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Ferdaus MZ, Terker AS, Koumangoye RB, Al-Qusairi L, Welling PA, Delpire E. Deletion of KS-WNK1 promotes NCC activation by increasing WNK1/4 abundance. Am J Physiol Renal Physiol 2024; 327:F373-F385. [PMID: 38961847 DOI: 10.1152/ajprenal.00101.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/25/2024] [Accepted: 06/25/2024] [Indexed: 07/05/2024] Open
Abstract
Dietary potassium deficiency causes stimulation of sodium reabsorption leading to an increased risk in blood pressure elevation. The distal convoluted tubule (DCT) is the main rheostat linking plasma K+ levels to the activity of the Na-Cl cotransporter (NCC). This occurs through basolateral membrane potential sensing by inwardly rectifying K+ channels (Kir4.1/5.1); decrease in intracellular Cl-; activation of WNK4 and interaction and phosphorylation of STE20/SPS1-related proline/alanine-rich kinase (SPAK); binding of calcium-binding protein 39 (cab39) adaptor protein to SPAK, leading to its trafficking to the apical membrane; and SPAK binding, phosphorylation, and activation of NCC. As kidney-specific with-no-lysine kinase 1 (WNK1) isoform (KS-WNK1) is another participant in this pathway, we examined its function in NCC regulation. We eliminated KS-WNK1 specifically in the DCT and demonstrated increased expression of WNK4 and long WNK1 (L-WNK1) and increased phosphorylation of NCC. As in other KS-WNK1 models, the mice were not hyperkalemic. Although wild-type mice under low-dietary K+ conditions demonstrated increased NCC phosphorylation, the phosphorylation levels of the transporter, already high in KS-WNK1, did not change under the low-K+ diet. Thus, in the absence of KS-WNK1, the transporter lost its sensitivity to low plasma K+. We also show that under low K+ conditions, in the absence of KS-WNK1, there was no formation of WNK bodies. These bodies were observed in adjacent segments, not affected by the targeting of KS-WNK1. As our data are overall consistent with those of the global KS-WNK1 knockout, they indicate that the DCT is the predominant segment affecting the salt transport regulated by KS-WNK1.NEW & NOTEWORTHY In this paper, we show that KS-WNK1 is a critical component of the distal convoluted tubule (DCT) K+ switch pathway. Its deletion results in an inability of the DCT to sense changes in plasma potassium. Absence of KS-WNK1 leads to abnormally high levels of WNK4 and L-WNK1 in the DCT, resulting in increased Na-Cl phosphorylation and function. Our data are consistent with KS-WNK1 targeting WNK4 and L-WNK1 to degradation.
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Affiliation(s)
- Mohammed Z Ferdaus
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Andrew S Terker
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Rainelli B Koumangoye
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Lama Al-Qusairi
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Paul A Welling
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
- Department of Physiology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
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Demko J, Weber R, Pearce D, Saha B. Aldosterone-independent regulation of K + secretion in the distal nephron. Curr Opin Nephrol Hypertens 2024; 33:526-534. [PMID: 38888034 PMCID: PMC11290980 DOI: 10.1097/mnh.0000000000001006] [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: 06/20/2024]
Abstract
PURPOSE OF REVIEW Maintenance of plasma K + concentration within a narrow range is critical to all cellular functions. The kidneys are the central organ for K + excretion, and robust renal excretory responses to dietary K + loads are essential for survival. Recent advances in the field have challenged the view that aldosterone is at the center of K + regulation. This review will examine recent findings and propose a new mechanism for regulating K + secretion. RECENT FINDINGS Local aldosterone-independent response systems in the distal nephron are increasingly recognized as key components of the rapid response to an acute K + load, as well as playing an essential role in sustained responses to increased dietary K + . The master kinase mTOR, best known for its role in mediating the effects of growth factors and insulin on growth and cellular metabolism, is central to these aldosterone-independent responses. Recent studies have shown that mTOR, particularly in the context of the "type 2" complex (mTORC2), is regulated by K + in a cell-autonomous fashion. SUMMARY New concepts related to cell-autonomous K + signaling and how it interfaces with aldosterone-dependent regulation are emerging. The underlying signaling pathways and effectors of regulated K + secretion, as well as implications for the aldosterone paradox and disease pathogenesis are discussed.
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Affiliation(s)
- John Demko
- Department of Medicine, Division of Nephrology, University of California at San Francisco, San Francisco, CA, USA
| | - Robert Weber
- Division of Endocrinology, University of California at San Francisco, San Francisco, CA, USA
| | - David Pearce
- Department of Medicine, Division of Nephrology, University of California at San Francisco, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA, USA
| | - Bidisha Saha
- Department of Medicine, Division of Nephrology, University of California at San Francisco, San Francisco, CA, USA
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Shu TT, Gao ZX, Mao ZH, Yang YY, Fu WJ, Pan SK, Zhao QQ, Liu DW, Liu ZS, Wu P. Defective natriuresis contributes to hyperkalemia in db/db mice during potassium supplementation. J Hypertens 2024; 42:1632-1640. [PMID: 38780161 DOI: 10.1097/hjh.0000000000003777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
OBJECTIVES Potassium supplementation reduces blood pressure and the occurrence of cardiovascular diseases, with K + -induced natriuresis playing a potential key role in this process. However, whether these beneficial effects occur in diabetes remains unknown. METHODS In this study, we examined the impact of high-K + intake on renal Na + /K + transport by determining the expression of major apical Na + transporters, diuretics responses (as a proxy for specific Na + transporter function), urinary Na + /K + excretion, and plasma Na + /K + concentrations in db/db mice, a model of type 2 diabetes mellitus. RESULTS Although db/m mice exhibited increased fractional excretion of sodium (FE Na ) and fractional excretion of potassium (FE K ) under high-K + intake, these responses were largely blunted in db/db mice, suggesting impaired K + -induced natriuresis and kaliuresis in diabetes. Consequently, high-K + intake increased plasma K + levels in db/db mice, which could be attributed to the abnormal activity of sodium-hydrogen exchanger 3 (NHE3), sodium-chloride cotransporter (NCC), and epithelial Na + channel (ENaC), as high-K + intake could not effectively decrease NHE3 and NCC and increase ENaC expression and activity in the diabetic group. Inhibition of NCC by hydrochlorothiazide could correct the hyperkalemia in db/db mice fed a high-K + diet, indicating a key role for NCC in K + -loaded diabetic mice. Treatment with metformin enhanced urinary Na + /K + excretion and normalized plasma K + levels in db/db mice with a high-K + diet, at least partially, by suppressing NCC activity. CONCLUSION Collectively, the impaired K + -induced natriuresis in diabetic mice under high-K + intake may be primarily attributed to impaired NCC-mediated renal K + excretion, despite the role of NHE3.
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Affiliation(s)
- Ting-Ting Shu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Zhong-Xiuzi Gao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Zi-Hui Mao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Yuan-Yuan Yang
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Wen-Jia Fu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Shao-Kang Pan
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Qian-Qian Zhao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Dong-Wei Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Zhang-Suo Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Peng Wu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University
- Institute of Nephrology, Zhengzhou University
- Henan Province Research Center for Kidney Disease
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
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Quelquejay H, Al-Rifai R, Silvestro M, Vandestienne M, Ferreira I, Mirault T, Henrion D, Zhong X, Santos-Zas I, Goudot G, Alayrac P, Robidel E, Autret G, Balvay D, Taleb S, Tedgui A, Boulanger CM, Zernecke A, Saliba AE, Hadchouel J, Ramkhelawon B, Cochain C, Bergaya S, Jeunemaitre X, Ait-Oufella H. L-Wnk1 Deletion in Smooth Muscle Cells Causes Aortitis and Inflammatory Shift. Circ Res 2024; 135:488-502. [PMID: 38979610 DOI: 10.1161/circresaha.124.324366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 06/27/2024] [Indexed: 07/10/2024]
Abstract
BACKGROUND The long isoform of the Wnk1 (with-no-lysine [K] kinase 1) is a ubiquitous serine/threonine kinase, but its role in vascular smooth muscle cells (VSMCs) pathophysiology remains unknown. METHODS AngII (angiotensin II) was infused in Apoe-/- to induce experimental aortic aneurysm. Mice carrying an Sm22-Cre allele were cross-bred with mice carrying a floxed Wnk1 allele to specifically investigate the functional role of Wnk1 in VSMCs. RESULTS Single-cell RNA-sequencing of the aneurysmal abdominal aorta from AngII-infused Apoe-/- mice revealed that VSMCs that did not express Wnk1 showed lower expression of contractile phenotype markers and increased inflammatory activity. Interestingly, WNK1 gene expression in VSMCs was decreased in human abdominal aortic aneurysm. Wnk1-deficient VSMCs lost their contractile function and exhibited a proinflammatory phenotype, characterized by the production of matrix metalloproteases, as well as cytokines and chemokines, which contributed to local accumulation of inflammatory macrophages, Ly6Chi monocytes, and γδ T cells. Sm22Cre+Wnk1lox/lox mice spontaneously developed aortitis in the infrarenal abdominal aorta, which extended to the thoracic area over time without any negative effect on long-term survival. AngII infusion in Sm22Cre+Wnk1lox/lox mice aggravated the aortic disease, with the formation of lethal abdominal aortic aneurysms. Pharmacological blockade of γδ T-cell recruitment using neutralizing anti-CXCL9 (anti-CXC motif chemokine ligand 9) antibody treatment, or of monocyte/macrophage using Ki20227, a selective inhibitor of CSF1 receptor, attenuated aortitis. Wnk1 deletion in VSMCs led to aortic wall remodeling with destruction of elastin layers, increased collagen content, and enhanced local TGF-β (transforming growth factor-beta) 1 expression. Finally, in vivo TGF-β blockade using neutralizing anti-TGF-β antibody promoted saccular aneurysm formation and aorta rupture in Sm22 Cre+ Wnk1lox/lox mice but not in control animals. CONCLUSION Wnk1 is a key regulator of VSMC function. Wnk1 deletion promotes VSMC phenotype switch toward a pathogenic proinflammatory phenotype, orchestrating deleterious vascular remodeling and spontaneous severe aortitis in mice.
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MESH Headings
- Animals
- Aortitis/genetics
- Aortitis/metabolism
- Aortitis/pathology
- Mice
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Angiotensin II
- Aortic Aneurysm, Abdominal/genetics
- Aortic Aneurysm, Abdominal/metabolism
- Aortic Aneurysm, Abdominal/pathology
- Humans
- WNK Lysine-Deficient Protein Kinase 1/genetics
- WNK Lysine-Deficient Protein Kinase 1/metabolism
- Mice, Inbred C57BL
- Male
- Cells, Cultured
- Mice, Knockout, ApoE
- Disease Models, Animal
- Inflammation/metabolism
- Inflammation/genetics
- Inflammation/pathology
- Aorta, Abdominal/metabolism
- Aorta, Abdominal/pathology
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Affiliation(s)
- Helene Quelquejay
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Rida Al-Rifai
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Michele Silvestro
- Division of Vascular and Endovascular Surgery, Department of Surgery and Department of Cell Biology, New York University Langone Medical Center (M.S., B.R.)
| | - Marie Vandestienne
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Irmine Ferreira
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Tristan Mirault
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Daniel Henrion
- MITOVASC Department, Team 2 (CarMe), ICAT SFR (Interactions Cellulaires et Applications Thérapeutiques Structure Fédérale de Recherche), University of Angers, Inserm U1083, France (D.H.)
| | - Xiaodan Zhong
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Icia Santos-Zas
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
- Laboratorio de Endocrinología Celular, Área de Endocrinología Molecular y Celular Instituto de Investigación Sanitaria de Santiago, Complejo Hospitalario Universitario de Santiago, Santiago de Compostela, Spain (I.S.-Z.)
| | - Guillaume Goudot
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Paul Alayrac
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Estelle Robidel
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Gwennhael Autret
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Daniel Balvay
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Soraya Taleb
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Alain Tedgui
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Chantal M Boulanger
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Alma Zernecke
- Institute of Experimental Biomedicine, University Hospital Würzburg, Germany (A.Z., C.C.)
| | - Antoine-Emmanuel Saliba
- Helmholtz Institute for RNA-Based Infection Research, Helmholtz-Center for Infection Research, Würzburg, Germany (A.-E.S.)
| | - Juliette Hadchouel
- Inserm UMRS 1155, Tenon Hospital (J.H.), Sorbonne Université, Paris, France
| | - Bhama Ramkhelawon
- Division of Vascular and Endovascular Surgery, Department of Surgery and Department of Cell Biology, New York University Langone Medical Center (M.S., B.R.)
| | - Clement Cochain
- Institute of Experimental Biomedicine, University Hospital Würzburg, Germany (A.Z., C.C.)
| | - Sonia Bergaya
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Xavier Jeunemaitre
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
| | - Hafid Ait-Oufella
- Université de Paris, Inserm U970, Paris-Cardiovascular Research Center, France (H.Q., R.A.-R., M.V., I.F., T.M., X.Z., I.S.-Z., G.G., P.A., E.R., G.A., D.B., S.T., A.T., C.M.B., S.B., X.J., H.A.-O.)
