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Roberto M, Varodayan FP. Synaptic targets: Chronic alcohol actions. Neuropharmacology 2017; 122:85-99. [PMID: 28108359 DOI: 10.1016/j.neuropharm.2017.01.013] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/23/2016] [Accepted: 01/14/2017] [Indexed: 01/02/2023]
Abstract
Alcohol acts on numerous cellular and molecular targets to regulate neuronal communication within the brain. Chronic alcohol exposure and acute withdrawal generate prominent neuroadaptations at synapses, including compensatory effects on the expression, localization and function of synaptic proteins, channels and receptors. The present article reviews the literature describing the synaptic effects of chronic alcohol exposure and their relevance for synaptic transmission in the central nervous system. This review is not meant to be comprehensive, but rather to highlight the effects that have been observed most consistently and that are thought to contribute to the development of alcohol dependence and the negative aspects of withdrawal. Specifically, we will focus on the major excitatory and inhibitory neurotransmitters in the brain, glutamate and GABA, respectively, and how their neuroadaptations after chronic alcohol exposure contributes to alcohol reinforcement, dependence and withdrawal. This article is part of the Special Issue entitled "Alcoholism".
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102
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Fullard JF, Halene TB, Giambartolomei C, Haroutunian V, Akbarian S, Roussos P. Understanding the genetic liability to schizophrenia through the neuroepigenome. Schizophr Res 2016; 177:115-124. [PMID: 26827128 PMCID: PMC4963306 DOI: 10.1016/j.schres.2016.01.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 01/14/2016] [Accepted: 01/18/2016] [Indexed: 12/17/2022]
Abstract
The Psychiatric Genomics Consortium-Schizophrenia Workgroup (PGC-SCZ) recently identified 108 loci associated with increased risk for schizophrenia (SCZ). The vast majority of these variants reside within non-coding sequences of the genome and are predicted to exert their effects by affecting the mechanism of action of cis regulatory elements (CREs), such as promoters and enhancers. Although a number of large-scale collaborative efforts (e.g. ENCODE) have achieved a comprehensive mapping of CREs in human cell lines or tissue homogenates, it is becoming increasingly evident that many risk-associated variants are enriched for expression Quantitative Trait Loci (eQTLs) and CREs in specific tissues or cells. As such, data derived from previous research endeavors may not capture fully cell-type and/or region specific changes associated with brain diseases. Coupling recent technological advances in genomics with cell-type specific methodologies, we are presented with an unprecedented opportunity to better understand the genetics of normal brain development and function and, in turn, the molecular basis of neuropsychiatric disorders. In this review, we will outline ongoing efforts towards this goal and will discuss approaches with the potential to shed light on the mechanism(s) of action of cell-type specific cis regulatory elements and their putative roles in disease, with particular emphasis on understanding the manner in which the epigenome and CREs influence the etiology of SCZ.
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Affiliation(s)
- John F. Fullard
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tobias B. Halene
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA
| | | | - Vahram Haroutunian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA
| | - Schahram Akbarian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Panos Roussos
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Genetics and Genomic Science and Institute for Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA.
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103
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McClain JA, Nixon K. Alcohol Induces Parallel Changes in Hippocampal Histone H3 Phosphorylation and c-Fos Protein Expression in Male Rats. Alcohol Clin Exp Res 2016; 40:102-12. [PMID: 26727528 DOI: 10.1111/acer.12933] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/08/2015] [Indexed: 01/04/2023]
Abstract
BACKGROUND Changes in gene expression associated with alcohol-induced neuroadaptations are controlled in part by post translational histone modifications. Serine 10 phosphorylation of histone H3 (H3S10ph) has been implicated in drug-induced changes in gene expression; however, ethanol (EtOH)'s effects on H3S10ph have yet to be examined in brain. Therefore, hippocampal H3S10ph was examined after acute EtOH exposure and EtOH dependence. METHODS Adult male Sprague Dawley rats received an acute exposure of EtOH (0 to 5 g/kg) via gavage. Or, rats were made EtOH dependent by administering 25% w/v EtOH every 8 hours for 4 days following a modified Majchrowicz protocol. In both cases, rats were perfused transcardially and paraformaldehyde-fixed brains were collected and processed for immunohistochemistry to detect H3S10ph or c-fos. RESULTS Acute EtOH exposure dose dependently altered the number of H3S10ph-positive (+) cells in the hippocampus. Specifically, 1 g/kg EtOH increased the number of H3S10ph+ cells in all neuronal layers, while 2.5 and 5 g/kg EtOH reduced the number of H3S10ph+ cells, an effect that was confined to the granule cell layer. In EtOH-dependent rats, the number of H3S10ph+ cells in the granule cell layer was reduced by 66% during intoxication; however, H3S10ph+ cells were increased in all neuronal layers during peak withdrawal. Subsequent examination of c-fos, a gene known to be regulated by H3S10ph, revealed that EtOH and withdrawal-associated changes in c-fos closely paralleled changes in H3S10ph. CONCLUSIONS These results suggest that H3S10ph regulates EtOH-mediated changes in c-fos expression, effects that likely have important implications for EtOH-induced changes in hippocampal neuronal plasticity.
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Affiliation(s)
- Justin A McClain
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky
| | - Kimberly Nixon
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky
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104
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Jangra A, Sriram CS, Pandey S, Choubey P, Rajput P, Saroha B, Bezbaruah BK, Lahkar M. Epigenetic Modifications, Alcoholic Brain and Potential Drug Targets. Ann Neurosci 2016; 23:246-260. [PMID: 27780992 PMCID: PMC5075742 DOI: 10.1159/000449486] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 06/25/2016] [Indexed: 12/19/2022] Open
Abstract
Acute and chronic alcohol exposure evidently influences epigenetic changes, both transiently and permanently, and these changes in turn influence a variety of cells and organ systems throughout the body. Many of the alcohol-induced epigenetic modifications can contribute to cellular adaptations that ultimately lead to behavioral tolerance and alcohol dependence. The persistence of behavioral changes demonstrates that long-lasting changes in gene expression, within particular regions of the brain, may contribute importantly to the addiction phenotype. The research activities over the past years have demonstrated a crucial role of epigenetic mechanisms in causing long lasting and transient changes in the expression of several genes in diverse tissues, including brain. This has stimulated recent research work that is aimed at characterizing the influence of epigenetic regulatory events in mediating the long lasting and transient effects of alcohol abuse on the brain in humans and animal models of alcohol addiction. In this study, we update our current understanding of the impact of alcohol exposure on epigenetic mechanisms in the brain and refurbish the knowledge of epigenetics in the direction of new drugs development.
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Affiliation(s)
- Ashok Jangra
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, India
| | - Chandra Shaker Sriram
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, India
| | - Suryanarayan Pandey
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, India
| | - Priyansha Choubey
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, India
| | - Prabha Rajput
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, India
| | - Babita Saroha
- Department of Biotechnology, University Institute of Engineering and Technology (UIET), Maharshi Dayanand University, Rohtak, India
| | - Babul Kumar Bezbaruah
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, India
- Department of Pharmacology, Gauhati Medical College, Narkachal Hilltop, Bhangagarh, Guwahati, India
| | - Mangala Lahkar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, India
- Department of Pharmacology, Gauhati Medical College, Narkachal Hilltop, Bhangagarh, Guwahati, India
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105
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FMRP regulates an ethanol-dependent shift in GABA BR function and expression with rapid antidepressant properties. Nat Commun 2016; 7:12867. [PMID: 27666021 PMCID: PMC5052688 DOI: 10.1038/ncomms12867] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/08/2016] [Indexed: 12/17/2022] Open
Abstract
Alcohol promotes lasting neuroadaptive changes that may provide relief from depressive symptoms, often referred to as the self-medication hypothesis. However, the molecular/synaptic pathways that are shared by alcohol and antidepressants are unknown. In the current study, acute exposure to ethanol produced lasting antidepressant and anxiolytic behaviours. To understand the functional basis of these behaviours, we examined a molecular pathway that is activated by rapid antidepressants. Ethanol, like rapid antidepressants, alters γ-aminobutyric acid type B receptor (GABABR) expression and signalling, to increase dendritic calcium. Furthermore, new GABABRs are synthesized in response to ethanol treatment, requiring fragile-X mental retardation protein (FMRP). Ethanol-dependent changes in GABABR expression, dendritic signalling, and antidepressant efficacy are absent in Fmr1-knockout (KO) mice. These findings indicate that FMRP is an important regulator of protein synthesis following alcohol exposure, providing a molecular basis for the antidepressant efficacy of acute ethanol exposure. Alcohol is thought to lead to neuroadaptive changes, although the underlying molecular mechanisms are unclear. Here, the authors find ethanol treatment alters GABAB-receptor expression via fragile-X mental retardation protein in mice, leading to antidepressant-like behaviours.
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106
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Xu YH, Wang LL, Shi L, Lei JP, Miao Q, Liu TQ, Hao W, Lu L, Zhang RL. The association of HTR3A mRNA expression and craving in Han Chinese alcohol-dependent patients: a preliminary study. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2016; 42:316-24. [PMID: 27144979 DOI: 10.3109/00952990.2016.1160098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Ya-Hui Xu
- Department of Addiction, Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Lin-Lin Wang
- Department of Psychology, Ninth People Hospital of Zhengzhou, Zhengzhou, Henan Province, China
| | - Le Shi
- Peking University Sixth Hospital/Institute of Mental Health and Key Laboratory of Mental Health and National Institute on Drug Dependence, Peking University, Beijing, China
| | - Jin-Ping Lei
- People Hospital of Cangzhou, Cangzhou, Hebei Province, China
| | - Qin Miao
- Department of Addiction, Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Tie-Qiao Liu
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Wei Hao
- Mental Health Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Lin Lu
- Peking University Sixth Hospital/Institute of Mental Health and Key Laboratory of Mental Health and National Institute on Drug Dependence, Peking University, Beijing, China
| | - Rui-Ling Zhang
- Department of Addiction, Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
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107
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Castilla-Ortega E, Serrano A, Blanco E, Araos P, Suárez J, Pavón FJ, Rodríguez de Fonseca F, Santín LJ. A place for the hippocampus in the cocaine addiction circuit: Potential roles for adult hippocampal neurogenesis. Neurosci Biobehav Rev 2016; 66:15-32. [PMID: 27118134 DOI: 10.1016/j.neubiorev.2016.03.030] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 03/08/2016] [Accepted: 03/08/2016] [Indexed: 02/07/2023]
Abstract
Cocaine addiction is a chronic brain disease in which the drug seeking habits and profound cognitive, emotional and motivational alterations emerge from drug-induced neuroadaptations on a vulnerable brain. Therefore, a 'cocaine addiction brain circuit' has been described to explain this disorder. Studies in both cocaine patients and rodents reveal the hippocampus as a main node in the cocaine addiction circuit. The contribution of the hippocampus to cocaine craving and the associated memories is essential to understand the chronic relapsing nature of addiction, which is the main obstacle for the recovery. Interestingly, the hippocampus holds a particular form of plasticity that is rare in the adult brain: the ability to generate new functional neurons. There is an active scientific debate on the contributions of these new neurons to the addicted brain. This review focuses on the potential role(s) of adult hippocampal neurogenesis (AHN) in cocaine addiction. Although the current evidence primarily originates from animal research, these preclinical studies support AHN as a relevant component for the hippocampal effects of cocaine.
