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Steckelings UM, Widdop RE, Sturrock ED, Lubbe L, Hussain T, Kaschina E, Unger T, Hallberg A, Carey RM, Sumners C. The Angiotensin AT 2 Receptor: From a Binding Site to a Novel Therapeutic Target. Pharmacol Rev 2022; 74:1051-1135. [PMID: 36180112 PMCID: PMC9553111 DOI: 10.1124/pharmrev.120.000281] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/19/2022] [Accepted: 06/27/2022] [Indexed: 11/22/2022] Open
Abstract
Discovered more than 30 years ago, the angiotensin AT2 receptor (AT2R) has evolved from a binding site with unknown function to a firmly established major effector within the protective arm of the renin-angiotensin system (RAS) and a target for new drugs in development. The AT2R represents an endogenous protective mechanism that can be manipulated in the majority of preclinical models to alleviate lung, renal, cardiovascular, metabolic, cutaneous, and neural diseases as well as cancer. This article is a comprehensive review summarizing our current knowledge of the AT2R, from its discovery to its position within the RAS and its overall functions. This is followed by an in-depth look at the characteristics of the AT2R, including its structure, intracellular signaling, homo- and heterodimerization, and expression. AT2R-selective ligands, from endogenous peptides to synthetic peptides and nonpeptide molecules that are used as research tools, are discussed. Finally, we summarize the known physiological roles of the AT2R and its abundant protective effects in multiple experimental disease models and expound on AT2R ligands that are undergoing development for clinical use. The present review highlights the controversial aspects and gaps in our knowledge of this receptor and illuminates future perspectives for AT2R research. SIGNIFICANCE STATEMENT: The angiotensin AT2 receptor (AT2R) is now regarded as a fully functional and important component of the renin-angiotensin system, with the potential of exerting protective actions in a variety of diseases. This review provides an in-depth view of the AT2R, which has progressed from being an enigma to becoming a therapeutic target.
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Affiliation(s)
- U Muscha Steckelings
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert E Widdop
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Edward D Sturrock
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Lizelle Lubbe
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Tahir Hussain
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Elena Kaschina
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Thomas Unger
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Anders Hallberg
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert M Carey
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Colin Sumners
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
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Interactions between the intrarenal dopaminergic and the renin-angiotensin systems in the control of systemic arterial pressure. Clin Sci (Lond) 2022; 136:1205-1227. [PMID: 35979889 DOI: 10.1042/cs20220338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/31/2022] [Accepted: 08/03/2022] [Indexed: 11/17/2022]
Abstract
Systemic arterial hypertension is one of the leading causes of morbidity and mortality in the general population, being a risk factor for many cardiovascular diseases. Although its pathogenesis is complex and still poorly understood, some systems appear to play major roles in its development. This review aims to update the current knowledge on the interaction of the intrarenal renin-angiotensin system (RAS) and dopaminergic system in the development of hypertension, focusing on recent scientific hallmarks in the field. The intrarenal RAS, composed of several peptides and receptors, has a critical role in the regulation of blood pressure (BP) and, consequently, the development of hypertension. The RAS is divided into two main intercommunicating axes: the classical axis, composed of angiotensin-converting enzyme, angiotensin II, and angiotensin type 1 receptor, and the ACE2/angiotensin-(1-7)/Mas axis, which appears to modulate the effects of the classical axis. Dopamine and its receptors are also increasingly showing an important role in the pathogenesis of hypertension, as abnormalities in the intrarenal dopaminergic system impair the regulation of renal sodium transport, regardless of the affected dopamine receptor subtype. There are five dopamine receptors, which are divided into two major subtypes: the D1-like (D1R and D5R) and D2-like (D2R, D3R, and D4R) receptors. Mice deficient in any of the five dopamine receptor subtypes have increased BP. Intrarenal RAS and the dopaminergic system have complex interactions. The balance between both systems is essential to regulate the BP homeostasis, as alterations in the control of both can lead to hypertension.
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Zhang Y, Ogola BO, Iyer L, Karamyan VT, Thekkumkara T. Estrogen Metabolite 2-Methoxyestradiol Attenuates Blood Pressure in Hypertensive Rats by Downregulating Angiotensin Type 1 Receptor. Front Physiol 2022; 13:876777. [PMID: 35586713 PMCID: PMC9108484 DOI: 10.3389/fphys.2022.876777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022] Open
Abstract
The therapeutic potential of 2-Methoxyestradiol (2ME2) is evident in cardiovascular disease. Our laboratory has previously demonstrated the mechanism involved in the 2ME2 regulation of angiotensin type 1 receptor (AT1R) in vitro. However, 2ME2 regulation of angiotensin receptors and its effects on blood pressure (BP) and resting heart rate (RHR) are uncertain. In this study, male and female Wistar-Kyoto (WKY) rats infused with angiotensin II (65 ng/min) and male spontaneously hypertensive rats (SHR) were surgically implanted with telemetric probes to continuously assess arterial BP and RHR. In both male and female WKY rats, 2ME2 treatment (20 mg/kg/day for 2 weeks) resulted in a significant reduction of Ang II-induced systolic, diastolic, and mean arterial BP. Moreover, significant weight loss and RHR were indicated in all groups. In a separate set of experiments, prolonged 2ME2 exposure in male SHR (20 mg/kg/day for 5 weeks) displayed a significant reduction in diastolic and mean arterial BP along with RHR. We also found downregulation of angiotensin receptors and angiotensinogen (AGT) in the kidney and liver and a reduction of plasma Ang II levels. Collectively, we demonstrate that 2ME2 attenuated BP and RHR in hypertensive rats involves downregulation of angiotensin receptors and body weight loss.
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Affiliation(s)
- Yong Zhang
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, United States
| | - Benard O. Ogola
- Department of Pharmacology, Tulane University, New Orleans, LA, United States
- *Correspondence: Benard O. Ogola,
| | - Laxmi Iyer
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, United States
| | - Vardan T. Karamyan
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, United States
| | - Thomas Thekkumkara
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TX, United States
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Zizzo MG, Cicio A, Corrao F, Lentini L, Serio R. Aging modifies receptor expression but not muscular contractile response to angiotensin II in rat jejunum. J Physiol Biochem 2022; 78:753-762. [PMID: 35394564 PMCID: PMC9684288 DOI: 10.1007/s13105-022-00892-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/23/2022] [Indexed: 12/03/2022]
Abstract
The involvement of renin-angiotensin system in the modulation of gut motility and age-related changes in mRNA expression of angiotensin (Ang II) receptors (ATR) are well accepted. We aimed to characterize, in vitro, the contractile responses induced by Ang II, in jejunum from young (3–6 weeks old) and old rats (≥ 1 year old), to evaluate possible functional differences associated to changes in receptor expression. Mechanical responses to Ang II were examined in vitro as changes in isometric tension. ATR expression was assessed by qRT-PCR. Ang II induced a contractile effect, antagonized by losartan, AT1R antagonist, and increased by PD123319, AT2R antagonist, as well by neural blocker ω-conotoxin and by nitric oxide (NO) synthase inhibitor. No difference in the response was observed between young and old groups. AT1 receptor-mediated contractile response was decreased by U-73122, phospholipase C (PLC) inhibitor; or 2-aminoethoxy-diphenylborate (2-APB), inositol triphosphate (IP3) receptor inhibitor; or nifedipine, l-type calcium channel blocker. Age-related changes in the expression of both AT1 receptor subtypes, AT1a and AT1b, and of AT2 receptors were detected. In conclusion, Ang II modulates the spontaneous contractility of rat jejunum via postjunctional AT1 receptors, involving Ca2+ mobilization from intracellular stores, via PLC/IP3 pathway, and Ca2+ influx from extracellular space, via l-type channels. Prejunctional AT2 receptors would counteract AT1 receptor effects, via NO synthesis. The observed age-related differences in the expression of all AT receptor subtypes are not reflected in the muscular contractile response to Ang II.
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Affiliation(s)
- Maria Grazia Zizzo
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, ed. 16, 90128, Palermo, Italy.
- ATeN (Advanced Technologies Network) Center, University of Palermo, Viale delle Scienze, ed.18, 90128, Palermo, Italy.
| | - Adele Cicio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, ed. 16, 90128, Palermo, Italy
| | - Federica Corrao
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, ed. 16, 90128, Palermo, Italy
| | - Laura Lentini
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, ed. 16, 90128, Palermo, Italy
| | - Rosa Serio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, ed. 16, 90128, Palermo, Italy
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Eckenstaler R, Sandori J, Gekle M, Benndorf RA. Angiotensin II receptor type 1 - An update on structure, expression and pathology. Biochem Pharmacol 2021; 192:114673. [PMID: 34252409 DOI: 10.1016/j.bcp.2021.114673] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 07/02/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022]
Abstract
The AT1 receptor, a major effector of the renin-angiotensin system, has been extensively studied in the context of cardiovascular and renal disease. Moreover, angiotensin receptor blockers, sartans, are among the most frequently prescribed drugs for the treatment of hypertension, chronic heart failure and chronic kidney disease. However, precise molecular insights into the structure of this important drug target have not been available until recently. In this context, seminal studies have now revealed exciting new insights into the structure and biased signaling of the receptor and may thus foster the development of novel therapeutic approaches to enhance the efficacy of pharmacological angiotensin receptor antagonism or to enable therapeutic induction of biased receptor activity. In this review, we will therefore highlight these and other seminal publications to summarize the current understanding of the tertiary structure, ligand binding properties and downstream signal transduction of the AT1 receptor.
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Affiliation(s)
| | - Jana Sandori
- Institute of Pharmacy, Martin-Luther-University, Halle, Germany
| | - Michael Gekle
- Julius-Bernstein-Institute of Physiology, Martin-Luther-University, Halle, Germany
| | - Ralf A Benndorf
- Institute of Pharmacy, Martin-Luther-University, Halle, Germany.
