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de Liyis BG, Sutedja JC, Kesuma PMI, Liyis S, Widyadharma IPE. A review of literature on Compound 21-loaded gelatin nanoparticle: a promising nose-to-brain therapy for multi-infarct dementia. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2023. [DOI: 10.1186/s41983-023-00621-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
AbstractMulti-infarct dementia (MID) is described as a chronic progressive decline in cortical cognitive function due to the occurrence of multiple infarcts in the cerebral vascularization throughout the gray and white matter. Current therapies of MID mostly focus only on slowing down MID progression and symptomatic medications. A novel therapy which is able to provide both preventive and curative properties for MID is of high interest. The purpose of this review is to identify the potential of Compound 21 (C21) gelatin nanoparticle through the nose-to-brain route as therapy for MID. C21, an angiotensin II type 2 receptor (AT2R) agonist, has shown to reduce the size of cerebral infarct in rodent models, resulting in the preservation and improvement of overall cognitive function and prevention of secondary neurodegenerative effects. It is also shown that C21 decreases neuronal apoptosis, improves damaged axons, and encourage synapse development. The challenge remains in preventing systemic AT2R activation and increasing its low oral bioavailability which can be overcome through nose-to-brain administration of C21. Nose-to-brain drug delivery of C21 significantly increases drug efficiency and limits C21 exposure in order to specifically target the multiple infarcts located in the cerebral cortex. Adhering C21 onto gelatin nanoparticles may enable longer contact time with the olfactory and the trigeminal nerve endings, increasing the potency of C21. In summary, treatment of C21 gelatin nanoparticle through nose-to-brain delivery shows high potential as therapy for vascular dementia. However, clinical trials must be further studied in order to test the safety and efficacy of C21.
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Steckelings UM, Widdop RE, Sturrock ED, Lubbe L, Hussain T, Kaschina E, Unger T, Hallberg A, Carey RM, Sumners C. The Angiotensin AT 2 Receptor: From a Binding Site to a Novel Therapeutic Target. Pharmacol Rev 2022; 74:1051-1135. [PMID: 36180112 PMCID: PMC9553111 DOI: 10.1124/pharmrev.120.000281] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/19/2022] [Accepted: 06/27/2022] [Indexed: 11/22/2022] Open
Abstract
Discovered more than 30 years ago, the angiotensin AT2 receptor (AT2R) has evolved from a binding site with unknown function to a firmly established major effector within the protective arm of the renin-angiotensin system (RAS) and a target for new drugs in development. The AT2R represents an endogenous protective mechanism that can be manipulated in the majority of preclinical models to alleviate lung, renal, cardiovascular, metabolic, cutaneous, and neural diseases as well as cancer. This article is a comprehensive review summarizing our current knowledge of the AT2R, from its discovery to its position within the RAS and its overall functions. This is followed by an in-depth look at the characteristics of the AT2R, including its structure, intracellular signaling, homo- and heterodimerization, and expression. AT2R-selective ligands, from endogenous peptides to synthetic peptides and nonpeptide molecules that are used as research tools, are discussed. Finally, we summarize the known physiological roles of the AT2R and its abundant protective effects in multiple experimental disease models and expound on AT2R ligands that are undergoing development for clinical use. The present review highlights the controversial aspects and gaps in our knowledge of this receptor and illuminates future perspectives for AT2R research. SIGNIFICANCE STATEMENT: The angiotensin AT2 receptor (AT2R) is now regarded as a fully functional and important component of the renin-angiotensin system, with the potential of exerting protective actions in a variety of diseases. This review provides an in-depth view of the AT2R, which has progressed from being an enigma to becoming a therapeutic target.
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Affiliation(s)
- U Muscha Steckelings
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert E Widdop
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Edward D Sturrock
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Lizelle Lubbe
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Tahir Hussain
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Elena Kaschina
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Thomas Unger
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Anders Hallberg
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert M Carey
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Colin Sumners
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
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Fouda AY, Ahmed HA, Pillai B, Kozak A, Hardigan T, Ergul A, Fagan SC, Ishrat T. Contralesional angiotensin type 2 receptor activation contributes to recovery in experimental stroke. Neurochem Int 2022; 158:105375. [PMID: 35688299 PMCID: PMC9719365 DOI: 10.1016/j.neuint.2022.105375] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 01/16/2023]
Abstract
We and others have previously shown that angiotensin II receptor type 2 receptor (AT2R) is upregulated in the contralesional hemisphere after stroke in normoglycemic Wistar rats. In this study, we examined the expression of AT2R in type 2 diabetic Goto-Kakizaki (GK) rats and control Wistars after stroke. We also tested the contribution of the contralesional AT2R in recovery after stroke through a specific knockdown of the AT2R in this hemisphere only. Two experiments were conducted. In the first experiment, GK rats were subjected to middle cerebral artery occlusion (MCAO) and treated with the angiotensin II receptor type 1 receptor (AT1R) blocker candesartan or saline at reperfusion. Stroke outcomes, as well as AT2R expression, were examined and compared to control Wistars at 24 h. In the second experiment, localized AT2R knockdown was achieved through intrastriatal injection of short hairpin RNA (shRNA) lentiviral particles or non-targeting control into the left-brain hemisphere of Wistar rats. After 14 days, rats were subjected to right MCAO and treated with the AT2R agonist, Compound 21 (C21), or saline for 7 days. Behavioral outcomes were assessed for up to 10 days. In the first experiment, stroke reduced the expression of AT2R in GK rats. Candesartan treatment failed to improve the neurobehavioral outcomes, preserve vascular integrity or reduce oxidative/nitrative stress or apoptotic markers at 24 h post stroke in these animals. In the second experiment, contralesional AT2R knockdown reduced the C21-mediated functional recovery after stroke. In conclusion, contralesional AT2R upregulation after stroke is blunted in diabetic rats which show reduced sensitivity to post-stroke candesartan treatment. Contralesional AT2R could be involved in C21-mediated functional recovery after stroke.
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Affiliation(s)
- Abdelrahman Y. Fouda
- University of Arkansas for Medical Sciences, Little Rock, AR, USA,Department of Clinical Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt,Corresponding author. University of Arkansas for Medical Sciences, Department of Pharmacology and Toxicology, Little Rock, AR, USA. (A.Y. Fouda)
| | - Heba A. Ahmed
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Bindu Pillai
- Charlie Norwood VA Medical Center, Augusta, GA, USA,Center for Pharmacy and Experimental Therapeutics, University of Georgia, College of Pharmacy, Augusta, GA, USA
| | - Anna Kozak
- Charlie Norwood VA Medical Center, Augusta, GA, USA,Center for Pharmacy and Experimental Therapeutics, University of Georgia, College of Pharmacy, Augusta, GA, USA
| | - Trevor Hardigan
- Department of Neurosurgery, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | - Adviye Ergul
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA,Ralph H. Jackson VA Medical Center, Charleston, SC, USA
| | - Susan C. Fagan
- Charlie Norwood VA Medical Center, Augusta, GA, USA,Center for Pharmacy and Experimental Therapeutics, University of Georgia, College of Pharmacy, Augusta, GA, USA
| | - Tauheed Ishrat
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA,Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA,Corresponding author. University of Tennessee Health Science Center, College of Medicine, Department of Anatomy and Neurobiology, 875 Monroe Avenue, Wittenborg Bldg, Room-231, Memphis, TN, 38163, USA. (T. Ishrat)
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4
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Sánchez KE, Rosenberg GA. Shared Inflammatory Pathology of Stroke and COVID-19. Int J Mol Sci 2022; 23:5150. [PMID: 35563537 PMCID: PMC9101120 DOI: 10.3390/ijms23095150] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 02/06/2023] Open
Abstract
Though COVID-19 is primarily characterized by symptoms in the periphery, it can also affect the central nervous system (CNS). This has been established by the association between stroke and COVID-19. However, the molecular mechanisms that cause stroke related to a COVID-19 infection have not been fully explored. More specifically, stroke and COVID-19 exhibit an overlap of molecular mechanisms. These similarities provide a way to better understand COVID-19 related stroke. We propose here that peripheral macrophages upregulate inflammatory proteins such as matrix metalloproteinases (MMPs) in response to SARS-CoV-2 infection. These inflammatory molecules and the SARS-CoV-2 virus have multiple negative effects related to endothelial dysfunction that results in the disruption of the blood-brain barrier (BBB). Finally, we discuss how the endothelial blood-brain barrier injury alters central nervous system function by leading to astrocyte dysfunction and inflammasome activation. Our goal is to elucidate such inflammatory pathways, which could provide insight into therapies to combat the negative neurological effects of COVID-19.
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Affiliation(s)
- Kathryn E. Sánchez
- Center for Memory and Aging, University of New Mexico, Albuquerque, NM 87106, USA;
| | - Gary A. Rosenberg
- Center for Memory and Aging, University of New Mexico, Albuquerque, NM 87106, USA;
- Department of Neurology, University of New Mexico, Albuquerque, NM 87106, USA
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5
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Annoni F, Moro F, Caruso E, Zoerle T, Taccone FS, Zanier ER. Angiotensin-(1-7) as a Potential Therapeutic Strategy for Delayed Cerebral Ischemia in Subarachnoid Hemorrhage. Front Immunol 2022; 13:841692. [PMID: 35355989 PMCID: PMC8959484 DOI: 10.3389/fimmu.2022.841692] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/04/2022] [Indexed: 01/06/2023] Open
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) is a substantial cause of mortality and morbidity worldwide. Moreover, survivors after the initial bleeding are often subject to secondary brain injuries and delayed cerebral ischemia, further increasing the risk of a poor outcome. In recent years, the renin-angiotensin system (RAS) has been proposed as a target pathway for therapeutic interventions after brain injury. The RAS is a complex system of biochemical reactions critical for several systemic functions, namely, inflammation, vascular tone, endothelial activation, water balance, fibrosis, and apoptosis. The RAS system is classically divided into a pro-inflammatory axis, mediated by angiotensin (Ang)-II and its specific receptor AT1R, and a counterbalancing system, presented in humans as Ang-(1-7) and its receptor, MasR. Experimental data suggest that upregulation of the Ang-(1-7)/MasR axis might be neuroprotective in numerous pathological conditions, namely, ischemic stroke, cognitive disorders, Parkinson's disease, and depression. In the presence of SAH, Ang-(1-7)/MasR neuroprotective and modulating properties could help reduce brain damage by acting on neuroinflammation, and through direct vascular and anti-thrombotic effects. Here we review the role of RAS in brain ischemia, with specific focus on SAH and the therapeutic potential of Ang-(1-7).
