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Souza-Silva IM, Peluso AA, Mortensen C, Nazarova AL, Stage TB, Sumners C, Katritch V, Steckelings UM. Development of an automated, high-throughput assay to detect angiotensin AT 2-receptor agonistic compounds by nitric oxide measurements in vitro. Peptides 2024; 172:171137. [PMID: 38142816 DOI: 10.1016/j.peptides.2023.171137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023]
Abstract
Angiotensin AT2-receptor (AT2R) agonists have shown a wide range of protective effects in many preclinical disease models. However, the availability of AT2R-agonists is very limited due to the lack of high-throughput assays for AT2R-agonist identification. Therefore, we aimed to design and validate an assay for high-throughput screening of AT2R-agonist candidates. The assay is based on nitric oxide (NO) release measurements in primary human aortic endothelial cells (HAEC), in AT2R-transfected CHO cells (AT2R-CHO) or in non-transfected CHO cells (Flp-CHO) using the fluorescent probe DAF-FM diacetate. It is run in 96-well plates and fluorescence signals are semi-automatically quantified. The assay was tested for sensitivity (recognition of true positive results), selectivity (recognition of true negative results), and reliability (by calculating the repeatability coefficient (RC)). The high-throughput, semi-automated method was proven suitable, as the NO-releasing agents C21, CGP42112A, angiotensin-(1-7) and acetylcholine significantly increased NO release from HAEC. The assay is sensitive and selective, since the established AT2R-agonists C21, CGP42112A and angiotensin II significantly increased NO release from AT2R-CHO cells, while the non-AT2R-agonists angiotensin-(1-7) and acetylcholine had no effect. Assay reliability was shown by high-throughput screening of a library comprised of 40 potential AT2R-agonists, of which 39 met our requirements for reliability (RC ≤ 20% different from RC for C21). Our newly developed high-throughput method for detection of AT2R-agonistic activity was proven to be sensitive, selective, and reliable. This method is suitable for the screening of potential AT2R-agonists in future drug development programs.
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Affiliation(s)
- Igor Maciel Souza-Silva
- Institute for Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - A Augusto Peluso
- Institute for Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Christina Mortensen
- Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Antonina L Nazarova
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA; Center for New Technologies in Drug Discovery and Development, Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
| | | | - Colin Sumners
- Department of Physiology and Aging, University of Florida, Gainesville, USA
| | - Vsevolod Katritch
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA; Center for New Technologies in Drug Discovery and Development, Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA; Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - U Muscha Steckelings
- Institute for Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark.
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2
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Peluso AA, Souza-Silva IM, Villela DC, Hansen PBL, Hallberg A, Bader M, Santos R, Sumners C, Steckelings UM. Functional assay for assessment of agonistic or antagonistic activity of angiotensin AT 2 receptor ligands reveals that EMA401 and PD123319 have agonistic properties. Biochem Pharmacol 2023; 216:115793. [PMID: 37689272 DOI: 10.1016/j.bcp.2023.115793] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023]
Abstract
With the discovery of the protective arm of the renin-angiotensin system (RAS), interest has grown in protective RAS-related receptors such as the angiotensin AT2-receptor [AT2R] as potential new drug targets. While it is known that AT2R couple to Gi, it is also apparent that they do not signal via inhibition of adenylyl cyclase/decrease in cAMP, as do many Gi-coupled receptors. Thus, standard commercially-available assays cannot be applied to test for agonistic or antagonistic properties of AT2R ligands. This lack of standard assays has hampered the development of new drugs targeting the AT2R. Therefore, we aimed at developing a reliable, technically easy assay for the determination of intrinsic activity of AT2R ligands, primarily for distinguishing between AT2R agonists and antagonists. We found that measurement of NO release by DAF-FM fluorescence in primary human aortic endothelial cells (HAEC) or in AT2R-transfected CHO cells is a reliable assay for the characterization of AT2R ligands. While testing the assay, we made several novel findings, including: a) C21 is a full agonist at the AT2R (with the same efficacy as angiotensin II); b) C21 has no intrinsic activity at the receptor Mas; c) AT2R-transfected HEK-293 cells are unresponsive to AT2R stimulation; d) EMA401 and PD123319, which are commonly regarded as AT2R antagonists, are partial agonists at the AT2R. Collectively, we have developed and tested an assay based on the measurement and quantification of NO release in HAEC or in AT2R-CHO cells that is suitable for the characterisation of novel and established AT2R ligands.
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Affiliation(s)
- A Augusto Peluso
- IMM - Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Igor M Souza-Silva
- IMM - Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Daniel C Villela
- Faculty of Medicine, University of the Jequitinhonha and Mucuri Valleys (UFVJM), Diamantina, Brazil
| | - Pernille B L Hansen
- IMM - Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Anders Hallberg
- Department of Medicinal Chemistry, BMC, Uppsala University, Uppsala, Sweden
| | - Michael Bader
- Max Delbrück Center for Molecular Medicine, Berlin, Germany; Charité-Universitätsmedizin Berlin, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Germany; Institute for Biology, University of Lübeck, Germany
| | - Robson Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Colin Sumners
- Department of Physiology and Aging, University of Florida, Gainesville, USA
| | - U Muscha Steckelings
- IMM - Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark.
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3
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Colombari DSA, Sumners C, Elsaafien K. Editorial: The neuroendocrine, autonomic and neuroinflammatory stress axes in cardiometabolic disease. Front Physiol 2023; 14:1293219. [PMID: 37817982 PMCID: PMC10561380 DOI: 10.3389/fphys.2023.1293219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 09/18/2023] [Indexed: 10/12/2023] Open
Affiliation(s)
- Débora S. A. Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Colin Sumners
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL, United States
- Centre for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, United States
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Khalid Elsaafien
- The Neuroscience Institute, Georgia State University, Atlanta, GA, United States
- Centre for Neuroinflammation and Cardiometabolic Diseases, Georgia State University, Atlanta, GA, United States
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4
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Baumer-Harrison C, Breza JM, Sumners C, Krause EG, de Kloet AD. Sodium Intake and Disease: Another Relationship to Consider. Nutrients 2023; 15:535. [PMID: 36771242 PMCID: PMC9921152 DOI: 10.3390/nu15030535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/14/2023] [Accepted: 01/15/2023] [Indexed: 01/22/2023] Open
Abstract
Sodium (Na+) is crucial for numerous homeostatic processes in the body and, consequentially, its levels are tightly regulated by multiple organ systems. Sodium is acquired from the diet, commonly in the form of NaCl (table salt), and substances that contain sodium taste salty and are innately palatable at concentrations that are advantageous to physiological homeostasis. The importance of sodium homeostasis is reflected by sodium appetite, an "all-hands-on-deck" response involving the brain, multiple peripheral organ systems, and endocrine factors, to increase sodium intake and replenish sodium levels in times of depletion. Visceral sensory information and endocrine signals are integrated by the brain to regulate sodium intake. Dysregulation of the systems involved can lead to sodium overconsumption, which numerous studies have considered causal for the development of diseases, such as hypertension. The purpose here is to consider the inverse-how disease impacts sodium intake, with a focus on stress-related and cardiometabolic diseases. Our proposition is that such diseases contribute to an increase in sodium intake, potentially eliciting a vicious cycle toward disease exacerbation. First, we describe the mechanism(s) that regulate each of these processes independently. Then, we highlight the points of overlap and integration of these processes. We propose that the analogous neural circuitry involved in regulating sodium intake and blood pressure, at least in part, underlies the reciprocal relationship between neural control of these functions. Finally, we conclude with a discussion on how stress-related and cardiometabolic diseases influence these circuitries to alter the consumption of sodium.
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Affiliation(s)
- Caitlin Baumer-Harrison
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32603, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Joseph M. Breza
- Department of Psychology, College of Arts and Sciences, Eastern Michigan University, Ypsilanti, MI 48197, USA
| | - Colin Sumners
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32603, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Eric G. Krause
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA
| | - Annette D. de Kloet
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32603, USA
- Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL 32610, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL 32610, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
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5
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Peluso AA, Kempf SJ, Verano-Braga T, Rodrigues-Ribeiro L, Johansen LE, Hansen MR, Kitlen G, Haugaard AH, Sumners C, Ditzel HJ, Santos RA, Bader M, Larsen MR, Steckelings UM. Quantitative Phosphoproteomics of the Angiotensin AT
2
-Receptor Signaling Network Identifies HDAC1 (Histone-Deacetylase-1) and p53 as Mediators of Antiproliferation and Apoptosis. Hypertension 2022; 79:2530-2541. [DOI: 10.1161/hypertensionaha.121.18620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Angiotensin AT
2
-receptor signaling is atypical for a G-protein coupled receptor and incompletely understood. To obtain novel insights into AT
2
-receptor signaling, we mapped changes in the phosphorylation status of the entire proteome of human aortic endothelial cells in response to AT
2
-receptor stimulation.
Methods:
Phosphorylation status of human aortic endothelial cells after stimulation with C21 (1 µM; 0, 1, 3, 5, 20 minutes) was determined utilizing time-resolved quantitative phosphoproteomics. Specific changes in protein phosphorylation and acetylation were confirmed by Western Blotting. Functional tests included resazurin assay for cell proliferation, and caspase 3/7 luminescence assay or FACS analysis of annexin V expression for apoptosis.
Results:
AT
2
-receptor stimulation significantly altered the phosphorylation status of 172 proteins (46% phosphorylations, 54% dephosphorylations). Bioinformatic analysis revealed a cluster of phospho-modified proteins involved in antiproliferation and apoptosis. Among these proteins, HDAC1 (histone-deacetylase-1) was dephosphorylated at serine
421/423
involving serine/threonine phosphatases. Resulting HDAC1 inhibition led to p53 acetylation and activation. AT
2
-receptor stimulation induced antiproliferation and apoptosis, which were absent when cells were co-incubated with the p53 inhibitor pifithrin-α, thus indicating p53-dependence of these AT
2
-receptor mediated functions.
Conclusions:
Contrary to the prevailing view that AT
2
-receptor signaling largely involves phosphatases, our study revealed significant involvement of kinases. HDAC1 inhibition and resulting p53 activation were identified as novel, AT
2
-receptor coupled signaling mechanisms. Furthermore, the study created an openly available dataset of AT
2
-receptor induced phospho-modified proteins, which has the potential to be the basis for further discoveries of currently unknown, AT
2
-receptor coupled signaling mechanisms.
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Affiliation(s)
- A. Augusto Peluso
- IMM - Department of Cardiovascular and Renal Research (A.A.P., G.K., A.H.H., U.M.S.), University of Southern Denmark, Odense
- Now with Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (A.A.P.)
| | - Stefan J. Kempf
- Department of Biochemistry and Molecular Biology (S.J.K., M.R.L.), University of Southern Denmark, Odense
- Now with CSL Behring, Department of Bioanalytical Sciences, Marburg, Germany (S.J.K.)
| | - Thiago Verano-Braga
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil (T.V.-B., L.R.-R., R.A.S.)
| | - Lucas Rodrigues-Ribeiro
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil (T.V.-B., L.R.-R., R.A.S.)
| | - Lene Egedal Johansen
- IMM - Department of Cancer and Inflammation Research (L.E.J., H.J.D.), University of Southern Denmark, Odense
| | | | - Gitte Kitlen
- IMM - Department of Cardiovascular and Renal Research (A.A.P., G.K., A.H.H., U.M.S.), University of Southern Denmark, Odense
| | - Andreas Houe Haugaard
- IMM - Department of Cardiovascular and Renal Research (A.A.P., G.K., A.H.H., U.M.S.), University of Southern Denmark, Odense
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville (C.S.)
| | - Henrik J. Ditzel
- IMM - Department of Cancer and Inflammation Research (L.E.J., H.J.D.), University of Southern Denmark, Odense
- Department of Oncology, Odense University Hospital, Denmark (H.J.D.)
| | - Robson A. Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil (T.V.-B., L.R.-R., R.A.S.)
| | - Michael Bader
- Max Delbrück Center for Molecular Medicine, Berlin, Germany (M.B.)
- Charite – University Medicine, Berlin, Germany (M.B.)
- DZHK, Berlin, Germany (M.B.)
- Institute for Biology, University of Lübeck, Germany (M.B.)
| | - Martin R. Larsen
- Department of Biochemistry and Molecular Biology (S.J.K., M.R.L.), University of Southern Denmark, Odense
| | - U. Muscha Steckelings
- IMM - Department of Cardiovascular and Renal Research (A.A.P., G.K., A.H.H., U.M.S.), University of Southern Denmark, Odense
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6
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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: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [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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7
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Silva IM, Peluso A, Nawrocki A, Jakobsen LA, Jensen P, Ribeiro LR, Mortensen C, Sumners C, Verano-Braga T, Larsen M, Steckelings UM. Abstract 116: Proof Of Biological Activity And Exploration Of Early Signaling Events Of Angiotensin-(1-5). Hypertension 2022. [DOI: 10.1161/hyp.79.suppl_1.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
Recombinant human ACE2 increases the circulating levels of angiotensin-(1-5) [Ang-(1-5)], a peptide thus far regarded as biologically inactive. Since ACE2 is a central component of the protective RAS, we hypothesized that Ang-(1-5) is a new biologically active peptide within this hormonal system.
Objective:
To investigate biological activity and signaling mechanisms of Ang-(1-5).
