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Brojakowska A, Narula J, Shimony R, Bander J. Clinical Implications of SARS-CoV-2 Interaction With Renin Angiotensin System: JACC Review Topic of the Week. J Am Coll Cardiol 2020; 75:3085-3095. [PMID: 32305401 PMCID: PMC7161517 DOI: 10.1016/j.jacc.2020.04.028] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/09/2020] [Accepted: 04/13/2020] [Indexed: 01/03/2023]
Abstract
Severe acute respiratory-syndrome coronavirus-2 (SARS-CoV-2) host cell infection is mediated by binding to angiotensin-converting enzyme 2 (ACE2). Systemic dysregulation observed in SARS-CoV was previously postulated to be due to ACE2/angiotensin 1-7 (Ang1-7)/Mas axis downregulation; increased ACE2 activity was shown to mediate disease protection. Because angiotensin II receptor blockers, ACE inhibitors, and mineralocorticoid receptor antagonists increase ACE2 receptor expression, it has been tacitly believed that the use of these agents may facilitate viral disease; thus, they should not be used in high-risk patients with cardiovascular disease. Based on the anti-inflammatory benefits of the upregulation of the ACE2/Ang1-7/Mas axis and previously demonstrated benefits of lung function improvement in SARS-CoV infections, it has been hypothesized that the benefits of treatment with renin-angiotensin system inhibitors in SARS-CoV-2 may outweigh the risks and at the very least should not be withheld.
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Affiliation(s)
- Agnieszka Brojakowska
- Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jagat Narula
- Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Rony Shimony
- Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jeffrey Bander
- Department of Cardiology, Icahn School of Medicine at Mount Sinai, New York, New York.
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52
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Gaspar MA. Renovascular hypertension: The current approach. Rev Port Cardiol 2020; 38:869-871. [PMID: 32139201 DOI: 10.1016/j.repc.2020.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Affiliation(s)
- Maria Augusta Gaspar
- Serviço de Nefrologia do Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, Carnaxide, Portugal.
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53
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Bryson TD, Pandrangi TS, Khan SZ, Xu J, Pavlov TS, Ortiz PA, Peterson E, Harding P. The deleterious role of the prostaglandin E 2 EP 3 receptor in angiotensin II hypertension. Am J Physiol Heart Circ Physiol 2020; 318:H867-H882. [PMID: 32142358 DOI: 10.1152/ajpheart.00538.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Angiotensin II (ANG II) plays a key role in regulating blood pressure and inflammation. Prostaglandin E2 (PGE2) signals through four different G protein-coupled receptors, eliciting a variety of effects. We reported that activation of the EP3 receptor reduces cardiac contractility. More recently, we have shown that overexpression of the EP4 receptor is protective in a mouse myocardial infarction model. We hypothesize in this study that the relative abundance of EP3 and EP4 receptors is a major determinant of end-organ damage in the diseased heart. Thus EP3 is detrimental to cardiac function and promotes inflammation, whereas antagonism of the EP3 receptor is protective in an ANG II hypertension (HTN) model. To test our hypothesis, male 10- to 12-wk-old C57BL/6 mice were anesthetized with isoflurane and osmotic minipumps containing ANG II were implanted subcutaneously for 2 wk. We found that antagonism of the EP3 receptor using L798,106 significantly attenuated the increase in blood pressure with ANG II infusion. Moreover, antagonism of the EP3 receptor prevented a decline in cardiac function after ANG II treatment. We also found that 10- to 12-wk-old EP3-transgenic mice, which overexpress EP3 in the cardiomyocytes, have worsened cardiac function. In conclusion, activation or overexpression of EP3 exacerbates end-organ damage in ANG II HTN. In contrast, antagonism of the EP3 receptor is beneficial and reduces cardiac dysfunction, inflammation, and HTN.NEW & NOTEWORTHY This study is the first to show that systemic treatment with an EP3 receptor antagonist (L798,106) attenuates the angiotensin II-induced increase in blood pressure in mice. The results from this project could complement existing hypertension therapies by combining blockade of the EP3 receptor with antihypertensive drugs.
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Affiliation(s)
- Timothy D Bryson
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan.,Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Teja S Pandrangi
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Safa Z Khan
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Jiang Xu
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Tengis S Pavlov
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Pablo A Ortiz
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan.,Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Edward Peterson
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan
| | - Pamela Harding
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan.,Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
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54
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Schiffrin EL. How Structure, Mechanics, and Function of the Vasculature Contribute to Blood Pressure Elevation in Hypertension. Can J Cardiol 2020; 36:648-658. [PMID: 32389338 DOI: 10.1016/j.cjca.2020.02.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/02/2020] [Accepted: 02/03/2020] [Indexed: 01/11/2023] Open
Abstract
Large conduit arteries and the microcirculation participate in the mechanisms of elevation of blood pressure (BP). Large vessels play roles predominantly in older subjects, with stiffening progressing after middle age leading to increases in systolic BP found in most humans with aging. Systolic BP elevation and increased pulsatility penetrate deeper into the distal vasculature, leading to microcirculatory injury, remodelling, and associated endothelial dysfunction. The result is target organ damage in the heart, brain, and kidney. In younger individuals genetically predisposed to high BP, increased salt intake or other exogenous or endogenous risk factors for hypertension, including overweight and excess alcohol intake, lead to enhanced sympathetic activity and vasoconstriction. Enhanced vasoconstrictor responses and myogenic tone become persistent when embedded in an increased extracellular matrix, resulting in remodelling of resistance arteries with a narrowed lumen and increased media-lumen ratio. Stimulation of the renin-angiotensin-aldosterone and endothelin systems and inflammatory and immune activation, to which gut microbiome dysbiosis may contribute as a result of salt intake, also participate in the injury and remodelling of the microcirculation and endothelial dysfunction. Inflammation of perivascular fat and loss of anticontractile factors play roles as well in microvessel remodelling. Exaggerated myogenic tone leads to closure of terminal arterioles, collapse of capillaries and venules, functional rarefaction, and eventually to anatomic rarefaction, compromising tissue perfusion. The remodelling of the microcirculation raises resistance to flow, and accordingly raises BP in a feedback process that over years results in stiffening of conduit arteries and systo-diastolic or predominantly systolic hypertension and, more rarely, predominantly diastolic hypertension. Thus, at different stages of life and the evolution of hypertension, large vessels and the microcirculation interact to contribute to BP elevation.
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Affiliation(s)
- Ernesto L Schiffrin
- Lady Davis Institute for Medical Research and Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montréal, Québec, Canada.
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55
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Gaspar MA. Renovascular hypertension: The current approach. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2019. [DOI: 10.1016/j.repce.2020.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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56
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Pang HW, Linares A, Couling L, Santollo J, Ancheta L, Daniels D, Speth RC. Novel high molecular weight albumin-conjugated angiotensin II activates β-arrestin and G-protein pathways. Endocrine 2019; 66:349-359. [PMID: 31020463 PMCID: PMC7901354 DOI: 10.1007/s12020-019-01930-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/08/2019] [Indexed: 12/30/2022]
Abstract
PURPOSE To study the ability of a novel bovine serum albumin-angiotensin II (BSA-Ang II) conjugate to effect responses of the AT1 angiotensin II receptor subtype mediated by the G-protein-coupled and the beta-arrestin pathways. METHODS Angiotensin II (Ang II) was conjugated with bovine serum albumin and compared with Ang II for competition binding to AT1 receptors, to stimulate aldosterone release from adrenocortical cells, to promote beta-arrestin binding to AT1 receptors, to promote calcium mobilization, and stimulate drinking of water and saline by rats. RESULTS The BSA-Ang II conjugate was less potent competing for AT1R binding, but was equally efficacious at stimulating aldosterone release from H295R adrenocortical cells. Both BSA-Ang II and Ang II stimulated calcium mobilization and beta-arrestin binding to AT1 receptors. BSA-Ang II and Ang II stimulated water appetite equivalently but BSA-Ang II stimulated saline appetite more than Ang II. Both BSA-Ang II and Ang II were considerably more potent at causing calcium mobilization than β-arrestin binding. CONCLUSIONS Addition of a high molecular weight molecule to Ang II reduced its AT1 receptor binding affinity, but did not significantly alter stimulation of aldosterone release or water consumption. The BSA-Ang II conjugate caused a greater saline appetite than Ang II suggesting that it may be a more efficacious agonist of this beta-arrestin-mediated response than Ang II. The higher potency calcium signaling response suggests that the G-protein-coupled responses predominate at physiological concentrations of Ang II, while the beta-arrestin response requires pathophysiological or pharmacological concentrations of Ang II to occur.
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Affiliation(s)
- Hong Weng Pang
- College of Pharmacy, Nova Southeastern University, Ft. Lauderdale, FL, 33328, USA
| | - Andrea Linares
- College of Pharmacy, Nova Southeastern University, Ft. Lauderdale, FL, 33328, USA
| | - Leena Couling
- College of Pharmacy, Nova Southeastern University, Ft. Lauderdale, FL, 33328, USA
| | - Jessica Santollo
- Behavioral Neuroscience Program, Department of Psychology, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
- Department of Biology, University of Kentucky, Lexington, KY, 40506, USA
| | - Leonardo Ancheta
- Advanced Targeting Systems, 10451 Roselle St. #300, San Diego, CA, 92121, USA
| | - Derek Daniels
- Behavioral Neuroscience Program, Department of Psychology, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
- Center for Ingestive Behavior Research, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Robert C Speth
- College of Pharmacy, Nova Southeastern University, Ft. Lauderdale, FL, 33328, USA.
- Department of Pharmacology and Physiology, College of Medicine, Georgetown University, Washington, DC, 20057, USA.
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57
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Thuesen AD, Finsen SH, Rasmussen LL, Andersen DC, Jensen BL, Hansen PBL. Deficiency of T-type Ca 2+ channels Ca v3.1 and Ca v3.2 has no effect on angiotensin II-induced hypertension but differential effect on plasma aldosterone in mice. Am J Physiol Renal Physiol 2019; 317:F254-F263. [PMID: 31042060 DOI: 10.1152/ajprenal.00121.2018] [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] [Indexed: 01/18/2023] Open
Abstract
T-type Ca2+ channel Cav3.1 promotes microvessel contraction ex vivo. It was hypothesized that in vivo, functional deletion of Cav3.1, but not Cav3.2, protects mice against angiotensin II (ANG II)-induced hypertension. Mean arterial blood pressure (MAP) and heart rate were measured continuously with chronically indwelling catheters during infusion of ANG II (30 ng·kg-1·min-1, 7 days) in wild-type (WT), Cav3.1-/-, and Cav3.2-/- mice. Plasma aldosterone and renin concentrations were measured by radioimmunoassays. In a separate series, WT mice were infused with ANG II (100 ng·kg-1·min-1) with and without the mineralocorticoid receptor blocker canrenoate. Cav3.1-/- and Cav3.2-/- mice exhibited no baseline difference in MAP compared with WT mice, but day-night variation was blunted in both Cav3.1 and Cav3.2-/- mice. ANG II increased significantly MAP in WT, Cav3.1-/-, and Cav3.2-/- mice with no differences between genotypes. Heart rate was significantly lower in Cav3.1-/- and Cav3.2-/- mice compared with control mice. After ANG II infusion, plasma aldosterone concentration was significantly lower in Cav3.1-/- compared with Cav3.2-/- mice. In response to ANG II, fibrosis was observed in heart sections from both WT and Cav3.1-/- mice and while cardiac atrial natriuretic peptide mRNA was similar, the brain natriuretic peptide mRNA increase was mitigated in Cav3.1-/- mice ANG II at 100 ng/kg yielded elevated pressure and an increased heart weight-to-body weight ratio in WT mice. Cardiac hypertrophy, but not hypertension, was prevented by the mineralocorticoid receptor blocker canrenoate. In conclusion, T-type channels Cav3.1and Cav3.2 do not contribute to baseline blood pressure levels and ANG II-induced hypertension. Cav3.1, but not Cav3.2, contributes to aldosterone secretion. Aldosterone promotes cardiac hypertrophy during hypertension.