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Affiliation(s)
- Estela Castilla-Ortega
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain.
| | - Antonia Serrano
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Eduardo Blanco
- Departament de Pedagogia i Psicologia, Facultat d'Educació, Psicologia i Treball Social, Universitat de Lleida, Spain
| | - Pedro Araos
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Juan Suárez
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Francisco J Pavón
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Fernando Rodríguez de Fonseca
- Unidad de Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Spain
| | - Luis J Santín
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Instituto de Investigación Biomédica de Málaga (IBIMA), Facultad de Psicología, Universidad de Málaga, Spain.
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108
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Troutwine BR, Ghezzi A, Pietrzykowski AZ, Atkinson NS. Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway. GENES, BRAIN, AND BEHAVIOR 2016; 15:382-94. [PMID: 26916032 PMCID: PMC4991213 DOI: 10.1111/gbb.12288] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/17/2016] [Accepted: 02/22/2016] [Indexed: 02/02/2023]
Abstract
A growing body of evidence has shown that alcohol alters the activity of the innate immune system and that changes in innate immune system activity can influence alcohol-related behaviors. Here, we show that the Toll innate immune signaling pathway modulates the level of alcohol resistance in Drosophila. In humans, a low level of response to alcohol is correlated with increased risk of developing an alcohol use disorder. The Toll signaling pathway was originally discovered in, and has been extensively studied in Drosophila. The Toll pathway is a major regulator of innate immunity in Drosophila, and mammalian Toll-like receptor signaling has been implicated in alcohol responses. Here, we use Drosophila-specific genetic tools to test eight genes in the Toll signaling pathway for effects on the level of response to ethanol. We show that increasing the activity of the pathway increases ethanol resistance whereas decreasing the pathway activity reduces ethanol resistance. Furthermore, we show that gene products known to be outputs of innate immune signaling are rapidly induced following ethanol exposure. The interaction between the Toll signaling pathway and ethanol is rooted in the natural history of Drosophila melanogaster.
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Affiliation(s)
- B R Troutwine
- Department of Neuroscience, The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX
| | - A Ghezzi
- Department of Neuroscience, The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX
| | - A Z Pietrzykowski
- The Biologically Inspired Neural & Dynamical Systems (BINDS) Lab, Department of Computer Science, University of Massachusetts Amherst, Amherst, MA, USA
| | - N S Atkinson
- Department of Neuroscience, The Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX
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109
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Transcriptome Analysis of the Human Striatum in Tourette Syndrome. Biol Psychiatry 2016; 79:372-382. [PMID: 25199956 PMCID: PMC4305353 DOI: 10.1016/j.biopsych.2014.07.018] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 07/04/2014] [Accepted: 07/11/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Genome-wide association studies have not revealed any risk-conferring common genetic variants in Tourette syndrome (TS), requiring the adoption of alternative approaches to investigate the pathophysiology of this disorder. METHODS We obtained the basal ganglia transcriptome by RNA sequencing in the caudate and putamen of nine TS and nine matched normal control subjects. RESULTS We found 309 downregulated and 822 upregulated genes in the caudate and putamen (striatum) of TS individuals. Using data-driven gene network analysis, we identified 17 gene coexpression modules associated with TS. The top-scoring downregulated module in TS was enriched in striatal interneuron transcripts, which was confirmed by decreased numbers of cholinergic and gamma-aminobutyric acidergic interneurons by immunohistochemistry in the same regions. The top-scoring upregulated module was enriched in immune-related genes, consistent with activation of microglia in patients' striatum. Genes implicated by copy number variants in TS were enriched in the interneuron module, as well as in a protocadherin module. Module clustering revealed that the interneuron module was correlated with a neuronal metabolism module. CONCLUSIONS Convergence of differential expression, network analyses, and module clustering, together with copy number variants implicated in TS, strongly implicates disrupted interneuron signaling in the pathophysiology of severe TS and suggests that metabolic alterations may be linked to their death or dysfunction.
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110
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Scholpa NE, Briggs SB, Wagner JJ, Cummings BS. Cyclin-Dependent Kinase Inhibitor 1a (p21) Modulates Response to Cocaine and Motivated Behaviors. J Pharmacol Exp Ther 2016; 357:56-65. [PMID: 26791604 DOI: 10.1124/jpet.115.230888] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/19/2016] [Indexed: 12/31/2022] Open
Abstract
This study investigated the functional role of cyclin-dependent kinase inhibitor 1a (Cdkn1a or p21) in cocaine-induced responses using a knockout mouse model. Acute locomotor activity after cocaine administration (15 mg/kg, i.p.) was decreased in p21(-/-) mice, whereas cocaine-induced place preference was enhanced. Interestingly, κ-opioid-induced place aversion was also significantly enhanced. Concentration-dependent analysis of locomotor activity in response to cocaine demonstrated a rightward shift in the p21(-/-) mice. Pretreatment with a 5-hydroxytryptamine receptor antagonist did not alter the enhancement of cocaine-induced conditioned place preference in p21(-/-) mice, indicating a lack of involvement of serotonergic signaling in this response. Cocaine exposure increased p21 expression exclusively in the ventral sector of the hippocampus of rodents after either contingent or noncontingent drug administration. Increased p21 expression was accompanied by increased histone acetylation of the p21 promoter region in rats. Finally, increased neurogenesis in the dorsal hippocampus of p21(-/-) mice was also observed. These results show that functional loss of p21 altered the acute locomotor response to cocaine and the conditioned responses to either rewarding or aversive stimuli. Collectively, these findings demonstrate a previously unreported involvement of p21 in modulating responses to cocaine and in motivated behaviors.
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Affiliation(s)
- Natalie E Scholpa
- Departments of Pharmaceutical and Biomedical Sciences (N.E.S., B.S.C.) and Physiology and Pharmacology (S.B.B., J.J.W.), University of Georgia, Athens, Georgia
| | - Sherri B Briggs
- Departments of Pharmaceutical and Biomedical Sciences (N.E.S., B.S.C.) and Physiology and Pharmacology (S.B.B., J.J.W.), University of Georgia, Athens, Georgia
| | - John J Wagner
- Departments of Pharmaceutical and Biomedical Sciences (N.E.S., B.S.C.) and Physiology and Pharmacology (S.B.B., J.J.W.), University of Georgia, Athens, Georgia
| | - Brian S Cummings
- Departments of Pharmaceutical and Biomedical Sciences (N.E.S., B.S.C.) and Physiology and Pharmacology (S.B.B., J.J.W.), University of Georgia, Athens, Georgia
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111
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Mons N, Beracochea D. Behavioral Neuroadaptation to Alcohol: From Glucocorticoids to Histone Acetylation. Front Psychiatry 2016; 7:165. [PMID: 27766083 PMCID: PMC5052254 DOI: 10.3389/fpsyt.2016.00165] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/21/2016] [Indexed: 01/21/2023] Open
Abstract
A prime mechanism that contributes to the development and maintenance of alcoholism is the dysregulation of the hypothalamic-pituitary-adrenal axis activity and the release of glucocorticoids (cortisol in humans and primates, corticosterone in rodents) from the adrenal glands. In the brain, sustained, local elevation of glucocorticoid concentration even long after cessation of chronic alcohol consumption compromises functional integrity of a circuit, including the prefrontal cortex (PFC), the hippocampus (HPC), and the amygdala (AMG). These structures are implicated in learning and memory processes as well as in orchestrating neuroadaptive responses to stress and anxiety responses. Thus, potentiation of anxiety-related neuroadaptation by alcohol is characterized by an abnormally AMG hyperactivity coupled with a hypofunction of the PFC and the HPC. This review describes research on molecular and epigenetic mechanisms by which alcohol causes distinct region-specific adaptive changes in gene expression patterns and ultimately leads to a variety of cognitive and behavioral impairments on prefrontal- and hippocampal-based tasks. Alcohol-induced neuroadaptations involve the dysregulation of numerous signaling cascades, leading to long-term changes in transcriptional profiles of genes, through the actions of transcription factors such as [cAMP response element-binding protein (CREB)] and chromatin remodeling due to posttranslational modifications of histone proteins. We describe the role of prefrontal-HPC-AMG circuit in mediating the effects of acute and chronic alcohol on learning and memory, and region-specific molecular and epigenetic mechanisms involved in this process. This review first discusses the importance of brain region-specific dysregulation of glucocorticoid concentration in the development of alcohol dependence and describes how persistently increased glucocorticoid levels in PFC may be involved in mediating working memory impairments and neuroadaptive changes during withdrawal from chronic alcohol intake. It then highlights the role of cAMP-PKA-CREB signaling cascade and histone acetylation within the PFC and limbic structures in alcohol-induced anxiety and behavioral impairments, and how an understanding of functional alterations of these pathways might lead to better treatments for neuropsychiatric disorders.
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Affiliation(s)
- Nicole Mons
- CNRS UMR 5287, Institut des Neurosciences cognitives et intégratives d'Aquitaine, Nouvelle Université de Bordeaux , Pessac , France
| | - Daniel Beracochea
- CNRS UMR 5287, Institut des Neurosciences cognitives et intégratives d'Aquitaine, Nouvelle Université de Bordeaux , Pessac , France
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112
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Cadet JL. Epigenetics of Stress, Addiction, and Resilience: Therapeutic Implications. Mol Neurobiol 2016; 53:545-560. [PMID: 25502297 PMCID: PMC4703633 DOI: 10.1007/s12035-014-9040-y] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 11/30/2014] [Indexed: 12/12/2022]
Abstract
Substance use disorders (SUDs) are highly prevalent. SUDs involve vicious cycles of binges followed by occasional periods of abstinence with recurrent relapses despite treatment and adverse medical and psychosocial consequences. There is convincing evidence that early and adult stressful life events are risks factors for the development of addiction and serve as cues that trigger relapses. Nevertheless, the fact that not all individuals who face traumatic events develop addiction to licit or illicit drugs suggests the existence of individual and/or familial resilient factors that protect these mentally healthy individuals. Here, I give a brief overview of the epigenetic bases of responses to stressful events and of epigenetic changes associated with the administration of drugs of abuse. I also discuss the psychobiology of resilience and alterations in epigenetic markers that have been observed in models of resilience. Finally, I suggest the possibility that treatment of addiction should involve cognitive and pharmacological approaches that enhance resilience in at risk individuals. Similar approaches should also be used with patients who have already succumbed to the nefarious effects of addictive substances.
