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Oh EY, Haam CE, Choi S, Byeon S, Choi SK, Lee YH. Ezetimibe Induces Vasodilation in Rat Mesenteric Resistance Arteries through Inhibition of Extracellular Ca 2+ Influx. Int J Mol Sci 2023; 24:13992. [PMID: 37762296 PMCID: PMC10531054 DOI: 10.3390/ijms241813992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Ezetimibe is a lipid-lowering agent that selectively inhibits cholesterol absorption by binding to the Niemann-Pick C1-like 1 (NPC1L1) protein. Although it is well known that administration of ezetimibe in hypercholesterolemia patients reduces the risk of cardiovascular events through attenuation of atherosclerosis, studies on the direct effect of ezetimibe on vascular function are not sufficient. The aim of the present study was to investigate the vascular effects of ezetimibe in rat mesenteric arteries. In the present study, 12-week-old male Sprague Dawley rats were used. After the rats were sacrificed, the second branches of the mesenteric arteries were isolated and cut into 2-3 mm segments and mounted in a multi-wire myography system to measure isometric tension. Ezetimibe reduced vasoconstriction induced by U46619 (500 nM) in endothelium-intact and endothelium-denuded arteries. Ezetimibe-induced vasodilation was not affected by the endothelial nitric oxide synthase (eNOS) inhibitor Nω-Nitro-L-arginine (L-NNA, 300 μM) or the non-selective potassium channel blocker, tetraethylammonium (TEA, 10 mM). Moreover, ezetimibe also completely blocked the contraction induced by an increase in external calcium concentration. Ezetimibe significantly reduced vascular contraction induced by L-type Ca2+ channel activator (Bay K 8644, 30 nM). Treatment with ezetimibe decreased the phosphorylation level of 20 kDa myosin light chain (MLC20) in vascular smooth muscle cells. In the present study, we found that ezetimibe has a significant vasodilatory effect in rat mesenteric resistance arteries. These results suggest that ezetimibe may have beneficial cardiovascular effects beyond its cholesterol-lowering properties.
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Affiliation(s)
| | | | | | | | - Soo-Kyoung Choi
- Department of Physiology, Yonsei University College of Medicine, 50 Yonseiro, Seodaemun-gu, Seoul 03722, Republic of Korea; (E.Y.O.); (C.E.H.); (S.C.); (S.B.)
| | - Young-Ho Lee
- Department of Physiology, Yonsei University College of Medicine, 50 Yonseiro, Seodaemun-gu, Seoul 03722, Republic of Korea; (E.Y.O.); (C.E.H.); (S.C.); (S.B.)
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2
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Boateng SY, Olfert IM, Chantler PD. Role of Perivascular Adipose Tissue and Exercise on Arterial Function with Obesity. Exerc Sport Sci Rev 2021; 49:188-196. [PMID: 33831902 PMCID: PMC8195847 DOI: 10.1249/jes.0000000000000251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Adipose tissue and arterial dysfunction are common in the obese state. Perivascular adipose tissue (PVAT) plays an important role in mediating arterial health, and with obesity, the PVAT dysfunction negatively affects arterial health. Exercise training exerts direct and beneficial effects on PVAT, providing an additional and novel pathway by which exercise can improve arterial health in diseased populations.
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Affiliation(s)
- Samuel Y Boateng
- Biological Sciences, School of Biological Sciences, University of Reading, UK
| | - I. Mark Olfert
- Department of Human Performance, Division of Exercise Physiology, School of Medicine, West Virginia University, USA
- West Virginia Clinical and Translational Science Institute (WVCTSI), Morgantown, WV
| | - Paul D Chantler
- Department of Human Performance, Division of Exercise Physiology, School of Medicine, West Virginia University, USA
- West Virginia Clinical and Translational Science Institute (WVCTSI), Morgantown, WV
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3
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Golforoush P, Yellon DM, Davidson SM. Mouse models of atherosclerosis and their suitability for the study of myocardial infarction. Basic Res Cardiol 2020; 115:73. [PMID: 33258000 PMCID: PMC7704510 DOI: 10.1007/s00395-020-00829-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/28/2020] [Indexed: 12/17/2022]
Abstract
Atherosclerotic plaques impair vascular function and can lead to arterial obstruction and tissue ischaemia. Rupture of an atherosclerotic plaque within a coronary artery can result in an acute myocardial infarction, which is responsible for significant morbidity and mortality worldwide. Prompt reperfusion can salvage some of the ischaemic territory, but ischaemia and reperfusion (IR) still causes substantial injury and is, therefore, a therapeutic target for further infarct limitation. Numerous cardioprotective strategies have been identified that can limit IR injury in animal models, but none have yet been translated effectively to patients. This disconnect prompts an urgent re-examination of the experimental models used to study IR. Since coronary atherosclerosis is the most prevalent morbidity in this patient population, and impairs coronary vessel function, it is potentially a major confounder in cardioprotective studies. Surprisingly, most studies suggest that atherosclerosis does not have a major impact on cardioprotection in mouse models. However, a major limitation of atherosclerotic animal models is that the plaques usually manifest in the aorta and proximal great vessels, and rarely in the coronary vessels. In this review, we examine the commonly used mouse models of atherosclerosis and their effect on coronary artery function and infarct size. We conclude that none of the commonly used strains of mice are ideal for this purpose; however, more recently developed mouse models of atherosclerosis fulfil the requirement for coronary artery lesions, plaque rupture and lipoprotein patterns resembling the human profile, and may enable the identification of therapeutic interventions more applicable in the clinical setting.
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MESH Headings
- Animals
- Aortic Diseases/complications
- Aortic Diseases/genetics
- Aortic Diseases/metabolism
- Aortic Diseases/pathology
- Atherosclerosis/complications
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Coronary Artery Disease/complications
- Coronary Artery Disease/genetics
- Coronary Artery Disease/metabolism
- Coronary Artery Disease/pathology
- Diet, High-Fat
- Disease Models, Animal
- Genetic Predisposition to Disease
- Mice, Knockout, ApoE
- Myocardial Infarction/etiology
- Myocardial Infarction/genetics
- Myocardial Infarction/metabolism
- Myocardial Infarction/pathology
- Myocardium/pathology
- Phenotype
- Plaque, Atherosclerotic
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Rupture, Spontaneous
- Scavenger Receptors, Class B/deficiency
- Scavenger Receptors, Class B/genetics
- Species Specificity
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Affiliation(s)
- Pelin Golforoush
- The Hatter Cardiovascular Institute, 67 Chenies Mews, London, WC1E 6HX, UK
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, 67 Chenies Mews, London, WC1E 6HX, UK
| | - Sean M Davidson
- The Hatter Cardiovascular Institute, 67 Chenies Mews, London, WC1E 6HX, UK.
