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Wang J, Lv F, Yin W, Gao Z, Liu H, Wang Z, Sun J. The organum vasculosum of the lamina terminalis and subfornical organ: regulation of thirst. Front Neurosci 2023; 17:1223836. [PMID: 37732311 PMCID: PMC10507174 DOI: 10.3389/fnins.2023.1223836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/22/2023] [Indexed: 09/22/2023] Open
Abstract
Thirst and water intake are regulated by the organum vasculosum of the lamina terminalis (OVLT) and subfornical organ (SFO), located around the anteroventral third ventricle, which plays a critical role in sensing dynamic changes in sodium and water balance in body fluids. Meanwhile, neural circuits involved in thirst regulation and intracellular mechanisms underlying the osmosensitive function of OVLT and SFO are reviewed. Having specific Nax channels in the glial cells and other channels (such as TRPV1 and TRPV4), the OVLT and SFO detect the increased Na+ concentration or hyperosmolality to orchestrate osmotic stimuli to the insular and cingulate cortex to evoke thirst. Meanwhile, the osmotic stimuli are relayed to the supraoptic nucleus (SON) and paraventricular nucleus of the hypothalamus (PVN) via direct neural projections or the median preoptic nucleus (MnPO) to promote the secretion of vasopressin which plays a vital role in the regulation of body fluid homeostasis. Importantly, the vital role of OVLT in sleep-arousal regulation is discussed, where vasopressin is proposed as the mediator in the regulation when OVLT senses osmotic stimuli.
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Affiliation(s)
- Jiaxu Wang
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Fenglin Lv
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Wei Yin
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Zhanpeng Gao
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Hongyu Liu
- Institute of Sport and Exercise Medicine, North University of China, Taiyuan, China
| | - Zhen Wang
- Department of Cardiology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Jinhao Sun
- Department of Anatomy and Neurobiology, School of Medicine, Shandong University, Jinan, Shandong, China
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2
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Kishi T. Clarification of hypertension mechanisms provided by the research of central circulatory regulation. Hypertens Res 2023; 46:1908-1916. [PMID: 37277436 DOI: 10.1038/s41440-023-01335-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 06/07/2023]
Abstract
Sympathoexcitation, under the regulatory control of the brain, plays a pivotal role in the etiology of hypertension. Within the brainstem, significant structures involved in the modulation of sympathetic nerve activity include the rostral ventrolateral medulla (RVLM), caudal ventrolateral medulla (CVLM), nucleus tractus solitarius (NTS), and paraventricular nucleus (paraventricular). The RVLM, in particular, is recognized as the vasomotor center. Over the past five decades, fundamental investigations on central circulatory regulation have underscored the involvement of nitric oxide (NO), oxidative stress, the renin-angiotensin system, and brain inflammation in regulating the sympathetic nervous system. Notably, numerous significant findings have come to light through chronic experiments conducted in conscious subjects employing radio-telemetry systems, gene transfer techniques, and knockout methodologies. Our research has centered on elucidating the role of NO and angiotensin II type 1 (AT1) receptor-induced oxidative stress within the RVLM and NTS in regulating the sympathetic nervous system. Additionally, we have observed that various orally administered AT1 receptor blockers effectively induce sympathoinhibition by reducing oxidative stress via blockade of the AT1 receptor in the RVLM of hypertensive rats. Recent advances have witnessed the development of several clinical interventions targeting brain mechanisms. Nonetheless, Future and further basic and clinical research are needed.
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Affiliation(s)
- Takuya Kishi
- Department of Graduate School of Medicine (Cardiology), International University of Health and Welfare, Okawa, Japan.
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3
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Wang B, Jie H, Wang S, Dong B, Zou Y. The role of (pro)renin receptor and its soluble form in cardiovascular diseases. Front Cardiovasc Med 2023; 10:1086603. [PMID: 36824459 PMCID: PMC9941963 DOI: 10.3389/fcvm.2023.1086603] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
The renin-angiotensin system (RAS) is a major classic therapeutic target for cardiovascular diseases. In addition to the circulating RAS, local tissue RAS has been identified in various tissues and plays roles in tissue inflammation and tissue fibrosis. (Pro)renin receptor (PRR) was identified as a new member of RAS in 2002. Studies have demonstrated the effects of PRR and its soluble form in local tissue RAS. Moreover, as an important part of vacuolar H+-ATPase, it also contributes to normal lysosome function and cell survival. Evidently, PRR participates in the pathogenesis of cardiovascular diseases and may be a potential therapeutic target of cardiovascular diseases. This review focuses on the effects of PRR and its soluble form on the physiological state, hypertension, myocardial ischemia reperfusion injury, heart failure, metabolic cardiomyopathy, and atherosclerosis. We aimed to investigate the possibilities and challenges of PRR and its soluble form as a new therapeutic target in cardiovascular diseases.
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Affiliation(s)
- Boyang Wang
- Department of Cardiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China,Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China,Department of Cardiology, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Haipeng Jie
- Department of Cardiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China,Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Shuangxi Wang
- Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, China,Shuangxi Wang,
| | - Bo Dong
- Department of Cardiology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China,Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China,Department of Cardiology, Shandong University of Traditional Chinese Medicine, Jinan, China,*Correspondence: Bo Dong,
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China,Yunzeng Zou,
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4
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Lansdell TA, Chambers LC, Dorrance AM. Endothelial Cells and the Cerebral Circulation. Compr Physiol 2022; 12:3449-3508. [PMID: 35766836 DOI: 10.1002/cphy.c210015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.
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Affiliation(s)
- Theresa A Lansdell
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Laura C Chambers
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
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5
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Xue B, Cui JL, Guo F, Beltz TG, Zhao ZG, Zhang GS, Johnson AK. Voluntary Exercise Prevents Hypertensive Response Sensitization Induced by Angiotensin II. Front Neurosci 2022; 16:848079. [PMID: 35250473 PMCID: PMC8891537 DOI: 10.3389/fnins.2022.848079] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 01/27/2022] [Indexed: 01/01/2023] Open
Abstract
Exercise training has profound effects on the renin-angiotensin system, inflammatory cytokines and oxidative stress, all of which affect autonomic nervous system activity and regulate blood pressure (BP) in both physiological and pathophysiological states. Using the Induction-Delay-Expression paradigm, our previous studies demonstrated that various challenges (stressors) during Induction resulted in hypertensive response sensitization (HTRS) during Expression. The present study tested whether voluntary exercise would protect against subpressor angiotensin (ANG) II-induced HTRS in rats. Adult male rats were given access to either “blocked” (sedentary rats) or functional running (exercise rats) wheels for 12 weeks, and the Induction-Delay-Expression paradigm was applied for the rats during the last 4 weeks. A subpressor dose of ANG II given during Induction produced an enhanced hypertensive response to a pressor dose of ANG II given during Expression in sedentary rats in comparison to sedentary animals that received saline (vehicle control) during Induction. Voluntary exercise did not attenuate the pressor dose of ANG II-induced hypertension but prevented the expression of HTRS seen in sedentary animals. Moreover, voluntary exercise reduced body weight gain and feed efficiency, abolished the augmented BP reduction after ganglionic blockade, reversed the increased mRNA expression of pro-hypertensive components, and upregulated mRNA expression of antihypertensive components in the lamina terminalis and hypothalamic paraventricular nucleus, two key brain nuclei involved in the control of sympathetic activity and BP regulation. These results indicate that exercise training plays a beneficial role in preventing HTRS and that this is associated with shifting the balance of the brain prohypertensive and antihypertensive pathways in favor of attenuated central activity driving sympathetic outflow and reduced BP.
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Affiliation(s)
- Baojian Xue
- Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States
- *Correspondence: Baojian Xue,
| | - Jun-Ling Cui
- Department of Neurosurgery, Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Fang Guo
- Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States
| | - Terry G. Beltz
- Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States
| | - Zi-Gang Zhao
- Institute of Microcirculation, Hebei North University, Zhangjiakou, China
| | - Geng-Shen Zhang
- Department of Neurosurgery, Second Hospital of Hebei Medical University, Shijiazhuang, China
- Geng-Shen Zhang,
| | - Alan Kim Johnson
- Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States
- Department of Neuroscience and Pharmacology, The University of Iowa, Iowa City, IA, United States
- Department of Health and Human Physiology, The University of Iowa, Iowa City, IA, United States
- François M. Abboud Cardiovascular Research Center, The University of Iowa, Iowa City, IA, United States
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6
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Saenz-Medina J, Muñoz M, Rodriguez C, Sanchez A, Contreras C, Carballido-Rodríguez J, Prieto D. Endothelial Dysfunction: An Intermediate Clinical Feature between Urolithiasis and Cardiovascular Diseases. Int J Mol Sci 2022; 23:ijms23020912. [PMID: 35055099 PMCID: PMC8778796 DOI: 10.3390/ijms23020912] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 02/08/2023] Open
Abstract
UNLABELLED An epidemiological relationship between urolithiasis and cardiovascular diseases has extensively been reported. Endothelial dysfunction is an early pathogenic event in cardiovascular diseases and has been associated with oxidative stress and low chronic inflammation in hypertension, coronary heart disease, stroke or the vascular complications of diabetes and obesity. The aim of this study is to summarize the current knowledge about the pathogenic mechanisms of urolithiasis in relation to the development of endothelial dysfunction and cardiovascular morbidities. METHODS A non-systematic review has been performed mixing the terms "urolithiasis", "kidney stone" or "nephrolithiasis" with "cardiovascular disease", "myocardial infarction", "stroke", or "endothelial dysfunction". RESULTS Patients with nephrolithiasis develop a higher incidence of cardiovascular disease with a relative risk estimated between 1.20 and 1.24 and also develop a higher vascular disease risk scores. Analyses of subgroups have rendered inconclusive results regarding gender or age. Endothelial dysfunction has also been strongly associated with urolithiasis in clinical studies, although no systemic serum markers of endothelial dysfunction, inflammation or oxidative stress could be clearly related. Analysis of urine composition of lithiasic patients also detected a higher expression of proteins related to cardiovascular disease. Experimental models of hyperoxaluria have also found elevation of serum endothelial dysfunction markers. CONCLUSIONS Endothelial dysfunction has been strongly associated with urolithiasis and based on the experimental evidence, should be considered as an intermediate and changeable feature between urolithiasis and cardiovascular diseases. Oxidative stress, a key pathogenic factor in the development of endothelial dysfunction has been also pointed out as an important factor of lithogenesis. Special attention must be paid to cardiovascular morbidities associated with urolithiasis in order to take advantage of pleiotropic effects of statins, angiotensin receptor blockers and allopurinol.
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Affiliation(s)
- Javier Saenz-Medina
- Department of Urology, Puerta de Hierro-Majadahonda University Hospital, 28222 Majadahonda, Spain
- Department of Medical Specialities and Public Health, Faculty of Health Sciences, King Juan Carlos University, 28933 Móstoles, Spain
- Correspondence:
| | - Mercedes Muñoz
- Department of Physiology, Pharmacy Faculty, Complutense University, 28040 Madrid, Spain; (M.M.); (C.R.); (A.S.); (C.C.); (D.P.)
| | - Claudia Rodriguez
- Department of Physiology, Pharmacy Faculty, Complutense University, 28040 Madrid, Spain; (M.M.); (C.R.); (A.S.); (C.C.); (D.P.)
| | - Ana Sanchez
- Department of Physiology, Pharmacy Faculty, Complutense University, 28040 Madrid, Spain; (M.M.); (C.R.); (A.S.); (C.C.); (D.P.)
| | - Cristina Contreras
- Department of Physiology, Pharmacy Faculty, Complutense University, 28040 Madrid, Spain; (M.M.); (C.R.); (A.S.); (C.C.); (D.P.)
| | - Joaquín Carballido-Rodríguez
- Department of Urology, Puerta de Hierro-Majadahonda University Hospital, Autonoma University, 08193 Bellaterra, Spain;
| | - Dolores Prieto
- Department of Physiology, Pharmacy Faculty, Complutense University, 28040 Madrid, Spain; (M.M.); (C.R.); (A.S.); (C.C.); (D.P.)
