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Schork A, Vogel E, Bohnert BN, Essigke D, Wörn M, Fischer I, Heyne N, Birkenfeld AL, Artunc F. Amiloride versus furosemide for the treatment of edema in patients with nephrotic syndrome: A pilot study (AMILOR). Acta Physiol (Oxf) 2024:e14183. [PMID: 38822593 DOI: 10.1111/apha.14183] [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: 04/04/2024] [Revised: 05/14/2024] [Accepted: 05/18/2024] [Indexed: 06/03/2024]
Abstract
AIM In rodent models of nephrotic syndrome (NS), edema formation was prevented by blockade of the epithelial sodium channel ENaC with amiloride. However, apart from case reports, there is no evidence favoring ENaC blockade in patients with NS. METHODS The monocentric randomized controlled AMILOR study investigated the antiedematous effect of amiloride (starting dose 5 mg/day, max. 15 mg/day) in comparison to standard therapy with the loop diuretic furosemide (40 mg/day, max. 120 mg/day) over 16 days. Overhydration (OH) was measured by bioimpedance spectroscopy (BCM, Fresenius). Depending on the OH response, diuretic dose was adjusted on days 2, 5, 8 and 12, and if necessary, hydrochlorothiazide (HCT) was added from d8 (12.5 mg/day, max. 25 mg/day). The primary endpoint was the decrease in OH on d8. The study was terminated prematurely due to insufficient recruitment and a low statistical power due to a low actual effect size. RESULTS Median baseline OH was +26.4 (interquartile range 15.5-35.1)% extracellular water (ECW) in the amiloride arm and + 27.9 (24.1-29.4)% ECW in the furosemide arm and decreased by 1.95 (0.80-6.40) and 5.15 (0.90-8.30)% ECW after 8 days, respectively, and by 10.10 (1.30-14.40) and 7.40 (2.80-10.10)% ECW after 16 days, respectively. OH decrease on d8 and d16 was not significantly different between both arms. CONCLUSION The AMILOR study is the first randomized controlled pilot study suggesting a similar antiedematous effect as furosemide. Further studies are required to better define the role of amiloride in NS (EudraCT 2019-002607-18).
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Affiliation(s)
- Anja Schork
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Elisabeth Vogel
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Bernhard N Bohnert
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Daniel Essigke
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Matthias Wörn
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Imma Fischer
- Institute for Clinical Epidemiology and Applied Biometry, University Hospital Tübingen, Tübingen, Germany
| | - Nils Heyne
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Andreas L Birkenfeld
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Ferruh Artunc
- Division of Diabetology, Endocrinology and Nephrology, Department of Internal Medicine IV, University Hospital Tübingen, Tübingen, Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
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Isaksson GL, Hinrichs GR, Andersen H, Bach ML, Weyer K, Zachar R, Henriksen JE, Madsen K, Lund IK, Mollet G, Bistrup C, Birn H, Jensen BL, Palarasah Y. Amiloride Reduces Urokinase/Plasminogen-Driven Intratubular Complement Activation in Glomerular Proteinuria. J Am Soc Nephrol 2024; 35:410-425. [PMID: 38254266 PMCID: PMC11000727 DOI: 10.1681/asn.0000000000000312] [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: 07/26/2023] [Accepted: 01/04/2024] [Indexed: 01/24/2024] Open
Abstract
SIGNIFICANCE STATEMENT Proteinuria predicts accelerated decline in kidney function in CKD. The pathologic mechanisms are not well known, but aberrantly filtered proteins with enzymatic activity might be involved. The urokinase-type plasminogen activator (uPA)-plasminogen cascade activates complement and generates C3a and C5a in vitro / ex vivo in urine from healthy persons when exogenous, inactive, plasminogen, and complement factors are added. Amiloride inhibits uPA and attenuates complement activation in vitro and in vivo . In conditional podocin knockout (KO) mice with severe proteinuria, blocking of uPA with monoclonal antibodies significantly reduces the urine excretion of C3a and C5a and lowers tissue NLRP3-inflammasome protein without major changes in early fibrosis markers. This mechanism provides a link to proinflammatory signaling in proteinuria with possible long-term consequences for kidney function. BACKGROUND Persistent proteinuria is associated with tubular interstitial inflammation and predicts progressive kidney injury. In proteinuria, plasminogen is aberrantly filtered and activated by urokinase-type plasminogen activator (uPA), which promotes kidney fibrosis. We hypothesized that plasmin activates filtered complement factors C3 and C5 directly in tubular fluid, generating anaphylatoxins, and that this is attenuated by amiloride, an off-target uPA inhibitor. METHODS Purified C3, C5, plasminogen, urokinase, and urine from healthy humans were used for in vitro / ex vivo studies. Complement activation was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and ELISA. Urine and plasma from patients with diabetic nephropathy treated with high-dose amiloride and from mice with proteinuria (podocin knockout [KO]) treated with amiloride or inhibitory anti-uPA antibodies were analyzed. RESULTS The combination of uPA and plasminogen generated anaphylatoxins C3a and C5a from intact C3 and C5 and was inhibited by amiloride. Addition of exogenous plasminogen was sufficient for urine from healthy humans to activate complement. Conditional podocin KO in mice led to severe proteinuria and C3a and C5a urine excretion, which was attenuated reversibly by amiloride treatment for 4 days and reduced by >50% by inhibitory anti-uPA antibodies without altering proteinuria. NOD-, LRR- and pyrin domain-containing protein 3-inflammasome protein was reduced with no concomitant effect on fibrosis. In patients with diabetic nephropathy, amiloride reduced urinary excretion of C3dg and sC5b-9 significantly. CONCLUSIONS In conditions with proteinuria, uPA-plasmin generates anaphylatoxins in tubular fluid and promotes downstream complement activation sensitive to amiloride. This mechanism links proteinuria to intratubular proinflammatory signaling. In perspective, amiloride could exert reno-protective effects beyond natriuresis and BP reduction. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER Increased Activity of a Renal Salt Transporter (ENaC) in Diabetic Kidney Disease, NCT01918488 and Increased Activity of ENaC in Proteinuric Kidney Transplant Recipients, NCT03036748 .
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Affiliation(s)
- Gustaf L. Isaksson
- Department of Molecular Medicine–Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
- Department of Nephrology, Odense University Hospital, Odense, Denmark
| | - Gitte R. Hinrichs
- Department of Molecular Medicine–Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
- Department of Nephrology, Odense University Hospital, Odense, Denmark
| | - Henrik Andersen
- Department of Molecular Medicine–Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Marie L. Bach
- Department of Molecular Medicine–Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Kathrin Weyer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Rikke Zachar
- Department of Molecular Medicine–Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Jan Erik Henriksen
- Steno Diabetes Center Odense, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Kirsten Madsen
- Department of Molecular Medicine–Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - Ida K. Lund
- The Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark
- Biotech Research and Innovation Center (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Géraldine Mollet
- Laboratory of Hereditary Kidney Diseases, Inserm UMR1163, Imagine Institute, Université Paris Cité, Paris, France
| | - Claus Bistrup
- Department of Nephrology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Henrik Birn
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Boye L. Jensen
- Department of Molecular Medicine–Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Yaseelan Palarasah
- Department of Molecular Medicine–Cancer and Inflammation, University of Southern Denmark, Odense, Denmark
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Frățilă G, Sorohan BM, Achim C, Andronesi A, Obrișcă B, Lupușoru G, Zilișteanu D, Jurubiță R, Bobeică R, Bălănică S, Micu G, Mocanu V, Ismail G. Oral Furosemide and Hydrochlorothiazide/Amiloride versus Intravenous Furosemide for the Treatment of Resistant Nephrotic Syndrome. J Clin Med 2023; 12:6895. [PMID: 37959360 PMCID: PMC10648037 DOI: 10.3390/jcm12216895] [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: 10/11/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
BACKGROUND Data on diuretic treatment in nephrotic syndrome (NS) are scarce. Our goal was to assess the non-inferiority of the combined oral diuretics (furosemide/hydrochlorothiazide/amiloride) compared to intravenous (i.v.) furosemide in patients with NS and resistant edema. METHODS We conducted a prospective randomized trial on 22 patients with resistant nephrotic edema (RNE), defined as hypervolemia and a FENa < 0.2%. Based on a computer-generated 1:1 randomization, we assigned patients to receive either intravenous furosemide (40 mg bolus and then continuous administration of 5 mg/h) or oral furosemide (40 mg/day) and hydrochlorothiazide/amiloride (50/5 mg/day) for a period of 5 days. Clinical and laboratory measurements were performed daily. Hydration status was assessed by bioimpedance on day 1 and at the end of day 5 after treatment initiation. The primary endpoint was weight change from baseline to day 5. Secondary endpoints were hydration status change measured by bioimpedance and safety outcomes (low blood pressure, severe electrolyte disturbances, acute kidney injury and worsening hypervolemia). RESULTS Primary endpoint analysis showed that after 5 days of treatment, there was a significant difference in weight change from baseline between groups [adjusted mean difference: -3.33 kg (95% CI: -6.34 to -0.31), p = 0.03], with a higher mean weight change in the oral diuretic treatment group [-7.10 kg (95% CI: -18.30 to -4.30) vs. -4.55 kg (95%CI: -6.73 to -2.36)]. Secondary endpoint analysis showed that there was no significant difference between groups regarding hydration status change [adjusted mean difference: -0.05 L (95% CI: -2.6 to 2.6), p = 0.96], with a mean hydration status change in the oral diuretic treatment group of -4.71 L (95% CI: -6.87 to -2.54) and -3.91 L (95% CI: -5.69 to -2.13) in the i.v. diuretic treatment group. We observed a significant decrease in adjusted mean serum sodium of -2.15 mmol/L [(95% CI: -4.25 to -0.05), p = 0.04]), favored by the combined oral diuretic treatment [-2.70 mmol/L (95% CI: -4.89 to -0.50) vs. -0.10 mmol/L (95%CI: -1.30 to 1.10)]. No statistically significant difference was observed between the two groups in terms of adverse events. CONCLUSIONS A combination of oral diuretics based on furosemide, amiloride and hydrochlorothiazide is non-inferior to i.v. furosemide in weight control of patients with RNE and a similar safety profile.