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4
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Sfyri PP, Yuldasheva NY, Tzimou A, Giallourou N, Crispi V, Aburima A, Beltran-Alvarez P, Patel K, Mougios V, Swann JR, Kearney MT, Matsakas A. Attenuation of oxidative stress-induced lesions in skeletal muscle in a mouse model of obesity-independent hyperlipidaemia and atherosclerosis through the inhibition of Nox2 activity. Free Radic Biol Med 2018; 129:504-519. [PMID: 30342191 DOI: 10.1016/j.freeradbiomed.2018.10.422] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 09/12/2018] [Accepted: 10/09/2018] [Indexed: 02/08/2023]
Abstract
Obesity leading to hyperlipidaemia and atherosclerosis is recognised to induce morphological and metabolic changes in many tissues. However, hyperlipidaemia can occur in the absence of obesity. The impact of the latter scenario on skeletal muscle and liver is not understood sufficiently. In this regard, we used the Apolipoprotein E-deficient (ApoE-/-) mouse model, an established model of hyperlipidaemia and atherosclerosis, that does not become obese when subjected to a high-fat diet, to determine the impact of Western-type diet (WD) and ApoE deficiency on skeletal muscle morphological, metabolic and biochemical properties. To establish the potential of therapeutic targets, we further examined the impact of Nox2 pharmacological inhibition on skeletal muscle redox biology. We found ectopic lipid accumulation in skeletal muscle and the liver, and altered skeletal muscle morphology and intramuscular triacylglycerol fatty acid composition. WD and ApoE deficiency had a detrimental impact in muscle metabolome, followed by perturbed gene expression for fatty acid uptake and oxidation. Importantly, there was enhanced oxidative stress in the skeletal muscle and development of liver steatosis, inflammation and oxidative protein modifications. Pharmacological inhibition of Nox2 decreased reactive oxygen species production and protein oxidative modifications in the muscle of ApoE-/- mice subjected to a Western-type diet. This study provides key evidence to better understand the pathophysiology of skeletal muscle in the context of hyperlipidaemia and atherosclerosis and identifies Nox2 as a potential target for attenuating oxidative stress in skeletal muscle in a mouse model of obesity-independent hyperlipidaemia.
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Affiliation(s)
- Pagona Panagiota Sfyri
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, United Kingdom
| | - Nadira Y Yuldasheva
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, United Kingdom
| | - Anastasia Tzimou
- Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sports Science at Thessaloniki, Aristotle University of Thessaloniki, Greece
| | - Natasa Giallourou
- Department of Surgery and Cancer, Division of Computational and Systems Medicine, Imperial College London, United Kingdom
| | - Vassili Crispi
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, United Kingdom
| | - Ahmed Aburima
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, United Kingdom
| | | | - Ketan Patel
- School of Biological Sciences, University of Reading, United Kingdom
| | - Vassilis Mougios
- Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sports Science at Thessaloniki, Aristotle University of Thessaloniki, Greece
| | - Jonathan R Swann
- Department of Surgery and Cancer, Division of Computational and Systems Medicine, Imperial College London, United Kingdom
| | - Mark T Kearney
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, United Kingdom
| | - Antonios Matsakas
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, United Kingdom.
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5
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Fancher IS, Ahn SJ, Adamos C, Osborn C, Oh MJ, Fang Y, Reardon CA, Getz GS, Phillips SA, Levitan I. Hypercholesterolemia-Induced Loss of Flow-Induced Vasodilation and Lesion Formation in Apolipoprotein E-Deficient Mice Critically Depend on Inwardly Rectifying K + Channels. J Am Heart Assoc 2018; 7:e007430. [PMID: 29502106 PMCID: PMC5866319 DOI: 10.1161/jaha.117.007430] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 01/17/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Hypercholesterolemia-induced decreased availability of nitric oxide (NO) is a major factor in cardiovascular disease. We previously established that cholesterol suppresses endothelial inwardly rectifying K+ (Kir) channels and that Kir2.1 is an upstream mediator of flow-induced NO production. Therefore, we tested the hypothesis that suppression of Kir2.1 is responsible for hypercholesterolemia-induced inhibition of flow-induced NO production and flow-induced vasodilation (FIV). We also tested the role of Kir2.1 in the development of atherosclerotic lesions. METHODS AND RESULTS Kir2.1 currents are significantly suppressed in microvascular endothelial cells exposed to acetylated-low-density lipoprotein or isolated from apolipoprotein E-deficient (Apoe-/- ) mice and rescued by cholesterol depletion. Genetic deficiency of Kir2.1 on the background of hypercholesterolemic Apoe-/- mice, Kir2.1+/-/Apoe-/- exhibit the same blunted FIV and flow-induced NO response as Apoe-/- or Kir2.1+/- alone, but while FIV in Apoe-/- mice can be rescued by cholesterol depletion, in Kir2.1+/-/Apoe-/- mice cholesterol depletion has no effect on FIV. Endothelial-specific overexpression of Kir2.1 in arteries from Apoe-/- and Kir2.1+/-/Apoe-/- mice results in full rescue of FIV and NO production in Apoe-/- mice with and without the addition of a high-fat diet. Conversely, endothelial-specific expression of dominant-negative Kir2.1 results in the opposite effect. Kir2.1+/-/Apoe-/- mice also show increased lesion formation, particularly in the atheroresistant area of descending aorta. CONCLUSIONS We conclude that hypercholesterolemia-induced reduction in FIV is largely attributable to cholesterol suppression of Kir2.1 function via the loss of flow-induced NO production, whereas the stages downstream of flow-induced Kir2.1 activation appear to be mostly intact. Kir2.1 channels also have an atheroprotective role.
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MESH Headings
- Animals
- Aorta/metabolism
- Aorta/pathology
- Aortic Diseases/genetics
- Aortic Diseases/metabolism
- Aortic Diseases/pathology
- Aortic Diseases/physiopathology
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Atherosclerosis/physiopathology
- Cells, Cultured
- Cholesterol/blood
- Disease Models, Animal
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Hypercholesterolemia/genetics
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/pathology
- Hypercholesterolemia/physiopathology
- Male
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mice, Inbred C57BL
- Mice, Knockout, ApoE
- Nitric Oxide/metabolism
- Plaque, Atherosclerotic
- Potassium Channels, Inwardly Rectifying/deficiency
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/metabolism
- Signal Transduction
- Vasodilation
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Affiliation(s)
- Ibra S Fancher
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Sang Joon Ahn
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
| | - Crystal Adamos
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Catherine Osborn
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
| | - Myung-Jin Oh
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, IL
| | - Yun Fang
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, IL
| | | | | | - Shane A Phillips
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Irena Levitan
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
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6
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LeBlanc AJ, Kelm NQ. Thrombospondin-1, Free Radicals, and the Coronary Microcirculation: The Aging Conundrum. Antioxid Redox Signal 2017; 27:785-801. [PMID: 28762749 PMCID: PMC5647494 DOI: 10.1089/ars.2017.7292] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
SIGNIFICANCE Successful matching of cardiac metabolism to perfusion is accomplished primarily through vasodilation of the coronary resistance arterioles, but the mechanism that achieves this effect changes significantly as aging progresses and involves the contribution of reactive oxygen species (ROS). Recent Advances: A matricellular protein, thrombospondin-1 (Thbs-1), has been shown to be a prolific contributor to the production and modulation of ROS in large conductance vessels and in the peripheral circulation. Recently, the presence of physiologically relevant circulating Thbs-1 levels was proven to also disrupt vasodilation to nitric oxide (NO) in coronary arterioles from aged animals, negatively impacting coronary blood flow reserve. CRITICAL ISSUES This review seeks to reconcile how ROS can be successfully utilized as a substrate to mediate vasoreactivity in the coronary microcirculation as "normal" aging progresses, but will also examine how Thbs-1-induced ROS production leads to dysfunctional perfusion and eventual ischemia and why this is more of a concern in advancing age. FUTURE DIRECTIONS Current therapies that may effectively disrupt Thbs-1 and its receptor CD47 in the vascular wall and areas for future exploration will be discussed. Antioxid. Redox Signal. 27, 785-801.
