1
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Kok M, Brodsky JL. The biogenesis of potassium transporters: implications of disease-associated mutations. Crit Rev Biochem Mol Biol 2024:1-45. [PMID: 38946646 DOI: 10.1080/10409238.2024.2369986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/16/2024] [Indexed: 07/02/2024]
Abstract
The concentration of intracellular and extracellular potassium is tightly regulated due to the action of various ion transporters, channels, and pumps, which reside primarily in the kidney. Yet, potassium transporters and cotransporters play vital roles in all organs and cell types. Perhaps not surprisingly, defects in the biogenesis, function, and/or regulation of these proteins are linked to range of catastrophic human diseases, but to date, few drugs have been approved to treat these maladies. In this review, we discuss the structure, function, and activity of a group of potassium-chloride cotransporters, the KCCs, as well as the related sodium-potassium-chloride cotransporters, the NKCCs. Diseases associated with each of the four KCCs and two NKCCs are also discussed. Particular emphasis is placed on how these complex membrane proteins fold and mature in the endoplasmic reticulum, how non-native forms of the cotransporters are destroyed in the cell, and which cellular factors oversee their maturation and transport to the cell surface. When known, we also outline how the levels and activities of each cotransporter are regulated. Open questions in the field and avenues for future investigations are further outlined.
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Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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2
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Al-Hosni R, Kaye R, Choi CS, Tammaro P. The TMEM16A channel as a potential therapeutic target in vascular disease. Curr Opin Nephrol Hypertens 2024; 33:161-169. [PMID: 38193301 PMCID: PMC10842660 DOI: 10.1097/mnh.0000000000000967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
PURPOSE OF REVIEW The transmembrane protein 16A (TMEM16A) Ca 2+ -activated Cl - channel constitutes a key depolarising mechanism in vascular smooth muscle and contractile pericytes, while in endothelial cells the channel is implicated in angiogenesis and in the response to vasoactive stimuli. Here, we offer a critical analysis of recent physiological investigations and consider the potential for targeting TMEM16A channels in vascular disease. RECENT FINDINGS Genetic deletion or pharmacological inhibition of TMEM16A channels in vascular smooth muscle decreases artery tone and lowers systemic blood pressure in rodent models. Inhibition of TMEM16A channels in cerebral cortical pericytes protects against ischemia-induced tissue damage and improves microvascular blood flow in rodent stroke models. In endothelial cells, the TMEM16A channel plays varied roles including modulation of cell division and control of vessel tone through spread of hyperpolarisation to the smooth muscle cells. Genetic studies implicate TMEM16A channels in human disease including systemic and pulmonary hypertension, stroke and Moyamoya disease. SUMMARY The TMEM16A channel regulates vascular function by controlling artery tone and capillary diameter as well as vessel formation and histology. Preclinical and clinical investigations are highlighting the potential for therapeutic exploitation of the channel in a range of maladaptive states of the (micro)circulation.
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Affiliation(s)
- Rumaitha Al-Hosni
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
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3
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Goto K, Kitazono T. Chloride Ions, Vascular Function and Hypertension. Biomedicines 2022; 10:biomedicines10092316. [PMID: 36140417 PMCID: PMC9496098 DOI: 10.3390/biomedicines10092316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/10/2022] [Accepted: 09/15/2022] [Indexed: 11/26/2022] Open
Abstract
Blood pressure is determined by cardiac output and systemic vascular resistance, and mediators that induce vasoconstriction will increase systemic vascular resistance and thus elevate blood pressure. While peripheral vascular resistance reflects a complex interaction of multiple factors, vascular ion channels and transporters play important roles in the regulation of vascular tone by modulating the membrane potential of vascular cells. In vascular smooth muscle cells, chloride ions (Cl−) are a type of anions accumulated by anion exchangers and the anion–proton cotransporter system, and efflux of Cl− through Cl− channels depolarizes the membrane and thereby triggers vasoconstriction. Among these Cl− regulatory pathways, emerging evidence suggests that upregulation of the Ca2+-activated Cl− channel TMEM16A in the vasculature contributes to the increased vascular contractility and elevated blood pressure in hypertension. A robust accumulation of intracellular Cl− in vascular smooth muscle cells through the increased activity of Na+–K+–2Cl− cotransporter 1 (NKCC1) during hypertension has also been reported. Thus, the enhanced activity of both TMEM16A and NKCC1 could act additively and sequentially to increase vascular contractility and hence blood pressure in hypertension. In this review, we discuss recent findings regarding the role of Cl− in the regulation of vascular tone and arterial blood pressure and its association with hypertension, with a particular focus on TMEM16A and NKCC1.
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Affiliation(s)
- Kenichi Goto
- Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- Correspondence:
| | - Takanari Kitazono
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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4
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Fujii S, Kikuchi E, Suzuyama H, Watanabe Y, Ishigami-Yuasa M, Masuno H, Mori T, Isobe K, Uchida S, Kagechika H. Structural Development of Salicylanilide-Based SPAK Inhibitors as Candidate Antihypertensive Agents. ChemMedChem 2021; 16:2817-2822. [PMID: 34109743 DOI: 10.1002/cmdc.202100273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/09/2021] [Indexed: 11/08/2022]
Abstract
Hypertension is an important target for drug discovery. We have focused on the with-no-lysine kinase (WNK)-oxidative stress-responsive 1 (OSR1) and STE20/SPS1-related proline-alanine-rich protein kinase (SPAK)-NaCl cotransporter (NCC) signal cascade as a potential target, and we previously developed a screening system for inhibitors of WNK-OSR1/SPAK-NCC signaling. Herein we used this system to examine the structure-activity relationship (SAR) of salicylanilide derivatives as SPAK kinase inhibitors. Structural design and development based on our previous hit compound, aryloxybenzanilide derivative 2, and the veterinary anthelmintic closantel (3) led to the discovery of compound 10 a as a potent SPAK inhibitor with reduced toxicity. Compound 10 a decreased the phosphorylation level of NCC in mouse kidney in vivo, and appears to be a promising lead compound for a new class of antihypertensive drugs.
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Affiliation(s)
- Shinya Fujii
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
| | - Eriko Kikuchi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Honoka Suzuyama
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
| | - Yuko Watanabe
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
| | - Mari Ishigami-Yuasa
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
| | - Hiroyuki Masuno
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Hiroyuki Kagechika
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-0062, Japan
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5
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Gagnon KB, Delpire E. Sodium Transporters in Human Health and Disease. Front Physiol 2021; 11:588664. [PMID: 33716756 PMCID: PMC7947867 DOI: 10.3389/fphys.2020.588664] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/06/2020] [Indexed: 12/12/2022] Open
Abstract
Sodium (Na+) electrochemical gradients established by Na+/K+ ATPase activity drives the transport of ions, minerals, and sugars in both excitable and non-excitable cells. Na+-dependent transporters can move these solutes in the same direction (cotransport) or in opposite directions (exchanger) across both the apical and basolateral plasma membranes of polarized epithelia. In addition to maintaining physiological homeostasis of these solutes, increases and decreases in sodium may also initiate, directly or indirectly, signaling cascades that regulate a variety of intracellular post-translational events. In this review, we will describe how the Na+/K+ ATPase maintains a Na+ gradient utilized by multiple sodium-dependent transport mechanisms to regulate glucose uptake, excitatory neurotransmitters, calcium signaling, acid-base balance, salt-wasting disorders, fluid volume, and magnesium transport. We will discuss how several Na+-dependent cotransporters and Na+-dependent exchangers have significant roles in human health and disease. Finally, we will discuss how each of these Na+-dependent transport mechanisms have either been shown or have the potential to use Na+ in a secondary role as a signaling molecule.
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Affiliation(s)
- Kenneth B. Gagnon
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States
| | - Eric Delpire
- Department of Anesthesiology, School of Medicine, Vanderbilt University, Nashville, TN, United States
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6
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Koumangoye R, Bastarache L, Delpire E. NKCC1: Newly Found as a Human Disease-Causing Ion Transporter. FUNCTION 2020; 2:zqaa028. [PMID: 33345190 PMCID: PMC7727275 DOI: 10.1093/function/zqaa028] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 01/06/2023] Open
Abstract
Among the electroneutral Na+-dependent chloride transporters, NKCC1 had until now evaded identification as a protein causing human diseases. The closely related SLC12A transporters, NKCC2 and NCC have been identified some 25 years ago as responsible for Bartter and Gitelman syndromes: two renal-dependent salt wasting disorders. Absence of disease was most surprising since the NKCC1 knockout mouse was shown in 1999 to be viable, albeit with a wide range of deleterious phenotypes. Here we summarize the work of the past 5 years that introduced us to clinical cases involving NKCC1. The most striking cases are of 3 children with inherited mutations, who have complete absence of NKCC1 expression. These cases establish that lack of NKCC1 causes deafness; CFTR-like secretory defects with mucus accumulation in lung and intestine; severe xerostomia, hypotonia, dysmorphic facial features, and severe neurodevelopmental disorder. Another intriguing case is of a patient with a dominant deleterious SLC12A2 allele. This de novo mutation introduced a premature stop codon leading to a truncated protein. This mutant transporter seems to exert dominant-negative effect on wild-type transporter only in epithelial cells. The patient who suffers from lung, bladder, intestine, pancreas, and multiple endocrine abnormalities has, however, normal hearing and cognition. Finally, new reports substantiate the haploinsufficiency prediction of the SLC12A2 gene. Cases with single allele mutations in SLC12A2 have been linked to hearing loss and neurodevelopmental disorders.
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Affiliation(s)
- Rainelli Koumangoye
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Lisa Bastarache
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA,Corresponding author. E-mail:
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7
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Garneau AP, Slimani S, Fiola MJ, Tremblay LE, Isenring P. Multiple Facets and Roles of Na+-K+-Cl−Cotransport: Mechanisms and Therapeutic Implications. Physiology (Bethesda) 2020; 35:415-429. [DOI: 10.1152/physiol.00012.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The Na+-K+-Cl−cotransporters play key physiological and pathophysiological roles by regulating the membrane potential of many cell types and the movement of fluid across a variety of epithelial or endothelial structures. As such, they should soon become invaluable targets for the treatment of various disorders including pain, epilepsy, brain edema, and hypertension. This review highlights the nature of these roles, the mechanisms at play, and the unresolved issues in the field.
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Affiliation(s)
- A. P. Garneau
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Canada; and
- Cardiometabolic Axis, School of Kinesiology and Physical Activity Sciences, University of Montréal, Montréal, Canada
| | - S. Slimani
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Canada; and
| | - M. J. Fiola
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Canada; and
| | - L. E. Tremblay
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Canada; and
| | - P. Isenring
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Canada; and
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8
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Meor Azlan NF, Zhang J. Role of the Cation-Chloride-Cotransporters in Cardiovascular Disease. Cells 2020; 9:E2293. [PMID: 33066544 PMCID: PMC7602155 DOI: 10.3390/cells9102293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/08/2020] [Accepted: 10/14/2020] [Indexed: 02/05/2023] Open
Abstract
The SLC12 family of cation-chloride-cotransporters (CCCs) is comprised of potassium chloride cotransporters (KCCs), which mediate Cl- extrusion and sodium-potassium chloride cotransporters (N[K]CCs), which mediate Cl- loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. The functions of CCCs influence a variety of physiological processes, many of which overlap with the pathophysiology of cardiovascular disease. Although not all of the cotransporters have been linked to Mendelian genetic disorders, recent studies have provided new insights into their functional role in vascular and renal cells in addition to their contribution to cardiovascular diseases. Particularly, an imbalance in potassium levels promotes the pathogenesis of atherosclerosis and disturbances in sodium homeostasis are one of the causes of hypertension. Recent findings suggest hypothalamic signaling as a key signaling pathway in the pathophysiology of hypertension. In this review, we summarize and discuss the role of CCCs in cardiovascular disease with particular emphasis on knowledge gained in recent years on NKCCs and KCCs.
