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Multiple Aspects of Inappropriate Action of Renin-Angiotensin, Vasopressin, and Oxytocin Systems in Neuropsychiatric and Neurodegenerative Diseases. J Clin Med 2022; 11:jcm11040908. [PMID: 35207180 PMCID: PMC8877782 DOI: 10.3390/jcm11040908] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 02/04/2023] Open
Abstract
The cardiovascular system and the central nervous system (CNS) closely cooperate in the regulation of primary vital functions. The autonomic nervous system and several compounds known as cardiovascular factors, especially those targeting the renin–angiotensin system (RAS), the vasopressin system (VPS), and the oxytocin system (OTS), are also efficient modulators of several other processes in the CNS. The components of the RAS, VPS, and OTS, regulating pain, emotions, learning, memory, and other cognitive processes, are present in the neurons, glial cells, and blood vessels of the CNS. Increasing evidence shows that the combined function of the RAS, VPS, and OTS is altered in neuropsychiatric/neurodegenerative diseases, and in particular in patients with depression, Alzheimer’s disease, Parkinson’s disease, autism, and schizophrenia. The altered function of the RAS may also contribute to CNS disorders in COVID-19. In this review, we present evidence that there are multiple causes for altered combined function of the RAS, VPS, and OTS in psychiatric and neurodegenerative disorders, such as genetic predispositions and the engagement of the RAS, VAS, and OTS in the processes underlying emotions, memory, and cognition. The neuroactive pharmaceuticals interfering with the synthesis or the action of angiotensins, vasopressin, and oxytocin can improve or worsen the effectiveness of treatment for neuropsychiatric/neurodegenerative diseases. Better knowledge of the multiple actions of the RAS, VPS, and OTS may facilitate programming the most efficient treatment for patients suffering from the comorbidity of neuropsychiatric/neurodegenerative and cardiovascular diseases.
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Nasimi A, Haddad F, Mirzaei-Damabi N, Rostami B, Hatam M. Another controller system for arterial pressure. AngII-vasopressin neural network of the parvocellular paraventricular nucleus may regulate arterial pressure during hypotension. Brain Res 2021; 1769:147618. [PMID: 34400123 DOI: 10.1016/j.brainres.2021.147618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 02/07/2023]
Abstract
Angiotensin II (AngII) immunoreactive cells, fibers and receptors, were found in the parvocelluar region of paraventricular nucleus (PVNp) and AngII receptors are present on vasopressinergic neurons. However, the mechanism by which vasopressin (AVP) and AngII may interact to regulate arterial pressure is not known. Thus, we tested the cardiovascular effects of blockade of the AngII receptors on AVP neurons and blockade of vasopressin V1a receptors on AngII neurons. We also explored whether the PVNp vasopressin plays a regulatory role during hypotension in anesthetized rat or not. Hypovolemic-hypotension was induced by gradual bleeding from femoral venous catheter. Either AngII or AVP injected into the PVNp produced pressor and tachycardia responses. The responses to AngII were blocked by V1a receptor antagonist. The responses to AVP were partially attenuated by AT1 antagonist and greatly attenuated by AT2 antagonist. Hemorrhage augmented the pressor response to AVP, indicating that during hemorrhage, sensitivity of PVNp to vasopressin was increased. By hemorrhagic-hypotension and bilateral blockade of V1a receptors of the PVNp, we found that vasopressinergic neurons of the PVNp regulate arterial pressure towards normal during hypotension. Taken together these findings and our previous findings about angII (Khanmoradi and Nasimi, 2017a) for the first time, we found that a mutual cooperative system of angiotensinergic and vasopressinergic neurons in the PVNp is a major regulatory controller of the cardiovascular system during hypotension.
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Affiliation(s)
- Ali Nasimi
- Dept. of Physiology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fatemeh Haddad
- Dept. of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Nafiseh Mirzaei-Damabi
- Dept. of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran; Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Bahar Rostami
- Dept. of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Masoumeh Hatam
- Dept. of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran.
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Szczepanska-Sadowska E, Cudnoch-Jedrzejewska A, Sadowski B. Differential role of specific cardiovascular neuropeptides in pain regulation: Relevance to cardiovascular diseases. Neuropeptides 2020; 81:102046. [PMID: 32284215 DOI: 10.1016/j.npep.2020.102046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 03/27/2020] [Accepted: 03/29/2020] [Indexed: 12/11/2022]
Abstract
In many instances, the perception of pain is disproportionate to the strength of the algesic stimulus. Excessive or inadequate pain sensation is frequently observed in cardiovascular diseases, especially in coronary ischemia. The mechanisms responsible for individual differences in the perception of cardiovascular pain are not well recognized. Cardiovascular disorders may provoke pain in multiple ways engaging molecules released locally in the heart due to tissue ischemia, inflammation or cellular stress, and through neurogenic and endocrine mechanisms brought into action by hemodynamic disturbances. Cardiovascular neuropeptides, namely angiotensin II (Ang II), angiotensin-(1-7) [Ang-(1-7)], vasopressin, oxytocin, and orexins belong to this group. Although participation of these peptides in the regulation of circulation and pain has been firmly established, their mutual interaction in the regulation of pain in cardiovascular diseases has not been profoundly analyzed. In the present review we discuss the regulation of the release, and mechanisms of the central and systemic actions of these peptides on the cardiovascular system in the context of their central and peripheral nociceptive (Ang II) and antinociceptive [Ang-(1-7), vasopressin, oxytocin, orexins] properties. We also consider the possibility that they may play a significant role in the modulation of pain in cardiovascular diseases. The rationale for focusing attention on these very compounds was based on the following premises (1) cardiovascular disturbances influence the release of these peptides (2) they regulate vascular tone and cardiac function and can influence the intensity of ischemia - the factor initiating pain signals in the cardiovascular system, (3) they differentially modulate nociception through peripheral and central mechanisms, and their effect strongly depends on specific receptors and site of action. Accordingly, an altered release of these peptides and/or pharmacological blockade of their receptors may have a significant but different impact on individual sensation of pain and comfort of an individual patient.