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Affiliation(s)
- Amanda J LeBlanc
- Department of Physiology, Cardiovascular Innovation Institute, University of Louisville , Louisville, Kentucky
| | - Natia Q Kelm
- Department of Physiology, Cardiovascular Innovation Institute, University of Louisville , Louisville, Kentucky
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7
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Sfyri P, Matsakas A. Crossroads between peripheral atherosclerosis, western-type diet and skeletal muscle pathophysiology: emphasis on apolipoprotein E deficiency and peripheral arterial disease. J Biomed Sci 2017; 24:42. [PMID: 28688452 PMCID: PMC5502081 DOI: 10.1186/s12929-017-0346-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/07/2017] [Indexed: 12/16/2022] Open
Abstract
Atherosclerosis is a chronic inflammatory process that, in the presence of hyperlipidaemia, promotes the formation of atheromatous plaques in large vessels of the cardiovascular system. It also affects peripheral arteries with major implications for a number of other non-vascular tissues such as the skeletal muscle, the liver and the kidney. The aim of this review is to critically discuss and assimilate current knowledge on the impact of peripheral atherosclerosis and its implications on skeletal muscle homeostasis. Accumulating data suggests that manifestations of peripheral atherosclerosis in skeletal muscle originates in a combination of increased i)-oxidative stress, ii)-inflammation, iii)-mitochondrial deficits, iv)-altered myofibre morphology and fibrosis, v)-chronic ischemia followed by impaired oxygen supply, vi)-reduced capillary density, vii)- proteolysis and viii)-apoptosis. These structural, biochemical and pathophysiological alterations impact on skeletal muscle metabolic and physiologic homeostasis and its capacity to generate force, which further affects the individual's quality of life. Particular emphasis is given on two major areas representing basic and applied science respectively: a)-the abundant evidence from a well-recognised atherogenic model; the Apolipoprotein E deficient mouse and the role of a western-type diet and b)-on skeletal myopathy and oxidative stress-induced myofibre damage from human studies on peripheral arterial disease. A significant source of reactive oxygen species production and oxidative stress in cardiovascular disease is the family of NADPH oxidases that contribute to several pathologies. Finally, strategies targeting NADPH oxidases in skeletal muscle in an attempt to attenuate cellular oxidative stress are highlighted, providing a better understanding of the crossroads between peripheral atherosclerosis and skeletal muscle pathophysiology.
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Affiliation(s)
- Peggy Sfyri
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Antonios Matsakas
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom.
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8
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Mandler WK, Nurkiewicz TR, Porter DW, Olfert IM. Thrombospondin-1 mediates multi-walled carbon nanotube induced impairment of arteriolar dilation. Nanotoxicology 2017; 11:112-122. [PMID: 28024456 DOI: 10.1080/17435390.2016.1277275] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pulmonary exposure to multi-walled carbon nanotubes (MWCNT) has been shown to disrupt endothelium-dependent arteriolar dilation in the peripheral microcirculation. The molecular mechanisms behind these arteriolar disruptions have yet to be fully elucidated. The secreted matricellular matrix protein thrombospondin-1 (TSP-1) is capable of moderating arteriolar vasodilation by inhibiting soluble guanylate cyclase activity. We hypothesized that TSP-1 may be a link between nanomaterial exposure and observed peripheral microvascular dysfunction. To test this hypothesis, wild-type C57B6J (WT) and TSP-1 knockout (KO) mice were exposed via lung aspiration to 50 μg MWCNT or a Sham dispersion medium control. Following exposure (24 h), arteriolar characteristics and reactivity were measured in the gluteus maximus muscle using intravital microscopy (IVM) coupled with microiontophoretic delivery of acetylcholine (ACh) or sodium nitroprusside (SNP). In WT mice exposed to MWCNT, skeletal muscle TSP-1 protein increased > fivefold compared to Sham exposed, and exhibited a 39% and 47% decrease in endothelium-dependent and -independent vasodilation, respectively. In contrast, TSP-1 protein was not increased following MWCNT exposure in KO mice and exhibited no loss in dilatory capacity. Microvascular leukocyte-endothelium interactions were measured by assessing leukocyte adhesion and rolling activity in third order venules. The WT + MWCNT group demonstrated 223% higher leukocyte rolling compared to the WT + Sham controls. TSP-1 KO animals exposed to MWCNT showed no differences from the WT + Sham control. These data provide evidence that TSP-1 is likely a central mediator of the systemic microvascular dysfunction that follows pulmonary MWCNT exposure.
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Affiliation(s)
- W Kyle Mandler
- a Division of Exercise Physiology , West Virginia University School of Medicine , Morgantown , WV , USA
| | - Timothy R Nurkiewicz
- b Department of Physiology and Pharmacology , West Virginia University School of Medicine , Morgantown , WV , USA.,c Center for Cardiovascular & Respiratory Sciences , West Virginia University, Robert C. Byrd Health Sciences Center , Morgantown , WV , USA
| | - Dale W Porter
- d National Institute for Occupational Safety and Health , Morgantown , WV , USA
| | - I Mark Olfert
- a Division of Exercise Physiology , West Virginia University School of Medicine , Morgantown , WV , USA.,c Center for Cardiovascular & Respiratory Sciences , West Virginia University, Robert C. Byrd Health Sciences Center , Morgantown , WV , USA
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Siangjong L, Goldman DH, Kriska T, Gauthier KM, Smyth EM, Puli N, Kumar G, Falck JR, Campbell WB. Vascular hepoxilin and trioxilins mediate vasorelaxation through TP receptor inhibition in mouse arteries. Acta Physiol (Oxf) 2017; 219:188-201. [PMID: 26666460 DOI: 10.1111/apha.12642] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/04/2015] [Accepted: 12/08/2015] [Indexed: 01/12/2023]
Abstract
AIM 12/15-lipoxygenase (12/15-LO) metabolizes arachidonic acid (AA) into several vasoactive eicosanoids. In mouse arteries, we previously characterized the enzyme's 15-LO metabolites 12(S)-hydroxyeicosatetraenoic acid (HETE), 15-HETE, hydroxyepoxyeicosatrienoic acids (HEETAs) and 11,12,15-trihydroxyeicosatrienoic acids (11,12,15-THETAs) as endothelium-derived relaxing factors. However, the observed 12-LO metabolites remained uncharacterized. The purpose of this study was to determine the structure and biological functions of eicosanoids generated by the enzyme's 12-LO activity. METHODS Metabolites extracted from aortas of C57BL/6 male mice were separated using a series of reverse and normal phase chromatographic steps and identified as hepoxilin A3 , trioxilin A3 and trioxilin C3 by mass spectrometry. Activities of these natural compounds were tested on isometric tension and intracellular calcium release. The role of thromboxane (TP) receptor was determined in HEK293 cells overexpressing TPα receptor (TPα -HEK). RESULTS All identified vascular 12-LO metabolites were biologically active. In mouse mesenteric arteries, trioxilin A3 , C3 and hepoxilin A3 (3 μm) relaxed arteries constricted with the thromboxane mimetic, U46619-constricted arteries (maximum relaxations of 78.9 ± 3.2, 29.7 ± 4.6, 82.2 ± 5.0 and 88.0 ± 2.4% respectively), but not phenylephrine-constricted arteries. In TPα-HEK cells, trioxilin A3 , C3 and hepoxilin A3 (10 μm) inhibited U46619 (10 nM)-induced increases in intracellular calcium by 53.0 ± 7.2%, 32.8 ± 5.0% and 37.9 ± 13.5% respectively. In contrast, trioxilin B3 and hepoxilin B3 were not synthesized in arteries and exhibited little biological activity. CONCLUSION Trioxilin A3 and C3 and hepoxilin A3 are endogenous vascular relaxing factors. They are not endothelium-derived hyperpolarizing factors but mediate vascular relaxation by inhibiting TP agonist-induced increases in intracellular calcium. Thus, they regulate vascular homeostasis by acting as endogenous TP antagonists.
