial tube and the electrophysiology/mechanics of a lumped arteriole, we show mechanistically that endothelial purinergic oxygen sensing of ATP released from erythrocytes and local infusion of acetylcholine are individually effective to induce vasodilatory signals to regulate blood flow in arterioles. We have recapitulated the upstream vasomotion in arterioles from the elevated oxygen tension in the downstream capillary domain. This study is a foundation for characterizing effective pharmaceutical strategies for ascending vasodilation and oxygenation.
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Arachidonic Acid Metabolites of CYP450 Enzymes and HIF-1α Modulate Endothelium-Dependent Vasorelaxation in Sprague-Dawley Rats under Acute and Intermittent Hyperbaric Oxygenation. Int J Mol Sci 2020; 21:ijms21176353. [PMID: 32883025 PMCID: PMC7503979 DOI: 10.3390/ijms21176353] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/26/2020] [Accepted: 08/29/2020] [Indexed: 01/12/2023] Open
Abstract
Acetylcholine-induced vasorelaxation (AChIR) and responses to reduced pO2 (hypoxia-induced relaxation (HIR), 0% O2) were assessed in vitro in aortic rings of healthy male Sprague-Dawley rats (N = 252) under hyperbaric (HBO2) protocols. The studied groups consisted of the CTRL group (untreated); the A-HBO2 group (single HBO2; 120 min of 100% O2 at 2.0 bars); the 24H-HBO2 group (examined 24 h after single exposure) and the 4D-HBO2 group (four consecutive days of single HBO2). AChIR, sensitivity to ACh and iNOS expression were decreased in the A-HBO2 group. HIR was prostanoid- and epoxyeicosatrienoic acid (EET)-mediated. HIF-1α expression was increased in the 24H-HBO2 and 4D-HBO2 groups. LW6 (HIF-1α inhibitor) decreased HIR in the 24H-HBO2 group. HBO2 affected the expression of COX-1 and COX-2. CYP2c11 expression was elevated in the 24H-HBO2 and 4D-HBO2 groups. Concentrations of arachidonic acid (AA) metabolites 14(15)-DiHET, 11(12)-DiHET and 8(9)-DiHET were increased in A-HBO2 and 24H-HBO2. An increased concentration of 8(9)-EET was observed in the A-HBO2 and 24h-HBO2 groups vs. the CTRL and 4D-HBO2 groups, and an increased concentration of 5(6)-DiHET was observed in the 24H-HBO2 group vs. the 4D-HBO2 group. The 20-HETE concentration was increased in the A-HBO2 group. All were determined by LC-MS/MS of the aorta. The results show that AChIR in all groups is mostly NO-dependent. HIR is undoubtedly mediated by the CYP450 enzymes’ metabolites of AA, whereas HIF-1α contributes to restored HIR. Vasoconstrictor metabolites of CYP450 enzymes contribute to attenuated AChIR and HIR in A-HBO2.
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Sallam NA, Laher I. Redox Signaling and Regional Heterogeneity of Endothelial Dysfunction in db/db Mice. Int J Mol Sci 2020; 21:ijms21176147. [PMID: 32858910 PMCID: PMC7504187 DOI: 10.3390/ijms21176147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/15/2020] [Accepted: 08/21/2020] [Indexed: 12/13/2022] Open
Abstract
The variable nature of vascular dysfunction in diabetes is not well understood. We explored the functional adaptation of different arteries in db/db mice in relation to increased severity and duration of diabetes. We compared endothelium-dependent and -independent vasodilation in the aortae, as well as the carotid and femoral arteries, of db/db mice at three ages in parallel with increased body weight, oxidative stress, and deterioration of glycemic control. Vascular responses to in vitro generation of reactive oxygen species (ROS) and expression of superoxide dismutase (SOD) isoforms were assessed. There was a progressive impairment of endothelium-dependent and -independent vasorelaxation in the aortae of db/db mice. The carotid artery was resistant to the effects of in vivo and in vitro induced oxidative stress, and it maintained unaltered vasodilatory responses, likely because the carotid artery relaxed in response to ROS. The femoral artery was more reliant on dilation mediated by endothelium-dependent hyperpolarizing factor(s), which was reduced in db/db mice at the earliest age examined and did not deteriorate with age. Substantial heterogeneity exists between the three arteries in signaling pathways and protein expression of SODs under physiological and diabetic conditions. A better understanding of vascular heterogeneity will help develop novel therapeutic approaches for targeted vascular treatments, including blood vessel replacement.
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Affiliation(s)
- Nada A. Sallam
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Kasr Al-Aini Street, Cairo 11562, Egypt;
| | - Ismail Laher
- Department of Anesthesiology, Faculty of Medicine, Pharmacology and Therapeutics, The University of British Columbia, 2176 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
- Correspondence: ; Tel.: +1-604-822-5882
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Moh MC, Low S, Ng TP, Ang K, Subramaniam T, Sum CF, Kwan PY, Lee SBM, Tang WE, Lim SC. Role of endothelium-independent vasodilation in the relationship between visceral adiposity and reduced cognitive performance in older adults with type 2 diabetes. Microcirculation 2020; 27:e12609. [PMID: 31999860 DOI: 10.1111/micc.12609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/30/2019] [Accepted: 01/27/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE In this cross-sectional analysis, we sought to assess the relationship of adiposity and forearm microvascular reactivity with cognitive dysfunction among older Asians with type 2 diabetes (T2D). METHODS Subjects with T2D aged ≥ 55 years were analyzed (N = 907). Cognitive performance was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Mini-Mental State Exam (MMSE). Visceral fat area (VFA) was estimated by tetrapolar multi-frequency bioimpedance. Forearm microvascular endothelium-dependent vasodilation (EDV) and endothelium-independent vasodilation (EIV) were assessed by laser Doppler imaging with iontophoresis. RESULTS RBANS total score was correlated with VFA, EDV, and EIV (all P < .05). However, VFA was correlated with EIV, but not with EDV. Multivariable linear regression showed significant association between VFA and RBANS total score (B = -0.02, 95% CI= -0.03 to -0.01) or memory (immediate and delayed) index scores. These associations were attenuated after adjustment for EIV. Mediation analysis showed that EIV partially mediated the relationship between visceral adiposity and RBANS scores (all Sobel tests P < .05). EIV also mediated the relationship between VFA and MMSE score. CONCLUSIONS Impaired endothelium-independent vascular smooth muscle reactivity may exert a mediatory effect on the association between increased visceral adiposity and decreased cognitive performance in older adults with T2D.
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Affiliation(s)
- Mei Chung Moh
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Serena Low
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore.,Diabetes Centre, Admiralty Medical Centre, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Tze Pin Ng
- Gerontology Research Programme, Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Keven Ang
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore
| | | | - Chee Fang Sum
- Diabetes Centre, Admiralty Medical Centre, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Pek Yee Kwan
- National Healthcare Group Polyclinics, Singapore, Singapore
| | | | - Wern Ee Tang
- National Healthcare Group Polyclinics, Singapore, Singapore
| | - Su Chi Lim
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore.,Diabetes Centre, Admiralty Medical Centre, Khoo Teck Puat Hospital, Singapore, Singapore.,Saw Swee Hock School of Public Health, National University Hospital, Singapore, Singapore
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14
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Raees A, Bakhamis A, Mohamed-Ali V, Bashah M, Al-Jaber M, Abraham D, Clapp LH, Orie NN. Altered cyclooxygenase-1 and enhanced thromboxane receptor activities underlie attenuated endothelial dilatory capacity of omental arteries in obesity. Life Sci 2019; 239:117039. [PMID: 31704447 DOI: 10.1016/j.lfs.2019.117039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 01/05/2023]
Abstract
AIMS Obesity is a risk factor for endothelial dysfunction, the severity of which is likely to vary depending on extent and impact of adiposity on the vasculature. This study investigates the roles of cyclooxygenase isoforms and thromboxane receptor activities in the differential endothelial dilatory capacities of arteries derived from omental and subcutaneous adipose tissues in obesity. MAIN METHODS Small arteries were isolated from omental and subcutaneous adipose tissues obtained from consented morbidly obese patients (n = 65, BMI 45 ± 6 kg m-2 [Mean ± SD]) undergoing bariatric surgery. Relaxation to acetylcholine was studied by wire myography in the absence or presence of indomethacin (10 μM, cyclooxygenase inhibitor), FR122047 (1 μM, cyclooxygenase-1 inhibitor), Celecoxib (4 μM, cyclooxygenase-2 inhibitor), Nω-Nitro-L-arginine methyl ester (L-NAME, 100 μM, nitric oxide synthase inhibitor) or combination of apamin (0.5 μM) and charybdotoxin (0.1 μM) that together inhibit endothelium-derived hyperpolarizing factor (EDHF). Contractions to U46619 (thromboxane A2 mimetic) were also studied. KEY FINDINGS Acetylcholine relaxation was significantly attenuated in omental compared with subcutaneous arteries from same patients (p < 0.01). Indomethacin (p < 0.01) and FR122047 (p < 0.001) but not Celecoxib significantly improved the omental arteriolar relaxation. Cyclooxygenase-1 mRNA and U46619 contractions were both increased in omental compared with subcutaneous arteries (p < 0.05). L-NAME comparably inhibited acetylcholine relaxation in both arteries, while apamin+charybdotoxin were less effective in omental compared with subcutaneous arteries. SIGNIFICANCE The results show that the depot-specific reduction in endothelial dilatory capacity of omental compared with subcutaneous arteries in obesity is in large part due to altered cyclooxygenase-1 and enhanced thromboxane receptor activities, which cause EDHF deficiency.
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Affiliation(s)
- Asmaa Raees
- Qatar Analytics and BioResearch Lab, Anti-Doping Lab Qatar, Qatar
| | - Aysha Bakhamis
- Qatar Analytics and BioResearch Lab, Anti-Doping Lab Qatar, Qatar
| | | | - Moataz Bashah
- Metabolic and Bariatric Surgery Department, Hamad Medical Corporation, Doha, Qatar
| | - Mashael Al-Jaber
- Qatar Analytics and BioResearch Lab, Anti-Doping Lab Qatar, Qatar
| | - David Abraham
- Centre for Rheumatology and Connective Tissue Diseases, Division of Medicine, University College London, UK
| | - Lucie H Clapp
- Institute of Cardiovascular Sciences, University College London, UK
| | - Nelson N Orie
- Qatar Analytics and BioResearch Lab, Anti-Doping Lab Qatar, Qatar.
