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Bhandari A, Seguin A, Rothenfluh A. Synaptic Mechanisms of Ethanol Tolerance and Neuroplasticity: Insights from Invertebrate Models. Int J Mol Sci 2024; 25:6838. [PMID: 38999947 PMCID: PMC11241699 DOI: 10.3390/ijms25136838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 06/09/2024] [Accepted: 06/10/2024] [Indexed: 07/14/2024] Open
Abstract
Alcohol tolerance is a neuroadaptive response that leads to a reduction in the effects of alcohol caused by previous exposure. Tolerance plays a critical role in the development of alcohol use disorder (AUD) because it leads to the escalation of drinking and dependence. Understanding the molecular mechanisms underlying alcohol tolerance is therefore important for the development of effective therapeutics and for understanding addiction in general. This review explores the molecular basis of alcohol tolerance in invertebrate models, Drosophila and C. elegans, focusing on synaptic transmission. Both organisms exhibit biphasic responses to ethanol and develop tolerance similar to that of mammals. Furthermore, the availability of several genetic tools makes them a great candidate to study the molecular basis of ethanol response. Studies in invertebrate models show that tolerance involves conserved changes in the neurotransmitter systems, ion channels, and synaptic proteins. These neuroadaptive changes lead to a change in neuronal excitability, most likely to compensate for the enhanced inhibition by ethanol.
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Affiliation(s)
- Aakriti Bhandari
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84112, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Alexandra Seguin
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Adrian Rothenfluh
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84112, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
- Neuroscience Graduate Program, University of Utah, Salt Lake City, UT 84112, USA
- Department of Neurobiology, University of Utah, Salt Lake City, UT 84112, USA
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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van Wijk MH, Davies AG, Sterken MG, Mathies LD, Quamme EC, Blackwell GG, Riksen JAG, Kammenga JE, Bettinger JC. Natural allelic variation modifies acute ethanol response phenotypes in wild strains of C. elegans. ALCOHOL, CLINICAL & EXPERIMENTAL RESEARCH 2023; 47:1505-1517. [PMID: 37356915 DOI: 10.1111/acer.15139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/12/2023] [Accepted: 06/20/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND Genetic variation contributes to the likelihood that an individual will develop an alcohol use disorder (AUD). Traditional laboratory studies in animal models have elucidated the molecular pharmacology of ethanol, but laboratory-derived genetic manipulations rarely model the naturally occurring genetic variation observed in wild populations. Rather, these manipulations are biased toward identifying genes of central importance in the phenotypes. Because changes in such genes can confer selective disadvantages, they are not ideal candidates for carrying AUD risk alleles in humans. We sought to exploit Caenorhabditis elegans to identify allelic variation existing in the wild that modulates ethanol response behaviors. METHODS We tested the acute ethanol responses of four strains recently isolated from the wild (JU1511, JU1926, JU1931, and JU1941) and 41 multiparental recombinant inbred lines (mpRILs) derived from them. We assessed locomotion at 10, 30, and 50 min on low and high ethanol concentrations. We performed principal component analyses (PCA) on the different phenotypes, tested for transgressive behavior, calculated heritability, and determined the correlations between behavioral responses. RESULTS We observed a range of responses to ethanol across the strains. We detected a low-concentration locomotor activation effect in some of the mpRILs not seen in the laboratory wild-type strain. PCA showed different ethanol response behaviors to be independent. We observed transgressive behavior for many of the measured phenotypes and found that multiple behaviors were uncorrelated. The average broad-sense heritability for all phenotypes was 23.2%. CONCLUSIONS Genetic variation significantly affects multiple acute ethanol response behaviors, many of which are independent of one another. This suggests that the genetic variation captured by these strains likely affects multiple biological mechanisms through which ethanol acts. Further study of these strains may allow these distinct mechanisms to be identified.
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Affiliation(s)
- Marijke H van Wijk
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Andrew G Davies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mark G Sterken
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Laura D Mathies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Elizabeth C Quamme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - GinaMari G Blackwell
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Joost A G Riksen
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jan E Kammenga
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jill C Bettinger
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
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Clites BL, Hofmann HA, Pierce JT. The Promise of an Evolutionary Perspective of Alcohol Consumption. Neurosci Insights 2023; 18:26331055231163589. [PMID: 37051560 PMCID: PMC10084549 DOI: 10.1177/26331055231163589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 02/27/2023] [Indexed: 04/07/2023] Open
Abstract
The urgent need for medical treatments of alcohol use disorders has motivated the search for novel molecular targets of alcohol response. Most studies exploit the strengths of lab animals without considering how these and other species may have adapted to respond to alcohol in an ecological context. Here, we provide an evolutionary perspective on the molecular and genetic underpinnings of alcohol consumption by reviewing evidence that alcohol metabolic enzymes have undergone adaptive evolution at 2 evolutionary junctures: first, to enable alcohol consumption accompanying the advent of a frugivorous diet in a primate ancestor, and second, to decrease the likelihood of excessive alcohol consumption concurrent with the spread of agriculture and fermentation in East Asia. By similarly considering how diverse vertebrate and invertebrate species have undergone natural selection for alcohol responses, novel conserved molecular targets of alcohol are likely be discovered that may represent promising therapeutic targets.
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Affiliation(s)
- Benjamin L Clites
- Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
- Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX, USA
- Institute for Cellular & Molecular Biology, University of Texas at Austin, Austin, TX, USA
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Hans A Hofmann
- Institute for Cellular & Molecular Biology, University of Texas at Austin, Austin, TX, USA
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Jonathan T Pierce
- Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
- Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX, USA
- Institute for Cellular & Molecular Biology, University of Texas at Austin, Austin, TX, USA
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA
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4
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Zahra A, Liu R, Han W, Meng H, Wang Q, Wang Y, Campbell SL, Wu J. K Ca-Related Neurological Disorders: Phenotypic Spectrum and Therapeutic Indications. Curr Neuropharmacol 2023; 21:1504-1518. [PMID: 36503451 PMCID: PMC10472807 DOI: 10.2174/1570159x21666221208091805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/21/2022] [Accepted: 07/23/2022] [Indexed: 12/14/2022] Open
Abstract
Although potassium channelopathies have been linked to a wide range of neurological conditions, the underlying pathogenic mechanism is not always clear, and a systematic summary of clinical manifestation is absent. Several neurological disorders have been associated with alterations of calcium-activated potassium channels (KCa channels), such as loss- or gain-of-function mutations, post-transcriptional modification, etc. Here, we outlined the current understanding of the molecular and cellular properties of three subtypes of KCa channels, including big conductance KCa channels (BK), small conductance KCa channels (SK), and the intermediate conductance KCa channels (IK). Next, we comprehensively reviewed the loss- or gain-of-function mutations of each KCa channel and described the corresponding mutation sites in specific diseases to broaden the phenotypic-genotypic spectrum of KCa-related neurological disorders. Moreover, we reviewed the current pharmaceutical strategies targeting KCa channels in KCa-related neurological disorders to provide new directions for drug discovery in anti-seizure medication.
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Affiliation(s)
- Aqeela Zahra
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
- Department of Zoology, University of Sialkot, Sialkot 51310, Pakistan
| | - Ru Liu
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Wenzhe Han
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Hui Meng
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Qun Wang
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - YunFu Wang
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Susan L. Campbell
- Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Jianping Wu
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
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Chang XW, Sun Y, Muhai JN, Li YY, Chen Y, Lu L, Chang SH, Shi J. Common and distinguishing genetic factors for substance use behavior and disorder: an integrated analysis of genomic and transcriptomic studies from both human and animal studies. Addiction 2022; 117:2515-2529. [PMID: 35491750 DOI: 10.1111/add.15908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 04/04/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND AIMS Genomic and transcriptomic findings greatly broaden the biological knowledge regarding substance use. However, systematic convergence and comparison evidence of genome-wide findings is lacking for substance use. Here, we combined all the genome-wide findings from both substance use behavior and disorder (SUBD) and identified common and distinguishing genetic factors for different SUBDs. METHODS Systemic literature search for genome-wide association (GWAS) and RNA-seq studies of alcohol/nicotine/drug use behavior (partially meets or not reported diagnostic criteria) and alcohol use behavior and disorder (AUBD), nicotine use behavior and disorder (NUBD) and drug use behavior and disorder (DUBD) was performed using PubMed and the GWAS catalog. Drug use was focused upon cannabis, opioid, cocaine and methamphetamine use. GWAS studies required case-control or case/cohort samples. RNA-seq studies were based on brain tissues. The genes which contained significant single nucleotide polymorphism (P ≤ 1 × 10-6 ) in GWAS and reported as significant in RNA-seq studies were extracted. Pathway enrichment was performed by using Metascape. Gene interaction networks were identified by using the Protein Interaction Network Analysis database. RESULTS Total SUBD-related 2910 genes were extracted from 75 GWAS studies (2 773 889 participants) and 17 RNA-seq studies. By overlapping the genes and pathways of AUBD, NUBD and DUBD, four shared genes (CACNB2, GRIN2B, PLXDC2 and PKNOX2), four shared pathways [two Gene Ontology (GO) terms of 'modulation of chemical synaptic transmission', 'regulation of trans-synaptic signaling', two Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of 'dopaminergic synapse', 'cocaine addiction'] were identified (significantly higher than random, P < 1 × 10-5 ). The top shared KEGG pathways (Benjamini-Hochberg-corrected P-value < 0.05) in the pairwise comparison of AUBD versus DUBD, NUBD versus DUBD, AUBD versus NUBD were 'Epstein-Barr virus infection', 'protein processing in endoplasmic reticulum' and 'neuroactive ligand-receptor interaction', respectively. We also identified substance-specific genetic factors: i.e. ADH1B and ALDH2 were unique for AUBD, while CHRNA3 and CHRNA4 were unique for NUBD. CONCLUSIONS This systematic review identifies the shared and unique genes and pathways for alcohol, nicotine and drug use behaviors and disorders at the genome-wide level and highlights critical biological processes for the common and distinguishing vulnerability of substance use behaviors and disorders.
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Affiliation(s)
- Xiang-Wen Chang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,National Institute on Drug Dependence, Peking University, Beijing, China
| | - Yan Sun
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,National Institute on Drug Dependence, Peking University, Beijing, China
| | - Jia-Na Muhai
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Yang-Yang Li
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,National Institute on Drug Dependence, Peking University, Beijing, China
| | - Yun Chen
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.,National Institute on Drug Dependence, Peking University, Beijing, China
| | - Lin Lu
- National Institute on Drug Dependence, Peking University, Beijing, China.,Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Su-Hua Chang
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China
| | - Jie Shi
- National Institute on Drug Dependence, Peking University, Beijing, China.,Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing, China.,The State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, China.,The Key Laboratory for Neuroscience of the Ministry of Education and Health, Peking University, Beijing, China
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Miller JP, Moldenhauer HJ, Keros S, Meredith AL. An emerging spectrum of variants and clinical features in KCNMA1-linked channelopathy. Channels (Austin) 2021; 15:447-464. [PMID: 34224328 PMCID: PMC8259716 DOI: 10.1080/19336950.2021.1938852] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/18/2021] [Accepted: 06/01/2021] [Indexed: 12/13/2022] Open
Abstract
KCNMA1-linked channelopathy is an emerging neurological disorder characterized by heterogeneous and overlapping combinations of movement disorder, seizure, developmental delay, and intellectual disability. KCNMA1 encodes the BK K+ channel, which contributes to both excitatory and inhibitory neuronal and muscle activity. Understanding the basis of the disorder is an important area of active investigation; however, the rare prevalence has hampered the development of large patient cohorts necessary to establish genotype-phenotype correlations. In this review, we summarize 37 KCNMA1 alleles from 69 patients currently defining the channelopathy and assess key diagnostic and clinical hallmarks. At present, 3 variants are classified as gain-of-function with respect to BK channel activity, 14 loss-of-function, 15 variants of uncertain significance, and putative benign/VUS. Symptoms associated with these variants were curated from patient-provided information and prior publications to define the spectrum of clinical phenotypes. In this newly expanded cohort, seizures showed no differential distribution between patients harboring GOF and LOF variants, while movement disorders segregated by mutation type. Paroxysmal non-kinesigenic dyskinesia was predominantly observed among patients with GOF alleles of the BK channel, although not exclusively so, while additional movement disorders were observed in patients with LOF variants. Neurodevelopmental and structural brain abnormalities were prevalent in patients with LOF mutations. In contrast to mutations, disease-associated KCNMA1 single nucleotide polymorphisms were not predominantly related to neurological phenotypes but covered a wider set of peripheral physiological functions. Together, this review provides additional evidence exploring the genetic and biochemical basis for KCNMA1-linked channelopathy and summarizes the clinical repository of patient symptoms across multiple types of KCNMA1 gene variants.