Methods:
In order to show a biological effect and to test whether Ang-(1-5) signals through the AT
2
-receptor (AT
2
R), nitric oxide (NO) release was measured by DAF-FM fluorescence in AT
2
R transfected (AT
2
R-CHO) or non-transfected (NT-CHO) CHO cells, treated with Ang-(1-5) or C21 (AT
2
R agonist, positive control) (0.1nM to 10μM) for 15 minutes. Vehicle (cell media) treated cells served as negative control. To investigate Ang-(1-5) signaling patterns, human aortic endothelial cells (HAEC) were treated with vehicle or Ang-(1-5) (1μM) for 1, 3, 5 or 20 minutes. Proteins were harvested, digested and labeled with TMTpro-16plex. Phosphopeptide enrichment was carried out by TiO
2
. Samples were subjected to LC-MS/MS analysis and the resulting mass spectra were searched against the human SwissProt database.
Results:
Ang-(1-5) induced a concentration-dependent increase in NO production in AT
2
-CHO cells (E
max
: 65.60 ± 14.02%), thus proving its biological activity. Ang-(1-5) had 69% higher efficacy than the established AT
2
R agonist C21 (E
max
: 38.76 ± 10.24%). Ang-(1-5) seems to signal through the AT
2
R, because effects on NO release were absent in NT-CHO cells. Treatment of HAEC with Ang-(1-5) significantly modified the phosphorylation status of 831 proteins at 1799 residues. The majority of residues (1079) were dephosphorylated while 729 residues were phosphorylated. Changes in protein phosphorylation in response to Ang-(1-5) occurred at all investigated time points, most of them after 20 minutes. Functional bioinformatic analysis revealed a cluster of proteins involved in cell cycle and cell division regulation.
Conclusion:
This study provides evidence that Ang-(1-5) is an endogenous AT
2
R agonist with high efficacy towards the AT
2
R. The early signaling phosphorylation pattern resembles those of other protective RAS agonists, such as C21 and Ang-(1-7).
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Affiliation(s)
| | | | | | | | - Pia Jensen
- Univ of Southern Denmark, Odense, Denmark
| | - Lucas R Ribeiro
- Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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8
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Elsaafien K, Eikenberry SA, Harden SW, Sheng W, Scott KA, Frazier CJ, Sumners C, Krause EG, De Kloet AD. Abstract 060: Angiotensin Type-2 Receptors In The Median Preoptic Nucleus Demarcate A Novel Depressor Neural Circuit In Mice. Hypertension 2022. [DOI: 10.1161/hyp.79.suppl_1.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Blood pressure (BP) is under constant control and regulation by an extensive neural network that spans a number of brain regions. This includes the median preoptic nucleus (MnPO) which directly projects to the pre-autonomic neurons of the hypothalamus to increase BP. While angiotensin type-1 receptors (AT
1
R) are expressed in the MnPO and project to the hypothalamus to increase BP, the role of angiotensin type-2 receptors (AT
2
R) is not clear. Here, we combine the use of AT
2
R-Cre mice, neuroanatomical techniques,
in vivo
optogenetics, pharmacology, and cardiovascular physiology to test the hypothesis that AT
2
R neurons of MnPO (MnPO
AT2R
) elicit cardioprotective effects. We found an abundance of AT
2
R-containing neurons in the MnPO that expressed the mRNA(s) for AT
2
R with high fidelity (~77%; 241 of 313 neurons; n=7). Using RNAscope
in situ
hybridization, we found that ~ 42% (153 of 364 neurons; n=8) of MnPO
AT2R
expressed genetic markers for GABA, an inhibitory neurotransmitter. Next, we delivered a Cre-inducible AAV to direct expression of channelrhodopsin-2 (ChR2) and/or enhanced yellow fluorescent protein (eYFP) within MnPO
AT2R
of AT
2
R-Cre mice. Using
in vitro
electrophysiology, we confirmed functional expression of ChR2 within MnPO
AT2R
, with pulses of light reliably producing action potentials (n= 12 neurons/3 animals). Subsequently, we found that activation of MnPO
AT2R
elicited inhibitory post-synaptic currents in neighboring AT
2
R-negative neurons. The
in vivo
optogenetic excitation of MnPO
AT2R
elicited depressor responses in both adult male (ΔSBP: +2.8 ± 1.3 vs. -4.1 ± 1.9 mmHg, p<0.05 eYFP vs. ChR2, n=15) and female mice (ΔSBP: +0.8 ± 2.2 vs.-5.3 ± 1.9 mmHg, p<0.05 eYFP vs. ChR2, n=5). These responses were abolished in the presence of the autonomic ganglion blocker, hexamethonium. Finally, to assess whether the depressor effects were AT
2
R-mediated, we administered the selective AT
2
R-agonist, compound 21, into the MnPO and observed depressor responses (ΔSBP: +0.5 ± 0.3 vs.-4.9 ± 1.0 mmHg, p<0.05 Saline vs. C21, n=7). In conclusion, our results demonstrate that MnPO
AT2R
are depressor inhibitory neurons that can be targeted with compound 21 to lower blood pressure.
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9
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Mohammed M, Johnson DN, Wang LA, Harden SW, Sheng W, Spector EA, Elsaafien K, Bader M, Steckelings UM, Scott KA, Frazier CJ, Sumners C, Krause EG, de Kloet AD. Targeting angiotensin type 2 receptors located on pressor neurons in the nucleus of the solitary tract to relieve hypertension in mice. Cardiovasc Res 2021; 118:883-896. [PMID: 33723600 DOI: 10.1093/cvr/cvab085] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 03/10/2021] [Indexed: 12/24/2022] Open
Abstract
AIMS These studies evaluate whether angiotensin type-2 receptors (AT2Rs) that are expressed on γ-aminobutyric acid (GABA) neurons in the nucleus of the solitary tract (NTS) represent a novel endogenous blood pressure lowering mechanism. METHODS AND RESULTS Experiments combined advanced genetic and neuroanatomical techniques, pharmacology, electrophysiology and optogenetics in mice to define the structure and cardiovascular-related function of NTS neurons that contain AT2R. Using mice with Cre-recombinase directed to the AT2R gene, we discovered that optogenetic stimulation of AT2R-expressing neurons in the NTS increases GABA release and blood pressure. To evaluate the role of the receptor, per se, in cardiovascular regulation, we chronically delivered C21, a selective AT2R agonist, into the brains of normotensive mice and found that central AT2R activation reduces GABA-related gene expression and blunts the pressor responses induced by optogenetic excitation of NTS AT2R neurons. Next, using in situ hybridization, we found that the levels of Agtr2 mRNAs in GABAergic NTS neurons rise during experimentally-induced hypertension, and we hypothesized that this increased expression may be exploited to ameliorate the disease. Consistent with this, final experiments revealed that central administration of C21 attenuates hypertension, an effect that is abolished in mice lacking AT2R in GABAergic NTS neurons. CONCLUSIONS These studies unveil novel hindbrain circuits that maintain arterial blood pressure, and reveal a specific population of AT2R that can be engaged to alleviate hypertension. The implication is that these discrete receptors may serve as an access point for activating an endogenous depressor circuit. TRANSLATIONAL PERSPECTIVE Hypertension is a widespread health problem and risk factor for cardiovascular disease and stroke. Although treatment options exist, many patients suffer from resistant hypertension, which is associated with enhanced sympathetic drive. Thus, many available therapeutics focus on dampening pressor mechanisms. The present studies take the alternative approach of treating hypertension by exploiting an endogenous depressor mechanism.
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Affiliation(s)
- Mazher Mohammed
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL
| | - Dominique N Johnson
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL
| | - Lei A Wang
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL
| | - Scott W Harden
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL
| | - Wanhui Sheng
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL
| | - Eliot A Spector
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL
| | - Khalid Elsaafien
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL
| | - Michael Bader
- Max-Delbrück Center for Molecular Medicine (MDC), Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany.,University of Lübeck, Institute for Biology, Ratzeburger Allee 160, 23562 Lübeck, Germany.,Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Germany
| | - U Muscha Steckelings
- Institute of Molecular Medicine, Department of Cardiovascular & Renal Research, University of Southern Denmark, Odense, Denmark
| | | | - Charles J Frazier
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL.,Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL.,Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL.,Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL
| | - Eric G Krause
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL.,Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL
| | - Annette D de Kloet
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL.,Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL.,Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL
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10
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Abstract
Pain in response to various types of acute injury can be a protective stimulus to prevent the organism from using the injured part and allow tissue repair and healing. On the other hand, neuropathic pain, defined as ‘pain caused by a lesion or disease of the somatosensory nervous system’, is a debilitating pathology. The TRPA1 neurons in the Dorsal Root Ganglion (DRG) respond to reactive oxygen species (ROS) and induce pain. In acute nerve injury and inflammation, macrophages infiltrating the site of injury undergo an oxidative burst, and generate ROS that promote tissue repair and induce pain via TRPA1. The latter discourages using the injured limb, with a lack of movement helping wound healing. In chronic inflammation caused by diabetes, cancer etc., ROS levels increase systemically and modulate TRPA1 neuronal functions and cause debilitating neuropathic pain. It is important to distinguish between drug targets that elicit protective vs. debilitating pain when developing effective drugs for neuropathic pain. In this context, the connection of the Angiotensin type 2 receptor (AT2R) to neuropathic pain presents an interesting dilemma. Several lines of evidence show that AT2R activation promotes anti-inflammatory and anti-nociceptive signaling, tissue repair, and suppresses ROS in chronic inflammatory models. Conversely, some studies suggest that AT2R antagonists are anti-nociceptive and therefore AT2R is a drug target for neuropathic pain. However, AT2R expression in nociceptive neurons is lacking, indicating that neuronal AT2R is not involved in neuropathic pain. It is also important to consider that Novartis terminated their phase II clinical trial (EMPHENE) to validate that AT2R antagonist EMA401 mitigates post-herpetic neuralgia. This trial, conducted in Australia, United Kingdom, and a number of European and Asian countries in 2019, was discontinued due to pre-clinical drug toxicity data. Moreover, early data from the trial did not show statistically significant positive outcomes. These facts suggest that may AT2R not be the proper drug target for neuropathic pain in humans and its inhibition can be harmful.
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Affiliation(s)
- Lakshmi Pulakat
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, United States.,Department of Medicine, Tufts University School of Medicine, Boston, MA, United States
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
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11
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Elsaafien K, de Kloet AD, Krause EG, Sumners C. Brain Angiotensin Type-1 and Type-2 Receptors in Physiological and Hypertensive Conditions: Focus on Neuroinflammation. Curr Hypertens Rep 2020; 22:48. [PMID: 32661792 PMCID: PMC7780348 DOI: 10.1007/s11906-020-01062-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE OF REVIEW To review recent data that suggest opposing effects of brain angiotensin type-1 (AT1R) and type-2 (AT2R) receptors on blood pressure (BP). Here, we discuss recent studies that suggest pro-hypertensive and pro-inflammatory actions of AT1R and anti-hypertensive and anti-inflammatory actions of AT2R. Further, we propose mechanisms for the interplay between brain angiotensin receptors and neuroinflammation in hypertension. RECENT FINDINGS The renin-angiotensin system (RAS) plays an important role in regulating cardiovascular physiology. This includes brain AT1R and AT2R, both of which are expressed in or adjacent to brain regions that control BP. Activation of AT1R within those brain regions mediate increases in BP and cause neuroinflammation, which augments the BP increase in hypertension. The fact that AT1R and AT2R have opposing actions on BP suggests that AT1R and AT2R may have similar opposing actions on neuroinflammation. However, the mechanisms by which brain AT1R and AT2R mediate neuroinflammatory responses remain unclear. The interplay between brain angiotensin receptor subtypes and neuroinflammation exacerbates or protects against hypertension.
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Affiliation(s)
- Khalid Elsaafien
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL, USA
| | - Annette D de Kloet
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Eric G Krause
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, FL, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, USA
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA.
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, USA.
- Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
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12
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Mohammed M, Sumners C, Sheng W, Harden SW, Frazier CJ, Johnson D, Scott KA, Krause EG, de Kloet AD. Angiotensin AT2 receptors in the solitary tract nucleus lower blood pressure via inhibition of GABA signaling. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.06415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Assersen KB, Sumners C, Steckelings UM. The Renin-Angiotensin System in Hypertension, a Constantly Renewing Classic: Focus on the Angiotensin AT 2-Receptor. Can J Cardiol 2020; 36:683-693. [PMID: 32389341 DOI: 10.1016/j.cjca.2020.02.095] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/28/2020] [Accepted: 02/29/2020] [Indexed: 02/07/2023] Open
Abstract
It is common knowledge that the renin-angiotensin system (RAS), in particular angiotensin II acting through the angiotensin AT1-receptor (AT1R), is pivotal for the regulation of blood pressure (BP) and extracellular volume. More recent findings have revealed that the RAS is far more complex than initially thought and that it harbours additional mediators and receptors, which are able to counteract and thereby fine-tune AT1R-mediated actions. This review will focus on the angiotensin AT2-receptor (AT2R), which is one of the "counter-regulatory" receptors within the RAS. It will review and discuss data related to the role of the AT2R in regulation of BP and focus on the following 3 questions: Do peripheral AT2R have an impact on BP regulation, and, if so, does this effect become apparent only under certain conditions? Are central nervous system AT2R involved in regulation of BP, and, if so, which brain areas are involved and what are the mechanisms? Does dysfunction of AT2R contribute to the pathogenesis of hypertension in preeclampsia?
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Affiliation(s)
- Kasper B Assersen
- Institute for Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - U Muscha Steckelings
- Institute for Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark.
