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Ogier M, Bricca G, Bader M, Bezin L. Locus Coeruleus Dysfunction in Transgenic Rats with Low Brain Angiotensinogen. CNS Neurosci Ther 2016; 22:230-7. [PMID: 26775713 DOI: 10.1111/cns.12488] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/30/2015] [Accepted: 10/30/2015] [Indexed: 12/25/2022] Open
Abstract
AIMS Transgenic TGR(ASrAOGEN)680 (TGR) rats with specific downregulation of glial angiotensinogen (AOGEN) synthesis develop cardiovascular deficits, anxiety, altered response to stress, and depression. Here, we evaluated whether these deficits are associated with alteration of the integrity of the noradrenergic system originating from locus coeruleus (LC) neurons. METHODS Adult TGR rats were compared to control Sprague Dawley rats in terms of the following: tissue levels of transcripts encoding noradrenergic markers, tissue tyrosine hydroxylase (TH) protein level, in vivo TH activity, density of TH-containing fibers, behavioral response to novelty, locomotor activity, and polysomnography. RESULTS TH expression was increased in the LC of TGR rats compared to controls. In LC terminal fields, there was an increase in density of TH-containing fibers in TGR rats that was associated with an elevation of in vivo TH activity. TGR rats also displayed locomotor hyperactivity in response to novelty. Moreover, polysomnographic studies indicated that daily paradoxical sleep duration was increased in TGR rats and that the paradoxical sleep rebound triggered by total sleep deprivation was blunted in these rats. CONCLUSIONS Altogether, these results suggest that disruption of astroglial AOGEN synthesis leads to cardiovascular, cognitive, behavioral, and sleep disorders that might be partly due to LC dysfunction.
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Affiliation(s)
- Michael Ogier
- INSERM U1028, CNRS UMR5292, University Claude Bernard Lyon 1, Lyon Neuroscience Research Center, Team TIGER, Lyon, France.,Institute for Epilepsy, IDEE, Lyon, France.,French Armed Forces Biomedical Research Institute, Bretigny-sur-Orge, France
| | | | - Michael Bader
- Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Laurent Bezin
- INSERM U1028, CNRS UMR5292, University Claude Bernard Lyon 1, Lyon Neuroscience Research Center, Team TIGER, Lyon, France.,Institute for Epilepsy, IDEE, Lyon, France
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Shaltout HA, Chappell MC, Rose JC, Diz DI. Exaggerated sympathetic mediated responses to behavioral or pharmacological challenges following antenatal betamethasone exposure. Am J Physiol Endocrinol Metab 2011; 300:E979-85. [PMID: 21386063 PMCID: PMC3118588 DOI: 10.1152/ajpendo.00636.2010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Glucocorticoid administration to women at risk for preterm delivery is standard practice to enhance neonatal survival. However, antenatal betamethasone exposure (β-exposure) increases mean arterial pressure (MAP) in adult sheep (1.8 yr old) and results in impaired baroreflex sensitivity (BRS) for control of heart rate (HR). In the current studies we tested the hypothesis that enhanced sympathetic nervous system and hypothalamo-pituitary-adrenal (HPA) axis-mediated responses are evident at an early age in β-exposed sheep. Pregnant ewes were administered betamethasone (0.17 mg/kg twice over 24 h) or vehicle (Veh-control) on the 80th day of gestation, and offspring were delivered at full term. Female β-exposed and control offspring instrumented at age 42 ± 3 days for conscious continuous recording of MAP and HR had similar resting values at baseline. However, BRS was ~45% lower in β-exposed offspring. β-Exposed lambs allowed to suckle for 10 min had a greater elevation in MAP than Veh-control lambs (19 ± 1 vs 12 ± 2 mmHg; n = 4-5, P < 0.05). MAP was reduced by 20% from baseline via sodium nitroprusside infusion (SNP) over 10 min, which triggered a rebound increase in MAP only in β-exposed lambs. HR increased with the reduction in MAP during SNP infusion in Veh-control lambs, whereas there was no change in HR with the reduction in MAP in β-exposed lambs. Combined vasopressin-CRF injection caused greater increases in MAP in the β-exposed lambs. Cortisol and ACTH responses were higher in response to SNP hypotension in the β-exposed lambs. The data reveal enhanced sympathetic and HPA axis responses associated with impaired BRS preceding differences in resting MAP in preweanling female lambs exposed in utero to glucocorticoids. The consequences of these alterations at an early age include eventual development of higher blood pressure in this ovine model of fetal programming.
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Affiliation(s)
- Hossam A Shaltout
- Hypertension and Vascular Research Center, Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1032, USA.
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Grammatopoulos TN, Outeiro TF, Hyman BT, Standaert DG. Angiotensin II protects against alpha-synuclein toxicity and reduces protein aggregation in vitro. Biochem Biophys Res Commun 2007; 363:846-51. [PMID: 17900533 PMCID: PMC2707356 DOI: 10.1016/j.bbrc.2007.09.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Accepted: 09/13/2007] [Indexed: 11/20/2022]
Abstract
In this study, we examined the effects of angiotensin II (AngII) in a genetic in vitro PD model produced by alpha-synuclein (alpha-syn) overexpression in the human neuroglioma H4 cell line. We observed a maximal decrease in alpha-syn-induced toxicity of 85% and reduction in inclusion formation by 19% when cultures were treated with AngII in the presence of the angiotensin type 1 (AT1) receptor antagonist losartan and AT2 receptor antagonist PD123319. When compared to AngII, the AT4 receptor agonist AngIV was moderately effective in protecting H4 cells against alpha-syn toxicity and did not significantly reduce inclusion formation. Here we show that AngII is protective against genetic, as well as neurotoxic models of PD. These data support the view that agents acting on the renin-angiotensin-system (RAS) may be useful in the prevention and/or treatment of Parkinson's disease.