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Affiliation(s)
- Jacob P. Miller
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Hans J. Moldenhauer
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sotirios Keros
- Department of Pediatrics, Weill Cornell Medical College, New York, NY, USA
| | - Andrea L. Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
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Li W, Thygesen JH, O'Brien NL, Heydtmann M, Smith I, Degenhardt F, Nöthen MM, Morgan MY, Bass NJ, McQuillin A. The influence of regression models on genome-wide association studies of alcohol dependence: a comparison of binary and quantitative analyses. Psychiatr Genet 2021; 31:13-20. [PMID: 33290381 DOI: 10.1097/ypg.0000000000000268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Genome-wide association studies (GWAS) of alcohol dependence syndrome (ADS) offer a platform to detect genetic risk loci. However, the majority of the ADS GWAS undertaken, to date, have utilized a case-control design and have failed to identify consistently replicable loci with the exception of protective variants within the alcohol metabolizing genes, notably ADH1B. The ADS phenotype shows considerable variability which means that the use of quantitative variables as a proxy for the severity of ADS has the potential to facilitate identification of risk loci by increasing statistical power. The current study aims to examine the influences of using binary and adjusted quantitative measures of ADS on GWAS outcomes and on calculated polygenic risk scores (PRS). METHODS A GWAS was performed in 1251 healthy controls with no history of excess alcohol use and 739 patients with ADS classified using binary DMS-IV criteria. Two additional GWAS were undertaken using a quantitative score based on DSM-IV criteria, which were applied assuming both normal and non-normal distributions of the phenotypic variables. PRS analyses were performed utilizing the data from the binary and the quantitative trait analyses. RESULTS No associations were identified at genome-wide significance in any of the individual GWAS; results were comparable in all three. The top associated single nucleotide polymorphism was located on the alcohol dehydrogenase gene cluster on chromosome 4, consistent with previous ADS GWAS. The quantitative trait analysis adjusted for the distribution of the criterion score and the associated PRS had the smallest standard errors and thus the greatest precision. CONCLUSION Further exploitation of the use of qualitative trait analysis in GWAS in ADS is warranted.
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Affiliation(s)
- Wenqianglong Li
- Molecular Psychiatry Laboratory, Division of Psychiatry, University College London, London
| | - Johan Hilge Thygesen
- Molecular Psychiatry Laboratory, Division of Psychiatry, University College London, London
| | - Niamh Louise O'Brien
- Molecular Psychiatry Laboratory, Division of Psychiatry, University College London, London
| | - Mathis Heydtmann
- Royal Alexandria Hospital, NHS Greater Glasgow and Clyde, Paisley
| | - Iain Smith
- Glasgow Addiction Services, NHS Greater Glasgow and Clyde, Glasgow, UK
| | - Franziska Degenhardt
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, Bonn
- Department of Child and Adolescent Psychiatry, University of Duisburg-Essen, Essen, Germany
| | - Markus Maria Nöthen
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, Bonn
| | - Marsha Yvonne Morgan
- UCL Institute for Liver & Digestive Health, Division of Medicine, Royal Free Campus, University College London, London, UK
| | - Nicholas James Bass
- Molecular Psychiatry Laboratory, Division of Psychiatry, University College London, London
| | - Andrew McQuillin
- Molecular Psychiatry Laboratory, Division of Psychiatry, University College London, London
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Demery-Poulos C, Chambers JM. Genetic variation in alcoholism and opioid addiction susceptibility and treatment: a pharmacogenomic approach. AIMS MOLECULAR SCIENCE 2021. [DOI: 10.3934/molsci.2021016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
<abstract>
<p>Alcohol and opioid abuse have pervasive and detrimental consequences from the individual to societal level. The extent of genetic contribution to alcoholism has been studied for decades, yielding speculative and often inconsistent results since the previous discovery of two pharmacokinetic variants strongly protective against alcoholism. The neurobiology of addiction involves innumerate genes with combinatorial and epistatic interactions, creating a difficult landscape for concrete conclusions. In contrast, pharmacogenomic variation in the treatment of alcoholism yields more immediate clinical utility, while also emphasizing pathways crucial to the progression of addiction. An improved understanding of genetic predisposition to alcohol abuse has inherent significance for opioid addiction and treatment, as the two drugs induce the same reward pathway. This review outlines current knowledge, treatments, and research regarding genetic predisposition to alcoholism, focusing on pharmacodynamic variation within the dopaminergic system and shared implications for opioid abuse. Multifaceted and highly polygenic, the phenotype of addiction seems to grow more complex as new research extends the scope of its impact on the brain, body, and progeny.</p>
</abstract>
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Alcohol. Alcohol 2021. [DOI: 10.1016/b978-0-12-816793-9.00001-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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10
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Blokhin IO, Khorkova O, Saveanu RV, Wahlestedt C. Molecular mechanisms of psychiatric diseases. Neurobiol Dis 2020; 146:105136. [PMID: 33080337 DOI: 10.1016/j.nbd.2020.105136] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 09/24/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
For most psychiatric diseases, pathogenetic concepts as well as paradigms underlying neuropsychopharmacologic approaches currently revolve around neurotransmitters such as dopamine, serotonin, and norepinephrine. However, despite the fact that several generations of neurotransmitter-based psychotropics including atypical antipsychotics, selective serotonin reuptake inhibitors, and serotonin-norepinephrine reuptake inhibitors are available, the effectiveness of these medications is limited, and relapse rates in psychiatric diseases are relatively high, indicating potential involvement of other pathogenetic pathways. Indeed, recent high-throughput studies in genetics and molecular biology have shown that pathogenesis of major psychiatric illnesses involves hundreds of genes and numerous pathways via such fundamental processes as DNA methylation, transcription, and splicing. Current review summarizes these and other molecular mechanisms of such psychiatric illnesses as schizophrenia, major depressive disorder, and alcohol use disorder and suggests a conceptual framework for future studies.
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Affiliation(s)
- Ilya O Blokhin
- Center for Therapeutic Innovation, University of Miami, Miami, FL, United States of America; Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, United States of America; Jackson Memorial Hospital, Miami, FL, United States of America
| | - Olga Khorkova
- OPKO Health Inc., Miami, FL, United States of America
| | - Radu V Saveanu
- Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, United States of America
| | - Claes Wahlestedt
- Center for Therapeutic Innovation, University of Miami, Miami, FL, United States of America; Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, United States of America.
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Parker CC, Lusk R, Saba LM. Alcohol Sensitivity as an Endophenotype of Alcohol Use Disorder: Exploring Its Translational Utility between Rodents and Humans. Brain Sci 2020; 10:E725. [PMID: 33066036 PMCID: PMC7600833 DOI: 10.3390/brainsci10100725] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/06/2020] [Accepted: 10/09/2020] [Indexed: 12/21/2022] Open
Abstract
Alcohol use disorder (AUD) is a complex, chronic, relapsing disorder with multiple interacting genetic and environmental influences. Numerous studies have verified the influence of genetics on AUD, yet the underlying biological pathways remain unknown. One strategy to interrogate complex diseases is the use of endophenotypes, which deconstruct current diagnostic categories into component traits that may be more amenable to genetic research. In this review, we explore how an endophenotype such as sensitivity to alcohol can be used in conjunction with rodent models to provide mechanistic insights into AUD. We evaluate three alcohol sensitivity endophenotypes (stimulation, intoxication, and aversion) for their translatability across human and rodent research by examining the underlying neurobiology and its relationship to consumption and AUD. We show examples in which results gleaned from rodents are successfully integrated with information from human studies to gain insight in the genetic underpinnings of AUD and AUD-related endophenotypes. Finally, we identify areas for future translational research that could greatly expand our knowledge of the biological and molecular aspects of the transition to AUD with the broad hope of finding better ways to treat this devastating disorder.
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Affiliation(s)
- Clarissa C. Parker
- Department of Psychology and Program in Neuroscience, Middlebury College, Middlebury, VT 05753, USA
| | - Ryan Lusk
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Laura M. Saba
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
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12
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Lathen DR, Merrill CB, Rothenfluh A. Flying Together: Drosophila as a Tool to Understand the Genetics of Human Alcoholism. Int J Mol Sci 2020; 21:E6649. [PMID: 32932795 PMCID: PMC7555299 DOI: 10.3390/ijms21186649] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 12/14/2022] Open
Abstract
Alcohol use disorder (AUD) exacts an immense toll on individuals, families, and society. Genetic factors determine up to 60% of an individual's risk of developing problematic alcohol habits. Effective AUD prevention and treatment requires knowledge of the genes that predispose people to alcoholism, play a role in alcohol responses, and/or contribute to the development of addiction. As a highly tractable and translatable genetic and behavioral model organism, Drosophila melanogaster has proven valuable to uncover important genes and mechanistic pathways that have obvious orthologs in humans and that help explain the complexities of addiction. Vinegar flies exhibit remarkably strong face and mechanistic validity as a model for AUDs, permitting many advancements in the quest to understand human genetic involvement in this disease. These advancements occur via approaches that essentially fall into one of two categories: (1) discovering candidate genes via human genome-wide association studies (GWAS), transcriptomics on post-mortem tissue from AUD patients, or relevant physiological connections, then using reverse genetics in flies to validate candidate genes' roles and investigate their molecular function in the context of alcohol. (2) Utilizing flies to discover candidate genes through unbiased screens, GWAS, quantitative trait locus analyses, transcriptomics, or single-gene studies, then validating their translational role in human genetic surveys. In this review, we highlight the utility of Drosophila as a model for alcoholism by surveying recent advances in our understanding of human AUDs that resulted from these various approaches. We summarize the genes that are conserved in alcohol-related function between humans and flies. We also provide insight into some advantages and limitations of these approaches. Overall, this review demonstrates how Drosophila have and can be used to answer important genetic questions about alcohol addiction.
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Affiliation(s)
- Daniel R. Lathen
- Department of Psychiatry and Neuroscience Ph.D. Program, University of Utah, Salt Lake City, UT 84108, USA;
| | - Collin B. Merrill
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA;
| | - Adrian Rothenfluh
- Department of Psychiatry and Neuroscience Ph.D. Program, University of Utah, Salt Lake City, UT 84108, USA;
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA;
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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Genetic Profiles Playing Opposite Roles of Pathogenesis in Schizophrenia and Glioma. JOURNAL OF ONCOLOGY 2020; 2020:3656841. [PMID: 32565801 PMCID: PMC7275202 DOI: 10.1155/2020/3656841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 03/27/2020] [Indexed: 11/17/2022]
Abstract
Background Patients diagnosed with schizophrenia were found having lower risks to develop cancers, including glioma. Based on this epidemiology, we hypothesized that there were gene profiles playing opposite roles in pathogenesis of schizophrenia and glioma. Methods Based on GEO datasets and TCGA, key genes of schizophrenia genes on the opposite development of glioma were screened by different expressed genes (DEGs) screening, weighted gene coexpression network analysis (WGCNA), disease-specific survival (DSS), and glioma grading and verified by gene set enrichment analysis (GSEA). Results First, 612 DEGs were screened from schizophrenia and control brain samples. Second, 134 key genes more specific to schizophrenia were left by WGCNA, with 93 key genes having annotations in TCGA. Third, DSS of glioma helped to find 42 key gene expressions of schizophrenia oppositely associated with survival of glioma. Finally, 24 key genes showed opposite expression trends in schizophrenia and different glioma grading, i.e., the upregulated key genes in schizophrenia expressed increasingly in higher grade glioma, and vice versa. CAMK2D and MPC2 were taken as the examples and evaluated by GSEA, which indeed showed opposite trends in the same pathways of schizophrenia and glioma. Conclusion This workflow of selecting novel targeted genes which may have opposite roles in pathogenesis of two diseases was firstly and innovatively generated by our team. Some filtered key genes were indeed found by their potential effects in several mechanism studies, indicating our process could be effective to generate novel targeted genes. These 24 key genes may provide potential directions for future biochemical and pharmacotherapeutic research studies.