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Affiliation(s)
- Nur Farah Meor Azlan
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, Hatherly Laboratories, University of Exeter, Exeter EX4 4PS, UK;
| | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, Hatherly Laboratories, University of Exeter, Exeter EX4 4PS, UK;
- Xiamen Cardiovascular Hospital, School of Medicine, Xiamen University, Xiamen 361004, Fujian, China
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9
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Garneau AP, Marcoux AA, Slimani S, Tremblay LE, Frenette-Cotton R, Mac-Way F, Isenring P. Physiological roles and molecular mechanisms of K + -Cl - cotransport in the mammalian kidney and cardiovascular system: where are we? J Physiol 2019; 597:1451-1465. [PMID: 30659612 DOI: 10.1113/jp276807] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/07/2018] [Indexed: 11/08/2022] Open
Abstract
In the early 80s, renal microperfusion studies led to the identification of a basolateral K+ -Cl- cotransport mechanism in the proximal tubule, thick ascending limb of Henle and collecting duct. More than ten years later, this mechanism was found to be accounted for by three different K+ -Cl- cotransporters (KCC1, KCC3 and KCC4) that are differentially distributed along the renal epithelium. Two of these isoforms (KCC1 and KCC3) were also found to be expressed in arterial walls, the myocardium and a variety of neurons. Subsequently, valuable insights have been gained into the molecular and physiological properties of the KCCs in both the mammalian kidney and cardiovascular system. There is now robust evidence indicating that KCC4 sustains distal renal acidification and that KCC3 regulates myogenic tone in resistance vessels. However, progress in understanding the functional significance of these transporters has been slow, probably because each of the KCC isoforms is not identically distributed among species and some of them share common subcellular localizations with other KCC isoforms or sizeable conductive Cl- pathways. In addition, the mechanisms underlying the process of K+ -Cl- cotransport are still ill defined. The present review focuses on the knowledge gained regarding the roles and properties of KCCs in renal and cardiovascular tissues.
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Affiliation(s)
- A P Garneau
- Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), Canada, G1R 2J6.,Cardiometabolic Axis, School of Kinesiology and Physical Activity Sciences, Montreal University, 900, rue Saint-Denis, Montréal, (Qc) H2X 0A9
| | - A A Marcoux
- Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), Canada, G1R 2J6
| | - S Slimani
- Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), Canada, G1R 2J6
| | - L E Tremblay
- Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), Canada, G1R 2J6
| | - R Frenette-Cotton
- Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), Canada, G1R 2J6
| | - F Mac-Way
- Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), Canada, G1R 2J6
| | - P Isenring
- Nephrology Research Group, Department of Medicine, Laval University, 11, côte du Palais, Québec (Qc), Canada, G1R 2J6
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10
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Kostyunina DS, Gaynullina DK, Matchkov VV, Tarasova OS. Pro-contractile role of chloride in arterial smooth muscle: Postnatal decline potentially governed by sympathetic nerves. Exp Physiol 2019; 104:1018-1022. [PMID: 30689263 DOI: 10.1113/ep087426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 01/25/2019] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the topic of this review? This symposium report discusses the previously unrecognized pro-contractile role of chloride ions in rat arteries at early stages of postnatal development. What advances does it highlight? It highlights the postnatal decline in the contribution of chloride ions to regulation of arterial contractile responses and potential trophic role of sympathetic nerves in these developmental alterations. ABSTRACT Chloride ions are important for smooth muscle contraction in adult vasculature. Arterial smooth muscle undergoes structural and functional remodelling during early postnatal development, including changes in K+ currents, Ca2+ handling and sensitivity. However, developmental change in the contribution of Cl- to regulation of arterial contraction has not yet been explored. Here, we provide the first evidence that the role of Cl- in α1 -adrenergic arterial contraction prominently decreases during early postnatal ontogenesis. The trophic influence of sympathetic nerves is a potential mechanism for postnatal decline of the contribution of Cl- to the vascular contraction.
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Affiliation(s)
- Daria S Kostyunina
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.,State Research Center of the Russian Federation - Institute for Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Dina K Gaynullina
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.,Department of Physiology, Russian National Research Medical University, Moscow, Russia
| | | | - Olga S Tarasova
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.,State Research Center of the Russian Federation - Institute for Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
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11
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Shen CH, Lin JY, Chang YL, Wu SY, Peng CK, Wu CP, Huang KL. Inhibition of NKCC1 Modulates Alveolar Fluid Clearance and Inflammation in Ischemia-Reperfusion Lung Injury via TRAF6-Mediated Pathways. Front Immunol 2018; 9:2049. [PMID: 30271405 PMCID: PMC6146090 DOI: 10.3389/fimmu.2018.02049] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 08/20/2018] [Indexed: 12/15/2022] Open
Abstract
Background: The expression of Na-K-2Cl cotransporter 1 (NKCC1) in the alveolar epithelium is responsible for fluid homeostasis in acute lung injury (ALI). Increasing evidence suggests that NKCC1 is associated with inflammation in ALI. We hypothesized that inhibiting NKCC1 would attenuate ALI after ischemia-reperfusion (IR) by modulating pathways that are mediated by tumor necrosis-associated factor 6 (TRAF6). Methods: IR-ALI was induced by producing 30 min of ischemia followed by 90 min of reperfusion in situ in an isolated and perfused rat lung model. The rats were randomly allotted into four groups comprising two control groups and two IR groups with and without bumetanide. Alveolar fluid clearance (AFC) was measured for each group. Mouse alveolar MLE-12 cells were cultured in control and hypoxia-reoxygenation (HR) conditions with or without bumetanide. Flow cytometry and transwell monolayer permeability assay were carried out for each group. Results: Bumetanide attenuated the activation of p-NKCC1 and lung edema after IR. In the HR model, bumetanide decreased the cellular volume and increased the transwell permeability. In contrast, bumetanide increased the expression of epithelial sodium channel (ENaC) via p38 mitogen-activated protein kinase (p38 MAPK), which attenuated the reduction of AFC after IR. Bumetanide also modulated lung inflammation via nuclear factor-κB (NF-κB). TRAF6, which is upstream of p38 MAPK and NF-κB, was attenuated by bumetanide after IR and HR. Conclusions: Inhibition of NKCC1 by bumetanide reciprocally modulated epithelial p38 MAPK and NF-κB via TRAF6 in IR-ALI. This interaction attenuated the reduction of AFC via upregulating ENaC expression and reduced lung inflammation.
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Affiliation(s)
- Chih-Hao Shen
- Division of Pulmonary and Critical Care, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan.,Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan.,Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Jr-Yu Lin
- Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Yung-Lung Chang
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Shu-Yu Wu
- Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Chung-Kan Peng
- Division of Pulmonary and Critical Care, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Chin-Pyng Wu
- Department of Critical Care Medicine, Landseed Hospital, Taoyuan, Taiwan
| | - Kun-Lun Huang
- Division of Pulmonary and Critical Care, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan.,Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan
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12
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Del Greco M F, Foco L, Pichler I, Eller P, Eller K, Benyamin B, Whitfield JB, Pramstaller PP, Thompson JR, Pattaro C, Minelli C. Serum iron level and kidney function: a Mendelian randomization study. Nephrol Dial Transplant 2018; 32:273-278. [PMID: 28186534 DOI: 10.1093/ndt/gfw215] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 04/25/2016] [Indexed: 01/01/2023] Open
Abstract
Background Iron depletion is a known consequence of chronic kidney disease (CKD), but there is contradicting epidemiological evidence on whether iron itself affects kidney function and whether its effect is protective or detrimental in the general population. While epidemiological studies tend to be affected by confounding and reverse causation, Mendelian randomization (MR) can provide unconfounded estimates of causal effects by using genes as instruments. Methods We performed an MR study of the effect of serum iron levels on estimated glomerular filtration rate (eGFR), using genetic variants known to be associated with iron. MR estimates of the effect of iron on eGFR were derived based on the association of each variant with iron and eGFR from two large genome-wide meta-analyses on 48 978 and 74 354 individuals. We performed a similar MR analysis for ferritin, which measures iron stored in the body, using variants associated with ferritin. Results A combined MR estimate across all variants showed a 1.3% increase in eGFR per standard deviation increase in iron (95% confidence interval 0.4–2.1%; P = 0.004). The results for ferritin were consistent with those for iron. Secondary MR analyses of the effects of iron and ferritin on CKD did not show significant associations but had very low statistical power. Conclusions Our study suggests a protective effect of iron on kidney function in the general population. Further research is required to confirm this causal association, investigate it in study populations at higher risk of CKD and explore its underlying mechanism of action.
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Affiliation(s)
- Fabiola Del Greco M
- Center for Biomedicine, European Academy of Bolzano/Bozen (EURAC), affiliated with the University of Lübeck, Via Galvani 31, Bolzano, Italy
| | - Luisa Foco
- Center for Biomedicine, European Academy of Bolzano/Bozen (EURAC), affiliated with the University of Lübeck, Via Galvani 31, Bolzano, Italy
| | - Irene Pichler
- Center for Biomedicine, European Academy of Bolzano/Bozen (EURAC), affiliated with the University of Lübeck, Via Galvani 31, Bolzano, Italy
| | | | | | - Beben Benyamin
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia
| | - John B Whitfield
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | | | - Peter P Pramstaller
- Center for Biomedicine, European Academy of Bolzano/Bozen (EURAC), affiliated with the University of Lübeck, Via Galvani 31, Bolzano, Italy
| | - John R Thompson
- Department of Health Sciences, University of Leicester, Leicester, UK
| | - Cristian Pattaro
- Center for Biomedicine, European Academy of Bolzano/Bozen (EURAC), affiliated with the University of Lübeck, Via Galvani 31, Bolzano, Italy
| | - Cosetta Minelli
- Population Health and Occupational Disease, National Heart and Lung Institute, Imperial College, Emmanuel Kaye Building, 1 Manresa Road, London, UK
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13
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Stoll S, Wang C, Qiu H. DNA Methylation and Histone Modification in Hypertension. Int J Mol Sci 2018; 19:ijms19041174. [PMID: 29649151 PMCID: PMC5979462 DOI: 10.3390/ijms19041174] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 03/23/2018] [Accepted: 04/09/2018] [Indexed: 12/22/2022] Open
Abstract
Systemic hypertension, which eventually results in heart failure, renal failure or stroke, is a common chronic human disorder that particularly affects elders. Although many signaling pathways involved in the development of hypertension have been reported over the past decades, which has led to the implementation of a wide variety of anti-hypertensive therapies, one half of all hypertensive patients still do not have their blood pressure controlled. The frontier in understanding the molecular mechanisms underlying hypertension has now advanced to the level of epigenomics. Particularly, increasing evidence is emerging that DNA methylation and histone modifications play an important role in gene regulation and are involved in alteration of the phenotype and function of vascular cells in response to environmental stresses. This review seeks to highlight the recent advances in our knowledge of the epigenetic regulations and mechanisms of hypertension, focusing on the role of DNA methylation and histone modification in the vascular wall. A better understanding of the epigenomic regulation in the hypertensive vessel may lead to the identification of novel target molecules that, in turn, may lead to novel drug discoveries for the treatment of hypertension.