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Affiliation(s)
- L. Siangjong
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
- Faculty of Pharmacy; Silpakorn University; Nakorn Pathom Thailand
| | - D. H. Goldman
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
| | - T. Kriska
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
| | - K. M. Gauthier
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
| | - E. M. Smyth
- Department of Pharmacology; University of Pennsylvania; Philadelphia PA USA
| | - N. Puli
- Department of Biochemistry; University of Texas Southwestern Medical Center; Dallas TX USA
| | - G. Kumar
- Department of Biochemistry; University of Texas Southwestern Medical Center; Dallas TX USA
| | - J. R. Falck
- Department of Biochemistry; University of Texas Southwestern Medical Center; Dallas TX USA
| | - W. B. Campbell
- Department of Pharmacology and Toxicology; Medical College of Wisconsin; Milwaukee WI USA
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10
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Chadderdon SM, Belcik JT, Bader L, Peters DM, Kievit P, Alkayed NJ, Kaul S, Grove KL, Lindner JR. Temporal Changes in Skeletal Muscle Capillary Responses and Endothelial-Derived Vasodilators in Obesity-Related Insulin Resistance. Diabetes 2016; 65:2249-57. [PMID: 27207517 PMCID: PMC4955987 DOI: 10.2337/db15-1574] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 04/05/2016] [Indexed: 12/18/2022]
Abstract
The inability of insulin to increase skeletal muscle capillary blood volume (CBV) reduces glucose uptake in insulin resistance (IR). We hypothesized that abnormalities in endothelial-derived vasodilator pathways are temporally associated with the development of IR and an impaired ability to increase skeletal muscle CBV. A comprehensive metabolic and vascular screening assessment was performed on 10 adult rhesus macaques at baseline and every 4-6 months for 2 years after starting a high-fat diet supplemented with fructose. Diet changes resulted in an 80% increase in truncal fat by 4 months. Hyperinsulinemia and decreased glucose utilization were observed from 4 to 18 months. At 24 months, pancreatic secretory function and the glucose utilization rate declined. CBV at rest and during an intravenous glucose tolerance test demonstrated a sustained increase from 4 to 18 months and then abruptly fell at 24 months. Nitric oxide bioavailability progressively decreased over 2 years. Conversely, endothelial-derived vasodilators progressively increased over 18 months and then abruptly decreased at 24 months in concert with the CBV. The increase in basal and glucose-mediated CBV early in IR may represent a compensatory response through endothelial-derived vasodilator pathways. The inability to sustain a vascular compensatory response limits glucose-mediated increases in CBV, which correlates with the severity of IR.
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Affiliation(s)
- Scott M Chadderdon
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR
| | - J Todd Belcik
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR
| | - Lindsay Bader
- Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR
| | - Dawn M Peters
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR
| | - Paul Kievit
- Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR
| | - Nabil J Alkayed
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR
| | - Sanjiv Kaul
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR
| | - Kevin L Grove
- Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR
| | - Jonathan R Lindner
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR
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Stead R, Musa MG, Bryant CL, Lanham SA, Johnston DA, Reynolds R, Torrens C, Fraser PA, Clough GF. Developmental conditioning of endothelium-derived hyperpolarizing factor-mediated vasorelaxation. J Hypertens 2016; 34:452-63; discussion 463. [PMID: 26682783 PMCID: PMC4732175 DOI: 10.1097/hjh.0000000000000833] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 10/26/2015] [Accepted: 11/20/2015] [Indexed: 01/13/2023]
Abstract
OBJECTIVES The endothelium maintains vascular homeostasis through the release of endothelium-derived relaxing factors (EDRF) and endothelium-derived hyperpolarization (EDH). The balance in EDH : EDRF is disturbed in cardiovascular disease and may also be susceptible to developmental conditioning through exposure to an adverse uterine environment to predispose to later risk of hypertension and vascular disease. METHODS Developmentally conditioned changes in EDH : EDRF signalling pathways were investigated in cremaster arterioles (18-32 μm diameter) and third-order mesenteric arteries of adult male mice offspring of dams fed either a fat-rich (high fat, HF, 45% energy from fat) or control (C, 10% energy from fat) diet. After weaning, offspring either continued on high fat or were placed on control diets to give four dietary groups (C/C, HF/C, C/HF, and HF/HF) and studied at 15 weeks of age. RESULTS EDH via intermediate (IKCa) and small (SKca) conductance calcium-activated potassium channels contributed less than 10% to arteriolar acetylcholine-induced relaxation in in-situ conditioned HF/C offspring compared with ∼60% in C/C (P < 0.01). The conditioned reduction in EDH signalling in HF/C offspring was reversed in offspring exposed to a high-fat diet both before and after weaning (HF/HF, 55%, P < 0.01 vs. HF/C). EDH signalling was unaffected in arterioles from C/HF offspring. The changes in EDH : EDRF were associated with altered endothelial cell expression and localization of IKCa channels. CONCLUSION This is the first evidence that EDH-mediated microvascular relaxation is susceptible to an adverse developmental environment through down-regulation of the IKCa signalling pathway. Conditioned offspring exposed to a 'second hit' (HF/HF) exhibit adaptive vascular mechanisms to preserve dilator function.
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Affiliation(s)
- Rebecca Stead
- Vascular Research Group
- Rebecca Stead and Moji G. Musa contributed equally to the writing of this article
| | - Moji G. Musa
- Vascular Research Group
- Rebecca Stead and Moji G. Musa contributed equally to the writing of this article
| | | | - Stuart A. Lanham
- Bone and Joint Research Group, Institute of Developmental Sciences
| | - David A. Johnston
- Faculty of Medicine, Biomedical Imaging Unit, University of Southampton, Southampton
| | | | | | - Paul A. Fraser
- Cardiovascular Division, BHF Centre of Research Excellence, School of Medicine, King's College London, London, United Kingdom
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Sacerdoti D, Pesce P, Di Pascoli M, Brocco S, Cecchetto L, Bolognesi M. Arachidonic acid metabolites and endothelial dysfunction of portal hypertension. Prostaglandins Other Lipid Mediat 2015; 120:80-90. [PMID: 26072731 DOI: 10.1016/j.prostaglandins.2015.05.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/20/2015] [Accepted: 05/25/2015] [Indexed: 12/12/2022]
Abstract
Increased resistance to portal flow and increased portal inflow due to mesenteric vasodilatation represent the main factors causing portal hypertension in cirrhosis. Endothelial cell dysfunction, defined as an imbalance between the synthesis, release, and effect of endothelial mediators of vascular tone, inflammation, thrombosis, and angiogenesis, plays a major role in the increase of resistance in portal circulation, in the decrease in the mesenteric one, in the development of collateral circulation. Reduced response to vasodilators in liver sinusoids and increased response in the mesenteric arterioles, and, viceversa, increased response to vasoconstrictors in the portal-sinusoidal circulation and decreased response in the mesenteric arterioles are also relevant to the pathophysiology of portal hypertension. Arachidonic acid (AA) metabolites through the three pathways, cyclooxygenase (COX), lipoxygenase, and cytochrome P450 monooxygenase and epoxygenase, are involved in endothelial dysfunction of portal hypertension. Increased thromboxane-A2 production by liver sinusoidal endothelial cells (LSECs) via increased COX-1 activity/expression, increased leukotriens, increased epoxyeicosatrienoic acids (EETs) (dilators of the peripheral arterial circulation, but vasoconstrictors of the portal-sinusoidal circulation), represent a major component in the increased portal resistance, in the decreased portal response to vasodilators and in the hyper-response to vasoconstrictors. Increased prostacyclin (PGI2) via COX-1 and COX-2 overexpression, and increased EETs/heme-oxygenase-1/K channels/gap junctions (endothelial derived hyperpolarizing factor system) play a major role in mesenteric vasodilatation, hyporeactivity to vasoconstrictors, and hyper-response to vasodilators. EETs, mediators of liver regeneration after hepatectomy and of angiogenesis, may play a role in the development of regenerative nodules and collateral circulation, through stimulation of vascular endothelial growth factor (VEGF) inside the liver and in the portal circulation. Pharmacological manipulation of AA metabolites may be beneficial for cirrhotic portal hypertension.
