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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] [What about the content of this article? (0)] [Affiliation(s)] [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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2
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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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Isaeva E, Bohovyk R, Fedoriuk M, Shalygin A, Klemens CA, Zietara A, Levchenko V, Denton JS, Staruschenko A, Palygin O. Crosstalk between ENaC and basolateral K ir 4.1/K ir 5.1 channels in the cortical collecting duct. Br J Pharmacol 2021; 179:2953-2968. [PMID: 34904226 DOI: 10.1111/bph.15779] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 10/06/2021] [Accepted: 12/06/2021] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND AND PURPOSE Inwardly rectifying K+ (Kir ) channels located on the basolateral membrane of epithelial cells of the distal nephron play a crucial role in K+ handling and blood pressure control, making these channels an attractive target for the treatment of hypertension. The purpose of the present study was to determine how the inhibition of basolateral Kir 4.1/Kir 5.1 heteromeric K+ channel affects epithelial sodium channel (ENaC)-mediated Na+ transport in the principal cells of cortical collecting duct (CCD). EXPERIMENTAL APPROACH The effect of fluoxetine, amitriptyline, and recently developed Kir inhibitor, VU0134992, on the activity of Kir 4.1, Kir 4.1/Kir 5.1, and ENaC were tested using electrophysiological approaches in Chinese hamster ovary (CHO) cells transfected with respective channel subunits, cultured polarized epithelial mCCDcl1 cells, and freshly isolated rat and human CCD tubules. To test the effect of pharmacological Kir 4.1/Kir 5.1 inhibition on electrolyte homeostasis in vivo and corresponding changes in distal tubule transport, Dahl salt-sensitive rats were injected with amitriptyline (15 mg kg-1 day-1 ) for three days. KEY RESULTS We found that inhibition of Kir 4.1/Kir 5.1, but not Kir 4.1 channel, depolarizes cell membrane, induces the elevation of intracellular Ca2+ concentration, and suppresses ENaC activity. Furthermore, we demonstrate that amitriptyline administration leads to a significant drop in plasma K+ level, triggering sodium excretion and diuresis. CONCLUSION AND IMPLICATIONS Present data uncovers a specific role of the Kir 4.1/Kir 5.1 channel in the modulation of ENaC activity and emphasizes the potential for using Kir 4.1/Kir 5.1 inhibitors to regulate electrolyte homeostasis and blood pressure.
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Affiliation(s)
- Elena Isaeva
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Ruslan Bohovyk
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kyiv, Ukraine.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Mykhailo Fedoriuk
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Alexey Shalygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Christine A Klemens
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Adrian Zietara
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Jerod S Denton
- Department of Anesthesiology and Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA.,Clement J. Zablocki VA Medical Center, Milwaukee, WI, USA.,Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, SC, USA
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Hyndman KA, Isaeva E, Palygin O, Mendoza LD, Rodan AR, Staruschenko A, Pollock JS. Role of collecting duct principal cell NOS1β in sodium and potassium homeostasis. Physiol Rep 2021; 9:e15080. [PMID: 34665521 PMCID: PMC8525323 DOI: 10.14814/phy2.15080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/15/2021] [Accepted: 09/27/2021] [Indexed: 12/15/2022] Open
Abstract
The nitric oxide (NO)-generating enzyme, NO synthase-1β (NOS1β), is essential for sodium (Na+ ) homeostasis and blood pressure control. We previously showed that collecting duct principal cell NOS1β is critical for inhibition of the epithelial sodium channel (ENaC) during high Na+ intake. Previous studies on freshly isolated cortical collecting ducts (CCD) demonstrated that exogenous NO promotes basolateral potassium (K+ ) conductance through basolateral channels, presumably Kir 4.1 (Kcnj10) and Kir 5.1 (Kcnj16). We, therefore, investigated the effects of NOS1β knockout on Kir 4.1/Kir 5.1 channel activity. Indeed, in CHO cells overexpressing NOS1β and Kir 4.1/Kir 5.1, the inhibition of NO signaling decreased channel activity. Male littermate control and principal cell NOS1β knockout mice (CDNOS1KO) on a 7-day, 4% NaCl diet (HSD) were used to detect changes in basolateral K+ conductance. We previously demonstrated that CDNOS1KO mice have high circulating aldosterone despite a high-salt diet and appropriately suppressed renin. We observed greater Kir 4.1 cortical abundance and significantly greater Kir 4.1/Kir 5.1 single-channel activity in the principal cells from CDNOS1KO mice. Moreover, blocking aldosterone action with in vivo spironolactone treatment resulted in lower Kir 4.1 abundance and greater plasma K+ in the CDNOS1KO mice compared to controls. Lowering K+ content in the HSD prevented the high aldosterone and greater plasma Na+ of CDNOS1KO mice and normalized Kir 4.1 abundance. We conclude that during chronic HSD, lack of NOS1β leads to increased plasma K+ , enhanced circulating aldosterone, and activation of ENaC and Kir 4.1/Kir 5.1 channels. Thus, principal cell NOS1β is required for the regulation of both Na+ and K+ by the kidney.
