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Xing H, Sabe SA, Shi G, Harris DD, Liu Y, Sellke FW, Feng J. Role of Protein Kinase C in Metabolic Regulation of Coronary Endothelial Small Conductance Calcium-Activated Potassium Channels. J Am Heart Assoc 2024; 13:e031028. [PMID: 38293916 PMCID: PMC11056132 DOI: 10.1161/jaha.123.031028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 11/02/2023] [Indexed: 02/01/2024]
Abstract
BACKGROUND Small conductance calcium-activated potassium (SK) channels are largely responsible for endothelium-dependent coronary arteriolar relaxation. Endothelial SK channels are downregulated by the reduced form of nicotinamide adenine dinucleotide (NADH), which is increased in the setting of diabetes, yet the mechanisms of these changes are unclear. PKC (protein kinase C) is an important mediator of diabetes-induced coronary endothelial dysfunction. Thus, we aimed to determine whether NADH signaling downregulates endothelial SK channel function via PKC. METHODS AND RESULTS SK channel currents of human coronary artery endothelial cells were measured by whole cell patch clamp method in the presence/absence of NADH, PKC activator phorbol 12-myristate 13-acetate, PKC inhibitors, or endothelial PKCα/PKCβ knockdown by using small interfering RNA. Human coronary arteriolar reactivity in response to the selective SK activator NS309 was measured by vessel myography in the presence of NADH and PKCβ inhibitor LY333531. NADH (30-300 μmol/L) or PKC activator phorbol 12-myristate 13-acetate (30-300 nmol/L) reduced endothelial SK current density, whereas the selective PKCᵦ inhibitor LY333531 significantly reversed the NADH-induced SK channel inhibition. PKCβ small interfering RNA, but not PKCα small interfering RNA, significantly prevented the NADH- and phorbol 12-myristate 13-acetate-induced SK inhibition. Incubation of human coronary artery endothelial cells with NADH significantly increased endothelial PKC activity and PKCβ expression and activation. Treating vessels with NADH decreased coronary arteriolar relaxation in response to the selective SK activator NS309, and this inhibitive effect was blocked by coadministration with PKCβ inhibitor LY333531. CONCLUSIONS NADH-induced inhibition of endothelial SK channel function is mediated via PKCβ. These findings may provide insight into novel therapeutic strategies to preserve coronary microvascular function in patients with metabolic syndrome and coronary disease.
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Affiliation(s)
- Hang Xing
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Sharif A. Sabe
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Guangbin Shi
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Dwight D. Harris
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Yuhong Liu
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Frank W. Sellke
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Jun Feng
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
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2
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Frara N, Giaddui D, Braverman AS, Jawawdeh K, Wu C, Ruggieri, Sr MR, Barbe MF. Mechanisms involved in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox)-derived reactive oxygen species (ROS) modulation of muscle function in human and dog bladders. PLoS One 2023; 18:e0287212. [PMID: 37352265 PMCID: PMC10289437 DOI: 10.1371/journal.pone.0287212] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/01/2023] [Indexed: 06/25/2023] Open
Abstract
Roles of redox signaling in bladder function is still under investigation. We explored the physiological role of reactive oxygen species (ROS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) in regulating bladder function in humans and dogs. Mucosa-denuded bladder smooth muscle strips obtained from 7 human organ donors and 4 normal dogs were mounted in muscle baths, and trains of electrical field stimulation (EFS) applied for 20 minutes at 90-second intervals. Subsets of strips were incubated with hydrogen peroxide (H2O2), angiotensin II (Ang II; Nox activator), apocynin (inhibitor of Noxs and ROS scavenger), or ZD7155 (specific inhibitor of angiotensin type 1 (AT1) receptor) for 20 minutes in continued EFS trains. Subsets treated with inhibitors were then treated with H2O2 or Ang II. In human and dog bladders, the ROS, H2O2 (100μM), caused contractions and enhanced EFS-induced contractions. Apocynin (100μM) attenuated EFS-induced strip contractions in both species; subsequent treatment with H2O2 restored strip activity. In human bladders, Ang II (1μM) did not enhance EFS-induced contractions yet caused direct strip contractions. In dog bladders, Ang II enhanced both EFS-induced and direct contractions. Ang II also partially restored EFS-induced contractions attenuated by prior apocynin treatment. In both species, treatment with ZD7155 (10μM) inhibited EFS-induced activity; subsequent treatment with Ang II did not restore strip activity. Collectively, these data provide evidence that ROS can modulate bladder function without exogenous stimuli. Since inflammation is associated with oxidative damage, the effects of Ang II on bladder smooth muscle function may have pathologic implications.
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Affiliation(s)
- Nagat Frara
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Dania Giaddui
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Alan S. Braverman
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Kais Jawawdeh
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Changhao Wu
- Department of Biochemistry and Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Michael R. Ruggieri, Sr
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Mary F. Barbe
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
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3
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Lansdell TA, Chambers LC, Dorrance AM. Endothelial Cells and the Cerebral Circulation. Compr Physiol 2022; 12:3449-3508. [PMID: 35766836 DOI: 10.1002/cphy.c210015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.
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Affiliation(s)
- Theresa A Lansdell
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Laura C Chambers
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
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4
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De Silva TM, Sobey CG. Cerebral Vascular Biology in Health and Disease. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00001-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Velásquez M, Peláez LF, Rojas M, Narváez-Sánchez R, Velásquez JA, Escudero C, San Martín S, Cadavid ÁP. Differences in Endothelial Activation and Dysfunction Induced by Antiphospholipid Antibodies Among Groups of Patients With Thrombotic, Refractory, and Non-refractory Antiphospholipid Syndrome. Front Physiol 2021; 12:764702. [PMID: 34925061 PMCID: PMC8675389 DOI: 10.3389/fphys.2021.764702] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/02/2021] [Indexed: 01/20/2023] Open
Abstract
Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by pregnancy morbidity or thrombosis and persistent antiphospholipid antibodies (aPL) that bind to the endothelium and induce endothelial activation, which is evidenced by the expression of adhesion molecules and the production of reactive oxygen species (ROS) and subsequent endothelial dysfunction marked by a decrease in the synthesis and release of nitric oxide (NO). These endothelial alterations are the key components for the development of severe pathological processes in APS. Patients with APS can be grouped according to the presence of other autoimmune diseases (secondary APS), thrombosis alone (thrombotic APS), pregnancy morbidity (obstetric APS), and refractoriness to conventional treatment regimens (refractory APS). Typically, patients with severe and refractory obstetric APS exhibit thrombosis and are classified as those having primary or secondary APS. The elucidation of the mechanisms underlying these alterations according to the different groups of patients with APS could help establish new therapies, particularly necessary for severe and refractory cases. Therefore, this study aimed to evaluate the differences in endothelial activation and dysfunction induced by aPL between patients with refractory obstetric APS and other APS clinical manifestations. Human umbilical vein endothelial cells (HUVECs) were stimulated with polyclonal immunoglobulin-G (IgG) from different groups of patients n = 21), including those with primary (VTI) and secondary thrombotic APS (VTII) and refractory primary (RI+), refractory secondary (RII+), and non-refractory primary (NR+) obstetric APS. All of them with thrombosis. The expression of adhesion molecules; the production of ROS, NO, vascular endothelial growth factor (VEGF), and endothelin-1; and the generation of microparticles were used to evaluate endothelial activation and dysfunction. VTI IgG induced the expression of adhesion molecules and the generation of microparticles and VEGF. RI+ IgG induced the expression of adhesion molecules and decreased NO production. RII+ IgG increased the production of microparticles, ROS, and endothelin-1 and reduced NO release. NR+ IgG increased the production of microparticles and endothelin-1 and decreased the production of VEGF and NO. These findings reveal differences in endothelial activation and dysfunction among groups of patients with APS, which should be considered in future studies to evaluate new therapies, especially in refractory cases.
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Affiliation(s)
- Manuela Velásquez
- Grupo Reproducción, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia UdeA, Medellín, Colombia
| | - Luisa F Peláez
- Grupo Reproducción, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia UdeA, Medellín, Colombia
| | - Mauricio Rojas
- Grupo de Inmunología Celular e Inmunogenética, Facultad de Medicina, Universidad de Antioquia UdeA, Unidad de Citometría de Flujo, Sede de Investigación Universitaria, Medellín, Colombia
| | - Raúl Narváez-Sánchez
- Physiology and Biochemistry Research Group-PHYSIS, Faculty of Medicine, University of Antioquia UdeA, Medellín, Colombia
| | | | - Carlos Escudero
- Red Iberoamericana de Alteraciones Vasculares Asociadas a TRanstornos del EMbarazo (RIVATREM), Chillán, Chile.,Vascular Physiology Laboratory, Basic Sciences Department, Faculty of Sciences, Universidad del Bio-Bio, Chillán, Chile.,Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile
| | - Sebastián San Martín
- Red Iberoamericana de Alteraciones Vasculares Asociadas a TRanstornos del EMbarazo (RIVATREM), Chillán, Chile.,Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile.,Biomedical Research Center School of Medicine, Universidad de Valparaíso, Valparaíso, Chile
| | - Ángela P Cadavid
- Grupo Reproducción, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia UdeA, Medellín, Colombia.,Red Iberoamericana de Alteraciones Vasculares Asociadas a TRanstornos del EMbarazo (RIVATREM), Chillán, Chile.,Grupo de Investigación en Trombosis, Facultad de Medicina, Universidad de Antioquia UdeA, Medellín, Colombia
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6
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Negri S, Faris P, Tullii G, Vismara M, Pellegata AF, Lodola F, Guidetti G, Rosti V, Antognazza MR, Moccia F. Conjugated polymers mediate intracellular Ca 2+ signals in circulating endothelial colony forming cells through the reactive oxygen species-dependent activation of Transient Receptor Potential Vanilloid 1 (TRPV1). Cell Calcium 2021; 101:102502. [PMID: 34896699 DOI: 10.1016/j.ceca.2021.102502] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/14/2021] [Accepted: 11/15/2021] [Indexed: 02/07/2023]
Abstract
Endothelial colony forming cells (ECFCs) represent the most suitable cellular substrate to induce revascularization of ischemic tissues. Recently, optical excitation of the light-sensitive conjugated polymer, regioregular Poly (3-hexyl-thiophene), rr-P3HT, was found to stimulate ECFC proliferation and tube formation by activating the non-selective cation channel, Transient Receptor Potential Vanilloid 1 (TRPV1). Herein, we adopted a multidisciplinary approach, ranging from intracellular Ca2+ imaging to pharmacological manipulation and genetic suppression of TRPV1 expression, to investigate the effects of photoexcitation on intracellular Ca2+ concentration ([Ca2+]i) in circulating ECFCs plated on rr-P3HT thin films. Polymer-mediated optical excitation induced a long-lasting increase in [Ca2+]i that could display an oscillatory pattern at shorter light stimuli. Pharmacological and genetic manipulation revealed that the Ca2+ response to light was triggered by extracellular Ca2+ entry through TRPV1, whose activation required the production of reactive oxygen species at the interface between rr-P3HT and the cell membrane. Light-induced TRPV1-mediated Ca2+ entry was able to evoke intracellular Ca2+ release from the endoplasmic reticulum through inositol-1,4,5-trisphosphate receptors, followed by store-operated Ca2+ entry on the plasma membrane. These data show that TRPV1 may serve as a decoder at the interface between rr-P3HT thin films and ECFCs to translate optical excitation in pro-angiogenic Ca2+ signals.