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Affiliation(s)
- Georgiana Frățilă
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
| | - Bogdan Marian Sorohan
- Department of Nephrology, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Department of Kidney Transplantation, Fundeni Clinical Institute, 022328 Bucharest, Romania
| | - Camelia Achim
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
- Department of Nephrology, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Andreea Andronesi
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
- Department of Nephrology, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Bogdan Obrișcă
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
- Department of Nephrology, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Gabriela Lupușoru
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
- Department of Nephrology, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Diana Zilișteanu
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
- Department of Nephrology, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Roxana Jurubiță
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
| | - Raluca Bobeică
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
| | - Sonia Bălănică
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
| | - Georgia Micu
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
| | - Valentin Mocanu
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
| | - Gener Ismail
- Department of Nephrology, Fundeni Clinical Institute, 022328 Bucharest, Romania; (G.F.); (C.A.); (A.A.); (B.O.); (G.L.); (D.Z.); (R.J.); (R.B.); (S.B.); (G.M.); (V.M.); (G.I.)
- Department of Nephrology, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
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Hinrichs GR, Nielsen JR, Birn H, Bistrup C, Jensen BL. Amiloride evokes significant natriuresis and weight loss in kidney transplant recipients with and without albuminuria. Am J Physiol Renal Physiol 2023; 325:F426-F435. [PMID: 37560772 DOI: 10.1152/ajprenal.00108.2023] [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: 04/26/2023] [Revised: 07/14/2023] [Accepted: 08/03/2023] [Indexed: 08/11/2023] Open
Abstract
Albuminuria in kidney transplant recipients (KTRs) is associated with hypertension and aberrant glomerular filtration of serine proteases that may proteolytically activate the epithelial Na+ channel (ENaC). The present nonrandomized, pharmacodynamic intervention study aimed to investigate if inhibition of ENaC increases Na+ excretion and reduces extracellular volume in KTRs dependent on the presence of albuminuria. KTRs with and without albuminuria (albumin-to-creatinine ratio > 300 mg/g, n = 7, and <30 mg/g, n = 7, respectively) were included and ingested a diet with fixed Na+ content (150 mmol/day) for 5 days. On the last day, amiloride at 10 mg was administered twice. Body weight, 24-h urine electrolyte excretion, body water content, and ambulatory blood pressure as well as plasma renin, angiotensin II, and aldosterone concentrations were determined before and after amiloride. Amiloride led to a significant decrease in body weight, increase in 24-h urinary Na+ excretion, and decrease in 24-h urinary K+ excretion in both groups. Urine output increased in the nonalbuminuric group only. There was no change in plasma renin, aldosterone, and angiotensin II concentrations after amiloride, whereas a significant decrease in nocturnal systolic blood pressure and increase in 24-h urine aldosterone excretion was observed in albuminuric KTRs only. There was a significant correlation between 24-h urinary albumin excretion and amiloride-induced 24-h urinary Na+ excretion. In conclusion, ENaC activity contributes to Na+ and water retention in KTRs with and without albuminuria. ENaC is a relevant pharmacological target in KTRs; however, larger and long-term studies are needed to evaluate whether the magnitude of this effect depends on the presence of albuminuria.NEW & NOTEWORTHY Amiloride has a significant natriuretic effect in kidney transplant recipients (KTRs) that relates to urinary albumin excretion. The epithelial Na+ channel may be a relevant direct pharmacological target to counter Na+ retention and hypertension in KTRs. Epithelial Na+ channel blockers should be further investigated as a mean to mitigate Na+ and water retention and to potentially obtain optimal blood pressure control in KTRs.
