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DeMartino AW, Poudel L, Dent MR, Chen X, Xu Q, Gladwin BS, Tejero J, Basu S, Alipour E, Jiang Y, Rose JJ, Gladwin MT, Kim-Shapiro DB. Thiol-catalyzed formation of NO-ferroheme regulates intravascular NO signaling. Nat Chem Biol 2023; 19:1256-1266. [PMID: 37710075 PMCID: PMC10897909 DOI: 10.1038/s41589-023-01413-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 07/27/2023] [Indexed: 09/16/2023]
Abstract
Nitric oxide (NO) is an endogenously produced signaling molecule that regulates blood flow and platelet activation. However, intracellular and intravascular diffusion of NO are limited by scavenging reactions with several hemoproteins, raising questions as to how free NO can signal in hemoprotein-rich environments. We explore the hypothesis that NO can be stabilized as a labile ferrous heme-nitrosyl complex (Fe2+-NO, NO-ferroheme). We observe a reaction between NO, labile ferric heme (Fe3+) and reduced thiols to yield NO-ferroheme and a thiyl radical. This thiol-catalyzed reductive nitrosylation occurs when heme is solubilized in lipophilic environments such as red blood cell membranes or bound to serum albumin. The resulting NO-ferroheme resists oxidative inactivation, is soluble in cell membranes and is transported intravascularly by albumin to promote potent vasodilation. We therefore provide an alternative route for NO delivery from erythrocytes and blood via transfer of NO-ferroheme and activation of apo-soluble guanylyl cyclase.
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Affiliation(s)
- Anthony W DeMartino
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Laxman Poudel
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Matthew R Dent
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiukai Chen
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Qinzi Xu
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Brendan S Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jesús Tejero
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Swati Basu
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
- Translational Science Center, Wake Forest University, Winston-Salem, NC, USA
| | - Elmira Alipour
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Yiyang Jiang
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Jason J Rose
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mark T Gladwin
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Daniel B Kim-Shapiro
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA.
- Translational Science Center, Wake Forest University, Winston-Salem, NC, USA.
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Lewis THJ, Getsy PM, Peroni JF, Ryan RM, Jenkins MW, Lewis SJ. Characterization of endothelium-dependent and -independent processes in occipital artery of the rat: Relevance to control of blood flow to nodose sensory cells. J Appl Physiol (1985) 2021; 131:1067-1079. [PMID: 34323595 DOI: 10.1152/japplphysiol.00221.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Circulating factors access cell bodies of vagal afferents in nodose ganglia (NG) via the occipital artery (OA). Constrictor responses of OA segments closer in origin from the external carotid artery (ECA) differ from segments closer to NG. Our objective was to determine the role of endothelium in this differential vasoreactivity in rat OA segments. Vasoreactivity of OA segments (proximal segments closer to ECA, distal segments closer to NG) were examined in wire myographs. We evaluated (a) vasoconstrictor effects of 5-hydroxytryptamine (5-HT) in intact and endothelium-denuded OA segments in absence/presence of soluble guanylate cyclase (SGC) inhibitor ODQ, (b) vasodilator responses elicited by NO-donor MAHMA NONOate in intact or endothelium-denuded OA segments in absence/presence of ODQ, and (c) vasodilator responses elicited by endothelium-dependent vasodilator, acetylcholine (ACh), in intact OA segments in absence/presence of ODQ. Intact distal OA responded more to 5-HT than intact proximal OA. Endothelium denudation increased 5-HT potency in both OA segments, especially proximal OA. ODQ increased maximal responses of 5HT in both segments, particularly proximal OA. ACh similarly relaxed both OA segments, effects abolished by endothelial denudation and attenuated by ODQ. MAHMA NONOate elicited transient vasodilation in both segments. Effects of ODQ against ACh were segment-dependent whereas those against MAHMA NONOate were not. The endothelium regulates OA responsiveness in a segment-dependently fashion. Endothelial cells at the OA-ECA junction more strongly influence vascular tone than those closer to NG. Differential endothelial regulation of OA tone may play a role in controlling blood flow and access of circulating factors to NG.
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Affiliation(s)
- Tristan H J Lewis
- Department of Biology, Case Western Reserve University, Cleveland, OH, United States
| | - Paulina M Getsy
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
| | - John F Peroni
- Department of Large Animal Medicine, University of Georgia, Athens, Georgia, United States
| | - Rita M Ryan
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
| | - Michael W Jenkins
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Stephen John Lewis
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States.,Department of Pharmacology, Case Western Reserve University, Cleveland, OH, United States.,Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH, United States
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3
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Gojkovic-Bukarica L, Markovic-Lipkovski J, Heinle H, Cirovic S, Rajkovic J, Djokic V, Zivanovic V, Bukarica A, Novakovic R. The red wine polyphenol resveratrol induced relaxation of the isolated renal artery of diabetic rats: The role of potassium channels. J Funct Foods 2019. [DOI: 10.1016/j.jff.2018.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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4
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Sommer N, Strielkov I, Pak O, Weissmann N. Oxygen sensing and signal transduction in hypoxic pulmonary vasoconstriction. Eur Respir J 2015; 47:288-303. [PMID: 26493804 DOI: 10.1183/13993003.00945-2015] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/24/2015] [Indexed: 01/17/2023]
Abstract
Hypoxic pulmonary vasoconstriction (HPV), also known as the von Euler-Liljestrand mechanism, is an essential response of the pulmonary vasculature to acute and sustained alveolar hypoxia. During local alveolar hypoxia, HPV matches perfusion to ventilation to maintain optimal arterial oxygenation. In contrast, during global alveolar hypoxia, HPV leads to pulmonary hypertension. The oxygen sensing and signal transduction machinery is located in the pulmonary arterial smooth muscle cells (PASMCs) of the pre-capillary vessels, albeit the physiological response may be modulated in vivo by the endothelium. While factors such as nitric oxide modulate HPV, reactive oxygen species (ROS) have been suggested to act as essential mediators in HPV. ROS may originate from mitochondria and/or NADPH oxidases but the exact oxygen sensing mechanisms, as well as the question of whether increased or decreased ROS cause HPV, are under debate. ROS may induce intracellular calcium increase and subsequent contraction of PASMCs via direct or indirect interactions with protein kinases, phospholipases, sarcoplasmic calcium channels, transient receptor potential channels, voltage-dependent potassium channels and L-type calcium channels, whose relevance may vary under different experimental conditions. Successful identification of factors regulating HPV may allow development of novel therapeutic approaches for conditions of disturbed HPV.
