1
|
Issotina Zibrila A, Wang Z, Sangaré-Oumar MM, Zeng M, Liu X, Wang X, Zeng Z, Kang YM, Liu J. Role of blood-borne factors in sympathoexcitation-mediated hypertension: Potential neurally mediated hypertension in preeclampsia. Life Sci 2022; 320:121351. [PMID: 36592790 DOI: 10.1016/j.lfs.2022.121351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/19/2022] [Accepted: 12/27/2022] [Indexed: 01/01/2023]
Abstract
Hypertension remains a threat for society due to its unknown causes, preventing proper management, for the growing number of patients, for its state as a high-risk factor for stroke, cardiac and renal complication and as cause of disability. Data from clinical and animal researches have suggested the important role of many soluble factors in the pathophysiology of hypertension through their neuro-stimulating effects. Central targets of these factors are of molecular, cellular and structural nature. Preeclampsia (PE) is characterized by high level of soluble factors with strong pro-hypertensive activity and includes immune factors such as proinflammatory cytokines (PICs). The potential neural effect of those factors in PE is still poorly understood. Shedding light into the potential central effect of the soluble factors in PE may advance our current comprehension of the pathophysiology of hypertension in PE, which will contribute to better management of the disease. In this paper, we summarized existing data in respect of hypothesis of this review, that is, the existence of the neural component in the pathophysiology of the hypertension in PE. Future studies would address this hypothesis to broaden our understanding of the pathophysiology of hypertension in PE.
Collapse
Affiliation(s)
- Abdoulaye Issotina Zibrila
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Sciences, Key Laboratory of Environment and Genes Related to Diseases, Xi'an 710061, Shaanxi, PR China; Department of Animal Physiology, Faculty of science and Technology, University of Abomey-Calavi, 06 BP 2584 Cotonou, Benin
| | - Zheng Wang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, PR China
| | - Machioud Maxime Sangaré-Oumar
- Department of Animal Physiology, Faculty of science and Technology, University of Abomey-Calavi, 06 BP 2584 Cotonou, Benin
| | - Ming Zeng
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Sciences, Key Laboratory of Environment and Genes Related to Diseases, Xi'an 710061, Shaanxi, PR China
| | - Xiaoxu Liu
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Sciences, Key Laboratory of Environment and Genes Related to Diseases, Xi'an 710061, Shaanxi, PR China
| | - Xiaomin Wang
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Sciences, Key Laboratory of Environment and Genes Related to Diseases, Xi'an 710061, Shaanxi, PR China
| | - Zhaoshu Zeng
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Sciences, Key Laboratory of Environment and Genes Related to Diseases, Xi'an 710061, Shaanxi, PR China
| | - Yu-Ming Kang
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Sciences, Key Laboratory of Environment and Genes Related to Diseases, Xi'an 710061, Shaanxi, PR China.
| | - Jinjun Liu
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Sciences, Key Laboratory of Environment and Genes Related to Diseases, Xi'an 710061, Shaanxi, PR China.
| |
Collapse
|
2
|
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.
Collapse
|
3
|
Luo S, Hou Y, Zhang Y, Feng L, Hunter RG, Yuan P, Jia Y, Li H, Wang G, K Manji H, S McEwen B, Xiao C, Bao H, Du J. Bag-1 mediates glucocorticoid receptor trafficking to mitochondria after corticosterone stimulation: Potential role in regulating affective resilience. J Neurochem 2020; 158:358-372. [PMID: 33025573 DOI: 10.1111/jnc.15211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 08/31/2020] [Accepted: 09/29/2020] [Indexed: 01/03/2023]
Abstract
Molecular abnormalities within the Glucocorticoid Receptor (GR) stress signaling pathway involved in dysfunction of mitochondria and confer vulnerability to stress-related psychiatric disorders. Bcl-2 associated athanogene (Bag-1) is a target for the actions of mood stabilizers. Bag-1 interacts with GR, thereby regulating glucocorticoid function. In this study, we investigate the potential role of Bag-1 in regulating GR translocation into mitochondria. Corticosterone (CORT) treatment significantly enhanced Bag-1/GR complex formation and GR mitochondrial translocation in cultured rat cortical neurons after treatment for 30 min and 24 hr. By contrast, after stimulation with CORT for 3 days, localization of the Bag-1/GR complex and mitochondrial GR were reduced. Similar results were obtained in mice, in which administrated CORT in drinking water for 21 days significantly impaired the GR levels in the mitochondria, while Bag-1 over-expression rescued this reduction. Furthermore, chronic CORT exposure led to anhedonia-like and depression-like behaviors in the sucrose-consumption test and forced swimming test, and these behaviors were rescued by Bag-1 over-expression. These results suggest that Bag-1 mediates GR trafficking to mitochondria and regulates affective resilience in response to a CORT increase and provide potential insight into the mechanisms by which Bag-1 and GR could contribute to the physiology and pathogenesis of psychiatric disorders in response to the change of stress hormone.