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Affiliation(s)
- Sharon Negri
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Pawan Faris
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Gabriele Tullii
- Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, 20133 Milano, Italy
| | - Mauro Vismara
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Alessandro F Pellegata
- Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, 20133 Milano, Italy
| | - Francesco Lodola
- Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, 20133 Milano, Italy
| | - Gianni Guidetti
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Vittorio Rosti
- Center for the Study of Myelofibrosis, Laboratory of Biochemistry, Biotechnology and Advanced Diagnosis, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy
| | - Maria Rosa Antognazza
- Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, 20133 Milano, Italy.
| | - Francesco Moccia
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, 27100 Pavia, Italy.
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7
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Costa TJ, Barros PR, Arce C, Santos JD, da Silva-Neto J, Egea G, Dantas AP, Tostes RC, Jiménez-Altayó F. The homeostatic role of hydrogen peroxide, superoxide anion and nitric oxide in the vasculature. Free Radic Biol Med 2021; 162:615-635. [PMID: 33248264 DOI: 10.1016/j.freeradbiomed.2020.11.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/08/2020] [Accepted: 11/19/2020] [Indexed: 02/07/2023]
Abstract
Reactive oxygen and nitrogen species are produced in a wide range of physiological reactions that, at low concentrations, play essential roles in living organisms. There is a delicate equilibrium between formation and degradation of these mediators in a healthy vascular system, which contributes to maintaining these species under non-pathological levels to preserve normal vascular functions. Antioxidants scavenge reactive oxygen and nitrogen species to prevent or reduce damage caused by excessive oxidation. However, an excessive reductive environment induced by exogenous antioxidants may disrupt redox balance and lead to vascular pathology. This review summarizes the main aspects of free radical biochemistry (formation, sources and elimination) and the crucial actions of some of the most biologically relevant and well-characterized reactive oxygen and nitrogen species (hydrogen peroxide, superoxide anion and nitric oxide) in the physiological regulation of vascular function, structure and angiogenesis. Furthermore, current preclinical and clinical evidence is discussed on how excessive removal of these crucial responses by exogenous antioxidants (vitamins and related compounds, polyphenols) may perturb vascular homeostasis. The aim of this review is to provide information of the crucial physiological roles of oxidation in the endothelium, vascular smooth muscle cells and perivascular adipose tissue for developing safer and more effective vascular interventions with antioxidants.
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Affiliation(s)
- Tiago J Costa
- Pharmacology Department, Ribeirao Preto Medical School, University of São Paulo, Brazil.
| | | | - Cristina Arce
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, Barcelona, Spain; Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS)-University of Barcelona, Barcelona, Spain; Institut de Nanociencies i Nanotecnologia (IN2UB), University of Barcelona, Barcelona, Spain
| | | | - Júlio da Silva-Neto
- Pharmacology Department, Ribeirao Preto Medical School, University of São Paulo, Brazil
| | - Gustavo Egea
- Department of Biomedical Sciences, University of Barcelona School of Medicine and Health Sciences, Barcelona, Spain; Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS)-University of Barcelona, Barcelona, Spain; Institut de Nanociencies i Nanotecnologia (IN2UB), University of Barcelona, Barcelona, Spain
| | - Ana Paula Dantas
- Institut Clínic del Tòrax, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Rita C Tostes
- Pharmacology Department, Ribeirao Preto Medical School, University of São Paulo, Brazil
| | - Francesc Jiménez-Altayó
- Department of Pharmacology, Therapeutics and Toxicology, Neuroscience Institute, School of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain.
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8
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Luo Y, Wang Y, Luo W. C allele of -786 T>C polymorphism in the promoter region of endothelial nitric oxide synthase is responsible for endothelial dysfunction in the patients with rheumatoid arthritis. J Cell Biochem 2019; 121:363-370. [PMID: 31209933 DOI: 10.1002/jcb.29184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 02/26/2019] [Accepted: 02/28/2019] [Indexed: 11/10/2022]
Abstract
BACKGROUND This study aimed to explore the roles of endothelial nitric oxide synthase (eNOS) in the control of metastasis of infection with endothelial dysfunction, as well as the roles of -786T>C polymorphism in eNOS promoter in the control of metastasis of endothelial function. METHOD In-silicon analysis and luciferase assay were used to identify the location of -786>C on the promoter of eNOS. Subsequently, real-time PCR and Western-blot were used to determine the expression level of eNOS. Ultrasound examination was used to detect baseline brachial artery diameter and flow-mediated dilation of patients in different treat groups. RESULTS -786T>C was located on the promoter of eNOS, and the luciferase activity of cells transfected with -786-C allele was much higher than empty vector, while even higher subsequent to transfection of -786-T allele. In addition, the result of ultrasound examination showed that the baseline brachial artery diameter was comparable between patients genotyped as TT, TC and CC, while the flow-mediated dilation of patients genotyped as TC was much higher compared with CC group, and the flow-mediated dilation of patients genotyped as TT even higher than TC group. We found eNOS messenger RNA and protein with TT genotype was significantly higher compared with other genotypes. And the production of NO was remarkably higher in TT groups compared with TC and CC, while the production of NO in TC and CC groups were similar. CONCLUSION These findings indicated that down-expression of -786T>C located on the promoter of eNOS is associated with an increased risk of endothelial dysfunction.
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Affiliation(s)
- Yanli Luo
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yang Wang
- Department of Internal Medicine, Yixing People's Hospital, Jiangsu, China
| | - Wanjun Luo
- Department of Cardiovascualr Surgery, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
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9
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Zavodnik I, Buko V, Lukivskaya O, Lapshina E, Ilyich T, Belonovskaya E, Kirko S, Naruta E, Kuzmitskaya I, Budryn G, Zyzelevicz D, Orach J, Zakrzeska A, Kiryukhina L. Cranberry (Vaccinium macrocarpon) peel polyphenol-rich extract attenuates rat liver mitochondria impairments in alcoholic steatohepatitis in vivo and after oxidative treatment in vitro. J Funct Foods 2019. [DOI: 10.1016/j.jff.2019.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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10
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Carvalho C, Moreira PI. Oxidative Stress: A Major Player in Cerebrovascular Alterations Associated to Neurodegenerative Events. Front Physiol 2018; 9:806. [PMID: 30018565 PMCID: PMC6037979 DOI: 10.3389/fphys.2018.00806] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/08/2018] [Indexed: 12/19/2022] Open
Abstract
The brain is one of the most exquisite organs in the body with high metabolic demands, and requires a tight regulation of the surrounding environment. This tight control is exerted by the neurovascular unit (NVU) comprising different cell types, where endothelial cells play the commander-in-chief role. Thus, it is assumable that even slight perturbations in NVU might affect, in some cases irreversibly, brain homeostasis and health. In this line, recent findings support the two-hit vascular hypothesis for neurodegenerative conditions, where vascular dysfunction underlies the development of neurodegenerative diseases, such as Alzheimer’s disease (AD). Knowing that endothelial cells are rich in mitochondria and nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, two major reactive oxygen species (ROS) sources, this review aims to gather information on how oxidative stress is in the front line of vascular alterations observed in brain aging and neurodegenerative conditions, particularly AD. Also, a brief discussion about the therapeutic strategies aimed to protect against cerebrovascular diseases is included.
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Affiliation(s)
- Cristina Carvalho
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Paula I Moreira
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Laboratory of Physiology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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11
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Coucha M, Abdelsaid M, Ward R, Abdul Y, Ergul A. Impact of Metabolic Diseases on Cerebral Circulation: Structural and Functional Consequences. Compr Physiol 2018; 8:773-799. [PMID: 29687902 DOI: 10.1002/cphy.c170019] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Metabolic diseases including obesity, insulin resistance, and diabetes have profound effects on cerebral circulation. These diseases not only affect the architecture of cerebral blood arteries causing adverse remodeling, pathological neovascularization, and vasoregression but also alter the physiology of blood vessels resulting in compromised myogenic reactivity, neurovascular uncoupling, and endothelial dysfunction. Coupled with the disruption of blood brain barrier (BBB) integrity, changes in blood flow and microbleeds into the brain rapidly occur. This overview is organized into sections describing cerebrovascular architecture, physiology, and BBB in these diseases. In each section, we review these properties starting with larger arteries moving into smaller vessels. Where information is available, we review in the order of obesity, insulin resistance, and diabetes. We also tried to include information on biological variables such as the sex of the animal models noted since most of the information summarized was obtained using male animals. © 2018 American Physiological Society. Compr Physiol 8:773-799, 2018.
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Affiliation(s)
- Maha Coucha
- South University, School of Pharmacy, Savannah, Georgia, USA
| | | | - Rebecca Ward
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Yasir Abdul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Adviye Ergul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
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12
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Cellular and Oxidative Mechanisms Associated with Interleukin-6 Signaling in the Vasculature. Int J Mol Sci 2017; 18:ijms18122563. [PMID: 29186034 PMCID: PMC5751166 DOI: 10.3390/ijms18122563] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/17/2017] [Accepted: 11/19/2017] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species, particularly superoxide, promote endothelial dysfunction and alterations in vascular structure. It is increasingly recognized that inflammatory cytokines, such as interleukin-6 (IL-6), contribute to endothelial dysfunction and vascular hypertrophy and fibrosis. IL-6 is increased in a number of cardiovascular diseases, including hypertension. IL-6 is also associated with a higher incidence of future cardiovascular events and all-cause mortality. Both immune and vascular cells produce IL-6 in response to a number of stimuli, such as angiotensin II. The vasculature is responsive to IL-6 produced from vascular and non-vascular sources via classical IL-6 signaling involving a membrane-bound IL-6 receptor (IL-6R) and membrane-bound gp130 via Jak/STAT as well as SHP2-dependent signaling pathways. IL-6 signaling is unique because it can also occur via a soluble IL-6 receptor (sIL-6R) which allows for IL-6 signaling in tissues that do not normally express IL-6R through a process referred to as IL-6 trans-signaling. IL-6 signaling mediates a vast array of effects in the vascular wall, including endothelial activation, vascular permeability, immune cell recruitment, endothelial dysfunction, as well as vascular hypertrophy and fibrosis. Many of the effects of IL-6 on vascular function and structure are representative of loss or reductions in nitric oxide (NO) bioavailability. IL-6 has direct effects on endothelial nitric oxide synthase activity and expression as well as increasing vascular superoxide, which rapidly inactivates NO thereby limiting NO bioavailability. The goal of this review is to highlight both the cellular and oxidative mechanisms associated with IL-6-signaling in the vascular wall in general, in hypertension, and in response to angiotensin II.
