1
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Schweda F. How kidney function adapts to changes in acid-base balance: the AE4 transporter as a central acid-base sensor in tubular cells. Pflugers Arch 2024; 476:7-8. [PMID: 38117329 PMCID: PMC10758356 DOI: 10.1007/s00424-023-02898-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/21/2023]
Affiliation(s)
- Frank Schweda
- Institute of Physiology, University of Regensburg, Universitaetsstr. 31, 93053, Regensburg, Germany.
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2
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Sinha F, Schweda F, Maier LS, Wagner S. Impact of Impaired Kidney Function on Arrhythmia-Promoting Cardiac Ion Channel Regulation. Int J Mol Sci 2023; 24:14198. [PMID: 37762501 PMCID: PMC10532292 DOI: 10.3390/ijms241814198] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Chronic kidney disease (CKD) is associated with a significantly increased risk of cardiovascular events and sudden cardiac death. Although arrhythmias are one of the most common causes of sudden cardiac death in CKD patients, the molecular mechanisms involved in the development of arrhythmias are still poorly understood. In this narrative review, therefore, we summarize the current knowledge on the regulation of cardiac ion channels that contribute to arrhythmia in CKD. We do this by first explaining the excitation-contraction coupling, outlining current translational research approaches, then explaining the main characteristics in CKD patients, such as abnormalities in electrolytes and pH, activation of the autonomic nervous system, and the renin-angiotensin-aldosterone system, as well as current evidence for proarrhythmic properties of uremic toxins. Finally, we discuss the substance class of sodium-glucose co-transporter 2 inhibitors (SGLT2i) on their potential to modify cardiac channel regulation in CKD and, therefore, as a treatment option for arrhythmias.
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Affiliation(s)
- Frederick Sinha
- Department for Internal Medicine II, University Medical Center Regensburg, 93053 Regensburg, Germany; (F.S.)
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany
| | - Lars S. Maier
- Department for Internal Medicine II, University Medical Center Regensburg, 93053 Regensburg, Germany; (F.S.)
| | - Stefan Wagner
- Department for Internal Medicine II, University Medical Center Regensburg, 93053 Regensburg, Germany; (F.S.)
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3
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Sinha F, Federlein A, Biesold A, Schwarzfischer M, Krieger K, Schweda F, Tauber P. Empagliflozin increases kidney weight due to increased cell size in the proximal tubule S3 segment and the collecting duct. Front Pharmacol 2023; 14:1118358. [PMID: 37033639 PMCID: PMC10076569 DOI: 10.3389/fphar.2023.1118358] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/14/2023] [Indexed: 04/11/2023] Open
Abstract
The inhibition of renal SGLT2 glucose reabsorption has proven its therapeutic efficacy in chronic kidney disease. SGLT2 inhibitors (SGLTi) have been intensively studied in rodent models to identify the mechanisms of SGLT2i-mediated nephroprotection. So far, the overwhelming effects from clinical trials, could only partially be reproduced in rodent models of renal injury. However, a commonly disregarded observation from these studies, is the increase in kidney weight after SGLT2i administration. Increased kidney mass often relies on tubular growth in response to reabsorption overload during glomerular hyperfiltration. Since SGLT2i suppress hyperfiltration but concomitantly increase renal weight, it seems likely that SGLT2i have a growth promoting effect on the kidney itself, independent of GFR control. This study aimed to investigate the effect of SGLT2i on kidney growth in wildtype animals, to identify enlarged nephron segments and classify the size increase as hypertrophic/hyperplastic growth or cell swelling. SGLT2i empagliflozin increased kidney weight in wildtype mice by 13% compared to controls, while bodyweight and other organs were not affected. The enlarged nephron segments were identified as SGLT2-negative distal segments of proximal tubules and as collecting ducts by histological quantification of tubular cell area. In both segments protein/DNA ratio, a marker for hypertrophic growth, was increased by 6% and 12% respectively, while tubular nuclei number (hyperplasia) was unchanged by empagliflozin. SGLT2-inhibition in early proximal tubules induces a shift of NaCl resorption along the nephron causing compensatory NaCl and H2O reabsorption and presumably cell growth in downstream segments. Consistently, in collecting ducts of empagliflozin-treated mice, mRNA expression of the Na+-channel ENaC and the H2O-channels Aqp-2/Aqp-3 were increased. In addition, the hypoxia marker Hif1α was found increased in intercalated cells of the collecting duct together with evidence for increased proton secretion, as indicated by upregulation of carbonic anhydrases and acidified urine pH in empagliflozin-treated animals. In summary, these data show that SGLT2i induce cell enlargement by hypertrophic growth and possibly cell swelling in healthy kidneys, probably as a result of compensatory glucose, NaCl and H2O hyperreabsorption of SGLT2-negative segments. Particularly affected are the SGLT2-negative proximal tubules (S3) and the collecting duct, areas of low O2 availability.
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4
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Heinl ES, Broeker KAE, Lehrmann C, Heydn R, Krieger K, Ortmaier K, Tauber P, Schweda F. Localization of natriuretic peptide receptors A, B, and C in healthy and diseased mouse kidneys. Pflugers Arch 2023; 475:343-360. [PMID: 36480070 PMCID: PMC9908653 DOI: 10.1007/s00424-022-02774-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 09/23/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022]
Abstract
The natriuretic peptides (NPs) ANP (atrial natriuretic peptide) and BNP (B-type natriuretic peptide) mediate their widespread effects by activating the natriuretic peptide receptor-A (NPR-A), while C-type natriuretic peptide (CNP) acts via natriuretic peptide receptor-B (NPR-B). NPs are removed from the circulation by internalization via the natriuretic peptide clearance receptor natriuretic peptide receptor-C (NPR-C). In addition to their well-known functions, for instance on blood pressure, all three NPs confer significant cardioprotection and renoprotection. Since neither the NP-mediated renal functions nor the renal target cells of renoprotection are completely understood, we performed systematic localization studies of NP receptors using in situ hybridization (RNAscope) in mouse kidneys. NPR-A mRNA is highly expressed in glomeruli (mainly podocytes), renal arterioles, endothelial cells of peritubular capillaries, and PDGFR-receptor β positive (PDGFR-β) interstitial cells. No NPR-A mRNA was detected by RNAscope in the tubular system. In contrast, NPR-B expression is highest in proximal tubules. NPR-C is located in glomeruli (mainly podocytes), in endothelial cells and PDGFR-β positive cells. To test for a possible regulation of NPRs in kidney diseases, their distribution was studied in adenine nephropathy. Signal intensity of NPR-A and NPR-B mRNA was reduced while their spatial distribution was unaltered compared with healthy kidneys. In contrast, NPR-C mRNA signal was markedly enhanced in cell clusters of myofibroblasts in fibrotic areas of adenine kidneys. In conclusion, the primary renal targets of ANP and BNP are glomerular, vascular, and interstitial cells but not the tubular compartment, while the CNP receptor NPR-B is highly expressed in proximal tubules. Further studies are needed to clarify the function and interplay of this specific receptor expression pattern.
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Affiliation(s)
- Elena-Sofia Heinl
- Institute for Physiology, University Regensburg, Regensburg, Germany.
| | | | - Claudia Lehrmann
- grid.7727.50000 0001 2190 5763Institute for Physiology, University Regensburg, Regensburg, Germany
| | - Rosmarie Heydn
- grid.7727.50000 0001 2190 5763Institute for Physiology, University Regensburg, Regensburg, Germany
| | - Katharina Krieger
- grid.7727.50000 0001 2190 5763Institute for Physiology, University Regensburg, Regensburg, Germany
| | - Katharina Ortmaier
- grid.7727.50000 0001 2190 5763Institute for Physiology, University Regensburg, Regensburg, Germany
| | - Philipp Tauber
- grid.7727.50000 0001 2190 5763Institute for Physiology, University Regensburg, Regensburg, Germany
| | - Frank Schweda
- Institute for Physiology, University Regensburg, Regensburg, Germany.
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5
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Bohley M, Dillinger AE, Schweda F, Ohlmann A, Braunger BM, Tamm ER, Goepferich A. A single intravenous injection of cyclosporin A-loaded lipid nanocapsules prevents retinopathy of prematurity. Sci Adv 2022; 8:eabo6638. [PMID: 36149956 PMCID: PMC9506721 DOI: 10.1126/sciadv.abo6638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Retinopathy of prematurity (ROP) is a retinal disease that threatens the vision of prematurely born infants. Severe visual impairment up to complete blindness is caused by neovascularization and inflammation, progressively destroying the immature retina. ROP primarily affects newborns in middle- and low-income countries with limited access to current standard treatments such as intraocular drug injections and laser- or cryotherapy. To overcome these limitations, we developed a nanotherapeutic that effectively prevents ROP development with one simple intravenous injection. Its lipid nanocapsules transport the antiangiogenic and anti-inflammatory cyclosporin A efficiently into disease-driving retinal pigment epithelium cells. In a mouse model of ROP, a single intravenous injection of the nanotherapeutic prevented ROP and led to normal retinal development by counteracting neovascularization and inflammation. This nanotherapeutic approach has the potential to bring about a change of paradigm in ROP therapy and prevent millions of preterm born infants from developing ROP.
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Affiliation(s)
- Marilena Bohley
- Department of Pharmaceutical Technology, University of Regensburg, 93053 Regensburg, Germany
| | - Andrea E. Dillinger
- Department of Human Anatomy and Embryology, University of Regensburg, 93053 Regensburg, Germany
| | - Frank Schweda
- Department of Physiology, University of Regensburg, 93053 Regensburg, Germany
| | - Andreas Ohlmann
- Department of Ophthalmology, Munich University Hospital, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
| | - Barbara M. Braunger
- Institute of Anatomy and Cell Biology, Julius-Maximilians-University of Wuerzburg, 97070 Wuerzburg, Germany
| | - Ernst R. Tamm
- Department of Human Anatomy and Embryology, University of Regensburg, 93053 Regensburg, Germany
| | - Achim Goepferich
- Department of Pharmaceutical Technology, University of Regensburg, 93053 Regensburg, Germany
- Corresponding author.
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6
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Tauber P, Sinha F, Berger RS, Gronwald W, Dettmer K, Kuhn M, Trum M, Maier LS, Wagner S, Schweda F. Empagliflozin Reduces Renal Hyperfiltration in Response to Uninephrectomy, but Is Not Nephroprotective in UNx/DOCA/Salt Mouse Models. Front Pharmacol 2021; 12:761855. [PMID: 34992532 PMCID: PMC8724563 DOI: 10.3389/fphar.2021.761855] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/06/2021] [Indexed: 12/20/2022] Open
Abstract
Large-scale clinical outcome studies demonstrated the efficacy of SGLT2 inhibitors in patients with type II diabetes. Besides their therapeutic efficacy in diabetes, significant renoprotection was observed in non-diabetic patients with chronic kidney disease (CKD), suggesting the existence of glucose-independent beneficial effects of SGLT2 inhibitors. However, the relevant mechanisms by which SGLT2 inhibition delays the progression of renal injury are still largely unknown and speculative. Previous studies showed that SGLT2 inhibitors reduce diabetic hyperfiltration, which is likely a key element in renoprotection. In line with this hypothesis, this study aimed to investigate the nephroprotective effects of the SGLT2 inhibitor empagliflozin (EMPA) in different mouse models with non-diabetic hyperfiltration and progressing CKD to identify the underlying diabetes-independent cellular mechanisms. Non-diabetic hyperfiltration was induced by unilateral nephrectomy (UNx). Since UNx alone does not result in renal damage, renal disease models with varying degrees of glomerular damage and albuminuria were generated by combining UNx with high NaCl diets ± deoxycorticosterone acetate (DOCA) in different mouse strains with and without genetic predisposition for glomerular injury. Renal parameters (GFR, albuminuria, urine volume) were monitored for 4–6 weeks. Application of EMPA via the drinking water resulted in sufficient EMPA plasma concentration and caused glucosuria, diuresis and in some models renal hypertrophy. EMPA had no effect on GFR in untreated wildtype animals, but significantly reduced hyperfiltration after UNx by 36%. In contrast, EMPA did not reduce UNx induced hyperfiltration in any of our kidney disease models, regardless of their degree of glomerular damage caused by DOCA/salt treatment. Consistent with the lack of reduction in glomerular hyperfiltration, EMPA-treated animals developed albuminuria and renal fibrosis to a similar extent as H2O control animals. Taken together, the data clearly indicate that blockade of SGLT2 has the potential to reduce non-diabetic hyperfiltration in otherwise untreated mice. However, no effects on hyperfiltration or progression of renal injury were observed in hypervolemic kidney disease models, suggesting that high salt intake and extracellular volume might attenuate the protective effects of SGLT2 blockers.