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Gupta I, Dandavate R, Gupta P, Agrawal V, Kapoor M. Recent advances in genetic studies of alcohol use disorders. CURRENT GENETIC MEDICINE REPORTS 2020; 8:27-34. [PMID: 33344068 PMCID: PMC7748121 DOI: 10.1007/s40142-020-00185-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE OF REVIEW Alcohol use disorder (AUD) is a complex genetic disorder with very high heritability. This polygenic disorder not only results in increased morbidity and mortality, it is also a substantial social and economic burden on families and the nation. For past three decades, several genetic studies were conducted to identify genes and pathways associated with AUD. This review aims to summarize past efforts and recent advances in genetic association studies of AUD and related traits. RECENT FINDINGS Initial genetic association studies achieved a limted success and suffered from low power due to small sample sizes. AUD is a polygenic trait and data from several thousands individuals was required to identify the genetic factors of small effect sizes. The scenario changed recently with technological advances and significant reduction in cost of the genome wide association analyses (GWAS). This enabled researchers to generate genomic data on mega biobanks and cohorts with access to extensive clinical and non-clinical phenotypes. Public access to data from biobanks and collaborative efforts of researchers lead to identification of several novel loci associated with AUDs and related traits. Efforts are now underway to identify the causal variants under the GWAS loci to identify target genes and biological mechanisms underpining AUDs. Many GWAS variants occur in promoter or enhancer regions of the genes and are involved in regulation of gene expression of causal genes. This, large amounts of "omics" data from projects such as "ENCODE", RoadMap and GTEx is also helping researchers to integrate "multi-omics" data to interpret functional significance of GWAS variants. SUMMARY With current review, we aim to present the recent advances in genetic and molecular studies of AUDs. Recent successes in genetic studies of AUDs will definetely motivate researchers and lead to better therapeutic interventions for this complex disorder.
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Affiliation(s)
| | - Rohan Dandavate
- Indian Institute of Science Education and Research, Bhopal, India
| | - Pallavi Gupta
- Indian Institute of Science Education and Research, Bhopal, India
| | - Viplav Agrawal
- Indian Institute of Science Education and Research, Bhopal, India
| | - Manav Kapoor
- Icahn School of Medicine at Mount Sinai, New york, USA
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Nieto SJ, Grodin EN, Ray LA. On the path towards personalized medicine: Implications of pharmacogenetic studies of alcohol use disorder medications. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2020; 5:43-54. [PMID: 34291172 DOI: 10.1080/23808993.2020.1724510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Introduction The heritability of alcohol use disorder (AUD) is estimated to be ~50%; however, the genetic basis of the disease is still poorly understood. The genetic variants identified thus far only explain a small percentage of AUD phenotypic variability. While genome-wide association studies (GWAS) are impacted by technical and methodological limitations, genetic variants that have been identified independently of GWAS findings can moderate the efficacy of AUD medications. Areas Covered This review discusses findings from clinical pharmacogenetic studies of AUD medications. While the pharmacogenetic studies reviewed involve several genetic variants in the major neurotransmitter systems, genetic loci in the opioid system have garnered the most attention. Expert Opinion The clinical utility of pharmacogenetics in AUD populations is uncertain at this time. There are several ongoing prospective clinical trials that will enhance knowledge regarding the applicability of pharmacogenetics in clinical populations. We recommend that future work in this area consider reverse translating from genotype to phenotype, mapping genes to stages of the addiction cycle, mapping genes to neural circuits, and harnessing large population-based cohorts.
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Affiliation(s)
- Steven J Nieto
- University of California Los Angeles, Department of Psychology, Los Angeles, CA, USA
| | - Erica N Grodin
- University of California Los Angeles, Department of Psychology, Los Angeles, CA, USA
| | - Lara A Ray
- University of California Los Angeles, Department of Psychology, Los Angeles, CA, USA.,University of California, Los Angeles, Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA.,University of California Los Angeles, Brain Research Institute, Los Angeles, CA, USA
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16
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Chang LH, Whitfield JB, Liu M, Medland SE, Hickie IB, Martin NG, Verhulst B, Heath AC, Madden PA, Statham DJ, Gillespie NA. Associations between polygenic risk for tobacco and alcohol use and liability to tobacco and alcohol use, and psychiatric disorders in an independent sample of 13,999 Australian adults. Drug Alcohol Depend 2019; 205:107704. [PMID: 31731259 DOI: 10.1016/j.drugalcdep.2019.107704] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/18/2019] [Accepted: 10/21/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Substance use, substance use disorders (SUDs), and psychiatric disorders commonly co-occur. Genetic risk common to these complex traits is an important explanation; however, little is known about how polygenic risk for tobacco or alcohol use overlaps the genetic risk for the comorbid SUDs and psychiatric disorders. METHODS We constructed polygenic risk scores (PRSs) using GWAS meta-analysis summary statistics from a large discovery sample, GWAS & Sequencing Consortium of Alcohol and Nicotine use (GSCAN), for smoking initiation (SI; N = 631,564), age of initiating regular smoking (AI; N = 258,251), cigarettes per day (CPD; N = 258,999), smoking cessation (SC; N = 312,273), and drinks per week (DPW; N = 527,402). We then estimated the fixed effect of these PRSs on the liability to 15 phenotypes related to tobacco and alcohol use, substance use disorders, and psychiatric disorders in an independent target sample of Australian adults. RESULTS After adjusting for multiple testing, 10 of 75 combinations of discovery and target phenotypes remained significant. PRS-SI (R2 range: 1.98%-5.09 %) was positively associated with SI, DPW, and with DSM-IV and FTND nicotine dependence, and conduct disorder. PRS-AI (R2: 3.91 %) negatively associated with DPW. PRS-CPD (R2: 1.56 %-1.77 %) positively associated with DSM-IV nicotine dependence and conduct disorder. PRS-DPW (R2: 3.39 %-6.26 %) positively associated with only DPW. The variation of DPW was significantly influenced by sex*PRS-SI, sex*PRS-AI and sex*PRS-DPW. Such interaction effect was not detected in the other 14 phenotypes. CONCLUSIONS Polygenic risks associated with tobacco use are also associated with liability to alcohol consumption, nicotine dependence, and conduct disorder.
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Affiliation(s)
- Lun-Hsien Chang
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston QLD 4006, Australia; Faculty of Medicine, the University of Queensland, 20 Weightman St, Herston QLD 4006, Australia.
| | - John B Whitfield
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston QLD 4006, Australia.
| | - Mengzhen Liu
- Department of Psychology, University of Minnesota Twin Cities, 75 E River Rd, Minneapolis, MN 55455, USA.
| | - Sarah E Medland
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston QLD 4006, Australia.
| | - Ian B Hickie
- Brain and Mind Centre, University of Sydney, 94 Mallett St, Camperdown NSW 2050, USA.
| | - Nicholas G Martin
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston QLD 4006, Australia.
| | - Brad Verhulst
- Department of psychology, Michigan State University, 316 Physics Road #262, East Lansing, MI 48824, USA.
| | - Andrew C Heath
- Department of Psychiatry, Washington University School of Medicine, 660 S Euclid Ave, St. Louis, MO 63110, USA.
| | - Pamela A Madden
- Department of Psychiatry, Washington University School of Medicine, 660 S Euclid Ave, St. Louis, MO 63110, USA.
| | - Dixie J Statham
- School of Health and Life Sciences, Federation University, Federation University Australia, PO Box 663, Ballarat, VIC 3353, Australia.
| | - Nathan A Gillespie
- Virginia Institute for Psychiatric and Behavioural Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA.
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17
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Palmer RHC, Brick LA, Chou YL, Agrawal A, McGeary JE, Heath AC, Bierut L, Keller MC, Johnson E, Hartz SM, Schuckit MA, Knopik VS. The etiology of DSM-5 alcohol use disorder: Evidence of shared and non-shared additive genetic effects. Drug Alcohol Depend 2019; 201:147-154. [PMID: 31229702 PMCID: PMC6929687 DOI: 10.1016/j.drugalcdep.2018.12.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/29/2018] [Accepted: 12/06/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Alcoholism is a multifactorial disorder influenced by multiple gene loci, each with small effect. Studies suggest shared genetic influences across DSM-IV alcohol dependence symptoms, but shared effects across DSM-5 alcohol use disorder remains unknown. We aimed to test the assumption of genetic homogeneity across the 11 criteria of DSM-5 alcohol use disorder (AUD). METHODS Data from 2596 alcohol using individuals of European ancestry from the Study of Addiction: Genetics and Environment were used to examine the genomewide SNP-heritability (h2SNP) and SNP-covariance (rGSNP) between 11 DSM-5 AUD symptoms. Phenotypic relationships between symptoms were examined to confirm an underlying liability of AUD and the SNP-heritability of the observed latent trait and the co-heritabilityamong AUD symptoms was assessed using Genomic-Relatedness-Matrix-Restricted-Maximum-Likelihood. Genetic covariance among symptoms was examined using factor analysis. RESULTS Phenotypic relationships confirmed a unidimensional underlying liability to AUD. Factor and parallel analyses of the observed genetic variance/covariance provided evidence of genetic homogeneity. Additive genetic effects on DSM-5 AUD symptoms varied from 0.10 to 0.37 and largely overlapped (rG-SNP across symptoms ranged from 0.49 - 0.92). The additive genetic effect on the DSM-5 AUD factor was 0.36, 0.14 for DSM-5 AUD diagnosis, and was 0.22 for DSM-5 AUD severity. CONCLUSIONS Common genetic variants influence DSM-5 AUD symptoms. Despite evidence for a common AUD factor, the evidence of only partially overlapping genetic effects across AUD symptoms further substantiates the need to simultaneously model common and symptom-specific genetic effects in molecular genetic studies in order to best characterize the genetic liability.
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Affiliation(s)
- Rohan H C Palmer
- Behavioral Genetics of Addiction Laboratory, Department of Psychology, Emory University, USA.
| | - Leslie A Brick
- Department of Psychiatry and Human Behavior, Brown University, USA; Division of Behavior Genetics, Department of Psychiatry, Rhode Island Hospital, USA
| | - Yi-Ling Chou
- Washington University in St. Louis, St. Louis, Missouri, USA
| | - Arpana Agrawal
- Washington University in St. Louis, St. Louis, Missouri, USA
| | - John E McGeary
- Department of Psychiatry and Human Behavior, Brown University, USA; Division of Behavior Genetics, Department of Psychiatry, Rhode Island Hospital, USA; Providence Veterans Affairs Medical Center, USA
| | - Andrew C Heath
- Washington University in St. Louis, St. Louis, Missouri, USA
| | - Laura Bierut
- Washington University in St. Louis, St. Louis, Missouri, USA
| | - Matthew C Keller
- Department of Psychology and Neuroscience, University of Colorado at Boulder, USA
| | | | - Sarah M Hartz
- Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Valerie S Knopik
- Department of Human Development and Family Studies, Purdue University, USA
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18
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Cornelis MC. Genetic determinants of beverage consumption: Implications for nutrition and health. ADVANCES IN FOOD AND NUTRITION RESEARCH 2019; 89:1-52. [PMID: 31351524 PMCID: PMC7047661 DOI: 10.1016/bs.afnr.2019.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Beverages make important contributions to nutritional intake and their role in health has received much attention. This review focuses on the genetic determinants of common beverage consumption and how research in this field is contributing insight to what and how much we consume and why this genetic knowledge matters from a research and public health perspective. The earliest efforts in gene-beverage behavior mapping involved genetic linkage and candidate gene analysis but these approaches have been largely replaced by genome-wide association studies (GWAS). GWAS have identified biologically plausible loci underlying alcohol and coffee drinking behavior. No GWAS has identified variants specifically associated with consumption of tea, juice, soda, wine, beer, milk or any other common beverage. Thus far, GWAS highlight an important behavior-reward component (as opposed to taste) to beverage consumption which may serve as a potential barrier to dietary interventions. Loci identified have been used in Mendelian randomization and gene×beverage interaction analysis of disease but results have been mixed. This research is necessary as it informs the clinical relevance of SNP-beverage associations and thus genotype-based personalized nutrition, which is gaining interest in the commercial and public health sectors.