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15
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Endothelium-Dependent Hyperpolarization (EDH) in Diabetes: Mechanistic Insights and Therapeutic Implications. Int J Mol Sci 2019; 20:ijms20153737. [PMID: 31370156 PMCID: PMC6695796 DOI: 10.3390/ijms20153737] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 02/07/2023] Open
Abstract
Diabetes mellitus is one of the major risk factors for cardiovascular disease and is an important health issue worldwide. Long-term diabetes causes endothelial dysfunction, which in turn leads to diabetic vascular complications. Endothelium-derived nitric oxide is a major vasodilator in large-size vessels, and the hyperpolarization of vascular smooth muscle cells mediated by the endothelium plays a central role in agonist-mediated and flow-mediated vasodilation in resistance-size vessels. Although the mechanisms underlying diabetic vascular complications are multifactorial and complex, impairment of endothelium-dependent hyperpolarization (EDH) of vascular smooth muscle cells would contribute at least partly to the initiation and progression of microvascular complications of diabetes. In this review, we present the current knowledge about the pathophysiology and underlying mechanisms of impaired EDH in diabetes in animals and humans. We also discuss potential therapeutic approaches aimed at the prevention and restoration of EDH in diabetes.
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16
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Abstract
Perivascular adipose tissue (PVAT) refers to the local aggregate of adipose tissue surrounding the vascular tree, exhibiting phenotypes from white to brown and beige adipocytes. Although PVAT has long been regarded as simply a structural unit providing mechanical support to vasculature, it is now gaining reputation as an integral endocrine/paracrine component, in addition to the well-established modulator endothelium, in regulating vascular tone. Since the discovery of anti-contractile effect of PVAT in 1991, the use of multiple rodent models of reduced amounts of PVAT has revealed its regulatory role in vascular remodeling and cardiovascular implications, including atherosclerosis. PVAT does not only release PVAT-derived relaxing factors (PVRFs) to activate multiple subsets of endothelial and vascular smooth muscle potassium channels and anti-inflammatory signals in the vasculature, but it does also provide an interface for neuron-adipocyte interactions in the vascular wall to regulate arterial vascular tone. In this review, we outline our current understanding towards PVAT and attempt to provide hints about future studies that can sharpen the therapeutic potential of PVAT against cardiovascular diseases and their complications.
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Affiliation(s)
- Chak Kwong Cheng
- School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, SAR, China
- Institute of Vascular Medicine, Shenzhen Research Institute and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Hamidah Abu Bakar
- Health Sciences Department, Universiti Selangor, 40000, Shah Alam, Selangor, Malaysia
| | - Maik Gollasch
- Experimental and Clinical Research Center (ECRC)-a joint cooperation between the Charité-University Medicine Berlin and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany.
- Medical Clinic for Nephrology and Internal Intensive Care, Charité Campus Virchow Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
| | - Yu Huang
- School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, SAR, China.
- Institute of Vascular Medicine, Shenzhen Research Institute and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, SAR, China.
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17
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Yada T, Shimokawa H, Tachibana H. Endothelium-dependent hyperpolarization-mediated vasodilatation compensates nitric oxide-mediated endothelial dysfunction during ischemia in diabetes-induced canine coronary collateral microcirculation in vivo. Microcirculation 2018; 25:e12456. [PMID: 29665152 DOI: 10.1111/micc.12456] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/09/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVES It has been previously demonstrated that endothelial caveolin-1 plays crucial roles to produce an endothelium-derived hyperpolarizing factor in mouse mesenteric arteries. We examined whether this mechanism is involved in the endothelium-dependent hyperpolarization-mediated responses to compensate reduced NO-mediated responses in diabetes mellitus during coronary occlusion in dogs in vivo. METHODS Canine subepicardial collateral coronary small arteries (≥100 μm) and arterioles (<100 μm) were observed by an intravital microscope. Experiments were performed during occlusion of the left anterior descending coronary artery (90 minutes) under the following conditions (n = 6 each); (i) control, (ii) diabetes mellitus, and (iii) diabetes mellitus+L-NMMA+KCa channel blockade. Vascular and myocardial levels of caveolin-1, eNOS, and caspase-3 were measured by ELISA. RESULTS Caveolin-1 levels in the ischemic area were greater in coronary microvessels than in conduit arteries in the control group. NO-mediated coronary vasodilatations of small arteries to bradykinin did not increase in diabetes mellitus associated with decreased eNOS phosphorylation at Ser1177 compared with baseline of controls and were restored by compensation of endothelium-dependent hyperpolarization and were suppressed by KCa channel blockade. CONCLUSIONS NO-mediated vasodilatations of small coronary arteries during coronary occlusion are impaired in diabetes mellitus and are compensated by endothelium-dependent hyperpolarization of arterioles in dogs in vivo.
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Affiliation(s)
- Toyotaka Yada
- Department of Biochemistry, Kawasaki Medical School, Kurashiki, Japan.,Department of Medical Engineering, Kawasaki University of Medical Welfare, Kurashiki, Japan
| | - Hiroaki Shimokawa
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroyuki Tachibana
- Department of Medical Engineering, Kawasaki University of Medical Welfare, Kurashiki, Japan
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18
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Acute Hyperbaric Oxygenation, Contrary to Intermittent Hyperbaric Oxygenation, Adversely Affects Vasorelaxation in Healthy Sprague-Dawley Rats due to Increased Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:7406027. [PMID: 29854092 PMCID: PMC5949176 DOI: 10.1155/2018/7406027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/27/2017] [Accepted: 02/15/2018] [Indexed: 02/07/2023]
Abstract
The present study was aimed at assessing endothelium-dependent vasorelaxation, at measuring superoxide production in the aorta and femoral artery, and at determining antioxidative enzyme expression and activity in aortas of male Sprague-Dawley rats (N = 135), randomized to an A-HBO2 group exposed to a single hyperbaric oxygenation session (120′ of 100% O2 at 2.0 bars), a 24H-HBO2 group (single session, examined 24 h after exposure), a 4D-HBO2 group (4 consecutive days of single sessions), and a CTRL group (untreated group). Vasorelaxation of aortic rings in response to acetylcholine (AChIR) and to reduced pO2 (HIR) was tested in vitro in the absence/presence of NOS inhibitor L-NAME and superoxide scavenger TEMPOL. eNOS, iNOS, antioxidative enzyme, and NADPH oxidase mRNA expression was assessed by qPCR. Serum oxidative stress markers and enzyme activity were assessed by spectrometry, and superoxide production was determined by DHE fluorescence. Impaired AChIR and HIR in the A-HBO2 group were restored by TEMPOL. L-NAME inhibited AChIR in all groups. Serum oxidative stress and superoxide production were increased in the A-HBO2 group compared to all other groups. The mRNA expression of iNOS was decreased in the A-HBO2 and 24H-HBO2 groups while SOD1 and 3 and NADPH oxidase were increased in the 4D-HBO2 group. The expression and activity of catalase and glutathione peroxidase were increased in the 4D-HBO2 group as well. AChIR was NO dependent. Acute HBO2 transiently impaired vasorelaxation due to increased oxidative stress. Vasorelaxation was restored and oxidative stress was normalized 24 h after the treatment.
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19
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Lemmey HAL, Ye X, Ding HC, Triggle CR, Garland CJ, Dora KA. Hyperglycaemia disrupts conducted vasodilation in the resistance vasculature of db/db mice. Vascul Pharmacol 2018; 103-105:29-35. [PMID: 29339138 PMCID: PMC5906692 DOI: 10.1016/j.vph.2018.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 11/27/2017] [Accepted: 01/10/2018] [Indexed: 11/17/2022]
Abstract
Vascular dysfunction in small resistance arteries is observed during chronic elevations in blood glucose. Hyperglycaemia-associated effects on endothelium-dependent vasodilation have been well characterized, but effects on conducted vasodilation in the resistance vasculature are not known. Small mesenteric arteries were isolated from healthy and diabetic db/db mice, which were used as a model of chronic hyperglycaemia. Endothelium-dependent vasodilation via the Gq/11-coupled proteinase activated receptor 2 (PAR2) was stimulated with the selective agonist SLIGRL. The Ca2+-sensitive fluorescent indicator fluo-8 reported changes in endothelial cell (EC) [Ca2+]i, and triple cannulated bifurcating mesenteric arteries were used to study conducted vasodilation. Chronic hyperglycaemia did not affect either EC Ca2+ or local vasodilation to SLIGRL. However, both acute and chronic exposure to high glucose or the mannitol osmotic control attenuated conducted vasodilation to 10μM SLIGRL. This investigation demonstrates for the first time that a hypertonic solution containing glucose or mannitol can interfere with the spread of a hyperpolarizing current along the endothelium in a physiological setting. Our findings reiterate the importance of studying the effects of hyperglycaemia in the vasculature, and provide the basis for further studies regarding the modulation of junctional proteins involved in cell to cell communication by diseases such as diabetes.
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Affiliation(s)
- Hamish A L Lemmey
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Xi Ye
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Hong C Ding
- Department of Pharmacology, Weill Cornell Medicine in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
| | - Christopher R Triggle
- Department of Pharmacology, Weill Cornell Medicine in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
| | - Christopher J Garland
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Kim A Dora
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
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20
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Lee J, Lee S, Zhang H, Hill MA, Zhang C, Park Y. Interaction of IL-6 and TNF-α contributes to endothelial dysfunction in type 2 diabetic mouse hearts. PLoS One 2017; 12:e0187189. [PMID: 29095915 PMCID: PMC5667841 DOI: 10.1371/journal.pone.0187189] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 10/16/2017] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES Inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), are individually considered as important contributors to endothelial dysfunction in obesity and type 2 diabetes (T2D). However, their interactions in coronary arteriole endothelial dysfunction are uncertain. Therefore, this study aimed to determine the effects of TNF-α and IL-6 interactions on coronary endothelial dysfunction in experimental T2D. METHODS The studies used wild type (WT), diabetic mice (db/db), db/db null for TNF (dbTNF-/dbTNF-), and db/db mice treated with neutralizing antibody to IL-6 (anti-IL-6). Endothelium-dependent (acetylcholine [ACh], or luminal flow-induced shear stress) and endothelium-independent (sodium nitroprusside [SNP]) vasodilation of isolated and pressurized coronary arterioles were determined. Quantitative PCR, Western blot, and immunofluorescence staining were utilized for mechanistic studies. RESULTS Relative to WT, arteriolar dilation to both ACh and flow was attenuated in db/db mice and dbTNF-/dbTNF-. Treatment of dbTNF-/dbTNF- and db/db mice with anti-IL-6 improved arteriolar dilation compared to db/db mice. Immunofluorescence staining illustrated localization of IL-6 within the endothelial cells of coronary arterioles. In db/db mice, mRNA and protein expression of IL-6 and superoxide (O2-) production were higher, but reduced by anti-IL-6 treatment. Also, in db/db mice, mRNA and protein expression of TNF-α suppressed by the anti-IL-6 treatment and the reduced expression of mRNA and protein expression of IL-6 by the genetic deletion of TNF-α both supported a reciprocal regulation between TNF-α and IL-6. Superoxide dismutase 2 (SOD2) expression and phosphorylation of eNOS (p-eNOS/eNOS) were lower in db/db mice coronary arterioles and were restored in db/db+Anti-IL-6 and dbTNF-/dbTNF- mice. CONCLUSION The interactions between TNF-α and IL-6 exacerbate oxidative stress and reduce phosphorylation of eNOS, thereby contributing to coronary endothelial dysfunction in T2D mice.