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7
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The Causal Relationship between Endothelin-1 and Hypertension: Focusing on Endothelial Dysfunction, Arterial Stiffness, Vascular Remodeling, and Blood Pressure Regulation. Life (Basel) 2021; 11:life11090986. [PMID: 34575135 PMCID: PMC8472034 DOI: 10.3390/life11090986] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 12/01/2022] Open
Abstract
Hypertension (HTN) is one of the most prevalent diseases worldwide and is among the most important risk factors for cardiovascular and cerebrovascular complications. It is currently thought to be the result of disturbances in a number of neural, renal, hormonal, and vascular mechanisms regulating blood pressure (BP), so crucial importance is given to the imbalance of a number of vasoactive factors produced by the endothelium. Decreased nitric oxide production and increased production of endothelin-1 (ET-1) in the vascular wall may promote oxidative stress and low-grade inflammation, with the development of endothelial dysfunction (ED) and increased vasoconstrictor activity. Increased ET-1 production can contribute to arterial aging and the development of atherosclerotic changes, which are associated with increased arterial stiffness and manifestation of isolated systolic HTN. In addition, ET-1 is involved in the complex regulation of BP through synergistic interactions with angiotensin II, regulates the production of catecholamines and sympathetic activity, affects renal hemodynamics and water–salt balance, and regulates baroreceptor activity and myocardial contractility. This review focuses on the relationship between ET-1 and HTN and in particular on the key role of ET-1 in the pathogenesis of ED, arterial structural changes, and impaired vascular regulation of BP. The information presented includes basic concepts on the role of ET-1 in the pathogenesis of HTN without going into detailed analyses, which allows it to be used by a wide range of specialists. Also, the main pathological processes and mechanisms are richly illustrated for better understanding.
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8
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Evans LE, Taylor JL, Smith CJ, Pritchard HAT, Greenstein AS, Allan SM. Cardiovascular co-morbidities, inflammation and cerebral small vessel disease. Cardiovasc Res 2021; 117:2575-2588. [PMID: 34499123 DOI: 10.1093/cvr/cvab284] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Indexed: 12/15/2022] Open
Abstract
Cerebral small vessel disease (cSVD) is the most common cause of vascular cognitive impairment and affects all levels of the brain's vasculature. Features include diverse structural and functional changes affecting small arteries and capillaries that lead to a decline in cerebral perfusion. Due to an aging population, incidence of cerebral small vessel disease (cSVD) is continually rising. Despite its prevalence and its ability to cause multiple debilitating illnesses, such as stroke and dementia, there are currently no therapeutic strategies for the treatment of cSVD. In the healthy brain, interactions between neuronal, vascular and inflammatory cells are required for normal functioning. When these interactions are disturbed, chronic pathological inflammation can ensue. The interplay between cSVD and inflammation has attracted much recent interest and this review discusses chronic cardiovascular diseases, particularly hypertension, and explores how the associated inflammation may impact on the structure and function of the small arteries of the brain in cSVD. Molecular approaches in animal studies are linked to clinical outcomes in patients and novel hypotheses regarding inflammation and cSVD are proposed that will hopefully stimulate further discussion and study in this important area.
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Affiliation(s)
- Lowri E Evans
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
| | - Jade L Taylor
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
| | - Craig J Smith
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.,Manchester Centre for Clinical Neurosciences, Manchester Academic Health Science Centre, Salford Royal Hospital, Manchester Academic Health Sciences Centre (MAHSC)
| | - Harry A T Pritchard
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
| | - Adam S Greenstein
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
| | - Stuart M Allan
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.,Division of Neuroscience and Experimental Psychology, The University of Manchester, Manchester, UK
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9
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Brain angiotensin converting enzyme-2 in central cardiovascular regulation. Clin Sci (Lond) 2021; 134:2535-2547. [PMID: 33016313 DOI: 10.1042/cs20200483] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 12/24/2022]
Abstract
The brain renin-angiotensin system (RAS) plays an important role in the regulation of autonomic and neuroendocrine functions, and maintains cardiovascular homeostasis. Ang-II is the major effector molecule of RAS and exerts most of its physiological functions, including blood pressure (BP) regulation, via activation of AT1 receptors. Dysregulation of brain RAS in the central nervous system results in increased Ang-II synthesis that leads to sympathetic outflow and hypertension. Brain angiotensin (Ang) converting enzyme-2 (ACE2) was discovered two decades ago as an RAS component, exhibiting a counter-regulatory role and opposing the adverse cardiovascular effects produced by Ang-II. Studies using synthetic compounds that can sustain the elevation of ACE2 activity or genetically overexpressed ACE2 in specific brain regions found various beneficial effects on cardiovascular function. More recently, ACE2 has been shown to play critical roles in neuro-inflammation, gut dysbiosis and the regulation of stress and anxiety-like behaviors. In the present review, we aim to highlight the anatomical locations and functional implication of brain ACE2 related to its BP regulation via modulation of the sympathetic nervous system and discuss the recent developments and future directions in the ACE2-mediated central cardiovascular regulation.
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10
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Abstract
PURPOSE OF REVIEW Rapidly emerging evidence implicates an important role of gut-brain-bone marrow (BM) axis involving gut microbiota (GM), gut epithelial wall permeability, increased production of pro-inflammatory BM cells and neuroinflammation in hypertension (HTN). However, the precise sequence of events involving these organs remains to be established. Furthermore, whether an impaired gut-brain-BM axis is a cause or consequence of HTN is actively under investigation. This will be extremely important for translation of this fundamental knowledge to novel, innovative approaches for the control and management of HTN. Therefore, our objectives are to summarize the latest hypothesis, provide evidence for and against the impaired gut, BM and brain interactions in HTN and discuss perspectives and future directions. RECENT FINDINGS Hypertensive stimuli activate autonomic neural pathways resulting in increased sympathetic and decreased parasympathetic cardiovascular modulation. This directly affects the functions of cardiovascular-relevant organs to increase blood pressure. Increases in sympathetic drive to the gut and BM also trigger sequences of signaling events that ultimately contribute to altered GM, increased gut permeability, enhanced gut- and brain-targeted pro-inflammatory cells from the BM in perpetuation and establishment of HTN. SUMMARY In this review, we present the mechanisms involving the brain, gut, and BM, whose dysfunctional interactions may be critical in persistent neuroinflammation and key in the development and establishment of HTN.
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Affiliation(s)
- Jing Li
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, USA
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Iovino M, Messana T, De Pergola G, Iovino E, Guastamacchia E, Licchelli B, Vanacore A, Giagulli VA, Triggiani V. Brain Angiotensinergic Regulation of the Immune System: Implications for Cardiovascular and Neuroendocrine Responses. Endocr Metab Immune Disord Drug Targets 2020; 20:15-24. [PMID: 31237219 DOI: 10.2174/1871530319666190617160934] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 05/08/2019] [Accepted: 05/08/2019] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The Renin-Angiotensin-Aldosterone System (RAAS) plays a major role in the regulation of cardiovascular functions, water and electrolytic balance, and hormonal responses. We perform a review of the literature, aiming at providing the current concepts regarding the angiotensin interaction with the immune system in the brain and the related implications for cardiovascular and neuroendocrine responses. METHODS Appropriate keywords and MeSH terms were identified and searched in Pubmed. Finally, references of original articles and reviews were examined. RESULTS Angiotensin II (ANG II), beside stimulating aldosterone, vasopressin and CRH-ACTH release, sodium and water retention, thirst, and sympathetic nerve activity, exerts its effects on the immune system via the Angiotensin Type 1 Receptor (AT 1R) that is located in the brain, pituitary, adrenal gland, and kidney. Several actions are triggered by the binding of circulating ANG II to AT 1R into the circumventricular organs that lack the Blood-Brain-Barrier (BBB). Furthermore, the BBB becomes permeable during chronic hypertension thereby ANG II may also access brain nuclei controlling cardiovascular functions. Subfornical organ, organum vasculosum lamina terminalis, area postrema, paraventricular nucleus, septal nuclei, amygdala, nucleus of the solitary tract and retroventral lateral medulla oblongata are the brain structures that mediate the actions of ANG II since they are provided with a high concentration of AT 1R. ANG II induces also T-lymphocyte activation and vascular infiltration of leukocytes and, moreover, oxidative stress stimulating inflammatory responses via inhibition of endothelial progenitor cells and stimulation of inflammatory and microglial cells facilitating the development of hypertension. CONCLUSION Besides the well-known mechanisms by which RAAS activation can lead to the development of hypertension, the interactions between ANG II and the immune system at the brain level can play a significant role.
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Affiliation(s)
- Michele Iovino
- Interdisciplinary Department of Medicine-Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Tullio Messana
- Infantile Neuropsychiatry, IRCCS - Institute of Neurological Sciences, Bologna, Italy
| | - Giovanni De Pergola
- Clinical Nutrition Unit, Medical Oncology, Department of Internal Medicine and Clinical Oncology, University of Bari, School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Emanuela Iovino
- Interdisciplinary Department of Medicine-Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Edoardo Guastamacchia
- Interdisciplinary Department of Medicine-Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Brunella Licchelli
- Interdisciplinary Department of Medicine-Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Aldo Vanacore
- Interdisciplinary Department of Medicine-Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Vito A Giagulli
- Interdisciplinary Department of Medicine-Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Vincenzo Triggiani
- Interdisciplinary Department of Medicine-Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, University of Bari "Aldo Moro", School of Medicine, Policlinico, Piazza Giulio Cesare 11, 70124 Bari, Italy
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12
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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.
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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
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13
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Cell seeding accelerates the vascularization of tissue engineering constructs in hypertensive mice. Hypertens Res 2020; 44:23-35. [PMID: 32778779 DOI: 10.1038/s41440-020-0524-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 11/08/2022]
Abstract
Rapid blood vessel ingrowth into transplanted constructs represents the key requirement for successful tissue engineering. Seeding three-dimensional scaffolds with suitable cells is an approved technique for this challenge. Since a plethora of patients suffer from widespread diseases that limit the capacity of neoangiogenesis (e.g., hypertension), we investigated the incorporation of cell-seeded poly-L-lactide-co-glycolide scaffolds in hypertensive (BPH/2J, group A) and nonhypertensive (BPN/3J, group B) mice. Collagen-coated scaffolds (A1 and B1) were additionally seeded with osteoblast-like (A2 and B2) and mesenchymal stem cells (A3 and B3). After implantation into dorsal skinfold chambers, inflammation and newly formed microvessels were measured using repetitive intravital fluorescence microscopy for 2 weeks. Apart from a weak inflammatory response in all groups, significantly increased microvascular densities were found in cell-seeded scaffolds (day 14, A2: 192 ± 12 cm/cm2, A3: 194 ± 10 cm/cm2, B2: 249 ± 19 cm/cm2, B3: 264 ± 17 cm/cm2) when compared with controls (A1: 129 ± 10 cm/cm2, B1: 185 ± 8 cm/cm2). In this context, hypertensive mice showed reduced neoangiogenesis in comparison with nonhypertensive animals. Therefore, seeding approved scaffolds with organ-specific or pluripotent cells is a very promising technique for tissue engineering in hypertensive organisms.
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14
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Yang T, Rodriguez V, Malphurs WL, Schmidt JT, Ahmari N, Sumners C, Martyniuk CJ, Zubcevic J. Butyrate regulates inflammatory cytokine expression without affecting oxidative respiration in primary astrocytes from spontaneously hypertensive rats. Physiol Rep 2019; 6:e13732. [PMID: 30039527 PMCID: PMC6056753 DOI: 10.14814/phy2.13732] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 01/16/2023] Open
Abstract
Neurons and glia exhibit metabolic imbalances in hypertensive animal models, and loss of metabolic homeostasis can lead to neuroinflammation and oxidative stress. The objective of this study was to determine the effects of the microbial metabolite butyrate on mitochondrial bioenergetics and inflammatory markers in mixed brainstem and hypothalamic primary cultures of astrocytes between normotensive (Sprague-Dawley, S-D) and spontaneously hypertensive (SHR) rats. Bioenergetics of mitochondria in astrocytes from normotensive S-D rats were modified with butyrate, but this was not the case in astrocytes derived from SHR, suggesting aberrant mitochondrial function. Transcripts related to oxidative stress, butyrate transporters, butyrate metabolism, and neuroinflammation were quantified in astrocyte cultures treated with butyrate at 0, 200, 600, and 1000 μmol/L. Butyrate decreased catalase and monocarboxylate transporter 1 mRNA in astrocytes of S-D rats but not in the SHR. Moreover, while butyrate did not directly regulate the expression of 3-hydroxybutyrate dehydrogenase 1 and 2 in astrocytes of either strain, the expression levels for these transcripts in untreated cultures were lower in the SHR compared to S-D. We observed higher levels of specific inflammatory cytokines in astrocytes of SHR, and treatment with butyrate decreased expression of Ccl2 and Tlr4 in SHR astrocytes only. Conversely, butyrate treatment increased expression of tumor necrosis factor in astrocytes from SHR but not from the S-D rats. This study improves our understanding of the role of microbial metabolites in regulating astrocyte function, and provides support that butyrate differentially regulates both the bioenergetics and transcripts related to neuroinflammation in astrocytes from SHR versus S-D rats.
