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Steckelings UM, Widdop RE, Sturrock ED, Lubbe L, Hussain T, Kaschina E, Unger T, Hallberg A, Carey RM, Sumners C. The Angiotensin AT 2 Receptor: From a Binding Site to a Novel Therapeutic Target. Pharmacol Rev 2022; 74:1051-1135. [PMID: 36180112 PMCID: PMC9553111 DOI: 10.1124/pharmrev.120.000281] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/19/2022] [Accepted: 06/27/2022] [Indexed: 11/22/2022] Open
Abstract
Discovered more than 30 years ago, the angiotensin AT2 receptor (AT2R) has evolved from a binding site with unknown function to a firmly established major effector within the protective arm of the renin-angiotensin system (RAS) and a target for new drugs in development. The AT2R represents an endogenous protective mechanism that can be manipulated in the majority of preclinical models to alleviate lung, renal, cardiovascular, metabolic, cutaneous, and neural diseases as well as cancer. This article is a comprehensive review summarizing our current knowledge of the AT2R, from its discovery to its position within the RAS and its overall functions. This is followed by an in-depth look at the characteristics of the AT2R, including its structure, intracellular signaling, homo- and heterodimerization, and expression. AT2R-selective ligands, from endogenous peptides to synthetic peptides and nonpeptide molecules that are used as research tools, are discussed. Finally, we summarize the known physiological roles of the AT2R and its abundant protective effects in multiple experimental disease models and expound on AT2R ligands that are undergoing development for clinical use. The present review highlights the controversial aspects and gaps in our knowledge of this receptor and illuminates future perspectives for AT2R research. SIGNIFICANCE STATEMENT: The angiotensin AT2 receptor (AT2R) is now regarded as a fully functional and important component of the renin-angiotensin system, with the potential of exerting protective actions in a variety of diseases. This review provides an in-depth view of the AT2R, which has progressed from being an enigma to becoming a therapeutic target.
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Affiliation(s)
- U Muscha Steckelings
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert E Widdop
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Edward D Sturrock
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Lizelle Lubbe
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Tahir Hussain
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Elena Kaschina
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Thomas Unger
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Anders Hallberg
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Robert M Carey
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
| | - Colin Sumners
- Institute of Molecular Medicine, Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark (U.M.S.); Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Clayton, Victoria, Australia (R.E.W.); Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Republic of South Africa (E.D.S., L.L.); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas (T.H.); Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Institute of Pharmacology, Cardiovascular-Metabolic-Renal (CMR) Research Center, DZHK (German Centre for Cardiovascular Research), Berlin, Germany (E.K.); CARIM - School for Cardiovascular Diseases, Maastricht University, The Netherlands (T.U.); Department of Medicinal Chemistry, Faculty of Pharmacy, Uppsala University, Uppsala, Sweden (A.H.); Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia (R.M.C.); and Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida (C.S.)
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Inverse Salt Sensitivity of Blood Pressure: Mechanisms and Potential Relevance for Prevention of Cardiovascular Disease. Curr Hypertens Rep 2022; 24:361-374. [PMID: 35708819 DOI: 10.1007/s11906-022-01201-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE OF REVIEW To review the etiology of inverse salt sensitivity of blood pressure (BP). RECENT FINDINGS Both high and low sodium (Na+) intake can be associated with increased BP and cardiovascular morbidity and mortality. However, little is known regarding the mechanisms involved in the increase in BP in response to low Na+ intake, a condition termed inverse salt sensitivity of BP, which affects approximately 15% of the adult population. The renal proximal tubule is important in regulating up to 70% of renal Na+ transport. The renin-angiotensin and renal dopaminergic systems play both synergistic and opposing roles in the regulation of Na+ transport in this nephron segment. Clinical studies have demonstrated that individuals express a "personal salt index" (PSI) that marks whether they are salt-resistant, salt-sensitive, or inverse salt-sensitive. Inverse salt sensitivity results in part from genetic polymorphisms in various Na+ regulatory genes leading to a decrease in natriuretic activity and an increase in renal tubular Na+ reabsorption leading to an increase in BP. This article reviews the potential mechanisms of a new pathophysiologic entity, inverse salt sensitivity of BP, which affects approximately 15% of the general adult population.
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Angiotensin Type-2 Receptors: Transducers of Natriuresis in the Renal Proximal Tubule. Int J Mol Sci 2022; 23:ijms23042317. [PMID: 35216442 PMCID: PMC8877933 DOI: 10.3390/ijms23042317] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 12/18/2022] Open
Abstract
Angiotensin II (Ang II) type-2 receptors (AT2R) are expressed in the adult kidney, prominently in renal proximal tubule cells (RPTCs), and play an important role in opposing renal sodium (Na+) retention induced by Ang II stimulation of Ang II type-1 receptor (AT1R). Natriuresis induced by AT1R blockade is due at least in part to AT2R activation and whole body deletion of AT2Rs reduces the natriuretic response to increased blood pressure (BP). The major endogenous AT2R agonist mediating the natriuretic response is Ang III, the Ang II heptapeptide metabolite generated by aminopeptidase A, and the principal nephron site mediating inhibition of Na+ reabsorption by the AT2R is the renal proximal tubule (RPT). AT2Rs induce natriuresis via a bradykinin, nitric oxide and cyclic GMP (cGMP) signaling cascade. Recent studies demonstrated a key role for protein phosphatase 2A (PP2A) in the AT2R-mediated natriuretic response upstream of cGMP. By inducing natriuresis, AT2Rs lower BP in the Ang II-infusion model of hypertension. PP2A activation and the natriuretic response to AT2R stimulation are defective in spontaneously hypertensive rats, a model of primary hypertension in humans. AT2R agonists are candidates for proximal tubule natriuretic agents in Na+ and fluid retention disorders.
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Kemp BA, Howell NL, Gildea JJ, Keller SR, Brautigan DL, Carey RM. Renal AT 2 Receptors Mediate Natriuresis via Protein Phosphatase PP2A. Circ Res 2022; 130:96-111. [PMID: 34794320 PMCID: PMC8741733 DOI: 10.1161/circresaha.121.319519] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND How signals from activated angiotensin type-2 receptors (AT2R) mediate inhibition of sodium ion (Na+) reabsorption in renal proximal tubule cells is currently unknown. Protein phosphatases including PP2A (protein phosphatase 2A) have been implicated in AT2R signaling in tissues other than kidney. We investigated whether inhibition of protein phosphatase PP2A reduced AT2R-mediated natriuresis and evaluated changes in PP2A activity and localization after renal AT2R activation in normal 4- and 10-week-old control Wistar-Kyoto rats and 4-week-old prehypertensive and 10-week-old hypertensive spontaneously hypertensive rats. METHODS AND RESULTS In Wistar-Kyoto rats, direct renal interstitial administration of selective AT2R nonpeptide agonist Compound-21 (C-21) increased renal interstitial cyclic GMP (cGMP) levels, urine Na+ excretion, and simultaneously increased PP2A activity ≈2-fold in homogenates of renal cortical tubules. The cyclic GMP and natriuretic responses were abolished by concurrent renal interstitial administration of protein phosphatase inhibitor calyculin A. In renal proximal tubule cells in response to C-21, PP2A subunits A, B55α and C, but not B56γ, were recruited to apical plasma membranes together with AT2Rs. Calyculin A treatment abolished C-21-induced translocation of both AT2R and PP2A regulatory subunit B55α to apical plasma membranes. Immunoprecipitation of AT2R solubilized from renal cortical homogenates demonstrated physical association of AT2R with PP2A A, B55α, and C but not B56γ subunits. In contrast, in spontaneously hypertensive rats, administration of C-21 did not alter urine Na+ excretion or PP2A activity and failed to translocate AT2Rs and PP2A subunits to apical plasma membranes. CONCLUSIONS In renal proximal tubule cells of Wistar-Kyoto rats, PP2A is activated and PP2A subunits AB55αC are recruited to C-21-activated AT2Rs during induction of natriuresis. This response is defective in prehypertensive and hypertensive spontaneously hypertensive rats, presenting a potential novel therapeutic target for treating renal Na+ retention and hypertension.
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Affiliation(s)
- Brandon A. Kemp
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA
| | - Nancy L. Howell
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA
| | - John J. Gildea
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA
| | - Susanna R. Keller
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA
| | - David L. Brautigan
- Department of Microbiology, Immunology & Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA
| | - Robert M. Carey
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA
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Garcia-Garrote M, Parga JA, Labandeira PJ, Labandeira-Garcia JL, Rodriguez-Pallares J. Dopamine regulates adult neurogenesis in the ventricular-subventricular zone via dopamine D3 angiotensin type 2 receptor interactions. Stem Cells 2021; 39:1778-1794. [PMID: 34521155 DOI: 10.1002/stem.3457] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 08/27/2021] [Indexed: 12/20/2022]
Abstract
Adult neurogenesis is a dynamic and highly regulated process and different studies suggest that dopamine modulates ventricular-subventricular zone (V-SVZ) neurogenesis. However, the specific role of dopamine and the mechanisms/factors underlying its effects on physiological and pathological conditions such as Parkinson's disease (PD) are not fully understood. Recent studies have described counter-regulatory interactions between renin-angiotensin system (RAS) and dopamine in peripheral tissues and in the nigrostriatal system. We have previously demonstrated that angiotensin receptors regulate proliferation and generation of neuroblasts in the rodent V-SVZ. However, possible interactions between dopamine receptors and RAS in the V-SVZ and their role in alterations of neurogenesis in animal models of PD have not been investigated. In V-SVZ cultures, activation of dopamine receptors induced changes in the expression of angiotensin receptors. Moreover, dopamine, via D2-like receptors and particularly D3 receptors, increased generation of neurospheres derived from the V-SVZ and this effect was mediated by angiotensin type-2 (AT2) receptors. In rats, we observed a marked reduction in proliferation and generation of neuroblasts in the V-SVZ of dopamine-depleted animals, and inhibition of AT1 receptors or activation of AT2 receptors restored proliferation and generation of neuroblasts to control levels. Moreover, intrastriatal mesencephalic grafts partially restored proliferation and generation of neuroblasts observed in the V-SVZ of dopamine-depleted rats. Our data revealed that dopamine and angiotensin receptor interactions play a major role in the regulation of V-SVZ and suggest potential beneficial effects of RAS modulators on the regulation of adult V-SVZ neurogenesis.