Collapse
Affiliation(s)
- Shaolei Luo
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China
| | - Yangyang Hou
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China
| | - Yaping Zhang
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China
| | - Lei Feng
- The National Clinical Research Center for Mental Disorders, Beijing Anding Hospital, & Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Richard G Hunter
- Department of Psychology, Developmental and Brain Sciences, University of Massachusetts Boston, Boston, MA, USA
| | - Peixiong Yuan
- Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Yue Jia
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China
| | - Haoran Li
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China
| | - Gang Wang
- The National Clinical Research Center for Mental Disorders, Beijing Anding Hospital, & Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | | | - Bruce S McEwen
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
| | - Chunjie Xiao
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China
| | - Hongkun Bao
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China
| | - Jing Du
- School of Medicine, Yunnan University, Kunming, Yunnan, P. R. China.,The National Clinical Research Center for Mental Disorders, Beijing Anding Hospital, & Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| |
Collapse
|
4
|
Biometric, nutritional, biochemical, and cardiovascular outcomes in male rats submitted to an experimental model of early weaning that mimics mother abandoning. J Dev Orig Health Dis 2020; 12:523-529. [PMID: 32900421 DOI: 10.1017/s2040174420000793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Literature describes breast milk as the best food for the newborn, recommending exclusive breastfeeding for up to 6 months of age. However, it is not available for more than 40% of children worldwide. Pharmacological and non-pharmacological models of 3-day early weaning were developed in rodents to investigate later outcomes related solely to this nutritional insult. Thus, the present work aimed to describe biometric, nutritional, biochemical, and cardiovascular outcomes in adult male rats submitted to 3-day early weaning achieved by maternal deprivation. This experimental model comprises not only nutritional insult but also emotional stress, simulating mother abandoning. Male offspring were physically separated from their mothers at 21st (control) or 18th (early weaning) postnatal day, receiving water/food ad libitum. Analysis performed at postnatal days 30, 90, 150, and 365 encompassed body mass and food intake monitoring and serum biochemistry determination. Further assessments included hemodynamic, echocardiographic, and cardiorespiratory evaluation. Early-weaned males presented higher body weight when compared to control as well as dyslipidemia, higher blood pressure, diastolic dysfunction, and cardiac hypertrophy in adult life. Animals early deprived of their mothers have also presented a worse performance on the maximal effort ergometer test. This work shows that 3-day early maternal deprivation favors the development of cardiovascular disease in male rats.
Collapse
|
5
|
Ma A, Gao L, Wafi AM, Yu L, Rudebush T, Zhou W, Zucker IH. Overexpression of Central ACE2 (Angiotensin-Converting Enzyme 2) Attenuates the Pressor Response to Chronic Central Infusion of Ang II (Angiotensin II): A Potential Role for Nrf2 (Nuclear Factor [Erythroid-Derived 2]-Like 2). Hypertension 2020; 76:1514-1525. [PMID: 32895018 DOI: 10.1161/hypertensionaha.120.15681] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We investigated the mechanism by which ACE2 (angiotensin-converting enzyme 2) overexpression alters neurohumoral outflow and central oxidative stress. Nrf2 (nuclear factor [erythroid-derived 2]-like 2) is a master antioxidant transcription factor that regulates cytoprotective and antioxidant genes. We hypothesized that upregulation of central ACE2 inhibits the pressor response to Ang II (angiotensin II) by reducing reactive oxygen species through a Nrf2/antioxidant enzyme-mediated mechanism in the rostral ventrolateral medulla. Synapsin human Angiotensin Converting Enzyme 2 positive (SynhACE2+/+) mice and their littermate controls synhACE2-/- were used to evaluate the consequence of intracerebroventricular infusion of Ang II. In control mice, Ang II infusion evoked a significant increase in blood pressure and norepinephrine excretion, along with polydipsia and polyuria. The pressor effect of central Ang II was completely blocked in synhACE2+/+ mice. Polydipsia, norepinephrine excretion, and markers of oxidative stress in response to central Ang II were also reduced in synhACE2+/+ mice. The MasR (Mas receptor) agonist Ang 1-7 and blocker A779 had no effects on blood pressure. synhACE2+/+ mice showed enhanced expression of Nrf2 in the rostral ventrolateral medulla which was blunted following Ang II infusion. Ang II evoked nuclear translocation of Nrf2 in cultured Neuro 2A (N2A) cells. In synhACE2-/- mice, the central Ang II pressor response was attenuated by simultaneous intracerebroventricular infusion of the Nrf2 activator sulforaphane; blood pressure was enhanced by knockdown of Nrf2 in the rostral ventrolateral medulla in Nrf2 floxed (Nrf2f/f) mice. These data suggest that the hypertensive effects of intracerebroventricular Ang II are attenuated by selective overexpression of brain synhACE2 and may be mediated by Nrf2-upregulated antioxidant enzymes in the rostral ventrolateral medulla.
