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Dunaway LS, Cook AK, Kellum CE, Edell C, Botta D, Molina PA, Sedaka RS, d’Uscio LV, Katusic ZS, Pollock DM, Inscho EW, Pollock JS. Endothelial histone deacetylase 1 activity impairs kidney microvascular NO signaling in rats fed a high-salt diet. Acta Physiol (Oxf) 2024; 240:e14201. [PMID: 39007513 PMCID: PMC11329346 DOI: 10.1111/apha.14201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/12/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024]
Abstract
AIM We aimed to test the hypothesis that a high-salt diet (HS) impairs NO signaling in kidney microvascular endothelial cells through a histone deacetylase 1 (HDAC1)-dependent mechanism. METHODS Male Sprague Dawley rats were fed normal salt diet (NS; 0.49% NaCl) or HS (4% NaCl) for 2 weeks. NO signaling was assessed by measuring L-NAME induced vasoconstriction of the afferent arteriole using the blood perfused juxtamedullary nephron (JMN) preparation. In this preparation, kidneys were perfused with blood from a donor rat on a matching or different diet to that of the kidney donor. Kidney endothelial cells were isolated with magnetic activated cell sorting and HDAC1 activity was measured. RESULTS We found HS-induced impaired NO signaling in the afferent arteriole. This was restored by inhibition of HDAC1 with MS-275. Consistent with these findings, HDAC1 activity was increased in kidney endothelial cells. We further found the loss of NO to be dependent upon the diet of the blood donor rather than the diet of the kidney donor and the plasma from HS-fed rats to be sufficient to induce impaired NO signaling. This indicates the presence of a humoral factor we termed plasma-derived endothelial dysfunction mediator (PDEM). Pretreatment with the antioxidants, PEG-SOD and PEG-catalase, as well as the NOS cofactor, tetrahydrobiopterin, restored NO signaling. CONCLUSION We conclude that HS activates endothelial HDAC1 through PDEM leading to decreased NO signaling. This study provides novel insights into the molecular mechanisms by which a HS decreases renal microvascular endothelial NO signaling.
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Affiliation(s)
- Luke S. Dunaway
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Anthony K. Cook
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Cailin E. Kellum
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Claudia Edell
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Davide Botta
- Department of Microbiology, Immunology Institute, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Patrick A. Molina
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Randee S. Sedaka
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Livius V. d’Uscio
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN USA
| | - Zvonimir S. Katusic
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN USA
| | - David M. Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Edward W. Inscho
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
| | - Jennifer S. Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL USA
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Dunaway LS, Cook AK, Botta D, Molina PA, d’Uscio LV, Katusic ZS, Pollock DM, Inscho EW, Pollock JS. Endothelial Histone Deacetylase 1 Activity Impairs Kidney Microvascular NO Signaling in Rats fed a High Salt Diet. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531731. [PMID: 36945391 PMCID: PMC10028933 DOI: 10.1101/2023.03.08.531731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Aim We aimed to identify new mechanisms by which a high salt diet (HS) decreases NO production in kidney microvascular endothelial cells. Specifically, we hypothesized HS impairs NO signaling through a histone deacetylase 1 (HDAC1)-dependent mechanism. Methods Male Sprague Dawley rats were fed normal salt diet (NS; 0.49% NaCl) or high salt diet (4% NaCl) for two weeks. NO signaling was assessed by measuring L-NAME induced vasoconstriction of the afferent arteriole using the blood perfused juxtamedullary nephron (JMN) preparation. In this preparation, kidneys were perfused with blood from a donor rat on a matching or different diet to that of the kidney donor. Kidney endothelial cells were isolated with magnetic activated cell sorting and HDAC1 activity was measured. Results We found that HS impaired NO signaling in the afferent arteriole. This was restored by inhibition of HDAC1 with MS-275. Consistent with these findings, HDAC1 activity was increased in kidney endothelial cells. We further found the loss of NO to be dependent upon the diet of the blood donor rather than the diet of the kidney donor and the plasma from HS fed rats to be sufficient to induce dysfunction suggesting a humoral factor, we termed Plasma Derived Endothelial-dysfunction Mediator (PDEM), mediates the endothelial dysfunction. The antioxidants, PEG-SOD and PEG-catalase, as well as the NOS cofactor, tetrahydrobiopterin, restored NO signaling. Conclusion We conclude that HS activates endothelial HDAC1 through PDEM leading to decreased NO signaling. This study provides novel insights into the molecular mechanisms by which a HS decreases renal microvascular endothelial NO signaling.
