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Maltsev AV, Evdokimovskii EV, Kokoz YM. α2-Adrenoceptor signaling in cardiomyocytes of spontaneously hypertensive rats starts to impair already at early age. Biochem Biophys Res Commun 2019; 512:908-913. [PMID: 30929926 DOI: 10.1016/j.bbrc.2019.03.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 03/18/2019] [Indexed: 11/26/2022]
Abstract
α2-Adrenoceptors (α2-AR) found in the cardiomyocyte's sarcolemma represent a very important negative feedback for control of myocardial contractility by endogenous catecholamines. Earlier, we showed that the endogenous neurotransmitter agmatine in micromolar concentrations via α2-AR activates the nitric oxide (NO) synthesis, enhancing the Ca2+ pumping into sarcoplasmic reticulum (SR). In the millimolar doses it inhibits Ca2+ sequestration by SR Ca2+ ATPase (SERCA), acting through the first type of imidazoline receptors. Here, we study the functional activity of agmatine, as well as a specific α2-agonist, guanabenz, in respect to spontaneous Ca2+-transients in SHR cardiomyocytes of the early age (2-2.5 months), and adulthood animals (8-9 months). α2-mediated cardioprotective effect was almost twofold decreased in SHR cardiac cells compared to normotensive rats of the corresponding age, despite the fact that both α2A- and α2B-AR protein levels were significantly increased in SHR cardiomyocytes. NO-mediated facilitation of SERCA activity is substantially reduced in SHR cardiomyocytes vs. normotensive rats. These data suggest that the SHR phenotype starting from early age shows signs of the impaired sarcolemmal α2-AR signaling, which can aggravate the development of this cardiovascular pathology.
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Affiliation(s)
- A V Maltsev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Moscow Region, Pushchino, Institutskaya, 3, 142290, Russia; Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Butlerova 5А, 117485, Russia.
| | - E V Evdokimovskii
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Moscow Region, Pushchino, Institutskaya, 3, 142290, Russia
| | - Y M Kokoz
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Moscow Region, Pushchino, Institutskaya, 3, 142290, Russia
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2
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Li G, Xiao Y, Estrella JL, Ducsay CA, Gilbert RD, Zhang L. Effect of Fetal Hypoxia on Heart Susceptibility to Ischemia and Reperfusion Injury in the Adult Rat. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/s1071-55760300074-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
| | | | | | | | - Raymond D. Gilbert
- Center for Perinatal Biology, Department of Physiology & Pharmacology, Loma Linda University School of Medicine, Loma Linda, California
| | - Lubo Zhang
- Center for Perinatal Biology, Department of Pharmacology & Physiology, Loma Linda University School of Medicine, Loma Linda, CA 92350
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Lee J, Bae EH, Ma SK, Kim SW. Altered Nitric Oxide System in Cardiovascular and Renal Diseases. Chonnam Med J 2016; 52:81-90. [PMID: 27231671 PMCID: PMC4880583 DOI: 10.4068/cmj.2016.52.2.81] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/14/2016] [Accepted: 03/22/2016] [Indexed: 01/02/2023] Open
Abstract
Nitric oxide (NO) is synthesized by a family of NO synthases (NOS), including neuronal, inducible, and endothelial NOS (n/i/eNOS). NO-mediated effects can be beneficial or harmful depending on the specific risk factors affecting the disease. In hypertension, the vascular relaxation response to acetylcholine is blunted, and that to direct NO donors is maintained. A reduction in the activity of eNOS is mainly responsible for the elevation of blood pressure, and an abnormal expression of iNOS is likely to be related to the progression of vascular dysfunction. While eNOS/nNOS-derived NO is protective against the development of atherosclerosis, iNOS-derived NO may be proatherogenic. eNOS-derived NO may prevent the progression of myocardial infarction. Myocardial ischemia/reperfusion injury is significantly enhanced in eNOS-deficient animals. An important component of heart failure is the loss of coronary vascular eNOS activity. A pressure-overload may cause severer left ventricular hypertrophy and dysfunction in eNOS null mice than in wild-type mice. iNOS-derived NO has detrimental effects on the myocardium. NO plays an important role in regulating the angiogenesis and slowing the interstitial fibrosis of the obstructed kidney. In unilateral ureteral obstruction, the expression of eNOS was decreased in the affected kidney. In triply n/i/eNOS null mice, nephrogenic diabetes insipidus developed along with reduced aquaporin-2 abundance. In chronic kidney disease model of subtotal-nephrectomized rats, treatment with NOS inhibitors decreased systemic NO production and induced left ventricular systolic dysfunction (renocardiac syndrome).
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Affiliation(s)
- JongUn Lee
- Department of Physiology, Chonnam National University Medical School, Gwangju, Korea
| | - Eun Hui Bae
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Seong Kwon Ma
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Soo Wan Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
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4
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Olaniyan T, Olatunji LA. Elevated Myocardial Oxygen Consumption During Cutaneous Cold Stress in Young Adult Overweight and Obese Africans. J Public Health Afr 2015; 6:420. [PMID: 28299141 PMCID: PMC5349268 DOI: 10.4081/jphia.2015.420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 07/13/2015] [Indexed: 11/23/2022] Open
Abstract
Exaggerated sympathetic-mediated cardiovascular responses to stressful stimuli (such as cold exposure) has been linked to the development of hypertension and cardiovascular disease, which in turn has been demonstrated to predict the development of future hypertension. The aim of the present study was to test the hypothesis that enhanced change in myocardial oxygen consumption (MVO2) to cutaneous cold stress may be one potential mechanism that predisposes overweight/obese individuals in Africa to developing hypertension. The Rate-Pressure-Product (a non-invasive determinant of MVO2) was measured in normotensive young individuals aged between 18 and 25 years at baseline and during sympathetic activation elicited by cutaneous cold stimulation (CCS). Following CCS, there was a significant enhanced rate pressure product (RPP) change in overweight individuals (P = 0.019). Furthermore, multivariate regression analysis showed that body mass index, but not body weight had a significant influence on RPP variation following CCS. Thus, it can be concluded that normotensive overweight or obese individuals have an exaggerated RPP response to the CCS. However, exposure to cold may augment sympathetic reactivity in overweight/obese individuals, which may contribute to increased risk of developing myocardial dysfunction, even in young normotensive individuals.