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Affiliation(s)
- Kelly A. Hyndman
- Department of MedicineDivision of NephrologySection of Cardio‐Renal Physiology and MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Elena Isaeva
- Department of Cellular Biology, Neurobiology and AnatomyMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Oleg Palygin
- Division of NephrologyDepartment of MedicineMedical University of South CarolinaCharlestonSouth CarolinaUSA
| | - Luciano D. Mendoza
- Department of MedicineDivision of NephrologySection of Cardio‐Renal Physiology and MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Aylin R. Rodan
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUtahUSA
- The Department of Internal MedicineDivision of Nephrology and HypertensionUniversity of UtahSalt Lake CityUtahUSA
- The Department of Human GeneticsUniversity of UtahSalt Lake CityUtahUSA
- The Medical ServiceVeterans Affairs Salt Lake City Health Care SystemSalt Lake CityUtahUSA
| | - Alexander Staruschenko
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- The James A. Haley Veterans HospitalTampaFloridaUSA
| | - Jennifer S. Pollock
- Department of MedicineDivision of NephrologySection of Cardio‐Renal Physiology and MedicineUniversity of Alabama at BirminghamBirminghamAlabamaUSA
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Manis AD, Palygin O, Khedr S, Levchenko V, Hodges MR, Staruschenko A. Relationship between the renin-angiotensin-aldosterone system and renal Kir5.1 channels. Clin Sci (Lond) 2019; 133:2449-2461. [PMID: 31799617 PMCID: PMC8474144 DOI: 10.1042/cs20190876] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/13/2019] [Accepted: 12/03/2019] [Indexed: 02/07/2023]
Abstract
Kir5.1 (encoded by the Kcnj16 gene) is an inwardly rectifying K+ (Kir) channel highly expressed in the aldosterone-sensitive distal nephron of the kidney, where it forms a functional channel with Kir4.1. Kir4.1/Kir5.1 channels are responsible for setting the transepithelial voltage in the distal nephron and collecting ducts and are thereby major determinants of fluid and electrolyte distribution. These channels contribute to renal blood pressure control and have been implicated in salt-sensitive hypertension. However, mechanisms pertaining to the impact of K ir4.1/Kir5.1-mediated K+ transport on the renin-angiotensin-aldosterone system (RAAS) remain unclear. Herein, we utilized a knockout of Kcnj16 in the Dahl salt-sensitive rat (SSKcnj16-/-) to investigate the relationship between Kir5.1 and RAAS balance and function in the sensitivity of blood pressure to the dietary Na+/K+ ratio. The knockout of Kcnj16 caused substantial elevations in plasma RAAS hormones (aldosterone and angiotensin peptides) and altered the RAAS response to changing the dietary Na+/K+ ratio. Blocking aldosterone with spironolactone caused rapid mortality in SSKcnj16-/- rats. Supplementation of the diet with high K+ was protective against mortality resulting from aldosterone-mediated mechanisms. Captopril and losartan treatment had no effect on the survival of SSKcnj16-/- rats. However, neither of these drugs prevented mortality of SSKcnj16-/- rats when switched to high Na+ diet. These studies revealed that the knockout of Kcnj16 markedly altered RAAS regulation and function, suggesting Kir5.1 as a key regulator of the RAAS, particularly when exposed to changes in dietary sodium and potassium content.
