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Zhang Y, Ma L, Wu J, Chen T. Hydronephrosis alters cardiac ACE2 and Mas receptor expression in mice. J Renin Angiotensin Aldosterone Syst 2015; 16:267-74. [PMID: 25650385 DOI: 10.1177/1470320314568439] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 12/16/2014] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Hydronephrosis is characterized by substantial loss of tubules and affects renin secretion in the kidney. However, whether alterations of angiotensin-converting enzyme (ACE), ACE2 and Mas receptor in the heart are observed in hydronephrosis is unknown. Thus, we assessed these components in hydronephrotic mice treated with AT1 receptor blockade and ACE inhibitor. MATERIALS AND METHODS Hydronephrosis was induced by left ureteral ligation in Balb/C mice except sham-operated animals. The levels of cardiac ACE, ACE2 and Mas receptor were measured after treatment of losartan or enalapril. RESULTS Hydronephrosis led to an increase of ACE level and a decrease of ACE2 and Mas receptor in the heart. Losartan decreased cardiac ACE level, but ACE2 and Mas receptor levels significantly increased in hydronephrotic mice (p < 0.01). Enalapril increased ACE2 levels (p < 0.01), but did not affect Mas receptor in the heart. Plasma renin activity (PRA) and Ang II decreased in hydronephrotic mice, but significantly increased after treatment with losartan or enalapril. CONCLUSIONS Hydronephrosis increased cardiac ACE and suppressed ACE2 and Mas receptor levels. AT1 blockade caused sustained activation of cardiac ACE2 and Mas receptor, but ACE inhibitor had the limitation of such activation of Mas receptor in hydronephrotic animals.
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Affiliation(s)
- Yanling Zhang
- Department of Physiology, Institute of Neurobiology, Taishan Medical University, China
| | - Lulu Ma
- Department of Physiology, Institute of Neurobiology, Taishan Medical University, China
| | - Junyan Wu
- Department of Physiology, Institute of Neurobiology, Taishan Medical University, China
| | - Tingting Chen
- Department of Physiology, Institute of Neurobiology, Taishan Medical University, China
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Zimmerman DL, Zimpelmann J, Xiao F, Gutsol A, Touyz R, Burns KD. The effect of angiotensin-(1-7) in mouse unilateral ureteral obstruction. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:729-40. [PMID: 25625676 DOI: 10.1016/j.ajpath.2014.11.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 10/27/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022]
Abstract
Angiotensin-(1-7) is a ligand for the Mas receptor and may protect against tissue injury associated with renin-angiotensin system activation. We determined the effects of endogenous or exogenous angiotensin-(1-7) in mice with unilateral ureteral obstruction (UUO). Mice with UUO were treated with or without the angiotensin-(1-7) antagonist A779 or with 6, 24, or 62 μg/kg per hour exogenous angiotensin-(1-7). After 10 days, kidneys were harvested for histology, immunoblots, and measurement of NADPH oxidase. Compared with controls, A779 treatment significantly increased fibronectin, transforming growth factor-β, and α-smooth muscle actin expression in obstructed kidneys and enhanced tubulointerstitial injury, apoptosis, and NADPH oxidase. Unexpectedly, administration of angiotensin-(1-7) to mice with UUO caused injury in obstructed kidneys compared with controls and increased macrophage infiltration. In obstructed kidneys from mice with gene deletion of Mas (Mas(-/-)), apoptosis and macrophage infiltration were increased compared with wild-type mice. Angiotensin-(1-7) (but not A779) further increased apoptosis and macrophage influx in obstructed kidneys from Mas(-/-) mice, compared with untreated Mas(-/-) mice. These data indicate that endogenous angiotensin-(1-7) protects against kidney injury in UUO. In mice with or without the Mas receptor, however, delivery of exogenous angiotensin-(1-7) worsens kidney damage. The results suggest dose-dependent effects of angiotensin-(1-7) in the kidney in UUO, with endogenous angiotensin-(1-7) promoting repair pathways via interaction with Mas and higher amounts exacerbating injury.
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Affiliation(s)
- Danielle L Zimmerman
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Joseph Zimpelmann
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Fengxia Xiao
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Alex Gutsol
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Rhian Touyz
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada; Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kevin D Burns
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
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Furuhashi M, Moniwa N, Mita T, Fuseya T, Ishimura S, Ohno K, Shibata S, Tanaka M, Watanabe Y, Akasaka H, Ohnishi H, Yoshida H, Takizawa H, Saitoh S, Ura N, Shimamoto K, Miura T. Urinary angiotensin-converting enzyme 2 in hypertensive patients may be increased by olmesartan, an angiotensin II receptor blocker. Am J Hypertens 2015; 28:15-21. [PMID: 24842388 DOI: 10.1093/ajh/hpu086] [Citation(s) in RCA: 193] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Angiotensin-converting enzyme 2 (ACE2) is highly expressed in the kidney and converts angiotensin (Ang) II to Ang-(1-7), a renoprotective peptide. Urinary ACE2 has been shown to be elevated in patients with chronic kidney disease. However, the effects of antihypertensive agents on urinary ACE2 remain unclear. METHODS Of participants in the Tanno-Sobetsu cohort study in 2011 (n = 617), subjects on no medication (n = 101) and hypertensive patients treated with antihypertensive agents, including the calcium channel blockers amlodipine and long-acting nifedipine; the ACE inhibitor enalapril; and the Ang II receptor blockers losartan, candesartan, valsartan, telmisartan, and olmesartan, for more than 1 year (n = 100) were enrolled, and urinary ACE2 level was measured. RESULTS Glucose and hemoglobin A1c were significantly higher in patients treated with enalapril, telmisartan or olmesartan than in the control subjects. Urinary albumin-to-creatinine ratio (UACR) was significantly higher in patients treated with enalapril than in the control subjects. Urinary ACE2 level was higher in the olmesartan-treated group, but not the other treatment groups, than in the control group. Urinary ACE2 level was positively correlated with systolic blood pressure (r = 0.211; P = 0.003), UACR (r = 0.367; P < 0.001), and estimated salt intake (r = 0.260; P < 0.001). Multivariable regression analysis after adjustment of age, sex, and the correlated indices showed that the use of olmesartan was an independent predictor of urinary ACE2 level. CONCLUSIONS In contrast with other antihypertensive drugs, olmesartan may uniquely increase urinary ACE2 level, which could potentially offer additional renoprotective effects.
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Affiliation(s)
- Masato Furuhashi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan;
| | - Norihito Moniwa
- Department of Nephrology, Teine Keijinkai Hospital, Sapporo, Japan
| | - Tomohiro Mita
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takahiro Fuseya
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Shutaro Ishimura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Kohei Ohno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Satoru Shibata
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Marenao Tanaka
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yuki Watanabe
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hiroshi Akasaka
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Educational Development, Sapporo Medical University Center for Medical Education, Sapporo, Japan
| | - Hirofumi Ohnishi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Public Health, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hideaki Yoshida
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hideki Takizawa
- Department of Nephrology, Teine Keijinkai Hospital, Sapporo, Japan
| | - Shigeyuki Saitoh
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Nursing, Division of Medical and Behavioral Subjects, Sapporo Medical University School of Health Sciences, Sapporo, Japan
| | | | | | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
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Animal Models with a Genetic Alteration of the ACE2/Ang-(1-7)/Mas Axis. THE PROTECTIVE ARM OF THE RENIN ANGIOTENSIN SYSTEM (RAS) 2015. [PMCID: PMC7150279 DOI: 10.1016/b978-0-12-801364-9.00022-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of this chapter is to describe the animal models generated by transgenic technology for the functional analysis of the protective axis of the renin–angiotensin system, consisting of angiotensin-converting enzyme 2 (ACE2), angiotensin (Ang)-(1-7), and Mas. Transgenic overexpression of the components of this axis in general led to an ameliorated cardiac and vascular damage in disease states and to an improved metabolic profile. Knockout models for ACE2 and Mas, however, show aggravated cardiovascular pathologies and a metabolic syndrome-like state. In particular, the local production of Ang-(1-7) in the vascular wall, in the heart, and in the brain was found to be of high physiological relevance by the use of transgenic animals overexpressing ACE2 or Ang-(1-7) in these tissues.
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Bertoncello N, Moreira RP, Arita DY, Aragão DS, Watanabe IKM, Dantas PS, Santos R, Mattar-Rosa R, Yokota R, Cunha TS, Casarini DE. Diabetic Nephropathy Induced by Increased Ace Gene Dosage Is Associated with High Renal Levels of Angiotensin (1-7) and Bradykinin. J Diabetes Res 2015; 2015:674047. [PMID: 26442284 PMCID: PMC4579315 DOI: 10.1155/2015/674047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 12/09/2014] [Indexed: 01/15/2023] Open
Abstract
Population studies have shown an association between diabetic nephropathy (DN) and insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene (ACE in humans, Ace in mice). The aim was to evaluate the modulation of Ace copies number and diabetes mellitus (DM) on renal RAS and correlate it with indicators of kidney function. Increased number of copies of the Ace gene, associated with DM, induces renal dysfunction. The susceptibility to the development of DN in 3 copies of animals is associated with an imbalance in activity of RAS enzymes leading to increased synthesis of Ang II and Ang-(1-7). Increased concentration of renal Ang-(1-7) appears to potentiate the deleterious effects triggered by Ang II on kidney structure and function. Results also show increased bradykinin concentration in 3 copies diabetic group. Taken together, results indicate that the deleterious effects described in 3 copies diabetic group are, at least in part, due to a combination of factors not usually described in the literature. Thus, the data presented here show up innovative and contribute to understanding the complex mechanisms involved in the development of DN, in order to optimize the treatment of patients with this complication.
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Affiliation(s)
- Nádia Bertoncello
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Roseli Peres Moreira
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Danielle Yuri Arita
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Danielle S. Aragão
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Ingrid Kazue Mizuno Watanabe
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Patricia S. Dantas
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Ralmony Santos
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Rodolfo Mattar-Rosa
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Rodrigo Yokota
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
| | - Tatiana Sousa Cunha
- Science and Technology Department, Federal University of São Paulo, São José dos Campos, SP, Brazil
| | - Dulce Elena Casarini
- Nephrology Division, Department of Medicine, Federal University of São Paulo, Rua Botucatu 740, Vila Clementino, 04023-900 São Paulo, SP, Brazil
- *Dulce Elena Casarini:
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107
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Abe M, Oikawa O, Okada K, Soma M. Urinary angiotensin-converting enzyme 2 increases in diabetic nephropathy by angiotensin II type 1 receptor blocker olmesartan. J Renin Angiotensin Aldosterone Syst 2014; 16:159-64. [PMID: 25287898 DOI: 10.1177/1470320314551443] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 08/17/2014] [Indexed: 01/06/2023] Open
Abstract
INTRODUCTION Angiotensin-converting enzyme 2 (ACE2) is a member of the renin-angiotensin system that degrades angiotensin (Ang) II to the seven-amino acid peptide fragment Ang-(1-7). We evaluated the changes in urinary ACE2 levels in response to treatment with the angiotensin II type 1 receptor blocker olmesartan in diabetes patients with nephropathy. MATERIALS AND METHODS This prospective, open-label, interventional study was conducted with 31 type 2 diabetes patients with nephropathy. After initial evaluation, patients received 20 mg/day olmesartan, which was increased to 40 mg/day over a 24-week period. RESULTS In diabetes patients with chronic kidney disease, olmesartan significantly increased urinary ACE2 levels independently of blood pressure and plasma aldosterone levels and reduced albuminuria, urinary liver-type fatty acid binding protein (L-FABP), and plasma aldosterone levels. Multivariable regression analysis revealed that the change in urinary L-FABP levels was an independent predictor of increased urinary ACE2 levels. CONCLUSION Olmesartan may have the unique effect of increasing urinary ACE2 levels. However, whether this contributes to olmesartan's renoprotective effect must be examined further.