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Affiliation(s)
| | - Lawrence A Olatunji
- Cardiovascular and Membrane Physiology Unit, Department of Physiology, University of Ilorin , Nigeria
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5
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Angelone T, Quintieri AM, Pasqua T, Filice E, Cantafio P, Scavello F, Rocca C, Mahata SK, Gattuso A, Cerra MC. The NO stimulator, Catestatin, improves the Frank-Starling response in normotensive and hypertensive rat hearts. Nitric Oxide 2015; 50:10-19. [PMID: 26241941 DOI: 10.1016/j.niox.2015.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/08/2015] [Accepted: 07/29/2015] [Indexed: 10/23/2022]
Abstract
The myocardial response to mechanical stretch (Frank-Starling law) is an important physiological cardiac determinant. Modulated by many endogenous substances, it is impaired in the presence of cardiovascular pathologies and during senescence. Catestatin (CST:hCgA352-372), a 21-amino-acid derivate of Chromogranin A (CgA), displays hypotensive/vasodilatory properties and counteracts excessive systemic and/or intra-cardiac excitatory stimuli (e.g., catecholamines and endothelin-1). CST, produced also by the myocardium, affects the heart by modulating inotropy, lusitropy and the coronary tone through a Nitric Oxide (NO)-dependent mechanism. This study evaluated the putative influence elicited by CST on the Frank-Starling response of normotensive Wistar-Kyoto (WKY) and hypertensive (SHR) hearts by using isolated and Langendorff perfused cardiac preparations. Functional changes were evaluated on aged (18-month-old) WKY rats and SHR which mimic human chronic heart failure (HF). Comparison to WKY rats, SHR showed a reduced Frank-Starling response. In both rat strains, CST administration improved myocardial mechanical response to increased end-diastolic pressures. This effect was mediated by EE/IP3K/NOS/NO/cGMP/PKG, as revealed by specific inhibitors. CST-dependent positive Frank-Starling response is paralleled by an increment in protein S-Nitrosylation. Our data suggested CST as a NO-dependent physiological modulator of the stretch-induced intrinsic regulation of the heart. This may be of particular importance in the aged hypertrophic heart, whose function is impaired because of a reduced systolic performance accompanied by delayed relaxation and increased diastolic stiffness.
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Affiliation(s)
- T Angelone
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy; National Institute of Cardiovascular Research, Bologna, Italy
| | - A M Quintieri
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - T Pasqua
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - E Filice
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - P Cantafio
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - F Scavello
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - C Rocca
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - S K Mahata
- Department of Medicine, University of California & VA San Diego Healthcare System, San Diego, USA
| | - A Gattuso
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy.
| | - M C Cerra
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy; National Institute of Cardiovascular Research, Bologna, Italy.
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Meng G, Yang S, Chen Y, Yao W, Zhu H, Zhang W. Attenuating effects of dihydromyricetin on angiotensin II-induced rat cardiomyocyte hypertrophy related to antioxidative activity in a NO-dependent manner. PHARMACEUTICAL BIOLOGY 2015; 53:904-912. [PMID: 25471017 DOI: 10.3109/13880209.2014.948635] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
CONTEXT Dihydromyricetin (DMY) displays a range of biological properties. However, whether DMY attenuates cardiomyocyte hypertrophy is unknown. OBJECTIVE To investigate whether DMY had potential therapeutic value to protect against angiotensin II (Ang II)-induced cardiomyocyte hypertrophy. MATERIALS AND METHODS Neonatal rat cardiomyocytes were pretreated with DMY (0-320 μM) followed with Ang II (100 nM) stimulation for 24 h, and then degree of hypertrophy was evaluated by cell surface analysis. Levels of reactive oxygen species (ROS) were measured with 2',7'-dichlorfluorescein-diacetate (DCFH-DA) fluorescent staining. Antioxidative activity was evaluated by malondialdehyde (MDA) level, superoxide dismutase (SOD) activity, and total antioxidant capacity (T-AOC). Cyclic guanosine monophosphate (cGMP) was determined with a radioimmunoassay. RESULTS Pre-incubation with DMY (20, 40, 80, and 160 μM) for 8 h, 12 h, 24 h, or 48 h decreased cell surface areas. It down-regulated mRNA expression of atrial natriuretic factor (1.95- to 1.24-fold) and β-myosin heavy chains (3.51- to 2.32-fold), reduced levels of MDA as well as increased SOD activity and T-AOC. Expression of SOD and thioredoxin were enhanced by DMY, whereas p22(phox) and phosphorylation of mitogen-activated protein kinases were inhibited. Content of cGMP (0.54- to 0.80-fold) and phosphorylation of endothelial nitric oxide synthase at serine 1177 (0.70- to 1.05-fold) were augmented by DMY. Moreover, attenuating effect of DMY on hypertrophy was abolished when NO production was inhibited by l-NAME. CONCLUSION Attenuating effects of DMY on Ang II-induced cardiomyocyte hypertrophy related to antioxidative activity in a NO-dependent manner.
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Affiliation(s)
- Guoliang Meng
- Department of Pharmacology, School of Pharmacy, Nantong University , Nantong, Jiangsu , China and
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7
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El-Awdan SA, Abdel Jaleel GA, Saleh DO. Grape seed extract attenuates hyperglycaemia-induced in rats by streptozotocin. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.bfopcu.2013.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Tsai EJ, Liu Y, Koitabashi N, Bedja D, Danner T, Jasmin JF, Lisanti MP, Friebe A, Takimoto E, Kass DA. Pressure-overload-induced subcellular relocalization/oxidation of soluble guanylyl cyclase in the heart modulates enzyme stimulation. Circ Res 2012; 110:295-303. [PMID: 22095726 PMCID: PMC4264382 DOI: 10.1161/circresaha.111.259242] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
RATIONALE Soluble guanylyl cyclase (sGC) generates cyclic guanosine monophophate (cGMP) upon activation by nitric oxide (NO). Cardiac NO-sGC-cGMP signaling blunts cardiac stress responses, including pressure-overload-induced hypertrophy. The latter itself depresses signaling through this pathway by reducing NO generation and enhancing cGMP hydrolysis. OBJECTIVE We tested the hypothesis that the sGC response to NO also declines with pressure-overload stress and assessed the role of heme-oxidation and altered intracellular compartmentation of sGC as potential mechanisms. METHODS AND RESULTS C57BL/6 mice subjected to transverse aortic constriction (TAC) developed cardiac hypertrophy and dysfunction. NO-stimulated sGC activity was markedly depressed, whereas NO- and heme-independent sGC activation by BAY 60-2770 was preserved. Total sGCα(1) and β(1) expression were unchanged by TAC; however, sGCβ(1) subunits shifted out of caveolin-enriched microdomains. NO-stimulated sGC activity was 2- to 3-fold greater in Cav3-containing lipid raft versus nonlipid raft domains in control and 6-fold greater after TAC. In contrast, BAY 60-2770 responses were >10 fold higher in non-Cav3 domains with and without TAC, declining about 60% after TAC within each compartment. Mice genetically lacking Cav3 had reduced NO- and BAY-stimulated sGC activity in microdomains containing Cav3 for controls but no change within non-Cav3-enriched domains. CONCLUSIONS Pressure overload depresses NO/heme-dependent sGC activation in the heart, consistent with enhanced oxidation. The data reveal a novel additional mechanism for reduced NO-coupled sGC activity related to dynamic shifts in membrane microdomain localization, with Cav3-microdomains protecting sGC from heme-oxidation and facilitating NO responsiveness. Translocation of sGC out of this domain favors sGC oxidation and contributes to depressed NO-stimulated sGC activity.
