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O'Connor AT, Haspula D, Alanazi AZ, Clark MA. Roles of Angiotensin III in the brain and periphery. Peptides 2022; 153:170802. [PMID: 35489649 DOI: 10.1016/j.peptides.2022.170802] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 10/18/2022]
Abstract
Angiotensin (Ang) III, a biologically active peptide of the renin angiotensin system (RAS) is predominantly known for its central effects on blood pressure. Our understanding of the RAS has evolved from the simplified, classical RAS, a hormonal system regulating blood pressure to a complex system affecting numerous biological processes. Ang II, the main RAS peptide has been widely studied, and its deleterious effects when overexpressed is well-documented. However, other components of the RAS such as Ang III are not well studied. This review examines the molecular and biological actions of Ang III and provides insight into Ang III's potential role in metabolic diseases.
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Affiliation(s)
- Ann Tenneil O'Connor
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Dhanush Haspula
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD NIH-20892, USA
| | - Ahmed Z Alanazi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Michelle A Clark
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, USA.
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2
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Mowry FE, Peaden SC, Stern JE, Biancardi VC. TLR4 and AT1R mediate blood-brain barrier disruption, neuroinflammation, and autonomic dysfunction in spontaneously hypertensive rats. Pharmacol Res 2021; 174:105877. [PMID: 34610452 PMCID: PMC8648989 DOI: 10.1016/j.phrs.2021.105877] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/03/2021] [Accepted: 09/05/2021] [Indexed: 01/23/2023]
Abstract
Angiotensin II (AngII) is implicated in neuroinflammation, blood-brain barrier (BBB) disruption, and autonomic dysfunction in hypertension. We have previously shown that exogenous AngII stimulates Toll-like receptor 4 (TLR4) via AngII type 1 receptor (AT1R), inducing activation of hypothalamic microglia ex vivo, and that AngII-AT1R signaling is necessary for the loss of BBB integrity in spontaneously hypertensive rats (SHRs). Herein, we hypothesized that microglial TLR4 and AT1R signaling interactions represent a crucial mechanistic link between AngII-mediated neuroinflammation and BBB disruption, thereby contributing to sympathoexcitation in SHRs. Male SHRs were treated with TAK-242 (TLR4 inhibitor; 2 weeks), Losartan (AT1R inhibitor; 4 weeks), or vehicle, and age-matched to control Wistar Kyoto rats (WKYs). TLR4 and AT1R inhibitions normalized increased TLR4, interleukin-6, and tumor necrosis factor-α protein densities in SHR cardioregulatory nuclei (hypothalamic paraventricular nucleus [PVN], rostral ventrolateral medulla [RVLM], and nucleus tractus solitarius [NTS]), and abolished enhanced microglial activation. PVN, RVLM, and NTS BBB permeability analyses revealed complete restoration after TAK-242 treatment, whereas SHRs presented with elevated dye leakage. Mean arterial pressure was normalized in Losartan-treated SHRs, and attenuated with TLR4 inhibition. In conscious assessments, TLR4 blockade rescued SHR baroreflex sensitivity to vasoactive drugs, and reduced the SHR pressor response to ganglionic blockade to normal levels. These data suggest that TLR4 activation plays a substantial role in mediating a feed-forward pro-hypertensive cycle involving BBB disruption, neuroinflammation, and autonomic dysfunction, and that TLR4-specific therapeutic interventions may represent viable alternatives in the treatment of hypertension.
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Affiliation(s)
- Francesca E Mowry
- Department of Anatomy, Physiology & Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA; Center for Neurosciences Initiative, Auburn University, Auburn, AL, USA
| | - Sarah C Peaden
- Department of Anatomy, Physiology & Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - Javier E Stern
- Center for Neuroinflammation, Georgia State University, Atlanta, GA, USA
| | - Vinicia C Biancardi
- Department of Anatomy, Physiology & Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA; Center for Neurosciences Initiative, Auburn University, Auburn, AL, USA.
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3
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Cookson TA. Bacterial-Induced Blood Pressure Reduction: Mechanisms for the Treatment of Hypertension via the Gut. Front Cardiovasc Med 2021; 8:721393. [PMID: 34485420 PMCID: PMC8414577 DOI: 10.3389/fcvm.2021.721393] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/16/2021] [Indexed: 01/08/2023] Open
Abstract
Hypertension is a major risk factor for the development of cardiovascular disease. As more research into the gut microbiome emerges, we are finding increasing evidence to support that these microbes may have significant positive and negative effects on blood pressure and associated disorders. The bacterial-derived metabolites that are produced in the gut are capable of widespread effects to several tissue types and organs in the body. It is clear that the extensive metabolic function that is lost with gut dysbiosis is unlikely to be replenished with a single metabolite or bacterial strain. Instead, combinations of bacteria and concomitant therapies will provide a more well-rounded solution to manage hypertension. The bioactive molecules that are recognized in this review will inform on ideal characteristics of candidate bacteria and provide direction for future research on the gut microbiome in hypertension.
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Álvarez Cilleros D, López-Oliva ME, Martín MÁ, Ramos S. (-)-Epicatechin and the colonic metabolite 2,3-dihydroxybenzoic acid protect against high glucose and lipopolysaccharide-induced inflammation in renal proximal tubular cells through NOX-4/p38 signalling. Food Funct 2020; 11:8811-8824. [PMID: 32959859 DOI: 10.1039/d0fo01805h] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Chronic hyperglycaemia and inflammation are present in diabetes and both processes have been related to the pathogenesis of diabetic kidney disease. Epicatechin (EC) and main colonic phenolic acids derived from flavonoid intake, such as 2,3-dihydroxybenzoic acid (DHBA), 3,4-dihydroxyphenylacetic acid (DHPAA) and 3-hydroxyphenylpropionic acid (HPPA), have been suggested to exert beneficial effects in diabetes. This study was aimed at investigating whether the mentioned compounds could prevent inflammation in renal proximal tubular NRK-52E cells induced by high glucose and lipopolysaccharide (LPS). Pre-treatment of cells with EC and DHBA (5 μM) reverted the enhanced levels of pro-inflammatory cytokines, such as tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein 1 (MCP-1), activated by high glucose and LPS. Additionally, EC and DHBA pre-incubation reduced the increased values of adhesion molecules, namely, intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), as well as those of mitogen-activated protein kinases (MAPKs) [extracellular signal-regulated kinase (ERK), -c-jun N-terminal kinase (JNK) and -p38 protein kinase (p38)] activated by the high glucose and LPS challenge. Thus, in EC and DHBA pre-treated cells ICAM-1, p-ERK and p-JNK were returned to control values, and VCAM-1 and p-p38 levels were reduced by ∼20 and 25%, respectively, when compared to high glucose plus LPS-stimulated cells. Likewise, pre-treatment with EC and DHBA protected against high glucose plus LPS-triggered oxidative stress by preventing increased ROS and NADPH oxidase 4 (NOX-4) levels (∼25 and 45% reduction, respectively). By using specific inhibitors of p38 and NOX-4, the participation of both proteins in EC- and DHBA-mediated protection against inflammation and associated oxidative stress was shown. Taken together, EC and DHBA exert beneficial effects in renal proximal tubular cells, as they contribute to preventing the inflammatory-induced milieu and the accompanying redox imbalance, playing NOX-4/p38 a crucial role.
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Affiliation(s)
- David Álvarez Cilleros
- Department of Metabolism and Nutrition, Institute of Food Science and Technology and Nutrition (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), José Antonio Novais 10, Ciudad Universitaria, 28040, Madrid, Spain.
| | - María Elvira López-Oliva
- Sección Departamental de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), Spain
| | - María Ángeles Martín
- Department of Metabolism and Nutrition, Institute of Food Science and Technology and Nutrition (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), José Antonio Novais 10, Ciudad Universitaria, 28040, Madrid, Spain. and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), ISCIII, Spain
| | - Sonia Ramos
- Department of Metabolism and Nutrition, Institute of Food Science and Technology and Nutrition (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), José Antonio Novais 10, Ciudad Universitaria, 28040, Madrid, Spain.
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Ao T, Kikuta J, Sudo T, Uchida Y, Kobayashi K, Ishii M. Local sympathetic neurons promote neutrophil egress from the bone marrow at the onset of acute inflammation. Int Immunol 2020; 32:727-736. [DOI: 10.1093/intimm/dxaa025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 04/09/2020] [Indexed: 01/08/2023] Open
Abstract
Abstract
The sympathetic nervous system plays critical roles in the differentiation, maturation and recruitment of immune cells under homeostatic conditions, and in responses to environmental stimuli, although its role in the migratory control of immune cells during acute inflammation remains unclear. In this study, using an advanced intravital bone imaging system established in our laboratory, we demonstrated that the sympathetic nervous system locally regulates neutrophil egress from the bone marrow for mobilization to inflammatory foci. We found that sympathetic neurons were located close to blood vessels in the bone marrow cavity; moreover, upon lipopolysaccharide (LPS) administration, local sympathectomy delayed neutrophil egress from the bone marrow and increased the proportion of neutrophils that remained in place. We also showed that vascular endothelial cells produced C-X-C motif chemokine ligand 1 (CXCL1), which is responsible for neutrophil egress out of the bone marrow. Its expression was up-regulated during acute inflammation, and was suppressed by β-adrenergic receptor blockade, which was accompanied with inhibition of neutrophil egress into the systemic circulation. Furthermore, systemic β-adrenergic signaling blockade decreased the recruitment of neutrophils in the lung under conditions of acute systemic inflammation. Taken together, the results of this study first suggested a new regulatory system, wherein local sympathetic nervous activation promoted neutrophil egress by enhancing Cxcl1 expression in bone marrow endothelial cells in a β-adrenergic signaling-dependent manner, contributing to the recruitment of neutrophils at the onset of inflammation in vivo.
