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Tawa M, Okamura T. Factors influencing the soluble guanylate cyclase heme redox state in blood vessels. Vascul Pharmacol 2022; 145:107023. [PMID: 35718342 DOI: 10.1016/j.vph.2022.107023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/09/2022] [Accepted: 06/12/2022] [Indexed: 11/15/2022]
Abstract
Soluble guanylate cyclase (sGC) plays an important role in maintaining vascular homeostasis, as an acceptor for the biological messenger nitric oxide (NO). However, only reduced sGC (with a ferrous heme) can be activated by NO; oxidized (ferric heme) and apo (absent heme) sGC cannot. In addition, the proportions of reduced, oxidized, and apo sGC change under pathological conditions. Although diseased blood vessels often show decreased NO bioavailability in the vascular wall, a shift of sGC heme redox balance in favor of the oxidized/apo forms can also occur. Therefore, sGC is of growing interest as a drug target for various cardiovascular diseases. Notably, the balance between NO-sensitive reduced sGC and NO-insensitive oxidized/apo sGC in the body is regulated in a reversible manner by various biological molecules and proteins. Many studies have attempted to identify endogenous factors and determinants that influence this redox state. For example, various reactive nitrogen and oxygen species are capable of inducing the oxidation of sGC heme. Conversely, a heme reductase and some antioxidants reduce the ferric heme in sGC to the ferrous state. This review summarizes the factors and mechanisms identified by these studies that operate to regulate the sGC heme redox state.
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Affiliation(s)
- Masashi Tawa
- Department of Pathological and Molecular Pharmacology, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki, Osaka 569-1094, Japan.
| | - Tomio Okamura
- Emeritus Professor, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan
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Aramide Modupe Dosunmu-Ogunbi A, Galley JC, Yuan S, Schmidt HM, Wood KC, Straub AC. Redox Switches Controlling Nitric Oxide Signaling in the Resistance Vasculature and Implications for Blood Pressure Regulation: Mid-Career Award for Research Excellence 2020. Hypertension 2021; 78:912-926. [PMID: 34420371 DOI: 10.1161/hypertensionaha.121.16493] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The arterial resistance vasculature modulates blood pressure and flow to match oxygen delivery to tissue metabolic demand. As such, resistance arteries and arterioles have evolved a series of highly orchestrated cell-cell communication mechanisms between endothelial cells and vascular smooth muscle cells to regulate vascular tone. In response to neurohormonal agonists, release of several intracellular molecules, including nitric oxide, evokes changes in vascular tone. We and others have uncovered novel redox switches in the walls of resistance arteries that govern nitric oxide compartmentalization and diffusion. In this review, we discuss our current understanding of redox switches controlling nitric oxide signaling in endothelial and vascular smooth muscle cells, focusing on new mechanistic insights, physiological and pathophysiological implications, and advances in therapeutic strategies for hypertension and other diseases.
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Affiliation(s)
- Atinuke Aramide Modupe Dosunmu-Ogunbi
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA
| | - Joseph C Galley
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA
| | - Shuai Yuan
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA
| | - Heidi M Schmidt
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA
| | - Katherine C Wood
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA
| | - Adam C Straub
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA.,Center for Microvascular Research (A.C.S.), University of Pittsburgh, PA
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Tawa M, Shimosato T, Sakonjo H, Masuoka T, Nishio M, Ishibashi T, Okamura T. Chronological Change of Vascular Reactivity to cGMP Generators in the Balloon-Injured Rat Carotid Artery. J Vasc Res 2019; 56:109-116. [PMID: 31085923 DOI: 10.1159/000498896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 02/13/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Soluble guanylate cyclase (sGC) exists as reduced, oxidized, and heme-free forms. Currently, it is unclear whether endovascular mechanical stenosis has an impact on vascular tone control by drugs targeting sGC, namely cGMP generators. METHODS Pharmacological responses to acidified sodium nitrite (reduced sGC stimulant) and BAY 60-2770 (oxidized/heme-free sGC stimulant) were studied in balloon-injured rat carotid arteries at several time points. In addition, sGC expression was detected by immunohistochemistry. RESULTS At 1 day after injury, acidified sodium nitrite-induced relaxation was attenuated in the injured artery, whereas BAY 60-2770-induced relaxation was augmented. Similar attenuation of response to acidified sodium nitrite was seen at 7 and 14 days after injury. On the other hand, the augmentation of response to BAY 60-2770 disappeared at 7 and 14 days after injury. At 1 day after injury, the immunohistochemical expression pattern of sGC in the smooth muscle layer of the injured artery was not different from that of the uninjured artery. However, in the injured artery, the intensity of sGC staining was weak at 7 and 14 days after injury. CONCLUSION Balloon injury alters vascular responsiveness to cGMP generators, which seems to be associated with the form and/or expression of sGC.