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Ranjit A, Khajehpour S, Aghazadeh-Habashi A. Update on Angiotensin II Subtype 2 Receptor: Focus on Peptide and Nonpeptide Agonists. Mol Pharmacol 2021; 99:469-487. [PMID: 33795351 DOI: 10.1124/molpharm.121.000236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 03/12/2021] [Indexed: 11/22/2022] Open
Abstract
Angiotensin II (Ang II) is the most dominant effector component of the renin-angiotensin system (RAS) that generally acts through binding to two main classes of G protein-coupled receptors, namely Ang II subtype 1 receptor (AT1R) and angiotensin II subtype 2 receptor (AT2R). Despite some controversial reports, the activation of AT2R generally antagonizes the effects of Ang II binding on AT1R. Studying AT2R signaling, function, and its specific ligands in cell culture or animal studies has confirmed its beneficial effects throughout the body. These characteristics classify AT2R as part of the protective arm of the RAS that, along with functions of Ang (1-7) through Mas receptor signaling, modulates the harmful effects of Ang II on AT1R in the activated classic arm of the RAS. Although Ang II is the primary ligand for AT2R, we have summarized other natural or synthetic peptide and nonpeptide agonists with critical evaluation of their structure, mechanism of action, and biologic activity. SIGNIFICANCE STATEMENT: AT2R is one of the main components of the RAS and has a significant prospective for mediating the beneficial action of the RAS through its protective arm on the body's homeostasis. Targeting AT2R offers substantial clinical application possibilities for modulating various pathological conditions. This review provided concise information regarding the AT2R peptide and nonpeptide agonists and their potential clinical applications for various diseases.
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Affiliation(s)
- Arina Ranjit
- College of Pharmacy, Idaho State University, Pocatello, Idaho, USA
| | - Sana Khajehpour
- College of Pharmacy, Idaho State University, Pocatello, Idaho, USA
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The Tissue Renin-Angiotensin System and Its Role in the Pathogenesis of Major Human Diseases: Quo Vadis? Cells 2021; 10:cells10030650. [PMID: 33804069 PMCID: PMC7999456 DOI: 10.3390/cells10030650] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/09/2021] [Accepted: 03/13/2021] [Indexed: 01/18/2023] Open
Abstract
Evidence has arisen in recent years suggesting that a tissue renin-angiotensin system (tRAS) is involved in the progression of various human diseases. This system contains two regulatory pathways: a pathological pro-inflammatory pathway containing the Angiotensin Converting Enzyme (ACE)/Angiotensin II (AngII)/Angiotensin II receptor type 1 (AGTR1) axis and a protective anti-inflammatory pathway involving the Angiotensin II receptor type 2 (AGTR2)/ACE2/Ang1–7/MasReceptor axis. Numerous studies reported the positive effects of pathologic tRAS pathway inhibition and protective tRAS pathway stimulation on the treatment of cardiovascular, inflammatory, and autoimmune disease and the progression of neuropathic pain. Cell senescence and aging are known to be related to RAS pathways. Further, this system directly interacts with SARS-CoV 2 and seems to be an important target of interest in the COVID-19 pandemic. This review focuses on the involvement of tRAS in the progression of the mentioned diseases from an interdisciplinary clinical perspective and highlights therapeutic strategies that might be of major clinical importance in the future.
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McFall A, Nicklin SA, Work LM. The counter regulatory axis of the renin angiotensin system in the brain and ischaemic stroke: Insight from preclinical stroke studies and therapeutic potential. Cell Signal 2020; 76:109809. [PMID: 33059037 PMCID: PMC7550360 DOI: 10.1016/j.cellsig.2020.109809] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 01/01/2023]
Abstract
Stroke is the 2nd leading cause of death worldwide and the leading cause of physical disability and cognitive issues. Although we have made progress in certain aspects of stroke treatment, the consequences remain substantial and new treatments are needed. Hypertension has long been recognised as a major risk factor for stroke, both haemorrhagic and ischaemic. The renin angiotensin system (RAS) plays a key role in blood pressure regulation and this, plus local expression and signalling of RAS in the brain, both support the potential for targeting this axis therapeutically in the setting of stroke. While historically, focus has been on suppressing classical RAS signalling through the angiotensin type 1 receptor (AT1R), the identification of a counter-regulatory axis of the RAS signalling via the angiotensin type 2 receptor (AT2R) and Mas receptor has renewed interest in targeting the RAS. This review describes RAS signalling in the brain and the potential of targeting the Mas receptor and AT2R in preclinical models of ischaemic stroke. The animal and experimental models, and the route and timing of intervention, are considered from a translational perspective.
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Affiliation(s)
- Aisling McFall
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Stuart A Nicklin
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Lorraine M Work
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK.
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Peng Y, Li Y, Chen M, Song J, Jiang Z, Shi S. High-dose nitrate therapy recovers the expression of subtypes α 1 and β-adrenoceptors and Ang II receptors of the renal cortex in rats with myocardial infarction-induced heart failures. BMC Cardiovasc Disord 2020; 20:99. [PMID: 32106816 PMCID: PMC7047386 DOI: 10.1186/s12872-020-01353-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 01/21/2020] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Few studies examined the effect of long-acting nitrates on renal function in chronic heart failure (CHF). Thus, we aimed to investigate the effect of long-acting nitrate on the expression of adrenoceptors (AR) and angiotensin II receptor (ATR) subtypes of the renal cortex, in rats with myocardial infarction-induced CHF. METHODS Rats were randomly divided into the following groups: control, sham-operated, CHF, low- and high-dose nitrate, positive drug control (olmesartan), and high-dose of long-acting nitrate + olmesartan. Ultrasound echocardiography markers were compared, and the levels of AR subtypes, AT1R, and AT2R were measured using reverse transcription-polymerase chain reaction and western blot analysis. Histopathology of the kidney was determined on hematoxylin and eosin-stained sections. RESULTS CHF significantly increased plasma renin activity (PRA) and angiotensin II levels, upregulated AT1R expression and downregulated α1A-, β1-, β2-AR, and AT2R expression compared to the sham control. High-dose nitrate or olmesartan alone, and especially in combination, decreased the levels of PRA and angiotensin II and downregulated the CHF-induced expression of AT1R, α1A-, β1-, and β2-AR, and AT2R. CHF resulted in significant impairment of the renal tissue, including inflammatory cells infiltration to the tubular interstitium and surrounding the renal glomerulus, and tubular necrosis, which was alleviated in all treatment groups to different degrees. CONCLUSIONS Long-acting nitrates could reverse CHF-induced changes in AR and ATR subtypes in the kidney, and improve cardiac function to protect renal function. Compared with monotherapy, the combination of nitrates and olmesartan shows more significant benefits in regulating AR and ATR subtypes.
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MESH Headings
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Animals
- Disease Models, Animal
- Drug Therapy, Combination
- Heart Failure/drug therapy
- Heart Failure/etiology
- Heart Failure/metabolism
- Heart Failure/physiopathology
- Imidazoles/pharmacology
- Isosorbide Dinitrate/analogs & derivatives
- Isosorbide Dinitrate/pharmacology
- Kidney Cortex/drug effects
- Kidney Cortex/metabolism
- Kidney Cortex/physiopathology
- Male
- Myocardial Infarction/complications
- Rats, Wistar
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
- Renin-Angiotensin System/drug effects
- Tetrazoles/pharmacology
- Time Factors
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Affiliation(s)
- Yubo Peng
- Department of Cardiology, Aviation General Hospital, Beijing, 10016 China
| | - Yanfang Li
- Department of Emergency, Anzhen Hospital, Capital Medical University, Beijing, 100029 China
| | - Mengmeng Chen
- Hong Kong University Shenzhen Hospitall, Shenzhen, 518053 China
| | - Junying Song
- HengShui people’s Hospital, Hengshui, 053000 HeBei Province China
| | - Zhili Jiang
- Department of Emergency, Anzhen Hospital, Capital Medical University, Beijing, 100029 China
| | - Shutian Shi
- Department of Emergency, Anzhen Hospital, Capital Medical University, Beijing, 100029 China
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10
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Arendse LB, Danser AHJ, Poglitsch M, Touyz RM, Burnett JC, Llorens-Cortes C, Ehlers MR, Sturrock ED. Novel Therapeutic Approaches Targeting the Renin-Angiotensin System and Associated Peptides in Hypertension and Heart Failure. Pharmacol Rev 2019; 71:539-570. [PMID: 31537750 PMCID: PMC6782023 DOI: 10.1124/pr.118.017129] [Citation(s) in RCA: 204] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Despite the success of renin-angiotensin system (RAS) blockade by angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type 1 receptor (AT1R) blockers, current therapies for hypertension and related cardiovascular diseases are still inadequate. Identification of additional components of the RAS and associated vasoactive pathways, as well as new structural and functional insights into established targets, have led to novel therapeutic approaches with the potential to provide improved cardiovascular protection and better blood pressure control and/or reduced adverse side effects. The simultaneous modulation of several neurohumoral mediators in key interconnected blood pressure-regulating pathways has been an attractive approach to improve treatment efficacy, and several novel approaches involve combination therapy or dual-acting agents. In addition, increased understanding of the complexity of the RAS has led to novel approaches aimed at upregulating the ACE2/angiotensin-(1-7)/Mas axis to counter-regulate the harmful effects of the ACE/angiotensin II/angiotensin III/AT1R axis. These advances have opened new avenues for the development of novel drugs targeting the RAS to better treat hypertension and heart failure. Here we focus on new therapies in preclinical and early clinical stages of development, including novel small molecule inhibitors and receptor agonists/antagonists, less conventional strategies such as gene therapy to suppress angiotensinogen at the RNA level, recombinant ACE2 protein, and novel bispecific designer peptides.