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Affiliation(s)
- Luke S. Dunaway
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA
| | - Anthony K. Cook
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA
| | - Davide Botta
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Patrick A. Molina
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA
| | - Livius V. d’Uscio
- Department of Anesthesiology and Pharmacology, Mayo Clinic, Rochester, MN USA
| | - Zvonimir S. Katusic
- Department of Anesthesiology and Pharmacology, Mayo Clinic, Rochester, MN USA
| | - David M. Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA
| | - Edward W. Inscho
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA
| | - Jennifer S. Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA
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Ma S, Lu G, Zhang Q, Ding N, Jie Y, Zhang H, Xu L, Xie L, Yang X, Zhang H, Jiang Y. Extracellular-superoxide dismutase DNA methylation promotes oxidative stress in homocysteine-induced atherosclerosis. Acta Biochim Biophys Sin (Shanghai) 2022; 54:1222-1233. [PMID: 35866603 PMCID: PMC9827811 DOI: 10.3724/abbs.2022093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In the present study, we investigate the effect of homocysteine (Hcy) on extracellular-superoxide dismutase (EC-SOD) DNA methylation in the aorta of mice, and explore the underlying mechanism in macrophages, trying to identify the key targets of Hcy-induced EC-SOD methylation changes. ApoE -/- mice are fed different diets for 15 weeks, EC-SOD and DNA methyltransferase 1 (DNMT1) expression levels are detected by RT-PCR and western blot analysis. EC-SOD methylation levels are assessed by ntMS-PCR. After EC-SOD overexpression or knockdown in macrophages, following the transfection of macrophages with pEGFP-N1-DNMT1, the methylation levels of EC-SOD are detected. Our data show that the concentrations of Hcy and the area of atherogenic lesions are significantly increased in ApoE -/- mice fed with a high-methionine diet, and have a positive correlation with the levels of superoxide anions, which indicates that Hcy-activated superoxide anions enhance the development of atherogenic lesions. EC-SOD expression is suppressed by Hcy, and the content of superoxide anion is increased when EC-SOD is silenced by RNAi in macrophages, suggesting that EC-SOD plays a major part in oxidative stress induced by Hcy. Furthermore, the promoter activity of EC-SOD is increased following transfection with the -1/-1100 fragment, and EC-SOD methylation level is significantly suppressed by Hcy, and more significantly decreased upon DNMT1 overexpression. In conclusion, Hcy may alter the DNA methylation status and DNMT1 acts as the essential enzyme in the methyl transfer process to disturb the status of EC-SOD DNA methylation, leading to decreased expression of EC-SOD and increased oxidative stress and atherosclerosis.
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Affiliation(s)
- Shengchao Ma
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China
| | - Guanjun Lu
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,Department of UrologyClinical School of MedicineNingxia Medical UniversityYinchuan750004China
| | - Qing Zhang
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China
| | - Ning Ding
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China
| | - Yuzhen Jie
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China,Department of UrologyClinical School of MedicineNingxia Medical UniversityYinchuan750004China
| | - Hui Zhang
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China
| | - Lingbo Xu
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China
| | - Lin Xie
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China
| | - Xiaoling Yang
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China
| | - Huiping Zhang
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China,Departments of Prenatal DiagnosisMaternal and Child health Hospital of Hunan ProvinceChangsha410008China,Correspondence address: Tel: +86-731-84332201; E-mail: (H.Z.) / Tel: +86-951-6980002; E-mail: (Y.J.) @163.com
| | - Yideng Jiang
- NHC Key Laboratory of Metabolic Cardiovascular Diseases ResearchNingxia Medical UniversityYinchuan750004China,Ningxia Key Laboratory of Vascular Injury and Repair ResearchNingxia Medical UniversityYinchuan750004China,The School of Basic Medical SciencesNingxia Medical University Yinchuan 750004China,Correspondence address: Tel: +86-731-84332201; E-mail: (H.Z.) / Tel: +86-951-6980002; E-mail: (Y.J.) @163.com
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Mechanisms of Dietary Sodium-Induced Impairments in Endothelial Function and Potential Countermeasures. Nutrients 2021; 13:nu13010270. [PMID: 33477837 PMCID: PMC7832854 DOI: 10.3390/nu13010270] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/13/2021] [Accepted: 01/16/2021] [Indexed: 01/11/2023] Open
Abstract
Despite decades of efforts to reduce sodium intake, excess dietary sodium remains commonplace, and contributes to increased cardiovascular morbidity and mortality independent of its effects on blood pressure. An increasing amount of research suggests that high-sodium diets lead to reduced nitric oxide-mediated endothelial function, even in the absence of a change in blood pressure. As endothelial dysfunction is an early step in the progression of cardiovascular diseases, the endothelium presents a target for interventions aimed at reducing the impact of excess dietary sodium. In this review, we briefly define endothelial function and present the literature demonstrating that excess dietary sodium results in impaired endothelial function. We then discuss the mechanisms through which sodium impairs the endothelium, including increased reactive oxygen species, decreased intrinsic antioxidant defenses, endothelial cell stiffening, and damage to the endothelial glycocalyx. Finally, we present selected research findings suggesting that aerobic exercise or increased intake of dietary potassium may counteract the deleterious vascular effects of a high-sodium diet.
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Abstract
The microcirculation maintains tissue homeostasis through local regulation of blood flow and oxygen delivery. Perturbations in microvascular function are characteristic of several diseases and may be early indicators of pathological changes in the cardiovascular system and in parenchymal tissue function. These changes are often mediated by various reactive oxygen species and linked to disruptions in pathways such as vasodilation or angiogenesis. This overview compiles recent advances relating to redox regulation of the microcirculation by adopting both cellular and functional perspectives. Findings from a variety of vascular beds and models are integrated to describe common effects of different reactive species on microvascular function. Gaps in understanding and areas for further research are outlined. © 2020 American Physiological Society. Compr Physiol 10:229-260, 2020.