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Affiliation(s)
- Jonghae Lee
- Department of Health and Human Performance, University of Houston, Houston, Texas, United States of America
| | - Sewon Lee
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Medical Pharmacology, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Division of Sport Science and Sport Science Institute, Incheon National University, Incheon, South Korea
| | - Hanrui Zhang
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Medical Pharmacology, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Division of Cardiology, Department of Medicine, Columbia University Medical Center, New York, United States of America
| | - Michael A. Hill
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Medical Pharmacology, University of Missouri-Columbia, Columbia, Missouri, United States of America
| | - Cuihua Zhang
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Medical Pharmacology, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Departments of Internal Medicine, University of Missouri-Columbia, Columbia, Missouri, United States of America
- Physiology and Nutritional Sciences, University of Missouri-Columbia, Columbia, Missouri, United States of America
| | - Yoonjung Park
- Department of Health and Human Performance, University of Houston, Houston, Texas, United States of America
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri, United States of America
- * E-mail:
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21
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Endothelial dysfunction in renal arcuate arteries of obese Zucker rats: The roles of nitric oxide, endothelium-derived hyperpolarizing factors, and calcium-activated K+ channels. PLoS One 2017; 12:e0183124. [PMID: 28817716 PMCID: PMC5560550 DOI: 10.1371/journal.pone.0183124] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/31/2017] [Indexed: 12/05/2022] Open
Abstract
The roles of nitric oxide (NO), endothelium-derived hyperpolarizing factors (EDHF), and calcium-activated K+ (KCa) channels in diabetes-associated endothelial dysfunction of small renal arteries are not clear. The present study investigated acetylcholine (ACh)-induced vasorelaxation of renal arcuate arteries from obese Zucker (OZ) rats at different diabetes durations, and the relative contribution of NO, EDHF, and KCa channels to the endothelial dysfunction. OZ rats of 7 weeks (prediabetic stage), 12 weeks (early diabetic stage), and 20 weeks (late diabetic stage), and time-matched lean control rats, were studied. Segments of arcuate arteries (130 to 180 μm) were isolated, cannulated and pressurized. Vascular endothelial functions were tested using ACh-induced vasodilation. Our experiments demonstrated: (1) ACh-elicited vasodilation was impaired in OZ rats of 20 weeks, but not in rats of 7 and 12 weeks; (2) inhibition of NO or EDHF (contributed by epoxyeicosatrienoic acids [EETs]) production significantly decreased ACh-induced vasodilation in both lean and OZ rats of 20 weeks. The reduction of ACh-induced vasodilation by inhibition of NO or EDHF formation was less in OZ rats, as compared to lean rats; and (3) inhibition of KCa channels markedly reduced ACh-induced vasodilation in lean control rats, but not in OZ rats of 20 weeks. Our observations indicated that endothelium-dependent vasodilation in renal arcuate arteries is impaired in diabetes mellitus; NO and EDHF, mainly EETs, dominate the ACh-induced vasodilation in renal arcuate arteries; the contribution of NO and EETs is impaired in diabetic rats; KCa channels are involved in ACh-induced vasodilation; and the activity of KCa channels is downregulated in diabetes mellitus.
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22
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The Role of Endoplasmic Reticulum Stress in Cardiovascular Disease and Exercise. Int J Vasc Med 2017; 2017:2049217. [PMID: 28875043 PMCID: PMC5569752 DOI: 10.1155/2017/2049217] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/06/2017] [Indexed: 12/18/2022] Open
Abstract
Endoplasmic reticulum (ER) stress, which is highly associated with cardiovascular disease, is triggered by a disturbance in ER function because of protein misfolding or an increase in protein secretion. Prolonged disruption of ER causes ER stress and activation of the unfolded protein response (UPR) and leads to various diseases. Eukaryotic cells respond to ER stress via three major sensors that are bound to the ER membrane: activating transcription factor 6 (ATF6), inositol-requiring protein 1α (IRE1α), and protein kinase RNA-like ER kinase (PERK). Chronic activation of ER stress causes damage in endothelial cells (EC) via apoptosis, inflammation, and oxidative stress signaling pathways. The alleviation of ER stress has recently been accepted as a potential therapeutic target to treat cardiovascular diseases such as heart failure, hypertension, and atherosclerosis. Exercise training is an effective nonpharmacological approach for preventing and alleviating cardiovascular disease. We here review the recent viewing of ER stress-mediated apoptosis and inflammation signaling pathways in cardiovascular disease and the role of exercise in ER stress-associated diseases.
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Labazi H, Trask AJ. Coronary microvascular disease as an early culprit in the pathophysiology of diabetes and metabolic syndrome. Pharmacol Res 2017; 123:114-121. [PMID: 28700893 DOI: 10.1016/j.phrs.2017.07.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/19/2017] [Accepted: 07/04/2017] [Indexed: 01/09/2023]
Abstract
Metabolic syndrome (MetS) is a group of cardio-metabolic risk factors that includes obesity, insulin resistance, hypertension, and dyslipidemia; these are also a combination of independent coronary artery disease (CAD) risk factors. Alarmingly, the prevalence of MetS risk factors are increasing and a leading cause for mortality. In the vasculature, complications from MetS and type 2 diabetes (T2D) can be divided into microvascular (retinopathy and nephropathy) and macrovascular (cardiovascular diseases and erectile dysfunction). In addition to vascular and endothelial dysfunction, vascular remodeling and stiffness are also hallmarks of cardiovascular disease (CVD), and well-characterized vascular changes that are observed in the early stages of hypertension, T2D, and obesity [1-3]. In the heart, the link between obstructive atherosclerosis of coronary macrovessels and myocardial ischemia (MI) is well established. However, recent studies show that abnormalities in the coronary microcirculation are associated with functional and structural changes in coronary microvessels (classically defined as being ≤150-200μm internal diameter), which may cause or contribute to MI even in the absence of obstractive CAD. This suggests a prognostic value of an abnormal coronary microcirculation as an early sub-clinical culprit in the pathogenesis and progression of heart disease in T2D and MetS. The aim of this review is to summarize recent studies investigating the coronary microvascular remodeling in an early pre-atherosclerotic phase of MetS and T2D, and to explore potential mechanisms associated with the timing of coronary microvascular remodeling relative to that of the macrovasculature.
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Affiliation(s)
- Hicham Labazi
- Center for Cardiovascular Research and The Heart Center, The Research Institute at Nationwide Children's Hospital Columbus, OH, United States
| | - Aaron J Trask
- Center for Cardiovascular Research and The Heart Center, The Research Institute at Nationwide Children's Hospital Columbus, OH, United States; Department of Pediatrics, The Ohio State University Columbus, OH, United States.
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24
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Abstract
The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. © 2017 American Physiological Society. Compr Physiol 7:321-382, 2017.
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Affiliation(s)
- Adam G Goodwill
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
| | - Gregory M Dick
- California Medical Innovations Institute, 872 Towne Center Drive, Pomona, CA
| | - Alexander M Kiel
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, Lafayette, IN
| | - Johnathan D Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
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25
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Marche P, Dubois S, Abraham P, Parot-Schinkel E, Gascoin L, Humeau-Heurtier A, Ducluzeau PH, Mahe G. Neurovascular microcirculatory vasodilation mediated by C-fibers and Transient receptor potential vanilloid-type-1 channels (TRPV 1) is impaired in type 1 diabetes. Sci Rep 2017; 7:44322. [PMID: 28287157 PMCID: PMC5347083 DOI: 10.1038/srep44322] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/06/2017] [Indexed: 01/20/2023] Open
Abstract
Microvascular dysfunction may have an early onset in type 1 diabetes (T1D) and can precede major complications. Our objectives were to assess the endothelial-dependent (acetylcholine, ACh; and post-occlusive hyperemia, PORH), non-endothelial-dependent (sodium nitroprusside, SNP) and neurovascular-dependent (local heating, LH and current induced vasodilation, CIV) microcirculatory vasodilation in T1D patients compared with matched control subjects using a laser speckle contrast imager. Seventeen T1D patients - matched with 17 subjects according to age, gender, Body-Mass-Index, and smoking status - underwent macro- and microvascular investigations. The LH early peak assessed the transient receptor potential vanilloid type 1 channels (TRPV1) mediated vasodilation, whereas the plateau assessed the Nitirc-Oxyde (NO) and endothelium-derived hyperpolarizing factor (EDHF) pathways. PORH explored sensory nerves and (EDHF), while CIV assessed sensory nerves (C-fibers) and prostaglandin-mediated vasodilation. Using neurological investigations, we observed that C-fiber and A-delta fiber functions in T1D patients were similar to control subjects. PORH, CIV, LH peak and plateau vasodilations were significantly decreased in T1D patients compared to controls, whereas there was no difference between the two groups for ACh and SNP vasodilations. Neurovascular microcirculatory vasodilations (C-fibers and TRPV 1-mediated vasodilations) are impaired in TD1 patients whereas no abnormalities were found using clinical neurological investigations. Clinicaltrials: No. NCT02538120.