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Affiliation(s)
- Filippo Annoni
- Laboratory of Acute Brain Injury and Therapeutic Strategies, Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy.,Department of Intensive Care, Erasme Hospital, Free University of Brussels, Anderlecht, Belgium
| | - Federico Moro
- Laboratory of Acute Brain Injury and Therapeutic Strategies, Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy
| | - Enrico Caruso
- Laboratory of Acute Brain Injury and Therapeutic Strategies, Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy.,Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Tommaso Zoerle
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Fabio Silvio Taccone
- Department of Intensive Care, Erasme Hospital, Free University of Brussels, Anderlecht, Belgium
| | - Elisa R Zanier
- Laboratory of Acute Brain Injury and Therapeutic Strategies, Department of Neuroscience, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy
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Neuroprotection in Stroke-Focus on the Renin-Angiotensin System: A Systematic Review. Int J Mol Sci 2022; 23:ijms23073876. [PMID: 35409237 PMCID: PMC8998496 DOI: 10.3390/ijms23073876] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 01/01/2023] Open
Abstract
Stroke is the primary cause of disability in the adult population. Hypertension represents the leading risk factor being present in almost half the patients. The renin-angiotensin system is involved in the physiopathology of stroke and has an essential impact on hypertension as a risk factor. This article targeted the role of the renin-angiotensin system in stroke neuroprotection by reviewing the current literature available. The mechanism of action of the renin-angiotensin system was observed through the effects on AT1, AT2, and Mas receptors. The neuroprotective properties ascertained by angiotensin in stroke seem to be independent of the blood pressure reduction mechanism, and include neuroregeneration, angiogenesis, and increased neuronal resistance to hypoxia. The future relationship of stroke and the renin-angiotensin system is full of possibilities, as new agonist molecules emerge as potential candidates to restrict the impairment caused by stroke.
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7
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Malek RJ, Bill CA, Vines CM. Clinical drug therapies and biologicals currently used or in clinical trial to treat COVID-19. Biomed Pharmacother 2021; 144:112276. [PMID: 34624681 PMCID: PMC8486678 DOI: 10.1016/j.biopha.2021.112276] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/19/2021] [Accepted: 09/28/2021] [Indexed: 01/18/2023] Open
Abstract
The potential emergence of SARS-CoV-2 variants capable of escaping vaccine-generated immune responses poses a looming threat to vaccination efforts and will likely prolong the duration of the COVID-19 pandemic. Additionally, the prevalence of beta coronaviruses circulating in animals and the precedent they have set in jumping into human populations indicates that they pose a continuous threat for future pandemics. Currently, only one therapeutic is approved by the U.S. Food and Drug Administration (FDA) for use in treating COVID-19, remdesivir, although other therapies are authorized for emergency use due to this pandemic being a public health emergency. In this review, twenty-four different treatments are discussed regarding their use against COVID-19 and any potential future coronavirus-associated illnesses. Their traditional use, mechanism of action against COVID-19, and efficacy in clinical trials are assessed. Six treatments evaluated are shown to significantly decrease mortality in clinical trials, and ten treatments have shown some form of clinical efficacy.
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Affiliation(s)
- Rory J. Malek
- University of Texas at Austin, Austin TX 78705, United States
| | - Colin A. Bill
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso TX 79968, United States
| | - Charlotte M. Vines
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso TX 79968, United States,Corresponding author
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8
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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] [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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9
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McFall A, Nicklin SA, Work LM. The counter regulatory axis of the renin angiotensin system in the brain and ischaemic stroke: Insight from preclinical stroke studies and therapeutic potential. Cell Signal 2020; 76:109809. [PMID: 33059037 PMCID: PMC7550360 DOI: 10.1016/j.cellsig.2020.109809] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 01/01/2023]
Abstract
Stroke is the 2nd leading cause of death worldwide and the leading cause of physical disability and cognitive issues. Although we have made progress in certain aspects of stroke treatment, the consequences remain substantial and new treatments are needed. Hypertension has long been recognised as a major risk factor for stroke, both haemorrhagic and ischaemic. The renin angiotensin system (RAS) plays a key role in blood pressure regulation and this, plus local expression and signalling of RAS in the brain, both support the potential for targeting this axis therapeutically in the setting of stroke. While historically, focus has been on suppressing classical RAS signalling through the angiotensin type 1 receptor (AT1R), the identification of a counter-regulatory axis of the RAS signalling via the angiotensin type 2 receptor (AT2R) and Mas receptor has renewed interest in targeting the RAS. This review describes RAS signalling in the brain and the potential of targeting the Mas receptor and AT2R in preclinical models of ischaemic stroke. The animal and experimental models, and the route and timing of intervention, are considered from a translational perspective.
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Affiliation(s)
- Aisling McFall
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Stuart A Nicklin
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Lorraine M Work
- Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK.
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10
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Correcting the imbalanced protective RAS in COVID-19 with angiotensin AT2-receptor agonists. Clin Sci (Lond) 2020; 134:2987-3006. [PMID: 33210709 DOI: 10.1042/cs20200922] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/22/2020] [Accepted: 11/02/2020] [Indexed: 12/13/2022]
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is responsible for the global corona virus disease 2019 (COVID-19) pandemic enters host cells via a mechanism that includes binding to angiotensin converting enzyme (ACE) 2 (ACE2). Membrane-bound ACE2 is depleted as a result of this entry mechanism. The consequence is that the protective renin-angiotensin system (RAS), of which ACE2 is an essential component, is compromised through lack of production of the protective peptides angiotensin-(1-7) and angiotensin-(1-9), and therefore decreased stimulation of Mas (receptor Mas) and angiotensin AT2-receptors (AT2Rs), while angiotensin AT1-receptors (AT1Rs) are overstimulated due to less degradation of angiotensin II (Ang II) by ACE2. The protective RAS has numerous beneficial actions, including anti-inflammatory, anti-coagulative, anti-fibrotic effects along with endothelial and neural protection; opposite to the deleterious effects caused by heightened stimulation of angiotensin AT1R. Given that patients with severe COVID-19 exhibit an excessive immune response, endothelial dysfunction, increased clotting, thromboses and stroke, enhancing the activity of the protective RAS is likely beneficial. In this article, we discuss the evidence for a dysfunctional protective RAS in COVID and develop a rationale that the protective RAS imbalance in COVID-19 may be corrected by using AT2R agonists. We further review preclinical studies with AT2R agonists which suggest that AT2R stimulation may be therapeutically effective to treat COVID-19-induced disorders of various organ systems such as lung, vasculature, or the brain. Finally, we provide information on the design of a clinical trial in which patients with COVID-19 were treated with the AT2R agonist Compound 21 (C21). This trial has been completed, but results have not yet been reported.
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11
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Patel SN, Fatima N, Ali R, Hussain T. Emerging Role of Angiotensin AT2 Receptor in Anti-Inflammation: An Update. Curr Pharm Des 2020; 26:492-500. [PMID: 31939729 DOI: 10.2174/1381612826666200115092015] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 11/21/2019] [Indexed: 12/16/2022]
Abstract
The hyperactive RAS and inflammation are closely associated. The angiotensin-II/AT1R axis of the RAS has been explored extensively for its role in inflammation and a plethora of pathological conditions. Understanding the role of AT2R in inflammation is an emerging area of research. The AT2R is expressed on a variety of immune and non-immune cells, which upon activation triggers the release of a host of cytokines and has multiple effects that coalesce to anti-inflammation and prevents maladaptive repair. The anti-inflammatory outcomes of AT2R activation are linked to its well-established signaling pathways involving formation of nitric oxide and activation of phosphatases. Collectively, these effects promote cell survival and tissue function. The consideration of AT2R as a therapeutic target requires further investigations.
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Affiliation(s)
- Sanket N Patel
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Naureen Fatima
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Riyasat Ali
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Tahir Hussain
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
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12
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Chrissobolis S, Luu AN, Waldschmidt RA, Yoakum ME, D'Souza MS. Targeting the renin angiotensin system for the treatment of anxiety and depression. Pharmacol Biochem Behav 2020; 199:173063. [PMID: 33115635 DOI: 10.1016/j.pbb.2020.173063] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/13/2020] [Accepted: 10/22/2020] [Indexed: 12/27/2022]
Abstract
Emotional disorders like anxiety and depression are responsible for considerable morbidity and mortality all over the world. Several antidepressant and anxiolytic medications are available for the treatment of anxiety and depression. However, a significant number of patients either do not respond to these medications or respond inadequately. Hence, there is a need to identify novel targets for the treatment of anxiety and depression. In this review we focus on the renin angiotensin system (RAS) as a potential target for the treatment of these disorders. We review work that has evaluated the effects of various compounds targeting the RAS on anxiety- and depression-like behaviors. Further, we suggest future work that must be carried out to fully exploit the RAS for the treatment of anxiety and depression. The RAS provides an attractive target for both the identification of novel anxiolytic and antidepressant medications and/or for enhancing the efficacy of currently available medications used for the treatment of anxiety and depression.
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Affiliation(s)
- Sophocles Chrissobolis
- Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, 525 S Main Street, Ada, OH 45810, United States of America
| | - Anh N Luu
- Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, 525 S Main Street, Ada, OH 45810, United States of America
| | - Ryan A Waldschmidt
- Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, 525 S Main Street, Ada, OH 45810, United States of America
| | - Madison E Yoakum
- Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, 525 S Main Street, Ada, OH 45810, United States of America
| | - Manoranjan S D'Souza
- Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, 525 S Main Street, Ada, OH 45810, United States of America.