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Affiliation(s)
- Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, DHHS/NIH/NIDA Intramural Research Program, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA.
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113
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Transcriptome organization for chronic alcohol abuse in human brain. Mol Psychiatry 2015; 20:1438-47. [PMID: 25450227 PMCID: PMC4452464 DOI: 10.1038/mp.2014.159] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 10/07/2014] [Accepted: 10/09/2014] [Indexed: 12/18/2022]
Abstract
Alcohol dependence is a heterogeneous psychiatric disorder characterized by high genetic heritability and neuroadaptations occurring from repeated drug exposure. Through an integrated systems approach we observed consistent differences in transcriptome organization within postmortem human brain tissue associated with the lifetime consumption of alcohol. Molecular networks, determined using high-throughput RNA sequencing, for drinking behavior were dominated by neurophysiological targets and signaling mechanisms of alcohol. The systematic structure of gene sets demonstrates a novel alliance of multiple ion channels, and related processes, underlying lifetime alcohol consumption. Coordinate expression of these transcripts was enriched for genome-wide association signals in alcohol dependence and a meta-analysis of alcohol self-administration in mice. Further dissection of genes within alcohol consumption networks revealed the potential interaction of alternatively spliced transcripts. For example, expression of a human-specific isoform of the voltage-gated sodium channel subunit SCN4B was significantly correlated to lifetime alcohol consumption. Overall, our work demonstrates novel convergent evidence for biological networks related to excessive alcohol consumption, which may prove fundamentally important in the development of pharmacotherapies for alcohol dependence.
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114
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Ozburn AR, Janowsky AJ, Crabbe JC. Commonalities and Distinctions Among Mechanisms of Addiction to Alcohol and Other Drugs. Alcohol Clin Exp Res 2015; 39:1863-77. [PMID: 26431116 PMCID: PMC4594192 DOI: 10.1111/acer.12810] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/10/2015] [Indexed: 01/25/2023]
Abstract
BACKGROUND Alcohol abuse is comorbid with abuse of many other drugs, some with similar pharmacology and others quite different. This leads to the hypothesis of an underlying, unitary dysfunctional neurobiological basis for substance abuse risk and consequences. METHODS In this review, we discuss commonalities and distinctions of addiction to alcohol and other drugs. We focus on recent advances in preclinical studies using rodent models of drug self-administration. RESULTS While there are specific behavioral and molecular manifestations common to alcohol, psychostimulant, opioid, and nicotine dependence, attempts to propose a unifying theory of the addictions inevitably face details where distinctions are found among classes of drugs. CONCLUSIONS For alcohol, versus other drugs of abuse, we discuss and compare advances in: (i) neurocircuitry important for the different stages of drug dependence; (ii) transcriptomics and genetical genomics; and (iii) enduring effects, noting in particular the contributions of behavioral genetics and animal models.
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Affiliation(s)
- Angela R. Ozburn
- Research & Development Service, Portland VA Medical Center, Portland, Oregon, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, School of Medicine, Portland, Oregon, USA
- Portland Alcohol Research Center, Oregon Health & Science University, Portland, Oregon, USA
| | - Aaron J. Janowsky
- Research & Development Service, Portland VA Medical Center, Portland, Oregon, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, School of Medicine, Portland, Oregon, USA
- Department of Psychiatry, Oregon Health & Science University, School of Medicine, Portland, Oregon, USA and Methamphetamine Abuse Research Center, Oregon Health & Science University, Portland, Oregon, USA
| | - John C. Crabbe
- Research & Development Service, Portland VA Medical Center, Portland, Oregon, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, School of Medicine, Portland, Oregon, USA
- Portland Alcohol Research Center, Oregon Health & Science University, Portland, Oregon, USA
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Veazey KJ, Parnell SE, Miranda RC, Golding MC. Dose-dependent alcohol-induced alterations in chromatin structure persist beyond the window of exposure and correlate with fetal alcohol syndrome birth defects. Epigenetics Chromatin 2015; 8:39. [PMID: 26421061 PMCID: PMC4587584 DOI: 10.1186/s13072-015-0031-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/15/2015] [Indexed: 01/16/2023] Open
Abstract
Background In recent years, we have come to recognize that a multitude of in utero exposures have the capacity to induce the development of congenital and metabolic defects. As most of these encounters manifest their effects beyond the window of exposure, deciphering the mechanisms of teratogenesis is incredibly difficult. For many agents, altered epigenetic programming has become suspect in transmitting the lasting signature of exposure leading to dysgenesis. However, while several chemicals can perturb chromatin structure acutely, for many agents (particularly alcohol) it remains unclear if these modifications represent transient responses to exposure or heritable lesions leading to pathology. Results Here, we report that mice encountering an acute exposure to alcohol on gestational Day-7 exhibit significant alterations in chromatin structure (histone 3 lysine 9 dimethylation, lysine 9 acetylation, and lysine 27 trimethylation) at Day-17, and that these changes strongly correlate with the development of craniofacial and central nervous system defects. Using a neural cortical stem cell model, we find that the epigenetic changes arising as a consequence of alcohol exposure are heavily dependent on the gene under investigation, the dose of alcohol encountered, and that the signatures arising acutely differ significantly from those observed after a 4-day recovery period. Importantly, the changes observed post-recovery are consistent with those modeled in vivo, and associate with alterations in transcripts encoding multiple homeobox genes directing neurogenesis. Unexpectedly, we do not observe a correlation between alcohol-induced changes in chromatin structure and alterations in transcription. Interestingly, the majority of epigenetic changes observed occur in marks associated with repressive chromatin structure, and we identify correlative disruptions in transcripts encoding Dnmt1, Eed, Ehmt2 (G9a), EzH2, Kdm1a, Kdm4c, Setdb1, Sod3, Tet1 and Uhrf1. Conclusions These observations suggest that the immediate and long-term impacts of alcohol exposure on chromatin structure are distinct, and hint at the existence of a possible coordinated
epigenetic response to ethanol during development. Collectively, our results indicate that alcohol-induced modifications to chromatin structure persist beyond the window of exposure, and likely contribute to the development of fetal alcohol syndrome-associated congenital abnormalities. Electronic supplementary material The online version of this article (doi:10.1186/s13072-015-0031-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kylee J Veazey
- Room 338 VMA, 4466 TAMU, Department of Veterinary Physiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466 USA
| | - Scott E Parnell
- Bowles Center for Alcohol Studies and Department of Cell Biology and Physiology, School of Medicine, CB# 7178, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Rajesh C Miranda
- Texas A&M Health Sciences Center, Texas A&M University, 8441 State Highway 47, Clinical Building 1, Suite 3100, Bryan, TX 77807 USA
| | - Michael C Golding
- Room 338 VMA, 4466 TAMU, Department of Veterinary Physiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466 USA
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116
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Finegersh A, Ferguson C, Maxwell S, Mazariegos D, Farrell D, Homanics GE. Repeated vapor ethanol exposure induces transient histone modifications in the brain that are modified by genotype and brain region. Front Mol Neurosci 2015; 8:39. [PMID: 26300722 PMCID: PMC4524924 DOI: 10.3389/fnmol.2015.00039] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/10/2015] [Indexed: 01/01/2023] Open
Abstract
Background: Emerging research implicates ethanol (EtOH)-induced epigenetic modifications in regulating gene expression and EtOH consumption. However, consensus on specific epigenetic modifications induced by EtOH has not yet emerged, making it challenging to identify mechanisms and develop targeted treatments. We hypothesized that chronic intermittent EtOH (CIE) induces persistent changes in histone modifications across the cerebral cortex (CCx), nucleus accumbens (NAc), and prefrontal cortex (PFC), and that these histone modifications are altered in a knock-in mouse strain with altered sensitivity to EtOH. Methods: C57BL/6J (B6) mice and α1SHLA knockin mice on a B6 background were exposed to 16 h of vapor EtOH or room air followed by 8 h of room air for 4 consecutive days and sacrificed at multiple time points up to 72 h following exposure. Histone modifications were assessed using Western blot and dot blot. RT-qPCR was used to study expression of chromatin modifying enzymes in NAc and PFC. Results: In NAc, CIE significantly increased acetylation of histone subunit H3 at lysine 9 (H3K9ac) but not lysine 14 (H3K14ac) or lysine 27 (H3K27ac). In PFC, CIE significantly increased H3K9ac but not H3K14 or H3K27ac. There were no significant changes at 8 or 72 h after EtOH exposure in either NAc or PFC. CIE was also associated with increased expression of Kat2b, Kat5, and Tet1 in NAc but not PFC. In CCx, CIE had a significant effect on levels of H3K18ac; there was also a significant effect of the α1SHLA mutation on levels of H3K27me3, H3K14ac, and H3K18ac as well as a trend for H3S10pK14ac. Conclusions: The EtOH-induced histone modifications observed were transient and varied significantly between brain regions. A genetic mutation that altered sensitivity to EtOH was associated with altered induction of histone modifications during CIE. These results have implications for studying EtOH-induced histone modifications and EtOH sensitivity.
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Affiliation(s)
- Andrey Finegersh
- Departments of Anesthesiology, Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA
| | - Carolyn Ferguson
- Departments of Anesthesiology, Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA
| | - Seth Maxwell
- Departments of Anesthesiology, Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA
| | - David Mazariegos
- Departments of Anesthesiology, Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA
| | - Daniel Farrell
- Departments of Anesthesiology, Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA
| | - Gregg E Homanics
- Departments of Anesthesiology, Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA
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Kordi-Tamandani DM, Tajoddini S, Salimi F. Promoter Methylation and BDNF and DAT1 Gene Expression Profiles in Patients with Drug Addiction. Pathobiology 2015; 82:94-9. [DOI: 10.1159/000430465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 04/14/2015] [Indexed: 11/19/2022] Open
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Simon-O'Brien E, Alaux-Cantin S, Warnault V, Buttolo R, Naassila M, Vilpoux C. The histone deacetylase inhibitor sodium butyrate decreases excessive ethanol intake in dependent animals. Addict Biol 2015; 20:676-89. [PMID: 25041570 DOI: 10.1111/adb.12161] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Converging evidence indicates that epigenetic mechanisms are involved in drug addiction, and that enzymes involved in chromatin remodeling may represent interesting targets in addiction treatment. No study has addressed whether histone deacetylase (HDAC) inhibitors (HDACi) can reduce excessive ethanol intake or prevent relapse in alcohol-dependent animals. Here, we assessed the effects of two HDACi, sodium butyrate (NaB) and MS-275, in the operant ethanol self-administration paradigm in dependent and non-dependent rats. To characterize some of the epigenetic mechanisms associated with alcohol dependence and NaB treatment, we measured the levels of histone H3 acetylation in different brain areas of dependent and non-dependent rats, submitted or not to NaB treatment. Our results demonstrated that (1) NaB and MS-275 strongly decreased excessive alcohol intake of dependent rats in the operant ethanol self-administration paradigm but not of non-dependent rats; (2) NaB reduced excessive drinking and prevented the escalation of ethanol intake in the intermittent access to 20% ethanol paradigm; and (3) NaB completely blocked the increase of ethanol consumption induced by an alcohol deprivation, thus demonstrating a preventive effect of NaB on relapse. The mapping of cerebral histone H3 acetylation revealed a hyperacetylation in the amygdala and cortical areas in dependent rats. Interestingly, NaB did not exacerbate the hyperacetylation observed in these regions, but instead restored it, specifically in cortical areas. Altogether, our results clearly demonstrated the efficacy of NaB in preventing excessive ethanol intake and relapse and support the hypothesis that HDACi may have a potential use in alcohol addiction treatment.