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Affiliation(s)
- Gitte Rye Hinrichs
- Department of Molecular Medicine, Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
- Department of Nephrology, Odense University Hospital, Odense, Denmark
- Department of Nephrology, University Hospital of Southern Denmark, Esbjerg, Denmark
| | | | - Henrik Birn
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Claus Bistrup
- Department of Nephrology, Odense University Hospital, Odense, Denmark
- Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Boye Lagerbon Jensen
- Department of Molecular Medicine, Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
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The serine protease plasmin plays detrimental roles in epithelial sodium channel activation and podocyte injury in Dahl salt-sensitive rats. Hypertens Res 2023; 46:50-62. [PMID: 36241707 DOI: 10.1038/s41440-022-01064-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/06/2022] [Accepted: 09/26/2022] [Indexed: 02/03/2023]
Abstract
Salt-sensitive hypertension is associated with poor clinical outcomes. The epithelial sodium channel (ENaC) in the kidney plays pivotal roles in sodium reabsorption and blood pressure regulation, in which its γ subunit is activated by extracellular serine proteases. In proteinuric nephropathies, plasmin filtered through injured glomeruli reportedly activates γENaC in the distal nephron and causes podocyte injury. We previously reported that Dahl salt-sensitive (DS) rats fed a high-salt (HS) diet developed hypertension and proteinuria along with γENaC activation and that a synthetic serine protease inhibitor, camostat mesilate, mitigated these changes. However, the role of plasmin in DS rats remained unclear. In this study, we evaluated the relationship between plasmin and hypertension as well as podocyte injury and the effects of plasmin inhibitors in DS rats. Five-week-old DS rats were divided into normal-salt diet, HS diet, and HS+plasmin inhibitor (either tranexamic acid [TA] or synthetic plasmin inhibitor YO-2) groups. After blood pressure measurement and 24 h urine collection over 5 weeks, rats were sacrificed for biochemical analyses. The HS group displayed severe hypertension and proteinuria together with activation of plasmin in urine and γENaC in the kidney, which was significantly attenuated by YO-2 but not TA. YO-2 inhibited the attachment of plasmin(ogen) to podocytes and alleviated podocyte injury by inhibiting apoptosis and inflammatory/profibrotic cytokines. YO-2 also suppressed upregulation of protease-activated receptor-1 and phosphorylated ERK1/2. These results indicate an important role of plasmin in the development of salt-sensitive hypertension and related podocyte injury, suggesting plasmin inhibition as a potential therapeutic strategy.
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Sen R, Sengupta D, Mukherjee A. Mechanical dependency of the SARS-CoV-2 virus and the renin-angiotensin-aldosterone (RAAS) axis: a possible new threat. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:62235-62247. [PMID: 34859345 PMCID: PMC8638800 DOI: 10.1007/s11356-021-16356-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 09/01/2021] [Indexed: 04/12/2023]
Abstract
Pathogens in our environment can act as agents capable of inflicting severe human diseases. Among them, the SARS-CoV-2 virus has recently plagued the globe and paralyzed the functioning of ordinary human life. The virus enters the cell through the angiotensin-converting enzyme-2 (ACE-2) receptor, an integral part of the renin-angiotensin system (RAAS). Reports on hypertension and its relation to the modulation of the RAAS are generating interest in the scientific community. This short review focuses on the SARS-CoV-2 infection's direct and indirect effects on our body through modulation of the RAAS axis. A patient having severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection, which causes COVID-19 relates to hypertension as a pre-existing disease or develops it in a post-COVID scenario. Several studies on how SARS-CoV-2 modulates the RAAS axis indicate that it alters our body's physiological balance. This review seeks to establish a hypothesis on the mechanical dependency of SARS-CoV-2 and RAAS modulation in the human body. This study intends to impart ideas on drug development and designing by targeting the modulation of the RAAS axis to inactivate the pathogenicity of the SARS-CoV-2 virus. A systematic hypothesis can severely attenuate the pathogenicity of the dreadful viruses of the future.