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Affiliation(s)
- Philipp Tauber
- Institute of Physiology, University of Regensburg, Regensburg, Germany
- *Correspondence: Philipp Tauber,
| | - Frederick Sinha
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Raffaela S. Berger
- Institute of Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Wolfram Gronwald
- Institute of Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Katja Dettmer
- Institute of Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Michaela Kuhn
- Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Maximilian Trum
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Lars S. Maier
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Stefan Wagner
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
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7
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Stehle D, Xu MZ, Schomber T, Hahn MG, Schweda F, Feil S, Kraehling JR, Eitner F, Patzak A, Sandner P, Feil R, Bénardeau A. Novel soluble guanylyl cyclase activators increase glomerular cGMP, induce vasodilation and improve blood flow in the murine kidney. Br J Pharmacol 2021; 179:2476-2489. [PMID: 34096053 PMCID: PMC9292672 DOI: 10.1111/bph.15586] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/07/2021] [Accepted: 05/23/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Generation of cGMP via NO-sensitive soluble guanylyl cyclase (sGC) has been implicated in the regulation of renal functions. Chronic kidney disease (CKD) is associated with decreased NO bioavailability, increased oxidative stress and oxidation of sGC to its haem-free form, apo-sGC. Apo-sGC cannot be activated by NO, resulting in impaired cGMP signalling that is associated with chronic kidney disease progression. We hypothesised that sGC activators, which activate apo-sGC independently of NO, increase renal cGMP production under conditions of oxidative stress, thereby improving renal blood flow (RBF) and kidney function. EXPERIMENTAL APPROACH Two novel sGC activators, runcaciguat and BAY-543, were tested on murine kidney. We measured cGMP levels in real time in kidney slices of cGMP sensor mice, vasodilation of pre-constricted glomerular arterioles and RBF in isolated perfused kidneys. Experiments were performed at baseline conditions, under L-NAME-induced NO deficiency, and in the presence of oxidative stress induced by ODQ. KEY RESULTS Mouse glomeruli showed NO-induced cGMP increases. Under baseline conditions, sGC activator did not alter glomerular cGMP concentration or NO-induced cGMP generation. In the presence of ODQ, NO-induced glomerular cGMP signals were markedly reduced, whereas sGC activator induced strong cGMP increases. L-NAME and ODQ pretreated isolated glomerular arterioles were strongly dilated by sGC activator. sGC activator also increased cGMP and RBF in ODQ-perfused kidneys. CONCLUSION AND IMPLICATION sGC activators increase glomerular cGMP, dilate glomerular arterioles and improve RBF under disease-relevant oxidative stress conditions. Therefore, sGC activators represent a promising class of drugs for chronic kidney disease treatment.
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Affiliation(s)
- Daniel Stehle
- Interfakultäres Institut für Biochemie (IFIB), University of Tübingen, Tübingen, Germany
| | - Min Ze Xu
- Institute of Vegetative Physiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Tibor Schomber
- Bayer AG, Cardiovascular Research, Pharma Research Center, Wuppertal, Germany
| | - Michael G Hahn
- Bayer AG, Cardiovascular Research, Pharma Research Center, Wuppertal, Germany
| | - Frank Schweda
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| | - Susanne Feil
- Interfakultäres Institut für Biochemie (IFIB), University of Tübingen, Tübingen, Germany
| | - Jan R Kraehling
- Bayer AG, Cardiovascular Research, Pharma Research Center, Wuppertal, Germany
| | - Frank Eitner
- Bayer AG, Cardiovascular Research, Pharma Research Center, Wuppertal, Germany.,Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Andreas Patzak
- Institute of Vegetative Physiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Peter Sandner
- Bayer AG, Cardiovascular Research, Pharma Research Center, Wuppertal, Germany.,Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Robert Feil
- Interfakultäres Institut für Biochemie (IFIB), University of Tübingen, Tübingen, Germany
| | - Agnès Bénardeau
- Bayer AG, Cardiovascular Research, Pharma Research Center, Wuppertal, Germany.,Novo Nordisk A/S, Cardio-Renal Biology, Måløv, Denmark
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8
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Špiranec Spes K, Chen W, Krebes L, Völker K, Abeßer M, Eder Negrin P, Cellini A, Nickel A, Nikolaev VO, Hofmann F, Schuh K, Schweda F, Kuhn M. Heart-Microcirculation Connection: Effects of ANP (Atrial Natriuretic Peptide) on Pericytes Participate in the Acute and Chronic Regulation of Arterial Blood Pressure. Hypertension 2020; 76:1637-1648. [PMID: 32951468 DOI: 10.1161/hypertensionaha.120.15772] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac ANP (atrial natriuretic peptide) moderates arterial blood pressure. The mechanisms mediating its hypotensive effects are complex and involve inhibition of the renin-angiotensin-aldosterone system, increased natriuresis, endothelial permeability, and vasodilatation. The contribution of the direct vasodilating effects of ANP to blood pressure homeostasis is controversial because variable levels of the ANP receptor, GC-A (guanylyl cyclase-A), are expressed among vascular beds. Here, we show that ANP stimulates GC-A/cyclic GMP signaling in cultured microvascular pericytes and thereby the phosphorylation of the regulatory subunit of myosin phosphatase 1 by cGMP-dependent protein kinase I. Moreover, ANP prevents the calcium and contractile responses of pericytes to endothelin-1 as well as microvascular constrictions. In mice with conditional inactivation (knock-out) of GC-A in microcirculatory pericytes, such vasodilating effects of ANP on precapillary arterioles and capillaries were fully abolished. Concordantly, these mice have increased blood pressure despite preserved renal excretory function. Furthermore, acute intravascular volume expansion, which caused release of cardiac ANP, did not affect blood pressure of control mice but provoked hypertensive reactions in pericyte GC-A knock-out littermates. We conclude that GC-A/cGMP-dependent modulation of pericytes and microcirculatory tone contributes to the acute and chronic moderation of arterial blood pressure by ANP. Graphic Abstract A graphic abstract is available for this article.
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Affiliation(s)
- Katarina Špiranec Spes
- From the Institute of Physiology, University of Würzburg (K.S.S., W.C., L.K., K.V., M.A., K.S., M.K.), University Hospital Würzburg, Germany.,Comprehensive Heart Failure Center (K.S.S., W.C., P.E.N., A.C., A.N., M.K.), University Hospital Würzburg, Germany
| | - Wen Chen
- From the Institute of Physiology, University of Würzburg (K.S.S., W.C., L.K., K.V., M.A., K.S., M.K.), University Hospital Würzburg, Germany.,Comprehensive Heart Failure Center (K.S.S., W.C., P.E.N., A.C., A.N., M.K.), University Hospital Würzburg, Germany.,The Affiliated Haimen Hospital, Nantong University, Jiangsu, China (W.C.)
| | - Lisa Krebes
- From the Institute of Physiology, University of Würzburg (K.S.S., W.C., L.K., K.V., M.A., K.S., M.K.), University Hospital Würzburg, Germany
| | - Katharina Völker
- From the Institute of Physiology, University of Würzburg (K.S.S., W.C., L.K., K.V., M.A., K.S., M.K.), University Hospital Würzburg, Germany
| | - Marco Abeßer
- From the Institute of Physiology, University of Würzburg (K.S.S., W.C., L.K., K.V., M.A., K.S., M.K.), University Hospital Würzburg, Germany
| | - Petra Eder Negrin
- Comprehensive Heart Failure Center (K.S.S., W.C., P.E.N., A.C., A.N., M.K.), University Hospital Würzburg, Germany
| | - Antonella Cellini
- Comprehensive Heart Failure Center (K.S.S., W.C., P.E.N., A.C., A.N., M.K.), University Hospital Würzburg, Germany
| | - Alexander Nickel
- Comprehensive Heart Failure Center (K.S.S., W.C., P.E.N., A.C., A.N., M.K.), University Hospital Würzburg, Germany
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (V.O.N.)
| | - Franz Hofmann
- Institute of Pharmacology and Toxicology, TU Munich, Germany (F.H.)
| | - Kai Schuh
- From the Institute of Physiology, University of Würzburg (K.S.S., W.C., L.K., K.V., M.A., K.S., M.K.), University Hospital Würzburg, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Germany (F.S.)
| | - Michaela Kuhn
- From the Institute of Physiology, University of Würzburg (K.S.S., W.C., L.K., K.V., M.A., K.S., M.K.), University Hospital Würzburg, Germany
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9
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Fleischmann D, Maslanka Figueroa S, Beck S, Abstiens K, Witzgall R, Schweda F, Tauber P, Goepferich A. Adenovirus-Mimetic Nanoparticles: Sequential Ligand-Receptor Interplay as a Universal Tool for Enhanced In Vitro/ In Vivo Cell Identification. ACS Appl Mater Interfaces 2020; 12:34689-34702. [PMID: 32639709 DOI: 10.1021/acsami.0c10057] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Viral infection patterns often rely on precisely coordinated sequences of distinct ligand-receptor interactions, leading in many cases to an outstanding target cell specificity. A successful mimicry of viral targeting strategies to create more site-specific nanoparticles (NPs) would therefore require particle-cell interactions to also be adequately controllable. In the present study, hetero-multivalent block-copolymer NPs present their attached ligands in a sterically controlled manner to create a sequential NP-cell interaction similar to the cell infiltration strategy of human adenovirus type 2. Targeting renal mesangial cells, particles therefore initially bind angiotensin II receptor type 1 (AT1r) on the cell surface via a structurally flexible AT1r antagonist. After a mandatory spatial approach, particle endocytosis is realized via binding of immobile αVβ3 integrins with a previously concealed secondary ligand, thereby creating a stepwise particle-cell interplay of primary NP attachment and subsequent uptake. Manufactured adenovirus-mimetic NPs show great avidity for both target motifs in vitro, leading to a substantial binding as well as subsequent cell uptake into target mesangial cells. Additionally, steric shielding of secondary ligand visibility leads to a highly controllable, sequential ligand-receptor interaction, whereby hetero-functional NPs activate mesangial cell surface integrins only after a successful prior binding to the AT1r. This stepwise cell identification significantly enhances mesangial cell specificity in co-culture assays with different off-target cells. Additionally, described NPs display excellent in vivo robustness by efficiently accumulating in the mesangium upon injection, thereby opening new paths for possible drug delivery applications.
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Affiliation(s)
- Daniel Fleischmann
- Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
| | - Sara Maslanka Figueroa
- Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
| | - Sebastian Beck
- Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
| | - Kathrin Abstiens
- Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
| | - Ralph Witzgall
- Institute for Molecular and Cellular Anatomy, University of Regensburg, 93053 Regensburg, Germany
| | - Frank Schweda
- Department of Physiology II, Institute for Physiology, University of Regensburg, 93053 Regensburg, Germany
| | - Philipp Tauber
- Department of Physiology II, Institute for Physiology, University of Regensburg, 93053 Regensburg, Germany
| | - Achim Goepferich
- Department of Pharmaceutical Technology, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany
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10
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Maslanka Figueroa S, Fleischmann D, Beck S, Tauber P, Witzgall R, Schweda F, Goepferich A. Nanoparticles Mimicking Viral Cell Recognition Strategies Are Superior Transporters into Mesangial Cells. Adv Sci (Weinh) 2020; 7:1903204. [PMID: 32537398 PMCID: PMC7284201 DOI: 10.1002/advs.201903204] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/12/2020] [Accepted: 03/17/2020] [Indexed: 05/22/2023]
Abstract
Poor drug availability in the tissue of interest is a frequent cause of therapy failure. While nanotechnology has developed a plethora of nanocarriers for drug transport, their ability to unequivocally identify cells of interest remains moderate. Viruses are the ideal nanosized carriers as they are able to address their embedded nucleic acids with high specificity to their host cells. Here, it is reported that particles endowed with a virus-like ability to identify cells by three consecutive checks have a superior ability to recognize mesangial cells (MCs) in vivo compared to conventional nanoparticles. Mimicking the initial viral attachment followed by a stepwise target cell recognition process leads to a 5- to 15-fold higher accumulation in the kidney mesangium and extensive cell uptake compared to particles lacking one or both of the viral traits. These results highlight the relevance that the viral cell identification process has on specificity and its application on the targeting strategies of nanomaterials. More so, these findings pave the way for transporting drugs into the mesangium, a tissue that is pivotal in the development of diabetic nephropathy and for which currently no efficient pharmacotherapy exists.