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Affiliation(s)
- Marilyn C Cornelis
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
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19
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Chang LH, Couvy-Duchesne B, Liu M, Medland SE, Verhulst B, Benotsch EG, Hickie IB, Martin NG, Gillespie NA. Association between polygenic risk for tobacco or alcohol consumption and liability to licit and illicit substance use in young Australian adults. Drug Alcohol Depend 2019; 197:271-279. [PMID: 30875648 PMCID: PMC11100300 DOI: 10.1016/j.drugalcdep.2019.01.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 12/25/2018] [Accepted: 01/19/2019] [Indexed: 11/21/2022]
Abstract
BACKGROUND Co-morbid substance use is very common. Despite a historical focus using genetic epidemiology to investigate comorbid substance use and misuse, few studies have examined substance-substance associations using polygenic risk score (PRS) methods. METHODS Using summary statistics from the largest substance use GWAS to date (258,797- 632,802 subjects), GWAS and Sequencing Consortium of Alcohol and Nicotine use (GSCAN), we constructed PRSs for smoking initiation (PRS-SI), age of initiation of regular smoking (PRS-AI), cigarettes per day (PRS-CPD), smoking cessation (PRS-SC), and drinks per week (PRS-DPW). We then estimated the fixed effect of individual PRSs on 22 lifetime substance use and substance use disorder phenotypes collected in an independent sample of 2463 young Australian adults using genetic restricted maximal likelihood (GREML) in Genome-wide Complex Trait Analysis (GCTA), separately in females, males and both sexes together. RESULTS After accounting for multiple testing, PRS-SI significantly explained variation in the risk of cocaine (0.67%), amphetamine (1.54%), hallucinogens (0.72%), ecstasy (1.66%) and cannabis initiation (0.97%), as well as DSM-5 alcohol use disorder (0.72%). PRS-DPW explained 0.75%, 0.59% and 0.90% of the variation of cocaine, amphetamine and ecstasy initiation respectively. None of the 22 phenotypes including emergent classes of substance use were significantly predicted by PRS-AI, PRS-CPD, and PRS-SC. CONCLUSIONS To our knowledge, this is the first study to report significant genetic overlap between the polygenic risks for smoking initiation and alcohol consumption and the risk of initiating major classes of illicit substances. PRSs constructed from large discovery GWASs allows the detection of novel genetic associations.
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Affiliation(s)
- Lun-Hsien Chang
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, Australia; Faculty of Medicine, the University of Queensland, Brisbane, Australia.
| | - Baptiste Couvy-Duchesne
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, Australia; Institute for Molecular Bioscience, the University of Queensland, Brisbane, Australia
| | - Mengzhen Liu
- Department of Psychology, University of Minnesota Twin Cities, Minneapolis, MN, USA
| | - Sarah E Medland
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Brad Verhulst
- Department of Psychology, Michigan State University, East Lansing, MI, USA
| | - Eric G Benotsch
- Psychology Department, Virginia Commonwealth University, VA, USA
| | - Ian B Hickie
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Nicholas G Martin
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Nathan A Gillespie
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, Australia; Department of Psychology, Michigan State University, East Lansing, MI, USA
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20
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Beeler E, Nobile ZL, Homanics GE. Paternal Preconception Every-Other-Day Ethanol Drinking Alters Behavior and Ethanol Consumption in Offspring. Brain Sci 2019; 9:brainsci9030056. [PMID: 30845665 PMCID: PMC6468863 DOI: 10.3390/brainsci9030056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 01/12/2023] Open
Abstract
Alcohol use disorder is a devastating disease with a complex etiology. Recent preclinical studies have revealed that paternal preconception chronic intermittent ethanol (EtOH) exposure via vaporized EtOH altered drinking behaviors and sensitivity to EtOH selectively in male offspring. In the current study, we used a voluntary oral route of paternal preconception EtOH exposure, i.e., intermittent every-other-day two-bottle choice drinking, and tested offspring for behavioral alterations. Fifteen EtOH drinking sires and 10 control sires were mated to EtOH naïve females to produce EtOH-sired and control-sired offspring. These offspring were tested using the elevated plus maze, open field, drinking in the dark, and unlimited access two-bottle choice assays. We found that paternal preconception every-other-day two-bottle choice drinking resulted in reduced EtOH consumption selectively in male offspring in the drinking in the dark assay compared to control-sired offspring. No differences were detected in either sex in the unlimited access two-bottle choice and elevated plus maze assays. Open field analysis revealed complex changes in basal behavior and EtOH-induced behaviors that were sex specific. We concluded that paternal preconception voluntary EtOH consumption has persistent effects that impact the next generation. This study adds to a growing appreciation that one’s behavioral response to EtOH and EtOH drinking behavior are impacted by EtOH exposure of the prior generation.
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Affiliation(s)
- Erik Beeler
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, 6068 Biomedical Science Tower-3, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
| | - Zachary L Nobile
- Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA.
| | - Gregg E Homanics
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, 6068 Biomedical Science Tower-3, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
- Center for Neuroscience, University of Pittsburgh School of Medicine, 6060 Biomedical Science Tower-3, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, 6060 Biomedical Science Tower-3, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
- Department of Neurobiology, University of Pittsburgh School of Medicine, 6060 Biomedical Science Tower-3, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
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21
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Salvatore JE, Han S, Farris SP, Mignogna KM, Miles MF, Agrawal A. Beyond genome-wide significance: integrative approaches to the interpretation and extension of GWAS findings for alcohol use disorder. Addict Biol 2019; 24:275-289. [PMID: 29316088 PMCID: PMC6037617 DOI: 10.1111/adb.12591] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 11/20/2017] [Accepted: 11/26/2017] [Indexed: 12/16/2022]
Abstract
Alcohol use disorder (AUD) is a heritable complex behavior. Due to the highly polygenic nature of AUD, identifying genetic variants that comprise this heritable variation has proved to be challenging. With the exception of functional variants in alcohol metabolizing genes (e.g. ADH1B and ALDH2), few other candidate loci have been confidently linked to AUD. Genome-wide association studies (GWAS) of AUD and other alcohol-related phenotypes have either produced few hits with genome-wide significance or have failed to replicate on further study. These issues reinforce the complex nature of the genetic underpinnings for AUD and suggest that both GWAS studies with larger samples and additional analysis approaches that better harness the nominally significant loci in existing GWAS are needed. Here, we review approaches of interest in the post-GWAS era, including in silico functional analyses; functional partitioning of single nucleotide polymorphism heritability; aggregation of signal into genes and gene networks; and validation of identified loci, genes and gene networks in postmortem brain tissue and across species. These integrative approaches hold promise to illuminate our understanding of the biological basis of AUD; however, we recognize that the main challenge continues to be the extremely polygenic nature of AUD, which necessitates large samples to identify multiple loci associated with AUD liability.
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Affiliation(s)
- Jessica E. Salvatore
- Department of Psychology; Virginia Commonwealth University; Richmond VA USA
- Virginia Institute for Psychiatric and Behavioral Genetics; Virginia Commonwealth University; Richmond VA USA
| | - Shizhong Han
- Department of Psychiatry; University of Iowa; Iowa City IA USA
- Department of Psychiatry and Behavioral Sciences; Johns Hopkins School of Medicine; Baltimore MD USA
| | - Sean P. Farris
- Waggoner Center for Alcohol and Addiction Research; The University of Texas at Austin; Austin TX USA
| | - Kristin M. Mignogna
- Virginia Institute for Psychiatric and Behavioral Genetics; Virginia Commonwealth University; Richmond VA USA
| | - Michael F. Miles
- Department of Pharmacology and Toxicology; Virginia Commonwealth University; Richmond VA USA
| | - Arpana Agrawal
- Department of Psychiatry; Washington University School of Medicine; Saint Louis MO USA
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Edenberg HJ, McClintick JN. Alcohol Dehydrogenases, Aldehyde Dehydrogenases, and Alcohol Use Disorders: A Critical Review. Alcohol Clin Exp Res 2018; 42:2281-2297. [PMID: 30320893 PMCID: PMC6286250 DOI: 10.1111/acer.13904] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/07/2018] [Indexed: 12/20/2022]
Abstract
Alcohol use disorders (AUDs) are complex traits, meaning that variations in many genes contribute to the risk, as does the environment. Although the total genetic contribution to risk is substantial, most individual variations make only very small contributions. By far the strongest contributors are functional variations in 2 genes involved in alcohol (ethanol [EtOH]) metabolism. A functional variant in alcohol dehydrogenase 1B (ADH1B) is protective in people of European and Asian descent, and a different functional variant in the same gene is protective in those of African descent. A strongly protective variant in aldehyde dehydrogenase 2 (ALDH2) is essentially only found in Asians. This highlights the need to study a wide range of populations. The likely mechanism of protection against heavy drinking and AUDs in both cases is alteration in the rate of metabolism of EtOH that at least transiently elevates acetaldehyde. Other ADH and ALDH variants, including functional variations in ADH1C, have also been implicated in affecting drinking behavior and risk for alcoholism. The pattern of linkage disequilibrium in the ADH region and the differences among populations complicate analyses, particularly of regulatory variants. This critical review focuses upon the ADH and ALDH genes as they affect AUDs.
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Affiliation(s)
- Howard J. Edenberg
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Jeanette N. McClintick
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
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23
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Yamamoto K, Kogiso T, Taniai M, Hashimoto E, Tokushige K. Differences in the genetic backgrounds of patients with alcoholic liver disease and non-alcoholic fatty liver disease. JGH OPEN 2018; 3:17-24. [PMID: 30834336 PMCID: PMC6386744 DOI: 10.1002/jgh3.12097] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/20/2018] [Accepted: 08/25/2018] [Indexed: 12/23/2022]
Abstract
Background and Aim Alcoholic liver disease (ALD) and non‐alcoholic fatty liver disease (NAFLD) have common hepatic histological features, but few studies have compared the genomic backgrounds of these two diseases. Here, we compared the genetic differences between ALD and NAFLD. Methods This study enrolled 318 Japanese patients with ALD (n = 118; male, 86%; median age, 62 years; liver cirrhosis, 58%; hepatocellular carcinoma [HCC], 31%) and NAFLD (n = 200; male, 55%; age, 61 years; cirrhosis, 19%; HCC, 12%). The genotype frequencies of 10 single nucleotide polymorphisms (SNPs) were analyzed. Results The ADH1B genotype GG and ALDH2 genotype GG were observed more frequently, and the percentage of patients with the MTP genotype GG was lower in ALD compared with NAFLD patients (ADH1B, 16 vs 4%; ALDH2 84 vs 44%; MTP 62 vs 72%, respectively; all P < 0.01). Comparing noncirrhosis to cirrhosis, the frequency of the potassium voltage‐gated channel subfamily Q member 1 (KCNQ1) genotype TT and adrenoceptor beta 3 (ADRB3) genotype TT was increased significantly in ALD‐related cirrhosis. In contrast, the patatin‐like phospholipase 3 (PNPLA3) genotype CC was decreased significantly in NAFLD‐related cirrhosis. A comparison of patients with and without HCC demonstrated that the KCNQ1 genotype TT was increased significantly in both HCC groups. In addition, associations between the KCNJ15 genotype GG and ALD‐HCC and the G allele of PNPLA3 and NAFLD‐HCC were identified. Conclusions SNPs in genes related to ethanol and lipid metabolism clearly differed between patients with ALD and NAFLD. KCNQ1 might affect the progression and hepatocarcinogenesis in both ALD and NAFLD.