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Affiliation(s)
- Maria Garcia-Garrote
- Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Juan A Parga
- Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Pablo J Labandeira
- Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Jose Luis Labandeira-Garcia
- Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jannette Rodriguez-Pallares
- Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), IDIS, University of Santiago de Compostela, Santiago de Compostela, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
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Luzes R, Crisóstomo T, Silva PA, Iack R, de Abreu VG, Francischetti EA, Vieyra A. Angiotensin-(3-4) normalizes blood pressure, decreases Na + and energy intake, but preserves urinary Na + excretion in overweight hypertensive rats. Biochim Biophys Acta Mol Basis Dis 2020; 1867:166012. [PMID: 33212189 DOI: 10.1016/j.bbadis.2020.166012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/26/2020] [Accepted: 11/10/2020] [Indexed: 01/13/2023]
Abstract
Hypertension, one of the most common and severe comorbidities of obesity and overweight, is a worldwide epidemic affecting over 30% of the population. We induced overweight in young male rats (aged 58 days) by exposure to a hypercaloric high lipid (HL) diet in which 70% of the calories originated from fat. The HL diet also contained 33 or 57% higher Na+ than the control (CTR) diet. Over the following weeks the HL rats gradually became overweight (490 ± 12 g vs 427 ± 7 g in the CTR group after 15 weeks) with high visceral fat. They developed elevated systolic blood pressure (SBP) (141 ± 1.9 mmHg), which was fully restored to CTR values (128 ± 1.1 mmHg) by oral administration of Ang-(3-4) (Val-Tyr), the shortest renin-angiotensin-derived peptide. The overweight rats had lower plasma Na+ concentration that augmented to CTR values by Ang-(3-4) treatment. Na+ ingestion was depressed by 40% as result of the Ang-(3-4) treatment, whereas the urinary excretion of Na+ (UNaV) remained unmodified. The preservation of UNaV after Ang-(3-4) treatment - despite the sharp decrease in the dietary Na+ intake - can be ascribed to the normalization of renal type 1 angiotensin II receptors and Na+-transporting ATPases, both up-regulated in overweight rats. These renal effects complete a counterregulatory action on elevated renin-angiotensin activity that allows the high SBP to be normalized and body Na+ homeostasis to be restored concomitantly in overweight rats.
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Affiliation(s)
- Rafael Luzes
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Graduate Program in Translational Biomedicine, University of Grande Rio, Duque de Caxias, Brazil
| | - Thuany Crisóstomo
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paulo A Silva
- Graduate Program in Translational Biomedicine, University of Grande Rio, Duque de Caxias, Brazil
| | - Roxane Iack
- Graduate Program in Translational Biomedicine, University of Grande Rio, Duque de Caxias, Brazil
| | | | - Emílio A Francischetti
- Graduate Program in Translational Biomedicine, University of Grande Rio, Duque de Caxias, Brazil
| | - Adalberto Vieyra
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Graduate Program in Translational Biomedicine, University of Grande Rio, Duque de Caxias, Brazil; National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
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CHANGES IN THE STRUCTURAL CHARACTERISTICS OF PLATELETS AND LEUKOCYTES IN PATIENTS WITH ARTERIAL HYPERTENSION UNDER THE INFLUENCE OF A HYDROGEN SULFIDE DONOR. EUREKA: HEALTH SCIENCES 2020. [DOI: 10.21303/2504-5679.2020.001288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aim of the research. The influence of hydrogen sulphide donor on some structural characteristics of platelets and leukocytes in patients with arterial hypertension was studied.
Materials and methods. The survey involved patients (men) with hypertension aged 30–60 years, who were divided into 2 age groups: 30–40 years and 40–60 years. Control groups (healthy men without signs of hypertension) were randomized by age. Electron microscopic and morphometric research methods were used in the investigation.
Results. Electron microscopic and morphometric evaluation of the structure of these cells has shown that it undergoes significant changes depending on patient’s age. In the persons of the older age group, the cells contained a reduced number of dense δ-granules and increased – α-granules, which may indicate an impaired serotonin balance and increased susceptibility to thrombogenesis. The younger age group presented structural changes in platelets in a reversed order. Adding hydrogen sulphide donor at a dose of 400 mg per day (phytopreparation Full Spectrum Garlic – Swanson Health Products, USA) to the traditional therapy of arterial hypertension leads to positive changes in the ultrastructure of the studied cells aimed at restoring the balance of serotonin, reducing the tendency to thrombogenesis, increasing the energy capacity of the mitochondrial apparatus.
Conclusion. The obtained results indicate that detected effects significantly depend on the patient’s age (younger people respond more intensively) and the duration of the use of hydrogen sulphide donor (longer use is accompanied by more pronounced positive changes).
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Kemp BA, Howell NL, Gildea JJ, Keller SR, Carey RM. Identification of a Primary Renal AT 2 Receptor Defect in Spontaneously Hypertensive Rats. Circ Res 2020; 126:644-659. [PMID: 31997705 DOI: 10.1161/circresaha.119.316193] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
RATIONALE Previous studies identified a defect in Ang III (angiotensin III [des-aspartyl1-angiotensin II])-elicited AT2R (Ang type-2 receptor)-mediated natriuresis in renal proximal tubule cells of spontaneously hypertensive rats (SHR). OBJECTIVE This study aimed to delineate in prehypertensive SHR kidneys the receptor or postreceptor defect causing impaired AT2R signaling and renal sodium (Na+) retention by utilizing the selective AT2R agonist compound-21 (C-21). METHODS AND RESULTS Female 4-week-old Wistar Kyoto and SHR rats were studied after 24-hour systemic AT1R (Ang II type-1 receptor) blockade. Left kidneys received 30-minute renal interstitial infusions of vehicle followed by C-21 (20, 40, and 60 ng/[kg·min], each dose 30 minutes). Right kidneys received vehicle infusions. In Wistar Kyoto, C-21 dose-dependently increased urine Na+ excretion from 0.023±0.01 to 0.064±0.02, 0.087±0.01, and 0.089±0.01 µmol/min (P=0.008, P<0.0001, and P<0.0001, respectively) and renal interstitial fluid levels of AT2R downstream signaling molecule cGMP (cyclic guanosine 3',5' monophosphate) from 0.91±0.3 to 3.1±1.0, 5.9±1.2 and 5.3±0.5 fmol/mL (P=nonsignificant, P<0.0001, and P<0.0001, respectively). In contrast, C-21 did not increase urine Na+ excretion or renal interstitial cGMP in SHR. Mean arterial pressure was slightly higher in SHR but within the normotensive range and unaffected by C-21. In Wistar Kyoto, but not SHR, C-21 induced AT2R translocation to apical plasma membranes of renal proximal tubule cells, internalization/inactivation of NHE-3 (sodium-hydrogen exchanger-3) and Na+/K+ATPase (sodium-potassium-atpase) and phosphorylation of AT2R-cGMP downstream signaling molecules Src (Src family kinase), ERK (extracellular signal-related kinase), and VASP (vasodilator-stimulated phosphoprotein). To test whether cGMP could bypass the natriuretic defect in SHR, we infused 8-bromo-cGMP. This restored natriuresis, Na+ transporter internalization/inactivation, and Src and VASP phosphorylation, but not apical plasma membrane AT2R recruitment. In contrast, 8-bromo-cAMP administration had no effect on natriuresis or AT2R recruitment in SHR. CONCLUSIONS The results demonstrate a primary renal proximal tubule cell AT2R natriuretic defect in SHR that may contribute to the development of hypertension. Since the defect is abrogated by exogenous intrarenal cGMP, the renal cGMP pathway may represent a viable target for the treatment of hypertension. Visual Overview: An online visual overview is available for this article.
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Affiliation(s)
- Brandon A Kemp
- From the Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville (B.A.K., N.L.H., S.R.K., R.M.C.)
| | - Nancy L Howell
- From the Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville (B.A.K., N.L.H., S.R.K., R.M.C.)
| | - John J Gildea
- Department of Pathology, University of Virginia Health System, Charlottesville (J.J.G.)
| | - Susanna R Keller
- From the Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville (B.A.K., N.L.H., S.R.K., R.M.C.)
| | - Robert M Carey
- From the Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville (B.A.K., N.L.H., S.R.K., R.M.C.)
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9
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Gildea JJ, Xu P, Kemp BA, Carey RM, Jose PA, Felder RA. The Dopamine D 1 Receptor and Angiotensin II Type-2 Receptor are Required for Inhibition of Sodium Transport Through a Protein Phosphatase 2A Pathway. Hypertension 2019; 73:1258-1265. [PMID: 31030607 DOI: 10.1161/hypertensionaha.119.12705] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Activation of the renal D1R (dopamine D1-like receptor) or AT2R (angiotensin II type-2 receptor), individually or both, simultaneously, is necessary in the normal regulation of renal sodium (Na+) transport and blood pressure. However, little is known regarding the precise mechanism of this interaction. Pharmacological stimulation, membrane biotinylation, and cell surface immunofluorescence were used to study the effect of the D1R/AT2R interaction in human renal proximal tubule cells. D1R activation of GαS stimulates AC (adenylyl cyclase) and induces apical plasma membrane recruitment of AT2Rs. We now show for the first time the reciprocal reaction, AT2R stimulation with Ang III (angiotensin III) leads to the apical plasma membrane recruitment of the D1R. The cell-permeable second messenger analogs of cAMP (8-Br-cAMP) or cGMP (8-Br-cGMP) induce translocation of both D1R and AT2R to the plasma membrane. Inhibition of PKA (protein kinase A) with Rp-cAMPS and PKG (protein kinase G) with Rp-8-CPT-cGMPS blocks D1R and AT2R recruitment, respectively, indicating that both PKA and PKG are necessary for D1R and AT2R trafficking. Both 8-Br-cAMP and 8-Br-cGMP activate PP2A (protein phosphatase 2A), which is necessary for both plasma membrane recruitment of D1R and AT2R and the inhibition of sodium hydrogen exchanger 3-dependent Na+ transport. These studies provide insights into the D1R/AT2R transregulation mechanisms that play a crucial role in maintaining Na+ and ultimately blood pressure homeostasis.
