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Van Beusecum JP, Rianto F, Teakell J, Kon V, Sparks MA, Hoorn EJ, Kirabo A, Ramkumar N. Novel Concepts in Nephron Sodium Transport: A Physiological and Clinical Perspective. ADVANCES IN KIDNEY DISEASE AND HEALTH 2023; 30:124-136. [PMID: 36868728 DOI: 10.1053/j.akdh.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/15/2022] [Accepted: 12/15/2022] [Indexed: 04/13/2023]
Abstract
The kidneys play a critical role in maintaining total body sodium (Na+) balance across a wide range of dietary intake, accomplished by a concerted effort involving multiple Na+ transporters along the nephron. Furthermore, nephron Na+ reabsorption and urinary Na+ excretion are closely linked to renal blood flow and glomerular filtration such that perturbations in either of them can modify Na+ transport along the nephron, ultimately resulting in hypertension and other Na+-retentive states. In this article, we provide a brief physiological overview of nephron Na+ transport and illustrate clinical syndromes and therapeutic agents that affect Na+ transporter function. We highlight recent advances in kidney Na+ transport, particularly the role of immune cells, lymphatics, and interstitial Na+ in regulating Na+ reabsorption, the emergence of potassium (K+) as a regulator of Na+ transport, and the evolution of the nephron to modulate Na+ transport.
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Affiliation(s)
- Justin P Van Beusecum
- Ralph H. Johnson VA Medical Center, Charleston, SC; Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC
| | - Fitra Rianto
- Division of Nephrology, Department of Medicine, Duke University School of Medicine and Renal Section, Durham VA Health Care System Durham, Durham, NC
| | - Jade Teakell
- Division of Renal Diseases and Hypertension, Department of Medicine, McGovern Medical School, University of Texas Health Science Center, Houston, TX
| | - Valentina Kon
- Division of Nephrology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University School of Medicine and Renal Section, Durham VA Health Care System Durham, Durham, NC
| | - Ewout J Hoorn
- Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Nirupama Ramkumar
- Division of Nephrology and Hypertension, Department of Medicine, University of Utah Health, Salt Lake City, UT.
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Li XC, Hassan R, Leite APO, Katsurada A, Dugas C, Sato R, Zhuo JL. Genetic Deletion of AT 1a Receptor or Na +/H + Exchanger 3 Selectively in the Proximal Tubules of the Kidney Attenuates Two-Kidney, One-Clip Goldblatt Hypertension in Mice. Int J Mol Sci 2022; 23:ijms232415798. [PMID: 36555438 PMCID: PMC9779213 DOI: 10.3390/ijms232415798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/30/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
The roles of angiotensin II (Ang II) AT1 (AT1a) receptors and its downstream target Na+/H+ exchanger 3 (NHE3) in the proximal tubules in the development of two-kidney, 1-clip (2K1C) Goldblatt hypertension have not been investigated previously. The present study tested the hypothesis that deletion of the AT1a receptor or NHE3 selectively in the proximal tubules of the kidney attenuates the development of 2K1C hypertension using novel mouse models with proximal tubule-specific deletion of AT1a receptors or NHE3. 2K1C Goldblatt hypertension was induced by placing a silver clip (0.12 mm) on the left renal artery for 4 weeks in adult male wild-type (WT), global Agtr1a−/−, proximal tubule (PT)-specific PT-Agtr1a−/− or PT-Nhe3−/− mice, respectively. As expected, telemetry blood pressure increased in a time-dependent manner in WT mice, reaching a maximal response by Week 3 (p < 0.01). 2K1C hypertension in WT mice was associated with increases in renin expression in the clipped kidney and decreases in the nonclipped kidney (p < 0.05). Plasma and kidney Ang II were significantly increased in WT mice with 2K1C hypertension (p < 0.05). Tubulointerstitial fibrotic responses were significantly increased in the clipped kidney (p < 0.01). Whole-body deletion of AT1a receptors completely blocked the development of 2K1C hypertension in Agtr1a−/− mice (p < 0.01 vs. WT). Likewise, proximal tubule-specific deletion of Agtr1a in PT-Agtr1a−/− mice or NHE3 in PT-Nhe3−/− mice also blocked the development of 2K1C hypertension (p < 0.01 vs. WT). Taken together, the present study provides new evidence for a critical role of proximal tubule Ang II/AT1 (AT1a)/NHE3 axis in the development of 2K1C Goldblatt hypertension.