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Affiliation(s)
- Masashi Tawa
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Japan, .,Department of Pharmacology, Kanazawa Medical University, Kahoku, Japan,
| | | | | | - Takayoshi Masuoka
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Japan
| | - Matomo Nishio
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Japan
| | | | - Tomio Okamura
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Japan
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Tawa M, Yamashita Y, Masuoka T, Nakano K, Yoshida J, Nishio M, Ishibashi T. Responsiveness of rat aorta and pulmonary artery to cGMP generators in the presence of thiol or heme oxidant. J Pharmacol Sci 2019; 140:43-47. [PMID: 31036520 DOI: 10.1016/j.jphs.2019.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/01/2019] [Accepted: 04/09/2019] [Indexed: 12/13/2022] Open
Abstract
This study investigated the effects of thiol and heme oxidants on responsiveness to cGMP generators in isolated rat aorta and pulmonary artery using an organ chamber. The nitric oxide (NO) donor sodium nitroprusside (SNP)-induced relaxation was impaired by exposure to the thiol oxidant diamide in both the aorta and the pulmonary artery, whereas the soluble guanylate cyclase (sGC) stimulator BAY 41-2272- or the sGC activator BAY 60-2770-induced relaxation was not affected. The impairment by diamide of SNP-induced aortic and pulmonary arterial relaxation was completely restored by post-treatment with the thiol reductant dithiothreitol. However, regardless of the vessel type, the relaxant response to SNP or BAY 41-2272 was impaired by exposure to the heme oxidant ODQ, whereas the response to BAY 60-2770 was enhanced. The ODQ-induced effects were reversed partially by post-treatment with the heme reductant dithionite. These findings indicate that thiol oxidation attenuates only the vascular responsiveness to NO donors and that heme oxidation attenuates the responsiveness to NO donors and sGC stimulators but augments that to sGC activators. Therefore, under oxidative stress, the order of usability of the vasodilators is suggested to be: NO donors < sGC stimulators < sGC activators.
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Affiliation(s)
- Masashi Tawa
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Ishikawa, 920-0293, Japan.
| | - Yuka Yamashita
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Ishikawa, 920-0293, Japan
| | - Takayoshi Masuoka
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Ishikawa, 920-0293, Japan
| | - Katsuya Nakano
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Ishikawa, 920-0293, Japan
| | - Junko Yoshida
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Ishikawa, 920-0293, Japan
| | - Matomo Nishio
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Ishikawa, 920-0293, Japan
| | - Takaharu Ishibashi
- Department of Pharmacology, Kanazawa Medical University, Kahoku, Ishikawa, 920-0293, Japan
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Comparative Studies of the Dynamics Effects of BAY60-2770 and BAY58-2667 Binding with Human and Bacterial H-NOX Domains. Molecules 2018; 23:molecules23092141. [PMID: 30149624 PMCID: PMC6225106 DOI: 10.3390/molecules23092141] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/11/2018] [Accepted: 08/22/2018] [Indexed: 11/16/2022] Open
Abstract
Soluble guanylate cyclase (sGC) is a key enzyme implicated in various physiological processes such as vasodilation, thrombosis and platelet aggregation. The enzyme’s Heme-Nitric oxide/Oxygen (H-NOX) binding domain is the only sensor of nitric oxide (NO) in humans, which on binding with NO activates sGC to produce the second messenger cGMP. H-NOX is thus a hot target for drug design programs. BAY60-2770 and BAY58-2667 are two widely studied activators of sGC. Here we present comparative molecular dynamics studies to understand the molecular details characterizing the binding of BAY60-2770 and BAY58-2667 with the human H-NOX (hH-NOX) and bacterial H-NOX (bH-NOX) domains. HartreeFock method was used for parametrization of both the activators. A 50 ns molecular dynamics (MD) simulation was run to identify the functionally critical regions of the H-NOX domains. The CPPTRAJ module was used for analysis. BAY60-2770 on binding with bH-NOX, triggered rotational movement in signaling helix F and significant dynamicity in loops α and β, but in hH-NOX domain the compound showed relatively lesser aforementioned structural fluctuations. Conversely, hH-NOX ligated BAY58-2667 experienced highest transitions in its helix F due to electrostatic interactions with D84, T85 and R88 residues which are not conserved in bH-NOX. These conformational transformations might be essential to communicate with downstream PAS, CC and cyclase domains of sGC. Comparative MD studies revealed that BAY bound bHNOX dynamics varied from that of hH-NOX, plausibly due to some key residues such as R40, F74 and Y112 which are not conserved in bacteria. These findings will help to the design of novel drug leads to cure diseases associated to human sGC.