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Affiliation(s)
- Shaunrick Stoll
- Division of Pharmacology and Physiology, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Charles Wang
- Center for Genomics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Hongyu Qiu
- Division of Pharmacology and Physiology, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
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Delpire E, Gagnon KB. Na + -K + -2Cl - Cotransporter (NKCC) Physiological Function in Nonpolarized Cells and Transporting Epithelia. Compr Physiol 2018; 8:871-901. [PMID: 29687903 DOI: 10.1002/cphy.c170018] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Two genes encode the Na+ -K+ -2Cl- cotransporters, NKCC1 and NKCC2, that mediate the tightly coupled movement of 1Na+ , 1K+ , and 2Cl- across the plasma membrane of cells. Na+ -K+ -2Cl- cotransport is driven by the chemical gradient of the three ionic species across the membrane, two of them maintained by the action of the Na+ /K+ pump. In many cells, NKCC1 accumulates Cl- above its electrochemical potential equilibrium, thereby facilitating Cl- channel-mediated membrane depolarization. In smooth muscle cells, this depolarization facilitates the opening of voltage-sensitive Ca2+ channels, leading to Ca2+ influx, and cell contraction. In immature neurons, the depolarization due to a GABA-mediated Cl- conductance produces an excitatory rather than inhibitory response. In many cell types that have lost water, NKCC is activated to help the cells recover their volume. This is specially the case if the cells have also lost Cl- . In combination with the Na+ /K+ pump, the NKCC's move ions across various specialized epithelia. NKCC1 is involved in Cl- -driven fluid secretion in many exocrine glands, such as sweat, lacrimal, salivary, stomach, pancreas, and intestine. NKCC1 is also involved in K+ -driven fluid secretion in inner ear, and possibly in Na+ -driven fluid secretion in choroid plexus. In the thick ascending limb of Henle, NKCC2 activity in combination with the Na+ /K+ pump participates in reabsorbing 30% of the glomerular-filtered Na+ . Overall, many critical physiological functions are maintained by the activity of the two Na+ -K+ -2Cl- cotransporters. In this overview article, we focus on the functional roles of the cotransporters in nonpolarized cells and in epithelia. © 2018 American Physiological Society. Compr Physiol 8:871-901, 2018.
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Affiliation(s)
- Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical School, Nashville, Tennessee, USA
| | - Kenneth B Gagnon
- Division of Nephrology and Hypertension, Department of Medicine, University of Louisville School of Medicine, Louisville, Keystone, USA
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15
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Garneau AP, Marcoux AA, Frenette-Cotton R, Mac-Way F, Lavoie JL, Isenring P. Molecular insights into the normal operation, regulation, and multisystemic roles of K +-Cl - cotransporter 3 (KCC3). Am J Physiol Cell Physiol 2017; 313:C516-C532. [PMID: 28814402 DOI: 10.1152/ajpcell.00106.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/26/2017] [Accepted: 08/14/2017] [Indexed: 12/12/2022]
Abstract
Long before the molecular identity of the Na+-dependent K+-Cl- cotransporters was uncovered in the mid-nineties, a Na+-independent K+-Cl- cotransport system was also known to exist. It was initially observed in sheep and goat red blood cells where it was shown to be ouabain-insensitive and to increase in the presence of N-ethylmaleimide (NEM). After it was established between the early and mid-nineties, the expressed sequence tag (EST) databank was found to include a sequence that was highly homologous to those of the Na+-dependent K+-Cl- cotransporters. This sequence was eventually found to code for the Na+-independent K+-Cl- cotransport function that was described in red blood cells several years before. It was termed KCC1 and led to the discovery of three isoforms called KCC2, KCC3, and KCC4. Since then, it has become obvious that each one of these isoforms exhibits unique patterns of distribution and fulfills distinct physiological roles. Among them, KCC3 has been the subject of great attention in view of its important role in the nervous system and its association with a rare hereditary sensorimotor neuropathy (called Andermann syndrome) that affects many individuals in Quebec province (Canada). It was also found to play important roles in the cardiovascular system, the organ of Corti, and circulating blood cells. As will be seen in this review, however, there are still a number of uncertainties regarding the transport properties, structural organization, and regulation of KCC3. The same is true regarding the mechanisms by which KCC3 accomplishes its numerous functions in animal cells.
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Affiliation(s)
- A P Garneau
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
- Cardiometabolic Axis, Kinesiology Department, University of Montréal, Montreal, Quebec, Canada
| | - A A Marcoux
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
| | - R Frenette-Cotton
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
| | - F Mac-Way
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
| | - J L Lavoie
- Cardiometabolic Axis, Kinesiology Department, University of Montréal, Montreal, Quebec, Canada
| | - P Isenring
- Nephrology Research Group, Department of Medicine, Laval University, Quebec City, Quebec, Canada; and
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16
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Bhuiyan MIH, Song S, Yuan H, Begum G, Kofler J, Kahle KT, Yang SS, Lin SH, Alper SL, Subramanya AR, Sun D. WNK-Cab39-NKCC1 signaling increases the susceptibility to ischemic brain damage in hypertensive rats. J Cereb Blood Flow Metab 2017; 37:2780-2794. [PMID: 27798271 PMCID: PMC5536788 DOI: 10.1177/0271678x16675368] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
With-no-lysine kinase (WNK) and Na+-K+-2Cl- cotransporter 1 (NKCC1) are involved in the pathogenesis of hypertension. In this study, we investigated the WNK-NKCC1 signaling pathway in spontaneously hypertensive rats (SHR) and their associated susceptibility to stroke injury. Basal NKCC1 protein levels were higher in SHR than in normotensive Wistar Kyoto (WKY) rat brains. After inducing ischemic stroke, adult male WKY and SHR received either saline or NKCC1 inhibitor bumetanide (10 mg/kg/day, i.p.) starting at 3-h post-reperfusion. NKCC1 inhibition blunted the extent of ischemic infarction in SHR and improved their neurobehavioral functions. Interestingly, ischemia led to increased NKCC1 phosphorylation in SHR but not in WKY rats. Pronounced elevation of WNK1, WNK2 and WNK4 protein and downregulation of WNK3 were detected in ischemic SHR, but not in ischemic WKY rats. Upregulation of WNK-NKCC1 complex in ischemic SHR brain was associated with increased Ca2+-binding protein 39 (Cab39), without increases in Ste20-related proline alanine-rich kinase or oxidative stress-responsive kinase-1. Moreover, subacute middle cerebral artery stroke human brain autopsy exhibited increased expression of NKCC1 protein. We conclude that augmented WNK-Cab39-NKCC1 signaling in SHR is associated with an increased susceptibility to ischemic brain damage and may serve as a novel target for anti-hypertensive and anti-ischemic stroke therapy.
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Affiliation(s)
| | - Shanshan Song
- 1 Department of Neurology, University of Pittsburgh, Pittsburgh, USA
| | - Hui Yuan
- 1 Department of Neurology, University of Pittsburgh, Pittsburgh, USA
| | - Gulnaz Begum
- 1 Department of Neurology, University of Pittsburgh, Pittsburgh, USA
| | - Julia Kofler
- 2 Department of Pathology, University of Pittsburgh, Pittsburgh, USA
| | - Kristopher T Kahle
- 3 Department of Neurosurgery, Yale University School of Medicine, New Haven, USA.,4 Department of Pediatrics, Yale University School of Medicine, New Haven, USA
| | - Sung-Sen Yang
- 5 Division of Nephrology, Department of Medicine, Tri-Service General Hospital, Taipei, Taiwan.,6 Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Hua Lin
- 5 Division of Nephrology, Department of Medicine, Tri-Service General Hospital, Taipei, Taiwan.,6 Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Seth L Alper
- 7 Division of Nephrology and Vascular Biology Center, Beth Israel Deaconess Medical Center, Boston, USA.,8 Department of Medicine, Harvard Medical School, Boston, USA
| | - Arohan R Subramanya
- 9 Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Dandan Sun
- 1 Department of Neurology, University of Pittsburgh, Pittsburgh, USA.,10 Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, USA
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17
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OSR1 and SPAK cooperatively modulate Sertoli cell support of mouse spermatogenesis. Sci Rep 2016; 6:37205. [PMID: 27853306 PMCID: PMC5112561 DOI: 10.1038/srep37205] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/06/2016] [Indexed: 02/06/2023] Open
Abstract
We investigated the role of oxidative stress-responsive kinase-1 (OSR1) and STE20 (sterile 20)/SPS1-related proline/alanine-rich kinase (SPAK), upstream regulators of the Na+-K+-2Cl− cotransporter (NKCC1)—essential for spermatogenesis—in mouse models of male fertility. Global OSR1+/− gene mutations, but not global SPAK−/− or Sertoli cell (SC)-specific OSR1 gene knockout (SC-OSR1−/−), cause subfertility with impaired sperm function and are associated with reduced abundance of phosphorylated (p)-NKCC1 but increased p-SPAK expression in testicular tissue and spermatozoa. To dissect further in a SC-specific manner the compensatory effect of OSR1 and SPAK in male fertility, we generated SC-OSR1−/− and SPAK−/− double knockout (DKO) male mice. These are infertile with defective spermatogenesis, presenting a SC-only-like syndrome. Disrupted meiotic progression and increased germ cell apoptosis occurred in the first wave of spermatogenesis. The abundance of total and p-NKCC1 was significantly decreased in the testicular tissues of DKO mice. These results indicate that OSR1 and SPAK cooperatively regulate NKCC1-dependent spermatogenesis in a SC-restricted manner.
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18
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Murthy M, Kurz T, O'Shaughnessy KM. WNK signalling pathways in blood pressure regulation. Cell Mol Life Sci 2016; 74:1261-1280. [PMID: 27815594 PMCID: PMC5346417 DOI: 10.1007/s00018-016-2402-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/17/2016] [Accepted: 10/27/2016] [Indexed: 01/11/2023]
Abstract
Hypertension (high blood pressure) is a major public health problem affecting more than a billion people worldwide with complications, including stroke, heart failure and kidney failure. The regulation of blood pressure is multifactorial reflecting genetic susceptibility, in utero environment and external factors such as obesity and salt intake. In keeping with Arthur Guyton's hypothesis, the kidney plays a key role in blood pressure control and data from clinical studies; physiology and genetics have shown that hypertension is driven a failure of the kidney to excrete excess salt at normal levels of blood pressure. There is a number of rare Mendelian blood pressure syndromes, which have shed light on the molecular mechanisms involved in dysregulated ion transport in the distal kidney. One in particular is Familial hyperkalemic hypertension (FHHt), an autosomal dominant monogenic form of hypertension characterised by high blood pressure, hyperkalemia, hyperchloremic metabolic acidosis, and hypercalciuria. The clinical signs of FHHt are treated by low doses of thiazide diuretic, and it mirrors Gitelman syndrome which features the inverse phenotype of hypotension, hypokalemic metabolic alkalosis, and hypocalciuria. Gitelman syndrome is caused by loss of function mutations in the thiazide-sensitive Na/Cl cotransporter (NCC); however, FHHt patients do not have mutations in the SCL12A3 locus encoding NCC. Instead, mutations have been identified in genes that have revealed a key signalling pathway that regulates NCC and several other key transporters and ion channels in the kidney that are critical for BP regulation. This is the WNK kinase signalling pathway that is the subject of this review.
