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Primary hypertension is a disease of premature vascular aging associated with neuro-immuno-metabolic abnormalities. Pediatr Nephrol 2016; 31:185-94. [PMID: 25724169 PMCID: PMC4689752 DOI: 10.1007/s00467-015-3065-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/19/2015] [Accepted: 02/03/2015] [Indexed: 02/07/2023]
Abstract
There is an increasing amount of data indicating that primary hypertension (PH) is not only a hemodynamic phenomenon but also a complex syndrome involving abnormal fat tissue distribution, over-activity of the sympathetic nervous system (SNS), metabolic abnormalities, and activation of the immune system. In children, PH usually presents with a typical phenotype of disturbed body composition, accelerated biological maturity, and subtle immunological and metabolic abnormalities. This stage of the disease is potentially reversible. However, long-lasting over-activity of the SNS and immuno-metabolic alterations usually lead to an irreversible stage of cardiovascular disease. We describe an intermediate phenotype of children with PH, showing that PH is associated with accelerated development, i.e., early premature aging of the immune, metabolic, and vascular systems. The associations and determinants of hypertensive organ damage, the principles of treatment, and the possibility of rejuvenation of the cardiovascular system are discussed.
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52
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Yang XL, Kim CK, Kim TJ, Sun J, Rim D, Kim YJ, Ko SB, Jang H, Yoon BW. Anti-inflammatory effects of fimasartan via Akt, ERK, and NFκB pathways on astrocytes stimulated by hemolysate. Inflamm Res 2015; 65:115-23. [PMID: 26608500 DOI: 10.1007/s00011-015-0895-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 09/19/2015] [Accepted: 11/01/2015] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE The aim of this study was to investigate whether fimasartan, a novel angiotensin II receptor blocker, modulates hemolysate-induced inflammation in astrocytes. METHODS We stimulated astrocytes with hemolysate to induce hemorrhagic inflammation in vitro. Astrocytes were pretreated with fimasartan and then incubated with hemolysate at different durations. Anti-inflammatory cell signaling molecules including Akt, extracellular signal regulated kinase (ERK), NFκB and cyclooxygenase-2 (COX-2) were assessed by western blotting. Pro-inflammatory mediators were evaluated by real-time RT-PCR and ELISA. RESULTS The stimulation by hemolysate generated a robust activation of inflammatory signaling pathways in astrocytes. Hemolysate increased the phosphorylation of Akt at 1 h, and ERK1/2 at 20 min compared with the control group and promoted the degradation of IκBα. Pretreated fimasartan significantly decreased hemolysate-induced phosphorylation of Akt and ERK1/2. In addition, fimasartan also suppressed NFκB-related inflammatory pathways induced by hemolysate, including reduction of the gene expression of NFκB, and decreased nuclear translocation of NFκB and degradation of IκB. This reduction of inflammatory upstream pathways decreased the expression of inflammatory end-products: COX-2 and interleukin-1 (IL-1β). Furthermore, the expression of COX-2 was attenuated by both Akt inhibitor (LY294002) and ERK inhibitor (U0126), and IκBα degradation was suppressed by LY294002. CONCLUSIONS These results demonstrate that pretreatment with fimasartan to astrocytes suppresses the inflammatory responses induced by hemolysate. Akt, ERK and NFκB were associated with hemolysate-induced COX-2 and IL-1β expression. Based on these mechanisms, fimasartan could be a candidate anti-inflammatory regulator for the treatment of intracerebral hemorrhage.
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Affiliation(s)
- Xiu-Li Yang
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Chi Kyung Kim
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03087, Republic of Korea
| | - Tae Jung Kim
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Jing Sun
- Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Doeun Rim
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Young-Ju Kim
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Sang-Bae Ko
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Hyunduk Jang
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Byung-Woo Yoon
- Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea. .,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03087, Republic of Korea.
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53
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Wittmann C, Reischl M, Shah AH, Kronfuss E, Mikut R, Liebel U, Grabher C. A Zebrafish Drug-Repurposing Screen Reveals sGC-Dependent and sGC-Independent Pro-Inflammatory Activities of Nitric Oxide. PLoS One 2015; 10:e0137286. [PMID: 26444552 PMCID: PMC4596872 DOI: 10.1371/journal.pone.0137286] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 08/14/2015] [Indexed: 12/03/2022] Open
Abstract
Tissue injury and infection trigger innate immune responses. However, dysregulation may result in chronic inflammation and is commonly treated with corticosteroids and non-steroidal anti-inflammatory drugs. Unfortunately, long-term administration of both therapeutic classes can cause unwanted side effects. To identify alternative immune-modulatory compounds we have previously established a novel screening method using zebrafish larvae. Using this method we here present results of an in vivo high-content drug-repurposing screen, identifying 63 potent anti-inflammatory drugs that are in clinical use for other indications. Our approach reveals a novel pro-inflammatory role of nitric oxide. Nitric oxide affects leukocyte recruitment upon peripheral sensory nervous system or epithelial injury in zebrafish larvae both via soluble guanylate cyclase and in a soluble guanylate cyclase -independent manner through protein S-nitrosylation. Together, we show that our screening method can help to identify novel immune-modulatory activities and provide new mechanistic insights into the regulation of inflammatory processes.
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Affiliation(s)
- Christine Wittmann
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Markus Reischl
- Institute for Applied Computer Science, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Asmi H. Shah
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Eva Kronfuss
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Ralf Mikut
- Institute for Applied Computer Science, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Urban Liebel
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Clemens Grabher
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
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54
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Hosseinimehr SJ. The use of angiotensin II receptor antagonists to increase the efficacy of radiotherapy in cancer treatment. Future Oncol 2015; 10:2381-90. [PMID: 25525846 DOI: 10.2217/fon.14.177] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Angiotensin II receptor antagonists inhibit various signaling pathways involved in the regulation of inflammation, apoptosis and angiogenesis. Radiation-induced activation of a proinflammatory cytokine network has been shown to mediate normal tissue injury induced by ionizing radiation in cancer patients, resulting in serious side effects. Hence, not only do angiotensin II receptor antagonists block inflammatory signaling both in cancer cells and in normal cells, but they are also effective in the treatment of cancer by inhibiting tumor progression, vascularization and metastasis. This review addresses the role of angiotensin II inhibitors in cancer therapy, and their potential to increase therapeutical index by protecting normal cells and sensitizing tumor cells to radiotherapy.
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Affiliation(s)
- Seyed Jalal Hosseinimehr
- Department of Radiopharmacy, Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran;
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55
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Lipopolysaccharides upregulate hepcidin in neuron via microglia and the IL-6/STAT3 signaling pathway. Mol Neurobiol 2015; 50:811-20. [PMID: 24659348 DOI: 10.1007/s12035-014-8671-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/28/2014] [Indexed: 12/13/2022]
Abstract
Neuroinflammation is closely related to brain iron homeostasis. Our previous study demonstrated that lipopolysaccharides (LPS) can regulate expression of iron-regulatory peptide hepcidin; however, the mechanism is undefined. Here, we demonstrated that intracerebroventricular injection of LPS in rat brain upregulated hepcidin and downregulated ferroportin 1 in the cortex and substantia nigra. LPS increased hepcidin expression in neurons only when they were co-cultured with BV-2 microglia, and the upregulation was suppressed by IL-6 neutralizing antibody in vitro. In addition, IL-6 but not IL-1α, IL-1β, or tumor necrosis factor-alpha increased hepcidin expression and signal transducer and activator of transcription 3 (STAT3) phosphorylation in cortical neurons and MES23.5 dopaminergic neurons. These effects were blocked by the STAT3 inhibitor, stattic. Our results show that neurons are the major source of increased hepcidin expression in response to LPS challenge but microglia play a key mediator role by releasing IL-6 and recruiting the STAT3 pathway. We conclude that LPS upregulates hepcidin expression in neurons via microglia and the IL-6/STAT3 signaling pathway.
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56
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de Kloet AD, Liu M, Rodríguez V, Krause EG, Sumners C. Role of neurons and glia in the CNS actions of the renin-angiotensin system in cardiovascular control. Am J Physiol Regul Integr Comp Physiol 2015; 309:R444-58. [PMID: 26084692 DOI: 10.1152/ajpregu.00078.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 06/15/2015] [Indexed: 02/07/2023]
Abstract
Despite tremendous research efforts, hypertension remains an epidemic health concern, leading often to the development of cardiovascular disease. It is well established that in many instances, the brain plays an important role in the onset and progression of hypertension via activation of the sympathetic nervous system. Further, the activity of the renin-angiotensin system (RAS) and of glial cell-mediated proinflammatory processes have independently been linked to this neural control and are, as a consequence, both attractive targets for the development of antihypertensive therapeutics. Although it is clear that the predominant effector peptide of the RAS, ANG II, activates its type-1 receptor on neurons to mediate some of its hypertensive actions, additional nuances of this brain RAS control of blood pressure are constantly being uncovered. One of these complexities is that the RAS is now thought to impact cardiovascular control, in part, via facilitating a glial cell-dependent proinflammatory milieu within cardiovascular control centers. Another complexity is that the newly characterized antihypertensive limbs of the RAS are now recognized to, in many cases, antagonize the prohypertensive ANG II type 1 receptor (AT1R)-mediated effects. That being said, the mechanism by which the RAS, glia, and neurons interact to regulate blood pressure is an active area of ongoing research. Here, we review the current understanding of these interactions and present a hypothetical model of how these exchanges may ultimately regulate cardiovascular function.
