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Xu W, Yan J, Travis ZD, Lenahan C, Gao L, Wu H, Zheng J, Zhang J, Shao A, Yu J. Apelin/APJ system: a novel promising target for anti-oxidative stress in stroke. Front Pharmacol 2025; 15:1352927. [PMID: 39881878 PMCID: PMC11775478 DOI: 10.3389/fphar.2024.1352927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 12/10/2024] [Indexed: 01/31/2025] Open
Abstract
The apelin/APJ system has garnered increasing attention in recent years. In this review, we comprehensively discuss the physiological and pathological mechanisms of the apelin/APJ system in stroke. The apelin/APJ system is widely expressed in the central nervous system (CNS). However, the distribution of the apelin/APJ system varies across different regions and subcellular organelles of the brain. Additionally, the neuroprotective effects of the apelin/APJ system have been reported to inhibit oxidative and nitrative stresses via various signaling pathways. Despite this, the clinical application of the apelin/APJ system remains distant, as apelin has numerous active forms and signaling pathways. The development of a range of drugs targeting the apelin/APJ system holds promise for treating stroke.
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Affiliation(s)
- Weilin Xu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, Hangzhou, Zhejiang, China
| | - Jun Yan
- Department of Neurosurgery, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, China
| | - Zachary D. Travis
- Department of Medical Science Education, College of Health Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Cameron Lenahan
- Burrell College of Osteopathic Medicine, New Mexico State University, Las Cruces, NM, United States
| | - Liansheng Gao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, Hangzhou, Zhejiang, China
| | - Haijian Wu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, Hangzhou, Zhejiang, China
| | - Jingwei Zheng
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, Hangzhou, Zhejiang, China
| | - Jianmin Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, Hangzhou, Zhejiang, China
| | - Anwen Shao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, Hangzhou, Zhejiang, China
| | - Jun Yu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Precise Treatment and Clinical Translational Research of Neurological Diseases, Hangzhou, Zhejiang, China
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2
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Shaftoe JB, Gillis TE. Effects of hemodynamic load on cardiac remodeling in fish and mammals: the value of comparative models. J Exp Biol 2024; 227:jeb247836. [PMID: 39429041 DOI: 10.1242/jeb.247836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2024]
Abstract
The ability of the vertebrate heart to remodel enables the cardiac phenotype to be responsive to changes in physiological conditions and aerobic demand. Examples include exercise-induced cardiac hypertrophy, and the significant remodeling of the trout heart during thermal acclimation. Such changes are thought to occur in response to a change in hemodynamic load (i.e. the forces that the heart must work against to circulate blood). Variations in hemodynamic load are caused by either a volume overload (high volume of blood returning to the heart, impairing contraction) or a pressure overload (elevated afterload pressure that the heart must contract against). The changes observed in the heart during remodeling are regulated by multiple cellular signaling pathways. The cardiac response to these regulatory mechanisms occurs across levels of biological organization, affecting cardiac morphology, tissue composition and contractile function. Importantly, prolonged exposure to pressure overload can cause a physiological response - that improves function - to transition to a pathological response that causes loss of function. This Review explores the role of changes in hemodynamic load in regulating the remodeling response, and considers the cellular signals responsible for regulating remodeling, incorporating knowledge gained from studying biomedical models and comparative animal models. We specifically focus on the renin-angiotensin system, and the role of nitric oxide, oxygen free radicals and transforming growth factor beta. Through this approach, we highlight the strong conservation of the regulatory pathways of cardiac remodeling, and the specific conditions within endotherms that may be conducive to the development of pathological phenotypes.
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Affiliation(s)
- Jared B Shaftoe
- Department of Integrative Biology, University of Guelph, Ontario, Canada, N1G 2W1
| | - Todd E Gillis
- Department of Integrative Biology, University of Guelph, Ontario, Canada, N1G 2W1
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Nwia SM, Leite APO, Li XC, Zhuo JL. Sex differences in the renin-angiotensin-aldosterone system and its roles in hypertension, cardiovascular, and kidney diseases. Front Cardiovasc Med 2023; 10:1198090. [PMID: 37404743 PMCID: PMC10315499 DOI: 10.3389/fcvm.2023.1198090] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/06/2023] [Indexed: 07/06/2023] Open
Abstract
Cardiovascular disease is a pathology that exhibits well-researched biological sex differences, making it possible for physicians to tailor preventative and therapeutic approaches for various diseases. Hypertension, which is defined as blood pressure greater than 130/80 mmHg, is the primary risk factor for developing coronary artery disease, stroke, and renal failure. Approximately 48% of American men and 43% of American women suffer from hypertension. Epidemiological data suggests that during reproductive years, women have much lower rates of hypertension than men. However, this protective effect disappears after the onset of menopause. Treatment-resistant hypertension affects approximately 10.3 million US adults and is unable to be controlled even after implementing ≥3 antihypertensives with complementary mechanisms. This indicates that other mechanisms responsible for modulating blood pressure are still unclear. Understanding the differences in genetic and hormonal mechanisms that lead to hypertension would allow for sex-specific treatment and an opportunity to improve patient outcomes. Therefore, this invited review will review and discuss recent advances in studying the sex-specific physiological mechanisms that affect the renin-angiotensin system and contribute to blood pressure control. It will also discuss research on sex differences in hypertension management, treatment, and outcomes.
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Affiliation(s)
- Sarah M. Nwia
- Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Ana Paula O. Leite
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Xiao Chun Li
- Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Jia Long Zhuo
- Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA, United States
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4
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Yi W, Chen F, Zhang H, Tang P, Yuan M, Wen J, Wang S, Cai Z. Role of angiotensin II in aging. Front Aging Neurosci 2022; 14:1002138. [PMID: 36533172 PMCID: PMC9755866 DOI: 10.3389/fnagi.2022.1002138] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 11/08/2022] [Indexed: 10/29/2023] Open
Abstract
Aging is an inevitable progressive decline in physiological organ function that increases the chance of disease and death. The renin-angiotensin system (RAS) is involved in the regulation of vasoconstriction, fluid homeostasis, cell growth, fibrosis, inflammation, and oxidative stress. In recent years, unprecedented advancement has been made in the RAS study, particularly with the observation that angiotensin II (Ang II), the central product of the RAS, plays a significant role in aging and chronic disease burden with aging. Binding to its receptors (Ang II type 1 receptor - AT1R in particular), Ang II acts as a mediator in the aging process by increasing free radical production and, consequently, mitochondrial dysfunction and telomere attrition. In this review, we examine the physiological function of the RAS and reactive oxygen species (ROS) sources in detail, highlighting how Ang II amplifies or drives mitochondrial dysfunction and telomere attrition underlying each hallmark of aging and contributes to the development of aging and age-linked diseases. Accordingly, the Ang II/AT1R pathway opens a new preventive and therapeutic direction for delaying aging and reducing the incidence of age-related diseases in the future.
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Affiliation(s)
- Wenmin Yi
- Department of Neurology, Chongqing Medical University, Chongqing, China
- Chongqing Institute Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
- Chongqing School, University of Chinese Academy of Sciences, Chongqing, China
- Department of Neurology, Chongqing General Hospital, Chongqing, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China
| | - Fei Chen
- Department of Neurology, Chongqing Medical University, Chongqing, China
- Chongqing Institute Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
- Chongqing School, University of Chinese Academy of Sciences, Chongqing, China
- Department of Neurology, Chongqing General Hospital, Chongqing, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China
| | - Huiji Zhang
- Department of Neurology, Chongqing Medical University, Chongqing, China
- Chongqing Institute Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
- Chongqing School, University of Chinese Academy of Sciences, Chongqing, China
- Department of Neurology, Chongqing General Hospital, Chongqing, China
| | - Peng Tang
- Chongqing Institute Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
- Chongqing School, University of Chinese Academy of Sciences, Chongqing, China
| | - Minghao Yuan
- Department of Neurology, Chongqing Medical University, Chongqing, China
- Chongqing Institute Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
- Chongqing School, University of Chinese Academy of Sciences, Chongqing, China
- Department of Neurology, Chongqing General Hospital, Chongqing, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China
| | - Jie Wen
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China
- Department and Institute of Neurology, Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Shengyuan Wang
- Department of Neurology, Chongqing Medical University, Chongqing, China
- Chongqing Institute Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
- Chongqing School, University of Chinese Academy of Sciences, Chongqing, China
- Department of Neurology, Chongqing General Hospital, Chongqing, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China
| | - Zhiyou Cai
- Department of Neurology, Chongqing Medical University, Chongqing, China
- Chongqing Institute Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
- Chongqing School, University of Chinese Academy of Sciences, Chongqing, China
- Department of Neurology, Chongqing General Hospital, Chongqing, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, China
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5
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Rodriguez R, Lee AY, Godoy-Lugo JA, Martinez B, Ohsaki H, Nakano D, Parkes DG, Nishiyama A, Vázquez-Medina JP, Ortiz RM. Chronic AT 1 blockade improves hyperglycemia by decreasing adipocyte inflammation and decreasing hepatic PCK1 and G6PC1 expression in obese rats. Am J Physiol Endocrinol Metab 2021; 321:E714-E727. [PMID: 34658252 PMCID: PMC8782654 DOI: 10.1152/ajpendo.00584.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 11/22/2022]
Abstract
Inappropriate activation of the renin-angiotensin system decreases glucose uptake in peripheral tissues. Chronic angiotensin receptor type 1 (AT1) blockade (ARB) increases glucose uptake in skeletal muscle and decreases the abundance of large adipocytes and macrophage infiltration in adipose. However, the contributions of each tissue to the improvement in hyperglycemia in response to AT1 blockade are not known. Therefore, we determined the static and dynamic responses of soleus muscle, liver, and adipose to an acute glucose challenge following the chronic blockade of AT1. We measured adipocyte morphology along with TNF-α expression, F4/80- and CD11c-positive cells in adipose and measured insulin receptor (IR) phosphorylation and AKT phosphorylation in soleus muscle, liver, and retroperitoneal fat before (T0), 60 (T60) and 120 (T120) min after an acute glucose challenge in the following groups of male rats: 1) Long-Evans Tokushima Otsuka (LETO; lean control; n = 5/time point), 2) obese Otsuka Long Evans Tokushima Fatty (OLETF; n = 7 or 8/time point), and 3) OLETF + ARB (ARB; 10 mg olmesartan/kg/day; n = 7 or 8/time point). AT1 blockade decreased adipocyte TNF-α expression and F4/80- and CD11c-positive cells. In retroperitoneal fat at T60, IR phosphorylation was 155% greater in ARB than in OLETF. Furthermore, in retroperitoneal fat AT1 blockade increased glucose transporter-4 (GLUT4) protein expression in ARB compared with OLETF. IR phosphorylation and AKT phosphorylation were not altered in the liver of OLETF, but AT1 blockade decreased hepatic Pck1 and G6pc1 mRNA expressions. Collectively, these results suggest that chronic AT1 blockade improves obesity-associated hyperglycemia in OLETF rats by improving adipocyte function and by decreasing hepatic glucose production via gluconeogenesis.NEW & NOTEWORTHY Inappropriate activation of the renin-angiotensin system increases adipocyte inflammation contributing to the impairment in adipocyte function and increases hepatic Pck1 and G6pc1 mRNA expression in response to a glucose challenge. Ultimately, these effects may contribute to the development of glucose intolerance.