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Affiliation(s)
- Kuniko Yamamoto
- Institute of Gastroenterology, Department of Internal Medicine Tokyo Women's Medical University Tokyo Japan
| | - Tomomi Kogiso
- Institute of Gastroenterology, Department of Internal Medicine Tokyo Women's Medical University Tokyo Japan
| | - Makiko Taniai
- Institute of Gastroenterology, Department of Internal Medicine Tokyo Women's Medical University Tokyo Japan
| | - Etsuko Hashimoto
- Institute of Gastroenterology, Department of Internal Medicine Tokyo Women's Medical University Tokyo Japan
| | - Katsutoshi Tokushige
- Institute of Gastroenterology, Department of Internal Medicine Tokyo Women's Medical University Tokyo Japan
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Prytkova I, Goate A, Hart RP, Slesinger PA. Genetics of Alcohol Use Disorder: A Role for Induced Pluripotent Stem Cells? Alcohol Clin Exp Res 2018; 42:1572-1590. [PMID: 29897633 PMCID: PMC6120805 DOI: 10.1111/acer.13811] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/04/2018] [Indexed: 12/13/2022]
Abstract
Alcohol use disorder (AUD) affects millions of people and costs nearly 250 billion dollars annually. Few effective FDA-approved treatments exist, and more are needed. AUDs have a strong heritability, but only a few genes have been identified with a large effect size on disease phenotype. Genomewide association studies (GWASs) have identified common variants with low effect sizes, most of which are in noncoding regions of the genome. Animal models frequently fail to recapitulate key molecular features of neuropsychiatric disease due to the polygenic nature of the disease, partial conservation of coding regions, and significant disparity in noncoding regions. By contrast, human induced pluripotent stem cells (hiPSCs) derived from patients provide a powerful platform for evaluating genes identified by GWAS and modeling complex interactions in the human genome. hiPSCs can be differentiated into a wide variety of human cells, including neurons, glia, and hepatic cells, which are compatible with numerous functional assays and genome editing techniques. In this review, we focus on current applications and future directions of patient hiPSC-derived central nervous system cells for modeling AUDs in addition to highlighting successful applications of hiPSCs in polygenic neuropsychiatric diseases.
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Affiliation(s)
- Iya Prytkova
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
| | - Alison Goate
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
- Ronald M. Loeb Center for Alzheimer’s disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Ronald P. Hart
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway NJ 08854, USA
| | - Paul A. Slesinger
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029, USA
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Johnstone AL, O'Reilly JJ, Patel AJ, Guo Z, Andrade NS, Magistri M, Nathanson L, Esanov R, Miller BH, Turecki G, Brothers SP, Zeier Z, Wahlestedt C. EZH1 is an antipsychotic-sensitive epigenetic modulator of social and motivational behavior that is dysregulated in schizophrenia. Neurobiol Dis 2018; 119:149-158. [PMID: 30099093 DOI: 10.1016/j.nbd.2018.08.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 07/07/2018] [Accepted: 08/08/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND With the capacity to modulate gene networks in an environmentally-sensitive manner, the role of epigenetic systems in mental disorders has come under intense investigation. Dysregulation of epigenetic effectors, including microRNAs and histone-modifying enzymes, may better explain the role of environmental risk factors and the observed heritability rate that cannot be fully attributed to known genetic risk alleles. Here, we aimed to identify novel epigenetic targets of the schizophrenia-associated microRNA 132 (miR-132). METHODS Histone modifications were quantified by immunodetection in response to viral-mediated overexpression of miR-132 while a luminescent reporter system was used to validate targets of miR-132 in vitro. Genome-wide profiling, quantitative PCR and NanoSting were used to quantify gene expression in post-mortem human brains, neuronal cultures and prefrontal cortex (PFC) of mice chronically exposed to antipsychotics. Following viral-mediated depletion of Enhancer of Zeste 1 (EZH1) in the murine PFC, behaviors including sociability and motivation were assessed using a 3-chambered apparatus and forced-swim test, respectively. RESULTS Overexpression of miR-132 decreased global histone 3 lysine 27 tri-methylation (H3K27me3), a repressive epigenetic mark. Moreover, the polycomb-associated H3K27 methyltransferase, EZH1, is regulated by miR-132 and upregulated in the PFC of schizophrenics. Unlike its homolog EZH2, expression of EZH1 in the murine PFC decreased following chronic exposure to antipsychotics. Viral-mediated depletion of EZH1 in the mouse PFC attenuated sociability, enhanced motivational behaviors, and affected gene expression pathways related to neurotransmission and behavioral phenotypes. CONCLUSIONS EZH1 is dysregulated in schizophrenia, sensitive to antipsychotic medications, and a brain-enriched miR-132 target that controls neurobehavioral phenotypes.
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Affiliation(s)
- Andrea L Johnstone
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; EpiCypher, Durham, NC, USA
| | - Jiaqi J O'Reilly
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; Institute for Biomedical Sciences, George Washington University, Washington, DC, USA
| | - Annika J Patel
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Zhihong Guo
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nadja S Andrade
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Marco Magistri
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Lubov Nathanson
- Institute for Neuro Immune Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Rustam Esanov
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Brooke H Miller
- McKnight Brain Institute and Department of Psychiatry, University of Florida College of Medicine, Gainesville, FL, USA
| | | | - Shaun P Brothers
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Zane Zeier
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Claes Wahlestedt
- The Center for Therapeutic Innovation and Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA.
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Koulentaki M, Kouroumalis E. GABA A receptor polymorphisms in alcohol use disorder in the GWAS era. Psychopharmacology (Berl) 2018; 235:1845-1865. [PMID: 29721579 DOI: 10.1007/s00213-018-4918-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/18/2018] [Indexed: 12/11/2022]
Abstract
Alcohol use disorder (AUD) is a chronic, relapsing, neuro-psychiatric illness of high prevalence and with a serious public health impact worldwide. It is complex and polygenic, with a heritability of about 50%, and influenced by environmental causal heterogeneity. Risk factors associated with its etiology have a genetic component. GABA (γ-aminobutyric acid) is a major inhibitory neurotransmitter in mammalian brain. GABAA receptors are believed to mediate some of the physiological and behavioral actions of alcohol. In this critical review, relevant genetic terms and type and methodology of the genetic studies are briefly explained. Postulated candidate genes that encode subunits of GABAA receptors, with all the reported SNPs, are presented. Genetic studies and meta-analyses examining polymorphisms of the GABAA receptor and their association with AUD predisposition are presented. The data are critically examined with reference to recent GWAS studies that failed to show relations between GABAA receptors and AUD. Restrictions and perspectives of the different findings are discussed.
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Affiliation(s)
- Mairi Koulentaki
- Alcohology Research Laboratory, Medical School, University of Crete, 71500, Heraklion, Crete, Greece.,Department of Gastroenterology, University Hospital Heraklion, 71500, Heraklion, Crete, Greece
| | - Elias Kouroumalis
- Department of Gastroenterology, University Hospital Heraklion, 71500, Heraklion, Crete, Greece.
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McGuier NS, Rinker JA, Cannady R, Fulmer DB, Jones SR, Hoffman M, Mulholland PJ. Identification and validation of midbrain Kcnq4 regulation of heavy alcohol consumption in rodents. Neuropharmacology 2018; 138:10-19. [PMID: 29775679 DOI: 10.1016/j.neuropharm.2018.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/27/2018] [Accepted: 05/14/2018] [Indexed: 12/12/2022]
Abstract
Currently available pharmacotherapies for treating alcohol use disorder (AUD) suffer from deleterious side effects and are not efficacious in diverse populations. Clinical and preclinical studies provide evidence that the Kcnq family of genes that encode KV7 channels influence alcohol intake and dependence. KV7 channels are a class of slowly activating voltage-dependent K+ channels that regulate neuronal excitability. Studies indicate that the KV7 channel positive modulator retigabine can decrease dopaminergic neuron firing, alter dopamine (DA) release, and reduce alcohol intake in heavy drinking rodents. Given the critical nature of ventral tegmental area (VTA) DA to the addiction process and predominant expression of Kcnq4 in DA neurons, we investigated the role of midbrain Kcnq genes and KV7 channels in the VTA of genetically diverse mice and long-term heavy drinking rats, respectively. Integrative bioinformatics analysis identified negative correlations between midbrain Kcnq4 expression and alcohol intake and seeking behaviors. Kcnq4 expression levels were also correlated with dopaminergic-related phenotypes in BXD strains, and Kcnq4 was present in support intervals for alcohol sensitivity and alcohol withdrawal severity QTLs in rodents. Pharmacological validation studies revealed that VTA KV7 channels regulate excessive alcohol intake in rats with a high-drinking phenotype. Administration of a novel and selective KV7.2/4 channel positive modulator also reduced alcohol drinking in rats. Together, these findings indicate that midbrain Kcnq4 expression regulates alcohol-related behaviors in genetically diverse mice and provide evidence that KV7.4 channels are a critical mediator of excessive alcohol drinking.
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Affiliation(s)
- Natalie S McGuier
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States
| | - Jennifer A Rinker
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States; Medical University of South Carolina, Department of Psychiatry & Behavioral Sciences, 67 President Street, Charleston, SC, 29425, United States
| | - Reginald Cannady
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States
| | - Diana B Fulmer
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States
| | - Sara R Jones
- Wake Forest School of Medicine, Department of Physiology and Pharmacology, 1 Medical Center Boulevard, Winston Salem, NC, 27157, United States
| | - Michaela Hoffman
- Medical University of South Carolina, Department of Psychiatry & Behavioral Sciences, 67 President Street, Charleston, SC, 29425, United States
| | - Patrick J Mulholland
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States; Medical University of South Carolina, Department of Psychiatry & Behavioral Sciences, 67 President Street, Charleston, SC, 29425, United States.
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Gene expression changes in the ventral hippocampus and medial prefrontal cortex of adolescent alcohol-preferring (P) rats following binge-like alcohol drinking. Alcohol 2018; 68:37-47. [PMID: 29448234 DOI: 10.1016/j.alcohol.2017.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 11/23/2022]
Abstract
Binge drinking of alcohol during adolescence is a serious public health concern with long-term consequences, including decreased hippocampal and prefrontal cortex volume and deficits in memory. We used RNA sequencing to assess the effects of adolescent binge drinking on gene expression in these regions. Male adolescent alcohol-preferring (P) rats were exposed to repeated binge drinking (three 1-h sessions/day during the dark/cycle, 5 days/week for 3 weeks starting at 28 days of age; ethanol intakes of 2.5-3 g/kg/session). Ethanol significantly altered the expression of 416 of 11,727 genes expressed in the ventral hippocampus. Genes and pathways involved in neurogenesis, long-term potentiation, and axonal guidance were decreased, which could relate to the impaired memory function found in subjects with adolescent alcohol binge-like exposure. The decreased expression of myelin and cholesterol genes and apparent decrease in oligodendrocytes in P rats could result in decreased myelination. In the medial prefrontal cortex, 638 of 11,579 genes were altered; genes in cellular stress and inflammatory pathways were increased, as were genes involved in oxidative phosphorylation. Overall, the results of this study suggest that adolescent binge-like alcohol drinking may alter the development of the ventral hippocampus and medial prefrontal cortex and produce long-term consequences on learning and memory, and on control of impulsive behaviors.
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Abstract
PURPOSE OF REVIEW With the advent of the genome-wide association study (GWAS), our understanding of the genetics of addiction has made significant strides forward. Here, we summarize genetic loci containing variants identified at genome-wide statistical significance (P < 5 × 10-8) and independently replicated, review evidence of functional or regulatory effects for GWAS-identified variants, and outline multi-omics approaches to enhance discovery and characterize addiction loci. RECENT FINDINGS Replicable GWAS findings span 11 genetic loci for smoking, eight loci for alcohol, and two loci for illicit drugs combined and include missense functional variants and noncoding variants with regulatory effects in human brain tissues traditionally viewed as addiction-relevant (e.g., prefrontal cortex [PFC]) and, more recently, tissues often overlooked (e.g., cerebellum). GWAS analyses have discovered several novel, replicable variants contributing to addiction. Using larger sample sizes from harmonized datasets and new approaches to integrate GWAS with multiple 'omics data across human brain tissues holds great promise to significantly advance our understanding of the biology underlying addiction.