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13
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Houston SA, Ugusman A, Gnanadesikan S, Kennedy S. An investigation of the antiplatelet effects of succinobucol (AGI-1067). Platelets 2016; 28:295-300. [PMID: 27681689 DOI: 10.1080/09537104.2016.1218456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Succinobucol is a phenolic antioxidant with anti-inflammatory and antiplatelet effects. Given the importance of oxidant stress in modulating platelet-platelet and platelet-vessel wall interactions, the aim of this study was to establish if antioxidant activity was responsible for the antiplatelet activity of succinobucol. Platelet aggregation in response to collagen and adenosine diphosphate (ADP) was studied in rabbit whole blood and platelet-rich plasma using impedance aggregometry. The effect of oxidant stress on aggregation, platelet lipid peroxides, and vascular tone was studied by incubating platelets, washed platelets or preconstricted rabbit iliac artery rings respectively with a combination of xanthine and xanthine oxidase (X/XO). To study the effect of succinobucol in vivo, anaesthetized rats were injected with up to 150 mg/kg succinobucol and aggregation measured in blood removed 15 mins later. Succinobucol (10-5-10-4 M) significantly attenuated platelet aggregation to collagen and ADP in whole blood and platelet-rich plasma. X/XO significantly increased aggregation to collagen and platelet lipid peroxides and this was reversed by succinobucol. Addition of X/XO to denuded rabbit iliac arteries caused a dose-dependent relaxation which was significantly inhibited by succinobucol. In vivo administration up to 150 mg/kg had no effect on heart rate or mean arterial blood pressure but significantly inhibited platelet aggregation to collagen ex vivo. In conclusion, succinobucol displays anti-platelet activity in rabbit and rat blood and reverses the increase in platelet aggregation in response to oxidant stress.
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Affiliation(s)
- Stephanie A Houston
- a Institute of Cardiovascular and Medical Sciences , University of Glasgow , Glasgow , UK.,b Manchester Immunology Group , Manchester , UK
| | - Azizah Ugusman
- a Institute of Cardiovascular and Medical Sciences , University of Glasgow , Glasgow , UK.,c Department of Physiology, Faculty of Medicine , National University of Malaysia Medical Centre , Kuala Lumpur , Malaysia
| | - Sukanya Gnanadesikan
- a Institute of Cardiovascular and Medical Sciences , University of Glasgow , Glasgow , UK
| | - Simon Kennedy
- a Institute of Cardiovascular and Medical Sciences , University of Glasgow , Glasgow , UK
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Jackson WF. Arteriolar oxygen reactivity: where is the sensor and what is the mechanism of action? J Physiol 2016; 594:5055-77. [PMID: 27324312 PMCID: PMC5023707 DOI: 10.1113/jp270192] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 06/13/2016] [Indexed: 01/02/2023] Open
Abstract
Arterioles in the peripheral microcirculation are exquisitely sensitive to changes in PO2 in their environment: increases in PO2 cause vasoconstriction while decreases in PO2 result in vasodilatation. However, the cell type that senses O2 (the O2 sensor) and the signalling pathway that couples changes in PO2 to changes in arteriolar tone (the mechanism of action) remain unclear. Many (but not all) ex vivo studies of isolated cannulated resistance arteries and large, first-order arterioles support the hypothesis that these vessels are intrinsically sensitive to PO2 with the smooth muscle, endothelial cells, or red blood cells serving as the O2 sensor. However, in situ studies testing these hypotheses in downstream arterioles have failed to find evidence of intrinsic O2 sensitivity, and instead have supported the idea that extravascular cells sense O2 . Similarly, ex vivo studies of isolated, cannulated resistance arteries and large first-order arterioles support the hypotheses that O2 -dependent inhibition of production of vasodilator cyclooxygenase products or O2 -dependent destruction of nitric oxide mediates O2 reactivity of these upstream vessels. In contrast, most in vivo studies of downstream arterioles have disproved these hypotheses and instead have provided evidence supporting the idea that O2 -dependent production of vasoconstrictors mediates arteriolar O2 reactivity, with significant regional heterogeneity in the specific vasoconstrictor involved. Oxygen-induced vasoconstriction may serve as a protective mechanism to reduce the oxidative burden to which a tissue is exposed, a process that is superimposed on top of the local mechanisms which regulate tissue blood flow to meet a tissue's metabolic demand.
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Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, 48824, USA.
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De Silva TM, Miller AA. Cerebral Small Vessel Disease: Targeting Oxidative Stress as a Novel Therapeutic Strategy? Front Pharmacol 2016; 7:61. [PMID: 27014073 PMCID: PMC4794483 DOI: 10.3389/fphar.2016.00061] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/04/2016] [Indexed: 12/25/2022] Open
Abstract
Cerebral small vessel disease (SVD) is a major contributor to stroke, and a leading cause of cognitive impairment and dementia. Despite the devastating effects of cerebral SVD, the pathogenesis of cerebral SVD is still not completely understood. Moreover, there are no specific pharmacological strategies for its prevention or treatment. Cerebral SVD is characterized by marked functional and structural abnormalities of the cerebral microcirculation. The clinical manifestations of these pathological changes include lacunar infarcts, white matter hyperintensities, and cerebral microbleeds. The main purpose of this review is to discuss evidence implicating oxidative stress in the arteriopathy of both non-amyloid and amyloid (cerebral amyloid angiopathy) forms of cerebral SVD and its most important risk factors (hypertension and aging), as well as its contribution to cerebral SVD-related brain injury and cognitive impairment. We also highlight current evidence of the involvement of the NADPH oxidases in the development of oxidative stress, enzymes that are a major source of reactive oxygen species in the cerebral vasculature. Lastly, we discuss potential pharmacological strategies for oxidative stress in cerebral SVD, including some of the historical and emerging NADPH oxidase inhibitors.
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Affiliation(s)
- T. Michael De Silva
- Department of Pharmacology, Biomedicine Discovery Institute, Monash UniversityMelbourne, VIC, Australia
| | - Alyson A. Miller
- Cerebrovascular and Stroke Laboratory, School of Health and Biomedical Sciences, RMIT UniversityMelbourne, VIC, Australia
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16
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Antonopoulos AS, Margaritis M, Verheule S, Recalde A, Sanna F, Herdman L, Psarros C, Nasrallah H, Coutinho P, Akoumianakis I, Brewer AC, Sayeed R, Krasopoulos G, Petrou M, Tarun A, Tousoulis D, Shah AM, Casadei B, Channon KM, Antoniades C. Mutual Regulation of Epicardial Adipose Tissue and Myocardial Redox State by PPAR-γ/Adiponectin Signalling. Circ Res 2016; 118:842-55. [PMID: 26838789 PMCID: PMC4772814 DOI: 10.1161/circresaha.115.307856] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/21/2016] [Indexed: 01/09/2023]
Abstract
RATIONALE Adiponectin has anti-inflammatory effects in experimental models, but its role in the regulation of myocardial redox state in humans is unknown. Although adiponectin is released from epicardial adipose tissue (EpAT), it is unclear whether it exerts any paracrine effects on the human myocardium. OBJECTIVE To explore the cross talk between EpAT-derived adiponectin and myocardial redox state in the human heart. METHODS AND RESULTS EpAT and atrial myocardium were obtained from 306 patients undergoing coronary artery bypass grafting. Functional genetic polymorphisms that increase ADIPOQ expression (encoding adiponectin) led to reduced myocardial nicotinamide adenine dinucleotide phosphate oxidase-derived O2 (-), whereas circulating adiponectin and ADIPOQ expression in EpAT were associated with elevated myocardial O2 (-). In human atrial tissue, we demonstrated that adiponectin suppresses myocardial nicotinamide adenine dinucleotide phosphate oxidase activity, by preventing AMP kinase-mediated translocation of Rac1 and p47(phox) from the cytosol to the membranes. Induction of O2 (-) production in H9C2 cardiac myocytes led to the release of a transferable factor able to induce peroxisome proliferator-activated receptor-γ-mediated upregulation of ADIPOQ expression in cocultured EpAT. Using a NOX2 transgenic mouse and a pig model of rapid atrial pacing, we found that oxidation products (such as 4-hydroxynonenal) released from the heart trigger peroxisome proliferator-activated receptor-γ-mediated upregulation of ADIPOQ in EpAT. CONCLUSIONS We demonstrate for the first time in humans that adiponectin directly decreases myocardial nicotinamide adenine dinucleotide phosphate oxidase activity via endocrine or paracrine effects. Adiponectin expression in EpAT is controlled by paracrine effects of oxidation products released from the heart. These effects constitute a novel defense mechanism of the heart against myocardial oxidative stress.
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Affiliation(s)
- Alexios S Antonopoulos
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Marios Margaritis
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Sander Verheule
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Alice Recalde
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Fabio Sanna
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Laura Herdman
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Costas Psarros
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Hussein Nasrallah
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Patricia Coutinho
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Ioannis Akoumianakis
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Alison C Brewer
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Rana Sayeed
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - George Krasopoulos
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Mario Petrou
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Akansha Tarun
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Dimitris Tousoulis
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Ajay M Shah
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Barbara Casadei
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Keith M Channon
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.)
| | - Charalambos Antoniades
- From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom (A.S.A., M.M., A.R., F.S., L.H., C.P., P.C., I.A., A.T., B.C., K.M.C., C.A.); Cardiac Electrophysiology Group, Department of Physiology, Maastricht University, Maastricht, The Netherlands (S.V., H.N.); Department of Cardiology, Athens University Medical School, Athens, Greece (D.T.); Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (A.C.B., A.M.S.); and Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, United Kingdom (R.S., G.K., M.P.).