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Affiliation(s)
- Emmanuelle Simon-O'Brien
- UFR de Pharmacie; INSERM ERI 24; Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP); Université de Picardie Jules Verne; Amiens France
| | - Stéphanie Alaux-Cantin
- UFR de Pharmacie; INSERM ERI 24; Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP); Université de Picardie Jules Verne; Amiens France
| | - Vincent Warnault
- UFR de Pharmacie; INSERM ERI 24; Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP); Université de Picardie Jules Verne; Amiens France
| | - Romain Buttolo
- UFR de Pharmacie; INSERM ERI 24; Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP); Université de Picardie Jules Verne; Amiens France
| | - Mickaël Naassila
- UFR de Pharmacie; INSERM ERI 24; Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP); Université de Picardie Jules Verne; Amiens France
| | - Catherine Vilpoux
- UFR de Pharmacie; INSERM ERI 24; Groupe de Recherche sur l'Alcool et les Pharmacodépendances (GRAP); Université de Picardie Jules Verne; Amiens France
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119
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Farris SP, Harris RA, Ponomarev I. Epigenetic modulation of brain gene networks for cocaine and alcohol abuse. Front Neurosci 2015; 9:176. [PMID: 26041984 PMCID: PMC4438259 DOI: 10.3389/fnins.2015.00176] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/30/2015] [Indexed: 12/19/2022] Open
Abstract
Cocaine and alcohol are two substances of abuse that prominently affect the central nervous system (CNS). Repeated exposure to cocaine and alcohol leads to longstanding changes in gene expression, and subsequent functional CNS plasticity, throughout multiple brain regions. Epigenetic modifications of histones are one proposed mechanism guiding these enduring changes to the transcriptome. Characterizing the large number of available biological relationships as network models can reveal unexpected biochemical relationships. Clustering analysis of variation from whole-genome sequencing of gene expression (RNA-Seq) and histone H3 lysine 4 trimethylation (H3K4me3) events (ChIP-Seq) revealed the underlying structure of the transcriptional and epigenomic landscape within hippocampal postmortem brain tissue of drug abusers and control cases. Distinct sets of interrelated networks for cocaine and alcohol abuse were determined for each abusive substance. The network approach identified subsets of functionally related genes that are regulated in agreement with H3K4me3 changes, suggesting cause and effect relationships between this epigenetic mark and gene expression. Gene expression networks consisted of recognized substrates for addiction, such as the dopamine- and cAMP-regulated neuronal phosphoprotein PPP1R1B/DARPP-32 and the vesicular glutamate transporter SLC17A7/VGLUT1 as well as potentially novel molecular targets for substance abuse. Through a systems biology based approach our results illustrate the utility of integrating epigenetic and transcript expression to establish relevant biological networks in the human brain for addiction. Future work with laboratory models may clarify the functional relevance of these gene networks for cocaine and alcohol, and provide a framework for the development of medications for the treatment of addiction.
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Affiliation(s)
- Sean P Farris
- Waggoner Center for Alcohol & Addiction Research and The College of Pharmacy, University of Texas at Austin Austin, TX, USA
| | - Robert A Harris
- Waggoner Center for Alcohol & Addiction Research and The College of Pharmacy, University of Texas at Austin Austin, TX, USA
| | - Igor Ponomarev
- Waggoner Center for Alcohol & Addiction Research and The College of Pharmacy, University of Texas at Austin Austin, TX, USA
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120
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Iancu OD, Colville A, Oberbeck D, Darakjian P, McWeeney SK, Hitzemann R. Cosplicing network analysis of mammalian brain RNA-Seq data utilizing WGCNA and Mantel correlations. Front Genet 2015; 6:174. [PMID: 26029240 PMCID: PMC4429622 DOI: 10.3389/fgene.2015.00174] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 04/21/2015] [Indexed: 01/06/2023] Open
Abstract
Across species and tissues and especially in the mammalian brain, production of gene isoforms is widespread. While gene expression coordination has been previously described as a scale-free coexpression network, the properties of transcriptome-wide isoform production coordination have been less studied. Here we evaluate the system-level properties of cosplicing in mouse, macaque, and human brain gene expression data using a novel network inference procedure. Genes are represented as vectors/lists of exon counts and distance measures sensitive to exon inclusion rates quantifies differences across samples. For all gene pairs, distance matrices are correlated across samples, resulting in cosplicing or cotranscriptional network matrices. We show that networks including cosplicing information are scale-free and distinct from coexpression. In the networks capturing cosplicing we find a set of novel hubs with unique characteristics distinguishing them from coexpression hubs: heavy representation in neurobiological functional pathways, strong overlap with markers of neurons and neuroglia, long coding lengths, and high number of both exons and annotated transcripts. Further, the cosplicing hubs are enriched in genes associated with autism spectrum disorders. Cosplicing hub homologs across eukaryotes show dramatically increasing intronic lengths but stable coding region lengths. Shared transcription factor binding sites increase coexpression but not cosplicing; the reverse is true for splicing-factor binding sites. Genes with protein-protein interactions have strong coexpression and cosplicing. Additional factors affecting the networks include shared microRNA binding sites, spatial colocalization within the striatum, and sharing a chromosomal folding domain. Cosplicing network patterns remain relatively stable across species.
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Affiliation(s)
- Ovidiu D Iancu
- Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Alexandre Colville
- Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Denesa Oberbeck
- Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Priscila Darakjian
- Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Shannon K McWeeney
- Division of Biostatistics, Public Health and Preventative Medicine, Oregon Health & Science University Portland, OR, USA
| | - Robert Hitzemann
- Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA ; Research Service, Veterans Affairs Medical Center Portland, OR, USA
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121
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Mitochondria in health, aging and diseases: the epigenetic perspective. Biogerontology 2015; 16:569-85. [DOI: 10.1007/s10522-015-9562-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 02/19/2015] [Indexed: 01/15/2023]
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122
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McClintick JN, McBride WJ, Bell RL, Ding ZM, Liu Y, Xuei X, Edenberg HJ. Gene expression changes in serotonin, GABA-A receptors, neuropeptides and ion channels in the dorsal raphe nucleus of adolescent alcohol-preferring (P) rats following binge-like alcohol drinking. Pharmacol Biochem Behav 2014; 129:87-96. [PMID: 25542586 PMCID: PMC4302739 DOI: 10.1016/j.pbb.2014.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/13/2014] [Accepted: 12/17/2014] [Indexed: 12/31/2022]
Abstract
Alcohol binge-drinking during adolescence is a serious public health concern with long-term consequences. We used RNA sequencing to assess the effects of excessive adolescent ethanol binge-drinking on gene expression in the dorsal raphe nucleus (DRN) of alcohol preferring (P) rats. Repeated binges across adolescence (three 1h sessions across the dark-cycle per day, 5 days per week for 3 weeks starting at 28 days of age; ethanol intakes of 2.5-3 g/kg/session) significantly altered the expression of approximately one-third of the detected genes. Multiple neurotransmitter systems were altered, with the largest changes in the serotonin system (21 of 23 serotonin-related genes showed decreased expression) and GABA-A receptors (8 decreased and 2 increased). Multiple neuropeptide systems were also altered, with changes in the neuropeptide Y and corticotropin-releasing hormone systems similar to those associated with increased drinking and decreased resistance to stress. There was increased expression of 21 of 32 genes for potassium channels. Expression of downstream targets of CREB signaling was increased. There were also changes in expression of genes involved in inflammatory processes, axonal guidance, growth factors, transcription factors, and several intracellular signaling pathways. These widespread changes indicate that excessive binge drinking during adolescence alters the functioning of the DRN and likely its modulation of many regions of the central nervous system, including the mesocorticolimbic system.
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Affiliation(s)
- Jeanette N McClintick
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, United States; Center for Medical Genomics, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - William J McBride
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Richard L Bell
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Zheng-Ming Ding
- Institute of Psychiatric Research, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Yunlong Liu
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Xiaoling Xuei
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, United States; Center for Medical Genomics, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Howard J Edenberg
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, United States; Center for Medical Genomics, Indiana University School of Medicine, Indianapolis, IN 46202, United States; Department of Medical & Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
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Dominguez G, Dagnas M, Decorte L, Vandesquille M, Belzung C, Béracochéa D, Mons N. Rescuing prefrontal cAMP-CREB pathway reverses working memory deficits during withdrawal from prolonged alcohol exposure. Brain Struct Funct 2014; 221:865-77. [PMID: 25388276 DOI: 10.1007/s00429-014-0941-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 11/03/2014] [Indexed: 11/26/2022]
Abstract
Both human and animal studies indicate that alcohol withdrawal following chronic alcohol consumption (CAC) impairs many of the cognitive functions which rely on the prefrontal cortex (PFC). A candidate signaling cascade contributing to memory deficits during alcohol withdrawal is the protein kinase A (PKA)/cAMP-responsive element binding (CREB) cascade, although the role of PKA/CREB cascade in behavioral and molecular changes during sustained withdrawal period remains largely unknown. We demonstrated that 1 week (1W) or 6 weeks (6W) withdrawal after 6-month CAC impairs working memory (WM) in a T-maze spontaneous alternation task and reduces phosphorylated CREB (pCREB) in the PFC but not the dorsal CA1 region (dCA1) of the hippocampus compared with CAC and water conditions. In contrast, both CAC-unimpaired and withdrawn-impaired mice exhibited decreased pCREB in dCA1 as well as reduced histone H4 acetylation in PFC and dCA1, compared with water controls. Next, we showed that enhancing CREB activity through rolipram administration prior to testing improved WM performance in withdrawn mice but impaired WM function in water mice. In addition, WM improvement correlates positively with increased pCREB level selectively in the PFC of withdrawn mice. Results further indicate that direct infusion of the PKA activator (Sp-cAMPS) into the PFC significantly improves or impairs, respectively, WM performance in withdrawn and water animals. In contrast, Sp-cAMPS had no effect on WM when infused into the dCA1. Collectively, these results provide strong support that dysregulation of PKA/CREB-dependent processes in prefrontal neurons is a critical molecular signature underlying cognitive decline during alcohol withdrawal.
