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Abstract
Salt (sodium chloride) is an essential nutrient required to maintain physiological functions. However, for most people, daily salt intake far exceeds their physiological need and is habitually greater than recommended upper thresholds. Excess salt intake leads to elevation in blood pressure which drives cardiovascular morbidity and mortality. Indeed, excessive salt intake is estimated to be responsible for ≈5 million deaths per year globally. For approximately one-third of otherwise healthy individuals (and >50% of those with hypertension), the effect of salt intake on blood pressure elevation is exaggerated; such people are categorized as salt sensitive and salt sensitivity of blood pressure is considered an independent risk factor for cardiovascular disease and death. The prevalence of salt sensitivity is higher in women than in men and, in both, increases with age. This narrative review considers the foundational concepts of salt sensitivity and the underlying effector systems that cause salt sensitivity. We also consider recent updates in preclinical and clinical research that are revealing new modifying factors that determine the blood pressure response to high salt intake.
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Affiliation(s)
- Matthew A Bailey
- Edinburgh Kidney, University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, United Kingdom (M.A.B., N.D.)
| | - Neeraj Dhaun
- Edinburgh Kidney, University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, United Kingdom (M.A.B., N.D.)
- Department of Renal Medicine, Royal Infirmary of Edinburgh, United Kingdom (N.D.)
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2
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Johnston JG, Welch AK, Cain BD, Sayeski PP, Gumz ML, Wingo CS. Aldosterone: Renal Action and Physiological Effects. Compr Physiol 2023; 13:4409-4491. [PMID: 36994769 DOI: 10.1002/cphy.c190043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Aldosterone exerts profound effects on renal and cardiovascular physiology. In the kidney, aldosterone acts to preserve electrolyte and acid-base balance in response to changes in dietary sodium (Na+ ) or potassium (K+ ) intake. These physiological actions, principally through activation of mineralocorticoid receptors (MRs), have important effects particularly in patients with renal and cardiovascular disease as demonstrated by multiple clinical trials. Multiple factors, be they genetic, humoral, dietary, or otherwise, can play a role in influencing the rate of aldosterone synthesis and secretion from the adrenal cortex. Normally, aldosterone secretion and action respond to dietary Na+ intake. In the kidney, the distal nephron and collecting duct are the main targets of aldosterone and MR action, which stimulates Na+ absorption in part via the epithelial Na+ channel (ENaC), the principal channel responsible for the fine-tuning of Na+ balance. Our understanding of the regulatory factors that allow aldosterone, via multiple signaling pathways, to function properly clearly implicates this hormone as central to many pathophysiological effects that become dysfunctional in disease states. Numerous pathologies that affect blood pressure (BP), electrolyte balance, and overall cardiovascular health are due to abnormal secretion of aldosterone, mutations in MR, ENaC, or effectors and modulators of their action. Study of the mechanisms of these pathologies has allowed researchers and clinicians to create novel dietary and pharmacological targets to improve human health. This article covers the regulation of aldosterone synthesis and secretion, receptors, effector molecules, and signaling pathways that modulate its action in the kidney. We also consider the role of aldosterone in disease and the benefit of mineralocorticoid antagonists. © 2023 American Physiological Society. Compr Physiol 13:4409-4491, 2023.
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Affiliation(s)
- Jermaine G Johnston
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
| | - Amanda K Welch
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
| | - Brian D Cain
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
| | - Peter P Sayeski
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - Michelle L Gumz
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
| | - Charles S Wingo
- Division of Nephrology, Hypertension and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida, USA
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
- Nephrology Section, Veteran Administration Medical Center, North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida, USA
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Ralph AF, Grenier C, Costello HM, Stewart K, Ivy JR, Dhaun N, Bailey MA. Activation of the Sympathetic Nervous System Promotes Blood Pressure Salt-Sensitivity in C57BL6/J Mice. Hypertension 2020; 77:158-168. [PMID: 33190558 PMCID: PMC7720873 DOI: 10.1161/hypertensionaha.120.16186] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Global salt intake averages >8 g/person per day, over twice the limit advocated by the American Heart Association. Dietary salt excess leads to hypertension, and this partly mediates its poor health outcomes. In ≈30% of people, the hypertensive response to salt is exaggerated. This salt-sensitivity increases cardiovascular risk. Mechanistic cardiovascular research relies heavily on rodent models and the C57BL6/J mouse is the most widely used reference strain. We examined the effects of high salt intake on blood pressure, renal, and vascular function in the most commonly used and commercially available C57BL6/J mouse strain. Changing from control (0.3% Na+) to high salt (3% Na+) diet increased systolic blood pressure in male mice by ≈10 mm Hg within 4 days of dietary switch. This hypertensive response was maintained over the 3-week study period. Returning to control diet gradually reduced blood pressure back to baseline. High-salt diet caused a rapid and sustained downregulation in mRNA encoding renal NHE3 (sodium-hydrogen-exchanger 3) and EnaC (epithelial sodium channel), although we did not observe a suppression in aldosterone until ≈7 days. During the development of salt-sensitivity, the acute pressure natriuresis relationship was augmented and neutral sodium balance was maintained throughout. High-salt diet increased ex vivo sensitivity of the renal artery to phenylephrine and increased urinary excretion of adrenaline, but not noradrenaline. The acute blood pressure-depressor effect of hexamethonium, a ganglionic blocker, was enhanced by high salt. Salt-sensitivity in commercially sourced C57BL6/J mice is attributable to sympathetic overactivity, increased adrenaline, and enhanced vascular sensitivity to alpha-adrenoreceptor activation and not sodium retention or attenuation of the acute pressure natriuresis response.