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Affiliation(s)
- Anne D Thuesen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Stine H Finsen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Louise L Rasmussen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Ditte C Andersen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark.,Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital , Odense , Denmark.,Clinical Institute, University of Southern Denmark , Odense , Denmark
| | - Boye L Jensen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Pernille B L Hansen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark.,Cardiovascular and Metabolic Disease, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Gothenburg , Sweden
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58
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CPI-17-mediated contraction of vascular smooth muscle is essential for the development of hypertension in obese mice. J Genet Genomics 2019; 46:109-118. [PMID: 30948334 DOI: 10.1016/j.jgg.2019.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/21/2019] [Accepted: 02/20/2019] [Indexed: 12/14/2022]
Abstract
Several factors have been implicated in obesity-related hypertension, but the genesis of the hypertension is largely unknown. In this study, we found a significantly upregulated expression of CPI-17 (C-kinase-potentiated protein phosphatase 1 inhibitor of 17 kDa) and protein kinase C (PKC) isoforms in the vascular smooth muscles of high-fat diet (HFD)-fed obese mice. The obese wild-type mice showed a significant elevation of blood pressure and enhanced calcium-sensitized contraction of vascular smooth muscles. However, the obese CPI-17-deficient mice showed a normotensive blood pressure, and the calcium-sensitized contraction was consistently reduced. In addition, the mutant muscle displayed an abolished responsive force to a PKC activator and a 30%-50% reduction in both the initial peak force and sustained force in response to various G protein-coupled receptor (GPCR) agonists. Our observations showed that CPI-17-mediated calcium sensitization is mediated through a GPCR/PKC/CPI-17/MLCP/RLC signaling pathway. We therefore propose that the upregulation of CPI-17-mediated calcium-sensitized vasocontraction by obesity contributes to the development of obesity-related hypertension.
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59
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Barrows IR, Ramezani A, Raj DS. Inflammation, Immunity, and Oxidative Stress in Hypertension-Partners in Crime? Adv Chronic Kidney Dis 2019; 26:122-130. [PMID: 31023446 DOI: 10.1053/j.ackd.2019.03.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 02/26/2019] [Accepted: 03/01/2019] [Indexed: 02/07/2023]
Abstract
Hypertension is considered as the most common risk factor for cardiovascular disease. Inflammatory processes link hypertension and cardiovascular disease, and participate in their pathophysiology. In recent years, there has been an increase in research focused on unraveling the role of inflammation and immune activation in development and maintenance of hypertension. Although inflammation is known to be associated with hypertension, whether inflammation is a cause or effect of hypertension remains to be elucidated. This review describes the recent studies that link inflammation and hypertension and demonstrate the involvement of oxidative stress and endothelial dysfunction-two of the key processes in the development of hypertension. Etiology of hypertension, including novel immune cell subtypes, cytokines, toll-like receptors, inflammasomes, and gut microbiome, found to be associated with inflammation and hypertension are summarized and discussed. Most recent findings in this field are presented with special emphasis on potential of anti-inflammatory drugs and statins for treatment of hypertension.
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60
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Herrera M, Yang T, Sparks MA, Manning MW, Koller BH, Coffman TM. Complex Role for E-Prostanoid 4 Receptors in Hypertension. J Am Heart Assoc 2019; 8:e010745. [PMID: 30764697 PMCID: PMC6405651 DOI: 10.1161/jaha.118.010745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 01/22/2019] [Indexed: 12/24/2022]
Abstract
Background Prostaglandin E2 ( PGE 2) is a major prostanoid with multiple actions that potentially affect blood pressure ( BP ). PGE 2 acts through 4 distinct E-prostanoid ( EP ) receptor isoforms: EP 1 to EP 4. The EP 4 receptor ( EP 4R) promotes PGE 2-dependent vasodilation, but its role in the pathogenesis of hypertension is not clear. Methods and Results To address this issue, we studied mice after temporal- and cell-specific deletion of EP 4R. First, using a mouse line with loss of EP 4 expression induced universally after birth, we confirm that EP 4R mediates a major portion of the acute vasodilatory effects of infused PGE 2. In addition, EP 4 contributes to control of resting BP , which was increased by 5±1 mm Hg in animals with generalized deficiency of this receptor. We also show that EP 4 is critical for limiting elevations in BP caused by high salt feeding and long-term infusion of angiotensin II . To more precisely identify the mechanism for these actions, we generated mice in which EP 4R loss is induced after birth and is limited to smooth muscle. In these mice, acute PGE 2-dependent vasodilation was attenuated, indicating that this response is mediated by EP 4R in vascular smooth muscle cells. However, absence of EP 4R only in this vascular compartment had a paradoxical effect of lowering resting BP , whereas the protective effect of EP 4R on limiting angiotensin II-dependent hypertension was unaffected. Conclusions Taken together, our findings support a complex role for EP 4R in regulation of BP and in hypertension, which appears to involve actions of the EP 4R in tissues beyond vascular smooth muscle cells.
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Affiliation(s)
- Marcela Herrera
- Division of NephrologyDepartment of MedicineDuke UniversityDurhamNC
| | - Ting Yang
- Division of NephrologyDepartment of MedicineDuke UniversityDurhamNC
| | - Matthew A. Sparks
- Division of NephrologyDepartment of MedicineDuke UniversityDurhamNC
- Renal SectionDurham VA Medical CenterDurhamNC
| | | | | | - Thomas M. Coffman
- Division of NephrologyDepartment of MedicineDuke UniversityDurhamNC
- Renal SectionDurham VA Medical CenterDurhamNC
- Cardiovascular and Metabolic Disorders Research ProgramDuke–National University of Singapore Graduate Medical SchoolSingapore
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Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
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Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
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Mishra JS, More AS, Gopalakrishnan K, Kumar S. Testosterone plays a permissive role in angiotensin II-induced hypertension and cardiac hypertrophy in male rats. Biol Reprod 2019; 100:139-148. [PMID: 30102356 PMCID: PMC6335213 DOI: 10.1093/biolre/ioy179] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/01/2018] [Accepted: 08/07/2018] [Indexed: 12/21/2022] Open
Abstract
Sex hormones contribute to sex differences in blood pressure. Inappropriate activation of the renin-angiotensin system is involved in vascular dysfunction and hypertension. This study evaluated the role of androgens (testosterone) in angiotensin II (Ang II)-induced increase in blood pressure, vascular reactivity, and cardiac hypertrophy. Eight-week-old male Wistar rats underwent sham operation, castration, or castration with testosterone replacement. After 12 weeks of chronic changes in androgen status, Ang II (120 ng/kg per minute) or saline was infused for 28 days via subcutaneous miniosmotic pump, and changes in blood pressure was measured. Vascular reactivity and Ang II receptor levels were examined in mesenteric arteries. Heart weight, cardiac ANP mRNA levels, and fibrosis were also assessed. Ang II infusion increased arterial pressure in intact males. The Ang II-induced increase in hypertensive response was prevented in castrated males. Testosterone replacement in castrated males restored Ang II-induced hypertensive responses. Castration reduced vascular AT1R/AT2R ratio, an effect that was reversed by testosterone replacement. Ang II-induced hypertension was associated with increased contractile response of mesenteric arteries to Ang II and phenylephrine in intact and testosterone-replaced castrated males; these increases were prevented in castrated males. Ang II infusion induced increased left ventricle-to-body weight ratio and ANP mRNA expression, indicators of left ventricular hypertrophy, and fibrosis in intact and testosterone-replaced castrated males, and castration prevented the increase in these parameters caused by Ang II. This study demonstrates that testosterone plays a permissive role in development and maintenance of Ang II-induced vascular dysfunction, hypertension, and cardiac hypertrophy.
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Affiliation(s)
- Jay S Mishra
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Amar S More
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas, USA
| | | | - Sathish Kumar
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Artamonov MV, Sonkusare SK, Good ME, Momotani K, Eto M, Isakson BE, Le TH, Cope EL, Derewenda ZS, Derewenda U, Somlyo AV. RSK2 contributes to myogenic vasoconstriction of resistance arteries by activating smooth muscle myosin and the Na +/H + exchanger. Sci Signal 2018; 11:11/554/eaar3924. [PMID: 30377223 DOI: 10.1126/scisignal.aar3924] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Smooth muscle contraction is triggered when Ca2+/calmodulin-dependent myosin light chain kinase (MLCK) phosphorylates the regulatory light chain of myosin (RLC20). However, blood vessels from Mlck-deficient mouse embryos retain the ability to contract, suggesting the existence of additional regulatory mechanisms. We showed that the p90 ribosomal S6 kinase 2 (RSK2) also phosphorylated RLC20 to promote smooth muscle contractility. Active, phosphorylated RSK2 was present in mouse resistance arteries under normal basal tone, and phosphorylation of RSK2 increased with myogenic vasoconstriction or agonist stimulation. Resistance arteries from Rsk2-deficient mice were dilated and showed reduced myogenic tone and RLC20 phosphorylation. RSK2 phosphorylated Ser19 in RLC in vitro. In addition, RSK2 phosphorylated an activating site in the Na+/H+ exchanger (NHE-1), resulting in cytosolic alkalinization and an increase in intracellular Ca2+ that promotes vasoconstriction. NHE-1 activity increased upon myogenic constriction, and the increase in intracellular pH was suppressed in Rsk2-deficient mice. In pressured arteries, RSK2-dependent activation of NHE-1 was associated with increased intracellular Ca2+ transients, which would be expected to increase MLCK activity, thereby contributing to basal tone and myogenic responses. Accordingly, Rsk2-deficient mice had lower blood pressure than normal littermates. Thus, RSK2 mediates a procontractile signaling pathway that contributes to the regulation of basal vascular tone, myogenic vasoconstriction, and blood pressure and may be a potential therapeutic target in smooth muscle contractility disorders.
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Affiliation(s)
- Mykhaylo V Artamonov
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Swapnil K Sonkusare
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.,Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Miranda E Good
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Ko Momotani
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.,Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigaku-dori, Sanyo-Onoda-shi, Yamaguchi 756-0884, Japan
| | - Masumi Eto
- Department of Molecular Physiology and Biophysics, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA.,Faculty of Veterinary Medicine, Okayama University of Science, 1-13 Ikoinooka-oka, Imabari, Ehime 794-0085, Japan
| | - Brant E Isakson
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.,Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Thu H Le
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.,Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Eric L Cope
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Zygmunt S Derewenda
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Urszula Derewenda
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Avril V Somlyo
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.
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Sun J, Yang GM, Tao T, Wei LS, Pan Y, Zhu MS. Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography. J Vis Exp 2018. [PMID: 30176012 DOI: 10.3791/58064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.
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Affiliation(s)
- Jie Sun
- Model Animal Research Center and MOE Key Laboratory of Model Animal and Disease Study, Nanjing University
| | | | - Tao Tao
- Model Animal Research Center and MOE Key Laboratory of Model Animal and Disease Study, Nanjing University
| | - Li Sha Wei
- Model Animal Research Center and MOE Key Laboratory of Model Animal and Disease Study, Nanjing University
| | - Yang Pan
- School of Pharmacy, Nanjing University of Chinese Medicine;
| | - Min Sheng Zhu
- Model Animal Research Center and MOE Key Laboratory of Model Animal and Disease Study, Nanjing University;
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Nadkarni GN, Coca SG. APOL1 and blood pressure changes in young adults. Kidney Int 2018; 92:793-795. [PMID: 28938952 DOI: 10.1016/j.kint.2017.05.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/12/2017] [Accepted: 05/18/2017] [Indexed: 01/19/2023]
Abstract
APOL1 risk variants have been shown to be associated with kidney disease and hypertension. In this study, Chen and colleagues assess the association of these risk variants with longitudinal blood pressure in young adults. We review the current literature on association of these alleles with blood pressure and propose future directions to resolve the existing controversies.