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Affiliation(s)
- Annette D de Kloet
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
| | - Meng Liu
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
| | - Vermalí Rodríguez
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
| | - Eric G Krause
- Department of Pharmacodynamics, University of Florida College of Pharmacy, Gainesville, Florida
| | - Colin Sumners
- Department of Physiology and Functional Genomics, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida; and
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Abstract
Angiotensin II receptor blockers (ARBs, collectively called sartans) are widely used compounds therapeutically effective in cardiovascular disorders, renal disease, the metabolic syndrome, and diabetes. It has been more recently recognized that ARBs are neuroprotective and have potential therapeutic use in many brain disorders. ARBs ameliorate inflammatory and apoptotic responses to glutamate, interleukin 1β and bacterial endotoxin in cultured neurons, astrocytes, microglial, and endothelial cerebrovascular cells. When administered systemically, ARBs enter the brain, protecting cerebral blood flow, maintaining blood brain barrier function and decreasing cerebral hemorrhage, excessive brain inflammation and neuronal injury in animal models of stroke, traumatic brain injury, Alzheimer's and Parkinson's disease and other brain conditions. Epidemiological analyses reported that ARBs reduced the progression of Alzheimer's disease, and clinical studies suggested amelioration of cognitive loss following stroke and aging. ARBs are pharmacologically heterogeneous; their effects are not only the result of Ang II type 1(AT1) receptor blockade but also of additional mechanisms selective for only some compounds of the class. These include peroxisome proliferator-activated receptor gamma activation and other still poorly defined mechanisms. However, the complete pharmacological spectrum and therapeutic efficacy of individual ARBs have never been systematically compared, and the neuroprotective efficacy of these compounds has not been rigorously determined in controlled clinical studies. The accumulation of pre-clinical evidence should promote further epidemiological and controlled clinical studies. Repurposing ARBs for the treatment of brain disorders, currently without effective therapy, may be of immediate and major translational value.
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Affiliation(s)
- Sonia Villapol
- Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Juan M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, District of Columbia, USA.
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58
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Simões e Silva AC, Silveira KD, Ferreira AJ, Teixeira MM. ACE2, angiotensin-(1-7) and Mas receptor axis in inflammation and fibrosis. Br J Pharmacol 2014; 169:477-92. [PMID: 23488800 DOI: 10.1111/bph.12159] [Citation(s) in RCA: 390] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 02/04/2013] [Accepted: 02/13/2013] [Indexed: 12/14/2022] Open
Abstract
Recent advances have improved our understanding of the renin-angiotensin system (RAS). These have included the recognition that angiotensin (Ang)-(1-7) is a biologically active product of the RAS cascade. The identification of the ACE homologue ACE2, which forms Ang-(1-7) from Ang II, and the GPCR Mas as an Ang-(1-7) receptor have provided the necessary biochemical and molecular background and tools to study the biological significance of Ang-(1-7). Most available evidence supports a counter-regulatory role for Ang-(1-7) by opposing many actions of Ang II on AT₁ receptors, especially vasoconstriction and proliferation. Many studies have now shown that Ang-(1-7) by acting via Mas receptor exerts inhibitory effects on inflammation and on vascular and cellular growth mechanisms. Ang-(1-7) has also been shown to reduce key signalling pathways and molecules thought to be relevant for fibrogenesis. Here, we review recent findings related to the function of the ACE2/Ang-(1-7)/Mas axis and focus on the role of this axis in modifying processes associated with acute and chronic inflammation, including leukocyte influx, fibrogenesis and proliferation of certain cell types. More attention will be given to the involvement of the ACE2/Ang-(1-7)/Mas axis in the context of renal disease because of the known relevance of the RAS for the function of this organ and for the regulation of kidney inflammation and fibrosis. Taken together, this knowledge may help in paving the way for the development of novel treatments for chronic inflammatory and renal diseases.
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Affiliation(s)
- A C Simões e Silva
- Departamento de Pediatria, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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59
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Labandeira-García JL, Garrido-Gil P, Rodriguez-Pallares J, Valenzuela R, Borrajo A, Rodríguez-Perez AI. Brain renin-angiotensin system and dopaminergic cell vulnerability. Front Neuroanat 2014; 8:67. [PMID: 25071471 PMCID: PMC4086395 DOI: 10.3389/fnana.2014.00067] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 06/24/2014] [Indexed: 01/11/2023] Open
Abstract
Although the renin-angiotensin system (RAS) was classically considered as a circulating system that regulates blood pressure, many tissues are now known to have a local RAS. Angiotensin, via type 1 receptors, is a major activator of the NADPH-oxidase complex, which mediates several key events in oxidative stress (OS) and inflammatory processes involved in the pathogenesis of major aging-related diseases. Several studies have demonstrated the presence of RAS components in the basal ganglia, and particularly in the nigrostriatal system. In the nigrostriatal system, RAS hyperactivation, via NADPH-oxidase complex activation, exacerbates OS and the microglial inflammatory response and contributes to progression of dopaminergic degeneration, which is inhibited by angiotensin receptor blockers and angiotensin converting enzyme (ACE) inhibitors. Several factors may induce an increase in RAS activity in the dopaminergic system. A decrease in dopaminergic activity induces compensatory upregulation of local RAS function in both dopaminergic neurons and glia. In addition to its role as an essential neurotransmitter, dopamine may also modulate microglial inflammatory responses and neuronal OS via RAS. Important counterregulatory interactions between angiotensin and dopamine have also been observed in several peripheral tissues. Neurotoxins and proinflammatory factors may also act on astrocytes to induce an increase in RAS activity, either independently of or before the loss of dopamine. Consistent with a major role of RAS in dopaminergic vulnerability, increased RAS activity has been observed in the nigra of animal models of aging, menopause and chronic cerebral hypoperfusion, which also showed higher dopaminergic vulnerability. Manipulation of the brain RAS may constitute an effective neuroprotective strategy against dopaminergic vulnerability and progression of Parkinson's disease.
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Affiliation(s)
- Jose L Labandeira-García
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Pablo Garrido-Gil
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Jannette Rodriguez-Pallares
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Rita Valenzuela
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Ana Borrajo
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
| | - Ana I Rodríguez-Perez
- Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, CIMUS, Faculty of Medicine, University of Santiago de Compostela Santiago de Compostela, Spain ; Networking Research Center on Neurodegenerative Diseases (CIBERNED) Madrid, Spain
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Biancardi VC, Son SJ, Ahmadi S, Filosa JA, Stern JE. Circulating angiotensin II gains access to the hypothalamus and brain stem during hypertension via breakdown of the blood-brain barrier. Hypertension 2013; 63:572-9. [PMID: 24343120 DOI: 10.1161/hypertensionaha.113.01743] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Angiotensin II-mediated vascular brain inflammation emerged as a novel pathophysiological mechanism in neurogenic hypertension. However, the precise underlying mechanisms and functional consequences in relation to blood-brain barrier (BBB) integrity and central angiotensin II actions mediating neurohumoral activation in hypertension are poorly understood. Here, we aimed to determine whether BBB permeability within critical hypothalamic and brain stem regions involved in neurohumoral regulation was altered during hypertension. Using digital imaging quantification after intravascularly injected fluorescent dyes and immunohistochemistry, we found increased BBB permeability, along with altered key BBB protein constituents, in spontaneously hypertensive rats within the hypothalamic paraventricular nucleus, the nucleus of the solitary tract, and the rostral ventrolateral medulla, all critical brain regions known to contribute to neurohumoral activation during hypertension. BBB disruption, including increased permeability and downregulation of constituent proteins, was prevented in spontaneously hypertensive rats treated with the AT1 receptor antagonist losartan, but not with hydralazine, a direct vasodilator. Importantly, we found circulating angiotensin II to extravasate into these brain regions, colocalizing with neurons and microglial cells. Taken together, our studies reveal a novel angiotensin II-mediated feed-forward mechanism during hypertension, by which circulating angiotensin II evokes increased BBB permeability, facilitating in turn its access to critical brain regions known to participate in blood pressure regulation.