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Affiliation(s)
- Masanori Abe
- Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Osamu Oikawa
- Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Kazuyoshi Okada
- Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Masayoshi Soma
- Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan Division of General Medicine, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan
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Haga S, Tsuchiya H, Hirai T, Hamano T, Mimori A, Ishizaka Y. A novel ACE2 activator reduces monocrotaline-induced pulmonary hypertension by suppressing the JAK/STAT and TGF-β cascades with restored caveolin-1 expression. Exp Lung Res 2014; 41:21-31. [PMID: 25275723 DOI: 10.3109/01902148.2014.959141] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Pulmonary hypertension (PH) is characterized by increased pressure in the pulmonary artery and right ventricular hypertrophy (RVH). Recently, angiotensin-converting enzyme 2 (ACE2), which converts angiotensin (Ang) II into Ang-(1-7), was shown to inhibit experimental PH. Here we identified a novel ACE2 activator and investigated how the compound reduced monocrotaline (MCT)-induced PH. METHODS To induce PH, Sprague-Dawley rats were injected subcutaneously with MCT, followed by the continuous administration of NCP-2454, an ACE2 activator, using osmotic pumps. Pulmonary arterial compliance was monitored every week until 4 weeks post-injection (wpi). RVH and lung remodeling was evaluated using lung tissue at 4 wpi. RESULTS NCP-2454 upregulated the production of Ang-(1-7) when incubated with ACE2 and Ang II. Notably, a continuous infusion of NCP-2454 significantly improved pulmonary arterial compliance, right ventricular systolic pressure, and RVH in MCT-treated rats. Interestingly, NCP-2454 increased the relative expression of ACE2 and MAS mRNA in lung tissue, especially in MCT-treated rats. In addition, the compound inhibited the MCT-induced overexpression of transforming growth factor β, phosphorylation of signal transducer and activator of transcription-3 (STAT3), and interleukin-6 production. The compound also restored the expression of caveolin-1 (Cav-1), which negatively regulates the Janus kinase-STAT signaling cascade. CONCLUSIONS NCP-2454 prevented MCT-induced PH by suppressing intracellular inflammatory cascades, an upstream molecular change of which is the disruption of Cav-1 expression.
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Affiliation(s)
- Shiori Haga
- 1Department of Intractable Diseases, Institute of National Center for Global Health and Medicine , Tokyo , Japan
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Simões e Silva AC, Silveira KD, Ferreira AJ, Teixeira MM. ACE2, angiotensin-(1-7) and Mas receptor axis in inflammation and fibrosis. Br J Pharmacol 2014; 169:477-92. [PMID: 23488800 DOI: 10.1111/bph.12159] [Citation(s) in RCA: 390] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 02/04/2013] [Accepted: 02/13/2013] [Indexed: 12/14/2022] Open
Abstract
Recent advances have improved our understanding of the renin-angiotensin system (RAS). These have included the recognition that angiotensin (Ang)-(1-7) is a biologically active product of the RAS cascade. The identification of the ACE homologue ACE2, which forms Ang-(1-7) from Ang II, and the GPCR Mas as an Ang-(1-7) receptor have provided the necessary biochemical and molecular background and tools to study the biological significance of Ang-(1-7). Most available evidence supports a counter-regulatory role for Ang-(1-7) by opposing many actions of Ang II on AT₁ receptors, especially vasoconstriction and proliferation. Many studies have now shown that Ang-(1-7) by acting via Mas receptor exerts inhibitory effects on inflammation and on vascular and cellular growth mechanisms. Ang-(1-7) has also been shown to reduce key signalling pathways and molecules thought to be relevant for fibrogenesis. Here, we review recent findings related to the function of the ACE2/Ang-(1-7)/Mas axis and focus on the role of this axis in modifying processes associated with acute and chronic inflammation, including leukocyte influx, fibrogenesis and proliferation of certain cell types. More attention will be given to the involvement of the ACE2/Ang-(1-7)/Mas axis in the context of renal disease because of the known relevance of the RAS for the function of this organ and for the regulation of kidney inflammation and fibrosis. Taken together, this knowledge may help in paving the way for the development of novel treatments for chronic inflammatory and renal diseases.
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Affiliation(s)
- A C Simões e Silva
- Departamento de Pediatria, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Wang W, Qiu L, Howard A, Solis N, Li C, Wang X, Kopp JB, Levi M. Protective effects of aliskiren and valsartan in mice with diabetic nephropathy. J Renin Angiotensin Aldosterone Syst 2014; 15:384-95. [PMID: 25031296 DOI: 10.1177/1470320313507123] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
AIM We investigated whether aliskiren, a direct renin inhibitor, provided protection in a model of diabetic nephropathy in mice and compared its protective effects to valsartan, an angiotensin II type 1 receptor blocker. MATERIALS AND METHODS Hyperglycemia was induced with streptozotocin (STZ, 40 mg/kg/day × 5 days) injection in DBA/2J mice fed on a high fat diet. Mice were treated with either aliskiren (25 mg/kg/day) or valsartan (8 mg/kg/day) for 6 weeks. RESULTS Aliskiren and/or valsartan treatment significantly attenuated albuminuria, urinary nephrin excretion and glomerulosclerosis. Aliskiren and/or valsartan prevented reduction of podocin and WT1 protein abundance in diabetic mice. Aliskiren and/or valsartan significantly prevented increased expression of profibrotic growth factors (TGFβ, CTGF and PAI-1), proinflammatory cytokines (MCP-1, TNFα and IL-1β), endoplasmic reticulum (ER) stress markers (CHOP and XBP-1) and lipid accumulation in the kidney of diabetic animals. Aliskiren showed similar efficacy compared to valsartan therapy and dual treatment in some aspects has synergistic protective effects. CONCLUSION Our study indicates that aliskiren and/or valsartan protects against diabetic kidney disease through multiple mechanisms, including decreasing podocyte injury, activation of profibrotic growth factors and proinflammatory cytokines, ER stress and accumulation of lipids.
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Affiliation(s)
- Weidong Wang
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado, USA Institute of Hypertension and Kidney Research, Zhongshan School of Medicine, Sun Yat-sen University, China
| | - Liru Qiu
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado, USA
| | - Allison Howard
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado, USA
| | - Nathaniel Solis
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado, USA
| | - Chunling Li
- Institute of Hypertension and Kidney Research, Zhongshan School of Medicine, Sun Yat-sen University, China
| | - Xiaoxin Wang
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado, USA
| | | | - Moshe Levi
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado, USA
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Márquez E, Riera M, Pascual J, Soler MJ. Albumin inhibits the insulin-mediated ACE2 increase in cultured podocytes. Am J Physiol Renal Physiol 2014; 306:F1327-34. [DOI: 10.1152/ajprenal.00594.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Podocytes are key cells in the glomerular filtration barrier with a major role in the development of diabetic nephropathy. Podocytes are insulin-sensitive cells and have a functionally active local renin-angiotensin system. The presence and activity of angiotensin-converting enzyme 2 (ACE2), the main role of which is cleaving profibrotic and proinflammatory angiotensin-II into angiotensin-(1–7), have been demonstrated in podocytes. Conditionally immortalized mouse podocytes were cultured with insulin in the presence and absence of albumin. We found that insulin increases ACE2 gene and protein expression, by real-time PCR and Western blotting, respectively, and enzymatic activity within the podocyte and these increases were maintained over time. Furthermore, insulin favored an “anti-angiotensin II” regarding ACE/ACE2 gene expression balance and decreased fibronectin gene expression as a marker of fibrosis in the podocytes, all studied by real-time PCR. Similarly, insulin incubation seemed to protect podocytes from cell death, studied by a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. However, all these effects disappeared in the presence of albumin, which may mimic albuminuria, a main feature of DN pathophysiology. Our results suggest that modulation of renin-angiotensin system balance, fibrosis, and apoptosis by insulin in the podocyte may be an important factor in preventing the development and progression of diabetic kidney disease, but the presence of albuminuria seems to block these beneficial effects.
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Affiliation(s)
- Eva Márquez
- Department of Nephrology, Hospital del Mar, Barcelona, Spain
- IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; and
| | - Marta Riera
- Department of Nephrology, Hospital del Mar, Barcelona, Spain
- IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; and
- Red de Investigación Renal (REDINREN), Instituto Carlos III, Madrid, Spain
| | - Julio Pascual
- Department of Nephrology, Hospital del Mar, Barcelona, Spain
- IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; and
- Red de Investigación Renal (REDINREN), Instituto Carlos III, Madrid, Spain
| | - María José Soler
- Department of Nephrology, Hospital del Mar, Barcelona, Spain
- IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; and
- Red de Investigación Renal (REDINREN), Instituto Carlos III, Madrid, Spain
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Jiang F, Yang J, Zhang Y, Dong M, Wang S, Zhang Q, Liu FF, Zhang K, Zhang C. Angiotensin-converting enzyme 2 and angiotensin 1-7: novel therapeutic targets. Nat Rev Cardiol 2014; 11:413-26. [PMID: 24776703 PMCID: PMC7097196 DOI: 10.1038/nrcardio.2014.59] [Citation(s) in RCA: 285] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Angiotensin-converting enzyme (ACE) 2 and its product angiotensin 1–7 are thought to have effects that counteract the adverse actions of other, better-known renin–angiotensin system (RAS) components Numerous experimental studies have suggested that ACE2 and angiotensin 1–7 have notable protective effects in the heart and blood vessels ACE2-mediated catabolism of angiotensin II is likely to have a major role in cardiovascular protection, whereas the functional importance and signalling mechanisms of angiotensin-1–7-induced actions remain unclear New pharmacological interventions targeting ACE2 are expected to be useful in clinical treatment of cardiovascular disease, especially those associated with overactivation of the conventional RAS More studies, especially randomized controlled clinical trials, are needed to clearly delineate the benefits of therapies targeting angiotensin 1–7 actions
Angiotensin-converting enzyme 2, and its product angiotensin 1–7, are thought to have counteracting effects against the adverse actions of the better-known members of the renin–angiotensin system and might, therefore, be useful therapeutic targets in patients with cardiovascular disease. Professor Jiang and colleagues review the evidence for the potential roles of these proteins in various cardiovascular conditions, including hypertension, atherosclerosis, myocardial remodelling, heart failure, ischaemic stroke, and diabetes. The renin–angiotensin system (RAS) has pivotal roles in the regulation of normal physiology and the pathogenesis of cardiovascular disease. Angiotensin-converting enzyme (ACE) 2, and its product angiotensin 1–7, are thought to have counteracting effects against the adverse actions of other, better known and understood, members of the RAS. The physiological and pathological importance of ACE2 and angiotensin 1–7 in the cardiovascular system are not completely understood, but numerous experimental studies have indicated that these components have protective effects in the heart and blood vessels. Here, we provide an overview on the basic properties of ACE2 and angiotensin 1–7 and a summary of the evidence from experimental and clinical studies of various pathological conditions, such as hypertension, atherosclerosis, myocardial remodelling, heart failure, ischaemic stroke, and diabetes mellitus. ACE2-mediated catabolism of angiotensin II is likely to have a major role in cardiovascular protection, whereas the relevant functions and signalling mechanisms of actions induced by angiotensin 1–7 have not been conclusively determined. The ACE2–angiotensin 1–7 pathway, however, might provide a useful therapeutic target for the treatment of cardiovascular disease, especially in patients with overactive RAS.