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Affiliation(s)
- Meena Murthy
- Division of Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, CB2 2QQ, UK
| | - Thimo Kurz
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Davidson Building, Glasgow, G12 8QQ, Scotland, UK
| | - Kevin M O'Shaughnessy
- Division of Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, CB2 2QQ, UK.
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19
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Boedtkjer E, Matchkov VV, Boedtkjer DMB, Aalkjaer C. Negative News: Cl− and HCO3− in the Vascular Wall. Physiology (Bethesda) 2016; 31:370-83. [DOI: 10.1152/physiol.00001.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Cl− and HCO3− are the most prevalent membrane-permeable anions in the intra- and extracellular spaces of the vascular wall. Outwardly directed electrochemical gradients for Cl− and HCO3− permit anion channel opening to depolarize vascular smooth muscle and endothelial cells. Transporters and channels for Cl− and HCO3− also modify vascular contractility and structure independently of membrane potential. Transport of HCO3− regulates intracellular pH and thereby modifies the activity of enzymes, ion channels, and receptors. There is also evidence that Cl− and HCO3− transport proteins affect gene expression and protein trafficking. Considering the extensive implications of Cl− and HCO3− in the vascular wall, it is critical to understand how these ions are transported under physiological conditions and how disturbances in their transport can contribute to disease development. Recently, sensing mechanisms for Cl− and HCO3− have been identified in the vascular wall where they modify ion transport and vasomotor function, for instance, during metabolic disturbances. This review discusses current evidence that transport (e.g., via NKCC1, NBCn1, Ca2+-activated Cl− channels, volume-regulated anion channels, and CFTR) and sensing (e.g., via WNK and RPTPγ) of Cl− and HCO3− influence cardiovascular health and disease.
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Affiliation(s)
| | | | - Donna M. B. Boedtkjer
- Department of Biomedicine, Aarhus University, Denmark
- Department of Clinical Medicine, Aarhus University, Denmark; and
| | - Christian Aalkjaer
- Department of Biomedicine, Aarhus University, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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20
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Dbouk HA, Huang CL, Cobb MH. Hypertension: the missing WNKs. Am J Physiol Renal Physiol 2016; 311:F16-27. [PMID: 27009339 PMCID: PMC4967160 DOI: 10.1152/ajprenal.00358.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 03/16/2016] [Indexed: 12/23/2022] Open
Abstract
The With no Lysine [K] (WNK) family of enzymes are central in the regulation of blood pressure. WNKs have been implicated in hereditary hypertension disorders, mainly through control of the activity and levels of ion cotransporters and channels. Actions of WNKs in the kidney have been heavily investigated, and recent studies have provided insight into not only the regulation of these enzymes but also how mutations in WNKs and their interacting partners contribute to hypertensive disorders. Defining the roles of WNKs in the cardiovascular system will provide clues about additional mechanisms by which WNKs can regulate blood pressure. This review summarizes recent developments in the regulation of the WNK signaling cascade and its role in regulation of blood pressure.
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Affiliation(s)
- Hashem A Dbouk
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Chou-Long Huang
- Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Melanie H Cobb
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; and
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21
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Garneau AP, Marcoux AA, Noël M, Frenette-Cotton R, Drolet MC, Couet J, Larivière R, Isenring P. Ablation of Potassium-Chloride Cotransporter Type 3 (Kcc3) in Mouse Causes Multiple Cardiovascular Defects and Isosmotic Polyuria. PLoS One 2016; 11:e0154398. [PMID: 27166674 PMCID: PMC4864296 DOI: 10.1371/journal.pone.0154398] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/12/2016] [Indexed: 12/20/2022] Open
Abstract
Inactivation of Kcc3 in a mixed 129/Sv×C57BL/6 mouse background has been previously found to increase systemic blood pressure (BP) through presumed neurogenic mechanisms. Yet, while this background is generally not considered ideal to investigate the cardiovascular system, KCC3 is also expressed in the arterial wall and proximal nephron. In the current study, the effects of Kcc3 ablation was investigated in a pure rather than mixed C57BL/6J background under regular- and high-salt diets to determine whether they could be mediated through vasculogenic and nephrogenic mechanisms. Aortas were also assessed for reactivity to pharmacological agents while isolated from the influence of sympathetic ganglia. This approach led to the identification of unforeseen abnormalities such as lower pulse pressure, heart rate, aortic reactivity and aortic wall thickness, but higher diastolic BP, left ventricular mass and urinary output in the absence of increased catecholamine levels. Salt loading also led systolic BP to be higher, but to no further changes in hemodynamic parameters. Importantly, aortic vascular smooth muscle cells and cardiomyocytes were both found to express KCC3 abundantly in heterozygous mice. Hence, Kcc3 inactivation in our model caused systemic vascular resistance and ventricular mass to increase while preventing extracellular fluid volume to accumulate. Given that it also affected the physiological properties of aortas in vitro, vasculogenic mechanisms could therefore account for a number of the hemodynamic abnormalities observed.
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Affiliation(s)
- Alexandre P. Garneau
- Nephrology Research Group, Centre de recherche L’Hôtel-Dieu de Québec, Centre hospitalier universitaire de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
| | - Andrée-Anne Marcoux
- Nephrology Research Group, Centre de recherche L’Hôtel-Dieu de Québec, Centre hospitalier universitaire de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
| | - Micheline Noël
- Nephrology Research Group, Centre de recherche L’Hôtel-Dieu de Québec, Centre hospitalier universitaire de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
| | - Rachelle Frenette-Cotton
- Nephrology Research Group, Centre de recherche L’Hôtel-Dieu de Québec, Centre hospitalier universitaire de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
| | - Marie-Claude Drolet
- Valvulopathy Research Group, Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
| | - Jacques Couet
- Valvulopathy Research Group, Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
| | - Richard Larivière
- Nephrology Research Group, Centre de recherche L’Hôtel-Dieu de Québec, Centre hospitalier universitaire de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
| | - Paul Isenring
- Nephrology Research Group, Centre de recherche L’Hôtel-Dieu de Québec, Centre hospitalier universitaire de Québec, Québec City, Canada
- Department of Medicine, Université Laval, Québec City, Canada
- * E-mail:
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Han L, Liu Y, Duan S, Perry B, Li W, He Y. DNA methylation and hypertension: emerging evidence and challenges. Brief Funct Genomics 2016; 15:460-469. [PMID: 27142121 DOI: 10.1093/bfgp/elw014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Hypertension is a multifactorial disease influenced by an interaction of environmental and genetic factors. The exact molecular mechanism of hypertension remains unknown. Aberrant DNA methylation is the most well-defined epigenetic modification that regulates gene transcription. However, studies on the association between DNA methylation and hypertension are still in their infancy. This review summarizes the latest evidence and challenges regarding the role of DNA methylation on hypertension.
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Carrisoza-Gaytan R, Carattino MD, Kleyman TR, Satlin LM. An unexpected journey: conceptual evolution of mechanoregulated potassium transport in the distal nephron. Am J Physiol Cell Physiol 2015; 310:C243-59. [PMID: 26632600 DOI: 10.1152/ajpcell.00328.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Flow-induced K secretion (FIKS) in the aldosterone-sensitive distal nephron (ASDN) is mediated by large-conductance, Ca(2+)/stretch-activated BK channels composed of pore-forming α-subunits (BKα) and accessory β-subunits. This channel also plays a critical role in the renal adaptation to dietary K loading. Within the ASDN, the cortical collecting duct (CCD) is a major site for the final renal regulation of K homeostasis. Principal cells in the ASDN possess a single apical cilium whereas the surfaces of adjacent intercalated cells, devoid of cilia, are decorated with abundant microvilli and microplicae. Increases in tubular (urinary) flow rate, induced by volume expansion, diuretics, or a high K diet, subject CCD cells to hydrodynamic forces (fluid shear stress, circumferential stretch, and drag/torque on apical cilia and presumably microvilli/microplicae) that are transduced into increases in principal (PC) and intercalated (IC) cell cytoplasmic Ca(2+) concentration that activate apical voltage-, stretch- and Ca(2+)-activated BK channels, which mediate FIKS. This review summarizes studies by ourselves and others that have led to the evolving picture that the BK channel is localized in a macromolecular complex at the apical membrane, composed of mechanosensitive apical Ca(2+) channels and a variety of kinases/phosphatases as well as other signaling molecules anchored to the cytoskeleton, and that an increase in tubular fluid flow rate leads to IC- and PC-specific responses determined, in large part, by the cell-specific composition of the BK channels.
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Affiliation(s)
| | - Marcelo D Carattino
- Renal-Electrolyte Division, Department of Medicine, Pittsburgh, Pennsylvania
| | - Thomas R Kleyman
- Renal-Electrolyte Division, Department of Medicine, Pittsburgh, Pennsylvania
| | - Lisa M Satlin
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York; and
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Zhang J, Siew K, Macartney T, O'Shaughnessy KM, Alessi DR. Critical role of the SPAK protein kinase CCT domain in controlling blood pressure. Hum Mol Genet 2015; 24:4545-58. [PMID: 25994507 PMCID: PMC4512625 DOI: 10.1093/hmg/ddv185] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 05/14/2015] [Indexed: 02/05/2023] Open
Abstract
The STE20/SPS1-related proline/alanine-rich kinase (SPAK) controls blood pressure (BP) by phosphorylating and stimulating the Na-Cl (NCC) and Na-K-2Cl (NKCC2) co-transporters, which regulate salt reabsorption in the kidney. SPAK possesses a conserved carboxy-terminal (CCT) domain, which recognises RFXV/I motifs present in its upstream activator [isoforms of the With-No-lysine (K) kinases (WNKs)] as well as its substrates (NCC and NKCC2). To define the physiological importance of the CCT domain, we generated knock-in mice in which the critical CCT domain Leu502 residue required for high affinity recognition of the RFXI/V motif was mutated to Alanine. The SPAK CCT domain defective knock-in animals are viable, and the Leu502Ala mutation abolished co-immunoprecipitation of SPAK with WNK1, NCC and NKCC2. The CCT domain defective animals displayed markedly reduced SPAK activity and phosphorylation of NCC and NKCC2 co-transporters at the residues phosphorylated by SPAK. This was also accompanied by a reduction in the expression of NCC and NKCC2 protein without changes in mRNA levels. The SPAK CCT domain knock-in mice showed typical features of Gitelman Syndrome with mild hypokalaemia, hypomagnesaemia, hypocalciuria and displayed salt wasting on switching to a low-Na diet. These observations establish that the CCT domain plays a crucial role in controlling SPAK activity and BP. Our results indicate that CCT domain inhibitors would be effective at reducing BP by lowering phosphorylation as well as expression of NCC and NKCC2.