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Ali MI, Chen X, Didion SP. Heterozygous eNOS deficiency is associated with oxidative stress and endothelial dysfunction in diet-induced obesity. Physiol Rep 2015; 3:e12630. [PMID: 26660551 PMCID: PMC4760452 DOI: 10.14814/phy2.12630] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/22/2015] [Accepted: 10/26/2015] [Indexed: 01/08/2023] Open
Abstract
Heterozygous endothelial nitric oxide synthase (eNOS) deficiency is associated with normal endothelium-dependent responses, however, little is known regarding the mechanisms that maintain or impair endothelial function with heterozygous eNOS deficiency. The goals of this study were to (1) determine mechanism(s) which serve to maintain normal endothelial function in the absence of a single eNOS gene; and (2) to determine whether heterozygous eNOS deficiency predisposes blood vessels to endothelial dysfunction in response to a high-fat diet (HFD). Responses of carotid arteries were examined in wild-type (eNOS(+/+)) and heterozygous eNOS-deficient (eNOS(+/-)) treated with either vehicle (saline), N(G)-nitro-L-arginine (L-NNA, 100 μmol/L), an inhibitor of nitric oxide synthase, or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 1 μmol/L), an inhibitor of soluble guanylyl cyclase (sGC), and in eNOS(+/+) and eNOS(+/-) mice fed a control (10%) or a 45% HFD (kcal from fat). Responses to acetylcholine (ACh) were similar in vehicle-treated arteries from eNOS(+/+) and eNOS(+/-) mice, and were equally inhibited by L-NNA and ODQ. Phosphorylation of eNOS Ser1176, a site associated with increased eNOS activity, was significantly greater in eNOS(+/-) mice most likely as a compensatory response for the loss of a single eNOS gene. In contrast, responses to ACh were markedly impaired in carotid arteries from eNOS(+/-), but not eNOS(+/+), mice fed a HFD. Vascular superoxide levels as well as plasma levels of the pro-inflammatory cytokine interleukin-6 (IL-6) were selectively increased in HFD-fed eNOS(+/-) mice. In reconstitution experiments, IL-6 produced concentration-dependent impairment of endothelial responses as well as greater increases in NADPH-stimulated superoxide levels in arteries from eNOS(+/-) mice fed a control diet compared to eNOS(+/+) mice. Our findings of increased Ser1176-phosphorylation reveal a mechanism by which NOS- and sGC-dependent endothelial function can be maintained with heterozygous eNOS deficiency. In addition, heterozygous eNOS deficiency predisposes blood vessels to developing endothelial dysfunction in response to a HFD. The impairment produced by a HFD in eNOS(+/-) mice appears to be mediated by IL-6-induced increases in vascular superoxide. These findings serve as an important example of eNOS haploinsufficiency, one that may contribute to the development of carotid artery disease in obese humans.
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Affiliation(s)
- M Irfan Ali
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia
| | - Xunsheng Chen
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia
| | - Sean P Didion
- Department of Pharmacology and Department of Neurology, The University of Mississippi Medical Center, Jackson, Mississippi
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Sullivan MN, Gonzales AL, Pires PW, Bruhl A, Leo MD, Li W, Oulidi A, Boop FA, Feng Y, Jaggar JH, Welsh DG, Earley S. Localized TRPA1 channel Ca2+ signals stimulated by reactive oxygen species promote cerebral artery dilation. Sci Signal 2015; 8:ra2. [PMID: 25564678 DOI: 10.1126/scisignal.2005659] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Reactive oxygen species (ROS) can have divergent effects in cerebral and peripheral circulations. We found that Ca(2+)-permeable transient receptor potential ankyrin 1 (TRPA1) channels were present and colocalized with NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidase 2 (NOX2), a major source of ROS, in the endothelium of cerebral arteries but not in other vascular beds. We recorded and characterized ROS-triggered Ca(2+) signals representing Ca(2+) influx through single TRPA1 channels, which we called "TRPA1 sparklets." TRPA1 sparklet activity was low under basal conditions but was stimulated by NOX-generated ROS. Ca(2+) entry during a single TRPA1 sparklet was twice that of a TRPV4 sparklet and ~200 times that of an L-type Ca(2+) channel sparklet. TRPA1 sparklets representing the simultaneous opening of two TRPA1 channels were more common in endothelial cells than in human embryonic kidney (HEK) 293 cells expressing TRPA1. The NOX-induced TRPA1 sparklets activated intermediate-conductance, Ca(2+)-sensitive K(+) channels, resulting in smooth muscle hyperpolarization and vasodilation. NOX-induced activation of TRPA1 sparklets and vasodilation required generation of hydrogen peroxide and lipid-peroxidizing hydroxyl radicals as intermediates. 4-Hydroxy-nonenal, a metabolite of lipid peroxidation, also increased TRPA1 sparklet frequency and dilated cerebral arteries. These data suggest that in the cerebral circulation, lipid peroxidation metabolites generated by ROS activate Ca(2+) influx through TRPA1 channels in the endothelium of cerebral arteries to cause dilation.
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Affiliation(s)
- Michelle N Sullivan
- Vascular Physiology Research Group, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Albert L Gonzales
- Department of Pharmacology, University of Vermont School of Medicine, Burlington, VT 05405, USA
| | - Paulo W Pires
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557-0318, USA
| | - Allison Bruhl
- Vascular Physiology Research Group, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - M Dennis Leo
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Wencheng Li
- Vascular Physiology Research Group, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Agathe Oulidi
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557-0318, USA
| | - Frederick A Boop
- Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Yumei Feng
- Vascular Physiology Research Group, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Jonathan H Jaggar
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Donald G Welsh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Scott Earley
- Department of Pharmacology, University of Nevada School of Medicine, Reno, NV 89557-0318, USA.
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Gomolak JR, Didion SP. Angiotensin II-induced endothelial dysfunction is temporally linked with increases in interleukin-6 and vascular macrophage accumulation. Front Physiol 2014; 5:396. [PMID: 25400581 PMCID: PMC4212611 DOI: 10.3389/fphys.2014.00396] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 09/24/2014] [Indexed: 01/18/2023] Open
Abstract
Angiotensin II (Ang II) is associated with vascular hypertrophy, endothelial dysfunction and activation of a number of inflammatory molecules, however the linear events involved in the development of hypertension and endothelial dysfunction produced in response to Ang II are not well defined. The goal of this study was to examine the dose- and temporal-dependent development of endothelial dysfunction in response to Ang II. Blood pressure and responses of carotid arteries were examined in control (C57Bl/6) mice and in mice infused with 50, 100, 200, 400, or 1000 ng/kg/min Ang II for either 14 or 28 Days. Infusion of Ang II was associated with graded and marked increases in systolic blood pressure and plasma Ang II concentrations. While low doses of Ang II (i.e., 50 and 100 ng/kg/min) had little to no effect on blood pressure or endothelial function, high doses of Ang II (e.g., 1000 ng/kg/min) were associated with large increases in arterial pressure and marked impairment of endothelial function. In contrast, intermediate doses of Ang II (200 and 400 ng/kg/min) while initially having no effect on systolic blood pressure were associated with significant increases in pressure over time. Despite increasing blood pressure, 200 ng/kg/min had no effect on endothelial function, whereas 400 ng/kg/min produced modest impairment on Day 14 and marked impairment of endothelial function on Day 28. The degree of endothelial dysfunction produced by 400 and 1000 ng/kg/min Ang II was reflective of parallel increases in plasma IL-6 levels and vascular macrophage content, suggesting that increases in arterial blood pressure precede the development of endothelial dysfunction. These findings are important as they demonstrate that along with increases in arterial pressure that increases in IL-6 and vascular macrophage accumulation correlate with the impairment of endothelial function produced by Ang II.
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Affiliation(s)
- Jessica R Gomolak
- Department of Pharmacology, The University of Mississippi Medical Center Jackson, MS, USA
| | - Sean P Didion
- Department of Pharmacology, The University of Mississippi Medical Center Jackson, MS, USA ; Department of Neurology, The University of Mississippi Medical Center Jackson, MS, USA
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Walker AE, Henson GD, Reihl KD, Nielson EI, Morgan RG, Lesniewski LA, Donato AJ. Beneficial effects of lifelong caloric restriction on endothelial function are greater in conduit arteries compared to cerebral resistance arteries. AGE (DORDRECHT, NETHERLANDS) 2014; 36:559-569. [PMID: 24065292 PMCID: PMC4039283 DOI: 10.1007/s11357-013-9585-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 09/04/2013] [Indexed: 06/02/2023]
Abstract
Endothelial dysfunction occurs in conduit and cerebral resistance arteries with advancing age. Lifelong caloric restriction (CR) can prevent the onset of age-related dysfunction in many tissues, but its effects on cerebral resistance artery function, as compared with conduit artery function, have not been determined. We measured endothelium-dependent dilation (EDD) in the carotid artery and middle cerebral artery (MCA) from young (5-7 months), old ad libitum fed (AL, 29-32 months), and old lifelong CR (CR, 40 % CR, 29-32 months) B6D2F1 mice. Compared with young, EDD for old AL was 24 % lower in the carotid and 47 % lower in the MCA (p < 0.05). For old CR, EDD was not different from young in the carotid artery (p > 0.05), but was 25 % lower than young in the MCA (p < 0.05). EDD was not different between groups after NO synthase inhibition with N(ω)-nitro-L-arginine methyl ester in the carotid artery or MCA. Superoxide production by the carotid artery and MCA was greater in old AL compared with young and old CR (p < 0.05). In the carotid, incubation with the superoxide scavenger TEMPOL improved EDD for old AL (p > 0.05), with no effect in young or old CR (p > 0.05). In the MCA, incubation with TEMPOL or the NADPH oxidase inhibitor apocynin augmented EDD in old AL (p < 0.05), but reduced EDD in young and old CR (p < 0.05). Thus, age-related endothelial dysfunction is prevented by lifelong CR completely in conduit arteries, but only partially in cerebral resistance arteries. These benefits of lifelong CR on EDD result from lower oxidative stress and greater NO bioavailability.
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Affiliation(s)
- Ashley E. Walker
- />Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84109 USA
| | - Grant D. Henson
- />Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84109 USA
- />Department of Exercise and Sports Science, University of Utah, Salt Lake City, UT USA
| | - Kelly D. Reihl
- />Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84109 USA
| | - Elizabeth I. Nielson
- />Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84109 USA
| | - R. Garrett Morgan
- />Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84109 USA
| | - Lisa A. Lesniewski
- />Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84109 USA
- />Department of Exercise and Sports Science, University of Utah, Salt Lake City, UT USA
- />Geriatrics Research Education and Clinical Center, Veteran’s Affairs Medical Center—Salt Lake City, Salt Lake City, UT USA
| | - Anthony J. Donato
- />Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84109 USA
- />Department of Exercise and Sports Science, University of Utah, Salt Lake City, UT USA
- />Geriatrics Research Education and Clinical Center, Veteran’s Affairs Medical Center—Salt Lake City, Salt Lake City, UT USA
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Golub AS, Pittman RN. Bang-bang model for regulation of local blood flow. Microcirculation 2014; 20:455-83. [PMID: 23441827 DOI: 10.1111/micc.12051] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 02/19/2013] [Indexed: 11/27/2022]
Abstract
The classical model of metabolic regulation of blood flow in muscle tissue implies the maintenance of basal tone in arterioles of resting muscle and their dilation in response to exercise and/or tissue hypoxia via the evoked production of vasodilator metabolites by myocytes. A century-long effort to identify specific metabolites responsible for explaining active and reactive hyperemia has not been successful. Furthermore, the metabolic theory is not compatible with new knowledge on the role of physiological radicals (e.g., nitric oxide, NO, and superoxide anion, O2 (-) ) in the regulation of microvascular tone. We propose a model of regulation in which muscle contraction and active hyperemia are considered the physiologically normal state. We employ the "bang-bang" or "on/off" regulatory model which makes use of a threshold and hysteresis; a float valve to control the water level in a tank is a common example of this type of regulation. Active bang-bang regulation comes into effect when the supply of oxygen and glucose exceeds the demand, leading to activation of membrane NADPH oxidase, release of O2 (-) into the interstitial space and subsequent neutralization of the interstitial NO. Switching arterioles on/off when local blood flow crosses the threshold is realized by a local cell circuit with the properties of a bang-bang controller, determined by its threshold, hysteresis, and dead-band. This model provides a clear and unambiguous interpretation of the mechanism to balance tissue demand with a sufficient supply of nutrients and oxygen.