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Sonsalla PK, Coleman C, Wong LY, Harris SL, Richardson JR, Gadad BS, Li W, German DC. The angiotensin converting enzyme inhibitor captopril protects nigrostriatal dopamine neurons in animal models of parkinsonism. Exp Neurol 2013; 250:376-83. [PMID: 24184050 PMCID: PMC3889207 DOI: 10.1016/j.expneurol.2013.10.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/11/2013] [Accepted: 10/23/2013] [Indexed: 11/21/2022]
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by a prominent loss of nigrostriatal dopamine (DA) neurons with an accompanying neuroinflammation. The peptide angiotensin II (AngII) plays a role in oxidative-stress induced disorders and is thought to mediate its detrimental actions via activation of AngII AT1 receptors. The brain renin-angiotensin system is implicated in neurodegenerative disorders including PD. Blockade of the angiotensin converting enzyme or AT1 receptors provides protection in acute animal models of parkinsonism. We demonstrate here that treatment of mice with the angiotensin converting enzyme inhibitor captopril protects the striatum from acutely administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrine (MPTP), and that chronic captopril protects the nigral DA cell bodies from degeneration in a progressive rat model of parkinsonism created by the chronic intracerebral infusion of 1-methyl-4-phenylpyridinium (MPP+). The accompanying activation of microglia in the substantia nigra of MPP+-treated rats was reduced by the chronic captopril treatment. These findings indicate that captopril is neuroprotective for nigrostriatal DA neurons in both acute and chronic rodent PD models. Targeting the brain AngII pathway may be a feasible approach to slowing neurodegeneration in PD.
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Affiliation(s)
- Patricia K Sonsalla
- Department of Neurology, Rutgers, The State University of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ, USA.
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Pan PP, Zhan QT, Le F, Zheng YM, Jin F. Angiotensin-converting enzymes play a dominant role in fertility. Int J Mol Sci 2013; 14:21071-86. [PMID: 24152441 PMCID: PMC3821659 DOI: 10.3390/ijms141021071] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 10/14/2013] [Accepted: 10/14/2013] [Indexed: 01/10/2023] Open
Abstract
According to the World Health Organization, infertility, associated with metabolic syndrome, has become a global issue with a 10%-20% incidence worldwide. An accumulating body of evidence has shown that the renin-angiotensin system is involved in the fertility problems observed in some populations. Moreover, alterations in the expression of angiotensin-converting enzyme-1, angiotensin-converting enzyme-2, and angiotensin-converting enzyme-3 might be one of the most important mechanisms underlying both female and male infertility. However, as a pseudogene in humans, further studies are needed to explore whether the abnormal angiotensin-converting enzyme-3 gene could result in the problems of human reproduction. In this review, the relationship between angiotensin-converting enzymes and fertile ability is summarized, and a new procedure for the treatment of infertility is discussed.
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Affiliation(s)
- Pei-Pei Pan
- Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, 1 Xueshi Road, Hangzhou 310006, China; E-Mails: (P.-P.P.); (Q.-T.Z.); (F.L.); (Y.-M.Z.)
| | - Qi-Tao Zhan
- Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, 1 Xueshi Road, Hangzhou 310006, China; E-Mails: (P.-P.P.); (Q.-T.Z.); (F.L.); (Y.-M.Z.)
| | - Fang Le
- Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, 1 Xueshi Road, Hangzhou 310006, China; E-Mails: (P.-P.P.); (Q.-T.Z.); (F.L.); (Y.-M.Z.)
| | - Ying-Ming Zheng
- Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, 1 Xueshi Road, Hangzhou 310006, China; E-Mails: (P.-P.P.); (Q.-T.Z.); (F.L.); (Y.-M.Z.)
| | - Fan Jin
- Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, 1 Xueshi Road, Hangzhou 310006, China; E-Mails: (P.-P.P.); (Q.-T.Z.); (F.L.); (Y.-M.Z.)
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63
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Häfner S, Baumert J, Emeny RT, Lacruz ME, Bidlingmaier M, Reincke M, Ladwig KH. Hypertension and depressed symptomatology: a cluster related to the activation of the renin-angiotensin-aldosterone system (RAAS). Findings from population based KORA F4 study. Psychoneuroendocrinology 2013; 38:2065-74. [PMID: 23608138 DOI: 10.1016/j.psyneuen.2013.03.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 03/20/2013] [Accepted: 03/21/2013] [Indexed: 10/26/2022]
Abstract
CONTEXT Preliminary evidence points to aldosterone being not only prominently involved in the systemic regulation of the blood pressure but also to play a role in the pathophysiology of depression. OBJECTIVE We evaluated whether the combination of hypertension and depressed symptomatology is useful to screen for individuals suffering an activation of the renin-angiotensin-aldosterone system (RAAS). DESIGN We conducted a cross-sectional analysis in participants from the Cooperative Health Research in the Region of Augsburg (KORA) F4 Study conducted between 2006 and 2008 in Southern Germany. A total of 1805 participants of the F4 study were included in the study. METHODS The association between aldosterone and renin levels and the different combinations of hypertension and depressed symptomatology was examined in four different models of multiple linear regression adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and behavioural risk factors. RESULTS Individuals suffering both, depressed symptomatology and hypertension exhibited highly significantly increased aldosterone levels (p<0.001) and slightly, not significantly increased renin levels (p=0.08) compared to individuals with no depressed symptomatology and no hypertension. No significant activation of the RAAS was seen in only depressed or only hypertensive individuals. CONCLUSIONS The finding of highly significantly increased aldosterone levels and increased renin levels in individuals suffering both, depressed symptomatology and hypertension provides further evidence for the involvement of the RAAS in the pathogenesis of depressed symptomatology. These findings have important implications for future research concerning the pathophysiological pathways that link depression and cardiovascular disease.
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Affiliation(s)
- S Häfner
- Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; Department of Psychiatry and Psychotherapy, Georg-August-University Goettingen, Goettingen, Germany.
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Kandalam U, Palanisamy M, Clark MA. Angiotensin II induces cell growth and IL-6 mRNA expression through the JAK2-STAT3 pathway in rat cerebellar astrocytes. JAKSTAT 2013; 1:83-9. [PMID: 24058756 PMCID: PMC3670299 DOI: 10.4161/jkst.19688] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The pleiotrophic effects of angiotensin II (Ang II) play important roles in astrocyte growth and inflammatory responses. We investigated whether Ang II induces astrocyte growth and interleukin-6 (IL-6) mRNA expression in rat cerebellar astrocytes through Janus kinase 2-signal transduction activator of transcription (JAK2-STAT3). Ang II increased JAK2 and STAT3 phosphorylation in a time- and a dose-dependent manner. One hundred nanomolar Ang II induced maximal phosphorylation of both JAK2 and STAT3 between 15 min and 30 min. The Ang II-mediated phosphorylation of both JAK2 and STAT3 was blocked by AG490, a selective JAK2 inhibitor. Losartan, a selective AT1 receptor antagonist, inhibited Ang II-mediated JAK2 and STAT3 phosphorylation, while pretreatment with an AT2 receptor blocker, PD123319, was ineffective. Ang II increased the mRNA expression of IL-6 in a concentration-and time-dependent manner. Maximal IL-6 mRNA expression occurred with 100 nM Ang II, and the peak effect occurred in a biphasic manner at 3 h and between 12 and 24 h. Moreover, pretreatments with AG490 attenuated Ang II-induced IL-6 mRNA levels, and Ang II-induced astrocyte growth. This study has demonstrated that Ang II induced the phosphorylation of both JAK2 and STAT3 via the AT1 receptor in cerebellar astrocytes. In addition, our results suggest that JAK2 and STAT3 are upstream signals that mediate Ang II-induced IL-6 mRNA expression and astrocyte growth. These findings represent a novel non-classical mechanism of Ang II signaling in cerebellar astrocytes.
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Affiliation(s)
- Umadevi Kandalam
- Department of Pediatric Dentistry; College of Dental Medicine; Nova Southeastern University; Fort Lauderdale, FL USA
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Litwin M, Michałkiewicz J, Gackowska L. Primary hypertension in children and adolescents is an immuno-metabolic disease with hemodynamic consequences. Curr Hypertens Rep 2013; 15:331-9. [PMID: 23737217 PMCID: PMC3712132 DOI: 10.1007/s11906-013-0360-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
With the rise in obesity epidemic primary hypertension (PH) is now one of the most common chronic diseases in adolescence. In contrast to hypertensive adults, hypertensive children usually are not exposed to other comorbidities such as diabetes, chronic kidney disease and atherosclerosis. Thus, PH in children and adolescents can be treated as the early stage of development of cardiovascular disease. There is increasing amount of data indicating that PH is not only hemodynamic phenomenon but a complex syndrome involving disturbed activity of sympathetic nervous system, metabolic abnormalities and activation of innate and adaptive immune system. We discuss results of the studies on clinical, metabolic and immunological phenotype of hypertensive children, associations between metabolic and immunological abnormalities with target organ damage and results of antihypertensive treatment.
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Affiliation(s)
- Mieczysław Litwin
- Department of Nephrology and Arterial Hypertension, The Children's Memorial Health Institute, Warsaw, Poland.