Collapse
Affiliation(s)
- Anyun Ma
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha
| | - Lie Gao
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha
| | - Ahmed M Wafi
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha
| | - Li Yu
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha
| | - Tara Rudebush
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha
| | - Wenxian Zhou
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha
| | - Irving H Zucker
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha
| |
Collapse
|
6
|
Tasker JG, Prager-Khoutorsky M, Teruyama R, Lemos JR, Amstrong WE. Advances in the neurophysiology of magnocellular neuroendocrine cells. J Neuroendocrinol 2020; 32:e12826. [PMID: 31917875 PMCID: PMC7192795 DOI: 10.1111/jne.12826] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 01/02/2020] [Accepted: 01/07/2020] [Indexed: 02/06/2023]
Abstract
Hypothalamic magnocellular neuroendocrine cells have unique electrical properties and a remarkable capacity for morphological and synaptic plasticity. Their large somatic size, their relatively uniform and dense clustering in the supraoptic and paraventricular nuclei, and their large axon terminals in the neurohypophysis make them an attractive target for direct electrophysiological interrogation. Here, we provide a brief review of significant recent findings in the neuroplasticity and neurophysiological properties of these neurones that were presented at the symposium "Electrophysiology of Magnocellular Neurons" during the 13th World Congress on Neurohypophysial Hormones in Ein Gedi, Israel in April 2019. Magnocellular vasopressin (VP) neurones respond directly to hypertonic stimulation with membrane depolarisation, which is triggered by cell shrinkage-induced opening of an N-terminal-truncated variant of transient receptor potential vanilloid type-1 (TRPV1) channels. New findings indicate that this mechanotransduction depends on actin and microtubule cytoskeletal networks, and that direct coupling of the TRPV1 channels to microtubules is responsible for mechanical gating of the channels. Vasopressin neurones also respond to osmostimulation by activation of epithelial Na+ channels (ENaC). It was shown recently that changes in ENaC activity modulate magnocellular neurone basal firing by generating tonic changes in membrane potential. Both oxytocin and VP neurones also undergo robust excitatory synapse plasticity during chronic osmotic stimulation. Recent findings indicate that new glutamate synapses induced during chronic salt loading express highly labile Ca2+ -permeable GluA1 receptors requiring continuous dendritic protein synthesis for synapse maintenance. Finally, recordings from the uniquely tractable neurohypophysial terminals recently revealed an unexpected property of activity-dependent neuropeptide release. A significant fraction of the voltage-dependent neurohypophysial neurosecretion was found to be independent of Ca2+ influx through voltage-gated Ca2+ channels. Together, these findings provide a snapshot of significant new advances in the electrophysiological signalling mechanisms and neuroplasticity of the hypothalamic-neurohypophysial system, a system that continues to make important contributions to the field of neurophysiology.
Collapse
Affiliation(s)
- Jeffrey G. Tasker
- Department of Cell and Molecular Biology and Tulane Brain Institute, Tulane University, New Orleans, LA, USA
- Correspondence: Jeffrey Tasker, PhD, Tulane University, Cell and Molecular Biology Dept, 2000 Percival Stern Hall, New Orleans, LA 70118, USA; .; William Armstrong, PhD, University of Tennessee Health Science Center, Anatomy and Neurobiology Dept and Neuroscience Institute, 855 Monroe Ave, Memphis, TN 38163, USA;
| | | | - Ryoichi Teruyama
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - José R. Lemos
- Department of Microbiology and Physiological Systems & Program in Neuroscience, University of Massachusetts Medical School, Worcester, MA, USA
| | - William E. Amstrong
- Department of Anatomy and Neurobiology and Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
- Correspondence: Jeffrey Tasker, PhD, Tulane University, Cell and Molecular Biology Dept, 2000 Percival Stern Hall, New Orleans, LA 70118, USA; .; William Armstrong, PhD, University of Tennessee Health Science Center, Anatomy and Neurobiology Dept and Neuroscience Institute, 855 Monroe Ave, Memphis, TN 38163, USA;
| |
Collapse
|
7
|
Leenen FHH, Wang HW, Hamlyn JM. Sodium pumps, ouabain and aldosterone in the brain: A neuromodulatory pathway underlying salt-sensitive hypertension and heart failure. Cell Calcium 2019; 86:102151. [PMID: 31954234 DOI: 10.1016/j.ceca.2019.102151] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 12/15/2019] [Indexed: 02/08/2023]
Abstract
Accumulating evidence obtained over the last three decades has revealed a neuroendocrine system in the brain that mediates long term increases in blood pressure. The system involves distinct ion transport pathways including the alpha-2 isoform of the Na,K pump and epithelial sodium channels, as well as critical hormone elements such as angiotensin II, aldosterone, mineralocorticoid receptors and endogenous ouabain. Activation of this system either by circulating or central sodium ions and/or angiotensin II leads to a cascading sequence of events that begins in the hypothalamus and involves the participation of several brain nuclei including the subfornical organ, supraoptic and paraventricular nuclei and the rostral ventral medulla. Key events include heightened aldosterone synthesis and mineralocorticoid receptor activation, upregulation of epithelial sodium channels, augmented synthesis and secretion of endogenous ouabain from hypothalamic magnocellular neurons, and sustained increases in sympathetic outflow. The latter step depends upon increased production of angiotensin II and the primary amplification of angiotensin II type I receptor signaling from the paraventricular nucleus to the rostral ventral lateral medulla. The transmission of sympathetic traffic is secondarily amplified in the periphery by increased short- and long-term potentiation in sympathetic ganglia and by sustained actions of endogenous ouabain in the vascular wall that augment expression of sodium calcium exchange, increase cytosolic Ca2+ and heighten myogenic tone and contractility. Upregulation of this multi-amplifier system participates in forms of hypertension where salt, angiotensin and/or aldosterone are elevated and contributes to adverse outcomes in heart failure.