- Medical Intensive Care Unit, Hôpital Saint-Antoine, AP-HP (Assistance Publique- Hôpitaux de Paris) (H.A.-O.), Sorbonne Université, Paris, France
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5
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Yin T, He L, Du Y, Liu J, Peng L, Yang M, Sun S, Liu J, Li J, Cao J, Zhu H, Wang S. Macrophage WNK1 senses intracellular hypo-chlorine to regulate vulnerability to sepsis attack during hypochloremia. Int Immunopharmacol 2024; 139:112721. [PMID: 39033662 DOI: 10.1016/j.intimp.2024.112721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 07/08/2024] [Accepted: 07/16/2024] [Indexed: 07/23/2024]
Abstract
Sepsis is one of the leading causes of death in critical patients worldwide and its occurrence is related to the excessive activation of macrophages. Chloride loss worsens the prognosis of patients with sepsis but the underlying mechanism is currently unclear. In this study, we founded that macrophages deficient in intracellular Cl- secrete more inflammatory cytokines such as IL-1β, IL-6 and TNF-α compared with control group. The intracellular chloride level decreased in WNK1 deficiency or activity inhibited macrophages with more severe inflammatory response after LPS treatment. Remimazolam, as classic GABAa receptor agonist, alleviates excessive inflammation cascade by promoting macrophage chloride influx during sepsis progression. Collectively, this study proves that macrophage WNK1 acts as a negative regulator of inflammatory response by sensing chloride to maintain intracellular chloride balance during sepsis coupled with hypochloremia.
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Affiliation(s)
- Tianyue Yin
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, Anhui 230001, China
| | - Lingwei He
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, Anhui 230001, China
| | - Yuhao Du
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Department of Anesthesiology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China
| | - Jiayuan Liu
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, Anhui 230001, China
| | - Li Peng
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, Anhui 230001, China
| | - Mengmeng Yang
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, Anhui 230001, China; Department of Anesthesiology, Anhui Provincial Hospital, Wannan Medical College, Hefei, Anhui 230001, China
| | - Shuaijie Sun
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, Anhui 230001, China; Department of Anesthesiology, Anhui Provincial Hospital, Wannan Medical College, Hefei, Anhui 230001, China
| | - Jingya Liu
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Jun Li
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Jiangbing Cao
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China; Core Facility Center, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Hefei, Anhui 230001, China; Department of Anesthesiology, Anhui Provincial Hospital, Wannan Medical College, Hefei, Anhui 230001, China
| | - Hongrui Zhu
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Sheng Wang
- Department of Anesthesiology, First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China.
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6
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Wu P, Li ST, Shu TT, Mao ZH, Fu WJ, Yang YY, Pan SK, Liu DW, Liu ZS, Gao ZX. Impaired distal renal potassium handling in streptozotocin-induced diabetic mice. Am J Physiol Renal Physiol 2024; 327:F158-F170. [PMID: 38779755 DOI: 10.1152/ajprenal.00240.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024] Open
Abstract
Diabetes is closely associated with K+ disturbances during disease progression and treatment. However, it remains unclear whether K+ imbalance occurs in diabetes with normal kidney function. In this study, we examined the effects of dietary K+ intake on systemic K+ balance and renal K+ handling in streptozotocin (STZ)-induced diabetic mice. The control and STZ mice were fed low or high K+ diet for 7 days to investigate the role of dietary K+ intake in renal K+ excretion and K+ homeostasis and to explore the underlying mechanism by evaluating K+ secretion-related transport proteins in distal nephrons. K+-deficient diet caused excessive urinary K+ loss, decreased daily K+ balance, and led to severe hypokalemia in STZ mice compared with control mice. In contrast, STZ mice showed an increased daily K+ balance and elevated plasma K+ level under K+-loading conditions. Dysregulation of the NaCl cotransporter (NCC), epithelial Na+ channel (ENaC), and renal outer medullary K+ channel (ROMK) was observed in diabetic mice fed either low or high K+ diet. Moreover, amiloride treatment reduced urinary K+ excretion and corrected hypokalemia in K+-restricted STZ mice. On the other hand, inhibition of SGLT2 by dapagliflozin promoted urinary K+ excretion and normalized plasma K+ levels in K+-supplemented STZ mice, at least partly by increasing ENaC activity. We conclude that STZ mice exhibited abnormal K+ balance and impaired renal K+ handling under either low or high K+ diet, which could be primarily attributed to the dysfunction of ENaC-dependent renal K+ excretion pathway, despite the possible role of NCC.NEW & NOTEWORTHY Neither low dietary K+ intake nor high dietary K+ intake effectively modulates renal K+ excretion and K+ homeostasis in STZ mice, which is closely related to the abnormality of ENaC expression and activity. SGLT2 inhibitor increases urinary K+ excretion and reduces plasma K+ level in STZ mice under high dietary K+ intake, an effect that may be partly due to the upregulation of ENaC activity.
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Affiliation(s)
- Peng Wu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Shu-Ting Li
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Ting-Ting Shu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Zi-Hui Mao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Wen-Jia Fu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Yuan-Yuan Yang
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Shao-Kang Pan
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Dong-Wei Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Zhang-Suo Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
| | - Zhong-Xiuzi Gao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
- Institute of Nephrology, Zhengzhou University, Zhengzhou, People's Republic of China
- Henan Province Research Center for Kidney Disease, Zhengzhou, People's Republic of China
- Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, People's Republic of China
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7
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Rioux AV, Nsimba-Batomene TR, Slimani S, Bergeron NAD, Gravel MAM, Schreiber SV, Fiola MJ, Haydock L, Garneau AP, Isenring P. Navigating the multifaceted intricacies of the Na +-Cl - cotransporter, a highly regulated key effector in the control of hydromineral homeostasis. Physiol Rev 2024; 104:1147-1204. [PMID: 38329422 PMCID: PMC11381001 DOI: 10.1152/physrev.00027.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 01/01/2024] [Accepted: 02/03/2024] [Indexed: 02/09/2024] Open
Abstract
The Na+-Cl- cotransporter (NCC; SLC12A3) is a highly regulated integral membrane protein that is known to exist as three splice variants in primates. Its primary role in the kidney is to mediate the cosymport of Na+ and Cl- across the apical membrane of the distal convoluted tubule. Through this role and the involvement of other ion transport systems, NCC allows the systemic circulation to reclaim a fraction of the ultrafiltered Na+, K+, Cl-, and Mg+ loads in exchange for Ca2+ and [Formula: see text]. The physiological relevance of the Na+-Cl- cotransport mechanism in humans is illustrated by several abnormalities that result from NCC inactivation through the administration of thiazides or in the setting of hereditary disorders. The purpose of the present review is to discuss the molecular mechanisms and overall roles of Na+-Cl- cotransport as the main topics of interest. On reading the narrative proposed, one will realize that the knowledge gained in regard to these themes will continue to progress unrelentingly no matter how refined it has now become.
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Affiliation(s)
- A V Rioux
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - T R Nsimba-Batomene
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - S Slimani
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - N A D Bergeron
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - M A M Gravel
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - S V Schreiber
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - M J Fiola
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - L Haydock
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
- Service de Néphrologie-Transplantation Rénale Adultes, Hôpital Necker-Enfants Malades, AP-HP, INSERM U1151, Université Paris Cité, Paris, France
| | - A P Garneau
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
- Service de Néphrologie-Transplantation Rénale Adultes, Hôpital Necker-Enfants Malades, AP-HP, INSERM U1151, Université Paris Cité, Paris, France
| | - P Isenring
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
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8
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Zhang Y, Bock F, Ferdaus M, Arroyo JP, L Rose K, Patel P, Denton JS, Delpire E, Weinstein AM, Zhang MZ, Harris RC, Terker AS. Low potassium activation of proximal mTOR/AKT signaling is mediated by Kir4.2. Nat Commun 2024; 15:5144. [PMID: 38886379 PMCID: PMC11183202 DOI: 10.1038/s41467-024-49562-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 06/07/2024] [Indexed: 06/20/2024] Open
Abstract
The renal epithelium is sensitive to changes in blood potassium (K+). We identify the basolateral K+ channel, Kir4.2, as a mediator of the proximal tubule response to K+ deficiency. Mice lacking Kir4.2 have a compensated baseline phenotype whereby they increase their distal transport burden to maintain homeostasis. Upon dietary K+ depletion, knockout animals decompensate as evidenced by increased urinary K+ excretion and development of a proximal renal tubular acidosis. Potassium wasting is not proximal in origin but is caused by higher ENaC activity and depends upon increased distal sodium delivery. Three-dimensional imaging reveals Kir4.2 knockouts fail to undergo proximal tubule expansion, while the distal convoluted tubule response is exaggerated. AKT signaling mediates the dietary K+ response, which is blunted in Kir4.2 knockouts. Lastly, we demonstrate in isolated tubules that AKT phosphorylation in response to low K+ depends upon mTORC2 activation by secondary changes in Cl- transport. Data support a proximal role for cell Cl- which, as it does along the distal nephron, responds to K+ changes to activate kinase signaling.
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Affiliation(s)
- Yahua Zhang
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Fabian Bock
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Mohammed Ferdaus
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Juan Pablo Arroyo
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Kristie L Rose
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
- Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Purvi Patel
- Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jerod S Denton
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alan M Weinstein
- Department of Physiology and Biophysics, Weil Medical College, New York, NY, USA
| | - Ming-Zhi Zhang
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Raymond C Harris
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center for Kidney Disease, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
| | - Andrew S Terker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt Center for Kidney Disease, Nashville, TN, USA.
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9
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Duan XP, Zheng JY, Jiang SP, Wang MX, Zhang C, Chowdhury T, Wang WH, Lin DH. mTORc2 in Distal Convoluted Tubule and Renal K + Excretion during High Dietary K + Intake. J Am Soc Nephrol 2024; 35:00001751-990000000-00330. [PMID: 38788191 PMCID: PMC11387030 DOI: 10.1681/asn.0000000000000406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 05/20/2024] [Indexed: 05/26/2024] Open
Abstract
Key Points
High K stimulates mechanistic target of rapamycin complex 2 (mTORc2) in the distal convoluted tubule (DCT).Inhibition of mTORc2 decreased the basolateral Kir4.1/Kir5.1 and Na-Cl cotransporter in the DCT.Inhibition of mTORc2 of the DCT compromised kidneys' ability to excrete potassium during high K intake.
Background
Renal mechanistic target of rapamycin complex 2 (mTORc2) plays a role in regulating renal K+ excretion (renal-EK) and K+ homeostasis. Inhibition of renal mTORc2 causes hyperkalemia due to suppressing epithelial Na+ channel and renal outer medullary K+ (Kir1.1) in the collecting duct. We now explore whether mTORc2 of distal convoluted tubules (DCTs) regulates basolateral Kir4.1/Kir5.1, Na-Cl cotransporter (NCC), and renal-EK.
Methods
We used patch-clamp technique to examine basolateral Kir4.1/Kir5.1 in early DCT, immunoblotting, and immunofluorescence to examine NCC expression and in vivo measurement of urinary K+ excretion to determine baseline renal-EK in mice treated with an mTORc2 inhibitor and in DCT-specific rapamycin-insensitive companion of mTOR knockout (DCT-RICTOR-KO) mice.
Results
Inhibition of mTORc2 with AZD8055 abolished high-K+–induced inhibition of Kir4.1/Kir5.1 in DCT, high potassium–induced depolarization of the DCT membrane, and high potassium–induced suppression of phosphorylated Na-Cl cotransporter (pNCC) expression. AZD8055 stimulated the 40-pS inwardly rectifying K+ channel (Kir4.1/Kir5.1-heterotetramer) in early DCT in the mice on overnight high potassium intake; this effect was absent in the presence of protein kinase C inhibitors, which also stimulated Kir4.1/Kir5.1. AZD8055 treatment decreased renal-EK in animals on overnight high-potassium diet. Deletion of RICTOR in the DCT increased the Kir4.1/Kir5.1-mediated K+ currents, hyperpolarized the DCT membrane, and increased the expression of pWNK4 and pNCC. Renal-EK was lower and plasma K+ was higher in DCT-RICTOR-KO mice than corresponding control mice. In addition, overnight high-potassium diet did not inhibit Kir4.1/Kir5.1 activity in the DCT and failed to inhibit the expression of pNCC in DCT-RICTOR-KO mice. Overnight high potassium intake stimulated renal-EK in control mice, but this effect was attenuated in DCT-RICTOR-KO mice. Thus, overnight high potassium intake induced hyperkalemia in DCT-RICTOR-KO mice but not in control mice.
Conclusions
mTORc2 of the DCT inhibits Kir4.1/Kir5.1 activity and NCC expression and stimulates renal-EK during high potassium intake.
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Affiliation(s)
- Xin-Peng Duan
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Jun-Ya Zheng
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Shao-Peng Jiang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Ming-Xiao Wang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Chengbiao Zhang
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Tanzina Chowdhury
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
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10
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Welling PA, Little R, Al-Qusairi L, Delpire E, Ellison DH, Fenton RA, Grimm PR. Potassium-Switch Signaling Pathway Dictates Acute Blood Pressure Response to Dietary Potassium. Hypertension 2024; 81:1044-1054. [PMID: 38465625 PMCID: PMC11023808 DOI: 10.1161/hypertensionaha.123.22546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/27/2024] [Indexed: 03/12/2024]
Abstract
BACKGROUND Potassium (K+)-deficient diets, typical of modern processed foods, increase blood pressure (BP) and NaCl sensitivity. A K+-dependent signaling pathway in the kidney distal convoluted tubule, coined the K+ switch, that couples extracellular K+ sensing to activation of the thiazide-sensitive NaCl cotransporter (NCC) and NaCl retention has been implicated, but causality has not been established. METHODS To test the hypothesis that small, physiological changes in plasma K+ (PK+) are translated to BP through the switch pathway, a genetic approach was used to activate the downstream switch kinase, SPAK (SPS1-related proline/alanine-rich kinase), within the distal convoluted tubule. The CA-SPAK (constitutively active SPS1-related proline/alanine-rich kinase mice) were compared with control mice over a 4-day PK+ titration (3.8-5.1 mmol) induced by changes in dietary K+. Arterial BP was monitored using radiotelemetry, and renal function measurements, NCC abundance, phosphorylation, and activity were made. RESULTS As PK+ decreased in control mice, BP progressively increased and became sensitive to dietary NaCl and hydrochlorothiazide, coincident with increased NCC phosphorylation and urinary sodium retention. By contrast, BP in CA-SPAK mice was elevated, resistant to the PK+ titration, and sensitive to hydrochlorothiazide and salt at all PK+ levels, concomitant with sustained and elevated urinary sodium retention and NCC phosphorylation and activity. Thus, genetically locking the switch on drives NaCl sensitivity and prevents the response of BP to potassium. CONCLUSIONS Low K+, common in modern ultraprocessed diets, presses the K+-switch pathway to turn on NCC activity, increasing sodium retention, BP, and salt sensitivity.