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Affiliation(s)
- Emily J. Tsai
- Section in Cardiology, Department of Medicine, Temple University School of Medicine, Philadelphia, PA
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - Yuchuan Liu
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA
| | - Norimichi Koitabashi
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - Djahida Bedja
- Department of Comparative Medicine and Comparative Pathology, Johns Hopkins University Medical Institutions, Baltimore, MD 21205
| | - Thomas Danner
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - Jean-Francois Jasmin
- Department of Stem Cell Biology & Regenerative Medicine, Thomas Jefferson University, Philadelphia, PA
| | - Michael P. Lisanti
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA
| | - Andreas Friebe
- Physiologisches Institut I, Universität Würzburg, Würzburg, Germany
| | - Eiki Takimoto
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - David A. Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
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9
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Umar S, van der Laarse A. Nitric oxide and nitric oxide synthase isoforms in the normal, hypertrophic, and failing heart. Mol Cell Biochem 2009; 333:191-201. [PMID: 19618122 DOI: 10.1007/s11010-009-0219-x] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Accepted: 07/07/2009] [Indexed: 02/07/2023]
Abstract
Nitric oxide (NO) produced in the heart by nitric oxide synthase (NOS) is a highly reactive signaling molecule and an important modulator of myocardial function. NOS catalyzes the conversion of L: -arginine to L: -citrulline and NO but under particular circumstances reactive oxygen species (ROS) can be formed instead of NO (uncoupling). In the heart, three NOS isoforms are present: neuronal NOS (nNOS, NOS1) and endothelial NOS (eNOS, NOS3) are constitutively present enzymes in distinct subcellular locations within cardiomyocytes, whereas inducible NOS (iNOS, NOS2) is absent in the healthy heart, but its expression is induced by pro-inflammatory mediators. In the tissue, NO has two main effects: (i) NO stimulates the activity of guanylate cyclase, leading to cGMP generation and activation of protein kinase G, and (ii) NO nitrosylates tyrosine and thiol-groups of cysteine in proteins. Upon nitrosylation, proteins may change their properties. Changes in (i) NOS expression and activity, (ii) subcellular compartmentation of NOS activity, and (iii) the occurrence of uncoupling may lead to multiple NO-induced effects, some of which being particularly evident during myocardial overload as occurs during aortic constriction and myocardial infarction. Many of these NO-induced effects are considered to be cardioprotective but particularly if NOS becomes uncoupled, formation of ROS in combination with a low NO bioavailability predisposes for cardiac damage.
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Affiliation(s)
- Soban Umar
- Department of Cardiology, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
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10
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Aravindan N, Shaw A. Effect of Furosemide Infusion on Renal Hemodynamics and Angiogenesis Gene Expression in Acute Renal Ischemia/Reperfusion. Ren Fail 2009; 28:25-35. [PMID: 16526316 DOI: 10.1080/08860220500461229] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Loop diuretics are known to affect renal hemodynamics and possibly gene transcription, but the specific effect of furosemide on renal angiogenesis gene expression after acute ischemia is not known. We utilized an acute renal failure model in rats to test the hypothesis that furosemide improves renal hemodynamics and alters the transcriptional signature of acute ischemic nephropathy. Twenty-four male Sprague-Dawley rats were anesthetized by the intraperitoneal administration of 50 mg/kg urethane. Animals were divided into four groups (n = 6 each): (1) sham-operated group infused with saline; (2) sham-operated group infused with 30 microg/kg/hr furosemide (equivalent to a human dosage of 2 mg/hr); (3) unilateral renal ischemia (1 hr, left renal artery cross-clamping) followed by 6 hr of reperfusion; and (4) renal ischemia/ reperfusion (I/R) with furosemide. Renal artery blood flow (RBF), renal cortical perfusion (RCP), and renal corticomedullary tissue oxygen tension (PO2) were recorded throughout. Following 6 hr of reperfusion, left kidney RNA was used to probe microarrays. Gene expression was measured as percent positive control and confirmed using reverse transcriptase polymerase chain reaction. Physiologic data were analyzed by calculating area under the curve, and gene expression data were compared by using multiple analysis of variance with Tukey's post-hoc tests. Furosemide significantly increased RBF (P < 0.05) and PO2 (P < 0.05) in postischemic kidneys. Furosemide attenuated nine of the 13 ischemia-induced and 41 of 78 ischemia-suppressed angiogenesis-related genes. This attenuation was statistically significant (P < 0.05) for 17 I/R injury-suppressed genes. Data from this rat model of ischemic nephropathy suggest that furosemide improves renal hemodynamics and attenuates ischemia-related changes in gene expression.
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Affiliation(s)
- Natarajan Aravindan
- Division of Cardiothoracic Anesthesia and Critical Care Medicine, Duke University, Durham, North Carolina, USA.
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11
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Allen CL, Bayraktutan U. Antioxidants attenuate hyperglycaemia-mediated brain endothelial cell dysfunction and blood-brain barrier hyperpermeability. Diabetes Obes Metab 2009; 11:480-90. [PMID: 19236439 DOI: 10.1111/j.1463-1326.2008.00987.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
AIMS Hyperglycaemia (HG), in stroke patients, is associated with worse neurological outcome by compromising endothelial cell function and the blood-brain barrier (BBB) integrity. We have studied the contribution of HG-mediated generation of oxidative stress to these pathologies and examined whether antioxidants as well as normalization of glucose levels following hyperglycaemic insult reverse these phenomena. METHODS Human brain microvascular endothelial cell (HBMEC) and human astrocyte co-cultures were used to simulate the human BBB. The integrity of the BBB was measured by transendothelial electrical resistance using STX electrodes and an EVOM resistance meter, while enzyme activities were measured by specific spectrophotometric assays. RESULTS After 5 days of hyperglycaemic insult, there was a significant increase in BBB permeability that was reversed by glucose normalization. Co-treatment of cells with HG and a number of antioxidants including vitamin C, free radical scavengers and antioxidant enzymes including catalase and superoxide dismutase mimetics attenuated the detrimental effects of HG. Inhibition of p38 mitogen-activated protein kinase (p38MAPK) and protein kinase C but not phosphoinositide 3 kinase (PI3 kinase) also reversed HG-induced BBB hyperpermeability. In HBMEC, HG enhanced pro-oxidant (NAD(P)H oxidase) enzyme activity and expression that were normalized by reverting to normoglycaemia. CONCLUSIONS HG impairs brain microvascular endothelial function through involvements of oxidative stress and several signal transduction pathways.
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Affiliation(s)
- C L Allen
- Division of Stroke Medicine, University of Nottingham, Nottingham, UK
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12
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CGRP-alpha responsiveness of adult rat ventricular cardiomyocytes from normotensive and spontaneously hypertensive rats. Eur J Cell Biol 2009; 88:227-41. [PMID: 19128857 DOI: 10.1016/j.ejcb.2008.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 11/07/2008] [Accepted: 11/12/2008] [Indexed: 11/23/2022] Open
Abstract
Calcitonin gene-related peptide (CGRP)-alpha is expressed in heart ventricles in sensory nerves and cardiomyocytes. It modifies inotropism and induces ischaemic preconditioning. This study investigates the effect of CGRP-alpha on the contractile responsiveness of isolated adult ventricular rat cardiomyocytes and the effect of chronic hypertension on this interaction. Cardiomyocytes were isolated and paced at 0.5-2.0 Hz. Cell shortening was recorded via a line camera with a reading frame of 500 Hz. CGRP-alpha exerted a dual effect on cardiomyocytes with a positive contractile effect at 10nM and a negative contractile effect at 10 pM. CGRP-alpha(8-37), a calcitonin receptor-like receptor (CRLR) antagonist, attenuated the positive contractile effect. H89, a protein kinase A antagonist, converted the positive contractile effect into a negative contractile effect. The negative contractile effect was converted again back to a positive contractile effect in the presence of l-nitro arginine. In cardiomyocytes isolated from spontaneously hypertensive rats (SHR) the mRNA expression of CRLR and the receptor-associated modifier protein (RAMP)-2 were lower. However, on the protein level CLRL was up-regulated, RAMP2 expression remained unchanged, and eNOS expression was down-regulated in these cells. These cells responded with a pure positive contractile response. In Langendorff preparations, CGRP-alpha slightly reduced the rate pressure product in hearts from normotensive rats but it caused an increase in hearts from SHR. In conclusion, it is shown that CGRP-alpha exerts dual effects on cardiomyocytes favouring the negative contractile effect at very low concentrations. This effect is compensated in chronic pressure-overloaded hearts and converted into a positive inotropism.
