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Birukov A, Jørgensen JS, Andersen LB, Herse F, Kitlen G, Golic M, Haase N, Kräker K, Kyhl HB, Müller DN, Andersen MS, Dechend R, Jensen BL. Aldosterone as independent predictor of placental and birth weights: Odense child cohort Study. Geburtshilfe Frauenheilkd 2018. [DOI: 10.1055/s-0038-1671178] [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: 10/28/2022] Open
Affiliation(s)
- A Birukov
- Experimental and Clinical Research Center, Charité Universitätsmedizin und Max-Delbrück-Center für Molekulare Medizin, Berlin, Deutschland
| | - JS Jørgensen
- Odense University Hospital, Department of Obstetrics and Gynecology, Odense, Dänemark
| | - LB Andersen
- Herlev Hospital, Department of Obstetrics and Gynecology, Copenhagen, Dänemark
| | - F Herse
- Experimental and Clinical Research Center, Charité Universitätsmedizin und Max-Delbrück-Center für Molekulare Medizin, Berlin, Deutschland
| | - G Kitlen
- Institute for Molecular Medicine, University of Southern Denmark, Odense, Dänemark
| | - M Golic
- Experimental and Clinical Research Center, Charité Universitätsmedizin und Max-Delbrück-Center für Molekulare Medizin, Berlin, Deutschland
| | - N Haase
- Experimental and Clinical Research Center, Charité Universitätsmedizin und Max-Delbrück-Center für Molekulare Medizin, Berlin, Deutschland
| | - K Kräker
- Experimental and Clinical Research Center, Charité Universitätsmedizin und Max-Delbrück-Center für Molekulare Medizin, Berlin, Deutschland
| | - HB Kyhl
- Odense University Hospital, Hans Christian Andersen Children's Hospital, Odense, Dänemark
| | - DN Müller
- Experimental and Clinical Research Center, Charité Universitätsmedizin und Max-Delbrück-Center für Molekulare Medizin, Berlin, Deutschland
| | - MS Andersen
- Odense University Hospital, Department of Endocrinology, Odense, Dänemark
| | - R Dechend
- Experimental and Clinical Research Center, Charité Universitätsmedizin und Max-Delbrück-Center für Molekulare Medizin, Berlin, Deutschland
| | - BL Jensen
- Institute for Molecular Medicine, University of Southern Denmark, Odense, Dänemark
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Kräker K, Golic M, O'Driscoll JM, Herse F, Birukov A, Verlohren S, Thilaganathan B, Müller DN, Dechend R, Haase N. Alterations in cardiac structure and function caused by preeclampsia. Geburtshilfe Frauenheilkd 2018. [DOI: 10.1055/s-0038-1671438] [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: 10/28/2022] Open
Affiliation(s)
- K Kräker
- Max Delbrück Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin, Deutschland
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
- Berlin Institute of Health (BIH), Berlin, Deutschland
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Berlin, Deutschland
| | - M Golic
- Max Delbrück Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin, Deutschland
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
- Berlin Institute of Health (BIH), Berlin, Deutschland
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Berlin, Deutschland
| | - JM O'Driscoll
- St George's Healthcare NHS Trust, London, Vereinigtes Königreich
| | - F Herse
- Max Delbrück Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin, Deutschland
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
- Berlin Institute of Health (BIH), Berlin, Deutschland
| | - A Birukov
- Max Delbrück Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin, Deutschland
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Berlin, Deutschland
| | - S Verlohren
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
| | - B Thilaganathan
- St George's Healthcare NHS Trust, London, Vereinigtes Königreich
| | - DN Müller
- Max Delbrück Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin, Deutschland
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
- Berlin Institute of Health (BIH), Berlin, Deutschland
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Berlin, Deutschland
| | - R Dechend
- Max Delbrück Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin, Deutschland
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
- Berlin Institute of Health (BIH), Berlin, Deutschland
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Berlin, Deutschland
- HELIOS Klinikum Berlin-Buch, Berlin, Deutschland
| | - N Haase
- Max Delbrück Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin, Deutschland
- Charité – Universitätsmedizin Berlin, Berlin, Deutschland
- Berlin Institute of Health (BIH), Berlin, Deutschland
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Berlin, Deutschland
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Przybyl L, Golic M, Haase N, Rugor J, Solano ME, Arck PC, Gauster M, Huppertz B, Stoppe C, Bernhagen J, Peetz D, Staff AC, Müller DN, Dechend R, Herse F. Verminderte CD74-Expression und gestörte Makrophagen-Trophoblasten Interaktion in der Präeklampsie. Geburtshilfe Frauenheilkd 2016. [DOI: 10.1055/s-0036-1593043] [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: 10/20/2022] Open
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Golic M, Haase N, Herse F, Wehner A, Pijnenborg R, Vercruysse L, Luft F, Alnaes-Katjavivi P, Staff AC, Henrich W, Verlohren S, Müller DN, Dechend R. Natural killer cell reduction induces uteroplacental vasculopathy and fetal growth restriction in wild type rats. Geburtshilfe Frauenheilkd 2016. [DOI: 10.1055/s-0036-1592911] [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: 10/20/2022] Open
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Golic M, Bittner C, Wehner A, Plehm R, Alenina N, Henrich W, Müller DN, Bader M, Dechend R. Kontinuierliche telemetrische Blutzuckermessung in Ratten ermöglicht die Detektion einer erhöhten Amplitude im Tag- und Nachtrhythmus diabetischer Ratten. DIABETOL STOFFWECHS 2015. [DOI: 10.1055/s-0035-1549716] [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: 10/23/2022]
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Golic M, Wehner A, Alenina N, Pijnenborg R, Vercruysse L, Verlohren S, Henrich W, Müller DN, Bader M, Dechend R. Reduktion der Trophoblastenzellinvasion durch Diabetes mellitus: Histologische Evaluation der uteroplazentaren Einheit in einem neuen Rattenmodell für Insulinresistenz. Geburtshilfe Frauenheilkd 2014. [DOI: 10.1055/s-0034-1388592] [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: 10/24/2022] Open
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Golic M, Wehner A, Halle S, Pijnenborg R, Vercruysse L, Alenina N, Müller DN, Bader M, Dechend R. Neues Rattenmodell ermöglicht Einblicke in die fetale Insulinresistenz bei maternalem Diabetes während der Schwangerschaft. DIABETOL STOFFWECHS 2014. [DOI: 10.1055/s-0034-1374859] [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: 10/25/2022]
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Herse F, Searle J, Vollert JO, Slagman A, Mueller C, Müller DN, Möckel M, Dechend R. Heparin Strongly Induces Soluble Fms-Like Tyrosine Kinase 1 (sFlt1) Release in vivo and in vitro. Geburtshilfe Frauenheilkd 2013. [DOI: 10.1055/s-0033-1347752] [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: 10/26/2022] Open