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Intratubular and intracellular renin-angiotensin system in the kidney: a unifying perspective in blood pressure control. Clin Sci (Lond) 2018; 132:1383-1401. [PMID: 29986878 DOI: 10.1042/cs20180121] [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: 02/15/2018] [Revised: 06/05/2018] [Accepted: 06/13/2018] [Indexed: 12/18/2022]
Abstract
The renin-angiotensin system (RAS) is widely recognized as one of the most important vasoactive hormonal systems in the physiological regulation of blood pressure and the development of hypertension. This recognition is derived from, and supported by, extensive molecular, cellular, genetic, and pharmacological studies on the circulating (tissue-to-tissue), paracrine (cell-to-cell), and intracrine (intracellular, mitochondrial, nuclear) RAS during last several decades. Now, it is widely accepted that circulating and local RAS may act independently or interactively, to regulate sympathetic activity, systemic and renal hemodynamics, body salt and fluid balance, and blood pressure homeostasis. However, there remains continuous debate with respect to the specific sources of intratubular and intracellular RAS in the kidney and other tissues, the relative contributions of the circulating RAS to intratubular and intracellular RAS, and the roles of intratubular compared with intracellular RAS to the normal control of blood pressure or the development of angiotensin II (ANG II)-dependent hypertension. Based on a lecture given at the recent XI International Symposium on Vasoactive Peptides held in Horizonte, Brazil, this article reviews recent studies using mouse models with global, kidney- or proximal tubule-specific overexpression (knockin) or deletion (knockout) of components of the RAS or its receptors. Although much knowledge has been gained from cell- and tissue-specific transgenic or knockout models, a unifying and integrative approach is now required to better understand how the circulating and local intratubular/intracellular RAS act independently, or with other vasoactive systems, to regulate blood pressure, cardiovascular and kidney function.
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Abstract
PURPOSE OF REVIEW The renin-angiotensin system (RAS) is a pivotal player in the physiology and pathophysiology of cardiovascular and renal systems. Discovery of angiotensin-converting enzyme 2 (ACE2), capable of cleaving RAS effector peptide angiotensin (Ang) II into biologically active Ang-(1-7), has increased the complexity of our knowledge of the RAS. ACE2 expression is abundant in the kidney and is thought to provide protection against injury. This review emphasizes current experimental and clinical findings that examine ACE2 in the context of kidney injury and its potential therapeutic impact for treatment of kidney disease. RECENT FINDINGS Clinical studies have reported upregulation of ACE2 in urine from diabetic patients, which may be reflective of pathological shedding of renal ACE2 as suggested by mechanistic experiments. Studies in experimental models have investigated the feasibility of pharmacological induction of ACE2 for improvement of renal function, inflammation, and fibrosis. SUMMARY Emerging concepts about the RAS indicate that ACE2 is a critical regulator of angiotensin peptide metabolism and the pathogenesis of renal disease. Human recombinant ACE2 is available and may be a practical clinical approach to enzyme replacement. Elucidating precise roles of ACE2 throughout disease progression will enrich our view of the RAS and help identify novel targets and appropriate strategies for intervention.
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Blood pressure regulation by the angiotensin type 1 receptor in the proximal tubule. Curr Opin Nephrol Hypertens 2018; 27:1-7. [PMID: 29045337 DOI: 10.1097/mnh.0000000000000373] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE OF REVIEW The renin-angiotensin system (RAS) plays a critical role in the pathogenesis of hypertension. Homeostatic actions of the RAS, such as increasing blood pressure (BP) and vasoconstriction, are mediated via type 1 (AT1) receptors for angiotensin II. All components of the RAS are present in the renal proximal tubule, which reabsorbs the bulk of the glomerular filtrate, making this segment of the nephron a location of great interest for solute handling under RAS influence. This review highlights recent studies that illustrate the key role of renal proximal tubule AT1 receptors in BP regulation. RECENT FINDINGS A variety of investigative approaches have demonstrated that angiotensin II signaling via AT1a receptors, specifically in the renal proximal tubule, is a major regulator of BP and sodium homeostasis. Reduction of proximal tubule AT1a receptors led to lower BPs, whereas overexpression generally caused increased BPs. SUMMARY AT1a receptors in the proximal tubule are critical to the regulation of BP by the kidney and the RAS. The pattern of BP modulation is associated with alterations in sodium transporters. As a key site for sodium homeostasis, the renal proximal tubule could hence be a potential target in the treatment of hypertension.
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Apperloo EM, Pena MJ, de Zeeuw D, Denig P, Heerspink HJL. Individual variability in response to renin angiotensin aldosterone system inhibition predicts cardiovascular outcome in patients with type 2 diabetes: A primary care cohort study. Diabetes Obes Metab 2018; 20:1377-1383. [PMID: 29345404 PMCID: PMC5969103 DOI: 10.1111/dom.13226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/20/2017] [Accepted: 12/27/2017] [Indexed: 12/19/2022]
Abstract
AIMS To assess variability in systolic blood pressure (SBP) and albuminuria (urinary albumin creatinine ratio [UACR]) responses in patients with type 2 diabetes mellitus initiating renin angiotensin aldosterone system (RAAS) inhibition, and to assess the association of response variability with cardiovascular outcomes. MATERIAL AND METHODS We performed an observational cohort study in patients with type 2 diabetes who started RAAS inhibition between 2007 and 2013 (n = 1600). Patients were identified from general practices in the Netherlands. Individual response in SBP and UACR was assessed during 15 months' follow-up. Patients were categorized as: good responders (∆SBP <0 mm Hg and ∆UACR <0%); intermediate responders (∆SBP <0 mm Hg and ∆UACR >0% or ∆SBP >0 mm Hg and ∆UACR <0%); or poor responders (∆SBP >0 mm Hg and ∆UACR >0%). Multivariable Cox regression was performed to test the association between initial RAAS inhibition response and subsequent cardiovascular outcomes. RESULTS After starting RAAS inhibition, the mean SBP change was -13.2 mm Hg and the median UACR was -36.6%, with large between-individual variability, both in SBP [5th to 95th percentile: 48.5-20] and UACR [5th to 95th percentile: -87.6 to 171.4]. In all, 812 patients (51%) were good responders, 353 (22%) had a good SBP but poor UACR response, 268 (17%) had a good UACR but poor SBP response, and 167 patients (10%) were poor responders. Good responders had a lower risk of cardiovascular events than poor responders (hazard ratio 0.51, 95% confidence interval 0.30-0.86; P = .012). CONCLUSIONS SBP and UACR response after RAAS inhibition initiation varied between and within individual patients with type 2 diabetes treated in primary care. Poor responders had the highest risk of cardiovascular events, therefore, more efforts are needed to develop personalized treatment plans for these patients.
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Affiliation(s)
- Ellen M. Apperloo
- University of Groningen, University Medical Centre GroningenDepartment of Clinical Pharmacy and PharmacologyGroningenThe Netherlands
| | - Michelle J. Pena
- University of Groningen, University Medical Centre GroningenDepartment of Clinical Pharmacy and PharmacologyGroningenThe Netherlands
| | - Dick de Zeeuw
- University of Groningen, University Medical Centre GroningenDepartment of Clinical Pharmacy and PharmacologyGroningenThe Netherlands
| | - Petra Denig
- University of Groningen, University Medical Centre GroningenDepartment of Clinical Pharmacy and PharmacologyGroningenThe Netherlands
| | - Hiddo J. L. Heerspink
- University of Groningen, University Medical Centre GroningenDepartment of Clinical Pharmacy and PharmacologyGroningenThe Netherlands
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Neubauer B, Schrankl J, Steppan D, Neubauer K, Sequeira-Lopez ML, Pan L, Gomez RA, Coffman TM, Gross KW, Kurtz A, Wagner C. Angiotensin II Short-Loop Feedback: Is There a Role of Ang II for the Regulation of the Renin System In Vivo? Hypertension 2018; 71:1075-1082. [PMID: 29661841 DOI: 10.1161/hypertensionaha.117.10357] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/11/2017] [Accepted: 03/19/2018] [Indexed: 11/16/2022]
Abstract
The activity of the renin-angiotensin-aldosterone system is triggered by the release of the protease renin from the kidneys, which in turn is controlled in the sense of negative feedback loops. It is widely assumed that Ang II (angiotensin II) directly inhibits renin expression and secretion via a short-loop feedback by an effect on renin-producing cells (RPCs) mediated by AT1 (Ang II type 1) receptors. Because the concept of such a direct short-loop negative feedback control, which originates mostly from in vitro experiments, has not yet been systematically proven in vivo, we aimed to test the validity of this concept by studying the regulation of renin synthesis and secretion in mice lacking Ang II-AT1 receptors on RPCs. We found that RPCs of the kidney express Ang II-AT1 receptors. Mice with conditional deletion of Ang II-AT1 receptors in RPCs were normal with regard to the number of renin cells, renal renin mRNA, and plasma renin concentrations. Renin expression and secretion of these mice responded to Ang I (angiotensin I)-converting enzyme inhibition and to Ang II infusion like in wild-type (WT) controls. In summary, we did not obtain evidence that Ang II-AT1 receptors on RPCs are of major relevance for the normal regulation of renin expression and secretion in mice. Therefore, we doubt the existence of a direct negative feedback function of Ang II on RPCs.
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Affiliation(s)
- Bjoern Neubauer
- From the Institute of Physiology, University of Regensburg, Germany (B.N., J.S., D.S., K.N., A.K., C.W.)
| | - Julia Schrankl
- From the Institute of Physiology, University of Regensburg, Germany (B.N., J.S., D.S., K.N., A.K., C.W.)
| | - Dominik Steppan
- From the Institute of Physiology, University of Regensburg, Germany (B.N., J.S., D.S., K.N., A.K., C.W.)
| | - Katharina Neubauer
- From the Institute of Physiology, University of Regensburg, Germany (B.N., J.S., D.S., K.N., A.K., C.W.).,Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center-University of Freiburg, Germany (K.N.)
| | - Maria Luisa Sequeira-Lopez
- Department of Pediatrics, Child Health Research Center, University of Virginia School of Medicine, Charlottesville (M.L.S.-L., R.A.G.)
| | - Li Pan
- Department of Pathology, Brigham and Women's Hospital, Boston, MA (L.P.)
| | - R Ariel Gomez
- Department of Pediatrics, Child Health Research Center, University of Virginia School of Medicine, Charlottesville (M.L.S.-L., R.A.G.)
| | - Thomas M Coffman
- Division of Nephrology, Department of Medicine, Durham Veterans Affairs Medical Centers, Duke University, NC (T.M.C.).,and Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY (K.W.G.)
| | - Kenneth W Gross
- and Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY (K.W.G.)
| | - Armin Kurtz
- From the Institute of Physiology, University of Regensburg, Germany (B.N., J.S., D.S., K.N., A.K., C.W.)
| | - Charlotte Wagner
- From the Institute of Physiology, University of Regensburg, Germany (B.N., J.S., D.S., K.N., A.K., C.W.)
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Titze J, Luft FC. Speculations on salt and the genesis of arterial hypertension. Kidney Int 2018; 91:1324-1335. [PMID: 28501304 DOI: 10.1016/j.kint.2017.02.034] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 02/17/2017] [Accepted: 02/21/2017] [Indexed: 12/25/2022]
Abstract
Blood pressure salt sensitivity and salt resistance are mechanistically imperfectly explained. A prescient systems medicine approach by Guyton and colleagues-more than 50 years ago-suggested how salt intake might influence blood pressure. They proposed that a high-salt diet engenders sodium accumulation, volume expansion, cardiac output adjustments, and then autoregulation for flow maintenance. The autoregulation in all vascular beds increases systemic vascular resistance, causing the kidneys to excrete more salt and water, thus reducing systems to normal and minimizing any changes in blood pressure. This schema, which is remarkably all encompassing, included all regulatory mechanisms Guyton could identify at the time. Guyton introduced the idea that the kidney is central, particularly concerning the regulation of renal pressure natriuresis. Numerous criticisms have been subsequently raised, particularly recently. Kurtz and colleagues argue that the ability of individuals to respond with an appropriate vasodilatory response to increased salt intake is pivotal. Data exist to address that issue. Salt-resistant hypertensive models provide additional information. We identified a mendelian form of hypertension not related to sodium reabsorption in the distal nephron. The hypertension develops because of increased systemic vascular resistance. In addition, we rediscovered a third salt-storage glycose-aminoglycan-related compartment, largely in the skin. This compartment operates independently of renal function, and when perturbed, is associated with salt sensitivity. More recently, we found novel molecular mechanisms demonstrating how large salt quantities are excreted by the kidneys with minimal water losses. We introduce novel interpretations as to how the kidneys excrete salt when the intake is high. The findings could have relevance as to how blood pressure may be regulated at varying salt intakes. Our purposes are to provide the readership with a banquet of thoughts to digest, to pursue Guyton's ideas, and to adjust them accordingly.