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Affiliation(s)
- Tom N Grammatopoulos
- MassGeneral Institute for Neurodegenerative Disease, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA.
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Grammatopoulos TN, Jones SM, Ahmadi FA, Hoover BR, Snell LD, Skoch J, Jhaveri VV, Poczobutt AM, Weyhenmeyer JA, Zawada WM. Angiotensin type 1 receptor antagonist losartan, reduces MPTP-induced degeneration of dopaminergic neurons in substantia nigra. Mol Neurodegener 2007; 2:1. [PMID: 17224059 PMCID: PMC1783655 DOI: 10.1186/1750-1326-2-1] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Accepted: 01/15/2007] [Indexed: 12/21/2022] Open
Abstract
Background Recent attention has focused on understanding the role of the brain-renin-angiotensin-system (RAS) in stroke and neurodegenerative diseases. Direct evidence of a role for the brain-RAS in Parkinson's disease (PD) comes from studies demonstrating the neuroprotective effect of RAS inhibitors in several neurotoxin based PD models. In this study, we show that an antagonist of the angiotensin II (Ang II) type 1 (AT1) receptor, losartan, protects dopaminergic (DA) neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity both in primary ventral mesencephalic (VM) cultures as well as in the substantia nigra pars compacta (SNpc) of C57BL/6 mice (Fig. 1). Results In the presence of exogenous Ang II, losartan reduced MPP+ (5 μM) induced DA neuronal loss by 72% in vitro. Mice challenged with MPTP showed a 62% reduction in the number of DA neurons in the SNpc and a 71% decrease in tyrosine hydroxylase (TH) immunostaining of the striatum, whereas daily treatment with losartan lessened MPTP-induced loss of DA neurons to 25% and reduced the decrease in striatal TH+ immunostaining to 34% of control. Conclusion Our study demonstrates that the brain-RAS plays an important neuroprotective role in the MPTP model of PD and points to AT1 receptor as a potential novel target for neuroprotection.
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Affiliation(s)
- Tom N Grammatopoulos
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
- Department of Pharmacology, University of Colorado at Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - Susan M Jones
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - Ferogh A Ahmadi
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
- Neuroscience Program, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - Brian R Hoover
- Department of Pharmacology, University of Colorado at Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - Lawrence D Snell
- Department of Pharmacology, University of Colorado at Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - Jesse Skoch
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - Vimal V Jhaveri
- Department of Pharmacology, University of Colorado at Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - Andy M Poczobutt
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
| | - James A Weyhenmeyer
- Department of Cell and Structural Biology, University of Illinois, Urbana, Illinois 61801, USA
| | - W Michael Zawada
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
- Neuroscience Program, Department of Medicine, Denver and Health Sciences Center, Denver, Colorado 80262, USA
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Maul B, Krause W, Pankow K, Becker M, Gembardt F, Alenina N, Walther T, Bader M, Siems WE. Central angiotensin II controls alcohol consumption via its AT1 receptor. FASEB J 2005; 19:1474-81. [PMID: 16126915 DOI: 10.1096/fj.05-3742com] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Pharmacological and genetic manipulations of the renin-angiotensin system (RAS) have been found to alter the voluntary consumption of alcohol. Here we characterize the role of central angiotensin II (Ang II) in alcohol intake first by using transgenic rats that express an antisense RNA against angiotensinogen and consequently have reduced Ang II levels exclusively in the central nervous system [TGR(ASrAOGEN)680]. These rats consumed markedly less alcohol in comparison to their wild-type controls. Second, Spirapril, an inhibitor of the angiotensin-converting enzyme (ACE), which passes the blood-brain barrier, did not influence the alcohol consumption in the TGR(ASrAOGEN)680, but it significantly reduced alcohol intake in wild-type rats. Studies in knockout mice indicated that the central effect of Ang II on alcohol consumption is mediated by the angiotensin receptor AT1 whereas the AT2 receptor and the bradykinin B2 receptor are not involved. Furthermore, the dopamine concentration in the ventral tegmental area (VTA) is markedly reduced in rats with low central Ang II, strengthening our hypothesis of a role of dopaminergic transmission in Ang II-controlled alcohol preference. Our results indicate that a distinct drug-mediated control of the central RAS could be a promising therapy for alcohol disease.
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Affiliation(s)
- Björn Maul
- Institute of Molecular Pharmacology, Berlin, Germany
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Abstract
Hypertension remains one of the largest human health problems, because hypertensive patients carry increased risk for ischemic heart disease, stroke, atherosclerosis, and renal failure. The renin-angiotensin system (RAS) has been intensively investigated for more than 100 years because it is a powerful regulator of blood pressure, and the antihypertensive benefits of RAS inhibitors are very clear. Despite a wealth of clinical and basic studies, the precise mechanisms by which the RAS regulates blood pressure remains incomplete. In this chapter, we review data demonstrating the existence and function of intrinsic tissue RAS, with a primary focus on the brain.
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Affiliation(s)
- Koji Sakai
- Departments of Internal Medicine and Physiology & Biophysics, 3181B Medical Education and Biomedical Research Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 52242 Iowa City, IA USA
| | - Curt D. Sigmund
- Departments of Internal Medicine and Physiology & Biophysics, 3181B Medical Education and Biomedical Research Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 52242 Iowa City, IA USA
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