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Affiliation(s)
- Paul A. Welling
- Department of Medicine, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Robert Little
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - Lama Al-Qusairi
- Department of Medicine, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, USA
| | - David H. Ellison
- Department of Medicine, Division of Nephrology, Oregon Health Science Center, Portland, Oregon, US
| | - Robert A. Fenton
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - P. Richard Grimm
- Department of Medicine, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, USA
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11
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Gritter M, Wei KY, Wouda RD, Musterd-Bhaggoe UM, Dijkstra KL, Kers J, Ramakers C, Vogt L, de Borst MH, Danser AHJ, Hoorn EJ, Rotmans JI. Chronic kidney disease increases the susceptibility to negative effects of low and high potassium intake. Nephrol Dial Transplant 2024; 39:795-807. [PMID: 37813819 PMCID: PMC11045281 DOI: 10.1093/ndt/gfad220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Indexed: 10/11/2023] Open
Abstract
BACKGROUND Dietary potassium (K+) has emerged as a modifiable factor for cardiovascular and kidney health in the general population, but its role in people with chronic kidney disease (CKD) is unclear. Here, we hypothesize that CKD increases the susceptibility to the negative effects of low and high K+ diets. METHODS We compared the effects of low, normal and high KChloride (KCl) diets and a high KCitrate diet for 4 weeks in male rats with normal kidney function and in male rats with CKD using the 5/6th nephrectomy model (5/6Nx). RESULTS Compared with rats with normal kidney function, 5/6Nx rats on the low KCl diet developed more severe extracellular and intracellular K+ depletion and more severe kidney injury, characterized by nephromegaly, infiltration of T cells and macrophages, decreased estimated glomerular filtration rate and increased albuminuria. The high KCl diet caused hyperkalemia, hyperaldosteronism, hyperchloremic metabolic acidosis and severe hypertension in 5/6Nx but not in sham rats. The high KCitrate diet caused hypochloremic metabolic alkalosis but attenuated hypertension despite higher abundance of the phosphorylated sodium chloride cotransporter (pNCC) and similar levels of plasma aldosterone and epithelial sodium channel abundance. All 5/6Nx groups had more collagen deposition than the sham groups and this effect was most pronounced in the high KCitrate group. Plasma aldosterone correlated strongly with kidney collagen deposition. CONCLUSIONS CKD increases the susceptibility to negative effects of low and high K+ diets in male rats, although the injury patterns are different. The low K+ diet caused inflammation, nephromegaly and kidney function decline, whereas the high K+ diet caused hypertension, hyperaldosteronism and kidney fibrosis. High KCitrate attenuated the hypertensive but not the pro-fibrotic effect of high KCl, which may be attributable to K+-induced aldosterone secretion. Our data suggest that especially in people with CKD it is important to identify the optimal threshold of dietary K+ intake.
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Affiliation(s)
- Martin Gritter
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Kuang-Yu Wei
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Rosa D Wouda
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Usha M Musterd-Bhaggoe
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Kyra L Dijkstra
- Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jesper Kers
- Pathology, Leiden University Medical Center, Leiden, The Netherlands
- Pathology, Amsterdam University Medical Center, Amsterdam, The Netherlands
- Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Liffert Vogt
- Department of Internal Medicine, Section of Nephrology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Martin H de Borst
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander H J Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Ewout J Hoorn
- Department of Internel Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joris I Rotmans
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
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12
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Vitzthum H, Meyer-Schwesinger C, Ehmke H. Novel functions of the anion exchanger AE4 (SLC4A9). Pflugers Arch 2024; 476:555-564. [PMID: 38195948 PMCID: PMC11006790 DOI: 10.1007/s00424-023-02899-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 01/11/2024]
Abstract
The kidney plays a crucial role in acid-base homeostasis. In the distal nephron, α-intercalated cells contribute to urinary acid (H+) secretion and β-intercalated cells accomplish urinary base (HCO3-) secretion. β-intercalated cells regulate the acid base status through modulation of the apical Cl-/HCO3- exchanger pendrin (SLC26A4) activity. In this review, we summarize and discuss our current knowledge of the physiological role of the renal transporter AE4 (SLC4A9). The AE4, as cation-dependent Cl-/HCO3- exchanger, is exclusively expressed in the basolateral membrane of β-intercalated cells and is essential for the sensing of metabolic acid-base disturbances in mice, but not for renal sodium reabsorption and plasma volume control. Potential intracellular signaling pathways are discussed that might link basolateral acid-base sensing through the AE4 to apical pendrin activity.
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Affiliation(s)
- Helga Vitzthum
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Heimo Ehmke
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
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13
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Mutchler SM, Hasan M, Murphy CP, Baty CJ, Boyd-Shiwarski C, Kirabo A, Kleyman TR. Dietary sodium alters aldosterone's effect on renal sodium transporter expression and distal convoluted tubule remodelling. J Physiol 2024; 602:967-987. [PMID: 38294810 PMCID: PMC10939779 DOI: 10.1113/jp284041] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 12/21/2023] [Indexed: 02/01/2024] Open
Abstract
Aldosterone is responsible for maintaining volume and potassium homeostasis. Although high salt consumption should suppress aldosterone production, individuals with hyperaldosteronism lose this regulation, leading to a state of high aldosterone despite dietary sodium consumption. The present study examines the effects of elevated aldosterone, with or without high salt consumption, on the expression of key Na+ transporters and remodelling in the distal nephron. Epithelial sodium channel (ENaC) α-subunit expression was increased with aldosterone regardless of Na+ intake. However, ENaC β- and γ-subunits unexpectedly increased at both a transcript and protein level with aldosterone when high salt was present. Expression of total and phosphorylated Na+ Cl- cotransporter (NCC) significantly increased with aldosterone, in association with decreased blood [K+ ], but the addition of high salt markedly attenuated the aldosterone-dependent NCC increase, despite equally severe hypokalaemia. We hypothesized this was a result of differences in distal convoluted tubule length when salt was given with aldosterone. Imaging and measurement of the entire pNCC-positive tubule revealed that aldosterone alone caused a shortening of this segment, although the tubule had a larger cross-sectional diameter. This was not true when salt was given with aldosterone because the combination was associated with a lengthening of the tubule in addition to increased diameter, suggesting that differences in the pNCC-positive area are not responsible for differences in NCC expression. Together, our results suggest the actions of aldosterone, and the subsequent changes related to hypokalaemia, are altered in the presence of high dietary Na+ . KEY POINTS: Aldosterone regulates volume and potassium homeostasis through effects on transporters in the kidney; its production can be dysregulated, preventing its suppression by high dietary sodium intake. Here, we examined how chronic high sodium consumption affects aldosterone's regulation of sodium transporters in the distal nephron. Our results suggest that high sodium consumption with aldosterone is associated with increased expression of all three epithelial sodium channel subunits, rather than just the alpha subunit. Aldosterone and its associated decrease in blood [K+ ] lead to an increased expression of Na-Cl cotransporter (NCC); the addition of high sodium consumption with aldosterone partially attenuates this NCC expression, despite similarly low blood [K+ ]. Upstream kinase regulators and tubule remodelling do not explain these results.
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Affiliation(s)
| | | | - Carolyn P Murphy
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Catherine J Baty
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, and Department of Molecular Physiology and Biophysics Vanderbilt University, Nashville, TN, USA
| | - Thomas R Kleyman
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
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14
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Untiet V. Astrocytic chloride regulates brain function in health and disease. Cell Calcium 2024; 118:102855. [PMID: 38364706 DOI: 10.1016/j.ceca.2024.102855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/18/2024]
Abstract
Chloride ions (Cl-) play a pivotal role in synaptic inhibition in the central nervous system, primarily mediated through ionotropic mechanisms. A recent breakthrough emphathizes the significant influence of astrocytic intracellular chloride concentration ([Cl-]i) regulation, a field still in its early stages of exploration. Typically, the [Cl-]i in most animal cells is maintained at lower levels than the extracellular chloride [Cl-]o, a critical balance to prevent cell swelling due to osmotic pressure. Various Cl- transporters are expressed differently across cell types, fine-tuning the [Cl-]i, while Cl- gradients are utilised by several families of Cl- channels. Although the passive distribution of ions within cells is governed by basic biophysical principles, astrocytes actively expend energy to sustain [Cl-]i at much higher levels than those achieved passively, and much higher than neuronal [Cl-]i. Beyond the role in volume regulation, astrocytic [Cl-]i is dynamically linked to brain states and influences neuronal signalling in actively behaving animals. As a vital component of brain function, astrocytic [Cl-]i also plays a role in the development of disorders where inhibitory transmission is disrupted. This review synthesises the latest insights into astrocytic [Cl-]i, elucidating its role in modulating brain function and its implications in various pathophysiological conditions.
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Affiliation(s)
- Verena Untiet
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark.
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15
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Mutchler SM, Whelan SCM, Marciszyn A, Chen J, Kleyman TR, Shi S. Role of paraoxonase 3 in regulating ENaC-mediated Na + transport in the distal nephron. J Physiol 2024; 602:737-757. [PMID: 38345534 PMCID: PMC10940207 DOI: 10.1113/jp285034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 01/11/2024] [Indexed: 02/18/2024] Open
Abstract
Paraoxonase 3 (PON3) is expressed in the aldosterone-sensitive distal nephron, where filtered Na+ is reabsorbed mainly via the epithelial Na+ channel (ENaC) and Na+ -coupled co-transporters. We previously showed that PON3 negatively regulates ENaC through a chaperone mechanism. The present study aimed to determine the physiological role of PON3 in renal Na+ and K+ homeostasis. Pon3 knockout (KO) mice had higher amiloride-induced natriuresis and lower plasma [K+ ] at baseline. Single channel recordings in split-open tubules showed that the number of active channels per patch was significantly higher in KO mice, resulting in a higher channel activity in the absence of PON3. Although whole kidney abundance of ENaC subunits was not altered in Pon3 KOs, ENaC gamma subunit was more apically distributed within the connecting tubules and cortical collecting ducts of Pon3 KO kidneys. Additionally, small interfering RNA-mediated knockdown of PON3 in cultured mouse cortical collecting duct cells led to an increased surface abundance of ENaC gamma subunit. As a result of lower plasma [K+ ], sodium chloride co-transporter phosphorylation was enhanced in the KO kidneys, a phenotype that was corrected by a high K+ diet. Finally, PON3 expression was upregulated in mouse kidneys under dietary K+ restriction, potentially providing a mechanism to dampen ENaC activity and associated K+ secretion. Taken together, our results show that PON3 has a role in renal Na+ and K+ homeostasis through regulating ENaC functional expression in the distal nephron. KEY POINTS: Paraoxonase 3 (PON3) is expressed in the distal nephron of mouse kidneys and functions as a molecular chaperone to reduce epithelial Na+ channel (ENaC) expression and activity in heterologous expression systems. We examined the physiological role of PON3 in renal Na+ and K+ handling using a Pon3 knockout (KO) mouse model. At baseline, Pon3 KO mice had lower blood [K+ ], more functional ENaC in connecting tubules/cortical collecting ducts, higher amiloride-induced natriuresis, and enhanced sodium chloride co-transporter (NCC) phosphorylation. Upon challenge with a high K+ diet, Pon3 KO mice had normalized blood [K+ ] and -NCC phosphorylation but lower circulating aldosterone levels compared to their littermate controls. Kidney PON3 abundance was altered in mice under dietary K+ loading or K+ restriction, providing a potential mechanism for regulating ENaC functional expression and renal Na+ and K+ homeostasis in the distal nephron.
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Affiliation(s)
| | | | - Allison Marciszyn
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jingxin Chen
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Thomas R. Kleyman
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shujie Shi
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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16
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Kim BS, Yu MY, Shin J. Effect of low sodium and high potassium diet on lowering blood pressure and cardiovascular events. Clin Hypertens 2024; 30:2. [PMID: 38163867 PMCID: PMC10759559 DOI: 10.1186/s40885-023-00259-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/30/2023] [Indexed: 01/03/2024] Open
Abstract
Incorporating aggressive lifestyle modifications along with antihypertensive medication therapy is a crucial treatment strategy to enhance the control rate of hypertension. Dietary modification is one of the important lifestyle interventions for hypertension, and it has been proven to have a clear effect. Among food ingredients, sodium and potassium have been found to have the strongest association with blood pressure. The blood pressure-lowering effect of a low sodium diet and a high potassium diet has been well established, especially in hypertensive population. A high intake of potassium, a key component of the Dietary Approaches to Stop Hypertension (DASH) diet, has also shown a favorable impact on the risk of cardiovascular events. Additionally, research conducted with robust measurement methods has shown cardiovascular benefits of low-sodium intake. In this review, we aim to discuss the evidence regarding the relationship between the low sodium and high potassium diet and blood pressure and cardiovascular events.