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Affiliation(s)
- Tomoka Ao
- Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Yamada-oka, Suita, Osaka, Japan
- WPI-Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Junichi Kikuta
- Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Yamada-oka, Suita, Osaka, Japan
- WPI-Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Takao Sudo
- Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Yamada-oka, Suita, Osaka, Japan
- WPI-Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Yutaka Uchida
- Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Yamada-oka, Suita, Osaka, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, National Institute of Natural Sciences, Aichi, Japan
| | - Masaru Ishii
- Department of Immunology and Cell Biology, Graduate School of Medicine and Frontier Biosciences, Osaka University, Yamada-oka, Suita, Osaka, Japan
- WPI-Immunology Frontier Research Center, Osaka University, Osaka, Japan
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Tan YC, Abdul Sattar M, Ahmeda AF, Abdul Karim Khan N, Murugaiyah V, Ahmad A, Hassan Z, Kaur G, Abdulla MH, Johns EJ. Apocynin and catalase prevent hypertension and kidney injury in Cyclosporine A-induced nephrotoxicity in rats. PLoS One 2020; 15:e0231472. [PMID: 32298299 PMCID: PMC7161975 DOI: 10.1371/journal.pone.0231472] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/24/2020] [Indexed: 01/17/2023] Open
Abstract
Oxidative stress is involved in the pathogenesis of a number of diseases including hypertension and renal failure. There is enhanced expression of nicotinamide adenine dinucleotide (NADPH oxidase) and therefore production of hydrogen peroxide (H2O2) during renal disease progression. This study investigated the effect of apocynin, an NADPH oxidase inhibitor and catalase, an H2O2 scavenger on Cyclosporine A (CsA) nephrotoxicity in Wistar-Kyoto rats. Rats received CsA (25mg/kg/day via gavage) and were assigned to vehicle, apocynin (2.5mmol/L p.o.), catalase (10,000U/kg/day i.p.) or apocynin plus catalase for 14 days. Renal functional and hemodynamic parameters were measured every week, and kidneys were harvested at the end of the study for histological and NADPH oxidase 4 (NOX4) assessment. Oxidative stress markers and blood urea nitrogen (BUN) were measured. CsA rats had higher plasma malondialdehyde (by 340%) and BUN (by 125%), but lower superoxide dismutase and total antioxidant capacity (by 40%, all P<0.05) compared to control. CsA increased blood pressure (by 46mmHg) and decreased creatinine clearance (by 49%, all P<0.05). Treatment of CsA rats with apocynin, catalase, and their combination decreased blood pressure to near control values (all P<0.05). NOX4 mRNA activity was higher in the renal tissue of CsA rats by approximately 63% (P<0.05) compared to controls but was reduced in apocynin (by 64%), catalase (by 33%) and combined treatment with apocynin and catalase (by 84%) compared to untreated CsA rats. Treatment of CsA rats with apocynin, catalase, and their combination prevented hypertension and restored renal functional parameters and tissue Nox4 expression in this model. NADPH inhibition and H2O2 scavenging is an important therapeutic strategy during CsA nephrotoxicity and hypertension.
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Affiliation(s)
- Yong Chia Tan
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia
- * E-mail:
| | - Munavvar Abdul Sattar
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia
| | - Ahmad F. Ahmeda
- Basic Medical Science Department, College of Medicine, Qatar University, Doha, Qatar
| | | | | | - Ashfaq Ahmad
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Virginia, Richmond, United States of America
- Department of Pharmacy, Abasyn University Islamabad Campus, Islamabad, Pakistan
| | - Zurina Hassan
- Centre for Drug Research, Universiti Sains Malaysia, Penang, Malaysia
| | - Gurjeet Kaur
- Institute for Molecular Medicine Research, Universiti Sains Malaysia, Penang, Malaysia
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Wang Q, Deng F, Zhu D. Superoxide anions modulate the effects of alarin in the paraventricular nucleus on sympathetic activity and blood pressure in spontaneously hypertensive rats. Neuropeptides 2020; 80:102021. [PMID: 32033788 DOI: 10.1016/j.npep.2020.102021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 01/19/2020] [Accepted: 01/19/2020] [Indexed: 12/19/2022]
Abstract
Neuropeptides are involved in the regulation of the sympathetic activity and blood pressure in the paraventricular nucleus of the hypothalamus (PVN). The present study was designed to determine how alarin modulates the renal sympathetic nerve activity (RSNA), arterial blood pressure and mean arterial pressure (MAP) in the PVN, and whether superoxide anions regulate the effects of alarin in the PVN of spontaneously hypertensive rats (SHRs). Acute experiment was carried out with male Wistar-Kyoto rats (WKY) and SHRs under anesthesia. RSNA, systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP were measured. Alarin microinjection into the PVN increased RSNA (7.8 ± 1.8 vs. 14.8 ± 2.3%), SBP (5.9 ± 1.4 vs. 12.1 ± 1.6 mmHg), DBP (5.1 ± 0.8 vs. 10.0 ± 1.1 mmHg), and MAP (5.4 ± 1.2 vs. 10.7 ± 1.3 mmHg) in WKY rats and SHRs,. Alarin antagonist ala6-25 Cys decreased RSNA, SBP, DBP, and MAP in SHRs, and inhibited the effects of alarin. The alarin level was increased in the PVN of SHR compared to WKY rats. (29.7 ± 4.9 vs. 14.6 ± 2.4 pg/mg protein). PVN microinjection of superoxide anion scavengers tempol and tiron, or NAD(P)H oxidase inhibitor apocynin, decreased RSNA, SBP, DBP, and MAP in SHRs, and inhibited the effects of alarin, but the superoxide dismutase inhibitor diethyldithiocarbamic acid potentiated the effects of alarin. Superoxide anions and NAD(P)H oxidase activity levels in the PVN were increased by alarin, but decreased by alarin antagonist ala6-25 Cys. The alarin-induced increases in superoxide anions and NAD(P)H oxidase activity levels were abolished by pre-treatment with ala6-25 Cys. The results suggest that alarin in the PVN increases sympathetic outflow and blood pressure. The enhanced activity of endogenous alarin in the PVN contributes to sympathetic activation in hypertension, and the superoxide anion is involved in these alarin-mediated processes in the PVN.
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Affiliation(s)
- Qian Wang
- Pediatric Department, Shanghai General Hospital, Shanghai, China
| | - Fanxin Deng
- Department of Cardiothoracic Surgery, Sir Run Run Hospital, Nanjing Medical University, Nanjing, China
| | - Dawei Zhu
- Department of Cardiothoracic Surgery, Sir Run Run Hospital, Nanjing Medical University, Nanjing, China.
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TLR4 participates in sympathetic hyperactivity Post-MI in the PVN by regulating NF-κB pathway and ROS production. Redox Biol 2019; 24:101186. [PMID: 30978539 PMCID: PMC6460304 DOI: 10.1016/j.redox.2019.101186] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 03/14/2019] [Accepted: 03/28/2019] [Indexed: 01/01/2023] Open
Abstract
Sympathetic nerve hyperactivity is a primary reason for fatal ventricular arrhythmias (VAs) following myocardial infarction (MI). Pro-inflammatory cytokines produced in the paraventricular nucleus (PVN) post-MI are associated with sympathetic overexcitation; however, the precise mechanism needs further investigation. Our aim was to explore the mechanism of toll-like receptor 4 (TLR4) and its downstream molecular pathway in mediating sympathetic activity post-MI within the PVN. A rat MI model was developed via left anterior descending coronary artery ligation. TLR4 was primarily localized in microglia and increased markedly within the PVN at 3 days in MI rats. Sympathoexcitation also increased, as indicated by high levels of renal sympathetic nerve activity (RSNA) and norepinephrine (NE) concentration. TLR4 knockdown via shRNA microinjection to the PVN resulted in decreased activation of Fos protein (+) neurons in the PVN and peripheral sympathetic nerve activity. TLR4 knockdown also exhibited a lower arrhythmia score following programmed electrical stimulation than those treated with MI surgery only, indicating that the knockdown of TLR4 decreased the incidence of malignant ventricular arrhythmias following MI. LPS-induced inflammatory response was analyzed to explore the underlying mechanism of TLR4 in sympathetic hyperactivity. High levels of NF-κB protein, the pro-inflammatory cytokines IL-1β and TNF-α, and ROS production were observed in the LPS group. PVN-targeted injection of the NF-κB inhibitor PDTC attenuated NF-κB expression and sympathetic activity. Taken together, the results suggested that knockdown of microglial TLR4 within the PVN decreased sympathetic hyperactivity and subsequent VAs post-MI. The downstream NF-κB pathway and ROS production participated in the process. Interventions targeting TLR4 signaling in the PVN may be a novel approach to ameliorate the incidence of VAs post-MI.
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Toral M, Robles-Vera I, de la Visitación N, Romero M, Yang T, Sánchez M, Gómez-Guzmán M, Jiménez R, Raizada MK, Duarte J. Critical Role of the Interaction Gut Microbiota - Sympathetic Nervous System in the Regulation of Blood Pressure. Front Physiol 2019; 10:231. [PMID: 30930793 PMCID: PMC6423906 DOI: 10.3389/fphys.2019.00231] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 02/21/2019] [Indexed: 12/11/2022] Open
Abstract
Association between gut dysbiosis and neurogenic diseases, such as hypertension, has been described. The aim of this study was to investigate whether changes in the gut microbiota alter gut-brain interactions inducing changes in blood pressure (BP). Recipient normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) were orally gavaged with donor fecal contents from SHR and WKY. We divided the animals into four groups: WKY transplanted with WKY microbiota (W-W), SHR with SHR (S-S), WKY with SHR (W-S) and SHR with WKY (S-W). Basal systolic BP (SBP) and diastolic BP (DBP) were reduced with no change in heart rate as a result of fecal microbiota transplantation (FMT) from WKY rats to SHR. Similarly, FMT from SHR to WKY increased basal SBP and DBP. Increases in both NADPH oxidase-driven reactive oxygen species production and proinflammatory cytokines in brain paraventricular nucleus linked to higher BP drop with pentolinium and plasmatic noradrenaline (NA) levels were found in the S-S group as compared to the W-W group. These parameters were reduced by FMT from WKY to SHR. Increased levels of pro-inflammatory cytokines, tyrosine hydroxylase mRNA levels and NA content in the proximal colon, whereas reduced mRNA levels of gap junction proteins, were found in the S-S group as compared to the W-W group. These changes were inhibited by FMT from WKY to SHR. According to our correlation analyses, the abundance of Blautia and Odoribacter showed a negative correlation with high SBP. In conclusion, in SHR gut microbiota is an important factor involved in BP control, at least in part, as consequence of its effect on neuroinflammation and the sympathetic nervous system activity.
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Affiliation(s)
- Marta Toral
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain
| | - Iñaki Robles-Vera
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain
| | - Néstor de la Visitación
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain
| | - Miguel Romero
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria de Granada, ibs.GRANADA, Granada, Spain
| | - Tao Yang
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Manuel Sánchez
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria de Granada, ibs.GRANADA, Granada, Spain
| | - Manuel Gómez-Guzmán
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain
| | - Rosario Jiménez
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria de Granada, ibs.GRANADA, Granada, Spain.,CIBERCV, University of Granada, Granada, Spain
| | - Mohan K Raizada
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, United States
| | - Juan Duarte
- Department of Pharmacology, School of Pharmacy, Centro de Investigación Biomédica, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria de Granada, ibs.GRANADA, Granada, Spain.,CIBERCV, University of Granada, Granada, Spain
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10
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Sun J, Ren XS, Kang Y, Dai HB, Ding L, Tong N, Zhu GQ, Zhou YB. Intermedin in Paraventricular Nucleus Attenuates Sympathoexcitation and Decreases TLR4-Mediated Sympathetic Activation via Adrenomedullin Receptors in Rats with Obesity-Related Hypertension. Neurosci Bull 2019; 35:34-46. [PMID: 30276527 PMCID: PMC6357274 DOI: 10.1007/s12264-018-0292-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/14/2018] [Indexed: 01/11/2023] Open
Abstract
Intermedin/adrenomedullin-2 (IMD/AM2), a member of the calcitonin gene-related peptide/AM family, plays an important role in protecting the cardiovascular system. However, its role in the enhanced sympathoexcitation in obesity-related hypertension is unknown. In this study, we investigated the effects of IMD in the paraventricular nucleus (PVN) of the hypothalamus on sympathetic nerve activity (SNA), and lipopolysaccharide (LPS)-induced sympathetic activation in obesity-related hypertensive (OH) rats induced by a high-fat diet for 12 weeks. Acute experiments were performed under anesthesia. The dynamic alterations of sympathetic outflow were evaluated as changes in renal SNA and mean arterial pressure (MAP) in response to specific drugs. Male rats were fed a control diet (12% kcal as fat) or a high-fat diet (42% kcal as fat) for 12 weeks to induce OH. The results showed that IMD protein in the PVN was downregulated, but Toll-like receptor 4 (TLR4) and plasma norepinephrine (NE, indicating sympathetic hyperactivity) levels, and systolic blood pressure were increased in OH rats. LPS (0.5 µg/50 nL)-induced enhancement of renal SNA and MAP was greater in OH rats than in obese or control rats. Bilateral PVN microinjection of IMD (50 pmol) caused greater decreases in renal SNA and MAP in OH rats than in control rats, and inhibited LPS-induced sympathetic activation, and these were effectively prevented in OH rats by pretreatment with the AM receptor antagonist AM22-52. The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) inhibitor U0126 in the PVN partially reversed the LPS-induced enhancement of SNA. However, IMD in the PVN decreased the LPS-induced ERK activation, which was also effectively prevented by AM22-52. Chronic IMD administration resulted in significant reductions in the plasma NE level and blood pressure in OH rats. Moreover, IMD lowered the TLR4 protein expression and ERK activation in the PVN, and decreased the LPS-induced sympathetic overactivity. These results indicate that IMD in the PVN attenuates SNA and hypertension, and decreases the ERK activation implicated in the LPS-induced enhancement of SNA in OH rats, and this is mediated by AM receptors.