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Affiliation(s)
- Lauren B Arendse
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
| | - A H Jan Danser
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
| | - Marko Poglitsch
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
| | - Rhian M Touyz
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
| | - John C Burnett
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
| | - Catherine Llorens-Cortes
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
| | - Mario R Ehlers
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
| | - Edward D Sturrock
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa (L.B.A., E.D.S.); Division of Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands (A.H.J.D.); Attoquant Diagnostics, Vienna, Austria (M.P.); Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom (R.M.T.); Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota (J.C.B.); Institut National de la Santé et de la Recherche Médicale, Paris, France (C.L.-C.); and Clinical Trials Group, Immune Tolerance Network, San Francisco, California (M.R.E.)
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11
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The angiotensin type 2 receptor in the human adrenocortical zona glomerulosa and in aldosterone-producing adenoma: low expression and no functional role. Clin Sci (Lond) 2018; 132:627-640. [PMID: 29436482 DOI: 10.1042/cs20171593] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/03/2018] [Accepted: 02/04/2018] [Indexed: 11/17/2022]
Abstract
The angiotensin II (Ang II) type 2 receptor (AT2R) and the angiotensin-(1-7) (Ang-(1-7)) receptor (MasR) play a cardiovascular protective role by counter-regulating Ang II type 1 receptor (AT1R)-mediated effects, but whether this involves blunting of adrenocortical hormone secretion is unknown. We investigated the presence of AT1R, AT2R, and MasR in aldosterone-producing adenoma (APA), a condition featuring hyperaldosteronism, and in APA-adjacent tissue. The effect of Compound 21 (C21), an AT2R agonist, on CYP11B1 (cortisol synthase) and CYP11B2 (aldosterone synthase) gene expression in NCI-H295R and HAC15 cell lines, and in APA and APA-adjacent tissue, was also assessed using the AT1R antagonist irbesartan to ascertain the specificity of C21 effect. We found that the AT1R, AT2R, and MasR were expressed in APA and APA-adjacent tissue, albeit heterogeneously. The gene expression of AT1R and AT2R was lower, and that of the MasR higher in APAs than in APA-adjacent tissue. In steroid-producing NCI-H295R and HAC15 cell lines, and in APA and APA-adjacent tissue, C21 was ineffective at nanomolar concentrations, but increased CYP11B1 and CYP11B2 gene expression at micromolar concentrations through AT1R, as this effect was blunted by irbesartan. The scant expression of the AT2R, along with the lack of any effect of C21 at low concentrations on CYP11B2, do not support the contention that the protective arm of renin-angiotensin system (RAS) blunts aldosterone synthase in the normal adrenal cortex and primary aldosteronism.
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12
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Pandey A, Gaikwad AB. Compound 21 and Telmisartan combination mitigates type 2 diabetic nephropathy through amelioration of caspase mediated apoptosis. Biochem Biophys Res Commun 2017; 487:827-833. [PMID: 28456626 DOI: 10.1016/j.bbrc.2017.04.134] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 04/24/2017] [Indexed: 01/18/2023]
Abstract
The current study aimed to understand the role of novel, highly selective, orally active, non-peptide Angiotensin II type 2 receptor (AT2R) agonist, Compound 21 and its potential additive effect with Telmisartan on apoptosis and underlying posttranslational modifications in a non-genetic murine model for type 2 diabetic nephropathy (T2DN). An experimental model for T2DN was developed by administering low dose Streptozotocin in high fat diet fed male Wistar rats, followed by their treatment with Telmisartan, C21 or their combination. Our results demonstrated that C21 and Telmisartan combination attenuated metabolic and renal dysfunction, renal morphological and micro-architectural aberrations and hemodynamic disturbances in type 2 diabetic rats. The anti-apoptotic and anti-inflammatory effects of Telmisartan were significantly accentuated by C21 indicated by expression of apoptotic markers (Parp1, Caspase 8, Caspase 7, cleaved PARP and cleaved Caspase 3) and NF-κB mediated inflammatory molecules like interleukin 6, tumour necrosis factor alpha; monocyte chemoattractant protein 1 and vascular cell adhesion molecule 1. C21 was found to improve Telmisartan mediated reversal of histone H3 acetylation at lysine 14 and 27 and expression of histone acetyl transferase, p300/CBP-associated factor also known to regulate NF-κB activity and DNA damage response. C21 in combination with Telmisartan markedly mitigates caspase mediated apoptosis and NF-κB signalling in T2D kidney, which could be partially attributed to its influence on PCAF mediated histone H3 acetylation. Hence further research should be done to develop this combination to treat T2DN.
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Affiliation(s)
- Anuradha Pandey
- Laboratory of Molecular Pharmacology, Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Pilani Campus, Rajasthan 333031, India
| | - Anil Bhanudas Gaikwad
- Laboratory of Molecular Pharmacology, Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Pilani Campus, Rajasthan 333031, India.
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13
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Kranch-Shorthouse RA, Bauer AS, Magness RR, Lopez GE, Segar JL, Blohowiak SE, Kling PJ. Ovine uterine space restriction causes dysregulation of the renin-angiotensin system in fetal kidneys. Biol Reprod 2017; 96:211-220. [PMID: 28395333 DOI: 10.1095/biolreprod.116.140079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 12/06/2016] [Indexed: 11/01/2022] Open
Abstract
In ovine pregnancy, uterine space restriction (USR) resulting from decreased space for placental attachment caused intrauterine growth restriction and impaired nephrogenesis. The fetal kidney renin-angiotensin system (RAS) is involved in nephrogenesis, fluid balance, and iron deposition. Angiotensin II exerts its effects via multiple receptors: angiotensin II 1-8 receptor type 1 (AT 1 R) and type 2 (AT 2 R), and angiotensin II 1-7 Mas receptor (MASR). Objective : To test the hypothesis that ovine USR is associated with dysregulation of the fetal renal RAS. Methods : Multiparous pregnant ewes (n = 32), 16 with surgical bifurcated disconnection of one uterine horn to further reduce placental attachment sites, were studied. USR (n = 31) ovine fetuses were compared to nonspace restricted (NSR) singleton controls (n = 22) on gestational day (GD) 120 or GD130, term GD147. Fetal plasma was collected to evaluate plasma renin activity and iron indices. Fetal kidney AT 1 R, AT 2 R, and MASR proteins were assessed by Western immunoblotting and immunohistochemistry. Results : AT 1 R, AT 2 R, and MASR protein expression was higher in USR at GD130 than aged-matched NSR and USR at GD120, ( P < 0.05 all). AT 1 R and AT 2 R localization was homogenous throughout proximal and distal tubules in both USR and NSR at both gestational dates. MASR localization was punctate throughout renal cortical structures including tubules and glomeruli in both USR and NSR, shifted to intranuclear at GD130. Plasma renin activity was inversely related to plasma osmolarity ( P < 0.02) and was downregulated in USR at GD130 ( P < 0.05). Conclusions : By late gestation, USR upregulated renal angiotensin receptor expression, an effect with potential functional implications.
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Affiliation(s)
- Rachel A Kranch-Shorthouse
- Department of Pediatrics, University of Wisconsin-Madison, Wisconsin, USA.,Department of Nutritional Science, The University of Arizona, Arizona, USA
| | - Adam S Bauer
- Department of Pediatrics, University of Wisconsin-Madison, Wisconsin, USA
| | - Ronald R Magness
- Department of Pediatrics, University of Wisconsin-Madison, Wisconsin, USA.,Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Wisconsin, USA.,Department of Animal Sciences, University of Wisconsin-Madison, Wisconsin, USA.,Department of Obstetrics and Gynecology, University of South Florida, Florida, USA
| | - Gladys E Lopez
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Wisconsin, USA
| | | | - Sharon E Blohowiak
- Department of Pediatrics, University of Wisconsin-Madison, Wisconsin, USA
| | - Pamela J Kling
- Department of Pediatrics, University of Wisconsin-Madison, Wisconsin, USA
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14
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Benitez S, Seltzer A, Acosta C. Nociceptor-like rat dorsal root ganglion neurons express the angiotensin-II AT2 receptor throughout development. Int J Dev Neurosci 2016; 56:10-17. [PMID: 27825832 DOI: 10.1016/j.ijdevneu.2016.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 10/31/2016] [Accepted: 11/01/2016] [Indexed: 01/06/2023] Open
Abstract
AT2 receptor (AT2R) plays a functional role in foetal development. Its expression declines in most tissues soon after birth but stays high in sensory areas of the adult nervous system. In the dorsal root ganglia (DRG) the expression pattern of AT2R during development and the identity of the subpopulation expressing it remain unknown. Using a combination of semi-quantitative PCR, western blotting and immunohistochemistry we examined the expression of AT2R at mRNA and protein levels in rat DRGs from embryonic day 15 (E15) until postnatal day 30 (PN30). We found that both AT2R mRNA and protein levels exhibited only minor (statistically non-significant) fluctuations from E15 to PN30. Detailed quantitative analysis of ABC/DAB AT2R staining showed a) that the receptor was present in most neurons at E15 and E18 and b) that postnatally it was predominantly expressed by small DRG neurons. Given that small neurons are putative C-nociceptors and the proposed role of AT2R in neuropathic pain, we next examined whether these AT2R-positive neurons co-localized with Ret and trkA embryonically and with IB4-binding postnatally. Most AT2R-positive neurons expressed trkA embryonically and bound IB4 postnatally. We found strong positive statistically highly significant correlations between AT2R cytoplasmic%intensities and trkA at E15/E18 and with Ret only at E18. Cytoplasmic AT2R also strongly and positively correlated with IB4-binding at PN3, 15 and 30. Our demonstration that a subpopulation of C-nociceptor-like neurons expresses AT2R during development supports a role for this receptor in neuropathic pain.
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Affiliation(s)
- Sergio Benitez
- Instituto de Histología y Embriología de Mendoza (IHEM), Facultad de Ciencias Medicas, Universidad Nacional de Cuyo, 5500, Mendoza, Argentina
| | - Alicia Seltzer
- Instituto de Histología y Embriología de Mendoza (IHEM), Facultad de Ciencias Medicas, Universidad Nacional de Cuyo, 5500, Mendoza, Argentina
| | - Cristian Acosta
- Instituto de Histología y Embriología de Mendoza (IHEM), Facultad de Ciencias Medicas, Universidad Nacional de Cuyo, 5500, Mendoza, Argentina.