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Affiliation(s)
- Rohit Sen
- Department of Zoology, Charuchandra College, University of Calcutta, 22, Lake Road, Kolkata, 700029 India
| | | | - Avinaba Mukherjee
- Department of Zoology, Charuchandra College, University of Calcutta, 22, Lake Road, Kolkata, 700029 India
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Xiao M, Bohnert BN, Grahammer F, Artunc F. Rodent models to study sodium retention in experimental nephrotic syndrome. Acta Physiol (Oxf) 2022; 235:e13844. [PMID: 35569011 DOI: 10.1111/apha.13844] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 05/02/2022] [Accepted: 05/10/2022] [Indexed: 12/12/2022]
Abstract
Sodium retention and edema are hallmarks of nephrotic syndrome (NS). Different experimental rodent models have been established for simulating NS, however, not all of them feature sodium retention which requires proteinuria to exceed a certain threshold. In rats, puromycin aminonucleoside nephrosis (PAN) is a classic NS model introduced in 1955 that was adopted as doxorubicin-induced nephropathy (DIN) in 129S1/SvImJ mice. In recent years, mice with inducible podocin deletion (Nphs2Δipod ) or podocyte apoptosis (POD-ATTAC) have been developed. In these models, sodium retention is thought to be caused by activation of the epithelial sodium channel (ENaC) in the distal nephron through aberrantly filtered serine proteases or proteasuria. Strikingly, rodent NS models follow an identical chronological time course after the development of proteinuria featuring sodium retention within days and spontaneous reversal thereafter. In DIN and Nphs2Δipod mice, inhibition of ENaC by amiloride or urinary serine protease activity by aprotinin prevents sodium retention, opening up new and promising therapeutic approaches that could be translated into the treatment of nephrotic patients. However, the essential serine protease(s) responsible for ENaC activation is (are) still unknown. With the use of nephrotic rodent models, there is the possibility that this (these) will be identified in the future. This review summarizes the various rodent models used to study experimental nephrotic syndrome and the insights gained from these models with regard to the pathophysiology of sodium retention.
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Affiliation(s)
- Mengyun Xiao
- Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine University Hospital Tübingen Tübingen Germany
| | - Bernhard N. Bohnert
- Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
| | - Florian Grahammer
- III. Department of Medicine University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Ferruh Artunc
- Division of Endocrinology, Diabetology and Nephrology, Department of Internal Medicine University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
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8
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van de Wouw J, Joles JA. Albumin is an interface between blood plasma and cell membrane, and not just a sponge. Clin Kidney J 2021; 15:624-634. [PMID: 35371452 PMCID: PMC8967674 DOI: 10.1093/ckj/sfab194] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Indexed: 12/16/2022] Open
Abstract
Albumin is the most abundant protein in blood plasma and acts as a carrier for many circulating molecules. Hypoalbuminaemia, mostly caused by either renal or liver disease or malnutrition, can perturb vascular homeostasis and is involved in the development of multiple diseases. Here we review four functions of albumin and the consequences of hypoalbuminaemia on vascular homeostasis. (i) Albumin is the main determinant of plasma colloid osmotic pressure. Hypoalbuminaemia was therefore thought to be the main mechanism for oedema in nephrotic syndrome (NS), however, experimental studies showed that intrarenal mechanisms rather than hypoalbuminaemia determine formation and, in particular, maintenance of oedema. (ii) Albumin functions as an interface between lysophosphatidylcholine (LPC) and circulating factors (lipoproteins and erythrocytes) and the endothelium. Consequently, hypoalbuminaemia results in higher LPC levels in lipoproteins and erythrocyte membrane, thereby increasing atherosclerotic properties of low-density lipoprotein and blood viscosity, respectively. Furthermore, albumin dose-dependently restores LPC-induced inhibition of vasodilation. (iii) Hypoalbuminaemia impacts on vascular nitric oxide (NO) signalling by directly increasing NO production in endothelial cells, leading to reduced NO sensitivity of vascular smooth muscle cells. (iv) Lastly, albumin binds free fatty acids (FFAs). FFAs can induce vascular smooth muscle cell apoptosis, uncouple endothelial NO synthase and decrease endothelium-dependent vasodilation. Unbound FFAs can increase the formation of reactive oxygen species by mitochondrial uncoupling in multiple cell types and induce hypertriglyceridemia in NS. In conclusion, albumin acts as an interface in the circulation and hypoalbuminaemia impairs multiple aspects of vascular function that may underlie the association of hypoalbuminaemia with adverse outcomes. However, hypoalbuminaemia is not a key to oedema in NS. These insights have therapeutic implications.