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Affiliation(s)
- Andrew O Kadlec
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - David D Gutterman
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Department of Medicine-Division of Cardiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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6
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Barić L, Drenjančević I, Matić A, Stupin M, Kolar L, Mihaljević Z, Lenasi H, Šerić V, Stupin A. Seven-Day Salt Loading Impairs Microvascular Endothelium-Dependent Vasodilation without Changes in Blood Pressure, Body Composition and Fluid Status in Healthy Young Humans. Kidney Blood Press Res 2019; 44:835-847. [PMID: 31430746 DOI: 10.1159/000501747] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/25/2019] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES We aimed to assess whether a 7-day high-salt (HS) diet affects endothelium-dependent and/or endothelium-independent microvascular function in the absence of changes in arterial blood pressure (BP), and to determine whether such microvascular changes are associated with changes in body composition and fluid status in healthy young humans. MATERIALS AND METHODS Fifty-three young healthy individuals (28 women and 25 men) were assigned to a 7-day low-salt diet (<3.5 g salt/day) followed by a 7-day HS diet (∼14 g salt/day). Skin microvascular blood flow in response to iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) was assessed by laser Doppler flowmetry, and BP, heart rate (HR), plasma renin activity (PRA), serum aldosterone, serum and 24 h-urine sodium, potassium, urea and creatinine levels, together with body composition and fluid status measurement with a 4-terminal portable impedance analyzer were measured before and after diet protocols. RESULTS BP, HR, body composition and fluid status were unchanged, and PRA and serum aldosterone level were significantly suppressed after HS diet. ACh-induced dilation (AChID) was significantly impaired, while SNP-induced dilation was not affected by HS diet. Impaired AChID and increased salt intake, as well as impaired AChID and suppressed renin-angiotensin system were significantly positively correlated. Changes in body composition and fluid status parameters were not associated with impaired AChID. CONCLUSION 7-day HS diet impairs microvascular reactivity by affecting its endothelium-dependent vasodilation in young healthy individuals. Changes are independent of BP, body composition changes or fluid retention, but are the consequences of the unique effect of HS on endothelial function.
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Affiliation(s)
- Lidija Barić
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Ines Drenjančević
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Anita Matić
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Marko Stupin
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.,Department for Cardiovascular Disease, Osijek University Hospital, Osijek, Croatia
| | - Luka Kolar
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Zrinka Mihaljević
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Helena Lenasi
- Institute of Physiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Vatroslav Šerić
- Department of Clinical Laboratory Diagnostics, Osijek University Hospital, Osijek, Croatia
| | - Ana Stupin
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia, .,Department of Pathophysiology, Physiology and Immunology, Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia,
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Priestley JRC, Fink KE, McCord JM, Lombard JH. NRF2 activation with Protandim attenuates salt-induced vascular dysfunction and microvascular rarefaction. Microcirculation 2019; 26:e12575. [PMID: 31132190 DOI: 10.1111/micc.12575] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 05/07/2019] [Accepted: 05/22/2019] [Indexed: 12/18/2022]
Abstract
HYPOTHESIS This study tested the hypothesis that dietary activation of the master antioxidant and cell protective transcription factor nuclear factor, erythroid -2-like 2 (NRF2), protects against salt-induced vascular dysfunction by restoring redox homeostasis in the vasculature. METHODS Male Sprague-Dawley rats and Syrian hamsters were fed a HS (4.0% NaCl) diet containing ~60 mg/kg/day Protandim supplement for 2 weeks and compared to controls fed HS diet alone. RESULTS Protandim supplementation restoredendothelium-dependent vasodilation in response to acetylcholine (ACh) in middle cerebral arteries (MCA)of HS-fed rats and hamster cheek pouch arterioles, and increased microvessel density in the cremastermuscle of HS-fed rats. The restored dilation to ACh in MCA of Protandim-treated rats was prevented by inhibiting nitric oxide synthase (NOS) with L-NAME [100 μM] and was absent in MCA from Nrf2(-/-) knockout rats fed HS diet. Basilar arteries from HS-fed rats treated with Protandim exhibited significantly lower staining for mitochondrial oxidizing species than untreated animals fed HS diet alone; and Protandim treatment increased MnSOD (SOD2) protein expression in mesenteric arteries of HS-fed rats. CONCLUSIONS These results suggest that dietary activation of NRF2 protects against salt-induced vascular dysfunction, vascular oxidative stress, and microvascular rarefaction by upregulating antioxidant defenses and reducing mitochondrial ROS levels.