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Affiliation(s)
- Byung Sik Kim
- Division of Cardiology, Department of Internal Medicine, Hanyang University Guri Hospital, Guri, South Korea
| | - Mi-Yeon Yu
- Division of Nephrology, Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea
| | - Jinho Shin
- Division of Cardiology, Department of Internal Medicine, Hanyang University Medical Center, Hanyang University College of Medicine, 222, Wangsimni-ro, Sungdong-gu, Seoul, 04763, South Korea.
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17
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Nakahari T, Suzuki C, Kawaguchi K, Hosogi S, Tanaka S, Asano S, Inui T, Marunaka Y. Ambroxol-Enhanced Frequency and Amplitude of Beating Cilia Controlled by a Voltage-Gated Ca 2+ Channel, Cav1.2, via pH i Increase and [Cl -] i Decrease in the Lung Airway Epithelial Cells of Mice. Int J Mol Sci 2023; 24:16976. [PMID: 38069298 PMCID: PMC10707002 DOI: 10.3390/ijms242316976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 11/25/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Ambroxol (ABX), a frequently prescribed secretolytic agent which enhances the ciliary beat frequency (CBF) and ciliary bend angle (CBA, an index of amplitude) by 30%, activates a voltage-dependent Ca2+ channel (CaV1.2) and a small transient Ca2+ release in the ciliated lung airway epithelial cells (c-LAECs) of mice. The activation of CaV1.2 alone enhanced the CBF and CBA by 20%, mediated by a pHi increasei and a [Cl-]i decrease in the c-LAECs. The increase in pHi, which was induced by the activation of the Na+-HCO3- cotransporter (NBC), enhanced the CBF (by 30%) and CBA (by 15-20%), and a decrease in [Cl-]i, which was induced by the Cl- release via anoctamine 1 (ANO1), enhanced the CBA (by 10-15%). While a Ca2+-free solution or nifedipine (an inhibitor of CaV1.2) inhibited 70% of the CBF and CBA enhancement using ABX, CaV1.2 enhanced most of the CBF and CBA increases using ABX. The activation of the CaV1.2 existing in the cilia stimulates the NBC to increase pHi and ANO1 to decrease the [Cl-]i in the c-LAECs. In conclusion, the pHi increase and the [Cl-]i decrease enhanced the CBF and CBA in the ABX-stimulated c-LAECs.
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Affiliation(s)
- Takashi Nakahari
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan;
- Medical Research Institute, Kyoto Industrial Health Association, Kyoto 604-8472, Japan
| | - Chihiro Suzuki
- Laboratory of Pharmacotherapy, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki 569-1094, Japan; (C.S.); (S.T.)
| | - Kotoku Kawaguchi
- Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan; (K.K.); (S.A.)
| | - Shigekuni Hosogi
- Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan;
| | - Saori Tanaka
- Laboratory of Pharmacotherapy, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki 569-1094, Japan; (C.S.); (S.T.)
| | - Shinji Asano
- Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan; (K.K.); (S.A.)
| | - Toshio Inui
- Saisei Mirai Clinics, Moriguchi 570-0012, Japan;
| | - Yoshinori Marunaka
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan;
- Medical Research Institute, Kyoto Industrial Health Association, Kyoto 604-8472, Japan
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18
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Grimm PR, Tatomir A, Rosenbaek LL, Kim BY, Li D, Delpire EJ, Fenton RA, Welling PA. Dietary potassium stimulates Ppp1Ca-Ppp1r1a dephosphorylation of kidney NaCl cotransporter and reduces blood pressure. J Clin Invest 2023; 133:e158498. [PMID: 37676724 PMCID: PMC10617769 DOI: 10.1172/jci158498] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/06/2023] [Indexed: 09/09/2023] Open
Abstract
Consumption of low dietary potassium, common with ultraprocessed foods, activates the thiazide-sensitive sodium chloride cotransporter (NCC) via the with no (K) lysine kinase/STE20/SPS1-related proline-alanine-rich protein kinase (WNK/SPAK) pathway to induce salt retention and elevate blood pressure (BP). However, it remains unclear how high-potassium "DASH-like" diets (dietary approaches to stop hypertension) inactivate the cotransporter and whether this decreases BP. A transcriptomics screen identified Ppp1Ca, encoding PP1A, as a potassium-upregulated gene, and its negative regulator Ppp1r1a, as a potassium-suppressed gene in the kidney. PP1A directly binds to and dephosphorylates NCC when extracellular potassium is elevated. Using mice genetically engineered to constitutively activate the NCC-regulatory kinase SPAK and thereby eliminate the effects of the WNK/SPAK kinase cascade, we confirmed that PP1A dephosphorylated NCC directly in a potassium-regulated manner. Prior adaptation to a high-potassium diet was required to maximally dephosphorylate NCC and lower BP in constitutively active SPAK mice, and this was associated with potassium-dependent suppression of Ppp1r1a and dephosphorylation of its cognate protein, inhibitory subunit 1 (I1). In conclusion, potassium-dependent activation of PP1A and inhibition of I1 drove NCC dephosphorylation, providing a mechanism to explain how high dietary K+ lowers BP. Shifting signaling of PP1A in favor of activation of WNK/SPAK may provide an improved therapeutic approach for treating salt-sensitive hypertension.
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Affiliation(s)
- P. Richard Grimm
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
| | - Anamaria Tatomir
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
| | - Lena L. Rosenbaek
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - Bo Young Kim
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
| | - Dimin Li
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
| | - Eric J. Delpire
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennssee, USA
| | - Robert A. Fenton
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Biomedicine, University of Aarhus, Aarhus, Denmark
| | - Paul A. Welling
- Department of Medicine (Nephrology), Johns Hopkins University School of Medicine Baltimore, Maryland, USA
- The LeDucq Potassium in Hypertension Research Network of Excellence is detailed in Supplemental Acknowledgments
- Department of Physiology, Johns Hopkins University School of Medicine Baltimore, Maryland, USA
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19
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Lashhab R, Essuman G, Chavez-Canales M, Alexander RT, Cordat E. Expression of the kidney anion exchanger 1 affects WNK4 and SPAK phosphorylation and results in claudin-4 phosphorylation. Heliyon 2023; 9:e22280. [PMID: 38034706 PMCID: PMC10687047 DOI: 10.1016/j.heliyon.2023.e22280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
In the renal collecting ducts, chloride reabsorption occurs through both transcellular and paracellular pathways. Recent literature highlights a functional interplay between both pathways. We recently showed that in polarized inner medullary collecting duct cells, expression of the basolateral kidney anion exchanger 1 (kAE1) results in a decreased transepithelial electrical resistance (TEER), in a claudin-4 dependent pathway. Claudin-4 is a paracellular sodium blocker and chloride pore. Here, we show that kAE1 expression in mouse inner medullary collecting duct cells triggers WNK4, SPAK and claudin-4 phosphorylation. Expression of a functionally dead kAE1 E681Q mutant has no effect on phosphorylation of these proteins. Expression of a catalytically inactive WNK4 D321A or chloride-insensitive WNK4 L319F mutant abolishes kAE1 effect on TEER, supporting a contribution of WNK4 to the process. We propose that variations of the cytosolic pH and chloride concentration upon kAE1 expression alter WNK4 kinase activity and tight junction properties.
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Affiliation(s)
- Rawad Lashhab
- Department of Physiology and Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Grace Essuman
- Department of Physiology and Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta, Canada
| | - Maria Chavez-Canales
- Unidad de Investigación UNAM-INCICh, Instituto Nacional de Cardiología Ignacio Chávez and Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Tlalpan, Mexico City, 14080, Mexico
| | - R. Todd Alexander
- Department of Physiology and Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Emmanuelle Cordat
- Department of Physiology and Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta, Canada
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20
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Gamba G. Thirty years of the NaCl cotransporter: from cloning to physiology and structure. Am J Physiol Renal Physiol 2023; 325:F479-F490. [PMID: 37560773 PMCID: PMC10639029 DOI: 10.1152/ajprenal.00114.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/08/2023] [Accepted: 08/08/2023] [Indexed: 08/11/2023] Open
Abstract
The primary structure of the thiazide-sensitive NaCl cotransporter (NCC) was resolved 30 years ago by the molecular identification of the cDNA encoding this cotransporter, from the winter's flounder urinary bladder, following a functional expression strategy. This review outlines some aspects of how the knowledge about thiazide diuretics and NCC evolved, the history of the cloning process, and the expansion of the SLC12 family of electroneutral cotransporters. The diseases associated with activation or inactivation of NCC are discussed, as well as the molecular model by which the activity of NCC is regulated. The controversies in the field are discussed as well as recent publication of the three-dimensional model of NCC obtained by cryo-electron microscopy, revealing not only the amino acid residues critical for Na+ and Cl- translocation but also the residues critical for polythiazide binding to the transporter, opening the possibility for a new era in thiazide diuretic therapy.
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Affiliation(s)
- Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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21
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Kettritz R, Loffing J. Potassium homeostasis - Physiology and pharmacology in a clinical context. Pharmacol Ther 2023; 249:108489. [PMID: 37454737 DOI: 10.1016/j.pharmthera.2023.108489] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/03/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023]
Abstract
Membrane voltage controls the function of excitable cells and is mainly a consequence of the ratio between the extra- and intracellular potassium concentration. Potassium homeostasis is safeguarded by balancing the extra-/intracellular distribution and systemic elimination of potassium to the dietary potassium intake. These processes adjust the plasma potassium concentration between 3.5 and 4.5 mmol/L. Several genetic and acquired diseases but also pharmacological interventions cause dyskalemias that are associated with increased morbidity and mortality. The thresholds at which serum K+ not only associates but also causes increased mortality are hotly debated. We discuss physiologic, pathophysiologic, and pharmacologic aspects of potassium regulation and provide informative case vignettes. Our aim is to help clinicians, epidemiologists, and pharmacologists to understand the complexity of the potassium homeostasis in health and disease and to initiate appropriate treatment strategies in dyskalemic patients.
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Affiliation(s)
- Ralph Kettritz
- Department of Nephrology and Medical Intensive Care, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité Universitätsmedizin Berlin, Germany.
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22
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Teixeira LR, Akella R, Humphreys JM, He H, Goldsmith EJ. Water and chloride as allosteric inhibitors in WNK kinase osmosensing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.29.555411. [PMID: 37693587 PMCID: PMC10491171 DOI: 10.1101/2023.08.29.555411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Previous observations showed that chloride and osmotic stress regulate the autophosphorylation and activity of the kinase domains of WNK1 and WNK3. Further, prior crystallography on the asymmetric dimeric of the unphosphorylated WNK1 kinase domain (WNK1/S382A, WNK1/SA) revealed conserved waters in the active site. Here we show by crystallography that PEG400 applied to crystals of dimeric WNK1/SA grown in space group P1 induces de-dimerization with a change in space group to P2 1 . Both the conserved waters, referred to here as conserved water network 1 (CWN1) and the chloride binding site are disrupted by PEG400. CWN1 is surrounded and stabilized by a pan-WNK-conserved cluster of charged residues. Here we mutagenized these charges in WNK3 to probe the importance of the CWN1 to WNK regulation. Two mutations at E314 in the Activation Loop (WNK3/E314Q and WNK3/E314A) enhanced activity, consistent with the idea that the CWN1 is inhibitory. Mutations of other residues in the cluster had similar or less activity than wild-type. PEG400 activation of WNK3 was not significantly reduced in the point mutants tested. The crystallographic and assay data support a role for CWN1 and the charged cluster in stabilizing an inactive configuration of WNKs and suggest that water functions as an allosteric inhibitor of WNKs.
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23
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Wang T, Liu T, Xu S, Frindt G, Weinstein AM, Palmer LG. High dietary K + intake inhibits proximal tubule transport. Am J Physiol Renal Physiol 2023; 325:F224-F234. [PMID: 37318989 PMCID: PMC10396284 DOI: 10.1152/ajprenal.00013.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/15/2023] [Accepted: 06/14/2023] [Indexed: 06/17/2023] Open
Abstract
The impact of chronic dietary K+ loading on proximal tubule (PT) function was measured using free-flow micropuncture along with measurements of overall kidney function, including urine volume, glomerular filtration rate, and absolute and fractional Na+ and K+ excretion in the rat. Feeding animals a diet with 5% KCl [high K+ (HK)] for 7 days reduced glomerular filtration rate by 29%, increased urine volume by 77%, and increased absolute K+ excretion by 202% compared with rats on a 1% KCl [control K+ (CK)] diet. HK did not change absolute Na+ excretion but significantly increased fraction excretion of Na+ (1.40% vs. 0.64%), indicating that fractional Na+ absorption is reduced by HK. PT reabsorption was assessed using free-flow micropuncture in anesthetized animals. At 80% of the accessible length of the PT, measurements of inulin concentration indicated volume reabsorption of 73% and 54% in CK and HK, respectively. At the same site, fractional PT Na+ reabsorption was 66% in CK animals and 37% in HK animals. Fractional PT K+ reabsorption was 66% in CK and 37% in HK. To assess the role of Na+/H+ exchanger isoform 3 (NHE3) in mediating these changes, we measured NHE3 protein expression in total kidney microsomes as well as surface membranes using Western blots. We found no significant changes in protein in either cell fraction. Expression of the Ser552 phosphorylated form of NHE3 was also similar in CK and HK animals. Reduction in PT transport may facilitate K+ excretion and help balance Na+ excretion by shifting Na+ reabsorption from K+-reabsorbing to K+-secreting nephron segments.NEW & NOTEWORTHY In rats fed a diet rich in K+, proximal tubules reabsorbed less fluid, Na+, and K+ compared with those in animals on a control diet. Glomerular filtration rates also decreased, probably due to glomerulotubular feedback. These reductions may help to maintain balance of the two ions simultaneously by shifting Na+ reabsorption to K+-secreting nephron segments.