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Affiliation(s)
- John J Gildea
- From the Departments of Pathology (J.J.G., P.X., R.A.F.)
| | - Peng Xu
- From the Departments of Pathology (J.J.G., P.X., R.A.F.)
| | - Brandon A Kemp
- Medicine (B.A.K., R.M.C.), University of Virginia, Charlottesville, VA
| | - Robert M Carey
- Medicine (B.A.K., R.M.C.), University of Virginia, Charlottesville, VA
| | - Pedro A Jose
- Division of Renal Disease & Hypertension Departments of Medicine and Pharmacology/Physiology, The George Washington University School of Medicine and Health Sciences, Washington DC (P.A.J.)
| | - Robin A Felder
- From the Departments of Pathology (J.J.G., P.X., R.A.F.)
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Forrester SJ, Booz GW, Sigmund CD, Coffman TM, Kawai T, Rizzo V, Scalia R, Eguchi S. Angiotensin II Signal Transduction: An Update on Mechanisms of Physiology and Pathophysiology. Physiol Rev 2018; 98:1627-1738. [PMID: 29873596 DOI: 10.1152/physrev.00038.2017] [Citation(s) in RCA: 662] [Impact Index Per Article: 110.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The renin-angiotensin-aldosterone system plays crucial roles in cardiovascular physiology and pathophysiology. However, many of the signaling mechanisms have been unclear. The angiotensin II (ANG II) type 1 receptor (AT1R) is believed to mediate most functions of ANG II in the system. AT1R utilizes various signal transduction cascades causing hypertension, cardiovascular remodeling, and end organ damage. Moreover, functional cross-talk between AT1R signaling pathways and other signaling pathways have been recognized. Accumulating evidence reveals the complexity of ANG II signal transduction in pathophysiology of the vasculature, heart, kidney, and brain, as well as several pathophysiological features, including inflammation, metabolic dysfunction, and aging. In this review, we provide a comprehensive update of the ANG II receptor signaling events and their functional significances for potential translation into therapeutic strategies. AT1R remains central to the system in mediating physiological and pathophysiological functions of ANG II, and participation of specific signaling pathways becomes much clearer. There are still certain limitations and many controversies, and several noteworthy new concepts require further support. However, it is expected that rigorous translational research of the ANG II signaling pathways including those in large animals and humans will contribute to establishing effective new therapies against various diseases.
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Affiliation(s)
- Steven J Forrester
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - George W Booz
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Curt D Sigmund
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Thomas M Coffman
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Tatsuo Kawai
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Victor Rizzo
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Rosario Scalia
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
| | - Satoru Eguchi
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University , Philadelphia, Pennsylvania ; Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center , Jackson, Mississippi ; Department of Pharmacology, Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa , Iowa City, Iowa ; and Duke-NUS, Singapore and Department of Medicine, Duke University Medical Center , Durham, North Carolina
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Abstract
PURPOSE OF REVIEW Angiotensin II is a main regulator of kidney function. Renal actions mediated by the angiotensin AT1 receptor have been well known for many years. In contrast, several details of angiotensin AT2 receptor actions in kidney physiology and pathophysiology were only described very recently. These findings are reviewed in this article. RECENT FINDINGS Regarding the role of the angiotensin AT2 receptor in kidney physiology, a major recent finding was that the AT2 receptor-mediated inhibition of Na-H exchanger-3 and Na/K-ATPase in the renal proximal tubules is caused by internalisation of these transporters, thus reducing reabsorption and increasing natriuresis/diuresis. Regarding renal pathology, several studies demonstrated an attenuation of renal injury caused by diabetes or by obesity with or without high-salt diet through anti-inflammatory, antifibrotic, and antioxidative mechanisms. Generally, AT2 receptor expression seems increased and AT2 receptor-mediated effects stronger in female and obese animals. SUMMARY The recent findings about the role of the angiotensin AT2 receptor in renal health and disease strongly suggest that pharmacological targeting of this receptor with selective agonists is a promising therapeutic strategy for inducing diuresis/natriuresis (also additive to established diuretics) and for the treatment of diabetic nephropathy or kidney disease of other pathogenesis.
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12
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Gildea JJ, Xu P, Kemp BA, Carlson JM, Tran HT, Bigler Wang D, Langouët-Astrié CJ, McGrath HE, Carey RM, Jose PA, Felder RA. Sodium bicarbonate cotransporter NBCe2 gene variants increase sodium and bicarbonate transport in human renal proximal tubule cells. PLoS One 2018; 13:e0189464. [PMID: 29642240 PMCID: PMC5895442 DOI: 10.1371/journal.pone.0189464] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/28/2017] [Indexed: 01/11/2023] Open
Abstract
RATIONALE Salt sensitivity of blood pressure affects >30% of the hypertensive and >15% of the normotensive population. Variants of the electrogenic sodium bicarbonate cotransporter NBCe2 gene, SLC4A5, are associated with increased blood pressure in several ethnic groups. SLC4A5 variants are also highly associated with salt sensitivity, independent of hypertension. However, little is known about how NBCe2 contributes to salt sensitivity, although NBCe2 regulates renal tubular sodium bicarbonate transport. We hypothesized that SLC4A5 rs10177833 and rs7571842 increase NBCe2 expression and human renal proximal tubule cell (hRPTC) sodium transport and may be a cause of salt sensitivity of blood pressure. OBJECTIVE To characterize the hRPTC ion transport of wild-type (WT) and homozygous variants (HV) of SLC4A5. METHODS AND RESULTS The expressions of NBCe2 mRNA and protein were not different between hRPTCs carrying WT or HV SLC4A5 before or after dopaminergic or angiotensin (II and III) stimulation. However, luminal to basolateral sodium transport, NHE3 protein, and Cl-/HCO3- exchanger activity in hRPTCs were higher in HV than WT SLC4A5. Increasing intracellular sodium enhanced the apical location of NBCe2 in HV hRPTCs (4.24±0.35% to 11.06±1.72% (P<0.05, N = 3, 2-way ANOVA, Holm-Sidak test)) as determined by Total Internal Reflection Fluorescence Microscopy (TIRFM). In hRPTCs isolated from kidney tissue, increasing intracellular sodium enhanced bicarbonate-dependent pH recovery rate and increased NBCe2 mRNA and protein expressions to a greater extent in HV than WT SLC4A5 (+38.00±6.23% vs HV normal salt (P<0.01, N = 4, 2-way ANOVA, Holm-Sidak test)). In hRPTCs isolated from freshly voided urine, bicarbonate-dependent pH recovery was also faster in those from salt-sensitive and carriers of HV SLC4A5 than from salt-resistant and carriers of WT SLC4A5. The faster NBCe2-specific bicarbonate-dependent pH recovery rate in HV SCL4A5 was normalized by SLC4A5- but not SLC4A4-shRNA. The binding of purified hepatocyte nuclear factor type 4A (HNF4A) to DNA was increased in hRPTCs carrying HV SLC4A5 rs7571842 but not rs10177833. The faster NBCe2-specific bicarbonate-dependent pH recovery rate in HV SCL4A5 was abolished by HNF4A antagonists. CONCLUSION NBCe2 activity is stimulated by an increase in intracellular sodium and is hyper-responsive in hRPTCs carrying HV SLC4A5 rs7571842 through an aberrant HNF4A-mediated mechanism.