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13
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Sharma N, Gaikwad AB. Effects of renal ischemia injury on brain in diabetic and non-diabetic rats: Role of angiotensin II type 2 receptor and angiotensin-converting enzyme 2. Eur J Pharmacol 2020; 882:173241. [PMID: 32565336 DOI: 10.1016/j.ejphar.2020.173241] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 01/19/2023]
Abstract
Clinically, patients with diabetes mellitus (DM) are more susceptible to ischemic renal injury (IRI) than non-diabetic (ND) patients. Besides, IRI predisposes distant organ dysfunctions including, neurological dysfunction, in which the major contributor remains renin-angiotensin system (RAS). Interestingly, the role of depressor arm of RAS on IRI-associated neurological sequalae remains unclear. Hence, this study aimed to delineate the role of angiotensin II type 2 receptor (AT2R) and angiotensin-converting enzyme 2 (ACE2) under the same. ND and Streptozotocin-induced DM rats with bilateral IRI were treated with AT2R agonist-Compound 21 (C21) (0.3 mg/kg/day, i.p.) or ACE2 activator-Diminazene Aceturate (Dize), (5 mg/kg/day, p.o.) either alone or as combination therapy. Effect of IRI on neurological functions were assessed by behavioural, biochemical, and histopathological analysis. Immunohistochemistry, ELISA and qRT-PCR experiments were conducted for evaluation of the molecular mechanisms. We found that in ND and DM rats, IRI causes increased hippocampal MDA and nitrite levels, augmented inflammatory cytokines (granulocyte-colony stimulating factor, glial fibrillary acidic protein), altered protein levels of Ang II, Ang-(1-7) and mRNA expressions of At1r, At2r and Masr. Treatment with C21 and Dize effectively normalised above-mentioned pathological alterations. Moreover, the protective effect of C21 and Dize combination therapy was better than respective monotherapies, and more likely, exerted via augmentation of protein and mRNA levels of depressor arm components. Thus, AT2R agonist and ACE2 activator therapy prevents the development of IRI-associated neurological dysfunction by attenuating oxidative stress and inflammation, upregulating depressor arm of RAS in brain under ND and DM conditions.
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Affiliation(s)
- Nisha Sharma
- Laboratory of Molecular Pharmacology, Department of Pharmacy, Birla Institute of Technology and Science Pilani, Pilani Campus, Rajasthan, 333031, India
| | - Anil Bhanudas Gaikwad
- Laboratory of Molecular Pharmacology, Department of Pharmacy, Birla Institute of Technology and Science Pilani, Pilani Campus, Rajasthan, 333031, India.
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14
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Janatpour ZC, Symes AJ. The extended renin-angiotensin system: a promising target for traumatic brain injury therapeutics. Neural Regen Res 2020; 15:1025-1026. [PMID: 31823875 PMCID: PMC7034274 DOI: 10.4103/1673-5374.270304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/03/2019] [Accepted: 10/10/2019] [Indexed: 02/06/2023] Open
Affiliation(s)
| | - Aviva J. Symes
- Department of Pharmacology, Uniformed Services University, Bethesda, MD, USA
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15
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Royea J, Lacalle-Aurioles M, Trigiani LJ, Fermigier A, Hamel E. AT2R's (Angiotensin II Type 2 Receptor's) Role in Cognitive and Cerebrovascular Deficits in a Mouse Model of Alzheimer Disease. Hypertension 2020; 75:1464-1474. [PMID: 32362228 DOI: 10.1161/hypertensionaha.119.14431] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Antihypertensive medications targeting the renin-angiotensin system have lowered the incidence and progression of Alzheimer disease. Understanding how these medications function could lead to novel therapeutic strategies. AT4Rs (angiotensin IV receptors) have been associated with angiotensin receptor blockers' cognitive, cerebrovascular, and neuroinflammatory rescue in Alzheimer disease models. Yet, whether AT4Rs act alone or with AT2Rs remains unknown. Here, we investigated whether AT2Rs contribute to losartan's benefits and whether chronic AT2R activation could mimic angiotensin receptor blocker benefits in transgenic mice overexpressing familial Alzheimer disease mutations of the human APP (amyloid precursor protein). Losartan-treated mice (10 mg/kg per day, drinking water, 7 months) received intracerebroventricular (1 month) administration of vehicle or AT2R antagonist PD123319 (1.6 nmol/day). PD123319 countered losartan's benefits on spatial learning and memory, neurovascular coupling, and hampered those on oxidative stress and nitric oxide bioavailability. PD123319 did not oppose losartan's benefits on short-term memory and vasodilatory function and had no benefit on neuroinflammation or Aβ (amyloid β) pathology. Mice receiving either vehicle or selective AT2R agonist compound 21 (intracerebroventricular: 1 nmol/day, 1 month or drinking water: 10 mg/kg per day, 7 months), showed no improvement in memory, vasodilatory function, or nitric oxide bioavailability. Compound 21 treatment normalized neurovascular coupling, reduced astrogliosis independent of persisting microgliosis, and exacerbated oxidative stress in APP mice. Compound 21 reduced dense core Aβ plaques, but not diffuse plaques or Aβ species. Our findings suggest that targeting AT2Rs is not an ideal strategy for restoring Aβ-related cognitive and cerebrovascular deficits.
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Affiliation(s)
- Jessika Royea
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Maria Lacalle-Aurioles
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Lianne J Trigiani
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Alice Fermigier
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Edith Hamel
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
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16
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Angiotensin II Type 2 Receptor-Expressing Neurons in the Central Amygdala Influence Fear-Related Behavior. Biol Psychiatry 2019; 86:899-909. [PMID: 31420088 DOI: 10.1016/j.biopsych.2019.05.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND The renin-angiotensin system has been implicated in posttraumatic stress disorder; however, the mechanisms responsible for this connection and the therapeutic potential of targeting the renin-angiotensin system in posttraumatic stress disorder remain unknown. Using an angiotensin receptor bacterial artificial chromosome (BAC) and enhanced green fluorescent protein (eGFP) reporter mouse, combined with neuroanatomical, pharmacological, and behavioral approaches, we examined the role of angiotensin II type 2 receptor (AT2R) in fear-related behavior. METHODS Dual immunohistochemistry with retrograde labeling was used to characterize AT2R-eGFP+ cells in the amygdala of the AT2R-eGFP-BAC reporter mouse. Pavlovian fear conditioning and behavioral pharmacological analyses were used to demonstrate the effects of AT2R activation on fear memory in male C57BL/6 mice. RESULTS AT2R-eGFP+ neurons in the amygdala were predominantly expressed in the medial amygdala and the medial division of the central amygdala (CeM), with little AT2R-eGFP expression in the basolateral amygdala or lateral division of the central amygdala. Characterization of AT2R-eGFP+ neurons in the CeM demonstrated distinct localization to gamma-aminobutyric acidergic projection neurons. Mice receiving acute intra-central amygdala injections of the selective AT2R agonist compound 21 prior to tests for cued or contextual fear expression displayed less freezing. Retrograde labeling of AT2R-eGFP+ neurons projecting to the periaqueductal gray revealed AT2R-eGFP+ neuronal projections from the CeM to the periaqueductal gray, a key brain structure mediating fear-related freezing. CONCLUSIONS These findings suggest that CeM AT2R-expressing neurons can modulate central amygdala outputs that play a role in fear expression, providing new evidence for a novel angiotensinergic circuit in the regulation of fear.
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17
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Jackson L, Dong G, Althomali W, Sayed MA, Eldahshan W, Baban B, Johnson MH, Filosa J, Fagan SC, Ergul A. Delayed Administration of Angiotensin II Type 2 Receptor (AT2R) Agonist Compound 21 Prevents the Development of Post-stroke Cognitive Impairment in Diabetes Through the Modulation of Microglia Polarization. Transl Stroke Res 2019; 11:762-775. [PMID: 31792796 DOI: 10.1007/s12975-019-00752-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/11/2019] [Accepted: 10/30/2019] [Indexed: 12/18/2022]
Abstract
A disabling consequence of stroke is cognitive impairment, occurring in 12%-48% of patients, for which there is no therapy. A critical barrier is the lack of understanding of how post-stroke cognitive impairment (PSCI) develops. While 70% of stroke victims present with comorbid diseases such as diabetes and hypertension, the limited use of comorbid disease models in preclinical research further contributes to this lack of progress. To this end, we used a translational model of diabetes to study the development of PSCI. In addition, we evaluated the application of compound 21 (C21), an angiotensin II Type 2 receptor agonist, for the treatment of PSCI by blinding the treatment assignment, setting strict inclusion criteria, and implementing a delayed administration time point. Diabetes was induced by a high-fat diet (HFD) and low-dose streptozotocin (STZ) combination. Control and diabetic rats were subjected to 1 h middle cerebral artery occlusion (MCAO) or sham surgery. Adhesive removal task (ART) and two-trial Y-maze were utilized to test sensorimotor and cognitive function. Three days post-stroke, rats that met the inclusion criteria were administered C21 or vehicle in drinking water at a dose of 0.12 mg/kg/day for 8 weeks. Samples from freshly harvested brains were analyzed by flow cytometry and immunohistochemistry (IHC). Diabetes exacerbated the development of PSCI and increased inflammation and demyelination. Delayed administration of C21 3 days post-stroke reduced mortality and improved sensorimotor and cognitive deficits. It also reduced inflammation and demyelination through modulation of the M1:M2 ratio in the diabetic animals.
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Affiliation(s)
- Ladonya Jackson
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA, USA.,Charlie Norwood Veterans Affairs Medical Center, Augusta, USA.,Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Guangkuo Dong
- Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Waleed Althomali
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA, USA.,Charlie Norwood Veterans Affairs Medical Center, Augusta, USA
| | - Mohammed A Sayed
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA, USA.,Charlie Norwood Veterans Affairs Medical Center, Augusta, USA
| | - Wael Eldahshan
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA, USA.,Charlie Norwood Veterans Affairs Medical Center, Augusta, USA.,Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Babak Baban
- Oral Biology, Dental College of Georgia, Augusta, GA, USA
| | - Maribeth H Johnson
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Jessica Filosa
- Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Susan C Fagan
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA, USA.,Charlie Norwood Veterans Affairs Medical Center, Augusta, USA
| | - Adviye Ergul
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Ave. MSC, Charleston, SC, 908, USA. .,Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA.