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Affiliation(s)
- David Sacerdoti
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy.
| | - Paola Pesce
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Marco Di Pascoli
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Silvia Brocco
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Lara Cecchetto
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Massimo Bolognesi
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
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Chantler PD, Frisbee JC. Arterial function in cardio-metabolic diseases: from the microcirculation to the large conduits. Prog Cardiovasc Dis 2014; 57:489-96. [PMID: 25220256 DOI: 10.1016/j.pcad.2014.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The metabolic syndrome (MetS) is characterized as a constellation of metabolic risk factors such as obesity, hypertension, dyslipidemia, and hyperglycemia that co-occur within a given individual. This consultation of risk factors exposes MetS to a 3-fold increased risk of cardiovascular disease and an even higher risk of developing type 2 diabetes compared to healthy individuals. The pathophysiological mechanisms underlying this increased cardiovascular risk are incompletely understood but likely include alterations to macro- and micro-vasculature. The vasculature plays an important role not only in delivery and adjusting the quantity of blood delivered to the tissues, but the dynamic changes in structure and compliance significantly alter the hemodynamic stress imposed on the heart and end-organs. This review will give an overview of the pathophysiological changes to the vasculature that accompany MetS in both human and animal models, as well as the possible mechanistic pathways.
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Affiliation(s)
- Paul D Chantler
- Division of Exercise Physiology, School of Medicine, West Virginia University, Morgantown, WV, USA; Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, USA
| | - Jefferson C Frisbee
- Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, USA; Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown, WV, USA.
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14
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Role of nitric oxide synthase isoforms for ophthalmic artery reactivity in mice. Exp Eye Res 2014; 127:1-8. [PMID: 25017185 DOI: 10.1016/j.exer.2014.06.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 06/12/2014] [Accepted: 06/19/2014] [Indexed: 11/23/2022]
Abstract
Nitric oxide synthases (NOS) are involved in regulation of ocular vascular tone and blood flow. While endothelial NOS (eNOS) has recently been shown to mediate endothelium-dependent vasodilation in mouse retinal arterioles, the contribution of individual NOS isoforms to vascular responses is unknown in the retrobulbar vasculature. Moreover, it is unknown whether the lack of a single NOS isoform affects neuron survival in the retina. Thus, the goal of the present study was to examine the hypothesis that the lack of individual nitric oxide synthase (NOS) isoforms affects the reactivity of mouse ophthalmic arteries and neuron density in the retinal ganglion cell (RGC) layer. Mice deficient in one of the three NOS isoforms (nNOS-/-, iNOS-/- and eNOS-/-) were compared to respective wild type controls. Intraocular pressure (IOP) was measured in conscious mice using rebound tonometry. To examine the role of each NOS isoform for mediating vascular responses, ophthalmic arteries were studied in vitro using video microscopy. Neuron density in the RGC layer was calculated from retinal wholemounts stained with cresyl blue. IOP was similar in all NOS-deficient genotypes and respective wild type controls. In ophthalmic arteries, phenylephrine, nitroprusside and acetylcholine evoked concentration-dependent responses that did not differ between individual NOS-deficient genotypes and their respective controls. In all genotypes except eNOS-/- mice, vasodilation to acetylcholine was markedly reduced after incubation with L-NAME, a non-isoform-selective inhibitor of NOS. In contrast, pharmacological inhibition of nNOS and iNOS had no effect on acetylcholine-induced vasodilation in any of the mouse genotypes. Neuron density in the RGC layer was similar in all NOS-deficient genotypes and respective controls. Our findings suggest that eNOS contributes to endothelium-dependent dilation of murine ophthalmic arteries. However, the chronic lack of eNOS is functionally compensated by NOS-independent vasodilator mechanisms. The lack of a single NOS isoform does not appear to affect IOP or neuron density in the RGC layer.
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15
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de Beer VJ, Merkus D, Bender SB, Tharp DL, Bowles DK, Duncker DJ, Laughlin MH. Familial hypercholesterolemia impairs exercise-induced systemic vasodilation due to reduced NO bioavailability. J Appl Physiol (1985) 2013; 115:1767-76. [PMID: 24157527 DOI: 10.1152/japplphysiol.00619.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypercholesterolemia impairs endothelial function [e.g., the nitric oxide (NO)-cyclic GMP-phosphodiesterase 5 (PDE5) pathway], limits shear stress-induced vasodilation, and is therefore expected to reduce exercise-induced vasodilation. To assess the actual effects of hypercholesterolemia on endothelial function and exercise-induced vasodilation, we compared the effects of endothelial NO synthase (eNOS) and PDE5 inhibition in chronically instrumented Yucatan (Control) and Rapacz familial hypercholesterolemic (FH) swine, at rest and during treadmill exercise. The increases in systemic vascular conductance produced by ATP (relative to nitroprusside) and exercise were blunted in FH compared with Control swine. The vasoconstrictor response to eNOS inhibition, with nitro-l-arginine (NLA), was attenuated in FH compared with Control swine, both at rest and during exercise. Furthermore, whereas the vasodilator response to nitroprusside was enhanced slightly, the vasodilator response to PDE5 inhibition, with EMD360527, was reduced in FH compared with Control swine. Finally, in the pulmonary circulation, FH resulted in attenuated vasodilator responses to ATP, while maintaining the responses to both NLA and EMD360527. In conclusion, hypercholesterolemia reduces exercise-induced vasodilation in the systemic but not the pulmonary circulation. This reduction appears to be the principal result of a decrease in NO bioavailability, which is mitigated by a lower PDE5 activity.
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Affiliation(s)
- Vincent J de Beer
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School Erasmus University Rotterdam, Erasmus University Medical Center, Rotterdam, The Netherlands
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16
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Abstract
Endothelium-derived hyperpolarizing factors (EDHFs) regulate vascular tone by contributing to the vasorelaxations to shear stress and endothelial agonists such as bradykinin and acetylcholine. 15(S)-Hydroxy-11,12-epoxyeicosatrienoic acid (15-H-11,12-EETA) and 11(R),12(S),15(S)-trihydroxyeicosatrienoic acid (11,12,15-THETA) are endothelial metabolites of the 15-lipoxygenase (15-LO) pathway of arachidonic acid metabolism and are EDHFs. 11,12,15-THETA activates small conductance, calcium-activated potassium channels on smooth muscle cells causing membrane hyperpolarization, and relaxation. Expression levels of 15-LO in the endothelium regulate the activity of the 15-LO/15-H-11,12-EETA/11,12,15-THETA pathway and its contribution to vascular tone. Regulation of its expression is by transcriptional, translational, and epigenetic mechanisms. Hypoxia, hypercholesterolemia, atherosclerosis, anemia, estrogen, interleukins, and possibly other hormones increase 15-LO expression. An increase in 15-LO results in increased synthesis of 15-H-11,12-EETA and 11,12,15-THETA, increased membrane hyperpolarization, and enhanced contribution to relaxation by endothelial agonists. Thus, the 15-LO pathway represents the first example of an inducible EDHF. In addition to 15-LO metabolites, a number of chemicals have been identified as EDHFs and their contributions to vascular tone vary with species and vascular bed. The reason for multiple EDHFs has evaded explanation. However, EDHF functioning as constitutive EDHFs or inducible EDHFs may explain the need for chemically and biochemically distinct pathways for EDHF activity and the variation in EDHFs between species and vascular beds. This new EDHF classification provides a framework for understanding EDHF activity in physiological and pathological conditions.