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13
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Kokoz YM, Grushin KS, Nenov MN, Dynnik VV, Semushina SG, Pakhomova IA, Murashev AN. Control of the L-type Ca2+ current by the NO-cGMP cascade in isolated cardiomyocytes of normotensive and spontaneously hypertensive rats. DOKL BIOCHEM BIOPHYS 2007; 415:170-3. [PMID: 17933327 DOI: 10.1134/s1607672907040023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Y M Kokoz
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, pr. Nauki, Pushchino, Moscow oblast, 142292, Russia
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14
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Wenzel S, Rohde C, Wingerning S, Roth J, Kojda G, Schlüter KD. Lack of Endothelial Nitric Oxide Synthase–Derived Nitric Oxide Formation Favors Hypertrophy in Adult Ventricular Cardiomyocytes. Hypertension 2007; 49:193-200. [PMID: 17075027 DOI: 10.1161/01.hyp.0000250468.02084.ce] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Reduced activity and expression of endothelial NO synthase (eNOS) is observed in cardiomyocytes from pressure-overloaded hearts with heart failure. The present study was aimed to investigate whether reduced eNOS-derived NO production contributes to the hypertrophic growth and phenotype of these cardiomyocytes. Cultured ventricular cardiomyocytes from adult rats were exposed to Nω-nitro-
l
-arginine (
l
-NNA) to inhibit global NO formation, and cultured cardiomyocytes derived from eNOS-deficient mice were used as a model of genetic knockout of eNOS. Cell growth, formation of oxygen-derived radicals (reactive oxygen species [ROS]), activation of p38 mitogen-activated protein (MAP) kinase phosphorylation, and cytokine expression in cardiomyocytes were investigated.
l
-NNA caused a concentration-dependent acceleration of the rate of protein synthesis and an increase in cell size. This effect was sensitive to p38 MAP kinase inhibition or antioxidants.
l
-NNA induced a rapid increase in ROS formation, subsequent activation of p38 MAP kinase, and p38 MAP kinase–dependent increases in the expression of transforming growth factor-β and tumor necrosis factor-α. Similar changes (increased ROS formation, p38 MAP kinase phosphorylation, and cytokine induction) were also observed in cardiomyocytes derived from eNOS+/+ mice when exposed to
l
-NNA. Cardiomyocytes from eNOS−/− mice displayed higher p38 MAP kinase phosphorylation and cytokine expression under basal conditions, but neither these 2 parameters nor ROS formation were increased in the presence of
l
-NNA. In conclusion, our data support the hypothesis that reduced eNOS activity in cardiomyocytes contributes to the onset of myocardial hypertrophy and increased cytokine expression, which are involved in the transition to heart failure.
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Affiliation(s)
- Sibylle Wenzel
- Justus-Liebig-Universität Giessen, Physiologisches Institut, Germany
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15
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Aravindan N, Natarajan M, Shaw AD. Fenoldopam Inhibits Nuclear Translocation of Nuclear Factor Kappa B in a Rat Model of Surgical Ischemic Acute Renal Failure. J Cardiothorac Vasc Anesth 2006; 20:179-86. [PMID: 16616657 DOI: 10.1053/j.jvca.2005.03.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2004] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Vasoactive compounds are known to modulate gene transcription, including nuclear factor kappa B (NF-kappaB), in renal tissues, but the molecular effects of fenoldopam in this setting are not known. The authors used a rat model of surgical acute ischemic nephropathy to test the hypothesis that fenoldopam attenuates ischemia/reperfusion (I/R)-induced NF-kappaB-mediated inflammation. DESIGN Prospective, single-blind, randomized, controlled animal study. SETTING Academic Department of Anesthesiology laboratory. SUBJECTS Twenty-four male Sprague-Dawley rats. INTERVENTIONS Rats were anesthetized by intraperitoneal administration of 50 mg/kg of urethane and randomly allocated into 4 groups (n = 6 each): sham operation, sham operation with infusion of 0.1 microg/kg/min of fenoldopam, unilateral renal ischemia (1 hour, left renal artery cross-clamping) followed by 4 hours of reperfusion, and unilateral renal I/R with fenoldopam infusion. MEASUREMENTS AND MAIN RESULTS Kidney samples were used to measure NF-kappaB DNA-binding activity with an electrophoretic mobility shift assay. NF-kappaB signaling-dependent gene transcription was assessed with microarray analysis, and validated with reverse transcriptase polymerase chain reaction (RT-PCR). Expression of insulin-like growth factor-1 and nitric oxide synthetase-3 messenger RNA (not included in the array) was studied with RT-PCR. NF-kappaB DNA binding activity was significantly higher (p < 0.001) after I/R injury. Of the 96 genes analyzed, 75 were induced and another 8 were suppressed completely (2-fold or greater change v control) after I/R. Treatment with fenoldopam prevented activation of NF-kappaB DNA binding activity (p < 0.001) and attenuated 72 of 75 I/R-induced genes and 3 of 8 I/R-suppressed genes. CONCLUSION Data from this rat model of renal I/R suggest that the mechanism by which fenoldopam attenuates I/R-induced inflammation appears to involve inhibition of NF-kappaB translocation and signal transduction.
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Affiliation(s)
- Natarajan Aravindan
- Division of Anesthesiology and Critical Care, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
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Thompson LP, Dong Y. Chronic hypoxia decreases endothelial nitric oxide synthase protein expression in fetal guinea pig hearts. ACTA ACUST UNITED AC 2006; 12:388-95. [PMID: 15982907 DOI: 10.1016/j.jsgi.2005.04.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVES The underlying cellular mechanisms mediating hypoxia-induced adaptations in the fetus are poorly understood. We tested the hypothesis that hypoxia up-regulates endothelial nitric oxide synthase (NOS3, type III) protein expression in fetal hearts similar to that observed in adult hearts as a cardioprotective adaptation. This study investigates the effect of chronic hypoxia on NOS3 protein expression in hearts and carotid arteries of fetal guinea pigs exposed to normoxia or intrauterine hypoxia. METHODS Time-mated pregnant guinea pigs (term = 65 days) were housed in either normoxic room air (NMX) or exposed to 12% O(2) (hypoxia; HPX) for 14 or 28 days of duration. At near term ( approximately 60 days of gestation), pregnant mothers were anesthetized and fetal guinea pig hearts and carotid arteries were excised from NMX and HPX animals and frozen until ready for study. In addition, hearts were also excised from anesthetized adult nonpregnant female guinea pigs exposed to either NMX or HPX for 14 days. NOS3 protein was extracted from all tissues and quantified using Western blot analysis. Fetal heart samples were also prepared for localization of NOS3 protein using immunohistochemistry. RESULTS Chronic hypoxia increased both maternal and fetal hematocrit after 28 days of duration. HPX decreased NOS3 protein levels in fetal guinea pig hearts by 29% after 28 days compared to NMX controls. In contrast, HPX increased both NOS3 protein levels in adult hearts by 62% and fetal carotid arteries by fourfold after 14 days of exposure compared to their respective NMX controls. Positive immunostaining of NOS3 protein of fetal hearts was localized in both cardiomyocytes and endothelial cells. CONCLUSION Contrary to our hypothesis, the hypoxia-induced decrease in fetal guinea pig heart NOS3 protein contrasts to the protein levels measured in either adult hearts or fetal carotid arteries. These results suggest that the NOS protein expression is altered differently by hypoxia in fetal and adult hearts and in a peripheral fetal artery exposed to the same level of hypoxia. Thus, the functional role of NO in the fetal heart during hypoxia may differ from that of the adult.