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66
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Neuroimmune communication in hypertension and obesity: a new therapeutic angle? Pharmacol Ther 2013; 138:428-40. [PMID: 23458610 DOI: 10.1016/j.pharmthera.2013.02.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 02/12/2013] [Indexed: 12/13/2022]
Abstract
Hypertension is an epidemic health concern and a major risk factor for the development of cardiovascular disease. Although there are available treatment strategies for hypertension, numerous hypertensive patients do not have their clinical symptoms under control and it is imperative that new avenues to treat or prevent high blood pressure in these patients are developed. It is well established that increases in sympathetic nervous system (SNS) outflow and enhanced renin-angiotensin system (RAS) activity are common features of hypertension and various pathological conditions that predispose individuals to hypertension. More recently, hypertension has also become recognized as an immune condition and accumulating evidence suggests that interactions between the RAS, SNS and immune systems play a role in blood pressure regulation. This review summarizes what is known about the interconnections between the RAS, SNS and immune systems in the neural regulation of blood pressure. Based on the reviewed studies, a model for RAS/neuroimmune interactions during hypertension is proposed and the therapeutic potential of targeting RAS/neuroimmune interactions in hypertensive patients is discussed. Special emphasis is placed on the applicability of the proposed model to obesity-related hypertension.
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Gay L, Miller MR, Ventura PB, Devasthali V, Vue Z, Thompson HL, Temple S, Zong H, Cleary MD, Stankunas K, Doe CQ. Mouse TU tagging: a chemical/genetic intersectional method for purifying cell type-specific nascent RNA. Genes Dev 2013; 27:98-115. [PMID: 23307870 PMCID: PMC3553287 DOI: 10.1101/gad.205278.112] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 11/19/2012] [Indexed: 12/16/2022]
Abstract
Transcriptional profiling is a powerful approach for understanding development and disease. Current cell type-specific RNA purification methods have limitations, including cell dissociation trauma or inability to identify all RNA species. Here, we describe "mouse thiouracil (TU) tagging," a genetic and chemical intersectional method for covalent labeling and purification of cell type-specific RNA in vivo. Cre-induced expression of uracil phosphoribosyltransferase (UPRT) provides spatial specificity; injection of 4-thiouracil (4TU) provides temporal specificity. Only UPRT(+) cells exposed to 4TU produce thio-RNA, which is then purified for RNA sequencing (RNA-seq). This method can purify transcripts from spatially complex and rare (<5%) cells, such as Tie2:Cre(+) brain endothelia/microglia (76% validated by expression pattern), or temporally dynamic transcripts, such as those acutely induced by lipopolysaccharide (LPS) injection. Moreover, generating chimeric mice via UPRT(+) bone marrow transplants identifies immune versus niche spleen RNA. TU tagging provides a novel method for identifying actively transcribed genes in specific cells at specific times within intact mice.
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Affiliation(s)
- Leslie Gay
- Institute of Neuroscience
- Institute of Molecular Biology
- Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon 97403, USA
| | - Michael R. Miller
- Institute of Neuroscience
- Institute of Molecular Biology
- Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon 97403, USA
| | | | | | - Zer Vue
- School of Natural Sciences, University of California at Merced, Merced, California 95340, USA
| | - Heather L. Thompson
- School of Natural Sciences, University of California at Merced, Merced, California 95340, USA
| | - Sally Temple
- Neural Stem Cell Institute, Rensselaer, New York 12144, USA
| | | | - Michael D. Cleary
- School of Natural Sciences, University of California at Merced, Merced, California 95340, USA
| | | | - Chris Q. Doe
- Institute of Neuroscience
- Institute of Molecular Biology
- Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon 97403, USA
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de Góis Queiroz AI, Medeiros CD, Ribeiro BMM, de Lucena DF, Macêdo DS. Angiotensin receptor blockers for bipolar disorder. Med Hypotheses 2012; 80:259-63. [PMID: 23265360 DOI: 10.1016/j.mehy.2012.11.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 11/22/2012] [Accepted: 11/27/2012] [Indexed: 12/20/2022]
Abstract
Studies have suggested that the brain renin angiotensin system (RAS) regulates cerebral flow, autonomic and hormonal systems, stress, innate immune response and behavior, being implicated in several brain disorders such as major depression, Parkinson's and Alzheimer's disease. The angiotensin II receptor subtype 1 (AT1R) is distributed in brain regions responsible for the control of stress response through peripheral and central sympathetic hyperactivation as well as in the hypothalamic paraventricular region, areas known for the release of several neurotransmitters related to inflammatory response facilitation. This relationship leads to the assumption that AT1R might be the receptor most related to the central deleterious actions of angiotensin II. New evidences from clinical studies have shown a possible role for RAS in the pathogenesis of bipolar disorder (BD), a multifactorial disorder with acknowledged presence of neuronal damage via oxidative stress in brain areas such as hippocampus, prefrontal cortex and striatum. Given the studies highlighting AT1R activation as a central pro-inflammatory pathway and, conversely, the involvement of inflammatory response in the pathogenesis of BD; this paper hypothesizes the use of AT1R antagonists for BD management and prevention of its neuroprogression, due to their anti-inflammatory and neuroprotective effects.
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Affiliation(s)
- Ana Isabelle de Góis Queiroz
- Neuropharmacology Laboratory, Postgraduate Pharmacology Program, Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Ceará, Brazil
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Mao GX, Cao YB, Lan XG, He ZH, Chen ZM, Wang YZ, Hu XL, Lv YD, Wang GF, Yan J. Therapeutic effect of forest bathing on human hypertension in the elderly. J Cardiol 2012; 60:495-502. [DOI: 10.1016/j.jjcc.2012.08.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/06/2012] [Accepted: 08/09/2012] [Indexed: 12/27/2022]
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Mugellini A, Nieswandt V. Candesartan plus hydrochlorothiazide: an overview of its use and efficacy. Expert Opin Pharmacother 2012; 13:2699-709. [PMID: 23170938 DOI: 10.1517/14656566.2012.745511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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71
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Waki H, Hendy EB, Hindmarch CCT, Gouraud S, Toward M, Kasparov S, Murphy D, Paton JFR. Excessive leukotriene B4 in nucleus tractus solitarii is prohypertensive in spontaneously hypertensive rats. Hypertension 2012; 61:194-201. [PMID: 23172924 DOI: 10.1161/hypertensionaha.112.192252] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Inflammation within the brain stem microvasculature has been associated with chronic cardiovascular diseases. We found that the expression of several enzymes involved in arachidonic acid-leukotriene B4 (LTB4) production was altered in nucleus tractus solitarii (NTS) of spontaneously hypertensive rat (SHR). LTB4 produced from arachidonic acid by 5-lipoxygenase is a potent chemoattractant of leukocytes. Leukotriene B4-12-hydroxydehydrogenase (LTB4-12-HD), which degrades LTB4, was downregulated in SHR rats compared with that in Wistar-Kyoto rats. Quantitative real-time PCR revealed that LTB4-12-HD was reduced by 63% and 58% in the NTS of adult SHR and prehypertensive SHR, respectively, compared with that in age-matched Wistar-Kyoto rats (n=6). 5-lipoxygenase gene expression was upregulated in the NTS of SHR (≈50%; n=6). LTB4 levels were increased in the NTS of the SHR, (17%; n=10, P<0.05). LTB4 receptors BLT1 (but not BLT2) were expressed on astroglia in the NTS but not neurons or vessels. Microinjection of LTB4 into the NTS of Wistar-Kyoto rats increased both leukocyte adherence and arterial pressure for over 4 days (peak: +15 mm Hg; P<0.01). In contrast, blockade of NTS BLT1 receptors lowered blood pressure in the SHR (peak: -13 mm Hg; P<0.05) but not in Wistar-Kyoto rats. Thus, excessive amounts of LTB4 in NTS of SHR, possibly as a result of upregulation of 5-lipoxygenase and downregulation of LTB4-12-HD, can induce inflammation. Because blockade of NTS BLT1 receptors lowered arterial pressure in the SHR, their endogenous activity may contribute to the hypertensive state of this rodent model. Thus, inflammatory reactions in the brain stem are causally associated with neurogenic hypertension.
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Affiliation(s)
- Hidefumi Waki
- School of Physiology and Pharmacology, Bristol Heart Institute, Medical Sciences Building, University of Bristol, Bristol, United Kingdom
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72
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Abstract
The effects of brain AngII (angiotensin II) depend on AT(1) receptor (AngII type 1 receptor) stimulation and include regulation of cerebrovascular flow, autonomic and hormonal systems, stress, innate immune response and behaviour. Excessive brain AT(1) receptor activity associates with hypertension and heart failure, brain ischaemia, abnormal stress responses, blood-brain barrier breakdown and inflammation. These are risk factors leading to neuronal injury, the incidence and progression of neurodegerative, mood and traumatic brain disorders, and cognitive decline. In rodents, ARBs (AT(1) receptor blockers) ameliorate stress-induced disorders, anxiety and depression, protect cerebral blood flow during stroke, decrease brain inflammation and amyloid-β neurotoxicity and reduce traumatic brain injury. Direct anti-inflammatory protective effects, demonstrated in cultured microglia, cerebrovascular endothelial cells, neurons and human circulating monocytes, may result not only in AT(1) receptor blockade, but also from PPARγ (peroxisome-proliferator-activated receptor γ) stimulation. Controlled clinical studies indicate that ARBs protect cognition after stroke and during aging, and cohort analyses reveal that these compounds significantly reduce the incidence and progression of Alzheimer's disease. ARBs are commonly used for the therapy of hypertension, diabetes and stroke, but have not been studied in the context of neurodegenerative, mood or traumatic brain disorders, conditions lacking effective therapy. These compounds are well-tolerated pleiotropic neuroprotective agents with additional beneficial cardiovascular and metabolic profiles, and their use in central nervous system disorders offers a novel therapeutic approach of immediate translational value. ARBs should be tested for the prevention and therapy of neurodegenerative disorders, in particular Alzheimer's disease, affective disorders, such as co-morbid cardiovascular disease and depression, and traumatic brain injury.