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Affiliation(s)
- Jinwei Zhang
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland and
| | - Keith Siew
- Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Thomas Macartney
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland and
| | - Kevin M O'Shaughnessy
- Experimental Medicine and Immunotherapeutics, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Dario R Alessi
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland and
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Sohara E, Uchida S. Kelch-like 3/Cullin 3 ubiquitin ligase complex and WNK signaling in salt-sensitive hypertension and electrolyte disorder. Nephrol Dial Transplant 2015; 31:1417-24. [DOI: 10.1093/ndt/gfv259] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 05/22/2015] [Indexed: 12/20/2022] Open
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26
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Orlov SN, Koltsova SV, Kapilevich LV, Gusakova SV, Dulin NO. NKCC1 and NKCC2: The pathogenetic role of cation-chloride cotransporters in hypertension. Genes Dis 2015; 2:186-196. [PMID: 26114157 PMCID: PMC4477834 DOI: 10.1016/j.gendis.2015.02.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 02/16/2015] [Indexed: 11/17/2022] Open
Abstract
This review summarizes the data on the functional significance of ubiquitous (NKCC1) and renal-specific (NKCC2) isoforms of electroneutral sodium, potassium and chloride cotransporters. These carriers contribute to the pathogenesis of hypertension via regulation of intracellular chloride concentration in vascular smooth muscle and neuronal cells and via sensing chloride concentration in the renal tubular fluid, respectively. Both NKCC1 and NKCC2 are inhibited by furosemide and other high-ceiling diuretics widely used for attenuation of extracellular fluid volume. However, the chronic usage of these compounds for the treatment of hypertension and other volume-expanded disorders may have diverse side-effects due to suppression of myogenic response in microcirculatory beds.
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Affiliation(s)
- Sergei N. Orlov
- Faculty of Biology, M.V. Lomonosov Moscow State University, Russia
- Тomsk State University, Russia
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Hübner CA, Schroeder BC, Ehmke H. Regulation of vascular tone and arterial blood pressure: role of chloride transport in vascular smooth muscle. Pflugers Arch 2015; 467:605-14. [DOI: 10.1007/s00424-014-1684-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/24/2014] [Accepted: 12/29/2014] [Indexed: 01/01/2023]
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Jin X, Shah S, Du X, Zhang H, Gamper N. Activation of Ca(2+) -activated Cl(-) channel ANO1 by localized Ca(2+) signals. J Physiol 2014; 594:19-30. [PMID: 25398532 PMCID: PMC4704509 DOI: 10.1113/jphysiol.2014.275107] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 11/08/2014] [Indexed: 12/13/2022] Open
Abstract
Ca2+‐activated chloride channels (CaCCs) regulate numerous physiological processes including epithelial transport, smooth muscle contraction and sensory processing. Anoctamin‐1 (ANO1, TMEM16A) is a principal CaCC subunit in many cell types, yet our understanding of the mechanisms of ANO1 activation and regulation are only beginning to emerge. Ca2+ sensitivity of ANO1 is rather low and at negative membrane potentials the channel requires several micromoles of intracellular Ca2+ for activation. However, global Ca2+ levels in cells rarely reach such levels and, therefore, there must be mechanisms that focus intracellular Ca2+ transients towards the ANO1 channels. Recent findings indeed indicate that ANO1 channels often co‐localize with sources of intracellular Ca2+ signals. Interestingly, it appears that in many cell types ANO1 is particularly tightly coupled to the Ca2+ release sites of the intracellular Ca2+ stores. Such preferential coupling may represent a general mechanism of ANO1 activation in native tissues.
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Affiliation(s)
- Xin Jin
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Sihab Shah
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Xiaona Du
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Hailin Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Nikita Gamper
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
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Kikuchi E, Mori T, Zeniya M, Isobe K, Ishigami-Yuasa M, Fujii S, Kagechika H, Ishihara T, Mizushima T, Sasaki S, Sohara E, Rai T, Uchida S. Discovery of Novel SPAK Inhibitors That Block WNK Kinase Signaling to Cation Chloride Transporters. J Am Soc Nephrol 2014; 26:1525-36. [PMID: 25377078 DOI: 10.1681/asn.2014060560] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/20/2014] [Indexed: 12/21/2022] Open
Abstract
Upon activation by with-no-lysine kinases, STE20/SPS1-related proline-alanine-rich protein kinase (SPAK) phosphorylates and activates SLC12A transporters such as the Na(+)-Cl(-) cotransporter (NCC) and Na(+)-K(+)-2Cl(-) cotransporter type 1 (NKCC1) and type 2 (NKCC2); these transporters have important roles in regulating BP through NaCl reabsorption and vasoconstriction. SPAK knockout mice are viable and display hypotension with decreased activity (phosphorylation) of NCC and NKCC1 in the kidneys and aorta, respectively. Therefore, agents that inhibit SPAK activity could be a new class of antihypertensive drugs with dual actions (i.e., NaCl diuresis and vasodilation). In this study, we developed a new ELISA-based screening system to find novel SPAK inhibitors and screened >20,000 small-molecule compounds. Furthermore, we used a drug repositioning strategy to identify existing drugs that inhibit SPAK activity. As a result, we discovered one small-molecule compound (Stock 1S-14279) and an antiparasitic agent (Closantel) that inhibited SPAK-regulated phosphorylation and activation of NCC and NKCC1 in vitro and in mice. Notably, these compounds had structural similarity and inhibited SPAK in an ATP-insensitive manner. We propose that the two compounds found in this study may have great potential as novel antihypertensive drugs.
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Affiliation(s)
- Eriko Kikuchi
- Department of Nephrology, Graduate School of Medical and Dental Sciences
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences
| | - Moko Zeniya
- Department of Nephrology, Graduate School of Medical and Dental Sciences
| | - Kiyoshi Isobe
- Department of Nephrology, Graduate School of Medical and Dental Sciences
| | | | - Shinya Fujii
- Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan; and
| | - Hiroyuki Kagechika
- Chemical Biology Screening Center, and Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan; and
| | - Tomoaki Ishihara
- Department of Analytical Chemistry, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Tohru Mizushima
- Department of Analytical Chemistry, Faculty of Pharmacy, Keio University, Tokyo, Japan
| | - Sei Sasaki
- Department of Nephrology, Graduate School of Medical and Dental Sciences
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences
| | - Tatemitsu Rai
- Department of Nephrology, Graduate School of Medical and Dental Sciences
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences,
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Wang HS, Chen Y, Vairamani K, Shull GE. Critical role of bicarbonate and bicarbonate transporters in cardiac function. World J Biol Chem 2014; 5:334-345. [PMID: 25225601 PMCID: PMC4160527 DOI: 10.4331/wjbc.v5.i3.334] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/06/2014] [Accepted: 05/19/2014] [Indexed: 02/05/2023] Open
Abstract
Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H+, HCO3- is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membranes. The functions of HCO3- and HCO3--transporters in epithelial tissues have been studied extensively, but their functions in heart are less well understood. Here we review studies of the identities and physiological functions of Cl-/HCO3- exchangers and Na+/HCO3- cotransporters of the SLC4A and SLC26A families in heart. We also present RNA Seq analysis of their cardiac mRNA expression levels. These studies indicate that slc4a3 (AE3) is the major Cl-/HCO3- exchanger and plays a protective role in heart failure, and that Slc4a4 (NBCe1) is the major Na+/HCO3- cotransporter and affects action potential duration. In addition, previous studies show that HCO3- has a positive inotropic effect in the perfused heart that is largely independent of effects on intracellular Ca2+. The importance of HCO3- in the regulation of contractility is supported by experiments showing that isolated cardiomyocytes exhibit sharply enhanced contractility, with no change in Ca2+ transients, when switched from Hepes-buffered to HCO3-- buffered solutions. These studies demonstrate that HCO3- and HCO3--handling proteins play important roles in the regulation of cardiac function.
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Fraser SA, Davies M, Katerelos M, Gleich K, Choy SW, Steel R, Galic S, Mount PF, Kemp BE, Power DA. Activation of AMPK reduces the co-transporter activity of NKCC1. Mol Membr Biol 2014; 31:95-102. [PMID: 24702155 DOI: 10.3109/09687688.2014.902128] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The co-transporter activity of Na(+)-K(+)-2Cl(-) 1 (NKCC1) is dependent on phosphorylation. In this study we show the energy-sensing kinase AMPK inhibits NKCC1 activity. Three separate AMPK activators (AICAR, Phenformin and A-769662) inhibited NKCC1 flux in a variety of nucleated cells. Treatment with A-769662 resulted in a reduction of NKCC1(T212/T217) phosphorylation, and this was reversed by treatment with the non-selective AMPK inhibitor Compound C. AMPK dependence was confirmed by treatment of AMPK null mouse embryonic fibroblasts, where A-769662 had no effect on NKCC1 mediated transport. AMPK was found to directly phosphorylate a recombinant human-NKCC1 N-terminal fragment (1-293) with the phosphorylated site identified as S77. Mutation of Serine 77 to Alanine partially prevented the inhibitory effect of A-769662 on NKCC1 activity. In conclusion, AMPK can act to reduce NKCC1-mediated transport. While the exact mechanism is still unclear there is evidence for both a direct effect on phosphorylation of S77 and reduced phosphorylation of T212/217.
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Affiliation(s)
- Scott A Fraser
- Institute for Breathing and Sleep, Kidney Laboratory , Melbourne, Australia
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Abstract
TMEM16 proteins, also known as anoctamins, are involved in a variety of functions that include ion transport, phospholipid scrambling, and regulation of other membrane proteins. The first two members of the family, TMEM16A (anoctamin-1, ANO1) and TMEM16B (anoctamin-2, ANO2), function as Ca2+-activated Cl- channels (CaCCs), a type of ion channel that plays important functions such as transepithelial ion transport, smooth muscle contraction, olfaction, phototransduction, nociception, and control of neuronal excitability. Genetic ablation of TMEM16A in mice causes impairment of epithelial Cl- secretion, tracheal abnormalities, and block of gastrointestinal peristalsis. TMEM16A is directly regulated by cytosolic Ca2+ as well as indirectly by its interaction with calmodulin. Other members of the anoctamin family, such as TMEM16C, TMEM16D, TMEM16F, TMEM16G, and TMEM16J, may work as phospholipid scramblases and/or ion channels. In particular, TMEM16F (ANO6) is a major contributor to the process of phosphatidylserine translocation from the inner to the outer leaflet of the plasma membrane. Intriguingly, TMEM16F is also associated with the appearance of anion/cation channels activated by very high Ca2+ concentrations. Furthermore, a TMEM16 protein expressed in Aspergillus fumigatus displays both ion channel and lipid scramblase activity. This finding suggests that dual function is an ancestral characteristic of TMEM16 proteins and that some members, such as TMEM16A and TMEM16B, have evolved to a pure channel function. Mutations in anoctamin genes (ANO3, ANO5, ANO6, and ANO10) cause various genetic diseases. These diseases suggest the involvement of anoctamins in a variety of cell functions whose link with ion transport and/or lipid scrambling needs to be clarified.
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Chemical library screening for WNK signalling inhibitors using fluorescence correlation spectroscopy. Biochem J 2014; 455:339-45. [PMID: 23981180 DOI: 10.1042/bj20130597] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
WNKs (with-no-lysine kinases) are the causative genes of a hereditary hypertensive disease, PHAII (pseudohypoaldosteronism type II), and form a signal cascade with OSR1 (oxidative stress-responsive 1)/SPAK (STE20/SPS1-related proline/alanine-rich protein kinase) and Slc12a (solute carrier family 12) transporters. We have shown that this signal cascade regulates blood pressure by controlling vascular tone as well as renal NaCl excretion. Therefore agents that inhibit this signal cascade could be a new class of antihypertensive drugs. Since the binding of WNK to OSR1/SPAK kinases was postulated to be important for signal transduction, we sought to discover inhibitors of WNK/SPAK binding by screening chemical compounds that disrupt the binding. For this purpose, we developed a high-throughput screening method using fluorescent correlation spectroscopy. As a result of screening 17000 compounds, we discovered two novel compounds that reproducibly disrupted the binding of WNK to SPAK. Both compounds mediated dose-dependent inhibition of hypotonicity-induced activation of WNK, namely the phosphorylation of SPAK and its downstream transporters NKCC1 (Na/K/Cl cotransporter 1) and NCC (NaCl cotransporter) in cultured cell lines. The two compounds could be the promising seeds of new types of antihypertensive drugs, and the method that we developed could be applied as a general screening method to identify compounds that disrupt the binding of two molecules.