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Kusch A, Hoff U, Bubalo G, Zhu Y, Fechner M, Schmidt-Ullrich R, Marko L, Müller DN, Schmidt-Ott KM, Gürgen D, Blum M, Schunck WH, Dragun D. Novel signalling mechanisms and targets in renal ischaemia and reperfusion injury. Acta Physiol (Oxf) 2013; 208:25-40. [PMID: 23432924 DOI: 10.1111/apha.12089] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 11/26/2012] [Accepted: 02/14/2013] [Indexed: 12/16/2022]
Abstract
Acute kidney injury (AKI) induced by ischaemia and reperfusion (I/R) injury is a common and severe clinical problem. Vascular dysfunction, immune system activation and tubular epithelial cell injury contribute to functional and structural deterioration. The search for novel therapeutic interventions for I/R-induced AKI is a dynamic area of experimental research. Pharmacological targeting of injury mediators and corresponding intracellular signalling in endothelial cells, inflammatory cells and the injured tubular epithelium could provide new opportunities yet may also pose great translational challenge. Here, we focus on signalling mediators, their receptors and intracellular signalling pathways which bear potential to abrogate cellular processes involved in the pathogenesis of I/R-induced AKI. Sphingosine 1 phosphate (S1P) and its respective receptors, cytochrome P450 (CYP450)-dependent vasoactive eicosanoids, NF-κB- and protein kinase-C (PKC)-related pathways are representatives of such 'druggable' pleiotropic targets. For example, pharmacological agents targeting S1P and PKC isoforms are already in clinical use for treatment for autoimmune diseases and were previously subject of clinical trials in kidney transplantation where I/R-induced AKI occurs as a common complication. We summarize recent in vitro and in vivo experimental studies using pharmacological and genomic targeting and highlight some of the challenges to clinical application of these advances.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - M. Blum
- Max-Delbrück Center for Molecular Medicine; Berlin; Germany
| | - W.-H. Schunck
- Max-Delbrück Center for Molecular Medicine; Berlin; Germany
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Singer E, Markó L, Paragas N, Barasch J, Dragun D, Müller DN, Budde K, Schmidt-Ott KM. Neutrophil gelatinase-associated lipocalin: pathophysiology and clinical applications. Acta Physiol (Oxf) 2013; 207:663-72. [PMID: 23375078 DOI: 10.1111/apha.12054] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 11/13/2012] [Accepted: 12/06/2012] [Indexed: 12/22/2022]
Abstract
Neutrophil gelatinase-associated lipocalin (NGAL), a 25 kDa protein produced by injured nephron epithelia, is one of the most promising new markers of renal epithelial injury. In contrast to serum creatinine and urinary output, which are the measures of kidney function, NGAL is specifically induced in the damaged nephron and then released into blood and urine, where it can be readily measured. Careful proof-of-concept studies using defined animal models have uncovered the sources and trafficking of NGAL in acute kidney injury (AKI) and have addressed the contributions of renal and non-renal sources. Clinical studies indicate that NGAL, unlike creatinine, is a marker responsive to tissue stress and nephron injury, but less so to adaptive hemodynamic responses. In certain clinical settings, NGAL is an earlier marker compared with serum creatinine. In addition, clinical studies have shown that NGAL is a powerful predictor of poor clinical outcomes, which can be used to risk stratify patients when combined with serum creatinine. NGAL has important limitations, including its responsiveness in systemic inflammation, which is partially uncoupled from its response to kidney injury and which needs to be considered when interpreting NGAL results clinically. This review covers the biology and pathophysiology of NGAL and summarizes the results of the growing body of clinical studies that have addressed the utility of NGAL in the early diagnosis of AKI, in the distinction of intrinsic AKI and in the prognostic assessment of broad patient populations.
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Affiliation(s)
- E. Singer
- Department of Nephrology; Campus Mitte; Charité - Universitätsmedizin Berlin; Berlin; Germany
| | - L. Markó
- Experimental and Clinical Research Center; a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine; Berlin; Germany
| | - N. Paragas
- Department of Medicine; Columbia University College of Physicians and Surgeons; New York; NY; USA
| | - J. Barasch
- Department of Medicine; Columbia University College of Physicians and Surgeons; New York; NY; USA
| | - D. Dragun
- Department of Nephrology and Intensive Care Medicine Campus Virchow Klinikum; Charité - Universitätsmedizin Berlin; Berlin; Germany
| | - D. N. Müller
- Experimental and Clinical Research Center; a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine; Berlin; Germany
| | - K. Budde
- Department of Nephrology; Campus Mitte; Charité - Universitätsmedizin Berlin; Berlin; Germany
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Machnik A, Neuhofer W, Jantsch J, Dahlmann A, Tammela T, Machura K, Park JK, Beck FX, Müller DN, Derer W, Goss J, Ziomber A, Dietsch P, Wagner H, van Rooijen N, Kurtz A, Hilgers KF, Alitalo K, Eckardt KU, Luft FC, Kerjaschki D, Titze J. New Approaches to Pathogenesis and Management of Hypertension. Clin J Am Soc Nephrol 2009. [DOI: 10.2215/01.cjn.0000927080.23541.88] [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: 03/29/2023]
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12
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Ritz E, Krum H, Wang Y, Machnik A, Schlaich M, Whitbourn R, Sobotka PA, Sadowski J, Bartus K, Kapelak B, Walton A, Sievert H, Thambar S, Abraham WT, Esler M, Tsun Z, Neuhofer W, Jantsch J, Dahlmann A, Tammela T, Machura K, Park JK, Beck FX, Müller DN, Derer W, Goss J, Ziomber A, Dietsch P, Wagner H, van Rooijen N, Kurtz A, Hilgers KF, Alitalo K, Eckardt KU, Luft FC, Kerjaschki D, Titze J. New Approaches to Pathogenesis and Management of HypertensionCatheter-based renal sympathetic denervation for resistant hypertension: A multicenter safety and proof-of-principle cohort study. Lancet 373: 1275–1281, 2009Klotho gene delivery prevents the progression of spontaneous hypertension and renal damage. Hypertension 54: 810–817, 2009Macrophages regulate salt-dependent volume and blood pressure by a vascular endothelial growth factor-C-dependent buffering mechanisms. Nat Med 15: 545–552, 2009. Clin J Am Soc Nephrol 2009; 4:1886-91. [DOI: 10.2215/cjn.07561009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Dechend R, Derer W, Müller DN. [Fixed-dose combinations in antihypertensive treatment: is it necessary to examine the effectiveness of each component?]. MMW Fortschr Med 2009; 151:46-47. [PMID: 19960726] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- R Dechend
- Klinik für Kardiologie/ Franz-Volhard-Klinik HELIOS Klinikum Berlin-Buch.