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17
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Gericke A, Goloborodko E, Sniatecki JJ, Steege A, Wojnowski L, Pfeiffer N. Contribution of nitric oxide synthase isoforms to cholinergic vasodilation in murine retinal arterioles. Exp Eye Res 2013; 109:60-6. [DOI: 10.1016/j.exer.2013.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 01/20/2013] [Accepted: 01/24/2013] [Indexed: 10/27/2022]
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18
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Impairment of coronary arteriolar endothelium-dependent dilation after multi-walled carbon nanotube inhalation: a time-course study. Int J Mol Sci 2012. [PMID: 23203034 PMCID: PMC3509550 DOI: 10.3390/ijms131113781] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Engineered nanomaterials have been developed for widespread applications due to many highly unique and desirable characteristics. The purpose of this study was to assess pulmonary inflammation and subepicardial arteriolar reactivity in response to multi-walled carbon nanotube (MWCNT) inhalation and evaluate the time course of vascular alterations. Rats were exposed to MWCNT aerosols producing pulmonary deposition. Pulmonary inflammation via bronchoalveolar lavage and MWCNT translocation from the lungs to systemic organs was evident 24 h post-inhalation. Coronary arterioles were evaluated 24-168 h post-exposure to determine microvascular response to changes in transmural pressure, endothelium-dependent and -independent reactivity. Myogenic responsiveness, vascular smooth muscle reactivity to nitric oxide, and α-adrenergic responses all remained intact. However, a severe impact on endothelium-dependent dilation was observed within 24 h after MWCNT inhalation, a condition which improved, but did not fully return to control after 168 h. In conclusion, results indicate that MWCNT inhalation not only leads to pulmonary inflammation and cytotoxicity at low lung burdens, but also a low level of particle translocation to systemic organs. MWCNT inhalation also leads to impairments of endothelium-dependent dilation in the coronary microcirculation within 24 h, a condition which does not fully dissipate within 168 h. The innovations within the field of nanotechnology, while exciting and novel, can only reach their full potential if toxicity is first properly assessed.
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Functional alterations in endothelial NO, PGI2 and EDHF pathways in aorta in ApoE/LDLR−/− mice. Prostaglandins Other Lipid Mediat 2012; 98:107-15. [DOI: 10.1016/j.prostaglandins.2012.02.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 02/12/2012] [Accepted: 02/13/2012] [Indexed: 01/22/2023]
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20
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Butcher JT, Goodwill AG, Frisbee JC. The ex vivo isolated skeletal microvessel preparation for investigation of vascular reactivity. J Vis Exp 2012:3674. [PMID: 22565845 DOI: 10.3791/3674] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The isolated microvessel preparation is an ex vivo preparation that allows for examination of the different contributions of factors that control vessel diameter, and thus, perfusion resistance(1-5). This is a classic experimental preparation that was, in large measure, initially described by Uchida et al.(15) several decades ago. This initial description provided the basis for the techniques that was extensively modified and enhanced, primarily in the laboratory of Dr. Brian Duling at the University of Virginia(6-8), and we present a current approach in the following pages. This preparation will specifically refer to the gracilis arteriole in a rat as the microvessel of choice, but the basic preparation can readily be applied to vessels isolated from nearly any other tissue or organ across species(9-13). Mechanical (i.e., dimensional) changes in the isolated microvessels can easily be evaluated in response to a broad array of physiological (e.g., hypoxia, intravascular pressure, or shear) or pharmacological challenges, and can provide insight into mechanistic elements comprising integrated responses in an intact, although ex vivo, tissue. The significance of this method is that it allows for facile manipulation of the influences on the integrated regulation of microvessel diameter, while also allowing for the control of many of the contributions from other sources, including intravascular pressure (myogenic), autonomic innervation, hemodynamic (e.g., shear stress), endothelial dependent or independent stimuli, hormonal, and parenchymal influences, to provide a partial list. Under appropriate experimental conditions and with appropriate goals, this can serve as an advantage over in vivo or in situ tissue/organ preparations, which do not readily allow for the facile control of broader systemic variables. The major limitation of this preparation is essentially the consequence of its strengths. By definition, the behavior of these vessels is being studied under conditions where many of the most significant contributors to the regulation of vascular resistance have been removed, including neural, humoral, metabolic, etc. As such, the investigator is cautioned to avoid over-interpretation and extrapolation of the data that are collected utilizing this preparation. The other significant area of concern with regard to this preparation is that it can be very easy to damage cellular components such as the endothelial lining or the vascular smooth muscle, such that variable source of error can be introduced. It is strongly recommended that the individual investigator utilize appropriate measurements to ensure the quality of the preparation, both at the initiation of the experiment and periodically throughout the course of a protocol.
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Affiliation(s)
- Joshua T Butcher
- Department of Physiology and Pharmacology, Center for Cardiovascular and Respiratory Sciences, West Virginia University, USA
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21
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Vasquez EC, Peotta VA, Gava AL, Pereira TM, Meyrelles SS. Cardiac and vascular phenotypes in the apolipoprotein E-deficient mouse. J Biomed Sci 2012; 19:22. [PMID: 22330242 PMCID: PMC3306747 DOI: 10.1186/1423-0127-19-22] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 02/13/2012] [Indexed: 02/07/2023] Open
Abstract
Cardiovascular death is frequently associated with atherosclerosis, a chronic multifactorial disease and a leading cause of death worldwide. Genetically engineered mouse models have proven useful for the study of the mechanisms underlying cardiovascular diseases. The apolipoprotein E-deficient mouse has been the most widely used animal model of atherosclerosis because it rapidly develops severe hypercholesterolemia and spontaneous atherosclerotic lesions similar to those observed in humans. In this review, we provide an overview of the cardiac and vascular phenotypes and discuss the interplay among nitric oxide, reactive oxygen species, aging and diet in the impairment of cardiovascular function in this mouse model.
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Affiliation(s)
- Elisardo C Vasquez
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espirito Santo, Vitoria, ES, Brazil.
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Meyrelles SS, Peotta VA, Pereira TMC, Vasquez EC. Endothelial dysfunction in the apolipoprotein E-deficient mouse: insights into the influence of diet, gender and aging. Lipids Health Dis 2011; 10:211. [PMID: 22082357 PMCID: PMC3247089 DOI: 10.1186/1476-511x-10-211] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Accepted: 11/14/2011] [Indexed: 02/07/2023] Open
Abstract
Since the early 1990s, several strains of genetically modified mice have been developed as models for experimental atherosclerosis. Among the available models, the apolipoprotein E-deficient (apoE⁻/⁻) mouse is of particular relevance because of its propensity to spontaneously develop hypercholesterolemia and atherosclerotic lesions that are similar to those found in humans, even when the mice are fed a chow diet. The main purpose of this review is to highlight the key achievements that have contributed to elucidating the mechanisms pertaining to vascular dysfunction in the apoE⁻/⁻ mouse. First, we summarize lipoproteins and atherosclerosis phenotypes in the apoE⁻/⁻ mouse, and then we briefly discuss controversial evidence relative to the influence of gender on the development of atherosclerosis in this murine model. Second, we discuss the main mechanisms underlying the endothelial dysfunction of conducting vessels and resistance vessels and examine how this vascular defect can be influenced by diet, aging and gender in the apoE⁻/⁻ mouse.