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Affiliation(s)
- Jing Sun
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Xing-Sheng Ren
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Ying Kang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Hang-Bing Dai
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Lei Ding
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
- Department of Pathophysiology, Xuzhou Medical College, Xuzhou, 221004, China
| | - Ning Tong
- Department of Neurology, Heze Municipal Hospital, Heze, 274000, China
| | - Guo-Qing Zhu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, 211166, China
| | - Ye-Bo Zhou
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, 211166, China.
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11
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Affiliation(s)
- Sasha A Fahme
- From the Center for Global Health, Weill Cornell Medical College, New York, NY (S.A.F., R.P.)
- Department of Internal Medicine, Weill Bugando School of Medicine, Mwanza, Tanzania (S.A.F., R.P.)
| | - Gerald S Bloomfield
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC (G.S.B.)
| | - Robert Peck
- From the Center for Global Health, Weill Cornell Medical College, New York, NY (S.A.F., R.P.)
- Department of Internal Medicine, Weill Bugando School of Medicine, Mwanza, Tanzania (S.A.F., R.P.)
- Mwanza Interventions Trial Unit, Tanzania (R.P.)
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12
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Zhu G, Chen Z, Dai B, Zheng C, Jiang H, Xu Y, Sheng X, Guo J, Dan Y, Liang S, Li G. Chronic lead exposure enhances the sympathoexcitatory response associated with P2X4 receptor in rat stellate ganglia. ENVIRONMENTAL TOXICOLOGY 2018; 33:631-639. [PMID: 29457680 DOI: 10.1002/tox.22547] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 01/25/2018] [Accepted: 02/03/2018] [Indexed: 06/08/2023]
Abstract
Chronic lead exposure causes peripheral sympathetic nerve stimulation, including increased blood pressure and heart rate. Purinergic receptors are involved in the sympathoexcitatory response induced by myocardial ischemia injury. However, whether P2X4 receptor participates in sympathoexcitatory response induced by chronic lead exposure and the possible mechanisms are still unknown. The aim of this study was to explore the change of the sympathoexcitatory response induced by chronic lead exposure via the P2X4 receptor in the stellate ganglion (SG). Rats were given lead acetate through drinking water freely at doses of 0 g/L (control group), 0.5 g/L (low lead group), and 2 g/L (high lead group) for 1 year. Our results demonstrated that lead exposure caused autonomic nervous dysfunction, including blood pressure and heart rate increased and heart rate variability (HRV) decreased. Western blotting results indicated that after lead exposure, the protein expression levels in the SG of P2X4 receptor, IL-1β and Cx43 were up-regulated, the phosphorylation of p38 mitogen-activated protein kinase (MAPK) was activated. Real-time PCR results showed that the mRNA expression of P2X4 receptor in the SG was higher in lead exposure group than that in the control group. Double-labeled immunofluorescence results showed that P2X4 receptor was co-expressed with glutamine synthetase (GS), the marker of satellite glial cells (SGCs). These changes were positively correlated with the dose of lead exposure. The up-regulated expression of P2X4 receptor in SGCs of the SG maybe enhance the sympathoexcitatory response induced by chronic lead exposure.
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Affiliation(s)
- Gaochun Zhu
- Department of Anatomy, Medical College of Nanchang University, Nanchang, China
| | - Zhenying Chen
- The Fourth Clinical, Medical College of Nanchang University, Nanchang, China
| | - Bo Dai
- The Fourth Clinical, Medical College of Nanchang University, Nanchang, China
| | - Chaoran Zheng
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Huaide Jiang
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Yurong Xu
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Xuan Sheng
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Jingjing Guo
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Yu Dan
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Shangdong Liang
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
| | - Guilin Li
- Department of Physiology, Medical College of Nanchang University, Nanchang, China
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13
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Zhao YW, Pan YQ, Tang MM, Lin WJ. Blocking p38 Signaling Reduces the Activation of Pro-inflammatory Cytokines and the Phosphorylation of p38 in the Habenula and Reverses Depressive-Like Behaviors Induced by Neuroinflammation. Front Pharmacol 2018; 9:511. [PMID: 29867510 PMCID: PMC5962764 DOI: 10.3389/fphar.2018.00511] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/27/2018] [Indexed: 12/11/2022] Open
Abstract
Increasing evidence has demonstrated that neuroinflammation contributes to the development of depressive-like behaviors, in both animal models and human patients; however, the brain areas and signaling pathways involved are still elusive. Recent studies have suggested novel roles of the habenula in the onset of depression and other psychiatric disorders; however, there is no evidence for whether the habenula has a function in neuroinflammation-induced depression. Using an animal model of depression, which is induced by the repeated central administration of lipopolysaccharide (LPS), we examined whether cytokine expression and p38 signal activation in the habenula were involved in the depressive-like behaviors. Body weight, saccharin preference test, and tail suspension test were used to measure depressive-like behaviors. Immunohistochemistry, quantitative-polymerase chain reaction (q-PCR), and western blot were used to measure the expression of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and the phosphorylation of p38 in the habenula. The results showed that central LPS administration induced depressive-like behaviors, characterized by anhedonia in the saccharin preference test and increased immobility in the tail suspension test. Central LPS administration also significantly increased the p-p38 level in microglial cells and increased TNF-α expression in the habenula. Treatment with fluoxetine, a widely prescribed antidepressant, or SB203580, a p38-specific inhibitor, reversed the depressive-like behaviors, normalized the alterations in p-p38 and TNF-α levels and increased the levels of the anti-inflammatory cytokine IL-10 in the habenula. The present findings suggest that the habenula is involved in the pathophysiology of behavioral depression induced by neuroinflammation, and the p38 pathway may serve as a novel mechanism-based target for the treatment of inflammation-related depression.
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Affiliation(s)
- Ya-Wei Zhao
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Yu-Qin Pan
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Ming-Ming Tang
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Wen-Juan Lin
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
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14
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Chen W, Luo S, Xie P, Hou T, Yu T, Fu X. Overexpressed UCP2 regulates mitochondrial flashes and reverses lipopolysaccharide-induced cardiomyocytes injury. Am J Transl Res 2018; 10:1347-1356. [PMID: 29887950 PMCID: PMC5992536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Background: Mitochondrial flashes (mitoflashes) are transient signals from transient bursts of reactive oxygen species (ROS) and changes in pH that occur in certain physiological or pathological conditions. Mitoflashes are closely related to metabolism, cell differentiation, stress response, diseases, and aging. Sepsis can trigger mitochondrial dysfunction in myocardial cells, which leads to ROS overproduction, while uncoupling protein 2 (UCP2) can reduce ROS production. This study aims to observe whether UCP2 overexpression can regulate the frequency of mitoflashes in cardiomyocytes during sepsis and thereby play a protective role. Methods: A cell model for sepsis-induced myocardial damage was established using lipopolysaccharide (LPS). UCP2 overexpression in cardiomyocytes was achieved by adenovirus transfection. Creatinine kinase (CK), lactate dehydrogenase (LDH), tumor necrosis factor (TNF-α), and interleukin (IL-6) activities were detected, and mitochondrial membrane potentials (MMP) were measured. The frequency of mitoflashes in cardiomyocytes was observed. Results: With LPS stimulation, mitoflashes in cardiomyocytes increased significantly, and the MMP was damaged. Additionally, significant increases in CK, LDH, TNF-α, and IL-6 expression levels were observed. UCP2 overexpression can significantly reverse myocardial cell injuries that result from LPS stimulation. Compared with the LPS group, the LPS+UCP2 overexpression group showed a decrease in mitoflash frequency, an improved MMP, and decreases in CK, LDH, TNF-α, and IL-6 expression levels. Conclusion: This study is the first to demonstrate the function of UCP2 overexpression in protecting the myocardium by regulating mitoflash frequency and reversing sepsis-induced myocardial injuries.
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Affiliation(s)
- Wenbo Chen
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
| | - Shiyu Luo
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
| | - Peng Xie
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
| | - Tingting Hou
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking UniversityBeijing 100871, China
| | - Tian Yu
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical UniversityZunyi, Guizhou, China
| | - Xiaoyun Fu
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
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15
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Sheng Y, Zhu L. The crosstalk between autonomic nervous system and blood vessels. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2018; 10:17-28. [PMID: 29593847 PMCID: PMC5871626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 02/24/2018] [Indexed: 06/08/2023]
Abstract
The autonomic nervous system (ANS), comprised of two primary branches, sympathetic and parasympathetic nervous system, plays an essential role in the regulation of vascular wall contractility and tension. The sympathetic and parasympathetic nerves work together to balance the functions of autonomic effector organs. The neurotransmitters released from the varicosities in the ANS can regulate the vascular tone. Norepinephrine (NE), adenosine triphosphate (ATP) and Neuropeptide Y (NPY) function as vasoconstrictors, whereas acetylcholine (Ach) and calcitonin gene-related peptide (CGRP) can mediate vasodilation. On the other hand, vascular factors, such as endothelium-derived relaxing factor nitric oxide (NO), and constriction factor endothelin, play an important role in the autonomic nervous system in physiologic conditions. Endothelial dysfunction and inflammation are associated with the sympathetic nerve activity in the pathological conditions, such as hypertension, heart failure, and diabetes mellitus. The dysfunction of the autonomic nervous system could be a risk factor for vascular diseases and the overactive sympathetic nerve is detrimental to the blood vessel. In this review, we summarize findings concerning the crosstalk between ANS and blood vessels in both physiological and pathological conditions and hope to provide insight into the development of therapeutic interventions of vascular diseases.
