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Keever MR, Zhang P, Bolt CR, Antonson AM, Rymut HE, Caputo MP, Houser AK, Hernandez AG, Southey BR, Rund LA, Johnson RW, Rodriguez-Zas SL. Lasting and Sex-Dependent Impact of Maternal Immune Activation on Molecular Pathways of the Amygdala. Front Neurosci 2020; 14:774. [PMID: 32848554 PMCID: PMC7431923 DOI: 10.3389/fnins.2020.00774] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/01/2020] [Indexed: 12/23/2022] Open
Abstract
The prolonged and sex-dependent impact of maternal immune activation (MIA) during gestation on the molecular pathways of the amygdala, a brain region that influences social, emotional, and other behaviors, is only partially understood. To address this gap, we investigated the effects of viral-elicited MIA during gestation on the amygdala transcriptome of pigs, a species of high molecular and developmental homology to humans. Gene expression levels were measured using RNA-Seq on the amygdala for 3-week-old female and male offspring from MIA and control groups. Among the 403 genes that exhibited significant MIA effect, a prevalence of differentially expressed genes annotated to the neuroactive ligand-receptor pathway, glutamatergic functions, neuropeptide systems, and cilium morphogenesis were uncovered. Genes in these categories included corticotropin-releasing hormone receptor 2, glutamate metabotropic receptor 4, glycoprotein hormones, alpha polypeptide, parathyroid hormone 1 receptor, vasointestinal peptide receptor 2, neurotensin, proenkephalin, and gastrin-releasing peptide. These categories and genes have been associated with the MIA-related human neurodevelopmental disorders, including schizophrenia and autism spectrum disorders. Gene network reconstruction highlighted differential vulnerability to MIA effects between sexes. Our results advance the understanding necessary for the development of multifactorial therapies targeting immune modulation and neurochemical dysfunction that can ameliorate the effects of MIA on offspring behavior later in life.
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Affiliation(s)
- Marissa R. Keever
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Pan Zhang
- Illinois Informatics Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Courtni R. Bolt
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Adrienne M. Antonson
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Haley E. Rymut
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Megan P. Caputo
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Alexandra K. Houser
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Alvaro G. Hernandez
- High-throughput Sequencing and Genotyping Unit, Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Bruce R. Southey
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Laurie A. Rund
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Rodney W. Johnson
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Sandra L. Rodriguez-Zas
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Illinois Informatics Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Department of Statistics, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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2
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Chaskiel L, Bristow AD, Bluthé RM, Dantzer R, Blomqvist A, Konsman JP. Interleukin-1 reduces food intake and body weight in rat by acting in the arcuate hypothalamus. Brain Behav Immun 2019; 81:560-573. [PMID: 31310797 DOI: 10.1016/j.bbi.2019.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 07/12/2019] [Accepted: 07/12/2019] [Indexed: 12/19/2022] Open
Abstract
A reduction in food intake is commonly observed after bacterial infection, a phenomenon that can be reproduced by peripheral administration of Gram-negative bacterial lipopolysaccharide (LPS) or interleukin-1beta (IL-1β), a pro-inflammatory cytokine released by LPS-activated macrophages. The arcuate nucleus of the hypothalamus (ARH) plays a major role in food intake regulation and expresses IL-1 type 1 receptor (IL-1R1) mRNA. In the present work, we tested the hypothesis that IL-1R1 expressing cells in the ARH mediate IL-1β and/or LPS-induced hypophagia in the rat. To do so, we developed an IL-1β-saporin conjugate, which eliminated IL-R1-expressing neurons in the hippocampus, and micro-injected it into the ARH prior to systemic IL-1β and LPS administration. ARH IL-1β-saporin injection resulted in loss of neuropeptide Y-containing cells and attenuated hypophagia and weight loss after intraperitoneal IL-1β, but not LPS, administration. In conclusion, the present study shows that ARH NPY-containing neurons express functional IL-1R1s that mediate peripheral IL-1β-, but not LPS-, induced hypophagia. Our present and previous findings indicate that the reduction of food intake after IL-1β and LPS are mediated by different neural pathways.