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Affiliation(s)
- Dana B Hancock
- Behavioral and Urban Health Program, Behavioral Health and Criminal Justice Division, RTI International, 3040 East Cornwallis Road, P. O. Box 12194, Research Triangle Park, NC, 27709, USA.
| | - Christina A Markunas
- Behavioral and Urban Health Program, Behavioral Health and Criminal Justice Division, RTI International, 3040 East Cornwallis Road, P. O. Box 12194, Research Triangle Park, NC, 27709, USA
| | - Laura J Bierut
- Department of Psychiatry, Washington University, St. Louis, MO, USA
| | - Eric O Johnson
- Fellow Program and Behavioral Health and Criminal Justice Division, RTI International, Research Triangle Park, NC, USA
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Cannady R, Rinker JA, Nimitvilai S, Woodward JJ, Mulholland PJ. Chronic Alcohol, Intrinsic Excitability, and Potassium Channels: Neuroadaptations and Drinking Behavior. Handb Exp Pharmacol 2018; 248:311-343. [PMID: 29374839 DOI: 10.1007/164_2017_90] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neural mechanisms underlying alcohol use disorder remain elusive, and this lack of understanding has slowed the development of efficacious treatment strategies for reducing relapse rates and prolonging abstinence. While synaptic adaptations produced by chronic alcohol exposure have been extensively characterized in a variety of brain regions, changes in intrinsic excitability of critical projection neurons are understudied. Accumulating evidence suggests that prolonged alcohol drinking and alcohol dependence produce plasticity of intrinsic excitability as measured by changes in evoked action potential firing and after-hyperpolarization amplitude. In this chapter, we describe functional changes in cell firing of projection neurons after long-term alcohol exposure that occur across species and in multiple brain regions. Adaptations in calcium-activated (KCa2), voltage-dependent (KV7), and G protein-coupled inwardly rectifying (Kir3 or GIRK) potassium channels that regulate the evoked firing and after-hyperpolarization parallel functional changes in intrinsic excitability induced by chronic alcohol. Moreover, there are strong genetic links between alcohol-related behaviors and genes encoding KCa2, KV7, and GIRK channels, and pharmacologically targeting these channels reduces alcohol consumption and alcohol-related behaviors. Together, these studies demonstrate that chronic alcohol drinking produces adaptations in KCa2, KV7, and GIRK channels leading to impaired regulation of the after-hyperpolarization and aberrant cell firing. Correcting the deficit in the after-hyperpolarization with positive modulators of KCa2 and KV7 channels and altering the GIRK channel binding pocket to block the access of alcohol represent a potentially highly effective pharmacological approach that can restore changes in intrinsic excitability and reduce alcohol consumption in affected individuals.
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Affiliation(s)
- Reginald Cannady
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Jennifer A Rinker
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Sudarat Nimitvilai
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - John J Woodward
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Patrick J Mulholland
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA.
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Quansah E, McGregor NW. Towards diversity in genomics: The emergence of neurogenomics in Africa? Genomics 2018; 110:1-9. [PMID: 28774809 DOI: 10.1016/j.ygeno.2017.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/24/2017] [Accepted: 07/30/2017] [Indexed: 12/11/2022]
Abstract
There is a high burden of mental and neurological disorders in Africa. Nevertheless, there appears to be an under-representation of African ancestry populations in large-scale genomic studies. Here, we evaluated the extent of under-representation of Africans in neurogenomic studies in the GWAS Catalog. We found 569 neurogenomic studies, of which 88.9% were exclusively focused on people with European ancestry and the remaining 11.1% having African ancestry cases included. In terms of population, only 1.2% of the total populations involved in these 569 GWAS studies were of African descent. Further, most of the individuals in the African ancestry category were identified to be African-Americans/Afro-Caribbeans, highlighting the huge under-representation of homogenous African populations in large-scale neurogenomic studies. Efforts geared at establishing strong collaborative ties with European/American researchers, maintaining freely accessible biobanks and establishing comprehensive African genome data repositories to track African genome variations are critical for propelling neurogenomics/precision medicine in Africa.
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Affiliation(s)
- Emmanuel Quansah
- Pharmacology, Faculty of Health and Life Sciences, De Montfort University, Leicester LE1 9BH, UK.
| | - Nathaniel W McGregor
- Department of Genetics, Stellenbosch University, Stellenbosch, South Africa; Department of Psychiatry, Stellenbosch University, Tygerberg Medical Campus, Tygerberg, South Africa.
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Chen G, Zhang F, Xue W, Wu R, Xu H, Wang K, Zhu J. An association study revealed substantial effects of dominance, epistasis and substance dependence co-morbidity on alcohol dependence symptom count. Addict Biol 2017; 22:1475-1485. [PMID: 27151647 DOI: 10.1111/adb.12402] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 02/27/2016] [Accepted: 03/15/2016] [Indexed: 12/12/2022]
Abstract
Alcohol dependence is a complex disease involving polygenes, environment and their interactions. Inadequate consideration of these interactions may have hampered the progress on genome-wide association studies of alcohol dependence. By using the dataset of the Study of Addiction: Genetics and Environment with 3838 subjects, we conducted a genome-wide association studies of alcohol dependence symptom count (ADSC) with a full genetic model considering additive, dominance, epistasis and their interactions with ethnicity, as well as conditions of co-morbid substance dependence. Twenty quantitative trait single nucleotide polymorphisms (QTSs) showed highly significant associations with ADSC, including four previously reported genes (ADH1C, PKNOX2, CPE and KCNB2) and the reported intergenic rs1363605, supporting the overall validity of the analysis. Two QTSs within or near ADH1C showed very strong association in a dominance inheritance mode and increased the phenotype value of ADSC when the effect of co-morbid opiate or marijuana dependence was controlled. Highly significant association was also identified in variants within four novel genes (RGS6, FMN1, NRM and BPTF), two non-coding RNA and two epistasis loci. QTS rs7616413, located near PTPRG encoding a protein tyrosine phosphatase receptor, interacted with rs10090742 within ANGPT1 encoding a protein tyrosine phosphatase in an additive × additive or dominance × additive manner. The detected QTSs contributed to about 20 percent of total heritability, in which dominance and epistasis effects accounted for over 50 percent. These results demonstrated that perturbations arising from gene-gene interaction and conditions of co-morbidity substantially influence the genetic architecture of complex trait.
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Affiliation(s)
- Gang Chen
- Center for Translational Systems Biology and Neuroscience, and Key Laboratory of Integrative Biomedicine for Brain Diseases; Nanjing University of Chinese Medicine; Nanjing China
| | - Futao Zhang
- Institute of Bioinformatics; Zhejiang University; Hangzhou China
| | - Wenda Xue
- Center for Translational Systems Biology and Neuroscience, and Key Laboratory of Integrative Biomedicine for Brain Diseases; Nanjing University of Chinese Medicine; Nanjing China
| | - Ruyan Wu
- Center for Translational Systems Biology and Neuroscience, and Key Laboratory of Integrative Biomedicine for Brain Diseases; Nanjing University of Chinese Medicine; Nanjing China
| | - Haiming Xu
- Institute of Bioinformatics; Zhejiang University; Hangzhou China
| | - Kesheng Wang
- Department of Biostatistics and Epidemiology, College of Public Health; East Tennessee State University; Johnson City TN USA
| | - Jun Zhu
- Institute of Bioinformatics; Zhejiang University; Hangzhou China
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Prom-Wormley EC, Ebejer J, Dick DM, Bowers MS. The genetic epidemiology of substance use disorder: A review. Drug Alcohol Depend 2017; 180:241-259. [PMID: 28938182 PMCID: PMC5911369 DOI: 10.1016/j.drugalcdep.2017.06.040] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 06/20/2017] [Accepted: 06/23/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Substance use disorder (SUD) remains a significant public health issue. A greater understanding of how genes and environment interact to regulate phenotypes comprising SUD will facilitate directed treatments and prevention. METHODS The literature studying the neurobiological correlates of SUD with a focus on the genetic and environmental influences underlying these mechanisms was reviewed. Results from twin/family, human genetic association, gene-environment interaction, epigenetic literature, phenome-wide association studies are summarized for alcohol, nicotine, cannabinoids, cocaine, and opioids. RESULTS There are substantial genetic influences on SUD that are expected to influence multiple neurotransmission pathways, and these influences are particularly important within the dopaminergic system. Genetic influences involved in other aspects of SUD etiology including drug processing and metabolism are also identified. Studies of gene-environment interaction emphasize the importance of environmental context in SUD. Epigenetic studies indicate drug-specific changes in gene expression as well as differences in gene expression related to the use of multiple substances. Further, gene expression is expected to differ by stage of SUD such as substance initiation versus chronic substance use. While a substantial literature has developed for alcohol and nicotine use disorders, there is comparatively less information for other commonly abused substances. CONCLUSIONS A better understanding of genetically-mediated mechanisms involved in the neurobiology of SUD provides increased opportunity to develop behavioral and biologically based treatment and prevention of SUD.
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Affiliation(s)
- Elizabeth C Prom-Wormley
- Dvision of Epidemiology, Department of Family Medicine and Population Health, Virginia Commonwealth University, PO Box 980212, Richmond, VA 23298-0212, USA.
| | - Jane Ebejer
- School of Cognitive Behavioural and Social Sciences, University of New England, Armidale, NSW 2350, Australia
| | - Danielle M Dick
- Department of Psychology, Virginia Commonwealth University, PO Box 842509, Richmond, VA 23284-2509, USA
| | - M Scott Bowers
- Faulk Center for Molecular Therapeutics, Biomedical Engeneering, Northwestern University, Evanston, IL 60201, USA
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Chen X, Long F, Cai B, Chen X, Chen G. A novel relationship for schizophrenia, bipolar and major depressive disorder Part 3: Evidence from chromosome 3 high density association screen. J Comp Neurol 2017; 526:59-79. [PMID: 28856687 DOI: 10.1002/cne.24311] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 07/29/2017] [Accepted: 07/31/2017] [Indexed: 12/30/2022]
Abstract
Familial clustering of schizophrenia (SCZ), bipolar disorder (BPD), and major depressive disorder (MDD) was systematically reported (Aukes et al, Genet Med 2012, 14, 338-341) and convergent evidence from genetics, symptomatology, and psychopharmacology imply that there are intrinsic connections between these three major psychiatric disorders, for example, any two or even three of these disorders could co-exist in some families. A total of 60, 838 single-nucleotide polymorphisms (SNPs) on chromosome 3 were genotyped by Affymetrix Genome-Wide Human SNP array 6.0 on 119 SCZ, 253 BPD (type-I), 177 MDD patients and 1,000 controls. The population of Shandong province was formed in 14 century and believed that it belongs to homogenous population. Associated SNPs were systematically revealed and outstanding susceptibility genes (CADPS, GRM7,KALRN, LSAMP, NLGN1, PRICKLE2, ROBO2) were identified. Unexpectedly, flanking genes for the associated SNPs distinctive for BPD and/or MDD were replicated in an enlarged cohort of 986 SCZ patients. The evidence from this chromosome 3 analysis supports the notion that both of bipolar and MDD might be subtypes of schizophrenia rather than independent disease entity. Also, a similar finding was detected on chromosome 5, 6, 7, and 8 (Chen et al. Am J Transl Res 2017;9 (5):2473-2491; Curr Mol Med 2016;16(9):840-854; Behav Brain Res 2015;293:241-251; Mol Neurobiol 2016. doi: 10.1007/s12035-016-0102-1). Furthermore, PRICKLE2 play an important role in the pathogenesis of three major psychoses in this population.