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Affiliation(s)
- G Dominguez
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Nouvelle Université de Bordeaux, CNRS UMR 5287, Talence, France
- U-930 Inserm, Université François Rabelais, Parc Grandmont, Tours, France
| | - M Dagnas
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Nouvelle Université de Bordeaux, CNRS UMR 5287, Talence, France
| | - L Decorte
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Nouvelle Université de Bordeaux, CNRS UMR 5287, Talence, France
| | - M Vandesquille
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Nouvelle Université de Bordeaux, CNRS UMR 5287, Talence, France
| | - C Belzung
- U-930 Inserm, Université François Rabelais, Parc Grandmont, Tours, France
| | - D Béracochéa
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Nouvelle Université de Bordeaux, CNRS UMR 5287, Talence, France
| | - N Mons
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Nouvelle Université de Bordeaux, CNRS UMR 5287, Talence, France.
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Enoch MA, Rosser AA, Zhou Z, Mash DC, Yuan Q, Goldman D. Expression of glutamatergic genes in healthy humans across 16 brain regions; altered expression in the hippocampus after chronic exposure to alcohol or cocaine. GENES, BRAIN, AND BEHAVIOR 2014; 13:758-68. [PMID: 25262781 PMCID: PMC4241133 DOI: 10.1111/gbb.12179] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 08/25/2014] [Accepted: 09/25/2014] [Indexed: 12/29/2022]
Abstract
We analyzed global patterns of expression in genes related to glutamatergic neurotransmission (glutamatergic genes) in healthy human adult brain before determining the effects of chronic alcohol and cocaine exposure on gene expression in the hippocampus. RNA-Seq data from 'BrainSpan' was obtained across 16 brain regions from nine control adults. We also generated RNA-Seq data from postmortem hippocampus from eight alcoholics, eight cocaine addicts and eight controls. Expression analyses were undertaken of 28 genes encoding glutamate ionotropic (AMPA, kainate, NMDA) and metabotropic receptor subunits, together with glutamate transporters. The expression of each gene was fairly consistent across the brain with the exception of the cerebellum, the thalamic mediodorsal nucleus and the striatum. GRIN1, encoding the essential NMDA subunit, had the highest expression across all brain regions. Six factors accounted for 84% of the variance in global gene expression. GRIN2B (encoding GluN2B), was up-regulated in both alcoholics and cocaine addicts (FDR corrected P = 0.008). Alcoholics showed up-regulation of three genes relative to controls and cocaine addicts: GRIA4 (encoding GluA4), GRIK3 (GluR7) and GRM4 (mGluR4). Expression of both GRM3 (mGluR3) and GRIN2D (GluN2D) was up-regulated in alcoholics and down-regulated in cocaine addicts relative to controls. Glutamatergic genes are moderately to highly expressed throughout the brain. Six factors explain nearly all the variance in global gene expression. At least in the hippocampus, chronic alcohol use largely up-regulates glutamatergic genes. The NMDA GluN2B receptor subunit might be implicated in a common pathway to addiction, possibly in conjunction with the GABAB1 receptor subunit.
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Affiliation(s)
- Mary-Anne Enoch
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Alexandra A. Rosser
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Zhifeng Zhou
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | | | - Qiaoping Yuan
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - David Goldman
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
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126
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Maze I, Shen L, Zhang B, Garcia BA, Shao N, Mitchell A, Sun H, Akbarian S, Allis CD, Nestler EJ. Analytical tools and current challenges in the modern era of neuroepigenomics. Nat Neurosci 2014; 17:1476-90. [PMID: 25349914 DOI: 10.1038/nn.3816] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 08/20/2014] [Indexed: 12/14/2022]
Abstract
Over the past decade, rapid advances in epigenomics research have extensively characterized critical roles for chromatin regulatory events during normal periods of eukaryotic cell development and plasticity, as well as part of aberrant processes implicated in human disease. Application of such approaches to studies of the CNS, however, is more recent. Here we provide a comprehensive overview of available tools for analyzing neuroepigenomics data, as well as a discussion of pending challenges specific to the field of neuroscience. Integration of numerous unbiased genome-wide and proteomic approaches will be necessary to fully understand the neuroepigenome and the extraordinarily complex nature of the human brain. This will be critical to the development of future diagnostic and therapeutic strategies aimed at alleviating the vast array of heterogeneous and genetically distinct disorders of the CNS.
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Affiliation(s)
- Ian Maze
- 1] Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, USA. [2] Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Li Shen
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ningyi Shao
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Amanda Mitchell
- 1] Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA. [2] Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - HaoSheng Sun
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Schahram Akbarian
- 1] Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA. [2] Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - C David Allis
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, New York, USA
| | - Eric J Nestler
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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127
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The role of DNA methylation: a challenge for the DOHaD paradigm in going beyond the historical debate. J Dev Orig Health Dis 2014; 6:2-4. [DOI: 10.1017/s2040174414000464] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A heritage of considerable research into such phenomena as parental imprinting and carcinogenesis is an almost axiomatic association of the DNA methylation epigenetic mark with the silencing of gene expression. However, the increasing technical resolution afforded by burgeoning -omics technologies reveals that a more elaborate interaction may exist between DNA methylation, within sub-regions of gene structure and/or specific dinucleotide sites, and levels of gene activity. Furthermore, seminal observations from the field of DOHaD, which clearly define the alignment of sequential epigenetic modifications and gene activity appear not to support a strictly causal relationship between DNA methylation and gene silencing. The temporal element implicit within DOHaD studies provides a useful framework within which to further explore the role of epigenetic mechanisms and in particular perhaps, to address the question of ‘deterministic intent’ when implicating the epigenetic regulation of gene activity in the manifestation of phenotype.
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128
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Sadri-Vakili G. Cocaine triggers epigenetic alterations in the corticostriatal circuit. Brain Res 2014; 1628:50-9. [PMID: 25301690 DOI: 10.1016/j.brainres.2014.09.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/22/2014] [Accepted: 09/27/2014] [Indexed: 01/04/2023]
Abstract
Acute and repeated exposure to cocaine induces long-lasting alterations in neural networks that underlie compulsive drug seeking and taking. Cocaine exposure triggers complex adaptations in the brain that are mediated by dynamic patterns of gene expression that are translated into enduring changes. Recently, epigenetic modifications have been unveiled as critical mechanisms underlying addiction that contribute to drug-induced plasticity by regulating gene expression. These alterations are also now linked to the heritability of cocaine-induced phenotypes. This review focuses on how changes in the epigenome, such as altered DNA methylation, histone modifications, and microRNAs, regulate transcription of specific genes that contribute to cocaine addiction.
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Affiliation(s)
- Ghazaleh Sadri-Vakili
- MassGeneral Institute for Neurodegenerative Disease Massachusetts General Hospital 114 16th Street, Charlestown, MA 02129-4404, USA.
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129
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Abstract
Despite the importance of numerous psychosocial factors, at its core, drug addiction involves a biological process: the ability of repeated exposure to a drug of abuse to induce changes in a vulnerable brain that drive the compulsive seeking and taking of drugs, and loss of control over drug use, that define a state of addiction. Here, we review the types of molecular and cellular adaptations that occur in specific brain regions to mediate addiction-associated behavioral abnormalities. These include alterations in gene expression achieved in part via epigenetic mechanisms, plasticity in the neurophysiological functioning of neurons and synapses, and associated plasticity in neuronal and synaptic morphology mediated in part by altered neurotrophic factor signaling. Each of these types of drug-induced modifications can be viewed as a form of “cellular or molecular memory.” Moreover, it is striking that most addiction-related forms of plasticity are very similar to the types of plasticity that have been associated with more classic forms of “behavioral memory,” perhaps reflecting the finite repertoire of adaptive mechanisms available to neurons when faced with environmental challenges. Finally, addiction-related molecular and cellular adaptations involve most of the same brain regions that mediate more classic forms of memory, consistent with the view that abnormal memories are important drivers of addiction syndromes. The goal of these studies which aim to explicate the molecular and cellular basis of drug addiction is to eventually develop biologically based diagnostic tests, as well as more effective treatments for addiction disorders.
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Affiliation(s)
- Eric J Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, USA
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130
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McClintick JN, Brooks AI, Deng L, Liang L, Wang JC, Kapoor M, Xuei X, Foroud T, Tischfield JA, Edenberg HJ. Ethanol treatment of lymphoblastoid cell lines from alcoholics and non-alcoholics causes many subtle changes in gene expression. Alcohol 2014; 48:603-10. [PMID: 25129674 PMCID: PMC4730944 DOI: 10.1016/j.alcohol.2014.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To elucidate the effects of a controlled exposure to ethanol on gene expression, we studied lymphoblastoid cell lines (LCLs) from 21 alcoholics and 21 controls. We cultured each cell line for 24 h with and without 75 mM ethanol and measured gene expression using microarrays. Differences in expression between LCLs from alcoholics and controls included 13 genes previously identified as associated with alcoholism or related traits, including KCNA3, DICER1, ZNF415, CAT, SLC9A9, and PPARGC1B. The paired design allowed us to detect very small changes due to ethanol treatment: ethanol altered the expression of 37% of the probe sets (51% of the unique named genes) expressed in these LCLs, most by modest amounts. Ninety-nine percent of the named genes expressed in the LCLs were also expressed in brain. Key pathways affected by ethanol include cytokine, TNF, and NFκB signaling. Among the genes affected by ethanol were ANK3, EPHB1, SLC1A1, SLC9A9, NRD1, and SH3BP5, which were reported to be associated with alcoholism or related phenotypes in 2 genome-wide association studies. Genes that either differed in expression between alcoholics and controls or were affected by ethanol exposure are candidates for further study.
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Affiliation(s)
- Jeanette N McClintick
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrew I Brooks
- Department of Genetics and the Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
| | - Li Deng
- Department of Genetics and the Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
| | - Li Liang
- Department of Genetics and the Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
| | - Jen C Wang
- Department of Psychiatry, B8134, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Manav Kapoor
- Department of Psychiatry, B8134, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Xiaoling Xuei
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Tatiana Foroud
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jay A Tischfield
- Department of Genetics and the Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
| | - Howard J Edenberg
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA.