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14
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Sharma RK, Yang T, Oliveira AC, Lobaton GO, Aquino V, Kim S, Richards EM, Pepine CJ, Sumners C, Raizada MK. Microglial Cells Impact Gut Microbiota and Gut Pathology in Angiotensin II-Induced Hypertension. Circ Res 2019; 124:727-736. [PMID: 30612527 DOI: 10.1161/circresaha.118.313882] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
RATIONALE Increased microglial activation and neuroinflammation within autonomic brain regions have been implicated in sustained hypertension, and their inhibition by minocycline-an anti-inflammatory antibiotic-produces beneficial effects. These observations led us to propose a dysfunctional brain-gut communication hypothesis for hypertension. However, it has been difficult to reconcile whether an anti-inflammatory or antimicrobial action is the primary beneficial effect of minocycline in hypertension. Accordingly, we utilized chemically modified tetracycline-3 (CMT-3)-a derivative of tetracycline that has potent anti-inflammatory activity-to address this question. OBJECTIVE Test the hypothesis that central administration of CMT-3 would inhibit microglial activation, attenuate neuroinflammation, alter selective gut microbial communities, protect the gut wall from developing hypertension-associated pathology, and attenuate hypertension. METHODS AND RESULTS Rats were implanted with radiotelemetry devices for recording mean arterial pressure. Ang II (angiotensin II) was infused subcutaneously using osmotic mini-pumps to induce hypertension. Another osmotic mini-pump was surgically implanted to infuse CMT-3 intracerebroventricularly. Intracerebroventricular CMT- 3 infusion was also investigated in SHR (spontaneously hypertensive rats). Physiological, pathological, immunohistological parameters, and fecal microbiota were analyzed. Intracerebroventricular CMT-3 significantly inhibited Ang II-induced increases in number of microglia, their activation, and proinflammatory cytokines in the paraventricular nucleus of hypothalamus. Further, intracerebroventricular CMT-3 attenuated increased mean arterial pressure, normalized sympathetic activity, and left ventricular hypertrophy in Ang II rats, as well as in the SHR. Finally, CMT-3 beneficially restored certain gut microbial communities altered by Ang II and attenuated pathological alterations in gut wall. CONCLUSIONS These observations demonstrate that inhibition of microglial activation alone was sufficient to induce significant antihypertensive effects. This was associated with unique changes in gut microbial communities and profound attenuation of gut pathology. They suggest, for the first time, a link between microglia and certain microbial communities that may have implications for treatment of hypertension.
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Affiliation(s)
- Ravindra K Sharma
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Tao Yang
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Aline C Oliveira
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Gilberto O Lobaton
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Victor Aquino
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Seungbum Kim
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Elaine M Richards
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Carl J Pepine
- Department of Medicine (C.J.P.), College of Medicine, University of Florida, Gainesville
| | - Colin Sumners
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
| | - Mohan K Raizada
- From the Department of Physiology and Functional Genomics (R.K.S., T.Y., A.C.O., G.O.L., V.A., S.K., E.M.R., C.S., M.K.R.), College of Medicine, University of Florida, Gainesville
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15
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Sumners C, Alleyne A, Rodríguez V, Pioquinto DJ, Ludin JA, Kar S, Winder Z, Ortiz Y, Liu M, Krause EG, de Kloet AD. Brain angiotensin type-1 and type-2 receptors: cellular locations under normal and hypertensive conditions. Hypertens Res 2019; 43:281-295. [PMID: 31853042 DOI: 10.1038/s41440-019-0374-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/25/2019] [Accepted: 11/02/2019] [Indexed: 12/15/2022]
Abstract
Brain angiotensin-II (Ang-II) type-1 receptors (AT1Rs), which exert profound effects on normal cardiovascular, fluid, and metabolic homeostasis, are overactivated in and contribute to chronic sympathoexcitation and hypertension. Accumulating evidence indicates that the activation of Ang-II type-2 receptors (AT2Rs) in the brain exerts effects that are opposite to those of AT1Rs, lowering blood pressure, and reducing hypertension. Thus, it would be interesting to understand the relative cellular localization of AT1R and AT2R in the brain under normal conditions and whether this localization changes during hypertension. Here, we developed a novel AT1aR-tdTomato reporter mouse strain in which the location of brain AT1aR was largely consistent with that determined in the previous studies. This AT1aR-tdTomato reporter mouse strain was crossed with our previously described AT2R-eGFP reporter mouse strain to yield a novel dual AT1aR/AT2R reporter mouse strain, which allowed us to determine that AT1aR and AT2R are primarily localized to different populations of neurons in brain regions controlling cardiovascular, fluid, and metabolic homeostasis. Using the individual AT1aR-tdTomato reporter mice, we also demonstrated that during hypertension induced by the administration of deoxycorticosterone acetate-salt, there was no shift in the expression of AT1aR from neurons to microglia or astrocytes in the paraventricular nucleus, a brain area important for sympathetic regulation. Using AT2R-eGFP reporter mice under similar hypertensive conditions, we demonstrated that the same was true of AT2R expression in the nucleus of the solitary tract (NTS), an area critical for baroreflex control. Collectively, these findings provided a novel means to assess the colocalization of AT1R and AT2R in the brain and a novel view of their cellular localization in hypertension.
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Affiliation(s)
- Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Amy Alleyne
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32611, USA
| | - Vermalí Rodríguez
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - David J Pioquinto
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32611, USA
| | - Jacob A Ludin
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32611, USA
| | - Shormista Kar
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Zachary Winder
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, 32611, USA.,Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32611, USA
| | - Yuma Ortiz
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32611, USA
| | - Meng Liu
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Eric G Krause
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32611, USA
| | - Annette D de Kloet
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, 32611, USA.
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16
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Yang T, Rodriguez V, Malphurs WL, Schmidt JT, Ahmari N, Sumners C, Martyniuk CJ, Zubcevic J. Butyrate regulates inflammatory cytokine expression without affecting oxidative respiration in primary astrocytes from spontaneously hypertensive rats. Physiol Rep 2019; 6:e13732. [PMID: 30039527 PMCID: PMC6056753 DOI: 10.14814/phy2.13732] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 01/16/2023] Open
Abstract
Neurons and glia exhibit metabolic imbalances in hypertensive animal models, and loss of metabolic homeostasis can lead to neuroinflammation and oxidative stress. The objective of this study was to determine the effects of the microbial metabolite butyrate on mitochondrial bioenergetics and inflammatory markers in mixed brainstem and hypothalamic primary cultures of astrocytes between normotensive (Sprague-Dawley, S-D) and spontaneously hypertensive (SHR) rats. Bioenergetics of mitochondria in astrocytes from normotensive S-D rats were modified with butyrate, but this was not the case in astrocytes derived from SHR, suggesting aberrant mitochondrial function. Transcripts related to oxidative stress, butyrate transporters, butyrate metabolism, and neuroinflammation were quantified in astrocyte cultures treated with butyrate at 0, 200, 600, and 1000 μmol/L. Butyrate decreased catalase and monocarboxylate transporter 1 mRNA in astrocytes of S-D rats but not in the SHR. Moreover, while butyrate did not directly regulate the expression of 3-hydroxybutyrate dehydrogenase 1 and 2 in astrocytes of either strain, the expression levels for these transcripts in untreated cultures were lower in the SHR compared to S-D. We observed higher levels of specific inflammatory cytokines in astrocytes of SHR, and treatment with butyrate decreased expression of Ccl2 and Tlr4 in SHR astrocytes only. Conversely, butyrate treatment increased expression of tumor necrosis factor in astrocytes from SHR but not from the S-D rats. This study improves our understanding of the role of microbial metabolites in regulating astrocyte function, and provides support that butyrate differentially regulates both the bioenergetics and transcripts related to neuroinflammation in astrocytes from SHR versus S-D rats.
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Affiliation(s)
- Tao Yang
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Vermali Rodriguez
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida
| | - Wendi L Malphurs
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Jordan T Schmidt
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Niousha Ahmari
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida
| | - Christopher J Martyniuk
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Jasenka Zubcevic
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
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17
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Sumners C, Peluso AA, Haugaard AH, Bertelsen JB, Steckelings UM. Anti-fibrotic mechanisms of angiotensin AT 2 -receptor stimulation. Acta Physiol (Oxf) 2019; 227:e13280. [PMID: 30957953 DOI: 10.1111/apha.13280] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/23/2019] [Accepted: 04/02/2019] [Indexed: 12/16/2022]
Abstract
The angiotensin AT2 -receptor is a main receptor of the protective arm of the renin-angiotensin system. Understanding of this unconventional G-protein coupled receptor has significantly advanced during the past decade, largely because of the availability of a selective non-peptide AT2 -receptor agonist, which allowed the conduct of a multitude of studies in animal disease models. This article reviews such preclinical studies that in their entirety provide strong evidence for an anti-fibrotic effect mediated by activation of the AT2 -receptor. Prevention of the development of fibrosis by AT2 -receptor stimulation has been demonstrated in lungs, heart, blood vessels, kidney, pancreas and skin. In lungs, AT2 -receptor stimulation was even able to reverse existing fibrosis. The article further discusses intracellular signalling mechanisms mediating the AT2 -receptor-coupled anti-fibrotic effect, including activation of phosphatases and subsequent interference with pro-fibrotic signalling pathways, induction of matrix-metalloproteinases and hetero-dimerization with the AT1 -receptor, the TGF-βRII-receptor or the RXFP1-receptor for relaxin. Knowledge of the anti-fibrotic effects of the AT2 -receptor is of particular relevance because drugs targeting this receptor have entered clinical development for indications involving fibrotic diseases.
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Affiliation(s)
- Colin Sumners
- Department of Physiology and Functional Genomics University of Florida Gainesville Florida
| | - Antonio Augusto Peluso
- IMM ‐ Department of Cardiovascular and Renal Research University of Southern Denmark Odense Denmark
| | - Andreas Houe Haugaard
- IMM ‐ Department of Cardiovascular and Renal Research University of Southern Denmark Odense Denmark
| | - Jesper Bork Bertelsen
- IMM ‐ Department of Cardiovascular and Renal Research University of Southern Denmark Odense Denmark
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18
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Verma A, Zhu P, de Kloet A, Krause E, Sumners C, Li Q. Angiotensin receptor expression revealed by reporter mice and beneficial effects of AT2R agonist in retinal cells. Exp Eye Res 2019; 187:107770. [PMID: 31449794 DOI: 10.1016/j.exer.2019.107770] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/08/2019] [Accepted: 08/17/2019] [Indexed: 02/08/2023]
Abstract
The renin-angiotensin system (RAS) plays a vital role in cardiovascular physiology and body homeostasis. In addition to circulating RAS, a local RAS exists in the retina. Dysfunction of local RAS, resulting in increased levels of Angiotensin II (Ang II) and activation of AT1R-mediated signaling pathways, contributes to tissue pathophysiology and end-organ damage. Activation of AT2R on other hand is known to counteract the effects of AT1R activation and produce anti-inflammatory and anti-oxidative effects. We examined the expression of angiotensin receptors in the retina by using transgenic dual reporter mice and by real-time RT-PCR. We further evaluated the effects of C21, a selective agonist of AT2R, in reducing Ang II, lipopolysaccharide (LPS) and hydrogen peroxide induced oxidative stress and inflammatory responses in cultured human ARPE-19 cells. We showed that both AT1Ra and AT2R positive cells are detected in different cell types of the eye, including the RPE/choroid complex, ciliary body/iris, and neural retina. AT1Ra is more abundantly expressed than AT2R in mouse retina, consistent with previous reports. In the neural retina, AT1Ra are also detected in photoreceptors whereas AT2R are mostly expressed in the inner retinal neurons and RGCs. In cultured human RPE cells, activation of AT2R with C21 significantly blocked Ang II, LPS and hydrogen peroxide -induced NF-κB activation and inflammatory cytokine expression; Ang II and hydrogen peroxide-induced reactive oxygen species (ROS) production and MG132-induced apoptosis, comparable to the effects of Angiotensin-(1-7) (Ang-(1-7)), another protective component of the RAS, although C21 is more potent in reducing some of the effects induced by Ang II, whereas Ang-(1-7) is more effective in reducing some of the LPS and hydrogen peroxide-induced effects. These results suggest that activation of AT2R may represent a new therapeutic approach for retinal diseases.
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Affiliation(s)
- Amrisha Verma
- Departments of Ophthalmology, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Ping Zhu
- Departments of Ophthalmology, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Annette de Kloet
- Physiology & Functional Genomics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Eric Krause
- College of Medicine, Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Colin Sumners
- Physiology & Functional Genomics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Qiuhong Li
- Departments of Ophthalmology, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA.
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19
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Abstract
Hypertension affects an estimated 103 million Americans, yet gaps in knowledge continue to limit its successful management. Rapidly emerging evidence is linking gut dysbiosis to many disorders and diseases including hypertension. The evolution of the -omics techniques has allowed determination of the abundance and potential function of gut bacterial species by next-generation bacterial sequencing, whereas metabolomics techniques report shifts in bacterial metabolites in the systemic circulation of hypertensive patients and rodent models of hypertension. The gut microbiome and host have evolved to exist in balance and cooperation, and there is extensive crosstalk between the 2 to maintain this balance, including during regulation of blood pressure. However, an understanding of the mechanisms of dysfunctional host-microbiome interactions in hypertension is still lacking. Here, we synthesize some of our recent data with published reports and present concepts and a rationale for our emerging hypothesis of a dysfunctional gut-brain axis in hypertension. Hopefully, this new information will improve the understanding of hypertension and help to address some of these knowledge gaps.