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15
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Mishra JS, Hankins GD, Kumar S. Testosterone downregulates angiotensin II type-2 receptor via androgen receptor-mediated ERK1/2 MAP kinase pathway in rat aorta. J Renin Angiotensin Aldosterone Syst 2016; 17:17/4/1470320316674875. [PMID: 27765882 PMCID: PMC5465964 DOI: 10.1177/1470320316674875] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/16/2016] [Indexed: 11/15/2022] Open
Abstract
Introduction: Blood pressure is lower in females than males. Angiotensin II type-2 receptor (AT2R) induces vasodilation. This study determined whether sex differences in vascular AT2R expression occur and if androgens exert control on AT2R expression in the vasculature. Methods: AT2Rs in the aorta of male and female Sprague-Dawley rats were examined following alteration in androgen levels by gonadectomy or hormone supplementation. Results: AT2R mRNA and protein expression levels were lower in the aortas of males than females. In males, testosterone withdrawal by castration significantly elevated AT2R mRNA and protein levels and testosterone replacement restored them. In females, increasing androgen levels decreased AT2R mRNA and protein expression and this was attenuated by androgen receptor blocker flutamide. Ex vivo, dihydrotestosterone downregulated AT2R in endothelium-intact but not endothelium-denuded aorta. Dihydrotestosterone-induced AT2R downregulation in isolated aorta was blocked by an androgen receptor antagonist. Furthermore, blockade of ERK1/2 but not p38 MAP kinase or TGFβ signaling with specific inhibitors abolished dihydrotestosterone-induced AT2R downregulation. Conclusion: Androgens downregulate AT2R expression levels in aorta, in vivo and ex vivo. The androgen receptor-mediated ERK1/2 MAP kinase-signaling pathway may be a key mechanism by which testosterone downregulates AT2R expression, implicating androgens’ contributing role to gender differences in vascular AT2R expression.
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Affiliation(s)
- Jay S Mishra
- Division of Reproductive Endocrinology, University of Texas Medical Branch at Galveston, Texas, USA
| | - Gary D Hankins
- Division of Reproductive Endocrinology, University of Texas Medical Branch at Galveston, Texas, USA
| | - Sathish Kumar
- Division of Reproductive Endocrinology, University of Texas Medical Branch at Galveston, Texas, USA
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16
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Abstract
Although angiotensin II subtype-2 receptor (AT2R) was discovered over 2 decades ago, its contribution to physiology and pathophysiology is not fully elucidated. Current knowledge suggests that under normal physiologic conditions, AT2R counterbalances the effects of angiotensin II subtype-1 receptor (AT1R). A major obstacle for AT2R investigations was the lack of specific agonists. Most of the earlier AT2R studies were performed using the peptidic agonist, CG42112A, or the nonpeptidic antagonist PD123319. CGP42112A is nonspecific for AT2R and in higher concentrations can bind to AT1R. Recently, the development of specific nonpeptidic AT2R agonists boosted the efforts in identifying the therapeutic potentials for AT2R stimulation. Unlike AT1R, AT2R is involved in vasodilation by the release of bradykinin and nitric oxide, anti-inflammation, and healing from injury. Interestingly, the vasodilatory effects of AT2R stimulation were not associated with significant reduction in blood pressure. In the kidney, AT2R stimulation produced natriuresis, increased renal blood flow, and reduced tissue inflammation. In animal studies, enhanced AT2R function led to reduction of cardiac inflammation and fibrosis, and reduced the size of the infarcted area. Similarly, AT2R stimulation demonstrated protective effects in vasculature and brain.
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17
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Ismail B, Hadizad T, Antoun R, Lortie M, deKemp RA, Beanlands RS, DaSilva JN. Evaluation of [11C]methyl-losartan and [11C]methyl-EXP3174 for PET imaging of renal AT1receptor in rats. Nucl Med Biol 2015; 42:850-7. [DOI: 10.1016/j.nucmedbio.2015.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 05/04/2015] [Accepted: 06/24/2015] [Indexed: 10/23/2022]
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18
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McCarthy CA, Facey LJ, Widdop RE. The protective arms of the renin-angiontensin system in stroke. Curr Hypertens Rep 2015; 16:440. [PMID: 24816974 DOI: 10.1007/s11906-014-0440-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
It is quite well established that activation of the so-called protective arms of the renin-angiotensin system (RAS), involving both AT2 and Mas receptors, provides a counter-regulatory role to AT1 receptor overactivity that may drive pathological changes in the cardiovascular system. In this brief review, we will focus on recent evidence that identifies at least three different pathways that may be effective in the setting of stroke and may be complementary with AT1 receptor blockade. Such mechanisms include AT2 receptor stimulation, Mas receptor stimulation and insulin-regulated aminopeptidase blockade. This report highlights recent data demonstrating striking neuroprotective effects in preclinical models of stroke targeting each of these pathways, which may pave the way for translational opportunities in this field.
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Affiliation(s)
- Claudia A McCarthy
- Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
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19
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Sriramula S, Xia H, Xu P, Lazartigues E. Brain-targeted angiotensin-converting enzyme 2 overexpression attenuates neurogenic hypertension by inhibiting cyclooxygenase-mediated inflammation. Hypertension 2014; 65:577-86. [PMID: 25489058 DOI: 10.1161/hypertensionaha.114.04691] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Overactivity of the renin-angiotensin system, oxidative stress, and cyclooxygenases (COX) in the brain are implicated in the pathogenesis of hypertension. We previously reported that angiotensin-converting enzyme 2 (ACE2) overexpression in the brain attenuates the development of deoxycorticosterone acetate-salt hypertension, a neurogenic hypertension model with enhanced brain renin-angiotensin system and sympathetic activity. To elucidate the mechanisms involved, we investigated whether oxidative stress, mitogen-activated protein kinase signaling and cyclooxygenase (COX) activation in the brain are modulated by ACE2 in neurogenic hypertension. Deoxycorticosterone acetate-salt hypertension significantly increased expression of Nox-2 (+61±5%), Nox-4 (+50±13%), and nitrotyrosine (+89±32%) and reduced activity of the antioxidant enzymes, catalase (-29±4%) and superoxide dismutase (-31±7%), indicating increased oxidative stress in the brain of nontransgenic mice. This increased oxidative stress was attenuated in transgenic mice overexpressing ACE2 in the brain. Deoxycorticosterone acetate-salt-induced reduction of neuronal nitric oxide synthase expression (-26±7%) and phosphorylated endothelial nitric oxide synthase/total endothelial nitric oxide synthase (-30±3%), and enhanced phosphorylation of protein kinase B and extracellular signal-regulated kinase 1/2 in the paraventricular nucleus, were reversed by ACE2 overexpression. In addition, ACE2 overexpression blunted the hypertension-mediated increase in gene and protein expression of COX-1 and COX-2 in the paraventricular nucleus. Furthermore, gene silencing of either COX-1 or COX-2 in the brain, reduced microglial activation and accompanied neuroinflammation, ultimately attenuating Deoxycorticosterone acetate-salt hypertension. Together, these data provide evidence that brain ACE2 overexpression reduces oxidative stress and COX-mediated neuroinflammation, improves antioxidant and nitric oxide signaling, and thereby attenuates the development of neurogenic hypertension.
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Affiliation(s)
- Srinivas Sriramula
- Department of Pharmacology and Experimental Therapeutics, Neurosciences and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans
| | - Huijing Xia
- Department of Pharmacology and Experimental Therapeutics, Neurosciences and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans
| | - Ping Xu
- Department of Pharmacology and Experimental Therapeutics, Neurosciences and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans
| | - Eric Lazartigues
- Department of Pharmacology and Experimental Therapeutics, Neurosciences and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans.
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Vinturache AE, Smith FG. Angiotensin type 1 and type 2 receptors during ontogeny: cardiovascular and renal effects. Vascul Pharmacol 2014; 63:145-54. [DOI: 10.1016/j.vph.2014.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/23/2014] [Accepted: 11/02/2014] [Indexed: 01/24/2023]
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21
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Liu M, Jing D, Wang Y, Liu Y, Yin S. Overexpression of angiotensin II type 2 receptor promotes apoptosis and impairs insulin secretion in rat insulinoma cells. Mol Cell Biochem 2014; 400:233-44. [DOI: 10.1007/s11010-014-2280-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/15/2014] [Indexed: 12/21/2022]
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Reporter mouse strain provides a novel look at angiotensin type-2 receptor distribution in the central nervous system. Brain Struct Funct 2014; 221:891-912. [PMID: 25427952 DOI: 10.1007/s00429-014-0943-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/07/2014] [Indexed: 02/07/2023]
Abstract
Angiotensin-II acts at its type-1 receptor (AT1R) in the brain to regulate body fluid homeostasis, sympathetic outflow and blood pressure. However, the role of the angiotensin type-2 receptor (AT2R) in the neural control of these processes has received far less attention, largely because of limited ability to effectively localize these receptors at a cellular level in the brain. The present studies combine the use of a bacterial artificial chromosome transgenic AT2R-enhanced green fluorescent protein (eGFP) reporter mouse with recent advances in in situ hybridization (ISH) to circumvent this obstacle. Dual immunohistochemistry (IHC)/ISH studies conducted in AT2R-eGFP reporter mice found that eGFP and AT2R mRNA were highly co-localized within the brain. Qualitative analysis of eGFP immunoreactivity in the brain then revealed localization to neurons within nuclei that regulate blood pressure, metabolism, and fluid balance (e.g., NTS and median preoptic nucleus [MnPO]), as well as limbic and cortical areas known to impact stress responding and mood. Subsequently, dual IHC/ISH studies uncovered the phenotype of specific populations of AT2R-eGFP cells. For example, within the NTS, AT2R-eGFP neurons primarily express glutamic acid decarboxylase-1 (80.3 ± 2.8 %), while a smaller subset express vesicular glutamate transporter-2 (18.2 ± 2.9 %) or AT1R (8.7 ± 1.0 %). No co-localization was observed with tyrosine hydroxylase in the NTS. Although AT2R-eGFP neurons were not observed within the paraventricular nucleus (PVN) of the hypothalamus, eGFP immunoreactivity is localized to efferents terminating in the PVN and within GABAergic neurons surrounding this nucleus. These studies demonstrate that central AT2R are positioned to regulate blood pressure, metabolism, and stress responses.