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Affiliation(s)
- Jens Titze
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Friedrich C Luft
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Experimental and Clinical Research Center, Max-Delbrück Center for Molecular Medicine, Charité Medical Faculty, Berlin, Germany.
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Oparil S, Acelajado MC, Bakris GL, Berlowitz DR, Cífková R, Dominiczak AF, Grassi G, Jordan J, Poulter NR, Rodgers A, Whelton PK. Hypertension. Nat Rev Dis Primers 2018; 4:18014. [PMID: 29565029 PMCID: PMC6477925 DOI: 10.1038/nrdp.2018.14] [Citation(s) in RCA: 546] [Impact Index Per Article: 91.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Systemic arterial hypertension is the most important modifiable risk factor for all-cause morbidity and mortality worldwide and is associated with an increased risk of cardiovascular disease (CVD). Fewer than half of those with hypertension are aware of their condition, and many others are aware but not treated or inadequately treated, although successful treatment of hypertension reduces the global burden of disease and mortality. The aetiology of hypertension involves the complex interplay of environmental and pathophysiological factors that affect multiple systems, as well as genetic predisposition. The evaluation of patients with hypertension includes accurate standardized blood pressure (BP) measurement, assessment of the patients' predicted risk of atherosclerotic CVD and evidence of target-organ damage, and detection of secondary causes of hypertension and presence of comorbidities (such as CVD and kidney disease). Lifestyle changes, including dietary modifications and increased physical activity, are effective in lowering BP and preventing hypertension and its CVD sequelae. Pharmacological therapy is very effective in lowering BP and in preventing CVD outcomes in most patients; first-line antihypertensive medications include angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, dihydropyridine calcium-channel blockers and thiazide diuretics.
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Affiliation(s)
- Suzanne Oparil
- Vascular Biology and Hypertension Program, Division of Cardiovascular Disease, Department of Medicine, School of Medicine, The University of Alabama at Birmingham (UAB), 1720 2nd Avenue South, Birmingham, AL, 35294-0007, USA
| | | | | | - Dan R Berlowitz
- Center for Healthcare Organization and Implementation Research, Bedford Veteran Affairs Medical Center, Bedford, MA, USA
- Schools of Medicine and Public Health, Boston University, Boston, MA, USA
| | - Renata Cífková
- Center for Cardiovascular Prevention, Charles University in Prague, First Faculty of Medicine and Thomayer Hospital, Prague, Czech Republic
| | - Anna F Dominiczak
- Institute of Cardiovascular and Medical Science, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Guido Grassi
- Clinica Medica, University of Milano-Bicocca, Milan, Italy
- IRCCS Multimedica, Sesto San Giovanni, Milan, Italy
| | - Jens Jordan
- Institute of Aerospace Medicine, German Aerospace Center (DLR), University of Cologne, Cologne, Germany
| | - Neil R Poulter
- Imperial Clinical Trials Unit, School of Public Health, Imperial College London, London, UK
| | - Anthony Rodgers
- The George Institute for Global Health, Sydney, New South Wales, Australia
| | - Paul K Whelton
- Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
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Pillai SM, Seebeck P, Fingerhut R, Huang J, Ming XF, Yang Z, Verrey F. Kidney Mass Reduction Leads to l-Arginine Metabolism-Dependent Blood Pressure Increase in Mice. J Am Heart Assoc 2018; 7:JAHA.117.008025. [PMID: 29478971 PMCID: PMC5866334 DOI: 10.1161/jaha.117.008025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background Uninephrectomy (UNX) is performed for various reasons, including kidney cancer or donation. Kidneys being the main site of l‐arginine production in the body, we tested whether UNX mediated kidney mass reduction impacts l‐arginine metabolism and thereby nitric oxide production and blood pressure regulation in mice. Methods and Results In a first series of experiments, we observed a significant increase in arterial blood pressure 8 days post‐UNX in female and not in male mice. Further experimental series were performed in female mice, and the blood pressure increase was confirmed by telemetry. l‐citrulline, that is used in the kidney to produce l‐arginine, was elevated post‐UNX as was also asymmetric dimethylarginine, an inhibitor of nitric oxide synthase that competes with l‐arginine and is a marker for renal failure. Interestingly, the UNX‐induced blood pressure increase was prevented by supplementation of the diet with 5% of the l‐arginine precursor, l‐citrulline. Because l‐arginine is metabolized in the kidney and other peripheral tissues by arginase‐2, we tested whether the lack of this metabolic pathway also compensates for decreased l‐arginine production in the kidney and/or for local nitric oxide synthase inhibition and consecutive blood pressure increase. Indeed, upon uninephrectomy, arginase‐2 knockout mice (Arg‐2−/−) neither displayed an increase in asymmetric dimethylarginine and l‐citrulline plasma levels nor a significant increase in blood pressure. Conclusions UNX leads to a small increase in blood pressure that is prevented by l‐citrulline supplementation or arginase deficiency, 2 measures that appear to compensate for the impact of kidney mass reduction on l‐arginine metabolism.
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Affiliation(s)
- Samyuktha Muralidharan Pillai
- Institute of Physiology, Zurich Center for Integrative Human Physiology (ZIHP) and NCCR Kidney.CH, University of Zurich, Switzerland
| | - Petra Seebeck
- Zurich Integrative Rodent Physiology (ZIRP), University of Zurich, Switzerland
| | - Ralph Fingerhut
- Swiss Newborn Screening Laboratory, Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Ji Huang
- Division of Physiology, Department of Medicine, Faculty of Science and NCCR Kidney.CH, University of Fribourg, Switzerland
| | - Xiu-Fen Ming
- Division of Physiology, Department of Medicine, Faculty of Science and NCCR Kidney.CH, University of Fribourg, Switzerland
| | - Zhihong Yang
- Division of Physiology, Department of Medicine, Faculty of Science and NCCR Kidney.CH, University of Fribourg, Switzerland
| | - François Verrey
- Institute of Physiology, Zurich Center for Integrative Human Physiology (ZIHP) and NCCR Kidney.CH, University of Zurich, Switzerland
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Boshra V, Abbas AM. Effects of peripherally and centrally applied ghrelin on the oxidative stress induced by renin angiotensin system in a rat model of renovascular hypertension. J Basic Clin Physiol Pharmacol 2018; 28:347-354. [PMID: 28315847 DOI: 10.1515/jbcpp-2016-0145] [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: 09/19/2016] [Accepted: 01/04/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Renovascular hypertension (RVH) is a result of renal artery stenosis, which is commonly due to astherosclerosis. In this study, we aimed to clarify the central and peripheral effects of ghrelin on the renin-angiotensin system (RAS) in a rat model of RVH. METHODS RVH was induced in rats by partial subdiaphragmatic aortic constriction. Experiment A was designed to assess the central effect of ghrelin via the intracerebroventricular (ICV) injection of ghrelin (5 μg/kg) or losartan (0.01 mg/kg) in RVH rats. Experiment B was designed to assess the peripheral effect of ghrelin via the subcutaneous (SC) injection of ghrelin (150 μg/kg) or losartan (10 mg/kg) for 7 consecutive days. Mean arterial blood pressure (MAP), heart rate, plasma renin activity (PRA), and oxidative stress markers were measured in all rats. In addition, angiotensin II receptor type 1 (AT1R) concentration was measured in the hypothalamus of rats in Experiment B. RESULTS RVH significantly increased brain AT1R, PRA, as well as the brain and plasma oxidative stress. Either SC or ICV ghrelin or losartan caused a significant decrease in MAP with no change in the heart rate. Central ghrelin or losartan caused a significant decrease in brain AT1R with significant alleviation of the brain oxidative stress. Central ghrelin caused a significant decrease in PRA, whereas central losartan caused a significant increase in PRA. SC ghrelin significantly decreased PRA and plasma oxidative stress, whereas SC losartan significantly increased PRA and decreased plasma oxidative stress. CONCLUSIONS The hypotensive effect of ghrelin is mediated through the amelioration of oxidative stress, which is induced by RAS centrally and peripherally.
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75
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Yao S, Agyei D, Udenigwe CC. Structural Basis of Bioactivity of Food Peptides in Promoting Metabolic Health. ADVANCES IN FOOD AND NUTRITION RESEARCH 2018; 84:145-181. [PMID: 29555068 DOI: 10.1016/bs.afnr.2017.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bioactive peptides have many structural features that enable them to become functional in controlling several biological processes in the body, especially those related to metabolic health. This chapter provides an overview of the multiple targets of food-derived peptides against metabolic health problems (e.g., hypertension, dyslipidemia, hyperglycemia, oxidative stress) and discusses the importance of structural chemistry in determining the bioactivities of peptides and protein hydrolysates.
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Affiliation(s)
- Shixiang Yao
- Southwest University, Chongqing, PR China; University of Ottawa, Ottawa, ON, Canada
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76
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Abstract
The link between inappropriate salt retention in the kidney and hypertension is well recognized. However, growing evidence suggests that the immune system can play surprising roles in sodium homeostasis, such that the study of inflammatory cells and their secreted effectors has provided important insights into salt sensitivity. As part of the innate immune system, myeloid cells have diverse roles in blood pressure regulation, ranging from prohypertensive actions in the kidney, vasculature, and brain, to effects in the skin that attenuate blood pressure elevation. In parallel, T lymphocyte subsets, as key constituents of the adaptive immune compartment, have variable effects on renal sodium handling and the hypertensive response, accruing from the functions of the cytokines that they produce. Conversely, salt can directly modulate the phenotypes of myeloid and T cells, illustrating bidirectional regulatory mechanisms through which sodium and the immune system coordinately impact blood pressure. This review details the complex interplay between myeloid cells, T cells, and salt in the pathogenesis of essential hypertension.
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Affiliation(s)
- A Justin Rucker
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27710, USA; .,Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA
| | - Nathan P Rudemiller
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27710, USA; .,Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA
| | - Steven D Crowley
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27710, USA; .,Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA
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Wang L, Wei J, Jiang S, Li HH, Fu L, Zhang J, Liu R. Effects of different storage solutions on renal ischemia tolerance after kidney transplantation in mice. Am J Physiol Renal Physiol 2017; 314:F381-F387. [PMID: 29141940 DOI: 10.1152/ajprenal.00475.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
storage is the most prevalent method for graft preservation in kidney transplantation (KTX). The protective effects of various preservation solutions have been studied extensively in both clinical trials and experimental animal models. However, a paucity of studies have examined the effect of different preservation solutions on graft function in mouse KTX; in addition, the tolerance of the transplanted grafts to further insult has not been evaluated, which was the objective of the present study. We performed mouse KTX in three groups, with the donor kidneys preserved in different solutions for 60 min: saline, mouse serum, and University of Wisconsin (UW) solution. The graft functions were assessed by kidney injury markers and glomerular filtration rate (GFR). The grafts that were preserved in UW solution exhibited better functions, reflected by 50 and 70% lower plasma creatinine levels as well as 30 and 55% higher plasma creatinine levels in GFR than serum and saline groups, respectively, during the first week after transplants. To examine the graft function in response to additional insult, we induced ischemia-reperfusion injury (IRI) by clamping the renal pedicle for 18 min at 4 wk after KTX. We found that the grafts preserved in UW solution exhibited ~30 and 20% less injury assessed by kidney injury markers and histology than in other two preservation solutions. Taken together, our results demonstrated that UW solution exhibited a better protective effect in transplanted renal grafts in mice. UW solution is recommended for use in mouse KTX for reducing confounding factors such as IRI during surgery.