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Affiliation(s)
- Fan Jiang
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Jianmin Yang
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Yongtao Zhang
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Mei Dong
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Shuangxi Wang
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Qunye Zhang
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Fang Fang Liu
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Kai Zhang
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
| | - Cheng Zhang
- Key Laboratory of Cardiovascular Remodelling and Function Research, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan 250012, Shandong Province, China
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Mori J, Patel VB, Ramprasath T, Alrob OA, DesAulniers J, Scholey JW, Lopaschuk GD, Oudit GY. Angiotensin 1–7 mediates renoprotection against diabetic nephropathy by reducing oxidative stress, inflammation, and lipotoxicity. Am J Physiol Renal Physiol 2014; 306:F812-21. [DOI: 10.1152/ajprenal.00655.2013] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The renin-angiotensin system, especially angiotensin II (ANG II), plays a key role in the development and progression of diabetic nephropathy. ANG 1–7 has counteracting effects on ANG II and is known to exert beneficial effects on diabetic nephropathy. We studied the mechanism of ANG 1–7-induced beneficial effects on diabetic nephropathy in db/db mice. We administered ANG 1–7 (0.5 mg·kg−1·day−1) or saline to 5-mo-old db/db mice for 28 days via implanted micro-osmotic pumps. ANG 1–7 treatment reduced kidney weight and ameliorated mesangial expansion and increased urinary albumin excretion, characteristic features of diabetic nephropathy, in db/db mice. ANG 1–7 decreased renal fibrosis in db/db mice, which correlated with dephosphorylation of the signal transducer and activator of transcription 3 (STAT3) pathway. ANG 1–7 treatment also suppressed the production of reactive oxygen species via attenuation of NADPH oxidase activity and reduced inflammation in perirenal adipose tissue. Furthermore, ANG 1–7 treatment decreased lipid accumulation in db/db kidneys, accompanied by increased expressions of renal adipose triglyceride lipase (ATGL). Alterations in ATGL expression correlated with increased SIRT1 expression and deacetylation of FOXO1. The upregulation of angiotensin-converting enzyme 2 levels in diabetic nephropathy was normalized by ANG 1–7. ANG 1–7 treatment exerts renoprotective effects on diabetic nephropathy, associated with reduction of oxidative stress, inflammation, fibrosis, and lipotoxicity. ANG 1–7 can represent a promising therapy for diabetic nephropathy.
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Affiliation(s)
- Jun Mori
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada; and
| | - Vaibhav B. Patel
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada; and
| | - Tharmarajan Ramprasath
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada; and
| | - Osama Abo Alrob
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Jessica DesAulniers
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada; and
| | - James W. Scholey
- Division of Nephrology, Department of Medicine, University of Toronto, Ontario, Canada
| | - Gary D. Lopaschuk
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Gavin Y. Oudit
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada; and
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Gray SP, Jandeleit-Dahm K. The pathobiology of diabetic vascular complications--cardiovascular and kidney disease. J Mol Med (Berl) 2014; 92:441-52. [PMID: 24687627 DOI: 10.1007/s00109-014-1146-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 02/03/2014] [Accepted: 03/14/2014] [Indexed: 02/06/2023]
Abstract
With the increasing incidence of obesity and type 2 diabetes, it is predicted that more than half of Americans will have diabetes or pre-diabetes by 2020. Diabetic patients develop vascular complications at a much faster rate in comparison to non-diabetic individuals, and cardiovascular risk is increased up to tenfold. With the increasing incidence of diabetes across the world, the development of vascular complications will become an increasing medical burden. Diabetic vascular complications affect the micro- and macro-vasculature leading to kidney disease often requiring dialysis and transplantation or cardiovascular disease increasing the risk for myocardial infarction, stroke and amputations as well as leading to premature mortality. It has been suggested that many complex pathways contribute to the pathobiology of diabetic complications including hyperglycaemia itself, the production of advanced glycation end products (AGEs) and interaction with the receptors for AGEs such as the receptor for advanced glycation end products (RAGE), as well as the activation of vasoactive systems such as the renin-angiotensin aldosterone system (RAAS) and the endothelin system. More recently, it has been hypothesised that reactive oxygen species derived from NAD(P)H oxidases (Nox) may represent a common downstream mediator of vascular injury in diabetes. Current standard treatment of care includes the optimization of blood glucose and blood pressure usually including inhibitors of the renin-angiotensin system. Although these interventions are able to delay progression, they fail to prevent the development of complications. Thus, there is an urgent medical need to identify novel targets in diabetic vascular complications which may include the blockade of Nox-derived ROS formation, as well as blockade of AGE formation and inhibitors of RAGE activation. These strategies may provide superior protection against the deleterious effects of diabetes on the vasculature.
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Affiliation(s)
- Stephen P Gray
- Diabetes Complications Division, Baker IDI Heart & Diabetes Research Institute, PO Box 6492, St Kilda Rd, Melbourne, VIC, 8008, Australia,
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115
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Halleck F, Schröder K, Holleck-Weithmann S, Kossmehl P, Kreutz R, Rothermund L. Cardiorenal protection in experimental hypertension with renal failure: comparison between vasopeptidase inhibition and angiotensin receptor blockade. Clin Exp Hypertens 2014; 37:26-32. [PMID: 24678912 DOI: 10.3109/10641963.2014.897718] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The aim of the present study was to compare the preventive impact of treatment with a vasopeptidase inhibitor (VPI) with an angiotensin-receptor blocker (ARB) on left ventricular (LV) function and renal damage in rats with renal failure after 5/6 renal ablation (Nx). METHODS Rats (n = 15-20, each group) underwent either sham-operation (Sham) or 5/6 renal ablation (Nx). Two additional groups of Nx-animals (groups Nx-VPI and Nx-ARB) were treated with the VPI ilepatril (AVE7688, 30 mg kg(-1) d(-1)) or with the ARB olmesartan (10 mg kg(-1 )d(-1)). Animals were followed for 4 weeks. RESULTS Systolic blood pressure (SBP), LV hypertrophy (LVH) and LV end-diastolic pressure (LVEDP) were increased 4 weeks after Nx (p < 0.05). LV pressure rise (+dP/dt/LVPmax), LV pressure fall (-dP/dt/LVPmax), and creatinine clearance decreased, while albuminuria and renal glomerulosclerosis index (GSI) increased with Nx (p < 0.05, respectively). In comparison to Nx, treatment with both VPI and ARB normalized SBP, LVH, LVEDP, +dP/dt/LVPmax, and -dP/dt/LVPmax to Sham control levels. GSI, but not creatinine clearance, was also normalized in response to both treatments. The significant increase in albuminuria observed in Nx (+230-fold versus Sham, p < 0.0001) was partially reduced in Nx-VPI (+47-fold versus Sham, p < 0.0001) and fully abolished in Nx-ARB. CONCLUSIONS Both ilepatril and olmesartan conferred strong cardiorenal protective effects in rats with renal failure. While cardioprotection was clearly comparable with both treatment regimens, the ARB provided a better protection against the increase in albuminuria, although renal function and structural kidney changes were similarly affected by the VIP and ARB.
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Affiliation(s)
- Fabian Halleck
- Institut für Klinische Pharmakologie und Toxikologie, Charité - Universitätsmedizin Berlin , Campus Mitte, Berlin , Germany and
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Varagic J, Ahmad S, Nagata S, Ferrario CM. ACE2: angiotensin II/angiotensin-(1-7) balance in cardiac and renal injury. Curr Hypertens Rep 2014; 16:420. [PMID: 24510672 PMCID: PMC4286874 DOI: 10.1007/s11906-014-0420-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Our current recognition of the renin-angiotensin system is more convoluted than originally thought due to the discovery of multiple novel enzymes, peptides, and receptors inherent in this interactive biochemical cascade. Over the last decade, angiotensin-converting enzyme 2 (ACE2) has emerged as a key player in the pathophysiology of hypertension and cardiovascular and renal disease due to its pivotal role in metabolizing vasoconstrictive/hypertrophic/proliferative angiotensin II into favorable angiotensin-(1-7). This review addresses the considerable advancement in research on the role of tissue ACE2 in the development and progression of hypertension and cardiac and renal injury. We summarize the results from recent clinical and experimental studies suggesting that serum or urine soluble ACE2 may serve as a novel biomarker or independent risk factor relevant for diagnosis and prognosis of cardiorenal disease. We also review recent proceedings on novel therapeutic approaches to enhance ACE2/angiotensin-(1-7) axis.
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Affiliation(s)
- Jasmina Varagic
- Hypertension & Vascular Research Center, Division of Surgical Sciences, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA,
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Manipulating angiotensin metabolism with angiotensin converting enzyme 2 (ACE2) in heart failure. ACTA ACUST UNITED AC 2014; 9:e141-e148. [PMID: 32362932 PMCID: PMC7185729 DOI: 10.1016/j.ddstr.2013.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Heart failure is increasing in prevalence associated with a huge economic burden. ACE2 is a negative regulator of the renin–angiotensin system. Elevated ACE2 activity is a biomarker in heart failure. Enhancing ACE2 action may have unique therapeutic effects in patients with heart failure.
Angiotensin converting enzyme 2 (ACE2), is a monocarboxypeptidase which metabolizes several peptides including the degradation of Ang II, a peptide with vasoconstrictive/proliferative/effects, to generate Ang 1–7, which acting through its receptor Mas exerts vasodilatory/anti-proliferative actions. The classical pathway of the RAS involving the ACE-Ang II-AT1 receptor axis is antagonized by the second arm constituted by the ACE2-Ang 1–7/Mas receptor axis. Loss of ACE2 enhances the adverse pathological remodeling susceptibility to pressure-overload and myocardial infarction. Human recombinant ACE2 is also a negative regulator of Ang II-induced myocardial hypertrophy, fibrosis and diastolic dysfunction and suppresses pressure-overload induced heart failure. Due to its characteristics, the ACE2-Ang 1–7/Mas axis may represent new possibilities for developing novel therapeutic strategies for the treatment of heart failure. Human recombinant ACE2 has been safely administered to healthy human volunteers intravenously resulting in sustained lowering of plasma Ang II levels. In this review, we will summarize the beneficial effects of ACE2 in heart disease and the potential use of human recombinant ACE2 as a novel therapy for heart failure.
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118
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Salem ESB, Grobe N, Elased KM. Insulin treatment attenuates renal ADAM17 and ACE2 shedding in diabetic Akita mice. Am J Physiol Renal Physiol 2014; 306:F629-39. [PMID: 24452639 DOI: 10.1152/ajprenal.00516.2013] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is located in several tissues and is highly expressed in renal proximal tubules, where it degrades the vasoconstrictor angiotensin II (ANG II) to ANG-(1-7). Accumulating evidence supports protective roles of ACE2 in several disease states, including diabetic nephropathy. A disintegrin and metalloprotease (ADAM) 17 is involved in the shedding of several transmembrane proteins, including ACE2. Our previous studies showed increased renal ACE2, ADAM17 expression, and urinary ACE2 in type 2 diabetic mice (Chodavarapu H, Grobe N, Somineni HK, Salem ES, Madhu M, Elased KM. PLoS One 8: e62833, 2013). The aim of the present study was to determine the effect of insulin on ACE2 shedding and ADAM17 in type 1 diabetic Akita mice. Results demonstrate increased renal ACE2 and ADAM17 expression and increased urinary ACE2 fragments (≈70 kDa) and albumin excretion in diabetic Akita mice. Immunostaining revealed colocalization of ACE2 with ADAM17 in renal tubules. Renal proximal tubular cells treated with ADAM17 inhibitor showed reduced ACE2 shedding into the media, confirming ADAM17-mediated shedding of ACE2. Treatment of Akita mice with insulin implants for 20 wk normalized hyperglycemia and decreased urinary ACE2 and albumin excretion. Insulin also normalized renal ACE2 and ADAM17 but had no effect on tissue inhibitor of metalloproteinase 3 (TIMP3) protein expression. There was a positive linear correlation between urinary ACE2 and albuminuria, blood glucose, plasma creatinine, glucagon, and triglycerides. This is the first report showing an association between hyperglycemia, cardiovascular risk factors, and increased shedding of urinary ACE2 in diabetic Akita mice. Urinary ACE2 could be used as a biomarker for diabetic nephropathy and as an index of intrarenal ACE2 status.