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Affiliation(s)
- Ewa Szczepanska-Sadowska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Banacha 1b, Warsaw, Poland.
| | - Agnieszka Cudnoch-Jedrzejewska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Banacha 1b, Warsaw, Poland
| | - Bogdan Sadowski
- School of Engineering and Health, Bitwy Warszawskiej 1920 r. 18, Warsaw, Poland
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Abstract
PURPOSE OF REVIEW Angiotensin type 2 receptor (AT2R) and receptor Mas (MasR) are part of the "protective arm" of the renin angiotensin system. Gene and pharmacological manipulation studies reveal that AT2R and MasR are involved in natriuretic, vasodilatory, and anti-inflammatory responses and in lowering blood pressure in various animal models under normal and pathological conditions such as salt-sensitive hypertension, obesity, and diabetes. The scope of this review is to discuss co-localization and heterodimerization as potential molecular mechanisms of AT2R- and MasR-mediated functions including antihypertensive activities. RECENT FINDINGS Accumulating evidences show that AT2R and MasR are co-localized, make a heterodimer, and are functionally interdependent in producing their physiological responses. Moreover, ang-(1-7) preferably may be an AT1R-biased agonist while acting as a MasR agonist. The physical interactions of AT2R and MasR appear to be an important mechanism by which these receptors are involved in blood pressure regulation and antihypertensive activity. Whether heteromers of these receptors influence affinity or efficacy of endogenous or synthetic agonists remains a question to be considered.
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Szczepanska-Sadowska E, Czarzasta K, Cudnoch-Jedrzejewska A. Dysregulation of the Renin-Angiotensin System and the Vasopressinergic System Interactions in Cardiovascular Disorders. Curr Hypertens Rep 2018; 20:19. [PMID: 29556787 PMCID: PMC5859051 DOI: 10.1007/s11906-018-0823-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Purpose of Review In many instances, the renin-angiotensin system (RAS) and the vasopressinergic system (VPS) are jointly activated by the same stimuli and engaged in the regulation of the same processes. Recent Findings Angiotensin II (Ang II) and arginine vasopressin (AVP), which are the main active compounds of the RAS and the VPS, interact at several levels. Firstly, Ang II, acting on AT1 receptors (AT1R), plays a significant role in the release of AVP from vasopressinergic neurons and AVP, stimulating V1a receptors (V1aR), regulates the release of renin in the kidney. Secondly, Ang II and AVP, acting on AT1R and V1aR, respectively, exert vasoconstriction, increase cardiac contractility, stimulate the sympathoadrenal system, and elevate blood pressure. At the same time, they act antagonistically in the regulation of blood pressure by baroreflex. Thirdly, the cooperative action of Ang II acting on AT1R and AVP stimulating both V1aR and V2 receptors in the kidney is necessary for the appropriate regulation of renal blood flow and the efficient resorption of sodium and water. Furthermore, both peptides enhance the release of aldosterone and potentiate its action in the renal tubules. Summary In this review, we (1) point attention to the role of the cooperative action of Ang II and AVP for the regulation of blood pressure and the water-electrolyte balance under physiological conditions, (2) present the subcellular mechanisms underlying interactions of these two peptides, and (3) provide evidence that dysregulation of the cooperative action of Ang II and AVP significantly contributes to the development of disturbances in the regulation of blood pressure and the water-electrolyte balance in cardiovascular diseases.
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Affiliation(s)
- Ewa Szczepanska-Sadowska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Banacha 1b, 02-097, Warsaw, Poland.
| | - Katarzyna Czarzasta
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Banacha 1b, 02-097, Warsaw, Poland
| | - Agnieszka Cudnoch-Jedrzejewska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Banacha 1b, 02-097, Warsaw, Poland
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Steckelings UM, Kloet AD, Sumners C. Centrally Mediated Cardiovascular Actions of the Angiotensin II Type 2 Receptor. Trends Endocrinol Metab 2017; 28:684-693. [PMID: 28733135 PMCID: PMC5563271 DOI: 10.1016/j.tem.2017.06.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/06/2017] [Accepted: 06/08/2017] [Indexed: 02/07/2023]
Abstract
Sustained increases in the activity of the sympathetic neural pathways that exit the brain and which increase blood pressure (BP) are a major underlying factor in resistant hypertension. Recently available information on the occurrence of angiotensin II type 2 receptors (AT2Rs) within or adjacent to brain cardiovascular control centers is consistent with findings that stimulation of these receptors lowers BP, particularly during hypertension of neurogenic origin. Until recently brain AT2R had not been considered by many to play a role in the central control of BP. Demonstration of these powerful antihypertensive effects of brain AT2R opens the door to reconsideration of their role in BP regulation, and their consideration as a novel therapeutic avenue for resistant hypertension.
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Affiliation(s)
- U Muscha Steckelings
- Institute of Molecular Medicine (IMM), Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Annette de Kloet
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, USA
| | - Colin Sumners
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, USA.
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Abstract
Copeptin is derived from the cleavage of the precursor of arginine vasopressin (AVP), produced in an equimolar ratio in hypothalamus and processed during axonal transport AVP is an unstable peptide and has a short half-life of 5-20 min. Unlike AVP, copeptin is a stable molecule and can easily be measured. Recent evidence suggest that increased copeptin levels have been associated with worse outcomes in various clinical conditions including chronic kidney disease (CKD) and hypertension. In this review, the data regarding copeptin with kidney function (evaluated as glomerular filtration rate, increased albumin/protein excretion or both) and hypertension with regard to performed studies, prognosis and pathogenesis was summarised.