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Affiliation(s)
- Yulan Sheng
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology of Jiangsu Province, State Key Laboratory of Radiation Medicine and Protection, Soochow UniversitySuzhou 215123, China
| | - Li Zhu
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology of Jiangsu Province, State Key Laboratory of Radiation Medicine and Protection, Soochow UniversitySuzhou 215123, China
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16
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Bhat SA, Goel R, Shukla S, Shukla R, Hanif K. Angiotensin Receptor Blockade by Inhibiting Glial Activation Promotes Hippocampal Neurogenesis Via Activation of Wnt/β-Catenin Signaling in Hypertension. Mol Neurobiol 2017; 55:5282-5298. [DOI: 10.1007/s12035-017-0754-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 08/23/2017] [Indexed: 12/21/2022]
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17
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Angiotensin II Receptor Blockers Attenuate Lipopolysaccharide-Induced Memory Impairment by Modulation of NF-κB-Mediated BDNF/CREB Expression and Apoptosis in Spontaneously Hypertensive Rats. Mol Neurobiol 2017; 55:1725-1739. [DOI: 10.1007/s12035-017-0450-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/07/2017] [Indexed: 11/28/2022]
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18
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Abstract
Hypertension is a highly prevalent condition with numerous health risks, and the incidence of hypertension is greatest among older adults. Traditional discussions of hypertension have largely focused on the risks for cardiovascular disease and associated events. However, there are a number of collateral effects, including risks for dementia, physical disability, and falls/fractures which are increasingly garnering attention in the hypertension literature. Several key mechanisms--including inflammation, oxidative stress, and endothelial dysfunction--are common to biologic aging and hypertension development and appear to have key mechanistic roles in the development of the cardiovascular and collateral risks of late-life hypertension. The objective of the present review is to highlight the multi-dimensional risks of hypertension among older adults and discuss potential strategies for treatment and future areas of research for improving overall care for older adults with hypertension.
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19
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Xu B, Li H. Brain mechanisms of sympathetic activation in heart failure: Roles of the renin‑angiotensin system, nitric oxide and pro‑inflammatory cytokines (Review). Mol Med Rep 2015; 12:7823-9. [PMID: 26499491 PMCID: PMC4758277 DOI: 10.3892/mmr.2015.4434] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 09/10/2015] [Indexed: 12/14/2022] Open
Abstract
Patients with chronic heart failure (CHF) have an insufficient perfusion to the peripheral tissues due to decreased cardiac output. The compensatory mechanisms are triggered even prior to the occurrence of clinical symptoms, which include activation of the sympathetic nervous system (SNS) and other neurohumoral factors. However, the long‑term activation of the SNS contributes to progressive cardiac dysfunction and has toxic effects on the cardiomyocytes. The mechanisms leading to the activation of SNS include changes in peripheral baroreceptor and chemoreceptor reflexes and the abnormal regulation of sympathetic nerve activity (SNA) in the central nervous system (CNS). Recent studies have focused on the role of brain mechanisms in the regulation of SNA and the progression of CHF. The renin‑angiotensin system, nitric oxide and pro‑inflammatory cytokines were shown to be involved in the abnormal regulation of SNA in the CNS. The alteration of these neurohumoral factors during CHF influences the activity of neurons in the autonomic regions and finally increase the sympathetic outflow. The present review summarizes the brain mechanisms contributing to sympathoexcitation in CHF.
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Affiliation(s)
- Bin Xu
- Department of Cardiology, Shanghai First People's Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai 200080, P.R. China
| | - Hongli Li
- Department of Cardiology, Shanghai First People's Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai 200080, P.R. China
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20
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Winklewski PJ, Radkowski M, Wszedybyl-Winklewska M, Demkow U. Brain inflammation and hypertension: the chicken or the egg? J Neuroinflammation 2015; 12:85. [PMID: 25935397 PMCID: PMC4432955 DOI: 10.1186/s12974-015-0306-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/23/2015] [Indexed: 12/24/2022] Open
Abstract
Inflammation of forebrain and hindbrain nuclei controlling the sympathetic nervous system (SNS) outflow from the brain to the periphery represents an emerging concept of the pathogenesis of neurogenic hypertension. Angiotensin II (Ang-II) and prorenin were shown to increase production of reactive oxygen species and pro-inflammatory cytokines (interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α)) while simultaneously decreasing production of interleukin-10 (IL-10) in the paraventricular nucleus of the hypothalamus and the rostral ventral lateral medulla. Peripheral chronic inflammation and Ang-II activity seem to share a common central mechanism contributing to an increase in sympathetic neurogenic vasomotor tone and entailing neurogenic hypertension. Both hypertension and obesity facilitate the penetration of peripheral immune cells in the brain parenchyma. We suggest that renin-angiotensin-driven hypertension encompasses feedback and feedforward mechanisms in the development of neurogenic hypertension while low-intensity, chronic peripheral inflammation of any origin may serve as a model of a feedforward mechanism in this condition.
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Affiliation(s)
- Pawel J Winklewski
- Institute of Human Physiology, Medical University of Gdansk, Tuwima Str. 15, 80-210, Gdansk, Poland.
| | - Marek Radkowski
- Department of Immunopathology of Infectious and Parasitic Diseases, Medical University of Warsaw, Pawinskiego Str. 3c, 02-106, Warsaw, Poland.
| | | | - Urszula Demkow
- Department of Laboratory Diagnostics and Clinical Immunology of Developmental Age, Medical University of Warsaw, Marszalkowska Str. 24, 00-576, Warsaw, Poland.
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21
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Goel R, Bhat SA, Rajasekar N, Hanif K, Nath C, Shukla R. Hypertension exacerbates predisposition to neurodegeneration and memory impairment in the presence of a neuroinflammatory stimulus: Protection by angiotensin converting enzyme inhibition. Pharmacol Biochem Behav 2015; 133:132-45. [PMID: 25869103 DOI: 10.1016/j.pbb.2015.04.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 03/17/2015] [Accepted: 04/06/2015] [Indexed: 01/06/2023]
Abstract
Hypertension is a risk factor for cognitive impairment. Furthermore, neuroinflammation and neurodegeneration are intricately associated with memory impairment. Therefore, the present study aimed to explore the involvement of hypertension and angiotensin system in neurodegeneration and memory dysfunction in the presence of neuroinflammatory stimulus. Memory impairment was induced by chronic neuroinflammation that was developed by repeated intracerebroventricular (ICV) injections of lipopolysaccharide (LPS) on the 1st, 4th, 7th, and 10th day. Memory functions were evaluated by the Morris water maze (MWM) test on days 13-15, followed by biochemical and molecular studies in the cortex and hippocampus regions of rat brain. LPS at the dose of 25μg ICV caused memory impairment in spontaneously hypertensive rats (SHRs) but not in normotensive Wistar rats (NWRs). Memory deficit was obtained with 50μg of LPS (ICV) in NWRs. Control SHRs already exhibited increased angiotensin converting enzyme (ACE) activity and expression, neuroinflammation (increased TNF-α, GFAP, COX-2 and NF-kB), oxidative stress (increased iNOS, ROS and nitrite levels), TLR-4 expression and TUNEL positive cells as compared to control NWRs. Further, LPS (25μg ICV) exaggerated inflammatory response, oxidative stress and apoptosis in SHRs but similar effects were witnessed at 50μg of LPS (ICV) in NWRs. Oral administration of perindopril (ACE inhibitor), at non-antihypertensive dose (0.1mg/kg), for 15days attenuated LPS induced deleterious changes in both NWRs and SHRs. Our data suggest that susceptibility of the brain for neurodegeneration and memory impairment induced by neuroinflammation is enhanced in hypertension, and that can be protected by ACE inhibition.
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Affiliation(s)
- Ruby Goel
- Divisions of Pharmacology and Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Shahnawaz Ali Bhat
- Divisions of Pharmacology and Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - N Rajasekar
- Divisions of Pharmacology and Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), India
| | - Kashif Hanif
- Divisions of Pharmacology and Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), India
| | - Chandishwar Nath
- Divisions of Pharmacology and Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), India
| | - Rakesh Shukla
- Divisions of Pharmacology and Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), India.
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22
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Abstract
The present review assesses the current state of literature defining integrative autonomic-immune physiological processing, focusing on studies that have employed electrophysiological, pharmacological, molecular biological, and central nervous system experimental approaches. Central autonomic neural networks are informed of peripheral immune status via numerous communicating pathways, including neural and non-neural. Cytokines and other immune factors affect the level of activity and responsivity of discharges in sympathetic and parasympathetic nerves innervating diverse targets. Multiple levels of the neuraxis contribute to cytokine-induced changes in efferent parasympathetic and sympathetic nerve outflows, leading to modulation of peripheral immune responses. The functionality of local sympathoimmune interactions depends on the microenvironment created by diverse signaling mechanisms involving integration between sympathetic nervous system neurotransmitters and neuromodulators; specific adrenergic receptors; and the presence or absence of immune cells, cytokines, and bacteria. Functional mechanisms contributing to the cholinergic anti-inflammatory pathway likely involve novel cholinergic-adrenergic interactions at peripheral sites, including autonomic ganglion and lymphoid targets. Immune cells express adrenergic and nicotinic receptors. Neurotransmitters released by sympathetic and parasympathetic nerve endings bind to their respective receptors located on the surface of immune cells and initiate immune-modulatory responses. Both sympathetic and parasympathetic arms of the autonomic nervous system are instrumental in orchestrating neuroimmune processes, although additional studies are required to understand dynamic and complex adrenergic-cholinergic interactions. Further understanding of regulatory mechanisms linking the sympathetic nervous, parasympathetic nervous, and immune systems is critical for understanding relationships between chronic disease development and immune-associated changes in autonomic nervous system function.
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Affiliation(s)
- M J Kenney
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas
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24
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Gomez-Sanchez EP. Brain mineralocorticoid receptors in cognition and cardiovascular homeostasis. Steroids 2014; 91:20-31. [PMID: 25173821 PMCID: PMC4302001 DOI: 10.1016/j.steroids.2014.08.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/10/2014] [Accepted: 08/04/2014] [Indexed: 12/20/2022]
Abstract
Mineralocorticoid receptors (MR) mediate diverse functions supporting osmotic and hemodynamic homeostasis, response to injury and inflammation, and neuronal changes required for learning and memory. Inappropriate MR activation in kidneys, heart, vessels, and brain hemodynamic control centers results in cardiovascular and renal pathology and hypertension. MR binds aldosterone, cortisol and corticosterone with similar affinity, while the glucocorticoid receptor (GR) has less affinity for cortisol and corticosterone. As glucocorticoids are more abundant than aldosterone, aldosterone activates MR in cells co-expressing enzymes with 11β-hydroxydehydrogenase activity to inactivate them. MR and GR co-expressed in the same cell interact at the molecular and functional level and these functions may be complementary or opposing depending on the cell type. Thus the balance between MR and GR expression and activation is crucial for normal function. Where 11β-hydroxydehydrogenase 2 (11β-HSD2) that inactivates cortisol and corticosterone in aldosterone target cells of the kidney and nucleus tractus solitarius (NTS) is not expressed, as in most neurons, MR are activated at basal glucocorticoid concentrations, GR at stress concentrations. An exception may be pre-autonomic neurons of the PVN which express MR and 11β-HSD1 in the absence of hexose-6-phosphate dehydrogenase required to generate the requisite cofactor for reductase activity, thus it acts as a dehydrogenase. MR antagonists, valuable adjuncts to the treatment of cardiovascular disease, also inhibit MR in the brain that are crucial for memory formation and exacerbate detrimental effects of excessive GR activation on cognition and mood. 11β-HSD1 inhibitors combat metabolic and cognitive diseases related to glucocorticoid excess, but may exacerbate MR action where 11β-HSD1 acts as a dehydrogenase, while non-selective 11β-HSD1&2 inhibitors cause injurious disruption of MR hemodynamic control. MR functions in the brain are multifaceted and optimal MR:GR activity is crucial. Therefore selectively targeting down-stream effectors of MR specific actions may be a better therapeutic goal.