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Affiliation(s)
- Tong Wang
- Department of Molecular and Cellular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Tommy Liu
- Department of Molecular and Cellular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Shuhua Xu
- Department of Molecular and Cellular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Gustavo Frindt
- Department of Physiology and Biophysics, Weill-Cornell Medicine, New York, New York, United States
| | - Alan M Weinstein
- Department of Physiology and Biophysics, Weill-Cornell Medicine, New York, New York, United States
| | - Lawrence G Palmer
- Department of Physiology and Biophysics, Weill-Cornell Medicine, New York, New York, United States
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24
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Ying S, Guo Q, Zhang C. KLHL3-dependent WNK4 degradation affected by potassium through the neddylation and autophagy pathway. BMC Nephrol 2023; 24:217. [PMID: 37481568 PMCID: PMC10362690 DOI: 10.1186/s12882-023-03257-4] [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: 05/11/2022] [Accepted: 06/29/2023] [Indexed: 07/24/2023] Open
Abstract
BACKGROUND Studies reported that kelch-like protein 3 (KLHL3)-Cullin3(CUL3) E3 ligase ubiquitinated with-no-lysine kinase 4 (WNK4). Impaired WNK4 ubiquitination plays a key role in Familial hyperkalemic hypertension (FHHt, also called pseudohypoaldosteronism type II) which results from overaction of thiazide-sensitive sodium chloride cotransport (NCC). In addition, researchers have also found that dietary potassium deficiency activates NCC along the renal distal convoluted tubule (DCT). However, the underlying mechanism remains unclear about the relationship between potassium and WNK4. METHODS In the present study, we conducted in vitro and in vivo experiments to confirm that KLHL3-dependent WNK4 degradation is affected by potassium through the neddylation and autophagy pathway. In vitro, the WNK4 and KLHL3 plasmids were cotransfected into HEK293 cell lines by lipofectamine 2000, and then incubated with different potassium concentrations (1mmol/L and 10mmol/L) for 24 h, and further treated with MLN4924 or the autophagy inhibitor or both of MLN4924 and the autophagy inhibitor for another 24 h respectively. In vivo, we created mice that were fed with low or high potassium diets and then were injected MLN4924 in the experimental groups. The expression of WNK4, pWNK4, KLHL3, NEDD8, LC3 ,and P62 was detected by western blotting in vitro and vivo experiments. RESULTS We found that the abundance and phosphorylation of WNK4 increase when neddylation is inhibited both in vitro and vivo. Furthermore, the abundance of pWNK4, WNK4, NEDD8, and KLHL3 was increased in the low potassium (LK) group. Inhibiting autophagy can ameliorate the effect of potassium on the abundance and activity of WNK4 to some extent. CONCLUSION These findings suggest a complex regulation of potassium in the degradation of WNK4. Low potassium can activate WNK4, which may be related to neddylation and autophagy, but the mechanism needs to be further studied.
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Affiliation(s)
- Siqi Ying
- Department of Nephrology, Jing'an District Center Hospital of Shanghai, Fudan University, Shanghai, 200040, China
| | - Qin Guo
- Department of Nephrology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Shi, China
| | - Chong Zhang
- Department of Nephrology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Shi, China.
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McCormick JA, Topf J, Tomacruz ID, Grimm PR. A New Understanding of Potassium's Influence Upon Human Health and Renal Physiology. ADVANCES IN KIDNEY DISEASE AND HEALTH 2023; 30:137-147. [PMID: 36868729 DOI: 10.1053/j.akdh.2023.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 12/28/2022] [Accepted: 01/03/2023] [Indexed: 03/05/2023]
Abstract
Potassium channels are expressed in virtually all cell types, and their activity is the dominant determinant of cellular membrane potential. As such, potassium flux is a key regulator of many cellular processes including the regulation of action potentials in excitable cells. Subtle changes in extracellular potassium can initiate signaling processes vital for survival (insulin signaling) while more extreme and chronic changes may lead to pathological states (acid-base disturbances and cardiac arrhythmia). While many factors acutely influence extracellular potassium levels, it is principally the role of the kidneys to maintain potassium balance by matching urinary excretion with dietary intake. When this balance is disrupted, human health is negatively impacted. In this review, we discuss evolving views of dietary potassium intake as means of preventing and mitigating diseases. We also provide an update on a molecular pathway called the potassium switch, a mechanism by which extracellular potassium regulates distal nephron sodium reabsorption. Finally, we review recent literature describing how several popular therapeutics influence potassium homeostasis.
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Affiliation(s)
- James A McCormick
- Division of Nephrology and Hypertension, Oregon Health and Science University, Portland, OR
| | - Joel Topf
- Department of Medicine, Oakland University William Beaumont School of Medicine, Rochester, MI
| | | | - P Richard Grimm
- Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, MD.
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26
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Gallafassi E, Bezerra M, Rebouças N. Control of sodium and potassium homeostasis by renal distal convoluted tubules. Braz J Med Biol Res 2023; 56:e12392. [PMID: 36790288 PMCID: PMC9925193 DOI: 10.1590/1414-431x2023e12392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/17/2022] [Indexed: 02/12/2023] Open
Abstract
Distal convoluted tubules (DCT), which contain the Na-Cl cotransporter (NCC) inhibited by thiazide diuretics, undergo complex modulation to preserve Na+ and K+ homeostasis. The lysine kinases 1 and 4 (WNK1 and WNK4), identified as hyperactive in the hereditary disease pseudohypoaldosteronism type 2, are responsible for activation of NCC and consequent hypokalemia and hypertension. WNK4, highly expressed in DCT, activates the SPAK/OSR1 kinases, which phosphorylate NCC and other regulatory proteins and transporters in the distal nephron. WNK4 works as a chloride sensor through a Cl- binding site, which acts as an on/off switch at this kinase in response to changes of basolateral membrane electrical potential, the driving force of cellular Cl- efflux. High intracellular Cl- in hyperkalemia decreases NCC phosphorylation and low intracellular Cl- in hypokalemia increases NCC phosphorylation and activity, which makes plasma K+ concentration a central modulator of NCC and of K+ secretion. The WNK4 phosphorylation by cSrc or SGK1, activated by angiotensin II or aldosterone, respectively, is another relevant mechanism of NCC, ENaC, and ROMK modulation in states such as volume reduction, hyperkalemia, and hypokalemia. Loss of NCC function induces upregulation of electroneutral NaCl reabsorption by type B intercalated cells through the combined activity of pendrin and NDCBE, as demonstrated in double knockout mice (KO) animal models, Ncc/pendrin or Ncc/NDCBE. The analysis of ks-Nedd-4-2 KO animal models introduced the modulation of NEDD4-2 by intracellular Mg2+ activity as an important regulator of NCC, explaining the thiazide-induced persistent hypokalemia.
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Affiliation(s)
- E.A. Gallafassi
- Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo, SP, Brasil
| | - M.B. Bezerra
- Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo, SP, Brasil
| | - N.A. Rebouças
- Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo, SP, Brasil
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27
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Abstract
The with no lysine (K) (WNK) kinases are an evolutionarily ancient group of kinases with atypical placement of the catalytic lysine and diverse physiological roles. Recent studies have shown that WNKs are directly regulated by chloride, potassium, and osmotic pressure. Here, we review the discovery of WNKs as chloride-sensitive kinases and discuss physiological contexts in which chloride regulation of WNKs has been demonstrated. These include the kidney, pancreatic duct, neurons, and inflammatory cells. We discuss the interdependent relationship of osmotic pressure and intracellular chloride in cell volume regulation. We review the recent demonstration of potassium regulation of WNKs and speculate on possible physiological roles. Finally, structural and mechanistic aspects of intracellular ion and osmotic pressure regulation of WNKs are discussed.
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Affiliation(s)
- Elizabeth J Goldsmith
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Aylin R Rodan
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA; .,Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.,Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA.,Medical Service, Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, Utah, USA
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28
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Gao ZX, Zhou R, Li MY, Li ST, Mao ZH, Shu TT, Liu DW, Liu ZS, Wu P. Activation of Kir4.1/Kir5.1 contributes to the cyclosporin A-induced stimulation of the renal NaCl cotransporter and hyperkalemic hypertension. Acta Physiol (Oxf) 2023; 238:e13948. [PMID: 36764674 DOI: 10.1111/apha.13948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/16/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023]
Abstract
AIM Cyclosporin A (CsA) is a widely used immunosuppressive drug that causes hypertension and hyperkalemia. Moreover, CsA-induced stimulation of the thiazide-sensitive NaCl cotransporter (NCC) in the kidney has been shown to be responsible for the development of hyperkalemic hypertension. In this study, we tested whether CsA induces the activation of NCC by stimulating the basolateral Kir4.1/Kir5.1 channel in the distal convoluted tubule (DCT). METHODS Electrophysiology, immunoblotting, metabolic cages, and radio-telemetry methods were used to examine the effects of CsA on Kir4.1/Kir5.1 activity in the DCT, NCC function, and blood pressure in wild-type (WT) and kidney-specific Kir4.1 knockout (KS-Kir4.1 KO) mice. RESULTS The single-channel patch clamp experiment demonstrated that CsA stimulated the basolateral 40 pS K+ channel in the DCT. Whole-cell recording showed that short-term CsA administration (2 h) not only increased DCT K+ currents but also shifted the K+ current (IK ) reversal potential to the negative range (hyperpolarization). Furthermore, CsA administration increased phosphorylated NCC (pNCC) levels and inhibited renal Na+ and K+ excretions in WT mice but not in KS-Kir4.1 KO mice, suggesting that Kir4.1 is required to mediate CsA effects on NCC function. Finally, long-term CsA infusion (14 days) increased blood pressure, plasma K+ concentration, and total NCC or pNCC abundance in WT mice, but these effects were blunted in KS-Kir4.1 KO mice. CONCLUSION We conclude that CsA stimulates basolateral K+ channel activity in the DCT and that Kir4.1 is essential for CsA-induced NCC activation and hyperkalemic hypertension.
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Affiliation(s)
- Zhong-Xiuzi Gao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Rui Zhou
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Ming-Yan Li
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Shu-Ting Li
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Zi-Hui Mao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Ting-Ting Shu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Dong-Wei Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Zhang-Suo Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Peng Wu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Institute of Nephrology, Zhengzhou University, Zhengzhou, China.,Henan Province Research Center for Kidney Disease, Zhengzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
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Carbajal-Contreras H, Gamba G, Castañeda-Bueno M. The serine-threonine protein phosphatases that regulate the thiazide-sensitive NaCl cotransporter. Front Physiol 2023; 14:1100522. [PMID: 36875042 PMCID: PMC9974657 DOI: 10.3389/fphys.2023.1100522] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 01/17/2023] [Indexed: 02/17/2023] Open
Abstract
The activity of the Na+-Cl- cotransporter (NCC) in the distal convoluted tubule (DCT) is finely tuned by phosphorylation networks involving serine/threonine kinases and phosphatases. While much attention has been paid to the With-No-lysine (K) kinase (WNK)- STE20-related Proline Alanine rich Kinase (SPAK)/Oxidative Stress Responsive kinase 1 (OSR1) signaling pathway, there remain many unanswered questions regarding phosphatase-mediated modulation of NCC and its interactors. The phosphatases shown to regulate NCC's activity, directly or indirectly, are protein phosphatase 1 (PP1), protein phosphatase 2A (PP2A), calcineurin (CN), and protein phosphatase 4 (PP4). PP1 has been suggested to directly dephosphorylate WNK4, SPAK, and NCC. This phosphatase increases its abundance and activity when extracellular K+ is increased, which leads to distinct inhibitory mechanisms towards NCC. Inhibitor-1 (I1), oppositely, inhibits PP1 when phosphorylated by protein kinase A (PKA). CN inhibitors, like tacrolimus and cyclosporin A, increase NCC phosphorylation, giving an explanation to the Familial Hyperkalemic Hypertension-like syndrome that affects some patients treated with these drugs. CN inhibitors can prevent high K+-induced dephosphorylation of NCC. CN can also dephosphorylate and activate Kelch-like protein 3 (KLHL3), thus decreasing WNK abundance. PP2A and PP4 have been shown in in vitro models to regulate NCC or its upstream activators. However, no studies in native kidneys or tubules have been performed to test their physiological role in NCC regulation. This review focuses on these dephosphorylation mediators and the transduction mechanisms possibly involved in physiological states that require of the modulation of the dephosphorylation rate of NCC.