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Affiliation(s)
- Tao Yang
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Vermali Rodriguez
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida
| | - Wendi L Malphurs
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Jordan T Schmidt
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Niousha Ahmari
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Colin Sumners
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida
| | - Christopher J Martyniuk
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Jasenka Zubcevic
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
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15
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Hassanpour H, Bahadoran S, Neidaripour F, Ehsanifar N, Tavasolifar I, Madreseh S. Brain renin-angiotensin system in broiler chickens with cold-induced pulmonary hypertension. Br Poult Sci 2019; 60:499-505. [PMID: 31213071 DOI: 10.1080/00071668.2019.1632415] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. The relative expression of angiotensinogen (AGT), renin, angiotensin-converting enzyme (ACE) and angiotensin II type 1 receptor (AT1R) was determined using quantitative real-time PCR on tissue from the brain (forebrain, midbrain and hindbrain) to investigate the effect of cold-induced pulmonary hypertension syndrome (PHS) in broilers aged 42 days. Brain angiotensin II (Ang II) and AT1R levels were measured using enzyme immunoassay. 2. The right ventricle/total ventricles (RV/TV) ratio of the heart was increased in broilers exposed to cold stress (PHS group) at the end of the experiment. 3. ACE and renin transcripts in three parts of the brain were significantly increased in the PHS group at 42 d of age compared to controls while AGT transcript was significantly increased only in the hindbrain of PHS birds. The amount of AT1R transcript did not differ between control and PHS groups. 4. The amount of Ang II significantly decreased only in the midbrain of PHS birds compared with controls while the amounts of AT1R were not different between treatments in the three segments of the brain. 5. It was concluded that brain gene expression of AGT (in the hindbrain), renin, and ACE was upregulated in broilers with PHS whereas Ang II and AT1R levels were not changed. These results provided evidence of diminished involvement of the renin-angiotensin system in the pathogenesis of chicken pulmonary hypertension.
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Affiliation(s)
- H Hassanpour
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahrekord University , Shahrekord , Iran
| | - S Bahadoran
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahrekord University , Shahrekord , Iran
| | - F Neidaripour
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahrekord University , Shahrekord , Iran
| | - N Ehsanifar
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahrekord University , Shahrekord , Iran
| | - I Tavasolifar
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahrekord University , Shahrekord , Iran
| | - S Madreseh
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahrekord University , Shahrekord , Iran
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16
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Hendricks AS, Lawson MJ, Figueroa JP, Chappell MC, Diz DI, Shaltout HA. Central ANG-(1-7) infusion improves blood pressure regulation in antenatal betamethasone-exposed sheep and reveals sex-dependent effects on oxidative stress. Am J Physiol Heart Circ Physiol 2019; 316:H1458-H1467. [PMID: 30951367 PMCID: PMC6620683 DOI: 10.1152/ajpheart.00497.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 03/12/2019] [Accepted: 03/28/2019] [Indexed: 12/25/2022]
Abstract
Fetal exposure to betamethasone (BMX) as a consequence of glucocorticoid administration to women threatening premature delivery may lead to long-term deleterious effects on the cardiovascular system and dysregulation of blood pressure in exposed adults. Indeed, adult offspring of BMX sheep exhibit increased mean arterial pressure (MAP) and attenuated baroreflex sensitivity (BRS) that are associated with lower medullary and cerebrospinal fluid (CSF) angiotensin-(1-7) [(ANG-(1-7)] content. Thus we determined the effects of ANG-(1-7) supplementation in the CSF on MAP, BRS, blood pressure (BPV) and heart rate variability (HRV) in conscious animals. The peptide or artificial CSF (aCSF) was infused continuously into the lateral ventricle (intracerebroventricular) of 4-mo-old male and female BMX sheep for 2 wk. Analysis of data from males and females combined revealed that intracerebroventricular ANG-(1-7) significantly lowered MAP and heart rate and improved BRS as compared with baseline; intracerebroventricular aCSF did not change these indexes. Similar patterns were observed for altered hemodynamics and autonomic function produced by intracerebroventricular ANG-(1-7) in both sexes. Oxidative stress and MAP kinase (MAPK) activation were lower in tissues from the dorsomedial medulla (DMM) of ANG-(1-7)-treated males but were unchanged in the treated females, when assessed at the end of the treatment period. We conclude that in the face of ANG-(1-7) deficiency in CSF and medullary tissue in BMX sheep intracerebroventricular supplementation of ANG-(1-7) lowers MAP and restores the impaired autonomic function to a similar degree in both males and females; however, the attenuation of MAPK and oxidative stress within the DMM was evident only in males. NEW & NOTEWORTHY We demonstrate that intracerebroventricular angiotensin-(1-7) [(ANG-(1-7)] treatment for 2 wk in antenatal betamethasone-exposed sheep provides beneficial effects on blood pressure and autonomic function. The physiological improvements are accompanied by an attenuation of oxidative stress in males but not females. The finding that ANG-(1-7) supplementation lowers blood pressure and restores the impaired autonomic function in a model of fetal programming previously shown to exhibit a deficiency in cerebrospinal fluid and brain tissue illustrates the potential for new therapeutic strategies for reducing cardiovascular dysfunction arising from prenatal events.
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Affiliation(s)
- Alexa S Hendricks
- Department of Surgery, Hypertension, and Vascular Research and the Cardiovascular Sciences Center, Wake Forest University School of Medicine , Winston-Salem, North Carolina
| | - Matthew J Lawson
- Department of Surgery, Hypertension, and Vascular Research and the Cardiovascular Sciences Center, Wake Forest University School of Medicine , Winston-Salem, North Carolina
| | - Jorge P Figueroa
- Department of Obstetrics and Gynecology, Wake Forest School of Medicine , Winston-Salem, North Carolina
| | - Mark C Chappell
- Department of Surgery, Hypertension, and Vascular Research and the Cardiovascular Sciences Center, Wake Forest University School of Medicine , Winston-Salem, North Carolina
| | - Debra I Diz
- Department of Surgery, Hypertension, and Vascular Research and the Cardiovascular Sciences Center, Wake Forest University School of Medicine , Winston-Salem, North Carolina
| | - Hossam A Shaltout
- Department of Surgery, Hypertension, and Vascular Research and the Cardiovascular Sciences Center, Wake Forest University School of Medicine , Winston-Salem, North Carolina
- Department of Obstetrics and Gynecology, Wake Forest School of Medicine , Winston-Salem, North Carolina
- Department of Pharmacology and Toxicology, School of Pharmacy, Alexandria University , Alexandria , Egypt
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17
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Chan JYH, Chan SHH. Differential impacts of brain stem oxidative stress and nitrosative stress on sympathetic vasomotor tone. Pharmacol Ther 2019; 201:120-136. [PMID: 31153955 DOI: 10.1016/j.pharmthera.2019.05.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 05/24/2019] [Indexed: 02/07/2023]
Abstract
Based on work-done in the rostral ventrolateral medulla (RVLM), this review presents four lessons learnt from studying the differential impacts of oxidative stress and nitrosative stress on sympathetic vasomotor tone and their clinical and therapeutic implications. The first lesson is that an increase in sympathetic vasomotor tone because of augmented oxidative stress in the RVLM is responsible for the generation of neurogenic hypertension. On the other hand, a shift from oxidative stress to nitrosative stress in the RVLM underpins the succession of increase to decrease in sympathetic vasomotor tone during the progression towards brain stem death. The second lesson is that, by having different cellular sources, regulatory mechanisms on synthesis and degradation, kinetics of chemical reactions, and downstream signaling pathways, reactive oxygen species and reactive nitrogen species should not be regarded as a singular moiety. The third lesson is that well-defined differential roles of oxidative stress and nitrosative stress with distinct regulatory mechanisms in the RVLM during neurogenic hypertension and brain stem death clearly denote that they are not interchangeable phenomena with unified cellular actions. Special attention must be paid to their beneficial or detrimental roles under a specific disease or a particular time-window of that disease. The fourth lesson is that, to be successful, future antioxidant therapies against neurogenic hypertension must take into consideration the much more complicated picture than that presented in this review on the generation, maintenance, regulation or modulation of the sympathetic vasomotor tone. The identification that the progression towards brain stem death entails a shift from oxidative stress to nitrosative stress in the RVLM may open a new vista for therapeutic intervention to slow down this transition.
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Affiliation(s)
- Julie Y H Chan
- Institute for Translational Research in Biomedicine, Chang Gung Memorial Hospital, Kaohsiung, Taiwan, Republic of China
| | - Samuel H H Chan
- Institute for Translational Research in Biomedicine, Chang Gung Memorial Hospital, Kaohsiung, Taiwan, Republic of China.
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18
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Chowen JA, Frago LM, Fernández-Alfonso MS. Physiological and pathophysiological roles of hypothalamic astrocytes in metabolism. J Neuroendocrinol 2019; 31:e12671. [PMID: 30561077 DOI: 10.1111/jne.12671] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/27/2018] [Accepted: 12/11/2018] [Indexed: 12/26/2022]
Abstract
The role of glial cells, including astrocytes, in metabolic control has received increasing attention in recent years. Although the original interest in these macroglial cells was a result of astrogliosis being observed in the hypothalamus of diet-induced obese subjects, studies have also focused on how they participate in the physiological control of appetite and energy expenditure. Astrocytes express receptors for numerous hormones, growth factors and neuropeptides. Some functions of astrocytes include transport of nutrients and hormones from the circulation to the brain, storage of glycogen, participation in glucose sensing, synaptic plasticity, uptake and metabolism of neurotransmitters, release of substances to modify neurotransmission, and cytokine production, amongst others. In the hypothalamus, these physiological glial functions impact on neuronal circuits that control systemic metabolism to modify their outputs. The initial response of astrocytes to poor dietary habits and obesity involves activation of neuroprotective mechanisms but, with chronic exposure to these situations, hypothalamic astrocytes participate in the development of some of the damaging secondary effects. The present review discusses not only some of the physiological functions of hypothalamic astrocytes in metabolism, but also their role in the secondary complications of obesity, such as insulin resistance and cardiovascular affectations.
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Affiliation(s)
- Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- CIBEROBN (Centro de Investigación Biomédica en Red sobre Fisiopatología de la Obesidad y Nutrición), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, Madrid, Spain
- CIBEROBN (Centro de Investigación Biomédica en Red sobre Fisiopatología de la Obesidad y Nutrición), Instituto de Salud Carlos III, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Soledad Fernández-Alfonso
- Instituto Pluridisciplinar UCM y Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
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19
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Guimarães DD, Cruz JC, Carvalho-Galvão A, Zhuge Z, Marques SM, Naves LM, Persson AEG, Weitzberg E, Lundberg JO, Balarini CM, Pedrino GR, Braga VA, Carlström M. Dietary Nitrate Reduces Blood Pressure in Rats With Angiotensin II–Induced Hypertension via Mechanisms That Involve Reduction of Sympathetic Hyperactivity. Hypertension 2019; 73:839-848. [DOI: 10.1161/hypertensionaha.118.12425] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Drielle D. Guimarães
- From the Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (D.D.G., J.C.C., Z.Z., A.E.G.P., E.W., J.O.L., M.C.)
- Biotechnology Center (D.D.G., J.C.C., A.C.-G., C.M.B., V.A.B.), Federal University of Paraiba, Joao Pessoa, Brazil
| | - Josiane C. Cruz
- From the Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (D.D.G., J.C.C., Z.Z., A.E.G.P., E.W., J.O.L., M.C.)