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Affiliation(s)
| | - Daniel Fleischmann
- Department of Pharmaceutical TechnologyUniversity of RegensburgRegensburg93053Germany
| | - Sebastian Beck
- Department of Pharmaceutical TechnologyUniversity of RegensburgRegensburg93053Germany
| | - Philipp Tauber
- Department of Physiology IIUniversity of RegensburgRegensburg93053Germany
| | - Ralph Witzgall
- Department of Molecular and Cellular AnatomyUniversity of RegensburgRegensburg93053Germany
| | - Frank Schweda
- Department of Physiology IIUniversity of RegensburgRegensburg93053Germany
| | - Achim Goepferich
- Department of Pharmaceutical TechnologyUniversity of RegensburgRegensburg93053Germany
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11
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Chennupati R, Wirth A, Favre J, Li R, Bonnavion R, Jin YJ, Wietelmann A, Schweda F, Wettschureck N, Henrion D, Offermanns S. Myogenic vasoconstriction requires G 12/G 13 and LARG to maintain local and systemic vascular resistance. eLife 2019; 8:49374. [PMID: 31549965 PMCID: PMC6777979 DOI: 10.7554/elife.49374] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022] Open
Abstract
Myogenic vasoconstriction is an autoregulatory function of small arteries. Recently, G-protein-coupled receptors have been involved in myogenic vasoconstriction, but the downstream signalling mechanisms and the in-vivo-function of this myogenic autoregulation are poorly understood. Here, we show that small arteries from mice with smooth muscle-specific loss of G12/G13 or the Rho guanine nucleotide exchange factor ARHGEF12 have lost myogenic vasoconstriction. This defect was accompanied by loss of RhoA activation, while vessels showed normal increases in intracellular [Ca2+]. In the absence of myogenic vasoconstriction, perfusion of peripheral organs was increased, systemic vascular resistance was reduced and cardiac output and left ventricular mass were increased. In addition, animals with defective myogenic vasoconstriction showed aggravated hypotension in response to endotoxin. We conclude that G12/G13- and Rho-mediated signaling plays a key role in myogenic vasoconstriction and that myogenic tone is required to maintain local and systemic vascular resistance under physiological and pathological condition.
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Affiliation(s)
- Ramesh Chennupati
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Angela Wirth
- Institute of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Julie Favre
- Laboratoire MITOVASC, UMR CNRS 6015 - INSERM 1083, Université d'Angers, Angers, France
| | - Rui Li
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Rémy Bonnavion
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Young-June Jin
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Astrid Wietelmann
- Scientific Service Group Nuclear Magnetic Resonance Imaging, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Nina Wettschureck
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,Centre for Molecular Medicine, Medical Faculty, JW Goethe University Frankfurt, Frankfurt, Germany.,German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - Daniel Henrion
- Laboratoire MITOVASC, UMR CNRS 6015 - INSERM 1083, Université d'Angers, Angers, France
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,Centre for Molecular Medicine, Medical Faculty, JW Goethe University Frankfurt, Frankfurt, Germany.,German Center for Cardiovascular Research (DZHK), Berlin, Germany
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12
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Špiranec K, Chen W, Werner F, Nikolaev VO, Naruke T, Koch F, Werner A, Eder-Negrin P, Diéguez-Hurtado R, Adams RH, Baba HA, Schmidt H, Schuh K, Skryabin BV, Movahedi K, Schweda F, Kuhn M. Endothelial C-Type Natriuretic Peptide Acts on Pericytes to Regulate Microcirculatory Flow and Blood Pressure. Circulation 2019; 138:494-508. [PMID: 29626067 DOI: 10.1161/circulationaha.117.033383] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Peripheral vascular resistance has a major impact on arterial blood pressure levels. Endothelial C-type natriuretic peptide (CNP) participates in the local regulation of vascular tone, but the target cells remain controversial. The cGMP-producing guanylyl cyclase-B (GC-B) receptor for CNP is expressed in vascular smooth muscle cells (SMCs). However, whereas endothelial cell-specific CNP knockout mice are hypertensive, mice with deletion of GC-B in vascular SMCs have unaltered blood pressure. METHODS We analyzed whether the vasodilating response to CNP changes along the vascular tree, ie, whether the GC-B receptor is expressed in microvascular types of cells. Mice with a floxed GC-B ( Npr2) gene were interbred with Tie2-Cre or PDGF-Rβ-Cre ERT2 lines to develop mice lacking GC-B in endothelial cells or in precapillary arteriolar SMCs and capillary pericytes. Intravital microscopy, invasive and noninvasive hemodynamics, fluorescence energy transfer studies of pericyte cAMP levels in situ, and renal physiology were combined to dissect whether and how CNP/GC-B/cGMP signaling modulates microcirculatory tone and blood pressure. RESULTS Intravital microscopy studies revealed that the vasodilatatory effect of CNP increases toward small-diameter arterioles and capillaries. CNP consistently did not prevent endothelin-1-induced acute constrictions of proximal arterioles, but fully reversed endothelin effects in precapillary arterioles and capillaries. Here, the GC-B receptor is expressed both in endothelial and mural cells, ie, in pericytes. It is notable that the vasodilatatory effects of CNP were preserved in mice with endothelial GC-B deletion, but abolished in mice lacking GC-B in microcirculatory SMCs and pericytes. CNP, via GC-B/cGMP signaling, modulates 2 signaling cascades in pericytes: it activates cGMP-dependent protein kinase I to phosphorylate downstream targets such as the cytoskeleton-associated vasodilator-activated phosphoprotein, and it inhibits phosphodiesterase 3A, thereby enhancing pericyte cAMP levels. These pathways ultimately prevent endothelin-induced increases of pericyte calcium levels and pericyte contraction. Mice with deletion of GC-B in microcirculatory SMCs and pericytes have elevated peripheral resistance and chronic arterial hypertension without a change in renal function. CONCLUSIONS Our studies indicate that endothelial CNP regulates distal arteriolar and capillary blood flow. CNP-induced GC-B/cGMP signaling in microvascular SMCs and pericytes is essential for the maintenance of normal microvascular resistance and blood pressure.
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Affiliation(s)
- Katarina Špiranec
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
| | - Wen Chen
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
| | - Franziska Werner
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (V.O.N.)
| | - Takashi Naruke
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
| | - Franziska Koch
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
| | - Andrea Werner
- Institute of Physiology, University of Regensburg, Germany (A.W., F.S.)
| | - Petra Eder-Negrin
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
| | - Rodrigo Diéguez-Hurtado
- Max-Planck-Institute for Molecular Biomedicine, Department of Tissue Morphogenesis (R.D.-H., R.H.A.)
| | - Ralf H Adams
- Max-Planck-Institute for Molecular Biomedicine, Department of Tissue Morphogenesis (R.D.-H., R.H.A.)
| | - Hideo A Baba
- Faculty of Medicine, University of Münster, Germany. Institute of Pathology, University Hospital Essen, University Duisburg-Essen, Germany (H.A.B.)
| | - Hannes Schmidt
- Interfaculty Institute of Biochemistry, University of Tübingen, Germany (H.S.)
| | - Kai Schuh
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
| | - Boris V Skryabin
- Core Facility Transgenic Animal and genetic engineering Models (B.V.S.)
| | - Kiavash Movahedi
- Myeloid Cell Immunology Lab, Vesalius Research Center, Center for Inflammation Research, and Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium (K.M.)
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Germany (A.W., F.S.)
| | - Michaela Kuhn
- Institute of Physiology, University of Würzburg and Comprehensive Heart Failure Center, University Hospital Würzburg, Germany (K. Špiranec, W.C., S.C., F.W., T.N., F.K., P.E.-N., K. Schuh, M.K.)
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13
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Steglich A, Kessel F, Hickmann L, Gerlach M, Lachmann P, Gembardt F, Lesche M, Dahl A, Federlein A, Schweda F, Hugo CPM, Todorov VT. Renin cells with defective Gsα/cAMP signaling contribute to renal endothelial damage. Pflugers Arch 2019; 471:1205-1217. [PMID: 31388748 DOI: 10.1007/s00424-019-02298-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/10/2019] [Accepted: 07/23/2019] [Indexed: 12/27/2022]
Abstract
Synthesis of renin in renal renin-producing cells (RPCs) is controlled via the intracellular messenger cAMP. Interference with cAMP-mediated signaling by inducible knockout of Gs-alpha (Gsα) in RPCs of adult mice resulted in a complex adverse kidney phenotype. Therein, glomerular endothelial damage was most striking. In this study, we investigated whether Gsα knockout leads to a loss of RPCs, which itself may contribute to the endothelial injury. We compared the kidney phenotype of three RPC-specific conditional mouse lines during continuous induction of recombination. Mice expressing red fluorescent reporter protein tdTomato (tdT) in RPCs served as controls. tdT was also expressed in RPCs of the other two strains used, namely with RPC-specific Gsα knockout (Gsα mice) or with RPC-specific diphtheria toxin A expression (DTA mice, in which the RPCs should be diminished). Using immunohistological analysis, we found that RPCs decreased by 82% in the kidneys of Gsα mice as compared with controls. However, the number of tdT-positive cells was similar in the two strains, demonstrating that after Gsα knockout, the RPCs persist as renin-negative descendants. In contrast, both renin-positive and tdT-labeled cells decreased by 80% in DTA mice suggesting effective RPC ablation. Only Gsα mice displayed dysregulated endothelial cell marker expression indicating glomerular endothelial damage. In addition, a robust induction of genes involved in tissue remodelling with microvascular damage was identified in tdT-labeled RPCs isolated from Gsα mice. We concluded that Gsα/renin double-negative RPC progeny essentially contributes for the development of glomerular endothelial damage in our Gsα-deficient mice.
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Affiliation(s)
- Anne Steglich
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Friederike Kessel
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Linda Hickmann
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Michael Gerlach
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
- Core Facility Cellular Imaging (CFCI), Medical Faculty Carl Gustav Carus, Technical University Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Peter Lachmann
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
- Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Florian Gembardt
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Mathias Lesche
- Dresden-concept Genome Center, c/o Center for Molecular and Cellular Bioengineering (CMCB), Technical University Dresden, Fetscherstr. 105, 01307, Dresden, Germany
| | - Andreas Dahl
- Dresden-concept Genome Center, c/o Center for Molecular and Cellular Bioengineering (CMCB), Technical University Dresden, Fetscherstr. 105, 01307, Dresden, Germany
| | - Anna Federlein
- Institute of Physiology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Christian P M Hugo
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Vladimir T Todorov
- Experimental Nephrology, Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus, TU Dresden, Fetscherstraße 74, 01307, Dresden, Germany.
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14
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Schramm A, Schweda F, Sequeira-Lopez MLS, Hofmann F, Sandner P, Schlossmann J. Protein Kinase G Is Involved in Acute but Not in Long-Term Regulation of Renin Secretion. Front Pharmacol 2019; 10:800. [PMID: 31379575 PMCID: PMC6657341 DOI: 10.3389/fphar.2019.00800] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/21/2019] [Indexed: 12/27/2022] Open
Abstract
Pharmacological inhibition of the renin–angiotensin–aldosterone system (RAAS) is, in combination with diuretics, the first-choice treatment for hypertension, although 10–20% of patients do not respond adequately. Next to the RAAS, the nitric oxide/cGMP/protein kinase G (PKG) system is the second fundamental blood pressure regulator. Whether both systems influence each other is not well-studied. It has been shown that nitric oxide (NO) supports renin recruitment via activation of soluble guanylate cyclase (sGC) and subsequent generation of cGMP. Whether this leads to an ensuing activation of PKGs in this context is not known. PKGIα, as well as PKGII, is expressed in renin-producing cells. Hence, we analyzed whether these enzymes play a role regarding renin synthesis, secretion, or recruitment. We generated renin-cell-specific PKGI-knockout mice and either stimulated or inhibited the renin system in these mice by salt diets. To exclude the possibility that one kinase isoform can compensate the lack of the other, we also studied double-knockout animals with a conditional knockout of PKGI in juxtaglomerular cells (JG cells) and a ubiquitous knockout of PKGII. We analyzed blood pressure, renin mRNA and renal renin protein content as well as plasma renin concentration. Furthermore, we stimulated the cGMP system in these mice using BAY 41-8543, an sGC stimulator, and examined renin regulation either after acute administration or after 7 days (application once daily). We did not reveal any striking differences regarding long-term renin regulation in the studied mouse models. Yet, when we studied the acute effect of BAY 41-8543 on renin secretion in isolated perfused kidneys as well as in living animals, we found that the administration of the substance led to a significant increase in plasma renin concentration in control animals. This effect was completely abolished in double-knockout animals. However, after 7 days of once daily application, we did not detect a persistent increase in renin mRNA or protein in any studied genotype. Therefore, we conclude that in mice, cGMP and PKG are involved in the acute regulation of renin release but have no influence on long-term renin adjustment.