Collapse
Affiliation(s)
- Frans H H Leenen
- Brain and Heart Research Group, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Hong-Wei Wang
- Brain and Heart Research Group, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - John M Hamlyn
- Department of Physiology, University of Maryland, Baltimore, MD, USA.
| |
Collapse
|
8
|
Lu J, Wang HW, Ahmad M, Keshtkar-Jahromi M, Blaustein MP, Hamlyn JM, Leenen FHH. Central and peripheral slow-pressor mechanisms contributing to Angiotensin II-salt hypertension in rats. Cardiovasc Res 2019; 114:233-246. [PMID: 29126194 DOI: 10.1093/cvr/cvx214] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/07/2017] [Indexed: 12/17/2022] Open
Abstract
Aims High salt intake markedly enhances hypertension induced by angiotensin II (Ang II). We explored central and peripheral slow-pressor mechanisms which may be activated by Ang II and salt. Methods and results In protocol I, Wistar rats were infused subcutaneously with low-dose Ang II (150 ng/kg/min) and fed regular (0.4%) or high salt (2%) diet for 14 days. In protocol II, Ang II-high salt was combined with intracerebroventricular infusion of mineralocorticoid receptor (MR) blockers (eplerenone, spironolactone), epithelial sodium channel (ENaC) blocker (benzamil), angiotensin II type 1 receptor (AT1R) blocker (losartan) or vehicles. Ang II alone raised mean arterial pressure (MAP) ∼10 mmHg, but Ang II-high salt increased MAP ∼50 mmHg. Ang II-high salt elevated plasma corticosterone, aldosterone and endogenous ouabain but not Ang II alone. Both Ang II alone and Ang II-high salt increased mRNA and protein expression of CYP11B2 (aldosterone synthase gene) in the adrenal cortex but not of CYP11B1 (11-β-hydroxylase gene). In the aorta, Ang II-high salt increased sodium-calcium exchanger-1 (NCX1) protein. The Ang II-high salt induced increase in MAP was largely prevented by central infusion of MR blockers, benzamil or losartan. Central blockades significantly lowered plasma aldosterone and endogenous ouabain and markedly decreased Ang II-high salt induced CYP11B2 mRNA expression in the adrenal cortex and NCX1 protein in the aorta. Conclusion These results suggest that in Ang II-high salt hypertension, MR-ENaC-AT1R signalling in the brain increases circulating aldosterone and endogenous ouabain, and arterial NCX1. These factors can amplify blood pressure responses to centrally-induced sympatho-excitation and thereby contribute to severe hypertension.
Collapse
Affiliation(s)
- Jiao Lu
- Brain and Heart Research Group, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y 4W7, Canada
| | - Hong-Wei Wang
- Brain and Heart Research Group, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y 4W7, Canada
| | - Monir Ahmad
- Brain and Heart Research Group, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y 4W7, Canada
| | - Marzieh Keshtkar-Jahromi
- Brain and Heart Research Group, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y 4W7, Canada.,Department of Physiology, University of Maryland School of Medicine, 655 West Baltimore S, Baltimore, MD 21201, USA
| | - Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, 655 West Baltimore S, Baltimore, MD 21201, USA.,Department of Medicine, University of Maryland School of Medicine, 655 West Baltimore S, Baltimore, MD 21201, USA
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, 655 West Baltimore S, Baltimore, MD 21201, USA
| | - Frans H H Leenen
- Brain and Heart Research Group, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y 4W7, Canada
| |
Collapse
|
9
|
Central antihypertensive effects of chronic treatment with RB150: an orally active aminopeptidase A inhibitor in deoxycorticosterone acetate-salt rats. J Hypertens 2019; 36:641-650. [PMID: 28968260 DOI: 10.1097/hjh.0000000000001563] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND OBJECTIVE Hyperactivity of the brain renin-angiotensin (Ang) system has been implicated in the development and maintenance of hypertension. AngIII, one of the main effector peptides of the brain renin-Ang system, exerts a tonic stimulatory control over blood pressure (BP) in hypertensive rats. Aminopeptidase A (APA), the enzyme generating brain AngIII, represents a new therapeutic target for the treatment of hypertension. We developed RB150, a prodrug of the specific and selective APA inhibitor, EC33. When given orally in acute treatment in hypertensive rats, RB150 crosses the gastrointestinal and blood-brain barriers, enters the brain, inhibits brain APA activity and decreases BP. We investigate, here, the antihypertensive effects of chronic oral RB150 (50 mg/kg per day) treatment over 24 days in alert hypertensive deoxycorticosterone acetate-salt rats. METHODS We measured variations in Brain APA enzymatic activity, SBP, plasma arginine vasopressin levels and metabolic parameters after RB150 chronic administration. RESULTS This resulted in a significant decrease in SBP over the 24-day treatment period showing that no tolerance to the antihypertensive RB150 effect was observed throughout the treatment period. Chronic RB150 treatment also significantly decreased plasma arginine vasopressin levels and increased diuresis, which participate to BP decrease by reducing the size of fluid compartment. Interestingly, we observed an increased natriuresis without modifying both plasma sodium and potassium levels. CONCLUSION Our results strengthen the interest of developing RB150 as a novel central-acting antihypertensive agent and evaluating its efficacy in salt-sensitive hypertension.