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Affiliation(s)
- Esam S B Salem
- Dept. of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State Univ., 3640 Colonel Glenn Highway, Dayton, OH 45435.
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119
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Salem ESB, Grobe N, Elased KM. Insulin treatment attenuates renal ADAM17 and ACE2 shedding in diabetic Akita mice. Am J Physiol Renal Physiol 2014. [PMID: 24452639 DOI: 10.1152/ajprenal.00516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is located in several tissues and is highly expressed in renal proximal tubules, where it degrades the vasoconstrictor angiotensin II (ANG II) to ANG-(1-7). Accumulating evidence supports protective roles of ACE2 in several disease states, including diabetic nephropathy. A disintegrin and metalloprotease (ADAM) 17 is involved in the shedding of several transmembrane proteins, including ACE2. Our previous studies showed increased renal ACE2, ADAM17 expression, and urinary ACE2 in type 2 diabetic mice (Chodavarapu H, Grobe N, Somineni HK, Salem ES, Madhu M, Elased KM. PLoS One 8: e62833, 2013). The aim of the present study was to determine the effect of insulin on ACE2 shedding and ADAM17 in type 1 diabetic Akita mice. Results demonstrate increased renal ACE2 and ADAM17 expression and increased urinary ACE2 fragments (≈70 kDa) and albumin excretion in diabetic Akita mice. Immunostaining revealed colocalization of ACE2 with ADAM17 in renal tubules. Renal proximal tubular cells treated with ADAM17 inhibitor showed reduced ACE2 shedding into the media, confirming ADAM17-mediated shedding of ACE2. Treatment of Akita mice with insulin implants for 20 wk normalized hyperglycemia and decreased urinary ACE2 and albumin excretion. Insulin also normalized renal ACE2 and ADAM17 but had no effect on tissue inhibitor of metalloproteinase 3 (TIMP3) protein expression. There was a positive linear correlation between urinary ACE2 and albuminuria, blood glucose, plasma creatinine, glucagon, and triglycerides. This is the first report showing an association between hyperglycemia, cardiovascular risk factors, and increased shedding of urinary ACE2 in diabetic Akita mice. Urinary ACE2 could be used as a biomarker for diabetic nephropathy and as an index of intrarenal ACE2 status.
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Affiliation(s)
- Esam S B Salem
- Dept. of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State Univ., 3640 Colonel Glenn Highway, Dayton, OH 45435.
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Xiao F, Zimpelmann J, Agaybi S, Gurley SB, Puente L, Burns KD. Characterization of angiotensin-converting enzyme 2 ectodomain shedding from mouse proximal tubular cells. PLoS One 2014; 9:e85958. [PMID: 24454948 PMCID: PMC3893316 DOI: 10.1371/journal.pone.0085958] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 12/02/2013] [Indexed: 01/15/2023] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is highly expressed in the kidney proximal tubule, where it cleaves angiotensin (Ang) II to Ang-(1-7). Urinary ACE2 levels increase in diabetes, suggesting that ACE2 may be shed from tubular cells. The aim of this study was to determine if ACE2 is shed from proximal tubular cells, to characterize ACE2 fragments, and to study pathways for shedding. Studies involved primary cultures of mouse proximal tubular cells, with ACE2 activity measured using a synthetic substrate, and analysis of ACE2 fragments by immunoblots and mass spectrometry. The culture media from mouse proximal tubular cells demonstrated a time-dependent increase in ACE2 activity, suggesting constitutive ACE2 shedding. ACE2 was detected in media as two bands at ∼90 kDa and ∼70 kDa on immunoblots. By contrast, full-length ACE2 appeared at ∼100 kDa in cell lysates or mouse kidney cortex. Mass spectrometry of the two deglycosylated fragments identified peptides matching mouse ACE2 at positions 18-706 and 18-577, respectively. The C-terminus of the 18-706 peptide fragment contained a non-tryptic site, suggesting that Met706 is a candidate ACE2 cleavage site. Incubation of cells in high D-glucose (25 mM) (and to a lesser extent Ang II) for 48–72 h increased ACE2 activity in the media (p<0.001), an effect blocked by inhibition of a disintegrin and metalloproteinase (ADAM)17. High D-glucose increased ADAM17 activity in cell lysates (p<0.05). These data indicate that two glycosylated ACE2 fragments are constitutively shed from mouse proximal tubular cells. ACE2 shedding is stimulated by high D-glucose, at least partly via an ADAM17-mediated pathway. The results suggest that proximal tubular shedding of ACE2 may increase in diabetes, which could enhance degradation of Ang II in the tubular lumen, and increase levels of Ang-(1-7).
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Affiliation(s)
- Fengxia Xiao
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Joseph Zimpelmann
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Samih Agaybi
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Susan B. Gurley
- Division of Nephrology, Department of Medicine, Duke University Medical Centre, Durham, North Carolina, United States of America
| | - Lawrence Puente
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Kevin D. Burns
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
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Riera M, Márquez E, Clotet S, Gimeno J, Roca-Ho H, Lloreta J, Juanpere N, Batlle D, Pascual J, Soler MJ. Effect of insulin on ACE2 activity and kidney function in the non-obese diabetic mouse. PLoS One 2014; 9:e84683. [PMID: 24400109 PMCID: PMC3882249 DOI: 10.1371/journal.pone.0084683] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 11/26/2013] [Indexed: 11/18/2022] Open
Abstract
We studied the non-obese diabetic (NOD) mice model because it develops autoimmune diabetes that resembles human type 1 diabetes. In diabetic mice, urinary albumin excretion (UAE) was ten-fold increased at an "early stage" of diabetes, and twenty-fold increased at a "later stage" (21 and 40 days, respectively after diabetes diagnosis) as compared to non-obese resistant controls. In NOD Diabetic mice, glomerular enlargement, increased glomerular filtration rate (GFR) and increased blood pressure were observed in the early stage. In the late stage, NOD Diabetic mice developed mesangial expansion and reduced podocyte number. Circulating and urine ACE2 activity were markedly increased both, early and late in Diabetic mice. Insulin administration prevented albuminuria, markedly reduced GFR, blood pressure, and glomerular enlargement in the early stage; and prevented mesangial expansion and the reduced podocyte number in the late stage of diabetes. The increase in serum and urine ACE2 activity was normalized by insulin administration at the early and late stages of diabetes in Diabetic mice. We conclude that the Diabetic mice develops features of early kidney disease, including albuminuria and a marked increase in GFR. ACE2 activity is increased starting at an early stage in both serum and urine. Moreover, these alterations can be completely prevented by the chronic administration of insulin.
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Affiliation(s)
- Marta Riera
- Department of Nephrology, Hospital del Mar-IMIM, Barcelona, Spain
| | - Eva Márquez
- Department of Nephrology, Hospital del Mar-IMIM, Barcelona, Spain
| | - Sergi Clotet
- Department of Nephrology, Hospital del Mar-IMIM, Barcelona, Spain
| | - Javier Gimeno
- Department of Pathology, Hospital del Mar-IMIM, Barcelona, Spain
| | - Heleia Roca-Ho
- Department of Pathology, Hospital del Mar-IMIM, Barcelona, Spain
| | - Josep Lloreta
- Department of Pathology, Hospital del Mar-IMIM, Barcelona, Spain
| | - Nuria Juanpere
- Department of Pathology, Hospital del Mar-IMIM, Barcelona, Spain
| | - Daniel Batlle
- Division of Nephrology and Hypertension, Department of Medicine, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Julio Pascual
- Department of Nephrology, Hospital del Mar-IMIM, Barcelona, Spain
| | - María José Soler
- Department of Nephrology, Hospital del Mar-IMIM, Barcelona, Spain
- * E-mail:
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Soler MJ, Wysocki J, Batlle D. ACE2 alterations in kidney disease. Nephrol Dial Transplant 2013; 28:2687-97. [PMID: 23956234 PMCID: PMC3811059 DOI: 10.1093/ndt/gft320] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 06/20/2013] [Indexed: 12/16/2022] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase that degrades angiotensin (Ang) II to Ang-(1-7). ACE2 is highly expressed within the kidneys, it is largely localized in tubular epithelial cells and less prominently in glomerular epithelial cells and in the renal vasculature. ACE2 activity has been shown to be altered in diabetic kidney disease, hypertensive renal disease and in different models of kidney injury. There is often a dissociation between tubular and glomerular ACE2 expression, particularly in diabetic kidney disease where ACE2 expression is increased at the tubular level but decreased at the glomerular level. In this review, we will discuss alterations in circulating and renal ACE2 recently described in different renal pathologies and disease models as well as their possible significance.
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Affiliation(s)
- María José Soler
- Department of Nephrology, Hospital del Mar-Fundació IMIM, Barcelona, Spain
| | - Jan Wysocki
- Division of Nephrology & Hypertension, Department of Medicine, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Daniel Batlle
- Division of Nephrology & Hypertension, Department of Medicine, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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Perlot T, Penninger JM. ACE2 - from the renin-angiotensin system to gut microbiota and malnutrition. Microbes Infect 2013; 15:866-73. [PMID: 23962453 PMCID: PMC7110844 DOI: 10.1016/j.micinf.2013.08.003] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 08/06/2013] [Indexed: 02/07/2023]
Abstract
The renin-angiotensin system (RAS) is a complex network that regulates blood pressure, electrolyte and fluid homeostasis, as well as the function of several organs. Angiotensin-converting enzyme 2 (ACE2) was identified as an enzyme that negatively regulates the RAS by converting Ang II, the main bioactive molecule of the RAS, to Ang 1-7. Thus, ACE2 counteracts the role of angiotensin-converting enzyme (ACE) which generates Ang II from Ang I. ACE and ACE2 have been implicated in several pathologies such as cardiovascular and renal disease or acute lung injury. In addition, ACE2 has functions independent of the RAS: ACE2 is the receptor for the SARS coronavirus and ACE2 is essential for expression of neutral amino acid transporters in the gut. In this context, ACE2 modulates innate immunity and influences the composition of the gut microbiota, which can explain diarrhea and intestinal inflammation observed in Hartnup disorder, Pellagra, or under conditions of severe malnutrition. Here we review and discuss the diverse functions of ACE2 and its relevance to human pathologies.
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Affiliation(s)
- Thomas Perlot
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
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Wysocki J, Garcia-Halpin L, Ye M, Maier C, Sowers K, Burns KD, Batlle D. Regulation of urinary ACE2 in diabetic mice. Am J Physiol Renal Physiol 2013; 305:F600-11. [PMID: 23761674 PMCID: PMC3891267 DOI: 10.1152/ajprenal.00600.2012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 06/06/2013] [Indexed: 01/30/2023] Open
Abstract
Angiotensin-converting enzyme-2 (ACE2) enhances the degradation of ANG II and its expression is altered in diabetic kidneys, but the regulation of this enzyme in the urine is unknown. Urinary ACE2 was studied in the db/db model of type 2 diabetes and stretozotocin (STZ)-induced type 1 diabetes during several physiological and pharmacological interventions. ACE2 activity in db/db mice was increased in the serum and to a much greater extent in the urine compared with db/m controls. Neither a specific ANG II blocker, telmisartan, nor an ACE inhibitor, captopril, altered the levels of urinary ACE2 in db/db or db/m control mice. High-salt diet (8%) increased whereas low-salt diet (0.1%) decreased urinary ACE2 activity in the urine of db/db mice. In STZ mice, urinary ACE2 was also increased, and insulin decreased it partly but significantly after several weeks of administration. The increase in urinary ACE2 activity in db/db mice reflected an increase in enzymatically active protein with two bands identified of molecular size at 110 and 75 kDa and was associated with an increase in kidney cortex ACE2 protein at 110 kDa but not at 75 kDa. ACE2 activity was increased in isolated tubular preparations but not in glomeruli from db/db mice. Administration of soluble recombinant ACE2 to db/m and db/db mice resulted in a marked increase in serum ACE2 activity, but no gain in ACE2 activity was detectable in the urine, further demonstrating that urinary ACE2 is of kidney origin. Increased urinary ACE2 was associated with more efficient degradation of exogenous ANG II (10(-9) M) in urine from db/db compared with that from db/m mice. Urinary ACE2 could be a potential biomarker of increased metabolism of ANG II in diabetic kidney disease.