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Affiliation(s)
- Andrea Schramm
- Institute of Pharmacy, Department of Pharmacology and Toxicology, University of Regensburg, Regensburg, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | | | - Franz Hofmann
- Institute of Pharmacology and Toxicology, Technical University of Munich, Munich, Germany
| | - Peter Sandner
- Bayer AG, Drug Discovery-Cardiology, Wuppertal, Germany
| | - Jens Schlossmann
- Institute of Pharmacy, Department of Pharmacology and Toxicology, University of Regensburg, Regensburg, Germany
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15
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Mustroph J, Wagemann O, Lücht CM, Trum M, Hammer KP, Sag CM, Lebek S, Tarnowski D, Reinders J, Perbellini F, Terracciano C, Schmid C, Schopka S, Hilker M, Zausig Y, Pabel S, Sossalla ST, Schweda F, Maier LS, Wagner S. Empagliflozin reduces Ca/calmodulin-dependent kinase II activity in isolated ventricular cardiomyocytes. ESC Heart Fail 2018; 5:642-648. [PMID: 30117720 PMCID: PMC6073019 DOI: 10.1002/ehf2.12336] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Accepted: 06/22/2018] [Indexed: 12/14/2022] Open
Abstract
AIMS The EMPA-REG OUTCOME study showed reduced mortality and hospitalization due to heart failure (HF) in diabetic patients treated with empagliflozin. Overexpression and Ca2+ -dependent activation of Ca2+ /calmodulin-dependent kinase II (CaMKII) are hallmarks of HF, leading to contractile dysfunction and arrhythmias. We tested whether empagliflozin reduces CaMKII- activity and improves Ca2+ -handling in human and murine ventricular myocytes. METHODS AND RESULTS Myocytes from wild-type mice, mice with transverse aortic constriction (TAC) as a model of HF, and human failing ventricular myocytes were exposed to empagliflozin (1 μmol/L) or vehicle. CaMKII activity was assessed by CaMKII-histone deacetylase pulldown assay. Ca2+ spark frequency (CaSpF) as a measure of sarcoplasmic reticulum (SR) Ca2+ leak was investigated by confocal microscopy. [Na+ ]i was measured using Na+ /Ca2+ -exchanger (NCX) currents (whole-cell patch clamp). Compared with vehicle, 24 h empagliflozin exposure of murine myocytes reduced CaMKII activity (1.6 ± 0.7 vs. 4.2 ± 0.9, P < 0.05, n = 10 mice), and also CaMKII-dependent ryanodine receptor phosphorylation (0.8 ± 0.1 vs. 1.0 ± 0.1, P < 0.05, n = 11 mice), with similar results upon TAC. In murine myocytes, empagliflozin reduced CaSpF (TAC: 1.7 ± 0.3 vs. 2.5 ± 0.4 1/100 μm-1 s-1 , P < 0.05, n = 4 mice) but increased SR Ca2+ load and Ca2+ transient amplitude. Importantly, empagliflozin also significantly reduced CaSpF in human failing ventricular myocytes (1 ± 0.2 vs. 3.3 ± 0.9, P < 0.05, n = 4 patients), while Ca2+ transient amplitude was increased (F/F0 : 0.53 ± 0.05 vs. 0.36 ± 0.02, P < 0.05, n = 3 patients). In contrast, 30 min exposure with empagliflozin did not affect CaMKII activity nor Ca2+ -handling but significantly reduced [Na+ ]i . CONCLUSIONS We show for the first time that empagliflozin reduces CaMKII activity and CaMKII-dependent SR Ca2+ leak. Reduced Ca2+ leak and improved Ca2+ transients may contribute to the beneficial effects of empagliflozin in HF.
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Affiliation(s)
- Julian Mustroph
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Olivia Wagemann
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Charlotte M. Lücht
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Maximilian Trum
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Karin P. Hammer
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Can Martin Sag
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Simon Lebek
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Daniel Tarnowski
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Jörg Reinders
- Leibniz Research Centre for Working Environment and Human FactorsUniversity of DortmundDortmundGermany
| | - Filippo Perbellini
- Laboratory of Myocardial Electrophysiology, Imperial Centre for Translational and Experimental MedicineImperial College LondonLondonUK
| | - Cesare Terracciano
- Laboratory of Myocardial Electrophysiology, Imperial Centre for Translational and Experimental MedicineImperial College LondonLondonUK
| | - Christof Schmid
- Department of Cardiothoracic SurgeryUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Simon Schopka
- Department of Cardiothoracic SurgeryUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Michael Hilker
- Department of Cardiothoracic SurgeryUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - York Zausig
- Department of AnesthesiologyUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Steffen Pabel
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Samuel T. Sossalla
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
- Clinic for Cardiology and PneumologyUniversity Medical Center GöttingenGöttingenGermany
| | - Frank Schweda
- Department of PhysiologyUniversity of RegensburgRegensburgGermany
| | - Lars S. Maier
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
| | - Stefan Wagner
- Department of Internal Medicine IIUniversity Medical Center RegensburgFranz‐Josef‐Strauß‐Allee 1193053RegensburgGermany
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16
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Mustroph J, Wagemann O, Trum M, Lebek S, Tarnowski D, Reinders J, Schmid C, Schopka S, Hilker M, Graf B, Pabel S, Sossalla S, Schweda F, Maier LS, Wagner S. 3145Empagliflozin potently reduces sarcoplasmic Ca leak and increases Ca transient amplitude of human failing ventricular cardiomyocytes. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.3145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- J Mustroph
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - O Wagemann
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - M Trum
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - S Lebek
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - D Tarnowski
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - J Reinders
- University of Regensburg, Institute of Functional Genomics, Regensburg, Germany
| | - C Schmid
- University Hospital Regensburg, Department of Cardio-thoracic surgery, Regensburg, Germany
| | - S Schopka
- University Hospital Regensburg, Department of Cardio-thoracic surgery, Regensburg, Germany
| | - M Hilker
- University Hospital Regensburg, Department of Cardio-thoracic surgery, Regensburg, Germany
| | - B Graf
- University Hospital Regensburg, Department of Anesthesiology, Regensburg, Germany
| | - S Pabel
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - S Sossalla
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - F Schweda
- University of Regensburg, Department of Physiology, Regensburg, Germany
| | - L S Maier
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
| | - S Wagner
- University Hospital Regensburg, Internal Medicine II, Regensburg, Germany
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17
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Meurer M, Ebert K, Schweda F, Höcherl K. The renal vasodilatory effect of prostaglandins is ameliorated in isolated-perfused kidneys of endotoxemic mice. Pflugers Arch 2018; 470:1691-1703. [DOI: 10.1007/s00424-018-2183-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 12/29/2022]
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18
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Abstract
The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. This is a prerequisite for studying the physiology of the isolated organ and for many innovative applications that may be possible in the future, including perfusion decellularization for kidney bioengineering or the administration of anti-rejection or genome-editing drugs in high doses to prime the kidney for transplantation. During the time of the perfusion, the kidney can be manipulated, renal function can be assessed, and various pharmaceuticals administered. After the procedure, the kidney can be transplanted or processed for molecular biology, biochemical analysis, or microscopy. This paper describes the perfusate and the surgical technique needed for the ex vivo perfusion of mouse kidneys. Details of the perfusion apparatus are given and data are presented showing the viability of the kidney's preparation: renal blood flow, vascular resistance, and urine data as functional, transmission electron micrographs of different nephron segments as morphological readouts, and western blots of transport proteins of different nephron segments as molecular readout.
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Affiliation(s)
- Jan Czogalla
- Institute of Anatomy, Swiss National Centre of Competence in Research Kidney, University of Zürich;
| | | | - Johannes Loffing
- Institute of Anatomy, Swiss National Centre of Competence in Research Kidney, University of Zürich
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19
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Koehler S, Brähler S, Kuczkowski A, Binz J, Hackl MJ, Hagmann H, Höhne M, Vogt MC, Wunderlich CM, Wunderlich FT, Schweda F, Schermer B, Benzing T, Brinkkoetter PT. Single and Transient Ca 2+ Peaks in Podocytes do not induce Changes in Glomerular Filtration and Perfusion. Sci Rep 2016; 6:35400. [PMID: 27759104 PMCID: PMC5069688 DOI: 10.1038/srep35400] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 09/27/2016] [Indexed: 12/25/2022] Open
Abstract
Chronic alterations in calcium (Ca2+) signalling in podocytes have been shown to cause proteinuria and progressive glomerular diseases. However, it is unclear whether short Ca2+ peaks influence glomerular biology and cause podocyte injury. Here we generated a DREADD (Designer Receptor Exclusively Activated by a Designer Drug) knock-in mouse line to manipulate intracellular Ca2+ levels. By mating to a podocyte-specific Cre driver we are able to investigate the impact of Ca2+ peaks on podocyte biology in living animals. Activation of the engineered G-protein coupled receptor with the synthetic compound clozapine-N-oxide (CNO) evoked a short and transient Ca2+ peak in podocytes immediately after CNO administration in vivo. Interestingly, this Ca2+ peak did neither affect glomerular perfusion nor filtration in the animals. Moreover, no obvious alterations in the glomerular morphology could be observed. Taken together, these in vivo findings suggest that chronic alterations and calcium overload rather than an induction of transient Ca2+ peaks contribute to podocyte disease.
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Affiliation(s)
- Sybille Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Sebastian Brähler
- Department of Pathology &Immunology, Division of Immunobiology, Washington University School of Medicine, St Louis, USA
| | - Alexander Kuczkowski
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Julia Binz
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Matthias J Hackl
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Henning Hagmann
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Merly C Vogt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Department of Biological Sciences, Columbia University, New York, NY, USA
| | | | | | - Frank Schweda
- Department of Physiology, University of Regensburg, Regensburg, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
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20
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Penton D, Czogalla J, Wengi A, Himmerkus N, Loffing-Cueni D, Carrel M, Rajaram RD, Staub O, Bleich M, Schweda F, Loffing J. Extracellular K + rapidly controls NaCl cotransporter phosphorylation in the native distal convoluted tubule by Cl - -dependent and independent mechanisms. J Physiol 2016; 594:6319-6331. [PMID: 27457700 DOI: 10.1113/jp272504] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [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: 03/23/2016] [Accepted: 07/14/2016] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS High dietary potassium (K+ ) intake dephosphorylates and inactivates the NaCl cotransporter (NCC) in the renal distal convoluted tubule (DCT). Using several ex vivo models, we show that physiological changes in extracellular K+ , similar to those occurring after a K+ rich diet, are sufficient to promote a very rapid dephosphorylation of NCC in native DCT cells. Although the increase of NCC phosphorylation upon decreased extracellular K+ appears to depend on cellular Cl- fluxes, the rapid NCC dephosphorylation in response to increased extracellular K+ is not Cl- -dependent. The Cl- -dependent pathway involves the SPAK/OSR1 kinases, whereas the Cl- independent pathway may include additional signalling cascades. ABSTRACT A high dietary potassium (K+ ) intake causes a rapid dephosphorylation, and hence inactivation, of the thiazide-sensitive NaCl cotransporter (NCC) in the renal distal convoluted tubule (DCT). Based on experiments in heterologous expression systems, it was proposed that changes in extracellular K+ concentration ([K+ ]ex ) modulate NCC phosphorylation via a Cl- -dependent modulation of the with no lysine (K) kinases (WNK)-STE20/SPS-1-44 related proline-alanine-rich protein kinase (SPAK)/oxidative stress-related kinase (OSR1) kinase pathway. We used the isolated perfused mouse kidney technique and ex vivo preparations of mouse kidney slices to test the physiological relevance of this model on native DCT. We demonstrate that NCC phosphorylation inversely correlates with [K+ ]ex , with the most prominent effects occurring around physiological plasma [K+ ]. Cellular Cl- conductances and the kinases SPAK/OSR1 are involved in the phosphorylation of NCC under low [K+ ]ex . However, NCC dephosphorylation triggered by high [K+ ]ex is neither blocked by removing extracellular Cl- , nor by the Cl- channel blocker 4,4'-diisothiocyano-2,2'-stilbenedisulphonic acid. The response to [K+ ]ex on a low extracellular chloride concentration is also independent of significant changes in SPAK/OSR1 phosphorylation. Thus, in the native DCT, [K+ ]ex directly and rapidly controls NCC phosphorylation by Cl- -dependent and independent pathways that involve the kinases SPAK/OSR1 and a yet unidentified additional signalling mechanism.