- Biotechnology Center (D.D.G., J.C.C., A.C.-G., C.M.B., V.A.B.), Federal University of Paraiba, Joao Pessoa, Brazil
| | - Alynne Carvalho-Galvão
- Biotechnology Center (D.D.G., J.C.C., A.C.-G., C.M.B., V.A.B.), Federal University of Paraiba, Joao Pessoa, Brazil
| | - Zhengbing Zhuge
- From the Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (D.D.G., J.C.C., Z.Z., A.E.G.P., E.W., J.O.L., M.C.)
| | - Stefanne M. Marques
- Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil (S.M.M., L.M.N., G.R.P.)
| | - Lara M. Naves
- Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil (S.M.M., L.M.N., G.R.P.)
| | - A. Erik G. Persson
- From the Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (D.D.G., J.C.C., Z.Z., A.E.G.P., E.W., J.O.L., M.C.)
- Department of Medical Cell Biology, Uppsala University, Sweden (A.E.G.P.)
| | - Eddie Weitzberg
- From the Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (D.D.G., J.C.C., Z.Z., A.E.G.P., E.W., J.O.L., M.C.)
| | - Jon O. Lundberg
- From the Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (D.D.G., J.C.C., Z.Z., A.E.G.P., E.W., J.O.L., M.C.)
| | - Camille M. Balarini
- Biotechnology Center (D.D.G., J.C.C., A.C.-G., C.M.B., V.A.B.), Federal University of Paraiba, Joao Pessoa, Brazil
- Health Sciences Center (C.M.B.), Federal University of Paraiba, Joao Pessoa, Brazil
| | - Gustavo R. Pedrino
- Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil (S.M.M., L.M.N., G.R.P.)
| | - Valdir A. Braga
- Biotechnology Center (D.D.G., J.C.C., A.C.-G., C.M.B., V.A.B.), Federal University of Paraiba, Joao Pessoa, Brazil
| | - Mattias Carlström
- From the Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (D.D.G., J.C.C., Z.Z., A.E.G.P., E.W., J.O.L., M.C.)
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20
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Chen J, Chen W, Han K, Qi E, Chen R, Yu M, Hou L, Lv L. Effect of oxidative stress in rostral ventrolateral medulla on sympathetic hyperactivity after traumatic brain injury. Eur J Neurosci 2019; 50:1972-1980. [PMID: 30762917 DOI: 10.1111/ejn.14374] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/18/2019] [Accepted: 02/07/2019] [Indexed: 02/05/2023]
Abstract
Sympathetic hyperactivity occurs in a subgroup of patients after traumatic brain injury (TBI). The rostral ventrolateral medulla (RVLM) is a key region for the activity of sympathetic nervous system. Oxidative stress in the RVLM is proved to be responsible for the increased level of sympathetic activity in animal models of hypertension and heart failure. In this study, we investigated whether oxidative stress in the RVLM contributed to the development of sympathetic hyperactivity after TBI in rats. Model of diffuse axonal injury was induced using Sprague-Dawley rats, and level of mean arterial pressure (MAP) and plasma Norepinephrine (NE) was measured to evaluate the sympathetic activity. For the assessment of oxidative stress, expression of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) in the RVLM was determined. Microinjection of Tempol into the RVLM was performed to determine the effect of oxidative stress on sympathetic hyperactivity. According to the results, TBI led to elevated MAP and plasma NE in rats. It also induced a significantly increased level of ROS, MDA production and decreased level of SOD in the RVLM. The sympathetic activity, ROS, and MDA in the RVLM decreased significantly after microinjection of Tempol. Therefore, the present results suggested that oxidative stress in the RVLM was involved in the development of sympathetic hyperactivity following TBI.
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Affiliation(s)
- Jigang Chen
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Wen Chen
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Kaiwei Han
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Enbo Qi
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Rongbin Chen
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Minkun Yu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Lijun Hou
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Liquan Lv
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
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21
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Santana DF, Ferreira DS, Braz GRF, Sousa SMS, Silva TLDA, Gomes DA, Fernandes MP, Andrade-da-Costa BL, Lagranha CJ. Maternal Protein Restriction in Two Successive Generations Impairs Mitochondrial Electron Coupling in the Progeny's Brainstem of Wistar Rats From Both Sexes. Front Neurosci 2019; 13:203. [PMID: 30930735 PMCID: PMC6427765 DOI: 10.3389/fnins.2019.00203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 02/20/2019] [Indexed: 12/20/2022] Open
Abstract
Maternal protein deficiency during the critical development period of the progeny disturbs mitochondrial metabolism in the brainstem, which increases the risk of developing cardiovascular diseases in the first-generation (F1) offspring, but is unknown if this effect persists in the second-generation (F2) offspring. The study tested whether mitochondrial health and oxidative balance will be restored in F2 rats. Male and female rats were divided into six groups according to the diet fed to their mothers throughout gestation and lactation periods. These groups were: (1) normoprotein (NP) and (2) low-protein (LP) rats of the first filial generation (F1-NP and F1-LP, respectively) and (3) NP and (4) LP rats of the second filial generation (F2-NP and F2-LP, respectively). After weaning, all groups received commercial chow and a portion of each group was sacrificed on the 30th day of life for determination of mitochondrial and oxidative parameters. The remaining portion of the F1 group was mated at adulthood and fed an NP or LP diet during the periods of gestation and lactation, to produce progeny belonging to (5) F2R-NP and (6) F2R-LP group, respectively. Our results demonstrated that male F1-LP rats suffered mitochondrial impairment associated with an 89% higher production of reactive species (RS) and 137% higher oxidative stress biomarkers, but that the oxidative stress was blunted in female F1-LP animals despite the antioxidant impairment. In the second generation following F0 malnutrition, brainstem antioxidant defenses were restored in the F2-LP group of both sexes. However, F2R-LP offspring, exposed to LP in the diets of the two preceding generations displayed a RS overproduction with a concomitant decrease in mitochondrial bioenergetics. Our findings demonstrate that nutritional stress during the reproductive life of the mother can negatively affect mitochondrial metabolism and oxidative balance in the brainstem of F1 progeny, but that restoration of a normal diet during the reproductive life of those individuals leads toward a mitochondrial recovery in their own (F2) progeny. Otherwise, if protein deprivation is continued from the F0 generation and into the F1 generation, the F2 progeny will exhibit no recovery, but instead will remain vulnerable to further oxidative damage.
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Affiliation(s)
- David F Santana
- Graduate Program in Neuroscience and Behaviour, Universidade Federal de Pernambuco, Recife, Brazil
| | - Diorginis S Ferreira
- Colegiado de Educação Física, Federal University of São Francisco Valley, Petrolina, Brazil
| | - Glauber Ruda F Braz
- Graduate Program in Neuroscience and Behaviour, Universidade Federal de Pernambuco, Recife, Brazil
| | - Shirley M S Sousa
- Graduate Program in Neuroscience and Behaviour, Universidade Federal de Pernambuco, Recife, Brazil
| | | | - Dayane Aparecida Gomes
- Graduate Program in Neuroscience and Behaviour, Universidade Federal de Pernambuco, Recife, Brazil.,Departamento de Fisiologia e Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, Brazil
| | - Mariana P Fernandes
- Graduate Program in Nutrition, Physical Activity and Phenotypic Plasticity, Academic Center of Vitoria - Universidade Federal de Pernambuco, Vitória de Santo Antão, Brazil.,Núcleo de Educação Física e Ciências do Esporte, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Recife, Brazil
| | - Belmira Lara Andrade-da-Costa
- Graduate Program in Neuroscience and Behaviour, Universidade Federal de Pernambuco, Recife, Brazil.,Departamento de Fisiologia e Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, Brazil
| | - Claudia J Lagranha
- Graduate Program in Neuroscience and Behaviour, Universidade Federal de Pernambuco, Recife, Brazil.,Núcleo de Educação Física e Ciências do Esporte, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Recife, Brazil
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22
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Li C, Li Y, Zhao Z, Lv Y, Gu B, Zhao L. Aerobic exercise regulates synaptic transmission and reactive oxygen species production in the paraventricular nucleus of spontaneously hypertensive rats. Brain Res 2019; 1712:82-92. [PMID: 30735639 DOI: 10.1016/j.brainres.2019.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 01/29/2019] [Accepted: 02/04/2019] [Indexed: 02/07/2023]
Abstract
Aerobic exercise lowers blood pressure in patients with hypertension, but the underlying mechanisms remain incompletely understood. The hypothalamic paraventricular nucleus (PVN) plays a key role in the control of sympathetic outflow and cardiovascular tone. We examined whether chronic aerobic exercise altered synaptic transmission and reactive oxygen species (ROS) production in the PVN. In the present study, spontaneously hypertensive rats (SHRs) were subjected to exercise training for 8 weeks, five times per week, with Wistar Kyoto (WKY) rats as the cohort control. Miniature excitatory and inhibitory postsynaptic currents (mEPSCs and mIPSCs) were recorded from the PVN in ex vivo hypothalamic slice preparations obtained after the last training, and biomarkers of oxidative stress and physical indexes were observed. The mean frequency and amplitude, as well as the rise time and the decay time constant of mIPSCs, significantly decreased in 20-wk-old SHRs compared to WKY 20-wk-old controls. In contrast to mIPSCs, only the mean mEPSC frequency was higher, and there were no other changes in mEPSCs in comparison to the control group. SHRs exhibited higher ROS, 8-OHdG, and MDA; and lower SOD1, SOD2, CAT, Ogg1, and SOD and CAT activity in the PVN. These SHRs also had a significant increase in heart rate, blood pressure and sympathetic nerve activity, and higher levels of norepinephrine (NE). Exercise training ameliorated all these abnormalities, resulting in an increase in the mean frequency, amplitude and kinetics of mIPSCs, accompanied by a decrease in the mean frequency of mEPSCs in the PVN. This study demonstrates that moderate intensity, high frequency exercise training induces a selective enhancement of inhibitory synaptic transmission in the PVN, which may dampen sympathetic activity and reduce blood pressure in hypertension. These changes may be due to antioxidant-related adaptations in the PVNs of SHRs.
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Affiliation(s)
- Cui Li
- Department of Exercise Physiology, Beijing Sport University, Beijing, China
| | - Yan Li
- Department of Exercise Physiology, Beijing Sport University, Beijing, China
| | - Ziqi Zhao
- College of Life Science, University of Chinese Academy of Science, Beijing, China
| | - Yuanyuan Lv
- Key Laboratory of Physical Fitness and Exercise, Ministry of Education, Beijing Sport University, Beijing, China
| | - Boya Gu
- Key Laboratory of Physical Fitness and Exercise, Ministry of Education, Beijing Sport University, Beijing, China
| | - Li Zhao
- Department of Exercise Physiology, Beijing Sport University, Beijing, China; Key Laboratory of Physical Fitness and Exercise, Ministry of Education, Beijing Sport University, Beijing, China.
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23
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Tayler HM, Palmer JC, Thomas TL, Kehoe PG, Paton JF, Love S. Cerebral Aβ 40 and systemic hypertension. J Cereb Blood Flow Metab 2018; 38:1993-2005. [PMID: 28782443 PMCID: PMC6259324 DOI: 10.1177/0271678x17724930] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mid-life hypertension and cerebral hypoperfusion may be preclinical abnormalities in people who later develop Alzheimer's disease. Although accumulation of amyloid-beta (Aβ) is characteristic of Alzheimer's disease and is associated with upregulation of the vasoconstrictor peptide endothelin-1 within the brain, it is unclear how this affects systemic arterial pressure. We have investigated whether infusion of Aβ40 into ventricular cerebrospinal fluid modulates blood pressure in the Dahl salt-sensitive rat. The Dahl salt-sensitive rat develops hypertension if given a high-salt diet. Intracerebroventricular infusion of Aβ induced a progressive rise in blood pressure in rats with pre-existing hypertension produced by a high-salt diet ( p < 0.0001), but no change in blood pressure in normotensive rats. The elevation in arterial pressure in high-salt rats was associated with an increase in low frequency spectral density in systolic blood pressure, suggesting autonomic imbalance, and reduced cardiac baroreflex gain. Our results demonstrate the potential for intracerebral Aβ to exacerbate hypertension, through modulation of autonomic activity. Present findings raise the possibility that mid-life hypertension in people who subsequently develop Alzheimer's disease may in some cases be a physiological response to reduced cerebral perfusion complicating the accumulation of Aβ within the brain.