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131
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Finegersh A, Homanics GE. Acute ethanol alters multiple histone modifications at model gene promoters in the cerebral cortex. Alcohol Clin Exp Res 2014; 38:1865-73. [PMID: 24942484 DOI: 10.1111/acer.12465] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 04/08/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Ethanol (EtOH) exposure alters gene expression in the cerebral cortex (CCx); however, mechanisms of EtOH-induced gene regulation are not well understood. We hypothesized that EtOH regulates gene expression by differentially altering histone modifications at gene promoters that are up- and down-regulated by EtOH. Such epigenetic mechanisms may ultimately contribute to EtOH-induced neuro-adaptations that underlie tolerance, dependence, and EtOH-use disorders. METHODS Eight-week-old, male C57BL/6J mice were treated with 3 g/kg EtOH (intraperitoneally) or saline and sacrificed 6 hours after injection; the CCx and hippocampus (HC) were immediately removed and flash frozen. Chromatin immunoprecipitation was used to study the association of model gene promoters with histone modifications. Western blot was used to detect global changes in the histone modifications studied. We also used a polymerase chain reaction (PCR) array to identify changes in expression of chromatin-modifying enzymes. RESULTS In CCx, acute EtOH decreased expression of Gad1, Hdac2, and Hdac11, which was associated with decreased histone acetylation at the Gad1 and Hdac2 promoters; we also identified increased expression of Mt1, Mt2, Egr1, which was associated with increased H3K4me3 levels at the Mt2 promoter and decreased H3K27me3 levels at the Mt1 promoter. We identified an increase in global levels of H3K4me3 in CCx as well as a global increase in H3K9ac and H3K14ac in HC. The PCR array identified decreased expression of Csrp2 bp, Hdac2, and Hdac11 as well as increased expression of Kat2b in CCx. CONCLUSIONS Acute EtOH induces chromatin remodeling at model up- and down-regulated genes in CCx. Different patterns of histone modifications at these gene promoters indicate that EtOH may be acting through multiple histone-modifying enzymes to alter gene expression; in particular, differential expression of Kat2b, Hdac2, Hdac11, and Csrp2 bp in CCx may mediate EtOH-induced chromatin remodeling. Additional studies are necessary to determine the relationship between EtOH-induced changes in histone-modifying enzymes, specific EtOH-induced histone modifications, and gene expression.
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Affiliation(s)
- Andrey Finegersh
- Departments of Anesthesiology and Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
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132
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Identification of a QTL in Mus musculus for alcohol preference, withdrawal, and Ap3m2 expression using integrative functional genomics and precision genetics. Genetics 2014; 197:1377-93. [PMID: 24923803 DOI: 10.1534/genetics.114.166165] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Extensive genetic and genomic studies of the relationship between alcohol drinking preference and withdrawal severity have been performed using animal models. Data from multiple such publications and public data resources have been incorporated in the GeneWeaver database with >60,000 gene sets including 285 alcohol withdrawal and preference-related gene sets. Among these are evidence for positional candidates regulating these behaviors in overlapping quantitative trait loci (QTL) mapped in distinct mouse populations. Combinatorial integration of functional genomics experimental results revealed a single QTL positional candidate gene in one of the loci common to both preference and withdrawal. Functional validation studies in Ap3m2 knockout mice confirmed these relationships. Genetic validation involves confirming the existence of segregating polymorphisms that could account for the phenotypic effect. By exploiting recent advances in mouse genotyping, sequence, epigenetics, and phylogeny resources, we confirmed that Ap3m2 resides in an appropriately segregating genomic region. We have demonstrated genetic and alcohol-induced regulation of Ap3m2 expression. Although sequence analysis revealed no polymorphisms in the Ap3m2-coding region that could account for all phenotypic differences, there are several upstream SNPs that could. We have identified one of these to be an H3K4me3 site that exhibits strain differences in methylation. Thus, by making cross-species functional genomics readily computable we identified a common QTL candidate for two related bio-behavioral processes via functional evidence and demonstrate sufficiency of the genetic locus as a source of variation underlying two traits.
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133
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Wu Y, Jin Y, Pan W, Ye C, Sun X, Sun Y, Hu B, Zhou J. Comparative proteomics analysis of host cells infected with Brucella abortus A19. Electrophoresis 2014; 35:1130-43. [PMID: 24519676 DOI: 10.1002/elps.201300378] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 01/18/2023]
Abstract
We carried out a proteomic analysis of THP-1-derived macrophages with and without Brucella abortus A19 (B. abortus A19) infection in order to study the cellular responses to B. abortus A19. The proteins were analyzed at different time points after infection with 2DE followed by MALDI-TOF/TOF identification. Comparative analysis of multiple 2DE gels revealed that the majority of changes in protein abundance appeared between 48 and 96 h after infection. MS identified 44 altered proteins, including 20 proteins increased in abundance and 24 proteins decreased in abundance, which were found to be involved in cytoskeleton, signal transduction, energy metabolism, host macromolecular biosynthesis, and stress response. Moreover, 22 genes corresponding to the altered proteins were quantified by real-time RT-PCR to examine the transcriptional profiles between infected and uninfected THP-1-derived macrophages. Finally, we mapped the altered pathways and networks using ingenuity pathway analysis, which suggested that the altered protein species were heavily favored germ cell-Sertoli cell junction signaling as the primary pathway. Furthermore, mechanisms of viral exit from host cell and macrophage stimulating protein-recepteur d'origine nantais signaling appeared to be major pathways modulated in infected cells. This study effectively provides useful dynamic protein-related information concerning B. abortus infection in macrophages.
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Affiliation(s)
- Yongping Wu
- College of Animal Sciences and Technology, Zhejiang A&F University, Hangzhou, P.R. China; Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, P.R. China
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134
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Caputi FF, Di Benedetto M, Carretta D, Bastias del Carmen Candia S, D'Addario C, Cavina C, Candeletti S, Romualdi P. Dynorphin/KOP and nociceptin/NOP gene expression and epigenetic changes by cocaine in rat striatum and nucleus accumbens. Prog Neuropsychopharmacol Biol Psychiatry 2014; 49:36-46. [PMID: 24184686 DOI: 10.1016/j.pnpbp.2013.10.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/23/2013] [Accepted: 10/23/2013] [Indexed: 12/11/2022]
Abstract
Cocaine induces neurochemical changes of endogenous prodynorphin-kappa opioid receptor (pDYN-KOP) and pronociceptin/orphaninFQ-nociceptin receptor (pN/OFQ-NOP) systems. Both systems play an important role in rewarding mechanisms and addictive stimulus processing by modulating drug-induced dopaminergic activation in the mesocortico-limbic brain areas. They are also involved in regulating stress mechanisms related to addiction. The aim of this study was to investigate possible changes of gene expression of the dynorphinergic and nociceptinergic system components in the nucleus accumbens (NA) and in medial and lateral caudate putamen (mCPu and lCPu, respectively) of rats, following chronic subcutaneous infusion of cocaine. In addition, the epigenetic histone modifications H3K4me3 and H3K27me3 (an activating and a repressive marker, respectively) at the promoter level of the pDYN, KOP, pN/OFQ and NOP genes were investigated. Results showed that cocaine induced pDYN gene expression up-regulation in the NA and lCPu, and its down-regulation in the mCPu, whereas KOP mRNA levels were unchanged. Moreover, cocaine exposure decreased pN/OFQ gene expression in the NA and lCPu, while NOP mRNA levels appeared significantly increased in the NA and decreased in the lCPu. Specific changes of the H3K4me3 and H3K27me3 levels were found at pDYN, pN/OFQ, and NOP gene promoter, consistent with the observed gene expression alterations. The present findings contribute to better define the role of endogenous pDYN-KOP and pN/OFQ-NOP systems in neuroplasticity mechanisms following chronic cocaine treatment. The epigenetic histone modifications underlying the gene expression changes likely mediate the effects of cocaine on transcriptional regulation of specific gene promoters that result in long-lasting drug-induced plasticity.
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Affiliation(s)
- Francesca Felicia Caputi
- Department of Pharmacy and Biotechnologies, Alma Mater Studiorum, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Manuela Di Benedetto
- Department of Pharmacy and Biotechnologies, Alma Mater Studiorum, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Donatella Carretta
- Department of Pharmacy and Biotechnologies, Alma Mater Studiorum, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | | | - Claudio D'Addario
- Department of Pharmacy and Biotechnologies, Alma Mater Studiorum, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Chiara Cavina
- Department of Pharmacy and Biotechnologies, Alma Mater Studiorum, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Sanzio Candeletti
- Department of Pharmacy and Biotechnologies, Alma Mater Studiorum, University of Bologna, Irnerio 48, 40126 Bologna, Italy
| | - Patrizia Romualdi
- Department of Pharmacy and Biotechnologies, Alma Mater Studiorum, University of Bologna, Irnerio 48, 40126 Bologna, Italy.
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135
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Tau GZ, Marsh R, Wang Z, Torres-Sanchez T, Graniello B, Hao X, Xu D, Packard MG, Duan Y, Kangarlu A, Martinez D, Peterson BS. Neural correlates of reward-based spatial learning in persons with cocaine dependence. Neuropsychopharmacology 2014; 39:545-55. [PMID: 23917430 PMCID: PMC3895231 DOI: 10.1038/npp.2013.189] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 07/05/2013] [Accepted: 07/08/2013] [Indexed: 01/21/2023]
Abstract
Dysfunctional learning systems are thought to be central to the pathogenesis of and impair recovery from addictions. The functioning of the brain circuits for episodic memory or learning that support goal-directed behavior has not been studied previously in persons with cocaine dependence (CD). Thirteen abstinent CD and 13 healthy participants underwent MRI scanning while performing a task that requires the use of spatial cues to navigate a virtual-reality environment and find monetary rewards, allowing the functional assessment of the brain systems for spatial learning, a form of episodic memory. Whereas both groups performed similarly on the reward-based spatial learning task, we identified disturbances in brain regions involved in learning and reward in CD participants. In particular, CD was associated with impaired functioning of medial temporal lobe (MTL), a brain region that is crucial for spatial learning (and episodic memory) with concomitant recruitment of striatum (which normally participates in stimulus-response, or habit, learning), and prefrontal cortex. CD was also associated with enhanced sensitivity of the ventral striatum to unexpected rewards but not to expected rewards earned during spatial learning. We provide evidence that spatial learning in CD is characterized by disturbances in functioning of an MTL-based system for episodic memory and a striatum-based system for stimulus-response learning and reward. We have found additional abnormalities in distributed cortical regions. Consistent with findings from animal studies, we provide the first evidence in humans describing the disruptive effects of cocaine on the coordinated functioning of multiple neural systems for learning and memory.
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Affiliation(s)
- Gregory Z Tau
- Division of Child and Adolescent Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Rachel Marsh
- Division of Child and Adolescent Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Zhishun Wang
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Tania Torres-Sanchez
- Division of Child and Adolescent Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Barbara Graniello
- Division of Child and Adolescent Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Xuejun Hao
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Dongrong Xu
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Mark G Packard
- Department of Psychology, Texas A&M University, College Station, TX, USA
| | - Yunsuo Duan
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Alayar Kangarlu
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Diana Martinez
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
- Division on Substance Abuse, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
| | - Bradley S Peterson
- Department of Psychiatry, Columbia University and The New York State Psychiatric Institute, New York, NY, USA
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136
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Krishnan HR, Sakharkar AJ, Teppen TL, Berkel TDM, Pandey SC. The epigenetic landscape of alcoholism. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 115:75-116. [PMID: 25131543 DOI: 10.1016/b978-0-12-801311-3.00003-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Alcoholism is a complex psychiatric disorder that has a multifactorial etiology. Epigenetic mechanisms are uniquely capable of accounting for the multifactorial nature of the disease in that they are highly stable and are affected by environmental factors, including alcohol itself. Chromatin remodeling causes changes in gene expression in specific brain regions contributing to the endophenotypes of alcoholism such as tolerance and dependence. The epigenetic mechanisms that regulate changes in gene expression observed in addictive behaviors respond not only to alcohol exposure but also to comorbid psychopathology such as the presence of anxiety and stress. This review summarizes recent developments in epigenetic research that may play a role in alcoholism. We propose that pharmacologically manipulating epigenetic targets, as demonstrated in various preclinical models, hold great therapeutic potential in the treatment and prevention of alcoholism.