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Affiliation(s)
- Natascha Sommer
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Ievgen Strielkov
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Oleg Pak
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Norbert Weissmann
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
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5
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NADPH oxidases—do they play a role in TRPC regulation under hypoxia? Pflugers Arch 2015; 468:23-41. [DOI: 10.1007/s00424-015-1731-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/23/2015] [Accepted: 08/25/2015] [Indexed: 12/25/2022]
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6
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Liu M, Zollbrecht C, Peleli M, Lundberg JO, Weitzberg E, Carlström M. Nitrite-mediated renal vasodilatation is increased during ischemic conditions via cGMP-independent signaling. Free Radic Biol Med 2015; 84:154-160. [PMID: 25841777 DOI: 10.1016/j.freeradbiomed.2015.03.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/17/2015] [Accepted: 03/23/2015] [Indexed: 11/16/2022]
Abstract
The kidney is vulnerable to hypoxia, and substantial efforts have been made to ameliorate renal ischemic injury secondary to pathological conditions. Stimulation of the nitrate-nitrite-nitric oxide pathway is associated with renal and cardiovascular protection in disease models, but less is known about the vascular effects during renal ischemia. This study was aimed at investigating the vascular effects of nitrite in the kidney during normoxic and ischemic conditions. Using a multiwire myograph system, we assessed nitrite-mediated relaxation (10(-9)-10(-4)mol/L) in isolated and preconstricted renal interlobar arteries from C57BL/6 mice under normal conditions (pO2 13kPa; pH 7.4) and with low oxygen tension and low pH to mimic ischemia (pO2 3kPa; pH 6.6). Xanthine oxidoreductase expression was analyzed by quantitative PCR, and production of reactive nitrogen species was measured by DAF-FM DA fluorescence. During normoxia significant vasodilatation (15±3%) was observed only at the highest concentration of nitrite, which was dependent on NO-sGC-cGMP signaling. The vasodilatory responses to nitrite were greatly sensitized and enhanced during hypoxia with low pH, demonstrating significant dilatation (11±1%) already in the physiological range (10(-8)mol/L), with a maximum response of 27±2% at 10(-4) mol/L. In contrast to normoxia, and to that observed with a classical NO donor (DEA NONOate), this sensitization was independent of sGC-cGMP signaling. Moreover, inhibition of various enzymatic systems reported to reduce nitrite in other vascular beds, i.e., aldehyde oxidase (raloxifene), aldehyde dehydrogenase (cyanamide), and NO synthase (L-NAME), had no effect on the nitrite response. However, inhibition of xanthine oxidoreductase (XOR; febuxostat or allopurinol) abolished the sensitized response to nitrite during hypoxia and acidosis. In conclusion, in contrast to normoxia, nitrite exerted potent vasorelaxation during ischemic conditions already at physiological concentrations. This effect was dependent on functional XOR but independent of classical downstream signaling by sGC-cGMP.
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Affiliation(s)
- Ming Liu
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Christa Zollbrecht
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Maria Peleli
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Jon O Lundberg
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Eddie Weitzberg
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Mattias Carlström
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden.
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Abstract
Pulmonary arterial hypertension is a progressive and debilitating disorder with an associated high morbidity and mortality rate. Significant advances in our understanding of the epidemiology, pathogenesis, and pathophysiology of pulmonary hypertension have occurred over the past several decades. This has allowed the development of new therapeutic options in this disease. Today, our selection of therapeutic modalities is broader, including calcium channel blockers, prostanoids, endothelin receptor antagonists, phosphodiesterase inhibitors, and soluble guanylate cyclase stimulators, but the disease remains fatal. This underscores the need for a continued search for novel therapies. Several potential pharmacologic agents for the treatment of pulmonary arterial hypertension are under clinical development and some promising results with these treatments have been reported. These agents include rho-kinase inhibitors, long-acting nonprostanoid prostacyclin receptor agonists, tyrosine protein kinase inhibitors, endothelial nitric oxide synthase couplers, synthetically produced vasoactive intestinal peptide, antagonists of the 5-HT2 receptors, and others. This article will review several of these promising new therapies and will discuss the current evidence regarding their potential benefit in pulmonary arterial hypertension.
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8
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Tawa M, Geddawy A, Shimosato T, Iwasaki H, Imamura T, Okamura T. Soluble guanylate cyclase redox state under hypoxia or hypoxia/reoxygenation in isolated monkey coronary arteries. J Pharmacol Sci 2014; 125:169-75. [PMID: 24859780 DOI: 10.1254/jphs.14046fp] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Hypoxia or hypoxia/reoxygenation impairs nitric oxide (NO)-mediated relaxation through the increase in superoxide generation in monkey coronary arteries. Soluble guanylate cyclase (sGC), the target enzyme of NO, has been shown to change from the NO-sensitive reduced form to the NO-insensitive oxidized/heme-free form under substantial oxidative stress, so the present study investigated whether hypoxia or hypoxia/reoxygenation influences sGC redox equilibrium. In isolated monkey coronary arteries without endothelium, the relaxation caused by the sGC stimulator BAY 41-2272 (Emax: 93.3% ± 2.2%) was somewhat impaired under hypoxia (Emax: 86.3% ± 2.6%) or hypoxia/reoxygenation (Emax: 86.1% ± 3.2%), whereas that by the sGC activator BAY 60-2770 (Emax: 86.0% ± 3.2%) was significantly augmented under hypoxia (Emax: 94.4% ± 1.3%) or hypoxia/reoxygenation (Emax: 95.5% ± 1.1%). In addition, cGMP formation in response to BAY 41-2272 and BAY 60-2770 was inhibited and stimulated, respectively, under hypoxia or hypoxia/reoxygenation. The effects of hypoxia or hypoxia/reoxygenation on BAY 41-2272- and BAY 60-2770-induced vasorelaxation were completely canceled by the treatment with the superoxide dismutase mimetic tempol. These findings suggest that sGC redox equilibrium in the coronary artery is shifted towards the NO-insensitive form under hypoxia or hypoxia/reoxygenation and that superoxide seems to play an important role in this shift.