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14
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Schmid M, Sollwedel A, Thuere C, Wafula PO, Zenclussen ML, Müller DN, Gratze P, Woiciechowsky C, Volk HD, Zenclussen AC. Murine Pre-Eclampsia Induced by Unspecific Activation of the Immune System Correlates with Alterations in the eNOS and AT1 Receptor Expression in the Kidneys and Placenta. Placenta 2007; 28:688-700. [PMID: 17129602 DOI: 10.1016/j.placenta.2006.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [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] [Received: 07/12/2006] [Revised: 10/12/2006] [Accepted: 10/14/2006] [Indexed: 11/17/2022]
Abstract
It remains arguable if an animal model can be of use in pre-eclampsia (PE) studies, as it is clearly a human disease not observed spontaneously in other species. The aim of this study was to investigate whether PE-like signs in mice inoculated with activated Th1 cells were accompanied by abnormal expression of molecules related to the regulation of blood pressure, viz. nitric oxide synthase enzymes (eNOS and iNOS) and angiotensin (Ang) II receptors (AT1R and AT2R), in order to analyse the relevance of this model for human disease. In this model, C57/BL6-mated BALB/c females received lymphocytes crosslined with anti-CD3 and cultured with interleukin (IL)-2 and IL-12 to mimic PE pathology. Control mice received PBS. eNOS, iNOS and AT1R but not AT2R expression was augmented in the kidneys of PE-mice compared with control pregnant mice. The expression of eNOS but not of iNOS was augmented at the fetal-maternal interface of PE-mice as compared with the controls. NOSs regulate the synthesis of NO, a blood pressure and parturition mediator. As its expression is increased in PE patients, our data suggest that the Th1 cells-induced signs in this model are due to similar mechanisms as in humans. AT1R and AT2R mediate the effect of Ang II, and particularly the AT1R appears to be involved in the pathogenesis of human PE. The increased AT1R expression in the kidneys of PE-mice reinforces the theory that Th1 cells elicit a pathological situation closely resembling the human PE. All together, our data support the use of this animal model to study mechanisms underlying clinically overt PE.
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MESH Headings
- Adoptive Transfer
- Animals
- Disease Models, Animal
- Female
- Immune System
- Kidney/chemistry
- Kidney/metabolism
- Kidney/pathology
- Mice/immunology
- Mice, Inbred Strains
- Nitric Oxide Synthase Type II/analysis
- Nitric Oxide Synthase Type II/genetics
- Nitric Oxide Synthase Type II/metabolism
- Nitric Oxide Synthase Type III/analysis
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- Placenta/chemistry
- Placenta/metabolism
- Placenta/pathology
- Pre-Eclampsia/immunology
- Pregnancy
- RNA, Messenger/metabolism
- Receptor, Angiotensin, Type 1/analysis
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 2/analysis
- Receptor, Angiotensin, Type 2/metabolism
- Th1 Cells/immunology
- Th1 Cells/transplantation
- Up-Regulation
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Affiliation(s)
- M Schmid
- Institute of Medical Immunology, Charité, Medical University of Berlin, Berlin, Germany
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Müller DN, Fiebeler A, Park JK, Dechend R, Luft FC. Angiotensin II and endothelin induce inflammation and thereby promote hypertension-induced end-organ damage. Clin Nephrol 2003; 60 Suppl 1:S2-12. [PMID: 12940529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Angiotensin (Ang) II and endothelin (ET-1) can both be regulated by NF-kappaB. They are, to variable degrees, also capable of activating NF-kappaB and increase the expression of NF-kappaB-dependent genes. Ang II-related vascular effects are in part mediated by ET-1. Nitric oxide synthase inhibition facilitates Ang II-related effects, which can be inhibited both by AT1-receptor blockers and by endothelin system inhibitors. This state-of-affairs supports the notion that a combined therapeutic strategy of inhibiting Ang II and ET-1 generation or blocking their effects at the receptor level would be superior to either strategy alone. Animal studies are encouraging but not without conflicting results. Angiotensin-converting enzyme inhibitors and AT1-receptor blockers have a superb track record in experimental animal models and in a host of clinical studies. Selective and nonselective blockers of the ET-1 receptors are important research tools and are also undergoing clinical trials. Inhibitors of the endothelin-converting enzyme have been developed. The recent elucidation of the endothelin-converting enzyme's physical structure should facilitate the development of still more novel compounds to inhibit ET-1 generation. We have recently engendered supportive evidence in this regard.
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Affiliation(s)
- D N Müller
- HELIOS Klinikum-Berlin, Medical Faculty of the Charitè, Humboldt University of Berlin, Germany
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Affiliation(s)
- D N Müller
- Franz Volhard Clinic and Max Delbrück Center for Molecular Medicine, Medical Faculty of the Charité, Humboldt University of Berlin, Germany
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Müller DN, Dechend R, Fiebeler A, Park JK, Haller H, Luft FC. Angiotensin-induced inflammation and novel approaches to treatment. Adv Nephrol Necker Hosp 2002; 31:89-103. [PMID: 11692473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
In a brief period, we have accrued a new view of Ang II. From conventional signaling pathways, our attention was directed toward signal transduction involving specific tyrosine kinases, inducing not only vasocontriction but also proto-oncogene expression, protein synthesis, hypertrophy and growth. More recently, our attention has been directed beyond these effects to inflammatory reactions involving NF-kappa B activation and related gene expression. The mechanisms are not known for certain but probably initially involve the generation of ROS. The subsequent NF-kappa B activation probably involves participation of endothelin signaling and, perhaps, NF-AT3 activation. It is possible that other compounds can also modulate Ang II-induced inflammatory responses.
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Affiliation(s)
- D N Müller
- Max Delbrück Center for Molecular Medicine, Medical Faculty of the Charité, Humboldt University of Berlin
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Bader M, Peters J, Baltatu O, Müller DN, Luft FC, Ganten D. Tissue renin-angiotensin systems: new insights from experimental animal models in hypertension research. J Mol Med (Berl) 2001; 79:76-102. [PMID: 11357942 DOI: 10.1007/s001090100210] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Renin was first isolated in the kidney by Tigerstedt and Bergman over 100 years ago. Almost 50 additional years were necessary to isolate the renin substrate angiotensinogen and to show its cleavage to angiotensin (Ang). Further studies were then needed to demonstrate that Ang I is converted via an angiotensin-converting enzyme to Ang II. The circulating renin-angiotensin system, with blood pressure regulatory and aldosterone stimulatory roles, served well for decades. However, more recent information on Ang II and its action in terms of cell proliferation, hypertrophy, and hyperplasia as well as immune-modulatory and even intracellular functions, have focused attention on local Ang II generation and effects. These investigations necessarily began in the kidney, but quickly moved to other organs including the brain, heart, adrenal gland, and vessel wall and formed the basis for the concept of independent tissue renin-angiotensin systems. Both renin and Ang II have even been implicated in intracellular activities. This review presents some selected aspects of the historical development of this concept and summarizes discoveries relying primarily on animal models which demonstrate that Ang II is generated locally and acts in tissues as a local peptidergic system. Comprehensiveness in such an endeavor is not possible. We focus largely on work from our own group, not because the work is necessarily worthy of such scrutiny but rather because of our own familiarity with the contents.