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Affiliation(s)
- P Marche
- Endocrinology Department, University Hospital of Angers, Angers, France
| | - S Dubois
- Endocrinology Department, University Hospital of Angers, Angers, France
| | - P Abraham
- Laboratory of Vascular Investigations, University Hospital of Angers, UMR CNRS6214/INSERM1083, LUNAM Université, Angers, France
| | - E Parot-Schinkel
- Methodology and Biostatistics Unit, University Hospital of Angers, Angers, France
| | - L Gascoin
- Laboratory of Vascular Investigations, University Hospital of Angers, UMR CNRS6214/INSERM1083, LUNAM Université, Angers, France
| | - A Humeau-Heurtier
- University of Angers, LARIS - Laboratoire Angevin de Recherche en Ingénierie des Systèmes, Angers, France
| | - P H Ducluzeau
- Endocrinology Department, University Hospital of Tours, Tours, France
| | - G Mahe
- INSERM Clinical Investigation Center (CIC 14 14), Rennes, France, Université de Rennes 1 and LUNAM University, Inserm 1083/CNRS 6214, Faculty of Medicine, Angers, France
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26
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Mazor R, Schmid-Schönbein GW. Proteolytic receptor cleavage in the pathogenesis of blood rheology and co-morbidities in metabolic syndrome. Early forms of autodigestion. Biorheology 2016; 52:337-52. [PMID: 26600265 DOI: 10.3233/bir-15045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abnormal blood rheological properties seldom occur in isolation and instead are accompanied by other complications, often designated as co-morbidities. In the metabolic syndrome with complications like hypertension, diabetes and lack of normal microvascular blood flow, the underlying molecular mechanisms that simultaneously lead to elevated blood pressure and diabetes as well as abnormal microvascular rheology and other cell dysfunctions have remained largely unknown. In this review, we propose a new hypothesis for the origin of abnormal cell functions as well as multiple co-morbidities. Utilizing experimental models for the metabolic disease with diverse co-morbidities we summarize evidence for the presence of an uncontrolled extracellular proteolytic activity that causes ectodomain receptor cleavage and loss of their associated cell function. We summarize evidence for unchecked degrading proteinase activity, e.g. due to matrix metalloproteases, in patients with hypertension, Type II diabetes and obesity, in addition to evidence for receptor cleavage in the form of receptor fragments and decreased extracellular membrane expression levels. The evidence suggest that a shift in blood rheological properties and other co-morbidities may in fact be derived from a common mechanism that is due to uncontrolled proteolytic activity, i.e. an early form of autodigestion. Identification of the particular proteases involved and the mechanisms of their activation may open the door to treatment that simultaneously targets multiple co-morbidities in the metabolic syndrome.
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Affiliation(s)
- Rafi Mazor
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Geert W Schmid-Schönbein
- Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA, USA
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27
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Ellinsworth DC, Sandow SL, Shukla N, Liu Y, Jeremy JY, Gutterman DD. Endothelium-Derived Hyperpolarization and Coronary Vasodilation: Diverse and Integrated Roles of Epoxyeicosatrienoic Acids, Hydrogen Peroxide, and Gap Junctions. Microcirculation 2016; 23:15-32. [PMID: 26541094 DOI: 10.1111/micc.12255] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 11/01/2015] [Indexed: 12/22/2022]
Abstract
Myocardial perfusion and coronary vascular resistance are regulated by signaling metabolites released from the local myocardium that act either directly on the VSMC or indirectly via stimulation of the endothelium. A prominent mechanism of vasodilation is EDH of the arteriolar smooth muscle, with EETs and H(2)O(2) playing important roles in EDH in the coronary microcirculation. In some cases, EETs and H(2)O(2) are released as transferable hyperpolarizing factors (EDHFs) that act directly on the VSMCs. By contrast, EETs and H(2)O(2) can also promote endothelial KCa activity secondary to the amplification of extracellular Ca(2+) influx and Ca(2+) mobilization from intracellular stores, respectively. The resulting endothelial hyperpolarization may subsequently conduct to the media via myoendothelial gap junctions or potentially lead to the release of a chemically distinct factor(s). Furthermore, in human isolated coronary arterioles dilator signaling involving EETs and H(2)O(2) may be integrated, being either complimentary or inhibitory depending on the stimulus. With an emphasis on the human coronary microcirculation, this review addresses the diverse and integrated mechanisms by which EETs and H(2)O(2) regulate vessel tone and also examines the hypothesis that myoendothelial microdomain signaling facilitates EDH activity in the human heart.
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Affiliation(s)
| | - Shaun L Sandow
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Nilima Shukla
- Bristol Heart Institute, University of Bristol, Bristol, UK
| | - Yanping Liu
- Division of Research Infrastructure, National Center for Research Resources, National Institutes of Health, Bethesda, Maryland, USA
| | - Jamie Y Jeremy
- Bristol Heart Institute, University of Bristol, Bristol, UK
| | - David D Gutterman
- Division of Cardiovascular Medicine, Departments of Medicine, Physiology and Pharmacology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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28
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Sorop O, van den Heuvel M, van Ditzhuijzen NS, de Beer VJ, Heinonen I, van Duin RWB, Zhou Z, Koopmans SJ, Merkus D, van der Giessen WJ, Danser AHJ, Duncker DJ. Coronary microvascular dysfunction after long-term diabetes and hypercholesterolemia. Am J Physiol Heart Circ Physiol 2016; 311:H1339-H1351. [PMID: 27591223 DOI: 10.1152/ajpheart.00458.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/01/2016] [Indexed: 02/07/2023]
Abstract
Coronary microvascular dysfunction (CMD) has been proposed as an important component of diabetes mellitus (DM)- and hypercholesterolemia-associated coronary artery disease (CAD). Previously we observed that 2.5 mo of DM and high-fat diet (HFD) in swine blunted bradykinin (BK)-induced vasodilation and attenuated endothelin (ET)-1-mediated vasoconstriction. Here we studied the progression of CMD after 15 mo in the same animal model of CAD. Ten male swine were fed a HFD in the absence (HFD, n = 5) or presence of streptozotocin-induced DM (DM + HFD, n = 5). Responses of small (∼300-μm-diameter) coronary arteries to BK, ET-1, and the nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine were examined in vitro and compared with those of healthy (Normal) swine (n = 12). Blood glucose was elevated in DM + HFD (17.6 ± 4.5 mmol/l) compared with HFD (5.1 ± 0.4 mmol/l) and Normal (5.8 ± 0.6 mmol/l) swine, while cholesterol was markedly elevated in DM + HFD (16.8 ± 1.7 mmol/l) and HFD (18.1 ± 2.6 mmol/l) compared with Normal (2.1 ± 0.2 mmol/l) swine (all P < 0.05). Small coronary arteries showed early atherosclerotic plaques in HFD and DM + HFD swine. Surprisingly, DM + HFD and HFD swine maintained BK responsiveness compared with Normal swine due to an increase in NO availability relative to endothelium-derived hyperpolarizing factors. However, ET-1 responsiveness was greater in HFD and DM + HFD than Normal swine (both P < 0.05), resulting mainly from ETB receptor-mediated vasoconstriction. Moreover, the calculated vascular stiffness coefficient was higher in DM + HFD and HFD than Normal swine (both P < 0.05). In conclusion, 15 mo of DM + HFD, as well as HFD alone, resulted in CMD. Although the overall vasodilation to BK was unperturbed, the relative contributions of NO and endothelium-derived hyperpolarizing factor pathways were altered. Moreover, the vasoconstrictor response to ET-1 was enhanced, involving the ETB receptors. In conjunction with our previous study, these findings highlight the time dependence of the phenotype of CMD.
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Affiliation(s)
- Oana Sorop
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands; and
| | - Mieke van den Heuvel
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands.,Department of Internal Medicine, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nienke S van Ditzhuijzen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Vincent J de Beer
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ilkka Heinonen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Richard W B van Duin
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Zhichao Zhou
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Sietse J Koopmans
- Livestock Research, Wageningen University and Research Center, Wageningen, The Netherlands
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Wim J van der Giessen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands; and
| | - A H Jan Danser
- Department of Internal Medicine, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Dirk Jan Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands;
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29
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Chen X, Zhang H, Hill MA, Zhang C, Park Y. Regulation of Coronary Endothelial Function by Interactions between TNF-α, LOX-1 and Adiponectin in Apolipoprotein E Knockout Mice. J Vasc Res 2016; 52:372-82. [PMID: 27050429 PMCID: PMC5091078 DOI: 10.1159/000443887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 01/10/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND/AIMS Although individual contributions of TNF-α, LOX-1 and adiponectin to the regulation of endothelial function were previously studied, their interactions in the regulation of coronary endothelial function remain unclear. The aim of this study is to investigate the interactions between TNF-α, LOX-1 and adiponectin in endothelial dysfunction in atherosclerosis. METHODS Vasodilator function was assessed in coronary arterioles isolated from wild-type, apolipoprotein (ApoE) knockout (KO) mice, ApoE KO null for TNF-α (ApoE KOTNF-/TNF-) and ApoE KO mice treated with neutralizing antibodies to either TNF-α and LOX-1, or recombinant adiponectin. Western blot analysis and immunofluorescence staining were used for mechanistic studies. RESULTS Acetylcholine (Ach) dilation was impaired in ApoE KO mice. KO of TNF-α, anti-TNF-α anti-LOX-1 or adiponectin restored impaired ACh vasodilation without affecting endothelium-derived hyperpolarizing factor-mediated vasodilation. Immunofluorescence staining demonstrated colocalization of TNF-α with vascular smooth muscle cells, and adiponectin with endothelial cells. ApoE KO mice showed increased protein expression of LOX-1, NF-x03BA;B, NADPH oxidase subunit NOX4 and nitrotyrosine (N-Tyr) levels in coronary arterioles. Treatment with anti-TNF-α, anti-LOX-1 and adiponectin suppressed protein expression of LOX-1, NOX4, NF-x03BA;B and N-Tyr levels. CONCLUSION Adiponectin, anti-TNF-α and anti-LOX-1 exert vasoprotective effects in atherosclerotic ApoE KO mice.