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Affiliation(s)
- Jan Wysocki
- Div. of Nephrology and Hypertension, Dept. of Medicine, The Feinberg School of Medicine, Northwestern Univ., 320 E. Superior, Chicago, IL 60611.
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Fang F, Liu GC, Zhou X, Yang S, Reich HN, Williams V, Hu A, Pan J, Konvalinka A, Oudit GY, Scholey JW, John R. Loss of ACE2 exacerbates murine renal ischemia-reperfusion injury. PLoS One 2013; 8:e71433. [PMID: 23951161 PMCID: PMC3739768 DOI: 10.1371/journal.pone.0071433] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 06/28/2013] [Indexed: 01/28/2023] Open
Abstract
Ischemia-reperfusion (I/R) is a model of acute kidney injury (AKI) that is characterized by vasoconstriction, oxidative stress, apoptosis and inflammation. Previous studies have shown that activation of the renin-angiotensin system (RAS) may contribute to these processes. Angiotensin converting enzyme 2 (ACE2) metabolizes angiotensin II (Ang II) to angiotensin-(1–7), and recent studies support a beneficial role for ACE2 in models of chronic kidney disease. However, the role of ACE2 in models of AKI has not been fully elucidated. In order to test the hypothesis that ACE2 plays a protective role in AKI we assessed I/R injury in wild-type (WT) mice and ACE2 knock-out (ACE2 KO) mice. ACE2 KO and WT mice exhibited similar histologic injury scores and measures of kidney function at 48 hours after reperfusion. Loss of ACE2 was associated with increased neutrophil, macrophage, and T cell infiltration in the kidney. mRNA levels for pro-inflammatory cytokines, interleukin-1β, interleukin-6 and tumour necrosis factor-α, as well as chemokines macrophage inflammatory protein 2 and monocyte chemoattractant protein-1, were increased in ACE2 KO mice compared to WT mice. Changes in inflammatory cell infiltrates and cytokine expression were also associated with greater apoptosis and oxidative stress in ACE2 KO mice compared to WT mice. These data demonstrate a protective effect of ACE2 in I/R AKI.
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Affiliation(s)
- Fei Fang
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - George Chu Liu
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Xiaohua Zhou
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Stuart Yang
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, Canada
| | - Heather Naomi Reich
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, Canada
| | - Vanessa Williams
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Amanda Hu
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Janice Pan
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Ana Konvalinka
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Gavin Yadram Oudit
- Division of Cardiology, Department of Medicine, Mazanlowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - James William Scholey
- Departments of Medicine and Institute of Medical Science, University of Toronto, Toronto, Canada
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, Canada
| | - Rohan John
- Department of Pathology, University Health Network and University of Toronto, Toronto, Canada
- * E-mail:
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126
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Rüster C, Wolf G. The role of the renin-angiotensin-aldosterone system in obesity-related renal diseases. Semin Nephrol 2013; 33:44-53. [PMID: 23374893 DOI: 10.1016/j.semnephrol.2012.12.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Obesity is an independent risk factor for the development and progression of chronic kidney disease and one of the emerging reasons for end-stage renal disease owing to its dramatic increase worldwide. Among the potential underlying pathophysiologic mechanisms, activation of the renin-angiotensin-aldosterone-system (RAAS) plays a central role. Increased angiotensin II (AngII) levels also are central in hypertension, dyslipidemia, and insulin resistance, which, taken together with obesity, represent the metabolic syndrome. Increased AngII levels contribute to hyperfiltration, glomerulomegaly, and subsequent focal glomerulosclerosis by altering renal hemodynamics via afferent arteriolar dilation, together with efferent renal arteriolar vasoconstriction as well as by its endocrine and paracrine properties linking the intrarenal and the systemic RAAS, adipose tissue dysfunction, as well as insulin resistance and hypertension. The imbalance between increased AngII levels and the angiotensin converting enzyme 2/Ang (1-7)/Mas receptor axis additionally contributes to renal injury in obesity and its concomitant metabolic disturbances. As shown in several large trials and experimental studies, treatment of obesity by weight loss is associated with an improvement of kidney disease because it also is beneficial in dyslipidemia, hypertension, and diabetes. The most promising data have been seen by RAAS blockade, pointing to the central position of RAAS within obesity, kidney disease, and the metabolic syndrome.
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Affiliation(s)
- Christiane Rüster
- Department of Internal Medicine III, University Hospital Jena, Jena, Germany
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127
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Abstract
The renin–angiotensin system (RAS) has recently been extended by the addition of a novel axis consisting of the angiotensin-converting enzyme 2 (ACE2), the heptapeptide angiotensin (1–7) (Ang-(1–7)), and the G protein-coupled receptor Mas. ACE2 converts the vasoconstrictive and pro-oxidative peptide angiotensin II (Ang II) into Ang-(1–7) which exerts vasodilatory and antioxidative effects via its receptor Mas. Thereby, ACE2 regulates the local actions of the RAS in cardiovascular tissues and the ACE2/Ang-(1–7)/Mas axis exerts protective actions in hypertension, diabetes, and other cardiovascular disorders. Consequently, this novel RAS axis represents a promising therapeutic target for cardiovascular and metabolic diseases.
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128
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Abstract
As new components of the renin–angiotensin system (RAS) are elucidated, our understanding of the complexities of their interactions also advances. Previous studies have determined that podocytes possess a local RAS that can generate angiotensin II. Podocytes have also been shown to express angiotensin-converting enzyme 2 (ACE2), which can decrease angiotensin II levels by generation of angiotensin-(1–7). Nadarajah et al. now show that increased podocyte ACE2 activity can attenuate the development of diabetic nephropathy.
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Affiliation(s)
- Raymond C Harris
- Department of Veterans Affairs, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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129
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Grobe N, Weir NM, Leiva O, Ong FS, Bernstein KE, Schmaier AH, Morris M, Elased KM. Identification of prolyl carboxypeptidase as an alternative enzyme for processing of renal angiotensin II using mass spectrometry. Am J Physiol Cell Physiol 2013; 304:C945-53. [PMID: 23392115 DOI: 10.1152/ajpcell.00346.2012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensin-converting enzyme 2 (ACE2) catalyzes conversion of ANG II to ANG-(1-7). The present study uses newly established proteomic approaches and genetic mouse models to examine the contribution of alternative renal peptidases to ACE2-independent formation of ANG-(1-7). In situ and in vitro mass spectrometric characterization showed that substrate concentration and pH control renal ANG II processing. At pH ≥6, ANG-(1-7) formation was significantly reduced in ACE2 knockout (KO) mice. However, at pH <6, formation of ANG-(1-7) in ACE2 KO mice was similar to that in wild-type (WT) mice, suggesting alternative peptidases for renal ANG II processing. Furthermore, the dual prolyl carboxypeptidase (PCP)-prolyl endopeptidase (PEP) inhibitor Z-prolyl-prolinal reduced ANG-(1-7) formation in ACE2 KO mice, while the ACE2 inhibitor MLN-4760 had no effect. Unlike the ACE2 KO mice, ANG-(1-7) formation from ANG II in PEP KO mice was not different from that in WT mice at any tested pH. However, at pH 5, this reaction was significantly reduced in kidneys and urine of PCP-depleted mice. In conclusion, results suggest that ACE2 metabolizes ANG II in the kidney at neutral and basic pH, while PCP catalyzes the same reaction at acidic pH. This is the first report demonstrating that renal ANG-(1-7) formation from ANG II is independent of ACE2. Elucidation of ACE2-independent ANG-(1-7) production pathways may have clinically important implications in patients with metabolic and renal disease.
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Affiliation(s)
- Nadja Grobe
- Department of Pharmacology and Toxicology, Wright State University Boonshoft School of Medicine, Dayton, OH 45435, USA
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130
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Chou CH, Chuang LY, Lu CY, Guh JY. Interaction between TGF-β and ACE2-Ang-(1-7)-Mas pathway in high glucose-cultured NRK-52E cells. Mol Cell Endocrinol 2013; 366:21-30. [PMID: 23174757 DOI: 10.1016/j.mce.2012.11.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 10/04/2012] [Accepted: 11/07/2012] [Indexed: 11/26/2022]
Abstract
Transforming growth factor-β (TGF-β) is pivotal in diabetic nephropathy (DN). Angiotensin converting enzyme-2 (ACE2) converts angiotensin II (Ang II) to angiotensin 1-7 (Ang-(1-7)), which binds to Mas. Proximal tubular ACE2 is decreased in DN. ACE2 deficiency exacerbates whereas ACE2 overexpression attenuates DN. Thus, we investigated the mechanism of high glucose-decreased ACE2 in terms of the interaction between TGF-β and ACE2-Ang-(1-7)-Mas in NRK-52E cells. We found that high glucose increased TGF-β1. SB431542 attenuated high glucose-inhibited ACE2 and Mas and Ang-(1-7) conversion from Ang II while attenuating high glucose-induced fibronectin. TGF-β1 also decreased ACE2 and Mas and Ang-(1-7) conversion from Ang II. A779 attenuated Ang-(1-7)-decreased TGF-β1 and Ang-(1-7)-activated JAK2-STAT3. Moreover, A779, LY294002 and AG490 attenuated Ang-(1-7)-inhibited TGF-β1. The combination of Ang-(1-7) and Mas attenuated TGF-β1 (but not high glucose)-induced fibronectin. Thus, high glucose decreases ACE2 via TGF-βR in NRK-52E cells. Additionally, there is a negative feedback function between TGF-β and ACE2, and the combined inhibition of TGF-β and activation of the ACE2-Ang-(1-7)-Mas may be useful for treating diabetic renal fibrosis.
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Affiliation(s)
- Chi-Hsien Chou
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Taiwan, ROC
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131
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Yuan L, Wang Y, Lu C, Li X. Angiotensin-Converting Enzyme 2 Deficiency Aggravates Glucose Intolerance via Impairment of Islet Microvascular Density in Mice with High-Fat Diet. J Diabetes Res 2013; 2013:405284. [PMID: 23671869 PMCID: PMC3647559 DOI: 10.1155/2013/405284] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 02/20/2013] [Indexed: 12/13/2022] Open
Abstract
The aim of this study was to evaluate the effects of angiotensin-converting enzyme 2 (ACE2) on glucose homeostasis and islet function in mice. Male wildtype (WT) and ACE2 knockout (ACE2 KO) mice were divided into chow diet group and long-term high-fat diet (HFD) group. After 16 weeks of feeding, the islet function of the animals was evaluated by intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin releasing test (IPIRT). The pancreas was immunohistochemically stained to analyze the relative content of insulin (IRC), vascular endothelial growth factor (VEGF), and microvessel density (MVD) in islets. There was no difference of body weight, area under curve of glucose (AUCG), area under curve of insulin from 0 to 5 min (AUGI0-5), MVD, and RVC (relative content of VEGF) between WT and ACE2 KO mice with regular chow diet. Under the condition of long-term HFD, the AUCG of ACE2 KO mice was increased obviously in comparison with the WT mice, with decreased IRC, MVD, AUGI0-5, AUCI0-30, and RVC (all P < 0.05). In conclusion, these results show that ACE2 deficiency deteriorates islet function of mice with long-term HFD via impairment of islet microvasculature.