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Affiliation(s)
- Loren P Thompson
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore 21201, USA.
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Zhao Y, Bell D, Smith LR, Zhao L, Devine AB, McHenry EM, Nicholls DP, McDermott BJ. Differential expression of components of the cardiomyocyte adrenomedullin/intermedin receptor system following blood pressure reduction in nitric oxide-deficient hypertension. J Pharmacol Exp Ther 2005; 316:1269-81. [PMID: 16326922 DOI: 10.1124/jpet.105.092783] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adrenomedullin (AM) and intermedin (IMD; adrenomedulln-2) are vasodilator peptides related to calcitonin gene-related peptide (CGRP). The actions of these peptides are mediated by the calcitonin receptor-like receptor (CLR) in association with one of three receptor activity-modifying proteins. CGRP is selective for CLR/receptor activity modifying protein (RAMP)1, AM for CLR/RAMP2 and -3, and IMD acts at both CGRP and AM receptors. In a model of pressure overload induced by inhibition of nitric-oxide synthase, up-regulation of AM was observed previously in cardiomyocytes demonstrating a hypertrophic phenotype. The current objective was to examine the effects of blood pressure reduction on cardiomyocyte expression of AM and IMD and their receptor components. Nomega-nitro-L-arginine methyl ester (L-NAME) (35 mg/kg/day) was administered to rats for 8 weeks, with or without concurrent administration of hydralazine (50 mg/kg/day) and hydrochlorothiazide (7.5 mg/kg/day). In left ventricular cardiomyocytes from L-NAME-treated rats, increases (-fold) in mRNA expression were 1.6 (preproAM), 8.4 (preproIMD), 3.4 (CLR), 4.1 (RAMP1), 2.8 (RAMP2), and 4.4 (RAMP3). Hydralazine/hydrochlorothiazide normalized systolic blood pressure (BP) and abolished mRNA up-regulation of hypertrophic markers sk-alpha-actin and BNP and of preproAM, CLR, RAMP2, and RAMP3 but did not normalize cardiomyocyte width nor preproIMD or RAMP1 mRNA expression. The robust increase in IMD expression indicates an important role for this peptide in the cardiac pathology of this model but, unlike AM, IMD is not associated with pressure overload upon the myocardium. The concordance of IMD and RAMP1 up-regulation indicates a CGRP-type receptor action; considering also a lack of response to BP reduction, IMD may, like CGRP, have an anti-ischemic function.
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Affiliation(s)
- YouYou Zhao
- Cardiovascular Research Group, Division of Medicine and Therapeutics, The Queen's University of Belfast, Whitla Medical Bldg., 97 Lisburn Rd., Belfast BT9 7BL, Northern Ireland, UK
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Bell D, Zhao YY, Kelso EJ, McHenry EM, Rush LM, Lamont VM, Nicholls DP, McDermott BJ. Upregulation of adrenomedullin and its receptor components during cardiomyocyte hypertrophy induced by chronic inhibition of nitric oxide synthesis in rats. Am J Physiol Heart Circ Physiol 2005; 290:H904-14. [PMID: 16040721 DOI: 10.1152/ajpheart.00152.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adrenomedullin may provide a compensatory mechanism to attenuate left ventricular hypertrophy (LVH). Nitric oxide synthase inhibition, induced by chronic administration of N(omega)-nitro-L-arginine methyl ester (L-NAME) to rats, induces cardiac hypertrophy in some, but not all cases; there are few reports of direct assessment of cardiomyocyte parameters. The objective was to characterize hypertrophic parameters in left (LV) and right ventricular (RV) cardiomyocytes after administration of L-NAME to rats for 8 wk and to determine whether adrenomedullin and its receptor components were upregulated. After treatment with L-NAME (20 and 50 mg x kg(-1) x day(-1)), compared with nontreated animals, 1) systolic blood pressure increased (by 34.2 and 104.9 mmHg), 2) heart weight-to-body wt ratio increased 24.1% at the higher dose (P < 0.05), 3) cardiomyocyte protein mass increased (P = NS), 4) cardiomyocyte protein synthesis ([14C]phenylalanine incorporation) increased (P < 0.05), 5) expression of skeletal alpha-actin, atrial natriuretic peptide, brain natriuretic peptide, and ET-1 mRNAs was enhanced (P < 0.05) in LV but not RV cardiomyocytes at 20 and 50 mg x kg(-1) x day(-1), respectively, and 6) expression of adrenomedullin, receptor activity-modifying protein 3 (RAMP3), and RAMP2 (but not calcitonin receptor-like receptor and RAMP1) mRNAs was increased by L-NAME (20 mg x kg(-1) x day(-1)) in LV. In conclusion, L-NAME enhanced protein synthesis in both LV and RV cardiomyocytes but elicited a hypertrophic phenotype accompanied by altered expression of the counterregulatory peptide adrenomedullin and receptor components (RAMP2, RAMP3) in LV only, indicating that the former is due to impaired nitric oxide synthesis, whereas the phenotypic changes are due to pressure overload.
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Affiliation(s)
- David Bell
- Division of Medicine and Therapeutics, School of Medicine, The Queen's Univ. of Belfast, Whitla Medical Bldg., 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, United Kingdom.
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Weidig P, McMaster D, Bayraktutan U. High glucose mediates pro-oxidant and antioxidant enzyme activities in coronary endothelial cells. Diabetes Obes Metab 2004; 6:432-41. [PMID: 15479219 DOI: 10.1111/j.1462-8902.2004.00364.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM Excess levels of free radicals such as nitric oxide (NO) and superoxide anion (O(2)(-)) are associated with the pathogenesis of endothelial cell dysfunction in diabetes mellitus. This study was designed to investigate the underlying causes of oxidative stress in coronary microvascular endothelial cells (CMECs) exposed to hyperglycaemia. METHODS CMECs were cultured under normal (5.5 mmol/l) or high glucose (22 mmol/l) concentrations for 7 days. The activity and expression (protein level) of endothelial NO synthase (eNOS), inducible NOS (iNOS), NAD(p)H oxidase and antioxidant enzymes, namely, superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) were investigated by specific activity assays and Western analyses, respectively, while the effects of hyperglycaemia on nitrite and O(2)(-) generation were investigated by Griess reaction and cytochrome C reduction assay, respectively. RESULTS Hyperglycaemia did not alter eNOS or iNOS protein expressions and overall nitrite generation, an index of NO production. However, it significantly reduced the levels of intracellular antioxidant glutathione by 50% (p < 0.05) and increased the protein expressions and activities of p22-phox, a membrane-bound component of pro-oxidant NAD(p)H oxidase and antioxidant enzymes (p < 0.05). Free radical scavengers, namely, Tiron and mercaptopropionylglycine (MPG) (0.1-1 micromol/l) reduced hyperglycaemia-induced antioxidant enzyme activity and increased glutathione and nitrite generation to the levels observed in CMEC cultured in normoglycaemic medium (p < 0.01). The differences in enzyme activity and expressions were independent of the increased osmolarity generated by high glucose levels as investigated by using equimolar concentrations of mannitol in parallel experiments. CONCLUSIONS These results suggest that hyperglycaemia-induced oxidative stress may arise in CMEC as a result of enhanced pro-oxidant enzyme activity and diminished generation of antioxidant glutathione. By increasing the antioxidant enzyme capacity, CMEC may protect themselves against free radical-induced cell damage in diabetic conditions.