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Affiliation(s)
- Xing Chen
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, Shandong, People's Republic of China
| | - Feng Long
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, Shandong, People's Republic of China
| | - Bin Cai
- CapitalBio corporation, Beijing, People's Republic of China
| | - Xiaohong Chen
- CapitalBio corporation, Beijing, People's Republic of China
| | - Gang Chen
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, Shandong, People's Republic of China
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Sakata K, Overacre AE. Promoter IV-BDNF deficiency disturbs cholinergic gene expression of CHRNA5, CHRM2, and CHRM5: effects of drug and environmental treatments. J Neurochem 2017; 143:49-64. [PMID: 28722769 DOI: 10.1111/jnc.14129] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/05/2017] [Accepted: 07/13/2017] [Indexed: 11/29/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) promotes maturation of cholinergic neurons. However, how activity-dependent BDNF expression affects specific cholinergic gene expression remains unclear. This study addressed this question by determining mRNA levels of 22 acetylcholine receptor subunits, the choline transporter (CHT), and the choline acetyltransferase (ChAT) in mice deficient in activity-dependent BDNF via promoter IV (KIV) and control wild-type mice. Quantitative RT-PCR revealed significant reductions in nicotinic acetylcholine receptor alpha 5 (CHRNA5) in the frontal cortex and hippocampus and M5 muscarinic acetylcholine receptor (CHRM5) in the hippocampus, but significant increases in M2 muscarinic acetylcholine receptor (CHRM2) in the frontal cortex of KIV mice compared to wild-type mice. Three-week treatments with fluoxetine, phenelzine, duloxetine, imipramine, or an enriched environment treatment (EET) did not affect the altered expression of these genes except that EET increased CHRNA5 levels only in KIV frontal cortex. EET also increased levels of CHRNA7, CHT, and ChAT, again only in the KIV frontal cortex. The imipramine treatment was most prominent among the four antidepressants; it up-regulated hippocampal CHRM2 and frontal cortex CHRM5 in both genotypes, and frontal cortex CHRNA7 only in KIV mice. To the best of our knowledge, this is the first evidence that BDNF deficiency disturbs expression of CHRNA5, CHRM2, and CHRM5. Our results suggest that promoter IV-BDNF deficiency - which occurs under chronic stress - causes cholinergic dysfunctions via these receptors. EET is effective on CHRNA5, while its compensatory induction of other cholinergic genes or drugs targeting CHRNA5, CHRM2, and CHRM5 may become an alternative strategy to reverse these BDNF-linked cholinergic dysfunctions.
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Affiliation(s)
- Kazuko Sakata
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Abigail E Overacre
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN, USA
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Dick DM, Barr P, Guy M, Nasim A, Scott D. Review: Genetic research on alcohol use outcomes in African American populations: A review of the literature, associated challenges, and implications. Am J Addict 2017; 26:486-493. [PMID: 28240821 PMCID: PMC5884102 DOI: 10.1111/ajad.12495] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 11/18/2016] [Accepted: 12/18/2016] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND OBJECTIVES There have been remarkable advances in understanding genetic influences on complex traits; however, individuals of African descent have been underrepresented in genetic research. METHODS We review the limitations of existing genetic research on alcohol phenotypes in African Americans (AA) including both twin and gene identification studies, possible reasons for underrepresentation of AAs in genetic research, the implications of the lack of racially diverse samples, and special considerations regarding conducting genetic research in AA populations. RESULTS There is a marked absence of large-scale AA twin studies so little is known about the genetic epidemiology of alcohol use and problems among AAs. Individuals of African descent have also been underrepresented in gene identification efforts; however, there have been recent efforts to enhance representation. It remains unknown the extent to which genetic variants associated with alcohol use outcomes in individuals of European and African descent will be shared. Efforts to increase representation must be accompanied by careful attention to the ethical, legal, and social implications of genetic research. This is particularly true for AAs due to the history of abuse by the biomedical community and the persistent racial discrimination targeting this population. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE Lack of representation in genetic studies limits our understanding of the etiological factors that contribute to substance use and psychiatric outcomes in populations of African descent and has the potential to further perpetuate health disparities. Involving individuals of diverse ancestry in discussions about genetic research will be critical to ensure that all populations benefit equally from genetic advances. (Am J Addict 2017;26:486-493).
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Affiliation(s)
- Danielle M Dick
- Department of Psychology, Virginia Commonwealth University, Richmond, Virginia
- Department of African American Studies, Virginia Commonwealth University, Richmond, Virginia
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - Peter Barr
- Department of Psychology, Virginia Commonwealth University, Richmond, Virginia
- Department of African American Studies, Virginia Commonwealth University, Richmond, Virginia
| | - Mignonne Guy
- Department of African American Studies, Virginia Commonwealth University, Richmond, Virginia
| | - Aashir Nasim
- Department of African American Studies, Virginia Commonwealth University, Richmond, Virginia
| | - Denise Scott
- Department of Pediatrics and Human Genetics and Alcohol Research Center, Howard University College of Medicine, Washington, District of Columbia
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Goulding SP, Szumlinski KK, Contet C, MacCoss MJ, Wu CC. A mass spectrometry-based proteomic analysis of Homer2-interacting proteins in the mouse brain. J Proteomics 2017; 166:127-137. [PMID: 28728878 DOI: 10.1016/j.jprot.2017.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 07/08/2017] [Accepted: 07/12/2017] [Indexed: 11/26/2022]
Abstract
In the brain, the Homer protein family modulates excitatory signal transduction and receptor plasticity through interactions with other proteins in dendritic spines. Homer proteins are implicated in a variety of psychiatric disorders such as schizophrenia and addiction. Since long Homers serve as scaffolding proteins, identifying their interacting partners is an important first step in understanding their biological function and could help to guide the design of new therapeutic strategies. The present study set out to document Homer2-interacting proteins in the mouse brain using a co-immunoprecipitation-based mass spectrometry approach where Homer2 knockout samples were used to filter out non-specific interactors. We found that in the mouse brain, Homer2 interacts with a limited subset of its previously reported interacting partners (3 out of 31). Importantly, we detected an additional 15 novel Homer2-interacting proteins, most of which are part of the N-methyl-D-aspartate receptor signaling pathway. These results corroborate the central role Homer2 plays in glutamatergic transmission and expand the network of proteins potentially contributing to the behavioral abnormalities associated with altered Homer2 expression. SIGNIFICANCE Long Homer proteins are scaffolding proteins that regulate signal transduction in neurons. Identifying their interacting partners is key to understanding their function. We used co-immunoprecipitation in combination with mass spectrometry to establish the first comprehensive list of Homer2-interacting partners in the mouse brain. The specificity of interactions was evaluated using Homer2 knockout brain tissue as a negative control. The set of proteins that we identified minimally overlaps with previously reported interacting partners of Homer2; however, we identified novel interactors that are part of a signaling cascade activated by glutamatergic transmission, which improves our mechanistic understanding of the role of Homer2 in behavior.
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Affiliation(s)
- Scott P Goulding
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, United States; Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, CO, United States; Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, United States.
| | - Karen K Szumlinski
- Department of Psychological and Brain Sciences, Molecular, Cellular and Developmental Biology, The Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Candice Contet
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, United States
| | - Michael J MacCoss
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, United States
| | - Christine C Wu
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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Cho SB, Aliev F, Clark SL, Adkins AE, Edenberg HJ, Bucholz KK, Porjesz B, Dick DM. Using Patterns of Genetic Association to Elucidate Shared Genetic Etiologies Across Psychiatric Disorders. Behav Genet 2017; 47:405-415. [PMID: 28343281 PMCID: PMC5996973 DOI: 10.1007/s10519-017-9844-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 03/09/2017] [Indexed: 11/28/2022]
Abstract
Twin studies indicate that latent genetic factors overlap across comorbid psychiatric disorders. In this study, we used a novel approach to elucidate shared genetic factors across psychiatric outcomes by clustering single nucleotide polymorphisms based on their genome-wide association patterns. We applied latent profile analysis (LPA) to p-values resulting from genome-wide association studies across three phenotypes: symptom counts of alcohol dependence (AD), antisocial personality disorder (ASP), and major depression (MD), using the European-American case-control genome-wide association study subsample of the collaborative study on the genetics of alcoholism (N = 1399). In the 3-class model, classes were characterized by overall low associations (85.6% of SNPs), relatively stronger association only with MD (6.8%), and stronger associations with AD and ASP but not with MD (7.6%), respectively. These results parallel the genetic factor structure identified in twin studies. The findings suggest that applying LPA to association results across multiple disorders may be a promising approach to identify the specific genetic etiologies underlying shared genetic variance.
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Affiliation(s)
- Seung Bin Cho
- Department of Psychology, Virginia Commonwealth University, PO Box 842018, 817W. Franklin Street, Richmond, VA, 23284-2018, USA.
- College Behavioral and Emotional Health Institute, Virginia Commonwealth University, Richmond, VA, USA.
| | - Fazil Aliev
- Department of Psychology, Virginia Commonwealth University, PO Box 842018, 817W. Franklin Street, Richmond, VA, 23284-2018, USA
- College Behavioral and Emotional Health Institute, Virginia Commonwealth University, Richmond, VA, USA
- Faculty of Business, Karabuk University, Karabuk, Turkey
| | - Shaunna L Clark
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Amy E Adkins
- Department of Psychology, Virginia Commonwealth University, PO Box 842018, 817W. Franklin Street, Richmond, VA, 23284-2018, USA
- College Behavioral and Emotional Health Institute, Virginia Commonwealth University, Richmond, VA, USA
| | - Howard J Edenberg
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - Bernice Porjesz
- Department of Psychiatry and Behavioral Sciences, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Danielle M Dick
- Department of Psychology, Virginia Commonwealth University, PO Box 842018, 817W. Franklin Street, Richmond, VA, 23284-2018, USA
- College Behavioral and Emotional Health Institute, Virginia Commonwealth University, Richmond, VA, USA
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA
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Kertes DA, Bhatt SS, Kamin HS, Hughes DA, Rodney NC, Mulligan CJ. BNDF methylation in mothers and newborns is associated with maternal exposure to war trauma. Clin Epigenetics 2017; 9:68. [PMID: 28680507 PMCID: PMC5493129 DOI: 10.1186/s13148-017-0367-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 06/14/2017] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The BDNF gene codes for brain-derived neurotrophic factor, a growth factor involved in neural development, cell differentiation, and synaptic plasticity. Present in both the brain and periphery, BDNF plays critical roles throughout the body and is essential for placental and fetal development. Rodent studies show that early life stress, including prenatal stress, broadly alters BDNF methylation, with presumed changes in gene expression. No studies have assessed prenatal exposure to maternal traumatic stress and BDNF methylation in humans. This study examined associations of prenatal exposure to maternal stress and BDNF methylation at CpG sites across the BDNF gene. RESULTS Among 24 mothers and newborns in the eastern Democratic Republic of Congo, a region with extreme conflict and violence to women, maternal experiences of war trauma and chronic stress were associated with BDNF methylation in umbilical cord blood, placental tissue, and maternal venous blood. Associations of maternal stress and BDNF methylation showed high tissue specificity. The majority of significant associations were observed in putative transcription factor binding regions. CONCLUSIONS This is the first study in humans to examine BDNF methylation in relation to prenatal exposure to maternal stress in three tissues simultaneously and the first in any mammalian species to report associations of prenatal stress and BDNF methylation in placental tissue. The findings add to the growing body of evidence highlighting the importance of considering epigenetic effects when examining the impacts of trauma and stress, not only for adults but also for offspring exposed via effects transmitted before birth.
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Affiliation(s)
- Darlene A Kertes
- Department of Psychology and University of Florida Genetics Institute, 945 Center Drive, Gainesville, FL 32611-2250 USA
| | - Samarth S Bhatt
- Department of Psychology, University of Florida, Gainesville, FL USA
| | - Hayley S Kamin
- Department of Psychology, University of Florida, Gainesville, FL USA
| | - David A Hughes
- Integrative Epidemiology Unit, University of Bristol, Bristol, UK
| | - Nicole C Rodney
- Department of Anthropology, University of Florida, Gainesville, FL USA
| | - Connie J Mulligan
- Department of Anthropology and University of Florida Genetics Institute, University of Florida, Gainesville, FL USA
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Chen X, Long F, Cai B, Chen X, Chen G. A novel relationship for schizophrenia, bipolar and major depressive disorder Part 5: a hint from chromosome 5 high density association screen. Am J Transl Res 2017; 9:2473-2491. [PMID: 28559998 PMCID: PMC5446530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 01/31/2017] [Indexed: 06/07/2023]
Abstract
Familial clustering of schizophrenia (SCZ), bipolar disorder (BPD), and major depressive disorder (MDD) was systematically reported (Aukes, M. F. Genet Med 2012, 14, 338-341) and any two or even three of these disorders could co-exist in some families. In addition, evidence from symptomatology and psychopharmacology also imply that there are intrinsic connections between these three major disorders. A total of 56,569 single nucleotide polymorphism (SNPs) on chromosome 5 were genotyped by Affymetrix Genome-Wide Human SNP array 6.0 on 119 SCZ, 253 BPD (type-I), 177 MDD patients and 1000 controls. Associated SNPs and flanking genes was screen out systematically, and cadherin pathway genes (CDH6, CDH9, CDH10, CDH12, and CDH18) belong to outstanding genes. Unexpectedly, nearly all flanking genes of the associated SNPs distinctive for BPD and MDD were replicated in an enlarged cohort of 986 SCZ patients (P ≤ 9.9E-8). Considering multiple bits of evidence, our chromosome 5 analyses implicated that bipolar and major depressive disorder might be subtypes of schizophrenia rather than two independent disease entities. Also, cadherin pathway genes play important roles in the pathogenesis of the three major mental disorders.