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18
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Ishrat T, Fouda AY, Pillai B, Eldahshan W, Ahmed H, Waller JL, Ergul A, Fagan SC. Dose-response, therapeutic time-window and tPA-combinatorial efficacy of compound 21: A randomized, blinded preclinical trial in a rat model of thromboembolic stroke. J Cereb Blood Flow Metab 2019; 39. [PMID: 29537907 PMCID: PMC6681526 DOI: 10.1177/0271678x18764773] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The aim of this translational, randomized, controlled, blinded preclinical trial was to determine the effect of compound 21 (C21) in embolic stroke. Rats were subjected to embolic-middle cerebral artery occlusion (eMCAO). They received C21 (0.01, 0.03 and 0.06 mg/kg/d) or saline (orally) for five days, with the first-dose given IV at 3 h post-eMCAO. For the time-window study, the optimal-dose of C21 was initiated at 3, 6 or 24 h post-eMCAO and continued for five days. For the combinatorial study, animals received IV-tissue plasminogen activator (tPA) at either 2 or 4 h, with IV-C21 (0.01 mg/kg) or saline at 3 h post-eMCAO and daily thereafter for five days. After performing the behavior tests, brains were collected for analyses. The dose-response study showed significant motor improvements with the lowest-dose (0.01 mg/kg) of C21. In the time-window study, this same dose resulted in improvements when given 6 h and 24 h post-eMCAO. Moreover, C21-treated animals performed better on the novel object recognition test. Neither the single treatment with C21 or tPA (4 h) nor the combination therapy was effective in reducing the hemorrhage or infarct size, although C21 alone lowered sensorimotor deficit scores post-eMCAO. Future studies should focus on the long-term cognitive benefits of C21, rather than acute neuroprotection.
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Affiliation(s)
- Tauheed Ishrat
- 1 Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis TN, USA
| | - Abdelrahman Y Fouda
- 2 Charlie Norwood VA Medical Center, and Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Bindu Pillai
- 2 Charlie Norwood VA Medical Center, and Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Wael Eldahshan
- 2 Charlie Norwood VA Medical Center, and Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Heba Ahmed
- 2 Charlie Norwood VA Medical Center, and Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Athens, GA, USA
| | - Jennifer L Waller
- 3 Department of Biostatistics and Epidemiology, Augusta University, Augusta, GA, USA
| | - Adviye Ergul
- 2 Charlie Norwood VA Medical Center, and Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Athens, GA, USA.,4 Department of Physiology, Augusta University, Augusta, GA, USA
| | - Susan C Fagan
- 2 Charlie Norwood VA Medical Center, and Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Athens, GA, USA.,5 Department of Neurology, Augusta University, Augusta, GA, USA
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19
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Khorooshi R, Tofte-Hansen EU, Tygesen C, Montanana-Rosell R, Limburg HL, Marczynska J, Asgari N, Steckelings UM, Owens T. Angiotensin AT2 receptor–induced interleukin-10 attenuates neuromyelitis optica spectrum disorder–like pathology. Mult Scler 2019; 26:1187-1196. [DOI: 10.1177/1352458519860327] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background: Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing inflammatory central nervous system (CNS) disease for which there is no cure. Immunoglobulin G autoantibodies specific for the water channel aquaporin-4 are a serum biomarker, believed to induce complement-dependent astrocyte damage with secondary demyelination. Objective: To investigate the effect of angiotensin AT2 receptor (AT2R) stimulation on NMOSD-like pathology and its underlying mechanism. Methods: NMOSD-like pathology was induced in mice by intracerebral injection of immunoglobulin-G isolated from NMOSD patient serum, with complement. This mouse model produces the characteristic histological features of NMOSD. A specific AT2R agonist, Compound 21 (C21), was given intracerebrally at day 0 and by intrathecal injection at day 2. Results: Loss of aquaporin-4 and glial fibrillary acidic protein was attenuated by treatment with C21. Administration of C21 induced mRNA for interleukin-10 in the brain. NMOSD-like pathology was exacerbated in interleukin-10-deficient mice, suggesting a protective role. C21 treatment did not attenuate NMOSD-like pathology in interleukin-10-deficient mice, indicating that the protective effect of AT2R stimulation was dependent on interleukin-10. Conclusion: Our findings identify AT2R as a novel potential therapeutic target for the treatment of NMOSD. Interleukin-10 signaling is an essential part of the protective mechanism counteracting NMOSD pathology.
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Affiliation(s)
- Reza Khorooshi
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Emil Ulrikkaholm Tofte-Hansen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Camilla Tygesen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Roser Montanana-Rosell
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Hannah Liska Limburg
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Joanna Marczynska
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Nasrin Asgari
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark/ Department of Neurology, Slagelse Hospital, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Ulrike Muscha Steckelings
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Trevor Owens
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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20
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Eldahshan W, Ishrat T, Pillai B, Sayed MA, Alwhaibi A, Fouda AY, Ergul A, Fagan SC. Angiotensin II type 2 receptor stimulation with compound 21 improves neurological function after stroke in female rats: a pilot study. Am J Physiol Heart Circ Physiol 2019; 316:H1192-H1201. [PMID: 30822121 PMCID: PMC6580399 DOI: 10.1152/ajpheart.00446.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 01/18/2019] [Accepted: 02/26/2019] [Indexed: 12/22/2022]
Abstract
The angiotensin II type 2 receptor (AT2R) agonist, compound 21 (C21), has been shown to be neurovascularly protective after ischemic stroke in male rats. In the current study, we aim to study the impact of C21 treatment on female rats. Young female Wistar rats were subjected to different durations of middle cerebral artery occlusion (MCAO) (3 h, 2 h, and 1 h) using a silicone-coated monofilament, treated at reperfusion with 0.03 mg/kg ip of C21 and followed up for different times (1, 3, and 14 days) after stroke. Behavioral tests were performed (Bederson, paw grasp, beam walk, and rotarod), and animals were euthanized for infarct size analysis and Western blot analysis. In vitro, primary male and female brain microvascular endothelial cells (ECs) were grown in culture, and the expression of the AT2R was compared between males and females. At 1 day, C21 treatment resulted in an improvement in Bederson scores. However, at 3 days and 14 days, the impact of C21 on stroke outcomes was less robust. In vitro, the expression of the AT2R was significantly higher in female ECs compared with male ECs. In conclusion, C21 improves Bederson scores after stroke in female rats when administered early at reperfusion. The ability of C21 to exert its neuroprotective effects might be affected by fluctuating levels of female hormones. NEW & NOTEWORTHY The present study shows the neuroprotective impact of C21 on ischemic stroke in female rats and how the protective effects of C21 can be influenced by the hormonal status of female rodents.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Brain/blood supply
- Brain/drug effects
- Brain/physiopathology
- Cells, Cultured
- Disease Models, Animal
- Endothelial Cells/drug effects
- Endothelial Cells/metabolism
- Female
- Infarction, Middle Cerebral Artery/diagnosis
- Infarction, Middle Cerebral Artery/drug therapy
- Infarction, Middle Cerebral Artery/physiopathology
- Infarction, Middle Cerebral Artery/psychology
- Male
- Microvessels/drug effects
- Microvessels/metabolism
- Motor Activity/drug effects
- Neuroprotective Agents/pharmacology
- PPAR gamma/agonists
- PPAR gamma/metabolism
- Pilot Projects
- Rats, Wistar
- Receptor, Angiotensin, Type 2/agonists
- Receptor, Angiotensin, Type 2/genetics
- Receptor, Angiotensin, Type 2/metabolism
- Recovery of Function
- Sex Factors
- Signal Transduction
- Sulfonamides/pharmacology
- Thiophenes/pharmacology
- Time Factors
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Affiliation(s)
- Wael Eldahshan
- Program in Clinical and Experimental Therapeutics, Charlie Norwood Veterans Affairs Medical Center and University of Georgia, College of Pharmacy , Augusta, Georgia
| | - Tauheed Ishrat
- Program in Clinical and Experimental Therapeutics, Charlie Norwood Veterans Affairs Medical Center and University of Georgia, College of Pharmacy , Augusta, Georgia
| | - Bindu Pillai
- Program in Clinical and Experimental Therapeutics, Charlie Norwood Veterans Affairs Medical Center and University of Georgia, College of Pharmacy , Augusta, Georgia
| | - Mohammed A Sayed
- Program in Clinical and Experimental Therapeutics, Charlie Norwood Veterans Affairs Medical Center and University of Georgia, College of Pharmacy , Augusta, Georgia
| | - Abdulrahman Alwhaibi
- Program in Clinical and Experimental Therapeutics, Charlie Norwood Veterans Affairs Medical Center and University of Georgia, College of Pharmacy , Augusta, Georgia
| | - Abdelrahman Y Fouda
- Program in Clinical and Experimental Therapeutics, Charlie Norwood Veterans Affairs Medical Center and University of Georgia, College of Pharmacy , Augusta, Georgia
| | - Adviye Ergul
- Department of Physiology, Augusta University , Augusta, Georgia
| | - Susan C Fagan
- Program in Clinical and Experimental Therapeutics, Charlie Norwood Veterans Affairs Medical Center and University of Georgia, College of Pharmacy , Augusta, Georgia
- Department of Neurology, Augusta University , Augusta, Georgia
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21
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Timaru-Kast R, Gotthardt P, Luh C, Huang C, Hummel R, Schäfer MKE, Thal SC. Angiotensin II Receptor 1 Blockage Limits Brain Damage and Improves Functional Outcome After Brain Injury in Aged Animals Despite Age-Dependent Reduction in AT1 Expression. Front Aging Neurosci 2019; 11:63. [PMID: 31105549 PMCID: PMC6499023 DOI: 10.3389/fnagi.2019.00063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/06/2019] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) is a frequent pathology associated with poor neurological outcome in the aged population. We recently observed accelerated cerebral inflammation in aged mice in response to TBI. Candesartan is a potent specific inhibitor of angiotensin II receptor type 1 (AT1) which limits cerebral inflammation and brain damage in juvenile animals after experimental TBI. In the present study, we show significantly lower posttraumatic AT1 mRNA levels in aged (21 months) compared to young (2 months) mice. Despite low cerebral At1 expression, pharmacologic blockade by treatment with candesartan [daily, beginning 30 min after experimental TBI by controlled cortical impact (CCI)] was highly effective in both young and aged animals and reduced histological brain damage by -20% after 5 days. In young mice, neurological improvement was enhanced by AT1 inhibition 5 days after CCI. In older animals, candesartan treatment reduced functional impairment already on day 3 after TBI and post-traumatic body weight (BW) loss was attenuated. Candesartan reduced microglia activation (-40%) in young and aged animals, and neutrophil infiltration (-40% to 50%) in aged mice, whereas T-cell infiltration was not changed in either age group. In young animals, markers of anti-inflammatory microglia M2a polarization [arginase 1 (Arg1), chitinase3-like 3 (Ym1)] were increased by candesartan at days 1 and 5 after insult. In older mice 5 days after insult, expression of Arg1 was significantly higher independently of the treatment, whereas Ym1 gene expression was further enhanced by AT1 inhibition. Despite age-dependent posttraumatic differences in At1 expression levels, inhibition of AT1 was highly effective in a posttreatment paradigm. Targeting inflammation with candesartan is, therefore, a promising therapeutic strategy to limit secondary brain damage independent of the age.