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Khanmoradi M, Nasimi A. Functions of AT1 and AT2 angiotensin receptors in the paraventricular nucleus of the rat, correlating single-unit and cardiovascular responses. Brain Res Bull 2017; 132:170-179. [DOI: 10.1016/j.brainresbull.2017.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/21/2017] [Accepted: 06/02/2017] [Indexed: 11/27/2022]
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Schwerg M, Slagman A, Stangl K, Stangl V. Copeptin, resistant hypertension and renal sympathetic denervation. Biomarkers 2016; 22:311-314. [PMID: 27775435 DOI: 10.1080/1354750x.2016.1252968] [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] [Indexed: 10/20/2022]
Abstract
BACKGROUND Renal denervation is used as a treatment option for patients with resistant hypertension. But only a subgroup of patients benefits from renal sympathetic denervation (RDN). Biomarkers might be helpful to identify patients who respond to RDN. Copeptin as a surrogate for vasopressin levels is increased in hypertension and other cardiovascular diseases. This study aims to evaluate the effect of RDN on Copeptin and its prognostic value for response to RDN. METHOD AND RESULTS A total of 40 patients have been included in the study. The responder rate was 47.5% on 24 h ambulatory blood pressure measurements. The mean systolic 24 h blood pressure dropped from 152 ± 10 mmHg to 147 ± 17 mmHg (p = .044) in the six month follow up. The mean baseline level of Copeptin was 7.4 pmol/l (interquartile range 3.7-11.6) for responders and 8.4 pmol/l (interquartile range 5.7-11-8) for non-responders (p = .53). The Copeptin levels did not change over time after renal denervation. CONCLUSION Baseline measurements of Copeptin in patients undergoing RDN for resistant hypertension have no predictive value for response to RDN. Despite lowering the blood pressure RDN has no influence on Copeptin levels in this short time follow up period.
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Affiliation(s)
- Marius Schwerg
- a Department of Cardiology and Angiology , Charité - Universitätsmedizin , Campus Mitte , Berlin , Germany
| | - Anna Slagman
- b Department of Emergency Medicine , Charité - Universitätsmedizin , Campus Virchow and Campus Mitte , Berlin , Germany
| | - Karl Stangl
- a Department of Cardiology and Angiology , Charité - Universitätsmedizin , Campus Mitte , Berlin , Germany
| | - Verena Stangl
- a Department of Cardiology and Angiology , Charité - Universitätsmedizin , Campus Mitte , Berlin , Germany
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Khanmoradi M, Nasimi A. Endogenous angiotensin II in the paraventricular nucleus regulates arterial pressure during hypotension in rat, a single-unit study. Neurosci Res 2016; 114:35-42. [PMID: 27637162 DOI: 10.1016/j.neures.2016.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 09/02/2016] [Accepted: 09/05/2016] [Indexed: 02/01/2023]
Abstract
The hypothalamic paraventricular nucleus (PVN) controls cardiovascular regulation through vasopressin and sympathetic system. The PVN contains angiotensin II (AngII) and AngII receptors. We have already shown that microinjection of AngII into PVN produced a pressor response concomitant with an increase in firing rate of some PVN neurons. This study was performed to find if PVN AngII plays a regulatory function during hypotension. Hypovolemic-hypotension was induced and the possible role of the PVN AngII in returning arterial pressure toward normal was assessed by monitoring cardiovascular response and single-unit activity of the PVN neurons. Hemorrhage augmented the pressor, tachycardic and single-unit responses to AngII. After-hemorrhage injection of PD123319, an AT2 antagonist, into PVN resulted in a significant decrease in firing rate of some neurons, indicating that AngII was released into the PVN due to hemorrhage. Using single-unit recording, we found that PVN receives electrical signals from baroreceptors and from circulating AngII through circumventricular organs. In addition, by producing hemorrhagic-hypotension and bilateral blockade of AT2 receptors of the PVN, we found that AngII regulates arterial pressure toward normal during hypotension. So for the first time, it was verified that brain renin-angiotensin system is also a major regulatory system of the cardiovascular system.
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Affiliation(s)
- Mehrangiz Khanmoradi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ali Nasimi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
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Cruz JC, Flôr AFL, França-Silva MS, Balarini CM, Braga VA. Reactive Oxygen Species in the Paraventricular Nucleus of the Hypothalamus Alter Sympathetic Activity During Metabolic Syndrome. Front Physiol 2015; 6:384. [PMID: 26779026 PMCID: PMC4688401 DOI: 10.3389/fphys.2015.00384] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 11/27/2015] [Indexed: 12/31/2022] Open
Abstract
The paraventricular nucleus of the hypothalamus (PVN) contains heterogeneous populations of neurons involved in autonomic and neuroendocrine regulation. The PVN plays an important role in the sympathoexcitatory response to increasing circulating levels of angiotensin II (Ang-II), which activates AT1 receptors in the circumventricular organs (OCVs), mainly in the subfornical organ (SFO). Circulating Ang-II induces a de novo synthesis of Ang-II in SFO neurons projecting to pre-autonomic PVN neurons. Activation of AT1 receptors induces intracellular increases in reactive oxygen species (ROS), leading to increases in sympathetic nerve activity (SNA). Chronic sympathetic nerve activation promotes a series of metabolic disorders that characterizes the metabolic syndrome (MetS): dyslipidemia, hyperinsulinemia, glucose intolerance, hyperleptinemia and elevated plasma hormone levels, such as noradrenaline, glucocorticoids, leptin, insulin, and Ang-II. This review will discuss the contribution of our laboratory and others regarding the sympathoexcitation caused by peripheral Ang-II-induced reactive oxygen species along the subfornical organ and paraventricular nucleus of the hypothalamus. We hypothesize that this mechanism could be involved in metabolic disorders underlying MetS.