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Affiliation(s)
- Ruben Rodriguez
- Department of Molecular & Cellular Biology, University of California, Merced, California
| | - Andrew Y Lee
- Department of Molecular & Cellular Biology, University of California, Merced, California
| | - Jose A Godoy-Lugo
- Department of Molecular & Cellular Biology, University of California, Merced, California
| | - Bridget Martinez
- Department of Molecular & Cellular Biology, University of California, Merced, California
| | - Hiroyuki Ohsaki
- Department of Medical Biophysics, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Daisuke Nakano
- Department of Pharmacology, Kagawa University Medical School, Kagawa, Japan
| | | | - Akira Nishiyama
- Department of Pharmacology, Kagawa University Medical School, Kagawa, Japan
| | | | - Rudy M Ortiz
- Department of Molecular & Cellular Biology, University of California, Merced, California
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Sparks MA, South AM, Badley AD, Baker-Smith CM, Batlle D, Bozkurt B, Cattaneo R, Crowley SD, Dell’Italia LJ, Ford AL, Griendling K, Gurley SB, Kasner SE, Murray JA, Nath KA, Pfeffer MA, Rangaswami J, Taylor WR, Garovic VD. Severe Acute Respiratory Syndrome Coronavirus 2, COVID-19, and the Renin-Angiotensin System: Pressing Needs and Best Research Practices. Hypertension 2020; 76:1350-1367. [PMID: 32981369 PMCID: PMC7685174 DOI: 10.1161/hypertensionaha.120.15948] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic is associated with significant morbidity and mortality throughout the world, predominantly due to lung and cardiovascular injury. The virus responsible for COVID-19-severe acute respiratory syndrome coronavirus 2-gains entry into host cells via ACE2 (angiotensin-converting enzyme 2). ACE2 is a primary enzyme within the key counter-regulatory pathway of the renin-angiotensin system (RAS), which acts to oppose the actions of Ang (angiotensin) II by generating Ang-(1-7) to reduce inflammation and fibrosis and mitigate end organ damage. As COVID-19 spans multiple organ systems linked to the cardiovascular system, it is imperative to understand clearly how severe acute respiratory syndrome coronavirus 2 may affect the multifaceted RAS. In addition, recognition of the role of ACE2 and the RAS in COVID-19 has renewed interest in its role in the pathophysiology of cardiovascular disease in general. We provide researchers with a framework of best practices in basic and clinical research to interrogate the RAS using appropriate methodology, especially those who are relatively new to the field. This is crucial, as there are many limitations inherent in investigating the RAS in experimental models and in humans. We discuss sound methodological approaches to quantifying enzyme content and activity (ACE, ACE2), peptides (Ang II, Ang-[1-7]), and receptors (types 1 and 2 Ang II receptors, Mas receptor). Our goal is to ensure appropriate research methodology for investigations of the RAS in patients with severe acute respiratory syndrome coronavirus 2 and COVID-19 to ensure optimal rigor and reproducibility and appropriate interpretation of results from these investigations.
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Affiliation(s)
- Matthew A. Sparks
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, NC
- Renal Section, Durham VA Health Care System, Durham, NC
- American Heart Association, Council on Kidney in Cardiovascular Disease
| | - Andrew M. South
- American Heart Association, Council on Kidney in Cardiovascular Disease
- American Heart Association, Council on Hypertension
- Section of Nephrology, Department of Pediatrics, Brenner Children’s Hospital, Wake Forest School of Medicine, Winston Salem, NC
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest School of Medicine, Winston Salem, NC
- Department of Surgery-Hypertension and Vascular Research, Wake Forest School of Medicine, Winston Salem, NC
- Cardiovascular Sciences Center, Wake Forest School of Medicine, Winston Salem, NC
| | - Andrew D. Badley
- Division of Infectious Diseases, Mayo Clinic College of Medicine, Rochester, MN
| | - Carissa M. Baker-Smith
- Director of Preventive Cardiology, Division of Pediatric Cardiology, Department of Pediatrics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE
- American Heart Association, Council on Lifelong Congenital Heart Disease and Heart Health in the Young
| | - Daniel Batlle
- Division of Nephrology and Hypertension, Northwestern University Feinberg Medical School, Chicago, IL
- American Heart Association, Council on Hypertension
| | - Biykem Bozkurt
- Section of Cardiology, Department of Internal Medicine, Baylor College of Medicine, Houston, TX
- Michael E. DeBakey VA Medical Center, Houston, TX
- American Heart Association, Council on Clinical Cardiology
| | - Roberto Cattaneo
- Department of Molecular Medicine, Mayo Clinic College of Medicine, Rochester, MN
| | - Steven D. Crowley
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, NC
- Renal Section, Durham VA Health Care System, Durham, NC
- American Heart Association, Council on Kidney in Cardiovascular Disease
| | - Louis J. Dell’Italia
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL
- Department of Veterans Affairs Medical Center, Birmingham, AL
- American Heart Association, Council on Basic Cardiovascular Sciences
| | - Andria L. Ford
- Department of Neurology, Washington University in St. Louis School of Medicine, St. Louis, MO
- American Heart Association, Stroke Council
| | - Kathy Griendling
- American Heart Association, Council on Basic Cardiovascular Sciences
- Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA
| | - Susan B. Gurley
- American Heart Association, Council on Kidney in Cardiovascular Disease
- Department of Medicine, Division of Nephrology and Hypertension, Oregon Health & Science University, Portland, OR
| | - Scott E. Kasner
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania
- American Heart Association, Stroke Council
| | - Joseph A. Murray
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN
| | - Karl A. Nath
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, MN
| | - Marc A. Pfeffer
- American Heart Association, Council on Clinical Cardiology
- Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Janani Rangaswami
- American Heart Association, Council on Kidney in Cardiovascular Disease
- Department of Medicine, Einstein Medical Center Philadelphia, Philadelphia, PA
- Sidney Kimmel College of Thomas Jefferson University, Philadelphia, PA
| | - W. Robert Taylor
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
- Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA
- Division of Cardiology, Atlanta VA Medical Center, Decatur, GA
- American Heart Association, Council on Arteriosclerosis, Thrombosis and Vascular Biology
| | - Vesna D. Garovic
- American Heart Association, Council on Hypertension
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, MN
- Department of Obstetrics and Gynecology, Mayo Clinic College of Medicine, Rochester, MN
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7
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Labandeira-Garcia JL, Valenzuela R, Costa-Besada MA, Villar-Cheda B, Rodriguez-Perez AI. The intracellular renin-angiotensin system: Friend or foe. Some light from the dopaminergic neurons. Prog Neurobiol 2020; 199:101919. [PMID: 33039415 PMCID: PMC7543790 DOI: 10.1016/j.pneurobio.2020.101919] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 08/20/2020] [Accepted: 10/04/2020] [Indexed: 12/11/2022]
Abstract
The renin-angiotensin system (RAS) is one of the oldest hormone systems in vertebrate phylogeny. RAS was initially related to regulation of blood pressure and sodium and water homeostasis. However, local or paracrine RAS were later identified in many tissues, including brain, and play a major role in their physiology and pathophysiology. In addition, a major component, ACE2, is the entry receptor for SARS-CoV-2. Overactivation of tissue RAS leads several oxidative stress and inflammatory processes involved in aging-related degenerative changes. In addition, a third level of RAS, the intracellular or intracrine RAS (iRAS), with still unclear functions, has been observed. The possible interaction between the intracellular and extracellular RAS, and particularly the possible deleterious or beneficial effects of the iRAS activation are controversial. The dopaminergic system is particularly interesting to investigate the RAS as important functional interactions between dopamine and RAS have been observed in the brain and several peripheral tissues. Our recent observations in mitochondria and nucleus of dopaminergic neurons may clarify the role of the iRAS. This may be important for the developing of new therapeutic strategies, since the effects on both extracellular and intracellular RAS must be taken into account, and perhaps better understanding of COVID-19 cell mechanisms.
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Affiliation(s)
- Jose L Labandeira-Garcia
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain.
| | - Rita Valenzuela
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
| | - Maria A Costa-Besada
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
| | - Begoña Villar-Cheda
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
| | - Ana I Rodriguez-Perez
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
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8
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Dell'Italia LJ, Collawn JF, Ferrario CM. Multifunctional Role of Chymase in Acute and Chronic Tissue Injury and Remodeling. Circ Res 2019; 122:319-336. [PMID: 29348253 DOI: 10.1161/circresaha.117.310978] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Chymase is the most efficient Ang II (angiotensin II)-forming enzyme in the human body and has been implicated in a wide variety of human diseases that also implicate its many other protease actions. Largely thought to be the product of mast cells, the identification of other cellular sources including cardiac fibroblasts and vascular endothelial cells demonstrates a more widely dispersed production and distribution system in various tissues. Furthermore, newly emerging evidence for its intracellular presence in cardiomyocytes and smooth muscle cells opens an entirely new compartment of chymase-mediated actions that were previously thought to be limited to the extracellular space. This review illustrates how these multiple chymase-mediated mechanisms of action can explain the residual risk in clinical trials of cardiovascular disease using conventional renin-angiotensin system blockade.
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Affiliation(s)
- Louis J Dell'Italia
- From the Department of Medicine, Division of Cardiology, Birmingham Veteran Affairs Medical Center (L.J.D.), Division of Cardiovascular Disease, Department of Medicine (L.J.D.), and Department of Cell, Developmental and Integrative Biology (J.F.C.), University of Alabama at Birmingham; and Division of Surgical Sciences, Wake Forest University School of Medicine, Winston-Salem, NC (C.M.F.).
| | - James F Collawn
- From the Department of Medicine, Division of Cardiology, Birmingham Veteran Affairs Medical Center (L.J.D.), Division of Cardiovascular Disease, Department of Medicine (L.J.D.), and Department of Cell, Developmental and Integrative Biology (J.F.C.), University of Alabama at Birmingham; and Division of Surgical Sciences, Wake Forest University School of Medicine, Winston-Salem, NC (C.M.F.)
| | - Carlos M Ferrario
- From the Department of Medicine, Division of Cardiology, Birmingham Veteran Affairs Medical Center (L.J.D.), Division of Cardiovascular Disease, Department of Medicine (L.J.D.), and Department of Cell, Developmental and Integrative Biology (J.F.C.), University of Alabama at Birmingham; and Division of Surgical Sciences, Wake Forest University School of Medicine, Winston-Salem, NC (C.M.F.)