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Affiliation(s)
| | - Katie E Fink
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Joe M McCord
- Division of Pulmonary Sciences and Critical Care Medicine Research, University of Colorado at Denver - Anschutz Medical Campus, Aurora, Colorado
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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8
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Allen LA, Schmidt JR, Thompson CT, Carlson BE, Beard DA, Lombard JH. High salt diet impairs cerebral blood flow regulation via salt-induced angiotensin II suppression. Microcirculation 2019; 26:e12518. [PMID: 30481399 DOI: 10.1111/micc.12518] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 10/03/2018] [Accepted: 11/22/2018] [Indexed: 01/11/2023]
Abstract
OBJECTIVES This study sought to determine whether salt-induced ANG II suppression contributes to impaired CBF autoregulation. METHODS Cerebral autoregulation was evaluated with LDF during graded reductions of blood pressure. Autoregulatory responses in rats fed HS (4% NaCl) diet vs LS (0.4% NaCl) diet were analyzed using linear regression analysis, model-free analysis, and a mechanistic theoretical model of blood flow through cerebral arterioles. RESULTS Autoregulation was intact in LS-fed animals as MAP was reduced via graded hemorrhage to approximately 50 mm Hg. Short-term (3 days) and chronic (4 weeks) HS diet impaired CBF autoregulation, as evidenced by progressive reductions of laser Doppler flux with arterial pressure reduction. Chronic low dose ANG II infusion (5 mg/kg/min, i.v.) restored CBF autoregulation between the pre-hemorrhage MAP and 50 mm Hg in rats fed short-term HS diet. Mechanistic-based model analysis showed a reduced myogenic response and reduced baseline VSM tone with short-term HS diet, which was restored by ANG II infusion. CONCLUSIONS Short-term and chronic HS diet lead to impaired autoregulation in the cerebral circulation, with salt-induced ANG II suppression as a major factor in the initiation of impaired CBF regulation.
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Affiliation(s)
- Linda A Allen
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - James R Schmidt
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Christopher T Thompson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Brian E Carlson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Daniel A Beard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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9
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Rosenblum WI. Endothelium-dependent responses in the microcirculation observed in vivo. Acta Physiol (Oxf) 2018; 224:e13111. [PMID: 29873936 DOI: 10.1111/apha.13111] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/19/2018] [Accepted: 06/04/2018] [Indexed: 12/17/2022]
Abstract
Endothelium-dependent responses were first demonstrated 40 years ago in the aorta. Since then, extensive research has been conducted in vitro using conductance vessels and materials derived from them. However, the microcirculation controls blood flow to vital organs and has been the focus of in vivo studies of endothelium-dependent dilation beginning immediately after the first in vitro report. Initial in vivo studies employed a light/dye technique for selectively damaging the endothelium to unequivocally prove, in vivo, the existence of endothelium-dependent dilation and in the microvasculature. Endothelium-dependent constriction was similarly proven. Endothelium-dependent agonists include acetylcholine (ACh), bradykinin, arachidonic acid, calcium ionophore A-23187, calcitonin gene-related peptide (CGRP), serotonin, histamine and endothelin-1. Normal and disease states have been studied. Endothelial nitric oxide synthase, cyclooxygenase and cytochrome P450 have been shown to generate the mediators of the responses. Some of the key enzyme systems generate reactive oxygen species (ROS) like superoxide which may prevent EDR. However, one ROS, namely H2 O2 , is one of a number of hyperpolarizing factors that cause dilation initiated by endothelium. Depending upon microvascular bed, a single agonist may use different pathways to elicit an endothelium-dependent response. Interpretation of studies using inhibitors of eNOS is complicated by the fact that these inhibitors may also inhibit ATP-sensitive potassium channels. Other in vivo observations of brain arterioles failed to establish nitric oxide as the mediator of responses elicited by CGRP or by ACh and suggest that a nitrosothiol may be a better fit for the latter.
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Affiliation(s)
- W. I. Rosenblum
- Department of Pathology; Icahn School of Medicine at Mt Sinai NYC; New York NY USA
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10
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Matic A, Jukic I, Stupin A, Baric L, Mihaljevic Z, Unfirer S, Tartaro Bujak I, Mihaljevic B, Lombard JH, Drenjancevic I. High salt intake shifts the mechanisms of flow-induced dilation in the middle cerebral arteries of Sprague-Dawley rats. Am J Physiol Heart Circ Physiol 2018; 315:H718-H730. [DOI: 10.1152/ajpheart.00097.2018] [Citation(s) in RCA: 10] [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
The goal of the present study was to examine the effect of 1 wk of high salt (HS) intake and the role of oxidative stress in changing the mechanisms of flow-induced dilation (FID) in isolated pressurized middle cerebral arteries of male Sprague-Dawley rats ( n = 15–16 rats/group). Reduced FID in the HS group was restored by intake of the superoxide scavenger tempol (HS + tempol in vivo group). The nitric oxide (NO) synthase inhibitor Nω-nitro-l-arginine methyl ester, cyclooxygenase inhibitor indomethacin, and selective inhibitor of microsomal cytochrome P-450 epoxidase activity N-(methylsulfonyl)-2-(2-propynyloxy)-benzenehexanamide significantly reduced FID in the low salt diet-fed group, whereas FID in the HS group was mediated by NO only. Cyclooxygenase-2 mRNA (but not protein) expression was decreased in the HS and HS + tempol in vivo groups. Hypoxia-inducible factor-1α and VEGF protein levels were increased in the HS group but decreased in the HS + tempol in vivo group. Assessment by direct fluorescence of middle cerebral arteries under flow revealed significantly reduced vascular NO levels and increased superoxide/reactive oxygen species levels in the HS group. These results suggest that HS intake impairs FID and changes FID mechanisms to entirely NO dependent, in contrast to the low-salt diet-fed group, where FID is NO, prostanoid, and epoxyeicosatrienoic acid dependent. These changes were accompanied by increased lipid peroxidation products in the plasma of HS diet-fed rats, increased vascular superoxide/reactive oxygen species levels, and decreased NO levels, together with increased expression of hypoxia-inducible factor-1α and VEGF. NEW & NOTEWORTHY High-salt (HS) diet changes the mechanisms of flow-induced dilation in rat middle cerebral arteries from a combination of nitric oxide-, prostanoid-, and epoxyeicosatrienoic acid-dependent mechanisms to, albeit reduced, a solely nitric oxide-dependent dilation. In vivo reactive oxygen species scavenging restores flow-induced dilation in HS diet-fed rats and ameliorates HS-induced increases in the transcription factor hypoxia-inducible factor-1α and expression of its downstream target genes.