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Affiliation(s)
- Lei Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine , Tampa, Florida
| | - Jin Wei
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine , Tampa, Florida
| | - Shan Jiang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine , Tampa, Florida
| | - Hui-Hua Li
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine , Tampa, Florida
| | - Liying Fu
- Tampa General Hospital , Tampa, Florida
| | - Jie Zhang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine , Tampa, Florida
| | - Ruisheng Liu
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine , Tampa, Florida
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Wang G, Wu L, Chen Z, Sun J. Identification of crucial miRNAs and the targets in renal cortex of hypertensive patients by expression profiles. Ren Fail 2017; 39:92-99. [PMID: 27802793 PMCID: PMC6014400 DOI: 10.1080/0886022x.2016.1244083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 09/04/2016] [Accepted: 09/16/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUNDS Defect in kidney is one major reason of hypertension. The study aimed ao uncovering the regulatory mechanisms of miRNAs and the targets in hypertensive kidney. METHODS Gene expression profile of GSE28345 and miRNA expression profile of GSE28283 were downloaded from GEO database. After data preprocessing, differently expressed genes (DEGs) and miRNAs (DE-miRs) were identified using limma package. Then targets of miRNAs were predicted according to information in relevant databases. Function and pathway enrichment analyses were performed for DEGs using DAVID software. Furthermore, protein-protein interaction (PPI) networks were constructed for up- and down-regulated genes, respectively, using the Cytoscape. Additionally, for down-regulated DEGs, the integrated regulatory network was established combining PPI network with the miRNA-mRNA interactions. RESULTS As a result, 285 DEGs were identified, including 177 up-regulated and 108 down-regulated genes. Combined with the predicted targets of miRNAs, 22 up-regulated DE-miRs were identified. In the integrated network for down-regulated DEGs, three crucial nodes were identified as ASPN, COL12A1, and SCN2A. ASPN was predicted as target of miR-21 and miR-374b, and COL12A1 was the target of miR-30e, miR-21, and miR-195, while SCN2A was the target of miR-30e, miR-374b, and miR-195. Notably, COL12A1 and ASPN were linked with each other in the network. CONCLUSION Three crucial genes were identified in hypertensive kidney, such as COL12A1, ASPN, and SCN2A. ASPN might co-function with COL12A1, and they both might be the targets of miR-21. SCN2A might be a novel target of miR-30e and miR-374b. However, more experiments are needed to validate these results.
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Affiliation(s)
- Guohua Wang
- Department of Pediatrics, The First Hospital of Jilin University, Changchun, China
| | - Lan Wu
- Department of Pediatrics, The First Hospital of Jilin University, Changchun, China
| | - Zhi Chen
- Department of Nephrology, The First Hospital of Jilin University, Changchun, China
| | - Jinghui Sun
- Department of Pediatrics, The First Hospital of Jilin University, Changchun, China
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79
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Wang L, Wang X, Qu HY, Jiang S, Zhang J, Fu L, Buggs J, Pang B, Wei J, Liu R. Role of Kidneys in Sex Differences in Angiotensin II-Induced Hypertension. Hypertension 2017; 70:1219-1227. [PMID: 29061720 DOI: 10.1161/hypertensionaha.117.10052] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 08/10/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022]
Abstract
The significance of kidneys in regulation of sodium and water balance and hemodynamics has been demonstrated both in patients and animal models. In the present study, we tested our hypothesis that kidneys play an essential role in control of sex differences in angiotensin II (Ang II)-dependent hypertension. Kidney transplantations (KTXs) were performed between male (M) and female (F) C57BL/6 mice (donor→recipient: F→F, M→M, F→M, and M→F). Radiotelemetry transmitters were implanted for measurement of mean arterial pressure during the infusion of Ang II (600 ng·kg-1·min-1). Gene expressions and inflammatory responses in the transplanted grafts were assessed. We found that same-sex-KTX mice still exhibited sex differences in Ang II-dependent hypertension (31.3±0.8 mm Hg in M→M versus 12.2±0.6 mm Hg in F→F), which were reduced between males and females when they received kidneys of the opposite sex (32.9±1 mm Hg in M→F versus 22.3±0.7 mm Hg in F→M). The sex differences in gene expressions, including AT1R (angiotensin II receptor, type 1), AT1R/AT2R, ET-1 (endothelin-1), ETA (endothelin receptor type A), NHE3 (sodium-hydrogen exchanger 3), α-ENaC (α-epithelial sodium channel), and γ-ENaC, were unaltered in same-sex KTXs and much lessened in cross-sex KTXs. In addition, the cross-sex KTXs exhibited more robust inflammatory responses reflected by higher expression of IL-6 (interleukin 6), TNFα (tumor necrosis factor α), and KC (keratinocyte-derived chemokine) than same-sex KTX. Our results indicate that kidneys play an essential role in sex differences of Ang II-dependent hypertension. KTX of male kidneys to females augmented the blood pressure response, whereas KTX of female kidneys to males attenuated the blood pressure response. The host's extrarenal systems modulate expressions of many genes and inflammatory response, which may also contribute to the sex differences in blood pressure regulation.
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Affiliation(s)
- Lei Wang
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL.
| | - Ximing Wang
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Helena Y Qu
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Shan Jiang
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Jie Zhang
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Liying Fu
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Jacentha Buggs
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Bo Pang
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Jin Wei
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
| | - Ruisheng Liu
- From the Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa (L.W., X.W., H.Y.Q., S.J., J.Z., B.P., J.W., R.L.); and Pathology (L.F.) and Tampa General Medical Group Transplant Surgery (J.B.), Tampa General Hospital, FL
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80
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Hirohama D, Ayuzawa N, Ueda K, Nishimoto M, Kawarazaki W, Watanabe A, Shimosawa T, Marumo T, Shibata S, Fujita T. Aldosterone Is Essential for Angiotensin II-Induced Upregulation of Pendrin. J Am Soc Nephrol 2017; 29:57-68. [PMID: 29021385 DOI: 10.1681/asn.2017030243] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022] Open
Abstract
The renin-angiotensin-aldosterone system has an important role in the control of fluid homeostasis and BP during volume depletion. Dietary salt restriction elevates circulating angiotensin II (AngII) and aldosterone levels, increasing levels of the Cl-/HCO3- exchanger pendrin in β-intercalated cells and the Na+-Cl- cotransporter (NCC) in distal convoluted tubules. However, the independent roles of AngII and aldosterone in regulating these levels remain unclear. In C57BL/6J mice receiving a low-salt diet or AngII infusion, we evaluated the membrane protein abundance of pendrin and NCC; assessed the phosphorylation of the mineralocorticoid receptor, which selectively inhibits aldosterone binding in intercalated cells; and measured BP by radiotelemetry in pendrin-knockout and wild-type mice. A low-salt diet or AngII infusion upregulated NCC and pendrin levels, decreased the phosphorylation of mineralocorticoid receptor in β-intercalated cells, and increased plasma aldosterone levels. Notably, a low-salt diet did not alter BP in wild-type mice, but significantly decreased BP in pendrin-knockout mice. To dissect the roles of AngII and aldosterone, we performed adrenalectomies in mice to remove aldosterone from the circulation. In adrenalectomized mice, AngII infusion again upregulated NCC expression, but did not affect pendrin expression despite the decreased phosphorylation of mineralocorticoid receptor. By contrast, AngII and aldosterone coadministration markedly elevated pendrin levels in adrenalectomized mice. Our results indicate that aldosterone is necessary for AngII-induced pendrin upregulation, and suggest that pendrin contributes to the maintenance of normal BP in cooperation with NCC during activation of the renin-angiotensin-aldosterone system by dietary salt restriction.
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Affiliation(s)
- Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan;
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Atsushi Watanabe
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Chiba, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Shigeru Shibata
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.,Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan; and
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan; .,CREST, Japan Science and Technology Agency, Tokyo, Japan
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81
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Mishra S, Ingole S, Jain R. Salt sensitivity and its implication in clinical practice. Indian Heart J 2017; 70:556-564. [PMID: 30170653 PMCID: PMC6116721 DOI: 10.1016/j.ihj.2017.10.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/01/2017] [Accepted: 10/10/2017] [Indexed: 02/06/2023] Open
Abstract
Hypertension (HTN) is a complex multi-factorial disease and is considered one of the foremost modifiable risk factors for stroke, heart failure, ischemic heart disease and renal dysfunction. Over the past century, salt and its linkage to HTN and cardiovascular (CV) mortality has been the subject of intense scientific scrutiny. There is now consensus that different individuals have different susceptibilities to blood pressure (BP)-raising effects of salt and this susceptiveness is called as salt sensitivity. Several renal and extra-renal mechanisms are believed to play a role. Blunted activity of the renin–angiotensin–aldosterone system (RAAS), adrenal Rac1-MR-Sgk1-NCC/ENaC pathway, renal SNS-GR-WNK4-NCC pathway, defect of membrane ion transportation, inflammation and abnormalities of Na+/Ca2+ exchange have all been implicated as pathophysiological basis for salt sensitive HTN. While salt restriction is definitely beneficial recent observation suggests that treatment with Azilsartan may improve salt sensitivity by selectively reducing renal proximal tubule Na+/H+ exchange. This encourages the future potential benefits of recognizing and therapeutically addressing the salt sensitive phenotype in humans.
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82
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Zhang J, Qu HY, Song J, Wei J, Jiang S, Wang L, Wang L, Buggs J, Liu R. Enhanced hemodynamic responses to angiotensin II in diabetes are associated with increased expression and activity of AT1 receptors in the afferent arteriole. Physiol Genomics 2017; 49:531-540. [PMID: 28842434 DOI: 10.1152/physiolgenomics.00025.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 12/28/2022] Open
Abstract
The prevalence of hypertension is about twofold higher in diabetic than in nondiabetic subjects. Hypertension aggravates the progression of diabetic complications, especially diabetic nephropathy. However, the mechanisms for the development of hypertension in diabetes have not been elucidated. We hypothesized that enhanced constrictive responsiveness of renal afferent arterioles (Af-Art) to angiotensin II (ANG II) mediated by ANG II type 1 (AT1) receptors contributes to the development of hypertension in diabetes. In response to an acute bolus intravenous injection of ANG II, alloxan-induced diabetic mice exhibited a higher mean arterial pressure (MAP) (119.1 ± 3.8 vs. 106.2 ± 3.5 mmHg) and a lower renal blood flow (0.25 ± 0.07 vs. 0.52 ± 0.14 ml/min) compared with nondiabetic mice. In response to chronic ANG II infusion, the MAP measured with telemetry increased by 55.8 ± 6.5 mmHg in diabetic mice, but only by 32.3 ± 3.8 mmHg in nondiabetic mice. The mRNA level of AT1 receptor increased by ~10-fold in isolated Af-Art of diabetic mice compared with nondiabetic mice, whereas ANG II type 2 (AT2) receptor expression did not change. The ANG II dose-response curve of the Af-Art was significantly enhanced in diabetic mice. Moreover, the AT1 receptor antagonist, losartan, blocked the ANG II-induced vasoconstriction in both diabetic mice and nondiabetic mice. In conclusion, we found enhanced expression of the AT1 receptor and exaggerated response to ANG II of the Af-Art in diabetes, which may contribute to the increased prevalence of hypertension in diabetes.
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Affiliation(s)
- Jie Zhang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
| | - Helena Y Qu
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
| | - Jiangping Song
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
| | - Jin Wei
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
| | - Shan Jiang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
| | - Lei Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
| | - Liqing Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
| | | | - Ruisheng Liu
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, Florida; and
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83
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Li XC, Zhuo JL. Recent Updates on the Proximal Tubule Renin-Angiotensin System in Angiotensin II-Dependent Hypertension. Curr Hypertens Rep 2017; 18:63. [PMID: 27372447 DOI: 10.1007/s11906-016-0668-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It is well recognized that the renin-angiotensin system (RAS) exists not only as circulating, paracrine (cell to cell), but also intracrine (intracellular) system. In the kidney, however, it is difficult to dissect the respective contributions of circulating RAS versus intrarenal RAS to the physiological regulation of proximal tubular Na(+) reabsorption and hypertension. Here, we review recent studies to provide an update in this research field with a focus on the proximal tubular RAS in angiotensin II (ANG II)-induced hypertension. Careful analysis of available evidence supports the hypothesis that both local synthesis or formation and AT1 (AT1a) receptor- and/or megalin-mediated uptake of angiotensinogen (AGT), ANG I and ANG II contribute to high levels of ANG II in the proximal tubules of the kidney. Under physiological conditions, nearly all major components of the RAS including AGT, prorenin, renin, ANG I, and ANG II would be filtered by the glomerulus and taken up by the proximal tubules. In ANG II-dependent hypertension, the expression of AGT, prorenin, and (pro)renin receptors, and angiotensin-converting enzyme (ACE) is upregulated rather than downregulated in the kidney. Furthermore, hypertension damages the glomerular filtration barrier, which augments the filtration of circulating AGT, prorenin, renin, ANG I, and ANG II and their uptake in the proximal tubules. Together, increased local ANG II formation and augmented uptake of circulating ANG II in the proximal tubules, via activation of AT1 (AT1a) receptors and Na(+)/H(+) exchanger 3, may provide a powerful feedforward mechanism for promoting Na(+) retention and the development of ANG II-induced hypertension.