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López RM, Castillo MC, López JS, Guevara G, López P, Castillo EF. Activation of upregulated angiotensin II type 2 receptors decreases carotid pulse pressure in rats with suprarenal abdominal aortic coarctation. Clin Exp Hypertens 2014; 37:271-9. [PMID: 25271908 DOI: 10.3109/10641963.2014.954714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Our aim was to determine whether angiotensin type 2 receptors (AT2R) are involved in the depression of carotid pulse pressure (PP) in rats with suprarenal aortic coarctation (SrC). We tested the effects of losartan, PD123319, and CGP42112 on PP in SrC and Sham-operated anesthetized rats. PP increased in SrC rats. Neither losartan nor PD123319 affected PP in SrC and Sham-operated rats. CGP42112 reduced PP, in SrC rats, combined with losartan. Moreover, PD123319 blocked this effect. AT2R protein increased in the thoracic aortas of SrC rats. Thus, upregulated AT2R stimulation by CGP42112 mediates depression of PP in rats under pressure overloading.
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Affiliation(s)
- Ruth M López
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina del Instituto Politécnico Nacional , México, D.F. , México and
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Li RF, Chen G, Ren JG, Zhang W, Wu ZX, Liu B, Zhao Y, Zhao YF. The adaptor protein p62 is involved in RANKL-induced autophagy and osteoclastogenesis. J Histochem Cytochem 2014; 62:879-88. [PMID: 25163928 DOI: 10.1369/0022155414551367] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Previous studies have implicated autophagy in osteoclast differentiation. The aim of this study was to investigate the potential role of p62, a characterized adaptor protein for autophagy, in RANKL-induced osteoclastogenesis. Real-time quantitative PCR and western blot analyses were used to evaluate the expression levels of autophagy-related markers during RANKL-induced osteoclastogenesis in mouse macrophage-like RAW264.7 cells. Meanwhile, the potential relationship between p62/LC3 localization and F-actin ring formation was tested using double-labeling immunofluorescence. Then, the expression of p62 in RAW264.7 cells was knocked down using small-interfering RNA (siRNA), followed by detecting its influence on RANKL-induced autophagy activation, osteoclast differentiation, and F-actin ring formation. The data showed that several key autophagy-related markers including p62 were significantly altered during RANKL-induced osteoclast differentiation. In addition, the expression and localization of p62 showed negative correlation with LC3 accumulation and F-actin ring formation, as demonstrated by western blot and immunofluorescence analyses, respectively. Importantly, the knockdown of p62 obviously attenuated RANKL-induced expression of autophagy- and osteoclastogenesis-related genes, formation of TRAP-positive multinuclear cells, accumulation of LC3, as well as formation of F-actin ring. Our study indicates that p62 may play essential roles in RANKL-induced autophagy and osteoclastogenesis, which may help to develop a novel therapeutic strategy against osteoclastogenesis-related diseases.
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Affiliation(s)
- Rui-Fang Li
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Gang Chen
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Jian-Gang Ren
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Wei Zhang
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Zhong-Xing Wu
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Bing Liu
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Yi Zhao
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Yi-Fang Zhao
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
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25
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Lipid rafts are required for signal transduction by angiotensin II receptor type 1 in neonatal glomerular mesangial cells. Exp Cell Res 2014; 324:92-104. [PMID: 24662198 DOI: 10.1016/j.yexcr.2014.03.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/10/2014] [Accepted: 03/13/2014] [Indexed: 11/24/2022]
Abstract
Angiotensin II (ANG-II) receptors (AGTRs) contribute to renal physiology and pathophysiology, but the underlying mechanisms that regulate AGTR function in glomerular mesangium are poorly understood. Here, we show that AGTR1 is the functional AGTR subtype expressed in neonatal pig glomerular mesangial cells (GMCs). Cyclodextrin (CDX)-mediated cholesterol depletion attenuated cell surface AGTR1 protein expression and ANG-II-induced intracellular Ca(2+) ([Ca(2+)]i) elevation in the cells. The COOH-terminus of porcine AGTR1 contains a caveolin (CAV)-binding motif. However, neonatal GMCs express CAV-1, but not CAV-2 and CAV-3. Colocalization and in situ proximity ligation assay detected an association between endogenous AGTR1 and CAV-1 in the cells. A synthetic peptide corresponding to the CAV-1 scaffolding domain (CSD) sequence also reduced ANG-II-induced [Ca(2+)]i elevation in the cells. Real-time imaging of cell growth revealed that ANG-II stimulates neonatal GMC proliferation. ANG-II-induced GMC growth was attenuated by EMD 66684, an AGTR1 antagonist; BAPTA, a [Ca(2+)]i chelator; KN-93, a Ca(2+)/calmodulin-dependent protein kinase II inhibitor; CDX; and a CSD peptide, but not PD 123319, a selective AGTR2 antagonist. Collectively, our data demonstrate [Ca(2+)]i-dependent proliferative effect of ANG-II and highlight a critical role for lipid raft microdomains in AGTR1-mediated signal transduction in neonatal GMCs.
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Behrends M, Wallinder C, Wieckowska A, Guimond MO, Hallberg A, Gallo-Payet N, Larhed M. N-Aryl Isoleucine Derivatives as Angiotensin II AT2 Receptor Ligands. ChemistryOpen 2014; 3:65-75. [PMID: 24808993 PMCID: PMC4000169 DOI: 10.1002/open.201300040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Indexed: 01/25/2023] Open
Abstract
A novel series of ligands for the recombinant human AT2 receptor has been synthesized utilizing a fast and efficient palladium-catalyzed procedure for aminocarbonylation as the key reaction. Molybdenum hexacarbonyl [Mo(CO)6] was employed as the carbon monoxide source, and controlled microwave heating was applied. The prepared N-aryl isoleucine derivatives, encompassing a variety of amide groups attached to the aromatic system, exhibit binding affinities at best with K i values in the low micromolar range versus the recombinant human AT2 receptor. Some of the new nonpeptidic isoleucine derivatives may serve as starting points for further structural optimization. The presented data emphasize the importance of using human receptors in drug discovery programs.
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Affiliation(s)
- Malte Behrends
- Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry, BMC, Uppsala University P.O. Box 574, SE-751 23 Uppsala (Sweden)
| | - Charlotta Wallinder
- Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry, BMC, Uppsala University P.O. Box 574, SE-751 23 Uppsala (Sweden)
| | - Anna Wieckowska
- Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry, BMC, Uppsala University P.O. Box 574, SE-751 23 Uppsala (Sweden)
| | - Marie-Odile Guimond
- Service of Endocrinology and Department of Physiology and Biophysics, Faculty of Medicine, University of Sherbrooke Sherbrooke, QC J1H 5N4 (Canada)
| | - Anders Hallberg
- Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry, BMC, Uppsala University P.O. Box 574, SE-751 23 Uppsala (Sweden)
| | - Nicole Gallo-Payet
- Service of Endocrinology and Department of Physiology and Biophysics, Faculty of Medicine, University of Sherbrooke Sherbrooke, QC J1H 5N4 (Canada)
| | - Mats Larhed
- Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry, BMC, Uppsala University P.O. Box 574, SE-751 23 Uppsala (Sweden)
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Shao C, Yu L, Gao L. Activation of angiotensin type 2 receptors partially ameliorates streptozotocin-induced diabetes in male rats by islet protection. Endocrinology 2014; 155:793-804. [PMID: 24302627 PMCID: PMC3929733 DOI: 10.1210/en.2013-1601] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have previously demonstrated that rat islets express a high density of angiotensin type 2 receptors and that activation of this receptor evokes insulinotropic effect. In this study, we evaluated the protective effects of Compound 21 (C21), a nonpeptide angiotensin type 2 receptor agonist, on islets in streptozotocin (STZ)-induced diabetes. Rats were assigned to five groups: normal, STZ, and STZ plus C21 (0.24, 0.48, and 0.96 mg/kg·d). C21 was continually infused by a sc implanted osmotic minipump for 14 days, and STZ was bolus injected on day 7. Body weight, water intake, urine excretion, and blood glucose were monitored daily. On the last day, the rats received an oral glucose tolerance test, and the pancreata were saved to examine islet morphology and biochemical parameters of oxidative stress and apoptosis. We found that, compared with control STZ rats, C21-treated STZ rats displayed less water intake and urine excretion, lower blood glucose, higher serum insulin concentration, and improved glucose tolerance. These rats had more islets, larger islet mass, and up-regulated insulin protein and proinsulin 2 mRNA expressions in the pancreas. Their islets displayed lower superoxide, decreased gp91 expression, and increased superoxide dismutase 1 expression as well as less apoptosis and down-regulated caspase-3 expression. In the epididymal adipose tissue of these rats, we found a decreased adipocyte size and up-regulated adipocyte protein 2 expression. The protective effects of C21 on β-cells against the toxic effects of STZ were also confirmed in cultured INS-1E cells. These data suggest that C21 ameliorates STZ-induced diabetes by protecting pancreatic islets via antioxidative and antiapoptotic effects.