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Affiliation(s)
- John J. Gildea
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Peng Xu
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Brandon A. Kemp
- The University of Virginia Department of Medicine, Charlottesville, VA, United States of America
| | - Julia M. Carlson
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Hanh T. Tran
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Dora Bigler Wang
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | | | - Helen E. McGrath
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Robert M. Carey
- The University of Virginia Department of Medicine, Charlottesville, VA, United States of America
| | - Pedro A. Jose
- The George Washington University School of Medicine & Health Sciences, Department of Medicine, Division of Renal Disease and Hypertension and Department of Pharmacology and Physiology, Washington, DC, United States of America
| | - Robin A. Felder
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
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13
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Isobe-Sasaki Y, Fukuda M, Ogiyama Y, Sato R, Miura T, Fuwa D, Mizuno M, Matsuoka T, Shibata H, Ito H, Ono M, Abe-Dohmae S, Kiyono K, Yamamoto Y, Kobori H, Michikawa M, Hayano J, Ohte N. Sodium balance, circadian BP rhythm, heart rate variability, and intrarenal renin-angiotensin-aldosterone and dopaminergic systems in acute phase of ARB therapy. Physiol Rep 2018; 5:5/11/e13309. [PMID: 28576855 PMCID: PMC5471446 DOI: 10.14814/phy2.13309] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 04/29/2017] [Accepted: 05/10/2017] [Indexed: 01/11/2023] Open
Abstract
We have revealed that even in humans, activated intrarenal renin–angiotensin–aldosterone system (RAAS) enhances tubular sodium reabsorption to facilitate salt sensitivity and nondipper rhythm of blood pressure (BP), and that angiotensin receptor blocker (ARB) could increase daytime urinary sodium excretion rate (UNaV) to produce lower sodium balance and restore nondipper rhythm. However, the sympathetic nervous system and intrarenal dopaminergic system can also contribute to renal sodium handling. A total of 20 patients with chronic kidney disease (61 ± 15 years) underwent 24‐h ambulatory BP monitoring before and during two‐day treatment with ARB, azilsartan. Urinary angiotensinogen excretion rate (UAGTV, μg/gCre) was measured as intrarenal RAAS; urinary dopamine excretion rate (UDAV, pg/gCre) as intrarenal dopaminergic system; heart rate variabilities (HRV, calculated from 24‐h Holter‐ECG) of non‐Gaussianity index λ25s as sympathetic nerve activity; and power of high‐frequency (HF) component or deceleration capacity (DC) as parasympathetic nerve activity. At baseline, glomerular filtration rate correlated inversely with UAGTV (r = −0.47, P = 0.04) and positively with UDAV (r = 0.58, P = 0.009). HF was a determinant of night/day BP ratio (β = −0.50, F = 5.8), rather than DC or λ25s. During the acute phase of ARB treatment, a lower steady sodium balance was not achieved. Increase in daytime UNaV preceded restoration of BP rhythm, accompanied by decreased UAGTV (r = −0.88, P = 0.05) and increased UDAV (r = 0.87, P = 0.05), but with no changes in HRVs. Diminished sodium excretion can cause nondipper BP rhythm. This was attributable to intrarenal RAAS and dopaminergic system and impaired parasympathetic nerve activity. During the acute phase of ARB treatment, cooperative effects of ARB and intrarenal dopaminergic system exert natriuresis to restore circadian BP rhythm.
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Affiliation(s)
- Yukako Isobe-Sasaki
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Michio Fukuda
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yoshiaki Ogiyama
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Ryo Sato
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Toshiyuki Miura
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Daisuke Fuwa
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Masashi Mizuno
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Tetsuhei Matsuoka
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiroko Shibata
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiroyuki Ito
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Minamo Ono
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Sumiko Abe-Dohmae
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Ken Kiyono
- Department of Mechanical Science and Bioengineering, Osaka University, Osaka, Japan
| | - Yoshiharu Yamamoto
- Department of Physical and Health Education, University of Tokyo Graduate School of Education, Tokyo, Japan
| | - Hiroyuki Kobori
- International University of Health and Welfare, Tokyo, Japan
| | - Makoto Michikawa
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Junichiro Hayano
- Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Nobuyuki Ohte
- Department of Cardio-Renal Medicine and Hypertension, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Lu X, Ye Z, Zheng S, Ren H, Zeng J, Wang X, Jose PA, Chen K, Zeng C. Long-Term Exposure of Fine Particulate Matter Causes Hypertension by Impaired Renal D 1 Receptor-Mediated Sodium Excretion via Upregulation of G-Protein-Coupled Receptor Kinase Type 4 Expression in Sprague-Dawley Rats. J Am Heart Assoc 2018; 7:e007185. [PMID: 29307864 PMCID: PMC5778966 DOI: 10.1161/jaha.117.007185] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/20/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Epidemiological evidence supports an important association between air pollution exposure and hypertension. However, the mechanisms are not clear. METHODS AND RESULTS Our present study found that long-term exposure to fine particulate matter (PM2.5) causes hypertension and impairs renal sodium excretion, which might be ascribed to lower D1 receptor expression and higher D1 receptor phosphorylation, accompanied with a higher G-protein-coupled receptor kinase type 4 (GRK4) expression. The in vivo results were confirmed in in vitro studies (ie, PM2.5 increased basal and decreased D1 receptor mediated inhibitory effect on Na+-K+ ATPase activity, decreased D1 receptor expression, and increased D1 receptor phosphorylation in renal proximal tubule cells). The downregulation of D1 receptor expression and function might be attributable to a higher GRK4 expression after the exposure of renal proximal tubule cells to PM2.5, because downregulation of GRK4 by small-interfering RNA reversed the D1 receptor expression and function. Because of the role of reactive oxygen species on D1 receptor dysfunction and its relationship with air pollution exposure, we determined plasma reactive oxygen species and found the levels higher in PM2.5-treated Sprague-Dawley rats. Inhibition of reactive oxygen species by tempol (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl) reduced blood pressure and increased sodium excretion in PM2.5-treated Sprague-Dawley rats, accompanied by an increase in the low D1 receptor expression, and decreased the hyperphosphorylated D1 receptor and GRK4 expression. CONCLUSIONS Our present study indicated that long-term exposure of PM2.5 increases blood pressure by decreasing D1 receptor expression and function; reactive oxygen species, via regulation of GRK4 expression, plays an important role in the pathogenesis of PM2.5-induced hypertension.
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Affiliation(s)
- Xi Lu
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
| | - Zhengmeng Ye
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
| | - Shuo Zheng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
| | - Hongmei Ren
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
| | - Jing Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
| | - Xinquan Wang
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
| | - Pedro A Jose
- Division of Renal Disease and Hypertension, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Ken Chen
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
- Department of Cardiology, Chengdu Military General Hospital, Chengdu, Sichuan, China
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
- Chongqing Institute of Cardiology and Chongqing Key Laboratory for Hypertension Research, Chongqing, China
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15
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Angiotensin II type 2 receptor (AT2R) in renal and cardiovascular disease. Clin Sci (Lond) 2017; 130:1307-26. [PMID: 27358027 DOI: 10.1042/cs20160243] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/06/2016] [Indexed: 12/14/2022]
Abstract
Angiotensin II (Ang II) is well-considered to be the principal effector of the renin-angiotensin system (RAS), which binds with strong affinity to the angiotensin II type 1 (AT1R) and type 2 (AT2R) receptor subtype. However, activation of both receptors is likely to stimulate different signalling mechanisms/pathways and produce distinct biological responses. The haemodynamic and non-haemodynamic effects of Ang II, including its ability to regulate blood pressure, maintain water-electrolyte balance and promote vasoconstriction and cellular growth are well-documented to be mediated primarily by the AT1R. However, its biological and functional effects mediated through the AT2R subtype are still poorly understood. Recent studies have emphasized that activation of the AT2R regulates tissue and organ development and provides in certain context a potential counter-regulatory mechanism against AT1R-mediated actions. Thus, this review will focus on providing insights into the biological role of the AT2R, in particular its actions within the renal and cardiovascular system.
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16
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Bohlender JM, Nussberger J, Birkhäuser F, Grouzmann E, Thalmann GN, Imboden H. Resetting of renal tissular renin-angiotensin and bradykinin-kallikrein systems after unilateral kidney denervation in rats. Histochem Cell Biol 2017; 147:585-593. [PMID: 28220244 DOI: 10.1007/s00418-017-1543-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2017] [Indexed: 01/11/2023]
Abstract
The renal tissular renin-angiotensin and bradykinin-kallikrein systems control kidney function together with the renal sympathetic innervation but their interaction is still unclear. To further elucidate this relationship, we investigated these systems in rats 6 days after left kidney denervation (DNX, n = 8) compared to sham-operated controls (CTR, n = 8). Plasma renin concentration was unchanged in DNX vs. CTR (p = NS). Kidney bradykinin (BK) and angiotensin (Ang) I and II concentrations decreased bilaterally in DNX vs. CTR rats (~20 to 40%, p < 0.05) together with Ang IV and V concentrations that were extremely low (p = NS). Renin, Ang III and dopamine concentrations decreased by ~25 to 50% and norepinephrine concentrations by 99% in DNX kidneys (p < 0.05) but were unaltered in opposite kidneys. Ang II/I and KA were comparable in DNX, contralateral and CTR kidneys. Ang III/II increased in right vs. DNX or CTR kidneys (40-50%, p < 0.05). Ang II was mainly located in tubular epithelium by immunocytological staining and its cellular distribution was unaffected by DNX. Moreover, the angiotensinergic and catecholaminergic innervation of right kidneys was unchanged vs. CTR. We found an important dependency of tissular Ang and BK levels on the renal innervation that may contribute to the resetting of kidney function after DNX. The DNX-induced peptide changes were not readily explained by kidney KA, renin or plasma Ang I generation. However, tissular peptide metabolism and compartmentalization may have played a central role. The mechanisms behind the concentration changes remain unclear and deserve further clarification.