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Affiliation(s)
- Anna D. Manis
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Sherif Khedr
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Physiology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Matthew R. Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Clement J. Zablocki VA Medical Center, Milwaukee, WI 53295, USA
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6
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Wang MX, Su XT, Wu P, Gao ZX, Wang WH, Staub O, Lin DH. Kir5.1 regulates Nedd4-2-mediated ubiquitination of Kir4.1 in distal nephron. Am J Physiol Renal Physiol 2018; 315:F986-F996. [PMID: 29897283 PMCID: PMC6230743 DOI: 10.1152/ajprenal.00059.2018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/11/2018] [Accepted: 05/29/2018] [Indexed: 11/22/2022] Open
Abstract
Kir4.1/5.1 heterotetramer participates in generating the negative cell membrane potential in distal convoluted tubule (DCT) and plays a critical role in determining the activity of Na-Cl cotransporter (NCC). Kir5.1 contains a phosphothreonine motif at its COOH terminus (AA249-252). Coimmunoprecipitation showed that Nedd4-2 was associated with Kir5.1 in HEK293 cells cotransfected with Kir5.1 or Kir4.1/Kir5.1. GST pull-down further confirmed the association between Nedd4-2 and Kir5.1. Ubiquitination assay showed that Nedd4-2 increased the ubiquitination of Kir4.1/Kir5.1 heterotetramer in the cells cotransfected with Kir4.1/Kir5.1, but it has no effect on Kir4.1 or Kir5.1 alone. Patch-clamp and Western blot also demonstrated that coexpression of Nedd4-2 but not Nedd4-1 decreased K currents and Kir4.1 expression in the cells cotransfected with Kir4.1 and Kir5.1. In contrast, Nedd4-2 fails to inhibit Kir4.1 in the absence of Kir5.1 or in the cells transfected with the inactivated form of Nedd4-2 (Nedd4-2C821A). Moreover, the mutation of TPVT motif in the COOH terminus of Kir5.1 largely abolished the association of Nedd4-2 with Kir5.1 and abolished the inhibitory effect of Nedd4-2 on K currents in HEK293 cells transfected with Kir4.1 and Kir5.1 mutant (Kir5.1T249A). Finally, the basolateral K conductance in the DCT and Kir4.1 expression is significantly increased in the kidney-specific Nedd4-2 knockout or in Kir5.1 knockout mice in comparison to their corresponding wild-type littermates. We conclude that Nedd4-2 binds to Kir5.1 at the phosphothreonine motif of the COOH terminus, and the association of Nedd4-2 with Kir5.1 facilitates the ubiquitination of Kir4.1, thereby regulating its plasma expression in the DCT.
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Affiliation(s)
- Ming-Xiao Wang
- Department of Physiology, Zunyi Medical College, Zunyi, China
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Xiao-Tong Su
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Peng Wu
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Zhong-Xiuzi Gao
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Olivier Staub
- Department of Pharmacology and Toxicology, University of Lausanne , Lausanne , Switzerland
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
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7
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Wang MX, Cuevas CA, Su XT, Wu P, Gao ZX, Lin DH, McCormick JA, Yang CL, Wang WH, Ellison DH. Potassium intake modulates the thiazide-sensitive sodium-chloride cotransporter (NCC) activity via the Kir4.1 potassium channel. Kidney Int 2018; 93:893-902. [PMID: 29310825 PMCID: PMC6481177 DOI: 10.1016/j.kint.2017.10.023] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/04/2017] [Accepted: 10/12/2017] [Indexed: 12/14/2022]
Abstract
Kir4.1 in the distal convoluted tubule plays a key role in sensing plasma potassium and in modulating the thiazide-sensitive sodium-chloride cotransporter (NCC). Here we tested whether dietary potassium intake modulates Kir4.1 and whether this is essential for mediating the effect of potassium diet on NCC. High potassium intake inhibited the basolateral 40 pS potassium channel (a Kir4.1/5.1 heterotetramer) in the distal convoluted tubule, decreased basolateral potassium conductance, and depolarized the distal convoluted tubule membrane in Kcnj10flox/flox mice, herein referred to as control mice. In contrast, low potassium intake activated Kir4.1, increased potassium currents, and hyperpolarized the distal convoluted tubule membrane. These effects of dietary potassium intake on the basolateral potassium conductance and membrane potential in the distal convoluted tubule were completely absent in inducible kidney-specific Kir4.1 knockout mice. Furthermore, high potassium intake decreased, whereas low potassium intake increased the abundance of NCC expression only in the control but not in kidney-specific Kir4.1 knockout mice. Renal clearance studies demonstrated that low potassium augmented, while high potassium diminished, hydrochlorothiazide-induced natriuresis in control mice. Disruption of Kir4.1 significantly increased basal urinary sodium excretion but it abolished the natriuretic effect of hydrochlorothiazide. Finally, hypokalemia and metabolic alkalosis in kidney-specific Kir4.1 knockout mice were exacerbated by potassium restriction and only partially corrected by a high-potassium diet. Thus, Kir4.1 plays an essential role in mediating the effect of dietary potassium intake on NCC activity and potassium homeostasis.