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Affiliation(s)
- Jasenka Zubcevic
- Department of Physiological Sciences, College of Veterinary Medicine; University of Florida, Gainesville FL32610
| | - Elaine M. Richards
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL32610
| | - Tao Yang
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL32610
| | - Seungbum Kim
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL32610
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL32610
| | - Carl J Pepine
- Division of Cardiovascular Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville FL32610
| | - Mohan K Raizada
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL32610
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20
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Mohammed M, Tan Y, Harrison CB, Scott KA, Sumners C, Kloet A, Krause EG. Cardiovascular Effects Of Acute Optogenetic Modulation Of Oxytocin‐PVN Neurons. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.691.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Yalun Tan
- PharmacodynamicsUniversity of FloridaGainesvilleFL
| | | | | | | | - Annette Kloet
- Physiology and Functional GenomicsUniversity of FloridaGainesvilleFL
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21
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Bennion DM, Jones CH, Donnangelo LL, Graham JT, Isenberg JD, Dang AN, Rodriguez V, Sinisterra RDM, Sousa FB, Santos RAS, Sumners C. Neuroprotection by post-stroke administration of an oral formulation of angiotensin-(1-7) in ischaemic stroke. Exp Physiol 2019; 103:916-923. [PMID: 29663576 DOI: 10.1113/ep086957] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/09/2018] [Indexed: 01/04/2023]
Abstract
NEW FINDINGS What is the central question of this study? Angiotensin-(1-7) decreases cerebral infarct volume and improves neurological function when delivered centrally before and during ischaemic stroke. Here, we assessed the neuroprotective effects of angiotensin-(1-7) when delivered orally post-stroke. What is the main finding and its importance? We show that oral delivery of angiotensin-(1-7) attenuates cerebral damage induced by middle cerebral artery occlusion in rats, without affecting blood pressure or cerebral blood flow. Importantly, these treatments begin post-stroke at times coincident with the treatment window for tissue plasminogen activator, providing supporting evidence for clinical translation of this new therapeutic strategy. ABSTRACT As a target for stroke therapies, the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas [ACE2/Ang-(1-7)/Mas] axis of the renin-angiotensin system can be activated chronically to induce neuroprotective effects, in opposition to the deleterious effects of angiotensin II via its type 1 receptor. However, more clinically relevant treatment protocols with Ang-(1-7) that involve its systemic administration beginning after the onset of ischaemia have not been tested. In this study, we tested systemic post-stroke treatments using a molecule where Ang-(1-7) is included within hydroxypropyl-β-cyclodextrin [HPβCD-Ang-(1-7)] as an orally bioavailable treatment. In three separate protocols, HPβCD-Ang-(1-7) was administered orally to Sprague-Dawley rats after induction of ischaemic stroke by endothelin-1-induced middle cerebral artery occlusion: (i) to assess its effects on cerebral damage and behavioural deficits; (ii) to determine its effects on cardiovascular parameters; and (iii) to determine whether it altered cerebral blood flow. The results indicate that post-stroke oral administration of HPβCD-Ang-(1-7) resulted in 25% reductions in cerebral infarct volumes and improvement in neurological functions (P < 0.05), without inducing any alterations in blood pressure, heart rate or cerebral blood flow. In conclusion, Ang-(1-7) treatment using an oral formulation after the onset of ischaemia induces significant neuroprotection in stroke and might represent a viable approach for taking advantage of the protective ACE2/Ang-(1-7)/Mas axis in this disease.
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Affiliation(s)
- Douglas M Bennion
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Chad H Jones
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Lauren L Donnangelo
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Justin T Graham
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Jacob D Isenberg
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Alex N Dang
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Vermali Rodriguez
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Ruben D M Sinisterra
- Department of Chemistry, Institute of Exact Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Frederico B Sousa
- Physics and Chemistry Institute, Federal University of Itajubá, Minas Gerais, Brazil
| | - Robson A S Santos
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, USA
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22
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Bruce EB, Sakarya Y, Kirichenko N, Toklu HZ, Sumners C, Morgan D, Tümer N, Scarpace PJ, Carter CS. ACE2 activator diminazene aceturate reduces adiposity but preserves lean mass in young and old rats. Exp Gerontol 2018; 111:133-140. [PMID: 30006298 DOI: 10.1016/j.exger.2018.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/11/2018] [Accepted: 07/10/2018] [Indexed: 12/17/2022]
Abstract
The obesity epidemic is multi-generational and is particularly debilitating in the aging population, necessitating the use of pharmaceutical interventions. Recent evidence suggests that increasing the activity of the angiotensin converting enzyme-2 [ACE2]/angiotensin-(1-7)[Ang-(1-7)]/Mas receptor (MasR) axis in obese animal models leads to significant reductions in body weight. It was hypothesized that activation of ACE2 via diminazene aceturate (DIZE) will significantly reduce body weight of rats fed a high fat diet. Young and old (4 and 23 months, respectively) male Fisher 344 × Brown Norway rats were fed 60% high fat diet for one week, and subsequently given either 15 mg/kg/day DIZE s.c. or vehicle for three weeks. DIZE treatment resulted in a significant reduction of food intake and body weight in both young and old animals. However, that decrease was so dramatic in the older animals that they all nearly stopped eating. Interestingly, the TD-NMR assessments revealed that the weight-loss was primarily a result of decreased body fat percentage, with a relative preservation of lean mass. Tissue weights confirm the significant loss of white adipose tissue (WAT), with no change in muscle weights. Gene expression and serum ACE2 activity analyses implied that increased activation of the ACE2/Ang-(1-7)/MasR axis plays a role in reducing fat mass. Collectively, our results suggest that DIZE may be a useful tool in the study of obesity; however, caution is recommended when using this compound in older animals due to severe anorectic effects, although there is a mechanism by which muscle is preserved.
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Affiliation(s)
- Erin B Bruce
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, United States of America
| | - Yasemin Sakarya
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, United States of America
| | - Nataliya Kirichenko
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, United States of America
| | - Hale Z Toklu
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, United States of America
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States of America
| | - Drake Morgan
- Department of Psychiatry, University of Florida, Gainesville, FL, United States of America
| | - Nihal Tümer
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, United States of America
| | - Philip J Scarpace
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, United States of America
| | - Christy S Carter
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, United States of America.
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23
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Rathinasabapathy A, Horowitz A, Horton K, Kumar A, Gladson S, Unger T, Martinez D, Bedse G, West J, Raizada MK, Steckelings UM, Sumners C, Katovich MJ, Shenoy V. The Selective Angiotensin II Type 2 Receptor Agonist, Compound 21, Attenuates the Progression of Lung Fibrosis and Pulmonary Hypertension in an Experimental Model of Bleomycin-Induced Lung Injury. Front Physiol 2018; 9:180. [PMID: 29636695 PMCID: PMC5881224 DOI: 10.3389/fphys.2018.00180] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/20/2018] [Indexed: 12/13/2022] Open
Abstract
Idiopathic Pulmonary Fibrosis (IPF) is a chronic lung disease characterized by scar formation and respiratory insufficiency, which progressively leads to death. Pulmonary hypertension (PH) is a common complication of IPF that negatively impacts clinical outcomes, and has been classified as Group III PH. Despite scientific advances, the dismal prognosis of IPF and associated PH remains unchanged, necessitating the search for novel therapeutic strategies. Accumulating evidence suggests that stimulation of the angiotensin II type 2 (AT2) receptor confers protection against a host of diseases. In this study, we investigated the therapeutic potential of Compound 21 (C21), a selective AT2 receptor agonist in the bleomycin model of lung injury. A single intra-tracheal administration of bleomycin (2.5 mg/kg) to 8-week old male Sprague Dawley rats resulted in lung fibrosis and PH. Two experimental protocols were followed: C21 was administered (0.03 mg/kg/day, ip) either immediately (prevention protocol, BCP) or after 3 days (treatment protocol, BCT) of bleomycin-instillation. Echocardiography, hemodynamic, and Fulton's index assessments were performed after 2 weeks of bleomycin-instillation. Lung tissue was processed for gene expression, hydroxyproline content (a marker of collagen deposition), and histological analysis. C21 treatment prevented as well as attenuated the progression of lung fibrosis, and accompanying PH. The beneficial effects of C21 were associated with decreased infiltration of macrophages in the lungs, reduced lung inflammation and diminished pulmonary collagen accumulation. Further, C21 treatment also improved pulmonary pressure, reduced muscularization of the pulmonary vessels and normalized cardiac function in both the experimental protocols. However, there were no major differences in any of the outcomes measured from the two experimental protocols. Collectively, our findings indicate that stimulation of the AT2 receptor by C21 attenuates bleomycin-induced lung injury and associated cardiopulmonary pathology, which needs to be further explored as a promising approach for the clinical treatment of IPF and Group III PH.
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Affiliation(s)
- Anandharajan Rathinasabapathy
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, United States.,Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Alana Horowitz
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, United States.,Anatomy, University of California at San Francisco, San Francisco, CA, United States
| | - Kelsey Horton
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, United States
| | - Ashok Kumar
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States.,Cardiopulmonary Vascular Biology Lab, Providence VA Medical Center, Brown University, Providence, RI, United States
| | - Santhi Gladson
- Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Thomas Unger
- Cardiovascular Research Institute Maastricht School for Cardiovascular Diseases, Maastricht University, Maastricht, Netherlands
| | - Diana Martinez
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, United States
| | - Gaurav Bedse
- Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - James West
- Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Mohan K Raizada
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Ulrike M Steckelings
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Michael J Katovich
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, United States
| | - Vinayak Shenoy
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, United States.,Department of Pharmaceutical and Biomedical Sciences, California Health Sciences University, Clovis, CA, United States
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24
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Mao Y, Pei N, Chen X, Chen H, Yan R, Bai N, Li A, Li J, Zhang Y, Du H, Chen B, Sumners C, Wang X, Wang S, Li H. Angiotensin 1-7 Overexpression Mediated by a Capsid-optimized AAV8 Vector Leads to Significant Growth Inhibition of Hepatocellular Carcinoma In vivo. Int J Biol Sci 2018; 14:57-68. [PMID: 29483825 PMCID: PMC5821049 DOI: 10.7150/ijbs.22235] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/14/2017] [Indexed: 12/19/2022] Open
Abstract
Background: Angiotensin-(1-7) [Ang-(1-7)] has been identified to inhibit the growth of many types of tumor cells both in vitro and in vivo. However, the rapid degradation of Ang-(1-7) in vivo limits its clinical application. Adeno-associated virus (AAV) serotype-8 is a remarkable vector for long-term in vivo gene delivery. Method: This study was designed to investigate the effects of AAV-mediated Ang-(1-7) overexpression on hepatocellular carcinoma. We first generated three different tyrosine (Y) to phenylalanine (F) mutants of AAV8 (Y447F, Y703F, Y708F) and evaluated their in vivo transduction efficiencies. Results: The data indicated that the Y703F mutant elicited a significant enhancement of liver gene delivery when compared with wild-type AAV8 (wtAAV8). The anti-tumor effect of Ang-(1-7) mediated by this optimized vector was evaluated in H22 hepatoma-bearing mice. Our results demonstrated that AAV-Ang-(1-7) persistently inhibited the growth of hepatocellular carcinoma by significantly downregulating angiogenesis. This was confirmed by observed decreases in the levels of the proangiogenic factors VEGF and PIGF. Conclusion: Collectively, these data suggest that Ang-(1-7) overexpression mediated by the optimized vector may be an effective alternative for hepatocellular carcinoma therapy due to its long-term and significant anti-tumor activity.
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Affiliation(s)
- Yingying Mao
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Nana Pei
- Department of Clinical Pathology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Xinglu Chen
- Clinical Laboratory,The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, Guangdong, China
| | - Huiying Chen
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Renhe Yan
- Guangzhou Bioneeds Biotechnology CO., LTD, Guangzhou, Guangdong, China
| | - Na Bai
- Deparement of Nuclear Medicine, People's Hospital of Yuxi City, Yuxi, Yunnan, China
| | - Andrew Li
- Department of Biomedical Engineering, The Johns University School of Medicine, Baltimore, USA
| | - Jinlong Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Yanling Zhang
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongyan Du
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Baihong Chen
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Colin Sumners
- Departments of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - Xuejun Wang
- Department of Biotechnology, Beijing Institute of Radiation Medicine, Beijing, China
- ✉ Corresponding authors: ; ;
| | - Shengqi Wang
- Department of Biotechnology, Beijing Institute of Radiation Medicine, Beijing, China
- ✉ Corresponding authors: ; ;
| | - Hongwei Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
- ✉ Corresponding authors: ; ;
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25
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Abstract
PURPOSE OF REVIEW The goal of this review is to assess the evidence that activation of angiotensin type 2 receptors (AT2R) in the brain can lower blood pressure and possibly constitute an endogenous anti-hypertensive mechanism. RECENT FINDINGS Recent studies that detail the location of AT2R in the brain, particularly within or near cardiovascular control centers, mesh well with findings from pharmacological and gene transfer studies which demonstrate that activation of central AT2R can influence cardiovascular regulation. Collectively, these studies indicate that selective activation of brain AT2R causes moderate decreases in blood pressure in normal animals and more profound anti-hypertensive effects, along with restoration of baroreflex function, in rodent models of neurogenic hypertension. These findings have opened the door to studies that can (i) assess the role of specific AT2R neuron populations in depressing blood pressure, (ii) determine the relevance of such mechanisms, and (iii) investigate interactions between AT2R and depressor angiotensin-(1-7)/Mas mechanisms in the brain.
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Affiliation(s)
- Annette D de Kloet
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, 1600 SW Archer Road, Box 100274, Gainesville, FL, 32610-0274, USA
| | - Ulrike M Steckelings
- IMM - Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, 1600 SW Archer Road, Box 100274, Gainesville, FL, 32610-0274, USA.