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Affiliation(s)
- Léa Chaskiel
- Psychoneuroimmunology, Nutrition and Genetics, UMR CNRS 5226-INRA 1286, University of Bordeaux, 33076 Bordeaux, France
| | - Adrian D Bristow
- National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK
| | - Rose-Marie Bluthé
- Psychoneuroimmunology, Nutrition and Genetics, UMR CNRS 5226-INRA 1286, University of Bordeaux, 33076 Bordeaux, France
| | - Robert Dantzer
- Department of Symptom Research, MD Anderson Cancer Center, The University of Texas, Houston, TX 770030, USA
| | - Anders Blomqvist
- Division of Neurobiology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, S-581 85 Linköping, Sweden
| | - Jan Pieter Konsman
- UMR CNRS 5287 Aquitaine Institute for Integrative and Cognitive Neuroscience, University of Bordeaux, 33076 Bordeaux, France.
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Wanlong Z, Di Z, Dongmin H, Guang Y. Roles of hypothalamic neuropeptide gene expression in body mass regulation in Eothenomys miletus (Mammalia: Rodentia: Cricetidae). THE EUROPEAN ZOOLOGICAL JOURNAL 2017. [DOI: 10.1080/24750263.2017.1334840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Z. Wanlong
- Key Laboratory of Adaptive Evolution and Ecological Conservation on Plants and Animals in Southwest Mountain Ecosystem of Yunnan Higher Education Institutes, School of Life Sciences, Yunnan Normal University, Kunming, People’s Republic of China
| | - Z. Di
- School of Life Sciences, Kunming, People’s Republic of China
| | - H. Dongmin
- Key Laboratory of Adaptive Evolution and Ecological Conservation on Plants and Animals in Southwest Mountain Ecosystem of Yunnan Higher Education Institutes, School of Life Sciences, Yunnan Normal University, Kunming, People’s Republic of China
| | - Y. Guang
- College of Life Sciences, Nanjing Normal University, Nanjing, People’s Republic of China
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4
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Agapito MA, Zhang C, Murugan S, Sarkar DK. Fetal alcohol exposure disrupts metabolic signaling in hypothalamic proopiomelanocortin neurons via a circadian mechanism in male mice. Endocrinology 2014; 155:2578-88. [PMID: 24797626 PMCID: PMC4060182 DOI: 10.1210/en.2013-2030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Early-life ethanol feeding (ELAF) alters the metabolic function of proopiomelanocortin (POMC)-producing neurons and the circadian expression of clock regulatory genes in the hypothalamus. We investigated whether the circadian mechanisms control the action of ELAF on metabolic signaling genes in POMC neurons. Gene expression measurements of Pomc and a selected group of metabolic signaling genes, Stat3, Sirt1, Pgc1-α, and Asb4 in laser-captured microdissected POMC neurons in the hypothalamus of POMC-enhanced green fluorescent protein mice showed circadian oscillations under light/dark and constant darkness conditions. Ethanol programmed these neurons such that the adult expression of Pomc, Stat3, Sirt, and Asb4 gene transcripts became arrhythmic. In addition, ELAF dampened the circadian peak of gene expression of Bmal1, Per1, and Per2 in POMC neurons. We crossed Per2 mutant mice with transgenic POMC-enhanced green fluorescent protein mice to determine the role of circadian mechanism in ELAF-altered metabolic signaling in POMC neurons. We found that ELAF failed to alter arrhythmic expression of most circadian genes, with the exception of the Bmal1 gene and metabolic signaling regulating genes in Per2 mutant mice. Comparison of the ELAF effects on the circadian blood glucose in wild-type and Per2 mutant mice revealed that ELAF dampened the circadian peak of glucose, whereas the Per2 mutation shifted the circadian cycle and prevented the ELAF dampening of the glucose peak. These data suggest the possibility that the Per2 gene mutation may regulate the ethanol actions on Pomc and the metabolic signaling genes in POMC neurons in the hypothalamus by blocking circadian mechanisms.