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Affiliation(s)
- Ailsa F Ralph
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Celine Grenier
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Hannah M Costello
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Kevin Stewart
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Jessica R Ivy
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Neeraj Dhaun
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
| | - Matthew A Bailey
- From the University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, United Kingdom
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Carvajal CA, Tapia-Castillo A, Vecchiola A, Baudrand R, Fardella CE. Classic and Nonclassic Apparent Mineralocorticoid Excess Syndrome. J Clin Endocrinol Metab 2020; 105:5691192. [PMID: 31909799 DOI: 10.1210/clinem/dgz315] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/28/2019] [Indexed: 02/13/2023]
Abstract
CONTEXT Arterial hypertension (AHT) is one of the most frequent pathologies in the general population. Subtypes of essential hypertension characterized by low renin levels allowed the identification of 2 different clinical entities: aldosterone-mediated mineralocorticoid receptor (MR) activation and cortisol-mediated MR activation. EVIDENCE ACQUISITION This review is based upon a search of Pubmed and Google Scholar databases, up to August 2019, for all publications relating to endocrine hypertension, apparent mineralocorticoid excess (AME) and cortisol (F) to cortisone (E) metabolism. EVIDENCE SYNTHESIS The spectrum of cortisol-mediated MR activation includes the classic AME syndrome to milder (nonclassic) forms of AME, the latter with a much higher prevalence (7.1%) than classic AME but different phenotype and genotype. Nonclassic AME (NC-AME) is mainly related to partial 11βHSD2 deficiency associated with genetic variations and epigenetic modifications (first hit) and potential additive actions of endogenous or exogenous inhibitors (ie, glycyrrhetinic acid-like factors [GALFS]) and other factors (ie, age, high sodium intake) (second hit). Subjects with NC-AME are characterized by a high F/E ratio, low E levels, normal to elevated blood pressure, low plasma renin and increased urinary potassium excretion. NC-AME condition should benefit from low-sodium and potassium diet recommendations and monotherapy with MR antagonists. CONCLUSION NC-AME has a higher prevalence and a milder phenotypical spectrum than AME. NC-AME etiology is associated to a first hit (gene and epigene level) and an additive second hit. NC-AME subjects are candidates to be treated with MR antagonists aimed to improve blood pressure, end-organ damage, and modulate the renin levels.
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Affiliation(s)
- Cristian A Carvajal
- Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy (IMII-ICM), Santiago, Chile
- Centro Traslacional de Endocrinología UC (CETREN), Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Alejandra Tapia-Castillo
- Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy (IMII-ICM), Santiago, Chile
- Centro Traslacional de Endocrinología UC (CETREN), Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Andrea Vecchiola
- Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy (IMII-ICM), Santiago, Chile
- Centro Traslacional de Endocrinología UC (CETREN), Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Rene Baudrand
- Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro Traslacional de Endocrinología UC (CETREN), Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Carlos E Fardella
- Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy (IMII-ICM), Santiago, Chile
- Centro Traslacional de Endocrinología UC (CETREN), Pontificia Universidad Catolica de Chile, Santiago, Chile
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Mansley MK, Bailey MA. Corticosteroid Regulation of ENaC‐Mediated Na
+
Transport in a Cellular Model of the Cortical Collecting Duct. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.751.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Morag K Mansley
- Centre For Cardiovascular ScienceThe University of EdinburghEdinburghUnited Kingdom
| | - Matthew A Bailey
- Centre For Cardiovascular ScienceThe University of EdinburghEdinburghUnited Kingdom
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White PC. Alterations of Cortisol Metabolism in Human Disorders. Horm Res Paediatr 2018; 89:320-330. [PMID: 29843121 DOI: 10.1159/000485508] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 11/21/2017] [Indexed: 11/19/2022] Open
Abstract
The interconversion of active and inactive corticosteroids - cortisol and cortisone, respectively, in humans - is modulated by isozymes of 11β-hydroxysteroid dehydrogenase (11-HSD). Studies of this process have provided crucial insights into glucocorticoid effects in a wide variety of tissues. The 11-HSD1 isozyme functions mainly as an oxoreductase (cortisone to cortisol) and is expressed at high levels in the liver and other glucocorticoid target tissues. Because it is required for full physiological effects of cortisol, it has emerged as a drug target for metabolic syndrome and type 2 diabetes. Mutations in the corresponding HSD11B1 gene, or in the H6PD gene encoding hexose-6-phosphate dehydrogenase (which supplies the NADPH required for the oxoreductase activity of 11-HSD1), cause apparent cortisone reductase deficiency, a rare syndrome of adrenocortical hyperactivity and hyperandrogenism. In contrast, the 11-HSD2 isozyme functions as a dehydrogenase (cortisol to cortisone) and is expressed mainly in mineralocorticoid target tissues, where it bars access of cortisol to the mineralocorticoid receptor. Mutations in the HSD11B2 gene encoding 11-HSD2 cause the syndrome of apparent mineralocorticoid excess, a severe form of familial hypertension. The role of this enzyme in the pathogenesis of common forms of low-renin hypertension remains uncertain.