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Affiliation(s)
- Masashi Tawa
- Department of Pharmacology, Shiga University of Medical Science, Japan
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Chettimada S, Rawat DK, Dey N, Kobelja R, Simms Z, Wolin MS, Lincoln TM, Gupte SA. Glc-6-PD and PKG contribute to hypoxia-induced decrease in smooth muscle cell contractile phenotype proteins in pulmonary artery. Am J Physiol Lung Cell Mol Physiol 2012; 303:L64-74. [PMID: 22582112 DOI: 10.1152/ajplung.00002.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Persistent hypoxic pulmonary vasoconstriction (HPV) plays a significant role in the pathogenesis of pulmonary hypertension, which is an emerging clinical problem around the world. We recently showed that hypoxia-induced activation of glucose-6-phosphate dehydrogenase (Glc-6-PD) in pulmonary artery smooth muscle links metabolic changes within smooth muscle cells to HPV and that inhibition of Glc-6PD reduces acute HPV. Here, we demonstrate that exposing pulmonary arterial rings to hypoxia (20-30 Torr) for 12 h in vitro significantly (P < 0.05) reduces (by 30-50%) SM22α and smooth muscle myosin heavy chain expression and evokes HPV. Glc-6-PD activity was also elevated in hypoxic pulmonary arteries. Inhibition of Glc-6-PD activity prevented the hypoxia-induced reduction in SM22α expression and inhibited HPV by 80-90% (P < 0.05). Furthermore, Glc-6-PD and protein kinase G (PKG) formed a complex in pulmonary artery, and Glc-6-PD inhibition increased PKG-mediated phosphorylation of VASP (p-VASP). In turn, increasing PKG activity upregulated SM22α expression and attenuated HPV evoked by Glc-6-PD inhibition. Increasing passive tension (from 0.8 to 3.0 g) in hypoxic arteries for 12 h reduced Glc-6-PD, increased p-VASP and SM22α levels, and inhibited HPV. The present findings indicate that increases in Glc-6-PD activity influence PKG activity and smooth muscle cell phenotype proteins, all of which affect pulmonary artery contractility and remodeling.
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Affiliation(s)
- Sukrutha Chettimada
- Department of Biochemistry & Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
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10
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Neo BH, Kandhi S, Wolin MS. Roles for redox mechanisms controlling protein kinase G in pulmonary and coronary artery responses to hypoxia. Am J Physiol Heart Circ Physiol 2011; 301:H2295-304. [PMID: 21926339 DOI: 10.1152/ajpheart.00624.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously reported that isolated endothelium-removed bovine pulmonary arteries (BPAs) contract to hypoxia associated with removal of peroxide- and cGMP-mediated relaxation. In contrast, bovine coronary arteries (BCAs) relax to hypoxia associated with cytosolic NADPH oxidation coordinating multiple relaxing mechanisms. Since we recently found that H(2)O(2) relaxes BPAs through PKG activation by both soluble guanylate cyclase (sGC)/cGMP-dependent and cGMP-independent thiol oxidation/subunit dimerization mechanisms, we investigated if these mechanisms participate in BPA contraction and BCA relaxation to hypoxia. The contraction of BPA (precontracted with 20 mM KCl) to hypoxia was associated with decreased PKG dimerization and PKG-mediated vasodilator-stimulated phosphoprotein (VASP) phosphorylation. In contrast, exposure of 20 mM KCl-precontracted endothelium-removed BCAs to hypoxia caused relaxation and increased dimerization and VASP phosphorylation. Depletion of sGC by organoid culture of BPAs with an oxidant of the sGC heme (10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) increased aerobic force generation, decreased VASP phosphorylation, and inhibited further contraction to hypoxia and changes in VASP phosphorylation. Thiol reduction with dithiothreitol increased aerobic force in BPAs and decreased PKG dimerization, VASP phosphorylation, and the contraction to hypoxia. Furthermore, PKG-1α and sGC β(1)-subunit small interfering RNA-transfected BPAs demonstrated increased aerobic K(+) force and inhibition of further contraction to hypoxia, associated with an attenuation of H(2)O(2)-elicited relaxation and VASP phosphorylation. Thus, decreases in both a sGC/cGMP-dependent and a dimerization-dependent activation of PKG by H(2)O(2) appear to contribute to the contraction of BPAs elicited by hypoxia. In addition, stimulation of PKG activation by dimerization may be important in the relaxation of coronary arteries to hypoxia.
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Affiliation(s)
- Boon Hwa Neo
- Department of Physiology, New York Medical College, Valhalla, 10595, USA
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11
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Mechanisms involved in the nitric oxide-induced vasorelaxation in porcine prostatic small arteries. Naunyn Schmiedebergs Arch Pharmacol 2011; 384:245-53. [DOI: 10.1007/s00210-011-0666-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 06/26/2011] [Indexed: 10/18/2022]
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12
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Tawa M, Yamamizu K, Geddawy A, Shimosato T, Imamura T, Ayajiki K, Okamura T. Impairment by hypoxia or hypoxia/reoxygenation of nitric oxide-mediated relaxation in isolated monkey coronary artery: the role of intracellular superoxide. J Pharmacol Sci 2011; 116:188-96. [PMID: 21597236 DOI: 10.1254/jphs.11031fp] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
To investigate the effect of hypoxia or hypoxia/reoxygenation on vascular smooth muscle function, mechanical response of monkey coronary artery without endothelium was studied under normoxia, hypoxia, and hypoxia/reoxygenation. Hypoxia or hypoxia/reoxygenation impaired the relaxation by nitroglycerin or isosorbide dinitrate but not that by 8-bromoguanosine-3',5'-cyclic monophosphate or isoproterenol. Tempol restored the impaired relaxation by nitroglycerin or isosorbide dinitrate, but superoxide dismutase had no effect. Apocynin, an NADPH oxidase inhibitor, improved the nitroglycerin-induced relaxation under hypoxia, but not under reoxygenation. Under combined treatment of apocynin with oxypurinol (xanthine oxidase inhibitor), rotenone (mitochondria electron transport inhibitor), or both, hypoxic impairment of vasorelaxation was restored more effectively. Similarly, impairment of the nitroglycerin-induced vasorelaxation under hypoxia/reoxygenation was restored by combined treatment with three inhibitors, apocynin, oxypurinol, and rotenone. Increase in superoxide production under hypoxia tended to be inhibited by apocynin and that under hypoxia/reoxygenation was abolished by combined treatment with three inhibitors. These findings suggest that increased intracellular superoxide production under hypoxia or hypoxia/reoxygenation attenuates vasodilation mediated with a nitric oxide/soluble guanylyl cyclase, but not adenylyl cyclase, signaling pathway. The main source of superoxide production under hypoxia seems to be different from that under reoxygenation: superoxide is produced by NADPH oxidase during hypoxia, whereas it is produced by xanthine oxidase, mitochondria, or both during reoxygenation.[Supplementary Figure: available only at http://dx.doi.org/10.1254/jphs.11031FP].