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Affiliation(s)
- Maria A Agapito
- Endocrine Program (M.A.A., C.Z., S.M., D.K.S.), Graduate Program in Neuroscience (M.A.A.), Graduate Program in Endocrinology and Animal Biosciences (C.Z.), and Department of Animal Sciences (S.M., D.K.S.), Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901
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5
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Nazarians-Armavil A, Chalmers JA, Lee CB, Ye W, Belsham DD. Cellular insulin resistance disrupts hypothalamic mHypoA-POMC/GFP neuronal signaling pathways. J Endocrinol 2014; 220:13-24. [PMID: 24134870 DOI: 10.1530/joe-13-0334] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
POMC neurons play a central role in the maintenance of whole-body energy homeostasis. This balance requires proper regulation of POMC neurons by metabolic hormones, such as insulin. However, the heterogeneous cellular population of the intact hypothalamus presents challenges for examining the molecular mechanisms underlying the potent anorexigenic effects of POMC neurons, and there is currently a complete lack of mature POMC neuronal cell models for study. To this end, we have generated novel, immortalized, adult-derived POMC-expressing/α-MSH-secreting cell models, mHypoA-POMC/GFP lines 1-4, representing the fluorescence-activated cell-sorted POMC population from primary POMC-eGFP mouse hypothalamus. The presence of Pomc mRNA in these cell lines was confirmed, and α-MSH was detected via immunofluorescence. α-MSH secretion in the mHypoA-POMC/GFP-1 was found to increase in response to 10 ng/ml ciliary neurotrophic factor (CNTF) or 10 nM insulin as determined by enzyme immunoassay. Further experiments using the mHypoA-POMC/GFP-1 cell line revealed that 10 ng/ml CNTF increases Pomc mRNA at 1 and 2 h after treatment, whereas insulin elicited an increase in Pomc mRNA level and decreases in insulin receptor (Insr (Ir)) mRNA level at 4 h. Furthermore, the activation of IR-mediated downstream second messengers was examined by western blot analysis, following the induction of cellular insulin resistance, which resulted in a loss of insulin-mediated regulation of Pomc and Ir mRNAs. The development of these immortalized neurons will be invaluable for the elucidation of the cellular and molecular mechanisms that underlie POMC neuronal function under normal and perturbed physiological conditions.
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Affiliation(s)
- Anaies Nazarians-Armavil
- Departments of Physiology, Obstetrics and Gynaecology Medicine, University of Toronto, Medical Sciences Building 3344, 1 Kings College Circle, Toronto, Ontario, Canada M5S 1A8 Division of Cellular and Molecular Biology, Toronto Genera Hospital Research Institute, University Health Network, Toronto, Ontario, Canada M5S 1A8
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6
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Barrett P, van den Top M, Wilson D, Mercer JG, Song CK, Bartness TJ, Morgan PJ, Spanswick D. Short photoperiod-induced decrease of histamine H3 receptors facilitates activation of hypothalamic neurons in the Siberian hamster. Endocrinology 2009; 150:3655-63. [PMID: 19372203 PMCID: PMC5393275 DOI: 10.1210/en.2008-1620] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nonhibernating seasonal mammals have adapted to temporal changes in food availability through behavioral and physiological mechanisms to store food and energy during times of predictable plenty and conserve energy during predicted shortage. Little is known, however, of the hypothalamic neuronal events that lead to a change in behavior or physiology. Here we show for the first time that a shift from long summer-like to short winter-like photoperiod, which induces physiological adaptation to winter in the Siberian hamster, including a body weight decrease of up to 30%, increases neuronal activity in the dorsomedial region of the arcuate nucleus (dmpARC) assessed by electrophysiological patch-clamping recording. Increased neuronal activity in short days is dependent on a photoperiod-driven down-regulation of H3 receptor expression and can be mimicked in long-day dmpARC neurons by the application of the H3 receptor antagonist, clobenproprit. Short-day activation of dmpARC neurons results in increased c-Fos expression. Tract tracing with the trans-synaptic retrograde tracer, pseudorabies virus, delivered into adipose tissue reveals a multisynaptic neuronal sympathetic outflow from dmpARC to white adipose tissue. These data strongly suggest that increased activity of dmpARC neurons, as a consequence of down-regulation of the histamine H3 receptor, contributes to the physiological adaptation of body weight regulation in seasonal photoperiod.