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Affiliation(s)
- Li Yuan
- Department of Endocrinology, Union Hospital, Tongji Medical College of HuaZhong, University of Science & Technology, Wuhan 430022, China
- *Li Yuan:
| | - Ying Wang
- Department of Endocrinology, Union Hospital, Tongji Medical College of HuaZhong, University of Science & Technology, Wuhan 430022, China
| | - Chunli Lu
- Department of Endocrinology, Union Hospital, Tongji Medical College of HuaZhong, University of Science & Technology, Wuhan 430022, China
| | - Xiaoya Li
- Department of Endocrinology, Union Hospital, Tongji Medical College of HuaZhong, University of Science & Technology, Wuhan 430022, China
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132
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Arao T, Okada Y, Mori H, Nishida K, Tanaka Y. Antihypertensive and metabolic effects of high-dose olmesartan and telmisartan in type 2 diabetes patients with hypertension. Endocr J 2013; 60:563-70. [PMID: 23303198 DOI: 10.1507/endocrj.ej12-0326] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We performed a crossover study in hypertensive patients with type 2 diabetes to compare olmesartan (40 mg/day) with telmisartan (80 mg/day) in terms of their antihypertensive and metabolic effects. The subjects were 36 patients (20 men and 16 women) with type 2 diabetes who did not achieve a blood pressure <130/80 mmHg following treatment with olmesartan at 40 mg/day or telmisartan at 80 mg/day for 8 weeks or more. The primary endpoint was the blood pressure reduction rate, while the secondary endpoints were BMI, parameters of glucose metabolism, HMW-adiponectin, hs-CRP and lipids metabolism. All parameters were measured in Weeks 0, 12, and 24. Treatments were switched in Week 0, and Week 12 and the following results were obtained. There were 1) no significant differences in baseline characteristics; 2) no significant difference of the blood pressure reduction rate; 3) significant reductions of HbA1c (NGSP), FPG and HOMA-IR in olmesartan group; 4) a significant increase of HDL-C in olmesartan group; 5) a decrease of hs-CRP and a increase of HMW-adiponectin in olmesartan group; and 6) a positive correlation between the percent changes of HOMA-IR and hs-CRP in olmesartan group. In conclusion, there was no difference of the blood pressure reduction achieved at the highest dose in olmesartan group and telmisartan group. But improvement of glycemic control and insulin resistance was only observed in olmesartan group. Because there was a correlation between the percent changes of HOMA-IR and hs-CRP, these effects of olmesartan might be mediated by an anti-inflammatory action.
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Affiliation(s)
- Tadashi Arao
- The First Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan.
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133
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Abstract
The renin-angiotensin system (RAS) constitutes one of the most important hormonal systems in the physiological regulation of blood pressure through renal and nonrenal mechanisms. Indeed, dysregulation of the RAS is considered a major factor in the development of cardiovascular pathologies, including kidney injury, and blockade of this system by the inhibition of angiotensin converting enzyme (ACE) or blockade of the angiotensin type 1 receptor (AT1R) by selective antagonists constitutes an effective therapeutic regimen. It is now apparent with the identification of multiple components of the RAS within the kidney and other tissues that the system is actually composed of different angiotensin peptides with diverse biological actions mediated by distinct receptor subtypes. The classic RAS can be defined as the ACE-Ang II-AT1R axis that promotes vasoconstriction, water intake, sodium retention, and other mechanisms to maintain blood pressure, as well as increase oxidative stress, fibrosis, cellular growth, and inflammation in pathological conditions. In contrast, the nonclassical RAS composed primarily of the AngII/Ang III-AT2R pathway and the ACE2-Ang-(1-7)-AT7R axis generally opposes the actions of a stimulated Ang II-AT1R axis through an increase in nitric oxide and prostaglandins and mediates vasodilation, natriuresis, diuresis, and reduced oxidative stress. Moreover, increasing evidence suggests that these non-classical RAS components contribute to the therapeutic blockade of the classical system to reduce blood pressure and attenuate various indices of renal injury, as well as contribute to normal renal function.
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Affiliation(s)
- Mark C Chappell
- The Hypertension & Vascular Disease Center, Department of Physiology & Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
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134
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The renin-angiotensin-aldosterone system in 2011: role in hypertension and chronic kidney disease. Pediatr Nephrol 2012; 27:1835-45. [PMID: 21947887 DOI: 10.1007/s00467-011-2002-y] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 08/27/2011] [Accepted: 08/30/2011] [Indexed: 12/16/2022]
Abstract
Over the past two decades, considerable advances have been made in our understanding of the renin-angiotensin-aldosterone system (RAAS) and its roles in various disease states. In this review, we will discuss the current state of knowledge of the many components of the RAAS, including new data on prorenin and its receptors, and important angiotensin fragments. The roles of these components of the RAAS in the pathogenesis of primary hypertension and the progression of chronic kidney disease (CKD) will also be highlighted. Given the new understanding of the many components and roles of the RAAS, it may be possible to develop improved therapies for hypertension and CKD.
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135
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Liu GC, Fang F, Zhou J, Koulajian K, Yang S, Lam L, Reich HN, John R, Herzenberg AM, Giacca A, Oudit GY, Scholey JW. Deletion of p47phox attenuates the progression of diabetic nephropathy and reduces the severity of diabetes in the Akita mouse. Diabetologia 2012; 55:2522-32. [PMID: 22653270 DOI: 10.1007/s00125-012-2586-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 04/17/2012] [Indexed: 01/06/2023]
Abstract
AIMS/HYPOTHESIS Reactive oxygen species (ROS) contribute to diabetes-induced glomerular injury and endoplasmic reticulum (ER) stress-induced beta cell dysfunction, but the source of ROS has not been fully elucidated. Our aim was to determine whether p47(phox)-dependent activation of NADPH oxidase is responsible for hyperglycaemia-induced glomerular injury in the Akita mouse, a model of type 1 diabetes mellitus resulting from ER stress-induced beta cell dysfunction. METHODS We examined the effect of deleting p47 (phox) (also known as Ncf1), the gene for the NADPH oxidase subunit, on diabetic nephropathy in the Akita mouse (Ins2 (WT/C96Y)) by studying four groups of mice: (1) non-diabetic mice (Ins2 (WT/WT)/p47 (phox+/+)); (2) non-diabetic p47 (phox)-null mice (Ins2 (WT/WT)/p47 (phox-/-)); (3) diabetic mice: (Ins2 (WT/C96Y)/p47 (phox+/+)); and (4) diabetic p47 (phox)-null mice (Ins2 (WT/C96Y)/p47 (phox-/-)). We measured the urinary albumin excretion rate, oxidative stress, mesangial matrix expansion, and plasma and pancreatic insulin concentrations in 16-week-old mice; we also measured glucose tolerance and insulin sensitivity, islet and glomerular NADPH oxidase activity and subunit expression, and pro-fibrotic gene expression in 8-week-old mice. In addition, we measured NADPH oxidase activity, subunit expression and pro-fibrotic gene expression in high glucose-treated murine mesangial cells. RESULTS Deletion of p47 (phox) reduced kidney hypertrophy, oxidative stress and mesangial matrix expansion, and also reduced hyperglycaemia by increasing pancreatic and circulating insulin concentrations. p47 (phox-/-) mice exhibited improved glucose tolerance, but modestly decreased insulin sensitivity. Deletion of p47 (phox) attenuated high glucose-induced activation of NADPH oxidase and pro-fibrotic gene expression in glomeruli and mesangial cells. CONCLUSIONS/INTERPRETATION Deletion of p47 (phox) attenuates diabetes-induced glomerular injury and beta cell dysfunction in the Akita mouse.
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Affiliation(s)
- G C Liu
- Institute of Medical Sciences, University of Toronto, 7326 Medical Sciences Building, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada.
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136
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Basu R, Lee J, Wang Z, Patel VB, Fan D, Das SK, Liu GC, John R, Scholey JW, Oudit GY, Kassiri Z. Loss of TIMP3 selectively exacerbates diabetic nephropathy. Am J Physiol Renal Physiol 2012; 303:F1341-52. [PMID: 22896043 DOI: 10.1152/ajprenal.00349.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Diabetic nephropathy is the most common cause of end-stage renal disease. Polymorphism in the tissue inhibitor of metalloproteinase-3 (TIMP3) gene, and the ECM-bound inhibitor of matrix metalloproteinases (MMPs), has been linked to diabetic nephropathy in humans. To elucidate the mechanism, we generated double mutant mice in which the TIMP3 gene was deleted in the genetic diabetic Akita mouse background. The aggravation of diabetic injury occurred in the absence of worsening of hypertension or hyperglycemia. In fact, myocardial TIMP3 levels were not affected in Akita hearts, and cardiac diastolic and systolic function remained unchanged in the double mutant mice. However, TIMP3 levels increased in Akita kidneys and deletion of TIMP3 exacerbated the diabetic renal injury in the Akita mouse, characterized by increased albuminuria, mesangial matrix expansion, and kidney hypertrophy. The progression of diabetic renal injury was accompanied by the upregulation of fibrotic and inflammatory markers, increased production of reactive oxygen species and NADPH oxidase activity, and elevated activity of TNF-α-converting enzyme (TACE) in the TIMP3(-/-)/Akita kidneys. Moreover, while the elevated phospho-Akt (S473 and T308) and phospho-ERK1/2 in the Akita mice was not detected in the TIMP3(-/-)/Akita kidneys, PKCβ1 (but not PKCα) was markedly elevated in the double mutant kidneys. Our data provide definitive evidence for a critical and selective role of TIMP3 in diabetic renal injury consistent with gene expression findings from human diabetic kidneys.
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Affiliation(s)
- Ratnadeep Basu
- Dept. of Physiology, Univ. of Alberta, Edmonton, Alberta, Canada T6G 2S2
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137
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Abstract
Ang-(1-7) [angiotensin-(1-7)] is a biologically active heptapeptide component of the RAS (renin-angiotensin system), and is generated in the kidney at relatively high levels, via enzymatic pathways that include ACE2 (angiotensin-converting enzyme 2). The biological effects of Ang-(1-7) in the kidney are primarily mediated by interaction with the G-protein-coupled receptor Mas. However, other complex effects have been described that may involve receptor-receptor interactions with AT(1) (angiotensin II type 1) or AT(2) (angiotensin II type 2) receptors, as well as nuclear receptor binding. In the renal vasculature, Ang-(1-7) has vasodilatory properties and it opposes growth-stimulatory signalling in tubular epithelial cells. In several kidney diseases, including hypertensive and diabetic nephropathy, glomerulonephritis, tubulointerstitial fibrosis, pre-eclampsia and acute kidney injury, a growing body of evidence supports a role for endogenous or exogenous Ang-(1-7) as an antagonist of signalling mediated by AT(1) receptors and thereby as a protector against nephron injury. In certain experimental conditions, Ang-(1-7) appears to paradoxically exacerbate renal injury, suggesting that dose or route of administration, state of activation of the local RAS, cell-specific signalling or non-Mas receptor-mediated pathways may contribute to the deleterious responses. Although Ang-(1-7) has promise as a potential therapeutic agent in humans with kidney disease, further studies are required to delineate its signalling mechanisms in the kidney under physiological and pathophysiological conditions.