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Prasad V, Lorenz JN, Lasko VM, Nieman ML, Al Moamen NJ, Shull GE. Loss of the AE3 Cl(-)/HCO(-) 3 exchanger in mice affects rate-dependent inotropy and stress-related AKT signaling in heart. Front Physiol 2013; 4:399. [PMID: 24427143 PMCID: PMC3875869 DOI: 10.3389/fphys.2013.00399] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 12/19/2013] [Indexed: 01/12/2023] Open
Abstract
Cl(-)/HCO(-) 3 exchangers are expressed abundantly in cardiac muscle, suggesting that HCO(-) 3 extrusion serves an important function in heart. Mice lacking Anion Exchanger Isoform 3 (AE3), a major cardiac Cl(-)/HCO(-) 3 exchanger, appear healthy, but loss of AE3 causes decompensation in a hypertrophic cardiomyopathy (HCM) model. Using intra-ventricular pressure analysis, in vivo pacing, and molecular studies we identified physiological and biochemical changes caused by loss of AE3 that may contribute to decompensation in HCM. AE3-null mice had normal cardiac contractility under basal conditions and after β-adrenergic stimulation, but pacing of hearts revealed that frequency-dependent inotropy was blunted, suggesting that AE3-mediated HCO(-) 3 extrusion is required for a robust force-frequency response (FFR) during acute biomechanical stress in vivo. Modest changes in expression of proteins that affect Ca(2+)-handling were observed, but Ca(2+)-transient analysis of AE3-null myocytes showed normal twitch-amplitude and Ca(2+)-clearance. Phosphorylation and expression of several proteins implicated in HCM and FFR, including phospholamban (PLN), myosin binding protein C, and troponin I were not altered in hearts of paced AE3-null mice; however, phosphorylation of Akt, which plays a central role in mechanosensory signaling, was significantly higher in paced AE3-null hearts than in wild-type controls and phosphorylation of AMPK, which is affected by Akt and is involved in energy metabolism and some cases of HCM, was reduced. These data show loss of AE3 leads to impaired rate-dependent inotropy, appears to affect mechanical stress-responsive signaling, and reduces activation of AMPK, which may contribute to decompensation in heart failure.
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Affiliation(s)
- Vikram Prasad
- Departments of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - John N Lorenz
- Departments of Cellular and Molecular Physiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - Valerie M Lasko
- Departments of Cellular and Molecular Physiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - Michelle L Nieman
- Departments of Cellular and Molecular Physiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - Nabeel J Al Moamen
- Genetic Laboratory, Department of Pathology, Salmaniya Medical Complex Manama, Bahrain
| | - Gary E Shull
- Departments of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
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Abstract
Ca(2+)-activated Cl(-) channels (CaCCs) are plasma membrane proteins involved in various important physiological processes. In epithelial cells, CaCC activity mediates the secretion of Cl(-) and of other anions, such as bicarbonate and thiocyanate. In smooth muscle and excitable cells of the nervous system, CaCCs have an excitatory role coupling intracellular Ca(2+) elevation to membrane depolarization. Recent studies indicate that TMEM16A (transmembrane protein 16 A or anoctamin 1) and TMEM16B (transmembrane protein 16 B or anoctamin 2) are CaCC-forming proteins. Induced expression of TMEM16A and B in null cells by transfection causes the appearance of Ca(2+)-activated Cl(-) currents similar to those described in native tissues. Furthermore, silencing of TMEM16A by RNAi causes disappearance of CaCC activity in cells from airway epithelium, biliary ducts, salivary glands, and blood vessel smooth muscle. Mice devoid of TMEM16A expression have impaired Ca(2+)-dependent Cl(-) secretion in the epithelial cells of the airways, intestine, and salivary glands. These animals also show a loss of gastrointestinal motility, a finding consistent with an important function of TMEM16A in the electrical activity of gut pacemaker cells, that is, the interstitial cells of Cajal. Identification of TMEM16 proteins will help to elucidate the molecular basis of Cl(-) transport.
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Affiliation(s)
- Loretta Ferrera
- Laboratory of Molecular Genetics, Istituto Giannina Gaslini, Genova, Italy
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Zeniya M, Sohara E, Kita S, Iwamoto T, Susa K, Mori T, Oi K, Chiga M, Takahashi D, Yang SS, Lin SH, Rai T, Sasaki S, Uchida S. Dietary Salt Intake Regulates WNK3–SPAK–NKCC1 Phosphorylation Cascade in Mouse Aorta Through Angiotensin II. Hypertension 2013; 62:872-8. [DOI: 10.1161/hypertensionaha.113.01543] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Na–K–Cl cotransporter isoform 1 (NKCC1) is involved in the regulation of vascular smooth muscle cell contraction. Recently, the with-no-lysine kinase (WNK)–STE20/SPS1-related proline/alanine-rich kinase (SPAK)–NKCC1 phosphorylation cascade in vascular smooth muscle cells was found to be important in the regulation of vascular tone. In this study, we investigated whether the WNK–SPAK–NKCC1 cascade in mouse aortic tissue is regulated by dietary salt intake and the mechanisms responsible. Phosphorylation of SPAK and NKCC1 was significantly reduced in the aorta in high-salt–fed mice and was increased in the aorta in low-salt–fed mice, indicating that the WNK–SPAK–NKCC1 phosphorylation cascade in the aorta was indeed regulated by dietary salt intake. Acute and chronic angiotensin II infusion increased phosphorylation of SPAK and NKCC1 in the mouse aorta. In addition, valsartan, an antagonist of angiotensin II type 1 receptor, inhibited low-salt diet–induced phosphorylation of SPAK and NKCC1, demonstrating that angiotensin II activates the WNK–SPAK–NKCC1 phosphorylation cascade through the angiotensin II type 1 receptor. However, a low-salt diet and angiotensin II together did not increase phosphorylation of SPAK and NKCC1 in the aorta in WNK3 knockout mice, indicating that activation of the WNK–SPAK–NKCC1 phosphorylation cascade induced by a low-salt diet and angiotensin II is dependent on WNK3. Indeed, angiotensin II–induced increases in blood pressure were diminished in WNK3 knockout mice. In addition, decreased response to angiotensin II in the mesenteric arteries was observed in WNK3 knockout mice. Our data also clarified a novel mechanism for regulation of vascular tonus by angiotensin II. Inhibition of this cascade could, therefore, be a novel therapeutic target in hypertension.
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Affiliation(s)
- Moko Zeniya
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Eisei Sohara
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Satomi Kita
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Takahiro Iwamoto
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Koichiro Susa
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Takayasu Mori
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Katsuyuki Oi
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Motoko Chiga
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Daiei Takahashi
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Sung-Sen Yang
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Shih-Hua Lin
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Tatemitsu Rai
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Sei Sasaki
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
| | - Shinichi Uchida
- From the Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan (M.Z., E.S., K.S., T.M., K.O., M.C., D.T., T.R., S.S., S.U.); Department of Pharmacology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan (S.K., T.I.); and Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (S.-S.Y., S.-H.L.)
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Ding B, Frisina RD, Zhu X, Sakai Y, Sokolowski B, Walton JP. Direct control of Na(+)-K(+)-2Cl(-)-cotransport protein (NKCC1) expression with aldosterone. Am J Physiol Cell Physiol 2013; 306:C66-75. [PMID: 24173102 DOI: 10.1152/ajpcell.00096.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Sodium/potassium/chloride cotransporter (NKCC1) proteins play important roles in Na(+) and K(+) concentrations in key physiological systems, including cardiac, vascular, renal, nervous, and sensory systems. NKCC1 levels and functionality are altered in certain disease states, and tend to decline with age. A sensitive, effective way of regulating NKCC1 protein expression has significant biotherapeutic possibilities. The purpose of the present investigation was to determine if the naturally occurring hormone aldosterone (ALD) could regulate NKCC1 protein expression. Application of ALD to a human cell line (HT-29) revealed that ALD can regulate NKCC1 protein expression, quite sensitively and rapidly, independent of mRNA expression changes. Utilization of a specific inhibitor of mineralocorticoid receptors, eplerenone, implicated these receptors as part of the ALD mechanism of action. Further experiments with cycloheximide (protein synthesis inhibitor) and MG132 (proteasome inhibitor) revealed that ALD can upregulate NKCC1 by increasing protein stability, i.e., reducing ubiquitination of NKCC1. Having a procedure for controlling NKCC1 protein expression opens the doors for therapeutic interventions for diseases involving the mis-regulation or depletion of NKCC1 proteins, for example during aging.
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Affiliation(s)
- Bo Ding
- Department of Communication Sciences and Disorders, Global Center for Hearing and Speech Research, University of South Florida, Tampa, Florida
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Smith L, Litman P, Liedtke CM. COMMD1 interacts with the COOH terminus of NKCC1 in Calu-3 airway epithelial cells to modulate NKCC1 ubiquitination. Am J Physiol Cell Physiol 2013; 305:C133-46. [PMID: 23515529 DOI: 10.1152/ajpcell.00394.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mice deficient in Na-K-2Cl cotransporter (NKCC1) have been generated by targeted disruption of the gene encoding NKCC1 involving the carboxy terminus (CT-NKCC1) but not the amino terminus. We hypothesize that the resulting physiological defects are due to loss of proteins interacting with CT-NKCC1. Using a yeast two-hybrid approach, adaptor protein COMMD1 was found to bind to CT-NKCC1 (aa 1,040-1,212). Binding was verified in a yeast-independent system using GST-COMMD1 and myc-CT-NKCC1. Truncated COMMD1 and CT-NKCC1 peptides were used in binding assays to identify the site of interaction. The results demonstrate concentration-dependent binding of COMMD1 (aa 1-47) to CT-NKCC1 (aa 1,040-1,134). Endogenous COMMD1 was detected in pull downs using recombinant FLAG-CT-NKCC1; this co-pull down was blocked by COMMD1 (aa 1-47). CT-NKCC1 (aa 1,040-1,137) decreased basolateral membrane expression of NKCC1, and COMMD1 (aa 1-47) increased NKCC1 membrane expression. Downregulation of COMMD1 using silencing (si)RNA led to a transient loss of endogenous COMMD1 but did not affect activation of NKCC1 by hyperosmotic sucrose. Hyperosmolarity caused a transient increase in NKCC1 membrane expression, indicating regulated trafficking of NKCC1; downregulation of COMMD1 using siRNA reduced baseline (unstimulated) NKCC1 expression and blunted a transient elevation in NKCC1 membrane expression caused by hyperosmolarity. Constitutive downregulation of COMMD1 in HT29 engineered cells exhibited loss of COMMD1 and decreased NKCC1 membrane expression with no effect on activation of NKCC1. Loss of COMMD1 in Calu-3 cells and in HT29 cells led to reduced ubiquitinated NKCC1. The results indicate a role for COMMD1 in the regulation of NKCC1 membrane expression and ubiquitination.