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Affiliation(s)
- Aleksander S Golub
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA.
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Golub AS, Song BK, Pittman RN. Muscle contraction increases interstitial nitric oxide as predicted by a new model of local blood flow regulation. J Physiol 2014; 592:1225-35. [PMID: 24445318 DOI: 10.1113/jphysiol.2013.267302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The prevailing metabolic theory of local blood flow regulation suggests the dilatation of arterioles in response to tissue hypoxia via the emission of multiple metabolic vasodilators by parenchymal cells. We have proposed a mechanism of regulation, built from well-known components, which assumes that arterioles are normally dilated in metabolically active tissues, due to the emission of NO by the endothelium of microvessels. Regulation of local blood flow aims at preventing an excessive supply of oxygen (O2) and glucose to the tissue and thus provides an adequate supply, in contrast to the metabolic regulation theory which requires permanent hypoxia to generate the metabolic vasodilators. The mediator of the restrictive signal is superoxide anion (O2(-)) released by membrane NAD(P)H oxidases into the interstitial space, where it neutralizes NO at a diffusion-limited rate. This model predicts that the onset of muscle contraction will lead to the cessation of O2(-) production, which will cause an elevation of interstitial NO concentration and an increase in fluorescence of the NO probe DAF-FM after its conversion to DAF-T. The time course of DAF-T fluorescence in contracting muscle is predicted by also considering the washout from the muscle of the interstitially loaded NO indicator. Experiments using pulse fluorimetry confirmed an increase in the interstitial concentration of NO available for reaction with DAF-FM during bouts of muscle contraction. The sharp increase in interstitial [NO] is consistent with the hypothesis that the termination of the neutralizing superoxide flow into the interstitium is associated with the activation of mitochondria and a reduction of the interstitial oxygen tension. The advantage of the new model is its ability to explain the interaction of metabolic activity and local blood flow through the adequate delivery of glucose and oxygen.
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Affiliation(s)
- Aleksander S Golub
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, 1101 E. Marshall Street, PO Box 980551, Richmond, VA 23298-0551, USA.
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The role of the vessel wall. Methods Mol Biol 2013; 992:31-46. [PMID: 23546703 DOI: 10.1007/978-1-62703-339-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The role of the vessel wall is complex and its effects are wide-ranging. The vessel wall, specifically the endothelial monolayer that lines the inner lumen, possesses the ability to influence various physiological states both locally and systemically by controlling vascular tone, basement membrane component synthesis, angiogenesis, haemostatic properties, and immunogenicity. This is an overview of the function and structure of the vessel wall and how disruption and dysfunction in any of these regulatory roles can lead to disease states.
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Lynch CM, Kinzenbaw DA, Chen X, Zhan S, Mezzetti E, Filosa J, Ergul A, Faulkner JL, Faraci FM, Didion SP. Nox2-derived superoxide contributes to cerebral vascular dysfunction in diet-induced obesity. Stroke 2013; 44:3195-201. [PMID: 24072007 DOI: 10.1161/strokeaha.113.001366] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Obesity is an increasing epidemic worldwide; however, little is known about effects of obesity produced by high-fat diet (HFD) on the cerebral circulation. The purpose of this study was to examine the functional and temporal effects of a HFD on carotid and cerebral vascular function and to identify mechanisms that contribute to such functional alterations. METHODS Responses of cerebral arterioles (in vivo) and carotid arteries (in vitro) were examined in C57Bl/6 (wild-type) and Nox2-deficient (Nox2(-/-)) mice fed a control (10%) or a HFD (45% or 60% kcal of fat) for 8, 12, 30, or 36 weeks. RESULTS In wild-type mice, a HFD produced obesity and endothelial dysfunction by 12 and 36 weeks in cerebral arterioles and carotid arteries, respectively. Endothelial function could be significantly improved with Tempol (a superoxide scavenger) treatment in wild-type mice fed a HFD. Despite producing a similar degree of obesity in both wild-type and Nox2(-/-) mice, endothelial dysfunction was observed only in wild-type, but not in Nox2(-/-), mice fed a HFD. CONCLUSIONS Endothelial dysfunction produced by a HFD occurs in a temporal manner and appears much earlier in cerebral arterioles than in carotid arteries. Genetic studies revealed that Nox2-derived superoxide plays a major role in endothelial dysfunction produced by a HFD. Such functional changes may serve to predispose blood vessels to reduced vasodilator responses and thus may contribute to alterations in cerebral blood flow associated with obesity.
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Affiliation(s)
- Cynthia M Lynch
- From the Departments of Internal Medicine (C.M.L., D.A.K., F.M.F.) and Pharmacology (F.M.F.), The University of Iowa Carver College of Medicine, Iowa City, IA; Vascular Biology Center (X.C., E.M.) and Department of Physiology, Medical College of Georgia (J.F., A.E.), Georgia Regents University, Augusta, GA; Departments of Pharmacology (S.Z., J.L.F., S.P.D.) and Neurology (S.P.D.), The University of Mississippi Medical Center, Jackson, MS; and Charlie Norwood VA Medical Center, Augusta, GA (A.E.)
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Chan SL, Baumbach GL. Nox2 deficiency prevents hypertension-induced vascular dysfunction and hypertrophy in cerebral arterioles. Int J Hypertens 2013; 2013:793630. [PMID: 23573415 PMCID: PMC3612447 DOI: 10.1155/2013/793630] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 02/16/2013] [Indexed: 11/17/2022] Open
Abstract
Oxidative stress is involved in many hypertension-related vascular diseases in the brain, including stroke and dementia. Thus, we examined the role of genetic deficiency of NADPH oxidase subunit Nox2 in the function and structure of cerebral arterioles during hypertension. Arterial pressure was increased in right-sided cerebral arterioles with transverse aortic banding for 4 weeks in 8-week-old wild-type (WT) and Nox2-deficient (-/y) mice. Mice were given N(G)-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg) or vehicle to drink. We measured the reactivity in cerebral arterioles through open cranial window in anesthetized mice and wall cross-sectional area and superoxide levels ex vivo. Aortic constriction increased systolic and pulse pressures in right-sided carotid arteries in all groups of mice. Ethidium fluorescence showed increased superoxide in right-sided cerebral arterioles in WT, but not in Nox2-/y mice. Dilation to acetylcholine, but not sodium nitroprusside, was reduced, and cross-sectional areas were increased in the right-sided arterioles in WT, but were unchanged in Nox2-/y mice. L-NAME reduced dilation to acetylcholine but did not result in hypertrophy in right-sided arterioles of Nox2-/y mice. In conclusion, hypertension-induced superoxide production derived from Nox2-containing NADPH oxidase promotes hypertrophy and causes endothelial dysfunction in cerebral arterioles, possibly involving interaction with nitric oxide.
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Affiliation(s)
- Siu-Lung Chan
- Department of Pathology, University of Iowa Carver College of Medicine, 5231D RCP, 200 Hawkins Drive, Iowa City, IA 52242, USA
- Department of Neurological Sciences, University of Vermont, 149 Beaumont Avenue, HSRF 416, Burlington, VT 05405, USA
| | - Gary L. Baumbach
- Department of Pathology, University of Iowa Carver College of Medicine, 5231D RCP, 200 Hawkins Drive, Iowa City, IA 52242, USA
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Early brain injury: a common mechanism in subarachnoid hemorrhage and global cerebral ischemia. Stroke Res Treat 2013; 2013:394036. [PMID: 23533958 PMCID: PMC3603523 DOI: 10.1155/2013/394036] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 01/27/2013] [Indexed: 12/19/2022] Open
Abstract
Early brain injury (EBI) has become an area of extreme interest in the recent years and seems to be a common denominator in the pathophysiology of global transient ischemia and subarachnoid hemorrhage (SAH). In this paper, we highlight the importance of cerebral hypoperfusion and other mechanisms that occur in tandem in both pathologies and underline their possible roles in triggering brain injury after hemorrhagic or ischemic strokes.
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28
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De Silva TM, Faraci FM. Effects of angiotensin II on the cerebral circulation: role of oxidative stress. Front Physiol 2013; 3:484. [PMID: 23316164 PMCID: PMC3539653 DOI: 10.3389/fphys.2012.00484] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/11/2012] [Indexed: 12/31/2022] Open
Abstract
Oxidative stress has emerged as a key component of many diseases that affect the vasculature. Oxidative stress is characterized as a cellular environment where the generation of oxidant molecules overwhelms endogenous anti-oxidant defense mechanisms. NADPH oxidases are a family of enzymes whose primary purpose is generation of reactive oxygen species (oxidant molecules) and therefore are likely to be key contributors to oxidative stress. Hypertension is associated with oxidative stress in the vasculature and is a major risk factor for stroke and cognitive abnormalities. Angiotensin II (Ang II) is the main effector peptide of the renin-angiotensin system (RAS) and plays a critical role in promoting oxidative stress in the vasculature. In the cerebral circulation, Ang II has been implicated in reactive oxygen species generation, alterations to vasomotor function, impaired neurovascular coupling, inflammation, and vascular remodeling. Furthermore, studies in humans have shown that cerebral blood flow is altered during hypertension and therapeutically targeting the RAS improves cerebral blood flow. Importantly, many of the aforementioned effects have been shown to be dependent on NADPH oxidases. Thus, Ang II, NADPH oxidases and oxidative stress are likely to play key roles in the pathogenesis of hypertension and associated cerebrovascular disease. This review will focus on our current understanding of the contribution of Ang II and NADPH oxidases to oxidative stress in the cerebral circulation.
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Affiliation(s)
- T Michael De Silva
- Department of Internal Medicine, Cardiovascular Center, The University of Iowa Carver College of Medicine Iowa City, IA, USA
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Bor-Seng-Shu E, Kita WS, Figueiredo EG, Paiva WS, Fonoff ET, Teixeira MJ, Panerai RB. Cerebral hemodynamics: concepts of clinical importance. ARQUIVOS DE NEURO-PSIQUIATRIA 2012; 70:352-6. [PMID: 22618788 DOI: 10.1590/s0004-282x2012000500010] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 12/06/2011] [Indexed: 11/22/2022]
Abstract
Cerebral hemodynamics and metabolism are frequently impaired in a wide range of neurological diseases, including traumatic brain injury and stroke, with several pathophysiological mechanisms of injury. The resultant uncoupling of cerebral blood flow and metabolism can trigger secondary brain lesions, particularly in early phases, consequently worsening the patient's outcome. Cerebral blood flow regulation is influenced by blood gas content, blood viscosity, body temperature, cardiac output, altitude, cerebrovascular autoregulation, and neurovascular coupling, mediated by chemical agents such as nitric oxide (NO), carbon monoxide (CO), eicosanoid products, oxygen-derived free radicals, endothelins, K+, H+, and adenosine. A better understanding of these factors is valuable for the management of neurocritical care patients. The assessment of both cerebral hemodynamics and metabolism in the acute phase of neurocritical care conditions may contribute to a more effective planning of therapeutic strategies for reducing secondary brain lesions. In this review, the authors have discussed concepts of cerebral hemodynamics, considering aspects of clinical importance.