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Affiliation(s)
- Hannah M Tayler
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
| | | | - Taya L Thomas
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Patrick G Kehoe
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Julian Fr Paton
- 2 School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Seth Love
- 1 School of Clinical Sciences, University of Bristol, Bristol, UK
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24
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Chan SHH, Chan JYH. Mitochondria and Reactive Oxygen Species Contribute to Neurogenic Hypertension. Physiology (Bethesda) 2018; 32:308-321. [PMID: 28615314 DOI: 10.1152/physiol.00006.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/05/2017] [Accepted: 04/13/2017] [Indexed: 02/07/2023] Open
Abstract
Beyond its primary role as fuel generators, mitochondria are engaged in a variety of cellular processes, including redox homeostasis. Mitochondrial dysfunction, therefore, may have a profound impact on high-energy-demanding organs such as the brain. Here, we review the roles of mitochondrial biogenesis and bioenergetics, and their associated signaling in cellular redox homeostasis, and illustrate their contributions to the oxidative stress-related neural mechanism of hypertension, focusing on specific brain areas that are involved in the generation or modulation of sympathetic outflows to the cardiovascular system. We also highlight future challenges of research on mitochondrial physiology and pathophysiology.
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Affiliation(s)
- Samuel H H Chan
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Julie Y H Chan
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
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25
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Yan JQ, Huang F, Hao F, Su XL, Meng Q, Xu MJ. Oxidative Stress in the Rostral Ventrolateral Medulla Contributes To Cardiovascular Regulation in Preeclampsia. Front Physiol 2017; 8:772. [PMID: 29085302 PMCID: PMC5649191 DOI: 10.3389/fphys.2017.00772] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/21/2017] [Indexed: 12/24/2022] Open
Abstract
Background: It has been demonstrated that preeclampsia, a pregnancy-specific hypertension disorder, is characterized by high blood pressure (BP) and sympathetic overactivity. Increased reactive oxygen species (ROS) in the rostral ventrolateral medulla (RVLM), a key region for controlling sympathetic tone, has been reported to contribute to high level of BP and sympathetic outflow. The aim of the present study was to determine the role of the RVLM ROS in mediating the preeclampsia-associated cardiovascular dysfunction. Methods: The animal model of preeclampsia was produced by administration of desoxycorticosterone acetate (DOCA) to pregnant rats. Results: Compared with normal pregnant rats without DOCA treatment (NP), the protein concentration and norepinephrine excretion in 24-h urine, as well as BP in pregnant rats with DOCA treatment (PDS) were significantly increased. The levels of superoxide anion and the protein expression of NADPH oxidase subtype (NOX4) in the RVLM were significantly increased in PDS than in NP groups. Furthermore, microinjection of the superoxide dismutase (SOD) mimic Tempol (5 nmol) into the RVLM significantly decreased BP, heart rate, and renal sympathetic never activity in PDS but not in NP group. Conclusion: The present data suggest that high BP and sympathetic overactivity in preeclampsia rats is associated with increased oxidative stress in the RVLM via upregulation of NOX4 expression.
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Affiliation(s)
- Jiu-Qiong Yan
- Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Fang Huang
- Department of Geriatics, Jinling Hospital, Nanjing, China
| | - Fan Hao
- Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Xiao-Ling Su
- Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Qi Meng
- Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Ming-Juan Xu
- Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai, China
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26
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Cao W, Li A, Li J, Wu C, Cui S, Zhou Z, Liu Y, Wilcox CS, Hou FF. Reno-Cerebral Reflex Activates the Renin-Angiotensin System, Promoting Oxidative Stress and Renal Damage After Ischemia-Reperfusion Injury. Antioxid Redox Signal 2017; 27:415-432. [PMID: 28030955 PMCID: PMC5549812 DOI: 10.1089/ars.2016.6827] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
AIMS A kidney-brain interaction has been described in acute kidney injury, but the mechanisms are uncertain. Since we recently described a reno-cerebral reflex, we tested the hypothesis that renal ischemia-reperfusion injury (IRI) activates a sympathetic reflex that interlinks the renal and cerebral renin-angiotensin axis to promote oxidative stress and progression of the injury. RESULTS Bilateral ischemia-reperfusion activated the intrarenal and cerebral, but not the circulating, renin-angiotensin system (RAS), increased sympathetic activity in the kidney and the cerebral sympathetic regulatory regions, and induced brain inflammation and kidney injury. Selective renal afferent denervation with capsaicin or renal denervation significantly attenuated IRI-induced activation of central RAS and brain inflammation. Central blockade of RAS or oxidative stress by intracerebroventricular (ICV) losartan or tempol reduced the renal ischemic injury score by 65% or 58%, respectively, and selective renal afferent denervation or reduction of sympathetic tone by ICV clonidine decreased the score by 42% or 52%, respectively (all p < 0.05). Ischemia-reperfusion-induced renal damage and dysfunction persisted after controlling blood pressure with hydralazine. INNOVATION This study uncovered a novel reflex pathway between ischemic kidney and the brain that sustains renal oxidative stress and local RAS activation to promote ongoing renal damage. CONCLUSIONS These data suggest that the renal and cerebral renin-angiotensin axes are interlinked by a reno-cerebral sympathetic reflex that is activated by ischemia-reperfusion, which contributes to ischemia-reperfusion-induced brain inflammation and worsening of the acute renal injury. Antioxid. Redox Signal. 27, 415-432.
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Affiliation(s)
- Wei Cao
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
| | - Aiqing Li
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
| | - Jiawen Li
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
| | - Chunyi Wu
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
| | - Shuang Cui
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
| | - Zhanmei Zhou
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
| | - Youhua Liu
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
| | - Christopher S Wilcox
- 2 Hypertension, Kidney and Vascular Research Center, Georgetown University , Washington, District of Columbia
| | - Fan Fan Hou
- 1 Division of Nephrology, Nanfang Hospital, Southern Medical University , State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangzhou, P.R. China
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27
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Hypothalamic and inflammatory basis of hypertension. Clin Sci (Lond) 2017; 131:211-223. [PMID: 28057892 DOI: 10.1042/cs20160001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 11/07/2016] [Accepted: 11/21/2016] [Indexed: 02/07/2023]
Abstract
Hypertension is a major health problem with great consequences for public health. Despite its role as the primary cause of significant morbidity and mortality associated with cardiovascular disease, the pathogenesis of essential hypertension remains largely unknown. The central nervous system (CNS) in general, and the hypothalamus in particular, are intricately involved in the development and maintenance of hypertension. Over the last several decades, the understanding of the brain's role in the development of hypertension has dramatically increased. This brief review is to summarize the neural mechanisms of hypertension with a focus on neuroendocrine and neurotransmitter involvement, highlighting recent findings that suggest that hypothalamic inflammation disrupts key signalling pathways to affect the central control of blood pressure, and therefore suggesting future development of interventional strategies that exploit recent findings pertaining to the hypothalamic control of blood pressure as well as the inflammatory-sympathetic mechanisms involved in hypertension.
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28
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Yu B, Cai D. Neural Programmatic Role of Leptin, TNFα, Melanocortin, and Glutamate in Blood Pressure Regulation vs Obesity-Related Hypertension in Male C57BL/6 Mice. Endocrinology 2017; 158:1766-1775. [PMID: 28419227 PMCID: PMC5460935 DOI: 10.1210/en.2016-1872] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 04/10/2017] [Indexed: 02/07/2023]
Abstract
Continuous nutritional surplus sets the stage for hypertension development. Whereas moderate dietary obesity in mice is normotensive, the homeostatic balance is disrupted concurrent with an increased risk of hypertension. However, it remains unclear how the obesity-associated prehypertensive state is converted into overt hypertension. Here, using mice with high-fat-diet (HFD)-induced moderate obesity vs control diet (CD)-fed lean mice, we comparatively studied the effects of central leptin and tumor necrosis factor-α (TNFα) as well as the involvement of the neuropeptide melanocortin pathway vs the neurotransmitter glutamate pathway. Compared with CD-fed lean mice, the pressor effect of central excess leptin and TNFα, but not melanocortin, was sensitized in HFD-fed mice. The pressor effect of central leptin in HFD-fed mice was strongly suppressed by glutamatergic inhibition but not by melanocortinergic inhibition. The pressor effect of central TNFα was substantially reversed by melanocortinergic inhibition in HFD-fed mice but barely in CD-fed mice. Regardless of diet, the hypertensive effects of central TNFα and melanocortin were both partially reversed by glutamatergic suppression. Hence, neural control of blood pressure is mediated by a signaling network between leptin, TNFα, melanocortin, and glutamate and changes in dynamics due to central excess leptin and TNFα mediate the switch from normal physiology to obesity-related hypertension.
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Affiliation(s)
- Bin Yu
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York 10461
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29
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Zubcevic J, Baker A, Martyniuk CJ. Transcriptional networks in rodent models support a role for gut-brain communication in neurogenic hypertension: a review of the evidence. Physiol Genomics 2017; 49:327-338. [PMID: 28550087 DOI: 10.1152/physiolgenomics.00010.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypertension (HTN) is the most prevalent condition observed in primary health care. Hypertension shows complex etiology, and neuroinflammation, overactive sympathetic drive, and the microbiome are each associated with the disease. To obtain mechanistic perspective into neurogenic HTN, we first constructed a framework for transcriptional regulators of the disease using the Comparative Toxicogenomics Database. This approach yielded a core group of 178 transcripts that are prevalent in studies of HTN, including leptin and neuropeptide Y. We then conducted a meta-analysis for transcriptome data generated in brain tissue from HTN studies. Eight expression studies were reanalyzed, in which transcriptomics was conducted in hypertensive animal models [spontaneously hypertensive rats (SHR) and high blood pressure (BPH/2J) Schlager mice] (140 microarrays). Most strikingly, a gut-brain connection was a dominant theme in both rodent models of HTN. The transcriptomic data in the rat CNS converged on processes that included gastrointestinal motility and appetite, among others. In the mouse model, pathways converged on gastrointestinal transit. Thus, our data provide a powerful review of current molecular evidence of the interplay between gut and brain in HTN. Analyses of meta-genome data also suggested that transcriptome networks related to natriuresis, thermoregulation, reproduction (lactation and pregnancy), and vasoconstriction were associated to HTN, supporting physiological observations in independent studies by others. Lastly, we present novel transcriptome networks that may contribute to a neurogenic origin of HTN. Using this framework, new therapeutic targets can be proposed and investigated in treatment strategies.
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Affiliation(s)
- Jasenka Zubcevic
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida.,University of Florida Interdisciplinary Program in Biomedical Sciences Neuroscience, Gainesville, Florida
| | - Ashley Baker
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida.,University of Florida Genetics Institute, Gainesville, Florida; and
| | - Christopher J Martyniuk
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida; .,University of Florida Genetics Institute, Gainesville, Florida; and.,University of Florida Interdisciplinary Program in Biomedical Sciences Neuroscience, Gainesville, Florida
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30
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Mandal A, Das RS, Singh B, Banerjee R, Mukhopadhyay S. Penicillamine and captopril: mechanistic exploration of defensive actions of thiol drugs against a metal bound-superoxo complex. J COORD CHEM 2017. [DOI: 10.1080/00958972.2017.1303488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Arabinda Mandal
- Department of Chemistry, Bidhannagar College, Kolkata, India
| | | | - Bula Singh
- Department of Chemistry, Visva-Bharati, Santiniketan, India
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31
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de Sousa SM, Braz GRF, Freitas CDM, de Santana DF, Sellitti DF, Fernandes MP, Lagranha CJ. Oxidative injuries induced by maternal low-protein diet in female brainstem. Nutr Neurosci 2017; 21:580-588. [PMID: 28494696 DOI: 10.1080/1028415x.2017.1325974] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Many studies have shown that a maternal low-protein diet increases the susceptibility of offspring to cardiovascular disease in later-life. Moreover, a lower incidence of cardiovascular disease in females than in males is understood to be largely due to the protective effect of high levels of estrogens throughout a woman's reproductive life. However, to our knowledge, the role of estradiol in moderating the later-life susceptibility of offspring of nutrient-deprived mothers to cardiovascular disease is not fully understood. The present study is aimed at investigating whether oxidative stress in the brainstem caused by a maternal low-protein diet administered during a critical period of fetal/neonatal brain development (i.e during gestation and lactation) is affected by estradiol levels. Female Wistar rat offspring were divided into four groups according to their mothers' diets and to the serum estradiol levels of the offspring at the time of testing: (1) 22 days of age/control diet: (2) 22 days of age/low-protein diet; (3) 122 days of age/control diet: (4) 122 days of age/low-protein diet. Undernutrition in the context of low serum estradiol compared to undernutrition in a higher estradiol context resulted in increased levels of oxidative stress biomarkers and a reduction in enzymatic and non-enzymatic antioxidant defenses. Total global oxy-score showed oxidative damage in 22-day-old rats whose mothers had received a low-protein diet. In the 122-day-old group, we observed a decrease in oxidative stress biomarkers, increased enzymatic antioxidant activity, and a positive oxy-score when compared to control. We conclude from these results that following a protein deficiency in the maternal diet during early development of the offspring, estrogens present at high levels at reproductive age may confer resistance to the oxidative damage in the brainstem that is very apparent in pre-pubertal rats.