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138
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Giani JF, Burghi V, Veiras LC, Tomat A, Muñoz MC, Cao G, Turyn D, Toblli JE, Dominici FP. Angiotensin-(1–7) attenuates diabetic nephropathy in Zucker diabetic fatty rats. Am J Physiol Renal Physiol 2012; 302:F1606-15. [DOI: 10.1152/ajprenal.00063.2012] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Angiotensin (ANG)-(1–7) is known to attenuate diabetic nephropathy; however, its role in the modulation of renal inflammation and oxidative stress in type 2 diabetes is poorly understood. Thus in the present study we evaluated the renal effects of a chronic ANG-(1–7) treatment in Zucker diabetic fatty rats (ZDF), an animal model of type 2 diabetes and nephropathy. Sixteen-week-old male ZDF and their respective controls [lean Zucker rats (LZR)] were used for this study. The protocol involved three groups: 1) LZR + saline, 2) ZDF + saline, and 3) ZDF + ANG-(1–7). For 2 wk, animals were implanted with subcutaneous osmotic pumps that delivered either saline or ANG-(1–7) (100 ng·kg−1·min−1) ( n = 4). Renal fibrosis and tissue parameters of oxidative stress were determined. Also, renal levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), ED-1, hypoxia-inducible factor-1α (HIF-1α), and neutrophil gelatinase-associated lipocalin (NGAL) were determined by immunohistochemistry and immunoblotting. ANG-(1–7) induced a reduction in triglyceridemia, proteinuria, and systolic blood pressure (SBP) together with a restoration of creatinine clearance in ZDF. Additionally, ANG-(1–7) reduced renal fibrosis, decreased thiobarbituric acid-reactive substances, and restored the activity of both renal superoxide dismutase and catalase in ZDF. This attenuation of renal oxidative stress proceeded with decreased renal immunostaining of IL-6, TNF-α, ED-1, HIF-1α, and NGAL to values similar to those displayed by LZR. Angiotensin-converting enzyme type 2 (ACE2) and ANG II levels remained unchanged after treatment with ANG-(1–7). Chronic ANG-(1–7) treatment exerts a renoprotective effect in ZDF associated with a reduction of SBP, oxidative stress, and inflammatory markers. Thus ANG-(1–7) emerges as a novel target for treatment of diabetic nephropathy.
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Affiliation(s)
- Jorge F. Giani
- Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Valeria Burghi
- Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Luciana C. Veiras
- Facultad de Farmacia y Bioquímica, Cátedra de Fisiología, Universidad de Buenos Aires, Buenos Aires, Argentina; and
| | - Analía Tomat
- Facultad de Farmacia y Bioquímica, Cátedra de Fisiología, Universidad de Buenos Aires, Buenos Aires, Argentina; and
| | - Marina C. Muñoz
- Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gabriel Cao
- Laboratory of Experimental Medicine, Hospital Alemán, Buenos Aires, Argentina
| | - Daniel Turyn
- Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jorge E. Toblli
- Laboratory of Experimental Medicine, Hospital Alemán, Buenos Aires, Argentina
| | - Fernando P. Dominici
- Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológicas, Universidad de Buenos Aires, Buenos Aires, Argentina
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139
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Xiao F, Hiremath S, Knoll G, Zimpelmann J, Srivaratharajah K, Jadhav D, Fergusson D, Kennedy CRJ, Burns KD. Increased urinary angiotensin-converting enzyme 2 in renal transplant patients with diabetes. PLoS One 2012; 7:e37649. [PMID: 22629438 PMCID: PMC3358292 DOI: 10.1371/journal.pone.0037649] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/23/2012] [Indexed: 12/16/2022] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is expressed in the kidney and may be a renoprotective enzyme, since it converts angiotensin (Ang) II to Ang-(1-7). ACE2 has been detected in urine from patients with chronic kidney disease. We measured urinary ACE2 activity and protein levels in renal transplant patients (age 54 yrs, 65% male, 38% diabetes, n = 100) and healthy controls (age 45 yrs, 26% male, n = 50), and determined factors associated with elevated urinary ACE2 in the patients. Urine from transplant subjects was also assayed for ACE mRNA and protein. No subjects were taking inhibitors of the renin-angiotensin system. Urinary ACE2 levels were significantly higher in transplant patients compared to controls (p = 0.003 for ACE2 activity, and p≤0.001 for ACE2 protein by ELISA or western analysis). Transplant patients with diabetes mellitus had significantly increased urinary ACE2 activity and protein levels compared to non-diabetics (p<0.001), while ACE2 mRNA levels did not differ. Urinary ACE activity and protein were significantly increased in diabetic transplant subjects, while ACE mRNA levels did not differ from non-diabetic subjects. After adjusting for confounding variables, diabetes was significantly associated with urinary ACE2 activity (p = 0.003) and protein levels (p<0.001), while female gender was associated with urinary mRNA levels for both ACE2 and ACE. These data indicate that urinary ACE2 is increased in renal transplant recipients with diabetes, possibly due to increased shedding from tubular cells. Urinary ACE2 could be a marker of renal renin-angiotensin system activation in these patients.
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Affiliation(s)
- Fengxia Xiao
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Swapnil Hiremath
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Greg Knoll
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Joseph Zimpelmann
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Kajenny Srivaratharajah
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Deepak Jadhav
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Dean Fergusson
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Chris R. J. Kennedy
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Kevin D. Burns
- Division of Nephrology, Department of Medicine, Ottawa Hospital Research Institute, Kidney Research Centre, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
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140
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Targeting the ACE2 and Apelin Pathways Are Novel Therapies for Heart Failure: Opportunities and Challenges. Cardiol Res Pract 2012; 2012:823193. [PMID: 22655211 PMCID: PMC3359660 DOI: 10.1155/2012/823193] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 02/21/2012] [Indexed: 11/17/2022] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2)/Ang II/Ang 1-7 and the apelin/APJ are two important peptide systems which exert diverse effects on the cardiovascular system. ACE2 is a key negative regulator of the renin-angiotensin system (RAS) where it metabolizes angiotensin (Ang) II into Ang 1-7, an endogenous antagonist of Ang II. Both the prolonged activation of RAS and the loss of ACE2 can be detrimental as they lead to functional deterioration of the heart and progression of cardiac, renal, and vascular diseases. Recombinant human ACE2 in an animal model of ACE2 knockout mice lowers Ang II. These interactions neutralize the pressor and subpressor pathologic effects of Ang II by producing Ang 1-7 levels in vivo, that might be cardiovascular protective. ACE2 hydrolyzes apelin to Ang II and, therefore, is responsible for the degradation of both peptides. Apelin has emerged as a promising peptide biomarker of heart failure. The serum level of apelin in cardiovascular diseases tends to be decreased. Apelin is recognized as an imperative controller of systemic blood pressure and myocardium contractility. Dysregulation of the apelin/APJ system may be involved in the predisposition to cardiovascular diseases, and enhancing apelin action may have important therapeutic effects.
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141
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Loss of angiotensin-converting enzyme 2 enhances TGF-β/Smad-mediated renal fibrosis and NF-κB-driven renal inflammation in a mouse model of obstructive nephropathy. J Transl Med 2012; 92:650-61. [PMID: 22330342 DOI: 10.1038/labinvest.2012.2] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
It is known that angiotensin (Ang)-converting enzyme (ACE) 2 catalyzes Ang II to Ang 1-7 to prevent the detrimental effect of Ang II on blood pressure, renal fibrosis, and inflammation. However, mechanisms of renoprotective role of Ace2 remain largely unclear. The present study tested the hypothesis that deficiency of Ace2 may accelerate intrarenal Ang II-mediated fibrosis and inflammation independent of blood pressure in a model of unilateral ureteral obstructive (UUO) nephropathy induced in Ace2(+/y) and Ace2(-/y) mice. Results showed that both Ace2(+/y) and Ace2(-/y) mice had normal levels of blood pressure and plasma Ang II/Ang 1-7. In contrast, deletion of ACE2 resulted in a fourfold increase in the ratio of intrarenal Ang II/Ang 1-7 in the UUO nephropathy. These changes were associated with the development of more intensive tubulointerstitial fibrosis (α-SMA, collagen I) and inflammation (TNF-α, IL-1β, MCP-1, F4/80(+) cells, and CD3(+)T cells) in Ace2(-/y) mice at day 3 (all P<0.05) after UUO, becoming more profound at day 7 (all P<0.01). Enhanced renal fibrosis and inflammation in the UUO kidney of Ace2(-/y) mice were largely attributed to a marked increase in the intrarenal Ang II signaling (AT1-ERK1/2 mitogen-activated protein kinase), TGF-β/Smad2/3, and NF-κB signaling pathways. Further studies revealed that enhanced TGF-β/Smad and NF-κB signaling in the UUO kidney of Ace2(-/y) mice was associated with upregulation of an E3 ligase Smurf2 and a loss of renal Smad7. In conclusion, enhanced Ang II-mediated TGF-β/Smad and NF-κB signaling may be the mechanisms by which loss of Ace2 enhances renal fibrosis and inflammation. Smad7 ubiquitin degradation mediated by Smurf2 may be a central mechanism by which Ace2(-/y) mice promote TGF-β/Smad2/3-mediated renal fibrosis and NF-κB-driven renal inflammation in a mouse model of UUO nephropathy.
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142
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Angiotensin-converting enzyme 2 regulates renal atrial natriuretic peptide through angiotensin-(1-7). Clin Sci (Lond) 2012; 123:29-37. [PMID: 22288735 DOI: 10.1042/cs20110403] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Deficiency of ACE2 (angiotensin-converting enzyme 2), which degrades Ang (angiotensin) II, promotes the development of glomerular lesions. However, the mechanisms explaining why the reduction in ACE2 is associated with the development of glomerular lesions have still to be fully clarified. We hypothesized that ACE2 may regulate the renoprotective actions of ANP (atrial natriuretic peptide). The aim of the present study was to investigate the effect of ACE2 deficiency on the renal production of ANP. We evaluated molecular and structural abnormalities, as well as the expression of ANP in the kidneys of ACE2-deficient mice and C57BL/6 mice. We also exposed renal tubular cells to AngII and Ang-(1-7) in the presence and absence of inhibitors and agonists of RAS (renin-angiotensin system) signalling. ACE2 deficiency resulted in increased oxidative stress, as well as pro-inflammatory and profibrotic changes. This was associated with a down-regulation of the gene and protein expression on the renal production of ANP. Consistent with a role for the ACE2 pathway in modulating ANP, exposing cells to either Ang-(1-7) or ACE2 or the Mas receptor agonist up-regulated ANP gene expression. This work demonstrates that ACE2 regulates renal ANP via the generation of Ang-(1-7). This is a new mechanism whereby ACE2 counterbalances the renal effects of AngII and which explains why targeting ACE2 may be a promising strategy against kidney diseases, including diabetic nephropathy.
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143
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Soler MJ, Riera M, Gutierrez A, Pascual J. New options and perspectives for proteinuria management after kidney transplantation. Transplant Rev (Orlando) 2012; 26:44-52. [PMID: 22137732 DOI: 10.1016/j.trre.2011.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 07/28/2011] [Indexed: 12/31/2022]
Abstract
Proteinuria has been strongly correlated with reduced function and graft survival in kidney-transplanted patients. Data regarding new strategies in proteinuria treatment and subsequent allograft survival are lacking. Similarities between chronic graft injury and chronic kidney disease (CKD) suggest that the same therapeutic antiproteinuric tools should be effective in kidney-transplanted patients. The classic strategies to decrease proteinuria such as blood pressure control, nicotine cessation, low-salt diet, and maintaining an ideal body weight seem to be not enough to achieve proteinuria control. Improvements in our understanding of the pathogenesis of CKD have led to the identification of several novel targets for proteinuria management. In this review, we discuss novel pharmacological approaches that aim to decrease proteinuria in CKD patients, including the use of direct renin inhibitors, vitamin D analogs, pentoxifylline, and endothelin receptor antagonists. We also discuss the promise of using antifibrotic agents to treat proteinuria. The identification of new biomarkers of CKD and its progression can help in the selection of the most effective treatment for decreasing proteinuria and maintaining kidney function.