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9
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Escobales N, Nuñez RE, Javadov S. Mitochondrial angiotensin receptors and cardioprotective pathways. Am J Physiol Heart Circ Physiol 2019; 316:H1426-H1438. [PMID: 30978131 PMCID: PMC6620675 DOI: 10.1152/ajpheart.00772.2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/15/2019] [Accepted: 04/01/2019] [Indexed: 12/13/2022]
Abstract
A growing body of data provides strong evidence that intracellular angiotensin II (ANG II) plays an important role in mammalian cell function and is involved in the pathogenesis of human diseases such as hypertension, diabetes, inflammation, fibrosis, arrhythmias, and kidney disease, among others. Recent studies also suggest that intracellular ANG II exerts protective effects in cells during high extracellular levels of the hormone or during chronic stimulation of the local tissue renin-angiotensin system (RAS). Notably, the intracellular RAS (iRAS) described in neurons, fibroblasts, renal cells, and cardiomyocytes provided new insights into regulatory mechanisms mediated by intracellular ANG II type 1 (AT1Rs) and 2 (AT2Rs) receptors, particularly, in mitochondria and nucleus. For instance, ANG II through nuclear AT1Rs promotes protective mechanisms by stimulating the AT2R signaling cascade, which involves mitochondrial AT2Rs and Mas receptors. The stimulation of nuclear ANG II receptors enhances mitochondrial biogenesis through peroxisome proliferator-activated receptor-γ coactivator-1α and increases sirtuins activity, thus protecting the cell against oxidative stress. Recent studies in ANG II-induced preconditioning suggest that plasma membrane AT2R stimulation exerts protective effects against cardiac ischemia-reperfusion by modulating mitochondrial AT1R and AT2R signaling. These studies indicate that iRAS promotes the protection of cells through nuclear AT1R signaling, which, in turn, promotes AT2R-dependent processes in mitochondria. Thus, despite abundant data on the deleterious effects of intracellular ANG II, a growing body of studies also supports a protective role for iRAS that could be of relevance to developing new therapeutic strategies. This review summarizes and discusses previous studies on the role of iRAS, particularly emphasizing the protective and counterbalancing actions of iRAS, mitochondrial ANG II receptors, and their implications for organ protection.
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Affiliation(s)
- Nelson Escobales
- Department of Physiology, University of Puerto Rico School of Medicine , San Juan, Puerto Rico
| | - Rebeca E Nuñez
- Department of Physiology, University of Puerto Rico School of Medicine , San Juan, Puerto Rico
| | - Sabzali Javadov
- Department of Physiology, University of Puerto Rico School of Medicine , San Juan, Puerto Rico
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10
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Intratubular and intracellular renin-angiotensin system in the kidney: a unifying perspective in blood pressure control. Clin Sci (Lond) 2018; 132:1383-1401. [PMID: 29986878 DOI: 10.1042/cs20180121] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/05/2018] [Accepted: 06/13/2018] [Indexed: 12/18/2022]
Abstract
The renin-angiotensin system (RAS) is widely recognized as one of the most important vasoactive hormonal systems in the physiological regulation of blood pressure and the development of hypertension. This recognition is derived from, and supported by, extensive molecular, cellular, genetic, and pharmacological studies on the circulating (tissue-to-tissue), paracrine (cell-to-cell), and intracrine (intracellular, mitochondrial, nuclear) RAS during last several decades. Now, it is widely accepted that circulating and local RAS may act independently or interactively, to regulate sympathetic activity, systemic and renal hemodynamics, body salt and fluid balance, and blood pressure homeostasis. However, there remains continuous debate with respect to the specific sources of intratubular and intracellular RAS in the kidney and other tissues, the relative contributions of the circulating RAS to intratubular and intracellular RAS, and the roles of intratubular compared with intracellular RAS to the normal control of blood pressure or the development of angiotensin II (ANG II)-dependent hypertension. Based on a lecture given at the recent XI International Symposium on Vasoactive Peptides held in Horizonte, Brazil, this article reviews recent studies using mouse models with global, kidney- or proximal tubule-specific overexpression (knockin) or deletion (knockout) of components of the RAS or its receptors. Although much knowledge has been gained from cell- and tissue-specific transgenic or knockout models, a unifying and integrative approach is now required to better understand how the circulating and local intratubular/intracellular RAS act independently, or with other vasoactive systems, to regulate blood pressure, cardiovascular and kidney function.
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11
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Abstract
It has become clear that the vasoactive peptide angiotensin II, like other so-called intracrines, can act in the intracellular space. Evidence has accumulated indicating that such angiotensin II activity can be upregulated in disease states and cause pathology. Indeed, other intracrines appear to be involved in disease pathogenesis as well. At the same time, nitric oxide, potentially a cell protective factor, has been shown to be upregulated by intracellular angiotensin II. Recently data have been developed indicating that other potentially protective factors are directly upregulated at neuronal nuclei by angiotensin II. This led to the suggestion that intracellular angiotensin II is cell protective and not pathological. Here, the data on both sides of this issue and a possible resolution are discussed. In summary, there is evidence for both protective and pathological actions of intracellular angiotensin, just as there is abundant evidence derived from whole animal physiology to indicate that angiotensin-driven signaling cascades, including angiotensin II type 2 receptor- and Mas receptor-mediated events, can mitigate the effects of the angiotensin II/angiotensin II type 1 receptor axis (25). This mitigation does not negate the physiological and pathological importance of angiotensin II/angiotensin II type 1 receptor action but does expand our understanding of the workings of both intracellular and extracellular angiotensin II.
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Affiliation(s)
- Richard N Re
- Division of Academics-Research, Ochsner Clinic Foundation , New Orleans, Louisiana
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12
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Jacques D, Abdel-Karim Abdel-Malak N, Abou Abdallah N, Al-Khoury J, Bkaily G. Difference in the response to angiotensin II between left and right ventricular endocardial endothelial cells. Can J Physiol Pharmacol 2017; 95:1271-1282. [PMID: 28727938 DOI: 10.1139/cjpp-2017-0280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Previous studies focused on the right ventricular endocardial endothelial cells (EECRs) and showed that angiotensin II (Ang II) induced increase in cytosolic and nuclear calcium via AT1 receptor activation. In the present study, we verified whether the response of left EECs (EECLs) to Ang II is different than that of EECRs. Our results showed that the EC50 of the Ang II-induced increase of cytosolic and nuclear calcium in EECLs was 10× higher (around 2 × 10-13 mol/L) than in EECRs (around 8 × 10-12 mol/L). The densities of both AT1 and AT2 receptors were also higher in EECLs than those previously reported in EECRs. The effect of Ang II was mediated in both cell types via the activation of AT1 receptors. Treatment with Ang II induced a significant increase of cytosolic and nuclear AT1 receptors in EECRs, whereas the opposite was found in EECLs. In both cell types, there was a transient increase of cytosolic and nuclear AT2 receptors following the Ang II treatment. In conclusion, our results showed that both AT1 and AT2 receptors densities are higher in both EECLs compared to what was reported in EECRs. The higher density of AT1 receptors in EECLs compared to REECs may explain, in part, the higher sensitivity of EECLs to Ang II.
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Affiliation(s)
- Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Nelly Abdel-Karim Abdel-Malak
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Nadia Abou Abdallah
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Johny Al-Khoury
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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13
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Morinelli TA, Luttrell LM, Strungs EG, Ullian ME. Angiotensin II receptors and peritoneal dialysis-induced peritoneal fibrosis. Int J Biochem Cell Biol 2016; 77:240-50. [PMID: 27167177 PMCID: PMC5038354 DOI: 10.1016/j.biocel.2016.04.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 12/22/2022]
Abstract
The vasoactive hormone angiotensin II initiates its major hemodynamic effects through interaction with AT1 receptors, a member of the class of G protein-coupled receptors. Acting through its AT1R, angiotensin II regulates blood pressure and renal salt and water balance. Recent evidence points to additional pathological influences of activation of AT1R, in particular inflammation, fibrosis and atherosclerosis. The transcription factor nuclear factor κB, a key mediator in inflammation and atherosclerosis, can be activated by angiotensin II through a mechanism that may involve arrestin-dependent AT1 receptor internalization. Peritoneal dialysis is a therapeutic modality for treating patients with end-stage kidney disease. The effectiveness of peritoneal dialysis at removing waste from the circulation is compromised over time as a consequence of peritoneal dialysis-induced peritoneal fibrosis. The non-physiological dialysis solution used in peritoneal dialysis, i.e. highly concentrated, hyperosmotic glucose, acidic pH as well as large volumes infused into the peritoneal cavity, contributes to the development of fibrosis. Numerous trials have been conducted altering certain components of the peritoneal dialysis fluid in hopes of preventing or delaying the fibrotic response with limited success. We hypothesize that structural activation of AT1R by hyperosmotic peritoneal dialysis fluid activates the internalization process and subsequent signaling through the transcription factor nuclear factor κB, resulting in the generation of pro-fibrotic/pro-inflammatory mediators producing peritoneal fibrosis.
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Affiliation(s)
- Thomas A Morinelli
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States.
| | - Louis M Luttrell
- Division of Endocrinology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, United States
| | - Erik G Strungs
- Division of Endocrinology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Michael E Ullian
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, United States
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14
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Toy-Miou-Leong M, Bachelet CM, Pélaprat D, Rostène W, Forgez P. NT Agonist Regulates Expression of Nuclear High-affinity Neurotensin Receptors. J Histochem Cytochem 2016; 52:335-45. [PMID: 14966200 DOI: 10.1177/002215540405200304] [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: 11/16/2022] Open
Abstract
Neurotensin (NT) exerts multiple functions in the central nervous system and peripheral tissues. Its actions are mainly mediated by a high-affinity G-protein-coupled receptor, the NT-1 receptor. In this study we demonstrated a nuclear NT binding site in different cellular models. We first noted that a large percentage of NT-1 receptor cell body immunoreactivity was located in the nuclear soma and nuclear envelope of rat substantia nigra, a brain area rich in NT-containing axon terminals. The NT-1 receptor was also visualized in purified nuclei from CHO cells stably transfected with NT-1 receptor coupled to the enhanced green fluorescence protein by immunocytochemistry. We observed that both the nuclear envelope and the nuclear soma were labeled, and the labeling intensity significantly increased after NT agonist treatment. These results suggested that NT-1 receptors, present in both the nuclear soma and the nuclear envelope, can be modulated by the ligand. Lastly, [125I]-NT binding experiments performed on isolated nuclei from a human lung cancer cell line endogenously expressing NT-1 receptor and NT, LNM35, revealed the existence of nuclear Gpp(NHp)-sensitive binding sites. These binding sites markedly decreased when cells were chronically treated with an NT-1 receptor antagonist, SR 48692. Taken together, these data suggest that the agonist regulates the expression of nuclear NT-1 receptors.