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Affiliation(s)
- Elise P Gomez-Sanchez
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA.
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25
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Dinh QN, Drummond GR, Sobey CG, Chrissobolis S. Roles of inflammation, oxidative stress, and vascular dysfunction in hypertension. BIOMED RESEARCH INTERNATIONAL 2014; 2014:406960. [PMID: 25136585 PMCID: PMC4124649 DOI: 10.1155/2014/406960] [Citation(s) in RCA: 364] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/20/2014] [Indexed: 02/07/2023]
Abstract
Hypertension is a complex condition and is the most common cardiovascular risk factor, contributing to widespread morbidity and mortality. Approximately 90% of hypertension cases are classified as essential hypertension, where the precise cause is unknown. Hypertension is associated with inflammation; however, whether inflammation is a cause or effect of hypertension is not well understood. The purpose of this review is to describe evidence from human and animal studies that inflammation leads to the development of hypertension, as well as the evidence for involvement of oxidative stress and endothelial dysfunction--both thought to be key steps in the development of hypertension. Other potential proinflammatory conditions that contribute to hypertension-such as activation of the sympathetic nervous system, aging, and elevated aldosterone--are also discussed. Finally, we consider the potential benefit of anti-inflammatory drugs and statins for antihypertensive therapy. The evidence reviewed suggests that inflammation can lead to the development of hypertension and that oxidative stress and endothelial dysfunction are involved in the inflammatory cascade. Aging and aldosterone may also both be involved in inflammation and hypertension. Hence, in the absence of serious side effects, anti-inflammatory drugs could potentially be used to treat hypertension in the future.
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Affiliation(s)
- Quynh N. Dinh
- Vascular Biology & Immunopharmacology Group, Department of Pharmacology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Grant R. Drummond
- Vascular Biology & Immunopharmacology Group, Department of Pharmacology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Christopher G. Sobey
- Vascular Biology & Immunopharmacology Group, Department of Pharmacology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Sophocles Chrissobolis
- Vascular Biology & Immunopharmacology Group, Department of Pharmacology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
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26
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Chen J, Gomez-Sanchez CE, Penman A, May PJ, Gomez-Sanchez E. Expression of mineralocorticoid and glucocorticoid receptors in preautonomic neurons of the rat paraventricular nucleus. Am J Physiol Regul Integr Comp Physiol 2014; 306:R328-40. [PMID: 24381176 PMCID: PMC3949076 DOI: 10.1152/ajpregu.00506.2013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 12/23/2013] [Indexed: 01/12/2023]
Abstract
Activation of mineralocorticoid receptors (MR) of the hypothalamic paraventricular nucleus (PVN) increases sympathetic excitation. To determine whether MR and glucocorticoid receptors (GR) are expressed in preautonomic neurons of the PVN and how they relate to endogenous aldosterone levels in healthy rats, retrograde tracer was injected into the intermediolateral cell column at T4 to identify preautonomic neurons in the PVN. Expression of MR, GR, 11-β hydroxysteroid dehydrogenase1 and 2 (11β-HSD1, 2), and hexose-6-phosphate dehydrogenase (H6PD) required for 11β-HSD1 reductase activity was assessed by immunohistochemistry. RT-PCR and Western blot analysis were used to determine MR gene and protein expression. Most preautonomic neurons were in the caudal mediocellular region of PVN, and most expressed MR; none expressed GR. 11β-HSD1, but not 11β-HSD2 nor H6PD immunoreactivity, was detected in the PVN. In rats with chronic low or high sodium intakes, the low-sodium diet was associated with significantly higher plasma aldosterone, MR mRNA and protein expression, and c-Fos immunoreactivity within labeled preautonomic neurons. Plasma corticosterone and sodium and expression of tonicity-responsive enhancer binding protein in the PVN did not differ between groups, suggesting osmotic adaptation to the altered sodium intake. These results suggest that MR within preautonomic neurons in the PVN directly participate in the regulation of sympathetic nervous system drive, and aldosterone may be a relevant ligand for MR in preautonomic neurons of the PVN under physiological conditions. Dehydrogenase activity of 11β-HSD1 occurs in the absence of H6PD, which regenerates NADP(+) from NADPH and may increase MR gene expression under physiological conditions.
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Affiliation(s)
- Jian Chen
- Department of Neurobiology and Anatomical Science, University of Mississippi Medical Center, Jackson, Mississippi
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27
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Abstract
SIGNIFICANCE There is now compelling evidence to substantiate the notion that by depressing baroreflex regulation of blood pressure and augmenting central sympathetic outflow through their actions on the nucleus tractus solitarii (NTS) and rostral ventrolateral medulla (RVLM), brain stem nitric oxide synthase (NOS) and reactive oxygen species (ROS) are important contributing factors to neural mechanisms of hypertension. This review summarizes our contemporary views on the impact of NOS and ROS in the NTS and RVLM on neurogenic hypertension, and presents potential antihypertensive strategies that target brain stem NOS/ROS signaling. RECENT ADVANCES NO signaling in the brain stem may be pro- or antihypertensive depending on the NOS isoform that generates this gaseous moiety and the site of action. Elevation of the ROS level when its production overbalances its degradation in the NTS and RVLM underlies neurogenic hypertension. Interventional strategies with emphases on alleviating the adverse actions of these molecules on blood pressure regulation have been investigated. CRITICAL ISSUES The pathological roles of NOS in the RVLM and NTS in neural mechanisms of hypertension are highly complex. Likewise, multiple signaling pathways underlie the deleterious roles of brain-stem ROS in neurogenic hypertension. There are recent indications that interactions between brain stem ROS and NOS may play a contributory role. FUTURE DIRECTIONS Given the complicity of action mechanisms of brain-stem NOS and ROS in neural mechanisms of hypertension, additional studies are needed to identify the most crucial therapeutic target that is applicable not only in animal models but also in patients suffering from neurogenic hypertension.
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Affiliation(s)
- Samuel H H Chan
- Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital , Kaohsiung, Taiwan, Republic of China
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Xu W, Cao M, Zheng H, Tan X, Li L, Cui G, Xu J, Cao J, Ke K, Wu Q. Upregulation of SYF2 is associated with neuronal apoptosis caused by reactive astrogliosis to neuroinflammation. J Neurosci Res 2013; 92:318-28. [PMID: 24301298 DOI: 10.1002/jnr.23312] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 09/17/2013] [Accepted: 09/17/2013] [Indexed: 12/27/2022]
Abstract
SYF2, known as CCNDBP1-interactor or p29, is likely involved in pre-mRNA splicing and cell cycle progression. The present study was designed to elucidate dynamic changes in SYF2 expression and distribution in the cerebral cortex in a lipopolysaccharide (LPS)-induced neuroinflammation rat model. It was found that SYF2 expression was induced strongly in active astrocytes after LPS injection. In vitro studies showed that the upregulation of SYF2 might be involved in the activation of C6 cells after LPS challenge and the neuronal apoptosis after conditioned media challenge. In addition, with silencing of SYF2 in C6 and PC12 cells by siRNA, the results indicated that SYF2 was required for astrocyte activation and neuronal apoptosis induced by LPS. Our findings on the cellular signaling pathway may provide a new therapeutic strategy against neuroinflammation in the CNS.
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Affiliation(s)
- Wei Xu
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, China
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Abstract
Statins (3-hydroxy-3-methylglutaryl-CoA reductase inhibitors) reduce plasma cholesterol and improve endothelium-dependent vasodilation, inflammation and oxidative stress. A ‘pleiotropic’ property of statins receiving less attention is their effect on the autonomic nervous system. Increased central sympathetic outflow and diminished cardiac vagal tone are disturbances characteristic of a range of cardiovascular conditions for which statins are now prescribed routinely to reduce cardiovascular events: following myocardial infarction, and in hypertension, chronic kidney disease, heart failure and diabetes. The purpose of the present review is to synthesize contemporary evidence that statins can improve autonomic circulatory regulation. In experimental preparations, high-dose lipophilic statins have been shown to reduce adrenergic outflow by attenuating oxidative stress in central brain regions involved in sympathetic and parasympathetic discharge induction and modulation. In patients with hypertension, chronic kidney disease and heart failure, lipophilic statins, such as simvastatin or atorvastatin, have been shown to reduce MNSA (muscle sympathetic nerve activity) by 12–30%. Reports concerning the effect of statin therapy on HRV (heart rate variability) are less consistent. Because of their implications for BP (blood pressure) control, insulin sensitivity, arrhythmogenesis and sudden cardiac death, these autonomic nervous system actions should be considered additional mechanisms by which statins lower cardiovascular risk.
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Chan SHH, Chan JYH. Angiotensin-generated reactive oxygen species in brain and pathogenesis of cardiovascular diseases. Antioxid Redox Signal 2013; 19:1074-84. [PMID: 22429119 DOI: 10.1089/ars.2012.4585] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
SIGNIFICANCE Overproduction of angiotensin II (Ang II) in brain contributes to the pathogenesis of cardiovascular diseases. One of the most promising theses that emerged during the last decade is that production of reactive oxygen species (ROS) and activation of redox-dependent signaling cascades underlie those Ang II actions. This review summarizes our status of understanding on the roles of ROS and redox-sensitive signaling in brain Ang II-dependent cardiovascular diseases, using hypertension and heart failure as illustrative examples. RECENT ADVANCES ROS generated by NADPH oxidase, mitochondrial electron transport chain, and proinflammatory cytokines activates mitogen-activated protein kinases and transcription factors, which in turn modulate ion channel functions and ultimately increase neuronal activity and sympathetic outflow in brain Ang II-dependent cardiovascular diseases. Antioxidants targeting ROS have been demonstrated to be beneficial to Ang II-induced hypertension and heart failure via protection from oxidative stress in brain regions that subserve cardiovascular regulation. CRITICAL ISSUES Intra-neuronal signaling and the downstream redox-sensitive proteins involved in controlling the neuronal discharge rate, the sympathetic outflow, and the pathogenesis of cardiovascular diseases need to be identified. The cross talk between Ang II-induced oxidative stress and neuroinflammation in neural mechanisms of cardiovascular diseases also warrants further elucidation. FUTURE DIRECTIONS Future studies are needed to identify new redox-based therapeutics that work not only in animal models, but also in patients suffering from the prevalent diseases. Upregulation of endogenous antioxidants in the regulation of ROS homeostasis is a potential therapeutic target, as are small molecule- or nanoformulated conjugate-based antioxidant therapy.