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Bruce EB, Domingos-Souza G, Smeltzer MD, Tan Y, Cahill K, Harden SW, Frazier CJ, Sumners C, Raizada MK, Krause EG, de Kloet AD. Abstract 084: Neurons in the Nodose Ganglion that Express Angiotensin Type 1a Receptors Function as Primary Baroreceptor Afferents: An
in vitro
and
in vivo
Optogenetic Study. Hypertension 2017. [DOI: 10.1161/hyp.70.suppl_1.084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The baroreflex is an essential regulator of blood pressure (BP); whereby, baroreceptors sense acute changes in BP and convey this information, via the nodose ganglia (NG), to the nucleus of the solitary tract (NTS). Manipulation of the baroreflex may provide a novel strategy in the treatment of hypertension. To that end, our neuroanatomical studies revealed a dense localization of angiotensin type 1a receptor (AT1a)-containing neuronal cell bodies in the NG and terminals in the NTS, thereby positioning them to play a role in the baroreflex. We, therefore, hypothesized that AT1a neurons residing in the NG potently influence cardiovascular function. Male and female mice expressing channelrhodopsin-2 (ChR2) and yellow fluorescent protein (eYFP) specifically in AT1a-expressing neurons (AT1aR-ChR2-eYFP) were used to determine the function of these neurons.
In vitro
patch clamp electrophysiological recordings from neurons in the NTS receiving axons expressing ChR2-eYFP revealed that optogenetic stimulation (473nm) reliably evoked excitatory postsynaptic currents (EPSCs). In concurrence with studies demonstrating that baroreceptor afferents utilize glutamate in the NTS, these EPSCs were eliminated by the presence of glutamate receptor antagonists. Next, the NG of anesthetized mice were subjected to optogenetic stimulation of varying frequencies (1, 15, 30Hz) for 1 min, and BP and HR responses were assessed. Optogenetic stimulation of these AT1a-expressing neurons led to significant decreases in mean arterial pressure (ΔMAP= -16±3*, -36±4*, -44±7* mmHg) and HR (ΔHR= -13±7, -104±44*, -163±59* bpm) in AT1a-ChR2-eYFP mice (n=6), but there was no effect on control mice harboring only the stop-FLOX-ChR2-eYFP gene (n=5; ΔMAP= 0±2, -2±1, 5±5 mmHg; ΔHR= 4±4, 3±4, -13±21 bpm). Additionally, AT1a-ChR2-eYFP mice rendered hypertensive via DOCA-salt (n=7) exhibited a dampened response to optogenetic stimulation (ΔMAP= -7±1#, -14±3*#, -30±6*# mmHg; ΔHR= -29±34, -71±37*, -178±50* bpm). Collectively, these data suggest that AT1a neurons in the NG are key regulators of the baroreflex, and may serve as a target for antihypertensive therapeutics. (p<0.05, *significantly different from control, #significantly different from normotensive AT1a-ChR2-eYFP)
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Steckelings UM, Kloet AD, Sumners C. Centrally Mediated Cardiovascular Actions of the Angiotensin II Type 2 Receptor. Trends Endocrinol Metab 2017; 28:684-693. [PMID: 28733135 PMCID: PMC5563271 DOI: 10.1016/j.tem.2017.06.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/06/2017] [Accepted: 06/08/2017] [Indexed: 02/07/2023]
Abstract
Sustained increases in the activity of the sympathetic neural pathways that exit the brain and which increase blood pressure (BP) are a major underlying factor in resistant hypertension. Recently available information on the occurrence of angiotensin II type 2 receptors (AT2Rs) within or adjacent to brain cardiovascular control centers is consistent with findings that stimulation of these receptors lowers BP, particularly during hypertension of neurogenic origin. Until recently brain AT2R had not been considered by many to play a role in the central control of BP. Demonstration of these powerful antihypertensive effects of brain AT2R opens the door to reconsideration of their role in BP regulation, and their consideration as a novel therapeutic avenue for resistant hypertension.
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Affiliation(s)
- U Muscha Steckelings
- Institute of Molecular Medicine (IMM), Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Annette de Kloet
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, USA
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, USA.
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28
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De Kloet AD, Domingos-Souza G, Smeltzer MD, Tan Y, Cahill K, Bruce EB, Raizada MK, Sumners C, Krause EG. Abstract 116: Potent Hypertensive Actions of Angiotensin-sensitive Neurons Within the Lamina Terminalis. Hypertension 2017. [DOI: 10.1161/hyp.70.suppl_1.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is accepted that activation of angiotensin type 1a receptors (AT1a) within the CNS elevates blood pressure by influencing sympathetic outflow and vasopressin (VP) secretion; however, the neuronal circuits mediating these effects are not completely understood. The present studies characterize the structure and function of AT1a neurons residing in the median preoptic nucleus (MnPO) and the organum vasculosum of the lamina terminalis (OVLT), thereby evaluating their potential role in blood pressure control. Using male mice that express Cre-recombinase prior to the STOP codon of the AT1a gene, initial studies combined genetic reporting with in situ hybridization to reveal that AT1a neurons in the MnPO and OVLT are largely excitatory (87±4% express vesicular glutamate transporter 2). Subsequently, AT1a-Cre mice were delivered a Cre-inducible adeno-associated virus to induce expression of channelrhodopsin-2 (ChR2) and enhanced yellow fluorescent protein (eYFP) specifically within AT1a neurons of the MnPO/OVLT (AAV-ChR2-eYFP; n = 4). Control mice were delivered AAV-eYFP (n = 4). Analysis of eYFP immunofluorescence revealed that neurons within the MnPO/OVLT that express AT1a send projections to the paraventricular nucleus of the hypothalamus (PVN; an area involved in sympathetic outflow and VP secretion) that appear to synapse onto VP synthesizing neurons. To evaluate the functionality of this connection, we optogenetically stimulated AT1a neurons in the region while recording cardiovascular parameters in anesthetized mice. Ten-minutes of optogenetic stimulation (473 nM;15 Hz; 20 ms pulse width; 60 s ON/OFF) robustly elevated systolic blood pressure in AAV-ChR2-eYFP mice relative to AAV-eYFP controls. This effect was rapid in its onset (34 ± 9 vs. -2 ± 4 mmHg at 5 min, p < 0.05) but persisted for the entire 50 min of cardiovascular recording (45 ± 11 vs. -3 ± 7 mmHg at 50 min, p < 0.05). Intriguingly, the optogenetic stimulation also resulted in 62% increase in Fos induction in AVP neurons within the PVN relative to AAV-eYFP controls (86 ± 5 vs. 52 ± 2 %; p<0.01). Collectively, these results suggest that excitation of AT1a neurons in the MnPO/OVLT recruits autonomic and neuroendocrine responses that promote robust and sustained increases in blood pressure.
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29
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Bennion DM, Isenberg JD, Harmel AT, DeMars K, Dang AN, Jones CH, Pignataro ME, Graham JT, Steckelings UM, Alexander JC, Febo M, Krause EG, de Kloet AD, Candelario-Jalil E, Sumners C. Post-stroke angiotensin II type 2 receptor activation provides long-term neuroprotection in aged rats. PLoS One 2017; 12:e0180738. [PMID: 28671997 PMCID: PMC5495490 DOI: 10.1371/journal.pone.0180738] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 06/20/2017] [Indexed: 11/18/2022] Open
Abstract
Activation of the angiotensin II type 2 receptor (AT2R) by administration of Compound 21 (C21), a selective AT2R agonist, induces neuroprotection in models of ischemic stroke in young adult animals. The mechanisms of this neuroprotective action are varied, and may include direct and indirect effects of AT2R activation. Our objectives were to assess the long-term protective effects of post-stroke C21 treatments in a clinically-relevant model of stroke in aged rats and to characterize the cellular localization of AT2Rs in the mouse brain of transgenic reporter mice following stroke. Intraperitoneal injections of C21 (0.03mg/kg) after ischemic stroke induced by transient monofilament middle cerebral artery occlusion resulted in protective effects that were sustained for up to at least 3-weeks post-stroke. These included improved neurological function across multiple assessments and a significant reduction in infarct volume as assessed by magnetic resonance imaging. We also found AT2R expression to be on neurons, not astrocytes or microglia, in normal female and male mouse brains. Stroke did not induce altered cellular localization of AT2R when assessed at 7 and 14 days post-stroke. These findings demonstrate that the neuroprotection previously characterized only during earlier time points using stroke models in young animals is sustained long-term in aged rats, implying even greater clinical relevance for the study of AT2R agonists for the acute treatment of ischemic stroke in human disease. Further, it appears that this sustained neuroprotection is likely due to a mix of both direct and indirect effects stemming from selective activation of AT2Rs on neurons or other cells besides astrocytes and microglia.
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Affiliation(s)
- Douglas M. Bennion
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Jacob D. Isenberg
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Allison T. Harmel
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Kelly DeMars
- Department of Neuroscience and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Alex N. Dang
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Chad H. Jones
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Megan E. Pignataro
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Justin T. Graham
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - U. Muscha Steckelings
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Jon C. Alexander
- Department of Psychiatry and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Marcelo Febo
- Department of Psychiatry and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Eric G. Krause
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida, United States of America
| | - Annette D. de Kloet
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Eduardo Candelario-Jalil
- Department of Neuroscience and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Colin Sumners
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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30
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Ju LS, Yang JJ, Gravenstein N, Seubert CN, Morey TE, Sumners C, Vasilopoulos T, Yang JJ, Martynyuk AE. Role of environmental stressors in determining the developmental outcome of neonatal anesthesia. Psychoneuroendocrinology 2017; 81:96-104. [PMID: 28433802 PMCID: PMC5492971 DOI: 10.1016/j.psyneuen.2017.04.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/28/2017] [Accepted: 04/04/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND The majority of studies evaluating neurocognition in humans who had procedures under anesthesia early in life found long-term deficits even though the typical anesthesia duration normalized to the human life span is much shorter than that shown to induce developmental abnormalities in rodents. Therefore, we studied whether subsequent environmental stressors contribute to deficiencies programmed by a brief neonatal etomidate exposure. METHODS Postnatal days (P) 4, 5, or 6, Sprague-Dawley rats, pretreated with vehicle or the Na+-K+-2Cl- (NKCC1) inhibitor, bumetanide, received two injections of etomidate resulting in anesthesia for 2h. To simulate stress after anesthesia, the animals were exposed to a single maternal separation for 3h at P10. 3-7days after exposure to etomidate the rats had increased hypothalamic NKCC1 mRNA and corticotropin releasing hormone (CRH) mRNA and decreased K+-2Cl- (KCC2) mRNA levels with greater changes in males. In rats neonatally exposed to both etomidate and maternal separation, these abnormalities persisted into adulthood. These animals also exhibited extended corticosterone responses to restraint stress with increases in total plasma corticosterone more robust in males, as well as behavioral abnormalities. Pretreatment with the NKCC1 inhibitor ameliorated most of these effects. CONCLUSIONS Post-anesthesia stressors may exacerbate/unmask neurodevelopmental abnormalities even after a relatively short anesthetic with etomidate, leading to dysregulated stress response systems and neurobehavioral deficiencies in adulthood. Amelioration by bumetanide suggests a mechanistic role for etomidate-enhanced gamma-aminobutyric acid type A receptor-mediated depolarization in initiating long-lasting alterations in gene expression that are further potentiated by subsequent maternal separation.
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Affiliation(s)
- Ling-Sha Ju
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States
| | - Jiao-Jiao Yang
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States
| | - Nikolaus Gravenstein
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States; The McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL, United States
| | - Christoph N Seubert
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States
| | - Timothy E Morey
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States
| | - Colin Sumners
- The McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL, United States; Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Terrie Vasilopoulos
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States
| | - Jian-Jun Yang
- Department of Anesthesiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Anatoly E Martynyuk
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, United States; The McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL, United States.
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31
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Hallberg M, Sumners C, Steckelings UM, Hallberg A. Small-molecule AT2 receptor agonists. Med Res Rev 2017; 38:602-624. [DOI: 10.1002/med.21449] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/03/2017] [Accepted: 05/16/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Mathias Hallberg
- The Beijer Laboratory, Department of Pharmaceutical Biosciences, BMC; Uppsala University; P.O. Box 591 SE751 24 Uppsala Sweden
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida; College of Medicine and McKnight Brain Institute; Gainesville FL 32611
| | - U. Muscha Steckelings
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research; University of Southern Denmark; P.O. Box 5230 Odense Denmark
| | - Anders Hallberg
- Department of Medicinal Chemistry, BMC; Uppsala University; P.O. Box 574 SE-751 23 Uppsala Sweden
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32
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Pei N, Mao Y, Wan P, Chen X, Li A, Chen H, Li J, Wan R, Zhang Y, Du H, Chen B, Jiang G, Xia M, Sumners C, Hu G, Gu D, Li H. Angiotensin II type 2 receptor promotes apoptosis and inhibits angiogenesis in bladder cancer. J Exp Clin Cancer Res 2017; 36:77. [PMID: 28599664 PMCID: PMC5466725 DOI: 10.1186/s13046-017-0542-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 05/19/2017] [Indexed: 12/27/2022]
Abstract
Background Bladder cancer (BCa) is the ninth most common form of cancer in the world. There is a continuing need not only for improving the accuracy of diagnostic markers but also for the development of new treatment strategies. Recent studies have shown that the renin-angiotensin system (RAS), which include the angiotensin type 1 (AT1R), type 2(AT2R), and Mas receptors, play an important role in tumorigenesis and may guide us in meeting those needs. Results In this study, we first observed that AT1R and Mas expression levels were significantly upregulated in BCa specimens while AT2R was significantly downregulated. Viral vector mediated overexpression of AT2R induced apoptosis and dramatically suppressed BCa cell proliferation in vitro, suggesting a therapeutic effect. Investigation into the mechanism revealed that the overexpression of AT2R increases the expression levels of caspase-3, caspase-8, and p38 and decreases the expression level of pErk. AT2R overexpression also leads to upregulation of 2 apoptosis-related genes (BCL2A1, TNFSF25) and downregulation of 8 apoptosis-related genes (CASP 6, CASP 9, DFFA, IGF1R, PYCARD, TNF, TNFRSF21, TNFSF10, NAIP) in transduced EJ cells as determined by PCR Array analysis. In vivo, we observed that AT2R overexpression caused significant reduction in xenograft tumors sizes by downregulation VEGF and induction of apoptosis. Conclusions Taken together, the data suggest that AT1R, AT2R or Mas could be used as a diagnostic marker of BCa and AT2R is a promising novel target gene for BCa gene therapy.