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Affiliation(s)
- M Bader
- Max Delbrück Center for Molecular Medicine and Franz Volhard Clinic, Berlin-Buch, Germany.
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Hilgers KF, Veelken R, Müller DN, Kohler H, Hartner A, Botkin SR, Stumpf C, Schmieder RE, Gomez RA. Renin uptake by the endothelium mediates vascular angiotensin formation. Hypertension 2001; 38:243-8. [PMID: 11509484 DOI: 10.1161/01.hyp.38.2.243] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We investigated the role of the vascular endothelium in the local production of angiotensin. Angiotensin release from isolated rat hindquarters perfused with an artificial medium was measured by high-performance liquid chromatography and radioimmunoassay. Perfused hindquarters with endothelium released angiotensin I spontaneously, indicating ongoing renin-angiotensinogen reaction. Endothelium denudation (by a detergent, validated by electron microscopy and by the absence of a vasodilator response to acetylcholine) reduced angiotensin I release by >90%, whereas bilateral nephrectomy 24 hours before perfusion abolished the release completely. Infusion of renin into perfused hindquarters induced sustained local angiotensin I release in the presence of an intact endothelium but not after endothelium denudation. The conversion of angiotensin I to angiotensin II was abrogated by endothelium denudation, whereas the disappearance of angiotensin II was unchanged. Endothelium denudation diminished the pressor response to angiotensin II but abolished the response to renin and angiotensin I. Expression of renin messenger RNA, investigated by reverse-transcription polymerase chain reaction using 4 different primer combinations, was not detected in up to 5 microg vascular RNA, whereas a renin signal was readily detected with 5 ng kidney RNA. The effects of endothelium destruction on Ang I formation support the notion that the endothelium mediates vascular angiotensin formation by taking up renin.
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Affiliation(s)
- K F Hilgers
- Department of Medicine-Nephrology, University of Erlangen-Nürnberg, Erlangen, Germany.
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Märki HP, Binggeli A, Bittner B, Bohner-Lang V, Breu V, Bur D, Coassolo PH, Clozel JP, D'Arcy A, Doebeli H, Fischli W, Funk CH, Foricher J, Giller T, Grüninger F, Guenzi A, Güller R, Hartung T, Hirth G, Jenny CH, Kansy M, Klinkhammer U, Lave T, Lohri B, Luft FC, Mervaala EM, Müller DN, Müller M, Montavon F, Oefner CH, Qiu C, Reichel A, Sanwald-Ducray P, Scalone M, Schleimer M, Schmid R, Stadler H, Treiber A, Valdenaire O, Vieira E, Waldmeier P, Wiegand-Chou R, Wilhelm M, Wostl W, Zell M, Zell R. Piperidine renin inhibitors: from leads to drug candidates. ACTA ACUST UNITED AC 2001; 56:21-7. [PMID: 11347960 DOI: 10.1016/s0014-827x(01)01004-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Non-peptidomimetic renin inhibitors of the piperidine type represent a novel structural class of compounds potentially free of the drawbacks seen with peptidomimetic compounds so far. Synthetic optimization in two structural series focusing on improvement of potency, as well as on physicochemical properties and metabolic stability, has led to the identification of two candidate compounds 14 and 23. Both display potent and long-lasting blood pressure lowering effects in conscious sodium-depleted marmoset monkeys and double transgenic rats harboring both the human angiotensinogen and the human renin genes. In addition, 14 normalizes albuminuria and kidney tissue damage in these rats when given over a period of 4 weeks. These data suggest that treatment of chronic renal failure patients with a renin inhibitor might result in a significant improvement of the disease status.
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Affiliation(s)
- H P Märki
- Pharma Research, F. Hoffmann-La Roche Ltd, Berlin, Germany.
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21
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Fiebeler A, Schmidt F, Müller DN, Park JK, Dechend R, Bieringer M, Shagdarsuren E, Breu V, Haller H, Luft FC. Mineralocorticoid receptor affects AP-1 and nuclear factor-kappab activation in angiotensin II-induced cardiac injury. Hypertension 2001; 37:787-93. [PMID: 11230374 DOI: 10.1161/01.hyp.37.2.787] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aldosterone is implicated in cardiac hypertrophy and fibrosis. We tested the role of the mineralocorticoid receptor in a model of angiotensin II-induced cardiac injury. We administered spironolactone (SPIRO; 20 mg. kg(-1). d(-1)), valsartan (VAL; 10 mg. kg(-1). d(-1)), or vehicle to rats double transgenic for the human renin and angiotensinogen genes (dTGR). We investigated basic fibroblast growth factor (bFGF), platelet-derived growth factor, transforming growth factor-beta(1), and the transcription factors AP-1 and nuclear factor (NF)-kappaB. We used immunohistochemistry, electrophoretic mobility shift assays, and TaqMan RT-PCR. Untreated dTGR developed hypertension, cardiac hypertrophy, vasculopathy, and fibrosis with a 50% mortality rates at 7 weeks. SPIRO and VAL prevented death and reversed cardiac hypertrophy, while only VAL normalized blood pressure. Both drugs prevented vasculopathy. bFGF was markedly upregulated in dTGR, whereas platelet-derived growth factor-B and transforming growth factor-beta(1) were little changed. VAL and SPIRO suppressed this upregulation. Both AP-1 and NF-kappaB were activated in dTGR compared with controls. VAL and SPIRO reduced both transcription factors and reduced bFGF, collagen I, fibronectin, and laminin in the interstitium. These findings show that aldosterone promotes hypertrophy, cardiac remodeling, and fibrosis, independent of blood pressure. The effects involve AP-1, NF-kappaB, and bFGF. Mineralocorticoid receptor blockade downregulates these effectors and reduces angiotensin II-induced cardiac damage.