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Affiliation(s)
- Jürgen M Bohlender
- Institute for Cell Biology, University of Bern, Bern, Switzerland. .,Department of Nephrology, Hypertension and Clinical Pharmacology, Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 4, 3010, Bern, Switzerland.
| | - Jürg Nussberger
- Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Frédéric Birkhäuser
- Department of Urology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Eric Grouzmann
- Service of Biomedicine, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - George N Thalmann
- Department of Urology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Hans Imboden
- Institute for Cell Biology, University of Bern, Bern, Switzerland
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17
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van der Laan JW, Kasper P, Silva Lima B, Jones DR, Pasanen M. Critical analysis of carcinogenicity study outcomes. Relationship with pharmacological properties. Crit Rev Toxicol 2016; 46:587-614. [DOI: 10.3109/10408444.2016.1163664] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | - Peter Kasper
- Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany
| | | | - David R. Jones
- Medicines and Healthcare Products Regulatory Agency, London, UK
| | - Markku Pasanen
- Faculty of Health Sciences, School of Pharmacy, University of Eastern Finland, Kuopio, Finland
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18
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Jiang X, Chen W, Liu X, Wang Z, Liu Y, Felder RA, Gildea JJ, Jose PA, Qin C, Yang Z. The Synergistic Roles of Cholecystokinin B and Dopamine D5 Receptors on the Regulation of Renal Sodium Excretion. PLoS One 2016; 11:e0146641. [PMID: 26751218 PMCID: PMC4709046 DOI: 10.1371/journal.pone.0146641] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/21/2015] [Indexed: 01/07/2023] Open
Abstract
Renal dopamine D1-like receptors (D1R and D5R) and the gastrin receptor (CCKBR) are involved in the maintenance of sodium homeostasis. The D1R has been found to interact synergistically with CCKBR in renal proximal tubule (RPT) cells to promote natriuresis and diuresis. D5R, which has a higher affinity for dopamine than D1R, has some constitutive activity. Hence, we sought to investigate the interaction between D5R and CCKBR in the regulation of renal sodium excretion. In present study, we found D5R and CCKBR increase each other’s expression in a concentration- and time-dependent manner in the HK-2 cell, the specificity of which was verified in HEK293 cells heterologously expressing both human D5R and CCKBR and in RPT cells from a male normotensive human. The specificity of D5R in the D5R and CCKBR interaction was verified further using a selective D5R antagonist, LE-PM436. Also, D5R and CCKBR colocalize and co-immunoprecipitate in BALB/c mouse RPTs and human RPT cells. CCKBR protein expression in plasma membrane-enriched fractions of renal cortex (PMFs) is greater in D5R-/- mice than D5R+/+ littermates and D5R protein expression in PMFs is also greater in CCKBR-/- mice than CCKBR+/+ littermates. High salt diet, relative to normal salt diet, increased the expression of CCKBR and D5R proteins in PMFs. Disruption of CCKBR in mice caused hypertension and decreased sodium excretion. The natriuresis in salt-loaded BALB/c mice was decreased by YF476, a CCKBR antagonist and Sch23390, a D1R/D5R antagonist. Furthermore, the natriuresis caused by gastrin was blocked by Sch23390 while the natriuresis caused by fenoldopam, a D1R/D5R agonist, was blocked by YF476. Taken together, our findings indicate that CCKBR and D5R synergistically interact in the kidney, which may contribute to the maintenance of normal sodium balance following an increase in sodium intake.
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Affiliation(s)
- Xiaoliang Jiang
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Centre, Peking Union Medical Collage (PUMC), Beijing, P. R. China
| | - Wei Chen
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Centre, Peking Union Medical Collage (PUMC), Beijing, P. R. China
| | - Xing Liu
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Centre, Peking Union Medical Collage (PUMC), Beijing, P. R. China
| | - Zihao Wang
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Centre, Peking Union Medical Collage (PUMC), Beijing, P. R. China
| | - Yunpeng Liu
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Centre, Peking Union Medical Collage (PUMC), Beijing, P. R. China
| | - Robin A. Felder
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - John J. Gildea
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Pedro A. Jose
- Division of Nephrology, Departments of Medicine and Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (PAJ); (CQ); (ZWY)
| | - Chuan Qin
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Centre, Peking Union Medical Collage (PUMC), Beijing, P. R. China
- * E-mail: (PAJ); (CQ); (ZWY)
| | - Zhiwei Yang
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Centre, Peking Union Medical Collage (PUMC), Beijing, P. R. China
- CollaborativeInnovation Center for Cardiovascular Disorders, Beijing, P. R. China
- * E-mail: (PAJ); (CQ); (ZWY)
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19
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Javkhedkar AA, Banday AA. Antioxidant resveratrol restores renal sodium transport regulation in SHR. Physiol Rep 2015; 3:3/11/e12618. [PMID: 26603454 PMCID: PMC4673646 DOI: 10.14814/phy2.12618] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 10/16/2015] [Indexed: 01/11/2023] Open
Abstract
Previously we have shown that in spontaneously hypertensive rats (SHR) renal angiotensin (Ang) II receptor (AT1R) upregulation leads to overstimulation of Na/K-ATPase by Ang II. There are reports that antioxidants can reduce oxidative stress and blood pressure (BP) in SHR, however the effect of these compounds on AT1R function remains to be determined. Therefore, we hypothesized that polyphenol antioxidant resveratrol would mitigate oxidative stress, normalize renal AT1R signaling, and reduce BP in SHR. SHR and wistar-kyoto (WKY) rats were treated with resveratrol for 8 weeks. Untreated SHR exhibited oxidative stress and enhanced renal proximal tubular Ang II-induced G-protein activation and Na/K-ATPase stimulation. Treatment of SHR with resveratrol mitigated oxidative stress, reduced BP, and normalized renal AT1R signaling. In SHR, nuclear expression of transcription factor NF-κB was increased while expression of Nrf2 was reduced. SHR also exhibited a significant decrease in renal antioxidant capacity and activities of phase II antioxidant enzymes. Resveratrol treatment of SHR abolished renal NF-κB activation, restored Nrf2-phase II antioxidant signaling and Ang II-mediated Na/K-ATPase regulation. These data show that in SHR, oxidative stress via activation of NF-κB upregulates AT1R–G-protein signaling resulting in overstimulation Na/K-ATPase which contributes to hypertension. Resveratrol, via Nrf2, activates phase II antioxidant enzymes, mitigates oxidative stress, normalizes AT1R–G-protein signaling and Na/K-ATPase regulation, and decreases BP in SHR.
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Affiliation(s)
- Apurva A Javkhedkar
- Heart and Kidney Institute, College of Pharmacy, University of Houston, Houston, Texas
| | - Anees A Banday
- Heart and Kidney Institute, College of Pharmacy, University of Houston, Houston, Texas
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20
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Sampaio LS, Taveira Da Silva R, Lima D, Sampaio CLC, Iannotti FA, Mazzarella E, Di Marzo V, Vieyra A, Reis RAM, Einicker-Lamas M. The endocannabinoid system in renal cells: regulation of Na(+) transport by CB1 receptors through distinct cell signalling pathways. Br J Pharmacol 2015; 172:4615-25. [PMID: 25537261 DOI: 10.1111/bph.13050] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 06/22/2015] [Accepted: 06/29/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE The function of the endocannabinoid system (ECS) in renal tissue is not completely understood. Kidney function is closely related to ion reabsorption in the proximal tubule, the nephron segment responsible for the re-absorption of 70-80% of the filtrate. We studied the effect of compounds modulating the activity of cannabinoid (CB) receptors on the active re-absorption of Na(+) in LLC-PK1 cells. EXPERIMENTAL APPROACH Changes in Na(+) /K(+) -ATPase activity were assessed after treatment with WIN55,212-2 (WIN), a non-selective lipid agonist, and haemopressin (HP), an inverse peptide agonist at CB1 receptors. Pharmacological tools were used to investigate the signalling pathways involved in the modulation of Na(+) transport. KEY RESULTS In addition to CB1 and CB2 receptors and TRPV1 channels, the mRNAs encoding for enzymes of the ECS were also expressed in LLC-PK1. WIN (10(-7) M) and HP (10(-6) M) altered Na(+) re-absorption in LLC-PK1 in a dual manner. They both acutely (after 1 min) increased Na(+) /K(+) -ATPase activity in a TRPV1 antagonist-sensitive way. WIN's stimulating effect persisted for 30 min, and this effect was partially blocked by a CB1 antagonist or a PKC inhibitor. In contrast, HP inhibited Na(+) /K(+) -ATPase after 30 min incubation, and this effect was attenuated by a CB1 antagonist or a PKA inhibitor. CONCLUSION AND IMPLICATIONS The ECS is expressed in LLC-PK1 cells. Both CB1 receptors and TRPV1 channels regulate Na(+) /K(+) -ATPase activity in these cells, and are modulated by lipid and peptide CB1 receptor ligands, which act via different signalling pathways.
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Affiliation(s)
- L S Sampaio
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Brazil.,CAPES Foundation, Ministry of Education of Brasil, Brasilia, Brazil
| | - R Taveira Da Silva
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Brazil
| | - D Lima
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Brazil
| | - C L C Sampaio
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Brazil
| | - F A Iannotti
- Endocanabinnoid Research Group, Istituto di Chimica Biomolecolare, CNR, Pozzuoli, Italy
| | - E Mazzarella
- Endocanabinnoid Research Group, Istituto di Chimica Biomolecolare, CNR, Pozzuoli, Italy
| | - V Di Marzo
- Endocanabinnoid Research Group, Istituto di Chimica Biomolecolare, CNR, Pozzuoli, Italy
| | - A Vieyra
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Brazil.,CAPES Foundation, Ministry of Education of Brasil, Brasilia, Brazil
| | - R A M Reis
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Neurociência Translacional, Brazil
| | - M Einicker-Lamas
- Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Brazil.,CAPES Foundation, Ministry of Education of Brasil, Brasilia, Brazil
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21
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Ali Q, Patel S, Hussain T. Angiotensin AT2 receptor agonist prevents salt-sensitive hypertension in obese Zucker rats. Am J Physiol Renal Physiol 2015; 308:F1379-85. [PMID: 25855512 PMCID: PMC4469886 DOI: 10.1152/ajprenal.00002.2015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/07/2015] [Indexed: 01/09/2023] Open
Abstract
High-sodium intake is a risk factor for the pathogenesis of hypertension, especially in obesity. The present study is designed to investigate whether angiotensin type 2 receptor (AT2R) activation with selective agonist C21 prevents high-sodium diet (HSD)-induced hypertension in obese animals. Male obese rats were treated with AT2R agonist C21 (1 mg·kg(-1)·day(-1), oral) while maintained on either normal-sodium diet (NSD; 0.4%) or HSD (4%) for 2 wk. Radiotelemetric recording showed a time-dependent increase in systolic blood pressure in HSD-fed obese rats, being maximal increase (∼27 mmHg) at day 12 of the HSD regimen. C21 treatment completely prevented the increase in blood pressure of HSD-fed rats. Compared with NSD controls, HSD-fed obese rats had greater natriuresis/diuresis and urinary levels of nitrates, and these parameters were further increased by C21 treatment. Also, C21 treatment improved glomerular filtration rate in HSD-fed rats. HSD-fed rats expressed higher level of cortical ANG II, which was reduced to 50% by C21 treatment. HSD feeding and/or C21 treatment had no effects on cortical renin activity and the expression of angiotensin-converting enzyme (ACE) and chymase, which are ANG II-producing enzymes. However, ANG(1-7) concentration and ACE2 activity in the renal cortex were reduced by HSD feeding, and C21 treatment rescued both the parameters. Also, C21 treatment reduced the cortical expression of AT1R in HSD-fed rats, but had no effect of AT2R expression. We conclude that chronic treatment with the AT2R agonist C21 prevents salt-sensitive hypertension in obese rats, and a reduction in the renal ANG II/AT1R and enhanced ACE2/ANG(1-7) levels may play a potential role in this phenomenon.