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Affiliation(s)
- Nana Pei
- Department of Clinical Pathology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China.,School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Yingying Mao
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Pengfei Wan
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Xinglu Chen
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Andrew Li
- Department of Biomedical Engineering, The Johns University School of Medicine, Baltimore, USA
| | - Huiying Chen
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Jinlong Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Renqiang Wan
- Department of Otolaryngology-Head and Neck Surgery, Guangdong No. 2 Provincial People's Hospital, Guangzhou, Guangdong, China
| | - Yanling Zhang
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Hongyan Du
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Baihong Chen
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China
| | - Guangyu Jiang
- Department of Clinical Pathology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Minghan Xia
- Department of Clinical Pathology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA
| | - Guixue Hu
- College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, People's Republic of China.
| | - Dongsheng Gu
- Department of Urology, the 421 St Hospital of PLA, No. 350, Xinggang Rd, Haizhu district, Guangzhou, Guangdong, 510318, China.
| | - Hongwei Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, 1023 South Shatai Road, Guangzhou, Guangdong, 510515, China.
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Barbosa RM, Speretta GF, Dias DPM, Ruchaya PJ, Li H, Menani JV, Sumners C, Colombari E, Colombari DSA. Increased Expression of Macrophage Migration Inhibitory Factor in the Nucleus of the Solitary Tract Attenuates Renovascular Hypertension in Rats. Am J Hypertens 2017; 30:435-443. [PMID: 28158469 PMCID: PMC5861587 DOI: 10.1093/ajh/hpx001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 10/20/2016] [Accepted: 01/02/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Macrophage migration inhibitory factor (MIF) is an intracellular inhibitory regulator of the actions of angiotensin II in the central nervous system. Renovascular hypertensive 2-kidney, 1-clip (2K1C) rats have an increased activity of the renin-angiotensin system and a decrease in baroreflex function compared to normotensive (NT) rats. In the present study, we tested the effects of MIF overexpression within the nucleus of the solitary tract (NTS), a key brainstem region for cardiovascular regulation, on the development of hypertension, on baroreflex function, and on water and food intake in 2K1C rats. METHODS Holtzman NT rats received a silver clip around the left renal artery to induce 2K1C hypertension. Three weeks later, rats were microinjected in the NTS with AAV2-CBA-MIF, to increase the expression of MIF, or with the control vector AAV2-CBA-enhanced green fluorescent protein. Mean arterial pressure (MAP) and heart rate were recorded by telemetry. Baroreflex function was tested, and water and food intake were also measured. RESULTS Increasing MIF expression in the NTS of 2K1C rats attenuated the development of hypertension, reversed the impairment of baroreflex function, and reduced the increase in water intake. In contrast to 2K1C rats, similar increases in MIF expression in the NTS of NT rats produced no changes in baseline MAP, baroreflex function, or water intake. CONCLUSIONS These results indicate that an increased expression of MIF within the NTS attenuates the development of hypertension and restores the baroreflex function in 2K1C rats.
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Affiliation(s)
- Rafaela Moreira Barbosa
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Guilherme F Speretta
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Daniel Penteado Martins Dias
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Prashant Jay Ruchaya
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Hongwei Li
- School of Biotechnology, Southern Medical University, Guangzhou, China
| | - José Vanderlei Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Débora S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
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Bennion DM, Isenberg JD, Dang AN, Jones CH, Graham JT, Steckelings UM, Sumners C. Abstract WMP84: Intranasal Trans-olfactory Delivery of the Angiotensin Type 2 Receptor Agonist Compound 21 is Neuroprotective in Ischemic Stroke. Stroke 2017. [DOI: 10.1161/str.48.suppl_1.wmp84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Compound 21 (C21), a selective small-molecule angiotensin type 2 receptor (AT2R) agonist, has been proven in multiple preclinical studies to reduce infarct size and ameliorate neurological deficits, when administered after ischemic stroke via intracerebroventricular or intraperitoneal routes. However, C21 poorly penetrates the blood brain barrier (BBB). In this study, we used the novel and non-invasive approach of intranasal trans-olfactory (INTO) application, in order to bypass the BBB and deliver C21 directly into the brain. The therapeutic efficacy of INTO application of C21 was assessed in a model of transient middle cerebral artery occlusion (MCAO).
Methods:
(i) Male SD rats (12 weeks old) underwent ischemic stroke by endothelin-1-induced MCAO. They were randomly divided into two treatment groups, either receiving 0.9% saline or C21 (1.5 ug/kg) at 1.5, 4, 24 and 48 h post-stroke, using a rat intranasal catheter device (Impel Neuropharma, Seattle, WA) for INTO application. All rats underwent blinded neurological assessments at 4, 24 and 72 h after stroke, and immediately after the 72 h tests, were euthanized and cerebral infarct volumes were assessed by TTC staining. (ii) Male SD rats (12 weeks old) underwent implantation of a telemetry transducer (DSI, St. Paul, MN) into the abdominal aorta for measurement of blood pressure, heart rate and locomotor activity after INTO C21 (1.5 ug/kg) vs. 0.9% saline at baseline and post-ischemic stroke.
Results:
(i) Post-stroke INTO delivery of C21 (1.5 ug/kg) elicited a significant lowering of % cerebral infarct volume (25.4 ± 4.7; n=9) compared with saline-treated rats (48.4 ± 4.4; n=21) [p<0.05; two-way Mann-Whitney test]. The C21 (1.5 ug/kg)-treated rats also displayed highly significant improvements in Garcia and Bederson neurological scores (p<0.01; two-way Mann-Whitney test]. (ii) INTO delivery of C21 (1.5 ug/kg) either in naïve rats (n=7), or in rats post-stroke (n=4), did not significantly alter baseline blood pressure, heart rate and locomotor activity.
Conclusions:
Our results demonstrate, that INTO delivery of C21 exerts protective effects after ischemic stroke. These studies suggest INTO administration as potential future route of application of C21 to stroke patients.
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Affiliation(s)
| | | | - Alex N Dang
- Physiology, Univ of Florida, Gainesville, FL
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35
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Ruchaya PJ, Speretta GF, Blanch GT, Li H, Sumners C, Menani JV, Colombari E, Colombari DSA. Overexpression of AT2R in the solitary-vagal complex improves baroreflex in the spontaneously hypertensive rat. Neuropeptides 2016; 60:29-36. [PMID: 27469059 DOI: 10.1016/j.npep.2016.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/20/2016] [Accepted: 06/05/2016] [Indexed: 02/07/2023]
Abstract
The aim of this study was to investigate the physiological effects of increased angiotensin II type 2 receptor (AT2R) expression in the solitary-vagal complex (nucleus of the solitary tract/dorsal motor nucleus of the vagus; NTS/DVM) on baroreflex function in non-anaesthetised normotensive (NT) and spontaneously hypertensive rats (SHR). Ten week old NT Holtzman and SHR were microinjected with either an adeno-associated virus expressing AT2R (AAV2-CBA-AT2R) or enhanced green fluorescent protein (control; AAV2-CBA-eGFP) into the NTS/DVM. Baroreflex and telemetry recordings were performed on four experimental groups: 1) NTeGFP, 2) NTAT2R, 3) SHReGFP and 4) SHRAT2R (n=4-7/group). Following in-vivo experimental procedures, brains were harvested for gene expression analysis. Impaired bradycardia in SHReGFP was restored in SHR rats overexpressing AT2R in the NTS/DMV. mRNA levels of angiotensin converting enzyme decreased and angiotensin converting enzyme 2 increased in the NTS/DMV of SHRAT2R compared to SHReGFP. Increased levels of pro-inflammatory cytokine mRNA levels in the SHReGFP group also decreased in the SHRAT2R group. AT2R overexpression did not elicit any significant change in mean arterial pressure (MAP) in all groups from baseline to 4weeks post viral transfection. Both SHReGFP and SHRAT2R showed a significant elevation in MAP compared to the NTeGFP and NTAT2R groups. Increased AT2R expression within the NTS/DMV of SHR was effective at improving baroreflex function but not MAP. We propose possible mediators involved in improving baroreflex are in the ANG II/ACE2 axis, suggesting a potential beneficial modulatory effect of AT2R overexpression in the NTS/DMV of neurogenic hypertensive rats.
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Affiliation(s)
- Prashant J Ruchaya
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, SP, Brazil
| | - Guilherme F Speretta
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, SP, Brazil
| | - Graziela Torres Blanch
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, SP, Brazil
| | - Hongwei Li
- School of Biotechnology, Southern Medical University, Guangzhou, China
| | - Colin Sumners
- Department of Physiology and Functional Genomics and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - José V Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, SP, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, SP, Brazil.
| | - Débora S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, SP, Brazil.
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36
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de Kloet AD, Wang L, Ludin JA, Hiller H, Smith JA, Scheuer DA, Steckelings UM, Krause EG, Sumners C. Abstract 073: Hindbrain Angiotensin Type-2 Receptors and Hypertension. Hypertension 2016. [DOI: 10.1161/hyp.68.suppl_1.073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The role of the angiotensin type-2 receptor (AT2R) in the neural control of cardiovascular homeostasis and hypertension is not well-characterized. Using a BAC transgenic AT2R-enhanced green fluorescent protein (eGFP) reporter mouse, dense localization of AT2R to GABA neurons was found within the nucleus of the solitary tract (NTS) of the hindbrain, an area important for regulating baroreflex function and blood pressure. This localization was confirmed by RNAscope fluorescence
in situ
hybridization. Considering that GABA is pressor in the intermediate NTS (intNTS), and that its effects are enhanced in models of neurogenic hypertension such as SHR and deoxycorticosterone acetate (DOCA)-salt rats, we tested the
hypothesis
that AT2R on GABA neurons in the NTS constitute a counter-regulatory, blood pressure lowering mechanism. In support of this idea, we have demonstrated that: (i) Optogenetic stimulation of GABA neurons in the intNTS of normal mice elicited a significant increase in blood pressure; (ii) mRNA levels for both the GABA synthetic enzyme Gad1 and for the AT2R are significantly increased in the intNTS of DOCA-salt hypertensive mice; (iii) Intracerebroventricular (ICV) infusion of the AT2R agonist Compound 21 (C21; 7.5 ng/h) into normotensive or DOCA-salt hypertensive mice elicited a significant reduction of systolic blood pressure, an effect that was much larger in hypertensive (126.2 ± 5.0 v. 139.8 ± 3.2 mmHg; n = 14; p = 0.02) than in normotensive (119.8 ± 2.6 v. 126.5 ± 2.5 mmHg; n = 16; p = 0.04) mice and was accompanied by decreased levels of the GABA synthetic enzymes Gad1 and Gad2 in the intNTS; (iv) Finally, the crucial involvement of GABA neurons in the blood pressure lowering effect of AT2R was proven by the lack of any effect of ICV C21 in DOCA-salt hypertensive mice containing a selective knockout of AT2R from GABA neurons. These novel data provide strong evidence for an anti-hypertensive action of AT2R within the intNTS, an effect that is exerted through decreases in GABA transmission.
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Affiliation(s)
| | - Lei Wang
- Univ of Florida, Gainesville, FL
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37
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Bennion DM, Rosado CA, Haltigan EA, Regenhardt RW, Sumners C, Waters MF. Serum activity of angiotensin converting enzyme 2 is decreased in patients with acute ischemic stroke. J Renin Angiotensin Aldosterone Syst 2016; 17:17/3/1470320316661060. [PMID: 27488276 PMCID: PMC5843889 DOI: 10.1177/1470320316661060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/21/2016] [Indexed: 11/18/2022] Open
Abstract
Levels of angiotensin converting enzyme 2 (ACE2), a cardio and neuro-protective carboxypeptidase, are dynamically altered after stroke in preclinical models. We sought to characterize the previously unexplored changes in serum ACE2 activity of stroke patients and the mechanism of these changes. Serum samples were obtained from patients during acute ischemic stroke (n=39), conditions mimicking stroke (stroke-alert, n=23), or from control participants (n=20). Enzyme activity levels were analyzed by fluorometric assay and correlated with clinical variables by regression analyses. Serum ACE2 activity was significantly lower in acute ischemic stroke as compared to both control and stroke-alert patients, followed by an increase to control levels at three days. Serum ACE2 activity significantly correlated with the presence of ischemic stroke after controlling for other factors (P=0.01). Additional associations with ACE2 activity included a positive correlation with systolic blood pressure at presentation in stroke-alert (R2=0.24, P=0.03), while stroke levels showed no correlation (R2=0.01, P=0.50). ACE2 sheddase activity was unchanged between groups. These dynamic changes in serum ACE2 activity in stroke, which concur with preclinical studies, are not likely to be driven primarily by acute changes in blood pressure or sheddase activity. These findings provide new insight for developing therapies targeting this protective system in ischemic stroke.