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Affiliation(s)
- Josiane C Cruz
- Centro de Biotecnologia, Universidade Federal da Paraíba João Pessoa, Brazil
| | - Atalia F L Flôr
- Centro de Biotecnologia, Universidade Federal da Paraíba João Pessoa, Brazil
| | | | - Camille M Balarini
- Centro de Biotecnologia, Universidade Federal da ParaíbaJoão Pessoa, Brazil; Centro de Ciências da Saúde, Universidade Federal da ParaíbaJoão Pessoa, Brazil
| | - Valdir A Braga
- Centro de Biotecnologia, Universidade Federal da Paraíba João Pessoa, Brazil
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Central nervous system circuits modified in heart failure: pathophysiology and therapeutic implications. Heart Fail Rev 2015; 19:759-79. [PMID: 24573960 DOI: 10.1007/s10741-014-9427-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The pathophysiology of heart failure (HF) is characterized by an abnormal activation of neurohumoral systems, including the sympathetic nervous and the renin-angiotensin-aldosterone systems, which have long-term deleterious effects on the disease progression. Perpetuation of this neurohumoral activation is partially dependent of central nervous system (CNS) pathways, mainly involving the paraventricular nucleus of the hypothalamus and some regions of the brainstem. Modifications in these integrative CNS circuits result in the attenuation of sympathoinhibitory and exacerbation of sympathoexcitatory pathways. In addition to the regulation of sympathetic outflow, these central pathways coordinate a complex network of agents with an established pathophysiological relevance in HF such as angiotensin, aldosterone, and proinflammatory cytokines. Central pathways could be potential targets in HF therapy since the current mainstay of HF pharmacotherapy aims primarily at antagonizing the peripheral mechanisms. Thus, in the present review, we describe the role of CNS pathways in HF pathophysiology and as potential novel therapeutic targets.
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Marques-Lopes J, Lynch MK, Van Kempen TA, Waters EM, Wang G, Iadecola C, Pickel VM, Milner TA. Female protection from slow-pressor effects of angiotensin II involves prevention of ROS production independent of NMDA receptor trafficking in hypothalamic neurons expressing angiotensin 1A receptors. Synapse 2015; 69:148-65. [PMID: 25559190 PMCID: PMC4355104 DOI: 10.1002/syn.21800] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 12/23/2014] [Indexed: 12/21/2022]
Abstract
Renin–angiotensin system overactivity, upregulation of postsynaptic NMDA receptor function, and increased reactive oxygen species (ROS) production in the hypothalamic paraventricular nucleus (PVN) are hallmarks of angiotensin II (AngII)-induced hypertension, which is far more common in young males than in young females. We hypothesize that the sex differences in hypertension are related to differential AngII-induced changes in postsynaptic trafficking of the essential NMDA receptor GluN1 subunit and ROS production in PVN cells expressing angiotensin Type 1a receptor (AT1aR). We tested this hypothesis using slow-pressor (14-day) infusion of AngII (600 ng/kg/min) in mice, which elicits hypertension in males but not in young females. Two-month-old male and female transgenic mice expressing enhanced green fluorescent protein (EGFP) in AT1aR-containing cells were used. In males, but not in females, AngII increased blood pressure and ROS production in AT1aR–EGFP PVN cells at baseline and following NMDA treatment. Electron microscopy showed that AngII increased cytoplasmic and total GluN1–silver-intensified immunogold (SIG) densities and induced a trend toward an increase in near plasmalemmal GluN1–SIG density in AT1aR–EGFP dendrites of males and females. Moreover, AngII decreased dendritic area and diameter in males, but increased dendritic area of small (<1 µm) dendrites and decreased diameter of large (>1 µm) dendrites in females. Fluorescence microscopy revealed that AT1aR and estrogen receptor β do not colocalize, suggesting that if estrogen is involved, its effect is indirect. These data suggest that the sexual dimorphism in AngII-induced hypertension is associated with sex differences in ROS production in AT1aR-containing PVN cells but not with postsynaptic NMDA receptor trafficking.
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Affiliation(s)
- Jose Marques-Lopes
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
| | - Mary-Katherine Lynch
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
| | - Tracey A. Van Kempen
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
| | - Elizabeth M. Waters
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065
| | - Gang Wang
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
| | - Costantino Iadecola
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
| | - Virginia M. Pickel
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
| | - Teresa A. Milner
- Brain and Mind Research Institute, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065
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Reporter mouse strain provides a novel look at angiotensin type-2 receptor distribution in the central nervous system. Brain Struct Funct 2014; 221:891-912. [PMID: 25427952 DOI: 10.1007/s00429-014-0943-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/07/2014] [Indexed: 02/07/2023]
Abstract
Angiotensin-II acts at its type-1 receptor (AT1R) in the brain to regulate body fluid homeostasis, sympathetic outflow and blood pressure. However, the role of the angiotensin type-2 receptor (AT2R) in the neural control of these processes has received far less attention, largely because of limited ability to effectively localize these receptors at a cellular level in the brain. The present studies combine the use of a bacterial artificial chromosome transgenic AT2R-enhanced green fluorescent protein (eGFP) reporter mouse with recent advances in in situ hybridization (ISH) to circumvent this obstacle. Dual immunohistochemistry (IHC)/ISH studies conducted in AT2R-eGFP reporter mice found that eGFP and AT2R mRNA were highly co-localized within the brain. Qualitative analysis of eGFP immunoreactivity in the brain then revealed localization to neurons within nuclei that regulate blood pressure, metabolism, and fluid balance (e.g., NTS and median preoptic nucleus [MnPO]), as well as limbic and cortical areas known to impact stress responding and mood. Subsequently, dual IHC/ISH studies uncovered the phenotype of specific populations of AT2R-eGFP cells. For example, within the NTS, AT2R-eGFP neurons primarily express glutamic acid decarboxylase-1 (80.3 ± 2.8 %), while a smaller subset express vesicular glutamate transporter-2 (18.2 ± 2.9 %) or AT1R (8.7 ± 1.0 %). No co-localization was observed with tyrosine hydroxylase in the NTS. Although AT2R-eGFP neurons were not observed within the paraventricular nucleus (PVN) of the hypothalamus, eGFP immunoreactivity is localized to efferents terminating in the PVN and within GABAergic neurons surrounding this nucleus. These studies demonstrate that central AT2R are positioned to regulate blood pressure, metabolism, and stress responses.