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Affiliation(s)
- Shirley Maria de Sousa
- a Laboratory of Biochemistry and Exercise Biochemistry CAV-Federal University of Pernambuco , UFPE 55608-680 , Brazil
| | - Glauber Rudá F Braz
- a Laboratory of Biochemistry and Exercise Biochemistry CAV-Federal University of Pernambuco , UFPE 55608-680 , Brazil
| | - Cristiane de Moura Freitas
- a Laboratory of Biochemistry and Exercise Biochemistry CAV-Federal University of Pernambuco , UFPE 55608-680 , Brazil
| | - David Filipe de Santana
- a Laboratory of Biochemistry and Exercise Biochemistry CAV-Federal University of Pernambuco , UFPE 55608-680 , Brazil
| | | | - Mariana P Fernandes
- a Laboratory of Biochemistry and Exercise Biochemistry CAV-Federal University of Pernambuco , UFPE 55608-680 , Brazil
| | - Claudia J Lagranha
- a Laboratory of Biochemistry and Exercise Biochemistry CAV-Federal University of Pernambuco , UFPE 55608-680 , Brazil
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32
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Gao L, Zimmerman MC, Biswal S, Zucker IH. Selective Nrf2 Gene Deletion in the Rostral Ventrolateral Medulla Evokes Hypertension and Sympathoexcitation in Mice. Hypertension 2017; 69:1198-1206. [PMID: 28461605 DOI: 10.1161/hypertensionaha.117.09123] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 02/05/2017] [Accepted: 03/06/2017] [Indexed: 12/13/2022]
Abstract
Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master transcriptional regulator of redox homeostasis that impacts antioxidant gene expression. Central oxidative stress and reduced antioxidant enzyme expression in the rostral ventrolateral medulla (RVLM) contributed to sympathoexcitation in chronic heart failure. In the current study, we hypothesized that deletion of Nrf2 in the RVLM would increase sympathetic drive and blood pressure. Experiments were performed in Nrf2-floxed mice treated with microinjection of lentiviral-Cre-GFP or lentiviral-GFP into the RVLM. Two weeks after viral administration, Nrf2 message, protein, oxidative stress, cardiovascular function, and sympathetic outflow were evaluated. We found that (1) Nrf2 mRNA and protein in the RVLM were significantly lower in Cre mice compared with control GFP mice. Nrf2-targeted antioxidant enzymes were downregulated, whereas reactive oxygen species were elevated. (2) Blood pressure measurements indicated that Cre mice displayed a significant increase in blood pressure (mean arterial pressure, 123.7±3.8 versus 100.2±2.2 mm Hg; P<0.05, n=6), elevated urinary norepinephrine (NE) concentration (456.4±16.9 versus 356.5±19.9 ng/mL; P<0.05, n=6), and decreased spontaneous baroreflex gain (up sequences, 1.66±0.17 versus 3.61±0.22 ms/mm Hg; P<0.05, n=6; down sequences, 1.89±0.12 versus 2.98±0.19 ms/mm Hg; P<0.05, n=6). (3) Cre mice displayed elevated baseline renal sympathetic nerve activity and impaired inducible baroreflex function. These data suggest that Nrf2 gene deletion in the RVLM elevates blood pressure, increases sympathetic outflow, and impairs baroreflex function potentially by impaired antioxidant enzyme expression.
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Affiliation(s)
- Lie Gao
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Nebraska Medical Center, Omaha (L.G., M.C.Z., I.H.Z.); and Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (S.B.)
| | - Matthew C Zimmerman
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Nebraska Medical Center, Omaha (L.G., M.C.Z., I.H.Z.); and Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (S.B.)
| | - Shyam Biswal
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Nebraska Medical Center, Omaha (L.G., M.C.Z., I.H.Z.); and Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (S.B.)
| | - Irving H Zucker
- From the Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Nebraska Medical Center, Omaha (L.G., M.C.Z., I.H.Z.); and Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (S.B.).
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33
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Alé A, Zhang Y, Han C, Cai D. Obesity-associated extracellular mtDNA activates central TGFβ pathway to cause blood pressure increase. Am J Physiol Endocrinol Metab 2017; 312:E161-E174. [PMID: 27894066 PMCID: PMC5374298 DOI: 10.1152/ajpendo.00337.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/25/2016] [Accepted: 11/09/2016] [Indexed: 02/07/2023]
Abstract
Hypothalamic inflammation was recently found to mediate obesity-related hypertension, but the responsible upstream mediators remain unexplored. In this study, we show that dietary obesity is associated with extracellular release of mitochondrial DNA (mtDNA) into the cerebrospinal fluid and that central delivery of mtDNA mimics transforming growth factor-β (TGFβ) excess to activate downstream signaling pathways. Physiological study reveals that central administration of mtDNA or TGFβ is sufficient to cause hypertension in mice. Knockout of the TGFβ receptor in proopiomelanocortin neurons counteracts the hypertensive effect of not only TGFβ but also mtDNA excess, while the hypertensive action of central mtDNA can be blocked pharmacologically by a TGFβ receptor antagonist or genetically by TGFβ receptor knockout. Finally, we confirm that obesity-induced hypertension can be reversed through central treatment with TGFβ receptor antagonist. In conclusion, circulating mtDNA in the brain employs neural TGFβ pathway to mediate a central inflammatory mechanism of obesity-related hypertension.
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MESH Headings
- Animals
- Benzamides/pharmacology
- Blood Pressure/immunology
- Blotting, Western
- DNA, Mitochondrial/cerebrospinal fluid
- DNA, Mitochondrial/immunology
- DNA, Mitochondrial/metabolism
- DNA, Mitochondrial/pharmacology
- Diet, High-Fat
- Dioxoles/pharmacology
- Hypertension/etiology
- Hypertension/immunology
- Hypothalamus/immunology
- Hypothalamus/metabolism
- Male
- Mice
- Mice, Knockout
- Neurons/immunology
- Neurons/metabolism
- Obesity/complications
- Obesity/immunology
- Pro-Opiomelanocortin/metabolism
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/immunology
- Receptor, Transforming Growth Factor-beta Type II
- Receptors, Transforming Growth Factor beta/antagonists & inhibitors
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/immunology
- Third Ventricle
- Transforming Growth Factor beta/immunology
- Transforming Growth Factor beta1/pharmacology
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Affiliation(s)
- Albert Alé
- Department of Molecular Pharmacology, Diabetes Research Center, and Institute for Aging Research, Albert Einstein College of Medicine, New York, New York
| | - Yalin Zhang
- Department of Molecular Pharmacology, Diabetes Research Center, and Institute for Aging Research, Albert Einstein College of Medicine, New York, New York
| | - Cheng Han
- Department of Molecular Pharmacology, Diabetes Research Center, and Institute for Aging Research, Albert Einstein College of Medicine, New York, New York
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, and Institute for Aging Research, Albert Einstein College of Medicine, New York, New York
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Abstract
It has become clear that reactive oxygen species (ROS) contribute to the development of hypertension via myriad effects. ROS are essential for normal cell function; however, they mediate pathologic changes in the brain, the kidney, and blood vessels that contribute to the genesis of chronic hypertension. There is also emerging evidence that ROS contribute to immune activation in hypertension. This article discusses these events and how they coordinate to contribute to hypertension and its consequent end-organ damage.
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Affiliation(s)
- Roxana Loperena
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, 2220 Pierce Drive, Room 536 Robinson Research Building, Nashville, TN 37232, USA
| | - David G Harrison
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Vanderbilt University, 2220 Pierce Drive, Room 536 Robinson Research Building, Nashville, TN 37232, USA.
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Gowrisankar YV, Clark MA. Angiotensin II induces interleukin-6 expression in astrocytes: Role of reactive oxygen species and NF-κB. Mol Cell Endocrinol 2016; 437:130-141. [PMID: 27539920 DOI: 10.1016/j.mce.2016.08.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/21/2016] [Accepted: 08/08/2016] [Indexed: 02/07/2023]
Abstract
Previously, we showed that the bio-peptide angiotensin (Ang) II induces interleukin-6 (IL-6) in cultured astrocytes; however, the mechanism(s) involved in this effect were unknown. In the current study, we determined in brainstem and cerebellum astrocytes from the spontaneously hypertensive rat (SHR), the effect of Ang II to induce IL-6 as well as reactive oxygen species (ROS) generation. Results from this study showed that Ang II significantly induced the differential expression of IL-6 mRNA and protein levels in astrocytes from both regions of Wistar and SHRs. There were differences in the ability of Ang II to induce IL-6 mRNA and protein levels, but these differences were not apparent at all time points examined. Ang II also induced ROS generation, but there were no significant differences between ROS generation in SHR samples as compared to the Wistar samples. Ang II-induced IL-6 levels were mediated via the AT1/Nuclear Factor Kappa beta/ROS pathway. Overall, our findings suggest that there may be dysregulation in IL-6 production from astrocytes, contributing to differences observed in SHRs versus its normotensive control. Elucidating the mechanisms involved in Ang II pro-inflammatory effects in the central nervous system may lead to the development of novel therapeutic strategies that can be harnessed not just to treat hypertension, but other Ang II-mediated diseases as well.
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Affiliation(s)
- Yugandhar V Gowrisankar
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, United States
| | - Michelle A Clark
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, United States.
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36
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Kostov K, Blazhev A, Atanasova M, Dimitrova A. Serum Concentrations of Endothelin-1 and Matrix Metalloproteinases-2, -9 in Pre-Hypertensive and Hypertensive Patients with Type 2 Diabetes. Int J Mol Sci 2016; 17:ijms17081182. [PMID: 27490532 PMCID: PMC5000590 DOI: 10.3390/ijms17081182] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/07/2016] [Accepted: 07/13/2016] [Indexed: 02/07/2023] Open
Abstract
Endothelin-1 (ET-1) is one of the most potent vasoconstrictors known to date. While its plasma or serum concentrations are elevated in some forms of experimental and human hypertension, this is not a consistent finding in all forms of hypertension. Matrix metalloproteinases -2 and -9 (MMP-2 and MMP-9), which degrade collagen type IV of the vascular basement membrane, are responsible for vascular remodeling, inflammation, and atherosclerotic complications, including in type 2 diabetes (T2D). In our study, we compared concentrations of ET-1, MMP-2, and MMP-9 in pre-hypertensive (PHTN) and hypertensive (HTN) T2D patients with those of healthy normotensive controls (N). ET-1, MMP-2, and MMP-9 were measured by ELISA. Concentrations of ET-1 in PHTN and N were very similar, while those in HTN were significantly higher. Concentrations of MMP-2 and MMP-9 in PHTN and HTN were also significantly higher compared to N. An interesting result in our study is that concentrations of MMP-2 and MMP-9 in HTN were lower compared to PHTN. In conclusion, we showed that increased production of ET-1 in patients with T2D can lead to long-lasting increases in blood pressure (BP) and clinical manifestation of hypertension. We also demonstrated that increased levels of MMP-2 and MMP-9 in pre-hypertensive and hypertensive patients with T2D mainly reflect the early vascular changes in extracellular matrix (ECM) turnover.
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Affiliation(s)
- Krasimir Kostov
- Department of Physiology and Pathophysiology, Medical University-Pleven, 1 Kliment Ohridski Str., 5800 Pleven, Bulgaria.
| | - Alexander Blazhev
- Division of Biology, Medical University-Pleven, 1 Kliment Ohridski Str., 5800 Pleven, Bulgaria.
| | - Milena Atanasova
- Division of Biology, Medical University-Pleven, 1 Kliment Ohridski Str., 5800 Pleven, Bulgaria.
| | - Anelia Dimitrova
- Department of Physiology and Pathophysiology, Medical University-Pleven, 1 Kliment Ohridski Str., 5800 Pleven, Bulgaria.