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MESH Headings
- Adiponectin/metabolism
- Adiponectin/pharmacology
- Animals
- Antibodies, Neutralizing/pharmacology
- Apolipoproteins E/deficiency
- Apolipoproteins E/genetics
- Arterioles/drug effects
- Arterioles/metabolism
- Arterioles/physiopathology
- Coronary Artery Disease/genetics
- Coronary Artery Disease/metabolism
- Coronary Artery Disease/physiopathology
- Coronary Artery Disease/prevention & control
- Coronary Vessels/drug effects
- Coronary Vessels/metabolism
- Coronary Vessels/physiopathology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Genetic Predisposition to Disease
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- NADPH Oxidase 4
- NADPH Oxidases/metabolism
- NF-kappa B/metabolism
- Phenotype
- Scavenger Receptors, Class E/antagonists & inhibitors
- Scavenger Receptors, Class E/metabolism
- Signal Transduction
- Tumor Necrosis Factor-alpha/antagonists & inhibitors
- Tumor Necrosis Factor-alpha/deficiency
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/metabolism
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
- Vasodilation/drug effects
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Xiuping Chen
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211
- Department of Internal Medicine, University of Missouri-Columbia, Columbia, MO 65211
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Hanrui Zhang
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211
- Department of Internal Medicine, University of Missouri-Columbia, Columbia, MO 65211
- Department of Medical Pharmacology & Physiology, University of Missouri-Columbia, Columbia, MO 65211
- Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, 19104
| | - Michael A Hill
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211
- Department of Medical Pharmacology & Physiology, University of Missouri-Columbia, Columbia, MO 65211
| | - Cuihua Zhang
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211
- Department of Internal Medicine, University of Missouri-Columbia, Columbia, MO 65211
- Department of Medical Pharmacology & Physiology, University of Missouri-Columbia, Columbia, MO 65211
- Department of Nutritional Sciences, University of Missouri-Columbia, Columbia, MO 65211
| | - Yoonjung Park
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211
- Department of Internal Medicine, University of Missouri-Columbia, Columbia, MO 65211
- Laboratory of Integrated Physiology, Department of Health & Human Performance, University of Houston, Houston, TX 77204
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30
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Yang L, Mäki-Petäjä K, Cheriyan J, McEniery C, Wilkinson IB. The role of epoxyeicosatrienoic acids in the cardiovascular system. Br J Clin Pharmacol 2015; 80:28-44. [PMID: 25655310 PMCID: PMC4500322 DOI: 10.1111/bcp.12603] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 01/19/2015] [Accepted: 01/23/2015] [Indexed: 12/29/2022] Open
Abstract
There is increasing evidence suggesting that epoxyeicosatrienoic acids (EETs) play an important role in cardioprotective mechanisms. These include regulating vascular tone, modulating inflammatory responses, improving cardiomyocyte function and reducing ischaemic damage, resulting in attenuation of animal models of cardiovascular risk factors. This review discusses the current knowledge on the role of EETs in endothelium-dependent control of vascular tone in the healthy and in subjects with cardiovascular risk factors, and considers the pharmacological potential of targeting this pathway.
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Affiliation(s)
- L Yang
- Experimental Medicine and Immunotherapeutics, Department of Medicine, Box 110, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - K Mäki-Petäjä
- Experimental Medicine and Immunotherapeutics, Department of Medicine, Box 110, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - J Cheriyan
- Experimental Medicine and Immunotherapeutics, Department of Medicine, Box 110, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - C McEniery
- Experimental Medicine and Immunotherapeutics, Department of Medicine, Box 110, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - I B Wilkinson
- Experimental Medicine and Immunotherapeutics, Department of Medicine, Box 110, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
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31
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MOKHTAR SS, RASOOL AHG. Role of endothelium-dependent hyperpolarisation and prostacyclin in diabetes. Malays J Med Sci 2015; 22:8-17. [PMID: 26023290 PMCID: PMC4438087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 11/11/2014] [Indexed: 06/04/2023] Open
Abstract
The endothelium plays a crucial role in maintaining vascular homeostasis by producing several vasodilating factors, including nitric oxide (NO), prostacyclin (PGI2), and endothelium-dependent hyperpolarisation (EDH); however, the balance between endothelial relaxing and contracting factors is disrupted in disease states such as diabetes mellitus and hypertension. Most reported studies of endothelial dysfunction in diabetes focused on the actions of NO; however, there is accumulating evidence demonstrating that in addition to NO, PGI2 and EDH are likely to contribute to the vasodilatation of blood vessels. EDH plays an important role as a regulator of vascular tone and reactivity in resistance and conduit arteries of animal models and humans. PGI2 only plays a minimal role in endothelium-dependent vasodilatation but may serve as an important compensatory mechanism in conditions in which NO and EDH activities are decreased. Further studies are needed to determine the exact roles of EDH and PGI2 in the development of endothelial dysfunction and clinical vasculopathy in humans with type 1 and type 2 diabetes.
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Affiliation(s)
- Siti Safiah MOKHTAR
- Pharmacology Vascular Laboratory, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Malaysia
| | - Aida Hanum Ghulam RASOOL
- Pharmacology Vascular Laboratory, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Malaysia
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32
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Bagi Z, Broskova Z, Feher A. Obesity and coronary microvascular disease - implications for adipose tissue-mediated remote inflammatory response. Curr Vasc Pharmacol 2015; 12:453-61. [PMID: 24846234 DOI: 10.2174/1570161112666140423221843] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 06/05/2013] [Accepted: 06/06/2013] [Indexed: 12/26/2022]
Abstract
It is believed that obesity has detrimental effects on the coronary circulation. These include immediate changes in coronary arterial vasomotor responsiveness and the development of occlusive large coronary artery disease. Despite its critical role in regulating myocardial perfusion, the altered behavior of coronary resistance arteries, which gives rise to coronary microvascular disease (CMD) is poorly understood in obesity. A chronic, low-grade vascular inflammation has been long considered as one of the main underlying pathology behind CMD. The expanded adipose tissue and the infiltrating macrophages are the major sources of pro-inflammatory mediators that have been implicated in causing inadequate myocardial perfusion and, in a long term, development of heart failure in obese patients. Much less is known the mechanisms regulating the release of these cytokines into the circulation that enable them to exert their remote effects in the coronary microcirculation. This mini review aims to examine recent studies describing alterations in the vasomotor function of coronary resistance arteries and the role of adipose tissue-derived pro-inflammatory cytokines and adipokines in contributing to CMD in obesity. We provide examples of regulatory mechanisms by which adipokines are released from adipose tissue to exert their remote inflammatory effects on coronary microvessels. We identify some of the important challenges and opportunities going forward.
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Affiliation(s)
| | | | - Attila Feher
- Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA.
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33
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Schach C, Resch M, Schmid PM, Riegger GA, Endemann DH. Type 2 diabetes: increased expression and contribution of IKCa channels to vasodilation in small mesenteric arteries of ZDF rats. Am J Physiol Heart Circ Physiol 2014; 307:H1093-102. [DOI: 10.1152/ajpheart.00240.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Impaired endothelial function, which is dysregulated in diabetes, also precedes hypertension. We hypothesized that in Type 2 diabetes, the impaired endothelium-dependent relaxation is due to a loss of endothelium-derived hyperpolarization (EDH) that is regulated by impaired ion channel function. Zucker diabetic fatty (ZDF), Zucker heterozygote, and homozygote lean control rats were used as the experimental models in our study. Third-order mesenteric arteries were dissected and mounted on a pressure myograph; mRNA was quantified by RT-PCR and channel proteins by Western blotting. Under nitric oxide (NO) synthase and cyclooxygenase inhibition, endothelial stimulation with ACh fully relaxes control but not diabetic arteries. In contrast, when small-conductance calcium-activated potassium (KCa) channels and intermediate- and large-conductance KCa (I/BKCa) are inhibited with apamin and charybdotoxin, NO is able to compensate for ACh-induced relaxation in control but not in diabetic vessels. After replacement of charybdotoxin with 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34; IKCa inhibitor), ACh-induced relaxation in diabetic animals is attenuated. Specific inhibition with TRAM-34 or charybdotoxin attenuates ACh relaxation in diabetes. Stimulation with 1-ethyl-2-benzimidazolinone (IKCa activator) shows a reduced relaxation in diabetes. Activation of BKCa with 1,3-dihydro-1-[2-hydroxy-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-2H-benzimidazol-2-one NS619 leads to similar relaxations of control and diabetic arteries. RT-PCR and Western blot analysis demonstrate elevated mRNA and protein expression levels of IKCa in diabetes. Our results suggest that the compensatory effect of NO and EDH-associated, endothelium-dependent relaxation is reduced in ZDF rats. Specific blockade of IKCa with TRAM-34 reduces NO and EDH-type relaxation in diabetic rats, indicating an elevated contribution of IKCa in diabetic small mesenteric artery relaxation. This finding correlates with increased IKCa mRNA and protein expression in this vessel.
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Affiliation(s)
- Christian Schach
- Department of Cardiology, University Hospital Regensburg, Regensburg, Germany
| | - Markus Resch
- Department of Cardiology, University Hospital Regensburg, Regensburg, Germany
| | - Peter M. Schmid
- Department of Cardiology, University Hospital Regensburg, Regensburg, Germany
| | - Guenter A. Riegger
- Department of Cardiology, University Hospital Regensburg, Regensburg, Germany
| | - Dierk H. Endemann
- Department of Cardiology, University Hospital Regensburg, Regensburg, Germany
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34
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Wang F, Guo X, Shen X, Kream RM, Mantione KJ, Stefano GB. Vascular dysfunction associated with type 2 diabetes and Alzheimer's disease: a potential etiological linkage. Med Sci Monit Basic Res 2014; 20:118-29. [PMID: 25082505 PMCID: PMC4138067 DOI: 10.12659/msmbr.891278] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The endothelium performs a crucial role in maintaining vascular integrity leading to whole organ metabolic homeostasis. Endothelial dysfunction represents a key etiological factor leading to moderate to severe vasculopathies observed in both Type 2 diabetic and Alzheimer’s Disease (AD) patients. Accordingly, evidence-based epidemiological factors support a compelling hypothesis stating that metabolic rundown encountered in Type 2 diabetes engenders severe cerebral vascular insufficiencies that are causally linked to long term neural degenerative processes in AD. Of mechanistic importance, Type 2 diabetes engenders an immunologically mediated chronic pro-inflammatory state involving interactive deleterious effects of leukocyte-derived cytokines and endothelial-derived chemotactic agents leading to vascular and whole organ dysfunction. The long term negative consequences of vascular pro-inflammatory processes on the integrity of CNS basal forebrain neuronal populations mediating complex cognitive functions establish a striking temporal comorbidity of AD with Type 2 diabetes. Extensive biomedical evidence supports the pivotal multi-functional role of constitutive nitric oxide (NO) production and release as a critical vasodilatory, anti-inflammatory, and anti-oxidant, mechanism within the vascular endothelium. Within this context, we currently review the functional contributions of dysregulated endothelial NO expression to the etiology and persistence of Type 2 diabetes-related and co morbid AD-related vasculopathies. Additionally, we provide up-to-date perspectives on critical areas of AD research with special reference to common NO-related etiological factors linking Type 2 diabetes to the pathogenesis of AD.