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Speth RC, Carrera EJ, Bretón C, Linares A, Gonzalez-Reiley L, Swindle JD, Santos KL, Schadock I, Bader M, Karamyan VT. Distribution of non-AT1, non-AT2 binding of 125I-sarcosine1, isoleucine8 angiotensin II in neurolysin knockout mouse brains. PLoS One 2014; 9:e105762. [PMID: 25147932 PMCID: PMC4141804 DOI: 10.1371/journal.pone.0105762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 06/13/2014] [Indexed: 11/18/2022] Open
Abstract
The recent identification of a novel binding site for angiotensin (Ang) II as the peptidase neurolysin (E.C. 3.4.24.16) has implications for the renin-angiotensin system (RAS). This report describes the distribution of specific binding of 125I-Sarcosine1, Isoleucine8 Ang II (125I-SI Ang II) in neurolysin knockout mouse brains compared to wild-type mouse brains using quantitative receptor autoradiography. In the presence of p-chloromercuribenzoic acid (PCMB), which unmasks the novel binding site, widespread distribution of specific (3 µM Ang II displaceable) 125I-SI Ang II binding in 32 mouse brain regions was observed. Highest levels of binding >700 fmol/g initial wet weight were seen in hypothalamic, thalamic and septal regions, while the lowest level of binding <300 fmol/g initial wet weight was in the mediolateral medulla. 125I-SI Ang II binding was substantially higher by an average of 85% in wild-type mouse brains compared to neurolysin knockout brains, suggesting the presence of an additional non-AT1, non-AT2, non-neurolysin Ang II binding site in the mouse brain. Binding of 125I-SI Ang II to neurolysin in the presence of PCMB was highest in hypothalamic and ventral cortical brain regions, but broadly distributed across all regions surveyed. Non-AT1, non-AT2, non-neurolysin binding was also highest in the hypothalamus but had a different distribution than neurolysin. There was a significant reduction in AT2 receptor binding in the neurolysin knockout brain and a trend towards decreased AT1 receptor binding. In the neurolysin knockout brains, the size of the lateral ventricles was increased by 56% and the size of the mid forebrain (−2.72 to +1.48 relative to Bregma) was increased by 12%. These results confirm the identity of neurolysin as a novel Ang II binding site, suggesting that neurolysin may play a significant role in opposing the pathophysiological actions of the brain RAS and influencing brain morphology.
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Affiliation(s)
- Robert C. Speth
- Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Eduardo J. Carrera
- Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
- Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Catalina Bretón
- Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
- Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Andrea Linares
- Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Luz Gonzalez-Reiley
- Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Jamala D. Swindle
- Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Kira L. Santos
- Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
- College of Dentistry, University of Florida, Gainesville, Florida, United States of America
| | - Ines Schadock
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Michael Bader
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Vardan T. Karamyan
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, Texas, United States of America
- Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center, Amarillo, Texas, United States of America
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16
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Silva MPD, Cedraz-Mercez PL, Varanda WA. Effects of nitric oxide on magnocellular neurons of the supraoptic nucleus involve multiple mechanisms. Braz J Med Biol Res 2014; 47:90-100. [PMID: 24519124 PMCID: PMC4051181 DOI: 10.1590/1414-431x20133326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 10/22/2013] [Indexed: 01/24/2023] Open
Abstract
Physiological evidence indicates that the supraoptic nucleus (SON) is an
important region for integrating information related to homeostasis of body
fluids. Located bilaterally to the optic chiasm, this nucleus is composed of
magnocellular neurosecretory cells (MNCs) responsible for the synthesis and
release of vasopressin and oxytocin to the neurohypophysis. At the cellular
level, the control of vasopressin and oxytocin release is directly linked to the
firing frequency of MNCs. In general, we can say that the excitability of these
cells can be controlled via two distinct mechanisms: 1) the intrinsic membrane
properties of the MNCs themselves and 2) synaptic input from circumventricular
organs that contain osmosensitive neurons. It has also been demonstrated that
MNCs are sensitive to osmotic stimuli in the physiological range. Therefore, the
study of their intrinsic membrane properties became imperative to explain the
osmosensitivity of MNCs. In addition to this, the discovery that several
neurotransmitters and neuropeptides can modulate their electrical activity
greatly increased our knowledge about the role played by the MNCs in fluid
homeostasis. In particular, nitric oxide (NO) may be an important player in
fluid balance homeostasis, because it has been demonstrated that the enzyme
responsible for its production has an increased activity following a hypertonic
stimulation of the system. At the cellular level, NO has been shown to change
the electrical excitability of MNCs. Therefore, in this review, we focus on some
important points concerning nitrergic modulation of the neuroendocrine system,
particularly the effects of NO on the SON.