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Affiliation(s)
- P Weidig
- Department of Medicine, Institute of Clinical Science Block B, Queen's University Belfast, Belfast BT12 6BJ, UK
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20
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Ulker S, McMaster D, McKeown PP, Bayraktutan U. Antioxidant vitamins C and E ameliorate hyperglycaemia-induced oxidative stress in coronary endothelial cells. Diabetes Obes Metab 2004; 6:442-51. [PMID: 15479220 DOI: 10.1111/j.1462-8902.2004.00443.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Vitamins C and E have protective features in many disease states associated with enhanced oxidative stress. The aim of this study was to investigate whether vitamin(s) C and/or E modulate hyperglycaemia-induced oxidative stress by regulating enzymatic activities of prooxidant, i.e. NAD(P)H oxidase and/or antioxidant enzymes, namely endothelial nitric oxide synthase (eNOS), superoxide dismutase, catalase and glutathione peroxidase, using coronary microvascular endothelial cells (CMEC). METHODS CMEC were cultured under normal (5.5 mM) or high glucose (22 mM) concentrations for 7 days. The enzyme activities were determined by specific assays. The levels of O(2) (-) and nitrite were measured by cytochrome c reduction and Griess assays respectively. RESULTS Hyperglycaemia did not alter eNOS activity or overall nitrite generation, an index of NO production. However, it increased NAD(P)H oxidase and antioxidant enzyme activities (p < 0.05). Specific inhibitors of NAD(P)H oxidase, i.e. phenylarsine oxide (0.1-3 microm) and 4-(2-aminoethyl)benzenesulfonyl fluoride (5-100 microm) and vitamins C and E (0.1-1 microm) significantly reduced prooxidant and antioxidant enzyme activities in CMEC exposed to hyperglycaemia (p < 0.01). The differences in enzyme activities were independent of increases in osmolarity generated by high glucose levels as investigated by using equimolar concentrations of mannitol in parallel experiments. CONCLUSIONS Vitamins C and E may protect CMEC against hyperglycaemia-induced oxidative stress by concomitantly regulating prooxidant and antioxidant enzyme activities.
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Affiliation(s)
- S Ulker
- Department of Medicine, Institute of Clinical Science Block B, Queen's University Belfast, Belfast BT12 6BJ, UK
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21
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Bayraktutan U. Effects of angiotensin II on nitric oxide generation in growing and resting rat aortic endothelial cells. J Hypertens 2003; 21:2093-101. [PMID: 14597853 DOI: 10.1097/00004872-200311000-00019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To assess the effects of angiotensin II (ang II) and its receptors on nitric oxide (NO) production and endothelial NO synthase (eNOS) activity and expression with respect to rat aortic endothelial cell (RAEC) growth. To also assess whether an intact endothelium is required for ang II activity. METHODS RAEC were treated with different doses of ang II, Ca(2+) ionophore A23187, valsartan (an AT(1) receptor inhibitor) or PD-123319 (an AT(2) receptor inhibitor) alone or in combination for 24 h before measuring nitrite levels by Griess reaction as an index of NO production and eNOS activity by L-[3H]-arginine to L-[3H]-citrulline conversion assay. eNOS mRNA and protein expressions were determined by Northern and Western analyses, respectively. The requirement of endothelium for ang II-mediated relaxant/contractile effects was investigated by isometric tension studies. RESULTS NO production and eNOS activity/expression were almost two-fold greater in proliferating RAEC. Ang II or Ca(2+) ionophore A23187 enhanced NO production in proliferating and confluent RAEC without altering the fold-difference in basal NO release. Both valsartan and PD-123319 significantly diminished NO production in RAEC treated with ang II but not Ca(2+) ionophore A23187 while NG-nitro-L-arginine (L-NNA, 10 micromol/l) equally decreased NO generation in response to both stimulators. L-NNA, valsartan and PD-123319 also abolished endothelium-dependent vasorelaxant responses to ACh and Ca(2+) ionophore A23187 in the presence of ang II. Sodium nitroprusside (SNP), a NO donor, increased endothelium-independent vasorelaxant responses that were augmented by valsartan but not L-NNA or PD-123319 in the presence of ang II. CONCLUSIONS Ang II induces vascular NO production through endothelial AT(1) and AT(2)-receptors. This may be beneficial in counterbalancing its vasoconstrictor effect on vascular smooth muscle cells.
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Affiliation(s)
- Ulvi Bayraktutan
- Department of Medicine, Institute of Clinical Science, University Belfast, Belfast, UK.
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Cohen AW, Park DS, Woodman SE, Williams TM, Chandra M, Shirani J, Pereira de Souza A, Kitsis RN, Russell RG, Weiss LM, Tang B, Jelicks LA, Factor SM, Shtutin V, Tanowitz HB, Lisanti MP. Caveolin-1 null mice develop cardiac hypertrophy with hyperactivation of p42/44 MAP kinase in cardiac fibroblasts. Am J Physiol Cell Physiol 2003; 284:C457-74. [PMID: 12388077 DOI: 10.1152/ajpcell.00380.2002] [Citation(s) in RCA: 190] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, development of a caveolin-1-deficient (Cav-1 null) mouse model has allowed the detailed analysis of caveolin-1's function in the context of a whole animal. Interestingly, we now report that the hearts of Cav-1 null mice are markedly abnormal, despite the fact that caveolin-1 is not expressed in cardiac myocytes. However, caveolin-1 is abundantly expressed in the nonmyocytic cells of the heart, i.e., cardiac fibroblasts and endothelia. Quantitative imaging studies of Cav-1 null hearts demonstrate a significantly enlarged right ventricular cavity and a thickened left ventricular wall with decreased systolic function. Histological analysis reveals myocyte hypertrophy with interstitial/perivascular fibrosis. Because caveolin-1 is thought to act as a negative regulator of the p42/44 MAP kinase cascade, we performed Western blot analysis with phospho-specific antibodies that only recognize activated ERK1/2. As predicted, the p42/44 MAP kinase cascade is hyperactivated in Cav-1 null heart tissue (i.e., interstitial fibrotic lesions) and isolated cardiac fibroblasts. In addition, endothelial and inducible nitric oxide synthase levels are dramatically upregulated. Thus loss of caveolin-1 expression drives p42/44 MAP kinase activation and cardiac hypertrophy.