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Affiliation(s)
- Fuzhou Wang
- Department of Anesthesiology and Critical Care Medicine, Nanjing Maternit and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - Xirong Guo
- Institutes of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - Xiaofeng Shen
- Department of Anesthesiology and Critical Care Medicine, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - Richard M Kream
- Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, USA
| | - Kirk J Mantione
- Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, USA
| | - George B Stefano
- Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, USA
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35
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Yada T. [Coronary microcirculation and hydrogen peroxide as an endothelium-derived hyperpolarizing factor]. Nihon Yakurigaku Zasshi 2014; 143:222-225. [PMID: 24813791 DOI: 10.1254/fpj.143.222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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36
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Ellinsworth DC, Shukla N, Fleming I, Jeremy JY. Interactions between thromboxane A₂, thromboxane/prostaglandin (TP) receptors, and endothelium-derived hyperpolarization. Cardiovasc Res 2014; 102:9-16. [PMID: 24469536 DOI: 10.1093/cvr/cvu015] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Endothelium-dependent smooth muscle hyperpolarization (EDH) increasingly predominates over endothelium-derived nitric oxide (NO) as a participant in vasodilation as vessel size decreases. Its underlying nature is highly variable between vessel types, species, disease states, and exact experimental conditions, and is variably mediated by one or more transferable endothelium-derived hyperpolarizing factors and/or the electrotonic spread of endothelial hyperpolarization into the media via gap junctions. Although generally regarded (and studied) as a mechanism that is independent of NO and prostanoids, evidence has emerged that the endothelium-derived contracting factor and prostanoid thromboxane A2 can modulate several signalling components central to EDH, and therefore potentially curtail vasodilation through mechanisms that are distinct from those putatively involved in direct smooth muscle contraction. Notably, vascular production of thromboxane A2 is elevated in a number of cardiovascular disease states that promote endothelial dysfunction. This review will therefore discuss the mechanisms through which thromboxane A2 interacts with and modulates EDH, and will also consider the implications of such cross-talk in vasodilator control in health and disease.
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Affiliation(s)
- David C Ellinsworth
- Bristol Heart Institute, University of Bristol, Queens Building Level 7, Upper Maudlin St, Bristol Royal Infirmary, Upper Maudlin Street, Bristol BS2 8HW, UK
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37
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Deer RR, Heaps CL. Exercise training enhances multiple mechanisms of relaxation in coronary arteries from ischemic hearts. Am J Physiol Heart Circ Physiol 2013; 305:H1321-31. [PMID: 23997097 DOI: 10.1152/ajpheart.00531.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Exercise training of coronary artery disease patients is of considerable interest, since it has been shown to improve vascular function and, thereby, enhance blood flow into compromised myocardial regions. However, the mechanisms underlying exercise-induced improvements in vascular function have not been fully elucidated. We tested the hypothesis that exercise training increases the contribution of multiple mediators to endothelium-dependent relaxation of coronary arteries in the underlying setting of chronic coronary artery occlusion. To induce gradual occlusion, an ameroid constrictor was placed around the proximal left circumflex coronary artery in Yucatan miniature swine. At 8 wk postoperatively, pigs were randomly assigned to sedentary or exercise (treadmill, 5 days/wk) regimens for 14 wk. Exercise training significantly enhanced the contribution of nitric oxide, prostanoids, and large-conductance Ca(2+)-dependent K(+) (BKCa) channels to endothelium-dependent, bradykinin-mediated relaxation in nonoccluded and collateral-dependent arteries. Combined nitric oxide synthase, prostanoid, and BKCa channel inhibition ablated the enhanced relaxation associated with exercise training. Exercise training significantly increased nitric oxide levels in response to bradykinin in endothelial cells isolated from nonoccluded and collateral-dependent arteries. Bradykinin treatment significantly increased PGI2 levels in all artery treatment groups and tended to be further enhanced after nitric oxide synthase inhibition in exercise-trained pigs. No differences were found in whole cell BKCa channel currents, BKCa channel protein levels, or arterial cyclic nucleotide levels. Although redundant, upregulation of parallel vasodilator pathways appears to contribute to enhanced endothelium-dependent relaxation, potentially providing a more refined control of blood flow after exercise training.
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Affiliation(s)
- Rachel R Deer
- Michael E. DeBakey Institute for Comparative Cardiovascular Science and Biomedical Devices, College of Veterinary Medicine and Biomedical Sciences, Texas A & M University, College Station, Texas; and
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Cho YE, Basu A, Dai A, Heldak M, Makino A. Coronary endothelial dysfunction and mitochondrial reactive oxygen species in type 2 diabetic mice. Am J Physiol Cell Physiol 2013; 305:C1033-40. [PMID: 23986204 DOI: 10.1152/ajpcell.00234.2013] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Endothelial cell (EC) dysfunction is implicated in cardiovascular diseases, including diabetes. The decrease in nitric oxide (NO) bioavailability is the hallmark of endothelial dysfunction, and it leads to attenuated vascular relaxation and atherosclerosis followed by a decrease in blood flow. In the heart, decreased coronary blood flow is responsible for insufficient oxygen supply to cardiomyocytes and, subsequently, increases the incidence of cardiac ischemia. In this study we investigate whether and how reactive oxygen species (ROS) in mitochondria contribute to coronary endothelial dysfunction in type 2 diabetic (T2D) mice. T2D was induced in mice by a high-fat diet combined with a single injection of low-dose streptozotocin. ACh-induced vascular relaxation was significantly attenuated in coronary arteries (CAs) from T2D mice compared with controls. The pharmacological approach reveals that NO-dependent, but not hyperpolarization- or prostacyclin-dependent, relaxation was decreased in CAs from T2D mice. Attenuated ACh-induced relaxation in CAs from T2D mice was restored toward control level by treatment with mitoTempol (a mitochondria-specific O2(-) scavenger). Coronary ECs isolated from T2D mice exhibited a significant increase in mitochondrial ROS concentration and decrease in SOD2 protein expression compared with coronary ECs isolated from control mice. Furthermore, protein ubiquitination of SOD2 was significantly increased in coronary ECs isolated from T2D mice. These results suggest that augmented SOD2 ubiquitination leads to the increase in mitochondrial ROS concentration in coronary ECs from T2D mice and attenuates coronary vascular relaxation in T2D mice.
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Affiliation(s)
- Young-Eun Cho
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
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Lee JO, Auger C, Park DH, Kang M, Oak MH, Kim KR, Schini-Kerth VB. An ethanolic extract of Lindera obtusiloba stems, YJP-14, improves endothelial dysfunction, metabolic parameters and physical performance in diabetic db/db mice. PLoS One 2013; 8:e65227. [PMID: 23755196 PMCID: PMC3670856 DOI: 10.1371/journal.pone.0065227] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 04/24/2013] [Indexed: 01/08/2023] Open
Abstract
Lindera obtusiloba is a medicinal herb traditionally used in Asia for improvement of blood circulation, treatment of inflammation, and prevention of liver damage. A previous study has shown that an ethanolic extract of Lindera obtusiloba stems (LOE) has vasoprotective and antihypertensive effects. The possibility that Lindera obtusiloba improves endothelial function and metabolic parameters in type 2 diabetes mellitus (T2DM) remains to be examined. Therefore, the aim of the present study was to determine the potential of LOE to prevent the development of an endothelial dysfunction, and improve metabolic parameters including hyperglycemia, albuminuria and physical exercise capacity in db/db mice, an experimental model of T2DM. The effect of LOE (100 mg/kg/day by gavage for 8 weeks) on these parameters was compared to that of an oral antidiabetic drug, pioglitazone (30 mg/kg/day by gavage). Reduced blood glucose level, body weight and albumin-creatinine ratio were observed in the group receiving LOE compared to the control db/db group. The LOE treatment improved endothelium-dependent relaxations, abolished endothelium-dependent contractions to acetylcholine in the aorta, and normalized the increased vascular oxidative stress and expression of NADPH oxidase, cyclooxygenases, angiotensin II, angiotensin type 1 receptors and peroxynitrite and the decreased expression of endothelial NO synthase in db/db mice. The angiotensin-converting enzyme (ACE) activity was reduced in the LOE group compared to that in the control db/db group. LOE also inhibited the activity of purified ACE, COX-1 and COX-2 in a dose-dependent manner. In addition, LOE improved physical exercise capacity. Thus, the present findings indicate that LOE has a beneficial effect on the vascular system in db/db mice by improving endothelium-dependent relaxations and vascular oxidative stress most likely by normalizing the angiotensin system, and also on metabolic parameters, and these effects are associated with an enhanced physical exercise capacity.
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MESH Headings
- Albuminuria/prevention & control
- Angiotensin II/genetics
- Angiotensin II/metabolism
- Animals
- Aorta/drug effects
- Aorta/physiopathology
- Blood Glucose/metabolism
- Body Weight/drug effects
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Disease Models, Animal
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Ethanol/chemistry
- Exercise Tolerance/drug effects
- Gene Expression/drug effects
- Humans
- Hyperglycemia/prevention & control
- Hypoglycemic Agents/pharmacology
- Lindera/chemistry
- Male
- Mice
- Mice, Transgenic
- NADPH Oxidases/genetics
- NADPH Oxidases/metabolism
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- Pioglitazone
- Plant Extracts/pharmacology
- Prostaglandin-Endoperoxide Synthases/genetics
- Prostaglandin-Endoperoxide Synthases/metabolism
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Thiazolidinediones/pharmacology
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Affiliation(s)
- Jung-Ok Lee
- UMR CNRS 7213, Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
- Research and Development Center, Hanwha Pharma. Co., Ltd., Chuncheon, Republic of Korea
| | - Cyril Auger
- UMR CNRS 7213, Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Dong Hyun Park
- Research Center, YangJi Chemicals, Suwon, Republic of Korea
| | - Moonkyu Kang
- Research and Development Center, Hanwha Pharma. Co., Ltd., Chuncheon, Republic of Korea
| | - Min-Ho Oak
- College of Pharmacy, Mokpo National University, Muan, Jeonam, Republic of Korea
| | - Kyoung Rak Kim
- Research and Development Center, Hanwha Pharma. Co., Ltd., Chuncheon, Republic of Korea
| | - Valérie B. Schini-Kerth
- UMR CNRS 7213, Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
- * E-mail:
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Liang CF, Liu JT, Wang Y, Xu A, Vanhoutte PM. Toll-like receptor 4 mutation protects obese mice against endothelial dysfunction by decreasing NADPH oxidase isoforms 1 and 4. Arterioscler Thromb Vasc Biol 2013; 33:777-84. [PMID: 23413427 DOI: 10.1161/atvbaha.112.301087] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To analyze the role of toll-like receptor 4 in modulating metabolism and endothelial function. APPROACH AND RESULTS Type 2 diabetic mice with mutated toll-like receptor 4 (DWM) were protected from hyperglycemia and hypertension, despite an increased body weight. Isometric tension was measured in arterial rings with endothelium. Relaxations to acetylcholine were blunted in aortae and mesenteric arteries of Lepr(db/db) mice, but not in DWM mice; the endothelial NO synthase dimer/monomer ratio and endothelial NO synthase phosphorylation levels were higher in DWM preparations. These differences were abolished by apocynin. Contractions to acetylcholine (in the presence of L-NAME) were larger in carotid arteries from Lepr(db/db) mice than from DWM mice and were inhibited by indomethacin and SC560, demonstrating involvement of cyclooxygenase-1. The release of 6-ketoprostaglandin F1α was lower in DWM mice arteries, implying lower cyclooxygenase-1 activity. Apocynin, manganese(III) tetrakis(1-methyl-4-pyridyl) porphyrin, catalase, and diethyldithiocarbamate inhibited endothelium-dependent contractions. The mRNA and protein levels of NADPH oxidase isoforms NOX1 and NOX4 were downregulated in DWM mice arteries. The in vivo and in vitro administration of lipopolysaccharide caused endothelial dysfunction in the arteries of wild-type, but not toll-like receptor 4-mutated mice. CONCLUSIONS Toll-like receptor 4 plays a key role in obesity and diabetes-associated endothelial dysfunction by increasing oxidative stress.