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Abstract
G protein-coupled receptors (GPCRs) play key physiological roles and represent a significant target for drug development. However, historically, drugs were developed with the understanding that GPCRs as a therapeutic target exist solely on cell surface membranes. More recently, GPCRs have been detected on intracellular membranes, including the nuclear membrane, and the concept that intracellular GPCRs are functional is become more widely accepted. Nuclear GPCRs couple to effectors and regulate signaling pathways, analogous to their counterparts at the cell surface, but may serve distinct biological roles. Hence, the physiological responses mediated by GPCR ligands, or pharmacological agents, result from the integration of their actions at extracellular and intracellular receptors. The net effect depends on the ability of a given ligand or drug to access intracellular receptors, as dictated by its structure, lipophilic properties, and affinity for nuclear receptors. This review will discuss angiotensin II, endothelin, and β-adrenergic receptors located on the nuclear envelope in cardiac cells in terms of their origin, activation, and role in cardiovascular function and pathology.
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Chaumet A, Wright GD, Seet SH, Tham KM, Gounko NV, Bard F. Nuclear envelope-associated endosomes deliver surface proteins to the nucleus. Nat Commun 2015; 6:8218. [PMID: 26356418 PMCID: PMC4579783 DOI: 10.1038/ncomms9218] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 07/29/2015] [Indexed: 01/16/2023] Open
Abstract
Endocytosis directs molecular cargo along three main routes: recycling to the cell surface, transport to the Golgi apparatus or degradation in endolysosomes. Pseudomonas exotoxin A (PE) is a bacterial protein that typically traffics to the Golgi and then the endoplasmic reticulum before translocating to the cytosol. Here we show that a substantial fraction of internalized PE is also located in nuclear envelope-associated endosomes (NAE), which display limited mobility, exhibit a propensity to undergo fusion and readily discharge their contents into the nuclear envelope. Electron microscopy and protein trapping in the nucleus indicate that NAE mediate PE transfer into the nucleoplasm. RNAi screening further revealed that NAE-mediated transfer depends on the nuclear envelope proteins SUN1 and SUN2, as well as the Sec61 translocon complex. These data reveal a novel endosomal route from the cell surface to the nucleoplasm that facilitates the accumulation of extracellular and cell surface proteins in the nucleus.
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Affiliation(s)
- Alexandre Chaumet
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Graham D. Wright
- Institute of Medical Biology, 8A Biomedical Grove, #06-06 Immunos, Singapore 138648, Singapore
- Joint IMB-IMCB Electron Microscopy Suite, 20 Biopolis Street, #B2-14 Matrix, Singapore 138671, Singapore
| | - Sze Hwee Seet
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Keit Min Tham
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Natalia V. Gounko
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Institute of Medical Biology, 8A Biomedical Grove, #06-06 Immunos, Singapore 138648, Singapore
- Joint IMB-IMCB Electron Microscopy Suite, 20 Biopolis Street, #B2-14 Matrix, Singapore 138671, Singapore
| | - Frederic Bard
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Department of Biochemistry, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore
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Della Penna SL, Rosón MI, Toblli JE, Fernández BE. Role of angiotensin II and oxidative stress in renal inflammation by hypernatremia: Benefits of atrial natriuretic peptide, losartan, and tempol. Free Radic Res 2015; 49:383-96. [DOI: 10.3109/10715762.2015.1006216] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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18
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Demurtas P, Corrias M, Zucca I, Maxia C, Piras F, Sirigu P, Perra MT. Angiotensin II: immunohistochemical study in Sardinian pterygium. Eur J Histochem 2014; 58:2426. [PMID: 25308851 PMCID: PMC4194399 DOI: 10.4081/ejh.2014.2426] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 06/25/2014] [Accepted: 07/02/2014] [Indexed: 11/22/2022] Open
Abstract
The Angiotensin II (Ang II) is the principal effector peptide of the RAS system. It has a pleiotropic effect and, beside its physiological role, it has the property to stimulate angiogenesis and activate multiple signalling pathways related to cell proliferation. The purpose of the study was to determinate the Ang II expression and localization in Sardinian pterygium and normal conjunctiva by immunohistochemistry, and its possible involvement in the development and progression of the disease. Twenty-three pterygiums and eleven normal conjunctiva specimens obtained from Sardinian patients, were processed for paraffin embedding and assessed for the immunohistochemi-cal revelation of Ang II. Significant Ang II expression was identified in pterygium and conjunctiva. Particularly, thirteen pterygium specimens (n=13) displayed exclusively moderate to strong nuclear staining; some specimens (n=5) showed exclusively a moderate cytoplasmic immunoreactivity, and few specimens (n=2) displayed moderate to strong immunoreactivity in both cytoplasm and nucleus. Only 3 specimens were negative. Statistical significance difference in respect of nuclear and cytoplasmic localization was observed between normal conjunctiva and pterygium (P=0.020). The results showed a predominant intranuclear localization of Ang II in pterygium epithelial cells, in spite of conjunctiva that mainly showed cytoplasmic localization. These findings suggest a possible role for Ang II in the development and/or progression of pterygium mediated by the activation of local RAS system.
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Chappell MC, Marshall AC, Alzayadneh EM, Shaltout HA, Diz DI. Update on the Angiotensin converting enzyme 2-Angiotensin (1-7)-MAS receptor axis: fetal programing, sex differences, and intracellular pathways. Front Endocrinol (Lausanne) 2014; 4:201. [PMID: 24409169 PMCID: PMC3886117 DOI: 10.3389/fendo.2013.00201] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 12/18/2013] [Indexed: 12/12/2022] Open
Abstract
The renin-angiotensin-system (RAS) constitutes an important hormonal system in the physiological regulation of blood pressure. Indeed, dysregulation of the RAS may lead to the development of cardiovascular pathologies including kidney injury. Moreover, the blockade of this system by the inhibition of angiotensin converting enzyme (ACE) or antagonism of the angiotensin type 1 receptor (AT1R) constitutes an effective therapeutic regimen. It is now apparent with the identification of multiple components of the RAS that the system is comprised of different angiotensin peptides with diverse biological actions mediated by distinct receptor subtypes. The classic RAS can be defined as the ACE-Ang II-AT1R axis that promotes vasoconstriction, sodium retention, and other mechanisms to maintain blood pressure, as well as increased oxidative stress, fibrosis, cellular growth, and inflammation in pathological conditions. In contrast, the non-classical RAS composed of the ACE2-Ang-(1-7)-Mas receptor axis generally opposes the actions of a stimulated Ang II-AT1R axis through an increase in nitric oxide and prostaglandins and mediates vasodilation, natriuresis, diuresis, and oxidative stress. Thus, a reduced tone of the Ang-(1-7) system may contribute to these pathologies as well. Moreover, the non-classical RAS components may contribute to the effects of therapeutic blockade of the classical system to reduce blood pressure and attenuate various indices of renal injury. The review considers recent studies on the ACE2-Ang-(1-7)-Mas receptor axis regarding the precursor for Ang-(1-7), the intracellular expression and sex differences of this system, as well as an emerging role of the Ang1-(1-7) pathway in fetal programing events and cardiovascular dysfunction.
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Affiliation(s)
- Mark C. Chappell
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Allyson C. Marshall
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Ebaa M. Alzayadneh
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Hossam A. Shaltout
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- Department of Pharmacology and Toxicology, School of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Debra I. Diz
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- *Correspondence: Debra I. Diz, The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157-1032, USA e-mail:
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Intracrine endothelin signaling evokes IP3-dependent increases in nucleoplasmic Ca²⁺ in adult cardiac myocytes. J Mol Cell Cardiol 2013; 62:189-202. [PMID: 23756157 DOI: 10.1016/j.yjmcc.2013.05.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 05/30/2013] [Accepted: 05/31/2013] [Indexed: 12/17/2022]
Abstract
Endothelin receptors are present on the nuclear membranes in adult cardiac ventricular myocytes. The objectives of the present study were to determine 1) which endothelin receptor subtype is in cardiac nuclear membranes, 2) if the receptor and ligand traffic from the cell surface to the nucleus, and 3) the effect of increased intracellular ET-1 on nuclear Ca(2+) signaling. Confocal microscopy using fluorescently-labeled endothelin analogs confirmed the presence of ETB at the nuclear membrane of rat cardiomyocytes in skinned-cells and isolated nuclei. Furthermore, in both cardiac myocytes and aortic endothelial cells, endocytosed ET:ETB complexes translocated to lysosomes and not the nuclear envelope. Although ETA and ETB can form heterodimers, the presence or absence of ETA did not alter ETB trafficking. Treatment of isolated nuclei with peptide: N-glycosidase F did not alter the electrophoretic mobility of ETB. The absence of N-glycosylation further indicates that these receptors did not originate at the cell surface. Intracellular photolysis of a caged ET-1 analog ([Trp-ODMNB(21)]ET-1) evoked an increase in nucleoplasmic Ca(2+) ([Ca(2+)]n) that was attenuated by inositol 1,4,5-trisphosphate receptor inhibitor 2-aminoethoxydiphenyl borate and prevented by pre-treatment with ryanodine. A caged cell-permeable analog of the ETB-selective antagonist IRL-2500 blocked the ability of intracellular cET-1 to increase [Ca(2+)]n whereas extracellular application of ETA and ETB receptor antagonists did not. These data suggest that 1) the endothelin receptor in the cardiac nuclear membranes is ETB, 2) ETB traffics directly to the nuclear membrane after biosynthesis, 3) exogenous endothelins are not ligands for ETB on nuclear membranes, and 4) ETB associated with the nuclear membranes regulates nuclear Ca(2+) signaling.
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21
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Immunohistochemical Localization of AT1a, AT1b, and AT2 Angiotensin II Receptor Subtypes in the Rat Adrenal, Pituitary, and Brain with a Perspective Commentary. Int J Hypertens 2013; 2013:175428. [PMID: 23573410 PMCID: PMC3614054 DOI: 10.1155/2013/175428] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/01/2013] [Accepted: 02/05/2013] [Indexed: 11/17/2022] Open
Abstract
Angiotensin II increases blood pressure and stimulates thirst and sodium appetite in the brain. It also stimulates secretion of aldosterone from the adrenal zona glomerulosa and epinephrine from the adrenal medulla. The rat has 3 subtypes of angiotensin II receptors: AT1a, AT1b, and AT2. mRNAs for all three subtypes occur in the adrenal and brain. To immunohistochemically differentiate these receptor subtypes, rabbits were immunized with C-terminal fragments of these subtypes to generate receptor subtype-specific antibodies. Immunofluorescence revealed AT1a and AT2 receptors in adrenal zona glomerulosa and medulla. AT1b immunofluorescence was present in the zona glomerulosa, but not the medulla. Ultrastructural immunogold labeling for the AT1a receptor in glomerulosa and medullary cells localized it to plasma membrane, endocytic vesicles, multivesicular bodies, and the nucleus. AT1b and AT2, but not AT1a, immunofluorescence was observed in the anterior pituitary. Stellate cells were AT1b positive while ovoid cells were AT2 positive. In the brain, neurons were AT1a, AT1b, and AT2 positive, but glia was only AT1b positive. Highest levels of AT1a, AT1b, and AT2 receptor immunofluorescence were in the subfornical organ, median eminence, area postrema, paraventricular nucleus, and solitary tract nucleus. These studies complement those employing different techniques to characterize Ang II receptors.