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Affiliation(s)
- David Penton
- Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Swiss National Centre of Competence in Research 'Kidney Control of Homeostasis', University of Zurich, Zurich, Switzerland
| | - Jan Czogalla
- Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Swiss National Centre of Competence in Research 'Kidney Control of Homeostasis', University of Zurich, Zurich, Switzerland
| | - Agnieszka Wengi
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Nina Himmerkus
- Institute of Physiology, Christian-Albrecht University, Kiel, Germany
| | | | - Monique Carrel
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Renuga Devi Rajaram
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,Swiss National Centre of Competence in Research 'Kidney Control of Homeostasis', University of Zurich, Zurich, Switzerland
| | - Olivier Staub
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,Swiss National Centre of Competence in Research 'Kidney Control of Homeostasis', University of Zurich, Zurich, Switzerland
| | - Markus Bleich
- Institute of Physiology, Christian-Albrecht University, Kiel, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Johannes Loffing
- Institute of Anatomy, University of Zurich, Zurich, Switzerland. .,Swiss National Centre of Competence in Research 'Kidney Control of Homeostasis', University of Zurich, Zurich, Switzerland.
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21
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Staffel J, Valletta D, Federlein A, Ehm K, Volkmann R, Füchsl AM, Witzgall R, Kuhn M, Schweda F. Natriuretic Peptide Receptor Guanylyl Cyclase-A in Podocytes is Renoprotective but Dispensable for Physiologic Renal Function. J Am Soc Nephrol 2016; 28:260-277. [PMID: 27153922 DOI: 10.1681/asn.2015070731] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [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: 07/03/2015] [Accepted: 03/29/2016] [Indexed: 12/20/2022] Open
Abstract
The cardiac natriuretic peptides (NPs), atrial NP and B-type NP, regulate fluid homeostasis and arterial BP through renal actions involving increased GFR and vascular and tubular effects. Guanylyl cyclase-A (GC-A), the transmembrane cGMP-producing receptor shared by these peptides, is expressed in different renal cell types, including podocytes, where its function is unclear. To study the effects of NPs on podocytes, we generated mice with a podocyte-specific knockout of GC-A (Podo-GC-A KO). Despite the marked reduction of GC-A mRNA in GC-A KO podocytes to 1% of the control level, Podo-GC-A KO mice and control littermates did not differ in BP, GFR, or natriuresis under baseline conditions. Moreover, infusion of synthetic NPs similarly increased the GFR and renal perfusion in both genotypes. Administration of the mineralocorticoid deoxycorticosterone-acetate (DOCA) in combination with high salt intake induced arterial hypertension of similar magnitude in Podo-GC-A KO mice and controls. However, only Podo-GC-A KO mice developed massive albuminuria (controls: 35-fold; KO: 5400-fold versus baseline), hypoalbuminemia, reduced GFR, and marked glomerular damage. Furthermore, DOCA treatment led to decreased expression of the slit diaphragm-associated proteins podocin, nephrin, and synaptopodin and to enhanced transient receptor potential canonical 6 (TRPC6) channel expression and ATP-induced calcium influx in podocytes of Podo-GC-A KO mice. Concomitant treatment of Podo-GC-A KO mice with the TRPC channel blocker SKF96365 markedly ameliorated albuminuria and glomerular damage in response to DOCA. In conclusion, the physiologic effects of NPs on GFR and natriuresis do not involve podocytes. However, NP/GC-A/cGMP signaling protects podocyte integrity under pathologic conditions, most likely by suppression of TRPC channels.
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Affiliation(s)
| | | | | | | | | | | | - Ralph Witzgall
- Anatomy, University of Regensburg, Regensburg, Germany; and
| | - Michaela Kuhn
- Institute of Physiology, University of Würzburg, Würzburg, Germany
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22
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Hennig R, Ohlmann A, Staffel J, Pollinger K, Haunberger A, Breunig M, Schweda F, Tamm ER, Goepferich A. Multivalent nanoparticles bind the retinal and choroidal vasculature. J Control Release 2015; 220:265-274. [DOI: 10.1016/j.jconrel.2015.10.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 10/22/2022]
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23
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Heitzmann D, Buehler P, Schweda F, Georgieff M, Warth R, Thomas J. The in vivo respiratory phenotype of the adenosine A1 receptor knockout mouse. Respir Physiol Neurobiol 2015; 222:16-28. [PMID: 26593641 DOI: 10.1016/j.resp.2015.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 05/01/2015] [Revised: 11/09/2015] [Accepted: 11/09/2015] [Indexed: 10/22/2022]
Abstract
The nucleoside adenosine has been implicated in the regulation of respiration, especially during hypoxia in the newborn. In this study the role of adenosine A1 receptors for the control of respiration was investigated in vivo. To this end, respiration of unrestrained adult and neonatal adenosine A1 receptor knockout mice (A1R(-/-)) was measured in a plethysmographic device. Under control conditions (21% O2) and mild hypoxia (12-15% O2) no difference of respiratory parameters was observed between adult wildtype (A1R(+/+)) and A1R(-/-) mice. Under more severe hypoxia (6-10% O2) A1R(+/+) mice showed, after a transient increase of respiration, a decrease of respiration frequency (fR) and tidal volume (VT) leading to a decrease of minute volume (MV). This depression of respiration during severe hypoxia was absent in A1R(-/-) mice which displayed a stimulated respiration as indicated by the enhancement of MV by some 50-60%. During hypercapnia-hyperoxia (3-10% CO2/97-90 % O2), no obvious differences in respiration of A1R(-/-) and A1R(+/+) was observed. In neonatal mice, the respiratory response to hypoxia was surprisingly similar in both genotypes. However, neonatal A1R(-/-) mice appeared to have more frequently periods of apnea during hypoxia and in the post-hypoxic control period. In conclusion, these data indicate that the adenosine A1 receptor is an important molecular component mediating hypoxic depression in adult mice and it appears to stabilize respiration of neonatal mice.
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Affiliation(s)
- Dirk Heitzmann
- Medizinische Klinik, University hospital Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Philipp Buehler
- University children's hospital, Steinwiesstr. 75, CH-8032 Zürich, Switzerland
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, D-93053 Regensburg, Germany
| | - Michael Georgieff
- Department of Anaesthesiology, University of Ulm, D-89075 Ulm, Germany
| | - Richard Warth
- Institute of Physiology, University of Regensburg, D-93053 Regensburg, Germany
| | - Joerg Thomas
- University children's hospital, Steinwiesstr. 75, CH-8032 Zürich, Switzerland.
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24
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Wirth A, Wang S, Takefuji M, Tang C, Althoff TF, Schweda F, Wettschureck N, Offermanns S. Age-dependent blood pressure elevation is due to increased vascular smooth muscle tone mediated by G-protein signalling. Cardiovasc Res 2015; 109:131-40. [PMID: 26531127 DOI: 10.1093/cvr/cvv249] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/29/2015] [Indexed: 12/22/2022] Open
Abstract
AIMS Arterial hypertension is a major risk factor for cardiovascular diseases. The kidney and its natriuretic function are in the centre of the prevailing models to explain the pathogenesis of hypertension; however, the mechanisms underlying blood pressure elevation remain unclear in most patients. Development of hypertension is strongly correlated with age, and this blood pressure increase typically accelerates in the fourth decade of life. The cause of age-dependent blood pressure elevation is poorly understood. This study aims to understand the role of procontractile G-protein-mediated signalling pathways in vascular smooth muscle in age-dependent hypertension. METHODS AND RESULTS Similar to humans at mid-life, we observed in 1-year-old mice elevated blood pressure levels without any evidence for increased vessel stiffness, impaired renal function, or endocrine abnormalities. Hypertensive aged mice showed signs of endothelial dysfunction and had an increased vascular formation of reactive oxygen species (ROS) and elevated endothelial ET-1 expression. Age-dependent hypertension could be normalized by ETA receptor blockade, smooth muscle-specific inactivation of the gene encoding the ETA receptor, as well as by acute disruption of downstream signalling via induction of smooth muscle-specific Gα12/Gα13, Gαq/Gα11, or LARG deficiency using tamoxifen-inducible smooth muscle-specific conditional mouse knock-out models. Induction of smooth muscle-specific ETA receptor deficiency normalized the blood pressure in aged mice despite the continuous presence of signs of endothelial dysfunction. CONCLUSION Age-dependent blood pressure elevation is due to a highly reversible activation of procontractile signalling in vascular smooth muscle cells indicating that increased vascular tone can be a primary factor in the development of hypertension.
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Affiliation(s)
- Angela Wirth
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany Institute of Pharmacology, University of Heidelberg, ImNeuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Shengpeng Wang
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany
| | - Mikito Takefuji
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany
| | - Cong Tang
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany
| | - Till F Althoff
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, 93053 Regensburg, Germany
| | - Nina Wettschureck
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany Medical Faculty, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Stefan Offermanns
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany Medical Faculty, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
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25
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Camacho Londoño JE, Tian Q, Hammer K, Schröder L, Camacho Londoño J, Reil JC, He T, Oberhofer M, Mannebach S, Mathar I, Philipp SE, Tabellion W, Schweda F, Dietrich A, Kaestner L, Laufs U, Birnbaumer L, Flockerzi V, Freichel M, Lipp P. A background Ca2+ entry pathway mediated by TRPC1/TRPC4 is critical for development of pathological cardiac remodelling. Eur Heart J 2015; 36:2257-66. [PMID: 26069213 DOI: 10.1093/eurheartj/ehv250] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 05/18/2015] [Indexed: 12/22/2022] Open
Abstract
AIMS Pathological cardiac hypertrophy is a major predictor for the development of cardiac diseases. It is associated with chronic neurohumoral stimulation and with altered cardiac Ca(2+) signalling in cardiomyocytes. TRPC proteins form agonist-induced cation channels, but their functional role for Ca(2+) homeostasis in cardiomyocytes during fast cytosolic Ca(2+) cycling and neurohumoral stimulation leading to hypertrophy is unknown. METHODS AND RESULTS In a systematic analysis of multiple knockout mice using fluorescence imaging of electrically paced adult ventricular cardiomyocytes and Mn(2+)-quench microfluorimetry, we identified a background Ca(2+) entry (BGCE) pathway that critically depends on TRPC1/C4 proteins but not others such as TRPC3/C6. Reduction of BGCE in TRPC1/C4-deficient cardiomyocytes lowers diastolic and systolic Ca(2+) concentrations both, under basal conditions and under neurohumoral stimulation without affecting cardiac contractility measured in isolated hearts and in vivo. Neurohumoral-induced cardiac hypertrophy as well as the expression of foetal genes (ANP, BNP) and genes regulated by Ca(2+)-dependent signalling (RCAN1-4, myomaxin) was reduced in TRPC1/C4 knockout (DKO), but not in TRPC1- or TRPC4-single knockout mice. Pressure overload-induced hypertrophy and interstitial fibrosis were both ameliorated in TRPC1/C4-DKO mice, whereas they did not show alterations in other cardiovascular parameters contributing to systemic neurohumoral-induced hypertrophy such as renin secretion and blood pressure. CONCLUSIONS The constitutively active TRPC1/C4-dependent BGCE fine-tunes Ca(2+) cycling in beating adult cardiomyocytes. TRPC1/C4-gene inactivation protects against development of maladaptive cardiac remodelling without altering cardiac or extracardiac functions contributing to this pathogenesis.