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Affiliation(s)
- M P da Silva
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão PretoSP, Brasil, Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - P L Cedraz-Mercez
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão PretoSP, Brasil, Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - W A Varanda
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão PretoSP, Brasil, Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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17
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Serum copeptin levels in adolescents with primary hypertension. Pediatr Nephrol 2014; 29:423-9. [PMID: 24375010 PMCID: PMC3913848 DOI: 10.1007/s00467-013-2683-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 10/25/2013] [Accepted: 10/25/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND The prevalence of hypertension continues to rise in the pediatric population. In recent years, there has been an increasing amount of reports on serum arginine vasopressin and its derivative, copeptin, in blood pressure control, but its role is still unclear. The objective of this study was to assess serum copeptin in adolescents with essential hypertension. METHODS The study cohort consisted of 84 subjects (30 girls and 54 boys) aged 11-18 years, divided into two groups: hypertension (HT) - 53 subjects with confirmed primary hypertension and R - reference group - 31 subjects in whom hypertension was excluded on the basis of ambulatory blood pressure monitoring (ABPM) (white-coat hypertension). Serum copeptin concentration was measured using a commercially available enzyme-linked immunosorbent assay kit (USCN). RESULTS Hypertensive patients had higher serum copeptin levels (median, 267 [Q1-Q3: 151.1-499.7 pg/ml]) than controls (median, 107.3 [Q1-Q3: 36.7-203.4 pg/ml]), (p < 0.01). Statistically significant difference was found both in males and females. In both groups, positive correlations between serum copeptin and uric acid levels (r = 0.31, p < 0.01), albuminuria (r = 0.45, p < 0.01), serum triglycerides (r = 0.3, p < 0.05), body mass index (BMI) standard deviation score (SDS) (r = 0.24, p < 0.05) and 24-h systolic blood pressure (SBP) (r = 0.37, p < 0.01) and diastolic blood pressure (DBP) (r = 0.23, p < 0.05) were found. CONCLUSIONS In summary, higher serum copeptin levels, a surrogate for arginine vasopressin (AVP) release, are associated not only with systolic and diastolic blood pressure but also with several components of metabolic syndrome including obesity, elevated concentration of triglycerides, albuminuria, and serum uric acid level. However, for the time being, more research is needed in order to confirm the role of serum copeptin as a novel marker of elevated blood pressure and predictor of metabolic syndrome.
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18
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Antunes-Rodrigues J, Ruginsk SG, Mecawi AS, Margatho LO, Cruz JC, Vilhena-Franco T, Reis WL, Ventura RR, Reis LC, Vivas LM, Elias LLK. Mapping and signaling of neural pathways involved in the regulation of hydromineral homeostasis. Braz J Med Biol Res 2013; 46:327-38. [PMID: 23579631 PMCID: PMC3854407 DOI: 10.1590/1414-431x20132788] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 02/05/2013] [Indexed: 11/22/2022] Open
Abstract
Several forebrain and brainstem neurochemical circuitries interact with
peripheral neural and humoral signals to collaboratively maintain both the
volume and osmolality of extracellular fluids. Although much progress has been
made over the past decades in the understanding of complex mechanisms underlying
neuroendocrine control of hydromineral homeostasis, several issues still remain
to be clarified. The use of techniques such as molecular biology, neuronal
tracing, electrophysiology, immunohistochemistry, and microinfusions has
significantly improved our ability to identify neuronal phenotypes and their
signals, including those related to neuron-glia interactions. Accordingly,
neurons have been shown to produce and release a large number of chemical
mediators (neurotransmitters, neurohormones and neuromodulators) into the
interstitial space, which include not only classic neurotransmitters, such as
acetylcholine, amines (noradrenaline, serotonin) and amino acids (glutamate,
GABA), but also gaseous (nitric oxide, carbon monoxide and hydrogen sulfide) and
lipid-derived (endocannabinoids) mediators. This efferent response, initiated
within the neuronal environment, recruits several peripheral effectors, such as
hormones (glucocorticoids, angiotensin II, estrogen), which in turn modulate
central nervous system responsiveness to systemic challenges. Therefore, in this
review, we shall evaluate in an integrated manner the physiological control of
body fluid homeostasis from the molecular aspects to the systemic and integrated
responses.
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Affiliation(s)
- J Antunes-Rodrigues
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
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19
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Littlejohn NK, Siel RB, Ketsawatsomkron P, Pelham CJ, Pearson NA, Hilzendeger AM, Buehrer BA, Weidemann BJ, Li H, Davis DR, Thompson AP, Liu X, Cassell MD, Sigmund CD, Grobe JL. Hypertension in mice with transgenic activation of the brain renin-angiotensin system is vasopressin dependent. Am J Physiol Regul Integr Comp Physiol 2013; 304:R818-28. [PMID: 23535460 DOI: 10.1152/ajpregu.00082.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
An indispensable role for the brain renin-angiotensin system (RAS) has been documented in most experimental animal models of hypertension. To identify the specific efferent pathway activated by the brain RAS that mediates hypertension, we examined the hypothesis that elevated arginine vasopressin (AVP) release is necessary for hypertension in a double-transgenic model of brain-specific RAS hyperactivity (the "sRA" mouse model). sRA mice experience elevated brain RAS activity due to human angiotensinogen expression plus neuron-specific human renin expression. Total daily loss of the 4-kDa AVP prosegment (copeptin) into urine was grossly elevated (≥8-fold). Immunohistochemical staining for AVP was increased in the supraoptic nucleus of sRA mice (~2-fold), but no quantitative difference in the paraventricular nucleus was observed. Chronic subcutaneous infusion of a nonselective AVP receptor antagonist conivaptan (YM-087, Vaprisol, 22 ng/h) or the V(2)-selective antagonist tolvaptan (OPC-41061, 22 ng/h) resulted in normalization of the baseline (~15 mmHg) hypertension in sRA mice. Abdominal aortas and second-order mesenteric arteries displayed AVP-specific desensitization, with minor or no changes in responses to phenylephrine and endothelin-1. Mesenteric arteries exhibited substantial reductions in V(1A) receptor mRNA, but no significant changes in V(2) receptor expression in kidney were observed. Chronic tolvaptan infusion also normalized the (5 mmol/l) hyponatremia of sRA mice. Together, these data support a major role for vasopressin in the hypertension of mice with brain-specific hyperactivity of the RAS and suggest a primary role of V(2) receptors.