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Affiliation(s)
- Masashi Tawa
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan
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Hedegaard ER, Stankevicius E, Simonsen U, Fröbert O. Non-endothelial endothelin counteracts hypoxic vasodilation in porcine large coronary arteries. BMC PHYSIOLOGY 2011; 11:8. [PMID: 21575165 PMCID: PMC3118136 DOI: 10.1186/1472-6793-11-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 05/15/2011] [Indexed: 11/25/2022]
Abstract
Background The systemic vascular response to hypoxia is vasodilation. However, reports suggest that the potent vasoconstrictor endothelin-1 (ET-1) is released from the vasculature during hypoxia. ET-1 is reported to augment superoxide anion generation and may counteract nitric oxide (NO) vasodilation. Moreover, ET-1 was proposed to contribute to increased vascular resistance in heart failure by increasing the production of asymmetric dimethylarginine (ADMA). We investigated the role of ET-1, the NO pathway, the potassium channels and radical oxygen species in hypoxia-induced vasodilation of large coronary arteries. Results In prostaglandin F2α (PGF2α, 10 μM)-contracted segments with endothelium, gradual lowering of oxygen tension from 95 to 1% O2 resulted in vasodilation. The vasodilation to O2 lowering was rightward shifted in segments without endothelium at all O2 concentrations except at 1% O2. The endothelin receptor antagonist SB217242 (10 μM) markedly increased hypoxic dilation despite the free tissue ET-1 concentration in the arterial wall was unchanged in 1% O2 versus 95% O2. Exogenous ET-1 reversed hypoxic dilation in segments with and without endothelium, and the hypoxic arteries showed an increased sensitivity towards ET-1 compared to the normoxic controls. Without affecting basal NO, hypoxia increased NO concentration in PGF2α-contracted arteries, and an NO synthase inhibitor, L-NOARG,(300 μM, NG-nitro-L-Arginine) reduced hypoxic vasodilation. NO-induced vasodilation was reduced in endothelin-contracted preparations. Arterial wall ADMA concentrations were unchanged by hypoxia. Blocking of potassium channels with TEA (tetraethylammounium chloride)(10 μM) inhibited vasodilation to O2 lowering as well as to NO. The superoxide scavenger tiron (10 μM) and the putative NADPH oxidase inhibitor apocynin (10 μM) leftward shifted concentration-response curves for O2 lowering without changing vasodilation to 1% O2. PEG (polyethylene glycol) catalase (300 u/ml) inhibited H2O2 vasodilation, but failed to affect vasodilation to O2 lowering. Neither did PEG-SOD (polyethylene glycol superoxide dismutase)(70 u/ml) affect vasodilation to O2 lowering. The mitochondrial inhibitors rotenone (1 μM) and antimycin A (1 μM) both inhibited hypoxic vasodilatation. Conclusion The present results in porcine coronary arteries suggest NO contributes to hypoxic vasodilation, probably through K channel opening, which is reversed by addition of ET-1 and enhanced by endothelin receptor antagonism. These latter findings suggest that endothelin receptor activation counteracts hypoxic vasodilation.
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Affiliation(s)
- Elise R Hedegaard
- Department of Pharmacology, Aarhus University, Wilhem Meyers Allé 4, Aarhus C, Denmark.
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Neo BH, Kandhi S, Wolin MS. Roles for soluble guanylate cyclase and a thiol oxidation-elicited subunit dimerization of protein kinase G in pulmonary artery relaxation to hydrogen peroxide. Am J Physiol Heart Circ Physiol 2010; 299:H1235-41. [PMID: 20709865 PMCID: PMC2957360 DOI: 10.1152/ajpheart.00513.2010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Accepted: 08/10/2010] [Indexed: 11/22/2022]
Abstract
We have previously provided evidence that hydrogen peroxide (H(2)O(2)) stimulates soluble guanylate cyclase (sGC) under conditions where it relaxes isolated endothelium-removed bovine pulmonary arteries (BPAs). Since it was recently reported that H(2)O(2) induces coronary vasorelaxation associated with a nitric oxide/cGMP-independent thiol oxidation/subunit dimerization-elicited activation of protein kinase G (PKG), we investigated whether this mechanism participates in the relaxation of BPAs to H(2)O(2). BPAs precontracted with serotonin (incubated under hypoxia to lower endogenous H(2)O(2)) were exposed to increasing concentrations of H(2)O(2). It was observed that 0.1-1 mM H(2)O(2) caused increased PKG dimerization and relaxation. These responses were associated with increased phosphorylation of vasodilator-stimulated phosphoprotein (VASP) at the serine-239 site known to be mediated by PKG. Treatment of BPAs with 1 mM DTT attenuated PKG dimerization, VASP phosphorylation, and relaxation to H(2)O(2). An organoid culture of BPAs for 48 h with 10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a heme oxidant inhibitor of sGC activation, depleted sGC expression by 85%, associated with a 67% attenuation of VASP phosphorylation and 48% inhibition of relaxation elicited by 100 μM H(2)O(2). Thus both a sGC activation/cGMP-dependent and a thiol oxidation subunit dimerization/cGMP-independent activation of PKG appear to contribute to the relaxation of BPAs elicited by H(2)O(2).