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Affiliation(s)
- Silvana S Meyrelles
- Departament of Physiological Sciences, Health Sciences Center, Federal University of Espirito Santo, Vitoria, ES, Brazil
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23
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Jackson WF. Standing out in a crowd: knockout of ApoE increases the potency of endothelium-dependent vasodilators in mesenteric arteries. Cardiovasc Res 2011; 92:183-4. [DOI: 10.1093/cvr/cvr253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Leonard S, Croy BA, Murrant CL. Arteriolar reactivity in lymphocyte-deficient mice. Am J Physiol Heart Circ Physiol 2011; 301:H1276-85. [DOI: 10.1152/ajpheart.00346.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mounting evidence suggests that lymphocytes have the capacity to contribute to the regulation of systemic circulatory control. We postulated that T and natural killer (NK) cells could modify basal microvascular activity under physiologically normal conditions. In situ intravital microscopy of mouse cremaster vasculature was used to evaluate arteriolar reactivities to the vasoconstrictors angiotensin II (ANG II) and phenylephrine (Phe) and the vasodilators acetylcholine (ACh) and adenosine (Ado) in normal [+/+; wild type (WT)] and genetically immunodeficient (T−B−NK+ or T−B−\NK−) C57BL/6 and BALB/c mice, strain backgrounds with differentially polarized T cell cytokine production. Immunodeficient mice tended to have smaller baseline and maximal diameters of third-order cremaster arterioles than their congenic WT partners. In C57BL/6, baseline diameters were similar in T-B− mice without or with NK cells; in BALB/c, baseline diameters were larger in T-B-NK− mice than in T−B−NK+ mice. Thus, at baseline, lymphocytes tended to promote vasodilation, except BALB/c NK cells, which mediated mild vasoconstriction. The presence of NK cells suppressed dilations to Ado in both strains, to ACh in the C57BL/6 strain, and dilatory responses to ANG II in C57BL/6 and to Phe in BALB/c. In the BALB/c strain, the presence of T and B cells promoted vasodilatory responses to Ado, attenuated dilations to low ACh concentrations, and exaggerated dilation and constriction responses to ANG II. Thus, under agonist challenge, NK cells generally promote constriction, whereas influences of T and B cells depend upon the stimulus. Therefore, lymphocytes or their products have physiological influences on microvascular arteriolar reactivity.
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Affiliation(s)
- Sean Leonard
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario; and
| | - B. Anne Croy
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Coral L. Murrant
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario; and
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Gauthier KM, Goldman DH, Aggarwal NT, Chawengsub Y, Falck JR, Campbell WB. Role of arachidonic acid lipoxygenase metabolites in acetylcholine-induced relaxations of mouse arteries. Am J Physiol Heart Circ Physiol 2010; 300:H725-35. [PMID: 21193584 DOI: 10.1152/ajpheart.00696.2009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Arachidonic acid (AA) metabolites function as EDHFs in arteries of many species. They mediate cyclooxygenase (COX)- and nitric oxide (NO)-independent relaxations to acetylcholine (ACh). However, the role of AA metabolites as relaxing factors in mouse arteries remains incompletely defined. ACh caused concentration-dependent relaxations of the mouse thoracic and abdominal aorta and carotid, femoral, and mesentery arteries (maximal relaxation: 57 ± 4%, 72 ± 4%, 82 ± 3%, 80 ± 3%, and 85 ± 3%, respectively). The NO synthase inhibitor nitro-L-arginine (L-NA; 30 μM) blocked relaxations in the thoracic aorta, and L-NA plus the COX inhibitor indomethacin (10 μM) inhibited relaxations in the abdominal aorta and carotid, femoral, and mesenteric arteries (maximal relaxation: 31 ± 10%, 33 ± 5%, 41 ± 8%, and 73 ± 3%, respectively). In mesenteric arteries, NO- and COX-independent relaxations to ACh were inhibited by the lipoxygenase (LO) inhibitors nordihydroguaiaretic acid (NDGA; 10 μM) and BW-755C (200 μM), the K(+) channel inhibitor apamin (1 μM), and 60 mM KCl and eliminated by endothelium removal. They were not altered by the cytochrome P-450 inhibitor N-methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide (20 μM) or the epoxyeicosatrienoic acid antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (10 μM). AA relaxations were attenuated by NDGA or apamin and eliminated by 60 mM KCl. Reverse-phase HPLC analysis revealed arterial [(14)C]AA metabolites that comigrated with prostaglandins, trihydroxyeicosatrienoic acids (THETAs), hydroxyepoxyeicosatrienoic acids (HEETAs), and hydroxyeicosatetraenoic acids (HETEs). Epoxyeicosatrienoic acids were not observed. Mass spectrometry confirmed the identity of 6-keto-PGF(1α), PGE(2), 12-HETE, 15-HETE, HEETAs, 11,12,15-THETA, and 11,14,15-THETA. AA metabolism was blocked by NDGA and endothelium removal. 11(R),12(S),15(S)-THETA relaxations (maximal relaxation: 73 ± 3%) were endothelium independent and blocked by 60 mM KCl. Western immunoblot analysis and RT-PCR of the aorta and mesenteric arteries demonstrated protein and mRNA expression of leukocyte-type 12/15-LO. Thus, in mouse resistance arteries, 12/15-LO AA metabolites mediate endothelium-dependent relaxations to ACh and AA.
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Affiliation(s)
- Kathryn M Gauthier
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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26
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Stapleton PA, Goodwill AG, James ME, Brock RW, Frisbee JC. Hypercholesterolemia and microvascular dysfunction: interventional strategies. JOURNAL OF INFLAMMATION-LONDON 2010; 7:54. [PMID: 21087503 PMCID: PMC2996379 DOI: 10.1186/1476-9255-7-54] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 11/18/2010] [Indexed: 11/10/2022]
Abstract
Hypercholesterolemia is defined as excessively high plasma cholesterol levels, and is a strong risk factor for many negative cardiovascular events. Total cholesterol levels above 200 mg/dl have repeatedly been correlated as an independent risk factor for development of peripheral vascular (PVD) and coronary artery disease (CAD), and considerable attention has been directed toward evaluating mechanisms by which hypercholesterolemia may impact vascular outcomes; these include both results of direct cholesterol lowering therapies and alternative interventions for improving vascular function. With specific relevance to the microcirculation, it has been clearly demonstrated that evolution of hypercholesterolemia is associated with endothelial cell dysfunction, a near-complete abrogation in vascular nitric oxide bioavailability, elevated oxidant stress, and the creation of a strongly pro-inflammatory condition; symptoms which can culminate in profound impairments/alterations to vascular reactivity. Effective interventional treatments can be challenging as certain genetic risk factors simply cannot be ignored. However, some hypercholesterolemia treatment options that have become widely used, including pharmaceutical therapies which can decrease circulating cholesterol by preventing either its formation in the liver or its absorption in the intestine, also have pleiotropic effects with can directly improve peripheral vascular outcomes. While physical activity is known to decrease PVD/CAD risk factors, including obesity, psychological stress, impaired glycemic control, and hypertension, this will also increase circulating levels of high density lipoprotein and improving both cardiac and vascular function. This review will provide an overview of the mechanistic consequences of the predominant pharmaceutical interventions and chronic exercise to treat hypercholesterolemia through their impacts on chronic sub-acute inflammation, oxidative stress, and microvascular structure/function relationships.
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Affiliation(s)
- Phoebe A Stapleton
- Center for Cardiovascular and Respiratory Sciences, West Virginia University School of Medicine, 1 Medical Center Drive, Morgantown, WV 26506, USA.