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Affiliation(s)
- Ralph Timaru-Kast
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Philipp Gotthardt
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Clara Luh
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Changsheng Huang
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Regina Hummel
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.,Center for Molecular Surgical Research, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.,Focus Program Translational Neurosciences, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Serge C Thal
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.,Center for Molecular Surgical Research, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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22
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Abstract
Purpose of Review Although an independent brain renin-angiotensin system is often assumed to exist, evidence for this concept is weak. Most importantly, renin is lacking in the brain, and both brain angiotensinogen and angiotensin (Ang) II levels are exceptionally low. In fact, brain Ang II levels may well represent uptake of circulating Ang II via Ang II type 1 (AT1) receptors. Recent Findings Nevertheless, novel drugs are now aimed at the brain RAS, i.e., aminopeptidase A inhibitors should block Ang III formation from Ang II, and hence diminish AT1 receptor stimulation by Ang III, while AT2 and Mas receptor agonists are reported to induce neuroprotection after stroke. The endogenous agonists of these receptors and their origin remain unknown. Summary This review addresses the questions whether independent angiotensin generation truly occurs in the brain, what its relationship with the kidney is, and how centrally acting RAS blockers/agonists might work.
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Affiliation(s)
- Liwei Ren
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands
- AstraZeneca-Shenzhen University Joint Institute of Nephrology, Department of Physiology, Shenzhen University Health Science Center, Shenzhen University, Shenzhen, China
| | - Xifeng Lu
- AstraZeneca-Shenzhen University Joint Institute of Nephrology, Department of Physiology, Shenzhen University Health Science Center, Shenzhen University, Shenzhen, China
| | - A H Jan Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands.
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23
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Assessing the effects of Ang-(1-7) therapy following transient middle cerebral artery occlusion. Sci Rep 2019; 9:3154. [PMID: 30816157 PMCID: PMC6395816 DOI: 10.1038/s41598-019-39102-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 01/15/2019] [Indexed: 11/09/2022] Open
Abstract
The counter-regulatory axis, Angiotensin Converting Enzyme 2, Angiotensin-(1-7), Mas receptor (ACE2/Ang-1-7/MasR), of the renin angiotensin system (RAS) is a potential therapeutic target in stroke, with Ang-(1-7) reported to have neuroprotective effects in pre-clinical stroke models. Here, an extensive investigation of the functional and mechanistic effects of Ang-(1-7) was performed in a rodent model of stroke. Using longitudinal magnetic resonance imaging (MRI) it was observed that central administration of Ang-(1-7) following transient middle cerebral artery occlusion (MCAO) increased the amount of tissue salvage compared to reperfusion alone. This protective effect was not due to early changes in blood brain barrier (BBB) permeability, microglia activation or inflammatory gene expression. However, increases in NADPH oxidase 1 (Nox1) mRNA expression were observed in the treatment group compared to control. In order to determine whether Ang-(1-7) has direct cerebrovascular effects, laser speckle contrast imaging (LSCI) was performed to measure dynamic changes in cortical perfusion following reperfusion. Delivery of Ang-(1-7) did not have any effect on cortical perfusion following reperfusion however; it showed an indication to prevent the 'steal phenomenon' within the contralateral hemisphere. The comprehensive series of studies have demonstrated a moderate protective effect of Ang-(1-7) when given alongside reperfusion to increase tissue salvage.
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24
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Luo Y, Tang H, Li H, Zhao R, Huang Q, Liu J. Recent advances in the development of neuroprotective agents and therapeutic targets in the treatment of cerebral ischemia. Eur J Med Chem 2019; 162:132-146. [DOI: 10.1016/j.ejmech.2018.11.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/30/2018] [Accepted: 11/06/2018] [Indexed: 11/25/2022]
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25
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Sharma N, Anders HJ, Gaikwad AB. Fiend and friend in the renin angiotensin system: An insight on acute kidney injury. Biomed Pharmacother 2018; 110:764-774. [PMID: 30554115 DOI: 10.1016/j.biopha.2018.12.018] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 12/05/2018] [Accepted: 12/05/2018] [Indexed: 02/06/2023] Open
Abstract
Besides assisting the maintenance of blood pressure and sodium homeostasis, the renin-angiotensin system (RAS) plays a pivotal role in pathogenesis of acute kidney injury (AKI). The RAS is equipped with two arms i) the pressor arm composed of Angiotensin II (Ang II)/Angiotensin converting enzyme (ACE)/Angiotensin II type 1 receptor (AT1R) also called conventional RAS, and ii) the depressor arm consisting of Angiotensin (1-7) (Ang 1-7)/Angiotensin converting enzyme 2 (ACE2)/MasR known as non-conventional RAS. Activation of conventional RAS triggers oxidative stress, inflammatory, hypertrophic, apoptotic, and pro-fibrotic signaling cascades which promote AKI. The preclinical and clinical studies have reported beneficial as well as deleterious effects of RAS blockage either by angiotensin receptor blocker or ACE inhibitor in AKI. On the contrary, the depressor arm opposes the conventional RAS, has beneficial effects on the kidney but has been less explored in pathogenesis of AKI. This review focuses on significance of RAS in pathogenesis of AKI and provides better understanding of novel and possible therapeutic approaches to combat AKI.
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Affiliation(s)
- Nisha Sharma
- Laboratory of Molecular Pharmacology, Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Pilani Campus, Rajasthan 333 031, India
| | - Hans-Joachim Anders
- Division of Nephrology, Department of Internal Medicine IV, University Hospital of the Ludwig Maximilians University Munich, 80336 Munich, Germany
| | - Anil Bhanudas Gaikwad
- Laboratory of Molecular Pharmacology, Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Pilani Campus, Rajasthan 333 031, India.
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26
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Neuroprotection via AT2 receptor agonists in ischemic stroke. Clin Sci (Lond) 2018; 132:1055-1067. [DOI: 10.1042/cs20171549] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 12/12/2022]
Abstract
Stroke is a devastating disease that afflicts millions of people each year worldwide. Ischemic stroke, which accounts for ~88% of cases, occurs when blood supply to the brain is decreased, often because of thromboembolism or atherosclerotic occlusion. This deprives the brain of oxygen and nutrients, causing immediate, irreversible necrosis within the core of the ischemic area, but more delayed and potentially reversible neuronal damage in the surrounding brain tissue, the penumbra. The only currently approved therapies for ischemic stroke, the thrombolytic agent recombinant tissue plasminogen activator (rtPA) and the endovascular clot retrieval/destruction processes, are aimed at restoring blood flow to the infarcted area, but are only available for a minority of patients and are not able in most cases to completely restore neurological deficits. Consequently, there remains a need for agents that will protect neurones against death following ischemic stroke. Here, we evaluate angiotensin II (Ang II) type 2 (AT2) receptor agonists as a possible therapeutic target for this disease. We first provide an overview of stroke epidemiology, pathophysiology, and currently approved therapies. We next review the large amount of preclinical evidence, accumulated over the past decade and a half, which indicates that AT2 receptor agonists exert significant neuroprotective effects in various animal models, and discuss the potential mechanisms involved. Finally, after discussing the challenges of delivering blood–brain barrier (BBB) impermeable AT2 receptor agonists to the infarcted areas of the brain, we summarize the evidence for and against the development of these agents as a promising therapeutic strategy for ischemic stroke.
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27
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Haspula D, Clark MA. Molecular Basis of the Brain Renin Angiotensin System in Cardiovascular and Neurologic Disorders: Uncovering a Key Role for the Astroglial Angiotensin Type 1 Receptor AT1R. J Pharmacol Exp Ther 2018; 366:251-264. [PMID: 29752427 DOI: 10.1124/jpet.118.248831] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/08/2018] [Indexed: 12/13/2022] Open
Abstract
The central renin angiotensin system (RAS) is one of the most widely investigated cardiovascular systems in the brain. It is implicated in a myriad of cardiovascular diseases. However, studies from the last decade have identified its involvement in several neurologic abnormalities. Understanding the molecular functionality of the various RAS components can thus provide considerable insight into the phenotypic differences and mechanistic drivers of not just cardiovascular but also neurologic disorders. Since activation of one of its primary receptors, the angiotensin type 1 receptor (AT1R), results in an augmentation of oxidative stress and inflammatory cytokines, it becomes essential to investigate not just neuronal RAS but glial RAS as well. Glial cells are key homeostatic regulators in the brain and are critical players in the resolution of overt oxidative stress and neuroinflammation. Designing better and effective therapeutic strategies that target the brain RAS could well hinge on understanding the molecular basis of both neuronal and glial RAS. This review provides a comprehensive overview of the major studies that have investigated the mechanisms and regulation of the brain RAS, and it also provides insight into the potential role of glial AT1Rs in the pathophysiology of cardiovascular and neurologic disorders.
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Affiliation(s)
- Dhanush Haspula
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin (D.H.); and College of Pharmacy, Department of Pharmaceutical Sciences, Nova Southeastern University, Ft. Lauderdale, Florida (M.A.C.)
| | - Michelle A Clark
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin (D.H.); and College of Pharmacy, Department of Pharmaceutical Sciences, Nova Southeastern University, Ft. Lauderdale, Florida (M.A.C.)