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Affiliation(s)
- Samuel H H Chan
- Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital , Kaohsiung, Taiwan, Republic of China
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The expression pattern of Nischarin after lipopolysaccharides (LPS)-induced neuroinflammation in rats brain cortex. Inflamm Res 2013; 62:929-40. [PMID: 24064952 DOI: 10.1007/s00011-013-0631-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 04/02/2013] [Accepted: 04/30/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVE To investigate whether Nischarin participated in neuronal apoptosis induced by neuroinflammation and via the phosphatidylinositol 3-kinase (PI3K) and PKB-dependent pathway. MATERIAL Use of male Sprague-Dawley rats, rat pheochromocytoma (PC12), and murine microglial cells (BV-2). Treatment lipopolysaccharides (LPS) were injected into the brain lateral ventricle of the rat. The BV-2 cells were treated by LPS. The PC12 cells were pretreated by or not pretreated by conditioned media and siRNA. METHODS Western blotting was used for analyzing the expression level of Nischarin, pAKT, BAD and Bcl-2. Immunohistochemistry and immunofluorescence were used to perform the morphology and localization of Nischarin. The siRNA could down-regulate the protein level of endogenous Nischarin. RESULTS The expression level of Nischarin was elevated after LPS injection; meanwhile, Nischarin was located in the neuron. Nischarin was involved in regulating the PI3K/PKB patway. CONCLUSION Nischarin might be involved in mediating the process of PI3K/PKB pathway-dependent neuronal apoptosis. After the silencing of Nischarin in cultured PC12 (pheochromocytoma) by siRNA, these results showed that it would induce a reduction of pAKT and Bcl-2 proteins expression; meanwhile, it induces an increase of BAD and active caspase-3.
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Ogawa K, Hirooka Y, Kishi T, Ide T, Sunagawa K. Partially silencing brain toll-like receptor 4 prevents in part left ventricular remodeling with sympathoinhibition in rats with myocardial infarction-induced heart failure. PLoS One 2013; 8:e69053. [PMID: 23874864 PMCID: PMC3706428 DOI: 10.1371/journal.pone.0069053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 06/04/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Left ventricular (LV) remodeling and activation of sympathetic nervous system (SNS) are cardinal features of heart failure. We previously demonstrated that enhanced central sympathetic outflow is associated with brain toll-like receptor 4 (TLR4) probably mediated by brain angiotensin II type 1 receptor in mice with myocardial infarction (MI)-induced heart failure. The purpose of the present study was to examine whether silencing brain TLR4 could prevent LV remodeling with sympathoinhibition in MI-induced heart failure. METHODOLOGY/PRINCIPAL FINDINGS MI-induced heart failure model rats were created by ligation of left coronary artery. The expression level of TLR4 in brainstem was significantly higher in MI-induced heart failure treated with intracerebroventricular (ICV) injection of hGAPDH-SiRNA than in sham. TLR4 in brainstem was significantly lower in MI-induced heart failure treated with ICV injection of TLR4-SiRNA than in that treated with ICV injection of hGAPDH-SiRNA. Lung weight, urinary norepinephrine excretion, and LV end-diastolic pressure were significantly lower and LV dimension was significantly smaller in MI-induced heart failure treated with TLR4-SiRNA than in that treated with hGAPDH-SiRNA for 2 weeks. CONCLUSIONS Partially silencing brain TLR4 by ICV injection of TLR4-SiRNA for 2 weeks could in part prevent LV remodeling with sympathoinhibition in rats with MI-induced heart failure. Brain TLR4 has a potential to be a target of the treatment for MI-induced heart failure.
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Affiliation(s)
- Kiyohiro Ogawa
- Departments of Cardiovascular Medicine, Kyushu University Graduate School of Medical Science, Fukuoka, Japan
| | - Yoshitaka Hirooka
- Advanced Cardiovascular Regulation and Therapeutics, Kyushu University Graduate School of Medical Science, Fukuoka, Japan
- * E-mail:
| | - Takuya Kishi
- Advanced Therapeutics for Cardiovascular Diseases, Kyushu University Graduate School of Medical Science, Fukuoka, Japan
| | - Tomomi Ide
- Departments of Cardiovascular Medicine, Kyushu University Graduate School of Medical Science, Fukuoka, Japan
| | - Kenji Sunagawa
- Departments of Cardiovascular Medicine, Kyushu University Graduate School of Medical Science, Fukuoka, Japan
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Resveratrol and grape juice differentially ameliorate cardiovascular autonomic modulation in L-NAME-treated rats. Auton Neurosci 2013; 179:9-13. [PMID: 23810687 DOI: 10.1016/j.autneu.2013.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 06/05/2013] [Accepted: 06/10/2013] [Indexed: 11/21/2022]
Abstract
Polyphenols consumption detected in red wine and grape juice may prevent or help in the treatment of hypertension. However, cardiovascular autonomic effects of polyphenols were poorly studied. Therefore, we evaluated the effects of resveratrol and grape juice treatments in hemodynamics, baroreflex sensitivity, heart rate (HR) and blood pressure (BP) variability and cardiac redox parameters. Male Wistar rats were divided in 3 groups (n=7/each) and treated for 30 days: only L-NAME-treated (60 mg/kg/day by oral gavage), L-NAME+resveratrol (L-NAME+R) and L-NAME+grape juice (L-NAME+G). BP signal was directly recorded and pulse interval (PI) and systolic arterial pressure (SAP) variability were analyzed in time and frequency domains. Baroreflex sensitivity (BRS) was determined by the alpha index. Oxidized and reduced glutathione concentrations were determined in cardiac tissue. L-NAME increased BP with no differences among groups (mean BP: L-NAME=124±4, L-NAME+R=126±3 and L-NAME+G=125±4 mmHg). PI and SAP variability expressed by total variance were also similar among groups. However, normalized low frequency (LF) and high frequency (HF) components of PI variability were lower and higher, respectively, in both R and G-treated groups when compared to only L-NAME group. Interestingly, sympathetic modulation to the vessels (LF from SAP variability) and BRS were decreased and increased, respectively, only in L-NAME+R rats. Additionally, GSH/GSSG ratios were higher in L-NAME+R and L-NAME+G than in L-NAME group. Our results indicate that resveratrol and grape juice treatments can modulate autonomic function and promote cardiac redox benefits even when nitric oxide is decreased. Moreover, resveratrol influences not only cardiac but also vascular autonomic modulation.
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Kreutmayer S, Csordas A, Kern J, Maass V, Almanzar G, Offterdinger M, Öllinger R, Maass M, Wick G. Chlamydia pneumoniae infection acts as an endothelial stressor with the potential to initiate the earliest heat shock protein 60-dependent inflammatory stage of atherosclerosis. Cell Stress Chaperones 2013; 18:259-68. [PMID: 23192457 PMCID: PMC3631098 DOI: 10.1007/s12192-012-0378-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Revised: 10/01/2012] [Accepted: 10/02/2012] [Indexed: 12/21/2022] Open
Abstract
We identified increased expression and redistribution of the intracellular protein 60-kDa human heat shock protein (hHSP60) (HSPD1) to the cell surface in human endothelial cells subjected to classical atherosclerosis risk factors and subsequent immunologic cross-reactivity against this highly conserved molecule, as key events occurring early in the process of atherosclerosis. The present study aimed at investigating the role of infectious pathogens as stress factors for vascular endothelial cells and, as such, contributors to early atherosclerotic lesion formation. Using primary donor-matched arterial and venous human endothelial cells, we show that infection with Chlamydia pneumoniae leads to marked upregulation and surface expression of hHSP60 and adhesion molecules. Moreover, we provide evidence for an increased susceptibility of arterial endothelial cells for redistribution of hHSP60 to the cellular membrane in response to C. pneumoniae infection as compared to autologous venous endothelial cells. We also show that oxidative stress has a central role to play in endothelial cell activation in response to chlamydial infection. These data provide evidence for a role of C. pneumoniae as a potent primary endothelial stressor for arterial endothelial cells leading to enrichment of hHSP60 on the cellular membrane and, as such, a potential initiator of atherosclerosis.
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Affiliation(s)
- Simone Kreutmayer
- />Laboratory of Autoimmunity, Division of Experimental Pathophysiology and Immunology, Biocenter, Innsbruck Medical University, Peter-Mayr Strasse 4a, 6020 Innsbruck, Austria
| | - Adam Csordas
- />Laboratory of Autoimmunity, Division of Experimental Pathophysiology and Immunology, Biocenter, Innsbruck Medical University, Peter-Mayr Strasse 4a, 6020 Innsbruck, Austria
- />Division of Cardiac and Vascular Surgery, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Jan Kern
- />Institute of Medical Microbiology, Hygiene and Infectious Diseases, Paracelsus Medical Private University of Salzburg, Salzburg, Austria
| | - Viola Maass
- />Institute of Medical Microbiology, Hygiene and Infectious Diseases, Paracelsus Medical Private University of Salzburg, Salzburg, Austria
| | - Giovanni Almanzar
- />Laboratory of Autoimmunity, Division of Experimental Pathophysiology and Immunology, Biocenter, Innsbruck Medical University, Peter-Mayr Strasse 4a, 6020 Innsbruck, Austria
| | - Martin Offterdinger
- />Biooptics Facility, Division of Neurobiochemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Robert Öllinger
- />Division of Visceral, Transplant and Thorax Surgery, Innsbruck Medical University, Innsbruck, Austria
| | - Matthias Maass
- />Institute of Medical Microbiology, Hygiene and Infectious Diseases, Paracelsus Medical Private University of Salzburg, Salzburg, Austria
| | - Georg Wick
- />Laboratory of Autoimmunity, Division of Experimental Pathophysiology and Immunology, Biocenter, Innsbruck Medical University, Peter-Mayr Strasse 4a, 6020 Innsbruck, Austria
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Van de Bittner GC, Bertozzi CR, Chang CJ. Strategy for dual-analyte luciferin imaging: in vivo bioluminescence detection of hydrogen peroxide and caspase activity in a murine model of acute inflammation. J Am Chem Soc 2013; 135:1783-95. [PMID: 23347279 PMCID: PMC3583381 DOI: 10.1021/ja309078t] [Citation(s) in RCA: 221] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In vivo molecular imaging holds promise for understanding the underlying mechanisms of health, injury, aging, and disease, as it can detect distinct biochemical processes such as enzymatic activity, reactive small-molecule fluxes, or post-translational modifications. Current imaging techniques often detect only a single biochemical process, but, within whole organisms, multiple types of biochemical events contribute to physiological and pathological phenotypes. In this report, we present a general strategy for dual-analyte detection in living animals that employs in situ formation of firefly luciferin from two complementary caged precursors that can be unmasked by different biochemical processes. To establish this approach, we have developed Peroxy Caged Luciferin-2 (PCL-2), a H(2)O(2)-responsive boronic acid probe that releases 6-hydroxy-2-cyanobenzothiazole (HCBT) upon reacting with this reactive oxygen species, as well as a peptide-based probe, z-Ile-Glu-ThrAsp-D-Cys (IETDC), which releases D-cysteine in the presence of active caspase 8. Once released, HCBT and D-cysteine form firefly luciferin in situ, giving rise to a bioluminescent signal if and only if both chemical triggers proceed. This system thus constitutes an AND-type molecular logic gate that reports on the simultaneous presence of H(2)O(2) and caspase 8 activity. Using these probes, chemoselective imaging of either H(2)O(2) or caspase 8 activity was performed in vitro and in vivo. Moreover, concomitant use of PCL-2 and IETDC in vivo establishes a concurrent increase in both H(2)O(2) and caspase 8 activity during acute inflammation in living mice. Taken together, this method offers a potentially powerful new chemical tool for studying simultaneous oxidative stress and inflammation processes in living animals during injury, aging, and disease, as well as a versatile approach for concurrent monitoring of multiple analytes using luciferin-based bioluminescence imaging technologies.