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Affiliation(s)
- Juan M Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA.
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73
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Wu KLH, Chan SHH, Chan JYH. Neuroinflammation and oxidative stress in rostral ventrolateral medulla contribute to neurogenic hypertension induced by systemic inflammation. J Neuroinflammation 2012; 9:212. [PMID: 22958438 PMCID: PMC3462714 DOI: 10.1186/1742-2094-9-212] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 08/27/2012] [Indexed: 02/07/2023] Open
Abstract
Background In addition to systemic inflammation, neuroinflammation in the brain, which enhances sympathetic drive, plays a significant role in cardiovascular diseases, including hypertension. Oxidative stress in rostral ventrolateral medulla (RVLM) that augments sympathetic outflow to blood vessels is involved in neural mechanism of hypertension. We investigated whether neuroinflammation and oxidative stress in RVLM contribute to hypertension following chronic systemic inflammation. Methods In normotensive Sprague-Dawley rats, systemic inflammation was induced by infusion of Escherichia coli lipopolysaccharide (LPS) into the peritoneal cavity via an osmotic minipump. Systemic arterial pressure and heart rate were measured under conscious conditions by the non-invasive tail-cuff method. The level of the inflammatory markers in plasma or RVLM was analyzed by ELISA. Protein expression was evaluated by Western blot or immunohistochemistry. Tissue level of superoxide anion (O2·-) in RVLM was determined using the oxidation-sensitive fluorescent probe dihydroethidium. Pharmacological agents were delivered either via infusion into the cisterna magna with an osmotic minipump or microinjection bilaterally into RVLM. Results Intraperitoneal infusion of LPS (1.2 mg/kg/day) for 14 days promoted sustained hypertension and induced a significant increase in plasma level of C-reactive protein, tumor necrosis factor-α (TNF-α), or interleukin-1β (IL-1β). This LPS-induced systemic inflammation was accompanied by activation of microglia, augmentation of IL-1β, IL-6, or TNF-α protein expression, and O2·- production in RVLM, all of which were blunted by intracisternal infusion of a cycloxygenase-2 (COX-2) inhibitor, NS398; an inhibitor of microglial activation, minocycline; or a cytokine synthesis inhibitor, pentoxifylline. Neuroinflammation in RVLM was also associated with a COX-2-dependent downregulation of endothelial nitric oxide synthase and an upregulation of intercellular adhesion molecule-1. Finally, the LPS-promoted long-term pressor response and the reduction in expression of voltage-gated potassium channel, Kv4.3 in RVLM were antagonized by minocycline, NS398, pentoxifylline, or a superoxide dismutase mimetic, tempol, either infused into cisterna magna or microinjected bilaterally into RVLM. The same treatments, on the other hand, were ineffective against LPS-induced systemic inflammation. Conclusion These results suggest that systemic inflammation activates microglia in RVLM to induce COX-2-dependent neuroinflammation that leads to an increase in O2·- production. The resultant oxidative stress in RVLM in turn mediates neurogenic hypertension.
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Affiliation(s)
- Kay L H Wu
- Center for Translational Research in Biomedical Sciences, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Kaohsiung, 83301, Taiwan
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74
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Lee TC, Greene-Schloesser D, Payne V, Diz DI, Hsu FC, Kooshki M, Mustafa R, Riddle DR, Zhao W, Chan MD, Robbins ME. Chronic administration of the angiotensin-converting enzyme inhibitor, ramipril, prevents fractionated whole-brain irradiation-induced perirhinal cortex-dependent cognitive impairment. Radiat Res 2012; 178:46-56. [PMID: 22687052 PMCID: PMC3422865 DOI: 10.1667/rr2731.1] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
We hypothesized that chronic administration of the angiotensin-converting enzyme inhibitor, ramipril, to young adult male rats would prevent/ameliorate fractionated whole-brain irradiation-induced perirhinal cortex-dependent cognitive impairment. Eighty 12-14-week-old young adult male Fischer 344 rats received either: (1) sham irradiation, (2) 40 Gy of fractionated whole-brain irradiation delivered as two 5 Gy fractions/week for 4 weeks, (3) sham irradiation plus continuous administration of 15 mg/L of ramipril in the drinking water starting 3 days before irradiation, or (4) fractionated whole-brain irradiation plus ramipril. Cognitive function was assessed using a perirhinal cortex-dependent version of the novel object recognition task 26 weeks after irradiation. Microglial activation was determined in the perirhinal cortex and the dentate gyrus of the hippocampus 28 weeks after irradiation using the ED1 antibody. Neurogenesis was assessed in the granular cell layer and subgranular zones of the dentate gyrus using a doublecortin antibody. Fractionated whole-brain irradiation led to: (1) a significant impairment in perirhinal cortex-dependent cognitive function, (2) a significant increase in activated microglia in the dentate gyrus but not in the perirhinal cortex, and (3) a significant decrease in neurogenesis. Continuous administration of ramipril before, during, and after irradiation prevented the fractionated whole-brain irradiation-induced changes in perirhinal cortex-dependent cognitive function, as well as in microglial activation in the dentate gyrus. Thus, as hypothesized, continuous administration of the angiotensin-converting enzyme inhibitor, ramipril, can prevent the fractionated whole-brain irradiation-induced impairment in perirhinal cortex-dependent cognitive function.
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Affiliation(s)
- Tammy C Lee
- Department of Molecular Medicine and Translational Science, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA
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75
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Renin-Angiotensin system hyperactivation can induce inflammation and retinal neural dysfunction. Int J Inflam 2012; 2012:581695. [PMID: 22536545 PMCID: PMC3321303 DOI: 10.1155/2012/581695] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 12/09/2011] [Accepted: 01/04/2012] [Indexed: 12/21/2022] Open
Abstract
The renin-angiotensin system (RAS) is a hormone system that has been classically known as a blood pressure regulator but is becoming well recognized as a proinflammatory mediator. In many diverse tissues, RAS pathway elements are also produced intrinsically, making it possible for tissues to respond more dynamically to systemic or local cues. While RAS is important for controlling normal inflammatory responses, hyperactivation of the pathway can cause neural dysfunction by inducing accelerated degradation of some neuronal proteins such as synaptophysin and by activating pathological glial responses. Chronic inflammation and oxidative stress are risk factors for high incidence vision-threatening diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), and glaucoma. In fact, increasing evidence suggests that RAS inhibition may actually prevent progression of various ocular diseases including uveitis, DR, AMD, and glaucoma. Therefore, RAS inhibition may be a promising therapeutic approach to fine-tune inflammatory responses and to prevent or treat certain ocular and neurodegenerative diseases.
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76
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Lee HY, Park JH, Lee CH, Yan B, Ahn JH, Lee YJ, Park CW, Cho JH, Choi SY, Won MH. Changes of ribosomal protein S3 immunoreactivity and its new expression in microglia in the mice hippocampus after lipopolysaccharide treatment. Cell Mol Neurobiol 2012; 32:577-86. [PMID: 22274408 DOI: 10.1007/s10571-012-9802-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 01/10/2012] [Indexed: 01/06/2023]
Abstract
Lipopolysaccharide (LPS) has been used as a reagent for a model of systemic inflammatory response. Ribosomal protein S3 (rpS3) is a multi-functional protein that is involved in transcription, metastasis, DNA repair, and apoptosis. In the present study, we examined the changes of rpS3 immunoreactivity in the mouse hippocampus after systemic administration of 1 mg/kg of LPS. From 6 h after LPS treatment, rpS3 immunoreactivity was decreased in pyramidale cells of the hippocampus proper (CA1-CA3 regions) and in granule cells of the dentate gyrus. At this point in time, rpS3 immunoreactivity began to increase in non-pyramidal cells and non-granule cells. From 1 day after LPS treatment, rpS3 immunoreactivity in pyramidal and granule cells was hardly detected; however, strong rpS3 immunoreactivity was shown in non-pyramidal and non-granule cells. Based on double immunofluorescence staining for rpS3/ionized calcium-binding adapter 1 (Iba-1, a marker for microglia) and glial fibrillary acidic protein (GFAP, a marker for astrocytes), strong rpS3 immunoreactivity was expressed in Iba-1-immunoreactive microglia, not in GFAP-immunoreactive astrocytes, at 1 and 2 days after LPS treatment. These results indicate that rpS3 immunoreactivity changes only in pyramidal and granule cells, and rpS3 is expressed only in activated microglia after LPS treatment: this may be associated with the neuroinflammatory responses in the brain.