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Affiliation(s)
- Chunhong Shao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska 68198
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28
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Veron JB, Joshi A, Wallinder C, Larhed M, Odell LR. Synthesis and evaluation of isoleucine derived angiotensin II AT(2) receptor ligands. Bioorg Med Chem Lett 2013; 24:476-9. [PMID: 24388688 DOI: 10.1016/j.bmcl.2013.12.040] [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: 10/17/2013] [Revised: 12/09/2013] [Accepted: 12/10/2013] [Indexed: 10/25/2022]
Abstract
Sixteen new C-terminally modified analogues of 2, a previously described potent and selective AT2R ligand, were designed, synthesized and evaluated for their affinity to the AT2R receptor. The introduction of large, hydrophobic substituents was shown to be beneficial and the most active compound (17, Ki=8.5 μM) was over 12-times more potent than the lead compound 2.
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Affiliation(s)
- Jean-Baptiste Veron
- Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University, Biomedical Center, Box 574, SE-751 23 Uppsala, Sweden
| | - Advait Joshi
- Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University, Biomedical Center, Box 574, SE-751 23 Uppsala, Sweden
| | - Charlotta Wallinder
- Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University, Biomedical Center, Box 574, SE-751 23 Uppsala, Sweden
| | - Mats Larhed
- Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University, Biomedical Center, Box 574, SE-751 23 Uppsala, Sweden
| | - Luke R Odell
- Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University, Biomedical Center, Box 574, SE-751 23 Uppsala, Sweden.
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Li Y, Li XH, Yuan H. Angiotensin II type-2 receptor-specific effects on the cardiovascular system. Cardiovasc Diagn Ther 2013; 2:56-62. [PMID: 24282697 DOI: 10.3978/j.issn.2223-3652.2012.02.02] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 02/02/2012] [Indexed: 01/11/2023]
Abstract
The renin-angiotensin system (RAS) is intricately involved in cardiovascular homeostasis. It is well known that angiotensin II, the key effector in RAS, contributes to a range of cardiovascular pathologies and diseases via angiotensin II type-1 receptor (AT1R) activation. However, the role of angiotensin II type-2 receptor (AT2R) regulation is less well understood. Recent studies describe the role of the AT2R on cardiovascular function in normal and pathologic conditions. The data describe an important role of AT2R in blood pressure regulation, cardiac hypertrophy and fibrosis, myocardial infarction and vascular homeostasis.
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Affiliation(s)
- Ying Li
- Center of Clinical Pharmacology, third Xiangya hospital, Central South University, Changsha 410013, China
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30
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Shao C, Zucker IH, Gao L. Angiotensin type 2 receptor in pancreatic islets of adult rats: a novel insulinotropic mediator. Am J Physiol Endocrinol Metab 2013; 305:E1281-91. [PMID: 24085035 PMCID: PMC3840212 DOI: 10.1152/ajpendo.00286.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In the present study, we evaluated the relative abundance of angiotensin type 2 receptor (AT2R) protein in various tissues of adult rats. We found that pancreatic islets expressed the highest AT2R protein compared with all other tissues. Accordingly, we then determined the functional significance of AT2R in the endocrine pancreas in in vivo and in vitro experiments by using angiotensin II (ANG II) alone, losartan (Los; AT1R antagonist), compound 21 (C21; AT2R agonist), and PD-123319 (PD; AT2R antagonist). Experiments carried out in rats indicated that, 1) ANG II treatment significantly increased plasma insulin concentration (1.51 ± 0.20 vs. 0.82 ± 0.14 ng/ml, n = 7, P < 0.05) in the fed state. This insulinotropic effect was further augmented by combined treatment with ANG II + Los (2.31 ± 0.25 ng/ml, n = 7, P < 0.01). C21 also elevated insulin levels (2.13 ± 0.20 ng/ml, n = 7, P < 0.01), which was completely abolished by PD. 2) ANG II impaired glucose tolerance, whereas ANG II + Los or C21 improved this function. 3) All treated rats displayed an enhanced insulin secretory response to a glucose challenge. 4) All treated rats displayed upregulated proinsulin 2 mRNA and insulin protein expression in the pancreas. In in vitro experiments using INS-1E cells and isolated rat islets, we found that AT2R activation significantly improved insulin biosynthesis and secretion. These results suggest that the AT2R functions as an insulinotropic mediator. AT2R and its downstream signaling pathways may be potential therapeutic targets for diabetes.
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Affiliation(s)
- Chunhong Shao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
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Vamos Z, Cseplo P, Ivic I, Matics R, Hamar J, Koller A. Age Determines the Magnitudes of Angiotensin II-Induced Contractions, mRNA, and Protein Expression of Angiotensin Type 1 Receptors in Rat Carotid Arteries. J Gerontol A Biol Sci Med Sci 2013; 69:519-26. [DOI: 10.1093/gerona/glt128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Chao J, Gao J, Parbhu KJK, Gao L. Angiotensin type 2 receptors in the intermediolateral cell column of the spinal cord: negative regulation of sympathetic nerve activity and blood pressure. Int J Cardiol 2013; 168:4046-55. [PMID: 23871345 DOI: 10.1016/j.ijcard.2013.06.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 05/07/2013] [Accepted: 06/30/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Our previous study demonstrated that AT2R in brainstem nuclei participated in the regulation of sympathetic outflow and cardiovascular function. However, the functional significance of AT2R in the intermediolateral cell column (IML) of the thoracic spinal cord in normal rats remains elusive. We hypothesized that AT2R activation in the IML exerts a sympatho-inhibitory effect. METHODS AND RESULTS Using Western-blot analysis, immunohistochemical staining and quantitative real-time PCR, both AT1R and AT2R expressions were detected in the spinal cord. The highest AT2R protein expression was found in the IML, while AT1R expression didn't display regional differences within the gray matter. Microinjection of Ang II into the IML dose-dependently elevated mean blood pressure (MAP, employing a transducer-tipped catheter) and renal sympathetic nerve activity (RSNA, using a pair of platinum-iridium recording electrodes), which were completely abolished by Losartan, and attenuated by TEMPOL and apocynin. Activation of AT2R in the IML with CGP42112 evoked hypotension (ΔMAP: -21 ± 4 mmHg) and sympatho-inhibition (RSNA: 73 ± 3% of baseline), which were completely abolished by PD123319 and l-NAME. Blockade of AT2R in the IML with PD123319 significantly increased MAP (11 ± 1 mmHg) and sympathetic nerve activity (RSNA: 133 ± 13% of baseline). Moreover, PD123319 significantly enhanced the Ang II induced pressor response. Furthermore, in isolated IML neurons, CGP42112 treatment augmented potassium current and decreased resting membrane potential by employing whole-cell patch clamp. CONCLUSION In the normal condition, AT2R in the IML tonically inhibits sympathetic activity through an NO/NOS dependent pathway and subsequent potassium channel activation.
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Affiliation(s)
- Jie Chao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, 985850 Nebraska Medical Center, Omaha, NE 68198-5850, USA
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Chao J, Yang L, Buch S, Gao L. Angiotensin II increased neuronal stem cell proliferation: role of AT2R. PLoS One 2013; 8:e63488. [PMID: 23691054 PMCID: PMC3655161 DOI: 10.1371/journal.pone.0063488] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 04/03/2013] [Indexed: 01/09/2023] Open
Abstract
Angiotensin II (Ang II), known a potent vasoactive substance in the renin-angiotensin system in the brain, plays a critical role in systemic blood pressure control. However, increasing evidence indicated that the physiological role of Ang II go beyond its vasoactive effect. In the present study, we demonstrated that Ang II type-1 receptor (AT1R) and type-2 receptor (AT2R) were expressed in primary rat hippocampal neuronal stem cells (NSCs). Treatment of rat hippocampal NSCs with Ang II increased cell proliferation. Pretreatment of NSCs with specific AT2R, but not AT1R, antagonist significantly suppressed Ang II-induced cell proliferation. Furthermore, Ang II stimulated ERK and Akt phosphorylation in NSCs. Pretreatment of MEK inhibitor, but not PI3K inhibitor, inhibited Ang II-induced ERK phosphorylation as well as cell proliferation. In addition, stimulation of NSCs with Ang II decreased expression of KV 1.2/KV 3.1 channels and blocked K+ currents which lie downstream of ERK activation. Taken together, these findings underpin the role of AT2R as a novel target that regulates cell proliferation mediated by Ang II with implications for therapeutic intervention for regulation of neurogenesis.
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Affiliation(s)
- Jie Chao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Lu Yang
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Lie Gao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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Shum M, Pinard S, Guimond MO, Labbé SM, Roberge C, Baillargeon JP, Langlois MF, Alterman M, Wallinder C, Hallberg A, Carpentier AC, Gallo-Payet N. Angiotensin II type 2 receptor promotes adipocyte differentiation and restores adipocyte size in high-fat/high-fructose diet-induced insulin resistance in rats. Am J Physiol Endocrinol Metab 2013; 304:E197-210. [PMID: 23149621 PMCID: PMC3543572 DOI: 10.1152/ajpendo.00149.2012] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study was aimed at establishing whether specific activation of angiotensin II (ANG II) type 2 receptor (AT2R) modulates adipocyte differentiation and function. In primary cultures of subcutaneous (SC) and retroperitoneal (RET) preadipocytes, both AT2R and AT1R were expressed at the mRNA and protein level. Cells were stimulated with ANG II or the AT2R agonist C21/M24, alone or in the presence of the AT1R antagonist losartan or the AT2R antagonist PD123,319. During differentiation, C21/M24 increased PPARγ expression in both RET and SC preadipocytes while the number of small lipid droplets and lipid accumulation solely increased in SC preadipocytes. In mature adipocytes, C21/M24 decreased the mean size of large lipid droplets. Upon abolishment of AT2R expression using AT2R-targeted shRNAs, expressions of AT2R, aP2, and PPARγ remained very low, and cells were unable to differentiate. In Wistar rats fed a 6-wk high-fat/high-fructose (HFHF) diet, a significant shift toward larger adipocytes was observed in RET and SC adipose tissue depots. C21/M24 treatments for 6 wk restored normal adipocyte size distribution in both these tissue depots. Moreover, C21/M24 and losartan decreased hyperinsulinemia and improved insulin sensitivity impaired by HFHF diet. A strong correlation between adipocyte size area and glucose infusion rate during euglycemic-hyperinsulinemic clamp was observed. These results indicate that AT2R is involved in early adipocyte differentiation, while in mature adipocytes and in a model of insulin resistance AT2R activation restores normal adipocyte morphology and improves insulin sensitivity.