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Affiliation(s)
- Chao-Fan Liang
- Department of Pharmacology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
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Hwang SM, Kim JS, Lee YJ, Yoon JJ, Lee SM, Kang DG, Lee HS. Anti-Diabetic Atherosclerosis Effect of Prunella vulgaris in db/db Mice with Type 2 Diabetes. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2012; 40:937-51. [DOI: 10.1142/s0192415x12500693] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Diabetes mellitus is the leading cause of vascular complications such as atherosclerosis. This study was designed to investigate whether Prunella vulgaris (APV) would inhibit diabetic atherosclerosis in db/db mice with type 2 diabetes. The db/db mice were treated with high fat/high cholesterol (HFHC) diet and an aqueous extract of APV (100 and 200 mg/kg/day) for eight weeks to examine the long-term effect on metabolic abnormalities and diabetic atherosclerosis. APV treatment markedly lowered blood glucose and systolic blood pressure. The db/db mice experienced an increase in blood urea nitrogen as well as a decrease of creatinine clearance, the latter of which was restored by treatment with APV. Treatment with APV markedly decreased total plasma cholesterol, triglyceride, and LDL-cholesterol and also increased the HDL-cholesterol. In addition, malondialdehyde and TGF-β1 were decreased by treatment of APV. On the other hand, total NO level was decreased in db/db mice. However, the NO level was increased by treatment with APV, suggesting an association with vascular dysfunction. Vascular relaxation of aortic rings by acetylcholine or SNP-inducement was ameliorated by APV in a dose-dependent manner. Damage of vascular intima and hypertrophic of media were observed in db/db mice; however its dysfunction was improved by the treatment of APV. APV treatment significantly reduced the aortic expressions of ICAM-1, VCAM-1, ET-1, and nitrotyrosine. Furthermore, expression of eNOS in aortic was remarkably increased by APV treatment. Taken together, APV suppressed hyperglycemia and diabetic vascular dysfunction in HFHC diet-db/db mice. The present data suggest that Prunella vulgaris may prevent development of diabetic atherosclerosis.
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Affiliation(s)
- Sun Mi Hwang
- College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Republic of Korea
- Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Daejeon 305-340, Republic of Korea
| | - Jin Sook Kim
- Korea Institute of Oriental Medicine, Daejeon 305-811, Republic of Korea
| | - Yun Jung Lee
- College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Republic of Korea
- Hanbang Body-Fluid Research Center, Wonkwang University, Jeonbuk 570-749, Republic of Korea
| | - Jung Joo Yoon
- College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Republic of Korea
- Hanbang Body-Fluid Research Center, Wonkwang University, Jeonbuk 570-749, Republic of Korea
| | - So Min Lee
- College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Republic of Korea
- Hanbang Body-Fluid Research Center, Wonkwang University, Jeonbuk 570-749, Republic of Korea
| | - Dae Gill Kang
- College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Republic of Korea
- Hanbang Body-Fluid Research Center, Wonkwang University, Jeonbuk 570-749, Republic of Korea
| | - Ho Sub Lee
- College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Republic of Korea
- Hanbang Body-Fluid Research Center, Wonkwang University, Jeonbuk 570-749, Republic of Korea
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Park Y, Booth FW, Lee S, Laye MJ, Zhang C. Physical activity opposes coronary vascular dysfunction induced during high fat feeding in mice. J Physiol 2012; 590:4255-68. [PMID: 22674721 DOI: 10.1113/jphysiol.2012.234856] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The study's purpose was to investigate if physical activity initiated with the start of high-fat feeding would oppose development of endothelial dysfunction, and if it does, then to determine some potential mechanisms. C57BL/6 female mice were randomly divided into three groups: (1) control low-fat diet (LF-SED; 15% of calories from fat), (2) high-fat diet (HF-SED; 45% of calories from fat), and (3) HF diet given access to a voluntary running wheel (HF-RUN). Our hypothesis was that HF-RUN would differ in multiple markers of endothelial dysfunction from HF-SED after 10 weeks of 45%-fat diet, but would not differ from LF-SED. HF-RUN differed from HF-SED in nine determinations in which HF-SED either had decreases in (1) acetylcholine (ACh)-induced and flow-induced vasodilatations in isolated, pressurized coronary arterioles, (2) heart phosphorylated endothelial nitric oxide synthase (p-eNOS/eNOS) protein, (3) coronary arteriole leptin (ob) receptor protein, (4) phosphorylated signal transducer and activator of transcription 3 (p-STAT3/STAT3) protein, and (5) coronary arteriole superoxide dismutase 1 protein; or had increases in (6) percentage body fat, (7) serum leptin, (8) coronary arteriole suppressor of cytokine signalling 3 (SOCS3) protein, and (9) coronary arteriole gp91(phox) protein. Higher endothelium-dependent vasodilatation by ACh or leptin was abolished with incubation of NOS inhibitor N(G)-nitro-l-arginine-methyl ester (l-NAME) in LF-SED and HF-RUN groups. Further, impaired ACh-induced vasodilatation in HF-SED was normalized by apocynin or TEMPOL to LF-SED and HF-RUN. These findings demonstrate multiple mechanisms (eNOS, leptin and redox balance) by which voluntary running opposes the development of impaired coronary arteriolar vasodilatation during simultaneous high-fat feeding.
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Affiliation(s)
- Yoonjung Park
- Internal Medicine, University of Missouri, Columbia, MO 65211, USA.
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Kerr PM, Tam R, Narang D, Potts K, McMillan D, McMillan K, Plane F. Endothelial calcium-activated potassium channels as therapeutic targets to enhance availability of nitric oxide. Can J Physiol Pharmacol 2012; 90:739-52. [PMID: 22626011 DOI: 10.1139/y2012-075] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The vascular endothelium plays a critical role in vascular health by controlling arterial diameter, regulating local cell growth, and protecting blood vessels from the deleterious consequences of platelet aggregation and activation of inflammatory responses. Circulating chemical mediators and physical forces act directly on the endothelium to release diffusible relaxing factors, such as nitric oxide (NO), and to elicit hyperpolarization of the endothelial cell membrane potential, which can spread to the surrounding smooth muscle cells via gap junctions. Endothelial hyperpolarization, mediated by activation of calcium-activated potassium (K(Ca)) channels, has generally been regarded as a distinct pathway for smooth muscle relaxation. However, recent evidence supports a role for endothelial K(Ca) channels in production of endothelium-derived NO, and indicates that pharmacological activation of these channels can enhance NO-mediated responses. In this review we summarize the current data on the functional role of endothelial K(Ca) channels in regulating NO-mediated changes in arterial diameter and NO production, and explore the tempting possibility that these channels may represent a novel avenue for therapeutic intervention in conditions associated with reduced NO availability such as hypertension, hypercholesterolemia, smoking, and diabetes mellitus.
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Affiliation(s)
- Paul M Kerr
- Department of Pharmacology, 9-62 Medical Sciences Building, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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Triggle CR, Samuel SM, Ravishankar S, Marei I, Arunachalam G, Ding H. The endothelium: influencing vascular smooth muscle in many ways. Can J Physiol Pharmacol 2012; 90:713-38. [PMID: 22625870 DOI: 10.1139/y2012-073] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The endothelium, although only a single layer of cells lining the vascular and lymphatic systems, contributes in multiple ways to vascular homeostasis. Subsequent to the 1980 report by Robert Furchgott and John Zawadzki, there has been a phenomenal increase in our knowledge concerning the signalling molecules and pathways that regulate endothelial - vascular smooth muscle communication. It is now recognised that the endothelium is not only an important source of nitric oxide (NO), but also numerous other signalling molecules, including the putative endothelium-derived hyperpolarizing factor (EDHF), prostacyclin (PGI(2)), and hydrogen peroxide (H(2)O(2)), which have both vasodilator and vasoconstrictor properties. In addition, the endothelium, either via transferred chemical mediators, such as NO and PGI(2), and (or) low-resistance electrical coupling through myoendothelial gap junctions, modulates flow-mediated vasodilatation as well as influencing mitogenic activity, platelet aggregation, and neutrophil adhesion. Disruption of endothelial function is an early indicator of the development of vascular disease, and thus an important area for further research and identification of potentially new therapeutic targets. This review focuses on the signalling pathways that regulate endothelial - vascular smooth muscle communication and the mechanisms that initiate endothelial dysfunction, particularly with respect to diabetic vascular disease.
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Affiliation(s)
- Chris R Triggle
- Department of Pharmacology, Weill Cornell Medical College in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
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Kagota S, Chia E, McGuire JJ. Preserved arterial vasodilatation via endothelial protease-activated receptor-2 in obese type 2 diabetic mice. Br J Pharmacol 2012; 164:358-71. [PMID: 21426317 PMCID: PMC3174416 DOI: 10.1111/j.1476-5381.2011.01356.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE In non-obese diabetic animals, protease-activated receptor-2 (PAR2) agonists are more effective vasodilators, which is attributed to increased COX-2 and endothelial NOS (eNOS) activities. Under conditions of diabetes and obesity, the effectiveness of PAR2 agonists is unknown. We compared the vasodilator responses of small calibre mesenteric arteries from obese diabetic B6.BKS(D)-Leprdb/J (db/db) induced by PAR2-activating agonists 2-furoyl-LIGRLO-amide (2fly) and trypsin to those obtained in controls [C57BL/6J (C57)], and assessed the contributions of COX, NOS and calcium-activated potassium channels (KCa) to these responses. EXPERIMENTAL APPROACH Arteries mounted in wire myographs under isometric tension conditions were contracted submaximally by U46619 then exposed to vasodilators. mRNA and protein expression of PAR2, eNOS and soluble GC (sGC) were determined by real-time PCR and Western blots. KEY RESULTS ACh- and nitroprusside-induced relaxations were attenuated in db/db compared with C57. In contrast, 2fly- and trypsin-induced relaxations were largely retained in db/db. A NOS inhibitor partly inhibited ACh- and 2fly-induced relaxations in C57, but not those in db/db. Inhibitors of the COX-cAMP pathway (FR122044, SC560, NS398, SC58125, SQ22536, CAY10441) did not affect these relaxation responses in either strain. Charybdotoxin (BKCa, SK3.1 blocker), but not iberiotoxin (BKCa blocker), inhibited responses to the PAR2 agonists in db/db. In db/db protein levels of eNOS were higher, whereas those of sGC were lower than in C57. PAR2 mRNA expression in db/db was higher than in C57. CONCLUSIONS AND IMPLICATIONS PAR2-mediated vasodilatation is protected against the negative effects of obesity and diabetes in mice. In diabetic vascular dysfunction, preserved PAR2 vasodilatation was linked to activation of SK3.1.