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Affiliation(s)
- Hui Young Lee
- Department of Internal Medicine, Institute of Medical Sciences, School of Medicine, Kangwon National University, Chuncheon, South Korea
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77
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Saavedra JM. Angiotensin II AT(1) receptor blockers ameliorate inflammatory stress: a beneficial effect for the treatment of brain disorders. Cell Mol Neurobiol 2011; 32:667-81. [PMID: 21938488 DOI: 10.1007/s10571-011-9754-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 08/26/2011] [Indexed: 01/06/2023]
Abstract
Excessive allostatic load as a consequence of deregulated brain inflammation participates in the development and progression of multiple brain diseases, including but not limited to mood and neurodegenerative disorders. Inhibition of the peripheral and brain Renin-Angiotensin System by systemic administration of Angiotensin II AT(1) receptor blockers (ARBs) ameliorates inflammatory stress associated with hypertension, cold-restraint, and bacterial endotoxin administration. The mechanisms involved include: (a) decreased inflammatory factor production in peripheral organs and their release to the circulation; (b) reduced progression of peripherally induced inflammatory cascades in the cerebral vasculature and brain parenchyma; and (c) direct anti-inflammatory effects in cerebrovascular endothelial cells, microglia, and neurons. In addition, ARBs reduce bacterial endotoxin-induced anxiety and depression. Further pre-clinical experiments reveal that ARBs reduce brain inflammation, protect cognition in rodent models of Alzheimer's disease, and diminish brain inflammation associated with genetic hypertension, ischemia, and stroke. The anti-inflammatory effects of ARBs have also been reported in circulating human monocytes. Clinical studies demonstrate that ARBs improve mood, significantly reduce cognitive decline after stroke, and ameliorate the progression of Alzheimer's disease. ARBs are well-tolerated and extensively used to treat cardiovascular and metabolic disorders such as hypertension and diabetes, where inflammation is an integral pathogenic mechanism. We propose that including ARBs in a novel integrated approach for the treatment of brain disorders such as depression and Alzheimer's disease may be of immediate translational relevance.
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Affiliation(s)
- Juan M Saavedra
- Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
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78
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Pavlatou MG, Mastorakos G, Margeli A, Kouskouni E, Tentolouris N, Katsilambros N, Chrousos GP, Papassotiriou I. Angiotensin blockade in diabetic patients decreases insulin resistance-associated low-grade inflammation. Eur J Clin Invest 2011; 41:652-8. [PMID: 21175613 DOI: 10.1111/j.1365-2362.2010.02453.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Insulin-resistant states, such as metabolic syndrome and diabetes mellitus type 2 (DM2), have been associated with chronic low-grade systemic inflammation. Elevated levels of interleukin-6 (IL-6), monocyte chemoattractant protein (MCP-1) and C-reactive protein (hs-CRP), are found in patients with type 2 diabetes with and without complications. Angiotensin II (Ang II), a potent vasopressor, seems to regulate also the expression of the above inflammatory mediators acting as proinflammatory cytokine. In this study, we examined the effects of candesartan, an angiotensin receptror blocker, in the chronic low-grade inflammation observed in DM 2. MATERIALS AND METHODS Seventeen patients with DM2 of <5years duration were recruited for the study. Patients received 4mg of candesartan, an angiotensin receptor blocker, for 6months. Blood levels of IL-6, MCP-1, hs-CRP and other inflammatory indices were measured before and at the end of candesartan administration. RESULTS At the end of treatment with candesartan, IL-6 levels decreased significantly (P<0·05). Serum levels of MCP-1 and hs-CRP showed a trend for significant decrease with treatment (P<0·08 and P<0·09, respectively). Statistically significant correlations were found between hs-CRP and MCP-1 (r=0·623, P< 0·05), IL-6 and MCP-1 (r=0·703, P<0·05) and TRT and MCP-1 (r=0·752, P<0·05), before but not at the end of candesartan administration. CONCLUSIONS Candesartan could decrease the low-grade inflammation of type 2 DM as shown by the decrease of inflammatory mediators. Thus, angiotensin receptor blockers could be useful for treating patients with DM2 not only for their antihypertensive capacity but also for their anti-inflammatory actions.
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Affiliation(s)
- Maria G Pavlatou
- First Department of Pediatrics, Athens University Medical School, Athens, Greece
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79
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Zubcevic J, Waki H, Raizada MK, Paton JFR. Autonomic-immune-vascular interaction: an emerging concept for neurogenic hypertension. Hypertension 2011; 57:1026-33. [PMID: 21536990 DOI: 10.1161/hypertensionaha.111.169748] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jasenka Zubcevic
- Department of Physiology and Functional Genomics, McKnight Brain Institute, 1600 SW Archer Rd, Gainesville, FL 32610, USA
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80
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Benicky J, Sánchez-Lemus E, Honda M, Pang T, Orecna M, Wang J, Leng Y, Chuang DM, Saavedra JM. Angiotensin II AT1 receptor blockade ameliorates brain inflammation. Neuropsychopharmacology 2011; 36:857-70. [PMID: 21150913 PMCID: PMC3055735 DOI: 10.1038/npp.2010.225] [Citation(s) in RCA: 176] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Brain inflammation has a critical role in the pathophysiology of brain diseases of high prevalence and economic impact, such as major depression, schizophrenia, post-traumatic stress disorder, Parkinson's and Alzheimer's disease, and traumatic brain injury. Our results demonstrate that systemic administration of the centrally acting angiotensin II AT(1) receptor blocker (ARB) candesartan to normotensive rats decreases the acute brain inflammatory response to administration of the bacterial endotoxin lipopolysaccharide (LPS), a model of brain inflammation. The broad anti-inflammatory effects of candesartan were seen across the entire inflammatory cascade, including decreased production and release to the circulation of centrally acting proinflammatory cytokines, repression of nuclear transcription factors activation in the brain, reduction of gene expression of brain proinflammatory cytokines, cytokine and prostanoid receptors, adhesion molecules, proinflammatory inducible enzymes, and reduced microglia activation. These effects are widespread, occurring not only in well-known brain target areas for circulating proinflammatory factors and LPS, that is, hypothalamic paraventricular nucleus and the subfornical organ, but also in the prefrontal cortex, hippocampus, and amygdala. Candesartan reduced the associated anorexic effects, and ameliorated associated body weight loss and anxiety. Direct anti-inflammatory effects of candesartan were also documented in cultured rat microglia, cerebellar granule cells, and cerebral microvascular endothelial cells. ARBs are widely used in the treatment of hypertension and stroke, and their anti-inflammatory effects contribute to reduce renal and cardiac failure. Our results indicate that these compounds may offer a novel and safe therapeutic approach for the treatment of brain disorders.
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Affiliation(s)
- Julius Benicky
- Section on Pharmacology, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Enrique Sánchez-Lemus
- Section on Pharmacology, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Masaru Honda
- Section on Pharmacology, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Tao Pang
- Section on Pharmacology, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Martina Orecna
- Section on Pharmacology, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Juan Wang
- Section on Pharmacology, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Yan Leng
- Molecular Neurobiology Section, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - De-Maw Chuang
- Molecular Neurobiology Section, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Juan M Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, Department of Health and Human Services, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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81
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Nasr SJ, Crayton JW, Agarwal B, Wendt B, Kora R. Lower frequency of antidepressant use in patients on renin-angiotensin-aldosterone system modifying medications. Cell Mol Neurobiol 2011; 31:615-8. [PMID: 21301954 DOI: 10.1007/s10571-011-9656-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 01/28/2011] [Indexed: 01/05/2023]
Abstract
Both hypertension and depression are common disorders which may both involve components of the hypothalamic-pituitary-adrenal axis system and the Renin-Angiotensin-Aldosterone System (RAAS). These observations, coupled with growing evidence that RAAS-active drugs may have anti-depressant properties prompted us to study the frequency of anti-depressant medication usage in the patients receiving RAAS-active agents. A chart review was performed on 378 patients who were seen during a 3-month period in a primary care clinic and who were diagnosed with hypertension. Demographic information and data on the rates of co-administration of antihypertensive and anti-depressant medications was collected. Overall, 23.7% of the sample was on an antidepressant. 20% of the patients taking a RAAS-modifying medication were on an antidepressant, compared to 34% of those not taking a RAAS-modifying medication (Χ(2) = 8.88, P = 0.003). The patients taking a beta-blocker alone had the highest rate of antidepressant usage (40%). The use of RAAS-modifying medications was associated with an even lower rate of anti-depressant usage in males compared with females. It was also observed that the patients taking an additional diuretic had a significantly lower rate of antidepressant use (17.6%, Χ(2) = 5.81, P = 0.016) compared with the patients not taking a diuretic. The patients being treated with an ACE inhibitor or ARB showed significantly lower rates of antidepressant usage. The data is supportive of the hypothesis that these agents may possess anti-depressant effects.