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Affiliation(s)
- Quaisar Ali
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Sanket Patel
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Tahir Hussain
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
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22
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Natarajan AR, Eisner GM, Armando I, Browning S, Pezzullo JC, Rhee L, Dajani M, Carey RM, Jose PA. The Renin-Angiotensin and Renal Dopaminergic Systems Interact in Normotensive Humans. J Am Soc Nephrol 2015; 27:265-79. [PMID: 25977313 DOI: 10.1681/asn.2014100958] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 03/26/2015] [Indexed: 12/22/2022] Open
Abstract
The renin-angiotensin-aldosterone (RAAS) and renal dopaminergic systems interact to maintain sodium balance. High NaCl intake increases renal synthesis of dopamine and dopaminergic receptor activity, decreasing epithelial sodium transport, whereas sodium deficit activates the RAAS, increasing epithelial sodium transport. We tested the hypothesis that attenuation of the natriuretic effect of dopamine D1-like receptors during salt restriction results in part from increased RAAS activity in seven salt-resistant normotensive adults using a double-blind placebo-controlled balanced crossover design. All subjects attained sodium balance on low (50 mmol Na(+)/day) and high (300 mmol Na(+)/day) NaCl diets, administered 4 weeks apart. Sodium, potassium, lithium, para-aminohippurate, and creatinine clearances were measured before, during, and after a 3-hour infusion of fenoldopam, a D1-like receptor agonist, with and without pretreatment with enalapril, an angiotensin converting enzyme inhibitor. On the high NaCl diet, fenoldopam-induced natriuresis was associated with the inhibition of renal proximal and distal tubule sodium transport. On the low NaCl diet, fenoldopam decreased renal distal tubule sodium transport but did not cause natriuresis. The addition of enalapril to fenoldopam restored the natriuretic effect of fenoldopam and its inhibitory effect on proximal tubule sodium transport. Thus, on a high NaCl diet fenoldopam causes natriuresis by inhibiting renal proximal and distal tubule transport, but on a low NaCl diet the increased RAAS activity prevents the D1-like receptor from inhibiting renal proximal tubule sodium transport, neutralizing the natriuretic effect of fenoldopam. These results demonstrate an interaction between the renin-angiotensin and renal dopaminergic systems in humans and highlight the influence of dietary NaCl on these interactions.
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Affiliation(s)
| | - Gilbert M Eisner
- Internal Medicine, MedStar-Georgetown University Hospital, Washington, DC
| | - Ines Armando
- Department of Medicine, Division of Nephrology, and
| | - Shaunagh Browning
- Clinical Research Unit, Georgetown University Medical Center, Washington, DC; and
| | - John C Pezzullo
- Clinical Research Unit, Georgetown University Medical Center, Washington, DC; and
| | - Lauren Rhee
- Clinical Research Unit, Georgetown University Medical Center, Washington, DC; and
| | | | - Robert M Carey
- Department of Internal Medicine, The University of Virginia, Charlottesville, Virginia
| | - Pedro A Jose
- Department of Medicine, Division of Nephrology, and Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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23
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Ennis RC, Asico LD, Armando I, Yang J, Feranil JB, Jurgens JA, Escano CS, Yu P, Wang X, Sibley DR, Jose PA, Villar VAM. Dopamine D₁-like receptors regulate the α₁A-adrenergic receptor in human renal proximal tubule cells and D₁-like dopamine receptor knockout mice. Am J Physiol Renal Physiol 2014; 307:F1238-48. [PMID: 25339698 DOI: 10.1152/ajprenal.00119.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The homeostatic control of blood pressure hinges upon the delicate balance between prohypertensinogenic and antihypertensinogenic systems. D₁-like dopamine receptors [dopamine D₁ and D₅ receptors (D₁Rs and D₅Rs, respectively)] and the α₁A-adrenergic receptor (α₁A-AR) are expressed in the renal proximal tubule and engender opposing effects on Na(+) transport, i.e., natriuresis (via D₁Rs and D5Rs) or antinatriuresis (via α₁A-ARs). We tested the hypothesis that the D₁R/D₅R regulates the α₁A-AR. D₁-like dopamine receptors coimmunoprecipitated, colocalized, and cofractionated with α₁A-ARs in lipid rafts in immortalized human renal proximal tubule cells. Long-term treatment with the D₁R/D₅R agonist fenoldopam resulted in decreased D₁R and D₅R expression but increased α₁A-AR abundance in the plasma membrane. Short-term fenoldopam treatment stimulated the translocation of Na(+)-K(+)-ATPase from the plasma membrane to the cytosol that was partially reversed by an α₁A-AR agonist, which by itself induced Na(+)-K(+)-ATPase translocation from the cytosol to the plasma membrane. The α₁A-AR-specific agonist A610603 also minimized the ability of fenoldopam to inhibit Na(+)-K(+)-ATPase activity. To determine the interaction among D₁Rs, D₅Rs, and α₁A-ARs in vivo, we used phenylephrine and A610603 to decrease Na(+) excretion in several D1-like dopamine receptor knockout mouse strains. Phenylephrine and A61603 treatment resulted in a partial reduction of urinary Na(+) excretion in wild-type mice and its abolition in D1R knockout, D₅R knockout, and D₁R-D₅R double-knockout mice. Our results demonstrate the ability of the D₁-like dopamine receptors to regulate the expression and activity of α₁A-AR. Elucidating the intricacies of the interaction among these receptors is crucial for a better understanding of the crosstalk between anti- and pro-hypertensive systems.
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Affiliation(s)
- Riley Charles Ennis
- Thomas Jefferson High School for Science and Technology, Alexandria, Virgina
| | - Laureano D Asico
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Ines Armando
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jian Yang
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jun B Feranil
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Julie A Jurgens
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Crisanto S Escano
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Peiying Yu
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Xiaoyan Wang
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - David R Sibley
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Pedro A Jose
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland; Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Van Anthony M Villar
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
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24
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Altered signaling pathways linked to angiotensin II underpin the upregulation of renal Na(+)-ATPase in chronically undernourished rats. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2357-66. [PMID: 25283821 DOI: 10.1016/j.bbadis.2014.09.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/17/2014] [Accepted: 09/30/2014] [Indexed: 01/23/2023]
Abstract
This study has investigated the participation of altered signaling linked to angiotensin II (Ang II) that could be associated with increased Na(+) reabsorption in renal proximal tubules during chronic undernutrition. A multideficient chow for rats (basic regional diet, BRD) was used, which mimics several human diets widely taken in developing countries. The Vmax of the ouabain-resistant Na(+)-ATPase resident in the basolateral membranes increased >3-fold (P<0.001) accompanied by an increase in Na(+) affinity from 4.0 to 0.2mM (P<0.001). BRD rats had a >3-fold acceleration of the formation of phosphorylated intermediates in the early stage of the catalytic cycle (in the E1 conformation) (P<0.001). Immunostaining showed a huge increase in Ang II-positive cells in the cortical tubulointerstitium neighboring the basolateral membranes (>6-fold, P<0.001). PKC isoforms (α, ε, λ, ζ), Ang II type 1 receptors and PP2A were upregulated in BRD rats (in %): 55 (P<0.001); 35 (P<0.01); 125, 55, 11 and 30 (P<0.001). PKA was downregulated by 55% (P<0.001). With NetPhosK 1.0 and NetPhos 2.0, we detected 4 high-score (>0.70) regulatory phosphorylation sites for PKC and 1 for PKA in the primary sequence of the Na(+)-ATPase α-subunit, which are located in domains that are key for Na(+) binding and catalysis. Therefore, chronic undernutrition stimulates tubulointerstitial activity of Ang II and impairs PKC- and PKA-mediated regulatory phosphorylation, which culminates in an exaggerated Na(+) reabsorption across the proximal tubular epithelium.
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25
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Silva PA, Monnerat-Cahli G, Pereira-Acácio A, Luzardo R, Sampaio LS, Luna-Leite MA, Lara LS, Einicker-Lamas M, Panizzutti R, Madeira C, Vieira-Filho LD, Castro-Chaves C, Ribeiro VS, Paixão ADO, Medei E, Vieyra A. Mechanisms involving Ang II and MAPK/ERK1/2 signaling pathways underlie cardiac and renal alterations during chronic undernutrition. PLoS One 2014; 9:e100410. [PMID: 24983243 PMCID: PMC4077653 DOI: 10.1371/journal.pone.0100410] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 05/27/2014] [Indexed: 02/07/2023] Open
Abstract
Background Several studies have correlated protein restriction associated with other nutritional deficiencies with the development of cardiovascular and renal diseases. The driving hypothesis for this study was that Ang II signaling pathways in the heart and kidney are affected by chronic protein, mineral and vitamin restriction. Methodology/Principal Findings Wistar rats aged 90 days were fed from weaning with either a control or a deficient diet that mimics those used in impoverished regions worldwide. Such restriction simultaneously increased ouabain-insensitive Na+-ATPase and decreased (Na++K+)ATPase activity in the same proportion in cardiomyocytes and proximal tubule cells. Type 1 angiotensin II receptor (AT1R) was downregulated by that restriction in both organs, whereas AT2R decreased only in the kidney. The PKC/PKA ratio increased in both tissues and returned to normal values in rats receiving Losartan daily from weaning. Inhibition of the MAPK pathway restored Na+-ATPase activity in both organs. The undernourished rats presented expanded plasma volume, increased heart rate, cardiac hypertrophy, and elevated systolic pressure, which also returned to control levels with Losartan. Such restriction led to electrical cardiac remodeling represented by prolonged ventricular repolarization parameters, induced triggered activity, early after-depolarization and delayed after-depolarization, which were also prevented by Losartan. Conclusion/Significance The mechanisms responsible for these alterations are underpinned by an imbalance in the PKC- and PKA-mediated pathways, with participation of angiotensin receptors and by activation of the MAPK/ERK1/2 pathway. These cellular and molecular alterations culminate in cardiac electric remodeling and in the onset of hypertension in adulthood.