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Craigie E, Menzies RI, Larsen CK, Jacquillet G, Carrel M, Wildman SS, Loffing J, Leipziger J, Shirley DG, Bailey MA, Unwin RJ. The renal and blood pressure response to low sodium diet in P2X4 receptor knockout mice. Physiol Rep 2018; 6:e13899. [PMID: 30350402 PMCID: PMC6198136 DOI: 10.14814/phy2.13899] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 09/25/2018] [Accepted: 09/27/2018] [Indexed: 01/02/2023] Open
Abstract
In the kidney, purinergic (P2) receptor-mediated ATP signaling has been shown to be an important local regulator of epithelial sodium transport. Appropriate sodium regulation is crucial for blood pressure (BP) control and disturbances in sodium balance can lead to hypo- or hypertension. Links have already been established between P2 receptor signaling and the development of hypertension, attributed mainly to vascular and/or inflammatory effects. A transgenic mouse model with deletion of the P2X4 receptor (P2X4-/- ) is known to have hypertension, which is thought to reflect endothelial dysfunction and impaired nitric oxide (NO) release. However, renal function in this model has not been characterized; moreover, studies in vitro have shown that the P2X4 receptor can regulate renal epithelial Na+ channel (ENaC) activity. Therefore, in the present study we investigated renal function and sodium handling in P2X4-/- mice, focusing on ENaC-mediated Na+ reabsorption. We confirmed an elevated BP in P2X4-/- mice compared with wild-type mice, but found that ENaC-mediated Na+ reabsorption is no different from wild-type and does not contribute to the raised BP observed in the knockout. However, when P2X4-/- mice were placed on a low sodium diet, BP normalized. Plasma aldosterone concentration tended to increase according to sodium restriction status in both genotypes; in contrast to wild-types, P2X4-/- mice did not show an increase in functional ENaC activity. Thus, although the increased BP in P2X4-/- mice has been attributed to endothelial dysfunction and impaired NO release, there is also a sodium-sensitive component.
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Affiliation(s)
- Eilidh Craigie
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
- Institue for AnatomyUniversity of ZürichZürichSwitzerland
| | - Robert I. Menzies
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUnited Kingdom
| | - Casper K. Larsen
- Department of Biomedicine, PhysiologyAarhus UniversityAarhus CDenmark
| | - Grégory Jacquillet
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
| | - Monique Carrel
- Institue for AnatomyUniversity of ZürichZürichSwitzerland
| | - Scott S. Wildman
- Urinary System Physiology UnitMedway School of PharmacyUniversity of KentKentUnited Kingdom
| | | | - Jens Leipziger
- Department of Biomedicine, PhysiologyAarhus UniversityAarhus CDenmark
| | - David G. Shirley
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
| | - Matthew A. Bailey
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUnited Kingdom
| | - Robert J. Unwin
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
- CVRM iMEDAstraZeneca GothenburgGothenburgSweden
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Ivy JR, Evans LC, Moorhouse R, Richardson RV, Al-Dujaili EAS, Flatman PW, Kenyon CJ, Chapman KE, Bailey MA. Renal and Blood Pressure Response to a High-Salt Diet in Mice With Reduced Global Expression of the Glucocorticoid Receptor. Front Physiol 2018; 9:848. [PMID: 30038578 PMCID: PMC6046455 DOI: 10.3389/fphys.2018.00848] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 06/14/2018] [Indexed: 01/02/2023] Open
Abstract
Salt-sensitive hypertension is common in glucocorticoid excess. Glucocorticoid resistance also presents with hypercortisolemia and hypertension but the relationship between salt intake and blood pressure (BP) is not well defined. GRβgeo/+ mice have global glucocorticoid receptor (GR) haploinsufficiency and increased BP. Here we examined the effect of high salt diet on BP, salt excretion and renal blood flow in GRβgeo/+mice. Basal BP was ∼10 mmHg higher in male GRβgeo/+ mice than in GR+/+ littermates. This modest increase was amplified by ∼10 mmHg following a high-salt diet in GRβgeo/+ mice. High salt reduced urinary aldosterone excretion but increased renal mineralocorticoid receptor expression in both genotypes. Corticosterone, and to a lesser extent deoxycorticosterone, excretion was increased in GRβgeo/+ mice following a high-salt challenge, consistent with enhanced 24 h production. GR+/+ mice increased fractional sodium excretion and reduced renal vascular resistance during the high salt challenge, retaining neutral sodium balance. In contrast, sodium excretion and renal vascular resistance did not adapt to high salt in GRβgeo/+ mice, resulting in transient sodium retention and sustained hypertension. With high-salt diet, Slc12a3 and Scnn1a mRNAs were higher in GRβgeo/+ than controls, and this was reflected in an exaggerated natriuretic response to thiazide and benzamil, inhibitors of NCC and ENaC, respectively. Reduction in GR expression causes salt-sensitivity and an adaptive failure of the renal vasculature and tubule, most likely reflecting sustained mineralocorticoid receptor activation. This provides a mechanistic basis to understand the hypertension associated with loss-of-function polymorphisms in GR in the context of habitually high salt intake.