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Shah RC, Sanker S, Wood KC, Durgin BG, Straub AC. Redox regulation of soluble guanylyl cyclase. Nitric Oxide 2018; 76:97-104. [PMID: 29578056 DOI: 10.1016/j.niox.2018.03.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 02/28/2018] [Accepted: 03/19/2018] [Indexed: 11/15/2022]
Abstract
The nitric oxide/soluble guanylyl cyclase (NO-sGC) signaling pathway regulates the cardiovascular, neuronal, and gastrointestinal systems. Impaired sGC signaling can result in disease and system-wide organ failure. This review seeks to examine the redox control of sGC through heme and cysteine regulation while discussing therapeutic drugs that target various conditions. Heme regulation involves mechanisms of insertion of the heme moiety into the sGC protein, the molecules and proteins that control switching between the oxidized (Fe3+) and reduced states (Fe2+), and the activity of heme degradation. Modifications to cysteine residues by S-nitrosation on the α1 and β1 subunits of sGC have been shown to be important in sGC signaling. Moreover, redox balance and localization of sGC is thought to control downstream effects. In response to altered sGC activity due to changes in the redox state, many therapeutic drugs have been developed to target decreased NO-sGC signaling. The importance and relevance of sGC continues to grow as sGC dysregulation leads to numerous disease conditions.
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Affiliation(s)
- Rohan C Shah
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Subramaniam Sanker
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Katherine C Wood
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brittany G Durgin
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Adam C Straub
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
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Lee KH, Lee SR, Cho H, Woo JS, Kang JH, Jeong YM, Cheng XW, Kim WS, Kim W. Cardioprotective effects of PKG activation by soluble GC activator, BAY 60-2770, in ischemia-reperfusion-injured rat hearts. PLoS One 2017; 12:e0180207. [PMID: 28671970 PMCID: PMC5495340 DOI: 10.1371/journal.pone.0180207] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 06/12/2017] [Indexed: 11/19/2022] Open
Abstract
Soluble guanylate cyclase (sGC) has been suggested as a therapeutic target for cardiac ischemia-reperfusion (IR) injury. Until now, the molecular mechanism of BAY 60-2770, a sGC activator, in cardiac IR injury has not been assessed. To identify the cardioprotective effects of BAY 60-2770 in IR-injured rat hearts, IR injury was established by occlusion of LAD for 40 min and reperfusion for 7 days, and the effects of BAY 60-2770 on myocardial protection were assessed by echocardiography and TTC staining. 5 nM and 5 μM of BAY 60-2770 were perfused into isolated rat hearts in a Langendorff system. After 10- or 30-min reperfusion with BAY 60-2770, cGMP and cAMP concentrations and PKG activation status were examined. Hearts were also perfused with 1 μM KT5823 or 100 μM 5-HD in conjunction with 5 nM Bay 60-2770 to evaluate the protective role of PKG. Mitochondrial oxidative stress was investigated under hypoxia-reoxygenation in H9c2 cells. In IR-injured rat hearts, BAY 60-2770 oral administration reduced infarct size by TTC staining and improved left ventricular function by echocardiography. Tissue samples from BAY 60-2770-perfused hearts had approximately two-fold higher cGMP levels. BAY 60-2770 increased PKG activity in the myocardium, and the reduced infarct area by BAY 60-2770 was abrogated by KT-5823 in isolated myocardium. In H9c2 cardiac myoblasts, hypoxia-reoxygenation-mediated mitochondrial ROS generation was diminished with BAY 60-2770 treatment, but was recovered by pretreatment with KT-5823. BAY 60-2770 demonstrated a protective effect against cardiac IR injury via mitoKATP opening and decreased mitoROS by PKG activation. BAY 60-2770 has a protective effect against cardiac IR injury via mitoKATP opening and decreased mitoROS by PKG activation. These results demonstrated that BAY 60-2770 may be used as a therapeutic agent for cardiac IR injury.