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Affiliation(s)
- P Barrett
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen AB21 9SB, United Kingdom
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7
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Breton C, Lukaszewski MA, Risold PY, Enache M, Guillemot J, Rivière G, Delahaye F, Lesage J, Dutriez-Casteloot I, Laborie C, Vieau D. Maternal prenatal undernutrition alters the response of POMC neurons to energy status variation in adult male rat offspring. Am J Physiol Endocrinol Metab 2009; 296:E462-72. [PMID: 19088253 DOI: 10.1152/ajpendo.90740.2008] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Epidemiological studies suggest that maternal undernutrition predisposes the offspring to development of energy balance metabolic pathologies in adulthood. Using a model of a prenatal maternal 70% food-restricted diet (FR30) in rats, we evaluated peripheral parameters involved in nutritional regulation, as well as the hypothalamic appetite-regulatory system, in nonfasted and 48-h-fasted adult offspring. Despite comparable glycemia in both groups, mild glucose intolerance, with a defect in glucose-induced insulin secretion, was observed in FR30 animals. They also exhibited hyperleptinemia, despite similar visible fat deposits. Using semiquantitative RT-PCR, we observed no basal difference of hypothalamic proopiomelanocortin (POMC) and neuropeptide Y (NPY) gene expression, but a decrease of the OB-Rb and an increase of insulin receptor mRNA levels, in FR30 animals. These animals also exhibited basal hypercorticosteronemia and a blunted increase of corticosterone in fasted compared with control animals. After fasting, FR30 animals showed no marked reduction of POMC mRNA levels or intensity of beta-endorphin-immunoreactive fiber projections. By contrast, NPY gene expression and immunoreactive fiber intensity increased. FR30 rats also displayed subtle alterations of food intake: body weight-related food intake was higher and light-dark phase rhythm and refeeding time course were modified after fasting. At rest, in the morning, hyperinsulinemia and a striking increase in the number of c-Fos-containing cells in the arcuate nucleus were observed. About 30% of the c-Fos-expressing cells were POMC neurons. Our data suggest that maternal undernutrition differently programs the long-term appetite-regulatory system of offspring, especially the response of POMC neurons to energy status and food intake rhythm.
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Affiliation(s)
- Christophe Breton
- Neurosciences et Physiologie Adaptatives, Université de Lille I, Villeneuve d'Ascq, France.
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8
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Chen CP, Kuhn P, Advis JP, Sarkar DK. Prenatal ethanol exposure alters the expression of period genes governing the circadian function of beta-endorphin neurons in the hypothalamus. J Neurochem 2006; 97:1026-33. [PMID: 16686691 DOI: 10.1111/j.1471-4159.2006.03839.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sleep-wake disturbances and stress hyper-responsiveness have been observed in human neonates, children and adolescents who were exposed to alcohol during the prenatal period. Using the laboratory rat as an animal model, we investigated whether fetal ethanol exposure during gestational days 10-21 affects the circadian function of the stress-axis regulatory beta-endorphin neurons in the hypothalamus. Fetal ethanol-exposed rats showed abnormality in the circadian expression of proopiomelanocortin (POMC) mRNA encoding the peptide beta-endorphin in the arcuate nucleus of the hypothalamus during the adult period. These rats also showed altered circadian expression of the clock governing Period genes rPer1, rPer2 and rPer3, in the arcuate nucleus, and rPer1 and rPer 2 mRNA levels in the suprachiasmatic nucleus. Laser captured microdissection analysis identified constitutive expression of rPer1, rPer2 and rPer3 genes in beta-endorphin-containing neurons. These data suggest for the first time that fetal exposure to ethanol significantly alters the clock mechanisms governing the circadian function of beta-endorphin neurons.