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28
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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] [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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29
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Protective effects of the angiotensin II AT 2 receptor agonist compound 21 in ischemic stroke: a nose-to-brain delivery approach. Clin Sci (Lond) 2018; 132:581-593. [PMID: 29500223 DOI: 10.1042/cs20180100] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 02/28/2018] [Accepted: 03/01/2018] [Indexed: 02/07/2023]
Abstract
Significant neuroprotective effects of angiotensin II type 2 (AT2) receptor (AT2 receptor) agonists in ischemic stroke have been previously demonstrated in multiple studies. However, the routes of agonist application used in these pre-clinical studies, direct intracerebroventricular (ICV) and systemic administration, are unsuitable for translation into humans; in the latter case because AT2 receptor agonists are blood-brain barrier (BBB) impermeable. To circumvent this problem, in the current study we utilized the nose-to-brain (N2B) route of administration to bypass the BBB and deliver the selective AT2 receptor agonist Compound 21 (C21) to naïve rats or rats that had undergone endothelin 1 (ET-1)-induced ischemic stroke. The results obtained from the present study indicated that C21 applied N2B entered the cerebral cortex and striatum within 30 min in amounts that are therapeutically relevant (8.4-9 nM), regardless of whether BBB was intact or disintegrated. C21 was first applied N2B at 1.5 h after stroke indeed provided neuroprotection, as evidenced by a highly significant, 57% reduction in cerebral infarct size and significant improvements in Bederson and Garcia neurological scores. N2B-administered C21 did not affect blood pressure or heart rate. Thus, these data provide proof-of-principle for the idea that N2B application of an AT2 receptor agonist can exert neuroprotective actions when administered following ischemic stroke. Since N2B delivery of other agents has been shown to be effective in certain human central nervous system diseases, the N2B application of AT2 receptor agonists may become a viable mode of delivering these neuroprotective agents for human ischemic stroke patients.
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30
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Saavedra JM, Armando I. Angiotensin II AT2 Receptors Contribute to Regulate the Sympathoadrenal and Hormonal Reaction to Stress Stimuli. Cell Mol Neurobiol 2018; 38:85-108. [PMID: 28884431 PMCID: PMC6668356 DOI: 10.1007/s10571-017-0533-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/01/2017] [Indexed: 12/14/2022]
Abstract
Angiotensin II, through AT1 receptor stimulation, mediates multiple cardiovascular, metabolic, and behavioral functions including the response to stressors. Conversely, the function of Angiotensin II AT2 receptors has not been totally clarified. In adult rodents, AT2 receptor distribution is very limited but it is particularly high in the adrenal medulla. Recent results strongly indicate that AT2 receptors contribute to the regulation of the response to stress stimuli. This occurs in association with AT1 receptors, both receptor types reciprocally influencing their expression and therefore their function. AT2 receptors appear to influence the response to many types of stressors and in all components of the hypothalamic-pituitary-adrenal axis. The molecular mechanisms involved in AT2 receptor activation, the complex interactions with AT1 receptors, and additional factors participating in the control of AT2 receptor regulation and activity in response to stressors are only partially understood. Further research is necessary to close this knowledge gap and to clarify whether AT2 receptor activation may carry the potential of a major translational advance.
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Affiliation(s)
- J M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road, Bldg. D, Room 287, Washington, DC, 20007, USA.
| | - I Armando
- The George Washington University School of Medicine and Health Sciences, Ross Hall Suite 738 2300 Eye Street, Washington, DC, USA
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31
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Abstract
Depression remains a debilitating condition with an uncertain aetiology. Recently, attention has been given to the renin-angiotensin system. In the central nervous system, angiotensin II may be important in multiple pathways related to neurodevelopment and regulation of the stress response. Studies of drugs targeting the renin-angiotensin system have yielded promising results. Here, we review the potential beneficial effects of angiotensin blockers in depression and their mechanisms of action. Drugs blocking the angiotensin system have efficacy in several animal models of depression. While no randomised clinical trials were found, case reports and observational studies showed that angiotensin-converting enzyme inhibitors or angiotensin receptor blockers had positive effects on depression, whereas other antihypertensive agents did not. Drugs targeting the renin-angiotensin system act on inflammatory pathways implicated in depression. Both preclinical and clinical data suggest that these drugs possess antidepressant properties. In light of these results, angiotensin system-blocking agents offer new horizons in mood disorder treatment.
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32
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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: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [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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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] [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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Role of interleukin-10 in the neuroprotective effect of the Angiotensin Type 2 Receptor agonist, compound 21, after ischemia/reperfusion injury. Eur J Pharmacol 2017; 799:128-134. [PMID: 28192099 DOI: 10.1016/j.ejphar.2017.02.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 02/08/2017] [Accepted: 02/09/2017] [Indexed: 01/04/2023]
Abstract
INTRODUCTION We and others have shown that the angiotensin type 2 (AT2) receptor agonist, compound 21 (C21), provides neuroprotection and enhances recovery in rodent stroke models yet the mechanism involved is not known. Moreover, C21 treatment is associated with an anti-inflammatory response. Here we tested the hypothesis that C21 mediates neuroprotection by upregulating the neuroprotective and anti-inflammatory cytokine, interleukin (IL)-10. METHODS Wistar rats were subjected to 3h-middle cerebral artery suture occlusion and treated at reperfusion with C21 (0.03mg/kg)±IL-10 neutralizing antibody (0.1mg/kg) both given i.p. Infarct size, behavioral outcomes, and molecular analysis were performed at 24h post-injury. Primary rat neurons were used to test the direct neuroprotective effect of C21 in vitro. RESULTS C21 treatment reduced infarct size, improved functional outcome and decreased the pro-inflammatory cytokine, tumor necrosis factor alpha (TNF-α) in the ischemic hemisphere compared to saline. Anti-IL-10 co-treatment blocked the C21-induced reduction in infarct size and inflammation, and the improvement in behavioral outcome. In vitro, C21 treatment increased neuron survival and reduced cell apoptosis after oxygen glucose deprivation (OGD) and OGD/reoxygenation. These effects were mediated through AT2R stimulation. CONCLUSION C21 provides direct neuroprotection as well as indirect protection through IL-10.
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Thatcher SE. A Brief Introduction into the Renin-Angiotensin-Aldosterone System: New and Old Techniques. Methods Mol Biol 2017; 1614:1-19. [PMID: 28500591 DOI: 10.1007/978-1-4939-7030-8_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The renin-angiotensin-aldosterone system (RAAS) is a complex system of enzymes, receptors, and peptides that help to control blood pressure and fluid homeostasis. Techniques in studying the RAAS can be difficult due to such factors as peptide/enzyme stability and receptor localization. This paper gives a brief account of the different components of the RAAS and current methods in measuring each component. There is also a discussion of different methods in measuring stem and immune cells by flow cytometry, hypertension, atherosclerosis, oxidative stress, energy balance, and other RAAS-activated phenotypes. While studies on the RAAS have been performed for over 100 years, new techniques have allowed scientists to come up with new insights into this system. These techniques are detailed in this Methods in Molecular Biology Series and give students new to studying the RAAS the proper controls and technical details needed to perform each procedure.
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Affiliation(s)
- Sean E Thatcher
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Charles T. Wethington Bldg, 593, 900 South Limestone Street, Lexington, KY, 40536, USA.
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Arroja MMC, Reid E, McCabe C. Therapeutic potential of the renin angiotensin system in ischaemic stroke. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2016; 8:8. [PMID: 27761230 PMCID: PMC5054604 DOI: 10.1186/s13231-016-0022-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/29/2016] [Indexed: 12/24/2022]
Abstract
The renin angiotensin system (RAS) consists of the systemic hormone system, critically involved in regulation and homeostasis of normal physiological functions [i.e. blood pressure (BP), blood volume regulation], and an independent brain RAS, which is involved in the regulation of many functions such as memory, central control of BP and metabolic functions. In general terms, the RAS consists of two opposing axes; the ‘classical axis’ mediated primarily by Angiotensin II (Ang II), and the ‘alternative axis’ mediated mainly by Angiotensin-(1–7) (Ang-(1–7)). An imbalance of these two opposing axes is thought to exist between genders and is thought to contribute to the pathology of cardiovascular conditions such as hypertension, a stroke co-morbidity. Ischaemic stroke pathophysiology has been shown to be influenced by components of the RAS with specific RAS receptor antagonists and agonists improving outcome in experimental models of stroke. Manipulation of the two opposing axes following acute ischaemic stroke may provide an opportunity for protection of the neurovascular unit, particularly in the presence of pre-existing co-morbidities where the balance may be shifted. In the present review we will give an overview of the experimental stroke studies that have investigated pharmacological interventions of the RAS.