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Affiliation(s)
- Kyung Hye Lee
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - So-Ra Lee
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - Haneul Cho
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - Jong Shin Woo
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - Jung Hee Kang
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - Yun-Mi Jeong
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - Xian Wu Cheng
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - Woo-Shik Kim
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
| | - Weon Kim
- Department of Cardiovascular of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Republic of Korea
- * E-mail:
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Tawa M, Kinoshita T, Asai T, Suzuki T, Imamura T, Okamura T. Impact of type 2 diabetes on vascular reactivity to cGMP generators in human internal thoracic arteries. Vascul Pharmacol 2017; 91:36-41. [PMID: 28302516 DOI: 10.1016/j.vph.2017.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/08/2017] [Accepted: 03/11/2017] [Indexed: 10/20/2022]
Abstract
OBJECTIVE The balance between nitric oxide (NO)-sensitive and -insensitive forms of soluble guanylate cyclase (sGC) has been demonstrated to be disrupted in certain lifestyle-related diseases. However, it remains unclear whether type 2 diabetes results in a shift of sGC to the NO-insensitive form. This study addressed this issue in the human blood vessel. METHODS Internal thoracic arteries were obtained from patients undergoing coronary artery bypass grafting. Helically cut strips of the arteries were suspended in organ chambers, and relaxant responses to nitroglycerin (NO-sensitive sGC stimulant) and BAY 60-2770 (NO-insensitive sGC stimulant) were assessed. RESULTS The patients were divided into two groups according to the presence of type 2 diabetes (HbA1c: 7.0±0.3%) or its absence (HbA1c: 5.6±0.1%). Nitroglycerin-induced relaxation was not different in the arteries obtained from type 2 diabetic and non-diabetic patients. In addition, the relaxant response to BAY 60-2770 in type 2 diabetics was comparable to that observed in non-diabetics. Although the patients enrolled often had vascular risk factors other than type 2 diabetes, the relaxant responses were still in the same range in a comparison based on the number of risk factors. However, in separate experiments, the relaxant response to nitroglycerin was attenuated by pre-incubation of the arteries with ODQ (sGC imbalance inducer), whereas the relaxant response to BAY-60-2770 was augmented. CONCLUSIONS These findings suggest that type 2 diabetes does not affect the balance between NO-sensitive and -insensitive sGC in human internal thoracic artery grafts.
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Affiliation(s)
- Masashi Tawa
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan.