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Affiliation(s)
- Boon Hwa Neo
- Department of Physiology, New York Medical College, Valhalla, NY 10595, USA
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15
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Pearce WJ, Williams JM, White CR, Lincoln TM. Effects of chronic hypoxia on soluble guanylate cyclase activity in fetal and adult ovine cerebral arteries. J Appl Physiol (1985) 2009; 107:192-9. [PMID: 19407253 DOI: 10.1152/japplphysiol.00233.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A broad variety of evidence obtained largely in pulmonary vasculature suggests that chronic hypoxia modulates vasoreactivity to nitric oxide (NO). The present study explores the general hypothesis that chronic hypoxia also modulates cerebrovascular reactivity to NO, and does so by modulating the activity of soluble guanylate cyclase (sGC), the primary target for NO in vascular smooth muscle. Pregnant and nonpregnant ewes were maintained at either sea level or at 3,820 m for the final 110 days of gestation, at which time middle cerebral arteries from term fetal lambs and nonpregnant adults were harvested. In both fetal and adult arteries, NO-induced vasodilatation was attenuated by chronic hypoxia and completely inhibited by 10 microM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a selective inhibitor of sGC. sGC abundance (in ng sGC/mg protein) measured via Western immunoblots was approximately 10-fold greater in fetal (17.6 +/- 1.6) than adult (1.7 +/- 0.3) arteries but was not affected by chronic hypoxia. The specific activity of sGC (in pmol cGMP.microg sGC(-1).min(-1)) was similar in fetal (255 +/- 64) and adult (280 +/- 75) arteries and was inhibited by chronic hypoxia in both fetal (120 +/- 10) and adult (132 +/- 26) arteries. Rates of cGMP degradation (in pmol cGMP.mg protein(-1).min(-1)) were similar in fetal (159 +/- 59) and adult (134 +/- 36) arteries but were not significantly depressed by chronic hypoxia in either fetal (115 +/- 25) or adult (108 +/- 25) arteries. The cGMP analog 8-(p-chlorophenylthio)-cGMP was a more potent vasorelaxant in fetal (pD(2) = 4.7 +/- 0.1) than adult (pD(2) = 4.3 +/- 0.1) arteries, but its ability to promote vasodilatation was not affected by chronic hypoxia in either age group. Together, these results reveal that hypoxic inhibition of NO-induced vasodilatation is attributable largely to attenuation of the specific activity of sGC and does not involve significant changes in sGC abundance, cGMP-phosphodiesterase activity, or the vasorelaxant activity of protein kinase G.
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Affiliation(s)
- William J Pearce
- Department of Physiology, Center for Perinatal Biology, Loma Linda Univ. School of Medicine, Loma Linda, CA 92350, USA.
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Laursen BE, Dam MY, Mulvany MJ, Simonsen U. Hypoxia-induced pulmonary vascular remodeling and right ventricular hypertrophy is unaltered by long-term oral L-arginine administration. Vascul Pharmacol 2008; 49:71-6. [DOI: 10.1016/j.vph.2008.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Revised: 03/10/2008] [Accepted: 03/13/2008] [Indexed: 11/25/2022]
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Mingone CJ, Ahmad M, Gupte SA, Chow JL, Wolin MS. Heme oxygenase-1 induction depletes heme and attenuates pulmonary artery relaxation and guanylate cyclase activation by nitric oxide. Am J Physiol Heart Circ Physiol 2008; 294:H1244-50. [PMID: 18178725 DOI: 10.1152/ajpheart.00846.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study examines in endothelium-denuded bovine pulmonary arteries the effects of increasing heme oxygenase-1 (HO-1) activity on relaxation and soluble guanylate cyclase (sGC) activation by nitric oxide (NO). A 24-h organ culture with 0.1 mM cobalt chloride (CoCl2) or 30 microM Co-protoporphyrin IX was developed as a method of increasing HO-1 expression. These treatments increased HO-1 expression and HO activity by approximately two- to fourfold and lowered heme levels by 40-45%. Induction of HO-1 was associated with an attenuation of pulmonary arterial relaxation to the NO-donor spermine-NONOate. The presence of a HO-1 inhibitor 30 microM chromium mesoporphyrin during the 24-h organ culture (but not acute treatment with this agent) reversed the attenuation of relaxation to NO seen in arteries co-cultured with agents that increased HO-1. Relaxation to isoproterenol, which is thought to be mediated through cAMP, was not altered in arteries with increased HO-1. Inducers of HO-1 did not appear to alter basal sGC activity in arterial homogenates or expression of the beta(1)-subunit of sGC. However, the increase in activity seen in the presence of 1 microM spermine-NONOate was attenuated in homogenates obtained from arteries with increased HO-1. Since arteries with increased HO-1 had decreased levels of superoxide detected by the chemiluminescence of 5 microM lucigenin, superoxide did not appear to be mediating the attenuation of relaxation to NO. These data suggest that increasing HO-1 activity depletes heme, and this is associated with an attenuation of pulmonary artery relaxation and sGC activation responses to NO.
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Wolin MS, Ahmad M, Gao Q, Gupte SA. Cytosolic NAD(P)H regulation of redox signaling and vascular oxygen sensing. Antioxid Redox Signal 2007; 9:671-8. [PMID: 17511583 DOI: 10.1089/ars.2007.1559] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This article considers how regulation of signaling controlled by cytosolic NADPH and NADH redox systems contained within the vascular smooth muscle cell may contribute to coordinating alterations in force generation elicited by acute changes in oxygen tension. Additional important issues considered include defining when oxidases generating reactive oxygen species (ROS), such as Nox oxidases, or ROS metabolizing activities which utilize cytosolic NADH and/or NADPH are key participants in eliciting responses that are observed, and assessing how mitochondria can potentially contribute to the regulation that is seen. Many important signaling mechanisms potentially involved in vascular oxygen sensing such as potassium channels, systems regulating intracellular calcium, and the sensitivity of the contractile apparatus to calcium, and the control of cGMP-mediated relaxation by soluble guanylate cyclase appear to be regulated by cytosolic NAD(P)H redox and or ROS. Differences in the processes controlling the maintenance of cytosolic NADPH redox by the pentose phosphate pathway of glucose metabolism are hypothesized to be a key factor in controlling the expression of a relaxation to hypoxia seen in systemic arteries compared to the hypoxic contractile response observed in pulmonary arterial smooth muscle.