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Affiliation(s)
- Xiao C Li
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, 2500 North State Street, Jackson, MS, 39216-4505, USA
| | - Jia L Zhuo
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, 2500 North State Street, Jackson, MS, 39216-4505, USA.
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84
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Stegbauer J, Chen D, Herrera M, Sparks MA, Yang T, Königshausen E, Gurley SB, Coffman TM. Resistance to hypertension mediated by intercalated cells of the collecting duct. JCI Insight 2017; 2:e92720. [PMID: 28405625 PMCID: PMC5374064 DOI: 10.1172/jci.insight.92720] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/14/2017] [Indexed: 01/09/2023] Open
Abstract
The renal collecting duct (CD), as the terminal segment of the nephron, is responsible for the final adjustments to the amount of sodium excreted in urine. While angiotensin II modulates reabsorptive functions of the CD, the contribution of these actions to physiological homeostasis is not clear. To examine this question, we generated mice with cell-specific deletion of AT1A receptors from the CD. Elimination of AT1A receptors from both principal and intercalated cells (CDKO mice) had no effect on blood pressures at baseline or during successive feeding of low- or high-salt diets. In contrast, the severity of hypertension caused by chronic infusion of angiotensin II was paradoxically exaggerated in CDKO mice compared with controls. In wild-type mice, angiotensin II induced robust expression of cyclooxygenase-2 (COX-2) in renal medulla, primarily localized to intercalated cells. Upregulation of COX-2 was diminished in CDKO mice, resulting in reduced generation of vasodilator prostanoids. This impaired expression of COX-2 has physiological consequences, since administration of a specific COX-2 inhibitor to CDKO and control mice during angiotensin II infusion equalized their blood pressures. Stimulation of COX-2 was also triggered by exposure of isolated preparations of medullary CDs to angiotensin II. Deletion of AT1A receptors from principal cells alone did not affect angiotensin II-dependent COX2 stimulation, implicating intercalated cells as the main source of COX2 in this setting. These findings suggest a novel paracrine role for the intercalated cell to attenuate the severity of hypertension. Strategies for preserving or augmenting this pathway may have value for improving the management of hypertension.
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Affiliation(s)
- Johannes Stegbauer
- Division of Nephrology, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
| | - Daian Chen
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
| | - Marcela Herrera
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
| | - Matthew A. Sparks
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
| | - Ting Yang
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
| | - Eva Königshausen
- Division of Nephrology, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Susan B. Gurley
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
| | - Thomas M. Coffman
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore
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85
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Horita S, Nakamura M, Suzuki M, Satoh N, Suzuki A, Homma Y, Nangaku M. The role of renal proximal tubule transport in the regulation of blood pressure. Kidney Res Clin Pract 2017; 36:12-21. [PMID: 28428931 PMCID: PMC5331971 DOI: 10.23876/j.krcp.2017.36.1.12] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/18/2016] [Accepted: 12/05/2016] [Indexed: 12/15/2022] Open
Abstract
The electrogenic sodium/bicarbonate cotransporter 1 (NBCe1) on the basolateral side of the renal proximal tubule plays a pivotal role in systemic acid-base homeostasis. Mutations in the gene encoding NBCe1 cause severe proximal renal tubular acidosis accompanied by other extrarenal symptoms. The proximal tubule reabsorbs most of the sodium filtered in the glomerulus, contributing to the regulation of plasma volume and blood pressure. NBCe1 and other sodium transporters in the proximal tubule are regulated by hormones, such as angiotensin II and insulin. Angiotensin II is probably the most important stimulator of sodium reabsorption. Proximal tubule AT1A receptor is crucial for the systemic pressor effect of angiotensin II. In rodents and rabbits, the effect on proximal tubule NBCe1 is biphasic; at low concentration, angiotensin II stimulates NBCe1 via PKC/cAMP/ERK, whereas at high concentration, it inhibits NBCe1 via NO/cGMP/cGKII. In contrast, in human proximal tubule, angiotensin II has a dose-dependent monophasic stimulatory effect via NO/cGMP/ERK. Insulin stimulates the proximal tubule sodium transport, which is IRS2-dependent. We found that in insulin resistance and overt diabetic nephropathy, stimulatory effect of insulin on proximal tubule transport was preserved. Our results suggest that the preserved stimulation of the proximal tubule enhances sodium reabsorption, contributing to the pathogenesis of hypertension with metabolic syndrome. We describe recent findings regarding the role of proximal tubule transport in the regulation of blood pressure, focusing on the effects of angiotensin II and insulin.
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Affiliation(s)
- Shoko Horita
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Motonobu Nakamura
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Masashi Suzuki
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Nobuhiko Satoh
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Atsushi Suzuki
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Yukio Homma
- Department of Urology, The University of Tokyo Hospital, Tokyo, Japan
| | - Masaomi Nangaku
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
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Affiliation(s)
- Jian Yang
- Department of Nutrition, Daping Hospital, The Third Military Medical University, Chongqing, China.,Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
| | - Pedro A Jose
- Division of Renal Disease & Hypertension, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
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87
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Yang T, Xu C. Physiology and Pathophysiology of the Intrarenal Renin-Angiotensin System: An Update. J Am Soc Nephrol 2017; 28:1040-1049. [PMID: 28255001 DOI: 10.1681/asn.2016070734] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The renin-angiotensin system (RAS) has a pivotal role in the maintenance of extracellular volume homeostasis and blood pressure through complex mechanisms. Apart from the well known systemic RAS, occurrence of a local RAS has been documented in multiple tissues, including the kidney. A large body of recent evidence from pharmacologic and genetic studies, particularly those using various transgenic approaches to manipulate intrarenal levels of RAS components, has established the important role of intrarenal RAS in hypertension. Recent studies have also begun to unravel the molecular mechanisms that govern intrarenal RAS activity. This local system is under the control of complex regulatory networks consisting of positive regulators of (pro)renin receptor, Wnt/β-catenin signaling, and PGE2/PGE2 receptor EP4 subtype, and negative regulators of Klotho, vitamin D receptor, and liver X receptors. This review highlights recent advances in defining the regulation and function of intrarenal RAS as a unique entity separate from systemic angiotensin II generation.
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Affiliation(s)
- Tianxin Yang
- Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah; and .,Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Chuanming Xu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
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88
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Chu PL, Gigliotti JC, Cechova S, Bodonyi-Kovacs G, Chan F, Ralph DL, Howell N, Kalantari K, Klibanov AL, Carey RM, McDonough AA, Le TH. Renal Collectrin Protects against Salt-Sensitive Hypertension and Is Downregulated by Angiotensin II. J Am Soc Nephrol 2017; 28:1826-1837. [PMID: 28062568 DOI: 10.1681/asn.2016060675] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022] Open
Abstract
Collectrin, encoded by the Tmem27 gene, is a transmembrane glycoprotein with approximately 50% homology with angiotensin converting enzyme 2, but without a catalytic domain. Collectrin is most abundantly expressed in the kidney proximal tubule and collecting duct epithelia, where it has an important role in amino acid transport. Collectrin is also expressed in endothelial cells throughout the vasculature, where it regulates L-arginine uptake. We previously reported that global deletion of collectrin leads to endothelial dysfunction, augmented salt sensitivity, and hypertension. Here, we performed kidney crosstransplants between wild-type (WT) and collectrin knockout (Tmem27Y/- ) mice to delineate the specific contribution of renal versus extrarenal collectrin on BP regulation and salt sensitivity. On a high-salt diet, WT mice with Tmem27Y/- kidneys had the highest systolic BP and were the only group to exhibit glomerular mesangial hypercellularity. Additional studies showed that, on a high-salt diet, Tmem27Y/- mice had lower renal blood flow, higher abundance of renal sodium-hydrogen antiporter 3, and lower lithium clearance than WT mice. In WT mice, administration of angiotensin II for 2 weeks downregulated collectrin expression in a type 1 angiotensin II receptor-dependent manner. This downregulation coincided with the onset of hypertension, such that WT and Tmem27Y/- mice had similar levels of hypertension after 2 weeks of angiotensin II administration. Altogether, these data suggest that salt sensitivity is determined by intrarenal collectrin, and increasing the abundance or activity of collectrin may have therapeutic benefits in the treatment of hypertension and salt sensitivity.
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Affiliation(s)
| | - Joseph C Gigliotti
- Division of Nephrology.,Department of Integrated Physiology and Pharmacology, Liberty University College of Osteopathic Medicine, Lynchburg, Virginia; and
| | | | | | | | - Donna Lee Ralph
- Department of Cell and Neurobiology, University of Southern California, Keck School of Medicine, Los Angeles, California
| | - Nancy Howell
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | | | | | - Robert M Carey
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - Alicia A McDonough
- Department of Cell and Neurobiology, University of Southern California, Keck School of Medicine, Los Angeles, California
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89
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Hisamichi M, Kamijo-Ikemori A, Sugaya T, Ichikawa D, Natsuki T, Hoshino S, Kimura K, Shibagaki Y. Role of angiotensin II type 1a receptor in renal injury induced by deoxycorticosterone acetate-salt hypertension. FASEB J 2016; 31:72-84. [PMID: 27663860 PMCID: PMC5161521 DOI: 10.1096/fj.201600684rr] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/07/2016] [Indexed: 12/19/2022]
Abstract
The aim of this study was to investigate the in vivo role of angiotensin II type 1a (AT1a) receptor in renal damage as a result of hypertension by using transgenic mice with AT1a receptor gene disruption. Transgenic mice that express human liver-type fatty acid binding protein (L-FABP) with or without disruption of the AT1a receptor gene (L-FABP+/− AT1a−/−, and L-FABP+/− AT1a+/+, respectively) were used with urinary L-FABP as an indicator of tubulointerstitial damage. Those female mice were administered subcutaneously deoxycorticosterone acetate (DOCA)–salt tablets plus drinking water that contained 1% saline for 28 d after uninephrectomy. In L-FABP+/− AT1a+/+ mice that received DOCA-salt treatment, hypertension was induced and slight expansion of glomerular area, glomerular sclerosis, and tubulointerstitial damage were observed. In L-FABP+/− AT1a−/− mice that received DOCA-salt treatment, hypertension was similarly induced and the degree of glomerular damage was significantly more severe than in L-FABP+/− AT1a+/+-DOCA mice. Urinary L-FABP levels were significantly higher in L-FABP+/− AT1a−/−-DOCA mice compared with those in L-FABP+/− AT1a+/+-DOCA mice. Hydralazine treatment significantly attenuated renal damage that was found in L-FABP+/− AT1a−/−-DOCA mice along with a reduction in blood pressure. In summary, activation of the AT1a receptor may contribute to maintenance of the glomerular structure against hypertensive renal damage.—Hisamichi, M., Kamijo-Ikemori, A., Sugaya, T., Ichikawa, D., Natsuki, T., Hoshino, S., Kimura, K., Shibagaki, Y. Role of angiotensin II type 1a receptor in renal injury induced by deoxycorticosterone acetate–salt hypertension.