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Affiliation(s)
- Paulo A. Silva
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Gustavo Monnerat-Cahli
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Amaury Pereira-Acácio
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Ricardo Luzardo
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Luzia S. Sampaio
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Marcia A. Luna-Leite
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucienne S. Lara
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo Einicker-Lamas
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Rogério Panizzutti
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Caroline Madeira
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leucio D. Vieira-Filho
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Carmen Castro-Chaves
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Valdilene S. Ribeiro
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Ana D. O. Paixão
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Emiliano Medei
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- * E-mail:
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Exosomal transfer from human renal proximal tubule cells to distal tubule and collecting duct cells. Clin Biochem 2014; 47:89-94. [PMID: 24976626 DOI: 10.1016/j.clinbiochem.2014.06.018] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 06/12/2014] [Accepted: 06/17/2014] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Exosomes are 50-90nm extracellular membrane particles that may mediate trans-cellular communication between cells and tissues. We have reported that human urinary exosomes contain miRNA that are biomarkers for salt sensitivity and inverse salt sensitivity of blood pressure. This study examines exosomal transfer between cultured human renal proximal tubule cells (RPTCs) and from RPTCs to human distal tubule and collecting duct cells. DESIGN AND METHODS For RPTC-to-RPTC exosomal transfer, we utilized 5 RPTC lines producing exosomes that were fluorescently labeled with exosomal-specific markers CD63-EGFP or CD9-RFP. Transfer between RPTCs was demonstrated by co-culturing CD63-EGFP and CD9-RFP stable clones and performing live confocal microscopy. For RPTC-to-distal segment exosomal transfer, we utilized 5 distal tubule and 3 collecting duct immortalized cell lines. RESULTS Time-lapse videos revealed unique proximal tubule cellular uptake patterns for exosomes and eventual accumulation into the multivesicular body. Using culture supernatant containing exosomes from 3 CD9-RFP and 2 CD63-EGFP RPTC cell lines, all 5 distal tubule cell lines and all 3 collecting duct cell lines showed exosomal uptake as measured by microplate fluorometry. Furthermore, we found that RPTCs stimulated with fenoldopam (dopamine receptor agonist) had increased production of exosomes, which upon transfer to distal tubule and collecting duct cells, reduced the basal reactive oxygen species (ROS) production rates in those recipient cells. CONCLUSION Due to the complex diversity of exosomal contents, this proximal-to-distal vesicular inter-nephron transfer may represent a previously unrecognized trans-renal communication system.
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Renal molecular mechanisms underlying altered Na+ handling and genesis of hypertension during adulthood in prenatally undernourished rats. Br J Nutr 2014; 111:1932-44. [PMID: 24661554 DOI: 10.1017/s0007114513004236] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In the present study, we investigated the development of hypertension in prenatally undernourished adult rats, including the mechanisms that culminate in dysfunctions of molecular signalling in the kidney. Dams were fed a low-protein multideficient diet throughout gestation with or without α-tocopherol during lactation. The time course of hypertension development followed in male offspring was correlated with alterations in proximal tubule Na+-ATPase activity, expression of angiotensin II (Ang II) receptors, and activity of protein kinases C and A. After the establishment of hypertension, Ang II levels, cyclo-oxygenase 2 (COX-2) and NADPH oxidase subunit expression, lipid peroxidation and macrophage infiltration were examined in renal tissue. Lipid peroxidation in undernourished rats, which was very intense at 60 d, decreased at 90 d and returned to control values by 150 d. During the prehypertensive phase, prenatally undernourished rats exhibited elevated renal Na+-ATPase activity, type 2 Ang II receptor down-regulation and altered protein kinase A:protein kinase C ratio. Stable late hypertension coexisted with highly elevated levels of Ang II-positive cells in the cortical tubulointerstitium, enhanced increase in the expression of p47phox (NADPH oxidase regulatory subunit), marked down-regulation of COX-2 expression, expanded plasma volume and decreased creatinine clearance. These alterations were reduced when the dams were given α-tocopherol during lactation. The offspring of well-nourished dams treated with α-tocopherol exhibited most of the alterations encountered in the offspring of undernourished dams not treated with α-tocopherol. Thus, alterations in proximal tubule Na+ transport, subcellular signalling pathways and reactive oxygen species handling in renal tissue underpin the development of hypertension.
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Carey RM, Padia SH. Role of angiotensin AT(2) receptors in natriuresis: Intrarenal mechanisms and therapeutic potential. Clin Exp Pharmacol Physiol 2014; 40:527-34. [PMID: 23336117 DOI: 10.1111/1440-1681.12059] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/16/2013] [Accepted: 01/16/2013] [Indexed: 01/11/2023]
Abstract
The renin-angiotensin system is a coordinated hormonal cascade critical for the regulation of blood pressure (BP) and kidney function. Angiotensin (Ang) II, the major angiotensin effector peptide, binds to two major receptors, namely AT1 and AT2 receptors. The AT1 receptors engender antinatriuresis and raise BP, whereas AT2 receptors oppose these effects, inducing natriuresis and reducing BP. There is high AT2 receptor expression in the adult kidney, especially in the proximal tubule. In AT2 receptor-null mice, long-term AngII infusion results in pressor and antinatriuretic hypersensivivity compared with responses in wild-type mice. The major endogenous receptor ligand for AT2 receptor-mediated natriuretic responses appears to be des-aspartyl(1) -AngII (AngIII) instead of AngII. Recent studies have demonstrated that AngII requires metabolism to AngIII by aminopeptidase A to induce natriuresis and that inhibition of aminopeptidase N increases intrarenal AngIII and augments AngIII-induced natriuresis. The renal dopaminergic system is another important natriuretic pathway. Renal proximal tubule the D1 and D5 receptor subtypes (D1 -like receptors (D1LIKE R)) control approximately 50% of basal sodium excretion. Recently, we have found that natriuresis induced by proximal tubule D1LIKE R requires AT2 receptor activation and that D1LIKE R stimulation induces recruitment of AT2 receptors to the apical plasma membrane via a cAMP-dependent mechanism. Initial studies using the potent AT2 receptor non-peptide agonist Compound 21 demonstrate natriuresis in both the presence and absence of AT1 receptor blockade, indicating the therapeutic potential of this compound in fluid-retaining states and hypertension.
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Affiliation(s)
- Robert M Carey
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA.
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Gildea JJ, Shah IT, Van Sciver RE, Israel JA, Enzensperger C, McGrath HE, Jose PA, Felder RA. The cooperative roles of the dopamine receptors, D1R and D5R, on the regulation of renal sodium transport. Kidney Int 2014; 86:118-26. [PMID: 24552847 PMCID: PMC4077925 DOI: 10.1038/ki.2014.5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/27/2013] [Accepted: 12/12/2013] [Indexed: 02/07/2023]
Abstract
Determining the individual roles of the two dopamine D1-like receptors (D1R and D5R) on sodium transport in the human renal proximal tubule has been complicated by their structural and functional similarity. Here we used a novel D5R-selective antagonist (LE-PM436) and D1R or D5R-specific gene silencing to determine second messenger coupling pathways and heterologous receptor interaction between the two receptors. D1R and D5R co-localized in renal proximal tubule cells and physically interact, as determined by co-immunoprecipitation and FRET microscopy. Stimulation of renal proximal tubule cells with fenoldopam (D1R/D5R agonist) led to both adenylyl cyclase and phospholipase C (PLC) activation using real-time FRET biosensors ICUE3 and CYPHR, respectively. Fenoldopam increased cAMP accumulation and PLC activity and inhibited both NHE3 and NaKATPase activities. LE-PM436 and D5R siRNA blocked the fenoldopam-stimulated PLC pathway but not cAMP accumulation, while D1R siRNA blocked both fenoldopam-stimulated cAMP accumulation and PLC signaling. Either D1R or D5R siRNA, or LE-PM436 blocked the fenoldopam dependent inhibition of sodium transport. Further studies using the cAMP-selective D1R/D5R agonist SKF83822 and PLC-selective D1R/D5R agonist SKF83959 confirmed the cooperative influence of the two pathways on sodium transport. Thus, D1R and D5R interact in the inhibition of NHE3 and NaKATPase activity, the D1R primarily by cAMP, while the D1R/D5R heteromer modulates the D1R effect through a PLC pathway.