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Affiliation(s)
- A Fiebeler
- Franz Volhard Clinic and Max Delbrück Center, Medical Faculty of the Charité, Humboldt University of Berlin, Germany
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22
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Mervaala EM, Cheng ZJ, Tikkanen I, Lapatto R, Nurminen K, Vapaatalo H, Müller DN, Fiebeler A, Ganten U, Ganten D, Luft FC. Endothelial dysfunction and xanthine oxidoreductase activity in rats with human renin and angiotensinogen genes. Hypertension 2001; 37:414-8. [PMID: 11230310 DOI: 10.1161/01.hyp.37.2.414] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We examined whether xanthine oxidoreductase (XOR), a hypoxia-inducible enzyme capable of generating reactive oxygen species, is involved in the onset of angiotensin (Ang) II-induced vascular dysfunction in double-transgenic rats (dTGR) harboring human renin and human angiotensinogen genes. In 7-week-old hypertensive dTGR, the endothelium-mediated relaxation of noradrenaline (NA)-precontracted renal arterial rings to acetylcholine (ACh) in vitro was markedly impaired compared with Sprague Dawley rats. Preincubation with superoxide dismutase (SOD) improved the endothelium-dependent vascular relaxation, indicating that in dTGR, endothelial dysfunction is associated with increased superoxide formation. Preincubation with the XOR inhibitor oxypurinol also improved endothelium-dependent vascular relaxation. The endothelium-independent relaxation to sodium nitroprusside was similar in both strains. In dTGR, serum 8-isoprostaglandin F(2alpha), a vasoconstrictor and antinatriuretic arachidonic acid metabolite produced by oxidative stress, was increased by 100%, and the activity of XOR in the kidney was increased by 40%. Urinary nitrate plus nitrite (NO(x)) excretion, a marker of total body NO generation, was decreased by 85%. Contractile responses of renal arteries to Ang II, endothelin-1 (ET-1), and NA were decreased in dTGR, suggesting hypertension-associated generalized changes in the vascular function rather than a receptor-specific desensitization. Valsartan (30 mg/kg PO for 3 weeks) normalized blood pressure, endothelial dysfunction, and the contractile responses to ET-1 and NA. Valsartan also normalized serum 8-isoprostaglandin F(2alpha) levels, renal XOR activity, and, to a degree, NO(x) excretion. Thus, overproduction of Ang II in dTGR induces pronounced endothelial dysfunction, whereas the sensitivity of vascular smooth muscle cells to nitric oxide is unaltered. Ang II-induced endothelial dysfunction is associated with increased oxidative stress and vascular xanthine oxidase activity.
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Affiliation(s)
- E M Mervaala
- Institute of Biomedicine, Department of Pharmacology and Toxicology, Department of Medical Chemistry, University of Helsinki, Helsinki, Finland.
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23
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Park JK, Müller DN, Mervaala EM, Dechend R, Fiebeler A, Schmidt F, Bieringer M, Schäfer O, Lindschau C, Schneider W, Ganten D, Luft FC, Haller H. Cerivastatin prevents angiotensin II-induced renal injury independent of blood pressure- and cholesterol-lowering effects. Kidney Int 2000; 58:1420-30. [PMID: 11012877 DOI: 10.1046/j.1523-1755.2000.00304.x] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Statins are effective in prevention of end-organ damage; however, the benefits cannot be fully explained on the basis of cholesterol reduction. We used an angiotensin II (Ang II)-dependent model to test the hypothesis that cerivastatin prevents leukocyte adhesion and infiltration, induction of inducible nitric oxide synthase (iNOS), and ameliorates end-organ damage. METHODS We analyzed intracellular targets, such as mitogen-activated protein kinase and transcription factor (nuclear factor-kappaB and activator protein-1) activation. We used immunohistochemistry, immunocytochemistry, electrophoretic mobility shift assays, and enzyme-linked immunosorbent assay techniques. We treated rats transgenic for human renin and angiotensinogen (dTGR) chronically from week 4 to 7 with cerivastatin (0.5 mg/kg by gavage). RESULTS Untreated dTGR developed hypertension, cardiac hypertrophy, and renal damage, with a 100-fold increased albuminuria and focal cortical necrosis. dTGR mortality at the age of seven weeks was 45%. Immunohistochemistry showed increased iNOS expression in the endothelium and media of small vessels, infiltrating cells, afferent arterioles, and glomeruli of dTGR, which was greater in cortex than medulla. Phosphorylated extracellular signal regulated kinase (p-ERK) was increased in dTGR; nuclear factor-kappaB and activator protein-1 were both activated. Cerivastatin decreased systolic blood pressure compared with untreated dTGR (147 +/- 14 vs. 201 +/- 6 mm Hg, P < 0.001). Albuminuria was reduced by 60% (P = 0.001), and creatinine was lowered (0.45 +/- 0.01 vs. 0.68 +/- 0.05 mg/dL, P = 0. 003); however, cholesterol was not reduced. Intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression was diminished, while neutrophil and monocyte infiltration in the kidney was markedly reduced. ERK phosphorylation and transcription factor activation were reduced. In addition, in vitro incubation of vascular smooth muscle cells with cerivastatin (0.5 micromol/L) almost completely prevented the Ang II-induced ERK phosphorylation. CONCLUSION Cerivastatin reduced inflammation, cell proliferation, and iNOS induction, which led to a reduction in cellular damage. Our findings suggest that 3-hydroxy-3-methylglutaryl coenzyme (HMG-CoA) reductase inhibition ameliorates Ang II-induced end-organ damage. We suggest that these effects were independent of cholesterol.
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Affiliation(s)
- J K Park
- Franz Volhard Clinic, Medical Faculty of the Charité, Humboldt University of Berlin, Berlin, Germany
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Mervaala E, Müller DN, Schmidt F, Park JK, Gross V, Bader M, Breu V, Ganten D, Haller H, Luft FC. Blood pressure-independent effects in rats with human renin and angiotensinogen genes. Hypertension 2000; 35:587-94. [PMID: 10679502 DOI: 10.1161/01.hyp.35.2.587] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The blood pressure-independent effects of angiotensin II (Ang II) were examined in double transgenic rats (dTGR) harboring human renin and human angiotensinogen genes, in which the end-organ damage is due to the human components of the renin angiotensin system. Triple-drug therapy (hydralazine 80 mg/L, reserpine 5 mg/L, and hydrochlorothiazide 25 mg/L in drinking water) was started immediately after weaning. Triple-drug therapy normalized blood pressure and coronary resistance, only partially prevented cardiac hypertrophy, and had no effect on ratio of renal weight to body weight. Although triple-drug therapy delayed the onset of renal damage, severe albuminuria nevertheless occurred. Semiquantitative scoring of ED-1-positive and MIB-5-positive (nuclear cell proliferation-associated antigen Ki-67) cells showed profound perivascular monocyte/macrophage infiltration and cell proliferation in kidneys and hearts of untreated dTGR. Triple-drug therapy had only a minimal effect on local inflammatory response or vascular cell proliferation. In contrast, a novel orally active human renin inhibitor (HRI), 30 mg/kg by gavage for 4 weeks, normalized blood pressure and coronary resistance and also prevented cardiac hypertrophy and albuminuria. ED-1-positive cells and MIB-5-positive cells were decreased by HRI in hearts and kidneys almost to levels observed in normotensive Sprague-Dawley rats. The renoprotective effects of HRI were at least in part due to improved renal hemodynamics and distal tubular function, since HRI shifted renal pressure-diuresis/natriuresis curves leftward by approximately 35 mm Hg, increased glomerular filtration rate and renal blood flow, and shifted the fractional water and sodium excretion curves leftward. In untreated dTGR, plasma Ang II was increased by 400% and renal Ang II level was increased by 300% compared with Sprague-Dawley rats. HRI decreased plasma human renin activity by 95% and normalized Ang II levels in both plasma and kidney compared with triple-drug therapy. Our findings indicate that in dTGR harboring human renin and angiotensinogen genes, Ang II causes end-organ damage and promotes inflammatory response and cellular growth largely independent of blood pressure.