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Affiliation(s)
- Jessica R Ivy
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Louise C Evans
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Rebecca Moorhouse
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Rachel V Richardson
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Emad A S Al-Dujaili
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Peter W Flatman
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Christopher J Kenyon
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Karen E Chapman
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
| | - Matthew A Bailey
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh Medical School, The University of Edinburgh, Edinburgh, United Kingdom
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Wiig H, Luft FC, Titze JM. The interstitium conducts extrarenal storage of sodium and represents a third compartment essential for extracellular volume and blood pressure homeostasis. Acta Physiol (Oxf) 2018; 222. [PMID: 29193764 DOI: 10.1111/apha.13006] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/31/2017] [Accepted: 11/23/2017] [Indexed: 12/15/2022]
Abstract
The role of salt in the pathogenesis of arterial hypertension is not well understood. According to the current understanding, the central mechanism for blood pressure (BP) regulation relies on classical studies linking BP and Na+ balance, placing the kidney at the very centre of long-term BP regulation. To maintain BP homeostasis, the effective circulating fluid volume and thereby body Na+ content has to be maintained within very narrow limits. From recent work in humans and rats, the notion has emerged that Na+ could be stored somewhere in the body without commensurate water retention to buffer free extracellular Na+ and that previously unidentified extrarenal, tissue-specific regulatory mechanisms are operative regulating the release and storage of Na+ from a kidney-independent reservoir. Moreover, immune cells from the mononuclear phagocyte system not only function as local on-site sensors of interstitial electrolyte concentration, but also, together with lymphatics, act as systemic regulators of body fluid volume and BP. These studies have established new and unexpected targets in studies of BP control and thus the pathophysiology of hypertension: the interstitium/extracellular matrix of the skin, its inherent interstitial fluid and the lymphatic vasculature forming a vessel network in the interstitium. Aspects of the interstitium in relation to Na+ balance and hypertension are the focus of this review. Taken together, observations of salt storage in the skin to buffer free extracellular Na+ and macrophage modulation of the extracellular matrix and lymphatics suggest that electrolyte homeostasis in the body cannot be achieved by renal excretion alone, but also relies on extrarenal regulatory mechanisms.
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Affiliation(s)
- H. Wiig
- Department of Biomedicine; University of Bergen; Bergen Norway
| | - F. C. Luft
- Experimental and Clinical Research Center; Max-Delbrück Center for Molecular Medicine; Charité Medical Faculty; Berlin Germany
- Division of Clinical Pharmacology; Department of Medicine; Vanderbilt University School of Medicine; Nashville TN USA
| | - J. M. Titze
- Division of Clinical Pharmacology; Department of Medicine; Vanderbilt University School of Medicine; Nashville TN USA
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Abstract
The metabolic syndrome describes a clustering of risk factors—visceral obesity, dyslipidaemia, insulin resistance, and salt-sensitive hypertension—that increases mortality related to cardiovascular disease, type 2 diabetes, cancer, and non-alcoholic fatty liver disease. The prevalence of these concurrent comorbidities is ~ 25–30% worldwide, and metabolic syndrome therefore presents a significant global public health burden. Evidence from clinical and preclinical studies indicates that glucocorticoid excess is a key causal feature of metabolic syndrome. This is not increased systemic in circulating cortisol, rather increased bioavailability of active glucocorticoids within tissues. This review examines the role of covert glucocorticoid excess on the hypertension of the metabolic syndrome. Here, the role of the 11β-hydroxysteroid dehydrogenase enzymes, which exert intracrine and paracrine control over glucocorticoid signalling, is examined. 11βHSD1 amplifies glucocorticoid action in cells and contributes to hypertension through direct and indirect effects on the kidney and vasculature. The deactivation of glucocorticoid by 11βHSD2 controls ligand access to glucocorticoid and mineralocorticoid receptors: loss of function promotes salt retention and hypertension. As for hypertension in general, high blood pressure in the metabolic syndrome reflects a complex interaction between multiple systems. The clear association between high dietary salt, glucocorticoid production, and metabolic disorders has major relevance for human health and warrants systematic evaluation.
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Affiliation(s)
- Matthew A Bailey
- The British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.
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Jiménez-Canino R, Lorenzo-Díaz F, Odermatt A, Bailey MA, Livingstone DEW, Jaisser F, Farman N, Alvarez de la Rosa D. 11β-HSD2 SUMOylation Modulates Cortisol-Induced Mineralocorticoid Receptor Nuclear Translocation Independently of Effects on Transactivation. Endocrinology 2017; 158:4047-4063. [PMID: 28938454 DOI: 10.1210/en.2017-00440] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/12/2017] [Indexed: 12/26/2022]
Abstract
The enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) has an essential role in aldosterone target tissues, conferring aldosterone selectivity for the mineralocorticoid receptor (MR) by converting 11β-hydroxyglucocorticoids to inactive 11-ketosteroids. Congenital deficiency of 11β-HSD2 causes a form of salt-sensitive hypertension known as the syndrome of apparent mineralocorticoid excess. The disease phenotype, which ranges from mild to severe, correlates well with reduction in enzyme activity. Furthermore, polymorphisms in the 11β-HSD2 coding gene (HSD11B2) have been linked to high blood pressure and salt sensitivity, major cardiovascular risk factors. 11β-HSD2 expression is controlled by different factors such as cytokines, sex steroids, or vasopressin, but posttranslational modulation of its activity has not been explored. Analysis of 11β-HSD2 sequence revealed a consensus site for conjugation of small ubiquitin-related modifier (SUMO) peptide, a major posttranslational regulatory event in several cellular processes. Our results demonstrate that 11β-HSD2 is SUMOylated at lysine 266. Non-SUMOylatable mutant K266R showed slightly higher substrate affinity and decreased Vmax, but no effects on protein stability or subcellular localization. Despite mild changes in enzyme activity, mutant K266R was unable to prevent cortisol-dependent MR nuclear translocation. The same effect was achieved by coexpression of wild-type 11β-HSD2 with sentrin-specific protease 1, a protease that catalyzes SUMO deconjugation. In the presence of 11β-HSD2-K266R, increased nuclear MR localization did not correlate with increased response to cortisol or increased recruitment of transcriptional coregulators. Taken together, our data suggests that SUMOylation of 11β-HSD2 at residue K266 modulates cortisol-mediated MR nuclear translocation independently of effects on transactivation.