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Affiliation(s)
- Nicole K Littlejohn
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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20
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Immunohistochemical Localization of AT1a, AT1b, and AT2 Angiotensin II Receptor Subtypes in the Rat Adrenal, Pituitary, and Brain with a Perspective Commentary. Int J Hypertens 2013; 2013:175428. [PMID: 23573410 PMCID: PMC3614054 DOI: 10.1155/2013/175428] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/01/2013] [Accepted: 02/05/2013] [Indexed: 11/17/2022] Open
Abstract
Angiotensin II increases blood pressure and stimulates thirst and sodium appetite in the brain. It also stimulates secretion of aldosterone from the adrenal zona glomerulosa and epinephrine from the adrenal medulla. The rat has 3 subtypes of angiotensin II receptors: AT1a, AT1b, and AT2. mRNAs for all three subtypes occur in the adrenal and brain. To immunohistochemically differentiate these receptor subtypes, rabbits were immunized with C-terminal fragments of these subtypes to generate receptor subtype-specific antibodies. Immunofluorescence revealed AT1a and AT2 receptors in adrenal zona glomerulosa and medulla. AT1b immunofluorescence was present in the zona glomerulosa, but not the medulla. Ultrastructural immunogold labeling for the AT1a receptor in glomerulosa and medullary cells localized it to plasma membrane, endocytic vesicles, multivesicular bodies, and the nucleus. AT1b and AT2, but not AT1a, immunofluorescence was observed in the anterior pituitary. Stellate cells were AT1b positive while ovoid cells were AT2 positive. In the brain, neurons were AT1a, AT1b, and AT2 positive, but glia was only AT1b positive. Highest levels of AT1a, AT1b, and AT2 receptor immunofluorescence were in the subfornical organ, median eminence, area postrema, paraventricular nucleus, and solitary tract nucleus. These studies complement those employing different techniques to characterize Ang II receptors.
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21
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Gonzalez AD, Wang G, Waters EM, Gonzales KL, Speth RC, Van Kempen TA, Marques-Lopes J, Young CN, Butler SD, Davisson RL, Iadecola C, Pickel VM, Pierce JP, Milner TA. Distribution of angiotensin type 1a receptor-containing cells in the brains of bacterial artificial chromosome transgenic mice. Neuroscience 2012; 226:489-509. [PMID: 22922351 DOI: 10.1016/j.neuroscience.2012.08.039] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/16/2012] [Accepted: 08/17/2012] [Indexed: 10/28/2022]
Abstract
In the central nervous system, angiotensin II (AngII) binds to angiotensin type 1 receptors (AT(1)Rs) to affect autonomic and endocrine functions as well as learning and memory. However, understanding the function of cells containing AT(1)Rs has been restricted by limited availability of specific antisera, difficulties discriminating AT(1)R-immunoreactive cells in many brain regions and, the identification of AT(1)R-containing neurons for physiological and molecular studies. Here, we demonstrate that an Agtr1a bacterial artificial chromosome (BAC) transgenic mouse line that expresses type A AT(1)Rs (AT1aRs) identified by enhanced green fluorescent protein (EGFP) overcomes these shortcomings. Throughout the brain, AT1aR-EGFP was detected in the nuclei and cytoplasm of cells, most of which were neurons. EGFP often extended into dendritic processes and could be identified either natively or with immunolabeling of GFP. The distribution of AT1aR-EGFP cells in brain closely corresponded to that reported for AngII binding and AT1aR protein and mRNA. In particular, AT1aR-EGFP cells were in autonomic regions (e.g., hypothalamic paraventricular nucleus, central nucleus of the amygdala, parabrachial nucleus, nuclei of the solitary tract and rostral ventrolateral medulla) and in regions involved in electrolyte and fluid balance (i.e., subfornical organ) and learning and memory (i.e., cerebral cortex and hippocampus). Additionally, dual label electron microscopic studies in select brain areas demonstrate that cells containing AT1aR-EGFP colocalize with AT(1)R-immunoreactivity. Assessment of AngII-induced free radical production in isolated EGFP cells demonstrated feasibility of studies investigating AT1aR signaling ex vivo. These findings support the utility of Agtr1a BAC transgenic reporter mice for future studies understanding the role of AT(1)R-containing cells in brain function.
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Affiliation(s)
- A D Gonzalez
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065, USA
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22
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Wang G, Coleman CG, Glass MJ, Zhou P, Yu Q, Park L, Anrather J, Pickel VM, Iadecola C. Angiotensin II type 2 receptor-coupled nitric oxide production modulates free radical availability and voltage-gated Ca2+ currents in NTS neurons. Am J Physiol Regul Integr Comp Physiol 2012; 302:R1076-83. [PMID: 22378773 PMCID: PMC3362142 DOI: 10.1152/ajpregu.00571.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 02/25/2012] [Indexed: 02/07/2023]
Abstract
The medial region of the nucleus tractus solitarius (mNTS) is a key brain stem site controlling cardiovascular function, wherein ANG II modulates neuronal L-type Ca(2+) currents via activation of ANG II type 1 receptors (AT(1)R) and production of reactive oxygen species (ROS). ANG II type 2 receptors (AT(2)R) induce production of nitric oxide (NO), which may interact with ROS and modulate AT(1)R signaling. We sought to determine whether AT(2)R-mediated NO production occurs in mNTS neurons and, if so, to elucidate the NO source and the functional interaction with AT(1)R-induced ROS or Ca(2+) influx. Electron microscopic (EM) immunolabeling showed that AT(2)R and neuronal NO synthase (nNOS) are coexpressed in neuronal somata and dendrites receiving synapses in the mNTS. In the presence of the AT(1)R antagonist losartan, ANG II increased NO production in isolated mNTS neurons, an effect blocked by the AT(2)R antagonist PD123319, but not the angiotensin (1-7) antagonist D-Ala. Studies in mNTS neurons of nNOS-null or endothelial NOS (eNOS)-null mice established nNOS as the source of NO. ANG II-induced ROS production was enhanced by PD123319, the NOS inhibitor N(G)-nitro-l-arginine (LNNA), or in nNOS-null mice. Moreover, in the presence of losartan, ANG II reduced voltage-gated L-type Ca(2+) current, an effect blocked by PD123319 or LNNA. We conclude that AT(2)R are closely associated and functionally coupled with nNOS in mNTS neurons. The resulting NO production antagonizes AT(1)R-mediated ROS and dampens L-type Ca(2+) currents. The ensuing signaling changes in the NTS may counteract the deleterious effects of AT(1)R on cardiovascular function.