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Affiliation(s)
- Héctor Carbajal-Contreras
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.,PECEM (MD/PhD), Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gerardo Gamba
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.,PECEM (MD/PhD), Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.,Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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30
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Guo L, Fu B, Liu Y, Hao N, Ji Y, Yang H. Diuretic resistance in patients with kidney disease: Challenges and opportunities. Biomed Pharmacother 2023; 157:114058. [PMID: 36473405 DOI: 10.1016/j.biopha.2022.114058] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/15/2022] [Accepted: 11/27/2022] [Indexed: 12/10/2022] Open
Abstract
Edema caused by kidney disease is called renal edema. Edema is a common symptom of many human kidney diseases. Patients with renal edema often need to take diuretics.However, After taking diuretics, patients with kidney diseases are prone to kidney congestion, decreased renal perfusion, decreased diuretics secreted by renal tubules, neuroendocrine system abnormalities, abnormal ion transporter transport, drug interaction, electrolyte disorder, and hypoproteinemia, which lead to ineffective or weakened diuretic use and increase readmission rate and mortality. The main causes and coping strategies of diuretic resistance in patients with kidney diseases were described in detail in this report. The common causes of DR included poor diet (electrolyte disturbance and hypoproteinemia due to patients' failure to limit diet according to correct sodium, chlorine, potassium, and protein level) and poor drug compliance (the patient did not take adequate doses of diuretics. true resistance occurs only if the patient takes adequate doses of diuretics, but they are not effective), changes in pharmacokinetics and pharmacodynamics, electrolyte disorders, changes in renal adaptation, functional nephron reduction, and decreased renal blood flow. Common treatment measures include increasing in the diuretic dose and/or frequency, sequential nephron blockade,using new diuretics, ultrafiltration treatment, etc. In clinical work, measures should be taken to prevent or delay the occurrence and development of DR in patients with kidney diseases according to the actual situation of patients and the mechanism of various causes. Currently, there are many studies on DR in patients with heart diseases. Although the phenomenon of DR in patients with kidney diseases is common, there is a relatively little overview of the mechanism and treatment strategy of DR in patients with kidney diseases. Therefore, this paper hopes to show the information on DR in patients with kidney diseases to clinicians and researchers and broaden the research direction and ideas to a certain extent.
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Affiliation(s)
- Luxuan Guo
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Baohui Fu
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Yang Liu
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Na Hao
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Yue Ji
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Hongtao Yang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China; National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300193, China; Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China.
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31
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Terker AS, Zhang Y, Arroyo JP, Cao S, Wang S, Fan X, Denton JS, Zhang MZ, Harris RC. Kir4.2 mediates proximal potassium effects on glutaminase activity and kidney injury. Cell Rep 2022; 41:111840. [PMID: 36543132 PMCID: PMC9827473 DOI: 10.1016/j.celrep.2022.111840] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 09/20/2022] [Accepted: 11/23/2022] [Indexed: 12/24/2022] Open
Abstract
Inadequate potassium (K+) consumption correlates with increased mortality and poor cardiovascular outcomes. Potassium effects on blood pressure have been described previously; however, whether or not low K+ independently affects kidney disease progression remains unclear. Here, we demonstrate that dietary K+ deficiency causes direct kidney injury. Effects depend on reduced blood K+ and are kidney specific. In response to reduced K+, the channel Kir4.2 mediates altered proximal tubule (PT) basolateral K+ flux, causing intracellular acidosis and activation of the enzyme glutaminase and the ammoniagenesis pathway. Deletion of either Kir4.2 or glutaminase protects from low-K+ injury. Reduced K+ also mediates injury and fibrosis in a model of aldosteronism. These results demonstrate that the PT epithelium, like the distal nephron, is K+ sensitive, with reduced blood K+ causing direct PT injury. Kir4.2 and glutaminase are essential mediators of this injury process, and we identify their potential for future targeting in the treatment of chronic kidney disease.
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Affiliation(s)
- Andrew S Terker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA.
| | - Yahua Zhang
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Juan Pablo Arroyo
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Shirong Cao
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Suwan Wang
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Xiaofeng Fan
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA
| | - Jerod S Denton
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ming-Zhi Zhang
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA.
| | - Raymond C Harris
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, S-3206 MCN 1161 21st Ave South, Nashville, TN 37232, USA; Vanderbilt Center for Kidney Disease, Nashville, TN, USA; Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA.
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Saha B, Leite-Dellova DCA, Demko J, Sørensen MV, Takagi E, Gleason CE, Shabbir W, Pearce D. WNK1 is a chloride-stimulated scaffold that regulates mTORC2 activity and ion transport. J Cell Sci 2022; 135:jcs260313. [PMID: 36373794 PMCID: PMC9789407 DOI: 10.1242/jcs.260313] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Mammalian (or mechanistic) target of rapamycin complex 2 (mTORC2) is a kinase complex that targets predominantly Akt family proteins, SGK1 and protein kinase C (PKC), and has well-characterized roles in mediating hormone and growth factor effects on a wide array of cellular processes. Recent evidence suggests that mTORC2 is also directly stimulated in renal tubule cells by increased extracellular K+ concentration, leading to activation of the Na+ channel, ENaC, and increasing the electrical driving force for K+ secretion. We identify here a signaling mechanism for this local effect of K+. We show that an increase in extracellular [K+] leads to a rise in intracellular chloride (Cl-), which stimulates a previously unknown scaffolding activity of the protein 'with no lysine-1' (WNK1) kinase. WNK1 interacts selectively with SGK1 and recruits it to mTORC2, resulting in enhanced SGK1 phosphorylation and SGK1-dependent activation of ENaC. This scaffolding effect of WNK1 is independent of its own kinase activity and does not cause a generalized stimulation of mTORC2 kinase activity. These findings establish a novel WNK1-dependent regulatory mechanism that harnesses mTORC2 kinase activity selectively toward SGK1 to control epithelial ion transport and electrolyte homeostasis.
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Affiliation(s)
- Bidisha Saha
- Division of Nephrology, Departments of Medicine and Cellular & Molecular Pharmacology,University of California at San Francisco, San Francisco, CA 94158, USA
| | - Deise C. A. Leite-Dellova
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga, Sao Paulo 13635-900, Brazil
| | - John Demko
- Division of Nephrology, Departments of Medicine and Cellular & Molecular Pharmacology,University of California at San Francisco, San Francisco, CA 94158, USA
| | - Mads Vaarby Sørensen
- Departments of Biomedicine and Physiology, Aarhus University, 8000 Aarhus C, Denmark
| | - Enzo Takagi
- Division of Nephrology, Departments of Medicine and Cellular & Molecular Pharmacology,University of California at San Francisco, San Francisco, CA 94158, USA
| | - Catherine E. Gleason
- Division of Nephrology, Departments of Medicine and Cellular & Molecular Pharmacology,University of California at San Francisco, San Francisco, CA 94158, USA
| | - Waheed Shabbir
- Division of Nephrology, Departments of Medicine and Cellular & Molecular Pharmacology,University of California at San Francisco, San Francisco, CA 94158, USA
| | - David Pearce
- Division of Nephrology, Departments of Medicine and Cellular & Molecular Pharmacology,University of California at San Francisco, San Francisco, CA 94158, USA
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33
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Johnston JG, Wingo CS. Potassium Homeostasis and WNK Kinases in the Regulation of the Sodium-Chloride Cotransporter: Hyperaldosteronism and Its Metabolic Consequences. KIDNEY360 2022; 3:1823-1828. [PMID: 36514400 PMCID: PMC9717643 DOI: 10.34067/kid.0005752022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 10/12/2022] [Indexed: 12/05/2022]
Affiliation(s)
- Jermaine G. Johnston
- Department of Medicine, University of Florida, Gainesville, Florida
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Veterans Administration Medical Center, North Florida/South Georgia Veterans Health Administration, Gainesville, Florida
| | - Charles S. Wingo
- Department of Medicine, University of Florida, Gainesville, Florida
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Veterans Administration Medical Center, North Florida/South Georgia Veterans Health Administration, Gainesville, Florida
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34
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Meng XX, Zhang H, Meng GL, Jiang SP, Duan XP, Wang WH, Wang MX. The effect of high-dietary K + (HK) on Kir4.1/Kir5.1 and ROMK in the distal convoluted tubule (DCT) is not affected by gender and Cl - content of the diet. Front Physiol 2022; 13:1039029. [PMID: 36439248 PMCID: PMC9682262 DOI: 10.3389/fphys.2022.1039029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022] Open
Abstract
Basolateral potassium channels in the distal convoluted tubule (DCT) are composed of inwardly-rectifying potassium channel 4.1 (Kir4.1) and Kir5.1. Kir4.1 interacts with Kir5.1 to form a 40 pS K+ channel which is the only type K+ channel expressed in the basolateral membrane of the DCT. Moreover, Kir4.1/Kir5.1 heterotetramer plays a key role in determining the expression and activity of thiazide-sensitive Na-Cl cotransport (NCC). In addition to Kir4.1/Kir5.1, Kir1.1 (ROMK) is expressed in the apical membrane of the late DCT (DCT2) and plays a key role in mediating epithelial Na+ channel (ENaC)-dependent K+ excretion. High dietary-K+-intake (HK) stimulates ROMK and inhibits Kir4.1/Kir5.1 in the DCT. Inhibition of Kir4.1/Kir5.1 is essential for HK-induced suppression of NCC whereas the stimulation of ROMK is important for increasing ENaC-dependent K+ excretion during HK. We have now used the patch-clamp-technique to examine whether gender and Cl- content of K+-diet affect HK-induced inhibition of basolateral Kir4.1/Kir5.1 and HK-induced stimulation of ROMK. Single-channel-recording shows that basolateral 40 pS K+ channel (Kir4.1/Kir5.1) activity of the DCT defined by NPo was 1.34 (1% KCl, normal K, NK), 0.95 (5% KCl) and 1.03 (5% K+-citrate) in male mice while it was 1.47, 1.02 and 1.05 in female mice. The whole-cell recording shows that Kir4.1/Kir5.1-mediated-K+ current of the early-DCT (DCT1) was 1,170 pA (NK), 725 pA (5% KCl) and 700 pA (5% K+-citrate) in male mice whereas it was 1,125 pA, 674 pA and 700 pA in female mice. Moreover, K+-currents (IK) reversal potential of DCT (an index of membrane potential) was -63 mV (NK), -49 mV (5% KCl) and -49 mV (5% K-citrate) in the male mice whereas it was -63 mV, -50 mV and -50 mV in female mice. Finally, TPNQ-sensitive whole-cell ROMK-currents in the DCT2 /initial-connecting tubule (CNT) were 910 pA (NK), 1,520 pA (5% KCl) and 1,540 pA (5% K+-citrate) in male mice whereas the ROMK-mediated K+ currents were 1,005 pA, 1,590 pA and 1,570 pA in female mice. We conclude that the effect of HK intake on Kir4.1/Kir5.1 of the DCT and ROMK of DCT2/CNT is similar between male and female mice. Also, Cl- content in HK diets has no effect on HK-induced inhibition of Kir4.1/Kir5.1 of the DCT and HK-induced stimulation of ROMK in DCT2/CNT.
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Affiliation(s)
- Xin-Xin Meng
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Hao Zhang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Gui-Lin Meng
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Shao-Peng Jiang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China
| | - Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, NY, United States
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, NY, United States,*Correspondence: Ming-Xiao Wang, ; Wen-Hui Wang,
| | - Ming-Xiao Wang
- Department of Physiology, Zhuhai Campus of Zunyi Medical University, Zhuhai, China,*Correspondence: Ming-Xiao Wang, ; Wen-Hui Wang,
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Gamba G. Arterial Blood Pressure, Neuronal Excitability, Mineral Metabolism and Cell Volume Regulation Mechanisms Revealed by Xenopus laevis oocytes. MEMBRANES 2022; 12:911. [PMID: 36295670 PMCID: PMC9612257 DOI: 10.3390/membranes12100911] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/16/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Xenopus laevis oocytes have been an invaluable tool to discover and explore the molecular mechanisms and characteristics of many proteins, in particular integral membrane proteins. The oocytes were fundamental in many projects designed to identify the cDNA encoding a diversity of membrane proteins including receptors, transporters, channels and pores. In addition to being a powerful tool for cloning, oocytes were later used to experiment with the functional characterization of many of the identified proteins. In this review I present an overview of my personal 30-year experience using Xenopus laevis oocytes and the impact this had on a variety of fields such as arterial blood pressure, neuronal excitability, mineral metabolism and cell volume regulation.
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Affiliation(s)
- Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México and Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City 04510, Mexico
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36
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Palmer LG. Directing two-way traffic in the kidney: A tale of two ions. J Gen Physiol 2022; 154:213433. [PMID: 36048011 PMCID: PMC9437110 DOI: 10.1085/jgp.202213179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The kidneys regulate levels of Na+ and K+ in the body by varying urinary excretion of the electrolytes. Since transport of each of the two ions can affect the other, controlling both at the same time is a complex task. The kidneys meet this challenge in two ways. Some tubular segments change the coupling between Na+ and K+ transport. In addition, transport of Na+ can shift between segments where it is coupled to K+ reabsorption and segments where it is coupled to K+ secretion. This permits the kidney to maintain electrolyte balance with large variations in dietary intake.