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Affiliation(s)
- Rubén Jiménez-Canino
- Department of Basic Medical Sciences, Institute of Biomedical Technologies and Center for Biomedical Research of the Canary Islands, Universidad de La Laguna, 38200 Tenerife, Spain
| | - Fabián Lorenzo-Díaz
- Department of Basic Medical Sciences, Institute of Biomedical Technologies and Center for Biomedical Research of the Canary Islands, Universidad de La Laguna, 38200 Tenerife, Spain
| | - Alex Odermatt
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, 4056 Basel, Switzerland
| | - Matthew A Bailey
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Dawn E W Livingstone
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Frederic Jaisser
- INSERM UMRS 1138, Team 1, Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, 75006 Paris, France
| | - Nicolette Farman
- INSERM UMRS 1138, Team 1, Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, 75006 Paris, France
| | - Diego Alvarez de la Rosa
- Department of Basic Medical Sciences, Institute of Biomedical Technologies and Center for Biomedical Research of the Canary Islands, Universidad de La Laguna, 38200 Tenerife, Spain
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Jones FE, Bailey MA, Murray LS, Lu Y, McNeilly S, Schlötzer-Schrehardt U, Lennon R, Sado Y, Brownstein DG, Mullins JJ, Kadler KE, Van Agtmael T. ER stress and basement membrane defects combine to cause glomerular and tubular renal disease resulting from Col4a1 mutations in mice. Dis Model Mech 2016; 9:165-76. [PMID: 26839400 PMCID: PMC4770143 DOI: 10.1242/dmm.021741] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Collagen IV is a major component of basement membranes, and mutations in COL4A1, which encodes collagen IV alpha chain 1, cause a multisystemic disease encompassing cerebrovascular, eye and kidney defects. However, COL4A1 renal disease remains poorly characterized and its pathomolecular mechanisms are unknown. We show that Col4a1 mutations in mice cause hypotension and renal disease, including proteinuria and defects in Bowman's capsule and the glomerular basement membrane, indicating a role for Col4a1 in glomerular filtration. Impaired sodium reabsorption in the loop of Henle and distal nephron despite elevated aldosterone levels indicates that tubular defects contribute to the hypotension, highlighting a novel role for the basement membrane in vascular homeostasis by modulation of the tubular response to aldosterone. Col4a1 mutations also cause diabetes insipidus, whereby the tubular defects lead to polyuria associated with medullary atrophy and a subsequent reduction in the ability to upregulate aquaporin 2 and concentrate urine. Moreover, haematuria, haemorrhage and vascular basement membrane defects confirm an important vascular component. Interestingly, although structural and compositional basement membrane defects occurred in the glomerulus and Bowman's capsule, no tubular basement membrane defects were detected. By contrast, medullary atrophy was associated with chronic ER stress, providing evidence for cell-type-dependent molecular mechanisms of Col4a1 mutations. These data show that both basement membrane defects and ER stress contribute to Col4a1 renal disease, which has important implications for the development of treatment strategies for collagenopathies. Summary: Structural and compositional basement membrane defects and ER stress due to Col4a1 mutations cause glomerular and tubular kidney disease, and indicate cell-type-specific disease mechanisms for collagen diseases.
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Affiliation(s)
- Frances E Jones
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Matthew A Bailey
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Lydia S Murray
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Yinhui Lu
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Sarah McNeilly
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | | | - Rachel Lennon
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Yoshikazu Sado
- Division of Immunology, Shigei Medical Research Institute, Okayama 701-02, Japan
| | - David G Brownstein
- Division of Pathology, School of Molecular and Clinical Medicine, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - John J Mullins
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Karl E Kadler
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Tom Van Agtmael
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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Pitt B, Pedro Ferreira J, Zannad F. Mineralocorticoid receptor antagonists in patients with heart failure: current experience and future perspectives. EUROPEAN HEART JOURNAL. CARDIOVASCULAR PHARMACOTHERAPY 2016; 3:48-57. [DOI: 10.1093/ehjcvp/pvw016] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 01/14/2023]
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Savas Ü, Wei S, Hsu MH, Falck JR, Guengerich FP, Capdevila JH, Johnson EF. 20-Hydroxyeicosatetraenoic Acid (HETE)-dependent Hypertension in Human Cytochrome P450 (CYP) 4A11 Transgenic Mice: NORMALIZATION OF BLOOD PRESSURE BY SODIUM RESTRICTION, HYDROCHLOROTHIAZIDE, OR BLOCKADE OF THE TYPE 1 ANGIOTENSIN II RECEPTOR. J Biol Chem 2016; 291:16904-19. [PMID: 27298316 DOI: 10.1074/jbc.m116.732297] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Indexed: 11/06/2022] Open
Abstract