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Affiliation(s)
- Harish R Krishnan
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
| | - Amul J Sakharkar
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
| | - Tara L Teppen
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
| | - Tiffani D M Berkel
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
| | - Subhash C Pandey
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA; Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois, USA.
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137
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Zhou Z, Enoch MA, Goldman D. Gene expression in the addicted brain. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 116:251-73. [PMID: 25172478 DOI: 10.1016/b978-0-12-801105-8.00010-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Addiction is due to changes in the structure and function of the brain, including neuronal networks and the cells that comprise them. Within cells, gene expression changes can track and help explain their altered function. Transcriptional changes induced by addictive agents are dynamic and divergent and range from signal pathway-specific perturbations to widespread molecular and cellular dysregulation that can be measured by "omic" methods and that can be used to identify new pathways. The molecular effects of addiction depend on timing of exposure or withdrawal, the stage of adaptation, the brain region, and the behavioral model, there being many models of addiction. However, the molecular neural adaptations across different drug exposures, conditions, and regions are to some extent shared and can reflect common actions on pathways relevant to addiction. Epigenetic studies of DNA methylation and histone modifications and studies of regulatory RNA networks have been informative for elucidating the mechanisms of transcriptional change in the addicted brain.
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Affiliation(s)
- Zhifeng Zhou
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA.
| | - Mary-Anne Enoch
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - David Goldman
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
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138
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Altobelli G, Bogdarina IG, Stupka E, Clark AJL, Langley-Evans S. Genome-wide methylation and gene expression changes in newborn rats following maternal protein restriction and reversal by folic acid. PLoS One 2013; 8:e82989. [PMID: 24391732 PMCID: PMC3877003 DOI: 10.1371/journal.pone.0082989] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 11/08/2013] [Indexed: 11/19/2022] Open
Abstract
A large body of evidence from human and animal studies demonstrates that the maternal diet during pregnancy can programme physiological and metabolic functions in the developing fetus, effectively determining susceptibility to later disease. The mechanistic basis of such programming is unclear but may involve resetting of epigenetic marks and fetal gene expression. The aim of this study was to evaluate genome-wide DNA methylation and gene expression in the livers of newborn rats exposed to maternal protein restriction. On day one postnatally, there were 618 differentially expressed genes and 1183 differentially methylated regions (FDR 5%). The functional analysis of differentially expressed genes indicated a significant effect on DNA repair/cycle/maintenance functions and of lipid, amino acid metabolism and circadian functions. Enrichment for known biological functions was found to be associated with differentially methylated regions. Moreover, these epigenetically altered regions overlapped genetic loci associated with metabolic and cardiovascular diseases. Both expression changes and DNA methylation changes were largely reversed by supplementing the protein restricted diet with folic acid. Although the epigenetic and gene expression signatures appeared to underpin largely different biological processes, the gene expression profile of DNA methyl transferases was altered, providing a potential link between the two molecular signatures. The data showed that maternal protein restriction is associated with widespread differential gene expression and DNA methylation across the genome, and that folic acid is able to reset both molecular signatures.
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Affiliation(s)
- Gioia Altobelli
- Centre for Endocrinology, William Harvey Research Centre, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Irina G. Bogdarina
- Centre for Endocrinology, William Harvey Research Centre, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Elia Stupka
- Institute of Cell and Molecular Bioscience, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Adrian J. L. Clark
- Centre for Endocrinology, William Harvey Research Centre, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Simon Langley-Evans
- School of Biosciences, University of Nottingham, Sutton Bonington, Loughborough, United Kingdom
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139
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Daniel ZC, Akyol A, McMullen S, Langley-Evans SC. Exposure of neonatal rats to maternal cafeteria feeding during suckling alters hepatic gene expression and DNA methylation in the insulin signalling pathway. GENES AND NUTRITION 2013; 9:365. [PMID: 24357221 DOI: 10.1007/s12263-013-0365-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/10/2013] [Indexed: 12/26/2022]
Abstract
Nutrition in early life is a determinant of lifelong physiological and metabolic function. Diseases that are associated with ageing may, therefore, have their antecedents in maternal nutrition during pregnancy and lactation. Rat mothers were fed either a standard laboratory chow diet (C) or a cafeteria diet (O) based upon a varied panel of highly palatable human foods, during lactation. Their offspring were then weaned onto chow or cafeteria diet giving four groups of animals (CC, CO, OC, OO n = 9-10). Livers were harvested 10 weeks post-weaning for assessment of gene and protein expression, and DNA methylation. Cafeteria feeding post-weaning impaired glucose tolerance and was associated with sex-specific altered mRNA expression of peroxisome proliferator activated receptor gamma and components of the insulin signalling pathway (Irs2, Akt1 and IrB). Exposure to the cafeteria diet during the suckling period modified the later response to the dietary challenge. Post-weaning cafeteria feeding only down-regulated IrB when associated with cafeteria feeding during suckling (group OO, interaction of diet in weaning and lactation P = 0.041). Responses to cafeteria diet during both phases of the experiment varied between males and females. Global DNA methylation was altered in the liver following cafeteria feeding in the post-weaning period, in males but not females. Methylation of the IrB promoter was increased in group OC, but not OO (P = 0.036). The findings of this study add to a growing evidence base that suggests tissue function across the lifespan a product of cumulative modifications to the epigenome and transcriptome, which may be both tissue and sex-specific.
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Affiliation(s)
- Zoe C Daniel
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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140
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Abstract
Alcoholism has a substantial heritability yet the detection of specific genetic influences has largely proved elusive. The strongest findings are with genes encoding alcohol metabolizing enzymes. A few candidate genes such as GABRA2 have shown robust associations with alcoholism. Moreover, it has become apparent that variants in stress-related genes such as CRHR1, may only confer risk in individuals exposed to trauma, particularly in early life. Over the past decade there have been tremendous advances in large scale SNP genotyping technologies allowing for genome-wide associations studies (GWAS). As a result, it is now recognized that genetic risk for alcoholism is likely to be due to common variants in very many genes, each of small effect, although rare variants with large effects might also play a role. This has resulted in a paradigm shift away from gene centric studies toward analyses of gene interactions and gene networks within biologically relevant pathways.
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Affiliation(s)
- Mary-Anne Enoch
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA,
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141
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McClintick JN, Xuei X, Tischfield JA, Goate A, Foroud T, Wetherill L, Ehringer MA, Edenberg HJ. Stress-response pathways are altered in the hippocampus of chronic alcoholics. Alcohol 2013; 47:505-15. [PMID: 23981442 DOI: 10.1016/j.alcohol.2013.07.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/02/2013] [Accepted: 07/09/2013] [Indexed: 12/26/2022]
Abstract
The chronic high-level alcohol consumption seen in alcoholism leads to dramatic effects on the hippocampus, including decreased white matter, loss of oligodendrocytes and other glial cells, and inhibition of neurogenesis. Examining gene expression in post mortem hippocampal tissue from 20 alcoholics and 19 controls allowed us to detect differentially expressed genes that may play a role in the risk for alcoholism or whose expression is modified by chronic consumption of alcohol. We identified 639 named genes whose expression significantly differed between alcoholics and controls at a False Discovery Rate (FDR) ≤ 0.20; 52% of these genes differed by at least 1.2-fold. Differentially expressed genes included the glucocorticoid receptor and the related gene FK506 binding protein 5 (FKBP5), UDP glycosyltransferase 8 (UGT8), urea transporter (SLC14A1), zinc transporter (SLC39A10), Interleukin 1 receptor type 1 (IL1R1), thioredoxin interacting protein (TXNIP), and many metallothioneins. Pathways related to inflammation, hypoxia, and stress showed activation, and pathways that play roles in neurogenesis and myelination showed decreases. The cortisol pathway dysregulation and increased inflammation identified here are seen in other stress-related conditions such as depression and post-traumatic stress disorder and most likely play a role in addiction. Many of the detrimental effects on the hippocampus appear to be mediated through NF-κB signaling. Twenty-four of the differentially regulated genes were previously identified by genome-wide association studies of alcohol use disorders; this raises the potential interest of genes not normally associated with alcoholism, such as suppression of tumorigenicity 18 (ST18), BCL2-associated athanogene 3 (BAG3), and von Willebrand factor (VWF).
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142
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Abstract
Identification of genes influencing complex traits is hampered by genetic heterogeneity, the modest effect size of many alleles, and the likely involvement of rare and uncommon alleles. Etiologic complexity can be simplified in model organisms. By genomic sequencing, linkage analysis, and functional validation, we identified that genetic variation of Grm2, which encodes metabotropic glutamate receptor 2 (mGluR2), alters alcohol preference in animal models. Selectively bred alcohol-preferring (P) rats are homozygous for a Grm2 stop codon (Grm2 *407) that leads to largely uncompensated loss of mGluR2. mGluR2 receptor expression was absent, synaptic glutamate transmission was impaired, and expression of genes involved in synaptic function was altered. Grm2 *407 was linked to increased alcohol consumption and preference in F2 rats generated by intercrossing inbred P and nonpreferring rats. Pharmacologic blockade of mGluR2 escalated alcohol self-administration in Wistar rats, the parental strain of P and nonpreferring rats. The causal role of mGluR2 in altered alcohol preference was further supported by elevated alcohol consumption in Grm2 (-/-) mice. Together, these data point to mGluR2 as an origin of alcohol preference and a potential therapeutic target.