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Affiliation(s)
- Lawrence G. Palmer
- Department of Physiology and Biophysics, Weill-Cornell Medical College, New York, NY,Correspondence to Lawrence G. Palmer:
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Role of inwardly rectifying K+ channel 5.1 (Kir5.1) in the regulation of renal membrane transport. Curr Opin Nephrol Hypertens 2022; 31:479-485. [PMID: 35894283 DOI: 10.1097/mnh.0000000000000817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Kir5.1 interacts with Kir4.2 in proximal tubule and with Kir4.1 in distal convoluted tubule (DCT), connecting tubule (CNT) and cortical collecting duct (CCD) to form basolateral-K+-channels. Kir4.2/Kir5.1 and Kir4.1/Kir5.1 play an important role in regulating Na+/HCO3--transport of the proximal tubule and Na+/K+ -transport in the DCT/CNT/CCD. The main focus of this review is to provide an overview of the recent development in the field regarding the role of Kir5.1 regulating renal electrolyte transport in the proximal tubule and DCT. RECENT FINDINGS Loss-of-function-mutations of KCNJ16 cause a new form of tubulopathy, characterized by hypokalaemia, Na+-wasting, acid-base-imbalance and metabolic-acidosis. Abnormal bicarbonate transport induced by loss-of-function of KCNJ16-mutants is recapitulated in Kir4.2-knockout-(Kir4.2 KO) mice. Deletion of Kir5.1 also abolishes the effect of dietary Na+ and K+-intakes on the basolateral membrane voltage and NCC expression/activity. Long-term high-salt intake or high-K+-intake causes hyperkalaemic in Kir5.1-deficient mice. SUMMARY Kir4.2/Kir5.1 activity in the proximal tubule plays a key role in regulating Na+, K+ and bicarbonate-transport through regulating electrogenic-Na+-bicarbonate-cotransporter-(NBCe1) and type 3-Na+/H+-exchanger-(NHE3). Kir4.1/Kir5.1 activity of the DCT plays a critical role in mediating the effect of dietary-K+ and Na+-intakes on NCC activity/expression. As NCC determines the Na+ delivery rate to the aldosterone-sensitive distal nephron (ASDN), defective regulation of NCC during high-salt and high-K+ compromises renal K+ excretion and K+ homeostasis.
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Wu A, Wolley MJ, Fenton RA, Stowasser M. Using human urinary extracellular vesicles to study physiological and pathophysiological states and regulation of the sodium chloride cotransporter. Front Endocrinol (Lausanne) 2022; 13:981317. [PMID: 36105401 PMCID: PMC9465297 DOI: 10.3389/fendo.2022.981317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/09/2022] [Indexed: 11/29/2022] Open
Abstract
The thiazide-sensitive sodium chloride cotransporter (NCC), expressed in the renal distal convoluted tubule, plays a major role in Na+, Cl- and K+ homeostasis and blood pressure as exemplified by the symptoms of patients with non-functional NCC and Gitelman syndrome. NCC activity is modulated by a variety of hormones, but is also influenced by the extracellular K+ concentration. The putative "renal-K+ switch" mechanism is a relatively cohesive model that links dietary K+ intake to NCC activity, and may offer new targets for blood pressure control. However, a remaining hurdle for full acceptance of this model is the lack of human data to confirm molecular findings from animal models. Extracellular vesicles (EVs) have attracted attention from the scientific community due to their potential roles in intercellular communication, disease pathogenesis, drug delivery and as possible reservoirs of biomarkers. Urinary EVs (uEVs) are an excellent sample source for the study of physiology and pathology of renal, urothelial and prostate tissues, but the diverse origins of uEVs and their dynamic molecular composition present both methodological and data interpretation challenges. This review provides a brief overview of the state-of-the-art, challenges and knowledge gaps in current uEV-based analyses, with a focus on the application of uEVs to study the "renal-K+ switch" and NCC regulation. We also provide recommendations regarding biospecimen handling, processing and reporting requirements to improve experimental reproducibility and interoperability towards the realisation of the potential of uEV-derived biomarkers in hypertension and clinical practice.
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Affiliation(s)
- Aihua Wu
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, QLD, Australia
| | - Martin J. Wolley
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, QLD, Australia
- Department of Nephrology, Royal Brisbane and Women’s Hospital, Brisbane, QLD, Australia
| | | | - Michael Stowasser
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, QLD, Australia
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Wu A, Wolley MJ, Matthews A, Cowley D, Welling PA, Fenton RA, Stowasser M. In Primary Aldosteronism Acute Potassium Chloride Supplementation Suppresses Abundance and Phosphorylation of the Sodium-Chloride Cotransporter. KIDNEY360 2022; 3:1909-1923. [PMID: 36514401 PMCID: PMC9717638 DOI: 10.34067/kid.0003632022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/25/2022] [Indexed: 01/12/2023]
Abstract
Background Elevated abundance of sodium-chloride cotransporter (NCC) and phosphorylated NCC (pNCC) are potential markers of primary aldosteronism (PA), but these effects may be driven by hypokalemia. Methods We measured plasma potassium in patients with PA. If potassium was <4.0 mmol/L, patients were given sufficient oral potassium chloride (KCl) over 24 hours to achieve as close to 4.0 mmol/L as possible. Clinical chemistries were assessed, and urinary extracellular vesicles (uEVs) were examined to investigate effects on NCC. Results Among 21 patients with PA who received a median total dose of 6.0 g (2.4-16.8 g) of KCl, increases were observed in plasma potassium (from 3.4 to 4.0 mmol/L; P<0.001), aldosterone (from 305 to 558 pmol/L; P=0.01), and renin (from 1.2 to 2.5 mIU/L; P<0.001), whereas decreases were detected in uEV levels of NCC (median fold change(post/basal) [FC]=0.71 [0.09-1.99]; P=0.02), pT60-NCC (FC=0.84 [0.06-1.66]; P=0.05), and pT55/60-NCC (FC=0.67 [0.08-2.42]; P=0.02). By contrast, in 10 patients with PA who did not receive KCl, there were no apparent changes in plasma potassium, NCC abundance, and phosphorylation status, but increases were observed in plasma aldosterone (from 178 to 418 pmol/L; P=0.006) and renin (from 2.0 to 3.0 mU/L; P=0.009). Plasma potassium correlated inversely with uEV levels of NCC (R 2=0.11; P=0.01), pT60-NCC (R 2=0.11; P=0.01), and pT55/60-NCC (R 2=0.11; P=0.01). Conclusions Acute oral KCl loading replenished plasma potassium in patients with PA and suppressed NCC abundance and phosphorylation, despite a significant rise in plasma aldosterone. This supports the view that potassium supplementation in humans with PA overrides the aldosterone stimulatory effect on NCC. The increased plasma aldosterone in patients with PA without KCl supplementation may be due to aldosterone response to posture challenge.
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Affiliation(s)
- Aihua Wu
- Endocrine Hypertension Research Centre, The University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| | - Martin J. Wolley
- Endocrine Hypertension Research Centre, The University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia,Department of Nephrology, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Alexandra Matthews
- Endocrine Hypertension Research Centre, The University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| | - Diane Cowley
- Endocrine Hypertension Research Centre, The University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| | - Paul A. Welling
- Department of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland
| | | | - Michael Stowasser
- Endocrine Hypertension Research Centre, The University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
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Rodan AR. Regulation of Distal Nephron Transport by Intracellular Chloride and Potassium. Nephron Clin Pract 2022; 147:203-211. [PMID: 35977527 PMCID: PMC9935751 DOI: 10.1159/000526051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 07/11/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Low potassium increases the phosphorylation and activity of the sodium chloride cotransporter (NCC) in the distal convoluted tubule of the nephron, which contributes to the hypertensive effect of the modern low potassium/high sodium diet. A central mediator of potassium regulation of NCC is the chloride-sensitive With No Lysine [K] (WNK) kinase. SUMMARY Chloride directly inhibits WNKs by binding to the active site. The mechanisms underlying WNK regulation by extracellular potassium are reviewed, as well as the modulatory effect of kidney-specific-WNK1. WNK1, but not WNK1 kinase activity, is also required for the aldosterone-independent regulation of the epithelial sodium channel by potassium. Whether intracellular chloride could be involved in this process is discussed. Recent studies demonstrating direct regulation of WNKs by intracellular potassium are also reviewed, and the potential physiological relevance to renal epithelial ion transport is discussed. KEY MESSAGES WNKs are sensors of the intracellular ionic milieu. In the nephron, changes in extracellular ion concentrations, resulting in changes in intracellular ion concentration, regulate WNK activity and downstream transporters and channels to maintain total body ion homeostasis.
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Affiliation(s)
- Aylin R Rodan
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
- Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah, USA
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Wang WH, Lin DH. Inwardly rectifying K + channels 4.1 and 5.1 (Kir4.1/Kir5.1) in the renal distal nephron. Am J Physiol Cell Physiol 2022; 323:C277-C288. [PMID: 35759440 PMCID: PMC9291425 DOI: 10.1152/ajpcell.00096.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The inwardly rectifying potassium channel (Kir) 4.1 (encoded by KCNJ10) interacts with Kir5.1 (encoded by KCNJ16) to form a major basolateral K+ channel in the renal distal convoluted tubule (DCT), connecting tubule (CNT), and the cortical collecting duct (CCD). Kir4.1/Kir5.1 heterotetramer plays an important role in regulating Na+ and K+ transport in the DCT, CNT, and CCD. A recent development in the field has firmly established the role of Kir4.1/Kir5.1 heterotetramer of the DCT in the regulation of thiazide-sensitive Na-Cl cotransporter (NCC). Changes in Kir4.1/Kir5.1 activity of the DCT are an essential step for the regulation of NCC expression/activity induced by dietary K+ and Na+ intakes and play a role in modulating NCC by type 2 angiotensin II receptor (AT2R), bradykinin type II receptor (BK2R), and β-adrenergic receptor. Since NCC activity determines the Na+ delivery rate to the aldosterone-sensitive distal nephron (ASDN), a distal nephron segment from late DCT to CCD, Kir4.1/Kir5.1 activity plays a critical role not only in the regulation of renal Na+ absorption but also in modulating renal K+ excretion and maintaining K+ homeostasis. Thus, Kir4.1/Kir5.1 activity serves as an important component of renal K+ sensing mechanism. The main focus of this review is to provide an overview regarding the role of Kir4.1 and Kir5.1 of the DCT and CCD in the regulation of renal K+ excretion and Na+ absorption.
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Affiliation(s)
- Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
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Ferdaus MZ, Terker AS, Koumangoye R, Delpire E. KCC3a, a Strong Candidate Pathway for K+ Loss in Alkalemia. Front Cell Dev Biol 2022; 10:931326. [PMID: 35874803 PMCID: PMC9301082 DOI: 10.3389/fcell.2022.931326] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
Loss-of-function mutations in the human potassium chloride cotransporter-3 (KCC3) cause a hereditary motor sensory neuropathy associated with agenesis of the corpus callosum. While recapitulating the neuropathy, KCC3-knockout mice also exhibit high blood pressure. This phenotype is believed to have neurogenic and/or vascular origins. The role of KCC3 in the kidney is poorly understood. KCC3 is encoded by two major isoforms originating from alternative promoters: KCC3a and KCC3b, with KCC3b being the predominant transcript in the kidney. Although the transporter has previously been localized to the proximal tubule, we show here the unique expression of the KCC3a isoform in the connecting tubule. Using a KCC3a-specific polyclonal antibody validated for both immunofluorescence and immunoblotting, we showed an intense KCC3a signal restricted to cortical intercalated cells. No overlap is detected between KCC3a and sodium chloride cotransporter (NCC), a distal convoluted tubule (DCT) marker; or between KCC3a and ENaC or calbindin, which are both principal cell markers. KCC3a signal was observed in cells expressing the apical V-ATPase and pendrin, establishing a unique expression pattern characteristic of intercalated cells of type-B or type-nonA/nonB. We further show that treatment of wild-type mice with hydrochlorothiazide, amiloride, or fed a K+-deficient diet up-regulates KCC3a level, suggesting that volume depletion increases KCC3a abundance. This hypothesis was confirmed by showing a higher abundance of KCC3a protein after 23-h water restriction or after placing the mice on a low-salt diet. More importantly, abundance of the Cl−/HCO3− exchanger, pendrin, which is known to secrete bicarbonate in alkalotic conditions, was significantly diminished in KCC3-knockout mice. In addition, KCC3a abundance increased significantly alongside pendrin abundance in bicarbonate-treated alkalotic mice, providing a credible mechanism for K+ loss in metabolic alkalosis.
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Affiliation(s)
- Mohammed Zubaerul Ferdaus
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Andrew Scott Terker
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Rainelli Koumangoye
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN, United States
- *Correspondence: Eric Delpire,
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Maeoka Y, Su XT, Wang WH, Duan XP, Sharma A, Li N, Staub O, McCormick JA, Ellison DH. Mineralocorticoid Receptor Antagonists Cause Natriuresis in the Absence of Aldosterone. Hypertension 2022; 79:1423-1434. [PMID: 35506380 PMCID: PMC9177775 DOI: 10.1161/hypertensionaha.122.19159] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND MR (mineralocorticoid receptor) antagonists are recommended for patients with resistant hypertension even when circulating aldosterone levels are not high. Although aldosterone activates MR to increase epithelial sodium channel (ENaC) activity, glucocorticoids also activate MR but are metabolized by 11βHSD2 (11β-hydroxysteroid dehydrogenase type 2). 11βHSD2 is expressed at increasing levels from distal convoluted tubule (DCT) through collecting duct. Here, we hypothesized that MR maintains ENaC activity in the DCT2 and early connecting tubule in the absence of aldosterone. METHODS We studied AS (aldosterone synthase)-deficient (AS-/-) mice, which were backcrossed onto the same C57BL6/J strain as kidney-specific MR knockout (KS-MR-/-) mice. KS-MR-/- mice were used to compare MR expression and ENaC localization and cleavage with AS-/- mice. RESULTS MR was highly expressed along DCT2 through the cortical collecting duct (CCD), whereas no 11βHSD2 expression was observed along DCT2. MR signal and apical ENaC localization were clearly reduced along both DCT2 and CCD in KS-MR-/- mice but were fully preserved along DCT2 and were partially reduced along CCD in AS-/- mice. Apical ENaC localization and ENaC currents were fully preserved along DCT2 in AS-/- mice and were not increased along CCD after low salt. AS-/- mice exhibited transient Na+ wasting under low-salt diet, but administration of the MR antagonist eplerenone to AS-/- mice led to hyperkalemia and decreased body weight with higher Na+ excretion, mimicking the phenotype of MR-/- mice. CONCLUSIONS Our results provide evidence that MR is activated in the absence of aldosterone along DCT2 and partially CCD, suggesting glucocorticoid binding to MR preserves sodium homeostasis along DCT2 in AS-/- mice.