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Affiliation(s)
- Edson Bor-Seng-Shu
- Division of Neurological Surgery, Hospital das Clínicas, University of São Paulo School of Medicine, São Paulo, SP, Brazil.
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Toth P, Rozsa B, Springo Z, Doczi T, Koller A. Isolated human and rat cerebral arteries constrict to increases in flow: role of 20-HETE and TP receptors. J Cereb Blood Flow Metab 2011; 31:2096-105. [PMID: 21610722 PMCID: PMC3208155 DOI: 10.1038/jcbfm.2011.74] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Elevation of intraluminal pressure increases vasomotor tone, which thought to have a substantial role in regulation of cerebral blood flow (CBF). Interestingly, responses of cerebral vessels to increases in flow varied and have not been studied in human cerebral arteries. We hypothesized that increases in flow elicit constrictions of isolated human and rat cerebral arteries and aimed to elucidate the underlying mechanisms. Human cerebral arteries and rat middle cerebral arteries constricted to increases in flow (P<0.05). Simultaneous increase in intraluminal flow+pressure further reduced the diameter compared with pressure-induced changes (P<0.05), leading to constant estimated CBF. Flow-induced constrictions were abolished by HET0016 (inhibitor of synthesis of 20-hydroxyeicosatetraenoic acid (20-HETE) or inhibition of COXs or blocking TP (thromboxane A(2)/prostaglandin H(2), receptors and attenuated by scavenging reactive oxygen species (ROS). Flow-enhanced ROS formation was significantly reduced by HET0016. In conclusion, in human and rat cerebral arteries (1) increases in flow elicit constrictions, (2) signaling mechanism of flow-induced constriction of cerebral arteries involves enhanced production of ROS, COX activity, and mediated by 20-HETE via TP receptors, and (3) we propose that simultaneous operation of pressure- and flow-induced constrictions is necessary to provide an effective autoregulation of CBF.
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Affiliation(s)
- Peter Toth
- Department of Physiology, New York Medical College, Valhalla, New York 10595, USA
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Noguchi K, Hamadate N, Matsuzaki T, Sakanashi M, Nakasone J, Uchida T, Arakaki K, Kubota H, Ishiuchi S, Masuzaki H, Sugahara K, Ohya Y, Sakanashi M, Tsutsui M. Increasing dihydrobiopterin causes dysfunction of endothelial nitric oxide synthase in rats in vivo. Am J Physiol Heart Circ Physiol 2011; 301:H721-9. [PMID: 21622822 DOI: 10.1152/ajpheart.01089.2010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An elevation of oxidized forms of tetrahydrobiopterin (BH(4)), especially dihydrobiopterin (BH(2)), has been reported in the setting of oxidative stress, such as arteriosclerotic/atherosclerotic disorders, where endothelial nitric oxide synthase (eNOS) is dysfunctional, but the role of BH(2) in the regulation of eNOS activity in vivo remains to be evaluated. This study was designed to clarify whether increasing BH(2) concentration causes endothelial dysfunction in rats. To increase vascular BH(2) levels, the BH(2) precursor sepiapterin (SEP) was intravenously given after the administration of the specific dihydrofolate reductase inhibitor methotrexate (MTX) to block intracellular conversion of BH(2) to BH(4). MTX/SEP treatment did not significantly affect aortic BH(4) levels compared with control treatment. However, MTX/SEP treatment markedly augmented aortic BH(2) levels (291.1 ± 29.2 vs. 33.4 ± 6.4 pmol/g, P < 0.01) in association with moderate hypertension. Treatment with MTX alone did not significantly alter blood pressure or BH(4) levels but decreased the BH(4)-to-BH(2) ratio. Treatment with MTX/SEP, but not with MTX alone, impaired ACh-induced vasodilator and depressor responses compared with the control treatment (both P < 0.05) and also aggravated ACh-induced endothelium-dependent relaxations (P < 0.05) of isolated aortas without affecting sodium nitroprusside-induced endothelium-independent relaxations. Importantly, MTX/SEP treatment significantly enhanced aortic superoxide production, which was diminished by NOS inhibitor treatment, and the impaired ACh-induced relaxations were reversed with SOD (P < 0.05), suggesting the involvement of eNOS uncoupling. These results indicate, for the first time, that increasing BH(2) causes eNOS dysfunction in vivo even in the absence of BH(4) deficiency, demonstrating a novel insight into the regulation of endothelial function.
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Affiliation(s)
- Katsuhiko Noguchi
- Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
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Yeh-Siang L, Subramaniam G, Hadi AHA, Murugan D, Mustafa MR. Reactive oxygen species-induced impairment of endothelium-dependent relaxations in rat aortic rings: protection by methanolic extracts of Phoebe grandis. Molecules 2011; 16:2990-3000. [PMID: 21471938 PMCID: PMC6260632 DOI: 10.3390/molecules16042990] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 03/15/2011] [Accepted: 04/01/2011] [Indexed: 11/23/2022] Open
Abstract
Generation of reactive oxygen species plays a pivotal role in the development of cardiovascular diseases. The present study describes the effects of the methanolic extract of Phoebe grandis (MPG) stem bark on reactive oxygen species-induced endothelial dysfunction in vitro. Endothelium-dependent (acetylcholine, ACh) and -independent relaxation (sodium nitroprusside, SNP) was investigated from isolated rat aorta of Sprague-Dawley (SD) in the presence of the β-NADH (enzymatic superoxide inducer) and MPG extract. Superoxide anion production in aortic vessels was measured by lucigen chemiluminesence. Thirty minutes incubation of the rat aorta in vitro with β-NADH increased superoxide radical production and significantly inhibited ACh-induced relaxations. Pretreatment with MPG (0.5, 5 and 50 μg/mL) restored the ACh-induced relaxations (Rmax: 92.29% ± 2.93, 91.02% ± 4.54 and 88.31 ± 2.36, respectively) in the presence of β-NADH. MPG was ineffective in reversing the impaired ACh-induced relaxations caused by pyrogallol, a non-enzymatic superoxide generator. Superoxide dismutase (a superoxide scavenger), however, reversed the impaired ACh relaxations induced by both β-NADH and pyrogallol. MPG also markedly inhibited the β-NADH-induced generation of the superoxide radicals. Furthermore, MPG scavenging peroxyl radicals generated by tBuOOH (10−4 M).These results indicate that MPG may improve the endothelium dependent relaxations to ACh through its scavenging activity as well as by inhibiting the NADH/NADPH oxidase induced generation of superoxide anions.
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Affiliation(s)
- Lau Yeh-Siang
- Centre of Natural Products and Drug Discovery (CENAR), Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; E-Mails: (L.Y.-S.); (G.S.); (D.M.)
| | - Gopal Subramaniam
- Centre of Natural Products and Drug Discovery (CENAR), Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; E-Mails: (L.Y.-S.); (G.S.); (D.M.)
| | - A. Hamid A. Hadi
- Centre of Natural Products and Drug Discovery (CENAR), Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia; E-Mail:
| | - Dharmani Murugan
- Centre of Natural Products and Drug Discovery (CENAR), Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; E-Mails: (L.Y.-S.); (G.S.); (D.M.)
| | - Mohd Rais Mustafa
- Centre of Natural Products and Drug Discovery (CENAR), Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; E-Mails: (L.Y.-S.); (G.S.); (D.M.)
- Author to whom correspondence should be addressed; E-Mail: ; Fax: 603 79674791
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Mayhan WG, Arrick DM, Patel KP, Sun H. Exercise training normalizes impaired NOS-dependent responses of cerebral arterioles in type 1 diabetic rats. Am J Physiol Heart Circ Physiol 2011; 300:H1013-20. [PMID: 21169403 PMCID: PMC3064313 DOI: 10.1152/ajpheart.00873.2010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 12/06/2010] [Indexed: 01/24/2023]
Abstract
Our goal was to examine whether exercise training (ExT) could normalize impaired nitric oxide synthase (NOS)-dependent dilation of cerebral (pial) arterioles during type 1 diabetes (T1D). We measured the in vivo diameter of pial arterioles in sedentary and exercised nondiabetic and diabetic rats in response to an endothelial NOS (eNOS)-dependent (ADP), an neuronal NOS (nNOS)-dependent [N-methyl-D-aspartate (NMDA)], and a NOS-independent (nitroglycerin) agonist. In addition, we measured superoxide anion levels in brain tissue under basal conditions in sedentary and exercised nondiabetic and diabetic rats. Furthermore, we used Western blot analysis to determine eNOS and nNOS protein levels in cerebral vessels/brain tissue in sedentary and exercised nondiabetic and diabetic rats. We found that ADP and NMDA produced a dilation of pial arterioles that was similar in sedentary and exercised nondiabetic rats. In contrast, ADP and NMDA produced only minimal vasodilation in sedentary diabetic rats. ExT restored impaired ADP- and NMDA-induced vasodilation observed in diabetic rats to that observed in nondiabetics. Nitroglycerin produced a dilation of pial arterioles that was similar in sedentary and exercised nondiabetic and diabetic rats. Superoxide levels in cortex tissue were similar in sedentary and exercised nondiabetic rats, were increased in sedentary diabetic rats, and were normalized by ExT in diabetic rats. Finally, we found that eNOS protein was increased in diabetic rats and further increased by ExT and that nNOS protein was not influenced by T1D but was increased by ExT. We conclude that ExT can alleviate impaired eNOS- and nNOS-dependent responses of pial arterioles during T1D.
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Affiliation(s)
- William G Mayhan
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5850, USA.
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Vascular Biology and Atherosclerosis of Cerebral Arteries. Stroke 2011. [DOI: 10.1016/b978-1-4160-5478-8.10001-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Mayhan WG, Arrick DM, Sun H, Patel KP. Exercise training restores impaired dilator responses of cerebral arterioles during chronic exposure to nicotine. J Appl Physiol (1985) 2010; 109:1109-14. [PMID: 20705948 DOI: 10.1152/japplphysiol.00564.2010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our goal was to determine whether exercise training (ExT) alleviates impaired nitric oxide synthase (NOS)-dependent dilation of pial arterioles during chronic exposure to nicotine. We measured dilation of cerebral (pial) arterioles in sedentary and exercised control and nicotine-treated (2 mg·kg(-1)·day(-1) for 4 wk via an osmotic minipump) rats to an endothelial NOS (eNOS)-dependent (ADP), a neuronal NOS (nNOS)-dependent [N-methyl-D-aspartic acid (NMDA)], and a NOS-independent (nitroglycerin) agonist. In addition, we harvested brain tissue from sedentary and exercised control and nicotine-treated rats to measure the production of superoxide anion and measured superoxide dismutase-1 (SOD-1) protein in cerebral microvessels using Western blot. We found that eNOS-and nNOS-dependent, but not NOS-independent, vasodilation was impaired in nicotine-treated compared with control rats. In addition, the production of superoxide anion (lucigenin chemiluminescence) was increased, and SOD-1 protein decreased, in rats treated with nicotine compared with control rats. Further, although ExT did not significantly affect eNOS- or nNOS-dependent vasodilation in control rats, ExT restored impaired eNOS- and nNOS-dependent responses in nicotine-treated rats. In addition, the increase in superoxide anion production observed in nicotine-treated rats was reduced by ExT, and SOD-1 protein was increased in nicotine-treated rats by ExT. We suggest that ExT restores impaired NOS-dependent dilation of pial arterioles during chronic exposure to nicotine by a mechanism related to the formation of superoxide anion.