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Affiliation(s)
- Laura Smith
- Willard Alan Bernbaum, Center for Cystic Fibrosis Research, Departments of Pediatrics at Rainbow Babies and Children Hospital and Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
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Gagnon KB, Delpire E. Physiology of SLC12 transporters: lessons from inherited human genetic mutations and genetically engineered mouse knockouts. Am J Physiol Cell Physiol 2013; 304:C693-714. [PMID: 23325410 DOI: 10.1152/ajpcell.00350.2012] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Among the over 300 members of the solute carrier (SLC) group of integral plasma membrane transport proteins are the nine electroneutral cation-chloride cotransporters belonging to the SLC12 gene family. Seven of these transporters have been functionally described as coupling the electrically silent movement of chloride with sodium and/or potassium. Although in silico analysis has identified two additional SLC12 family members, no physiological role has been ascribed to the proteins encoded by either the SLC12A8 or the SLC12A9 genes. Evolutionary conservation of this gene family from protists to humans confirms their importance. A wealth of physiological, immunohistochemical, and biochemical studies have revealed a great deal of information regarding the importance of this gene family to human health and disease. The sequencing of the human genome has provided investigators with the capability to link several human diseases with mutations in the genes encoding these plasma membrane proteins. The availability of bacterial artificial chromosomes, recombination engineering techniques, and the mouse genome sequence has simplified the creation of targeting constructs to manipulate the expression/function of these cation-chloride cotransporters in the mouse in an attempt to recapitulate some of these human pathologies. This review will summarize the three human disorders that have been linked to the mutation/dysfunction of the Na-Cl, Na-K-2Cl, and K-Cl cotransporters (i.e., Bartter's, Gitleman's, and Andermann's syndromes), examine some additional pathologies arising from genetically modified mouse models of these cotransporters including deafness, blood pressure, hyperexcitability, and epithelial transport deficit phenotypes.
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Affiliation(s)
- Kenneth B Gagnon
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Gagnon KB, Delpire E. Molecular physiology of SPAK and OSR1: two Ste20-related protein kinases regulating ion transport. Physiol Rev 2013; 92:1577-617. [PMID: 23073627 DOI: 10.1152/physrev.00009.2012] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
SPAK (Ste20-related proline alanine rich kinase) and OSR1 (oxidative stress responsive kinase) are members of the germinal center kinase VI subfamily of the mammalian Ste20 (Sterile20)-related protein kinase family. Although there are 30 enzymes in this protein kinase family, their conservation across the fungi, plant, and animal kingdom confirms their evolutionary importance. Already, a large volume of work has accumulated on the tissue distribution, binding partners, signaling cascades, and physiological roles of mammalian SPAK and OSR1 in multiple organ systems. After reviewing this basic information, we will examine newer studies that demonstrate the pathophysiological consequences to SPAK and/or OSR1 disruption, discuss the development and analysis of genetically engineered mouse models, and address the possible role these serine/threonine kinases might have in cancer proliferation and migration.
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Affiliation(s)
- Kenneth B Gagnon
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2520, USA
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Developmental programming of hypertension and kidney disease. Int J Nephrol 2012; 2012:760580. [PMID: 23251800 PMCID: PMC3516001 DOI: 10.1155/2012/760580] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 09/18/2012] [Accepted: 10/21/2012] [Indexed: 02/05/2023] Open
Abstract
A growing body of evidence supports the concept that changes in the intrauterine milieu during "sensitive" periods of embryonic development or in infant diet after birth affect the developing individual, resulting in general health alterations later in life. This phenomenon is referred to as "developmental programming" or "developmental origins of health and disease." The risk of developing late-onset diseases such as hypertension, chronic kidney disease (CKD), obesity or type 2 diabetes is increased in infants born prematurely at <37 weeks of gestation or in low birth weight (LBW) infants weighing <2,500 g at birth. Both genetic and environmental events contribute to the programming of subsequent risks of CKD and hypertension in premature or LBW individuals. A number of observations suggest that susceptibility to subsequent CKD and hypertension in premature or LBW infants is mediated, at least in part, by reduced nephron endowment. The major factors influencing in utero environment that are associated with a low final nephron number include uteroplacental insufficiency, maternal low-protein diet, hyperglycemia, vitamin A deficiency, exposure to or interruption of endogenous glucocorticoids, and ethanol exposure. This paper discusses the effect of premature birth, LBW, intrauterine milieu, and infant feeding on the development of hypertension and renal disease in later life as well as examines the role of the kidney in developmental programming of hypertension and CKD.
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Schnermann J, Briggs JP. Tubular control of renin synthesis and secretion. Pflugers Arch 2012; 465:39-51. [PMID: 22665048 DOI: 10.1007/s00424-012-1115-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 05/04/2012] [Accepted: 05/07/2012] [Indexed: 01/11/2023]
Abstract
The intratubular composition of fluid at the tubulovascular contact site of the juxtaglomerular apparatus serves as regulatory input for secretion and synthesis of renin. Experimental evidence, mostly from in vitro perfused preparations, indicates an inverse relation between luminal NaCl concentration and renin secretion. The cellular transduction mechanism is initiated by concentration-dependent NaCl uptake through the Na-K-2Cl cotransporter (NKCC2) with activation of NKCC2 causing inhibition and deactivation of NKCC2 causing stimulation of renin release. Changes in NKCC2 activity are coupled to alterations in the generation of paracrine factors that interact with granular cells. Among these factors, generation of PGE2 in a COX-2-dependent fashion appears to play a dominant role in the stimulatory arm of tubular control of renin release. [NaCl] is a determinant of local PG release over an appropriate concentration range, and blockade of COX-2 activity interferes with the NaCl dependency of renin secretion. The complex array of local paracrine controls also includes nNOS-mediated synthesis of nitric oxide, with NO playing the role of a modifier of the intracellular signaling pathway. A role of adenosine may be particularly important when [NaCl] is increased, and at least some of the available evidence is consistent with an important suppressive effect of adenosine at higher salt concentrations.
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Affiliation(s)
- Jurgen Schnermann
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10, Rm 4D50, NIDDK, NIH, 10 Center Drive MSC 1370, Bethesda, MD 20892, USA.
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Abstract
PURPOSE OF REVIEW Sodium and chloride transport play a fundamental role in many physiological processes. In the kidney, sodium secretion and reabsorption are essential to maintain the extracellular volume and, thus, blood pressure (BP). In vascular smooth muscle, it is important for contractility and in the nervous system for the functioning of GABAergic neurons. Hence, the emergence of a WNK/SPAK/OSR1 kinase cascade that activates NaCl cotransporters has widespread physiological implications. This review gives an overview of the actions of SPAK and OSR1 kinases on NaCl cotransporters and highlights their possible therapeutic potential. RECENT FINDINGS Evidence has emerged from in-vitro phosphorylation assays that WNK kinases can activate SPAK and OSR1 kinases by phosphorylation of a key Thr residue in their catalytic domains. Once activated, SPAK and OSR1 in turn activate members of the SCL12A family of solute carriers by phosphorylation of conserved Ser/Thr residues in the N-terminal domain of these carrier proteins. The importance of this pathway has recently emerged from studies on mice that lack a catalytically active SPAK enzyme. These models are strikingly hypotensive with marked reduction in the phosphorylation of Na⁺/Cl⁻ cotransporter (NCC) in the kidney, and reduced Na⁺/K⁺/2Cl⁻ cotransporter (NKCC1) phosphorylation in the vessel wall. SUMMARY SPAK and OSR1 kinases regulate SCL12A transporters with important physiological effects for sodium homeostasis by the kidney, aortic contractility and neuronal excitability. In vivo, SPAK plays a major role in the regulation of blood pressure and represents a potential target for the development of novel diuretics.
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Cho HM, Lee HA, Kim HY, Han HS, Kim IK. Expression of Na+-K+ -2Cl- cotransporter 1 is epigenetically regulated during postnatal development of hypertension. Am J Hypertens 2011; 24:1286-93. [PMID: 21814290 DOI: 10.1038/ajh.2011.136] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The expression of Na(+)-K(+)-2Cl(-) cotransporter 1 (NKCC1) is upregulated in spontaneously hypertensive rat (SHR). We investigated whether expression of NKCC1 is epigenetically regulated during postnatal development of hypertension. METHODS The mesenteric arteries from 5-, 10-, and 18-week-old Wistar-Kyoto rats (WKY) and SHRs were subjected to vascular contraction. We determined expression levels of Nkcc1 mRNA and protein, methylation status, and histone modification of Nkcc1 promoter, and DNA methyltransferase (DNMT) activity. RESULTS The inhibition of dose-response curves by bumetanide, an inhibitor of NKCC1, as well as the expression of Nkcc1 mRNA and protein was comparable between 5-week-old SHR and age-matched WKY, but greater in 18-week-old SHR than in age-matched WKY. Nkcc1 promoter in WKY was getting methylated with age whereas that in SHR mostly remained hypomethylated after development of hypertension. DNMT3B was highly associated with the promoter of WKY, whereas the CXXC finger protein 1 (Cfp1) was highly bound to the promoter of SHR. At the age of 18 weeks, the DNMT activity in aorta of WKY was about threefold higher than that of SHR. The transcription-activating histone code acetyl H3 was higher in SHR than in WKY, whereas suppressive histone code dimethyl H3K9 was greater in WKY than in SHR. CONCLUSION It is concluded that expression of NKCC1 is epigenetically upregulated during postnatal development of hypertension. Our data indicate that maintenance of hypomethylation in Nkcc1 promoter of SHR resulting from low DNMT activity plays an important role in the upregulation of NKCC1 during development of spontaneous hypertension.
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Oi K, Sohara E, Rai T, Misawa M, Chiga M, Alessi DR, Sasaki S, Uchida S. A minor role of WNK3 in regulating phosphorylation of renal NKCC2 and NCC co-transporters in vivo. Biol Open 2011; 1:120-7. [PMID: 23213404 PMCID: PMC3507202 DOI: 10.1242/bio.2011048] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Mutations in WNK1 and WNK4 kinase genes have been shown to cause a human hereditary hypertensive disease, pseudohypoaldosteronism type II (PHAII). We previously discovered that WNK kinases phosphorylate and activate OSR1/SPAK kinases that regulate renal SLC12A family transporters such as NKCC2 and NCC, and clarified that the constitutive activation of this cascade causes PHAII. WNK3, another member of the WNK kinase family, was reported to be a strong activator of NCC/NKCC2 when assayed in Xenopus oocytes, suggesting that WNK3 also plays a major role in regulating blood pressure and sodium reabsorption in the kidney. However, it remains to be determined whether WNK3 is in fact involved in the regulation of these transporters in vivo. To clarify this issue, we generated and analyzed WNK3 knockout mice. Surprisingly, phosphorylation and expression of OSR1, SPAK, NKCC2 and NCC did not decrease in knockout mouse kidney under normal and low-salt diets. Similarly, expression of epithelial Na channel and Na/H exchanger 3 were not affected in knockout mice. Na+ and K+ excretion in urine in WNK3 knockout mice was not affected under different salt diets. Blood pressure in WNK3 knockout mice was not lower under normal diet. However, lower blood pressure was observed in WNK3 knockout mice fed low-salt diet. WNK4 and WNK1 expression was slightly elevated in the knockout mice under low-salt diet, suggesting compensation for WNK3 knockout by these WNKs. Thus, WNK3 may have some role in the WNK-OSR1/SPAK-NCC/NKCC2 signal cascade in the kidney, but its contribution to total WNK kinase activity may be minimal.