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Affiliation(s)
| | - Carolyn R. Bertozzi
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, United States
| | - Christopher J. Chang
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, United States
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Al-Saffar H, Lewis K, Liu E, Schober A, Corrigan JJ, Shibata K, Steiner AA. Lipopolysaccharide-induced hypothermia and hypotension are associated with inflammatory signaling that is triggered outside the brain. Brain Behav Immun 2013. [PMID: 23207106 DOI: 10.1016/j.bbi.2012.11.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Little is known about the neuroimmune mechanisms responsible for the switch from fever to hypothermia observed in severe forms of systemic inflammation. We evaluated whether bacterial lipopolysaccharide (LPS) acting directly on the brain could promote a fever-hypothermia switch as well as the hypotension that is often associated with hypothermia in models of systemic inflammation. At an ambient temperature of 22°C, freely moving rats received intracerebroventricular (i.c.v.) injections of LPS at doses ranging from 0.5 to 25μg. Despite the use of such high doses, the prevailing thermal response was fever. To investigate if a hypothermic response could be hidden within the prevailing febrile response, rats were pretreated with a cyclooxygenase-2 inhibitor (SC-236, 3.5mg/kg i.v.) known to block fever, but this strategy also failed to reveal any consistent hypothermic response following i.c.v. LPS. At the doses tested, i.c.v. LPS was similarly ineffective at inducing hypotension. Additional doses of LPS did not need to be tested because the 25-μg dose was already sufficient to induce both hypothermia and hypotension when administered peripherally (intra-arterially). An empirical 3D model of the interplay among body temperature, arterial pressure and heart rate following intra-arterial LPS reinforced the strong association of hypothermia with hypotension and, at the same time, exposed a bell-shaped relationship between heart rate and body temperature. In summary, the present study demonstrates that hypothermia and hypotension are triggered exclusively by LPS acting outside the brain and provides an integrated model of the thermal and cardiovascular responses to peripheral LPS.
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Affiliation(s)
- Hiba Al-Saffar
- Albany College of Pharmacy and Health Sciences, Albany, NY, USA
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Manner IW, Baekken M, Kvale D, Oektedalen O, Pedersen M, Nielsen SD, Nowak P, Os I, Trøseid M. Markers of microbial translocation predict hypertension in HIV-infected individuals. HIV Med 2013; 14:354-61. [PMID: 23332095 DOI: 10.1111/hiv.12015] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2012] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The aim of the study was to test the hypothesis that microbial translocation, quantified by levels of lipopolysaccharide (LPS) and subsequent monocyte activation [soluble (sCD14)], is associated with hypertension in HIV-infected individuals. METHODS In this exploratory substudy, 42 patients were recruited from a larger, longitudinal HIV-infected cohort study on blood pressure. LPS and sCD14 levels were measured retrospectively at the time of nadir CD4 cell count, selecting untreated HIV-infected patients with both advanced immunodeficiency and preserved immunocompetence at the time of nadir. Patients with later sustained hypertension (n = 16) or normotension (n = 26) throughout the study were identified. LPS was analysed using the Limulus Amebocyte Lysate colorimetric assay (Lonza, Walkersville, MD) and sCD14 using an enzyme-linked immunosorbent assay (ELISA). Nonparametric statistical tests were applied. RESULTS In the HIV-infected patients [median (interquartile range) age 42 (32-46) years; 79% male and 81% Caucasian], LPS and sCD14 levels were both negatively correlated with nadir CD4 cell count. Plasma levels of LPS (P < 0.001) and sCD14 (P = 0.024) were elevated in patients with later hypertension compared with patients with normotension. There was a stepwise increase in the number of patients with hypertension across tertiles of LPS (P = 0.001) and sCD14 (P = 0.007). Both LPS and sCD14 were independent predictors of elevated blood pressure after adjustment for age and gender. For each 10-unit increase in LPS (range 66-272 pg/ml), the increment in mean blood pressure in the first period of blood pressure recording was 0.86 (95% confidence interval 0.31-1.41) mmHg (P = 0.003). CONCLUSIONS As LPS and sCD14 were both independently associated with elevated blood pressure, microbial translocation may be linked to the development of hypertension.
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Affiliation(s)
- I W Manner
- Department of Nephrology, Oslo University Hospital, Oslo, Norway
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Therapeutic role of toll-like receptor modification in cardiovascular dysfunction. Vascul Pharmacol 2012; 58:231-9. [PMID: 23070056 DOI: 10.1016/j.vph.2012.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/28/2012] [Accepted: 10/05/2012] [Indexed: 01/04/2023]
Abstract
Toll-like receptors (TLR) are key pattern recognition receptors in the innate immune system. The TLR-mediated immune response against pathogens is usually protective however inappropriate TLR activation may lead to excessive tissue damage. It is well recognised that TLRs respond to a variety of endogenous as well as exogenous ligands. By responding to endogenous ligands that are exposed during cellular damage, TLRs have been implicated in a range of pathological conditions associated with cardiovascular dysfunction. Increasing knowledge on the mechanisms involved in TLR signalling has encouraged the exploration of therapeutic pharmacological modulation of TLR activation in conditions such as atherosclerosis, ischaemic heart disease, heart failure and ischaemic reperfusion injury. The aim of this review is to explore the translational potentials of TLR modification in cardiovascular dysfunction, where these agents have been studied.
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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: 139] [Impact Index Per Article: 11.6] [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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Pang T, Wang J, Benicky J, Sánchez-Lemus E, Saavedra JM. Telmisartan directly ameliorates the neuronal inflammatory response to IL-1β partly through the JNK/c-Jun and NADPH oxidase pathways. J Neuroinflammation 2012; 9:102. [PMID: 22642771 PMCID: PMC3410820 DOI: 10.1186/1742-2094-9-102] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 05/29/2012] [Indexed: 12/18/2022] Open
Abstract
Background Blockade of angiotensin II type 1 (AT1) receptors ameliorates brain inflammation, and reduces excessive brain interleukin-1 beta (IL-1β) production and release from cortical microglia. The aim of this study was to determine whether, in addition, AT1 receptor blockade directly attenuates IL-1β-induced inflammatory responses in neuronal cultures. Methods SK-N-SH human neuroblasts and primary rat cortical neurons were pretreated with telmisartan followed by exposure to IL-1β. Gene expression was determined by reverse transcriptase (RT)-PCR, protein expression and kinase activation by western blotting, NADPH oxidase activity by the lucigenin method, prostaglandin E2 (PGE2) release by enzyme immunoassay, reactive oxygen species (ROS) generation by the dichlorodihydrofluorescein diacetate fluorescent probe assay, and peroxisome proliferator-activated receptor gamma (PPARγ) involvement was assessed with the antagonists GW9662 and T0070907, the agonist pioglitazone and the expression of PPARγ target genes ABCG1 and CD36. Results We found that SK-N-SH neuroblasts expressed AT1 but not AT2 receptor mRNA. Telmisartan reduced IL-1β-induced cyclooxygenase-2 (COX-2) expression and PGE2 release more potently than did candesartan and losartan. Telmisartan reduced the IL-1β-induced increase in IL-1R1 receptor and NADPH oxidase-4 (NOX-4) mRNA expression, NADPH oxidase activity, and ROS generation, and reduced hydrogen peroxide-induced COX-2 gene expression. Telmisartan did not modify IL-1β-induced ERK1/2 and p38 mitogen-activated protein kinase (MAPK) phosphorylation or nuclear factor-κB activation but significantly decreased IL-1β-induced c-Jun N-terminal kinase (JNK) and c-Jun activation. The JNK inhibitor SP600125 decreased IL-1β-induced PGE2 release with a potency similar to that of telmisartan. The PPARγ agonist pioglitazone reduced IL-1β-induced inflammatory reaction, whereas telmisartan did not activate PPARγ, as shown by its failure to enhance the expression of the PPARγ target genes ABCG1 and CD36, and the inability of the PPARγ antagonists GW9662 and T0070907 to modify the effect of telmisartan on COX-2 induction. The effect of telmisartan on IL-1β-stimulated COX-2 and IL-1R1 mRNA expression and ROS production was replicated in primary rat cortical neurons. Conclusions Telmisartan directly ameliorates IL-1β-induced neuronal inflammatory response by inhibition of oxidative stress and the JNK/c-Jun pathway. Our results support the hypothesis that AT1 receptor blockers are directly neuroprotective, and should be considered for the treatment of inflammatory conditions of the brain.
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Affiliation(s)
- Tao Pang
- Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Section on Pharmacology, NIMH, NIH, DHHS, 10 Center Drive, Bldg, 10, Room # 2D-57, Bethesda, MD, 20892, USA.
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Abstract
The hypothalamus is one of the master regulators of various physiological processes, including energy balance and nutrient metabolism. These regulatory functions are mediated by discrete hypothalamic regions that integrate metabolic sensing with neuroendocrine and neural controls of systemic physiology. Neurons and nonneuronal cells in these hypothalamic regions act supportively to execute metabolic regulations. Under conditions of brain and hypothalamic inflammation, which may result from overnutrition-induced intracellular stresses or disease-associated systemic inflammatory factors, extracellular and intracellular environments of hypothalamic cells are disrupted, leading to central metabolic dysregulations and various diseases. Recent research has begun to elucidate the effects of hypothalamic inflammation in causing diverse components of metabolic syndrome leading to diabetes and cardiovascular disease. These new understandings have provocatively expanded previous knowledge on the cachectic roles of brain inflammatory response in diseases, such as infections and cancers. This review describes the molecular and cellular characteristics of hypothalamic inflammation in metabolic syndrome and related diseases as opposed to cachectic diseases, and also discusses concepts and potential applications of inhibiting central/hypothalamic inflammation to treat nutritional diseases.