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Affiliation(s)
- Anita Matic
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer of Osijek, Osijek, Croatia
| | - Ivana Jukic
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer of Osijek, Osijek, Croatia
| | - Ana Stupin
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer of Osijek, Osijek, Croatia
| | - Lidija Baric
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer of Osijek, Osijek, Croatia
| | - Zrinka Mihaljevic
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer of Osijek, Osijek, Croatia
| | - Sanela Unfirer
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer of Osijek, Osijek, Croatia
| | - Ivana Tartaro Bujak
- Radiation Chemistry and Dosimetry Laboratory, Division of Materials Chemistry, Ruđer Bošković Institute, Zagreb, Croatia
| | - Branka Mihaljevic
- Radiation Chemistry and Dosimetry Laboratory, Division of Materials Chemistry, Ruđer Bošković Institute, Zagreb, Croatia
| | - Julian H. Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ines Drenjancevic
- Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer of Osijek, Osijek, Croatia
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11
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Lukaszewicz KM, Paudyal MP, Falck JR, Lombard JH. Role of vascular reactive oxygen species in regulating cytochrome P450-4A enzyme expression in Dahl salt-sensitive rats. Microcirculation 2018; 23:540-548. [PMID: 27537772 DOI: 10.1111/micc.12304] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/15/2016] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The potential contribution of CYP4A enzymes to endothelial dysfunction in Dahl salt-sensitive rats was determined by comparison to SS-5BN consomic rats having chromosome 5 carrying CYP4A alleles from the BN rat introgressed into the SS genetic background. METHODS The following experiments were performed in cerebral arteries from HS-fed SS and SS-5BN rats ± the SOD inhibitor DETC and/or the superoxide scavenger Tempol: (i) endothelial function was determined via video microscopy ± acute addition of the CYP4A inhibitor DDMS or Tempol; (ii) vascular oxidative stress was assessed with DHE fluorescence ± acute addition of DDMS, l-NAME, or PEG-SOD; and (iii) CYP4A protein levels were compared by western blotting. RESULTS In DETC-treated SS-5BN and HS-fed SS rats, (i) DDMS or Tempol ameliorated vascular dysfunction, (ii) DDMS reduced vascular oxidative stress to control levels, (iii) chronic Tempol treatment reduced vascular CYP4A protein expression, and (iv) combined treatment with Tempol and l-NAME prevented the reduction in CYP4A protein expression in MCA of HS-fed SS rats. CONCLUSION The CYP4A pathway plays a role in vascular dysfunction in SS rats and there appears to be a direct role of reduced NO availability due to salt-induced oxidant stress in upregulating CYP4A enzyme expression.
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Affiliation(s)
| | - Mahesh P Paudyal
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - John R Falck
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.
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12
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Lukaszewicz KM, Durand MJ, Priestley JRC, Schmidt JR, Allen LA, Geurts AM, Lombard JH. Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats. J Vis Exp 2017. [PMID: 29286398 DOI: 10.3791/56133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This protocol describes the use of in vitro television microscopy to evaluate vascular function in isolated cerebral resistance arteries (and other vessels), and describes techniques for evaluating tissue perfusion using Laser Doppler Flowmetry (LDF) and microvessel density utilizing fluorescently labeled Griffonia simplicifolia (GS1) lectin. Current methods for studying isolated resistance arteries at transmural pressures encountered in vivo and in the absence of parenchymal cell influences provide a critical link between in vivo studies and information gained from molecular reductionist approaches that provide limited insight into integrative responses at the whole animal level. LDF and techniques to selectively identify arterioles and capillaries with fluorescently-labeled GS1 lectin provide practical solutions to enable investigators to extend the knowledge gained from studies of isolated resistance arteries. This paper describes the application of these techniques to gain fundamental knowledge of vascular physiology and pathology in the rat as a general experimental model, and in a variety of specialized genetically engineered "designer" rat strains that can provide important insight into the influence of specific genes on important vascular phenotypes. Utilizing these valuable experimental approaches in rat strains developed by selective breeding strategies and new technologies for producing gene knockout models in the rat, will expand the rigor of scientific premises developed in knockout mouse models and extend that knowledge to a more relevant animal model, with a well understood physiological background and suitability for physiological studies because of its larger size.