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Abadir PM, Walston JD, Carey RM. Subcellular characteristics of functional intracellular renin-angiotensin systems. Peptides 2012; 38:437-45. [PMID: 23032352 PMCID: PMC3770295 DOI: 10.1016/j.peptides.2012.09.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 09/14/2012] [Indexed: 02/06/2023]
Abstract
The renin-angiotensin system (RAS) is now regarded as an integral component in not only the development of hypertension, but also in physiologic and pathophysiologic mechanisms in multiple tissues and chronic disease states. While many of the endocrine (circulating), paracrine (cell-to-different cell) and autacrine (cell-to-same cell) effects of the RAS are believed to be mediated through the canonical extracellular RAS, a complete, independent and differentially regulated intracellular RAS (iRAS) has also been proposed. Angiotensinogen, the enzymes renin and angiotensin-converting enzyme (ACE) and the angiotensin peptides can all be synthesized and retained intracellularly. Angiotensin receptors (types I and 2) are also abundant intracellularly mainly at the nuclear and mitochondrial levels. The aim of this review is to focus on the most recent information concerning the subcellular localization, distribution and functions of the iRAS and to discuss the potential consequences of activation of the subcellular RAS on different organ systems.
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Affiliation(s)
- Peter M. Abadir
- Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging Program, Johns Hopkins University School of Medicine, Baltimore, MD 21224, United States
| | - Jeremy D. Walston
- Division of Geriatric Medicine and Gerontology, Biology of Healthy Aging Program, Johns Hopkins University School of Medicine, Baltimore, MD 21224, United States
| | - Robert M. Carey
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908, United States
- Corresponding author at: P.O. Box 801414, University of Virginia Health System, Charlottesville, VA 22908-1414, United States. Tel.: +1 434 924 5510; fax: +1 434 982 3626. (R.M. Carey)
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Abstract
The RAS (renin-angiotensin system) is one of the earliest and most extensively studied hormonal systems. The RAS is an atypical hormonal system in several ways. The major bioactive peptide of the system, AngII (angiotensin II), is neither synthesized in nor targets one specific organ. New research has identified additional peptides with important physiological and pathological roles. More peptides also mean newer enzymatic cascades that generate these peptides and more receptors that mediate their function. In addition, completely different roles of components that constitute the RAS have been uncovered, such as that for prorenin via the prorenin receptor. Complexity of the RAS is enhanced further by the presence of sub-systems in tissues, which act in an autocrine/paracrine manner independent of the endocrine system. The RAS seems relevant at the cellular level, wherein individual cells have a complete system, termed the intracellular RAS. Thus, from cells to tissues to the entire organism, the RAS exhibits continuity while maintaining independent control at different levels. The intracellular RAS is a relatively new concept for the RAS. The present review provides a synopsis of the literature on this system in different tissues.
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Presence of urotensin-II receptors at the cell nucleus: Specific tissue distribution and hypoxia-induced modulation. Int J Biochem Cell Biol 2012; 44:639-47. [DOI: 10.1016/j.biocel.2011.12.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 12/14/2011] [Accepted: 12/27/2011] [Indexed: 02/07/2023]
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25
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Chatenet D, Nguyen TTM, Létourneau M, Fournier A. Update on the urotensinergic system: new trends in receptor localization, activation, and drug design. Front Endocrinol (Lausanne) 2012; 3:174. [PMID: 23293631 PMCID: PMC3533682 DOI: 10.3389/fendo.2012.00174] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/10/2012] [Indexed: 12/17/2022] Open
Abstract
The urotensinergic system plays central roles in the physiological regulation of major mammalian organ systems, including the cardiovascular system. As a matter of fact, this system has been linked to numerous pathophysiological states including atherosclerosis, heart failure, hypertension, diabetes as well as psychological, and neurological disorders. The delineation of the (patho)physiological roles of the urotensinergic system has been hampered by the absence of potent and selective antagonists for the urotensin II-receptor (UT). Thus, a more precise definition of the molecular functioning of the urotensinergic system, in normal conditions as well as in a pathological state is still critically needed. The recent discovery of nuclear UT within cardiomyocytes has highlighted the cellular complexity of this system and suggested that UT-associated biological responses are not only initiated at the cell surface but may result from the integration of extracellular and intracellular signaling pathways. Thus, such nuclear-localized receptors, regulating distinct signaling pathways, may represent new therapeutic targets. With the recent observation that urotensin II (UII) and urotensin II-related peptide (URP) exert different biological effects and the postulate that they could also have distinct pathophysiological roles in hypertension, it appears crucial to reassess the recognition process involving UII and URP with UT, and to push forward the development of new analogs of the UT system aimed at discriminating UII- and URP-mediated biological activities. The recent development of such compounds, i.e. urocontrin A and rUII(1-7), is certainly useful to decipher the specific roles of UII and URP in vitro and in vivo. Altogether, these studies, which provide important information regarding the pharmacology of the urotensinergic system and the conformational requirements for binding and activation, will ultimately lead to the development of potent and selective drugs.
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Affiliation(s)
- David Chatenet
- Laboratoire d'études moléculaires et pharmacologiques des peptides, INRS – Institut Armand-Frappier, Université du Québec, Ville de LavalQC, Canada
- Laboratoire International Associé Samuel de Champlain (INSERM/INRS-Université de Rouen)France
- *Correspondence: David Chatenet and Alain Fournier, Laboratoire d'études moléculaires et pharmacologiques des peptides, INRS – Institut Armand-Frappier, Université du Québec, 531 Boulevard des Prairies, Ville de Laval, QC H7V 1B7, Canada. e-mail: ;
| | - Thi-Tuyet M. Nguyen
- Laboratoire d'études moléculaires et pharmacologiques des peptides, INRS – Institut Armand-Frappier, Université du Québec, Ville de LavalQC, Canada
- Laboratoire International Associé Samuel de Champlain (INSERM/INRS-Université de Rouen)France
| | - Myriam Létourneau
- Laboratoire d'études moléculaires et pharmacologiques des peptides, INRS – Institut Armand-Frappier, Université du Québec, Ville de LavalQC, Canada
- Laboratoire International Associé Samuel de Champlain (INSERM/INRS-Université de Rouen)France
| | - Alain Fournier
- Laboratoire d'études moléculaires et pharmacologiques des peptides, INRS – Institut Armand-Frappier, Université du Québec, Ville de LavalQC, Canada
- Laboratoire International Associé Samuel de Champlain (INSERM/INRS-Université de Rouen)France
- *Correspondence: David Chatenet and Alain Fournier, Laboratoire d'études moléculaires et pharmacologiques des peptides, INRS – Institut Armand-Frappier, Université du Québec, 531 Boulevard des Prairies, Ville de Laval, QC H7V 1B7, Canada. e-mail: ;
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Tadevosyan A, Vaniotis G, Allen BG, Hébert TE, Nattel S. G protein-coupled receptor signalling in the cardiac nuclear membrane: evidence and possible roles in physiological and pathophysiological function. J Physiol 2011; 590:1313-30. [PMID: 22183719 DOI: 10.1113/jphysiol.2011.222794] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptors (GPCRs) play key physiological roles in numerous tissues, including the heart, and their dysfunction influences a wide range of cardiovascular diseases. Recently, the notion of nuclear localization and action of GPCRs has become more widely accepted. Nuclear-localized receptors may regulate distinct signalling pathways, suggesting that the biological responses mediated by GPCRs are not solely initiated at the cell surface but may result from the integration of extracellular and intracellular signalling pathways. Many of the observed nuclear effects are not prevented by classical inhibitors that exclusively target cell surface receptors, presumably because of their structures, lipophilic properties, or affinity for nuclear receptors. In this topical review, we discuss specifically how angiotensin-II, endothelin, β-adrenergic and opioid receptors located on the nuclear envelope activate signalling pathways, which convert intracrine stimuli into acute responses such as generation of second messengers and direct genomic effects, and thereby participate in the development of cardiovascular disorders.
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Affiliation(s)
- Artavazd Tadevosyan
- Department of Medicine, Université de Montréal, Montréal, Québec, Canada H3C 3J7
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Kumar R, Yong QC, Thomas CM, Baker KM. Intracardiac intracellular angiotensin system in diabetes. Am J Physiol Regul Integr Comp Physiol 2011; 302:R510-7. [PMID: 22170614 DOI: 10.1152/ajpregu.00512.2011] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The renin-angiotensin system (RAS) has mainly been categorized as a circulating and a local tissue RAS. A new component of the local system, known as the intracellular RAS, has recently been described. The intracellular RAS is defined as synthesis and action of ANG II intracellularly. This RAS appears to differ from the circulating and the local RAS, in terms of components and the mechanism of action. These differences may alter treatment strategies that target the RAS in several pathological conditions. Recent work from our laboratory has demonstrated significant upregulation of the cardiac, intracellular RAS in diabetes, which is associated with cardiac dysfunction. Here, we have reviewed evidence supporting an intracellular RAS in different cell types, ANG II's actions in cardiac cells, and its mechanism of action, focusing on the intracellular cardiac RAS in diabetes. We have discussed the significance of an intracellular RAS in cardiac pathophysiology and implications for potential therapies.
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Affiliation(s)
- Rajesh Kumar
- Division of Molecular Cardiology, Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA
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28
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Ellis B, Li XC, Miguel-Qin E, Gu V, Zhuo JL. Evidence for a functional intracellular angiotensin system in the proximal tubule of the kidney. Am J Physiol Regul Integr Comp Physiol 2011; 302:R494-509. [PMID: 22170616 DOI: 10.1152/ajpregu.00487.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
ANG II is the most potent and important member of the classical renin-angiotensin system (RAS). ANG II, once considered to be an endocrine hormone, is now increasingly recognized to also play novel and important paracrine (cell-to-cell) and intracrine (intracellular) roles in cardiovascular and renal physiology and blood pressure regulation. Although an intracrine role of ANG II remains an issue of continuous debates and requires further confirmation, a great deal of research has recently been devoted to uncover the novel actions and elucidate underlying signaling mechanisms of the so-called intracellular ANG II in cardiovascular, neural, and renal systems. The purpose of this article is to provide a comprehensive review of the intracellular actions of ANG II, either administered directly into the cells or expressed as an intracellularly functional fusion protein, and its effects throughout a variety of target tissues susceptible to the impacts of an overactive ANG II, with a particular focus on the proximal tubules of the kidney. While continuously reaffirming the roles of extracellular or circulating ANG II in the proximal tubules, our review will focus on recent evidence obtained for the novel biological roles of intracellular ANG II in cultured proximal tubule cells in vitro and the potential physiological roles of intracellular ANG II in the regulation of proximal tubular reabsorption and blood pressure in rats and mice. It is our hope that the new knowledge on the roles of intracellular ANG II in proximal tubules will serve as a catalyst to stimulate further studies and debates in the field and to help us better understand how extracellular and intracellular ANG II acts independently or interacts with each other, to regulate proximal tubular transport and blood pressure in both physiological and diseased states.