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Affiliation(s)
| | - Jaap A Joles
- Department of Nephrology and Hypertension, University Medical Center, Utrecht, the Netherlands
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9
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Zhang J, Yuan HK, Chen S, Zhang ZR. Detrimental or beneficial: Role of endothelial ENaC in vascular function. J Cell Physiol 2021; 237:29-48. [PMID: 34279047 DOI: 10.1002/jcp.30505] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 12/19/2022]
Abstract
In the past, it was believed that the expression of the epithelial sodium channel (ENaC) was restricted to epithelial tissues, such as the distal nephron, airway, sweat glands, and colon, where it is critical for sodium homeostasis. Over the past two decades, this paradigm has shifted due to the finding that ENaC is also expressed in various nonepithelial tissues, notably in vascular endothelial cells. In this review, the recent findings of the expression, regulation, and function of the endothelial ENaC (EnNaC) are discussed. The expression of EnNaC subunits is reported in a variety of endothelial cell lines and vasculatures, but this is controversial across different species and vessels and is not a universal finding in all vascular beds. The expression density of EnNaC is very faint compared to ENaC in the epithelium. To date, little is known about the regulatory mechanism of EnNaC. Through it can be regulated by aldosterone, the detailed downstream signaling remains elusive. EnNaC responds to increased extracellular sodium with the feedforward activation mechanism, which is quite different from the Na+ self-inhibition mechanism of ENaC. Functionally, EnNaC was shown to be a determinant of cellular mechanics and vascular tone as it can sense shear stress, and its activation or insertion into plasma membrane causes endothelial stiffness and reduced nitric oxide production. However, in some blood vessels, EnNaC is essential for maintaining the integrity of endothelial barrier function. In this context, we discuss the possible reasons for the distinct role of EnNaC in vasculatures.
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Affiliation(s)
- Jun Zhang
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China
| | - Hui-Kai Yuan
- Department of General Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shuo Chen
- Department of Biopharmaceutical Sciences, School of Pharmacy, Harbin Medical University (Daqing), Daqing, China
| | - Zhi-Ren Zhang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
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10
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Kallash M, Mahan JD. Mechanisms and management of edema in pediatric nephrotic syndrome. Pediatr Nephrol 2021; 36:1719-1730. [PMID: 33216218 DOI: 10.1007/s00467-020-04779-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/18/2020] [Accepted: 09/11/2020] [Indexed: 10/23/2022]
Abstract
Edema is the abnormal accumulation of fluid in the interstitial compartment of tissues within the body. In nephrotic syndrome, edema is often seen in dependent areas such as the legs, but it can progress to cause significant accumulation in other areas leading to pulmonary edema, ascites, and/or anasarca. In this review, we focus on mechanisms and management of edema in children with nephrotic syndrome. We review the common mechanisms of edema, its burden in pediatric patients, and then present our approach and algorithm for management of edema in pediatric patients. The extensive body of experience accumulated over the last 5 decades means that there are many options, and clinicians may choose among these options based on their experience and careful monitoring of responses in individual patients.
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Affiliation(s)
- Mahmoud Kallash
- Division of Pediatric Nephrology, Nationwide Children's Hospital, 700 Children's Dr., Columbus, OH, 43205, USA. .,The Ohio State University College of Medicine, Columbus, OH, USA.
| | - John D Mahan
- Division of Pediatric Nephrology, Nationwide Children's Hospital, 700 Children's Dr., Columbus, OH, 43205, USA.,The Ohio State University College of Medicine, Columbus, OH, USA
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11
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Versmissen J, Mirabito Colafella KM, Koolen SLW, Danser AHJ. Vascular Cardio-Oncology: Vascular Endothelial Growth Factor inhibitors and hypertension. Cardiovasc Res 2020; 115:904-914. [PMID: 30726882 DOI: 10.1093/cvr/cvz022] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/16/2018] [Accepted: 01/24/2019] [Indexed: 12/27/2022] Open
Abstract
Since the formation of new blood vessels is essential for tumour growth and metastatic spread, inhibition of angiogenesis by targeting the vascular endothelial growth factor (VEGF) pathway is an effective strategy for various types of cancer, most importantly renal cell carcinoma, thyroid cancer, and hepatocellular carcinoma. However, VEGF inhibitors have serious side effects, most importantly hypertension and nephropathy. In case of fulminant hypertension, this may only be handled by lowering the dosage since the blood pressure rise is proportional to the amount of VEGF inhibition. These effects pathophysiologically and clinically resemble the most severe complication of pregnancy, preeclampsia, in which case an insufficient placenta leads to a rise in sFlt-1 levels causing a decrease in VEGF availability. Due to this overlap, studies in preeclampsia may provide important information for VEGF inhibitor-induced toxicity and vice versa. In both VEGF inhibitor-induced toxicity and preeclampsia, endothelin (ET)-1 appears to be a pivotal player. In this review, after briefly summarizing the anticancer effects, we discuss the mechanisms that potentially underlie the unwanted effects of VEGF inhibitors, focusing on ET-1, nitric oxide and oxidative stress, the renin-angiotensin-aldosterone system, and rarefaction. Given the salt sensitivity of this phenomenon, as well as the beneficial effects of aspirin in preeclampsia and cancer, we next provide novel treatment options for VEGF inhibitor-induced toxicity, including salt restriction, ET receptor blockade, and cyclo-oxygenase inhibition, in addition to classical antihypertensive and renoprotective drugs. We conclude with the recommendation of therapeutic drug monitoring to improve patient outcome.