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Affiliation(s)
| | | | | | - James R Schmidt
- Graduate Programs of Nurse Anesthesia, Texas Wesleyan University
| | | | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin
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13
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Raffai G, Lombard JH. Angiotensin-(1-7) Selectively Induces Relaxation and Modulates Endothelium-Dependent Dilation in Mesenteric Arteries of Salt-Fed Rats. J Vasc Res 2016; 53:105-118. [PMID: 27676088 DOI: 10.1159/000448714] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/26/2016] [Indexed: 12/19/2022] Open
Abstract
This study investigated the acute effects of angiotensin-(1-7) and AVE0991 on active tone and vasodilator responses to bradykinin and acetylcholine in isolated mesenteric arteries from Sprague-Dawley rats fed a high-salt (HS; 4% NaCl) versus a normal salt (NS; 0.4% NaCl) diet. Angiotensin-(1-7) and AVE0991 elicited relaxation, and angiotensin-(1-7) unmasked vasodilator responses to bradykinin in arteries from HS-fed rats. These effects of angiotensin-(1-7) and AVE0991 were inhibited by endothelium removal, A779, PD123319, HOE140 and L-NAME. Angiotensin-(1-7) also restored the acetylcholine-induced relaxation that was suppressed by the HS diet. Vasodilator responses to bradykinin and acetylcholine in the presence of angiotensin-(1-7) were mimicked by captopril and the AT2 receptor agonist CGP42112 in arteries from HS-fed rats. Thus, in contrast to salt-induced impairment of vascular relaxation in response to vasodilator stimuli, angiotensin-(1-7) induces endothelium-dependent and NO-mediated relaxation, unmasks bradykinin responses via activation of mas and AT2 receptors, and restores acetylcholine-induced vasodilation in HS-fed rats. AT2 receptor activation and angiotensin-converting enzyme (ACE) inhibition shared the ability of angiotensin-(1-7) to enhance bradykinin and acetylcholine responses in HS-fed rats. These findings suggest a therapeutic potential for mas and/or AT2 receptor activation and ACE inhibition in restoring endothelial function impaired by elevated dietary salt intake or other pathological conditions.
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Affiliation(s)
- Gábor Raffai
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wis., USA
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14
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Chuang KJ, Lee KY, Pan CH, Lai CH, Lin LY, Ho SC, Ho KF, Chuang HC. Effects of zinc oxide nanoparticles on human coronary artery endothelial cells. Food Chem Toxicol 2016; 93:138-44. [PMID: 27185063 DOI: 10.1016/j.fct.2016.05.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 05/09/2016] [Accepted: 05/11/2016] [Indexed: 12/11/2022]
Abstract
Inhalation of zinc oxide (ZnO) metal fumes is known to cause metal fume fever and to have systemic effects; however, the effects of ZnO nanoparticles (ZnONPs) on the cardiovascular system remain unclear. The objective of this study was to investigate the cardiovascular toxicity of ZnONPs. Human coronary artery endothelial cells (HCAECs) were exposed to ZnONPs of different sizes to investigate the cell viability, 8-hydroxy-2'-deoxyguanosine (8-OHdG), interleukin (IL)-6, nitric oxide (NO), and regulation of cardiovascular disease-related genes. Exposure of HCAECs to ZnONPs resulted in decreased cell viability and increased levels of 8-OHdG, IL-6, and NO. Downregulation of cardiovascular-associated genes was observed in response to ZnONPs in HCAECs determined by qPCR, suggesting that the calcium signaling pathway, neuroactive ligand-receptor interaction, hypertrophic cardiomyopathy, dilated cardiomyopathy, and renin-angiotensin system are important affected pathways in response to ZnONPs. Furthermore, we observed a significant response of AGTR1 to ZnONP exposure in HCAECs. Our results suggest that ZnONPs cause toxicity to HCAECs, which could be associated with cardiovascular dysfunction.