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Affiliation(s)
- E Mervaala
- Franz Volhard Clinic, Medical Faculty of the Charité, Humboldt University of Berlin, Germany
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25
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Mervaala E, Müller DN, Park JK, Dechend R, Schmidt F, Fiebeler A, Bieringer M, Breu V, Ganten D, Haller H, Luft FC. Cyclosporin A protects against angiotensin II-induced end-organ damage in double transgenic rats harboring human renin and angiotensinogen genes. Hypertension 2000; 35:360-6. [PMID: 10642325 DOI: 10.1161/01.hyp.35.1.360] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Leukocyte infiltration and adhesion molecule activation play a central role in the pathogenesis of angiotensin II (Ang II)-induced end-organ damage in double transgenic rats (dTGR) harboring human renin and angiotensinogen genes. We tested the hypothesis that the immunosuppressive agent cyclosporine (CsA) protects against the Ang II-induced myocardial and renal damage in dTGR. Furthermore, we investigated the influence of CsA on interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) expression and the DNA binding activity of transcription factor necrosis factor-kappaB (NF-kappaB). The 4-week-old rats were divided into 4 groups: (1) control dTGR (n=20), (2) dTGR plus CsA (5 mg/kg SC for 3 weeks, n=15), (3) normotensive Sprague-Dawley (SD) rats (n=10), and (4) SD rats plus CsA (n=8). In dTGR, CsA completely prevented cardiovascular death (0 of 15 versus 9 of 20), decreased 24-hour albuminuria by 90% and systolic blood pressure by 35 mm Hg, and protected against the development of cardiac hypertrophy. Whole blood CsA concentrations 24 hours after the last drug treatment were 850+/-15 ng/mL. Semiquantitative ED-1 and Ki-67 (a nuclear cell proliferation-associated antigen) scoring showed that CsA prevented perivascular monocyte/macrophage infiltration and prevented cell proliferation in the kidneys and hearts of dTGR, respectively. The beneficial effects of CsA were, at least in part, mediated by the suppression of IL-6 and iNOS expression. Electrophoretic mobility shift assay revealed that CsA regulated inflammatory response in part through the NF-kappaB transcriptional pathway. In contrast to dTGR, CsA increased blood pressure in normotensive SD rats by 10 mm Hg and had no effect on cardiac mass or 24-hour urinary albumin excretion. Perivascular monocyte/macrophage infiltration, IL-6, and iNOS expression or cell proliferation were not affected by CsA in SD rats. Our findings indicate that CsA protects against Ang II-induced end-organ damage and underscore the central role of vascular inflammatory response in the pathogenesis of myocardial and renal damage in dTGR. The beneficial effects of CsA in the kidney and heart are mediated, at least in part, by suppression of IL-6 and iNOS expression via NF-kappaB transcriptional pathway.
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Affiliation(s)
- E Mervaala
- Franz Volhard Clinic, Medical Faculty of the Charité, Humboldt University of Berlin, Germany
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26
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Luft FC, Mervaala E, Müller DN, Gross V, Schmidt F, Park JK, Schmitz C, Lippoldt A, Breu V, Dechend R, Dragun D, Schneider W, Ganten D, Haller H. Hypertension-induced end-organ damage : A new transgenic approach to an old problem. Hypertension 1999; 33:212-8. [PMID: 9931107 DOI: 10.1161/01.hyp.33.1.212] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Angiotensin (Ang) II-induced organ damage has fascinated students of hypertension since the work of Wilson and Byrom. We are investigating a double transgenic rat (dTGR) model, in which rats transgenic for the human angiotensinogen and renin genes are crossed. These rats develop moderately severe hypertension but die of end-organ cardiac and renal damage by week 7. The heart shows necrosis and fibrosis, whereas the kidneys resemble the hemolytic-uremic syndrome vasculopathy. Surface adhesion molecules (ICAM-1 and VCAM-1) are expressed early on the endothelium, while the corresponding ligands are found on circulating leukocytes. Leukocyte infiltration in the vascular wall accompanies PAI-1, MCP-1, and VEGF expression. The expression of TGF-beta and deposition of extracellular matrix proteins follows, which is accompanied by fibrinoid vasculitis in small vessels of the heart and kidneys. Angiotensin-converting enzyme inhibitors and AT1 receptor blockers each lowered blood pressure and shifted pressure natriuresis partially leftward by different mechanisms. When combined, they normalized blood pressure, pressure natriuresis, and protected from vasculopathy completely. Renin inhibition lowered blood pressure partially, but protected from vasculopathy completely. Endothelin receptor blockade had no influence on blood pressure but protected from vasculopathy and improved survival. We show evidence that Ang II stimulates oxidative stress directly or indirectly via endothelin 1 and that NFkappaB is upregulated in this model. We speculate that the transcription factors NFkappaB and AP-1 are involved with initiating chemokine and cytokine expression, leading to the above cascade. The unique model and our pharmacological probes will enable us to test these hypotheses.
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Affiliation(s)
- F C Luft
- Franz Volhard Clinic and Max Delbrück Center for Molecular Medicine, Medical Faculty of the Charité, Humboldt University of Berlin, Germany
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Abstract
The physiological role of prorenin is unknown; however, the possibility that prorenin inhibits renin locally has been suggested. We tested the hypothesis that prorenin may be an endogenous competitor for renin uptake in the tissue. We also investigated whether prorenin can be activated to active renin and affect mean arterial pressure (MAP). Isolated perfused hindquarters of rats transgenic for human angiotensinogen were infused with human renin and/or prorenin. The plateau phase of angiotensin (Ang) I release 15 minutes after cessation of infusions was used as a parameter for renin uptake. Renin (10 ng/mL for 15 minutes) caused sustained release of Ang I (153+/-16 fmol/mL). Coinfusion with a 15-fold excess of prorenin did not affect local Ang I formation (153+/-19 fmol/mL). Prorenin infusion alone showed no activation to active renin. In addition, we investigated MAP and plasma Ang II levels after injection of saline (DeltaMAP, -1+/-2 mm Hg; 40+/-5 fmol/mL Ang II), 9 ng renin (DeltaMAP, +37+/-3 mm Hg; 378+/-39 fmol/mL), and 144 ng prorenin (DeltaMAP, +10+/-5 mm Hg; 61+/-5 fmol/mL) and the coinjection of renin and prorenin (DeltaMAP, +41+/-4 mm Hg; 305+/-23 fmol/mL) in anesthetized rats. The data show that prorenin was not activated to active renin and did not affect MAP in short-term experiments. Renin-induced Ang formation was not affected by prorenin. Renin may have been taken up specifically because of its physical and chemical properties or because of nonspecific sequestration in the extravascular space. We conclude that prorenin does not act as an endogenous antagonist for the long-lasting effects of renin in the vascular wall. Moreover, prorenin does not affect acute renin-related effects on blood pressure.