Male and female homozygous 129/Sv mice carrying four copies of the human cytochrome P450 4A11 gene (CYP4A11) under control of its native promoter (B-129/Sv-4A11(+/+)) develop hypertension (142 ± 8 versus 113 ± 7 mm Hg systolic blood pressure (BP)), and exhibit increased 20-hydroxyeicosatetraenoic acid (20-HETE) in kidney and urine. The hypertension is reversible by a low-sodium diet and by the CYP4A inhibitor HET0016. B-129/Sv-4A11(+/+) mice display an 18% increase of plasma potassium (p < 0.02), but plasma aldosterone, angiotensin II (ANGII), and renin activities are unchanged. This phenotype resembles human genetic disorders with elevated activity of the sodium chloride co-transporter (NCC) and, accordingly, NCC abundance is increased by 50% in transgenic mice, and NCC levels are normalized by HET0016. ANGII is known to increase NCC abundance, and renal mRNA levels of its precursor angiotensinogen are increased 2-fold in B-129/Sv-4A11(+/+), and blockade of the ANGII receptor type 1 with losartan normalizes BP. A pro-hypertensive role for 20-HETE was implicated by normalization of BP and reversal of renal angiotensin mRNA increases by administration of the 20-HETE antagonists 2-((6Z,15Z)-20-hydroxyicosa-6,15-dienamido)acetate or (S)-2-((6Z,15Z)-20-hydroxyicosa-6,15-dienamido)succinate. SGK1 expression is also increased in B-129/Sv-4A11(+/+) mice and paralleled increases seen for NCC. Losartan, HET0016, and 20-HETE antagonists each normalized SGK1 mRNA expression. These results point to a potential 20-HETE dependence of intrarenal angiotensinogen production and ANGII receptor type 1 activation that are associated with increases in NCC and SGK1 and identify elevated P450 4A11 activity and 20-HETE as potential risk factors for salt-sensitive human hypertension by perturbation of the renal renin-angiotensin axis.
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Affiliation(s)
- Üzen Savas
- From the Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037
| | | | - Mei-Hui Hsu
- From the Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - John R Falck
- the Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - F Peter Guengerich
- Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, and
| | | | - Eric F Johnson
- From the Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037,
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Evans LC, Ivy JR, Wyrwoll C, McNairn JA, Menzies RI, Christensen TH, Al-Dujaili EAS, Kenyon CJ, Mullins JJ, Seckl JR, Holmes MC, Bailey MA. Conditional Deletion of Hsd11b2 in the Brain Causes Salt Appetite and Hypertension. Circulation 2016; 133:1360-70. [PMID: 26951843 PMCID: PMC4819772 DOI: 10.1161/circulationaha.115.019341] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 02/12/2016] [Indexed: 11/30/2022]
Abstract
Supplemental Digital Content is available in the text. Background— The hypertensive syndrome of Apparent Mineralocorticoid Excess is caused by loss-of-function mutations in the gene encoding 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), allowing inappropriate activation of the mineralocorticoid receptor by endogenous glucocorticoid. Hypertension is attributed to sodium retention in the distal nephron, but 11βHSD2 is also expressed in the brain. However, the central contribution to Apparent Mineralocorticoid Excess and other hypertensive states is often overlooked and is unresolved. We therefore used a Cre-Lox strategy to generate 11βHSD2 brain-specific knockout (Hsd11b2.BKO) mice, measuring blood pressure and salt appetite in adults. Methods and Results— Basal blood pressure, electrolytes, and circulating corticosteroids were unaffected in Hsd11b2.BKO mice. When offered saline to drink, Hsd11b2.BKO mice consumed 3 times more sodium than controls and became hypertensive. Salt appetite was inhibited by spironolactone. Control mice fed the same daily sodium intake remained normotensive, showing the intrinsic salt resistance of the background strain. Dexamethasone suppressed endogenous glucocorticoid and abolished the salt-induced blood pressure differential between genotypes. Salt sensitivity in Hsd11b2.BKO mice was not caused by impaired renal sodium excretion or volume expansion; pressor responses to phenylephrine were enhanced and baroreflexes impaired in these animals. Conclusions— Reduced 11βHSD2 activity in the brain does not intrinsically cause hypertension, but it promotes a hunger for salt and a transition from salt resistance to salt sensitivity. Our data suggest that 11βHSD2-positive neurons integrate salt appetite and the blood pressure response to dietary sodium through a mineralocorticoid receptor–dependent pathway. Therefore, central mineralocorticoid receptor antagonism could increase compliance to low-sodium regimens and help blood pressure management in cardiovascular disease.
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Affiliation(s)
- Louise C Evans
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Jessica R Ivy
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Caitlin Wyrwoll
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Julie A McNairn
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Robert I Menzies
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Thorbjørn H Christensen
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Emad A S Al-Dujaili
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Christopher J Kenyon
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - John J Mullins
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Jonathan R Seckl
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Megan C Holmes
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense
| | - Matthew A Bailey
- From British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom (L.C.E., J.R.I., C.W., J.A.M., R.I.M., T.H.C., C.J.K., J.J.M., J.R.S., M.C.H., M.A.B.); and Dietetics, Nutrition and Biological Sciences Department, Queen Margaret University, Edinburgh, United Kingdom (E.A.S.Al-D.). The current address for Dr Evans is Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee; the current address for Dr Wyrwoll is School of Anatomy, Physiology & Human Biology, The University of Western Australia, Crawley, Australia; and the current address for Dr Christensen is Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense.