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Affiliation(s)
- Kai-Jen Chuang
- School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan; Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Kang-Yun Lee
- Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Chih-Hong Pan
- Institute of Labor, Occupational Safety and Health, Ministry of Labor, New Taipei City, Taiwan; School of Public Health, National Defense Medical Center, Taipei, Taiwan.
| | - Ching-Huang Lai
- School of Public Health, National Defense Medical Center, Taipei, Taiwan.
| | - Lian-Yu Lin
- Department of Internal Medicine, Division of Cardiology, National Taiwan University Hospital, Taipei, Taiwan.
| | - Shu-Chuan Ho
- Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Kin-Fai Ho
- Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong; Shenzhen Municipal Key Laboratory for Health Risk Analysis, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
| | - Hsiao-Chi Chuang
- Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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15
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Overview of Antagonists Used for Determining the Mechanisms of Action Employed by Potential Vasodilators with Their Suggested Signaling Pathways. Molecules 2016; 21:495. [PMID: 27092479 PMCID: PMC6274436 DOI: 10.3390/molecules21040495] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/23/2016] [Accepted: 03/28/2016] [Indexed: 01/04/2023] Open
Abstract
This paper is a review on the types of antagonists and the signaling mechanism pathways that have been used to determine the mechanisms of action employed for vasodilation by test compounds. Thus, we exhaustively reviewed and analyzed reports related to this topic published in PubMed between the years of 2010 till 2015. The aim of this paperis to suggest the most appropriate type of antagonists that correspond to receptors that would be involved during the mechanistic studies, as well as the latest signaling pathways trends that are being studied in order to determine the route(s) that atest compound employs for inducing vasodilation. The methods to perform the mechanism studies were included. Fundamentally, the affinity, specificity and selectivity of the antagonists to their receptors or enzymes were clearly elaborated as well as the solubility and reversibility. All the signaling pathways on the mechanisms of action involved in the vascular tone regulation have been well described in previous review articles. However, the most appropriate antagonists that should be utilized have never been suggested and elaborated before, hence the reason for this review.
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16
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Boegehold MA, Drenjancevic I, Lombard JH. Salt, Angiotensin II, Superoxide, and Endothelial Function. Compr Physiol 2015; 6:215-54. [PMID: 26756632 DOI: 10.1002/cphy.c150008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Proper function of the vascular endothelium is essential for cardiovascular health, in large part due to its antiproliferative, antihypertrophic, and anti-inflammatory properties. Crucial to the protective role of the endothelium is the production and liberation of nitric oxide (NO), which not only acts as a potent vasodilator, but also reduces levels of reactive oxygen species, including superoxide anion (O2•-). Superoxide anion is highly injurious to the vasculature because it not only scavenges NO molecules, but has other damaging effects, including direct oxidative disruption of normal signaling mechanisms in the endothelium and vascular smooth muscle cells. The renin-angiotensin system plays a crucial role in the maintenance of normal blood pressure. This function is mediated via the peptide hormone angiotensin II (ANG II), which maintains normal blood volume by regulating Na+ excretion. However, elevation of ANG II above normal levels increases O2•- production, promotes oxidative stress and endothelial dysfunction, and plays a major role in multiple disease conditions. Elevated dietary salt intake also leads to oxidant stress and endothelial dysfunction, but these occur in the face of salt-induced ANG II suppression and reduced levels of circulating ANG II. While the effects of abnormally high levels of ANG II have been extensively studied, far less is known regarding the mechanisms of oxidant stress and endothelial dysfunction occurring in response to chronic exposure to abnormally low levels of ANG II. The current article focuses on the mechanisms and consequences of this less well understood relationship among salt, superoxide, and endothelial function.
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Affiliation(s)
| | - Ines Drenjancevic
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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17
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Priestley JRC, Kautenburg KE, Casati MC, Endres BT, Geurts AM, Lombard JH. The NRF2 knockout rat: a new animal model to study endothelial dysfunction, oxidant stress, and microvascular rarefaction. Am J Physiol Heart Circ Physiol 2015; 310:H478-87. [PMID: 26637559 DOI: 10.1152/ajpheart.00586.2015] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/01/2015] [Indexed: 12/26/2022]
Abstract
Nuclear factor (erythroid-derived 2)-like-2 (NRF2) is a master antioxidant and cell protective transcription factor that upregulates antioxidant defenses. In this study we developed a strain of Nrf2 null mutant rats to evaluate the role of reduced NRF2-regulated antioxidant defenses in contributing to endothelial dysfunction and impaired angiogenic responses during salt-induced ANG II suppression. Nrf2(-/-) mutant rats were developed using transcription activator-like effector nuclease technology in the Sprague-Dawley genetic background, and exhibited a 41-bp deletion that included the start codon for Nrf2 and an absence of immunohistochemically detectable NRF2 protein. Expression of mRNA for the NRF2-regulated indicator enzymes heme oxygenase-1, catalase, superoxide dismutase 1, superoxide dismutase 2, and glutathione reductase was significantly lower in livers of Nrf2(-/-) mutant rats fed high salt (HS; 4% NaCl) for 2 wk compared with wild-type controls. Endothelium-dependent dilation to acetylcholine was similar in isolated middle cerebral arteries (MCA) of Nrf2(-/-) mutant rats and wild-type littermates fed low-salt (0.4% NaCl) diet, and was eliminated by short-term (3 days) HS diet in both strains. Low-dose ANG II infusion (100 ng/kg sc) reversed salt-induced endothelial dysfunction in MCA and prevented microvessel rarefaction in wild-type rats fed HS diet, but not in Nrf2(-/-) mutant rats. The results of this study indicate that suppression of NRF2 antioxidant defenses plays an essential role in the development of salt-induced oxidant stress, endothelial dysfunction, and microvessel rarefaction in normotensive rats and emphasize the potential therapeutic benefits of directly upregulating NRF2-mediated antioxidant defenses to ameliorate vascular oxidant stress in humans.