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Affiliation(s)
- María José Soler
- Department of Nephrology, Hospital del Mar-IMIM, Barcelona, Spain.
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144
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Clarke NE, Fisher MJ, Porter KE, Lambert DW, Turner AJ. Angiotensin converting enzyme (ACE) and ACE2 bind integrins and ACE2 regulates integrin signalling. PLoS One 2012; 7:e34747. [PMID: 22523556 PMCID: PMC3327712 DOI: 10.1371/journal.pone.0034747] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 03/08/2012] [Indexed: 12/22/2022] Open
Abstract
The angiotensin converting enzymes (ACEs) are the key catalytic components of the renin-angiotensin system, mediating precise regulation of blood pressure by counterbalancing the effects of each other. Inhibition of ACE has been shown to improve pathology in cardiovascular disease, whilst ACE2 is cardioprotective in the failing heart. However, the mechanisms by which ACE2 mediates its cardioprotective functions have yet to be fully elucidated. Here we demonstrate that both ACE and ACE2 bind integrin subunits, in an RGD-independent manner, and that they can act as cell adhesion substrates. We show that cellular expression of ACE2 enhanced cell adhesion. Furthermore, we present evidence that soluble ACE2 (sACE2) is capable of suppressing integrin signalling mediated by FAK. In addition, sACE2 increases the expression of Akt, thereby lowering the proportion of the signalling molecule phosphorylated Akt. These results suggest that ACE2 plays a role in cell-cell interactions, possibly acting to fine-tune integrin signalling. Hence the expression and cleavage of ACE2 at the plasma membrane may influence cell-extracellular matrix interactions and the signalling that mediates cell survival and proliferation. As such, ectodomain shedding of ACE2 may play a role in the process of pathological cardiac remodelling.
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Affiliation(s)
- Nicola E. Clarke
- Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Martin J. Fisher
- Department of Chemistry, University of Leeds, Leeds, United Kingdom
| | - Karen E. Porter
- Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, United Kingdom
| | - Daniel W. Lambert
- Oral Disease Research Group, University of Sheffield, Sheffield, United Kingdom
| | - Anthony J. Turner
- Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- * E-mail:
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145
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Podocyte-specific overexpression of human angiotensin-converting enzyme 2 attenuates diabetic nephropathy in mice. Kidney Int 2012; 82:292-303. [PMID: 22475818 PMCID: PMC3410252 DOI: 10.1038/ki.2012.83] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Angiotensin-converting enzyme 2 (ACE2) degrades angiotensin II to angiotensin-(1–7) and is expressed in podocytes. Here we overexpressed ACE2 in podocytes in experimental diabetic nephropathy using transgenic methods where a nephrin promoter drove the expression of human ACE2. Glomeruli from these mice had significantly increased mRNA, protein, and activity of ACE2 compared to wild-type mice. Male mice were treated with streptozotocin to induce diabetes. After 16 weeks, there was no significant difference in plasma glucose levels between wild-type and transgenic diabetic mice. Urinary albumin was significantly increased in wild-type diabetic mice at 4 weeks, whereas albuminuria in transgenic diabetic mice did not differ from wild-type nondiabetic mice. However, this effect was transient and by 16 weeks both transgenic and nontransgenic diabetic mice had similar rates of proteinuria. Compared to wild-type diabetic mice, transgenic diabetic mice had an attenuated increase in mesangial area, decreased glomerular area, and a blunted decrease in nephrin expression. Podocyte numbers decreased in wild-type diabetic mice at 16 weeks, but were unaffected in transgenic diabetic mice. At 8 weeks, kidney cortical expression of transforming growth factor-β1 was significantly inhibited in transgenic diabetic mice as compared to wild-type diabetic mice. Thus, the podocyte-specific overexpression of human ACE2 transiently attenuates the development of diabetic nephropathy.
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146
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Patel VB, Bodiga S, Basu R, Das SK, Wang W, Wang Z, Lo J, Grant MB, Zhong J, Kassiri Z, Oudit GY. Loss of angiotensin-converting enzyme-2 exacerbates diabetic cardiovascular complications and leads to systolic and vascular dysfunction: a critical role of the angiotensin II/AT1 receptor axis. Circ Res 2012; 110:1322-35. [PMID: 22474255 DOI: 10.1161/circresaha.112.268029] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
RATIONALE Diabetic cardiovascular complications are reaching epidemic proportions. Angiotensin-converting enzyme-2 (ACE2) is a negative regulator of the renin-angiotensin system. We hypothesize that loss of ACE2 exacerbates cardiovascular complications induced by diabetes. OBJECTIVE To define the role of ACE2 in diabetic cardiovascular complications. METHODS AND RESULTS We used the well-validated Akita mice, a model of human diabetes, and generated double-mutant mice using the ACE2 knockout (KO) mice (Akita/ACE2(-/y)). Diabetic state was associated with increased ACE2 in Akita mice, whereas additional loss of ACE2 in these mice leads to increased plasma and tissue angiotensin II levels, resulting in systolic dysfunction on a background of impaired diastolic function. Downregulation of SERCA2 and lipotoxicity were equivalent in Akita and Akita/ACE2KO hearts and are likely mediators of the diastolic dysfunction. However, greater activation of protein kinase C and loss of Akt and endothelial nitric oxide synthase phosphorylation occurred in the Akita/ACE2KO hearts. Systolic dysfunction in Akita/ACE2KO mice was linked to enhanced activation of NADPH oxidase and metalloproteinases, resulting in greater oxidative stress and degradation of the extracellular matrix. Impaired flow-mediated dilation in vivo correlated with increased vascular oxidative stress in Akita/ACE2KO mice. Treatment with the AT1 receptor blocker, irbesartan rescued the systolic dysfunction, normalized altered signaling pathways, flow-mediated dilation, and the increased oxidative stress in the cardiovascular system. CONCLUSIONS Loss of ACE2 disrupts the balance of the renin-angiotensin system in a diabetic state and leads to an angiotensin II/AT1 receptor-dependent systolic dysfunction and impaired vascular function. Our study demonstrates that ACE2 serves as a protective mechanism against diabetes-induced cardiovascular complications.
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Affiliation(s)
- Vaibhav B Patel
- Division of Cardiology, Department of Medicine, Mazankowski Alberta Heart Institute, University of Alberta, Alberta, Edmonton, Canada
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147
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Angiotensin-Converting Enzyme 2 (ACE2) Is a Key Modulator of the Renin Angiotensin System in Health and Disease. INTERNATIONAL JOURNAL OF PEPTIDES 2012; 2012:256294. [PMID: 22536270 PMCID: PMC3321295 DOI: 10.1155/2012/256294] [Citation(s) in RCA: 378] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 12/05/2011] [Indexed: 12/29/2022]
Abstract
Angiotensin-converting enzyme 2 (ACE2) shares some homology with angiotensin-converting enzyme (ACE) but is not inhibited by ACE inhibitors. The main role of ACE2 is the degradation of Ang II resulting in the formation of angiotensin 1–7 (Ang 1–7) which opposes the actions of Ang II. Increased Ang II levels are thought to upregulate ACE2 activity, and in ACE2 deficient mice Ang II levels are approximately double that of wild-type mice, whilst Ang 1–7 levels are almost undetectable. Thus, ACE2 plays a crucial role in the RAS because it opposes the actions of Ang II. Consequently, it has a beneficial role in many diseases such as hypertension, diabetes, and cardiovascular disease where its expression is decreased. Not surprisingly, current therapeutic strategies for ACE2 involve augmenting its expression using ACE2 adenoviruses, recombinant ACE2 or compounds in these diseases thereby affording some organ protection.
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148
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Abstract
The renin-angiotensin system (RAS) exercises fundamental control over sodium and water handling in the kidney. Accordingly, dysregulation of the RAS leads to blood pressure elevation with ensuing renal and cardiovascular damage. Recent studies have revealed that the RAS hormonal cascade is more complex than initially posited with multiple enzymes, effector molecules, and receptors that coordinately regulate the effects of the RAS on the kidney and vasculature. Moreover, recently identified tissue-specific RAS components have pleomorphic effects independent of the circulating RAS that influence critical homeostatic mechanisms including the immune response and fetal development. Further characterization of the diverse interactions between the RAS and other signaling pathways within specific tissues should lead to novel treatments for renal and cardiovascular disease.
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149
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Yamaleyeva LM, Gilliam-Davis S, Almeida I, Brosnihan KB, Lindsey SH, Chappell MC. Differential regulation of circulating and renal ACE2 and ACE in hypertensive mRen2.Lewis rats with early-onset diabetes. Am J Physiol Renal Physiol 2012; 302:F1374-84. [PMID: 22378820 DOI: 10.1152/ajprenal.00656.2011] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We examined the impact of early diabetes on the circulating and kidney renin-angiotensin system (RAS) in male and female mRen2.Lewis (mRen2) hypertensive rats. Diabetes (DB) was induced by streptozotocin (STZ; 65 mg/kg) at 11 wk of age for 4 wk without insulin replacement. Systolic blood pressures were not increased in DB males or females compared with controls (CON). Circulating angiotensin-converting enzyme 2 (ACE2) increased ninefold (P < 0.05) in DB females and threefold (P < 0.05) in DB males, but circulating ACE and ANG II were higher in the DB groups. Serum C-reactive protein was elevated in DB females but not DB males, and the vascular responses to acetylcholine and estradiol were attenuated in the DB females. Proteinuria, albuminuria, and angiotensinogen excretion increased to a similar extent in both DB females and males. Glomerular VEGF expression also increased to a similar extent in both DB groups. Renal inflammation (CD68(+)cells) increased only in DB females although males exhibited greater inflammation that was not different with DB. Cortical ACE2 did not change in DB females but was reduced (30%) in DB males. Renal neprilysin activity (>75%, P < 0.05) was markedly reduced in the DB females to that in the DB and CON males. ACE activity was significantly lower in both female (75%, P < 0.05) and male (50%; P < 0.05) DB groups, while cortical ANG II and Ang-(1-7) levels were unchanged. In conclusion, female mRen2 rats are not protected from vascular damage, renal inflammation, and kidney injury in early STZ-induced diabetes despite a marked increase in circulating ACE2 and significantly reduced ACE within the kidney.
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Affiliation(s)
- Liliya M Yamaleyeva
- Hypertension and Vascular Research Center, Wake Forest School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157, USA
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150
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Angiotensin converting enzyme 2, Angiotensin-(1-7), and receptor MAS axis in the kidney. Int J Hypertens 2012; 2012:414128. [PMID: 22518283 PMCID: PMC3296191 DOI: 10.1155/2012/414128] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 11/02/2011] [Indexed: 02/07/2023] Open
Abstract
In the past few years the understanding of the renin-angiotensin system (RAS) has improved, helping to better define the role of this system in physiological conditions and in human diseases. Besides Angiotensin (Ang) II, the biological importance of other Ang fragments was progressively evidenced. In this regard, Angiotensin- (Ang-) (1-7) was recognized as a biologically active product of the RAS cascade with a specific receptor, the G-protein-coupled receptor Mas, and that is mainly formed by the action of the angiotensin-converting enzyme (ACE) homolog enzyme, ACE2, which converts Ang II into Ang-(1-7). Taking into account the biological effects of these two mediators, Ang II and Ang-(1-7), the RAS can be envisioned as a dual function system in which the vasoconstrictor/proliferative or vasodilator/antiproliferative actions are primarily driven by the balance between Ang II and Ang-(1-7), respectively. In this paper, we will discuss our current understanding of the ACE2/Ang-(1-7)/Mas axis of the RAS in renal physiology and in the pathogenesis of primary hypertension and chronic kidney disease.
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