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37
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Marvar PJ, Hendy EB, Cruise TD, Walas D, DeCicco D, Vadigepalli R, Schwaber JS, Waki H, Murphy D, Paton JFR. Systemic leukotriene B 4 receptor antagonism lowers arterial blood pressure and improves autonomic function in the spontaneously hypertensive rat. J Physiol 2016; 594:5975-5989. [PMID: 27230966 DOI: 10.1113/jp272065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/09/2016] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Evidence indicates an association between hypertension and chronic systemic inflammation in both human hypertension and experimental animal models. Previous studies in the spontaneously hypertensive rat (SHR) support a role for leukotriene B4 (LTB4 ), a potent chemoattractant involved in the inflammatory response, but its mode of action is poorly understood. In the SHR, we observed an increase in T cells and macrophages in the brainstem; in addition, gene expression profiling data showed that LTB4 production, degradation and downstream signalling in the brainstem of the SHR are dynamically regulated during hypertension. When LTB4 receptor 1 (BLT1) receptors were blocked with CP-105,696, arterial pressure was reduced in the SHR compared to the normotensive control and this reduction was associated with a significant decrease in systolic blood pressure (BP) indicators. These data provide new evidence for the role of LTB4 as an important neuro-immune pathway in the development of hypertension and therefore may serve as a novel therapeutic target for the treatment of neurogenic hypertension. ABSTRACT Accumulating evidence indicates an association between hypertension and chronic systemic inflammation in both human hypertension and experimental animal models. Previous studies in the spontaneously hypertensive rat (SHR) support a role for leukotriene B4 (LTB4 ), a potent chemoattractant involved in the inflammatory response. However, the mechanism for LTB4 -mediated inflammation in hypertension is poorly understood. Here we report in the SHR, increased brainstem infiltration of T cells and macrophages plus gene expression profiling data showing that LTB4 production, degradation and downstream signalling in the brainstem of the SHR are dynamically regulated during hypertension. Chronic blockade of the LTB4 receptor 1 (BLT1) receptor with CP-105,696, reduced arterial pressure in the SHR compared to the normotensive control and this reduction was associated with a significant decrease in low and high frequency spectra of systolic blood pressure, and an increase in spontaneous baroreceptor reflex gain (sBRG). These data provide new evidence for the role of LTB4 as an important neuro-immune pathway in the development of hypertension and therefore may serve as a novel therapeutic target for the treatment of neurogenic hypertension.
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Affiliation(s)
- Paul J Marvar
- Department of Pharmacology and Physiology Washington, The George Washington University School of Medical and Health Sciences, Washington, DC, USA
| | - Emma B Hendy
- School of Physiology, Pharmacology & Neuroscience, Medical Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Thomas D Cruise
- School of Physiology, Pharmacology & Neuroscience, Medical Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Dawid Walas
- School of Physiology, Pharmacology & Neuroscience, Medical Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Danielle DeCicco
- Daniel Baugh Institute for Functional Genomics and Computational Biology, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Rajanikanth Vadigepalli
- Daniel Baugh Institute for Functional Genomics and Computational Biology, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - James S Schwaber
- Daniel Baugh Institute for Functional Genomics and Computational Biology, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Hidefumi Waki
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
| | - David Murphy
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Dorothy Hodgkin Building, University of Bristol, Whitson Street, Bristol, BS1 3NY, UK
| | - Julian F R Paton
- School of Physiology, Pharmacology & Neuroscience, Medical Sciences, University of Bristol, Bristol, BS8 1TD, UK.
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38
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Han C, Rice MW, Cai D. Neuroinflammatory and autonomic mechanisms in diabetes and hypertension. Am J Physiol Endocrinol Metab 2016; 311:E32-41. [PMID: 27166279 PMCID: PMC4967151 DOI: 10.1152/ajpendo.00012.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/03/2016] [Indexed: 02/07/2023]
Abstract
Interdisciplinary studies in the research fields of endocrinology and immunology show that obesity-associated overnutrition leads to neuroinflammatory molecular changes, in particular in the hypothalamus, chronically causing various disorders known as elements of metabolic syndrome. In this process, neural or hypothalamic inflammation impairs the neuroendocrine and autonomic regulation of the brain over blood pressure and glucose homeostasis as well as insulin secretion, and elevated sympathetic activation has been appreciated as a critical mediator. This review describes the involved physiology and mechanisms, with a focus on glucose and blood pressure balance, and suggests that neuroinflammation employs the autonomic nervous system to mediate the development of diabetes and hypertension.
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Affiliation(s)
- Cheng Han
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
| | - Matthew W Rice
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
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39
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Protein undernutrition during development and oxidative impairment in the central nervous system (CNS): potential factors in the occurrence of metabolic syndrome and CNS disease. J Dev Orig Health Dis 2016; 7:513-524. [DOI: 10.1017/s2040174416000246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mitochondria play a regulatory role in several essential cell processes including cell metabolism, calcium balance and cell viability. In recent years, it has been postulated that mitochondria participate in the pathogenesis of a number of chronic diseases, including central nervous system disorders. Thus, the concept of mitochondrial function now extends far beyond the common view of this organelle as the ‘powerhouse’ of the cell to a new appreciation of the mitochondrion as a transducer of early metabolic insult into chronic disease in later life. In this review, we have attempted to describe some of the associations between nutritional status and mitochondrial function (and dysfunction) during embryonic development with the occurrence of neural oxidative imbalance and neurogenic disease in adulthood.
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40
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VOKURKOVÁ M, RAUCHOVÁ H, ŘEZÁČOVÁ L, VANĚČKOVÁ I, ZICHA J. NADPH Oxidase Activity and Reactive Oxygen Species Production in Brain and Kidney of Adult Male Hypertensive Ren-2 Transgenic Rats. Physiol Res 2015; 64:849-56. [DOI: 10.33549/physiolres.933254] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play an important role in brain control of blood pressure (BP). One of the important mechanisms involved in the pathogenesis of hypertension is the elevation of reactive oxygen species (ROS) production by nicotine adenine dinucleotide phosphate (NADPH) oxidase. The aim of our present study was to investigate NADPH oxidase-mediated superoxide (O2-) production and to search for the signs of lipid peroxidation in hypothalamus and medulla oblongata as well as in renal medulla and cortex of hypertensive male rats transgenic for the murine Ren-2 renin gene (Ren-2 TGR) and their age-matched normotensive controls ‒ Hannover Sprague Dawley rats (HanSD). We found no difference in the activity of NADPH oxidase measured as a lucigenin-mediated O2- production in the hypothalamus and medulla oblongata. However, we observed significantly elevated NADPH oxidase in both renal cortex and medulla of Ren-2 TGR compared with HanSD. Losartan (LOS) treatment (10 mg/kg body weight/day) for 2 months (Ren-2 TGR+LOS) did not change NADPH oxidase-dependent O2- production in the kidney. We detected significantly elevated indirect markers of lipid peroxidation measured as thiobarbituric acid-reactive substances (TBARS) in Ren-2 TGR, while they were significantly decreased in Ren-2 TGR+LOS. In conclusion, the present study shows increased NADPH oxidase activities in renal cortex and medulla with significantly increased TBARS in renal cortex. No significant changes of NADPH oxidase and markers of lipid peroxidation were detected in the studied brain regions.
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Affiliation(s)
| | - H. RAUCHOVÁ
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
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41
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Gusdon AM, Fernandez-Bueno GA, Wohlgemuth S, Fernandez J, Chen J, Mathews CE. Respiration and substrate transport rates as well as reactive oxygen species production distinguish mitochondria from brain and liver. BMC BIOCHEMISTRY 2015; 16:22. [PMID: 26358560 PMCID: PMC4564979 DOI: 10.1186/s12858-015-0051-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 09/02/2015] [Indexed: 12/04/2022]
Abstract
BACKGROUND Aberrant mitochondrial function, including excessive reactive oxygen species (ROS) production, has been implicated in the pathogenesis of human diseases. The use of mitochondrial inhibitors to ascertain the sites in the electron transport chain (ETC) resulting in altered ROS production can be an important tool. However, the response of mouse mitochondria to ETC inhibitors has not been thoroughly assessed. Here we set out to characterize the differences in phenotypic response to ETC inhibitors between the more energetically demanding brain mitochondria and less energetically demanding liver mitochondria in commonly utilized C57BL/6J mice. RESULTS We show that in contrast to brain mitochondria, inhibiting distally within complex I or within complex III does not increase liver mitochondrial ROS production supported by complex I substrates, and liver mitochondrial ROS production supported by complex II substrates occurred primarily independent of membrane potential. Complex I, II, and III enzymatic activities and membrane potential were equivalent between liver and brain and responded to ETC. inhibitors similarly. Brain mitochondria exhibited an approximately two-fold increase in complex I and II supported respiration compared with liver mitochondria while exhibiting similar responses to inhibitors. Elevated NADH transport and heightened complex II-III coupled activity accounted for increased complex I and II supported respiration, respectively in brain mitochondria. CONCLUSIONS We conclude that important mechanistic differences exist between mouse liver and brain mitochondria and that mouse mitochondria exhibit phenotypic differences compared with mitochondria from other species.
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Affiliation(s)
- Aaron M Gusdon
- Department of Pathology, Immunology, and Laboratory Medicine, The University of Florida College of Medicine, Gainesville, FL, 32610, USA.
- Department of Neurology, Weill Cornell Medical Center/NewYork-Presbyterian Hospital, New York, NY, 10065, USA.
| | - Gabriel A Fernandez-Bueno
- Department of Pathology, Immunology, and Laboratory Medicine, The University of Florida College of Medicine, Gainesville, FL, 32610, USA.
| | - Stephanie Wohlgemuth
- Department of Animal Sciences, Institute of Food and Agricultural Sciences, The University of Florida, Gainesville, FL, 32610, USA.
| | - Jenelle Fernandez
- Department of Pathology, Immunology, and Laboratory Medicine, The University of Florida College of Medicine, Gainesville, FL, 32610, USA.
| | - Jing Chen
- Department of Pathology, Immunology, and Laboratory Medicine, The University of Florida College of Medicine, Gainesville, FL, 32610, USA.
| | - Clayton E Mathews
- Department of Pathology, Immunology, and Laboratory Medicine, The University of Florida College of Medicine, Gainesville, FL, 32610, USA.
- , Present address: 1275 Center Dr, Room J597, P.O. Box 100275, Gainesville, FL, 32610-0275, USA.
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42
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Young CN, Davisson RL. Angiotensin-II, the Brain, and Hypertension: An Update. Hypertension 2015; 66:920-6. [PMID: 26324508 DOI: 10.1161/hypertensionaha.115.03624] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 08/06/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Colin N Young
- From the Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, DC (C.N.Y.); Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY (R.L.D.); and Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY (R.L.D.).
| | - Robin L Davisson
- From the Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, DC (C.N.Y.); Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY (R.L.D.); and Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY (R.L.D.)
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43
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Huber MJ, Basu R, Cecchettini C, Cuadra AE, Chen QH, Shan Z. Activation of the (pro)renin receptor in the paraventricular nucleus increases sympathetic outflow in anesthetized rats. Am J Physiol Heart Circ Physiol 2015; 309:H880-7. [PMID: 26116710 DOI: 10.1152/ajpheart.00095.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 06/24/2015] [Indexed: 02/07/2023]
Abstract
Previous studies have indicated that hyperactivity of brain prorenin receptors (PRR) is implicated in neurogenic hypertension. However, the role of brain PRR in regulating arterial blood pressure (ABP) is not well understood. Here, we test the hypothesis that PRR activation in the hypothalamic paraventricular nucleus (PVN) contributes to increased sympathetic nerve activity (SNA). In anaesthetized adult Sprague-Dawley (SD) rats, bilateral PVN microinjection of human prorenin (2 pmol/side) significantly increased splanchnic SNA (SSNA; 71 ± 15%, n = 7). Preinjection of either prorenin handle region peptide, the PRR binding blocker (PRRB), or tiron (2 nmol/side), the scavenger of reactive oxygen species (ROS), significantly attenuated the increase in SSNA (PRRB: 32 ± 5% vs. control, n = 6; tiron: 8 ± 10% vs. control, n = 5; P < 0.05) evoked by prorenin injection. We further investigated the effects of PRR activation on ROS production as well as downstream gene expression using cultured hypothalamus neurons from newborn SD rats. Incubation of brain neurons with human prorenin (100 nM) dramatically enhanced ROS production and induced a time-dependent increase in mRNA levels of inducible nitric oxide synthase (iNOS), NAPDH oxidase 2 subunit cybb, and FOS-like antigen 1 (fosl1), a marker for neuronal activation and a component of transcription factor activator protein-1 (AP-1). The maximum mRNA increase in these genes occurred 6 h following incubation (iNOS: 201-fold; cybb: 2 -fold; Ffosl1: 11-fold). The increases in iNOS and cybb mRNA were not attenuated by the AT1 receptor antagonist losartan but abolished by the AP-1 blocker curcumin. Our results suggest that PVN PRR activation induces sympathoexcitation possibly through stimulation of an ANG II-independent, ROS-AP-1-iNOS signaling pathway.