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Affiliation(s)
- Michael S Wolin
- Department of Physiology, New York Medical College, Valhalla, New York 10595, USA.
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Mingone CJ, Gupte SA, Chow JL, Ahmad M, Abraham NG, Wolin MS. Protoporphyrin IX generation from δ-aminolevulinic acid elicits pulmonary artery relaxation and soluble guanylate cyclase activation. Am J Physiol Lung Cell Mol Physiol 2006; 291:L337-44. [PMID: 16899710 DOI: 10.1152/ajplung.00482.2005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Protoporphyrin IX is an activator of soluble guanylate cyclase (sGC), but its role as an endogenous regulator of vascular function through cGMP has not been previously reported. In this study we examined whether the heme precursor δ-aminolevulinic acid (ALA) could regulate vascular force through promoting protoporphyrin IX-elicited activation of sGC. Exposure of endothelium-denuded bovine pulmonary arteries (BPA) in organoid culture to increasing concentrations of the heme precursor ALA caused a concentration-dependent increase in BPA epifluorescence, consistent with increased tissue protoporphyrin IX levels, associated with decreased force generation to increasing concentrations of serotonin. The force-depressing actions of 0.1 mM ALA were associated with increased cGMP-associated vasodilator-stimulated phosphoprotein (VASP) phosphorylation and increased sGC activity in homogenates of BPA cultured with ALA. Increasing iron availability with 0.1 mM FeSO4inhibited the decrease in contraction to serotonin and increase in sGC activity caused by ALA, associated with decreased protoporphyrin IX and increased heme. Chelating endogenous iron with 0.1 mM deferoxamine increased the detection of protoporphyrin IX and force depressing activity of 10 μM ALA. The inhibition of sGC activation with the heme oxidant 10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) attenuated the force depressing actions of an NO donor without altering the actions of ALA. Thus control of endogenous formation of protoporphyrin IX from ALA by the availability of iron is potentially a novel physiological mechanism of controlling vascular function through regulating the activity of sGC.
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Mingone CJ, Gupte SA, Ali N, Oeckler RA, Wolin MS. Thiol oxidation inhibits nitric oxide-mediated pulmonary artery relaxation and guanylate cyclase stimulation. Am J Physiol Lung Cell Mol Physiol 2005; 290:L549-57. [PMID: 16272175 DOI: 10.1152/ajplung.00331.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanisms through which thiol oxidation and cellular redox influence the regulation of soluble guanylate cyclase (sGC) are poorly understood. This study investigated whether promoting thiol oxidation via inhibition of NADPH generation by the pentose phosphate pathway (PPP) with 1 mM 6-aminonicotinamide (6-AN) or the thiol oxidant diamide (1 mM) alters sGC activity and cGMP-associated relaxation to nitric oxide (NO) donors [S-nitroso-N-acetylpenicillamine (SNAP) and spermine-NONOate]. Diamide and 6-AN inhibited NO-elicited relaxation of endothelium-denuded bovine pulmonary arteries (BPA) and stimulation of sGC activity in BPA homogenates. Treatment of BPA with the thiol reductant DTT (1 mM) reversed inhibition of NO-mediated relaxation and sGC stimulation by 6-AN. The increase in cGMP protein kinase-associated phosphorylation of vasodilator-stimulated phosphoprotein on Ser239 elicited by 10 microM SNAP was also inhibited by diamide. Activation of sGC by SNAP was attenuated by low micromolar concentrations of GSSG in concentrated, but not dilute, homogenates of BPA, suggesting that an enzymatic process contributes to the actions of GSSG. Relaxation to agents that function through cAMP (forskolin and isoproterenol) was not altered by inhibition of the pentose phosphate pathway or diamide. Thus a thiol oxidation mechanism controlled by the regulation of thiol redox by NADPH generated via the pentose phosphate pathway appears to inhibit sGC activation and cGMP-mediated relaxation by NO in a manner consistent with its function as an important physiological redox-mediated regulator of vascular function.
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Schlemper V, Medeiros R, Ferreira J, Campos MM, Calixto JB. Mechanisms underlying the relaxation response induced by bradykinin in the epithelium-intact guinea-pig trachea in vitro. Br J Pharmacol 2005; 145:740-50. [PMID: 15852038 PMCID: PMC1576187 DOI: 10.1038/sj.bjp.0706222] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In this study, we investigated some of the signalling pathways involved in bradykinin (BK)-induced relaxation in epithelium-intact strips of the guinea-pig trachea (GPT + E). BK induced time- and concentration-dependent relaxation of GPT + E. Similar responses were observed for prostaglandin E2 (PGE2) or the combination of subthreshold concentrations of BK plus PGE2. The nonselective cyclooxygenase (COX) inhibitors indomethacin or pyroxicam, or the selective COX-2 inhibitors DFU, NS 398 or rofecoxib, but not the selective COX-1 inhibitor SC 560, all abolished BK-induced relaxation. The tyrosine kinase inhibitors herbimycin A and AG 490 also abolished BK-induced relaxation in GPT + E. The nonselective nitric oxide synthase (NOS) inhibitor 7-NINA concentration-dependently inhibited BK effects. BK-induced relaxation was prevented by the selective antagonists for EP3 (L 826266), but not by EP1 (SC 19221), EP1/EP2 (AH 6809) or EP4 (L161982) receptor antagonists. Otherwise, the selective inhibitors of protein kinases A, G and C, mitogen-activated protein kinases, phospholipases C and A2, nuclear factor-kappaB or potassium channels all failed to significantly interfere with BK-mediated relaxation.BK caused a marked increase in PGE2 levels, an effect that was prevented by NS 398, HOE 140 or AG 490. COX-2 expression did not differ in preparations with or without epithelium, and it was not changed by BK stimulation. However, incubation with BK significantly increased the endothelial NOS (eNOS) and neuronal NOS (nNOS) expression, independent of the epithelium integrity. Our results indicate that BK-induced relaxation in GPT + E depends on prostanoids (probably PGE2 acting via EP3 receptors) and NO release and seems to involve complex interactions between kinin B2 receptors, COX-2, nNOS, eNOS and tyrosine kinases.