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MESH Headings
- Alcohol-Induced Disorders, Nervous System/genetics
- Alcohol-Induced Disorders, Nervous System/metabolism
- Alcohol-Induced Disorders, Nervous System/physiopathology
- Animals
- Animals, Newborn
- Cell Cycle Proteins
- Central Nervous System Depressants/adverse effects
- Chronobiology Disorders/chemically induced
- Chronobiology Disorders/genetics
- Chronobiology Disorders/metabolism
- Disease Models, Animal
- Ethanol/adverse effects
- Female
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Hypothalamo-Hypophyseal System/drug effects
- Hypothalamo-Hypophyseal System/metabolism
- Hypothalamo-Hypophyseal System/physiopathology
- Hypothalamus/drug effects
- Hypothalamus/metabolism
- Hypothalamus/physiopathology
- Male
- Neurons/drug effects
- Neurons/metabolism
- Nuclear Proteins/biosynthesis
- Nuclear Proteins/genetics
- Period Circadian Proteins
- Pregnancy
- Prenatal Exposure Delayed Effects/genetics
- Prenatal Exposure Delayed Effects/metabolism
- Prenatal Exposure Delayed Effects/physiopathology
- Pro-Opiomelanocortin/biosynthesis
- Pro-Opiomelanocortin/genetics
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Sleep Wake Disorders/chemically induced
- Sleep Wake Disorders/genetics
- Sleep Wake Disorders/metabolism
- Stress, Physiological/chemically induced
- Stress, Physiological/genetics
- Stress, Physiological/metabolism
- beta-Endorphin/metabolism
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Affiliation(s)
- Cui Ping Chen
- Endocrine Program, Biomedical Division of the Center of Alcohol Studies and Department of Animal Sciences, The State University of New Jersey, New Brunswick, New Jersey 08901-8525, USA
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9
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Chen CP, Kuhn P, Advis JP, Sarkar DK. Chronic ethanol consumption impairs the circadian rhythm of pro-opiomelanocortin and period genes mRNA expression in the hypothalamus of the male rat. J Neurochem 2004; 88:1547-54. [PMID: 15009656 DOI: 10.1046/j.1471-4159.2003.02300.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Certain psychiatric disorders are known to alter the body's biological rhythms. However, currently, very little information is known about the effect of chronic ethanol administration on the circadian clock or the rhythm of beta-endorphin-containing neurons that participate in the control of the reward and reinforcement of alcohol drinking. Here, we report that administration of ethanol, via a liquid diet paradigm for a period of 2 weeks, abolishes the circadian rhythm of pro-opiomelanocortin mRNA expression of beta-endorphin neurons in the arcuate nucleus of the hypothalamus. The circadian expression of the clock governing rat period genes (rPeriod1 mRNA and rPeriod2 mRNA) in the arcuate nucleus was significantly altered, suggesting that ethanol administration disrupted the internal clock. Moreover, ethanol consumption altered the circadian rhythms of rPeriod2 and rPeriod3 mRNA levels in the suprachiasmatic nucleus, suggesting that ethanol also affected the function of the central pacemaker. Our findings identified the vulnerability of the body's clock machinery and its opioidergic system to chronic alcohol drinking.