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Affiliation(s)
- Yujiro Maeoka
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR
| | - Xiao-Tong Su
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Avika Sharma
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR
| | - Na Li
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Olivier Staub
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland,LeDucq Transatlantic Network of Excellence
| | - James A. McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR
| | - David H. Ellison
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR,LeDucq Transatlantic Network of Excellence,Veterans Affairs Portland Healthcare System, Portland, Oregon
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Lee CH, Shin J. Effect of low sodium and high potassium diet on lowering blood pressure. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2022. [DOI: 10.5124/jkma.2022.65.6.368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Background: Hypertension is the leading factor of cardiovascular mortality and morbidity. Although antihypertensive medical treatment is the cornerstone of blood pressure control, lifestyle modification, including optimal diet therapy, such as dietary approaches to stop hypertension (DASH), cannot be overemphasized.Current Concepts: Due to the mismatch between sodium intake and excretion process being the key mechanisms according to physiologic principles, low sodium and high potassium intakes are the critical components of DASH. If the patient has a sensitive elevation of blood pressure following increased sodium intake, a low sodium diet could be essential for optimal blood pressure control. Salt sensitivity is increased by the activated reninangiotensin system, sympathetic nervous activity, sodium channels disorder, and endothelial dysfunction and frequently observed in the elderly and patients with obesity and chronic kidney disease. Increased potassium intake could attenuate sodium absorption by affecting the intracellular chloride and WNK4 activity, especially in patients with salt sensitivity or high salt intake.Discussion and Conclusion: For low sodium and high potassium intakes, the Na/K diet ratio could be a good target for intervention, and this approach is a critical component of DASH.
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Xiao H, Yan Y, Gu Y, Zhang Y. Strategy for sodium-salt substitution: On the relationship between hypertension and dietary intake of cations. Food Res Int 2022; 156:110822. [PMID: 35650987 DOI: 10.1016/j.foodres.2021.110822] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/28/2021] [Accepted: 11/22/2021] [Indexed: 11/04/2022]
Abstract
Chronic diseases, especially cardiovascular diseases (CVD), have become one of the main causes affecting human health. Hypertension is a prominent representative of CVD. The formation and development of hypertension is closely related to people's daily diet. A large number of studies have shown that excessive intake of salt (NaCl) could increase the risk of hypertension. In recent years, more and more investigations have focused on other cations that may be contained in edible salt, exploring whether they have an effect on hypertension and the underlying mechanism. This article focuses on the relationship between four metal elements (potassium, calcium, magnesium, and zinc) and hypertension, by discussing the main metabolic pathway, the impact of diet intake on blood pressure, and especially the regulation mechanisms on blood pressure in detail. At the same time, some opinions and suggestions are put forward, combined with the current hot topics "salt reduction" and "salt substitution".
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Affiliation(s)
- Hongrui Xiao
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Yali Yan
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Yanpei Gu
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Ying Zhang
- College of Biosystems Engineering and Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Center for Food Technology and Equipment, Zhejiang University, Hangzhou 310058, Zhejiang, China.
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Hou CY, Ma CY, Yuh CH. WNK1 kinase signaling in metastasis and angiogenesis. Cell Signal 2022; 96:110371. [DOI: 10.1016/j.cellsig.2022.110371] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 02/06/2023]
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Schellinger JN, Sun Q, Pleinis JM, An SW, Hu J, Mercenne G, Titos I, Huang CL, Rothenfluh A, Rodan AR. Chloride oscillation in pacemaker neurons regulates circadian rhythms through a chloride-sensing WNK kinase signaling cascade. Curr Biol 2022; 32:1429-1438.e6. [PMID: 35303418 PMCID: PMC8972083 DOI: 10.1016/j.cub.2022.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/02/2021] [Accepted: 03/04/2022] [Indexed: 12/21/2022]
Abstract
Central pacemaker neurons regulate circadian rhythms and undergo diurnal variation in electrical activity in mammals and flies.1,2 Circadian variation in the intracellular chloride concentration of mammalian pacemaker neurons has been proposed to influence the response to GABAergic neurotransmission through GABAA receptor chloride channels.3 However, results have been contradictory,4-9 and a recent study demonstrated circadian variation in pacemaker neuron chloride without an effect on GABA response.10 Therefore, whether and how intracellular chloride regulates circadian rhythms remains controversial. Here, we demonstrate a signaling role for intracellular chloride in the Drosophila small ventral lateral (sLNv) pacemaker neurons. In control flies, intracellular chloride increases in sLNvs over the course of the morning. Chloride transport through sodium-potassium-2-chloride (NKCC) and potassium-chloride (KCC) cotransporters is a major determinant of intracellular chloride concentrations.11Drosophila melanogaster with loss-of-function mutations in the NKCC encoded by Ncc69 have abnormally low intracellular chloride 6 h after lights on, loss of morning anticipation, and a prolonged circadian period. Loss of kcc, which is expected to increase intracellular chloride, suppresses the long-period phenotype of Ncc69 mutant flies. Activation of a chloride-inhibited kinase cascade, consisting of WNK (with no lysine [K]) kinase and its downstream substrate, Fray, is necessary and sufficient to prolong period length. Fray activation of an inwardly rectifying potassium channel, Irk1, is also required for the long-period phenotype. These results indicate that the NKCC-dependent rise in intracellular chloride in Drosophila sLNv pacemakers restrains WNK-Fray signaling and overactivation of an inwardly rectifying potassium channel to maintain normal circadian period length.
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Affiliation(s)
- Jeffrey N Schellinger
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Qifei Sun
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern, Dallas, TX 75390, USA
| | - John M Pleinis
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Sung-Wan An
- Department of Internal Medicine, Division of Nephrology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Jianrui Hu
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Gaëlle Mercenne
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Iris Titos
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Chou-Long Huang
- Department of Internal Medicine, Division of Nephrology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Adrian Rothenfluh
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Department of Psychiatry, Huntsman Mental Health Institute, University of Utah, Salt Lake City, UT 84108, USA; Department of Neurobiology, University of Utah, Salt Lake City, UT 84112, USA; Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Aylin R Rodan
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA; Department of Internal Medicine, Division of Nephrology and Hypertension, University of Utah, Salt Lake City, UT 84132, USA; Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, UT 84148, USA.
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Wu A, Wolley MJ, Wu Q, Cowley D, Palmfeldt J, Welling PA, Fenton RA, Stowasser M. Acute Intravenous NaCl and Volume Expansion Reduces Sodium-Chloride Cotransporter Abundance and Phosphorylation in Urinary Extracellular Vesicles. KIDNEY360 2022; 3:910-921. [PMID: 36128481 PMCID: PMC9438418 DOI: 10.34067/kid.0000362022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/28/2022] [Indexed: 01/12/2023]
Abstract
Background Sodium chloride (NaCl) loading and volume expansion suppress the renin-angiotensin-aldosterone system to reduce renal tubular reabsorption of NaCl and water, but effects on the sodium-chloride cotransporter (NCC) and relevant renal transmembrane proteins that are responsible for this modulation in humans are less well investigated. Methods We used urinary extracellular vesicles (uEVs) as an indirect readout to assess renal transmembrane proteins involved in NaCl and water homeostasis in 44 patients with hypertension who had repeatedly raised aldosterone/renin ratios undergoing infusion of 2 L of 0.9% saline over 4 hours. Results When measured by mass spectrometry in 13 patients, significant decreases were observed in NCC (median fold change [FC]=0.70); pendrin (FC=0.84); AQP2 (FC=0.62); and uEV markers, including ALIX (FC=0.65) and TSG101 (FC=0.66). Immunoblotting reproduced the reduction in NCC (FC=0.54), AQP2 (FC=0.42), ALIX (FC=0.52), and TSG101 (FC=0.55) in the remaining 31 patients, and demonstrated a significant decrease in phosphorylated NCC (pNCC; FC=0.49). However, after correction for ALIX, the reductions in NCC (FC=0.90) and pNCC (FC=1.00) were no longer apparent, whereas the significant decrease in AQP2 persisted (FC=0.62). Conclusion We conclude that (1) decreases in NCC and pNCC, induced by acute NaCl loading and volume expansion, may be due to diluted post-test urines; (2) the lack of change of NCC and pNCC when corrected for ALIX, despite a fall in plasma aldosterone, may be due to the lack of change in plasma K+; and (3) the decrease in AQP2 may be due to a decrease in vasopressin in response to volume expansion.
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Affiliation(s)
- Aihua Wu
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| | - Martin J. Wolley
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia,Department of Nephrology, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Qi Wu
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Diane Cowley
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
| | - Johan Palmfeldt
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Paul A. Welling
- Department of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland
| | | | - Michael Stowasser
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia
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Svendsen SL, Kornvig S, Berg P, Jensen IS, Araujo IBBA, Larsen CK, Leipziger J, Sørensen MV. Dietary K + acts as a genuine diuretic. Acta Physiol (Oxf) 2022; 234:e13762. [PMID: 34984847 DOI: 10.1111/apha.13762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/29/2021] [Accepted: 01/01/2022] [Indexed: 12/11/2022]
Abstract
K+ balance in mammals relies on regulated renal K+ excretion matching unregulated fluctuating K+ intake. Upon a K+ rich meal, rapid and powerful K+ excretion is needed. Renal K+ secretion is stimulated by the increased tubular flow. We speculated that high K+ intake acutely increases urinary flow to stimulate K+ excretion. METHODS Mice were K+ challenged through diets or gavage. Post K+ loading urinary output, osmolarity, [K+ ]u , [Na+ ]u , plasma osmolarity, [copeptin]p , [K+ ]p , and [Na+ ]p were measured. To locate the mechanism of K+ -induced diuresis in the glomerular/tubular system we measured creatinine excretion and assessed functional transport in isolated perfused TALs and CDs during an acute [K+ ]bl switch from 3.6 to 6.5 mM. Molecular adaptations of transport proteins involved in water reabsorption were investigated by immunoblotting. RESULTS (1) Mice switched from a 1% to 2% K+ diet increased diuresis within 12 hours and reciprocally reduced diuresis when switched from 1% to 0.01% K+ diet. (2) A single K+ gavage load, corresponding to 25%-50% of daily K+ intake, induced 100% increase in diuresis within 30 minutes. This occurred despite augmented plasma osmolarity and AVP synthesis. (3) K+ gavage did not change GFR. (4) In isolated perfused TALs, shifting [K+ ]bl from 3.6 to 6.5 mM did not affect AVP-induced NaCl transport. (5) In sharp contrast, in isolated perfused CDs, shifting [K+ ]bl from 3.6 to 6.5 mM markedly reduced CD AVP sensitivity, ie inhibited water absorption. CONCLUSION Dietary K+ loading induces a rapidly on-setting diuresis. The mechanism of K+ -induced diuresis involves desensitization of the CD to AVP.
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Affiliation(s)
- Samuel L. Svendsen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Simon Kornvig
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Peder Berg
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Iben S. Jensen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | | | - Casper K. Larsen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Jens Leipziger
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
| | - Mads V. Sørensen
- Department of Biomedicine, Physiology, Health Aarhus University Aarhus C Denmark
- Aarhus Institute for Advanced Studies (AIAS) Aarhus University Aarhus C Denmark
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Polidoro JZ, Luchi WM, Seguro AC, Malnic G, Girardi ACC. Paracrine and endocrine regulation of renal potassium secretion. Am J Physiol Renal Physiol 2022; 322:F360-F377. [DOI: 10.1152/ajprenal.00251.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The seminal studies conducted by Giebisch and colleagues in the 1960s paved the way for understanding the renal mechanisms involved in K+ homeostasis. It was demonstrated that differential handling of K+ in the distal segments of the nephron is crucial for proper K+ balance. Although aldosterone had been classically ascribed as the major ion transport regulator in the distal nephron, thereby contributing to K+ homeostasis, it became clear that aldosterone per se could not explain the kidney's ability to modulate kaliuresis in both acute and chronic settings. The existence of alternative kaliuretic and antikaliuretic mechanisms was suggested by physiological studies in the 1980s but only gained form and shape with the advent of molecular biology. It is now established that the kidneys recruit several endocrine and paracrine mechanisms for adequate kaliuretic response. These mechanisms include the direct effects of peritubular K+, a gut-kidney regulatory axis sensing dietary K+ levels, the kidney secretion of kallikrein during postprandial periods, the upregulation of angiotensin II receptors in the distal nephron during chronic changes in the K+ diet, and the local increase of prostaglandins by low K+ diet. This review discusses recent advances in the understanding of endocrine and paracrine mechanisms underlying the modulation of K+ secretion and how these mechanisms impact kaliuresis and K+ balance. We also highlight important unknowns about the regulation of renal K+ excretion under physiological circumstances.
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Affiliation(s)
- Juliano Z. Polidoro
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Weverton Machado Luchi
- Department of Internal Medicine, Federal University of Espírito Santo (UFES), Vitória, Espírito Santo, Brazil
| | - Antonio Carlos Seguro
- Department of Nephrology (LIM 12), University of São Paulo Medical School, São Paulo, São Paulo, Brazil
| | - Gerhard Malnic
- Department of Physiology and Biophysics, University of São Paulo Medical School, São Paulo, Brazil
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