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MESH Headings
- Adipocytes/drug effects
- Adipocytes/metabolism
- Adipocytes/pathology
- Adipocytes/physiology
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Animals
- Cell Differentiation/drug effects
- Cell Differentiation/genetics
- Cell Size/drug effects
- Cells, Cultured
- Diet, High-Fat/adverse effects
- Dietary Carbohydrates/adverse effects
- Dietary Fats/adverse effects
- Fructose/adverse effects
- Insulin Resistance/genetics
- Insulin Resistance/physiology
- Male
- RNA, Small Interfering/pharmacology
- Rats
- Rats, Wistar
- Receptor, Angiotensin, Type 2/genetics
- Receptor, Angiotensin, Type 2/metabolism
- Receptor, Angiotensin, Type 2/physiology
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Affiliation(s)
- Michaël Shum
- Division of Endocrinology, Department of Medicine, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Developmental expression patterns for angiotensin receptors in mouse skin and brain. J Renin Angiotensin Aldosterone Syst 2012. [DOI: 10.1177/1470320312467557] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Wang G, Coleman CG, Glass MJ, Zhou P, Yu Q, Park L, Anrather J, Pickel VM, Iadecola C. Angiotensin II type 2 receptor-coupled nitric oxide production modulates free radical availability and voltage-gated Ca2+ currents in NTS neurons. Am J Physiol Regul Integr Comp Physiol 2012; 302:R1076-83. [PMID: 22378773 PMCID: PMC3362142 DOI: 10.1152/ajpregu.00571.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 02/25/2012] [Indexed: 02/07/2023]
Abstract
The medial region of the nucleus tractus solitarius (mNTS) is a key brain stem site controlling cardiovascular function, wherein ANG II modulates neuronal L-type Ca(2+) currents via activation of ANG II type 1 receptors (AT(1)R) and production of reactive oxygen species (ROS). ANG II type 2 receptors (AT(2)R) induce production of nitric oxide (NO), which may interact with ROS and modulate AT(1)R signaling. We sought to determine whether AT(2)R-mediated NO production occurs in mNTS neurons and, if so, to elucidate the NO source and the functional interaction with AT(1)R-induced ROS or Ca(2+) influx. Electron microscopic (EM) immunolabeling showed that AT(2)R and neuronal NO synthase (nNOS) are coexpressed in neuronal somata and dendrites receiving synapses in the mNTS. In the presence of the AT(1)R antagonist losartan, ANG II increased NO production in isolated mNTS neurons, an effect blocked by the AT(2)R antagonist PD123319, but not the angiotensin (1-7) antagonist D-Ala. Studies in mNTS neurons of nNOS-null or endothelial NOS (eNOS)-null mice established nNOS as the source of NO. ANG II-induced ROS production was enhanced by PD123319, the NOS inhibitor N(G)-nitro-l-arginine (LNNA), or in nNOS-null mice. Moreover, in the presence of losartan, ANG II reduced voltage-gated L-type Ca(2+) current, an effect blocked by PD123319 or LNNA. We conclude that AT(2)R are closely associated and functionally coupled with nNOS in mNTS neurons. The resulting NO production antagonizes AT(1)R-mediated ROS and dampens L-type Ca(2+) currents. The ensuing signaling changes in the NTS may counteract the deleterious effects of AT(1)R on cardiovascular function.
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Affiliation(s)
- Gang Wang
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, New York 10065, USA.
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Gao J, Chao J, Parbhu KJK, Yu L, Xiao L, Gao F, Gao L. Ontogeny of angiotensin type 2 and type 1 receptor expression in mice. J Renin Angiotensin Aldosterone Syst 2012; 13:341-52. [PMID: 22526820 DOI: 10.1177/1470320312443720] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In the current experiment, we determined angiotensin type 2 receptor (AT2R) and angiotensin type 1 receptor (AT1R) protein expression by western blot analysis in developing normal mice. The results indicate that: (1) in all detected brain regions and in the spinal cord, adult mice exhibited significantly higher AT2R expression and lower AT1R expression in total protein extracts compared to fetuses and neonates; (2) other major organs, including heart, lung, liver and kidney, exhibited the same expression pattern as the brain and spinal cord; (3) reciprocal changes in AT2R and AT1R expression were found in the total protein extracts from the brainstems of mice from one-day prenatal to six weeks of age, and there was a negative correlation between AT2R and AT1R protein expression; (4) in both membrane and cytosolic fractions from the brainstem, adult mice exhibited higher AT2R and lower AT1R expression than did fetuses and neonates; and (5) in the brainstem, there were no significant differences in AT2R and AT1R messenger RNA (mRNA) levels among fetal, neonatal and adult mice. The above results reconfirmed our previous finding in rats that adult animals have higher AT2R and lower AT1R expression compared to fetuses and neonates. These data imply an involvement of AT1R in fetal development and of AT2R in adult function.
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Affiliation(s)
- Juan Gao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, USA
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Verdonk K, Danser AHJ, van Esch JHM. Angiotensin II type 2 receptor agonists: where should they be applied? Expert Opin Investig Drugs 2012; 21:501-13. [PMID: 22348403 DOI: 10.1517/13543784.2012.664131] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
INTRODUCTION Angiotensin II, the active endproduct of the renin-angiotensin system (RAS), exerts its effects via angiotensin II type 1 and type 2 (AT(1), AT(2)) receptors. AT(1) receptors mediate all well-known effects of angiotensin II, ranging from vasoconstriction to tissue remodeling. Thus, to treat cardiovascular disease, RAS blockade aims at preventing angiotensin II-AT(1) receptor interaction. Yet RAS blockade is often accompanied by rises in angiotensin II, which may exert beneficial effects via AT(2) receptors. AREAS COVERED This review summarizes our current knowledge on AT(2) receptors, describing their location, function(s), endogenous agonist(s) and intracellular signaling cascades. It discusses the beneficial effects obtained with C21, a recently developed AT(2) receptor agonist. Important questions that are addressed are do these receptors truly antagonize AT(1) receptor-mediated effects? What about their role in the diseased state and their heterodimerization with other receptors? EXPERT OPINION The general view that AT(2) receptors exclusively exert beneficial effects has been challenged, and in pathological models, their function sometimes mimics that of AT(1) receptors, for example, inducing vasoconstriction and cardiac hypertrophy. Yet given its upregulation in various pathological conditions, the AT(2) receptor remains a promising target for treatment, allowing effects beyond blood pressure-lowering, for example, in stroke, aneurysm formation, inflammation and myocardial fibrosis.
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Affiliation(s)
- Koen Verdonk
- Erasmus Medical Center, Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Rotterdam, The Netherlands
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Xue B, Zhang Z, Johnson RF, Johnson AK. Sensitization of slow pressor angiotensin II (Ang II)-initiated hypertension: induction of sensitization by prior Ang II treatment. Hypertension 2012; 59:459-66. [PMID: 22215719 DOI: 10.1161/hypertensionaha.111.185116] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sensitization involving the central nervous system has been studied in many conditions but has received little attention in investigation of the pathogenesis of hypertension. Our experiments were initiated to determine whether angiotensin II (Ang II)-induced hypertension can be sensitized by prior Ang II treatment and the role of the brain renin-angiotensin-aldosterone system (RAAS) in this process. To demonstrate Ang II-induced sensitization, we used an experimental design of induction-delay-expression. Male rats were implanted for telemetered blood pressure (BP) recording. During induction (I), low doses of subcutaneous or intracerebroventricular Ang II were delivered for 1 week, and then the rats were rested for 1 week (delay [D]) to ensure that any exogenous Ang II was metabolized. After this, a second higher dose of Ang II was given subcutaneously for 2 weeks (expression [E]). During I and D, the low doses of Ang II had no sustained effects on BP. However, during E, the Ang II-induced BP increase was greater in the groups that had received low doses of Ang II during I in comparison to the group receiving saline during I. Central angiotensin type 1 receptor antagonist delivery blocked this sensitization. Brain tissue collected at the end of D and E showed increased mRNA expression of several RAAS components in key forebrain regions of sensitized rats. Fos-related antigen-like immunoreactivity was also increased at the end of E in the sensitized forebrain. These results indicate that subpressor doses of Ang II act on the brain to sensitize the hypertensive response to subsequent Ang II and that sensitization is associated with altered expression of RAAS components in forebrain cardiovascular control structures.
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Affiliation(s)
- Baojian Xue
- Department of Psychology, University of Iowa, 11 Seashore Hall E, Iowa City, IA 52242, USA.
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Guimond MO, Gallo-Payet N. How does angiotensin AT(2) receptor activation help neuronal differentiation and improve neuronal pathological situations? Front Endocrinol (Lausanne) 2012; 3:164. [PMID: 23267346 PMCID: PMC3525946 DOI: 10.3389/fendo.2012.00164] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 11/29/2012] [Indexed: 01/08/2023] Open
Abstract
The angiotensin type 2 (AT(2)) receptor of angiotensin II has long been thought to be limited to few tissues, with the primary effect of counteracting the angiotensin type 1 (AT(1)) receptor. Functional studies in neuronal cells have demonstrated AT(2) receptor capability to modulate neuronal excitability, neurite elongation, and neuronal migration, suggesting that it may be an important regulator of brain functions. The observation that the AT(2) receptor was expressed in brain areas implicated in learning and memory led to the hypothesis that it may also be implicated in cognitive functions. However, linking signaling pathways to physiological effects has always proven challenging since information relative to its physiological functions has mainly emerged from indirect observations, either from the blockade of the AT(1) receptor or through the use of transgenic animals. From a mechanistic standpoint, the main intracellular pathways linked to AT(2) receptor stimulation include modulation of phosphorylation by activation of kinases and phosphatases or the production of nitric oxide and cGMP, some of which are associated with the Gi-coupling protein. The receptor can also interact with other receptors, either G protein-coupled such as bradykinin, or growth factor receptors such as nerve growth factor or platelet-derived growth factor receptors. More recently, new advances have also led to identification of various partner proteins, thus providing new insights into this receptor's mechanism of action. This review summarizes the recent advances regarding the signaling pathways induced by the AT(2) receptor in neuronal cells, and discussed the potential therapeutic relevance of central actions of this enigmatic receptor. In particular, we highlight the possibility that selective AT(2) receptor activation by non-peptide and selective agonists could represent new pharmacological tools that may help to improve impaired cognitive performance in Alzheimer's disease and other neurological cognitive disorders.