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MESH Headings
- Alkalosis/genetics
- Alkalosis/metabolism
- Alkalosis/physiopathology
- Animals
- Disease Models, Animal
- Female
- Homeostasis
- Hydrochlorothiazide/pharmacology
- Hypokalemia/genetics
- Hypokalemia/metabolism
- Hypokalemia/physiopathology
- Kidney Tubules, Distal/drug effects
- Kidney Tubules, Distal/metabolism
- Kidney Tubules, Distal/physiopathology
- Male
- Membrane Potentials
- Mice, Knockout
- Natriuresis
- Potassium Channels, Inwardly Rectifying/deficiency
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/metabolism
- Potassium, Dietary/metabolism
- Renal Elimination
- Sodium/urine
- Sodium Chloride Symporter Inhibitors/pharmacology
- Solute Carrier Family 12, Member 3/genetics
- Solute Carrier Family 12, Member 3/metabolism
- Kir5.1 Channel
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Affiliation(s)
- Ming-Xiao Wang
- Department of Physiology, Zunyi Medical College, Zunyi, China; Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - Catherina A Cuevas
- Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA
| | - Xiao-Tong Su
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - Peng Wu
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - Zhong-Xiuzi Gao
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - James A McCormick
- Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA
| | - Chao-Ling Yang
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York, USA.
| | - David H Ellison
- Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA.
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Wang L, Zhang C, Su XT, Lin DH, Wu P, Schwartzman ML, Wang WH. PGF 2α regulates the basolateral K channels in the distal convoluted tubule. Am J Physiol Renal Physiol 2017; 313:F254-F261. [PMID: 28356287 PMCID: PMC5582901 DOI: 10.1152/ajprenal.00102.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 03/17/2017] [Accepted: 03/23/2017] [Indexed: 11/22/2022] Open
Abstract
Our aim is to examine the role of PGF2α receptor (FP), a highly expressed prostaglandin receptor in the distal convoluted tubule (DCT) in regulating the basolateral 40-pS K channel. The single-channel studies demonstrated that PGF2α had a biphasic effect on the 40-pS K channel in the DCT-PGF2α stimulated at low concentrations (less than 500 nM), while at high concentrations (above 1 µM), it inhibited the 40-pS K channels. Moreover, neither 13,14-dihydro-15-keto-PGF2α (a metabolite of PGF2α) nor PGE2 was able to mimic the effect of PGF2α on the 40-pS K channel in the DCT. The inhibition of PKC had no significant effect on the 40-pS K channel; however, it abrogated the inhibitory effect of 5 µM PGF2α on the K channel. Moreover, stimulation of PKC inhibited the 40-pS K channel in the DCT, suggesting that PKC mediates the inhibitory effect of PGF2α on the 40-pS K channel. Conversely, the stimulatory effect of PGF2α on the 40-pS K channel was absent in the DCT treated with DPI, a NADPH oxidase (NOX) inhibitor. Also, adding 100 µM H2O2 mimicked the stimulatory effect of PGF2α and increased the 40-pS K channel activity in DCT. Moreover, the stimulatory effect of 500 nM PGF2α and H2O2 was not additive, suggesting the role of superoxide-related species in mediating the stimulatory effect of PGF2α on the 40-pS K channel. The inhibition of Src family tyrosine protein kinase (SFK) not only inhibited the 40-pS K channel in the DCT but also completely abolished the stimulatory effects of PGF2α and H2O2 on the 40-pS K channel. We conclude that PGF2α at low doses stimulates the basolateral 40-pS K channel by a NOX- and SFK-dependent mechanism, while at high concentrations, it inhibits the K channel by a PKC-dependent pathway.