Collapse
|
10
|
Specific Inhibition of Brain Angiotensin III Formation as a New Strategy for Prevention of Heart Failure After Myocardial Infarction. J Cardiovasc Pharmacol 2019; 73:82-91. [DOI: 10.1097/fjc.0000000000000638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
11
|
|
12
|
Leenen FHH, Blaustein MP, Hamlyn JM. Update on angiotensin II: new endocrine connections between the brain, adrenal glands and the cardiovascular system. Endocr Connect 2017; 6:R131-R145. [PMID: 28855243 PMCID: PMC5613704 DOI: 10.1530/ec-17-0161] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/30/2017] [Indexed: 12/11/2022]
Abstract
In the brain, angiotensinergic pathways play a major role in chronic regulation of cardiovascular and electrolyte homeostasis. Increases in plasma angiotensin II (Ang II), aldosterone, [Na+] and cytokines can directly activate these pathways. Chronically, these stimuli also activate a slow neuromodulatory pathway involving local aldosterone, mineralocorticoid receptors (MRs), epithelial sodium channels and endogenous ouabain (EO). This pathway increases AT1R and NADPH oxidase subunits and maintains/further increases the activity of angiotensinergic pathways. These brain pathways not only increase the setpoint of sympathetic activity per se, but also enhance its effectiveness by increasing plasma EO and EO-dependent reprogramming of arterial and cardiac function. Blockade of any step in this slow pathway or of AT1R prevents Ang II-, aldosterone- or salt and renal injury-induced forms of hypertension. MR/AT1R activation in the CNS also contributes to the activation of sympathetic activity, the circulatory and cardiac RAAS and increase in circulating cytokines in HF post MI. Chronic central infusion of an aldosterone synthase inhibitor, MR blocker or AT1R blocker prevents a major part of the structural remodeling of the heart and the decrease in LV function post MI, indicating that MR activation in the CNS post MI depends on aldosterone, locally produced in the CNS. Thus, Ang II, aldosterone and EO are not simply circulating hormones that act on the CNS but rather they are also paracrine neurohormones, locally produced in the CNS, that exert powerful effects in key CNS pathways involved in the long-term control of sympathetic and neuro-endocrine function and cardiovascular homeostasis.
Collapse
Affiliation(s)
- Frans H H Leenen
- Brain and Heart Research GroupUniversity of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Mordecai P Blaustein
- Department of PhysiologyUniversity of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of MedicineUniversity of Maryland School of Medicine, Baltimore, Maryland, USA
| | - John M Hamlyn
- Department of PhysiologyUniversity of Maryland School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
13
|
Carvalho JC, Lisboa PC, de Oliveira E, Peixoto-Silva N, Nobre JL, Fraga MC, Manhães AC, Moura EG. Effects of postnatal bromocriptine injection on thyroid function and prolactinemia of rats at adulthood. Neuropeptides 2016; 59:71-81. [PMID: 27261099 DOI: 10.1016/j.npep.2016.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/28/2016] [Accepted: 05/23/2016] [Indexed: 12/24/2022]
Abstract
Previously, we demonstrated that maternal prolactin inhibition at the end of lactation, using bromocriptine (BRO), leads to an increase in leptin transfer via milk and induces the adult progeny to present hypothyroidism, leptin resistance and metabolic syndrome (obesity, hyperglycemia, hypertriglyceridemia, lower HDL). To test if these alterations are due to direct BRO action on the pups, in the present study we evaluated the long-term effects of direct injection of BRO (0.1μg/once daily) in male Wistar rats from postnatal (PN) day 1 to 10 (early treatment) or from PN11 to 20 (late treatment) on: food intake, body mass, cardiovascular parameters, hormone profile, hypothalamic leptin signaling, glucose homeostasis and thyroid hormone-dependent proteins. The respective controls were injected with methanol-saline. Offspring were killed at adulthood (PN180). Adult PN1-10 BRO-treated animals had lower food intake, hypoprolactinemia, lower leptin action (lower OBR-b, STAT-3 and SOCS-3 mRNA levels in the arcuate nucleus), lower TRH-TSH-thyroid axis as well as lower thyroid hormone markers. On the other hand, adult animals that were BRO-treated during the PN11-20 period showed hyperphagia, higher blood pressure, higher prolactinemia and OBR-b, higher TRH and plasma T3, hypercorticosteronemia as well as higher Dio2 and UCP1 mRNA expression in the brown adipose tissue. Glucose homeostasis was not changed treatment in either period. Our data show that early and late dopamine overexposure during lactation induces diverse metabolic disturbances later in life, increasing the risk of thyroid dysfunction and, consequently, changes in prolactinemia.