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Affiliation(s)
- Mikako Hisamichi
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Atsuko Kamijo-Ikemori
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan; .,Department of Anatomy, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Takeshi Sugaya
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Daisuke Ichikawa
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Takayuki Natsuki
- Institute for Ultrastructural Morphology, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Seiko Hoshino
- Department of Anatomy, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Kenjiro Kimura
- Department of Internal Medicine, Japan Community Health Care Organization, Tokyo Takanawa Hospital, Tokyo, Japan
| | - Yugo Shibagaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan
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90
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Ramkumar N, Stuart D, Calquin M, Wang S, Niimura F, Matsusaka T, Kohan DE. Possible role for nephron-derived angiotensinogen in angiotensin-II dependent hypertension. Physiol Rep 2016; 4:4/1/e12675. [PMID: 26755736 PMCID: PMC4760401 DOI: 10.14814/phy2.12675] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The role of intranephron angiotensinogen (AGT) in blood pressure (BP) regulation is not fully understood. Previous studies showed that proximal tubule‐specific overexpression of AGT increases BP, whereas proximal tubule‐specific deletion of AGT did not alter BP. The latter study may not have completely eliminated nephron AGT production; in addition, BP was only assessed on a normal salt diet. To evaluate this issue in greater detail, we developed mice with inducible nephron‐wide AGT deletion. Mice were generated which were hemizygous for the Pax8‐rtTA and LC‐1 transgenes and homozygous for loxP‐flanked AGT alleles to achieve nephron‐wide AGT disruption after doxycycline induction. Compared to controls, AGT knockout (KO) mice demonstrated markedly reduced renal AGT immunostaining, mRNA, and protein levels; unexpectedly AGT KO mice had reduced AGT mRNA levels in the liver along with 50% reduction in plasma AGT levels. BP was significantly lower in the AGT KO mice compared to controls fed a normal, low, or high Na+ intake, with the highest BP reduction on a low Na+ diet. Regardless of Na+ intake, AGT KO mice had higher plasma renin concentration (PRC) and markedly reduced urinary AGT levels compared to controls. Following angiotensin‐II (Ang‐II) infusion, AGT KO mice demonstrated an attenuated hypertensive response despite similar suppression of PRC in the two groups. Taken together, these data suggest that nephron‐derived AGT may be involved in Ang‐II‐dependent hypertension, however, a clear role for nephron‐derived AGT in physiological BP regulation remains to be determined.
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Affiliation(s)
- Nirupama Ramkumar
- Division of Nephrology and Hypertension, University of Utah Health Sciences Center, Salt Lake City, Utah
| | - Deborah Stuart
- Division of Nephrology and Hypertension, University of Utah Health Sciences Center, Salt Lake City, Utah
| | - Matias Calquin
- Division of Nephrology and Hypertension, University of Utah Health Sciences Center, Salt Lake City, Utah
| | - Shuping Wang
- Division of Nephrology and Hypertension, University of Utah Health Sciences Center, Salt Lake City, Utah
| | - Fumio Niimura
- Institute of Medical Science, Tokai University, Isehara, Japan
| | - Taiji Matsusaka
- Institute of Medical Science, Tokai University, Isehara, Japan
| | - Donald E Kohan
- Division of Nephrology and Hypertension, University of Utah Health Sciences Center, Salt Lake City, Utah Veterans Affairs Medical Center, Salt Lake City, Utah
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91
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Deficiency of T-regulatory cells exaggerates angiotensin II-induced microvascular injury by enhancing immune responses. J Hypertens 2016; 34:97-108. [PMID: 26630215 DOI: 10.1097/hjh.0000000000000761] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS T-regulatory lymphocyte (Treg) adoptive transfer prevented angiotensin (Ang) II-induced hypertension and microvascular injury. Scurfy mice are deficient in Treg because of a mutation in the transcription factor forkhead box P3 (Foxp3) gene. Enhanced Ang II effects in the absence of Treg would unambiguously demonstrate their vascular protective role. We hypothesized that adoptive transfer of Scurfy vs. wild-type T cells will exacerbate Ang II-induced microvascular damage in T and B-cell-deficient recombination-activating gene 1 (Rag1) knockout mice. METHODS AND RESULTS Rag1 knockout mice were injected with vehicle, 10(7) T cells from wild-type or Scurfy mice or 10 (6)wild-type Treg alone or in combination with Scurfy T cells, and then infused or not with Ang II (490 ng/kg per min, subcutaneous) for 14 days. Ang II increased SBP in all the groups, but DBP only in wild-type and Scurfy T-cell groups. Ang II-induced endothelial dysfunction and oxidative stress in perivascular adipose tissue (PVAT) of mesenteric arteries of the wild-type T-cell group, whereas these were exaggerated in the Scurfy T-cell group. Ang II enhanced microvascular remodeling and stiffness in vehicle and Scurfy T-cell groups. Ang II increased monocyte chemotactic protein-1 expression in the vascular wall and PVAT, monocyte/macrophage infiltration and proinflammatory polarization in PVAT and the renal cortex, and T-cell infiltration in the renal cortex only in the Scurfy T-cell group. Treg coinjection in the vehicle and Scurfy T-cell groups prevented or reduced the effects of Ang II. CONCLUSION FOXP3+ Treg deficiency exaggerates Ang II-induced microvascular injury by modulating innate and adaptive immune responses.
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92
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Pena MJ, Heinzel A, Rossing P, Parving HH, Dallmann G, Rossing K, Andersen S, Mayer B, Heerspink HJL. Serum metabolites predict response to angiotensin II receptor blockers in patients with diabetes mellitus. J Transl Med 2016; 14:203. [PMID: 27378474 PMCID: PMC4932762 DOI: 10.1186/s12967-016-0960-3] [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: 01/12/2016] [Accepted: 06/23/2016] [Indexed: 12/15/2022] Open
Abstract
Background Individual patients show a large variability in albuminuria response to angiotensin receptor blockers (ARB). Identifying novel biomarkers that predict ARB response may help tailor therapy. We aimed to discover and validate a serum metabolite classifier that predicts albuminuria response to ARBs in patients with diabetes mellitus and micro- or macroalbuminuria. Methods Liquid chromatography-tandem mass spectrometry metabolomics was performed on serum samples. Data from patients with type 2 diabetes and microalbuminuria (n = 49) treated with irbesartan 300 mg/day were used for discovery. LASSO and ridge regression were performed to develop the classifier. Improvement in albuminuria response prediction was assessed by calculating differences in R2 between a reference model of clinical parameters and a model with clinical parameters and the classifier. The classifier was externally validated in patients with type 1 diabetes and macroalbuminuria (n = 50) treated with losartan 100 mg/day. Molecular process analysis was performed to link metabolites to molecular mechanisms contributing to ARB response. Results In discovery, median change in urinary albumin excretion (UAE) was −42 % [Q1–Q3: −69 to −8]. The classifier, consisting of 21 metabolites, was significantly associated with UAE response to irbesartan (p < 0.001) and improved prediction of UAE response on top of the clinical reference model (R2 increase from 0.10 to 0.70; p < 0.001). In external validation, median change in UAE was −43 % [Q1–Q35: −63 to −23]. The classifier improved prediction of UAE response to losartan (R2 increase from 0.20 to 0.59; p < 0.001). Specifically ADMA impacting eNOS activity appears to be a relevant factor in ARB response. Conclusions A serum metabolite classifier was discovered and externally validated to significantly improve prediction of albuminuria response to ARBs in diabetes mellitus. Electronic supplementary material The online version of this article (doi:10.1186/s12967-016-0960-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michelle J Pena
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, P. O. Box 30.001, 9700RB, Groningen, The Netherlands
| | | | - Peter Rossing
- Steno Diabetes Center, Gentofte, Denmark.,Faculty of Health Science, University of Aarhus, Aarhus, Denmark.,University of Copenhagen, Copenhagen, Denmark
| | - Hans-Henrik Parving
- Department of Medical Endocrinology, Rigshospitalet University Hospital of Copenhagen, Copenhagen, Denmark
| | | | | | | | - Bernd Mayer
- emergentec biodevelopment GmbH, Vienna, Austria
| | - Hiddo J L Heerspink
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, P. O. Box 30.001, 9700RB, Groningen, The Netherlands.
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93
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Porpino SKP, Zollbrecht C, Peleli M, Montenegro MF, Brandão MCR, Athayde-Filho PF, França-Silva MS, Larsson E, Lundberg JO, Weitzberg E, Persson EG, Braga VA, Carlström M. Nitric oxide generation by the organic nitrate NDBP attenuates oxidative stress and angiotensin II-mediated hypertension. Br J Pharmacol 2016; 173:2290-302. [PMID: 27160064 DOI: 10.1111/bph.13511] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/11/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE NO deficiency and oxidative stress are crucially involved in the development or progression of cardiovascular disease, including hypertension and stroke. We have previously demonstrated that acute treatment with the newly discovered organic nitrate, 2-nitrate-1,3-dibuthoxypropan (NDBP), is associated with NO-like effects in the vasculature. This study aimed to further characterize the mechanism(s) and to elucidate the therapeutic potential in a model of hypertension and oxidative stress. EXPERIMENTAL APPROACH A combination of ex vivo, in vitro and in vivo approaches was used to assess the effects of NDBP on vascular reactivity, NO release, NADPH oxidase activity and in a model of hypertension. KEY RESULTS Ex vivo vascular studies demonstrated NDBP-mediated vasorelaxation in mesenteric resistance arteries, which was devoid of tolerance. In vitro studies using liver and kidney homogenates revealed dose-dependent and sustained NO generation by NDBP, which was attenuated by the xanthine oxidase inhibitor febuxostat. In addition, NDBP reduced NADPH oxidase activity in the liver and prevented angiotensin II-induced activation of NADPH oxidase in the kidney. In vivo studies showed that NDBP halted the progression of hypertension in mice with chronic angiotensin II infusion. This was associated with attenuated cardiac hypertrophy, and reduced NADPH oxidase-derived oxidative stress and fibrosis in the kidney and heart. CONCLUSION AND IMPLICATIONS The novel organic nitrate NDBP halts the progression of angiotensin II-mediated hypertension. Mechanistically, our findings suggest that NDBP treatment is associated with sustained NO release and attenuated activity of NADPH oxidase, which to some extent requires functional xanthine oxidase.
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Affiliation(s)
- Suênia K P Porpino
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Dept. of Medical Cell Biology, Uppsala University, Uppsala, Sweden.,Biotechnology Center, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Christa Zollbrecht
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Peleli
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Maria C R Brandão
- Biotechnology Center, Federal University of Paraíba, João Pessoa, PB, Brazil
| | | | | | - Erik Larsson
- Dept. of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Jon O Lundberg
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Eddie Weitzberg
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Erik G Persson
- Dept. of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Valdir A Braga
- Biotechnology Center, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Mattias Carlström
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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94
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Affiliation(s)
- Pedro A Jose
- From the Departments of Medicine and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC (P.A.J.); Department of Pathology, The University of Virginia, Charlottesville (R.A.F.); Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medicine Centre, Peking Union Medical College, Beijing, P.R. China (Z.Y.); Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing Institute of Cardiology, Chongqing, P.R. China (C.Z.); and Department of Medicine, Georgetown University Medical Center, Washington, DC (G.M.E.).
| | - Robin A Felder
- From the Departments of Medicine and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC (P.A.J.); Department of Pathology, The University of Virginia, Charlottesville (R.A.F.); Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medicine Centre, Peking Union Medical College, Beijing, P.R. China (Z.Y.); Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing Institute of Cardiology, Chongqing, P.R. China (C.Z.); and Department of Medicine, Georgetown University Medical Center, Washington, DC (G.M.E.)
| | - Zhiwei Yang
- From the Departments of Medicine and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC (P.A.J.); Department of Pathology, The University of Virginia, Charlottesville (R.A.F.); Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medicine Centre, Peking Union Medical College, Beijing, P.R. China (Z.Y.); Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing Institute of Cardiology, Chongqing, P.R. China (C.Z.); and Department of Medicine, Georgetown University Medical Center, Washington, DC (G.M.E.)
| | - Chunyu Zeng
- From the Departments of Medicine and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC (P.A.J.); Department of Pathology, The University of Virginia, Charlottesville (R.A.F.); Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medicine Centre, Peking Union Medical College, Beijing, P.R. China (Z.Y.); Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing Institute of Cardiology, Chongqing, P.R. China (C.Z.); and Department of Medicine, Georgetown University Medical Center, Washington, DC (G.M.E.)
| | - Gilbert M Eisner
- From the Departments of Medicine and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC (P.A.J.); Department of Pathology, The University of Virginia, Charlottesville (R.A.F.); Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medicine Centre, Peking Union Medical College, Beijing, P.R. China (Z.Y.); Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing Institute of Cardiology, Chongqing, P.R. China (C.Z.); and Department of Medicine, Georgetown University Medical Center, Washington, DC (G.M.E.)