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Affiliation(s)
- Xiao Chun Li
- Tulane Hypertension and Renal Center of Excellence, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Rumana Hassan
- Tulane Hypertension and Renal Center of Excellence, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Ana Paula O. Leite
- Tulane Hypertension and Renal Center of Excellence, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Akemi Katsurada
- Tulane Hypertension and Renal Center of Excellence, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Courtney Dugas
- Tulane Hypertension and Renal Center of Excellence, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Ryosuke Sato
- Tulane Hypertension and Renal Center of Excellence, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Jia Long Zhuo
- Tulane Hypertension and Renal Center of Excellence, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Department of Physiology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
- Correspondence: ; Tel.: +1-504-988-4363; Fax: +1-504-988-2675
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Yang T, Song C, Ralph DL, Andrews P, Sparks MA, Koller BH, McDonough AA, Coffman TM. Cell-Specific Actions of the Prostaglandin E-Prostanoid Receptor 4 Attenuating Hypertension: A Dominant Role for Kidney Epithelial Cells Compared With Macrophages. J Am Heart Assoc 2022; 11:e026581. [PMID: 36172956 PMCID: PMC9673718 DOI: 10.1161/jaha.122.026581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background A beneficial role for prostanoids in hypertension is suggested by clinical studies showing nonsteroidal anti-inflammatory drugs, which block the production of all prostanoids, cause sodium retention and exacerbate hypertension. Among prostanoids, prostaglandin E2 and its E-prostanoid receptor 4 receptor (EP4R) have been implicated in blood pressure control. Our previous study found that conditional deletion of EP4R from all tissues in adult mice exacerbates angiotensin II-dependent hypertension, suggesting a powerful effect of EP4R to resist blood pressure elevation. We also found that elimination of EP4R from vascular smooth muscle cells did not affect the severity of hypertension, suggesting nonvascular targets of prostaglandin E mediate this antihypertensive effect. Methods and Results Here we generated mice with cell-specific deletion of EP4R from macrophage-specific EP4 receptor knockouts or kidney epithelial cells (KEKO) to assess the contributions of EP4R in these cells to hypertension pathogenesis. Macrophage-specific EP4 receptor knockouts showed similar blood pressure responses to alterations in dietary sodium or chronic angiotensin II infusion as Controls. By contrast, angiotensin II-dependent hypertension was significantly augmented in KEKOs (mean arterial pressure: 146±3 mm Hg) compared with Controls (137±4 mm Hg; P=0.02), which was accompanied by impaired natriuresis in KEKOs. Because EP4R expression in the kidney is enriched in the collecting duct, we compared responses to amiloride in angiotensin II-infused KEKOs and Controls. Blockade of the epithelial sodium channel with amiloride caused exaggerated natriuresis in KEKOs compared with Controls (0.21±0.01 versus 0.15±0.02 mmol/24 hour per 20 g; P=0.015). Conclusions Our data suggest EP4R in kidney epithelia attenuates hypertension. This antihypertension effect of EP4R may be mediated by reducing the activity of the epithelial sodium channel, thereby promoting natriuresis.
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Affiliation(s)
- Ting Yang
- Division of Nephrology‐Department of MedicineDuke UniversityDurhamNC
| | - Chengcheng Song
- Division of Nephrology‐Department of MedicineDuke UniversityDurhamNC,Department of AnesthesiologyTianjin Medical University General HospitalTianjinChina
| | - Donna L. Ralph
- Department of Physiology and NeuroscienceKeck School of Medicine of the University of Southern CaliforniaLos AngelesCA
| | - Portia Andrews
- Division of Nephrology‐Department of MedicineDuke UniversityDurhamNC
| | - Matthew A. Sparks
- Division of Nephrology‐Department of MedicineDuke UniversityDurhamNC
| | | | - Alicia A. McDonough
- Department of Physiology and NeuroscienceKeck School of Medicine of the University of Southern CaliforniaLos AngelesCA
| | - Thomas M. Coffman
- Division of Nephrology‐Department of MedicineDuke UniversityDurhamNC,Cardiovascular and Metabolic Disorders Research ProgramDuke‐National University of Singapore Graduate Medical SchoolSingapore
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Mutengo KH, Masenga SK, Mwesigwa N, Patel KP, Kirabo A. Hypertension and human immunodeficiency virus: A paradigm for epithelial sodium channels? Front Cardiovasc Med 2022; 9:968184. [PMID: 36093171 PMCID: PMC9452753 DOI: 10.3389/fcvm.2022.968184] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/10/2022] [Indexed: 02/03/2023] Open
Abstract
Hypertension is a risk factor for end organ damage and death and is more common in persons with HIV compared to the general population. Several mechanisms have been studied in the pathogenesis of hypertension. Current evidence suggests that the epithelial sodium channel (ENaC) plays a key role in regulating blood pressure through the transport of sodium and water across membranes in the kidney tubules, resulting in retention of sodium and water and an altered fluid balance. However, there is scarcity of information that elucidates the role of ENaC in HIV as it relates to increasing the risk for development or pathogenesis of hypertension. This review summarized the evidence to date implicating a potential role for altered ENaC activity in contributing to hypertension in patients with HIV.
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Affiliation(s)
- Katongo H. Mutengo
- School of Medicine and Health Sciences, HAND Research Group, Mulungushi University, Livingstone Campus, Livingstone, Zambia,School of Public Health and Medicine, University of Zambia, Lusaka, Zambia
| | - Sepiso K. Masenga
- School of Medicine and Health Sciences, HAND Research Group, Mulungushi University, Livingstone Campus, Livingstone, Zambia,School of Public Health and Medicine, University of Zambia, Lusaka, Zambia
| | - Naome Mwesigwa
- Department of Medicine and Dentistry, Kampala International University, Kampala, Uganda
| | - Kaushik P. Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States,*Correspondence: Annet Kirabo,
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