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Affiliation(s)
- Suhayl J Nasr
- Nasr Psychiatric Services, 2814 S Franklin St, Michigan City, IN 46360, USA.
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82
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Shoja MM, Agutter PS, Tubbs RS, Payner TD, Ghabili K, Cohen-Gadol AA. The role of the renin—angiotensin system in the pathogenesis of intracranial aneurysms. J Renin Angiotensin Aldosterone Syst 2011; 12:262-73. [DOI: 10.1177/1470320310387845] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Introduction: Recent work has begun to elucidate the pathogenesis of intracranial aneurysms (IA) and has shown that many genes are involved in the risk for this condition. There has also been increasing research interest in the renin—angiotensin system (RAS) in the brain and its involvement in a range of cardiovascular and neurological disorders. The possibility that the RAS is implicated in the pathogenesis of IA merits further investigation. The aim of this article is to review the literature on the pathogenesis of IA and the pathophysiological significance of the brain RAS, and to identify directions for research into their association. Methods and results : A survey of the literature in these fields shows that although factors contributing to systemic hypertension predispose to IA, a large number of genes involved in endothelial cell adhesion, smooth muscle activity, extracellular matrix dynamics and the inflammatory and immune responses are also implicated. The brain RAS has a significant role in regulating blood pressure and in maintaining cerebrovascular autoregulation, but angiotensin II receptors are also involved in the maintenance of endothelial cell and vascular smooth muscle function and in the inflammatory response in the brain. Conclusions: There is strong, albeit largely circumstantial, evidence in the literature for a relationship between the brain RAS and the formation of IA. Research on the association between polymorphisms in RAS-related genes and the incidence of unruptured and ruptured IA is indicated.
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Affiliation(s)
- Mohammadali M Shoja
- Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Paul S Agutter
- Theoretical Medicine and Biology Group, Glossop, Derbyshire, UK
| | - R Shane Tubbs
- Section of Pediatric Neurosurgery, Children's Hospital, Birmingham, Alabama, USA
| | - Troy D Payner
- Clarian Neuroscience Institute, Indianapolis Neurosurgical Group and Indiana University Department of Neurosurgery, Indianapolis, USA
| | - Kamyar Ghabili
- Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Aaron A Cohen-Gadol
- Clarian Neuroscience Institute, Indianapolis Neurosurgical Group and Indiana University Department of Neurosurgery, Indianapolis, USA,
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83
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Saavedra JM, Sánchez-Lemus E, Benicky J. Blockade of brain angiotensin II AT1 receptors ameliorates stress, anxiety, brain inflammation and ischemia: Therapeutic implications. Psychoneuroendocrinology 2011; 36:1-18. [PMID: 21035950 PMCID: PMC2998923 DOI: 10.1016/j.psyneuen.2010.10.001] [Citation(s) in RCA: 187] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 09/29/2010] [Accepted: 10/01/2010] [Indexed: 12/22/2022]
Abstract
Poor adaptation to stress, alterations in cerebrovascular function and excessive brain inflammation play critical roles in the pathophysiology of many psychiatric and neurological disorders such as major depression, schizophrenia, post traumatic stress disorder, Parkinson's and Alzheimer's diseases and traumatic brain injury. Treatment for these highly prevalent and devastating conditions is at present very limited and many times inefficient, and the search for novel therapeutic options is of major importance. Recently, attention has been focused on the role of a brain regulatory peptide, Angiotensin II, and in the translational value of the blockade of its physiological AT(1) receptors. In addition to its well-known cardiovascular effects, Angiotensin II, through AT(1) receptor stimulation, is a pleiotropic brain modulatory factor involved in the control of the reaction to stress, in the regulation of cerebrovascular flow and the response to inflammation. Excessive brain AT(1) receptor activity is associated with exaggerated sympathetic and hormonal response to stress, vulnerability to cerebrovascular ischemia and brain inflammation, processes leading to neuronal injury. In animal models, inhibition of brain AT(1) receptor activity with systemically administered Angiotensin II receptor blockers is neuroprotective; it reduces exaggerated stress responses and anxiety, prevents stress-induced gastric ulcerations, decreases vulnerability to ischemia and stroke, reverses chronic cerebrovascular inflammation, and reduces acute inflammatory responses produced by bacterial endotoxin. These effects protect neurons from injury and contribute to increase the lifespan. Angiotensin II receptor blockers are compounds with a good margin of safety widely used in the treatment of hypertension and their anti-inflammatory and vascular protective effects contribute to reduce renal and cardiovascular failure. Inhibition of brain AT(1) receptors in humans is also neuroprotective, reducing the incidence of stroke, improving cognition and decreasing the progression of Alzheimer's disease. Blockade of AT(1) receptors offers a novel and safe therapeutic approach for the treatment of illnesses of increasing prevalence and socioeconomic impact, such as mood disorders and neurodegenerative diseases of the brain.
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Affiliation(s)
- Juan M Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, 10 Center Drive, Building 10, Room 2D-57, Bethesda, MD 20892, USA.
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84
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Robbins ME, Zhao W, Garcia-Espinosa MA, Diz DI. Renin-angiotensin system blockers and modulation of radiation-induced brain injury. Curr Drug Targets 2010; 11:1413-22. [PMID: 20583976 PMCID: PMC3068470 DOI: 10.2174/1389450111009011413] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2009] [Accepted: 04/05/2010] [Indexed: 01/05/2023]
Abstract
Radiation-induced brain injury remains a major cause of morbidity in cancer patients with primary or metastatic brain tumors. Approximately 200,000 individuals/year are treated with fractionated partial or whole-brain irradiation, and > half will survive long enough (≤6 months) to develop radiation-induced brain injury, including cognitive impairment. Although short-term treatments have shown efficacy, no long-term treatments or preventive approaches are presently available for modulating radiation-induced brain injury. Based on previous preclinical studies clearly demonstrating that renin-angiotensin system (RAS) blockers can modulate radiation-induced late effects in the kidney and lung, we and others hypothesized that RAS blockade would similarly modulate radiation-induced brain injury. Indeed, studies in the last 5 years have shown that both angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor antagonists (AT(1)RAs) can prevent/ameliorate radiation-induced brain injury, including cognitive impairment, in the rat. The mechanistic basis for this RAS blocker-mediated effect remains the subject of ongoing investigations. Putative mechanisms include, i] blockade of Ang II/NADPH oxidase-mediated oxidative stress and neuroinflammation, and ii] a change in the balance of angiotensin (Ang) peptides from the pro-inflammatory and pro-oxidative Ang II to the anti-inflammatory and anti-oxidative Ang-1-7). However, given that both ACEIs and AT(1)RAs are 1] well-tolerated drugs routinely prescribed for hypertension, 2] exhibit some antitumor properties, and 3] can prevent/ameliorate radiation-induced brain injury, they appear to be ideal drugs for future clinical trials, offering the promise of improving the quality of life of brain tumor patients receiving brain irradiation.
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Affiliation(s)
- M E Robbins
- Department of Radiation Oncology, Brain Tumor Center of Excellence, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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85
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The neuroinflammatory hypothesis of delirium. Acta Neuropathol 2010; 119:737-54. [PMID: 20309566 DOI: 10.1007/s00401-010-0674-1] [Citation(s) in RCA: 253] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 03/08/2010] [Accepted: 03/13/2010] [Indexed: 01/08/2023]
Abstract
Delirium is a neuropsychiatric syndrome characterized by a sudden and global impairment in consciousness, attention and cognition. It is particularly frequent in elderly subjects with medical or surgical conditions and is associated with short- and long-term adverse outcomes. The pathophysiology of delirium remains poorly understood as it involves complex multi-factorial dynamic interactions between a diversity of risk factors. Several conditions associated with delirium are characterized by activation of the inflammatory cascade with acute release of inflammatory mediators into the bloodstream. There is compelling evidence that acute peripheral inflammatory stimulation induces activation of brain parenchymal cells, expression of proinflammatory cytokines and inflammatory mediators in the central nervous system. These neuroinflammatory changes induce neuronal and synaptic dysfunction and subsequent neurobehavioural and cognitive symptoms. Furthermore, ageing and neurodegenerative disorders exaggerate microglial responses following stimulation by systemic immune stimuli such as peripheral inflammation and/or infection. In this review we explore the neuroinflammatory hypothesis of delirium based on recent evidence derived from animal and human studies.