Collapse
Affiliation(s)
- Janaine C Carvalho
- Laboratory of Endocrine Physiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil
| | - Patricia C Lisboa
- Laboratory of Endocrine Physiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil.
| | - Elaine de Oliveira
- Laboratory of Endocrine Physiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil
| | - Nayara Peixoto-Silva
- Laboratory of Endocrine Physiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil
| | - Jessica L Nobre
- Laboratory of Endocrine Physiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil
| | - Mabel C Fraga
- Laboratory of Endocrine Physiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil
| | - Alex C Manhães
- Laboratory of Neurophysiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil
| | - Egberto G Moura
- Laboratory of Endocrine Physiology, Roberto Alcantara Gomes Biology Institute, State University of Rio de Janeiro, Rio de Janeiro, RJ 20551-031, Brazil
| |
Collapse
|
14
|
Affiliation(s)
- John M Hamlyn
- From the Departments of Physiology (J.M.H., M.P.B.) and Medicine (M.P.B.), University of Maryland School of Medicine, Baltimore.
| | - Mordecai P Blaustein
- From the Departments of Physiology (J.M.H., M.P.B.) and Medicine (M.P.B.), University of Maryland School of Medicine, Baltimore.
| |
Collapse
|
15
|
Wang HW, Huang BS, White RA, Chen A, Ahmad M, Leenen FHH. Mineralocorticoid and angiotensin II type 1 receptors in the subfornical organ mediate angiotensin II - induced hypothalamic reactive oxygen species and hypertension. Neuroscience 2016; 329:112-21. [PMID: 27163380 DOI: 10.1016/j.neuroscience.2016.04.050] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
Abstract
Activation of angiotensinergic pathways by central aldosterone (Aldo)-mineralocorticoid receptor (MR) pathway plays a critical role in angiotensin II (Ang II)-induced hypertension. The subfornical organ (SFO) contains both MR and angiotensin II type 1 receptors (AT1R) and can relay the signals of circulating Ang II to downstream nuclei such as the paraventricular nucleus (PVN), supraoptic nucleus (SON) and rostral ventrolateral medulla (RVLM). In Wistar rats, subcutaneous (sc) infusion of Ang II at 500ng/min/kg for 1 or 2weeks increased reactive oxygen species (ROS) as measured by dihydroethidium (DHE) staining in a nucleus - specific pattern. Intra-SFO infusion of AAV-MR- or AT1aR-siRNA prevented the Ang II-induced increase in AT1R mRNA expression in the SFO and decreased MR mRNA. Both MR- and AT1aR-siRNA prevented increases in ROS in the PVN and RVLM. MR- but not AT1aR-siRNA in the SFO prevented the Ang II-induced ROS in the SON. Both MR- and AT1aR-siRNA in the SFO prevented most of the Ang II-induced hypertension as assessed by telemetry. These results indicate that Aldo-MR signaling in the SFO is needed for the activation of Ang II-AT1R-ROS signaling from the SFO to the PVN and RVLM. Activation of Aldo-MR signaling from the SFO to the SON may enhance AT1R dependent activation of pre-sympathetic neurons in the PVN.
Collapse
Affiliation(s)
- Hong-Wei Wang
- University of Ottawa Heart Institute, Ottawa, Canada
| | - Bing S Huang
- University of Ottawa Heart Institute, Ottawa, Canada
| | | | - Aidong Chen
- University of Ottawa Heart Institute, Ottawa, Canada
| | - Monir Ahmad
- University of Ottawa Heart Institute, Ottawa, Canada
| | | |
Collapse
|
16
|
Role of brain aldosterone and mineralocorticoid receptors in aldosterone-salt hypertension in rats. Neuroscience 2016; 314:90-105. [DOI: 10.1016/j.neuroscience.2015.11.055] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/09/2015] [Accepted: 11/23/2015] [Indexed: 11/23/2022]
|
17
|
Hamlyn JM, Manunta P. Endogenous cardiotonic steroids in kidney failure: a review and an hypothesis. Adv Chronic Kidney Dis 2015; 22:232-44. [PMID: 25908473 DOI: 10.1053/j.ackd.2014.12.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 12/17/2014] [Accepted: 12/22/2014] [Indexed: 02/06/2023]
Abstract
In response to progressive nephron loss, volume and humoral signals in the circulation have increasing relevance. These signals, including plasma sodium, angiotensin II, and those related to volume status, activate a slow neuromodulatory pathway within the central nervous system (CNS). The slow CNS pathway includes specific receptors for angiotensin II, mineralocorticoids, and endogenous ouabain (EO). Stimulation of the pathway leads to elevated sympathetic nervous system activity (SNA) and increased circulating EO. The sustained elevation of circulating EO (or ouabain) stimulates central and peripheral mechanisms that amplify the impact of SNA on vascular tone. These include changes in synaptic plasticity in the brain and sympathetic ganglia that increase preganglionic tone and amplify ganglionic transmission, amplification of the impact of SNA on arterial tone in the vascular wall, and the reprogramming of calcium signaling proteins in arterial myocytes. These increase SNA, raise basal and evoked arterial tone, and elevate blood pressure (BP). In the setting of CKD, we suggest that sustained activation/elevation of the slow CNS pathway, plasma EO, and the cardiotonic steroid marinobufagenin, comprises a feed-forward system that raises BP and accelerates kidney and cardiac damage. Block of the slow CNS pathway and/or circulating EO and marinobufagenin may reduce BP and slow the progression to ESRD.