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Affiliation(s)
- Juan E Camacho Londoño
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany
| | - Qinghai Tian
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | - Karin Hammer
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | - Laura Schröder
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | | | - Jan C Reil
- Innere Medizin III Universität des Saarlandes, 66421 Homburg, Germany
| | - Tao He
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany Research Unit Cardiac Epigenetics, Department of Cardiology, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan, China
| | | | - Stefanie Mannebach
- Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | - Ilka Mathar
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | - Stephan E Philipp
- Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | | | - Frank Schweda
- Institut für Physiologie, Universität Regensburg, 93053 Regensburg, Germany
| | - Alexander Dietrich
- Walther-Straub-Institut für Pharmakologie und Toxikologie, LMU, 80336 München, Germany
| | - Lars Kaestner
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | - Ulrich Laufs
- Innere Medizin III Universität des Saarlandes, 66421 Homburg, Germany
| | - Lutz Birnbaumer
- Transmembrane Signaling Group, NIEHS, PO Box 12233, NC 27709, USA
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | - Marc Freichel
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany
| | - Peter Lipp
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
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26
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Staffel J, Valletta D, Federlein A, Kuhn M, Schweda F. Natriuretic Peptides Exert Marked Renoprotective Effects Via Activation of the Natriuretic Peptide Receptor GC‐A in Podocytes. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.808.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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27
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Valletta D, Schreiber A, Schießl IM, Schweda F. Increase in tubular flow directly induces hypertrophy of proximal tubular cells. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.809.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Frank Schweda
- University of Regensburg Institute of PhysiologyGermany
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28
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Schweda F. Salt feedback on the renin-angiotensin-aldosterone system. Pflugers Arch 2014; 467:565-76. [DOI: 10.1007/s00424-014-1668-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/02/2014] [Accepted: 12/02/2014] [Indexed: 12/21/2022]
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29
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Tinning AR, Jensen BL, Schweda F, Machura K, Hansen PBL, Stubbe J, Gramsbergen JB, Madsen K. The water channel aquaporin-1 contributes to renin cell recruitment during chronic stimulation of renin production. Am J Physiol Renal Physiol 2014; 307:F1215-26. [DOI: 10.1152/ajprenal.00136.2014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Both the processing and release of secretory granules involve water movement across granule membranes. It was hypothesized that the water channel aquaporin (AQP)1 directly contributes to the recruitment of renin-positive cells in the afferent arteriole. AQP1−/− and AQP1+/+ mice were fed a low-salt (LS) diet [0.004% (wt/wt) NaCl] for 7 days and given enalapril [angiotensin-converting enzyme inhibitor (ACEI), 0.1 mg/ml] in drinking water for 3 days. There were no differences in plasma renin concentration at baseline. After LS-ACEI, plasma renin concentrations increased markedly in both genotypes but was significantly lower in AQP1−/− mice compared with AQP1+/+ mice. Tissue renin concentrations were higher in AQP1−/− mice, and renin mRNA levels were not different between genotypes. Mean arterial blood pressure was not different at baseline and during LS diet but decreased significantly in both genotypes after the addition of ACEI; the response was faster in AQP1−/− mice but then stabilized at a similar level. Renin release after 200 μl blood withdrawal was not different. Isoprenaline-stimulated renin release from isolated perfused kidneys did not differ between genotypes. Cortical tissue norepinephrine concentrations were lower after LS-ACEI compared with baseline with no difference between genotypes. Plasma nitrite/nitrate concentrations were unaffected by genotype and LS-ACEI. In AQP1−/− mice, the number of afferent arterioles with recruitment was significantly lower compared with AQP1+/+ mice after LS-ACEI. We conclude that AQP1 is not necessary for acutely stimulated renin secretion in vivo and from isolated perfused kidneys, whereas recruitment of renin-positive cells in response to chronic stimulation is attenuated or delayed in AQP1−/− mice.
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Affiliation(s)
- Anne R. Tinning
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Boye L. Jensen
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Katharina Machura
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Pernille B. L. Hansen
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Jane Stubbe
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Jan Bert Gramsbergen
- Department of Neurobiology Research, University of Southern Denmark, Odense, Denmark; and
| | - Kirsten Madsen
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
- Department of Pathology, Odense University Hospital, Odense, Denmark
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30
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Abstract
The renin-angiotensin-aldosterone system and cardiac natriuretic peptides [atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP)] are opposing control mechanisms for arterial blood pressure. Accordingly, an inverse relationship between plasma renin concentration (PRC) and ANP exists in most circumstances. However, PRC and ANP levels are both elevated in renovascular hypertension. Because ANP can directly suppress renin release, we used ANP knockout (ANP−/−) mice to investigate whether high ANP levels attenuate the increase in PRC in response to renal hypoperfusion, thus buffering renovascular hypertension. ANP−/− mice were hypertensive and had reduced PRC compared with that in wild-type ANP+/+ mice under control conditions. Unilateral renal artery stenosis (2-kidney, 1-clip) for 1 wk induced similar increases in blood pressure and PRC in both genotypes. Unexpectedly, plasma BNP concentrations in ANP−/− mice significantly increased in response to two-kidney, one-clip treatment, potentially compensating for the lack of ANP. In fact, in mice lacking guanylyl cyclase A (GC-A−/− mice), which is the common receptor for both ANP and BNP, renovascular hypertension was markedly augmented compared with that in wild-type GC-A+/+ mice. However, the higher blood pressure in GC-A−/− mice was not caused by disinhibition of the renin system because PRC and renal renin synthesis were significantly lower in GC-A−/− mice than in GC-A+/+ mice. Thus, natriuretic peptides buffer renal vascular hypertension via renin-independent effects, such as vasorelaxation. The latter possibility is supported by experiments in isolated perfused mouse kidneys, in which physiological concentrations of ANP and BNP elicited renal vasodilatation and attenuated renal vasoconstriction in response to angiotensin II.
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Affiliation(s)
- Theo Demerath
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Janina Staffel
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Andrea Schreiber
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Daniela Valletta
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
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Knuth S, Abdelsalam RM, Khayyal MT, Schweda F, Heilmann J, Kees MG, Mair G, Kees F, Jürgenliemk G. Catechol conjugates are in vivo metabolites of Salicis cortex. Planta Med 2013; 79:1489-1494. [PMID: 24146062 DOI: 10.1055/s-0033-1350898] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
After oral administration of 100 mg/kg b. w. (235.8 µmol/kg) salicortin to Wistar rats, peak serum concentrations of 1.43 mg/L (13.0 µM) catechol were detected after 0.5 h in addition to salicylic acid by HPLC-DAD after serum processing with β-glucuronidase and sulphatase. Both metabolites could also be detected in the serum of healthy volunteers following oral administration of a willow bark extract (Salicis cortex, Salix spec., Salicaceae) corresponding to 240 mg of salicin after processing with both enzymes. In humans, the cmax (1.46 mg/L, 13.3 µM) of catechol was reached after 1.2 h. The predominant phase-II metabolite in humans and rats was catechol sulphate, determined by HPLC analysis of serum samples processed with only one kind of enzyme. Without serum processing with glucuronidase and sulphatase, no unconjugated catechol could be detected in human and animal serum samples. As catechol is described as an anti-inflammatory compound, these results may contribute to the elucidation of the mechanism of the action of willow bark extract.
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Affiliation(s)
- Susanne Knuth
- University of Regensburg, Institute of Pharmacy, Department of Pharmaceutical Biology, Regensburg, Germany
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32
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Bandulik S, Tauber P, Penton D, Schweda F, Tegtmeier I, Sterner C, Lalli E, Lesage F, Hartmann M, Barhanin J, Warth R. Severe hyperaldosteronism in neonatal Task3 potassium channel knockout mice is associated with activation of the intraadrenal renin-angiotensin system. Endocrinology 2013; 154:2712-22. [PMID: 23698720 DOI: 10.1210/en.2013-1101] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Task3 K(+) channels are highly expressed in the adrenal cortex and contribute to the angiotensin II and K(+) sensitivity of aldosterone-producing glomerulosa cells. Adult Task3(-/-) mice display a partially autonomous aldosterone secretion, subclinical hyperaldosteronism, and salt-sensitive hypertension. Here, we investigated the age dependence of the adrenal phenotype of Task3(-/-) mice. Compared with adults, newborn Task3(-/-) mice displayed a severe adrenal phenotype with strongly increased plasma levels of aldosterone, corticosterone, and progesterone. This adrenocortical dysfunction was accompanied by a modified gene expression profile. The most strongly up-regulated gene was the protease renin. Real-time PCR corroborated the strong increase in adrenal renin expression, and immunofluorescence revealed renin-expressing cells in the zona fasciculata. Together with additional factors, activation of the local adrenal renin system is probably causative for the severely disturbed steroid hormone secretion of neonatal Task3(-/-) mice. The changes in gene expression patterns of neonatal Task3(-/-) mice could also be relevant for other forms of hyperaldosteronism.
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Affiliation(s)
- Sascha Bandulik
- Department of Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany.
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Mederle K, Schweda F, Kattler V, Doblinger E, Miyata K, Höcherl K, Oike Y, Castrop H. The angiotensin II AT1 receptor-associated protein Arap1 is involved in sepsis-induced hypotension. Crit Care 2013; 17:R130. [PMID: 23844607 PMCID: PMC4056110 DOI: 10.1186/cc12809] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 07/11/2013] [Indexed: 11/22/2022] Open
Abstract
Introduction Hypotension in septic patients results from hypovolemia, vasodilatation and hyporeactivity to vasoconstrictors, such as angiotensin II. The AT1 receptor-associated protein 1 (Arap1) is expressed in vascular smooth muscle cells and increases the surface expression of the AT1-receptor in vitro. We hypothesized that dysregulation of Arap1 may contribute to vascular hyporeactivity to angiotensin II during endotoxemia. Methods Arap1-deficient mice were used to assess the role of Arap1 in sepsis-induced hypotension. The isolated perfused kidney was used as an in vitro model to determine the relevance of Arap1 for vascular resistance and sensitivity to angiotensin II. Results During endotoxemia, mean arterial blood pressure (MAP) decreased in both genotypes, with the time course of sepsis-induced hypotension being markedly accelerated in Arap1-/- compared to +/+ mice. However, baseline MAP was similar in Arap1-/- and wildtype mice (102 ± 2 vs.103 ± 2 mmHg; telemetry measurements; n = 10; P = 0.66). Following lipopolysaccharide (LPS) injections (3 mg/kg), Arap1 expression was successively down-regulated in the wildtype mice, reaching levels below 10% of baseline expression. The endotoxemia-related decline in Arap1 expression could be recapitulated in cultured mesangial cells by incubation with pro-inflammatory cytokines, such as tumor necrosis factor α and interferon γ. Plasma renin concentration was increased in Arap1-/- mice compared to wildtype mice (66 ± 6 vs. 41 ± 4 ng AngI/ml/h; n = 23; P = 0.001), presumably contributing to preserved MAP under baseline conditions. The sensitivity of the vasculature to angiotensin II was reduced in Arap1-/- compared to +/+ mice, as determined in the isolated perfused kidney. Conclusions Our data suggest that down-regulation of Arap1 expression during sepsis contributes to the development of hypotension by causing reduced vascular sensitivity to angiotensin II.
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Braeunig JH, Schweda F, Han PL, Seifert R. Similarly potent inhibition of adenylyl cyclase by P-site inhibitors in hearts from wild type and AC5 knockout mice. PLoS One 2013; 8:e68009. [PMID: 23840883 PMCID: PMC3698094 DOI: 10.1371/journal.pone.0068009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 05/24/2013] [Indexed: 01/26/2023] Open
Abstract
Adenylyl cyclase type 5 (AC5) was described as major cardiac AC isoform. The knockout of AC5 (AC5KO) exerted cardioprotective effects in heart failure. Our study explored the impact of AC5KO on mouse heart AC activities and evaluated putative AC5-selective inhibitors. In cardiac membranes from AC5KO mice, basal AC activity was decreased, while AC stimulation was intact. The putative AC5-selective P-site inhibitors SQ22,536 [9-(tetra-hydro-2-furanyl)-9H-purin-6-amine], vidarabine (9-β-D-arabinosyladenine) and NKY80 [2-amino-7-(2-furanyl)-7,8-dihydro-5(6H)-quinazolinone] inhibited recombinant AC5 more potently than AC2 and AC1, but selectivity was only modest (∼4-40-fold). These compounds inhibited cardiac AC from WT and AC5KO mice with similar potencies. In conclusion, AC regulation in AC5KO hearts was unimpaired, questioning the supposed dominant role of AC5 in the heart. Moreover, the AC inhibitors SQ22,536, NKY80 and vidarabine lack adequate selectivity for AC5 and, therefore, do not present suitable tools to study AC5-specific functions.