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Affiliation(s)
- D N Müller
- Franz Volhard Clinic at the Max Delbrück Center for Molecular Medicine, Medical Faculty of the Charité, Humboldt University of Berlin, Germany
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28
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Mervaala EM, Müller DN, Park JK, Schmidt F, Löhn M, Breu V, Dragun D, Ganten D, Haller H, Luft FC. Monocyte infiltration and adhesion molecules in a rat model of high human renin hypertension. Hypertension 1999; 33:389-95. [PMID: 9931135 DOI: 10.1161/01.hyp.33.1.389] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypertension and kidney damage in the double transgenic rat (dTGR) harboring both human renin and human angiotensinogen genes are dependent on the human components of the renin angiotensin system. We tested the hypothesis that monocyte infiltration and increased adhesion molecule expression are involved in the pathogenesis of kidney damage in dTGR. We also evaluated the effects of long-term angiotensin-converting enzyme (ACE) inhibition, AT1 blockade, and human renin inhibition on monocyte recruitment and inflammatory response in dTGR. Systolic blood pressure and 24-hour albuminuria were markedly increased in 7-week-old dTGR as compared with age-matched normotensive Sprague Dawley rats. We found a significant monocyte/macrophage infiltration in the renal perivascular space and increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the interstitium, intima, and adventitia of the small renal vessels. alphaLbeta2 integrin and alpha4beta1 integrin, the corresponding ligands for ICAM-1 and VCAM-1, were also found on infiltrating monocytes/macrophages. The expression of plasminogen activator inhibitor-1 and fibronectin in the kidneys of dTGR were increased and distributed similarly to ICAM-1. In 4-week-old dTGR, long-term treatment with ACE inhibition (cilazapril), AT1 receptor blockade (valsartan), and human renin inhibition (RO 65-7219) (each drug 10 mg/kg by gavage once a day for 3 weeks) completely prevented the development of albuminuria. However, only cilazapril and valsartan were able to decrease blood pressure to normotensive levels. Interestingly, the drugs were all equally effective in preventing monocyte/macrophage infiltration and the overexpression of adhesion molecules, plasminogen activator inhibitor-1, and fibronectin in the kidney. Our findings indicate that angiotensin II causes monocyte recruitment and vascular inflammatory response in the kidney by blood pressure-dependent and blood pressure-independent mechanisms. ACE inhibition, AT1 receptor blockade, and human renin inhibition all prevent monocyte/macrophage infiltration and increased adhesion molecule expression in the kidneys of dTGR.
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Affiliation(s)
- E M Mervaala
- Franz Volhard Clinic, Medical Faculty of the Charite', Humboldt University of Berlin, Germany, FRG
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29
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Abstract
The behavior of the circulating renin-angiotensin system is well known; however, the actions of renin and the generation of angiotensin (ANG) II at the tissue level are less appreciated. We have used rat models to study this issue. We examined the cleavage of human angiotensinogen to ANG I by human renin and its inhibition by a human renin inhibitor in an isolated perfused hindlimb preparation from rats which express the human angiotensinogen gene. With this model, we were able to show that renin acts at the site of the vascular wall, rather than in the lumen, to generate ANG I, which is subsequently converted to ANG II. Furthermore, the cleavage is specifically dependent on renin and not on other lysosomal proteases. The renin gene is present in the vascular wall; however, whether or not renin is generated locally to act locally, or whether renin is taken up from the circulation to act locally was not clear. We used the same strain of transgenic rats to test this issue and showed that renin can be taken up by cardiac or coronary vasculature tissue and induces long-lasting local ANG II generation. Locally formed ANG I was converted to ANG II more effectively than infused ANG I. We did additional studies to examine the conversion step from ANG I to ANG II in the vessel wall. We perfused hindlimbs from Sprague-Dawley rats with ANG I and observed ANG II production, which was linear over a 10,000-fold concentration range of ANG I. However, when we increased angiotensin converting enzyme (ACE) gene expression in the vascular bed, which also increased ACE tissue concentrations, we were nevertheless able to demonstrate increased ANG II production with ACE upregulation. Taken together, these results demonstrate (1) the cleavage of local angiotensinogen to ANG I within the vascular wall by renin, (2) renin uptake from the circulation to evoke that local effect, and (3) a potential regulatory effect by vascular tissue ACE on ANG II production in the vessel wall. The findings support the notion of localized renin-angiotensin system-related effects on vascular function and structure.
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30
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Müller DN, Fischli W, Clozel JP, Hilgers KF, Bohlender J, Ménard J, Busjahn A, Ganten D, Luft FC. Local angiotensin II generation in the rat heart: role of renin uptake. Circ Res 1998; 82:13-20. [PMID: 9440700 DOI: 10.1161/01.res.82.1.13] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [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: 02/05/2023]
Abstract
To elucidate the local effects of renin in the coronary circulation, we examined local angiotensin (Ang) I and II formation, as well as coronary vasoconstriction in response to renin administration, and compared the effects with exogenous infused Ang I. We perfused isolated hearts from rats overexpressing the human angiotensinogen gene in a Langendorff preparation and measured the hemodynamic effects and the released products. We also investigated cardiac Ang I conversion, including the contribution of non-angiotensin-converting enzyme-dependent Ang II-generating pathways. Finally, we studied Ang I conversion in vitro in heart homogenates. Renin and Ang I infusion both generated Ang II. Ang II release and vasoconstriction continued after renin infusion was stopped, even though renin disappeared immediately from the perfusate. In contrast, after Ang I infusion, Ang II release and coronary flow returned to basal levels. Ang I conversion (Ang II/Ang I ratio) was higher after renin infusion (0.109+/-0.027 versus 0.026+/-0.003, 15 minutes, P<.02) compared with infused Ang I. Remikiren added to the renin infusion abolished Ang I and II; captopril suppressed only Ang II, whereas an AT1 receptor blocker did not affect Ang I and II formation. All the drugs prevented renin-induced coronary flow changes. Total cardiac Ang II-forming activity was only partially inhibited by cilazaprilat (4.1+/-0.1 fmol x min(-1) x mg[-1]) and on a larger extent by chymostatin (2.6+/-0.3 fmol x min(-1) x mg[-1]) compared with control values (5.6+/-0.4 fmol x min(-1) x mg[-1]). We conclude that renin can be taken up by cardiac or coronary vascular tissue and induces long-lasting local Ang II generation and vasoconstriction. Locally formed Ang I was converted more effectively than infused Ang I. Furthermore, the comparison of in vivo and in vitro Ang I conversion suggests that in vitro assays may underestimate the functional contribution of angiotensin-converting enzyme to intracardiac Ang II formation.