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Affiliation(s)
- Alex W Cohen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Bayraktutan U, Ulker S. Effects of Angiotensin II on Nitric Oxide Generation in Proliferating and Quiescent Rat Coronary Microvascular Endothelial Cells. Hypertens Res 2003; 26:749-57. [PMID: 14620932 DOI: 10.1291/hypres.26.749] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Nitric oxide (NO) and the mitogenic peptide angiotensin II (Ang II) have been implicated in endothelial cell growth. However, the putative relationship between these two opposing agents with respect to endothelial cell growth remains unknown. In this study, proliferating and confluent rat coronary microvascular endothelial cells (CMEC) were treated with different doses of Ang II, Ca2+ ionophore A23187, or valsartan (an Ang II type 1 (AT1) receptor inhibitor) alone or in combination for 24 h before measuring the nitrite levels as an index of NO generation. NO production and endothelial NO synthase (eNOS) mRNA/protein expression were found to be 3-fold greater in proliferating vs. quiescent CMEC. Treatments of CMEC with Ang II or Ca2+ ionophore A23187 equally increased NO production without altering the fold-difference in the basal release of NO from proliferating vs. confluent CMEC. Valsartan abolished NO production in CMEC treated with Ang II but not Ca2+ ionophore A23187. Treatments of endothelium-intact vascular rings with Ang II (1 nmol/l to 10 micromol/l) plus valsartan or PD-123319, an Ang II type 2 (AT2) receptor inhibitor, attenuated vascular responses to acetylcholine in an Ang II dose-dependent manner. In these rings, phenylephrine produced significant increases in contractile responses only at nmol/l concentrations of Ang II. In contrast, pharmacological and mechanical inactivation of endothelium enhanced contractile responses to phenylephrine at micromol/I concentrations of Ang II. These data demonstrate that Ang II stimulates NO production in CMEC in both an AT1- and an AT2 receptor-regulated manner, and that this stimulation of NO may be beneficial in counterbalancing the direct vasoconstrictor effect of Ang II on underlying smooth muscle cells.
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Affiliation(s)
- Ulvi Bayraktutan
- Department of Medicine, Institute of Clinical Science, Block B, Queen's University Belfast, Grosvenor Road, Belfast BT12 6BJ, UK.
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Brutsaert DL. Cardiac endothelial-myocardial signaling: its role in cardiac growth, contractile performance, and rhythmicity. Physiol Rev 2003; 83:59-115. [PMID: 12506127 DOI: 10.1152/physrev.00017.2002] [Citation(s) in RCA: 500] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Experimental work during the past 15 years has demonstrated that endothelial cells in the heart play an obligatory role in regulating and maintaining cardiac function, in particular, at the endocardium and in the myocardial capillaries where endothelial cells directly interact with adjacent cardiomyocytes. The emerging field of targeted gene manipulation has led to the contention that cardiac endothelial-cardiomyocytal interaction is a prerequisite for normal cardiac development and growth. Some of the molecular mechanisms and cellular signals governing this interaction, such as neuregulin, vascular endothelial growth factor, and angiopoietin, continue to maintain phenotype and survival of cardiomyocytes in the adult heart. Cardiac endothelial cells, like vascular endothelial cells, also express and release a variety of auto- and paracrine agents, such as nitric oxide, endothelin, prostaglandin I(2), and angiotensin II, which directly influence cardiac metabolism, growth, contractile performance, and rhythmicity of the adult heart. The synthesis, secretion, and, most importantly, the activities of these endothelium-derived substances in the heart are closely linked, interrelated, and interactive. It may therefore be simplistic to try and define their properties independently from one another. Moreover, in relation specifically to the endocardial endothelium, an active transendothelial physicochemical gradient for various ions, or blood-heart barrier, has been demonstrated. Linkage of this blood-heart barrier to the various other endothelium-mediated signaling pathways or to the putative vascular endothelium-derived hyperpolarizing factors remains to be determined. At the early stages of cardiac failure, all major cardiovascular risk factors may cause cardiac endothelial activation as an adaptive response often followed by cardiac endothelial dysfunction. Because of the interdependency of all endothelial signaling pathways, activation or disturbance of any will necessarily affect the others leading to a disturbance of their normal balance, leading to further progression of cardiac failure.
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Li H, Wallerath T, Münzel T, Förstermann U. Regulation of endothelial-type NO synthase expression in pathophysiology and in response to drugs. Nitric Oxide 2002; 7:149-64. [PMID: 12381413 DOI: 10.1016/s1089-8603(02)00111-8] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In many types of cardiovascular pathophysiology such as hypercholesterolemia and atherosclerosis, diabetes, cigarette smoking, or hypertension (with its sequelae stroke and heart failure) the expression of endothelial NO synthase (eNOS) is altered. Both up- and downregulation of eNOS have been observed, depending on the underlying disease. When eNOS is upregulated, the upregulation is often futile and goes along with a reduction in bioactive NO. This is due to an increased production of superoxide generated by NAD(P)H oxidase and by an uncoupled eNOS. A number of drugs with favorable effects on cardiovascular disease upregulate eNOS expression. The resulting increase in vascular NO production may contribute to their beneficial effects. These compounds include statins, angiotensin-converting enzyme inhibitors, AT1 receptor antagonists, calcium channel blockers, and some antioxidants. Other drugs such as glucocorticoids, whose administration is associated with cardiovascular side effects, downregulate eNOS expression. Stills others such as the immunosuppressants cyclosporine A and FK506/tacrolimus or erythropoietin have inconsistent effects on eNOS. Thus regulation of eNOS expression and activity contributes to the overall action of several classes of drugs, and the development of compounds that specifically upregulate this protective enzyme appears as a desirable target for drug development.
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Affiliation(s)
- Huige Li
- Department of Pharmacology, Johannes Gutenberg University, Obere Zahlbacher Strasse 67, D-55101, Mainz, Germany
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Sampaio RC, Tanus-Santos JE, Melo SESFC, Hyslop S, Franchini KG, Luca IM, Moreno H. Hypertension plus diabetes mimics the cardiomyopathy induced by nitric oxide inhibition in rats. Chest 2002; 122:1412-20. [PMID: 12377873 DOI: 10.1378/chest.122.4.1412] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
STUDY OBJECTIVES We compared the myocardial lesions caused by the long-term inhibition of nitric oxide (NO) biosynthesis with those associated with renovascular hypertension (two-kidney, one-clip model [2K-1C]) and superimposed streptozotocin-induced diabetes mellitus (DM). DESIGN Prospective trial. SETTING University laboratory. INTERVENTIONS Male Wistar rats were classified into the following groups: (1) a control group; (2) the L-NAME group (treatment with the NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester [L-NAME], 75 micro mol per rat per day, orally); (3) the 2K-1C group (renovascular hypertension); (4) the DM group (treatment with streptozotocin, 60 mg/kg via intraperitoneal route); and (5) the 2K-1C plus DM group (renovascular hypertension and streptozotocin-induced DM). Arterial BP was measured by a tail-cuff method for 3 weeks, after which histologic and stereological analysis of the heart was done and cardiac NO synthase type 3 (NOS3) levels were assessed by Western blotting. The circulating levels of nitrates/nitrites and thromboxane B(2) (TXB(2), the stable metabolite of thromboxane A(2)) were also measured. RESULTS In DM and 2K-1C rats, the myocardial lesions consisted mainly of recent myocardial infarcts, which were more severe in the 2K-1C plus DM group. In L-NAME-treated rats, multiple foci of reparative fibrosis and fresh myocardial necrosis resembled the severe lesions found in the 2K-1C plus DM group. Although NOS3 protein expression increased (19 to 44%; p < 0.05) in all treated groups, serum nitrate/nitrite levels decreased only in the L-NAME group and the 2K-1C plus DM group. These two groups also showed a more pronounced increase in TXB(2) concentrations. CONCLUSIONS These results indicate that the association of hypertension and DM mimics the alterations induced by L-NAME in rats, which suggests a role for NO in the pathophysiology of hypertensive-diabetic cardiomyopathy.