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143
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Kano S, Colantuoni C, Han F, Zhou Z, Yuan Q, Wilson A, Takayanagi Y, Lee Y, Rapoport J, Eaton W, Cascella N, Ji H, Goldman D, Sawa A. Genome-wide profiling of multiple histone methylations in olfactory cells: further implications for cellular susceptibility to oxidative stress in schizophrenia. Mol Psychiatry 2013; 18:740-2. [PMID: 22925834 PMCID: PMC3582810 DOI: 10.1038/mp.2012.120] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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144
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Enoch MA, Baghal B, Yuan Q, Goldman D. A factor analysis of global GABAergic gene expression in human brain identifies specificity in response to chronic alcohol and cocaine exposure. PLoS One 2013; 8:e64014. [PMID: 23717525 PMCID: PMC3661725 DOI: 10.1371/journal.pone.0064014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 04/07/2013] [Indexed: 12/15/2022] Open
Abstract
Although expression patterns of GABAergic genes in rodent brain have largely been elucidated, no comprehensive studies have been performed in human brain. The purpose of this study was to identify global patterns of GABAergic gene expression in healthy adults, including trans and cis effects in the GABAA gene clusters, before determining the effects of chronic alcohol and cocaine exposure on gene expression in the hippocampus. RNA-Seq data from ‘BrainSpan’ was obtained across 16 brain regions from postmortem samples from nine adults. A factor analysis was performed on global expression of 21 GABAergic pathway genes. Factor specificity for response to chronic alcohol/cocaine exposure was subsequently determined from the analysis of RNA-Seq data from postmortem hippocampus of eight alcoholics, eight cocaine addicts and eight controls. Six gene expression factors were identified. Most genes loaded (≥0.5) onto one factor; six genes loaded onto two. The largest factor (0.30 variance) included the chromosome 5 gene cluster that encodes the most common GABAA receptor, α1β2γ2, and genes encoding the α3β3γ2 receptor. Genes within this factor were largely unresponsive to chronic alcohol/cocaine exposure. In contrast, the chromosome 4 gene cluster factor (0.14 variance) encoding the α2β1γ1 receptor was influenced by chronic alcohol/cocaine exposure. Two other factors (0.17 and 0.06 variance) showed expression changes in alcoholics/cocaine addicts; these factors included genes involved in GABA synthesis and synaptic transport. Finally there were two factors that included genes with exceptionally low (0.10 variance) and high (0.09 variance) expression in the cerebellum; the former factor was unaffected by alcohol/cocaine exposure. This study has shown that there appears to be specificity of GABAergic gene groups, defined by covariation in expression, for response to chronic alcohol/cocaine exposure. These findings might have implications for combating stress-related craving and relapse.
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Affiliation(s)
- Mary-Anne Enoch
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA.
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145
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Osterndorff-Kahanek E, Ponomarev I, Blednov YA, Harris RA. Gene expression in brain and liver produced by three different regimens of alcohol consumption in mice: comparison with immune activation. PLoS One 2013; 8:e59870. [PMID: 23555817 PMCID: PMC3612084 DOI: 10.1371/journal.pone.0059870] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 02/19/2013] [Indexed: 12/17/2022] Open
Abstract
Chronically available alcohol escalates drinking in mice and a single injection of the immune activator lipopolysaccharide can mimic this effect and result in a persistent increase in alcohol consumption. We hypothesized that chronic alcohol drinking and lipopolysaccharide injections will produce some similar molecular changes that play a role in regulation of alcohol intake. We investigated the molecular mechanisms of chronic alcohol consumption or lipopolysaccharide insult by gene expression profiling in prefrontal cortex and liver of C57BL/6J mice. We identified similar patterns of transcriptional changes among four groups of animals, three consuming alcohol (vs water) in different consumption tests and one injected with lipopolysaccharide (vs. vehicle). The three tests of alcohol consumption are the continuous chronic two bottle choice (Chronic), two bottle choice available every other day (Chronic Intermittent) and limited access to one bottle of ethanol (Drinking in the Dark). Gene expression changes were more numerous and marked in liver than in prefrontal cortex for the alcohol treatments and similar in the two tissues for lipopolysaccharide. Many of the changes were unique to each treatment, but there was significant overlap in prefrontal cortex for Chronic-Chronic Intermittent and for Chronic Intermittent-lipopolysaccharide and in liver all pairs showed overlap. In silico cell-type analysis indicated that lipopolysaccharide had strongest effects on brain microglia and liver Kupffer cells. Pathway analysis detected a prefrontal cortex-based dopamine-related (PPP1R1B, DRD1, DRD2, FOSB, PDNY) network that was highly over-represented in the Chronic Intermittent group, with several genes from the network being also regulated in the Chronic and lipopolysaccharide (but not Drinking in the Dark) groups. Liver showed a CYP and GST centered metabolic network shared in part by all four treatments. We demonstrate common consequences of chronic alcohol consumption and immune activation in both liver and brain and show distinct genomic consequences of different types of alcohol consumption.
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Affiliation(s)
- Elizabeth Osterndorff-Kahanek
- Waggoner Center for Alcohol and Addiction Research, Colleges of Natural Science and Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
| | - Igor Ponomarev
- Waggoner Center for Alcohol and Addiction Research, Colleges of Natural Science and Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
| | - Yuri A. Blednov
- Waggoner Center for Alcohol and Addiction Research, Colleges of Natural Science and Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
| | - R. Adron Harris
- Waggoner Center for Alcohol and Addiction Research, Colleges of Natural Science and Pharmacy, University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
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146
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Schmidt HD, McGinty JF, West AE, Sadri-Vakili G. Epigenetics and psychostimulant addiction. Cold Spring Harb Perspect Med 2013; 3:a012047. [PMID: 23359110 DOI: 10.1101/cshperspect.a012047] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Chronic drug exposure alters gene expression in the brain and produces long-term changes in neural networks that underlie compulsive drug taking and seeking. Exactly how drug-induced changes in synaptic plasticity and subsequent gene expression are translated into persistent neuroadaptations remains unclear. Emerging evidence suggests that complex drug-induced neuroadaptations in the brain are mediated by highly synchronized and dynamic patterns of gene regulation. Recently, it has become clear that epigenetic mechanisms contribute to drug-induced structural, synaptic, and behavioral plasticity by regulating expression of gene networks. Here we review how alterations in histone modifications, DNA methylation, and microRNAs regulate gene expression and contribute to psychostimulant addiction with a focus on the epigenetic mechanisms that regulate brain-derived neurotrophic factor (BDNF) expression following chronic cocaine exposure. Identifying epigenetic signatures that define psychostimulant addiction may lead to novel, efficacious treatments for drug craving and relapse.
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Affiliation(s)
- Heath D Schmidt
- Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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147
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Hitzemann R, Bottomly D, Darakjian P, Walter N, Iancu O, Searles R, Wilmot B, McWeeney S. Genes, behavior and next-generation RNA sequencing. GENES, BRAIN, AND BEHAVIOR 2013; 12:1-12. [PMID: 23194347 PMCID: PMC6050050 DOI: 10.1111/gbb.12007] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 10/31/2012] [Accepted: 11/21/2012] [Indexed: 12/30/2022]
Abstract
Advances in next-generation sequencing suggest that RNA-Seq is poised to supplant microarray-based approaches for transcriptome analysis. This article briefly reviews the use of microarrays in the brain-behavior context and then illustrates why RNA-Seq is a superior strategy. Compared with microarrays, RNA-Seq has a greater dynamic range, detects both coding and noncoding RNAs, is superior for gene network construction, detects alternative spliced transcripts, detects allele specific expression and can be used to extract genotype information, e.g. nonsynonymous coding single nucleotide polymorphisms. Examples of where RNA-Seq has been used to assess brain gene expression are provided. Despite the advantages of RNA-Seq, some disadvantages remain. These include the high cost of RNA-Seq and the computational complexities associated with data analysis. RNA-Seq embraces the complexity of the transcriptome and provides a mechanism to understand the underlying regulatory code; the potential to inform the brain-behavior relationship is substantial.
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Affiliation(s)
- R Hitzemann
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239-3098, USA.
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148
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Abstract
Long-term memory formation requires transcription and protein synthesis. Over the past few decades, a great amount of knowledge has been gained regarding the molecular players that regulate the transcriptional program linked to memory consolidation. Epigenetic mechanisms have been shown to be essential for the regulation of neuronal gene expression, and histone acetylation has been one of the most studied and best characterized. In this review, we summarize the lines of evidence that have shown the relevance of histone acetylation in memory in both physiological and pathological conditions. Great advances have been made in identifying the writers and erasers of histone acetylation marks during learning. However, the identities of the upstream regulators and downstream targets that mediate the effect of changes in histone acetylation during memory consolidation remain restricted to a handful of molecules. We outline a general model by which corepressors and coactivators regulate histone acetylation during memory storage and discuss how the recent advances in high-throughput sequencing have the potential to radically change our understanding of how epigenetic control operates in the brain.
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Affiliation(s)
- Lucia Peixoto
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA
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149
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Ponomarev I. Epigenetic control of gene expression in the alcoholic brain. Alcohol Res 2013; 35:69-76. [PMID: 24313166 PMCID: PMC3860426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Chronic alcohol exposure causes widespread changes in brain gene expression in humans and animal models. Many of these contribute to cellular adaptations that ultimately lead to behavioral tolerance and alcohol dependence. There is an emerging appreciation for the role of epigenetic processes in alcohol-induced changes in brain gene expression and behavior. For example, chronic alcohol exposure produces changes in DNA and histone methylation, histone acetylation, and microRNA expression that affect expression of multiple genes in various types of brain cells (i.e., neurons and glia) and contribute to brain pathology and brain plasticity associated with alcohol abuse and dependence. Drugs targeting the epigenetic "master regulators" are emerging as potential therapeutics for neurodegenerative disorders and drug addiction.
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150
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Contet C. Gene Expression Under the Influence: Transcriptional Profiling of Ethanol in the Brain. CURRENT PSYCHOPHARMACOLOGY 2012; 1:301-314. [PMID: 24078902 PMCID: PMC3783024 DOI: 10.2174/2211556011201040301] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sensitivity to ethanol intoxication, propensity to drink ethanol and vulnerability to develop alcoholism are all influenced by genetic factors. Conversely, exposure to ethanol or subsequent withdrawal produce gene expression changes, which, in combination with environmental variables, may participate in the emergence of compulsive drinking and relapse. The present review offers an integrated perspective on brain gene expression profiling in rodent models of predisposition to differential ethanol sensitivity or consumption, in rats and mice subjected to acute or chronic ethanol exposure, as well as in human alcoholics. The functional categories over-represented among differentially expressed genes suggest that the transcriptional effects of chronic ethanol consumption contribute to the neuroplasticity and neurotoxicity characteristic of alcoholism. Importantly, ethanol produces distinct transcriptional changes within the different brain regions involved in intoxication, reinforcement and addiction. Special emphasis is put on recent profiling studies that have provided some insights into the molecular mechanisms potentially mediating genome-wide regulation of gene expression by ethanol. In particular, current evidence for a role of transcription factors, chromatin remodeling and microRNAs in coordinating the expression of large sets of genes in animals predisposed to excessive ethanol drinking or exposed to protracted abstinence, as well as in human alcoholics, is presented. Finally, studies that have compared ethanol with other drugs of abuse have highlighted common gene expression patterns that may play a central role in drug addiction. The availability of novel technologies and a focus on mechanistic approaches are shaping the future of ethanol transcriptomics.
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Affiliation(s)
- Candice Contet
- The Scripps Research Institute, Committee on the Neurobiology of Addictive Disorders, La Jolla, CA, USA
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