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Affiliation(s)
- William G Mayhan
- Dept. of Cellular and Integrative Physiology, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA.
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Kim BW, Lee JW, Choo HJ, Lee CS, Jung SY, Yi JS, Ham YM, Lee JH, Hong J, Kang MJ, Chi SG, Hyung SW, Lee SW, Kim HM, Cho BR, Min DS, Yoon G, Ko YG. Mitochondrial oxidative phosphorylation system is recruited to detergent-resistant lipid rafts during myogenesis. Proteomics 2010; 10:2498-515. [DOI: 10.1002/pmic.200900826] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Soylemez S, Sepici A, Akar F. Resveratrol supplementation gender independently improves endothelial reactivity and suppresses superoxide production in healthy rats. Cardiovasc Drugs Ther 2010; 23:449-58. [PMID: 19809869 DOI: 10.1007/s10557-009-6198-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Resveratrol, a polyphenolic compound mainly abundant in red wines, has beneficial cardiovascular effects on various pathological conditions. However, at present, the effect of resveratrol on health promotion remains unclear. Therefore, in this study, we assessed whether long-term resveratrol supplementation changes endothelial function, vascular contractility, nitric oxide and superoxide production in healthy male and female rats. METHODS Wistar rats were treated with resveratrol (50 mg/l) in their drinking water for 3 weeks. We investigated relaxation to acetylcholine (10(-9)-10(-4) M) and contractions to phenylephrine (10(-9)-3 x 10(-4) M) and angiotensin II (10(-10)-10(-5) M) in either endothelium-intact or denuded aortae from control and resveratrol-treated male and female rats. Aortic superoxide production capacity was measured in response to provocation by angiotensin II and NAD(P)H. Plasma nitrite/nitrate levels and superoxide dismutase (SOD) activity were also evaluated. RESULTS Resveratrol supplementation gender independently increased relaxation to acetylcholine and decreased contractions to phenylephrine and angiotensin II in endothelium-intact aortic rings, but not in endothelium-denuded arteries, from healthy male and female rats. This was associated with increased plasma nitrite/nitrate levels. Furthermore, resveratrol caused a refractoriness to angiotensin II and NAD(P)H-induced provocation in superoxide production. CONCLUSION Our results suggest that resveratrol supplementation gender independently could improve the capacity of endothelial function and suppression of oxidative stress under physiological conditions. Resveratrol ingestion indicates a potential for cardiovascular health promotion.
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Affiliation(s)
- Selen Soylemez
- Department of Pharmacology, Faculty of Pharmacy, Gazi University, Etiler, Ankara, Turkey
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Vecchione C, Frati A, Di Pardo A, Cifelli G, Carnevale D, Gentile MT, Carangi R, Landolfi A, Carullo P, Bettarini U, Antenucci G, Mascio G, Busceti CL, Notte A, Maffei A, Cantore GP, Lembo G. Tumor Necrosis Factor-α Mediates Hemolysis-Induced Vasoconstriction and the Cerebral Vasospasm Evoked by Subarachnoid Hemorrhage. Hypertension 2009; 54:150-6. [DOI: 10.1161/hypertensionaha.108.128124] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Carmine Vecchione
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Alessandro Frati
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Alba Di Pardo
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Giuseppe Cifelli
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Daniela Carnevale
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Maria Teresa Gentile
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Rosa Carangi
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Alessandro Landolfi
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Pierluigi Carullo
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Umberto Bettarini
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Giovanna Antenucci
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Giada Mascio
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Carla Letizia Busceti
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Antonella Notte
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Angelo Maffei
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Gian Paolo Cantore
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
| | - Giuseppe Lembo
- From the Departments of Angiocardioneurology (C.V., A.D.P., G.C., M.T.G., R.C., A.L., P.C., U.B., G.A., G.M., C.L.B., A.N., A.M., G.L.) and Neurosurgery (A.F., G.P.C.), IRCCS Neuromed, Pozzilli (IS), Italy; Department of Cell Biology and Neurosciences (D.C.), Istituto Superiore di Sanità, Rome, Italy; and Department of Experimental Medicine (G.L.), Sapienza University, Rome, Italy
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Toda N, Ayajiki K, Okamura T. Cerebral Blood Flow Regulation by Nitric Oxide: Recent Advances. Pharmacol Rev 2009; 61:62-97. [DOI: 10.1124/pr.108.000547] [Citation(s) in RCA: 268] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Jackman KA, Miller AA, De Silva TM, Crack PJ, Drummond GR, Sobey CG. Reduction of cerebral infarct volume by apocynin requires pretreatment and is absent in Nox2-deficient mice. Br J Pharmacol 2009; 156:680-8. [PMID: 19175604 DOI: 10.1111/j.1476-5381.2008.00073.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Reactive oxygen species (ROS) derived from Nox2-containing reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity is reportedly detrimental in cerebrovascular disease. However, ROS generation by other Nox isoforms may have a physiological role. No Nox2-selective inhibitors have yet been identified, and thus it is unclear whether isoform non-selective Nox inhibitors would necessarily improve outcome after stroke. We assessed the effect of apocynin on cerebrovascular ROS production and also on outcome following cerebral ischaemia when administered either before ischaemia or after cerebral reperfusion. The involvement of Nox2-containing NADPH oxidase in the effects of apocynin was assessed using Nox2(-/-) mice. EXPERIMENTAL APPROACH Transient cerebral ischaemia was induced by 0.5 h middle cerebral artery occlusion followed by 23.5 h reperfusion. Mice received apocynin (2.5 mg.kg(-1), i.p.) either 0.5 h before ischaemia or 1 h after reperfusion. In situ superoxide production after cerebral ischaemia-reperfusion was measured in brain sections of wild-type mice at 24 h using dihydroethidium fluorescence. KEY RESULTS Treatment with apocynin 0.5 h before ischaemia reduced total infarct volume, neurological impairment and mortality in wild-type but not Nox2(-/-) mice. Conversely, treatment with apocynin 1 h after initiation of reperfusion had no protective effect. Cerebral ischaemia and reperfusion increased superoxide production in the brain at 24 h, and pretreatment but not posttreatment with apocynin reduced superoxide levels. CONCLUSIONS AND IMPLICATIONS Apocynin improves outcome following stroke when administered before ischaemia in wild-type but not Nox2(-/-) mice.
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Affiliation(s)
- K A Jackman
- Department of Pharmacology, Monash University, Clayton, VIC, Australia
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Miller AA, Drummond GR, De Silva TM, Mast AE, Hickey H, Williams JP, Broughton BRS, Sobey CG. NADPH oxidase activity is higher in cerebral versus systemic arteries of four animal species: role of Nox2. Am J Physiol Heart Circ Physiol 2009; 296:H220-5. [DOI: 10.1152/ajpheart.00987.2008] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We previously reported that NADPH oxidase activity is greater in intracranial cerebral versus systemic arteries of the rat. Here, we first tested whether NADPH oxidase activity is also greater in intracranial cerebral than systemic arteries of three other animal species, i.e., mouse, rabbit, and pig. Second, using Nox2-deficient mice, we evaluated the involvement of Nox2-containing NADPH oxidases in any such regional differences. NADPH-stimulated superoxide (O2−) production by basilar, middle cerebral arteries (MCA), and common carotid arteries (CA) and thoracic aorta (AO) from rat, mouse, rabbit, and pig was measured using lucigenin-enhanced chemiluminescence. Basal production of O2− and hydrogen peroxide (H2O2) by cerebral arteries, AO, and CA from wild-type (WT) and Nox2−/− mice was measured using L-012-enhanced chemiluminescence and Amplex Red fluorescence, respectively. Western blotting was used to measure Nox2 and SOD1–3 protein expression, and immunofluorescence was used to localize Nox2, in mouse arteries. In rats, WT mice, rabbits, and pigs, NADPH-stimulated O2− production by cerebral arteries was up to 40-fold greater than that in AO and CA. In WT mice, basal O2− and H2O2 production by cerebral arteries was ninefold and ∼2.5-fold higher, respectively, than that in AO and CA and was associated with ∼40% greater expression of Nox2 protein. Nox2 immunofluorescence was localized to the endothelium, and to a lesser extent the adventitia, in all mouse arteries and appeared to be more intense in endothelium of MCA than AO or CA. In Nox2−/− mice, NADPH-stimulated O2− production by cerebral arteries was ∼35% lower than that in WT mice, whereas Nox2 deletion had no significant effect on O2− production by AO or CA. Thus NADPH oxidase activity is greater in intracranial cerebral versus systemic arteries of several animal species and is associated with higher cerebrovascular expression and activity of Nox2.
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Wong CHY, Bozinovski S, Hertzog PJ, Hickey MJ, Crack PJ. Absence of glutathione peroxidase-1 exacerbates cerebral ischemia-reperfusion injury by reducing post-ischemic microvascular perfusion. J Neurochem 2008; 107:241-52. [DOI: 10.1111/j.1471-4159.2008.05605.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hypertension increases middle cerebral artery resting tone in spontaneously hypertensive rats: role of tonic vasoactive factor availability. Clin Sci (Lond) 2008; 114:651-9. [DOI: 10.1042/cs20070361] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The present study explores the contribution of alterations in resting tone to cerebral artery narrowing in SHRs (spontaneously hypertensive rats) and the role of hypertension development. Young pre-hypertensive and adult fully hypertensive SHRs and age-matched Wistar–Kyoto rat controls were used. The contribution of basal vasoactive factors to resting tone was studied in middle cerebral arteries with pressure myography. Basal NO and O2− (superoxide anion) availability were determined with fluorescent indicators using confocal microscopy and lucigenin-enhanced chemiluminescence. Basal O2− was also assessed in mesenteric resistance arteries. Middle cerebral arteries from adult rats, but not young pre-hypertensive rats, had augmented myogenic responses and resting tone and decreased relaxation to sodium nitroprusside compared with their normotensive counterparts. Cerebral arteries from adult SHRs also had an increase in tonic NO associated with a decrease in basal O2− availability. Basal O2− was instead increased in mesenteric arteries from SHRs. The present results indicate that large cerebral arteries from SHRs have an increase in their resting tone as a consequence of sustained hypertension and that this is related to a decrease in NO responsiveness. We suggest that this increase in resting tone and myogenic responses could act as a protective mechanism against the development of stroke in SHRs. The present study also demonstrates some unusual findings regarding the current understanding of the NO/O2− balance in hypertension with important differences between vascular beds and draws attention to the complexity of this balance in cardiovascular health and disease.