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Affiliation(s)
- Joerg H. Braeunig
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Pyung-Lim Han
- Department of Brain and Cognitive Science, Graduate School, Ewha Woman University, Seoul, Korea
| | - Roland Seifert
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
- * E-mail:
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Schmid J, Oelbe M, Saftig P, Schwake M, Schweda F. Parallel regulation of renin and lysosomal integral membrane protein 2 in renin-producing cells: further evidence for a lysosomal nature of renin secretory vesicles. Pflugers Arch 2013; 465:895-905. [PMID: 23229015 DOI: 10.1007/s00424-012-1192-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 11/23/2012] [Accepted: 11/23/2012] [Indexed: 01/21/2023]
Abstract
The protease renin is the key enzyme in the renin-angiotensin system (RAS) that regulates extracellular volume and blood pressure. Renin is synthesized in renal juxtaglomerular cells (JG cells) as the inactive precursor prorenin. Activation of prorenin by cleavage of the prosegment occurs in renin storage vesicles that have lysosomal properties. To characterize the renin storage vesicles more precisely, the expression and functional relevance of the major lysosomal membrane proteins lysosomal-associated membrane protein 1 (LAMP-1), LAMP-2, and lysosomal integral membrane protein 2 (LIMP-2) were determined in JG cells. Immunostaining experiments revealed strong coexpression of renin with the LIMP-2 (SCARB2), while faint staining of LAMP-1 and LAMP-2 was detected in some JG cells only. Stimulation of the renin system (ACE inhibitor, renal hypoperfusion) resulted in the recruitment of renin-producing cells in the afferent arterioles and parallel upregulation of LIMP-2, but not LAMP-1 or LAMP-2. Despite the coregulation of renin and LIMP-2, LIMP-2-deficient mice had normal renal renin mRNA levels, renal renin and prorenin contents, and plasma renin and prorenin concentrations under control conditions and in response to stimulation with a low salt diet (with or without angiotensin-converting enzyme (ACE) inhibition). No differences in the size or number of renin vesicles were detected using electron microscopy. Acute stimulation of renin release by isoproterenol exerted similar responses in both genotypes in vivo and in isolated perfused kidneys. Renin and the major lysosomal protein LIMP-2 are colocalized and coregulated in renal JG cells, further corroborating the lysosomal nature of renin storage vesicles. LIMP-2 does not appear to play an obvious role in the regulation of renin synthesis or release.
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Affiliation(s)
- Johannes Schmid
- Institut für Physiologie, Universität Regensburg, 93040, Regensburg, Germany
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36
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Mederle K, Castrop H, Schweda F, Höcherl K. Inhibition of COX‐1 ameliorates endotoxemia‐induced fall in GFR in mice. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.705.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Hayo Castrop
- Institute of PhysiologyUniversity of RegensburgRegensburgGermany
| | - Frank Schweda
- Institute of PhysiologyUniversity of RegensburgRegensburgGermany
| | - Klaus Höcherl
- Institute of PhysiologyUniversity of RegensburgRegensburgGermany
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37
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Mederle K, Doblinger E, Kattler V, Höcherl K, Schweda F, Castrop H. Regulation of AT1‐Receptors by ARAP1 is involved in vasodilatation during sepsis‐induced hypotension. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.909.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Veronika Kattler
- Institute of PhysiologyUniversity of RegensburgRegensburgGermany
| | - Klaus Höcherl
- Institute of PhysiologyUniversity of RegensburgRegensburgGermany
| | - Frank Schweda
- Institute of PhysiologyUniversity of RegensburgRegensburgGermany
| | - Hayo Castrop
- Institute of PhysiologyUniversity of RegensburgRegensburgGermany
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38
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Reinhold SW, Uihlein DC, Böger CA, Kloiber S, Frölich K, Bergler T, Banas B, Schweda F, Krämer BK. Renin, endothelial NO synthase and endothelin gene expression in the 2kidney-1clip Goldblatt model of long-term renovascular hypertension. Eur J Med Res 2013; 14:520-5. [PMID: 20149985 PMCID: PMC3351937 DOI: 10.1186/2047-783x-14-12-520] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Objective Numerous reports have shown the influence of renin, nitric oxide (NO) and the endothelin (ET) systems for regulation of blood pressure and renal function. Furthermore, interactions between these peptides have been reported. Aim of our study was to investigate the relative contribution of these compounds in long-term renovascular hypertension/renal ischemia. Methods Hypertension/left-sided renal ischemia was induced using the 2K1C-Goldblatt rat model. Renal renin, ET-1, ET-3 and endothelial NO synthase (eNOS) gene expression was measured by means of RNAse protection assay at different timepoints up to 10 weeks after induction of renal artery stenosis. Results Plasma renin activity and renal renin gene expression in the left kidney were increased in the clipped animals while eNOS expression was unchanged. Furthermore, an increase in ET-1 expression and a decrease of ET-3 expression was detected in early stenosis. Conclusions While renin is obviously involved in regulation of blood pressure and renal function in unilateral renal artery stenosis, ET-1, ET-3 and endothelium derived NO do not appear to play an important role in renal adaptation processes in long-term renal artery stenosis, although ET-1 and ET-3 might be involved in short-term adaptation processes.
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Affiliation(s)
- S W Reinhold
- Klinik und Poliklinik für Innere Medizin II, University of Regensburg, Regensburg, Germany.
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Penton D, Bandulik S, Schweda F, Haubs S, Tauber P, Reichold M, Cong LD, El Wakil A, Budde T, Lesage F, Lalli E, Zennaro MC, Warth R, Barhanin J. Task3 potassium channel gene invalidation causes low renin and salt-sensitive arterial hypertension. Endocrinology 2012; 153:4740-8. [PMID: 22878402 DOI: 10.1210/en.2012-1527] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Task1 and Task3 potassium channels (Task: tandem of P domains in a weak inward rectifying K(+) channel-related acid-sensitive K(+) channel) are believed to control the membrane voltage of aldosterone-producing adrenal glomerulosa cells. This study aimed at understanding the role of Task3 for the control of aldosterone secretion. The adrenal phenotype of Task3(-/-) mice was investigated using electrophysiology, adrenal slices, and blood pressure measurements. Primary adrenocortical cells of Task3(-/-) mice were strongly depolarized compared with wild-type (-52 vs. -79 mV), and in fresh adrenal slices Ca(2+) signaling of Task3(-/-) glomerulosa cells was abnormal. In living Task3(-/-) mice, the regulation of aldosterone secretion showed specific deficits: Under low Na(+) and high K(+) diets, protocols known to increase aldosterone, and under standard diet, Task3 inactivation was compensated and aldosterone was normal. However, high Na(+) and low K(+) diets, two protocols known to lower aldosterone, failed to lower aldosterone in Task3(-/-) mice. The physiological regulation of aldosterone was disturbed: aldosterone-renin ratio, an indicator of autonomous aldosterone secretion, was 3-fold elevated at standard and high Na(+) diets. Isolated adrenal glands of Task3(-/-) produced 2-fold more aldosterone. As a consequence, Task3(-/-) mice showed salt-sensitive arterial hypertension (plus 10 mm Hg). In conclusion, Task3 plays an important role in the adaptation of aldosterone secretion to dietary salt intake.
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Affiliation(s)
- David Penton
- University of Regensburg, 93053 Regensburg, Germany
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40
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Birner C, Ulucan C, Bratfisch M, Götz T, Dietl A, Schweda F, Riegger GA, Luchner A. Antihypertrophic effects of combined inhibition of the renin–angiotensin system (RAS) and neutral endopeptidase (NEP) in progressive, tachycardia-induced experimental heart failure. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:1117-25. [DOI: 10.1007/s00210-012-0791-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/29/2012] [Indexed: 11/24/2022]
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Schreiber A, Shulhevich Y, Geraci S, Hesser J, Stsepankou D, Neudecker S, Koenig S, Heinrich R, Hoecklin F, Pill J, Friedemann J, Schweda F, Gretz N, Schock-Kusch D. Transcutaneous measurement of renal function in conscious mice. Am J Physiol Renal Physiol 2012; 303:F783-8. [PMID: 22696603 DOI: 10.1152/ajprenal.00279.2012] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Determination of glomerular filtration rate (GFR) in conscious mice is cumbersome for the experimenter and stressful for the animals. Here we report on a simple new technique allowing the transcutaneous measurement of GFR in conscious mice. This approach extends our previously developed technique for rats to mice. The technique relies on a miniaturized device equipped with an internal memory that permits the transcutaneous measurement of the elimination kinetics of the fluorescent renal marker FITC-sinistrin. This device is described and validated compared with FITC-sinistrin plasma clearance in healthy, unilaterally nephrectomized and pcy mice. In summary, we describe a technique allowing the measurement of renal function in freely moving mice independent of blood or urine sampling as well as of laboratory assays.
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Affiliation(s)
- Andrea Schreiber
- Institute of Physiology, University of Regensburg, Regensburg, Germany
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Abstract
Severe sepsis is often accompanied by acute renal failure with renal tubular dysfunction. Albuminuria is a common finding in septic patients and we studied whether it was due to an impairment of proximal tubular endocytosis of filtered albumin. We studied the regulation of megalin and cubilin, the two critical multiligand receptors responsible for albumin absorption, during severe experimental endotoxemia. Lipopolysaccharide (LPS) caused a time- and dose-dependent suppression of megalin and cubilin expression that was paralleled by a decrease in plasma albumin levels and an increase in the urine concentration of albumin in mice. Incubation of rat renal cortical slices with LPS also reduced the mRNA expression of megalin and cubilin. Further, LPS suppressed megalin and cubilin mRNA expression in murine primary proximal tubule cells and decreased the uptake of FITC albumin in these cells. In addition, the increase in urine levels of albumin in response to ischemia/reperfusion-induced acute renal failure was paralleled by a decrease in the expression of megalin and cubilin. Thus, our data indicate that the expression of megalin and cubilin is decreased during experimental endotoxemia and in response to renal ischemia/reperfusion injury. This downregulation may contribute, in part, to an increase in urine levels of albumin during acute renal failure.
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Affiliation(s)
- Andrea Schreiber
- Institute of Physiology, University of Regensburg, Regensburg, Germany
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Abstract
Proteinase-activated receptors (PARs) 1 to 4 are highly expressed in the kidney and are involved in the regulation of renal hemodynamics and tubular function. Since intravascular infusion of the proteinase thrombin, which activates PARs, has been shown to decrease plasma renin activity in rats, we investigated the effects of the respective PAR subtypes on renin release using the isolated perfused mouse kidney model. Thrombin dose-dependently reduced perfusate flow and inhibited renin secretion rates (RSRs) that had been prestimulated by the β-adrenoreceptor agonist isoproterenol. The suppression of RSRs was prevented by the selective PAR1 inhibitor SCH79797, and direct activation of PAR1 by TFLLR mimicked the effects of thrombin on RSRs and vascular tone. Moreover, TFLLR suppressed the stimulations of RSRs in response to the loop diuretic bumetanide, to prostaglandin E
2
, or to a decrease in renal perfusion pressure but not in response to a reduction in extracellular calcium. The PAR2-activating peptide SLIGRL concentration dependently increased RSR and perfusate flow. The stimulation of RSRs by SLIGRL was markedly attenuated by
N
G
-nitro-
l
-arginine methyl ester, suggesting an NO-dependent mechanism. Activation of PAR4 by AYPGKF did not modulate RSRs or perfusate flow. PAR1 and PAR2 immunoreactivity were detected in the juxtaglomerular region and were colocalized with renin immunoreactivity. Our data provide evidence that PAR1 activation inhibits renal renin secretion and induces renal vasoconstriction, whereas PAR2 activation stimulates renin release and induces vasodilation mainly via the release of NO.
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Affiliation(s)
- Klaus Höcherl
- From the Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Melanie Gerl
- From the Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Frank Schweda
- From the Institute of Physiology, University of Regensburg, Regensburg, Germany
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Lübkemeier I, Machura K, Kurtz L, Neubauer B, Dobrowolski R, Schweda F, Wagner C, Willecke K, Kurtz A. The connexin 40 A96S mutation causes renin-dependent hypertension. J Am Soc Nephrol 2011; 22:1031-40. [PMID: 21597036 PMCID: PMC3103723 DOI: 10.1681/asn.2010101047] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 01/16/2011] [Indexed: 11/03/2022] Open
Abstract
Deletion of the gap-junction-forming protein connexin40 leads to renin-dependent hypertension in mice, but whether observed human variants in connexin40, such as A96S, promote hypertension is unknown. Here, we generated mice with the A96S variant in the mouse connexin40 gene. Although mice homozygous for the A96S mutations had normal expression patterns of connexin40 in the kidney, they were hypertensive, had sixfold higher plasma renin concentrations, and had 40% higher levels of renin mRNA than controls. Renin-expressing cells were aberrantly located outside the media layer of afferent arterioles, and increased renal perfusion pressure did not inhibit renin secretion from kidneys isolated from homozygous A96S mice. Treatment with a low-salt diet in combination with an ACE inhibitor increased renin mRNA levels, plasma renin concentrations, and the number of aberrantly localized renin-producing cells. Taken together, these findings suggest that the A96S mutation in connexin40 leads to renin-dependent hypertension in mice. Modulation of renin secretion by BP critically depends on functional connexin40; with the A96S mutation, the aberrant extravascular localization of renin-secreting cells in the kidney likely impairs the pressure-mediated inhibition of renin secretion.