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Affiliation(s)
- Cui Ping Chen
- Endocrine Program, Center of Alcohol Studies and Department of Animal Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901-8525, USA
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10
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Shu IW, Lindenberg DL, Mizuno TM, Roberts JL, Mobbs CV. The fatty acid synthase inhibitor cerulenin and feeding, like leptin, activate hypothalamic pro-opiomelanocortin (POMC) neurons. Brain Res 2003; 985:1-12. [PMID: 12957363 DOI: 10.1016/s0006-8993(03)02806-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hypothalamic POMC neurons mediate catabolic responses such as decreased food intake and increased energy expenditure by, in part, monitoring levels of metabolic factors such as glucose, insulin and leptin. Recently, fatty acid synthase inhibitors were reported to reduce body weight, inhibit food intake, and increase metabolic rate, possibly by acting on hypothalamic neurons through a mechanism involving malonyl-CoA accumulation. Given the observation that leptin mediates similar catabolic effects by, in part, activating hypothalamic POMC neurons, it is possible that other catabolic signals such as feeding and fatty acid synthase inhibition may also activate POMC neurons. To test this hypothesis, hypothalamic sections from mice that were fed or injected with the fatty acid synthase inhibitor cerulenin were examined for Fos (a marker for neuronal activation) and POMC product immunoreactivity and compared with similarly processed sections from leptin-injected mice. Feeding increased Fos immunoreactivity in the lateral peri-arcuate area of the hypothalamus of both wild-type and leptin-deficient ob/ob mice (P<0.05), indicating that nutritional activation of the hypothalamus can be leptin-independent. Furthermore, feeding significantly induced Fos immunoreactivity in neurons expressing POMC (P<0.003), indicating that feeding, like leptin, activates POMC neurons. Injection with cerulenin, like feeding and leptin, also increased Fos immunoreactivity in the lateral peri-arcuate area (P<0.03) and, more specifically, in neurons expressing POMC. In contrast, injection with cerulenin had no grossly observable effects on cortical Fos immunoreactivity and appeared to suppress fasting-induced Fos immunoreactivity by about 35% (although the decrease did not reach statistical significance) in the medial arcuate nucleus, an area associated with anabolic responses such as increased food intake. Injection with cerulenin also decreased Fos immunoreactivity in the granular layer of the dentate gyrus of the hippocampus by about 30% (P<0.05), further suggesting that cerulenin does not non-specifically activate wide varieties of neurons. These results suggest that activation of hypothalamic POMC neurons may help to mediate some of the catabolic effects associated with feeding, cerulenin and leptin.
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Affiliation(s)
- I-Wei Shu
- Fishberg Research Center for Neurobiology, New York, NY, USA
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11
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Jamali KA, Tramu G. Control of rat hypothalamic pro-opiomelanocortin neurons by a circadian clock that is entrained by the daily light-off signal. Neuroscience 1999; 93:1051-61. [PMID: 10473270 DOI: 10.1016/s0306-4522(99)00208-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Previous studies have clearly demonstrated that the immediate-early gene, c-fos can regulate, through its protein product Fos, the expression of the pro-opiomelanocortin gene. In the present study, immunohistochemistry for Fos and beta-endorphin was used to assess the basal activity of hypothalamic pro-opiomelanocortin-producing neurons throughout a 12 h light/12 h dark cycle. Here, we showed that Fos is undetectable in most beta-endorphin neurons from late morning until 30 min after light offset in the evening, whereas Fos is spontaneously expressed in these neurons after 1 h following dark onset. The number of beta-endorphin neurons expressing Fos increases continuously during the first half of the dark phase, is maximal at the middle of this phase and decreases through late night and early morning, reaching a nadir 2-3 h after light onset. Acute shifts of lighting parameters allowed us to demonstrate that the light-off signal per se is neither sufficient nor necessary for Fos expression in beta-endorphin neurons. However, when recurrent, this signal is able to entrain Fos expression after a period of adaptation to the new light/dark schedule. Moreover, an expression of Fos in beta-endorphin neurons persists during subjective night in rat exposed to constant light or constant dark for two to three days. Thus, the occurrence of the daily rhythmic increase in the expression of Fos protein in hypothalamic pro-opiomelanocortin neurons exclusively at (subjective) night suggests that these neurons are, most likely, controlled by a (circadian) nocturnal oscillator. Our data also reveal an interesting property of this oscillator: its entrainment by the daily light-to-dark transition signal.