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Bae ON, Lim KM, Han JY, Jung BI, Lee JY, Noh JY, Chung SM, Lee MY, Lee JY, Chung JH. U-shaped Dose Response in Vasomotor Tone: A Mixed Result of Heterogenic Response of Multiple Cells to Xenobiotics. Toxicol Sci 2008; 103:181-90. [DOI: 10.1093/toxsci/kfn023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Arrick DM, Sharpe GM, Sun H, Mayhan WG. nNOS-dependent reactivity of cerebral arterioles in Type 1 diabetes. Brain Res 2007; 1184:365-71. [PMID: 17991456 DOI: 10.1016/j.brainres.2007.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 10/02/2007] [Accepted: 10/03/2007] [Indexed: 12/20/2022]
Abstract
Our goals were to determine whether Type 1 diabetes (T1D) alters neuronal nitric oxide synthase (nNOS)-dependent reactivity of cerebral arterioles and to identify a potential role for oxidative stress in T1D-induced impairment in nNOS-dependent responses of cerebral arterioles. Rats were injected with vehicle (sodium citrate buffer) or streptozotocin (50 mg/kg IP) to induce T1D. Two to three months later, we measured functional responses of cerebral arterioles to nNOS-dependent (NMDA and kainate) and -independent (nitroglycerin) agonists in nondiabetic and diabetic rats before and during inhibition of oxidative stress using tempol (100 microM). In addition, we measured superoxide anion production under basal conditions, during stimulation with NMDA and kainate, and during treatment with tempol. We found that nNOS-dependent, but -independent, vasodilatation was impaired in diabetic compared to nondiabetic rats. In addition, treatment of the cerebral microcirculation with tempol restored impaired nNOS-dependent vasodilatation in diabetic rats toward that observed in nondiabetic rats. Furthermore, the production of superoxide anion (lucigenin chemiluminescence) was increased in parietal cortical tissue of diabetic rats under basal conditions. Application of NMDA and kainate did not increase superoxide anion production in nondiabetic or diabetic rats. However, tempol decreased basal production of superoxide anion in diabetic rats. Our findings suggest that T1D impairs nNOS-dependent dilatation of cerebral arterioles by a mechanism that appears to be related to the formation of superoxide anion.
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Affiliation(s)
- Denise M Arrick
- Department of Cellular and Integrative Physiology, University of Nebraska, Omaha, NE 68198-5850, USA
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Arrick DM, Mayhan WG. Acute infusion of nicotine impairs nNOS-dependent reactivity of cerebral arterioles via an increase in oxidative stress. J Appl Physiol (1985) 2007; 103:2062-7. [PMID: 17901243 DOI: 10.1152/japplphysiol.00411.2007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our goals were to determine whether acute exposure to nicotine alters neuronal nitric oxide synthase (nNOS)-dependent reactivity of cerebral arterioles and to identify a potential role for oxidative stress in nicotine-induced impairment in nNOS-dependent responses of cerebral arterioles. We measured in vivo diameter of cerebral arterioles to nNOS-dependent (N-methyl-d-aspartate and kainate) and -independent (nitroglycerin) agonists before and during acute treatment with nicotine. We found that nNOS-dependent, but not -independent, vasodilatation was impaired during treatment with nicotine. In addition, treatment of the cerebral microcirculation with tempol (1 h before infusion of nicotine) prevented nicotine-induced impairment in nNOS-dependent vasodilatation. Furthermore, the production of superoxide anion (lucigenin chemiluminescence) was increased in parietal cortex tissue of rats by treatment with nicotine, and this increase in superoxide anion production could be inhibited by tempol. Our findings suggest that acute exposure to nicotine impairs nNOS-dependent dilatation of cerebral arterioles by a mechanism that appears to be related to the formation of superoxide anion.
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Affiliation(s)
- Denise M Arrick
- Department of Cellular and Integrative Physiology, Omaha, NE 68198-5850, USA
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Abstract
BACKGROUND AND PURPOSE Studies of peripheral arteries in hypercholesterolemic animals suggest that increased generation of superoxide contributes to endothelial dysfunction, especially in the presence of atherosclerotic lesions. We tested the hypothesis that vasomotor function is impaired in cerebral arterioles during hypercholesterolemia through a mechanism that involves oxidative stress. METHODS Apolipoprotein E-deficient (apoE(-/-)) mice were fed a normal or a high-fat diet for >6 months. ApoE(+/-) mice fed a normal diet were used as normocholesterolemic controls. Responses of cerebral arterioles were examined in open cranial windows in vivo in anesthetized mice. RESULTS In apoE(-/-) mice, intimal area was increased only in the proximal aorta on the normal diet and also markedly increased in the distal aorta on the high-fat diet. There were no increases in intimal area in the aortas of control mice or in the cerebral arterioles in any group. The dilator response of cerebral arterioles to ACh (10 micromol/L) in control mice (26+/-4% increase in diameter) was reduced in apoE(-/-) mice on either the normal (13+/-2%) or the high-fat (13+/-3%) diet (P<0.05 vs control). NADPH (10 micromol/L), a substrate for NADPH oxidase, produced dilator responses in control mice (8+/-4%) that were significantly increased in apoE(-/-) mice on the high-fat diet (16+/-2%, P<0.05 vs control). Tempol, a superoxide scavenger, and apocynin, an inhibitor of NADPH oxidase, significantly increased vasodilator responses to ACh and decreased vasodilation to NADPH in apoE(-/-) mice on the high-fat diet. Nitroprusside produced a similar dilatation in the cerebral arterioles of all groups. CONCLUSIONS Hypercholesterolemia is associated with oxidative stress and endothelial dysfunction in cerebral arterioles, despite the absence of atherosclerotic lesions.
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Affiliation(s)
- Jiro Kitayama
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1081, USA
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Miller AA, Drummond GR, Mast AE, Schmidt HHHW, Sobey CG. Effect of gender on NADPH-oxidase activity, expression, and function in the cerebral circulation: role of estrogen. Stroke 2007; 38:2142-9. [PMID: 17525399 DOI: 10.1161/strokeaha.106.477406] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND AND PURPOSE This study tested whether NADPH-oxidase activity, expression, and functional effects on vascular tone are influenced by gender in the rat cerebral circulation and whether such differences are estrogen-dependent. METHODS NADPH-stimulated superoxide production by cerebral (basilar [BA]; middle cerebral) arteries from male and female Sprague-Dawley rats was measured using lucigenin-enhanced chemiluminescence and dihydroethidium. Protein expression of Nox1, Nox2, Nox4, superoxide dismutase 1 (SOD1), SOD2, and SOD3 was measured using Western blotting. Vascular responses of BA to NADPH were assessed in a myograph. Some female rats were ovariectomized and treated with either vehicle (dimethyl sulfoxide) or 17beta-estradiol. RESULTS NADPH-stimulated superoxide production by BA and middle cerebral arteries from males was approximately 2-fold greater than vessels from females. Superoxide production was virtually abolished by the NADPH-oxidase inhibitor, diphenyleneiodonium. Protein expression of Nox1 and Nox4 in BA was also higher in males than in females (2.4- and 2.8-fold, respectively), whereas Nox2, SOD1, SOD2, and SOD3 expression did not differ between genders. NADPH induced greater vasorelaxant effects in BA from males versus females (P<0.05). The hydrogen peroxide scavenger, catalase, abolished these NADPH-induced relaxations. NADPH-stimulated superoxide production by BA from ovariectomized rats treated with vehicle was 3-fold greater than levels in intact females. Treatment of ovariectomized rats with 17beta-estradiol decreased superoxide production (P<0.05). NADPH-induced relaxations of BA were smaller in 17beta-estradiol-treated than in vehicle-treated ovariectomized rats (P<0.05). CONCLUSIONS NADPH-oxidase activity and function are lower in cerebral arteries of female rats. These gender differences are estrogen-dependent and are associated with lower Nox1 and Nox4 expression.
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Affiliation(s)
- Alyson A Miller
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
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50
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Machha A, Achike FI, Mohd MA, Mustafa MR. Baicalein impairs vascular tone in normal rat aortas: role of superoxide anions. Eur J Pharmacol 2007; 565:144-50. [PMID: 17442302 DOI: 10.1016/j.ejphar.2007.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2006] [Revised: 02/21/2007] [Accepted: 03/06/2007] [Indexed: 11/28/2022]
Abstract
Acute exposure to the flavonoid baicalein inhibited endothelium-dependent relaxation in physiological arteries, although the mechanisms are not fully understood. We investigated the effect of baicalein on vascular tone in Wistar-Kyoto (WKY) rat isolated aortic rings in the presence and absence of oxidative stress to further determine the underlying mechanisms. Exposure to baicalein (10 microM) completely abolished endothelium-dependent relaxation induced by acetylcholine and attenuated significantly the endothelium-independent relaxation induced by sodium nitroprusside. Baicalein, similar to Nomega-nitro-L-arginine methyl ester (L-NAME, 10 microM), potentiated significantly the contractile response of aortic rings to alpha1-adrenoceptor agonist phenylephrine. In the presence of L-NAME the baicalein effect on phenylphrine contraction or acetylcholine relaxation was unaltered, suggesting that these effects of baicalein are (like L-NAME effect) endothelial nitric oxide synthase (eNOS)/endothelium-derived nitric oxide-dependent. Inhibition of cyclooxygenase activity with indomethacin (10 microM) or scavenging of superoxide anions with superoxide dismutase (150 units/ml), but not scavenging of hydrogen peroxide with catalase (800 units/ml), enhanced significantly by an essentially similar extent the relaxation to acetylcholine in baicalein-pretreated aortic rings. Relaxant effect to acetylcholine was significantly attenuated in control aortic rings, but was completely abolished in baicalein-pretreated aortic rings in the presence of reduced form of beta-nicotinamide adenine di-nucleotide (beta-NADH, 300 microM). Baicalein blocked beta-NADH (300 microM)-induced transient contractions, suggesting that baicalein may have inhibited activity of NADH/NADPH-oxidase. Baicalein did not alter the failure of acetylcholine to induce relaxation in the presence of pyrogallol (300 microM). In summary, acute exposure to baicalein impairs eNOS/endothelium-derived nitric oxide-mediated vascular tone in rat aortas through the inhibition of endothelium-derived nitric oxide bioavailability coupled to reduced bioactivity of endothelium-derived nitric oxide and to cyclooxygenase-mediated release of superoxide anions.
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Affiliation(s)
- Ajay Machha
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia.
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