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Affiliation(s)
- Lijun Wang
- Department of Physiology, Harbin Medical University, Harbin, China; and.,Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Chengbiao Zhang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Xiao-Tong Su
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Dao-Hong Lin
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Peng Wu
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | | | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
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9
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Palygin O, Pochynyuk O, Staruschenko A. Role and mechanisms of regulation of the basolateral K ir 4.1/K ir 5.1K + channels in the distal tubules. Acta Physiol (Oxf) 2017; 219:260-273. [PMID: 27129733 PMCID: PMC5086442 DOI: 10.1111/apha.12703] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/28/2016] [Accepted: 04/28/2016] [Indexed: 12/11/2022]
Abstract
Epithelial K+ channels are essential for maintaining electrolyte and fluid homeostasis in the kidney. It is recognized that basolateral inward-rectifying K+ (Kir ) channels play an important role in the control of resting membrane potential and transepithelial voltage, thereby modulating water and electrolyte transport in the distal part of nephron and collecting duct. Monomeric Kir 4.1 (encoded by Kcnj10 gene) and heteromeric Kir 4.1/Kir 5.1 (Kir 4.1 together with Kir 5.1 (Kcnj16)) channels are abundantly expressed at the basolateral membranes of the distal convoluted tubule and the cortical collecting duct cells. Loss-of-function mutations in KCNJ10 cause EAST/SeSAME tubulopathy in humans associated with salt wasting, hypomagnesaemia, metabolic alkalosis and hypokalaemia. In contrast, mice lacking Kir 5.1 have severe renal phenotype that, apart from hypokalaemia, is the opposite of the phenotype seen in EAST/SeSAME syndrome. Experimental advances using genetic animal models provided critical insights into the physiological role of these channels in electrolyte homeostasis and the control of kidney function. Here, we discuss current knowledge about K+ channels at the basolateral membrane of the distal tubules with specific focus on the homomeric Kir 4.1 and heteromeric Kir 4.1/Kir 5.1 channels. Recently identified molecular mechanisms regulating expression and activity of these channels, such as cell acidification, dopamine, insulin and insulin-like growth factor-1, Src family protein tyrosine kinases, as well as the role of these channels in NCC-mediated transport in the distal convoluted tubules, are also described.
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Affiliation(s)
- Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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Fan L, Wang X, Zhang D, Duan X, Zhao C, Zu M, Meng X, Zhang C, Su XT, Wang MX, Wang WH, Gu R. Vasopressin-induced stimulation of the Na(+)-activated K(+) channels is responsible for maintaining the basolateral K(+) conductance of the thick ascending limb (TAL) in EAST/SeSAME syndrome. Biochim Biophys Acta Mol Basis Dis 2015; 1852:2554-62. [PMID: 26319417 DOI: 10.1016/j.bbadis.2015.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/07/2015] [Accepted: 08/25/2015] [Indexed: 11/29/2022]
Abstract
The renal phenotype of EAST syndrome, a disease caused by the loss-of-function-mutations of Kcnj10 (Kir4.1), is a reminiscence of Gitelman's syndrome characterized by the defective function in the distal convoluted tubule (DCT). The aim of the present study is to test whether antidiuretic hormone (vasopressin)-induced stimulation of the Na(+)-activated 80-150pS K(+) channel is responsible for compensating the lost function of Kcnj10 in the thick ascending limb (TAL) of subjects with EAST syndrome. Immunostaining and western blot showed that the expression of aquaporin 2 (AQP2) was significantly higher in Kcnj10(-/-) mice than those of WT littermates, suggesting that the disruption of Kcnj10 stimulates vasopressin response in the kidney. The role of vasopressin in stimulating the basolateral K(+) conductance of the TAL was strongly indicated by the finding that the application of arginine-vasopressin (AVP) hyperpolarized the membrane in the TAL of Kcnj10(-/-) mice. Application of AVP significantly stimulated the 80-150pS K(+) channel in the TAL and this effect was blocked by tolvaptan (V2 receptor antagonist) or by inhibiting PKA. Moreover, the water restriction for 24h significantly increased the probability of finding the 80-150pS K(+) channel and the K(+) channel open probability in the TAL. The application of a membrane permeable cAMP analog also mimicked the effect of AVP and activated this K(+) channel, suggesting that cAMP-PKA pathway stimulates the 80-150pS K(+) channels. The role of the basolateral K(+) conductance in maintaining transcellular Cl(-) transport is further suggested by the finding that the inhibition of basolateral K(+) channels significantly diminished the AVP-induced stimulation of the basolateral 10pS Cl(-) channels. We conclude that vasopressin stimulates the 80-150pS K(+) channel in the TAL via a cAMP-dependent mechanism. The vasopressin-induced stimulation of K(+) channels is responsible for compensating lost function of Kcnj10 thereby rescuing the basolateral K(+) conductance which is essential for the transport function in the TAL.
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Affiliation(s)
- Lili Fan
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Xiaoyan Wang
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Dandan Zhang
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Xinpeng Duan
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Chunlei Zhao
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Mingxue Zu
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Xinxin Meng
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Chengbiao Zhang
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, United States
| | - Xiao-Tong Su
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, United States
| | - Ming-Xiao Wang
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, United States
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, United States.
| | - Ruimin Gu
- Department of Physiology, Harbin Medical University, Harbin, China.
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