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Affiliation(s)
- Mariana Moreira Coutinho Arroja
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow, G61 1QH UK
| | - Emma Reid
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow, G61 1QH UK
| | - Christopher McCabe
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow, G61 1QH UK
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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] [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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Mateos L, Perez-Alvarez MJ, Wandosell F. Angiotensin II type-2 receptor stimulation induces neuronal VEGF synthesis after cerebral ischemia. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1297-308. [DOI: 10.1016/j.bbadis.2016.03.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 03/04/2016] [Accepted: 03/30/2016] [Indexed: 10/22/2022]
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Caillon A, Grenier C, Grimaud L, Vessieres E, Guihot AL, Blanchard S, Lelievre E, Chabbert M, Foucher ED, Jeannin P, Beauvillain C, Abraham P, Loufrani L, Delneste Y, Henrion D. The angiotensin II type 2 receptor activates flow-mediated outward remodelling through T cells-dependent interleukin-17 production. Cardiovasc Res 2016; 112:515-25. [PMID: 27328880 DOI: 10.1093/cvr/cvw172] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 06/09/2016] [Indexed: 12/11/2022] Open
Abstract
AIMS The angiotensin II type 1 receptor (AT1R) through the activation of immune cells plays a key role in arterial inward remodelling and reduced blood flow in cardiovascular disorders. On the other side, flow (shear stress)-mediated outward remodelling (FMR), involved in collateral arteries growth in ischaemic diseases, allows revascularization. We hypothesized that the type 2 receptor (AT2R), described as opposing the effects of AT1R, could be involved in FMR. METHODS AND RESULTS We studied FMR using a model of ligation of feed arteries supplying collateral pathways in the mouse mesenteric arterial bed in vivo. Seven days after ligation, diameter increased by 30% in high flow (HF) arteries compared with normal flow vessels. FMR was absent in mice lacking AT2R. At Day 2, T lymphocytes expressing AT2R were present preferentially around HF arteries. FMR did not occur in athymic (nude) mice lacking T cells and in mice treated with anti-CD3ε antibodies. AT2R activation induced interleukin-17 production by memory T cells. Treatment of nude mice or AT2R-deficient mice with interleukin-17 restored diameter enlargement in HF arteries. Interleukin-17 increased NO-dependent relaxation and matrix metalloproteinases activity, both important in FMR. Remodelling of feeding arteries in the skin flap model of ischaemia was also absent in AT2R-deficient mice and in anti-interleukin-17-treated mice. Finally, remodelling, absent in 12-month-old mice, was restored by a treatment with the AT2R non-peptidic agonist C21. CONCLUSION AT2R-dependent interleukin-17 production by T lymphocyte is necessary for collateral artery growth and could represent a new therapeutic target in ischaemic disorders.
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Affiliation(s)
- Antoine Caillon
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France UMR CNRS 6299, UMR INSERM 892, Angers University, F-49045 Angers, France
| | - Céline Grenier
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France
| | - Linda Grimaud
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France
| | - Emilie Vessieres
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France Cardiovascular Functions In Vitro (CARFI) Facility, Angers University, F-49045 Angers, France
| | - Anne-Laure Guihot
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France
| | - Simon Blanchard
- UMR CNRS 6299, UMR INSERM 892, Angers University, F-49045 Angers, France Department of Immunology and Allergology, University Hospital, F-49045 Angers, France
| | - Eric Lelievre
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France
| | - Marie Chabbert
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France
| | - Etienne D Foucher
- UMR CNRS 6299, UMR INSERM 892, Angers University, F-49045 Angers, France
| | - Pascale Jeannin
- UMR CNRS 6299, UMR INSERM 892, Angers University, F-49045 Angers, France Department of Immunology and Allergology, University Hospital, F-49045 Angers, France
| | - Céline Beauvillain
- UMR CNRS 6299, UMR INSERM 892, Angers University, F-49045 Angers, France Department of Immunology and Allergology, University Hospital, F-49045 Angers, France
| | - Pierre Abraham
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France Department of Vascular Medicine, University Hospital, F-49045 Angers, France
| | - Laurent Loufrani
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France
| | - Yves Delneste
- UMR CNRS 6299, UMR INSERM 892, Angers University, F-49045 Angers, France Department of Immunology and Allergology, University Hospital, F-49045 Angers, France
| | - Daniel Henrion
- MITOVASC Institute, UMR CNRS 6214, INSERM U1083, Angers University, F-49045 Angers, France Cardiovascular Functions In Vitro (CARFI) Facility, Angers University, F-49045 Angers, France Department of Vascular Medicine, University Hospital, F-49045 Angers, France
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Renin-angiotensin system as a potential therapeutic target in stroke and retinopathy: experimental and clinical evidence. Clin Sci (Lond) 2016; 130:221-38. [PMID: 26769658 DOI: 10.1042/cs20150350] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
As our knowledge expands, it is now clear that the renin-angiotensin (Ang) system (RAS) mediates functions other than regulating blood pressure (BP). The RAS plays a central role in the pathophysiology of different neurovascular unit disorders including stroke and retinopathy. Moreover, the beneficial actions of RAS modulation in brain and retina have been documented in experimental research, but not yet exploited clinically. The RAS is a complex system with distinct yet interconnected components. Understanding the different RAS components and their functions under brain and retinal pathological conditions is crucial to reap their benefits. The aim of the present review is to provide an experimental and clinical update on the role of RAS in the pathophysiology and treatment of stroke and retinopathy. Combining the evidence from both these disorders allows a unique opportunity to move both fields forward.
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Compound 21 is pro-angiogenic in the brain and results in sustained recovery after ischemic stroke. J Hypertens 2016; 33:170-80. [PMID: 25304472 DOI: 10.1097/hjh.0000000000000364] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Angiotensin II type 2 receptor (AT2R) stimulation is neuroprotective after experimental stroke. However, the therapeutic utility of AT2R stimulation has been hampered by the lack of a specific agonist with favourable bioavailability. Compound 21 (C21) - the first non-peptide AT2R agonist - offers a potential option to enhance stroke recovery. This study aimed to investigate the effect of C21 administration on early and late stroke outcomes, and the molecular mediators involved. METHODS Rats were subjected to 3 h or 90 min of middle cerebral artery occlusion (MCAO) and randomized to intraperitoneal C21 (0.03 mg/kg) or saline at reperfusion. Animals were sacrificed at 24 h or 7 days and brains were collected for molecular analysis and immunostaining, respectively. Functional outcome at days 1, 4 and 7 was assessed blindly. C21 angiogenic potential was assessed in vitro. RESULTS After 3 h of MCAO, C21 treatment reduced infarct size and improved behavioural outcome at 24 h without affecting blood pressure. Co-administration of the AT2R antagonist (PD123319) blocked these effects. On the molecular level, C21 decreased brain haemoglobin content, down-regulated apoptotic and oxidative markers, and increased pro-survival molecules in the brain. After 90 min of MCAO, C21 treatment resulted in sustained functional improvement at 7 days, together with increased vascular density in the ischemic penumbra. In vitro, C21 showed a pro-angiogenic effect that was blocked with brain-derived neurotrophic factor neutralization. CONCLUSION These findings demonstrate that a single dose of C21 is neurovascular-protective and improves stroke outcome possibly through increasing neurotrophin activity, mitigating brain inflammation, and promoting antioxidant and pro-angiogenic effects.
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Schwengel K, Namsolleck P, Lucht K, Clausen BH, Lambertsen KL, Valero-Esquitino V, Thöne-Reineke C, Müller S, Widdop RE, Denton KM, Horiuchi M, Iwai M, Boato F, Dahlöf B, Hallberg A, Unger T, Steckelings UM. Angiotensin AT2-receptor stimulation improves survival and neurological outcome after experimental stroke in mice. J Mol Med (Berl) 2016; 94:957-66. [PMID: 26983606 DOI: 10.1007/s00109-016-1406-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/30/2016] [Accepted: 02/18/2016] [Indexed: 01/09/2023]
Abstract
This study investigated the effect of post-stroke, direct AT2-receptor (AT2R) stimulation with the non-peptide AT2R-agonist compound 21 (C21) on infarct size, survival and neurological outcome after middle cerebral artery occlusion (MCAO) in mice and looked for potential underlying mechanisms. C57/BL6J or AT2R-knockout mice (AT2-KO) underwent MCAO for 30 min followed by reperfusion. Starting 45 min after MCAO, mice were treated once daily for 4 days with either vehicle or C21 (0.03 mg/kg ip). Neurological deficits were scored daily. Infarct volumes were measured 96 h post-stroke by MRI. C21 significantly improved survival after MCAO when compared to vehicle-treated mice. C21 treatment had no impact on infarct size, but significantly attenuated neurological deficits. Expression of brain-derived neurotrophic factor (BDNF), tyrosine kinase receptor B (TrkB) (receptor for BDNF) and growth-associated protein 43 (GAP-43) were significantly increased in the peri-infarct cortex of C21-treated mice when compared to vehicle-treated mice. Furthermore, the number of apoptotic neurons was significantly decreased in the peri-infarct cortex in mice treated with C21 compared to controls. There were no effects of C21 on neurological outcome, infarct size and expression of BDNF or GAP-43 in AT2-KO mice. From these data, it can be concluded that AT2R stimulation attenuates early mortality and neurological deficits after experimental stroke through neuroprotective mechanisms in an AT2R-specific way. Key message • AT2R stimulation after MCAO in mice reduces mortality and neurological deficits.• AT2R stimulation increases BDNF synthesis and protects neurons from apoptosis.• The AT2R-agonist C21 acts protectively when applied post-stroke and peripherally.
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Affiliation(s)
- Katja Schwengel
- Center for Cardiovascular Research, Medical Faculty, Charité, Berlin, Germany
| | | | - Kristin Lucht
- Center for Cardiovascular Research, Medical Faculty, Charité, Berlin, Germany
| | - Bettina H Clausen
- Department of Neurobiology, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Kate L Lambertsen
- Department of Neurobiology, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | | | | | - Susanne Müller
- Experimental Neurology, Medical Faculty, Charité, Berlin, Germany
| | - Robert E Widdop
- Department of Pharmacology, Monash University, Clayton, Australia
| | - Kate M Denton
- Department of Physiology, Monash University, Clayton, Australia
| | - Masatsugu Horiuchi
- Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University, Ehime, Japan
| | - Masaru Iwai
- Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University, Ehime, Japan
| | - Francesco Boato
- Burke Medical Research Institute, Weill Cornell Medical College, Cornell University, White Plains, USA
| | - Björn Dahlöf
- Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Anders Hallberg
- Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Thomas Unger
- CARIM, Maastricht University, Maastricht, The Netherlands
| | - U Muscha Steckelings
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark.
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Abstract
Although angiotensin II subtype-2 receptor (AT2R) was discovered over 2 decades ago, its contribution to physiology and pathophysiology is not fully elucidated. Current knowledge suggests that under normal physiologic conditions, AT2R counterbalances the effects of angiotensin II subtype-1 receptor (AT1R). A major obstacle for AT2R investigations was the lack of specific agonists. Most of the earlier AT2R studies were performed using the peptidic agonist, CG42112A, or the nonpeptidic antagonist PD123319. CGP42112A is nonspecific for AT2R and in higher concentrations can bind to AT1R. Recently, the development of specific nonpeptidic AT2R agonists boosted the efforts in identifying the therapeutic potentials for AT2R stimulation. Unlike AT1R, AT2R is involved in vasodilation by the release of bradykinin and nitric oxide, anti-inflammation, and healing from injury. Interestingly, the vasodilatory effects of AT2R stimulation were not associated with significant reduction in blood pressure. In the kidney, AT2R stimulation produced natriuresis, increased renal blood flow, and reduced tissue inflammation. In animal studies, enhanced AT2R function led to reduction of cardiac inflammation and fibrosis, and reduced the size of the infarcted area. Similarly, AT2R stimulation demonstrated protective effects in vasculature and brain.