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Affiliation(s)
| | - Nicole Gallo-Payet
- *Correspondence: Nicole Gallo-Payet, Service d’Endocrinologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e Avenue Nord, Sherbrooke, QC, Canada J1H 5N4. e-mail:
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Qi Y, Li H, Shenoy V, Li Q, Wong F, Zhang L, Raizada MK, Sumners C, Katovich MJ. Moderate cardiac-selective overexpression of angiotensin II type 2 receptor protects cardiac functions from ischaemic injury. Exp Physiol 2011; 97:89-101. [PMID: 21967903 DOI: 10.1113/expphysiol.2011.060673] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We hypothesized that moderate cardiac-selective overexpression of the angiotensin II type 2 receptor (AT2R) would protect the myocardium from ischaemic injury after a myocardial infarction (MI) induced by coronary artery ligation. For in vitro studies, adenoviral vector expressing genomic DNA of AT2R and enhanced green fluorescence protein (EGFP) was used to overexpress AT2R in rat neonatal cardiac myocytes. Expression of AT2R, measured by real-time PCR and immunostaining, demonstrated efficient transduction of AT2R in a dose-dependent pattern. The AT2R constitutively induced apoptosis in rat neonatal cardiac myocytes in dose-dependent patterns. For in vivo studies, 4 × 10(10) vector genomes (vg) of recombinant adeno-associated virus serotype 9 (rAAV9)-chicken β actin promoter-AT2R was injected into the left ventricle of 5-day-old Sprague-Dawley rats. At 6 weeks of age, hearts were harvested and expression of AT2R determined by real-time PCR and Western blotting. Expression was increased onefold over control hearts, and no apoptosis was detected. Two subsequent in vivo studies were performed. In a prevention study, 4 × 10(10) vg of rAAV9-CBA-AT2R was injected into the left ventricle of 5-day-old Sprague-Dawley rats and MI was induced at 6 weeks of age. For a post-treatment study, 4 × 10(10) vg of rAAV9-CBA-AT2R was administrated to the peri-infarcted myocardium area immediately after MI in 6-week-old animals. For both in vivo studies, cardiac functions were assessed using echocardiography and haemodynamic measurements 4 weeks after coronary artery ligation. In the in vivo studies, the rats subjected to MI showed significant decreases in fractional shortening and rate of change of left ventricular pressure, with increased left ventricular end-diastolic pressure and ventricular hypertrophy. For the prevention study, the moderate cardiac-selective overexpression of AT2R attenuated these MI-induced impairments and also caused a decrease in ventricular wall thinning. In the post-treatment study, the overexpression of AT2R partly reversed the MI-induced cardiac dysfunction. Myocardial infarction also induced the upregulation of angiotensin II type 1 receptor, angiotensin-converting enzyme and collagen I mRNA expression, all of which were attenuated by the overexpression of AT2R. It is concluded that moderate cardiac-selective overexpression of AT2R protects heart function from ischaemic injury, which may be mediated, at least in part, through modulation of components of the cardiac renin-angiotensin system and collagen levels in the myocardium.
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Affiliation(s)
- Yanfei Qi
- Department of Pharmacodynamics, University of Florida, SW 1600 Archer Road, Gainesville, FL 32610, USA
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Gao J, Zhang H, Le KD, Chao J, Gao L. Activation of central angiotensin type 2 receptors suppresses norepinephrine excretion and blood pressure in conscious rats. Am J Hypertens 2011; 24:724-30. [PMID: 21394088 DOI: 10.1038/ajh.2011.33] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND We have previously documented the finding that central angiotensin type 2 receptors (AT2R) negatively modulate sympathetic outflow and arterial blood pressure (BP). In this study, we investigated the effects of intracerebroventricular (icv) infusion of Compound 21 (C21), the first selective nonpeptide AT2R agonist, on norepinephrine (NE) excretion and BP in rats. METHODS C21 was infused icv for 7 days, using a micro-osmotic pump. Urinary NE concentration was measured using the NE enzyme immunoassay kit. BP was recorded by radiotelemetry. After 7 days, the rats were killed and three relevant samples from sympathetic brain regions and the cerebral cortex were obtained by micro-punching to measure neuronal nitric oxide synthase (nNOS) protein expression by western blot. In addition, the influence of C21 on neuronal potassium current (I(Kv)) was determined by whole-cell patch-clamp in a neuron cell line, CATH.a. RESULTS (i) Icv treatment with C21 significantly decreased both the concentration and the amount of NE in night time urine, but had no effect on daytime urine. (ii) C21-treated rats exhibited a slight but significant decrease in BP. (iii) The effects of C21 on NE excretion and BP were abolished by use of the AT2R antagonist, PD123319, and nitric oxide synthase (NOS) inhibitor, N-omega-nitro-L-arginine methyl ester (L-NAME). (iv) C21 treatment significantly upregulated nNOS expression in the paraventricular nucleus of the hypothalamus (PVN) and rostral ventrolateral medulla (RVLM), but not in the nucleus of the solitary tract (NTS) and cerebral cortex. (v) In CATH.a neurons, C21 treatment significantly increased I(Kv), and this increase was completely abolished by PD123319 and L-NAME. CONCLUSIONS These results demonstrate a central inhibitory influence of C21 on sympathetic outflow by means of a nNOS-dependent mechanism that might be mediated by facilitating the neuronal potassium channel.
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Xu P, Sriramula S, Lazartigues E. ACE2/ANG-(1-7)/Mas pathway in the brain: the axis of good. Am J Physiol Regul Integr Comp Physiol 2010; 300:R804-17. [PMID: 21178125 DOI: 10.1152/ajpregu.00222.2010] [Citation(s) in RCA: 202] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The last decade has seen the discovery of several new components of the renin-angiotensin system (RAS). Among them, angiotensin converting enzyme-2 (ACE2) and the Mas receptor have forced a reevaluation of the original cascade and led to the emergence of a new arm of the RAS: the ACE2/ANG-(1-7)/Mas axis. Accordingly, the new system is now seen as a balance between a provasoconstrictor, profibrotic, progrowth axis (ACE/ANG-II/AT(1) receptor) and a provasodilatory, antifibrotic, antigrowth arm (ACE2/ANG-(1-7)/Mas receptor). Already, this simplistic vision is evolving and new components are branching out upstream [ANG-(1-12) and (pro)renin receptor] and downstream (angiotensin-IV and other angiotensin peptides) of the classical cascade. In this review, we will summarize the role of the ACE2/ANG-(1-7)/Mas receptor, focusing on the central nervous system with respect to cardiovascular diseases such as hypertension, chronic heart failure, and stroke, as well as neurological diseases. In addition, we will discuss the new pharmacological (antagonists, agonists, activators) and genomic (knockout and transgenic animals) tools that are currently available. Finally, we will review the latest data regarding the various signaling pathways downstream of the Mas receptor.
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Affiliation(s)
- Ping Xu
- Department of Pharmacology and Experimental Therapeutics and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA
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Gao L, Zucker IH. AT2 receptor signaling and sympathetic regulation. Curr Opin Pharmacol 2010; 11:124-30. [PMID: 21159555 DOI: 10.1016/j.coph.2010.11.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 11/19/2010] [Accepted: 11/22/2010] [Indexed: 11/28/2022]
Abstract
There is a growing consensus that the balance between Angiotensin Type 1 (AT1R) and Angiotensin Type 2 (AT2R) signaling in many tissues may determine the magnitude and, in some cases the direction, of the biological response. Sympatho-excitation in cardiovascular diseases is mediated by a variety of factors and is, in part, dependent on Angiotensin II signaling in the central nervous system. Recent data have provided evidence that the AT2R can modulate sympatho-excitation in animals with hypertension and heart failure. The evidence for this concept is reviewed and a model is put forward to support the rationale that therapeutic targeting of the central AT2R may be beneficial in the setting of chronic heart failure.
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Affiliation(s)
- Lie Gao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198-5850, USA
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Dasgupta C, Zhang L. Angiotensin II receptors and drug discovery in cardiovascular disease. Drug Discov Today 2010; 16:22-34. [PMID: 21147255 DOI: 10.1016/j.drudis.2010.11.016] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 10/12/2010] [Accepted: 11/26/2010] [Indexed: 12/19/2022]
Abstract
Hypertension is one of the cardiovascular diseases that might cause cardiovascular remodeling and endothelial dysfunction besides high blood pressure. Angiotensin II (Ang II) receptors are implicated in hypertension. Genetic and epigenetic manipulations of the Ang II receptors play a crucial part in the programming of cardiovascular diseases, and certain variants of the Ang II type 1 and Ang II type 2 receptors are constitutively predisposed to higher cardiovascular risk and hypertension. In this review, we focus on the expression, mode of action of Ang II receptors, and their role in programming the cardiovascular diseases in utero. In addition, we discuss possible therapeutic interventions of Ang II stimulation. Collectively, this information might lead us to new drug designs against cardiovascular diseases.
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Affiliation(s)
- Chiranjib Dasgupta
- Fetal-Origin Diseases Institute, First Affiliated Hospital of Soochow University, Suzhou 215000, China
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