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Affiliation(s)
| | | | - Lisa Kurtz
- Department of Internal Medicine, University of Regensburg, Regensburg, Germany
| | | | | | | | | | - Klaus Willecke
- Institute of Genetics, University of Bonn, Bonn, Germany; and
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Takahashi K, Yamamoto H, Kato I, Shibasaki A, Ohba K, Kaneko K, Morimoto R, Murakami O, Satoh F, Hirose T, Totsune K, Hocherl K, Gerl M, Schweda F, Menne J, Schmidt B, Pichlmaier M, Haller H, Zanoli L, Alivon M, Estrugo N, Ketthab H, Pruny JF, Yanes S, Bean K, Empana JP, Jouven X, Laude RD, Laurent S, Boutouyrie P, Gellner K, Saint-Remy A, Weekers L, Bonvoisin C, Graceffa MA, Focan M, Krzesinski JM. Hypertension. Clin Kidney J 2011. [DOI: 10.1093/ndtplus/4.s2.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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46
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Raupach T, Lüthje L, Kögler H, Duve C, Schweda F, Hasenfuß G, Andreas S. Local and systemic effects of angiotensin receptor blockade in an emphysema mouse model. Pulm Pharmacol Ther 2011; 24:215-20. [DOI: 10.1016/j.pupt.2010.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 12/02/2010] [Accepted: 12/18/2010] [Indexed: 11/17/2022]
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Aldehni F, Tang T, Madsen K, Plattner M, Schreiber A, Friis UG, Hammond HK, Han PL, Schweda F. Stimulation of renin secretion by catecholamines is dependent on adenylyl cyclases 5 and 6. Hypertension 2011; 57:460-8. [PMID: 21282557 DOI: 10.1161/hypertensionaha.110.167130] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The sympathetic nervous system stimulates renin release from juxtaglomerular cells via the β-adrenoreceptor-cAMP pathway. Recent in vitro studies have suggested that the calcium-inhibited adenylyl cyclases (ACs) 5 and 6 possess key roles in the control of renin exocytosis. To investigate the relative contribution of AC5 and AC6 to the regulation of renin release in vivo we performed experiments using AC5 and AC6 knockout mice. Male AC5(-/-) mice exhibited normal plasma renin concentrations, renal renin synthesis (mRNA and renin content), urinary volume, and systolic blood pressure. In male AC6(-/-) mice, plasma renin concentration (AC6(-/-): 732 ± 119; AC6 (+/+): 436 ± 78 ng of angiotensin I per hour*mL(-1); P<0.05), and renin synthesis were stimulated associated with an increased excretion of dilute urine (1.55-fold; P<0.05) and reduced blood pressure (-10.6 mm Hg; P<0.001). Stimulation of plasma renin concentration by a single injection of the β-adrenoreceptor agonist isoproterenol (10 mg/kg IP) was significantly attenuated in AC5(-/-) (male: -20%; female: -33%) compared with wild-type mice in vivo. The mitigation of the plasma renin concentration response to isoproterenol was even more pronounced in AC6(-/-) (male: -63%; female: -50% versus AC6(+/+)). Similarly, the effects of isoproterenol, prostaglandin E2, and pituitary adenylyl cyclase-activating polypeptide on renin release from isolated perfused kidneys were attenuated to a higher extent in AC6(-/-) (-51% to -98% versus AC6(+/+)) than in AC5(-/-) (-31% to 46% versus AC5(+/+)). In conclusion, both AC5 and AC6 are involved in the stimulation of renin secretion in vivo, and AC6 is the dominant isoforms in this process.
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Affiliation(s)
- Fadi Aldehni
- Institute of Physiology, University of Regensburg, 93040 Regensburg, Germany
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48
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Hausmann R, Kuppe C, Egger H, Schweda F, Knecht V, Elger M, Menzel S, Somers D, Braun G, Fuss A, Uhlig S, Kriz W, Tanner G, Floege J, Moeller MJ. Electrical forces determine glomerular permeability. J Am Soc Nephrol 2010; 21:2053-8. [PMID: 20947631 PMCID: PMC3014018 DOI: 10.1681/asn.2010030303] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Accepted: 09/03/2010] [Indexed: 11/03/2022] Open
Abstract
There is ongoing controversy about the mechanisms that determine the characteristics of the glomerular filter. Here, we tested whether flow across the glomerular filter generates extracellular electrical potential differences, which could be an important determinant of glomerular filtration. In micropuncture experiments in Necturus maculosus, we measured a potential difference across the glomerular filtration barrier that was proportional to filtration pressure (-0.045 mV/10 cm H₂O). The filtration-dependent potential was generated without temporal delay and was negative within Bowman's space. Perfusion with the cationic polymer protamine abolished the potential difference. We propose a mathematical model that considers the relative contributions of diffusion, convection, and electrophoretic effects on the total flux of albumin across the filter. According to this model, potential differences of -0.02 to -0.05 mV can induce electrophoretic effects that significantly influence the glomerular sieving coefficient of albumin. This model of glomerular filtration has the potential to provide a mechanistic theory, based on experimental data, about the filtration characteristics of the glomerular filtration barrier. It provides a unique approach to the microanatomy of the glomerulus, renal autoregulation, and the pathogenesis of proteinuria.
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Affiliation(s)
- Ralf Hausmann
- Molecular Pharmacology, University Hospital of Rheinisch Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Christoph Kuppe
- Department of Nephrology and Clinical Immunology, University Hospital of RWTH Aachen University, Aachen, Germany
| | - Herbert Egger
- Computational Mathematics, Center for Computational Engineering Science, RWTH Aachen University, Aachen, Germany
| | - Frank Schweda
- Institute for Physiology, Regensburg University, Regensburg, Germany
| | - Volker Knecht
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, Potsdam, Germany
| | - Marlies Elger
- Centrum für Biomedizin und Medizintechnik Mannheim, Anatomy and Developmental Biology, Medical Faculty Mannheim, University Heidelberg, Mannheim, Germany
| | - Sylvia Menzel
- Department of Nephrology and Clinical Immunology, University Hospital of RWTH Aachen University, Aachen, Germany
| | - Douglas Somers
- Department of Internal Medicine, Nephrology, University of Iowa College of Medicine, Iowa City, Iowa; and
| | - Gerald Braun
- Department of Nephrology and Clinical Immunology, University Hospital of RWTH Aachen University, Aachen, Germany
| | - Astrid Fuss
- Department of Nephrology and Clinical Immunology, University Hospital of RWTH Aachen University, Aachen, Germany
| | - Sandra Uhlig
- Department of Nephrology and Clinical Immunology, University Hospital of RWTH Aachen University, Aachen, Germany
| | - Wilhelm Kriz
- Centrum für Biomedizin und Medizintechnik Mannheim, Anatomy and Developmental Biology, Medical Faculty Mannheim, University Heidelberg, Mannheim, Germany
| | - George Tanner
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jürgen Floege
- Department of Nephrology and Clinical Immunology, University Hospital of RWTH Aachen University, Aachen, Germany
| | - Marcus J. Moeller
- Department of Nephrology and Clinical Immunology, University Hospital of RWTH Aachen University, Aachen, Germany
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49
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Wagner C, Jobs A, Schweda F, Kurtz L, Kurt B, Sequeira Lopez ML, Gomez RA, van Veen TA, de Wit C, Kurtz A. Selective deletion of Connexin 40 in renin-producing cells impairs renal baroreceptor function and is associated with arterial hypertension. Kidney Int 2010; 78:762-8. [PMID: 20686449 PMCID: PMC3033195 DOI: 10.1038/ki.2010.257] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [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] [Indexed: 11/10/2022]
Abstract
Renin-producing juxtaglomerular cells are connected to each other and to endothelial cells of afferent arterioles by gap junctions containing Connexin 40 (Cx40), abundantly expressed by these two cell types. Here, we generated mice with cell-specific deletion of Cx40 in endothelial and in renin-producing cells, as its global deletion caused local dissociation of renin-producing cells from endothelial cells, renin hypersecretion, and hypertension. In mice lacking endothelial Cx40, the blood pressure, renin-producing cell distribution, and the control of renin secretion were similar to wild-type mice. In contrast, mice deficient for Cx40 in renin-producing cells were hypertensive and these cells were ectopically localized. Although plasma renin activity and kidney renin mRNA levels of these mice were not different from controls, the negative regulation of renin secretion by pressure was inverted to a positive feedback in kidneys lacking Cx40 in renin-producing cells. Thus, our findings show that endothelial Cx40 is not essential for the control of renin expression and/or release. Cx40 in renin-producing cells is required for their correct positioning in the juxtaglomerular area and the control of renin secretion by pressure.
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Affiliation(s)
- Charlotte Wagner
- Physiologisches Institut der Universität Regensburg, Regensburg, Germany
| | - Alexander Jobs
- Physiologisches Institut der Universität zu Lübeck, Lübeck, Germany
| | - Frank Schweda
- Physiologisches Institut der Universität Regensburg, Regensburg, Germany
| | - Lisa Kurtz
- Klinik und Poliklinik II für Innere Medizin der Universität Regensburg, Regensburg, Germany
| | - Birguel Kurt
- Physiologisches Institut der Universität Regensburg, Regensburg, Germany
| | - Maria L. Sequeira Lopez
- Department of Pediatrics and Internal Medicine, University of Virginia at Charlottesville, Charlottesville, Virginia, USA
| | - R. Ariel Gomez
- Department of Pediatrics and Internal Medicine, University of Virginia at Charlottesville, Charlottesville, Virginia, USA
| | - Toon A.B. van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Cor de Wit
- Physiologisches Institut der Universität zu Lübeck, Lübeck, Germany
| | - Armin Kurtz
- Physiologisches Institut der Universität Regensburg, Regensburg, Germany
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50
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Mathar I, Vennekens R, Meissner M, Kees F, Van der Mieren G, Camacho Londoño JE, Uhl S, Voets T, Hummel B, van den Bergh A, Herijgers P, Nilius B, Flockerzi V, Schweda F, Freichel M. Increased catecholamine secretion contributes to hypertension in TRPM4-deficient mice. J Clin Invest 2010; 120:3267-79. [PMID: 20679729 DOI: 10.1172/jci41348] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 06/23/2010] [Indexed: 11/17/2022] Open
Abstract
Hypertension is an underlying risk factor for cardiovascular disease. Despite this, its pathogenesis remains unknown in most cases. Recently, the transient receptor potential (TRP) channel family was associated with the development of several cardiovascular diseases linked to hypertension. The melastatin TRP channels TRPM4 and TRPM5 have distinct properties within the TRP channel family: they form nonselective cation channels activated by intracellular calcium ions. Here we report the identification of TRPM4 proteins in endothelial cells, heart, kidney, and chromaffin cells from the adrenal gland, suggesting that they have a role in the cardiovascular system. Consistent with this hypothesis, Trpm4 gene deletion in mice altered long-term regulation of blood pressure toward hypertensive levels. No changes in locomotor activity, renin-angiotensin system function, electrolyte and fluid balance, vascular contractility, and cardiac contractility under basal conditions were observed. By contrast, inhibition of ganglionic transmission with either hexamethonium or prazosin abolished the difference in blood pressure between Trpm4-/- and wild-type mice. Strikingly, plasma epinephrine concentration as well as urinary excretion of catecholamine metabolites were substantially elevated in Trpm4-/- mice. In freshly isolated chromaffin cells, lack of TRPM4 was shown to cause markedly more acetylcholine-induced exocytotic release events, while neither cytosolic calcium concentration, size, nor density of vesicles were different. We therefore conclude that TRPM4 proteins limit catecholamine release from chromaffin cells and that this contributes to increased sympathetic tone and hypertension.
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Affiliation(s)
- Ilka Mathar
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, Homburg, Germany
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