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Neuroprotective mechanisms of the ACE2-angiotensin-(1-7)-Mas axis in stroke. Curr Hypertens Rep 2016; 17:3. [PMID: 25620630 DOI: 10.1007/s11906-014-0512-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The discovery of beneficial neuroprotective effects of the angiotensin converting enzyme 2-angiotensin-(1-7)-Mas axis [ACE2-Ang-(1-7)-Mas] in ischemic and hemorrhagic stroke has spurred interest in a more complete characterization of its mechanisms of action. Here, we summarize findings that describe the protective role of the ACE2-Ang-(1-7)-Mas axis in stroke, along with a focused discussion on the potential mechanisms of neuroprotective effects of Ang-(1-7) in stroke. The latter incorporates evidence describing the actions of Ang-(1-7) to counter the deleterious effects of angiotensin II (AngII) via its type 1 receptor, including anti-inflammatory, anti-oxidant, vasodilatory, and angiogenic effects, and the role of altered kinase-phosphatase signaling. Interactions of Mas with other receptors, including bradykinin receptors and AngII type 2 receptors are also considered. A more complete understanding of the mechanisms of action of Ang-(1-7) to elicit neuroprotection will serve as an essential step toward research into potential targeted therapeutics in the clinical setting.
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Lee S, Evans MA, Chu HX, Kim HA, Widdop RE, Drummond GR, Sobey CG. Effect of a Selective Mas Receptor Agonist in Cerebral Ischemia In Vitro and In Vivo. PLoS One 2015; 10:e0142087. [PMID: 26540167 PMCID: PMC4634944 DOI: 10.1371/journal.pone.0142087] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 10/16/2015] [Indexed: 11/19/2022] Open
Abstract
Functional modulation of the non-AT1R arm of the renin-angiotensin system, such as via AT2R activation, is known to improve stroke outcome. However, the relevance of the Mas receptor, which along with the AT2R forms the protective arm of the renin-angiotensin system, as a target in stroke is unclear. Here we tested the efficacy of a selective MasR agonist, AVE0991, in in vitro and in vivo models of ischemic stroke. Primary cortical neurons were cultured from E15-17 mouse embryos for 7–9 d, subjected to glucose deprivation for 24 h alone or with test drugs, and percentage cell death was determined using trypan blue exclusion assay. Additionally, adult male mice were subjected to 1 h middle cerebral artery occlusion and were administered either vehicle or AVE0991 (20 mg/kg i.p.) at the commencement of 23 h reperfusion. Some animals were also treated with the MasR antagonist, A779 (80 mg/kg i.p.) 1 h prior to surgery. Twenty-four h after MCAo, neurological deficits, locomotor activity and motor coordination were assessed in vivo, and infarct and edema volumes estimated from brain sections. Following glucose deprivation, application of AVE0991 (10−8 M to 10−6 M) reduced neuronal cell death by ~60% (P<0.05), an effect prevented by the MasR antagonist. By contrast, AVE0991 administration in vivo had no effect on functional or histological outcomes at 24 h following stroke. These findings indicate that the classical MasR agonist, AVE0991, can directly protect neurons from injury following glucose-deprivation. However, this effect does not translate into an improved outcome in vivo when administered systemically following stroke.
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Affiliation(s)
- Seyoung Lee
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Megan A. Evans
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Hannah X. Chu
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Hyun Ah Kim
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Robert E. Widdop
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Grant R. Drummond
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
- Department of Surgery, Southern Clinical School, Monash University, Clayton, Victoria, Australia
| | - Christopher G. Sobey
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
- Department of Surgery, Southern Clinical School, Monash University, Clayton, Victoria, Australia
- * E-mail:
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Villapol S, Balarezo MG, Affram K, Saavedra JM, Symes AJ. Neurorestoration after traumatic brain injury through angiotensin II receptor blockage. Brain 2015; 138:3299-315. [PMID: 26115674 DOI: 10.1093/brain/awv172] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/22/2015] [Indexed: 02/06/2023] Open
Abstract
See Moon (doi:10.1093/awv239) for a scientific commentary on this article.Traumatic brain injury frequently leads to long-term cognitive problems and physical disability yet remains without effective therapeutics. Traumatic brain injury results in neuronal injury and death, acute and prolonged inflammation and decreased blood flow. Drugs that block angiotensin II type 1 receptors (AT1R, encoded by AGTR1) (ARBs or sartans) are strongly neuroprotective, neurorestorative and anti-inflammatory. To test whether these drugs may be effective in treating traumatic brain injury, we selected two sartans, candesartan and telmisartan, of proven therapeutic efficacy in animal models of brain inflammation, neurodegenerative disorders and stroke. Using a validated mouse model of controlled cortical impact injury, we determined effective doses for candesartan and telmisartan, their therapeutic window, mechanisms of action and effect on cognition and motor performance. Both candesartan and telmisartan ameliorated controlled cortical impact-induced injury with a therapeutic window up to 6 h at doses that did not affect blood pressure. Both drugs decreased lesion volume, neuronal injury and apoptosis, astrogliosis, microglial activation, pro-inflammatory signalling, and protected cerebral blood flow, when determined 1 to 3 days post-injury. Controlled cortical impact-induced cognitive impairment was ameliorated 30 days after injury only by candesartan. The neurorestorative effects of candesartan and telmisartan were reduced by concomitant administration of the peroxisome proliferator-activated receptor gamma (PPARγ, encoded by PPARG) antagonist T0070907, showing the importance of PPARγ activation for the neurorestorative effect of these sartans. AT1R knockout mice were less vulnerable to controlled cortical impact-induced injury suggesting that the sartan's blockade of the AT1R also contributes to their efficacy. This study strongly suggests that sartans with dual AT1R blocking and PPARγ activating properties have therapeutic potential for traumatic brain injury.
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Affiliation(s)
- Sonia Villapol
- 1 Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA *Present address: Georgetown University Medical Centre, Department of Neuroscience, Washington, DC, USA
| | - María G Balarezo
- 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Kwame Affram
- 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Juan M Saavedra
- 3 Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, USA
| | - Aviva J Symes
- 1 Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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Vascular change and opposing effects of the angiotensin type 2 receptor in a mouse model of vascular cognitive impairment. J Cereb Blood Flow Metab 2015; 35:476-84. [PMID: 25492118 PMCID: PMC4348389 DOI: 10.1038/jcbfm.2014.221] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/03/2014] [Accepted: 11/10/2014] [Indexed: 01/16/2023]
Abstract
Our aims were to assess the spatiotemporal development of brain pathology in a mouse model of chronic hypoperfusion using magnetic resonance imaging (MRI), and to test whether the renin-angiotensin system (RAS) can offer therapeutic benefit. For the first time, different patterns of cerebral blood flow alterations were observed in hypoperfused mice that ranged from an immediate and dramatic to a delayed decrease in cerebral perfusion. Diffusion tensor imaging revealed increases in several quantitative parameters in different brain regions that are indicative of white-matter degeneration; this began around 3 weeks after induction of hypoperfusion. While this model may be more variable than previously reported, neuroimaging tools represent a promising way to identify surrogate markers of pathology. Vascular remodelling was observed in hypoperfused mice, particularly in the anterior part of the Circle of Willis. While the angiotensin II receptor type 2 agonist, Compound 21 (C21), did not influence this response, it did promote expansion of the basilar artery in microcoil animals. Furthermore, C21-treated animals exhibited increased brain lymphocyte infiltration, and importantly, C21 had opposing effects on spatial reference memory in hypoperfused and sham mice. These results suggest that the RAS may have a role in vascular cognitive impairment.
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Angiotensin type 2 receptors: blood pressure regulation and end organ damage. Curr Opin Pharmacol 2015; 21:115-21. [PMID: 25677800 DOI: 10.1016/j.coph.2015.01.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 01/21/2015] [Accepted: 01/22/2015] [Indexed: 12/15/2022]
Abstract
In most situations, the angiotensin AT2-receptor (AT2R) mediates physiological actions opposing those mediated by the AT1-receptor (AT1R), including a vasorelaxant effect. Nevertheless, experimental evidence vastly supports that systemic application of AT2R-agonists is blood pressure neutral. However, stimulation of AT2R locally within the brain or the kidney apparently elicits a systemic blood pressure lowering effect. A systemic effect of AT2R stimulation on blood pressure can also be achieved, when the prevailing effect of continuous background AT1R-stimulation is attenuated by low-dose AT1R blockade. Despite a lack of effect on blood pressure, AT2R stimulation still protects from hypertensive end-organ damage. Current data and evidence therefore suggest that AT2R agonists will not be suitable as future anti-hypertensive drugs, but that they may well be useful for end-organ protection in combination with established anti-hypertensives.
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McCarthy CA, Facey LJ, Widdop RE. The protective arms of the renin-angiontensin system in stroke. Curr Hypertens Rep 2015; 16:440. [PMID: 24816974 DOI: 10.1007/s11906-014-0440-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
It is quite well established that activation of the so-called protective arms of the renin-angiotensin system (RAS), involving both AT2 and Mas receptors, provides a counter-regulatory role to AT1 receptor overactivity that may drive pathological changes in the cardiovascular system. In this brief review, we will focus on recent evidence that identifies at least three different pathways that may be effective in the setting of stroke and may be complementary with AT1 receptor blockade. Such mechanisms include AT2 receptor stimulation, Mas receptor stimulation and insulin-regulated aminopeptidase blockade. This report highlights recent data demonstrating striking neuroprotective effects in preclinical models of stroke targeting each of these pathways, which may pave the way for translational opportunities in this field.
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Affiliation(s)
- Claudia A McCarthy
- Department of Pharmacology, Monash University, Clayton, Victoria, 3800, Australia
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