| | - Takeshi Kinoshita
- Division of Cardiovascular Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tohru Asai
- Division of Cardiovascular Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tomoaki Suzuki
- Division of Cardiovascular Surgery, Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Takeshi Imamura
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tomio Okamura
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan
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Shimosato T, Tawa M, Iwasaki H, Imamura T, Okamura T. Aging does not affect soluble guanylate cyclase redox state in mouse aortas. Physiol Rep 2016; 4:4/10/e12816. [PMID: 27233303 PMCID: PMC4886176 DOI: 10.14814/phy2.12816] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 05/07/2016] [Indexed: 11/24/2022] Open
Abstract
Aging is associated with endothelial dysfunction, defined as a reduction in nitric oxide (NO) bioavailability. Although the redox state of the NO acceptor soluble guanylate cyclase (sGC) is another determinant factor for its bioavailability and is disturbed by reactive oxygen species (ROS) known to be increased with age, it is unclear whether aging actually has an impact on vascular sGC redox equilibrium. Therefore, this study investigated this issue using two different types of compounds, the sGC stimulator BAY 41‐2272 and the sGC activator BAY 60‐2770. Plasma thiobarbituric acid‐reactive substances (TBARS) levels were markedly higher in aged (19–20 months old) mice than in young (2–3 months old) mice, whereas superoxide levels in endothelium‐denuded aortas were not different between the groups. The relaxant response of endothelium‐denuded aortas to either BAY 41‐2272 or BAY 60‐2770 was identical in aged and young mice. In addition, the vascular cGMP production stimulated with BAY 41‐2272 or BAY 60‐2770 in aged mice was the same level as that in young mice. These findings suggest that aging accompanied by an increase in systemic oxidative stress does not affect vascular smooth muscle ROS generation and sGC redox equilibrium. Unless ROS are increased in vascular smooth muscle, the sGC redox equilibrium might remain unchanged.
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Affiliation(s)
- Takashi Shimosato
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Masashi Tawa
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Hirotaka Iwasaki
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Takeshi Imamura
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tomio Okamura
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Shiga, Japan
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Tawa M, Okamura T. Soluble guanylate cyclase redox state under oxidative stress conditions in isolated monkey coronary arteries. Pharmacol Res Perspect 2016; 4:e00261. [PMID: 27713826 PMCID: PMC5045941 DOI: 10.1002/prp2.261] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 08/10/2016] [Accepted: 08/10/2016] [Indexed: 12/23/2022] Open
Abstract
Coronary artery disease is associated with oxidative stress due to the excessive generation of free radicals in the vascular wall. This study investigated the impact of tert‐butyl hydroperoxide (t‐BuOOH), a peroxyl radical generator, on the redox state of soluble guanylate cyclase (sGC) in isolated monkey coronary arteries. Helically cut strips of endothelium‐intact monkey coronary arteries treated with the nitric oxide synthase inhibitor NG‐nitro‐L‐arginine (10 μmol/L) were exposed for approximately 60 min to either no drug or t‐BuOOH (100 μmol/L) in the presence and absence of α‐tocopherol (300 μmol/L). Relaxation and cGMP levels in response to the sGC stimulator BAY 41‐2272 and the sGC activator BAY 60‐2770 were assessed by organ chamber technique and enzyme immunoassay, respectively. The relaxant response to BAY 41‐2272 was significantly impaired by the exposure to t‐BuOOH, whereas the response to BAY 60‐2770 was significantly augmented. In addition, vascular cGMP accumulation caused by BAY 41‐2272 was decreased by the exposure to t‐BuOOH, whereas for BAY 60‐2770, it was increased. These effects of t‐BuOOH were abolished by coincubation with α‐tocopherol. Furthermore, correlations were observed between BAY compound‐induced relaxant magnitudes and cGMP levels. Therefore, it is concluded that increased oxidative stress leads to disruption of the sGC redox state in monkey coronary arteries. This finding is of great importance for understanding coronary physiology in primates.