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Affiliation(s)
- Brianne Ellis
- Laboratoory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
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29
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Noncanonical intracrine action. ACTA ACUST UNITED AC 2011; 5:435-48. [DOI: 10.1016/j.jash.2011.07.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 06/09/2011] [Accepted: 07/05/2011] [Indexed: 12/24/2022]
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Abstract
The title of the proposed series of reviews is Translational Success Stories. The definition of "translation" according to Webster is, "an act, process, or instance of translating as a rendering of one language into another." In the context of this inaugural review, it is the translation of Tigerstedt's and Bergman's(1) discovery in 1898 of the vasoconstrictive effects of an extract of rabbit kidney to the treatment of heart failure. As recounted by Marks and Maxwell,(2) their discovery was heavily influenced by the original experiments of the French physiologist Brown-Séquard, who was the author of the doctrine that "many organs dispense substances into the blood which are not ordinary waste products, but have specific functions." They were also influenced by Bright's(3) original observation that linked kidney disease with hypertension with the observation that patients dying with contracted kidneys often exhibited a hard, full pulse and cardiac hypertrophy. However, from Tigerstedt's initial discovery, there was a long and arduous transformation of ideas and paradigms that eventually translated to clinical applications. Although the role of the renin-angiotensin system in the pathophysiology of hypertension and heart failure was suspected through the years, beneficial effects from its blockade were not realized until the early 1970s. Thus, this story starts with a short historical perspective that provides the reader some insight and appreciation into the long delay in translation.
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Affiliation(s)
- Louis J Dell'Italia
- Birmingham Veteran Affairs Medical Center, Department of Medicine, Division of Cardiovascular Disease, University Station, University of Alabama, Birmingham, USA.
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31
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de Cavanagh EMV, Inserra F, Ferder L. Angiotensin II blockade: a strategy to slow ageing by protecting mitochondria? Cardiovasc Res 2010; 89:31-40. [PMID: 20819950 DOI: 10.1093/cvr/cvq285] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Protein and lipid oxidation-mainly by mitochondrial reactive oxygen species (mtROS)-was proposed as a crucial determinant of health and lifespan. Angiotensin II (Ang II) enhances ROS production by activating NAD(P)H oxidase and uncoupling endothelial nitric oxide synthase (NOS). Ang II also stimulates mtROS production, which depresses mitochondrial energy metabolism. In rodents, renin-angiotensin system blockade (RAS blockade) increases survival and prevents age-associated changes. RAS blockade reduces mtROS and enhances mitochondrial content and function. This suggests that Ang II contributes to the ageing process by prompting mitochondrial dysfunction. Since Ang II is a pleiotropic peptide, the age-protecting effects of RAS blockade are expected to involve a variety of other mechanisms. Caloric restriction (CR)-an age-retarding intervention in humans and animals-and RAS blockade display a number of converging effects, i.e. they delay the manifestations of hypertension, diabetes, nephropathy, cardiovascular disease, and cancer; increase body temperature; reduce body weight, plasma glucose, insulin, and insulin-like growth factor-1; ameliorate insulin sensitivity; lower protein, lipid, and DNA oxidation, and mitochondrial H(2)O(2) production; and increase uncoupling protein-2 and sirtuin expression. A number of these overlapping effects involve changes in mitochondrial function. In CR, peroxisome proliferator-activated receptors (PPARs) seem to contribute to age-retardation partly by regulating mitochondrial function. RAS inhibition up-regulates PPARs; therefore, it is feasible that PPAR modulation is pivotal for mitochondrial protection by RAS blockade during rodent ageing. Other potential mechanisms that may underlie RAS blockade's mitochondrial benefits are TGF-β down-regulation and up-regulation of Klotho and sirtuins. In conclusion, the available data suggest that RAS blockade deserves further research efforts to establish its role as a potential tool to mitigate the growing problem of age-associated chronic disease.
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Affiliation(s)
- Elena M V de Cavanagh
- Center of Hypertension, Cardiology Department, Austral University Hospital, Derqui, Argentina
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32
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Re M, Pampillo M, Savard M, Dubuc C, McArdle CA, Millar RP, Conn PM, Gobeil F, Bhattacharya M, Babwah AV. The human gonadotropin releasing hormone type I receptor is a functional intracellular GPCR expressed on the nuclear membrane. PLoS One 2010; 5:e11489. [PMID: 20628612 PMCID: PMC2900216 DOI: 10.1371/journal.pone.0011489] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 06/11/2010] [Indexed: 12/02/2022] Open
Abstract
The mammalian type I gonadotropin releasing hormone receptor (GnRH-R) is a structurally unique G protein-coupled receptor (GPCR) that lacks cytoplasmic tail sequences and displays inefficient plasma membrane expression (PME). Compared to its murine counterparts, the primate type I receptor is inefficiently folded and retained in the endoplasmic reticulum (ER) leading to a further reduction in PME. The decrease in PME and concomitant increase in intracellular localization of the mammalian GnRH-RI led us to characterize the spatial distribution of the human and mouse GnRH receptors in two human cell lines, HEK 293 and HTR-8/SVneo. In both human cell lines we found the receptors were expressed in the cytoplasm and were associated with the ER and nuclear membrane. A molecular analysis of the receptor protein sequence led us to identify a putative monopartite nuclear localization sequence (NLS) in the first intracellular loop of GnRH-RI. Surprisingly, however, neither the deletion of the NLS nor the addition of the Xenopus GnRH-R cytoplasmic tail sequences to the human receptor altered its spatial distribution. Finally, we demonstrate that GnRH treatment of nuclei isolated from HEK 293 cells expressing exogenous GnRH-RI triggers a significant increase in the acetylation and phosphorylation of histone H3, thereby revealing that the nuclear-localized receptor is functional. Based on our findings, we conclude that the mammalian GnRH-RI is an intracellular GPCR that is expressed on the nuclear membrane. This major and novel discovery causes us to reassess the signaling potential of this physiologically and clinically important receptor.
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Affiliation(s)
- Michelle Re
- The Children's Health Research Institute, London, Canada
- Lawson Health Research Institute, London, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
| | - Macarena Pampillo
- The Children's Health Research Institute, London, Canada
- Lawson Health Research Institute, London, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Canada
| | - Martin Savard
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Canada
| | - Céléna Dubuc
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Canada
| | - Craig A. McArdle
- Laboratories for Integrated Neuroscience and Endocrinology, Department of Clinical Sciences at South Bristol, University of Bristol, Bristol, United Kingdom
| | - Robert P. Millar
- MRC Human Reproductive Sciences Unit, The Queen's Medical Research Institute, Edinburgh, United Kingdom
| | - P. Michael Conn
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Fernand Gobeil
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Canada
| | - Moshmi Bhattacharya
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
| | - Andy V. Babwah
- The Children's Health Research Institute, London, Canada
- Lawson Health Research Institute, London, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
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Redding KM, Chen BL, Singh A, Re RN, Navar LG, Seth DM, Sigmund CD, Tang WW, Cook JL. Transgenic mice expressing an intracellular fluorescent fusion of angiotensin II demonstrate renal thrombotic microangiopathy and elevated blood pressure. Am J Physiol Heart Circ Physiol 2010; 298:H1807-18. [PMID: 20363893 PMCID: PMC2886647 DOI: 10.1152/ajpheart.00027.2010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 03/29/2010] [Indexed: 01/09/2023]
Abstract
We have generated transgenic mice that express angiotensin II (ANG II) fused downstream of enhanced cyan fluorescent protein, expression of which is regulated by the mouse metallothionein promoter. The fusion protein, which lacks a secretory signal, is retained intracellularly. In the present study, RT-PCR, immunoblot analyses, whole-animal fluorescent imaging, and fluorescent microscopy of murine embryonic fibroblasts confirm expression of the fusion protein in vivo and in vitro. The transgene is expressed in all tissues tested (including brain, heart, kidney, liver, lung, and testes), and radioimmunoassay of plasma samples obtained from transgenic mice indicate no increase in circulating ANG II over wild-type levels, consistent with intracellular retention of the transgene product. Kidneys from transgenic and corresponding wild-type littermates were histologically evaluated, and abnormalities in transgenic mice consistent with thrombotic microangiopathy were observed; microthrombosis was frequently observed within the glomerular capillaries and small vessels. In addition, systolic and diastolic blood pressures, measured by telemetry (n = 8 for each group), were significantly higher in transgenic mice compared with wild-type littermates. Blood pressure of line A male transgenic mice was 125 + or - 1.7 over 97 + or - 1.6 compared with 109 + or - 1.7 over 83 + or - 1.4 mmHg in wild-type littermates (systolic over diastolic). In summary, overexpression of an intracellular fluorescent fusion protein of ANG II correlates with elevated blood pressure and kidney pathology. This transgenic model may be useful to further explore the intracellular renin-angiotensin system and its implication in abnormal kidney function and hypertension.
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Affiliation(s)
| | | | - A. Singh
- Department of Molecular Genetics and
| | - R. N. Re
- Department of Cardiology, Ochsner Clinic Foundation, and
| | - L. G. Navar
- Department of Physiology, Tulane University Health Sciences Center, New Orleans, Louisiana
| | - D. M. Seth
- Department of Physiology, Tulane University Health Sciences Center, New Orleans, Louisiana
| | - C. D. Sigmund
- Department of Physiology, University of Iowa, Carver College of Medicine, Iowa City, Iowa; and
| | - W. W. Tang
- Department of Pathology, Ochsner Clinic Foundation, New Orleans, Louisiana
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34
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Rosón MI, Della Penna SL, Cao G, Gorzalczany S, Pandolfo M, Toblli JE, Fernández BE. Different protective actions of losartan and tempol on the renal inflammatory response to acute sodium overload. J Cell Physiol 2010; 224:41-8. [PMID: 20232302 DOI: 10.1002/jcp.22087] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The aim of this work was to study the role of local intrarenal angiotensin II (Ang II) and the oxidative stress in the up-regulation of pro-inflammatory cytokines expression observed in rats submitted to an acute sodium overload. Sprague-Dawley rats were infused for 2 h with isotonic saline solution (Control group) and with hypertonic saline solution alone (Na group), plus the AT1 receptor antagonist losartan (10 mg kg(-1) in bolus) (Na-Los group), or plus the superoxide dismutase mimetic tempol (0.5 mg min(-1) kg(-1)) (Na-Temp group). Mean arterial pressure, glomerular filtration rate, and fractional sodium excretion (FE(Na)) were measured. Ang II, NF-kappaB, hypoxia inducible factor-1 alpha (HIF-1 alpha), transforming growth factor beta1 (TGF-beta1), smooth muscle actin (alpha-SMA), endothelial nitric oxide synthase (eNOS), and RANTES renal expression was evaluated by immunohistochemistry. Ang II, NF-kappaB, and TGF-beta1 and RANTES early inflammatory markers were overexpressed in Na group, accompanied by enhanced HIF-1 alpha immunostaining, lower eNOS expression, and unmodified alpha-SMA. Losartan and tempol increased FE(Na) in sodium overload group. Although losartan reduced Ang II and NF-kappaB staining and increased eNOS expression, it did not restore HIF-1 alpha expression and did not prevent inflammation. Conversely, tempol increased eNOS and natriuresis, restored HIF-1 alpha expression, and prevented inflammation. Early inflammatory markers observed in rats with acute sodium overload is associated with the imbalance between HIF-1 alpha and eNOS expression. While both losartan and tempol increased natriuresis and eNOS expression, only tempol was effective in restoring HIF-1 alpha expression and down-regulating TGF-beta1 and RANTES expression. The protective role of tempol, but not of losartan, in the inflammatory response may be associated with its greater antioxidant effects.