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Stapleton PA, Goodwill AG, James ME, D'Audiffret AC, Frisbee JC. Differential impact of familial hypercholesterolemia and combined hyperlipidemia on vascular wall and network remodeling in mice. Microcirculation 2010; 17:47-58. [PMID: 20141600 DOI: 10.1111/j.1549-8719.2009.00003.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Genetic familial hypercholesterolemia (FH) and combined hyperlipidemia (FCH) are characterized by elevated plasma low-density lipoprotein (LDL) (FH) and LDL/triglycerides (FCH), with mouse models represented by LDL receptor (LDLR) and apolipoprotein E (ApoE) gene deletion mice, respectively. Given the impact of FH and FCH on health outcomes, we determined the impact of FH/FCH on vascular structure in LDLR and ApoE mice. LDLR, ApoE and control mice were utilized at 12-13 and 22-23 weeks when gracilis arteries were studied for wall mechanics and gastrocnemius muscles were harvested for microvessel density measurements. Conduit arteries and plasma samples were harvested for biochemical analyses. Arteries from ApoE and LDLR exhibited blunted expansion versus control, reduced distensibility and left-shifted stress versus strain relation (LDLR > ApoE). Microvessel density was reduced in ApoE and LDLR (ApoE > LDLR). Secondary analyses suggested that wall remodeling in LDLR was associated with cholesterol and MCP-1, while rarefaction in ApoE was associated with tumor necrosis factors-alpha, triglycerides and vascular production of TxA(2). Remodeling in ApoE and LDLR appears distinct; as that in LDLR is preferential for vascular walls, while that for ApoE is stronger for rarefaction. Remodeling in LDLR may be associated with cellular adhesion, while that in ApoE may be associated with pro-apoptotsis and constrictor prostanoid generation.
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Affiliation(s)
- Phoebe A Stapleton
- Center for Cardiovascular and Respiratory Sciences, West Virginia University School of Medicine, Morgantown, WV 26506, USA
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Frisbee JC, Goodwill AG, Stapleton PA, Frisbee SJ, d'Audiffret AC. Aspirin resistance with genetic dyslipidemia: contribution of vascular thromboxane generation. Physiol Genomics 2010; 42:331-41. [PMID: 20530721 DOI: 10.1152/physiolgenomics.00090.2010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
One clinical intervention against the negative outcomes associated with atherothrombotic vascular disease (AVD) is low-dose, chronic aspirin therapy. However, epidemiological studies suggest that recurrence of adverse vascular events with aspirin therapy is growing and associated with therapy duration. The contributors to this outcome are unclear and include poor patient compliance and aspirin-resistant platelet thromboxane A(2) (TxA(2)) production. Based on previous results in hypercholesterolemic mice, we hypothesized that elevated aspirin-insensitive arachidonic acid (AA)-induced TxA(2) production by the vascular endothelium contributes to aspirin resistance in AVD independent of platelet behavior. AA-induced dilation was blunted in aortic rings and in arterioles from apolipoprotein E (ApoE) and low-density lipoprotein receptor (LDLR) gene deletion mice (vs. C57/Bl6/J), partially due to elevated TxA(2) production. Acute inhibition of cyclooxygenases or TxA(2) synthase attenuated the increased TxA(2) production in ApoE and LDLR and improved AA-induced dilation, responses that were mirrored by chronic treatment with low-dose aspirin of 16 wk duration. However, this effect was not temporally stable, and, with longer-duration therapy, the beneficial impact of aspirin on outcomes diminished. A similar, though less robust, pattern to the impact of chronic aspirin therapy on vascular outcomes was identified with chronic antioxidant treatment (TEMPOL). These results suggest that in dyslipidemic mice, the beneficial impact of chronic aspirin therapy on improving vascular outcomes decay with time and that a contributing element to subsequent negative vascular events may be the development of aspirin-resistant TxA(2) production by the vasculature itself.
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Affiliation(s)
- Jefferson C Frisbee
- Department of Physiology and Pharmacology, West Virginia University Health Sciences Center, Morgantown, West Virginia 26505, USA.
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Chawengsub Y, Gauthier KM, Campbell WB. Role of arachidonic acid lipoxygenase metabolites in the regulation of vascular tone. Am J Physiol Heart Circ Physiol 2009; 297:H495-507. [PMID: 19525377 DOI: 10.1152/ajpheart.00349.2009] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stimulation of vascular endothelial cells with agonists such as acetylcholine (ACh) or bradykinin or with shear stress activates phospholipases and releases arachidonic acid (AA). AA is metabolized by cyclooxygenases, cytochrome P-450s, and lipoxygenases (LOs) to vasoactive products. In some arteries, a substantial component of the vasodilator response is dependent on LO metabolites of AA. Nitric oxide (NO)- and prostaglandin (PG)-independent vasodilatory responses to ACh and AA are reduced by inhibitors of LO and by antisense oligonucleotides specifically against 15-LO-1. Vasoactive 15-LO metabolites derived from the vascular endothelium include 15-hydroxy-11,12-epoxyeicosatrienoic acid (15-H-11,12-HEETA) that is hydrolyzed by soluble epoxide hydrolase to 11,12,15-trihydroxyeicosatrienoic acid (11,12,15-THETA). HEETA and THETA are endothelium-derived hyperpolarizing factors that induce vascular relaxations by activation of smooth muscle apamin-sensitive, calcium-activated, small-conductance K(+) channels causing hyperpolarization. In other arteries, the 12-LO metabolite 12-hydroxyeicosatetraenoic acid is synthesized by the vascular endothelium and relaxes smooth muscle by large-conductance, calcium-activated K(+) channel activation. Thus formation of vasodilator eicosanoids derived from LO pathways contributes to the regulation of vascular tone, local blood flow, and blood pressure.
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Affiliation(s)
- Yuttana Chawengsub
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Goodwill AG, Stapleton PA, James ME, D'Audiffret AC, Frisbee JC. Increased arachidonic acid-induced thromboxane generation impairs skeletal muscle arteriolar dilation with genetic dyslipidemia. Microcirculation 2009; 15:621-31. [PMID: 18720229 DOI: 10.1080/10739680802308334] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The aim of this study was to determine if arachidonic acid (AA)-induced skeletal muscle arteriolar dilation is altered with hypercholesterolemia in ApoE and low-density lipoprotein receptor (LDLR) gene deletion mice fed a normal diet. This study also determined contributors to altered AA-induced dilation between dyslipidemic mice and controls, C57/Bl/6J (C57). METHODS Gracilis muscle arterioles were isolated, with mechanical responses assessed following a challenge with AA under control conditions and after elements of AA metabolism pathways were inhibited. Conduit arteries from each strain were used to assess AA-induced production of PGI(2) and TxA(2). RESULTS Arterioles from ApoE and LDLR exhibited a blunted dilation to AA versus C57. While responses were cyclo-oxygenase-dependent in all strains, inhibition of thromboxane synthase or blockade of PGH(2)/TxA(2) receptors improved dilation in ApoE and LDLR only. AA-induced generation of PGI(2) was comparable across strains, although TxA(2) generation was increased in ApoE and LDLR. Arteriolar reactivity to PGI(2) and TxA(2) was comparable across strains. Treatment with TEMPOL improved dilation and reduced TxA(2) production with AA in ApoE and LDLR. CONCLUSIONS These results suggest that AA-induced arteriolar dilation is constrained in ApoE and LDLR via an increased production of TxA(2). While partially due to elevated oxidant stress, additional mechanisms contribute that are independent of acute alterations in oxidant tone.
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Affiliation(s)
- Adam G Goodwill
- Department of Physiology and Pharmacology, Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia 26505, USA
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