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Affiliation(s)
- Valfredo Schlemper
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina – UFSC, Florianópolis, SC, Brazil
- Department of Biological and Health Sciences, Universidade do Planalto Catarinense – UNIPLAC, Lages, SC, Brazil
| | - Rodrigo Medeiros
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina – UFSC, Florianópolis, SC, Brazil
| | - Juliano Ferreira
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina – UFSC, Florianópolis, SC, Brazil
| | - Maria M Campos
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina – UFSC, Florianópolis, SC, Brazil
| | - João B Calixto
- Department of Pharmacology, Centre of Biological Sciences, Universidade Federal de Santa Catarina – UFSC, Florianópolis, SC, Brazil
- Author for correspondence:
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Jernigan NL, Broughton BRS, Walker BR, Resta TC. Impaired NO-dependent inhibition of store- and receptor-operated calcium entry in pulmonary vascular smooth muscle after chronic hypoxia. Am J Physiol Lung Cell Mol Physiol 2005; 290:L517-25. [PMID: 16243900 DOI: 10.1152/ajplung.00308.2004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have recently demonstrated that chronic hypoxia (CH) attenuates nitric oxide (NO)-mediated decreases in pulmonary vascular smooth muscle (VSM) intracellular free calcium concentration ([Ca2+]i) and promotes NO-dependent VSM Ca2+ desensitization. The objective of the current study was to identify potential mechanisms by which CH interferes with regulation of [Ca2+]i by NO. We hypothesized that CH impairs NO-mediated inhibition of store-operated (capacitative) Ca2+ entry (SOCE) or receptor-operated Ca2+ entry (ROCE) in pulmonary VSM. To test this hypothesis, we examined effects of the NO donor, spermine NONOate, on SOCE resulting from depletion of intracellular Ca2+ stores with cyclopiazonic acid, and on UTP-induced ROCE in isolated, endothelium-denuded, pressurized pulmonary arteries (213 +/- 8 microm inner diameter) from control and CH (4 wk at 0.5 atm) rats. Arteries were loaded with fura-2 AM to continuously monitor VSM [Ca2+]i. We found that the change in [Ca2+]i associated with SOCE and ROCE was significantly reduced in vessels from CH animals. Furthermore, spermine NONOate diminished SOCE and ROCE in vessels from control, but not CH animals. We conclude that NO-mediated inhibition of SOCE and ROCE is impaired after CH-induced pulmonary hypertension.
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MESH Headings
- Animals
- Bronchodilator Agents/pharmacology
- Calcium/metabolism
- Calcium Channels/drug effects
- Calcium Channels/metabolism
- Calcium-Transporting ATPases/antagonists & inhibitors
- Chronic Disease
- Endothelium, Vascular/metabolism
- Enzyme Inhibitors/pharmacology
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/pathology
- Hypoxia/metabolism
- Indoles/pharmacology
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nitric Oxide/pharmacology
- Nitric Oxide Donors/pharmacology
- Nitrogen Oxides/pharmacology
- Pulmonary Artery/cytology
- Pulmonary Artery/drug effects
- Pulmonary Artery/metabolism
- Rats
- Rats, Sprague-Dawley
- Spermine/analogs & derivatives
- Spermine/pharmacology
- Uridine Triphosphate/pharmacology
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Affiliation(s)
- Nikki L Jernigan
- Vascular Physiology Group, Dept. of Cell Biology and Physiology, Univ. of New Mexico Health Sciences Center, MSC 08-4750, 1 Univ. of New Mexico, Albuquerque, NM 87131-0001, USA
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23
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Priviero FBM, Baracat JS, Teixeira CE, Claudino MA, De Nucci G, Antunes E. MECHANISMS UNDERLYING RELAXATION OF RABBIT AORTA BY BAY 41-2272, A NITRIC OXIDE-INDEPENDENT SOLUBLE GUANYLATE CYCLASE ACTIVATOR. Clin Exp Pharmacol Physiol 2005; 32:728-34. [PMID: 16173929 DOI: 10.1111/j.1440-1681.2005.04262.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. The compound BAY 41-2272 (5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine) has been described as a potent, nitric oxide (NO)-independent, stimulator of soluble guanylate cyclase. In the present study, the mechanisms underlying the relaxant effect of BAY 41-2272 in endothelium-intact and -denuded precontracted rabbit aortic rings were investigated. 2. Male New Zealand white rabbits were anaesthetized with pentobarbital sodium. Aortic rings were transferred to 10 mL organ baths containing oxygenated and warmed Krebs' solution. Tissues were connected to force-displacement transducers and changes in isometric force were recorded. Aortic rings were precontracted submaximally with phenylephrine (1 micromol/L). 3. The addition of BAY 41-2272 (0.01-10 micromol/L) to the organ bath produced concentration-dependent relaxations of the aortic rings with a higher potency in endothelium-intact (pEC50 6.59 +/- 0.05) compared with endothelium-denuded (pEC50 6.19 +/- 0.04; P < 0.05) preparations. No differences in maximal responses were observed in either preparation. The NO synthesis inhibitor NG-nitro-L-arginine methyl ester (100 micromol/L) produced a 2.1-fold rightward shift in endothelium-intact (P < 0.01) rings, but had no effect in endothelium-denuded rings. The soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 1 micromol/L) caused significant rightward shifts of the concentration-response curves to BAY 41-2272 of 4.9- and 2.6-fold in endothelium-intact and -denuded rings, respectively. The phosphodiesterase-5 inhibitor sildenafil (0.1 micromol/L) significantly potentiated the relaxant effects of BAY 41-2272 in both endothelium-intact and -denuded rings. 4. At 1 micromol/L, BAY 41-2272 significantly elevated the aortic cGMP content above basal levels in both endothelium-intact and -denuded rings. Furthermore, ODQ reduced BAY 41-2272-elicited increases in cGMP content by 17 and 90% in endothelium-intact and -denuded rings, respectively (P < 0.01). 5. In conclusion, BAY 41-2272 potently relaxes endothelium-intact and -denuded rabbit aortic rings. The basal release of endothelium-derived NO enhances BAY 41-2272-induced relaxations, suggesting a synergistic effect of BAY 41-2272 and NO on soluble guanylate cyclase. In addition, the endothelium-independent relaxation involves both GMP-dependent and -independent mechanisms.