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Affiliation(s)
- Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Angiotensin II AT1 receptor blocker candesartan prevents the fast up-regulation of cerebrocortical benzodiazepine-1 receptors induced by acute inflammatory and restraint stress. Behav Brain Res 2012; 232:84-92. [PMID: 22503782 DOI: 10.1016/j.bbr.2012.03.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 03/23/2012] [Accepted: 03/28/2012] [Indexed: 01/12/2023]
Abstract
Centrally acting Angiotensin II AT(1) receptor blockers (ARBs) protect from stress-induced disorders and decrease anxiety in a model of inflammatory stress, the systemic injection of bacterial endotoxin lipopolysaccharide (LPS). In order to better understand the anxiolytic effect of ARBs, we treated rats with LPS (50 μg/kg) with or without 3 days of pretreatment with the ARB candesartan (1mg/kg/day), and studied cortical benzodiazepine (BZ) and corticotrophin-releasing factor (CRF) receptors. We compared the cortical BZ and CRF receptors expression pattern induced by LPS with that produced in restraint stress. Inflammation stress produced a generalized increase in cortical BZ(1) receptors and reduced mRNA expression of the GABA(A) receptor γ(2) subunit in cingulate cortex; changes were prevented by candesartan pretreatment. Moreover, restraint stress produced similar increases in cortical BZ(1) receptor binding, and candesartan prevented these changes. Treatment with candesartan alone increased cortical BZ(1) binding, and decreased γ(2) subunit mRNA expression in the cingulate cortex. Conversely, we did not find changes in CRF(1) receptor expression in any of the cortical areas studied, either after inflammation or restraint stress. Cortical CRF(2) receptor binding was undetectable, but CRF(2) mRNA expression was decreased by inflammation stress, a change prevented by candesartan. We conclude that stress promotes rapid and widespread changes in cortical BZ(1) receptor expression; and that the stress-induced BZ(1) receptor expression is under the control of AT(1) receptor activity. The results suggest that the anti-anxiety effect of ARBs may be associated with their capacity to regulate stress-induced alterations in cortical BZ(1) receptors.
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Gomez-Sanchez EP, Gomez-Sanchez CE. Central regulation of blood pressure by the mineralocorticoid receptor. Mol Cell Endocrinol 2012; 350:289-98. [PMID: 21664417 PMCID: PMC3189429 DOI: 10.1016/j.mce.2011.05.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 05/19/2011] [Accepted: 05/22/2011] [Indexed: 12/30/2022]
Abstract
Addition of mineralocorticoid receptor (MR) antagonists to standard therapy for heart failure, kidney disease, metabolic syndrome, and diabetes is increasing steadily in response to clinical trials demonstrating clear benefits. In addition to blocking deleterious activity of MR within the heart, vessels and kidneys, MR antagonists target MR in hemodynamic regulatory centers in the brain, thereby decreasing excessive sympathetic nervous system drive, vasopressin release, abnormal baroreceptor function, and circulating and tissue pro-inflammatory cytokines. However, brain MR are also involved with cognition, memory, affect and functions yet to be determined. Understanding specific central mechanisms involved in blood pressure regulation by MR is necessary for the development of agents to target downstream events specific to central hemodynamic regulation, not only to avoid the hypokalemia caused by inhibition of renal tubular MR, but also to avoid untoward long term effects of inhibiting brain MR that are not involved in blood pressure control.
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Affiliation(s)
- Elise P Gomez-Sanchez
- Research Service, G.V. (Sonny) Montgomery VA Medical Center, 1500 Woodrow Wilson Dr., Jackson, MS 39216, USA.
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Zhang ZH, Yu Y, Wei SG, Felder RB. Aldosterone-induced brain MAPK signaling and sympathetic excitation are angiotensin II type-1 receptor dependent. Am J Physiol Heart Circ Physiol 2011; 302:H742-51. [PMID: 22081704 DOI: 10.1152/ajpheart.00856.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Angiotensin II (ANG II)-induced mitogen-activated protein kinase (MAPK) signaling upregulates angiotensin II type-1 receptors (AT(1)R) in hypothalamic paraventricular nucleus (PVN) and contributes to AT(1)R-mediated sympathetic excitation in heart failure. Aldosterone has similar effects to increase AT(1)R expression in the PVN and sympathetic drive. The present study was undertaken to determine whether aldosterone also activates the sympathetic nervous system via MAPK signaling and, if so, whether its effect is independent of ANG II and AT(1)R. In anesthetized rats, a 4-h intravenous infusion of aldosterone induced increases (P < 0.05) in phosphorylated (p-) p44/42 MAPK in PVN, PVN neuronal excitation, renal sympathetic nerve activity (RSNA), mean blood pressure (MBP), and heart rate (HR). Intracerebroventricular or bilateral PVN microinjection of the p44/42 MAPK inhibitor PD-98059 reduced the aldosterone-induced RSNA, HR, and MBP responses. Intracerebroventricular pretreatment (5 days earlier) with pooled small interfering RNAs targeting p44/42 MAPK reduced total and p-p44/42 MAPK, aldosterone-induced c-Fos expression in the PVN, and the aldosterone-induced increases in RSNA, HR, and MBP. Intracerebroventricular infusion of either the mineralocorticoid receptor antagonist RU-28318 or the AT(1)R antagonist losartan blocked aldosterone-induced phosphorylation of p44/42 MAPK and prevented the increases in RSNA, HR, and MBP. These data suggest that aldosterone-induced sympathetic excitation depends upon that AT(1)R-induced MAPK signaling in the brain. The short time course of this interaction suggests a nongenomic mechanism, perhaps via an aldosterone-induced transactivation of the AT(1)R as described in peripheral tissues.
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Affiliation(s)
- Zhi-Hua Zhang
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, owa City, IA52242, USA.
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Brain AT1 Receptor Activates the Sympathetic Nervous System Through Toll-like Receptor 4 in Mice With Heart Failure. J Cardiovasc Pharmacol 2011; 58:543-9. [DOI: 10.1097/fjc.0b013e31822e6b40] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Zhang ZH, Yu Y, Wei SG, Nakamura Y, Nakamura K, Felder RB. EP₃ receptors mediate PGE₂-induced hypothalamic paraventricular nucleus excitation and sympathetic activation. Am J Physiol Heart Circ Physiol 2011; 301:H1559-69. [PMID: 21803943 DOI: 10.1152/ajpheart.00262.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Prostaglandin E(2) (PGE(2)), an important mediator of the inflammatory response, acts centrally to elicit sympathetic excitation. PGE(2) acts on at least four E-class prostanoid (EP) receptors known as EP(1), EP(2), EP(3), and EP(4). Since PGE(2) production within the brain is ubiquitous, the different functions of PGE(2) depend on the expression of these prostanoid receptors in specific brain areas. The type(s) and location(s) of the EP receptors that mediate sympathetic responses to central PGE(2) remain unknown. We examined this question using PGE(2), the relatively selective EP receptor agonists misoprostol and sulprostone, and the available selective antagonists for EP(1), EP(3), and EP(4). In urethane-anesthetized rats, intracerebroventricular (ICV) administration of PGE(2), sulprostone or misoprostol increased renal sympathetic nerve activity, blood pressure, and heart rate. These responses were significantly reduced by ICV pretreatment with the EP(3) receptor antagonist; the EP(1) and EP(4) receptor antagonists had little or no effect. ICV PGE(2) or misoprostol increased the discharge of neurons in the hypothalamic paraventricular nucleus (PVN). ICV misoprostol increased the c-Fos immunoreactivity of PVN neurons, an effect that was substantially reduced by the EP(3) receptor antagonist. Real-time PCR detected EP(3) receptor mRNA in PVN, and immunohistochemical studies revealed sparsely distributed EP(3) receptors localized in GABAergic terminals and on a few PVN neurons. Direct bilateral PVN microinjections of PGE(2) or sulprostone elicited sympathoexcitatory responses that were significantly reduced by the EP(3) receptor antagonist. These data suggest that EP(3) receptors mediate the central excitatory effects of PGE(2) on PVN neurons and sympathetic discharge.
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Affiliation(s)
- Zhi-Hua Zhang
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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Gomez-Sanchez EP. Mineralocorticoid receptors in the brain and cardiovascular regulation: minority rule? Trends Endocrinol Metab 2011; 22:179-87. [PMID: 21429762 PMCID: PMC3140534 DOI: 10.1016/j.tem.2011.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/28/2011] [Accepted: 02/02/2011] [Indexed: 01/05/2023]
Abstract
A small proportion of brain mineralocorticoid receptors (MR) mediate control of blood pressure, water and electrolyte balance, sodium appetite, and sympathetic drive to the periphery. Circulating inflammatory cytokines modulate MR-mediated changes in sympathoexcitation. Aldosterone binding to MR in the brain occurs, despite concentrations that are 2-3 orders of magnitude less than those of cortisol and corticosterone, which have similar affinity for the MR. The possible mechanisms for selective MR activation by aldosterone, the cellular mechanisms of MR action and the effects of brain MR on hemodynamic homeostasis are considered in this review. MR antagonists are valuable adjuncts to the treatment of chronic cardiovascular and renal disease; the crucial need to discover targets for development of selective therapy for specific MR functions is also discussed.
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Affiliation(s)
- Elise P Gomez-Sanchez
- Research Service, G.V. (Sonny) Montgomery VA Medical Center and Department of Medicine, Division of Endocrinology, The University of Mississippi Medical Center, Jackson, MO, USA.
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Nitescu N, Grimberg E, Guron G. Urotensin-II receptor antagonism does not improve renal haemodynamics or function in rats with endotoxin-induced acute kidney injury. Clin Exp Pharmacol Physiol 2011; 37:1170-5. [PMID: 20880186 DOI: 10.1111/j.1440-1681.2010.05449.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. Urotensin-II (U-II) is a vasoactive peptide that influences renal haemodynamics and kidney function. The aim of the present study was to examine the effects of the selective U-II receptor antagonist, urantide, on renal haemodynamics, oxygenation and function in endotoxaemic rats. 2. Endotoxaemia was induced in Sprague-Dawley rats by an intraperitoneal dose of lipopolysaccharide (LPS; Escherichia coli O127:B8, 7.5 mg/kg). At 16 h after endotoxin was given, renal clearance experiments were carried out in thiobutabarbital anaesthetized rats. Group 1, sham-saline; group 2, sham-urantide; group 3 LPS-saline; and group 4, LPS-urantide received isotonic saline or urantide (0.2 mg/kg bolus intravenously, followed by an infusion of 1.2 mg/kg/h throughout) after baseline measurements. Kidney function, renal blood flow (RBF), and cortical and outer medullary perfusion (laser-Doppler flowmetry) and oxygen tension (Clark-type microelectrodes) were analysed during 2 h of drug administration. 3. At baseline, endotoxaemic rats showed approximately 50% reductions in glomerular filtration rate (GFR) and RBF (P < 0.05), a decline in cortical and outer medullary perfusion and pO(2) (P < 0.05), and a significant increase in mean arterial pressure (MAP; P < 0.05) compared with saline-injected controls. In sham animals, urantide in a dose that did not significantly influence MAP or RBF, increased GFR (P < 0.05 time × treatment interaction) and filtration fraction (P < 0.05 treatment effect). However, urantide had no statistically significant effects on any of the investigated variables in endotoxaemic rats. 4. These findings show that U-II, through the UT receptor, does not contribute to abnormalities in renal haemodynamics and function in endotoxaemic rats.
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Affiliation(s)
- Nicoletta Nitescu
- Department of Anesthesiology and Intensive Care, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
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