Collapse
|
18
|
Hamlyn JM, Linde CI, Gao J, Huang BS, Golovina VA, Blaustein MP, Leenen FHH. Neuroendocrine humoral and vascular components in the pressor pathway for brain angiotensin II: a new axis in long term blood pressure control. PLoS One 2014; 9:e108916. [PMID: 25275393 PMCID: PMC4183521 DOI: 10.1371/journal.pone.0108916] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 08/26/2014] [Indexed: 11/29/2022] Open
Abstract
Central nervous system (CNS) administration of angiotensin II (Ang II) raises blood pressure (BP). The rise in BP reflects increased sympathetic outflow and a slower neuromodulatory pressor mechanism mediated by CNS mineralocorticoid receptors (MR). We investigated the hypothesis that the sustained phase of hypertension is associated also with elevated circulating levels of endogenous ouabain (EO), and chronic stimulation of arterial calcium transport proteins including the sodium-calcium exchanger (NCX1), the type 6 canonical transient receptor potential protein (TRPC6), and the sarcoplasmic reticulum calcium ATPase (SERCA2). Wistar rats received a chronic intra-cerebroventricular infusion of vehicle (C) or Ang II (A, 2.5 ng/min, for 14 days) alone or combined with the MR blocker, eplerenone (A+E, 5 µg/day), or the aldosterone synthase inhibitor, FAD286 (A+F, 25 µg/day). Conscious mean BP increased (P<0.05) in A (123±4 mm Hg) vs all other groups. Blood, pituitary and adrenal samples were taken for EO radioimmunoassay (RIA), and aortas for NCX1, TRPC6 and SERCA2 immunoblotting. Central infusion of Ang II raised plasma EO (0.58±0.08 vs C 0.34±0.07 nM (P<0.05), but not in A + E and A + F groups as confirmed by off-line liquid chromatography (LC)-RIA and LC-multistage mass spectrometry. Two novel isomers of EO were elevated by Ang II; the second less polar isomer increased >50-fold in the A+F group. Central Ang II increased arterial expression of NCX1, TRPC6 and SERCA2 (2.6, 1.75 and 3.7-fold, respectively; P<0.01)) but not when co-infused with E or F. Adrenal and pituitary EO were unchanged. We conclude that brain Ang II activates a CNS-humoral axis involving plasma EO. The elevated EO reprograms peripheral ion transport pathways known to control arterial Na+ and Ca2+ homeostasis; this increases contractility and augments sympathetic effects. The new axis likely contributes to the chronic pressor effect of brain Ang II.
Collapse
Affiliation(s)
- John M. Hamlyn
- Department of Physiology, University of Maryland Baltimore, Baltimore, Maryland, United States of America
- * E-mail:
| | - Cristina I. Linde
- Department of Physiology, University of Maryland Baltimore, Baltimore, Maryland, United States of America
| | - Junjie Gao
- Department of Physiology, University of Maryland Baltimore, Baltimore, Maryland, United States of America
| | - Bing S. Huang
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Vera A. Golovina
- Department of Physiology, University of Maryland Baltimore, Baltimore, Maryland, United States of America
| | - Mordecai P. Blaustein
- Department of Physiology, University of Maryland Baltimore, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland Baltimore, Baltimore, Maryland, United States of America
| | | |
Collapse
|
19
|
Leenen FHH. Actions of circulating angiotensin II and aldosterone in the brain contributing to hypertension. Am J Hypertens 2014; 27:1024-32. [PMID: 24742639 DOI: 10.1093/ajh/hpu066] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In the past 1-2 decades, it has become apparent that the brain renin-angiotensin-aldosterone system (RAAS) plays a crucial role in the regulation of blood pressure (BP) by the circulating RAAS. In the brain, angiotensinergic sympatho-excitatory pathways do not contribute to acute, second-to-second regulation but play a major role in the more chronic regulation of the setpoint for sympathetic tone and BP. Increases in plasma angiotensin II (Ang II) or aldosterone and in cerebrospinal fluid [Na(+)] can directly activate these pathways and chronically further activate/maintain enhanced activity by a slow neuromodulatory pathway involving local aldosterone, mineralocorticoid receptors (MRs), epithelial sodium channels, and endogenous ouabain. Blockade of any step in this slow pathway prevents Ang II-, aldosterone-, or salt and renal injury-induced forms of hypertension. It appears that the renal and arterial actions of circulating aldosterone and Ang II act as amplifiers but are not sufficient to cause chronic hypertension if their central actions are prevented, except perhaps at high concentrations. From a clinical perspective, oral treatment with an angiotensin type 1 (AT1)-receptor blocker at high doses can cause central AT1-receptor blockade and, in humans, lower sympathetic nerve activity. Low doses of the MR blocker spironolactone appear sufficient to cause central MR blockade and a decrease in sympathetic nerve activity. Integrating the brain actions of the circulating RAAS with its direct renal and arterial actions provides a better framework to understand the role of the circulating RAAS in the pathophysiology of hypertension and heart failure and to direct therapeutic strategies.