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Affiliation(s)
- Fernanda B M Priviero
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil
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Nozik-Grayck E, Whalen EJ, Stamler JS, McMahon TJ, Chitano P, Piantadosi CA. S-nitrosoglutathione inhibits alpha1-adrenergic receptor-mediated vasoconstriction and ligand binding in pulmonary artery. Am J Physiol Lung Cell Mol Physiol 2005; 290:L136-43. [PMID: 16126786 DOI: 10.1152/ajplung.00230.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endogenous nitric oxide donor compounds (S-nitrosothiols) contribute to low vascular tone by both cGMP-dependent and -independent pathways. We have reported that S-nitrosoglutathione (GSNO) inhibits 5-hydroxytryptamine (5-HT)-mediated pulmonary vasoconstriction via a cGMP-independent mechanism likely involving S-nitrosylation of its G protein-coupled receptor (GPCR) system. Because catecholamines, like 5-HT, constrict lung vessels via a GPCR coupled to G(q), we hypothesized that S-nitrosothiols modify the alpha1-adrenergic GPCR system to inhibit pulmonary vasoconstriction by receptor agonists, e.g., phenylephrine (PE). Rat pulmonary artery rings were pretreated for 30 min with and without an S-nitrosothiol, either GSNO or S-nitrosocysteine (CSNO), and constricted with sequential concentrations of PE (10(-8)-10(-6) M). Effective cGMP-dependence was tested in rings pretreated with soluble guanylate cyclase inhibitors {either 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or LY-83583} or G kinase inhibitor (KT-5823), and a thiol reductant [dithiothreitol (DTT)] was used to test reversibility of S-nitrosylation. Both S-nitrosothiols attenuated the PE dose response. The GSNO effect was not prevented by LY-83583, ODQ, or KT-5823, indicating cGMP independence. GSNO inhibition was reversed by DTT, consistent with S-nitrosylation or other GSNO-mediated cysteine modifications. In CSNO-treated lung protein, the alpha1-adrenergic receptor was shown to undergo S-nitrosylation in vitro using a biotin switch assay. Studies of alpha1-adrenergic receptor subtype expression and receptor density by saturation binding with 125I-HEAT showed that GSNO decreased alpha1-adrenergic receptor density but did not alter affinity for antagonist or agonist. These data demonstrate a novel cGMP-independent mechanism of reversible alpha1-adrenergic receptor inhibition by S-nitrosothiols.
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Affiliation(s)
- Eva Nozik-Grayck
- Department of Pediatrics, University of Colorado Health Science Center, Denver, CO 80262, USA.
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Abstract
Persistent pulmonary hypertension of the newborn (PPHN), among the most rapidly progressive and potentially fatal of vasculopathies, is a disorder of vascular transition from fetal to neonatal circulation, manifesting as hypoxemic respiratory failure. PPHN represents a common pathway of vascular injury activated by numerous perinatal stresses: hypoxia, hypoglycemia, cold stress, sepsis, and direct lung injury. As with other multifactorial diseases, a single inciting event may be augmented by multiple concurrent/subsequent phenomena that result in differing courses of disease progression. I review the various mechanisms of vascular injury involved in neonatal pulmonary hypertension: endothelial dysfunction, inflammation, hypoxia, and mechanical strain, in the context of downstream effects on pulmonary vascular endothelial-myocyte interactions and myocyte phenotypic plasticity.
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Affiliation(s)
- S Dakshinamurti
- Department of Pediatrics, University of Manitoba, Manitoba Institute of Child Health, Winnipeg, Canada.
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Turkseven S, Kruger A, Mingone CJ, Kaminski P, Inaba M, Rodella LF, Ikehara S, Wolin MS, Abraham NG. Antioxidant mechanism of heme oxygenase-1 involves an increase in superoxide dismutase and catalase in experimental diabetes. Am J Physiol Heart Circ Physiol 2005; 289:H701-7. [PMID: 15821039 DOI: 10.1152/ajpheart.00024.2005] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Increased heme oxygenase (HO)-1 activity attenuates endothelial cell apoptosis and decreases superoxide anion (O2-) formation in experimental diabetes by unknown mechanisms. We examined the effect of HO-1 protein and HO activity on extracellular SOD (EC-SOD), catalase, O2-, inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) levels and vascular responses to ACh in control and diabetic rats. Vascular EC-SOD and plasma catalase activities were significantly reduced in diabetic compared with nondiabetic rats (P < 0.05). Upregulation of HO-1 expression by intermittent administration of cobalt protoporphyrin, an inducer of HO-1 protein and activity, resulted in a robust increase in EC-SOD but no significant change in Cu-Zn-SOD. Administration of tin mesoporphyrin, an inhibitor of HO-1 activity, decreased EC-SOD protein. Increased HO-1 activity in diabetic rats was associated with a decrease in iNOS but increases in eNOS and plasma catalase activity. On the other hand, aortic ring segments from diabetic rats exhibited a significant reduction in vascular relaxation to ACh, which was reversed with cobalt protoporphyrin treatment. These data demonstrate that an increase in HO-1 protein and activity, i.e., CO and bilirubin production, in diabetic rats brings about a robust increase in EC-SOD, catalase, and eNOS with a concomitant increase in endothelial relaxation and a decrease in O2-. These observations in experimental diabetes suggest that the vascular cytoprotective mechanism of HO-1 against oxidative stress requires an increase in EC-SOD and catalase.
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Affiliation(s)
- Saadet Turkseven
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA
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Resta TC. Hypoxic regulation of nitric oxide signaling in vascular smooth muscle. Am J Physiol Lung Cell Mol Physiol 2003; 285:L293-5. [PMID: 12851210 DOI: 10.1152/ajplung.00133.2003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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