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Affiliation(s)
- María I Rosón
- School of Pharmacy and Biochemistry, Department of Pathophysiology, Pharmacology and Clinical Biochemistry, University of Buenos Aires, INFIBIOC, CONICET, Buenos Aires, Argentina.
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35
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Basset O, Deffert C, Foti M, Bedard K, Jaquet V, Ogier-Denis E, Krause KH. NADPH oxidase 1 deficiency alters caveolin phosphorylation and angiotensin II-receptor localization in vascular smooth muscle. Antioxid Redox Signal 2009; 11:2371-84. [PMID: 19309260 DOI: 10.1089/ars.2009.2584] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The superoxide-generating NADPH oxidase NOX1 is thought to be involved in signaling by the angiotensin II-receptor AT1R. However, underlying signaling steps are poorly understood. In this study, we investigated the effect of AngII on aortic smooth muscle from wild-type and NOX1-deficient mice. NOX1-deficient cells showed decreased basal ROS generation and did not produce ROS in response to AngII. Unexpectedly, AngII-dependent Ca(2+) signaling was markedly decreased in NOX1-deficient cells. Immunostaining demonstrated that AT1R was localized on the plasma membrane in wild-type, but intracellularly in NOX1-deficient cells. Immunohistochemistry and immunoblotting showed a decreased expression of AT1R in the aorta of NOX1-deficient mice. To investigate the basis of the abnormal AT1R targeting, we studied caveolin expression and phosphorylation. The amounts of total caveolin and of caveolae were not different in NOX1-deficient mice, but a marked decrease occurred in the phosphorylated form of caveolin. Exogenous H(2)O(2) or transfection of a NOX1 plasmid restored AngII responses in NOX1-deficient cells. Based on these findings, we propose that NOX1-derived reactive oxygen species regulate cell-surface expression of AT1R through mechanisms including caveolin phosphorylation. The lack cell-surface AT1R expression in smooth muscle could be involved in the decreased blood pressure in NOX1-deficient mice.
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MESH Headings
- Angiotensin II/genetics
- Angiotensin II/metabolism
- Animals
- Aorta/anatomy & histology
- Calcium/metabolism
- Caveolins/metabolism
- Cells, Cultured
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- NADH, NADPH Oxidoreductases/deficiency
- NADH, NADPH Oxidoreductases/genetics
- NADPH Oxidase 1
- Phosphorylation
- Reactive Oxygen Species/metabolism
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Signal Transduction/physiology
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Affiliation(s)
- Olivier Basset
- Department of Pathology and Immunology, Centre Medical Universitaire, University of Geneva, Geneva, Switzerland
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36
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Morinelli TA, Kendall RT, Luttrell LM, Walker LP, Ullian ME. Angiotensin II-induced cyclooxygenase 2 expression in rat aorta vascular smooth muscle cells does not require heterotrimeric G protein activation. J Pharmacol Exp Ther 2009; 330:118-24. [PMID: 19351865 PMCID: PMC11047153 DOI: 10.1124/jpet.109.151829] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 04/06/2009] [Indexed: 01/04/2023] Open
Abstract
Angiotensin II (AngII) initiates cellular effects via its G protein-coupled angiotensin 1 (AT(1)) receptor (AT(1)R). Previously, we showed that AngII-induced expression of the prostanoid-producing enzyme cyclooxygenase 2 (COX-2) was dependent upon nuclear trafficking of activated AT(1)R. In the present study, mastoparan (an activator of G proteins), suramin (an inhibitor of G proteins), 1-[6-[[17beta-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122; a specific inhibitor of phospholipase C), and sarcosine(1)-Ile(4)-Ile(8)-AngII (SII-AngII; a G protein-independent AT(1)R agonist) were used to determine the involvement of G proteins and AT(1A)R trafficking in AngII-stimulated COX-2 protein expression in human embryonic kidney-293 cells stably expressing AT(1A)/green fluorescent protein receptors and cultured vascular smooth muscle cells, respectively. Mastoparan alone stimulated release of intracellular calcium and increased COX-2 expression. Preincubation with mastoparan inhibited AngII-induced calcium signaling without altering AngII-induced AT(1A)R trafficking, p42/44 extracellular signal-regulated kinase (ERK) activation, or COX-2 expression. Suramin or U73122 had no significant effect on their own; they did not inhibit AngII-induced AT(1A)R trafficking, p42/44 ERK activation, or COX-2 expression; but they did inhibit AngII-induced calcium responses. SII-AngII stimulated AT(1A)R trafficking and increased COX-2 protein expression without activating intracellular calcium release. These data suggest that G protein activation results in increased COX-2 protein expression, but AngII-induced COX-2 expression seems to occur independently of G protein activation.
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MESH Headings
- 1-Sarcosine-8-Isoleucine Angiotensin II/pharmacology
- Angiotensin II/physiology
- Animals
- Aorta/enzymology
- Aorta/metabolism
- Aorta/physiology
- Cell Line
- Cells, Cultured
- Cyclooxygenase 2/biosynthesis
- Cyclooxygenase 2/genetics
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Gene Expression Regulation, Enzymologic/drug effects
- Gene Expression Regulation, Enzymologic/physiology
- Heterotrimeric GTP-Binding Proteins/antagonists & inhibitors
- Heterotrimeric GTP-Binding Proteins/metabolism
- Humans
- Intercellular Signaling Peptides and Proteins
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/physiology
- Peptides/pharmacology
- Rats
- Wasp Venoms/pharmacology
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Affiliation(s)
- Thomas A Morinelli
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA.
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37
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38
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Gwathmey TM, Shaltout HA, Pendergrass KD, Pirro NT, Figueroa JP, Rose JC, Diz DI, Chappell MC. Nuclear angiotensin II type 2 (AT2) receptors are functionally linked to nitric oxide production. Am J Physiol Renal Physiol 2009; 296:F1484-93. [PMID: 19244399 DOI: 10.1152/ajprenal.90766.2008] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Expression of nuclear angiotensin II type 1 (AT(1)) receptors in rat kidney provides further support for the concept of an intracellular renin-angiotensin system. Thus we examined the cellular distribution of renal ANG II receptors in sheep to determine the existence and functional roles of intracellular ANG receptors in higher order species. Receptor binding was performed using the nonselective ANG II antagonist (125)I-[Sar(1),Thr(8)]-ANG II ((125)I-sarthran) with the AT(1) antagonist losartan (LOS) or the AT(2) antagonist PD123319 (PD) in isolated nuclei (NUC) and plasma membrane (PM) fractions obtained by differential centrifugation or density gradient separation. In both fetal and adult sheep kidney, PD competed for the majority of cortical NUC (> or =70%) and PM (> or =80%) sites while LOS competition predominated in medullary NUC (> or =75%) and PM (> or =70%). Immunodetection with an AT(2) antibody revealed a single approximately 42-kDa band in both NUC and PM extracts, suggesting a mature molecular form of the NUC receptor. Autoradiography for receptor subtypes localized AT(2) in the tubulointerstitium, AT(1) in the medulla and vasa recta, and both AT(1) and AT(2) in glomeruli. Loading of NUC with the fluorescent nitric oxide (NO) detector DAF showed increased NO production with ANG II (1 nM), which was abolished by PD and N-nitro-l-arginine methyl ester, but not LOS. Our studies demonstrate ANG II receptor subtypes are differentially expressed in ovine kidney, while nuclear AT(2) receptors are functionally linked to NO production. These findings provide further evidence of a functional intracellular renin-angiotensin system within the kidney, which may represent a therapeutic target for the regulation of blood pressure.
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Affiliation(s)
- Tanya M Gwathmey
- Hypertension and Vascular Research Center, Wake Forest Univ. School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157, USA.
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39
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Navar LG, Arendshorst WJ, Pallone TL, Inscho EW, Imig JD, Bell PD. The Renal Microcirculation. Compr Physiol 2008. [DOI: 10.1002/cphy.cp020413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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40
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Hume GE, Radford-Smith GL. ACE inhibitors and angiotensin II receptor antagonists in Crohn's disease management. Expert Rev Gastroenterol Hepatol 2008; 2:645-51. [PMID: 19072342 DOI: 10.1586/17474124.2.5.645] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An increasing repertoire of therapeutic indications for the angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists has followed an explosion of research exploring the role of the proinflammatory and profibrotic renin-angiotensin-aldosterone system in numerous organ systems. This evidence also implicates the renin-angiotensin-aldosterone system in the pathogenesis of other chronic inflammatory and fibrotic disorders, such as Crohn's disease. While the research to date supports this hypothesis, further investigation of the renin-angiotensin-aldosterone system in human Crohn's disease is required before these agents can realistically be investigated in human trials.
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Affiliation(s)
- Georgia E Hume
- Inflammatory Bowel Disease Laboratory, Royal Brisbane and Women's Research Foundation, Brisbane, Australia.