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Mullins LJ, Kenyon CJ, Bailey MA, Conway BR, Diaz ME, Mullins JJ. Mineralocorticoid Excess or Glucocorticoid Insufficiency: Renal and Metabolic Phenotypes in a Rat Hsd11b2 Knockout Model. Hypertension 2015; 66:667-73. [PMID: 26077568 PMCID: PMC4847935 DOI: 10.1161/hypertensionaha.115.05262] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 05/27/2015] [Indexed: 01/06/2023]
Abstract
Obesity and hypertension are 2 major health issues of the 21st century. The syndrome of apparent mineralocorticoid excess is caused by deficiency of 11β-hydroxysteroid dehydrogenase type 2 (Hsd11b2), which normally inactivates glucocorticoids, rendering the mineralocorticoid receptor aldosterone–specific. The metabolic consequences of Hsd11b2 knockout in the rat are investigated in parallel with electrolyte homeostasis. Hsd11b2 was knocked out, by pronuclear microinjection of targeted zinc-finger nuclease mRNAs, and 1 line was characterized for its response to renal and metabolic challenges. Plasma 11-dehydrocorticosterone was below detection thresholds, and Hsd11b2 protein was undetected by Western blot, indicating complete ablation. Homozygotes were 13% smaller than wild-type littermates, and were polydipsic and polyuric. Their kidneys, adrenals, and hearts were significantly enlarged, but mesenteric fat pads and liver were significantly smaller. On a 0.3% Na diet, mean arterial blood pressure was ≈65 mm Hg higher than controls but only 25 mm Hg higher on a 0.03% Na+ diet. Urinary Na/K ratio of homozygotes was similar to controls on 0.3% Na+ diet but urinary albumin and calcium were elevated. Corticosterone and aldosterone levels showed normal circadian variation on both a 0.3% and 0.03% Na+ diet, but plasma renin was suppressed in homozygotes on both diets. Plasma glucose responses to an oral glucose challenge were reduced despite low circulating insulin, indicating much greater sensitivity to insulin in homozygotes. The rat model reveals mechanisms linking electrolyte homeostasis and metabolic control through the restriction of Hsd11b1 substrate availability.
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Affiliation(s)
- Linda J Mullins
- From the Molecular Physiology Laboratory, University of Edinburgh/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, United Kingdom.
| | - Christopher J Kenyon
- From the Molecular Physiology Laboratory, University of Edinburgh/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, United Kingdom
| | - Matthew A Bailey
- From the Molecular Physiology Laboratory, University of Edinburgh/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, United Kingdom
| | - Bryan R Conway
- From the Molecular Physiology Laboratory, University of Edinburgh/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, United Kingdom
| | - Mary E Diaz
- From the Molecular Physiology Laboratory, University of Edinburgh/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, United Kingdom
| | - John J Mullins
- From the Molecular Physiology Laboratory, University of Edinburgh/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, United Kingdom
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Hunter RW, Bailey MA. Glucocorticoids and 11β-hydroxysteroid dehydrogenases: mechanisms for hypertension. Curr Opin Pharmacol 2015; 21:105-14. [DOI: 10.1016/j.coph.2015.01.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/20/2015] [Accepted: 01/22/2015] [Indexed: 11/26/2022]
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Zahraldin K, Janahi IA, Ben-Omran T, Alsulaiman R, Hamad B, Imam A. Two Qatari siblings with cystic fibrosis and apparent mineralocorticoid excess. Ann Thorac Med 2015; 10:69-72. [PMID: 25593612 PMCID: PMC4286850 DOI: 10.4103/1817-1737.146892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/25/2014] [Indexed: 11/04/2022] Open
Abstract
Cystic fibrosis (CF) and apparent mineralocorticoid excess (AME) syndrome are both autosomal recessive disorders that result from mutations of specific identified genes for each condition. CF is caused by defects in the Cystic fibrosis trans membrane conductance regulator (CFTR) gene which encodes for a protein that functions as a chloride channel and regulates the flow of other ions across the apical surface of epithelial cells. AME is due to the deficiency of 11β-hydroxysteroid dehydrogenase type 2 enzyme (11βHSD2), which is responsible for the peripheral inactivation of cortisol to cortisone. Cortisol excess stimulates the mineralocoritoid receptors (MR) resulting in intense sodium retention, hypokalemia and hypertension. We report on a consanguineous Arab family, in which two sibs inherited both CF and AME. Gene testing for AME revealed previously unreported mutation in the 11βHSD2 gene. This report draws attention to the importance of recognizing the possibility of two recessive disorders in the same child in complex consanguineous families. Moreover, it provides a unique opportunity to highlight the implications of the coexistence of two genetic disorders on patient care and genetic counseling of the family.