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Affiliation(s)
- Masashi Tawa
- Department of Pharmacology Shiga University of Medical Science Otsu Shiga Japan
| | - Tomio Okamura
- Department of Pharmacology Shiga University of Medical Science Otsu Shiga Japan
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Tawa M, Shimosato T, Iwasaki H, Imamura T, Okamura T. Effects of hydrogen peroxide on relaxation through the NO/sGC/cGMP pathway in isolated rat iliac arteries. Free Radic Res 2016; 49:1479-87. [PMID: 26334090 DOI: 10.3109/10715762.2015.1089987] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The production of reactive oxygen species, including hydrogen peroxide (H(2)O(2)), is increased in diseased blood vessels. Although H(2)O(2) leads to impairment of the nitric oxide (NO)/soluble guanylate cyclase (sGC)/cGMP signaling pathway, it is not clear whether this reactive molecule affects the redox state of sGC, a key determinant of NO bioavailability. To clarify this issue, mechanical responses of endothelium-denuded rat external iliac arteries to BAY 41-2272 (sGC stimulator), BAY 60-2770 (sGC activator), nitroglycerin (NO donor), acidified NaNO(2) (exogenous NO) and 8-Br-cGMP (cGMP analog) were studied under exposure to H(2)O(2). The relaxant response to BAY 41-2272 (pD2: 6.79 ± 0.10 and 6.62 ± 0.17), BAY 60-2770 (pD2: 9.57 ± 0.06 and 9.34 ± 0.15) or 8-Br-cGMP (pD2: 5.19 ± 0.06 and 5.24 ± 0.08) was not apparently affected by exposure to H(2)O(2). In addition, vascular cGMP production stimulated with BAY 41-2272 or BAY 60-2770 in the presence of H(2)O(2) was identical to that in its absence. On the other hand, nitroglycerin-induced relaxation was markedly attenuated by exposing the arteries to H(2)O(2) (pD2: 8.73 ± 0.05 and 8.30 ± 0.05), which was normalized in the presence of catalase (pD2: 8.59 ± 0.05). Likewise, H(2)O(2) exposure impaired the relaxant response to acidified NaNO(2) (pD2: 6.52 ± 0.17 and 6.09 ± 0.16). These findings suggest that H(2)O(2) interferes with the NO-mediated action, but the sGC redox equilibrium and the downstream target(s) of cGMP are unlikely to be affected in the vasculature.
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Affiliation(s)
- Masashi Tawa
- a Department of Pharmacology , Shiga University of Medical Science , Otsu , Shiga , Japan
| | - Takashi Shimosato
- a Department of Pharmacology , Shiga University of Medical Science , Otsu , Shiga , Japan
| | - Hirotaka Iwasaki
- a Department of Pharmacology , Shiga University of Medical Science , Otsu , Shiga , Japan
| | - Takeshi Imamura
- a Department of Pharmacology , Shiga University of Medical Science , Otsu , Shiga , Japan
| | - Tomio Okamura
- a Department of Pharmacology , Shiga University of Medical Science , Otsu , Shiga , Japan
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Tawa M, Kinoshita T, Asai T, Suzuki T, Imamura T, Okamura T. Influence of smoking on vascular reactivity to cGMP generators in human internal thoracic arteries. BMC Pharmacol Toxicol 2015. [PMCID: PMC4565467 DOI: 10.1186/2050-6511-16-s1-a93] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Tawa M, Shimosato T, Iwasaki H, Imamura T, Okamura T. Effects of peroxynitrite on relaxation through the NO/sGC/cGMP pathway in isolated rat iliac arteries. J Vasc Res 2015; 51:439-46. [PMID: 25634663 DOI: 10.1159/000371491] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 12/02/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The present study investigated the mechanism by which peroxynitrite impairs vascular function through the nitric oxide (NO)/soluble guanylate cyclase (sGC)/cGMP pathway. METHODS Mechanical responses of rat external iliac arteries without endothelium were studied under exposure to peroxynitrite. cGMP concentrations were determined by enzyme immunoassay. RESULTS Relaxation induced by BAY 41-2272 (sGC stimulator) was impaired under exposure to peroxynitrite, whereas that by BAY 60-2770 (sGC activator) was enhanced. These responses were correlated with tissue levels of cGMP. Effects of peroxynitrite on the relaxant responses to BAY compounds were also observed in the presence of superoxide dismutase (SOD) or tempol, both of which scavenge a certain kind of reactive molecules other than peroxynitrite. As is the case with the relaxant response to BAY 41-2272, acidified NaNO2- and nitroglycerin-induced relaxations were markedly attenuated by exposing the arteries to peroxynitrite, which was not abolished by preincubation with SOD or tempol. On the other hand, peroxynitrite exposure had no effect on the 8-Br-cGMP-induced vasorelxation. CONCLUSION These findings suggest that peroxynitrite interferes with the NO/sGC/cGMP pathway by altering the redox state of sGC. It is likely that peroxynitrite can shift the sGC redox equilibrium to the NO-insensitive state in the vasculature.
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Affiliation(s)
- Masashi Tawa
- Department of Pharmacology, Shiga University of Medical Science, Otsu, Japan
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