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Affiliation(s)
- Jorie Versmissen
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, CA Rotterdam, The Netherlands
| | - Katrina M Mirabito Colafella
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, CA Rotterdam, The Netherlands.,Cardiovascular Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia.,Department of Physiology, Monash University, Melbourne, Australia
| | - Stijn L W Koolen
- Department of Medical Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.,Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - A H Jan Danser
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC University Medical Center, CA Rotterdam, The Netherlands
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12
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Hinrichs GR, Weyer K, Friis UG, Svenningsen P, Lund IK, Nielsen R, Mollet G, Antignac C, Bistrup C, Jensen BL, Birn H. Sodium retention by uPA-plasmin-ENaC in nephrotic syndrome-Authors reply. Acta Physiol (Oxf) 2020; 228:e13432. [PMID: 31845496 DOI: 10.1111/apha.13432] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/06/2019] [Accepted: 12/11/2019] [Indexed: 01/13/2023]
Affiliation(s)
- Gitte R. Hinrichs
- Department of Molecular Medicine, Cardiovascular and Renal Research University of Southern Denmark Odense Denmark
| | - Kathrin Weyer
- Department of Biomedicine Aarhus University Aarhus Denmark
| | - Ulla G. Friis
- Department of Molecular Medicine, Cardiovascular and Renal Research University of Southern Denmark Odense Denmark
| | - Per Svenningsen
- Department of Molecular Medicine, Cardiovascular and Renal Research University of Southern Denmark Odense Denmark
| | - Ida Katrine Lund
- The Finsen Laboratory Biotech Research & Innovation Centre (BRIC) University of Copenhagen Copenhagen Denmark
| | - Rikke Nielsen
- Department of Biomedicine Aarhus University Aarhus Denmark
| | - Géraldine Mollet
- Laboratory of Hereditary Kidney Diseases Paris Descartes‐Sorbonne Paris Cité University Paris France
| | - Corinne Antignac
- Laboratory of Hereditary Kidney Diseases Paris Descartes‐Sorbonne Paris Cité University Paris France
- Department of Genetics Necker HospitalAssistance Publique‐Hôpitaux de Paris Paris France
| | - Claus Bistrup
- Department of Nephrology Odense University Hospital Odense Denmark
- Department of Clinical Research University of Southern Denmark Odense Denmark
| | - Boye L. Jensen
- Department of Molecular Medicine, Cardiovascular and Renal Research University of Southern Denmark Odense Denmark
| | - Henrik Birn
- Department of Biomedicine Aarhus University Aarhus Denmark
- Department of Renal Medicine Aarhus University Hospital Aarhus Denmark
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13
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14
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Abstract
Epithelial Na+ channels (ENaCs) are members of a family of cation channels that function as sensors of the extracellular environment. ENaCs are activated by specific proteases in the biosynthetic pathway and at the cell surface and remove embedded inhibitory tracts, which allows channels to transition to higher open-probability states. Resolved structures of ENaC and an acid-sensing ion channel revealed highly organized extracellular regions. Within the periphery of ENaC subunits are unique domains formed by antiparallel β-strands containing the inhibitory tracts and protease cleavage sites. ENaCs are inhibited by Na+ binding to specific extracellular site(s), which promotes channel transition to a lower open-probability state. Specific inositol phospholipids and channel modification by Cys-palmitoylation enhance channel open probability. How these regulatory factors interact in a concerted manner to influence channel open probability is an important question that has not been resolved. These various factors are reviewed, and the impact of specific factors on human disorders is discussed.