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Affiliation(s)
- Satomi Kagota
- Cardiovascular Research Group, Division of BioMedical Sciences, Memorial University, St. John's, Newfoundland and Labrador, Canada.
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Selvaraju V, Joshi M, Suresh S, Sanchez JA, Maulik N, Maulik G. Diabetes, oxidative stress, molecular mechanism, and cardiovascular disease--an overview. Toxicol Mech Methods 2012; 22:330-5. [PMID: 22394340 DOI: 10.3109/15376516.2012.666648] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In recent years, diabetes and its associated complications have come to represent a major public health concern. It is a complex disease characterized by multiple metabolic derangements and is known to impair cardiac function by disrupting the balance between pro-oxidants and antioxidants at the cellular level. The subsequent generation of reactive oxygen species (ROS) and accompanying oxidative stress are hallmarks of the molecular mechanisms responsible for cardiovascular disease. Among several oxidative stress-mediated mechanisms that have been proposed, ROS-mediated oxidative stress has received the most attention. ROS have been shown to interact with proteins, lipids, and DNA, causing damage to the cellular macromolecules and subsequently, deterioration of cellular function. Induction of thioredoxin-1 (Trx1) gene expression has been demonstrated to protect the diabetic myocardium from dysfunction by reducing oxidative stress and enhancing the expression of heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF). The failure of antioxidants to consistently demonstrate clinical benefit necessitates further investigation of the role of oxidative stress in diabetes-mediated cardiovascular disease.
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Affiliation(s)
- Vaithinathan Selvaraju
- Molecular Cardiology and Angiogenesis Laboratory, Department of Surgery, University of Connecticut Health Center, Farmington Avenue, Farmington, Connecticut, USA
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Elmarakby AA. Reno-protective mechanisms of epoxyeicosatrienoic acids in cardiovascular disease. Am J Physiol Regul Integr Comp Physiol 2012; 302:R321-30. [DOI: 10.1152/ajpregu.00606.2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiovascular disease (CVD) is the leading cause of mortality worldwide, and it is well known that end-stage renal disease (ESRD) is a profound consequence of the progression of CVD. Present treatments only slow CVD progression to ESRD, and it is imperative that new therapeutic strategies are developed to prevent the incidence of ESRD. Because epoxyeicosatrienoic acids (EETs) have been shown to elicit reno-protective effects in hypertensive animal models, the current review will focus on addressing the reno-protective mechanisms of EETs in CVD. The cytochrome P-450 epoxygenase catalyzes the oxidation of arachidonic acid to EETs. EETs have been identified as endothelium-derived hyperpolarizing factors (EDHFs) with vasodilatory, anti-inflammatory, antihypertensive, and antiplatelet aggregation properties. EETs also have profound effects on vascular migration and proliferation and promote angiogenesis. The progression of CVD has been linked to decreased EETs levels, leading to the concept that EETs should be therapeutically targeted to prevent end-organ damage associated with CVD. However, EETs are quickly degraded by the enzyme soluble epoxide hydrolase (sEH) to their less active diols, dihydroxyeicosatrienoic acids (DHETs). As such, one way to increase EETs level is to inhibit their degradation to DHETs by using sEH inhibitors. Inhibition of sEH has been shown to effectively reduce blood pressure and organ damage in experimental models of CVD. Another approach to target EETs is to develop EET analogs with improved solubility and resistance to auto-oxidation and metabolism by sEH. For example, stable ether EET analogs dilate afferent arterioles and lower blood pressure in hypertensive rodent animal models. EET agonists also improve insulin signaling and vascular function in animal models of metabolic syndrome.
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Affiliation(s)
- Ahmed A. Elmarakby
- Department of Oral Biology, Division of Pharmacology, Georgia Health Sciences University, Augusta, Georgia
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Huang A, Yang YM, Feher A, Bagi Z, Kaley G, Sun D. Exacerbation of endothelial dysfunction during the progression of diabetes: role of oxidative stress. Am J Physiol Regul Integr Comp Physiol 2012; 302:R674-81. [PMID: 22262308 DOI: 10.1152/ajpregu.00699.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
To test the deterioration of endothelial function during the progression of diabetes, shear stress-induced dilation (SSID; 10, 20, and 40 dyn/cm(2)) was determined in isolated mesenteric arteries (80-120 μm in diameter) of 6-wk (6W), 3-mo (3M), and 9-mo (9M)-old male db/db mice and their wild-type (WT) controls. Nitric oxide (NO)-mediated SSID was comparable in 6W WT and db/db mice, but the dilation was significantly reduced in 3M db/db mice and declined further in 9M db/db mice. Vascular superoxide production was progressively increased in 3M and 9M db/db mice, associated with an increased expression of NADPH oxidase. Inhibition of NADPH oxidase significantly improved NO-mediated SSID in arteries of 3M, but not in 9M, db/db mice. Although endothelial nitric oxide synthase (eNOS) expression was comparable in all groups, a progressive reduction in shear stress-induced eNOS phosphorylation existed in vessels of 3M and 9M db/db mice. Moreover, inducible NOS (iNOS) that was not detected in WT, nor in 6W and 3M db/db mice, was expressed in vessels of 9M db/db mice. A significantly increased expression of nitrotyrosine in total protein and immunoprecipitated eNOS was also found in vessels of 9M db/db mice. Thus, impaired NO bioavailability plays an essential role in the endothelial dysfunction of diabetic mice, which becomes aggravated when endothelial nitrosative stress is further activated via perhaps, an additional iNOS-mediated pathway during the progression of diabetes.
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Affiliation(s)
- An Huang
- Department of Physiology, New York Medical College, Valhalla, New York, USA
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Fluoxetine effect on aortic nitric oxide-dependent vasorelaxation in the unpredictable chronic mild stress model of depression in mice. Psychosom Med 2012; 74:63-72. [PMID: 22210237 DOI: 10.1097/psy.0b013e31823a43e0] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
OBJECTIVE Major depression is an independent risk factor for the development of cardiovascular diseases. However, the exact mechanism by which depression may induce cardiovascular events is unclear. Endothelial dysfunction has been reported as a possible link between depression and subsequent cardiovascular events as described in depressed subjects. The purpose of this study was to investigate endothelial dysfunction and atherosclerosis formation in the aorta of mice exposed to the unpredictable chronic mild stress (UCMS) procedure. METHODS BALB/c mice were exposed to two 7-week UCMS procedures separated by 6 weeks. Treatments (fluoxetine 10 mg/kg; NaCl 0.9%) started at the third week until the end of the seventh week of each procedure. Endothelial function was evaluated by in vitro assessment of acetylcholine-induced vasorelaxation in aortic rings. By using specific inhibitors for nitric oxide (NO)- and prostacyclin-dependent relaxation, we assessed the part played by NO, prostacyclin, and endothelium-derived hyperpolarizing factor (EDHF)-like mediators in endothelium-dependent relaxation. Atherosclerosis was evaluated by histological examination. RESULTS Depression-like behavior was increased in the UCMS versus unstressed group and was reversed by chronic fluoxetine treatment. Vascular reactivity study indicated that UCMS induced a decrease in the NO-dependent relaxation that was partially compensated by an EDHF-like dependent relaxation. Because fluoxetine per se increased the NO-dependent relaxation, fluoxetine was able to reverse UCMS effect on the NO component and abolished the EDHF-like component. Atherosclerotic lesion was found in aorta of UCMS and nonstressed animals. CONCLUSIONS As an independent risk factor, UCMS reproduced the endothelial alterations observed in depression but was not sufficient to provoke morphological alterations.
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Zhang H, Dellsperger KC, Zhang C. The link between metabolic abnormalities and endothelial dysfunction in type 2 diabetes: an update. Basic Res Cardiol 2011; 107:237. [PMID: 22189563 DOI: 10.1007/s00395-011-0237-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 11/30/2011] [Accepted: 12/05/2011] [Indexed: 01/06/2023]
Abstract
Despite abundant clinical evidence linking metabolic abnormalities to diabetic vasculopathy, the molecular basis of individual susceptibility to diabetic vascular complications is still largely undetermined. Endothelial dysfunction in diabetes-associated vascular complications is considered an early stage of vasculopathy and has attracted considerable research interests. Type 2 diabetes is characterized by metabolic abnormalities, such as hyperglycemia, excess liberation of free fatty acids (FFA), insulin resistance and hyperinsulinemia. These abnormalities exert pathological impact on endothelial function by attenuating endothelium-mediated vasomotor function, enhancing endothelial apoptosis, stimulating endothelium activation/endothelium-monocyte adhesion, promoting an atherogenic response and suppressing barrier function. There are multiple signaling pathways contributing to the adverse effects of glucotoxicity on endothelial function. Insulin maintains the normal balance for release of several factors with vasoactive properties. Abnormal insulin signaling in the endothelium does not affect the whole-body glucose metabolism, but impairs endothelial response to insulin and accelerates atherosclerosis. Excessive level of FFA is implicated in the pathogenesis of insulin resistance. FFA induces endothelial oxidative stress, apoptosis and inflammatory response, and inhibits insulin signaling. Although hyperglycemia, insulin resistance, hyperinsulinemia and dyslipidemia independently contribute to endothelial dysfunction via various distinct mechanisms, the mutual interactions may synergistically accelerate their adverse effects. Oxidative stress and inflammation are predicted to be among the first alterations which may trigger other downstream mediators in diabetes associated with endothelial dysfunction. These mechanisms may provide insights into potential therapeutic targets that can delay or reverse diabetic vasculopathy.
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Affiliation(s)
- Hanrui Zhang
- Departments of Internal Medicine, Medical Pharmacology & Physiology and Nutritional Sciences, Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211, USA.
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