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Affiliation(s)
| | - Katie E Kautenburg
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Marc C Casati
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Bradley T Endres
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
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18
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Mahmoudabady M, Kazemi N, Niazmand S, Rezaee SA, Soukhtanloo M, Hosseini M. The effect of angiotensin-converting enzyme inhibition on inflammatory and angiogenic factors in hypercholesterolemia. Pharmacol Rep 2015; 67:837-41. [PMID: 26398373 DOI: 10.1016/j.pharep.2015.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 01/10/2015] [Accepted: 01/13/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND Renin-angiotensin system (RAS) can be activated during hyperlipidemia. Angiotensin II increases the migration of monocytes, cytokine levels, and gene expressions of VEGF and VCAM-1. With this in mind, the present work attempted to investigate the effect of angiotensin-converting enzyme (ACE) inhibition on VEGF, VCAM-1, and nitric oxide (NO) serum levels in hypercholesterolemic rats. METHODS Forty male Wistar rats were divided into 4 groups including normal diet+saline injection (control), hypercholesterol diet+saline injection, normal diet+captopril injection, and hypercholesterol diet+captopril injection. Before and after the beginning of the diet and after the treatment, the serum levels of cholesterol, triglycerides, LDL, HDL, and NO were measured. Finally, gene expressions of VCAM-1 and VEGF in the vascular cells from aorta were determined. RESULTS Hypercholesterolemic diet increased the serum levels of cholesterol, LDL (p<0.001), triglycerides (p<0.01) and decreased HDL (p<0.001). Captopril caused a reduction in the serum levels of cholesterol, LDL (p<0.001), and triglycerides (p<0.05) as well as an increase in HDL levels (p<0.01). Although the serum levels of NO decreased after hypercholesterolemic diet (p<0.001), no significant change was observed after the treatment. Increased gene expressions of VEGF (p<0.05) and VCAM-1 (p<0.01) in hypercholesterolemia were regressed in captopril treated rats (p<0.01 and p<0.05, respectively). CONCLUSION Captopril, an ACE inhibitor, improves hyperlipidemia and prevents from overexpression of genes for VEGF and VCAM-1, that are implicated in the inflammation and angiogenesis.
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Affiliation(s)
- Maryam Mahmoudabady
- Neurogenic Inflammation Research Centre and Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Narges Kazemi
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Saeed Niazmand
- Neurogenic Inflammation Research Centre and Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Seyyed Abdolrahim Rezaee
- Immunology Research Centre, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Mohammad Soukhtanloo
- Department of Clinical Biochemistry, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Mahmoud Hosseini
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
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19
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Beyer AM, Raffai G, Weinberg BD, Fredrich K, Rodgers MS, Geurts AM, Jacob HJ, Dwinell MR, Lombard JH. Amelioration of salt-induced vascular dysfunction in mesenteric arteries of Dahl salt-sensitive rats by missense mutation of extracellular superoxide dismutase. Am J Physiol Heart Circ Physiol 2013; 306:H339-47. [PMID: 24322611 DOI: 10.1152/ajpheart.00619.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Superoxide dismutase (SOD) enzymes, including extracellular SOD (ecSOD), are important for scavenging superoxide radicals (O2(·-)) in the vasculature. This study investigated vascular control in rats [SS-Sod(3m1Mcwi) (ecSOD(E124D))] with a missense mutation that alters a single amino acid (E124D) of ecSOD that produces a malfunctioning protein in the salt-sensitive (Dahl SS) genetic background. We hypothesized that this mutation would exacerbate endothelial dysfunction due to elevated vascular O2(·-) levels in SS, even under normal salt (NS; 0.4% NaCl) conditions. Aortas of ecSOD(E124D) rats fed standard rodent chow showed enhanced sensitivity to phenylephrine and reduced relaxation to acetylcholine (ACh) vs. SS rats. Endothelium-dependent dilation to ACh was unaffected by the mutation in small mesenteric arteries of ecSOD(E124D) rats fed NS diet, and mesenteric arteries of ecSOD(E124D) rats were protected from endothelial dysfunction during short-term (3-5 days) high-salt (HS; 4% NaCl) diet. ACh-induced dilation of mesenteric arteries of ecSOD(E124D) rats and SS rats fed NS diet was inhibited by N(G)-nitro-l-arginine methyl ester and/or by H2O2 scavenging with polyethylene glycol-catalase at higher concentrations of ACh. Total SOD activity was significantly higher in ecSOD(E124D) rats vs. SS controls fed HS diet, most likely reflecting a compensatory response to loss of a functional ecSOD isoform. These findings indicate that, contrary to its effect in the aorta, this missense mutation of ecSOD in the SS rat genome has no negative effect on vascular function in small resistance arteries, but instead protects against salt-induced endothelial dysfunction, most likely via compensatory mechanisms involving an increase in total SOD activity.
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Affiliation(s)
- Andreas M Beyer
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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