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86
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Current Opinion in Endocrinology, Diabetes & Obesity. Current world literature. Curr Opin Endocrinol Diabetes Obes 2010; 17:293-312. [PMID: 20418721 DOI: 10.1097/med.0b013e328339f31e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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87
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The effect of chronic candesartan therapy on the metabolic profile and renal tissue cytokine levels in the obese Zucker rat. Mediators Inflamm 2010; 2010:841343. [PMID: 20490358 PMCID: PMC2872766 DOI: 10.1155/2010/841343] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 01/27/2010] [Accepted: 03/05/2010] [Indexed: 01/13/2023] Open
Abstract
The effect of candesartan, an angiotensin-II type-1 receptor antagonist, on the metabolic profile and renal inflammation is unclear. We evaluated this relationship by feeding male lean (LZ) and obese (OZ) Zucker rats chow or chow with candesartan (23.5 mg/kg · diet) for 14 weeks (n = 6–8/treatment/body type). Candesartan reduced serum triglycerides, plasma creatinine, urine albumin, and renal cortical collagen and glycogen deposition in the OZ. An ELISA-based cytokine array revealed that candesartan normalized elevated renal interleukin (IL) 1-β and monocyte chemoattractant protein-1 (MCP-1) levels in OZ. Nonetheless, candesartan impaired glucose tolerance, and did not lower blood insulin or glucose levels. Moreover, renal IL-1α, -2, -4, -6 and -10 tumor necrosis factor-α, interferon-γ, were
significantly reduced in OZ relative to LZ, and increased by candesartan. Furthermore, candesartan increased growth-regulated oncogene, transforming growth factor-β1 and IL-18
in OZ kidneys to a level higher than LZ or untreated OZ. Candesartan did not affect renal cytokine levels in LZ. Overall, candesartan attenuated renal disease and improved renal function in OZ, despite mixed effects on metabolic factors and cytokines. Reduced plasma
triglycerides and/or renal MCP-1 and IL-1β may have had a role in this protection. However,
these effects were clearly independent of any improvement in glucose tolerance.
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88
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Gard PR. Implications of the angiotensin converting enzyme gene insertion/deletion polymorphism in health and disease: a snapshot review. INTERNATIONAL JOURNAL OF MOLECULAR EPIDEMIOLOGY AND GENETICS 2010; 1:145-57. [PMID: 21537387 PMCID: PMC3076761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Accepted: 03/16/2010] [Indexed: 05/30/2023]
Abstract
This review considers the 250+ papers concerning the association of the angiotensin converting enzyme (ACE) gene insertion/deletion polymorphism (rs1799752) and various disease conditions published in 2009. The deletion allele occurs in approximately 55% of the population and is associated with increased activity of the ACE enzyme. It might be predicted that the D allele, therefore, might be associated with pathologies involving increased activity of the renin-angiotensin system. The D allele was seen to be associated with an increased risk of hypertension, pre-eclampsia, heart failure, cerebral infarct, diabetic nephropathy, encephalopathy, asthma, severe hypoglycaemia in diabetes, gastric cancer (in Caucasians) and poor prognosis following kidney transplant. On the positive side, the D allele appears to offer protection against schizophrenia and chronic periodontitis and confers greater up-per-body strength in old age. The I allele, meanwhile, offers improved endurance/athletic performance and aerobic capacity as determined by lung function tests, although it does increase the risk of oral squamous cell carcinoma and obstructive sleep apnoea in hypertensives.
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Affiliation(s)
- Paul R Gard
- Centre for Biomedical and Health Sciences Research, University of Brighton Moulsecoomb, BRIGHTON BN2 4GJ UK
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89
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Kandalam U, Clark MA. Angiotensin II activates JAK2/STAT3 pathway and induces interleukin-6 production in cultured rat brainstem astrocytes. ACTA ACUST UNITED AC 2010; 159:110-6. [PMID: 19748527 DOI: 10.1016/j.regpep.2009.09.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 08/13/2009] [Accepted: 09/02/2009] [Indexed: 01/09/2023]
Abstract
We have shown that tyrosine kinases and mitogen-activated protein kinases mediate angiotensin II (Ang II) effects in cultured rat astrocytes. In this study, we investigated whether Ang II induces Janus kinase (JAK) 2, signal transducer and activators of transcription (STAT) 3 phosphorylation, and interleukin-6 (IL-6) secretion in cultured brainstem rat astrocytes. Ang II increased JAK2 phosphorylation in a time- and dose-dependent manner. Maximal phosphorylation of 1.7+/-0.4 fold above basal was observed at 15 min with 100 nM Ang II. Losartan (10 microM), an AT(1) receptor blocker, inhibited Ang II-mediated JAK2 phosphorylation, while 10 microM PD123319, an AT(2) receptor blocker, was ineffective. The JAK2 inhibitor, AG490 (50 microM), prevented Ang II JAK2 phosphorylation. Ang II also stimulated STAT3 in a concentration- and time-dependent manner. Maximal phosphorylation of 0.8+/-0.11 above basal was observed at 15 min with 100 nM Ang II. Treatment with AG490 reduced Ang II phosphorylation of STAT3 and Ang II-induced astrocyte growth suggesting that JAK2 is an upstream signal in these Ang II effects. Ang II also stimulated IL-6 secretion from brainstem astrocytes in a concentration- and time-dependent manner. Maximal IL-6 secretion of 0.7+/-0.2 above basal was observed with 100 nM Ang II after 48 h of treatment. Losartan decreased Ang II-induced IL-6 secretion while PD123319 was ineffective. Interestingly, AG490 reduced Ang II-stimulated IL-6 secretion. Our study showed for the first time that Ang II induced JAK2/STAT3 phosphorylation and IL-6 secretion through activation of the Ang II AT(1) receptor in brainstem astrocytes. In addition, Ang II stimulated IL-6 secretion and astrocyte growth through the JAK2 pathway in brainstem astrocytes. These results provide new insights into pro-inflammatory and mitogenic signaling mechanisms of Ang II in astrocytes.
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Affiliation(s)
- Umadevi Kandalam
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, 3200 S. University Drive, Fort Lauderdale, FL 33328, USA
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90
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Sumbalová Z, Kucharská J, Kristek F. Losartan improved respiratory function and coenzyme Q content in brain mitochondria of young spontaneously hypertensive rats. Cell Mol Neurobiol 2010; 30:751-8. [PMID: 20145991 DOI: 10.1007/s10571-010-9501-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 01/27/2010] [Indexed: 01/23/2023]
Abstract
Increased production of free radicals and impairment of mitochondrial function are important factors in the pathogenesis of hypertension. This study examined the impact of hypertension on mitochondrial respiratory chain function, coenzyme Q(9) (CoQ(9)), coenzyme Q(10) (CoQ(10)), and alpha-tocopherol content in brain mitochondria, and the effect of blockade of angiotensin II type 1 receptors (AT1R) in the prehypertensive period on these parameters. In addition, blood pressure, heart and brain weight to body weight ratios, and the geometry of the basilar artery supplying the brain were evaluated. In the 9th week blood pressure and heart weight/body weight ratio were significantly increased and brain weight/body weight ratio was significantly decreased in spontaneously hypertensive rats (SHR) when compared to Wistar rats (WR). The cross-sectional area of the basilar artery was increased in SHR. Glutamate-supported respiration, the rate of ATP production, and concentrations of CoQ(9), CoQ(10), and alpha-tocopherol were decreased in SHR. The succinate-supported function and cytochrome oxidase activity were not changed. The treatment of SHR with losartan (20 mg/kg/day) from 4th to 9th week of age exerted preventive effect against hypertension, heart and arterial wall hypertrophy, and brain weight/body weight decline. After the therapy, the rate of ATP production and the concentration of CoQ increased in comparison to untreated SHR. The impairment of energy production and decreased level of lipid-soluble antioxidants in brain mitochondria as well as structural alterations in the basilar artery may contribute to increased vulnerability of brain tissue in hypertension. Long-term treatment with AT1R blockers may prevent brain dysfunction in hypertension.
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Affiliation(s)
- Z Sumbalová
- Pharmacobiochemical Laboratory of Third Department of Internal Medicine, Faculty of Medicine, Comenius University, Spitálska 24, 81372 Bratislava, Slovak Republic.
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91
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Effects of age, genes, and pulse pressure on executive functions in healthy adults. Neurobiol Aging 2009; 32:1124-37. [PMID: 19559505 DOI: 10.1016/j.neurobiolaging.2009.05.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 04/21/2009] [Accepted: 05/23/2009] [Indexed: 11/24/2022]
Abstract
Executive functions (EF) evidence significant age-related declines, but the mechanisms underpinning those changes are unclear. In this study, we focus on two potential sources of variation: a physiological indicator of vascular health, and genetic variants related to vascular functions. In a sample of healthy adults (n=158, ages 18-81), we examine the effects of age, pulse pressure, and two polymorphisms (comt val158met and ace insertion/deletion) on working memory and cognitive flexibility. Results indicate that in addition to often-replicated age differences, the alleles of two polymorphisms that promote vasoconstriction (comt val and ace D) and reduced availability of dopamine in neocortical synapses (comt val), negatively impact virtually all aspects of EF tasks that involve working memory. In some cases, suppression of cognitive performance is limited to men or necessitates a combination of both risk-associated alleles. After accounting for genetic and age-related variation, pulse pressure had no additional effect on EF. These findings suggest that in healthy adults, the effects of genetic risk factors significantly modulate the course of cognitive aging.
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