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Affiliation(s)
- D N Müller
- Franz Volhard Clinic and the Max Delbrück Center for Molecular Medicine, Virchow Klinikum, Humboldt University of Berlin, Germany
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31
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Hilgers KF, Bingener E, Stumpf C, Müller DN, Schmieder RE, Veelken R. Angiotensinases restrict locally generated angiotensin II to the blood vessel wall. Hypertension 1998; 31:368-72. [PMID: 9453330 DOI: 10.1161/01.hyp.31.1.368] [Citation(s) in RCA: 17] [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] [Indexed: 02/06/2023]
Abstract
We tested the hypothesis that angiotensinases limit the spillover of locally formed angiotensin II into the circulation. The release of angiotensin peptides from isolated rat hindquarters perfused with an artificial medium was measured by high-performance liquid chromatography and radioimmunoassay. The spontaneous release of angiotensins was increased by the angiotensinase inhibitors phenanthroline (850+/-195 versus 95+/-33 fmol of angiotensin I per 30 minutes in controls, P<.05, n=5 each) and amastatin (P<.05, n=5 each). Infusion of renin induced sustained local angiotensin I formation, which was also increased by phenanthroline. Stimulation of local angiotensin formation by renin infusion was compared with infusion of exogenous angiotensin II. Renin caused similar increases of perfusion pressure (11.1+/-2.2 versus 7.6+/-1.9 mm Hg after angiotensin II, P>.05) despite lower angiotensin II levels in the venous effluent than during infusion of exogenous angiotensin II (65+/-2 versus 482+/-33 fmol/mL, P<.05, n=7 each). Thus, renin must have caused higher angiotensin II tissue levels than indicated by the measurements in the venous effluent. The pressor response to renin was abolished by the type 1 angiotensin II receptor antagonist losartan. We conclude that the major part of locally generated angiotensins is not released into the circulation but degraded by angiotensinases within the tissue compartment.
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Affiliation(s)
- K F Hilgers
- Department of Medicine IV, University of Erlangen, Germany.
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Müller DN, Bohlender J, Hilgers KF, Dragun D, Costerousse O, Ménard J, Luft FC. Vascular angiotensin-converting enzyme expression regulates local angiotensin II. Hypertension 1997; 29:98-104. [PMID: 9039087 DOI: 10.1161/01.hyp.29.1.98] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We tested the hypothesis that changes in angiotensin-converting enzyme (ACE) gene expression can regulate the rate of local vascular angiotensin II (Ang II) production. We perfused isolated rat hindlimbs with an artificial medium and infused renin and Ang I via the perfusate. Ang I and II were measured by radioimmunoassay. We then increased ACE gene expression and ACE levels in the rat aorta by producing two-kidney, one clip (2K1C) hypertension for 4 weeks. Gene expression was measured by RNAse protection assay, and ACE activity in the vessel wall was measured by the Cushman-Cheung assay. Angiotensin I infusion at 1, 10, 100, and 1000 pmol/mL led to 371 +/- 14 (+/-SEM), 3611 +/- 202, 44,828 +/- 1425, and 431,503 +/- 16,439 fmol/mL Ang II released, respectively, from the hindlimbs (r = .98, P < .001). Thus, the conversion rate did not change across four orders of magnitude, and the system was not saturable under these conditions. In 2K1C hindlimbs, Ang I infusion (0.5 pmol/mL) resulted in increased Ang II generation (157 +/- 16 versus 123 +/- 23 fmol/mL, P = .014 at minute 10) compared with controls. ACE gene expression and ACE activity were increased in 2K1C hindlimbs compared with controls (36 +/- 4 versus 17 +/- 1 mU/mg protein, P < .001). Ang II degradation in the two groups did not differ. To investigate the conversion of locally generated Ang I, we infused porcine renin (0.5 milliunits per mL) into 2K1C and control hindlimbs. Despite markedly higher Ang I release in sham-operated than in 2K1C rats (71 +/- 8 versus 37 +/- 6 pmol/mL, P = .008 at minute 12), Ang II was only moderately increased (36 +/- 3 versus 25 +/- 6 pmol/mL, P = .12 at minute 12). This difference between 2K1C rats and controls reflected a higher rate of conversion in 2K1C rats. Thus, Ang I conversion in the rat hindlimb is linear over a wide range of substrate concentrations and occurs at a fixed relationship. Nevertheless, increased ACE gene expression and ACE activity in the vessel wall lead to an increase in the conversion of Ang I to Ang II. We conclude that local ACE gene expression and ACE activity can influence the local rate of Ang II production.
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Affiliation(s)
- D N Müller
- Franz Volhard Clinic Virchow Klinikum, Humboldt University of Berlin, Germany
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Müller DN, Hilgers KF, Bohlender J, Lippoldt A, Wagner J, Fischli W, Ganten D, Mann JF, Luft FC. Effects of human renin in the vasculature of rats transgenic for human angiotensinogen. Hypertension 1995; 26:272-8. [PMID: 7635534 DOI: 10.1161/01.hyp.26.2.272] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Transgenic rats, which express the human angiotensinogen gene, provide a unique model for studying local vascular effects of human renin. We examined the cleavage of human angiotensinogen to angiotensin I (Ang I) by human renin and its inhibition by a human renin inhibitor in an isolated perfused hindlimb preparation from such rats. Perfusion resulted in the sustained release of human angiotensinogen, which decreased from 19.4 to 11.8 pmol/mL over 45 minutes. Active human renin at doses of 3, 10, and 30 ng/mL perfusate for 15 minutes increased Ang I release from undetectable levels (mean +/- SEM) to 31.9 +/- 3.3, 147.1 +/- 26.2, and 206.4 +/- 17.1 fmol/mL, respectively, by 9 minutes. In separate experiments aimed at the quantification of renin-induced vasoconstriction, captopril decreased the perfusion pressure and lowered Ang II concentrations to nondetectable levels, whereas Ang I values increased sharply. When renin (30 ng/mL) was infused for 15 minutes, renin values in the perfusate decreased to barely detectable levels within minutes after termination of the infusion. However, Ang I values remained high for at least 30 minutes thereafter. The addition of a human renin inhibitor during renin infusion caused Ang I values to promptly decrease within minutes to undetectable levels. Hindlimbs from non-transgenic control rats released no detectable amounts of Ang I, with or without human renin. Finally, by in situ hybridization we documented the presence of human angiotensinogen message in the vessels of the hindlimb. We conclude that renin acts on angiotensinogen at a site in the vascular wall. The cleavage depends on renin and not on other lysosomal proteases.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D N Müller
- Franz Volhard Clinic, Rudolph Virchow University Hospitals, Berlin, Germany
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