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Affiliation(s)
- Michael J Huber
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Rupsa Basu
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Cassie Cecchettini
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Adolfo E Cuadra
- Department of Biology, University of Massachusetts, Amherst, Massachusetts; and
| | - Qing-Hui Chen
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan; Biotech Research Center, Michigan Technological University, Houghton, Michigan
| | - Zhiying Shan
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan; Biotech Research Center, Michigan Technological University, Houghton, Michigan
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Superoxide Mediates Depressive Effects Induced by Hydrogen Sulfide in Rostral Ventrolateral Medulla of Spontaneously Hypertensive Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:927686. [PMID: 26078823 PMCID: PMC4442288 DOI: 10.1155/2015/927686] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/04/2015] [Accepted: 01/04/2015] [Indexed: 12/02/2022]
Abstract
Hydrogen sulfide (H2S) plays a crucial role in the regulation of blood pressure and oxidative stress. In the present study, we tested the hypothesis that H2S exerts its cardiovascular effects by reducing oxidative stress via inhibition of NADPH oxidase activity in the rostral ventrolateral medulla (RVLM). We examined cell distributions of cystathionine-β-synthase (CBS) and effects of H2S on reactive oxygen species (ROS) and mean arterial blood pressure (MAP) in spontaneously hypertensive rats (SHRs). We found that CBS was expressed in neurons of the RVLM, and the expression was lower in SHRs than in Wistar-Kyoto rats. Microinjection of NaHS (H2S donor), S-adenosyl-l-methionine (SAM, a CBS agonist), or Apocynin (NADPH oxidase inhibitor) into the RVLM reduced the ROS level, NADPH oxidase activity, and MAP, whereas microinjection of hydroxylamine hydrochloride (HA, a CBS inhibitor) increased MAP. Furthermore, intracerebroventricular infusion of NaHS inhibited phosphorylation of p47phox, a key step of NADPH oxidase activation. Since decreasing ROS level in the RVLM reduces MAP and heart rate and increasing H2S reduces ROS production, we conclude that H2S exerts an antihypertensive effect via suppressing ROS production. H2S, as an antioxidant, may be a potential target for cardiovascular diseases.
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45
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Brain Angiotensin II Type 1 Receptor Blockade Improves Dairy Blood Pressure Variability via Sympathoinhibition in Hypertensive Rats. Int J Hypertens 2015; 2015:759629. [PMID: 25918643 PMCID: PMC4396736 DOI: 10.1155/2015/759629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 12/15/2014] [Accepted: 12/15/2014] [Indexed: 11/17/2022] Open
Abstract
Abnormal blood pressure (BP) elevation in early morning is known to cause cardiovascular events. Previous studies have suggested that one of the reasons in abnormal dairy BP variability is sympathoexcitation. We have demonstrated that brain angiotensin II type 1 receptor (AT1R) causes sympathoexcitation. The aim of the present study was to investigate whether central AT1R blockade attenuates the excess BP elevation in rest-to-active phase in hypertensive rats or not. Stroke-prone spontaneously hypertensive rats (SHRSP) were treated with intracerebroventricular infusion (ICV) of AT1R receptor blocker (ARB), oral administration of hydralazine (HYD), or ICV of vehicle (VEH). Telemetric averaged mean BP (MBP) was measured at early morning (EM), after morning (AM), and night (NT). At EM, MBP was significantly lower in ARB to a greater extent than in HYD compared to VEH, though MBP at AM was the same in ARB and HYD. At NT, MBP was also significantly lower in ARB than in HYD. These results in MBP were compatible to those in sympathoexcitation and suggest that central AT1R blockade attenuates excess BP elevation in early active phase and continuous BP elevation during rest phase independent of depressor response in hypertensive rats.
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46
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Nagayama T, Hirooka Y, Kishi T, Mukai Y, Inoue S, Takase S, Takemoto M, Chishaki A, Sunagawa K. Blockade of brain angiotensin II type 1 receptor inhibits the development of atrial fibrillation in hypertensive rats. Am J Hypertens 2015; 28:444-51. [PMID: 25352232 DOI: 10.1093/ajh/hpu196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Hypertension is a powerful risk factor of atrial fibrillation (AF). The pathophysiology of AF with hypertension is associated with sympathoexcitation or the renin-angiotensin system; however, current therapies cannot sufficiently prevent its development. We previously revealed that brain angiotensin II type 1 receptor (AT1R) blockade causes a depressor response via sympathoinhibition. Herein, we evaluated whether brain AT1R contributes to AF development in hypertensive rats. METHODS We divided the stroke-prone spontaneously hypertensive rats (SHRSP) treated with intracerebroventricular (ICV) infusion of vehicle, ICV infusion of losartan (S-LOS), or oral administration of hydralazine (S-HYD); and Wistar Kyoto rats treated with ICV S-VEH. RESULTS Two weeks later, systolic blood pressure was significantly lower in the S-LOS group than in the S-VEH group and was even lower in the S-HYD group. Urinary norepinephrine excretion for 24h, an indirect marker of sympathoexcitation, significantly reduced in the S-LOS group but increased in the S-HYD group despite depressor response. AF was induced by transesophageal burst pacing. AF duration was significantly shorter in the S-LOS group than in the S-VEH group (5.0±0.4 vs. 15.2±3.7 s; n = 8 each; P < 0.05). However, it was significantly longer in the S-HYD group than in the S-VEH group. Interstitial atrial fibrosis and echocardiographic parameters did not differ between the SHRSP groups. CONCLUSIONS Brain AT1R blockade suppresses AF inducibility and maintenance independent of depressor response in hypertensive rats.
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Affiliation(s)
- Tomomi Nagayama
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Yoshitaka Hirooka
- Department of Advanced Cardiovascular Regulation and Therapeutics, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan;
| | - Takuya Kishi
- Department of Advanced Therapeutics for Cardiovascular Diseases, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Yasushi Mukai
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Shujiro Inoue
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Susumu Takase
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | | | - Akiko Chishaki
- Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Kenji Sunagawa
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
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47
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The utility of iron chelators in the management of inflammatory disorders. Mediators Inflamm 2015; 2015:516740. [PMID: 25878400 PMCID: PMC4386698 DOI: 10.1155/2015/516740] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/01/2014] [Accepted: 09/01/2014] [Indexed: 01/19/2023] Open
Abstract
Since iron can contribute to detrimental radical generating processes through the Fenton and Haber-Weiss reactions, it seems to be a reasonable approach to modulate iron-related pathways in inflammation. In the human organism a counterregulatory reduction in iron availability is observed during inflammatory diseases. Under pathological conditions with reduced or increased baseline iron levels different consequences regarding protection or susceptibility to inflammation have to be considered. Given the role of iron in development of inflammatory diseases, pharmaceutical agents targeting this pathway promise to improve the clinical outcome. The objective of this review is to highlight the mechanisms of iron regulation and iron chelation, and to demonstrate the potential impact of this strategy in the management of several acute and chronic inflammatory diseases, including cancer.
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Deo SH, Holwerda SW, Keller DM, Fadel PJ. Elevated peripheral blood mononuclear cell-derived superoxide production in healthy young black men. Am J Physiol Heart Circ Physiol 2014; 308:H548-52. [PMID: 25527783 DOI: 10.1152/ajpheart.00784.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several studies have demonstrated that blacks exhibit elevations in systemic oxidative stress. However, the source(s) and mechanism(s) contributing to the elevation in oxidative stress remain unclear. Given that peripheral blood mononuclear cells (PBMCs) can be a major source of NADPH oxidase-derived superoxide production, we tested the hypothesis that young black men demonstrate greater superoxide production and NADPH oxidase expression in PBMCs compared with whites. PBMCs were freshly isolated from whole blood in young normotensive black (n = 18) and white (n = 16) men. Intracellular superoxide production in PBMCs was measured using dihydroethidium fluorescence, protein expression of NADPH oxidase subunits, gp91(phox) (membranous) and p47(phox) (cytosolic) in PBMCs were assessed using Western blot analysis, and plasma protein carbonyls were measured as a marker of systemic oxidative stress. Black men showed elevated intracellular superoxide production (4.3 ± 0.5 vs. 2.0 ± 0.6 relative fluorescence units; black men vs. white men, P < 0.05), increased protein expression for gp91(phox) and p47(phox) (e.g., p47(phox): 1.1 ± 0.2, black men vs. 0.4 ± 0.1, white men, P < 0.05) in PBMCs and higher circulating protein carbonyl levels (22 ± 4 vs. 14 ± 2 nmol/ml; black men vs. white men, P < 0.05). Interestingly, a positive family history of hypertension in black men did not further enhance PBMC-derived intracellular superoxide production or NADPH oxidase subunit protein expression. These findings indicate that black men exhibit greater resting PBMC-derived superoxide production and an upregulation of the NADPH oxidase pathway with a possible contribution to increases in systemic oxidative stress.
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Affiliation(s)
- Shekhar H Deo
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Seth W Holwerda
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - David M Keller
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - Paul J Fadel
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; and
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CNS inflammation and bone marrow neuropathy in type 1 diabetes. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 183:1608-20. [PMID: 24160325 DOI: 10.1016/j.ajpath.2013.07.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 06/28/2013] [Accepted: 07/12/2013] [Indexed: 02/06/2023]
Abstract
By using pseudorabies virus expressing green fluorescence protein, we found that efferent bone marrow-neural connections trace to sympathetic centers of the central nervous system in normal mice. However, this was markedly reduced in type 1 diabetes, suggesting a significant loss of bone marrow innervation. This loss of innervation was associated with a change in hematopoiesis toward generation of more monocytes and an altered diurnal release of monocytes in rodents and patients with type 1 diabetes. In the hypothalamus and granular insular cortex of mice with type 1 diabetes, bone marrow-derived microglia/macrophages were activated and found at a greater density than in controls. Infiltration of CD45(+)/CCR2(+)/GR-1(+)/Iba-1(+) bone marrow-derived monocytes into the hypothalamus could be mitigated by treatment with minocycline, an anti-inflammatory agent capable of crossing the blood-brain barrier. Our studies suggest that targeting central inflammation may facilitate management of microvascular complications.
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Brandes RP, Weissmann N, Schröder K. Nox family NADPH oxidases in mechano-transduction: mechanisms and consequences. Antioxid Redox Signal 2014; 20:887-98. [PMID: 23682993 PMCID: PMC3924808 DOI: 10.1089/ars.2013.5414] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SIGNIFICANCE The majority of cells in a multi-cellular organism are continuously exposed to ever-changing physical forces. Mechano-transduction links these events to appropriate reactions of the cells involving stimulation of signaling cascades, reorganization of the cytoskeleton and alteration of gene expression. RECENT ADVANCES Mechano-transduction alters the cellular redox balance and the formation of reactive oxygen species (ROS). Nicotine amide adenine dinucleotide reduced form (NADPH) oxidases of the Nox family are prominent ROS generators and thus, contribute to this stress-induced ROS formation. CRITICAL ISSUES Different types and patterns of mechano-stress lead to Nox-dependent ROS formation and Nox-mediated ROS formation contributes to cellular responses and adaptation to physical forces. Thereby, Nox enzymes can mediate vascular protection during physiological mechano-stress. Despite this, over-activation and induction of Nox enzymes and a subsequent substantial increase in ROS formation also promotes oxidative stress in pathological situations like disturbed blood flow or extensive stretch. FUTURE DIRECTIONS Individual protein targets of Nox-mediated redox-signaling will be identified to better understand the specificity of Nox-dependent ROS signaling in mechano-transduction. Nox-inhibitors will be tested to reduce cellular activation in response to mechano-stimuli.
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Affiliation(s)
- Ralf P Brandes
- 1 Institut für Kardiovaskuläre Physiologie, Goethe-Universität Frankfurt , Frankfurt am Main, Germany
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