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Affiliation(s)
- K A Jamali
- Laboratoire de Neurocytochimie Fonctionnelle, CNRS-UMR 5807, Université de Bordeaux I, Talence, France
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12
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Lee Y, Voogt JL. Rhythmicity of beta-endorphinergic neuronal activity in the mediobasal hypothalamus during pregnancy in the rat. Brain Res 1999; 837:152-60. [PMID: 10433997 DOI: 10.1016/s0006-8993(99)01603-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
During the first half of gestation in the rat, prolactin (PRL) from the anterior pituitary gland exerts its luteotropic function on the ovary to stimulate progesterone secretion. During this period, beta-endorphin stimulates PRL secretion by regulation of dopaminergic neurons in the hypothalamus. During the second half, placental lactogens (PLs) take the place of PRL in maintenance of pregnancy, and initiate a negative feedback to suppress PRL secretion. However, the effect of PLs on beta-endorphinergic neurons is not known. The aim of this study was to examine the possibility that PLs suppress PRL secretion by inhibiting beta-endorphinergic neuronal activity. To accomplish this aim, we examined the changes in the neuronal activity of beta-endorphinergic neurons in the mediobasal hypothalamus, as measured by Fos immunoreactivity, after manipulating the levels of PRL and PLs during pregnancy. On day 4 of pregnancy, animals received either Rcho-1 cells in the lateral ventricle that secrete PLs or HRP-1 cells as controls. In a separate experiment on day 12, hysterectomy was performed to remove the intrinsic source of PLs. These rats received Rcho-1 cells, HRP-1 cells, or nothing. Intracerebroventricular (i.c.v.) injection of Rcho-1 into hysterectomized rats was done to examine the effect of PL replacement. Sham-hysterectomy was also performed as a control. Animals were sacrificed 2 days after each treatment at 0200 h, 1400 h, and 1800 h. Brains were used for dual immunocytochemistry of Fos/beta-endorphin. The neuronal activity of beta-endorphinergic neurons of HRP-1 i.c.v. injected animals showed a daily rhythm, with high levels at 0200 h and 1800 h, and a low level at 1400 h. These animals also exhibited two surges of PRL secretion on day 6 of pregnancy. This rhythmicity of beta-endorphinergic neurons was also observed in Rcho-1 i.c.v. injected animals, which showed very low and unchanging PRL levels. However, the magnitude of neuronal activity was reduced. On day 14 of pregnancy, all four experimental groups showed diurnal rhythms of beta-endorphinergic neurons. This rhythmicity occurred even though PRL was elevated at all three time points in the hysterectomized rats and very low in the Rcho-1 i.c.v. injected hysterectomized and sham-hysterectomized rats. Our results demonstrate that there is a diurnal rhythm of beta-endorphinergic neuronal activity in the mediobasal hypothalamus during pregnancy in the rat. PLs might reduce the neuronal activity of beta-endorphinergic neurons, but only during the first half of pregnancy, partially explaining the suppression of PRL surges.
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Affiliation(s)
- Y Lee
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160-7401, USA
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Jamali KA, Corio M, Dubourg P, Thenailler C, Tramu G. The daily pattern of Fos synthesis by hypothalamic pro-opiomelanocortin neurons is unaffected by adrenalectomy in the rat. Neurosci Lett 1998; 250:119-22. [PMID: 9697933 DOI: 10.1016/s0304-3940(98)00446-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
At the onset of dark, a large population of rat mediobasal hypothalamic (MBH) pro-opiomelanocortin (POMC) neurons starts spontaneously expressing Fos-immunoreactivity (Fos-IR). Here we studied the effect of adrenalectomy upon this expression since circulating corticosteroids, which increase in the rat with the onset of behavioural wakening, are thought to modulate the basal expression of MBH POMC mRNA. Hence, groups of intact, adrenalectomised and sham-operated rats were sacrificed at times when Fos synthesis by POMC neurons is known to show either nadir (at light-offset) or peak (6 h after light-offset) values. Brains were processed for Fos- and/or POMC immunohistochemistry. This allowed us to show that, in all experimental groups, Fos-IR is hardly expressed in MBH POMC neurons at the onset of dark, whereas it is strongly induced 6 h later. We concluded that such an induction is not triggered through the known evening rise of plasma corticosteroid levels.
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Affiliation(s)
- K A Jamali
- Laboratoire de Neurocytochimie Fonctionnelle, Université de Bordeaux I, CNRS URA 339, Talence, France
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