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Morinelli TA, Walker LP, Ullian ME. COX-2 expression stimulated by Angiotensin II depends upon AT1 receptor internalization in vascular smooth muscle cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:1048-54. [DOI: 10.1016/j.bbamcr.2008.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 01/03/2008] [Accepted: 01/14/2008] [Indexed: 11/17/2022]
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42
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The apelin–APJ system in heart failure. Biochem Pharmacol 2008; 75:1882-92. [DOI: 10.1016/j.bcp.2007.12.015] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 12/21/2007] [Accepted: 12/26/2007] [Indexed: 12/17/2022]
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Raizada V, Skipper B, Luo W, Griffith J. Intracardiac and intrarenal renin-angiotensin systems: mechanisms of cardiovascular and renal effects. J Investig Med 2008; 55:341-59. [PMID: 18062896 DOI: 10.2310/6650.2007.00020] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The renin-angiotensin system (RAS) is a hormonal system that controls body fluid volume, blood pressure, and cardiovascular function in both health and disease. Various tissues, including the heart and kidneys, possess individual locally regulated RASs. In each RAS, the substrate protein angiotensinogen is cleaved by the peptidases renin and angiotensin-converting enzyme to form the biologically active product angiotensin II, which acts as an intracrine cardiac and renal hormone. The components of each RAS, including aldosterone (ALDO), may be produced locally and/or may be delivered by or sequestered from the circulation. Overactivity of the cardiac RAS has been associated with cardiac diseases, including cardiac hypertrophy due to volume and/or pressure overload, heart failure, coronary artery disease with myocardial infarction, and hypertension. Overactivity of the renal RAS has been associated with various kidney diseases, including nephropathies and renal artery stenosis. The principal effects of an overactive RAS include the generation of reactive oxygen species, which leads to "oxidative stress," activation of the nuclear transcription factor kappaB, and stimulation of pathways and genes that promote vasoconstriction, endothelial dysfunction, cell hypertrophy, fibroblast proliferation, inflammation, excess extracellular matrix deposition, atherosclerosis, and thrombosis. It has been suggested that oxidative stress is the central mechanism underlying the pathogenesis of RAS-related and ALDO-related chronic cardiovascular and renal tissue injury and of cardiac arrhythmias and conduction disturbances.
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Affiliation(s)
- Veena Raizada
- Department of Internal Medicine, University of New Mexico, Albuquerque, NM 87131-0001, USA.
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Li XC, Zhuo JL. Intracellular ANG II directly induces in vitro transcription of TGF-beta1, MCP-1, and NHE-3 mRNAs in isolated rat renal cortical nuclei via activation of nuclear AT1a receptors. Am J Physiol Cell Physiol 2008; 294:C1034-45. [PMID: 18256274 PMCID: PMC2410035 DOI: 10.1152/ajpcell.00432.2007] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The present study tested the hypothesis that intracellular ANG II directly induces transcriptional effects by stimulating AT(1a) receptors in the nucleus of rat renal cortical cells. Intact nuclei were freshly isolated from the rat renal cortex, and transcriptional responses to ANG II were studied using in vitro RNA transcription assays and semiquantitative RT-PCR. High-power phase-contrast micrographs showed that isolated nuclei were encircled by an intact nuclear envelope and stained strongly by the DNA marker 4',6-diamidino-2-phenylindole, but not by the membrane or endosomal markers. Fluorescein isothiocyanate-labeled ANG II and [(125)I]Val(5)-ANG II binding confirmed the presence of ANG II receptors in the nuclei with a predominance of AT(1) receptors. RT-PCR showed that AT(1a) mRNA expression was threefold greater than AT(1b) receptor mRNAs in these nuclei. In freshly isolated nuclei, ANG II increased in vitro [alpha-(32)P]CTP incorporation in a concentration-dependent manner, and the effect was confirmed by autoradiography and RNA electrophoresis. ANG II markedly increased in vitro transcription of mRNAs for transforming growth factor-beta1 by 143% (P < 0.01), macrophage chemoattractant protein-1 by 89% (P < 0.01), and the sodium and hydrogen exchanger-3 by 110% (P < 0.01). These transcriptional effects of ANG II on the nuclei were completely blocked by the AT(1) receptor antagonist losartan (P < 0.01). By contrast, ANG II had no effects on transcription of angiotensinogen and glyceraldehyde-3-phosphate dehydrogenase mRNAs. Because these transcriptional effects of ANG II in isolated nuclei were induced by ANG II in the absence of cell surface receptor-mediated signaling and completely blocked by losartan, we concluded that ANG II may directly stimulate nuclear AT(1a) receptors to induce transcriptional responses that are associated with tubular epithelial sodium transport, cellular growth and hypertrophy, and proinflammatory cytokines.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin II/pharmacology
- Animals
- Chemokine CCL2/genetics
- Chemokine CCL2/metabolism
- Kidney Cortex/cytology
- Male
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 2/genetics
- Receptor, Angiotensin, Type 2/metabolism
- Sodium-Hydrogen Exchanger 3
- Sodium-Hydrogen Exchangers/genetics
- Sodium-Hydrogen Exchangers/metabolism
- Transcription, Genetic/drug effects
- Transforming Growth Factor beta1/genetics
- Transforming Growth Factor beta1/metabolism
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Affiliation(s)
- Xiao C. Li
- Laboratory of Receptor and Signal Transduction, Division of Hypertension and Vascular Research, Department of Internal Medicine, Henry Ford Hospital, Detroit, MI 48202
| | - Jia L. Zhuo
- Laboratory of Receptor and Signal Transduction, Division of Hypertension and Vascular Research, Department of Internal Medicine, Henry Ford Hospital, Detroit, MI 48202
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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The significance of brain aminopeptidases in the regulation of the actions of angiotensin peptides in the brain. Heart Fail Rev 2008; 13:299-309. [PMID: 18188697 DOI: 10.1007/s10741-007-9078-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Accepted: 12/21/2007] [Indexed: 01/05/2023]
Abstract
From the outset, the concept of a brain renin-angiotensin system (RAS) has been controversial and this controversy continues to this day. In addition to the unresolved questions as to the means by which, and location(s) where brain Ang II is synthesized, and the uncertainties regarding the functionality of the different subtypes of Ang II receptors in the brain, a new controversy has arisen with respect to the identity of the angiotensin peptide(s) that activate brain AT(1) receptors. While it has been known for some time that Ang III can activate Ang II receptors with equivalent or near-equivalent efficacy to Ang II, it has been proposed that in the brain, only Ang III is active. This proposal, which we have named "The Angiotensin III Hypothesis" states that Ang II must be converted to Ang III in order to activate brain AT(1) receptors. This review examines several aspects of the controversies regarding the brain RAS with a special focus on brain aminopeptidases, studies that either support or refute The Angiotensin III Hypothesis, and the implications of The Angiotensin III Hypothesis for the activity of the brain RAS. It also addresses the need for further research that can test The Angiotensin III Hypothesis and definitively identify the angiotensin peptide(s) that activate brain AT(1) receptor-mediated effects.
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Boivin B, Vaniotis G, Allen BG, Hébert TE. G protein-coupled receptors in and on the cell nucleus: a new signaling paradigm? J Recept Signal Transduct Res 2008; 28:15-28. [PMID: 18437627 DOI: 10.1080/10799890801941889] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Signaling from internalizing and endosomal receptors has almost become a classic GPCR paradigm in the last several years. However, it has become clear in recent years that GPCRs also elicit signals when resident at other subcellular sites including the endoplasmic reticulum, Golgi apparatus, and the nucleus. In this review we discuss the nature, function, and trafficking of nuclear GPCR signaling complexes, as well as potential sources of endogenous and exogenous ligands. Finally, we pose a series of questions that will need to be answered in the coming years to confirm and extend this as a new paradigm for GPCR signaling.
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Affiliation(s)
- Benoit Boivin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
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de Cavanagh EMV, Ferder L, Toblli JE, Piotrkowski B, Stella I, Fraga CG, Inserra F. Renal mitochondrial impairment is attenuated by AT1 blockade in experimental Type I diabetes. Am J Physiol Heart Circ Physiol 2007; 294:H456-65. [PMID: 18024545 DOI: 10.1152/ajpheart.00926.2007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To investigate whether ANG II type 1 (AT(1)) receptor blockade could protect kidney mitochondria in streptozotocin-induced Type 1 diabetes, we treated 8-wk-old male Sprague-Dawley rats with a single streptozotocin injection (65 mg/kg ip; STZ group), streptozotocin and drinking water containing either losartan (30 mg.kg(-1).day(-1); STZ+Los group) or amlodipine (3 mg.kg(-1).day(-1); STZ+Amlo group), or saline (intraperitoneally) and pure water (control group). Four-month-long losartan or amlodipine treatments started 30 days before streptozotocin injection to improve the antioxidant defenses. The number of renal lesions, plasma glucose and lipid levels, and proteinuria were higher and creatinine clearance was lower in STZ and STZ+Amlo compared with STZ+Los and control groups. Glycemia was higher in STZ+Los compared with control. Blood pressure, basal mitochondrial membrane potential and mitochondrial pyruvate content, and renal oxidized glutathione levels were higher and NADH/cytochrome c oxidoreductase activity was lower in STZ compared with the other groups. In STZ and STZ+Amlo groups, mitochondrial H(2)O(2) production rate was higher and uncoupling protein-2 content, cytochrome c oxidase activity, and renal glutathione level were lower than in STZ+Los and control groups. Mitochondrial nitric oxide synthase activity was higher in STZ+Amlo compared with the other groups. Mitochondrial pyruvate content and H(2)O(2) production rate negatively contributed to electron transfer capacity and positively contributed to renal lesions. Uncoupling protein-2 content negatively contributed to mitochondrial H(2)O(2) production rate and renal lesions. Renal glutathione reduction potential positively contributed to mitochondria electron transfer capacity. In conclusion, AT(1) blockade protects kidney mitochondria and kidney structure in streptozotocin-induced diabetes independently of blood pressure and glycemia.
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Affiliation(s)
- Elena M V de Cavanagh
- Department of Nutrition, University of California, One Shields Avenue, Davis, CA 95616, USA
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Kumar R, Singh VP, Baker KM. The intracellular renin-angiotensin system: a new paradigm. Trends Endocrinol Metab 2007; 18:208-14. [PMID: 17509892 DOI: 10.1016/j.tem.2007.05.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 04/11/2007] [Accepted: 05/04/2007] [Indexed: 11/19/2022]
Abstract
More than a century after its discovery, the physiological implications of the renin-angiotensin system (RAS) continue to expand, with the identification of new components, functions and subsystems. These advancements have led to better management and understanding of a broad range of cardiovascular and metabolic disorders. The RAS has traditionally been viewed as a circulatory system, involved in the short-term regulation of volume and blood pressure homeostasis. Recently, local RASs have been described as regulators of chronic tissue effects. Most recently, studies have provided evidence of a complete, functional RAS within cells, described as an 'intracrine' or intracellular system. A more comprehensive understanding of the intracellular RAS provides for new strategies in system regulation and a more efficacious approach to the management of RAS-related diseases.
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Affiliation(s)
- Rajesh Kumar
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M Health Science Center, College of Medicine, Temple, TX 76508, USA
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50
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Re R. Intracellular renin-angiotensin system: the tip of the intracrine physiology iceberg. Am J Physiol Heart Circ Physiol 2007; 293:H905-6. [PMID: 17526648 DOI: 10.1152/ajpheart.00552.2007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Richard Re
- Research Division, Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
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