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95
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Abstract
PURPOSE OF REVIEW Hypertension, which is present in about one quarter of the world's population, is responsible for about 41% of the number one cause of death - cardiovascular disease. Not included in these statistics is the effect of sodium intake on blood pressure, even though an increase or a marked decrease in sodium intake can increase blood pressure. This review deals with the interaction of gut microbiota and the kidney with genetics and epigenetics in the regulation of blood pressure and salt sensitivity. RECENT FINDINGS The abundance of the gut microbes, Firmicutes and Bacteroidetes, is associated with increased blood pressure in several models of hypertension, including the spontaneously hypertensive and Dahl salt-sensitive rats. Decreasing gut microbiota by antibiotics can increase or decrease blood pressure that is influenced by genotype. The biological function of probiotics may also be a consequence of epigenetic modification, related, in part, to microRNA. Products of the fermentation of nutrients by gut microbiota can influence blood pressure by regulating expenditure of energy, intestinal metabolism of catecholamines, and gastrointestinal and renal ion transport, and thus, salt sensitivity. SUMMARY The beneficial or deleterious effect of gut microbiota on blood pressure is a consequence of several variables, including genetics, epigenetics, lifestyle, and intake of antibiotics. These variables may influence the ultimate level of blood pressure and control of hypertension.
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96
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Chen D, Stegbauer J, Sparks MA, Kohan D, Griffiths R, Herrera M, Gurley SB, Coffman TM. Impact of Angiotensin Type 1A Receptors in Principal Cells of the Collecting Duct on Blood Pressure and Hypertension. Hypertension 2016; 67:1291-7. [PMID: 27141055 DOI: 10.1161/hypertensionaha.115.06987] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/16/2016] [Indexed: 01/09/2023]
Abstract
The main actions of the renin-angiotensin system to control blood pressure (BP) are mediated by the angiotensin type 1 receptors (AT1Rs). The major murine AT1R isoform, AT1AR, is expressed throughout the nephron, including the collecting duct in both principal and intercalated cells. Principal cells play the major role in sodium and water reabsorption. Although aldosterone is considered to be the dominant regulator of sodium reabsorption by principal cells, recent studies suggest a role for direct actions of AT1R. To specifically examine the contributions of AT1AR in principal cells to BP regulation and the development of hypertension in vivo, we generated inbred 129/SvEv mice with deletion of AT1AR from principal cells (PCKO). At baseline, we found that BPs measured by radiotelemetry were similar between PCKOs and controls. During 1-week of low-salt diet (<0.02% NaCl), BPs fell significantly (P<0.05) and to a similar extent in both groups. On a high-salt (6% NaCl) diet, BP increased but was not different between groups. During the initial phase of angiotensin II-dependent hypertension, there was a modest but significant attenuation of hypertension in PCKOs (163±6 mm Hg) compared with controls (178±2 mm Hg; P<0.05) that was associated with enhanced natriuresis and decreased alpha epithelial sodium channel activation in the medulla of PCKOs. However, from day 9 onward, BPs were indistinguishable between groups. Although effects of AT1AR on baseline BP and adaptation to changes in dietary salt are negligible, our studies suggest that direct actions of AT1AR contribute to the initiation of hypertension and epithelial sodium channel activation.
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Affiliation(s)
- Daian Chen
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.)
| | - Johannes Stegbauer
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.)
| | - Matthew A Sparks
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.)
| | - Donald Kohan
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.)
| | - Robert Griffiths
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.)
| | - Marcela Herrera
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.)
| | - Susan B Gurley
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.)
| | - Thomas M Coffman
- From the Division of Nephrology, Department of Medicine, Duke University, and Durham VA Medical Centers, NC (D.C., M.A.S., R.G., M.H., S.B.G., T.M.C.); Department of Nephrology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany (J.S.); School of Medicine, University of Utah Health Sciences Center, Salt Lake City (D.K.); and Cardiovascular and Metabolic Disorders Research Program, Duke-NUS Graduate Medical School, Singapore, Singapore (T.M.C.).
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97
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Farquhar WB, Edwards DG, Jurkovitz CT, Weintraub WS. Dietary sodium and health: more than just blood pressure. J Am Coll Cardiol 2016; 65:1042-50. [PMID: 25766952 DOI: 10.1016/j.jacc.2014.12.039] [Citation(s) in RCA: 188] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 12/09/2014] [Accepted: 12/16/2014] [Indexed: 12/24/2022]
Abstract
Sodium is essential for cellular homeostasis and physiological function. Excess dietary sodium has been linked to elevations in blood pressure (BP). Salt sensitivity of BP varies widely, but certain subgroups tend to be more salt sensitive. The mechanisms underlying sodium-induced increases in BP are not completely understood but may involve alterations in renal function, fluid volume, fluid-regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. Recent pre-clinical and clinical data support that even in the absence of an increase in BP, excess dietary sodium can adversely affect target organs, including the blood vessels, heart, kidneys, and brain. In this review, the investigators review these issues and the epidemiological research relating dietary sodium to BP and cardiovascular health outcomes, addressing recent controversies. They also provide information and strategies for reducing dietary sodium.
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Affiliation(s)
- William B Farquhar
- Department of Kinesiology & Applied Physiology, College of Health Sciences, University of Delaware, Newark, Delaware
| | - David G Edwards
- Department of Kinesiology & Applied Physiology, College of Health Sciences, University of Delaware, Newark, Delaware
| | - Claudine T Jurkovitz
- Department of Medicine, Section of Cardiology, Christiana Care Outcomes Research Center, Christiana Care Health System, Newark, Delaware
| | - William S Weintraub
- Department of Medicine, Section of Cardiology, Christiana Care Outcomes Research Center, Christiana Care Health System, Newark, Delaware.
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98
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Jose PA, Yang Z, Zeng C, Felder RA. The importance of the gastrorenal axis in the control of body sodium homeostasis. Exp Physiol 2016; 101:465-70. [PMID: 26854262 DOI: 10.1113/ep085286] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 02/01/2016] [Indexed: 12/27/2022]
Abstract
NEW FINDINGS What is the topic of this review? Sensing the amount of ingested sodium is one mechanism by which sodium balance is regulated. This review describes the role of gastrin in the cross-talk between the stomach and the kidney following the ingestion of sodium. What advances does it highlight? Neural mechanisms and several gut hormones, including cholecystokinin and uroguanylin, have been suggested to mediate the natriuresis after an oral sodium load. It is proposed that gastrin produced by G-cells via its receptor, cholecystokinin B receptor, interacts with renal D1 -like dopamine receptors to increase renal sodium excretion. Hypertension develops with chronically increased sodium intake when sodium that accumulates in the body can no longer be sequestered, extracellular fluid volume is expanded, and compensatory neural, hormonal and pressure-natriuresis mechanisms fail. Sensing the amount of ingested sodium, by the stomach, is one mechanism by which sodium balance is regulated. The natriuresis following the ingestion of a certain amount of sodium may be due to an enterokine, gastrin, secreted by G-cells in the stomach and duodenum and released into the circulation. Circulating gastrin levels are 10- to 20-fold higher than those for cholecystokinin. Of all the gut hormones circulating in the plasma, gastrin is the one that is reabsorbed to the greatest extent by renal tubules. Gastrin, via its receptor, the cholecystokinin type B receptor (CCKBR), is natriuretic in mammals, including humans, by inhibition of renal sodium transport. Germline deletion of gastrin (Gast) or Cckbr gene in mice causes salt-sensitive hypertension. Selective silencing of Gast in the stomach and duodenum impairs the ability to excrete an oral sodium load and also increases blood pressure. Thus, the gastrorenal axis, mediated by gastrin, can complement pronatriuretic hormones, such as dopamine, to increase sodium excretion after an oral sodium load. These studies in mice may be translatable to humans because the chromosomal loci of CCKBR and GAST are linked to human essential hypertension. Understanding the role of genes in the regulation of renal function and blood pressure may lead to the tailoring of antihypertensive treatment based on genetic make-up.
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Affiliation(s)
- Pedro A Jose
- Department of Medicine, The George Washington University School of Medicine, Washington, DC, USA.,Department of Physiology, The George Washington University School of Medicine, Washington, DC, USA
| | - Zhiwei Yang
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences & Comparative Medicine Centre, Peking Union Medical College, Beijing, PR China
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing Institute of Cardiology, Chongqing 400042, PR China
| | - Robin A Felder
- Department of Pathology, The University of Virginia, Charlottesville, VA, USA
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Jose PA, Welch W. Do You Want to Ditch Sodium? Meet Nitric Oxide Synthase 1β at the Macula Densa. J Am Soc Nephrol 2016; 27:2217-8. [PMID: 26903534 DOI: 10.1681/asn.2015121378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Pedro A Jose
- Department of Medicine, Division of Kidney Diseases and Hypertension and Department of Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC; and
| | - William Welch
- Department of Medicine, Division of Nephrology and Hypertension, Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, DC
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Zhang J, Rudemiller NP, Patel MB, Wei Q, Karlovich NS, Jeffs AD, Wu M, Sparks MA, Privratsky JR, Herrera M, Gurley SB, Nedospasov SA, Crowley SD. Competing Actions of Type 1 Angiotensin II Receptors Expressed on T Lymphocytes and Kidney Epithelium during Cisplatin-Induced AKI. J Am Soc Nephrol 2016; 27:2257-64. [PMID: 26744488 DOI: 10.1681/asn.2015060683] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 11/25/2015] [Indexed: 12/18/2022] Open
Abstract
Inappropriate activation of the renin-angiotensin system (RAS) contributes to many CKDs. However, the role of the RAS in modulating AKI requires elucidation, particularly because stimulating type 1 angiotensin II (AT1) receptors in the kidney or circulating inflammatory cells can have opposing effects on the generation of inflammatory mediators that underpin the pathogenesis of AKI. For example, TNF-α is a fundamental driver of cisplatin nephrotoxicity, and generation of TNF-α is suppressed or enhanced by AT1 receptor signaling in T lymphocytes or the distal nephron, respectively. In this study, cell tracking experiments with CD4-Cre mT/mG reporter mice revealed robust infiltration of T lymphocytes into the kidney after cisplatin injection. Notably, knockout of AT1 receptors on T lymphocytes exacerbated the severity of cisplatin-induced AKI and enhanced the cisplatin-induced increase in TNF-α levels locally within the kidney and in the systemic circulation. In contrast, knockout of AT1 receptors on kidney epithelial cells ameliorated the severity of AKI and suppressed local and systemic TNF-α production induced by cisplatin. Finally, disrupting TNF-α production specifically within the renal tubular epithelium attenuated the AKI and the increase in circulating TNF-α levels induced by cisplatin. These results illustrate discrepant tissue-specific effects of RAS stimulation on cisplatin nephrotoxicity and raise the concern that inflammatory mediators produced by renal parenchymal cells may influence the function of remote organs by altering systemic cytokine levels. Our findings suggest selective inhibition of AT1 receptors within the nephron as a promising intervention for protecting patients from cisplatin-induced nephrotoxicity.
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Affiliation(s)
| | | | | | - QingQing Wei
- Department of Cellular Biology and Anatomy, Georgia Regents University, Augusta, Georgia; and
| | | | | | - Min Wu
- Division of Nephrology, Department of Medicine and
| | | | - Jamie R Privratsky
- Department of Anesthesiology, Duke University and Durham Veterans Affairs Medical Centers, Durham, North Carolina
| | | | | | - Sergei A Nedospasov
- Laboratory of Molecular Immunology, Engelhardt Institute of Molecular Biology and Lomonosov Moscow State University, Moscow, Russia
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