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Affiliation(s)
- Douglas M Bennion
- Department of Physiology and Functional Genomics, University of Florida, USA
| | - Christian A Rosado
- Neurovascular Division, Department of Neurology, University of Florida, USA
| | - Emily A Haltigan
- Department of Physiology and Functional Genomics, University of Florida, USA
| | - Robert W Regenhardt
- Department of Physiology and Functional Genomics, University of Florida, USA
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, USA
| | - Michael F Waters
- Neurovascular Division, Department of Neurology, University of Florida, USA
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38
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de Kloet AD, Pitra S, Wang L, Hiller H, Pioquinto DJ, Smith JA, Sumners C, Stern JE, Krause EG. Angiotensin Type-2 Receptors Influence the Activity of Vasopressin Neurons in the Paraventricular Nucleus of the Hypothalamus in Male Mice. Endocrinology 2016; 157:3167-80. [PMID: 27267713 PMCID: PMC4967126 DOI: 10.1210/en.2016-1131] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It is known that angiotensin-II acts at its type-1 receptor to stimulate vasopressin (AVP) secretion, which may contribute to angiotensin-II-induced hypertension. Less well known is the impact of angiotensin type-2 receptor (AT2R) activation on these processes. Studies conducted in a transgenic AT2R enhanced green fluorescent protein reporter mouse revealed that although AT2R are not themselves localized to AVP neurons within the paraventricular nucleus of the hypothalamus (PVN), they are localized to neurons that extend processes into the PVN. In the present set of studies, we set out to characterize the origin, phenotype, and function of nerve terminals within the PVN that arise from AT2R-enhanced green fluorescent protein-positive neurons and synapse onto AVP neurons. Initial experiments combined genetic and neuroanatomical techniques to determine that γ-aminobutyric acid (GABA)ergic neurons derived from the peri-PVN area containing AT2R make appositions onto AVP neurons within the PVN, thereby positioning AT2R to negatively regulate neuroendocrine secretion. Subsequent patch-clamp electrophysiological experiments revealed that selective activation of AT2R in the peri-PVN area using compound 21 facilitates inhibitory (ie, GABAergic) neurotransmission and leads to reduced activity of AVP neurons within the PVN. Final experiments determined the functional impact of AT2R activation by testing the effects of compound 21 on plasma AVP levels. Collectively, these experiments revealed that AT2R expressing neurons make GABAergic synapses onto AVP neurons that inhibit AVP neuronal activity and suppress baseline systemic AVP levels. These findings have direct implications in the targeting of AT2R for disorders of AVP secretion and also for the alleviation of high blood pressure.
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39
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Isenberg JD, Bennion DM, Irwin AJ, Harmel AT, Candelario-Jalil E, Sumners C. Abstract TMP58: Post Stroke Activation of Angiotensin II Type 2 Receptors Shows Sustained Neuroprotective Effects in Aged Rats. Stroke 2016. [DOI: 10.1161/str.47.suppl_1.tmp58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
The renin angiotensin system is a promising target for stroke neuroprotection and therapy through activation of angiotensin type II receptors (AT2Rs). Compound 21 (C21), a selective non-peptide AT2R agonist, has been shown to exhibit neuroprotection and improve stroke outcomes in preclinical studies. Stimulation of AT2Rs is believed to counteract the negative effects of angiotensin type 1 receptor and provide distinctive beneficial anti-inflammatory and neurotropic effects. We hypothesized that C21 given after stroke through peripheral injections would have sustained neuroprotective effects in aged rats.
Methods:
Aged adult male SD rats (18-20 months) underwent ischemic stroke by monofilament middle cerebral artery occlusion (MCAO) and were randomly divided into two groups that received intraperitoneal (IP) injections of either 0.9% NaCl or 0.03mg/kg C21 at reperfusion (90 min), 24h, and 48h after stroke. All animals received blinded neurological exams at 4h, 24h, 72h, 7d, 14d, and 21d post-stroke. Infarct size was assessed by magnetic resonance imaging at 21 days.
Results:
Post-stroke treatment with C21 significantly improved neurological function, as evidenced by neurological testing using Rotarod and somatosensory dysfunction exams. At 7d and 14d after stroke, C21-treated rats had significantly increased Rotarod times versus saline-treated rats, and at 21d, the somatosensory function was significantly improved as measured by time to removal of paw adhesive. Infarct volume tended to be non-significantly decreased by C21 treatment at 21d post-stroke.
Conclusions:
Our findings indicate that targeting the renin-angiotensin system, specifically by stimulation of AT2Rs with C21, improves neurological function in aged rats with stroke over a sustained period of 21 days. These findings encourage further research into the renin-angiotensin system and specifically AT2Rs, and offers hope for effective alternatives for treating stroke.
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Affiliation(s)
- Jacob D Isenberg
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
| | - Douglas M Bennion
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
| | - Alexander J Irwin
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
| | - Allison T Harmel
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
| | | | - Colin Sumners
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
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40
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Bennion DM, Rosado CA, Haltigan EA, Sumners C, Waters MF. Abstract TP214: Serum Activity of Angiotensin Converting Enzyme 2 is Decreased During Ischemic Stroke in Humans. Stroke 2016. [DOI: 10.1161/str.47.suppl_1.tp214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
Abundant preclinical studies show efficacy for therapies targeted to the protective axis of the renin-angiotensin system in stroke. The expression and activity of angiotensin converting enzyme 2 (ACE2), a cardio and neuro-protective carboxypeptidase in this axis, have recently been shown to be dynamically altered during stroke in animal models.
Hypothesis:
The aim of this study was to characterize the previously unexplored changes in activity of ACE2, and other RAS enzymes, in the serum of patients experiencing acute ischemic stroke.
Methods:
Blood samples were obtained from patients with acute ischemic stroke (n=20) at presentation and again at three days post-stroke and enzyme activity levels in isolated serum were analyzed by fluorometric assay. These were compared to enzyme activity levels in samples obtained from a cohort of patients presenting with transient ischemic attack or other clinical presentations mimicking stroke and from healthy control participants (n=20).
Results:
Ischemic stroke resulted in significantly lower levels of serum ACE2 activity at an average of 3.5 hours after stroke as compared to both transient ischemic attack/stroke mimic and healthy control participant levels, followed three days later by an increase back to control levels. ACE activity was also significantly decreased following stroke, but without increases at three days. Renin enzyme activity during stroke did not significantly differ from controls at either time point. Serum ACE2 activity was negatively correlated with systolic blood pressure at presentation among stroke patients, while activity levels from a separate cohort of healthy young adults were positively correlated. Multiple regression analyses indicated that ACE2 activity levels were significantly correlated with a diagnosis of ischemic stroke, with those in the lowest tertile of all participants were at 7.7 times increased odds of having had a stroke.
Conclusions:
The characterization of the dynamic and novel changes in serum ACE2 activity in human stroke, which concur with preclinical studies, along with the demonstration of correlations with systolic blood pressure, provides new insight for the development of therapies that target this protective system in ischemic stroke.
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Affiliation(s)
- Douglas M Bennion
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
| | | | - Emily A Haltigan
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
| | - Colin Sumners
- Physiology and Functional Genomics, Univ of Florida, Gainesville, FL
| | - Michael F Waters
- Neurovascular Div, Dept of Neurology, Univ of Florida, Gainesville, FL
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41
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Li J, Luo J, Gu D, Jie F, Pei N, Li A, Chen X, Zhang Y, Du H, Chen B, Gu W, Sumners C, Li H. Adenovirus-Mediated Angiotensin II Type 2 Receptor Overexpression Inhibits Tumor Growth of Prostate Cancer In Vivo. J Cancer 2016; 7:184-91. [PMID: 26819642 PMCID: PMC4716851 DOI: 10.7150/jca.12841] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 10/17/2015] [Indexed: 12/29/2022] Open
Abstract
The renin-angiotensin system (RAS) plays important roles in tumorigenesis and is involved with several hallmarks of cancer. Evidence shows that angiotensin II (AngII) type 1 receptor (AT1R) blockers may be associated with improved outcome in prostate cancer patients. Furthermore, our previous studies indicate that increased expression of Ang II type 2 receptor (AT2R) alone induced apoptosis in human prostate cancer lines, an effect that did not require Ang II. This study aimed to investigate the effects of AT2R on tumor growth in vivo and we hypothesized that AT2R over-expression would inhibit proliferation and induce apoptosis in vivo. Human prostate cancer DU145 xenograft mouse model was used to assess the effect of AT2R on tumor growth in vivo. Mice bearing a palpable tumor were chosen and divided randomly into three treatment groups: AT2R, GFP, and PBS. Then we directly injected into the xenograft tumors of the mice every three days with recombinant adenoviruses encoding AT2R (Ad5-CMV-AT2R-EGFP), EGFP (Ad5-CMV-EGFP) and PBS, respectively. The tumor sizes of the tumor bearing mice were then measured. Immunohistochemical Ki-67 staining and TUNEL assay were performed to examine the inhibitory effect of AT2R on tumor cell proliferation. The results showed that AT2R overexpression can inhibit tumor growth of prostate cancer in vivo by inhibiting proliferation and inducing apoptosis of tumor cells. GADD45A is involved in the AT2R-induced antitumor activity. This suggests that AT2R is a potentially useful gene for prostate gene therapy.
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Affiliation(s)
- Jinlong Li
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Jie Luo
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Dongsheng Gu
- 5. Department of Urology, the 421st Hospital of PLA, Guangzhou, Guangdong, China
| | - Feilong Jie
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Nana Pei
- 6. Department of Clinical Pathology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Andrew Li
- 3. Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, USA
| | - Xinglu Chen
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Yanling Zhang
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongyan Du
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Baihong Chen
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Weiwang Gu
- 2. Institute of Comparative Medicine and Center of Laboratory Animals, Southern Medical University, Guangzhou, Guangdong, China
| | - Colin Sumners
- 4. Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA; and
| | - Hongwei Li
- 1. School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
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42
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Pei N, Wan R, Chen X, Li A, Zhang Y, Li J, Du H, Chen B, Wei W, Qi Y, Zhang Y, Katovich MJ, Sumners C, Zheng H, Li H. Angiotensin-(1-7) Decreases Cell Growth and Angiogenesis of Human Nasopharyngeal Carcinoma Xenografts. Mol Cancer Ther 2015; 15:37-47. [PMID: 26671566 DOI: 10.1158/1535-7163.mct-14-0981] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 10/27/2015] [Indexed: 11/16/2022]
Abstract
Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, heptapeptide hormone acting through the Mas receptor (MasR), with antiproliferative and antiangiogenic properties. Recent studies have shown that Ang-(1-7) has an antiproliferative action on lung adenocarcinoma cells and prostate cancer cells. In this study, we report that MasR levels were significantly upregulated in nasopharyngeal carcinoma (NPC) specimens and NPC cell lines. Viral vector-mediated expression of Ang-(1-7) dramatically suppressed NPC cell proliferation and migration in vitro. These effects were completely blocked by the specific Ang-(1-7) receptor antagonist A-779, suggesting that they are mediated by the Ang-(1-7) receptor Mas. In this study, Ang-(1-7) not only caused a significant reduction in the growth of human nasopharyngeal xenografts, but also markedly decreased vessel density, suggesting that the heptapeptide inhibits angiogenesis to reduce tumor size. Mechanistic investigations revealed that Ang-(1-7) inhibited the expression of the proangiogenic factors VEGF and PlGF. Taken together, the data suggest that upregulation of MasR could be used as a diagnostic marker of NPC and Ang-(1-7) may be a novel therapeutic agent for nasopharyngeal cancer therapy because it exerts significant antiangiogenic activity.
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Affiliation(s)
- Nana Pei
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China. Department of Clinical Pathology, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Renqiang Wan
- Department of Otolaryngology-Head and Neck Surgery, Guangdong NO.2 Provincial People's Hospital, Guangzhou, Guangdong, China
| | - Xinglu Chen
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Andrew Li
- Department of Biomedical Engineering, The Johns University School of Medicine, Baltimore, Maryland
| | - Yanling Zhang
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Jinlong Li
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongyan Du
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Baihong Chen
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Wenjin Wei
- Beijing Minhai Biotechnology Co. Ltd., Beijing, China
| | - Yanfei Qi
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Yi Zhang
- Department of Pharmacology, University of Florida, Gainesville, Florida
| | - Michael J Katovich
- Department of Pharmacodynamics, University of Florida, Gainesville, Florida
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Haifa Zheng
- Beijing Minhai Biotechnology Co. Ltd., Beijing, China.
| | - Hongwei Li
- School of Biotechnology, Southern Medical University, Guangzhou, Guangdong, China.
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43
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Yang H, Zheng S, Mao Y, Chen Z, Zheng C, Li H, Sumners C, Li Q, Yang P, Lei B. Modulating of ocular inflammation with macrophage migration inhibitory factor is associated with notch signalling in experimental autoimmune uveitis. Clin Exp Immunol 2015; 183:280-93. [PMID: 26400205 DOI: 10.1111/cei.12710] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 09/11/2015] [Accepted: 09/22/2015] [Indexed: 12/29/2022] Open
Abstract
The aim of this study was to examine whether macrophage migration inhibitory factor (MIF) could exaggerate inflammatory response in a mouse model of experimental autoimmune uveitis (EAU) and to explore the underlying mechanism. Mutant serotype 8 adeno-associated virus (AAV8) (Y733F)-chicken β-actin (CBA)-MIF or AAV8 (Y733F)-CBA-enhanced green fluorescent protein (eGFP) vector was delivered subretinally into B10.RIII mice, respectively. Three weeks after vector delivery, EAU was induced with a subcutaneous injection of a mixture of interphotoreceptor retinoid binding protein (IRBP) peptide with CFA. The levels of proinflammatory cytokines were detected by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Retinal function was evaluated with electroretinography (ERG). We found that the expression of MIF and its two receptors CD74 and CD44 was increased in the EAU mouse retina. Compared to AAV8.CBA.eGFP-injected and untreated EAU mice, the level of proinflammatory cytokines, the expression of Notch1, Notch4, delta-like ligand 4 (Dll4), Notch receptor intracellular domain (NICD) and hairy enhancer of split-1 (Hes-1) increased, but the ERG a- and b-wave amplitudes decreased in AAV8.CBA.MIF-injected EAU mice. The Notch inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) reduced the expression of NICD, Hes-1 and proinflammatory cytokines. Further, a MIF antagonist ISO-1 attenuated intraocular inflammation, and inhibited the differentiation of T helper type 1 (Th1) and Th17 in EAU mice. We demonstrated that over-expression of MIF exaggerated ocular inflammation, which was associated with the activation of the Notch signalling. The expression of both MIF and its receptors are elevated in EAU mice. Over-expression of MIF exaggerates ocular inflammation, and this exaggerated inflammation is associated with the activation of the Notch signalling and Notch pathway. Our data suggest that the MIF-Notch axis may play an important role in the pathogenesis of EAU. Both the MIF signalling pathways may be promising targets for developing novel therapeutic interventions for uveitis.