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Affiliation(s)
- Thomas R Kleyman
- Renal-Electrolyte Division, Department of Medicine, and Departments of Cell Biology and of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Douglas C Eaton
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia
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15
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Ray EC. ENaC blockade in proteinuria-associated extracellular fluid volume overload - effective but risky. Physiol Rep 2019; 6:e13835. [PMID: 30178569 PMCID: PMC6121123 DOI: 10.14814/phy2.13835] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Evan C Ray
- Renal-Electrolyte Division, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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16
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Artunc F, Wörn M, Schork A, Bohnert BN. Proteasuria-The impact of active urinary proteases on sodium retention in nephrotic syndrome. Acta Physiol (Oxf) 2019; 225:e13249. [PMID: 30597733 DOI: 10.1111/apha.13249] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 12/14/2022]
Abstract
Sodium retention and extracellular volume expansion are typical features of patients with nephrotic syndrome. In recent years, from in vitro data, endoluminal activation of the epithelial sodium channel (ENaC) by aberrantly filtered serine proteases has been proposed as an underlying mechanism. Recently, this concept was supported in vivo in nephrotic mice that were protected from proteolytic ENaC activation and sodium retention by the use of aprotinin for the pharmacological inhibition of urinary serine protease activity. These and other findings from studies in both rodents and humans highlight the impact of active proteases in the urine, or proteasuria, on ENaC-mediated sodium retention and edema formation in nephrotic syndrome. Targeting proteasuria could become a therapeutic approach to treat patients with nephrotic syndrome. However, pathophysiologically relevant proteases remain to be identified. In this review, we introduce the concept of proteasuria to explain tubular sodium avidity and conclude that proteasuria can be considered as a key mechanism of sodium retention in patients with nephrotic syndrome.
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Affiliation(s)
- Ferruh Artunc
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
| | - Matthias Wörn
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
| | - Anja Schork
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
| | - Bernhard N. Bohnert
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
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17
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Mutchler SM, Kleyman TR. New insights regarding epithelial Na+ channel regulation and its role in the kidney, immune system and vasculature. Curr Opin Nephrol Hypertens 2019; 28:113-119. [PMID: 30585851 PMCID: PMC6349474 DOI: 10.1097/mnh.0000000000000479] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW This review describes recent findings regarding the epithelial Na channel (ENaC) and its roles in physiologic and pathophysiologic states. We discuss new insights regarding ENaC's structure, its regulation by various factors, its potential role in hypertension and nephrotic syndrome, and its roles in the immune system and vasculature. RECENT FINDINGS A recently resolved structure of ENaC provides clues regarding mechanisms of ENaC activation by proteases. The use of amiloride in nephrotic syndrome, and associated complications are discussed. ENaC is expressed in dendritic cells and contributes to immune system activation and increases in blood pressure in response to NaCl. ENaC is expressed in endothelial ENaC and has a role in regulating vascular tone. SUMMARY New findings have emerged regarding ENaC and its role in the kidney, immune system, and vasculature.
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Affiliation(s)
- Stephanie M. Mutchler
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA
| | - Thomas R. Kleyman
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA
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18
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Gupta S, Pepper RJ, Ashman N, Walsh SB. Nephrotic Syndrome: Oedema Formation and Its Treatment With Diuretics. Front Physiol 2019; 9:1868. [PMID: 30697163 PMCID: PMC6341062 DOI: 10.3389/fphys.2018.01868] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/11/2018] [Indexed: 01/01/2023] Open
Abstract
Oedema is a defining element of the nephrotic syndrome. Its' management varies considerably between clinicians, with no national or international clinical guidelines, and hence variable outcomes. Oedema may have serious sequelae such as immobility, skin breakdown and local or systemic infection. Treatment of nephrotic oedema is often of limited efficacy, with frequent side-effects and interactions with other pharmacotherapy. Here, we describe the current paradigms of oedema in nephrosis, including insights into emerging mechanisms such as the role of the abnormal activation of the epithelial sodium channel in the collecting duct. We then discuss the physiological basis for traditional and novel therapies for the treatment of nephrotic oedema. Despite being the cardinal symptom of nephrosis, few clinical studies guide clinicians to the rational use of therapy. This is reflected in the scarcity of publications in this field; it is time to undertake new clinical trials to direct clinical practice.
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Affiliation(s)
- Sanjana Gupta
- UCL Centre for Nephrology, University College London, London, United Kingdom.,Renal Unit, The Royal London Hospital, Bart's Health NHS Trust, London, United Kingdom
| | - Ruth J Pepper
- UCL Centre for Nephrology, University College London, London, United Kingdom
| | - Neil Ashman
- Renal Unit, The Royal London Hospital, Bart's Health NHS Trust, London, United Kingdom
| | - Stephen B Walsh
- UCL Centre for Nephrology, University College London, London, United Kingdom
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