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Affiliation(s)
- John J Gildea
- The University of Virginia Health System, Department of Pathology, Charlottesville, Virginia, USA
| | - Ishan T Shah
- The University of Virginia Health System, Department of Pathology, Charlottesville, Virginia, USA
| | - Robert E Van Sciver
- The University of Virginia Health System, Department of Pathology, Charlottesville, Virginia, USA
| | - Jonathan A Israel
- The University of Virginia Health System, Department of Pathology, Charlottesville, Virginia, USA
| | - Christoph Enzensperger
- Institut für Pharmazie, Lehrstuhl für Pharmazeutische/Medizinische Chemie, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Helen E McGrath
- The University of Virginia Health System, Department of Pathology, Charlottesville, Virginia, USA
| | - Pedro A Jose
- University of Maryland School of Medicine, Departments of Medicine and Physiology, Baltimore, Maryland, USA
| | - Robin A Felder
- The University of Virginia Health System, Department of Pathology, Charlottesville, Virginia, USA
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Chen Y, Asico LD, Zheng S, Villar VAM, He D, Zhou L, Zeng C, Jose PA. Gastrin and D1 dopamine receptor interact to induce natriuresis and diuresis. Hypertension 2013; 62:927-33. [PMID: 24019399 DOI: 10.1161/hypertensionaha.113.01094] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Oral NaCl produces a greater natriuresis and diuresis than the intravenous infusion of the same amount of NaCl. Gastrin is the major gastrointestinal hormone taken up by renal proximal tubule (RPT) cells. We hypothesized that renal gastrin and dopamine receptors interact to synergistically increase sodium excretion, an impaired interaction of which may be involved in the pathogenesis of hypertension. In Wistar-Kyoto rats, infusion of gastrin induced natriuresis and diuresis, which was abrogated in the presence of a gastrin (cholecystokinin B receptor [CCKBR]; CI-988) or a D1-like receptor antagonist (SCH23390). Similarly, the natriuretic and diuretic effects of fenoldopam, a D1-like receptor agonist, were blocked by SCH23390, as well as by CI-988. However, the natriuretic effects of gastrin and fenoldopam were not observed in spontaneously hypertensive rats. The gastrin/D1-like receptor interaction was also confirmed in RPT cells. In RPT cells from Wistar-Kyoto but not spontaneously hypertensive rats, stimulation of either D1-like receptor or gastrin receptor inhibited Na(+)-K(+)-ATPase activity, an effect that was blocked in the presence of SCH23390 or CI-988. In RPT cells from Wistar-Kyoto and spontaneously hypertensive rats, CCKBR and D1 receptor coimmunoprecipitated, which was increased after stimulation of either D1 receptor or CCKBR in RPT cells from Wistar-Kyoto rats; stimulation of one receptor increased the RPT cell membrane expression of the other receptor, effects that were not observed in spontaneously hypertensive rats. These data suggest that there is a synergism between CCKBR and D1-like receptors to increase sodium excretion. An aberrant interaction between the renal CCK BR and D1-like receptors (eg, D1 receptor) may play a role in the pathogenesis of hypertension.
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Affiliation(s)
- Yue Chen
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042, China.
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Abstract
In this review three major issues of sodium homeostasis are addressed. Specifically, volume-dependent (salt-sensitive) hypertension, sodium chloride content of maintenance fluid and clinical evaluation of hyponatremia are discussed. Regarding volume-dependent hypertension the endocrine/paracrine systems mediating renal sodium retention, the relationship between salt intake, plasma sodium levels and blood pressure, as well as data on the dissociation of sodium and volume regulation are presented. The concept of perinatal programming of salt-preference is also mentioned. Some theoretical and practical aspects of fluid therapy are summarized with particular reference to using hypotonic sodium chloride solution for maintenance fluid as opposed to the currently proposed isotonic sodium chloride solution. Furthermore, the incidence, the aetiological classification and central nervous system complications of hyponatremia are presented, too. In addition, clinical and pathophysical features of hyponatremic encephalophathy and osmotic demyelinisation are given. The adaptive reactions of the brain to hypotonic stress are also described with particular emphasis on the role of brain-specific water channel proteins (aquaporin-4) and the benzamil-inhibitable sodium channels. In view of the outmost clinical significance of hyponatremia, the principles of efficient and safe therapeutic approaches are outlined. Orv. Hetil., 2013, 154, 1488–1497.
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Affiliation(s)
- Endre Sulyok
- Pécsi Tudományegyetem Egészségtudományi Kar Pécs Vörösmarty u. 4. 7621
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Abstract
The kidney plays a fundamental role in maintaining body salt and fluid balance and blood pressure homeostasis through the actions of its proximal and distal tubular segments of nephrons. However, proximal tubules are well recognized to exert a more prominent role than distal counterparts. Proximal tubules are responsible for reabsorbing approximately 65% of filtered load and most, if not all, of filtered amino acids, glucose, solutes, and low molecular weight proteins. Proximal tubules also play a key role in regulating acid-base balance by reabsorbing approximately 80% of filtered bicarbonate. The purpose of this review article is to provide a comprehensive overview of new insights and perspectives into current understanding of proximal tubules of nephrons, with an emphasis on the ultrastructure, molecular biology, cellular and integrative physiology, and the underlying signaling transduction mechanisms. The review is divided into three closely related sections. The first section focuses on the classification of nephrons and recent perspectives on the potential role of nephron numbers in human health and diseases. The second section reviews recent research on the structural and biochemical basis of proximal tubular function. The final section provides a comprehensive overview of new insights and perspectives in the physiological regulation of proximal tubular transport by vasoactive hormones. In the latter section, attention is particularly paid to new insights and perspectives learnt from recent cloning of transporters, development of transgenic animals with knockout or knockin of a particular gene of interest, and mapping of signaling pathways using microarrays and/or physiological proteomic approaches.
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Affiliation(s)
- Jia L Zhuo
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi, USA.
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Gildea JJ, Tran HT, Van Sciver RE, Bigler Wang D, Carlson JM, Felder RA. A novel role for c-Myc in G protein-coupled receptor kinase 4 (GRK4) transcriptional regulation in human kidney proximal tubule cells. Hypertension 2013; 61:1021-7. [PMID: 23509080 DOI: 10.1161/hypertensionaha.111.00321] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The G protein-coupled receptor kinase 4 (GRK4) negatively regulates the dopaminergic system by desensitizing the dopamine-1-receptor. The expressional control of GRK4 has not been reported, but here we show that the transcription factor c-Myc binds to the promoter of GRK4 and positively regulates GRK4 protein expression in human renal proximal tubule cells (RPTCs). Addition of phorbol esters to RPTCs not only increased c-Myc binding to the GRK4 promoter but also increased both phospho-c-Myc and GRK4 expression. The phorbol ester-mediated increase in GRK4 expression was completely blocked by the c-Myc inhibitor, 10074-G5, indicating that GRK4 is downstream of phospho-c-Myc. The autocrine production of angiotensin II (Ang II) in RPTCs increased the phosphorylation and activation of c-Myc and subsequently GRK4 expression. 3-Amino-4-thio-butyl sulfonate, an inhibitor of aminopeptidase A, increased RPTC secretion of Ang II. 3-Amino-4-thio-butyl sulfonate or Ang II increased the expression of both phospho-c-Myc and GRK4, which was blocked by 10074-G5. Blockade of the Ang II type 1 receptor with losartan decreased phospho-c-Myc and GRK4 expression. Both inhibition of c-Myc activity and blockade of Ang II type 1 receptor restored the coupling of dopamine-1-receptor to adenylyl cyclase stimulation in uncoupled RPTCs, whereas phorbol esters or Ang II caused the uncoupling of normally coupled RPTCs. We suggest that the Ang II type 1 receptor impairs dopamine-1-receptor function via c-Myc activation of GRK4. This novel pathway may be involved in the increase in blood pressure in hypertension that is mediated by increased activity of the renin-angiotensin system and decreased activity of the renal dopaminergic system.
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Affiliation(s)
- John J Gildea
- Department of Pathology, University of Virginia Health System, Charlottesville, VA 22908, USA.
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Gildea JJ, Lahiff DT, Van Sciver RE, Weiss RS, Shah N, McGrath HE, Schoeffel CD, Jose PA, Carey RM, Felder RA. A linear relationship between the ex-vivo sodium mediated expression of two sodium regulatory pathways as a surrogate marker of salt sensitivity of blood pressure in exfoliated human renal proximal tubule cells: the virtual renal biopsy. Clin Chim Acta 2013; 421:236-42. [PMID: 23454474 DOI: 10.1016/j.cca.2013.02.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 01/14/2013] [Accepted: 02/21/2013] [Indexed: 12/30/2022]
Abstract
BACKGROUND Salt sensitivity (SS) of blood pressure (BP) affects 25% of adults, shares comorbidity with hypertension, and has no convenient diagnostic test. We tested the hypothesis that urine-derived exfoliated renal proximal tubule cells (RPTCs) could diagnose the degree of an individual's SS of BP. METHODS Subjects were selected who had their SS of BP determined 5 y prior to this study (salt-sensitive: ≥7 mm Hg increase in mean arterial pressure (MAP) following transition from a random weekly diet of low (10 mmol/day) to high (300 mmol/day) sodium (Na(+)) intake, N=4; inverse salt-sensitive (ISS): ≥7 mm Hg increase in MAP transitioning from a high to low Na(+) diet, N=3, and salt-resistant (SR): <7 mm Hg change in MAP transitioned on either diet, N=5). RPTC responses to 2 independent Na(+) transport pathways were measured. RESULTS There was a negative correlation between the degree of SS and dopamine-1 receptor (D1R) plasma membrane recruitment (y=-0.0107x+0.68 relative fluorescent units (RFU), R(2)=0.88, N=12, P<0.0001) and angiotensin II-stimulated intracellular Ca(++) (y=-0.0016x+0.0336, R(2)=0.7112, P<0.001, N=10) concentration over baseline. CONCLUSIONS Isolating RPTCs from urine provides a personalized cell-based diagnostic test of SS index that offers advantages over a 2-week controlled diet with respect to cost and patient compliance. Furthermore, the linear relationship between the change in MAP and response to 2 Na(+) regulatory pathways suggests that an individual's RPTC response to intracellular Na(+) is personalized and predictive.
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Affiliation(s)
- John J Gildea
- University of Virginia, Charlottesville, VA 22903, United States
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