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Affiliation(s)
- H Yang
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - S Zheng
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - Y Mao
- School of Biotechnology, Southern Medical University, Guangzhou, China
| | - Z Chen
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - C Zheng
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - H Li
- School of Biotechnology, Southern Medical University, Guangzhou, China
| | - C Sumners
- Department of Physiology and Functional Genomics and McKnight Brain Institute, Gainesville, FL, USA
| | - Q Li
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - P Yang
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - B Lei
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
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44
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Barbosa R, Speretta G, Freiria-Oliveira A, Li H, Sumners C, Menani J, Colombari E, Colombari D. Increased expression of macrophage migration inhibitory factor in the nucleus of solitary tract attenuates the renovascular hypertension. Auton Neurosci 2015. [DOI: 10.1016/j.autneu.2015.07.130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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Sumners C. Antioxidant proteins in the brain: Role in RAS-induced blood pressure control and hypertension. Auton Neurosci 2015. [DOI: 10.1016/j.autneu.2015.07.318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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46
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Liu M, Shi P, Sumners C. Direct anti-inflammatory effects of angiotensin-(1-7) on microglia. J Neurochem 2015; 136:163-71. [PMID: 26448556 DOI: 10.1111/jnc.13386] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 01/18/2023]
Abstract
Much evidence indicates that pro-inflammatory effects of the renin-angiotensin system within the hypothalamus, including microglial activation and production of pro-inflammatory cytokines, play a role in chronic neurogenic hypertension. Our objective here was to examine whether angiotensin-(1-7) [Ang-(1-7)], a protective component of the renin-angiotensin system, exerts direct actions at microglia to counteract these pro-inflammatory effects. Mas, the Ang-(1-7) receptor, was shown to be present on cultured hypothalamic microglia. Treatment of these cells with Ang-(1-7) (100-1000 nM, 3-12 h) elicited significant decreases in basal levels of mRNAs for the pro-inflammatory cytokines interleukin-1β (IL-1β) and tumor-necrosis factor α (TNFα) and of the microglia-macrophage marker CD11b, and increases in basal levels of the anti-inflammatory cytokine interleukin-10. Incubation of microglial cultures with (pro)renin (PRO) (10-50 nM; 6 h) elicited significant increases in mRNAs for IL-1β, TNFα and CD11b. The effects of PRO (10 nM) on IL-1β and TNFα mRNAs, and TNFα protein, were significantly attenuated by co-treatment with Ang-(1-7) (100 nM). Lastly, these actions of Ang-(1-7) were abolished by the Mas antagonist A-779, and were associated with reductions in NF-κB subunit expression. Collectively, these data provide the first evidence that Ang-(1-7) can exert direct effects at microglia to lower baseline and counteract PRO-induced increases in pro-inflammatory cytokines. Renin-Angiotensin system mediated microglial activation and pro-inflammatory cytokine production within the hypothalamus are components of the chronic neuroinflammation associated with 'neurogenic' hypertension. We demonstrated that angiotension-(1-7) acting via its receptor Mas on hypothalamic microglia lessens baseline and (pro)renin-induced increases in pro-inflammatory cytokine production by these cells. This is the first evidence that angiotensin-(1-7) has direct anti-inflammatory effects via microglia.
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Affiliation(s)
- Meng Liu
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Peng Shi
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida, USA
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Xu C, Tan S, Zhang J, Seubert CN, Gravenstein N, Sumners C, Vasilopoulos T, Martynyuk AE. Anesthesia with sevoflurane in neonatal rats: Developmental neuroendocrine abnormalities and alleviating effects of the corticosteroid and Cl(-) importer antagonists. Psychoneuroendocrinology 2015; 60:173-81. [PMID: 26150359 PMCID: PMC4526322 DOI: 10.1016/j.psyneuen.2015.06.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 05/22/2015] [Accepted: 06/22/2015] [Indexed: 12/20/2022]
Abstract
BACKGROUND 1.5 million children under 12 months of age are exposed to general anesthesia annually in the United States alone. Human and especially animal studies provide evidence that exposure to general anesthesia during the early postnatal period may lead to long-term neurocognitive abnormalities via poorly understood mechanisms. We investigated whether an immature stress response system and γ-aminobutyric acid (GABA) type A receptor activities are involved in mediating these abnormalities. METHODS Sprague-Dawley rats at postnatal days 4, 5 or 6 were anesthetized with 2.1% sevoflurane for 6h; maternally separated and house reared rats served as controls. RESULTS Sevoflurane anesthesia markedly increased corticosterone levels in rat pups of both genders. In adulthood, these rats responded to stress with heightened secretion of corticosterone and a greater increase in corticosterone levels in males versus females. Only male rats, previously exposed to neonatal sevoflurane, had a higher frequency of miniature inhibitory postsynaptic currents in CA1 neurons, spent a shorter time in open arms of the elevated plus maze (EPM) and exhibited impaired prepulse inhibition (PPI) of startle. Pretreatment of male rats prior to sevoflurane with the Na(+)-K(+)-2Cl(-) cotransporter inhibitor, bumetanide, or the mineralocorticoid receptor antagonist, RU28318, normalized endocrine responses to stress and the EPM behavior in adulthood, while only those pretreated with bumetanide exhibited normalized PPI of startle responses. Neither bumetanide nor RU28318 altered the effect of sevoflurane on synaptic activity. CONCLUSIONS Sevoflurane-enhanced neuronal excitation and elevated corticosteroid levels at the time of anesthesia contribute to the mechanisms initiating neonatal sevoflurane-induced long-term endocrine and neurobehavioral abnormalities.
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Affiliation(s)
- Changqing Xu
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL
| | - Sijie Tan
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL
| | - Jiaqiang Zhang
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL,Department of Anesthesiology, People’s Hospital of Zhengzhou University, Zhengzhou, P.R.China
| | - Christoph N. Seubert
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL
| | - Nikolaus Gravenstein
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL,McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL
| | - Colin Sumners
- McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL,Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL
| | - Terrie Vasilopoulos
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL
| | - Anatoly E. Martynyuk
- Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL,McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL
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Liu M, De Kloet AD, Krause EG, Sumners C. Abstract P621: Cellular Localization of Angiotensin Type 1a Receptor mRNA in the Paraventricular Nucleus of the Hypothalamus. Hypertension 2015. [DOI: 10.1161/hyp.66.suppl_1.p621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The chronic neurogenic hypertension that involves increased effects of angiotensin II (Ang II) via its type 1 receptor (AT1R) within brain cardiovascular control centers is associated with induction of microglial activation and neuroinflammation in the paraventricular nucleus of the hypothalamus (PVN). However, whether Ang II exerts
direct
effects via AT1R located on microglia is not established. Therefore, the objective of this study was to determine the cellular localization of AT1R in the PVN. Naïve twelve-week old normotensive (Sprague Dawley, SD; Wistar Kyoto, WKY) rats and spontaneously hypertensive rats (SHR) were euthanized and perfused with 4% paraformaldehyde. Brains were removed and sectioned coronally at the level of the PVN. Sections throughout the entire PVN underwent RNAscope fluorescence
in situ
hybridization to determine AT1aR mRNA expression, combined with immunohistochemistry using microglia (Ionized calcium binding adaptor molecule 1; Iba1)-, neuron (HuC/D)-, or astrocyte (Glial fibrillary acidic protein; GFAP)-specific markers. The results, obtained from at least 3 SD and 3 WKY rats indicate strong co-localization of AT1aR transcripts with neurons in the neuroendocrine and parvocellular PVN regions, as expected. By contrast, there was no detectable co-localization of AT1aR mRNA with either microglia or astrocytes throughout the PVN of these rats. Further, qRT-PCR revealed that while both AT1aR- and AT1bR mRNAs were detectable in SD rat hypothalamus (1.00±0.14; 0.40±0.12; n=7), neither transcript was detectable in microglia cultured from the hypothalamus of SD rats (n=6). The pattern of AT1aR mRNA expression in the PVN of SHR, a hypertensive model that exhibits over activity of Ang II/AT1R actions at the PVN, was similar to that observed in the SD and WKY rats, i.e. strong co-localization with HuC/D-positive cells, and no detectable co-localization with either Iba1 or GFAP-positive cells. Collectively, these findings indicate that AT1R are localized to neurons, not glia, in the PVN of normotensive rats or SHR
in situ
. Further, they suggest that it is unlikely that Ang II exerts direct effects at microglia in the PVN, and that induction of microglial activation at this site following Ang II infusion is likely an indirect action.
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Affiliation(s)
- Meng Liu
- Univ of Florida, Gainesville, FL
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de Kloet AD, Liu M, Rodríguez V, Krause EG, Sumners C. Role of neurons and glia in the CNS actions of the renin-angiotensin system in cardiovascular control. Am J Physiol Regul Integr Comp Physiol 2015; 309:R444-58. [PMID: 26084692 DOI: 10.1152/ajpregu.00078.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 06/15/2015] [Indexed: 02/07/2023]
Abstract
Despite tremendous research efforts, hypertension remains an epidemic health concern, leading often to the development of cardiovascular disease. It is well established that in many instances, the brain plays an important role in the onset and progression of hypertension via activation of the sympathetic nervous system. Further, the activity of the renin-angiotensin system (RAS) and of glial cell-mediated proinflammatory processes have independently been linked to this neural control and are, as a consequence, both attractive targets for the development of antihypertensive therapeutics. Although it is clear that the predominant effector peptide of the RAS, ANG II, activates its type-1 receptor on neurons to mediate some of its hypertensive actions, additional nuances of this brain RAS control of blood pressure are constantly being uncovered. One of these complexities is that the RAS is now thought to impact cardiovascular control, in part, via facilitating a glial cell-dependent proinflammatory milieu within cardiovascular control centers. Another complexity is that the newly characterized antihypertensive limbs of the RAS are now recognized to, in many cases, antagonize the prohypertensive ANG II type 1 receptor (AT1R)-mediated effects. That being said, the mechanism by which the RAS, glia, and neurons interact to regulate blood pressure is an active area of ongoing research. Here, we review the current understanding of these interactions and present a hypothetical model of how these exchanges may ultimately regulate cardiovascular function.
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Affiliation(s)
- Annette D de Kloet
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
| | - Meng Liu
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
| | - Vermalí Rodríguez
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
| | - Eric G Krause
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, Florida
| | - Colin Sumners
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
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Erdos B, Clifton RR, Liu M, Li H, McCowan ML, Sumners C, Scheuer DA. Novel mechanism within the paraventricular nucleus reduces both blood pressure and hypothalamic pituitary-adrenal axis responses to acute stress. Am J Physiol Heart Circ Physiol 2015; 309:H634-45. [PMID: 26071542 DOI: 10.1152/ajpheart.00207.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 06/05/2015] [Indexed: 02/07/2023]
Abstract
Macrophage migration inhibitory factor (MIF) counteracts pressor effects of angiotensin II (ANG II) in the paraventricular nucleus of the hypothalamus (PVN) in normotensive rats, but this mechanism is absent in spontaneously hypertensive rats (SHRs) due to a lack of MIF in PVN neurons. Since endogenous ANG II in the PVN modulates stress reactivity, we tested the hypothesis that replacement of MIF in PVN neurons would reduce baseline blood pressure and inhibit stress-induced increases in blood pressure and plasma corticosterone in adult male SHRs. Radiotelemetry transmitters were implanted to measure blood pressure, and then an adeno-associated viral vector expressing either enhanced green fluorescent protein (GFP) or MIF was injected bilaterally into the PVN. Cardiovascular responses to a 15-min water stress (1-cm deep, 25°C) and a 60-min restraint stress were evaluated 3-4 wk later. MIF treatment in the PVN attenuated average restraint-induced increases in blood pressure (37.4 ± 2.0 and 27.6 ± 3.5 mmHg in GFP and MIF groups, respectively, P < 0.05) and corticosterone (42 ± 2 and 36 ± 3 μg/dl in GFP and MIF groups, respectively, P < 0.05). MIF treatment in the PVN also reduced stress-induced elevations in the number of c-Fos-positive cells in the rostral ventrolateral medulla (71 ± 5 in GFP and 47 ± 5 in MIF SHRs, P < 0.01) and corticotropin-releasing factor mRNA expression in the PVN. However, MIF had no significant effects on the cardiovascular responses to water stress in SHRs or to either stress in Sprague-Dawley rats. Therefore, viral vector-mediated restoration of MIF in PVN neurons of SHRs attenuates blood pressure and hypothalamic pituitary adrenal axis responses to stress.
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Affiliation(s)
- Benedek Erdos
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Rebekah R Clifton
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Meng Liu
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Hongwei Li
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Michael L McCowan
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Deborah A Scheuer
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
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