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Affiliation(s)
- Rita C Sampaio
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, Brazil 14049-900
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Affiliation(s)
- U Bayraktutan
- Department of Medicine, Institute of Clinical Science, The Queen's University of Belfast, Belfast, UK.
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Piech A, Massart PE, Dessy C, Feron O, Havaux X, Morel N, Vanoverschelde JL, Donckier J, Balligand JL. Decreased expression of myocardial eNOS and caveolin in dogs with hypertrophic cardiomyopathy. Am J Physiol Heart Circ Physiol 2002; 282:H219-31. [PMID: 11748066 DOI: 10.1152/ajpheart.2002.282.1.h219] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Because nitric oxide (NO) regulates cardiac and vessel contraction, we compared the expression and activity of the endothelial NO synthase (eNOS) and caveolin, which tonically inhibits eNOS in normal and hypertrophic cardiomyopathic hearts. NOS activity (L-[(3)H]citrulline formation), eNOS immunostaining, and caveolin abundance were measured in heart tissue of 23 mongrel dogs before and at 3 and 7 wk of perinephritic hypertension (PHT). Hemodynamic parameters in vivo and endothelial NO-dependent relaxation of macro- and coronary microvessels in vitro were assessed in the same animals. eNOS immunostaining and total calcium-dependent NOS activity decreased at 7 wk in all four heart cavities (in left ventricle, from 17.0 +/- 1.3 to 0.2 +/- 0.2 fmol. min(-1). mg protein(-1), P < 0.001). Caveolin-1 and -3 also decreased in PHT dog hearts. Accordingly, basal vascular tone was preserved, but maximal endothelial NO-dependent relaxation was impaired in all vessels from 7-wk PHT dogs. The latter had preserved systolic function but impaired diastolic relaxation [relaxation time constant (T(1)), 25.1 +/- 0.9 vs. 22.0 +/- 1 ms in controls; P < 0.05]. Peripheral infusion of the NOS inhibitor N(G)-nitro-L-arginine methyl ester increased mean aortic pressure in both groups and reduced diastolic (T(1), 31.9 +/- 1.4 ms) and systolic function in PHT dogs (DP40, 47.5 +/- 2.5 vs. 59.4 +/- 3.8 s(-1) in control animals). In conclusion, both eNOS and caveolin proteins are decreased in the hypertrophic hearts of PHT dogs. This is associated with altered maximal (but not basal) vascular relaxation and impaired diastolic function. Further degradation of cardiac function after NOS inhibition suggests a critical role of residual NOS activity, probably supported by the concurrent downregulation of caveolin.
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Affiliation(s)
- A Piech
- Unit of Pharmacology and Therapeutics, Dept. of Medicine, FATH 5349, Université Catholique de Louvain, 53, Ave. E. Mounier, B-1200 Brussels, Belgium
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29
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Bloch W, Addicks K, Hescheler J, Fleischmann BK. Nitric oxide synthase expression and function in embryonic and adult cardiomyocytes. Microsc Res Tech 2001; 55:259-69. [PMID: 11748864 DOI: 10.1002/jemt.1175] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nitric oxide (NO) is an important signalling molecule that plays a relevant role in different cell systems, among them the adult heart. The effects of NO are primarily mediated through modulation of Ca(2+) homeostasis, myofibrillar contractility, and metabolic regulation in cardiomyocytes. Recent evidence also suggests an important role of NO for cardiomyogenesis by modulating proliferation and differentiation and regulating cardiac function. In the embryonic, but also the healthy and diseased, adult mammalian heart, the inducible (iNOS) and the endothelial (eNOS) nitric oxide synthases (NOS) are detected. However, the expression pattern of NO and its function differ during development. Furthermore, under pathophysiological conditions NOS expression can also change and cause impairment of cardiac performance and cytotoxic effects. The present review focuses on the role and function of NO during cardiomyogenesis, the mechanisms responsible for eNOS availability, and the paracrine effects of NO generated by cardiomyocytes.
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Affiliation(s)
- W Bloch
- Institut I für Anatomie, Universität zu Köln, 50931 Köln, Federal Republic of Germany.
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30
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Grieve DJ, MacCarthy PA, Gall NP, Cave AC, Shah AM. Divergent biological actions of coronary endothelial nitric oxide during progression of cardiac hypertrophy. Hypertension 2001; 38:267-73. [PMID: 11509488 DOI: 10.1161/01.hyp.38.2.267] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coronary endothelial NO synthase expression and NO bioactivity were investigated at sequential stages during the progression of left ventricular hypertrophy. Male guinea pigs underwent abdominal aortic banding or sham operation. Left ventricular contractile function was quantified in isolated ejecting hearts. Coronary endothelial and vasodilator function were assessed in isolated isovolumic hearts in response to boluses of bradykinin (0.001 to 10 micromol/L), substance P (0.01 to 100 micromol/L), diethylamine NONOate (DEA-NO) (0.1 to 1000 micromol/L), N(G)-monomethyl-L-arginine monoacetate (L-NMMA) (10 mmol/L), and adenosine (10 mmol/L). At a stage of compensated left ventricular hypertrophy (3 weeks), left ventricular endothelial NO synthase protein expression was unaltered (Western blot and immunocytochemistry). Vasoconstriction in response to L-NMMA was increased in banded animals compared with sham-operated animals (13.8+/-2.1% versus 6.2+/-1.3%, n=10; P<0.05), but agonist- and DEA-NO-induced vasodilation was similar in the 2 groups. At a stage of decompensated left ventricular hypertrophy (8 to 10 weeks), left ventricular endothelial NO synthase protein expression was significantly lower in banded animals (on Western analysis: banded animals, 7.8+/-0.4 densitometric units; sham-operated animals, 12.2+/-1.7 densitometric units; n=5; P<0.05). At this time point, vasoconstriction in response to L-NMMA was similar in the 2 groups, but vasodilatation in response to bradykinin (30.9+/-2.4% versus 39.7+/-2.2%, n=10; P<0.05), DEA-NO (26.2+/-1.8% versus 34.6+/-1.8%, n=10; P<0.05), and adenosine (24.3+/-2.0% versus 35.7+/-2.0%, n=10; P<0.01) was attenuated in banded animals. These findings indicate that there is an increase in the basal activity of NO (without a significant change in endothelial NO synthase expression) in early compensated left ventricular hypertrophy, followed by a decrease in both endothelial NO synthase expression and NO bioactivity during the transition to myocardial failure.
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Affiliation(s)
- D J Grieve
- Department of Cardiology, Guy's, King's and St Thomas' School of Medicine, King's College London (Denmark Hill Campus), London, United Kingdom
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