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Affiliation(s)
- Khalid Zahraldin
- Pulmonary Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Ibrahim Ahmed Janahi
- Pulmonary Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Tawfeg Ben-Omran
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Reem Alsulaiman
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Bajes Hamad
- Nephrology Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Abubakr Imam
- Nephrology Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
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Hunter RW, Ivy JR, Bailey MA. Glucocorticoids and renal Na+ transport: implications for hypertension and salt sensitivity. J Physiol 2014; 592:1731-44. [PMID: 24535442 PMCID: PMC4001748 DOI: 10.1113/jphysiol.2013.267609] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The clinical manifestations of glucocorticoid excess include central obesity, hyperglycaemia, dyslipidaemia, electrolyte abnormalities and hypertension. A century on from Cushing's original case study, these cardinal features are prevalent in industrialized nations. Hypertension is the major modifiable risk factor for cardiovascular and renal disease and reflects underlying abnormalities of Na+ homeostasis. Aldosterone is a master regulator of renal Na+ transport but here we argue that glucocorticoids are also influential, particularly during moderate excess. The hypothalamic–pituitary–adrenal axis can affect renal Na+ homeostasis on multiple levels, systemically by increasing mineralocorticoid synthesis and locally by actions on both the mineralocorticoid and glucocorticoid receptors, both of which are expressed in the kidney. The kidney also expresses both of the 11β-hydroxysteroid dehydrogenase (11βHSD) enzymes. The intrarenal generation of active glucocorticoid by 11βHSD1 stimulates Na+ reabsorption; failure to downregulate the enzyme during adaption to high dietary salt causes salt-sensitive hypertension. The deactivation of glucocorticoid by 11βHSD2 underpins the regulatory dominance for Na+ transport of mineralocorticoids and defines the ‘aldosterone-sensitive distal nephron’. In summary, glucocorticoids can stimulate renal transport processes conventionally attributed to the renin–angiotensin–aldosterone system. Importantly, Na+ and volume homeostasis do not exert negative feedback on the hypothalamic–pituitary–adrenal axis. These actions are therefore clinically relevant and may contribute to the pathogenesis of hypertension in conditions associated with elevated glucocorticoid levels, such as the metabolic syndrome and chronic stress.
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Affiliation(s)
- Robert W Hunter
- University/BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
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Warnock DG, Kusche-Vihrog K, Tarjus A, Sheng S, Oberleithner H, Kleyman TR, Jaisser F. Blood pressure and amiloride-sensitive sodium channels in vascular and renal cells. Nat Rev Nephrol 2014; 10:146-57. [PMID: 24419567 DOI: 10.1038/nrneph.2013.275] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sodium transport in the distal nephron is mediated by epithelial sodium channel activity. Proteolytic processing of external domains and inhibition with increased sodium concentrations are important regulatory features of epithelial sodium channel complexes expressed in the distal nephron. By contrast, sodium channels expressed in the vascular system are activated by increased external sodium concentrations, which results in changes in the mechanical properties and function of endothelial cells. Mechanosensitivity and shear stress affect both epithelial and vascular sodium channel activity. Guyton's hypothesis stated that blood pressure control is critically dependent on vascular tone and fluid handling by the kidney. The synergistic effects, and complementary regulation, of the epithelial and vascular systems are consistent with the Guytonian model of volume and blood pressure regulation, and probably reflect sequential evolution of the two systems. The integration of vascular tone, renal perfusion and regulation of renal sodium reabsorption is the central underpinning of the Guytonian model. In this Review, we focus on the expression and regulation of sodium channels, and we outline the emerging evidence that describes the central role of amiloride-sensitive sodium channels in the efferent (vascular) and afferent (epithelial) arms of this homeostatic system.
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Affiliation(s)
- David G Warnock
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, AL 34294-0007, USA
| | - Kristina Kusche-Vihrog
- Institut für Physiologie II, Westfälische Wilhelms Universität, Robert-Koch-Straße 27, 48149 Münster, Germany
| | - Antoine Tarjus
- INSERM U872 Team 1, Centre de Recherche des Cordeliers, Université René Descartes, Université Pierre et Marie Curie, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Shaohu Sheng
- Renal and Electrolyte Division, Department of Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Hans Oberleithner
- Institut für Physiologie II, Westfälische Wilhelms Universität, Robert-Koch-Straße 27, 48149 Münster, Germany
| | - Thomas R Kleyman
- Renal and Electrolyte Division, Department of Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Frederic Jaisser
- INSERM U872 Team 1, Centre de Recherche des Cordeliers, Université René Descartes, Université Pierre et Marie Curie, 15 rue de l'Ecole de Médecine, 75006 Paris, France
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HSD11B2 CA-repeat and sodium balance. Hypertens Res 2013; 36:614-9. [PMID: 23446772 DOI: 10.1038/hr.2013.13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 11/24/2012] [Accepted: 12/13/2012] [Indexed: 11/08/2022]
Abstract
Type 2 11β-hydroxysteroid dehydrogenase encoded by the HSD11B2 gene converts cortisol to inactive cortisone and thus protects the mineralocorticoid receptor from cortisol exposure. Impaired activity of this enzyme leads to mineralocorticoid excess, suggesting HSD11B2 as a candidate locus for patients at risk of developing low renin or salt-sensitive essential hypertension. In the present study, we searched for frequent polymorphisms in 155 Japanese subjects but detected none in the proximal promoter or coding regions of HSD11B2. Following this result, we genotyped a highly polymorphic CA-repeat polymorphism within the first intron in 848 normotensive and 430 hypertensive Japanese patients, and we then analyzed its association with disease and clinical parameters. We confirmed 12 alleles (12, 15-25 CA repeats) in the population and found no significant difference in the distribution of the allele length between normotensive and hypertensive patients. In 174 normal subjects without medication, urinary cortisol excretion was higher in subjects with more CA repeats in the shorter allele, but the ratio of urinary cortisone to cortisol, a reliable marker of renal HSD11B2 activity, did not differ. However, longer CA-repeat length was positively correlated with 24-h urinary sodium excretion, fractional sodium excretion and potassium clearance, and this observation was confirmed when the longer CA-repeat length was dichotomized. Thus, HSD11B2 CA-repeat genotype is not associated with hypertension itself, but with renal sodium excretion, probably through salt intake/appetite.
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