Collapse
Affiliation(s)
- Frans H H Leenen
- Hypertension Unit, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| |
Collapse
|
20
|
Chen A, Huang BS, Wang HW, Ahmad M, Leenen FHH. Knockdown of mineralocorticoid or angiotensin II type 1 receptor gene expression in the paraventricular nucleus prevents angiotensin II hypertension in rats. J Physiol 2014; 592:3523-36. [PMID: 24973408 DOI: 10.1113/jphysiol.2014.275560] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Circulating Ang II activates an aldosterone-mineralocorticoid receptor (MR) - angiotensin II (Ang II) - angiotensin type 1 receptor (AT1R) pathway in the hypothalamus. To obtain insights into the actual neuronal projections involved, adeno-associated virus carrying small interfering RNA against either AT1aR (AAV-AT1aR-siRNA) or MR (AAV-MR-siRNA) were infused into the paraventricular nucleus (PVN) in Wistar rats. Intra-PVN infusion of AAV-AT1aR-siRNA or AAV-MR-siRNA decreased AT1R or MR expression in the PVN but not in the subfornical organ (SFO) or supraoptic nucleus (SON). Subcutaneous infusion of Ang II at 500 ng kg(-1) min(-1) for 2 weeks increased mean arterial pressure by 60-70 mmHg, and increased AT1R and MR expression in the SFO, SON and PVN. Intra-PVN AT1aR-siRNA prevented the Ang II-induced increase in AT1R but not MR expression in the PVN, and MR-siRNA prevented MR but not AT1R expression in the PVN. The increases in AT1R and MR expression in both the SFO and the SON were not changed by the two AAV-siRNAs. Specific knockdown of AT1R or MR in the PVN by AAV-siRNA each prevented most of the Ang II-induced hypertension. Prevention of the subcutaneous Ang II-induced increase in MR but not the increase in AT1R by knockdown of MR and vice versa suggests an independent regulation of MR and AT1R expression in the PVN. Both AT1R and MR activation in the PVN play a critical role in Ang II-induced hypertension in rats.
Collapse
Affiliation(s)
- Aidong Chen
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| | - Bing S Huang
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| | - Hong-Wei Wang
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| | - Monir Ahmad
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| | - Frans H H Leenen
- University of Ottawa Heart Institute, Ottawa, ON, K1Y 4W7, Canada
| |
Collapse
|
21
|
Zubcevic J, Santisteban MM, Pitts T, Baekey DM, Perez PD, Bolser DC, Febo M, Raizada MK. Functional neural-bone marrow pathways: implications in hypertension and cardiovascular disease. Hypertension 2014; 63:e129-39. [PMID: 24688127 PMCID: PMC4295780 DOI: 10.1161/hypertensionaha.114.02440] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 03/07/2014] [Indexed: 02/07/2023]
Affiliation(s)
- Jasenka Zubcevic
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL 32610
| | - Monica M. Santisteban
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL 32610
| | - Teresa Pitts
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville FL 32610
| | - David M. Baekey
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville FL 32610
| | - Pablo D. Perez
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville FL 32610
| | - Donald C. Bolser
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville FL 32610
| | - Marcelo Febo
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville FL 32610
| | - Mohan K. Raizada
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville FL 32610
| |
Collapse
|
22
|
Vasopressor meets vasodepressor: The AT1-B2 receptor heterodimer. Biochem Pharmacol 2014; 88:284-90. [PMID: 24462918 DOI: 10.1016/j.bcp.2014.01.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/10/2014] [Accepted: 01/13/2014] [Indexed: 01/08/2023]
Abstract
The AT1 receptor for the vasopressor angiotensin II is one of the most important drug targets for the treatment of cardiovascular diseases. Sensitization of the AT1 receptor system is a common feature contributing to the pathogenesis of many cardiovascular disorders but underlying mechanisms are not fully understood. More than a decade ago, evidence was provided for control of AT1R activation by heterodimerization with the B2 receptor for the vasodepressor peptide, bradykinin, a physiological counterpart of the vasoconstrictor angiotensin II. AT1-B2 receptor heterodimerization was shown to enhance AT1R-stimulated signaling under pathophysiological conditions such as experimental and human pregnancy hypertension. Notably, AT1R signal sensitization of patients with preeclampsia hypertension was attributed to AT1R-B2R heterodimerization. Vice versa, transgenic mice lacking the AT1-B2 receptor heterodimer due to targeted deletion of the B2R gene showed a significantly reduced AT1R-stimulated vasopressor response compared to transgenic mice with abundant AT1R-B2R heterodimerization. Biophysical methods such as BRET and FRET confirmed those data by demonstrating efficient AT1-B2 receptor heterodimerization in transfected cells and transgenic mice. Recently, a study on AT1R-specific biased agonism directed the focus to the AT1-B2 receptor heterodimer again. The β-arrestin-biased [Sar1,Ile4,Ile8]-angiotensin II promoted not only the recruitment of β-arrestin to the AT1R but also stimulated the down-regulation of the AT1R-associated B2 receptor by co-internalization. Thereby specific targeting of the AT1R-B2R heterodimer became feasible and could open the way to a new class of drugs, which specifically interfere with pathological angiotensin II-AT1 receptor system activation.
Collapse
|
23
|
Scheuer DA. Stimulation of aldosterone synthesis by angiotensin II in the brain: support for positive feedback in hypertension? Hypertension 2013; 62:459-60. [PMID: 23856491 DOI: 10.1161/hypertensionaha.113.01649] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|