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Affiliation(s)
- Gang Wang
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, New York 10065, USA.
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23
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Gao L, Zucker IH. AT2 receptor signaling and sympathetic regulation. Curr Opin Pharmacol 2010; 11:124-30. [PMID: 21159555 DOI: 10.1016/j.coph.2010.11.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 11/19/2010] [Accepted: 11/22/2010] [Indexed: 11/28/2022]
Abstract
There is a growing consensus that the balance between Angiotensin Type 1 (AT1R) and Angiotensin Type 2 (AT2R) signaling in many tissues may determine the magnitude and, in some cases the direction, of the biological response. Sympatho-excitation in cardiovascular diseases is mediated by a variety of factors and is, in part, dependent on Angiotensin II signaling in the central nervous system. Recent data have provided evidence that the AT2R can modulate sympatho-excitation in animals with hypertension and heart failure. The evidence for this concept is reviewed and a model is put forward to support the rationale that therapeutic targeting of the central AT2R may be beneficial in the setting of chronic heart failure.
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Affiliation(s)
- Lie Gao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198-5850, USA
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24
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Milner TA, Thompson LI, Wang G, Kievits JA, Martin E, Zhou P, McEwen BS, Pfaff DW, Waters EM. Distribution of estrogen receptor β containing cells in the brains of bacterial artificial chromosome transgenic mice. Brain Res 2010; 1351:74-96. [PMID: 20599828 DOI: 10.1016/j.brainres.2010.06.038] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 06/04/2010] [Accepted: 06/11/2010] [Indexed: 01/11/2023]
Abstract
In the brain, estrogen receptor beta (ERbeta) plays important roles in autonomic functions, stress reactivity and learning and memory processes. However, understanding the function of ERbeta has been restricted by the limited availability of specific antisera, by difficulties discriminating the discrete localization of ERbeta-immunoreactivity (ir) at the light microscopic level in many brain regions and the identification of ERbeta-containing neurons in neurophysiological and molecular studies. Here, we demonstrate that a Esr2 bacterial artificial chromosome (BAC) transgenic mouse line that expresses ERbeta identified by enhanced green fluorescent protein (EGFP) overcomes these shortcomings. Throughout the brain, ERbeta-EGFP was detected in the nuclei and cytoplasm of cells, the majority of which resembled neurons. EGFP often extended into dendritic processes and could be identified either natively or following intensification of EGFP using immunolabeling. The distribution of ERbeta-EGFP cells in brain closely corresponded to that reported for ERbeta protein and mRNA. In particular, ERbeta-EGFP cells were found in autonomic brain regions (i.e., hypothalamic paraventricular nucleus, rostral ventrolateral medulla and nucleus of the solitary tract), in regions associated with anxiety and stress behaviors (i.e., bed nucleus of the stria terminalis, amygdala, periaqueductal gray, raphe and parabrachial nuclei) and in regions involved in learning and memory processes (i.e., basal forebrain, cerebral cortex and hippocampus). Additionally, dual label light and electron microscopic studies in select brain areas demonstrate that cell containing ERbeta-EGFP colocalize with both nuclear and extranuclear ERbeta-immunoreactivity. These findings support the utility of Esr2 BAC transgenic reporter mice for future studies understanding the role of ERbeta in CNS function.
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Affiliation(s)
- Teresa A Milner
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065, USA; Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Louisa I Thompson
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065, USA; Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Gang Wang
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065, USA
| | - Justin A Kievits
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065, USA
| | - Eugene Martin
- Laboratory of Neurobiology and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Ping Zhou
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065, USA
| | - Bruce S McEwen
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Donald W Pfaff
- Laboratory of Neurobiology and Behavior, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Elizabeth M Waters
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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25
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Rodriguez-Perez AI, Valenzuela R, Villar-Cheda B, Guerra MJ, Lanciego JL, Labandeira-Garcia JL. Estrogen and angiotensin interaction in the substantia nigra. Relevance to postmenopausal Parkinson's disease. Exp Neurol 2010; 224:517-26. [PMID: 20580712 DOI: 10.1016/j.expneurol.2010.05.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 05/11/2010] [Accepted: 05/18/2010] [Indexed: 02/07/2023]
Abstract
Epidemiological studies have reported that the incidence of Parkinson's disease (PD) is higher in postmenopausal than in premenopausal women of similar age. Several laboratory observations have revealed that estrogen has protective effects against dopaminergic toxins. The mechanism by which estrogen protects dopaminergic neurons has not been clarified, although estrogen-induced attenuation of the neuroinflammatory response plays a major role. We have recently shown that activation of the nigral renin-angiotensin system (RAS), via type 1 (AT1) receptors, leads to NADPH complex and microglial activation and induces dopaminergic neuron death. In the present study we investigated the effect of ovariectomy and estrogen replacement on the nigral RAS and on dopaminergic degeneration induced by intrastriatal injection of 6-OHDA. We observed a marked loss of dopaminergic neurons in ovariectomized rats treated with 6-OHDA, which was significantly reduced by estrogen replacement or treatment with the AT1 receptor antagonist candesartan. We also observed that estrogen replacement induces significant downregulation of the activity of the angiotensin converting enzyme as well as downregulation of AT1 receptors, upregulation of AT2 receptors and downregulation of the NADPH complex activity in the substantia nigra in comparison with ovariectomized rats. The present results suggest that estrogen-induced down-regulation of RAS and NADPH activity may be associated with the reduced risk of PD in premenopausal women, and increased risk in conditions causing early reduction in endogenous estrogen, and that manipulation of brain RAS system may be an efficient approach for the prevention or coadjutant treatment of PD in estrogen-deficient women.
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Affiliation(s)
- Ana I Rodriguez-Perez
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Faculty of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain
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