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Affiliation(s)
- Katsuyuki Oi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University , 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519 , Japan
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Impaired phosphorylation of Na(+)-K(+)-2Cl(-) cotransporter by oxidative stress-responsive kinase-1 deficiency manifests hypotension and Bartter-like syndrome. Proc Natl Acad Sci U S A 2011; 108:17538-43. [PMID: 21972418 DOI: 10.1073/pnas.1107452108] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Na(+)-K(+)-2Cl(-) cotransporters (NKCCs), including NKCC1 and renal-specific NKCC2, and the Na(+)-Cl(-) cotransporter (NCC) play pivotal roles in the regulation of blood pressure (BP) and renal NaCl reabsorption. Oxidative stress-responsive kinase-1 (OSR1) is a known upstream regulator of N(K)CCs. We generated and analyzed global and kidney tubule-specific (KSP) OSR1 KO mice to elucidate the physiological role of OSR1 in vivo, particularly on BP and kidney function. Although global OSR1(-/-) mice were embryonically lethal, OSR1(+/-) mice had low BP associated with reduced phosphorylated (p) STE20 (sterile 20)/SPS1-related proline/alanine-rich kinase (SPAK) and p-NKCC1 abundance in aortic tissue and attenuated p-NKCC2 abundance with increased total and p-NCC expression in the kidney. KSP-OSR1(-/-) mice had normal BP and hypercalciuria and maintained significant hypokalemia on a low-K(+) diet. KSP-OSR1(-/-) mice exhibited impaired Na(+) reabsorption in the thick ascending loop on a low-Na(+) diet accompanied by remarkably decreased expression of p-NKCC2 and a blunted response to furosemide, an NKCC2 inhibitor. The expression of total SPAK and p-SPAK was significantly increased in parallel to that of total NCC and p-NCC despite unchanged total NKCC2 expression. These results suggest that, globally, OSR1 is involved in the regulation of BP and renal tubular Na(+) reabsorption mainly via the activation of NKCC1 and NKCC2. In the kidneys, NKCC2 but not NCC is the main target of OSR1 and the reduced p-NKCC2 in KSP-OSR1(-/-) mice may lead to a Bartter-like syndrome.
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Liu W, Schreck C, Coleman RA, Wade JB, Hernandez Y, Zavilowitz B, Warth R, Kleyman TR, Satlin LM. Role of NKCC in BK channel-mediated net K⁺ secretion in the CCD. Am J Physiol Renal Physiol 2011; 301:F1088-97. [PMID: 21816753 DOI: 10.1152/ajprenal.00347.2011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Apical SK/ROMK and BK channels mediate baseline and flow-induced K secretion (FIKS), respectively, in the cortical collecting duct (CCD). BK channels are detected in acid-base transporting intercalated (IC) and Na-absorbing principal (PC) cells. Although the density of BK channels is greater in IC than PC, Na-K-ATPase activity in IC is considered inadequate to sustain high rates of urinary K secretion. To test the hypothesis that basolateral NKCC in the CCD contributes to BK channel-mediated FIKS, we measured net K secretion (J(K)) and Na absorption (J(Na)) at slow (∼1) and fast (∼5 nl·min(-1)·mm(-1)) flow rates in rabbit CCDs microperfused in vitro in the absence and presence of bumetanide, an inhibitor of NKCC, added to the bath. Bumetanide inhibited FIKS but not basal J(K), J(Na), or the flow-induced [Ca(2+)](i) transient necessary for BK channel activation. Addition of luminal iberiotoxin, a BK channel inhibitor, to bumetanide-treated CCDs did not further reduce J(K). Basolateral Cl removal reversibly inhibited FIKS but not basal J(K) or J(Na). Quantitative PCR performed on single CCD samples using NKCC1- and 18S-specific primers and probes and the TaqMan assay confirmed the presence of the transcript in this nephron segment. To identify the specific cell type to which basolateral NKCC is localized, we exploited the ability of NKCC to accept NH(4)(+) at its K-binding site to monitor the rate of bumetanide-sensitive cytosolic acidification after NH(4)(+) addition to the bath in CCDs loaded with the pH indicator dye BCECF. Both IC and PC were found to have a basolateral bumetanide-sensitive NH(4)(+) entry step and NKCC1-specific antibodies labeled the basolateral surfaces of both cell types in CCDs. These results suggest that BK channel-mediated FIKS is dependent on a basolateral bumetanide-sensitive, Cl-dependent transport pathway, proposed to be NKCC1, in both IC and PC in the CCD.
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Affiliation(s)
- Wen Liu
- Division of Pediatric Nephrology, Department of Pediatrics, Mount Sinai School of Medicine, New York, New York 10029, USA
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Bergaya S, Faure S, Baudrie V, Rio M, Escoubet B, Bonnin P, Henrion D, Loirand G, Achard JM, Jeunemaitre X, Hadchouel J. WNK1 regulates vasoconstriction and blood pressure response to α 1-adrenergic stimulation in mice. Hypertension 2011; 58:439-45. [PMID: 21768522 DOI: 10.1161/hypertensionaha.111.172429] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Gain-of-function mutations in the human WNK1 (with-no-lysine[K]1) gene are responsible for a monogenic form of arterial hypertension, and WNK1 polymorphisms have been associated with common essential hypertension. The role of WNK1 in renal ionic reabsorption has been established, but no investigation of its possible influence on vascular tone, an essential determinant of blood pressure, has been performed until now. WNK1 complete inactivation in the mouse is embryonically lethal. We, thus, examined in Wnk1(+/-) haploinsufficient adult mice whether WNK1 could regulate in vivo vascular tone and whether this was correlated with blood pressure variation. Wnk1(+/-) mice displayed a pronounced decrease in blood pressure responses in vivo and in vascular contractions ex vivo following α(1)-adrenergic receptor activation with no change in basal blood pressure and renal function. We also observed a major loss of the pressure-induced contractile (myogenic) response in Wnk1(+/-) arteries associated with a specific alteration of the smooth muscle cell contractile function. These alterations in vascular tone were associated with a decreased phosphorylation level of the WNK1 substrate SPAK (STE20/SPS1-related proline/alanine-rich kinase) and its target NKCC1 (Na(+)-K(+)-2Cl(-) cotransporter 1) in Wnk1(+/-) arteries. Our study identifies a novel and major role for WNK1 in maintaining in vivo blood pressure and vasoconstriction responses specific to α(1)-adrenergic receptor activation. Our findings uncover a vascular signaling pathway linking α(1)-adrenergic receptors and pressure to WNK1, SPAK, and NKCC1 and may, thus, significantly broaden the comprehension of the regulatory mechanisms of vascular tone in arterial hypertension.
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Affiliation(s)
- Sonia Bergaya
- INSERM U970, Paris Cardiovascular Research Center PARCC, 56 rue Leblanc, 75015 Paris, France.
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Keyes JT, Haskett DG, Utzinger U, Azhar M, Vande Geest JP. Adaptation of a planar microbiaxial optomechanical device for the tubular biaxial microstructural and macroscopic characterization of small vascular tissues. J Biomech Eng 2011; 133:075001. [PMID: 21823753 PMCID: PMC3383843 DOI: 10.1115/1.4004495] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 05/24/2011] [Indexed: 11/08/2022]
Abstract
Murine models of disease are a powerful tool for researchers to gain insight into disease formation, progression, and therapies. The biomechanical indicators of diseased tissue provide a unique insight into some of these murine models, since the biomechanical properties in scenarios such as aneurysm and Marfan syndrome can dictate tissue failure and mortality. Understanding the properties of the tissue on the macroscopic scale has been shown to be important, as one can then understand the tissue's ability to withstand the high stresses seen in the cardiac pulsatile cycle. Alterations in the biomechanical response can foreshadow prospective mechanical failure of the tissue. These alterations are often seen on the microstructural level, and obtaining detailed information on such changes can offer a better understanding of the phenomena seen on the macroscopic level. Unfortunately, mouse models present problems due to the size and delicate features in the mechanical testing of such tissues. In addition, some smaller arteries in large-animal studies (e.g., coronary and cerebral arteries) can present the same issues, and are sometimes unsuitable for planar biaxial testing. The purpose of this paper is to present a robust method for the investigation of the mechanical properties of small arteries and the classification of the microstructural orientation and degree of fiber alignment. This occurs through the cost-efficient modification of a planar biaxial tester that works in conjunction with a two-photon nonlinear microscope. This system provides a means to further investigate how microstructure and mechanical properties are modified in diseased transgenic animals where the tissue is in small tube form. Several other hard-to-test tubular specimens such as cerebral aneurysm arteries and atherosclerotic coronary arteries can also be tested using the described modular device.
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Affiliation(s)
| | - Darren G. Haskett
- Graduate Interdisciplinary Program in Biomedical Engineering,
The University of Arizona, Tucson, AZ 85721
| | - Urs Utzinger
- Graduate Interdisciplinary Program in Biomedical Engineering,
BIO5 Institute for Biocollaborative Research, Department of
Biomedical Engineering, The University of Arizona, Tucson, AZ
85721
| | - Mohamad Azhar
- BIO5 Institute for Biocollaborative Research, Department of Cell Biology
and Anatomy, The University of Arizona, Tucson, AZ 85721
| | - Jonathan P. Vande Geest
- Graduate Interdisciplinary Program in Biomedical Engineering,
The Department of Aerospace and Mechanical Engineering,
BIO5 Institute for Biocollaborative Research, Department of
Biomedical Engineering, The University of Arizona, Tucson, AZ
85721 e-mail:
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Yang SS, Lo YF, Wu CC, Lin SW, Yeh CJ, Chu P, Sytwu HK, Uchida S, Sasaki S, Lin SH. SPAK-knockout mice manifest Gitelman syndrome and impaired vasoconstriction. J Am Soc Nephrol 2010; 21:1868-77. [PMID: 20813865 DOI: 10.1681/asn.2009121295] [Citation(s) in RCA: 214] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Polymorphisms in the gene encoding sterile 20/SPS1-related proline/alanine-rich kinase (SPAK) associate with hypertension susceptibility in humans. SPAK interacts with WNK kinases to regulate the Na(+)-K(+)-2Cl(-) and Na(+)-Cl(-) co-transporters [collectively, N(K)CC]. Mutations in WNK1/4 and N(K)CC can cause changes in BP and dyskalemia in humans, but the physiologic role of SPAK in vivo is unknown. We generated and analyzed SPAK-null mice by targeting disruption of exons 9 and 10 of SPAK. Compared with SPAK(+/+) littermates, SPAK(+/-) mice exhibited hypotension without significant electrolyte abnormalities, and SPAK(-/-) mice not only exhibited hypotension but also recapitulated Gitelman syndrome with hypokalemia, hypomagnesemia, and hypocalciuria. In the kidney tissues of SPAK(-/-) mice, the expression of total and phosphorylated (p-)NCC was markedly decreased, but that of p-OSR1, total NKCC2, and p-NKCC2 was significantly increased. We observed a blunted response to thiazide but normal response to furosemide in SPAK(-/-) mice. In aortic tissues, total NKCC1 expression was increased but p-NKCC1 was decreased in SPAK-deficient mice. Both SPAK(+/-) and SPAK(-/-) mice had impaired responses to the selective α(1)-adrenergic agonist phenylephrine and the NKCC1 inhibitor bumetanide, suggesting that impaired aortic contractility may contribute to the hypotension of SPAK-null mice. In summary, SPAK-null mice have defects of NCC in the kidneys and NKCC1 in the blood vessels, leading to hypotension through renal salt wasting and vasodilation. SPAK may be a promising target for antihypertensive therapy.
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Affiliation(s)
- Sung-Sen Yang
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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