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Affiliation(s)
- Xing Chen
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences18877 Jingshi Road, Jinan 250062, Shandong, People’s Republic of China
| | - Feng Long
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences18877 Jingshi Road, Jinan 250062, Shandong, People’s Republic of China
| | - Bin Cai
- Capital Bio Corporation18 Life Science Parkway, Changping District, Beijing 102206, People’s Republic of China
| | - Xiaohong Chen
- Capital Bio Corporation18 Life Science Parkway, Changping District, Beijing 102206, People’s Republic of China
| | - Gang Chen
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences18877 Jingshi Road, Jinan 250062, Shandong, People’s Republic of China
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Tandon N, Nanda P, Padmanabhan JL, Mathew IT, Eack SM, Narayanan B, Meda SA, Bergen SE, Ruaño G, Windemuth A, Kocherla M, Petryshen TL, Clementz B, Sweeney J, Tamminga C, Pearlson G, Keshavan MS. Novel gene-brain structure relationships in psychotic disorder revealed using parallel independent component analyses. Schizophr Res 2017; 182:74-83. [PMID: 27789186 DOI: 10.1016/j.schres.2016.10.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/14/2016] [Accepted: 10/16/2016] [Indexed: 01/13/2023]
Abstract
BACKGROUND Schizophrenia, schizoaffective disorder, and psychotic bipolar disorder overlap with regard to symptoms, structural and functional brain abnormalities, and genetic risk factors. Neurobiological pathways connecting genes to clinical phenotypes across the spectrum from schizophrenia to psychotic bipolar disorder remain largely unknown. METHODS We examined the relationship between structural brain changes and risk alleles across the psychosis spectrum in the multi-site Bipolar-Schizophrenia Network for Intermediate Phenotypes (B-SNIP) cohort. Regional MRI brain volumes were examined in 389 subjects with a psychotic disorder (139 schizophrenia, 90 schizoaffective disorder, and 160 psychotic bipolar disorder) and 123 healthy controls. 451,701 single-nucleotide polymorphisms were screened and processed using parallel independent component analysis (para-ICA) to assess associations between genes and structural brain abnormalities in probands. RESULTS 482 subjects were included after quality control (364 individuals with psychotic disorder and 118 healthy controls). Para-ICA identified four genetic components including several risk genes already known to contribute to schizophrenia and bipolar disorder and revealed three structural components that showed overlapping relationships with the disease risk genes across the three psychotic disorders. Functional ontologies representing these gene clusters included physiological pathways involved in brain development, synaptic transmission, and ion channel activity. CONCLUSIONS Heritable brain structural findings such as reduced cortical thickness and surface area in probands across the psychosis spectrum were associated with somewhat distinct genes related to putative disease pathways implicated in psychotic disorders. This suggests that brain structural alterations might represent discrete psychosis intermediate phenotypes along common neurobiological pathways underlying disease expression across the psychosis spectrum.
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Affiliation(s)
- Neeraj Tandon
- Psychiatry, Harvard Medical School, Beth Israel Deaconess Medical Ctr, Boston, MA, USA; Baylor College of Medicine, Texas Medical Center, Houston, TX, USA.
| | - Pranav Nanda
- Psychiatry, Harvard Medical School, Beth Israel Deaconess Medical Ctr, Boston, MA, USA; College of Physicians & Surgeons, Columbia University Medical Center, New York, NY, USA
| | - Jaya L Padmanabhan
- Psychiatry, Harvard Medical School, Beth Israel Deaconess Medical Ctr, Boston, MA, USA
| | - Ian T Mathew
- Psychiatry, Harvard Medical School, Beth Israel Deaconess Medical Ctr, Boston, MA, USA
| | - Shaun M Eack
- School of Social Work, University of Pittsburgh, Pittsburgh, PA, USA
| | - Balaji Narayanan
- Olin Neuropsychiatry Research Center, Hartford, CT, USA; Department of Psychiatry and Neurobiology, Yale University, New Haven, CT, USA
| | - Shashwath A Meda
- Olin Neuropsychiatry Research Center, Hartford, CT, USA; Department of Psychiatry and Neurobiology, Yale University, New Haven, CT, USA
| | - Sarah E Bergen
- Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research and Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA; Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden
| | | | | | | | - Tracey L Petryshen
- Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research and Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Brett Clementz
- Department of Psychology, Department of Neuroscience, Bio-Imaging Research Center, University of Georgia, Athens, GA, USA
| | | | | | - Godfrey Pearlson
- Olin Neuropsychiatry Research Center, Hartford, CT, USA; Department of Psychiatry and Neurobiology, Yale University, New Haven, CT, USA
| | - Matcheri S Keshavan
- Psychiatry, Harvard Medical School, Beth Israel Deaconess Medical Ctr, Boston, MA, USA
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Comstra HS, McArthy J, Rudin-Rush S, Hartwig C, Gokhale A, Zlatic SA, Blackburn JB, Werner E, Petris M, D'Souza P, Panuwet P, Barr DB, Lupashin V, Vrailas-Mortimer A, Faundez V. The interactome of the copper transporter ATP7A belongs to a network of neurodevelopmental and neurodegeneration factors. eLife 2017; 6. [PMID: 28355134 PMCID: PMC5400511 DOI: 10.7554/elife.24722] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/28/2017] [Indexed: 02/04/2023] Open
Abstract
Genetic and environmental factors, such as metals, interact to determine neurological traits. We reasoned that interactomes of molecules handling metals in neurons should include novel metal homeostasis pathways. We focused on copper and its transporter ATP7A because ATP7A null mutations cause neurodegeneration. We performed ATP7A immunoaffinity chromatography and identified 541 proteins co-isolating with ATP7A. The ATP7A interactome concentrated gene products implicated in neurodegeneration and neurodevelopmental disorders, including subunits of the Golgi-localized conserved oligomeric Golgi (COG) complex. COG null cells possess altered content and subcellular localization of ATP7A and CTR1 (SLC31A1), the transporter required for copper uptake, as well as decreased total cellular copper, and impaired copper-dependent metabolic responses. Changes in the expression of ATP7A and COG subunits in Drosophila neurons altered synapse development in larvae and copper-induced mortality of adult flies. We conclude that the ATP7A interactome encompasses a novel COG-dependent mechanism to specify neuronal development and survival.
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Affiliation(s)
- Heather S Comstra
- Departments of Cell Biology, Emory University, Atlanta, United States
| | - Jacob McArthy
- School of Biological Sciences, Illinois State University, Normal, United States
| | | | - Cortnie Hartwig
- Department of Chemistry, Agnes Scott College, Decatur, Georgia
| | - Avanti Gokhale
- Departments of Cell Biology, Emory University, Atlanta, United States
| | | | - Jessica B Blackburn
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, United States
| | - Erica Werner
- Department of Biochemistry, Emory University, Atlanta, United States
| | - Michael Petris
- Department of Biochemistry, University of Missouri, Columbia, United States
| | - Priya D'Souza
- Rollins School of Public Health, Emory University, Atlanta, United States
| | - Parinya Panuwet
- Rollins School of Public Health, Emory University, Atlanta, United States
| | - Dana Boyd Barr
- Rollins School of Public Health, Emory University, Atlanta, United States
| | - Vladimir Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, United States
| | | | - Victor Faundez
- Departments of Cell Biology, Emory University, Atlanta, United States
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Rinker JA, Mulholland PJ. Promising pharmacogenetic targets for treating alcohol use disorder: evidence from preclinical models. Pharmacogenomics 2017; 18:555-570. [PMID: 28346058 DOI: 10.2217/pgs-2016-0193] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Inherited genetic variants contribute to risk factors for developing an alcohol use disorder, and polymorphisms may inform precision medicine strategies for treating alcohol addiction. Targeting genetic mutations linked to alcohol phenotypes has provided promising initial evidence for reducing relapse rates in alcoholics. Although successful in some studies, there are conflicting findings and the reports of adverse effects may ultimately limit their clinical utility, suggesting that novel pharmacogenetic targets are necessary to advance precision medicine approaches. Here, we describe promising novel genetic variants derived from preclinical models of alcohol consumption and dependence that may uncover disease mechanisms that drive uncontrolled drinking and identify novel pharmacogenetic targets that facilitate therapeutic intervention for the treatment of alcohol use disorder.
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Affiliation(s)
- Jennifer A Rinker
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA.,Department of Psychiatry & Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Patrick J Mulholland
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA.,Department of Psychiatry & Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC 29425, USA
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Webb BT, Edwards AC, Wolen AR, Salvatore JE, Aliev F, Riley BP, Sun C, Williamson VS, Kitchens JN, Pedersen K, Adkins A, Cooke ME, Savage JE, Neale Z, Cho SB, Dick DM, Kendler KS. Molecular Genetic Influences on Normative and Problematic Alcohol Use in a Population-Based Sample of College Students. Front Genet 2017; 8:30. [PMID: 28360924 PMCID: PMC5350109 DOI: 10.3389/fgene.2017.00030] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 02/27/2017] [Indexed: 11/13/2022] Open
Abstract
Background: Genetic factors impact alcohol use behaviors and these factors may become increasingly evident during emerging adulthood. Examination of the effects of individual variants as well as aggregate genetic variation can clarify mechanisms underlying risk. Methods: We conducted genome-wide association studies (GWAS) in an ethnically diverse sample of college students for three quantitative outcomes including typical monthly alcohol consumption, alcohol problems, and maximum number of drinks in 24 h. Heritability based on common genetic variants (h2SNP) was assessed. We also evaluated whether risk variants in aggregate were associated with alcohol use outcomes in an independent sample of young adults. Results: Two genome-wide significant markers were observed: rs11201929 in GRID1 for maximum drinks in 24 h, with supportive evidence across all ancestry groups; and rs73317305 in SAMD12 (alcohol problems), tested only in the African ancestry group. The h2SNP estimate was 0.19 (SE = 0.11) for consumption, and was non-significant for other outcomes. Genome-wide polygenic scores were significantly associated with alcohol outcomes in an independent sample. Conclusions: These results robustly identify genetic risk for alcohol use outcomes at the variant level and in aggregate. We confirm prior evidence that genetic variation in GRID1 impacts alcohol use, and identify novel loci of interest for multiple alcohol outcomes in emerging adults. These findings indicate that genetic variation influencing normative and problematic alcohol use is, to some extent, convergent across ancestry groups. Studying college populations represents a promising avenue by which to obtain large, diverse samples for gene identification.
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Affiliation(s)
- Bradley T Webb
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychiatry, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Human and Molecular Genetics, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Alexis C Edwards
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychiatry, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Aaron R Wolen
- Center for Clinical and Translational Research, Virginia Commonwealth University Richmond, VA, USA
| | - Jessica E Salvatore
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychology, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Fazil Aliev
- Department of African-American Studies, Virginia Commonwealth UniversityRichmond, VA, USA; Faculty of Business, Karabuk UniversityKarabuk, Turkey; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Brien P Riley
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychiatry, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Human and Molecular Genetics, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Cuie Sun
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychiatry, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Vernell S Williamson
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University Richmond, VA, USA
| | - James N Kitchens
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University Richmond, VA, USA
| | - Kimberly Pedersen
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychiatry, Virginia Commonwealth UniversityRichmond, VA, USA; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Amy Adkins
- Department of Psychology, Virginia Commonwealth UniversityRichmond, VA, USA; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Megan E Cooke
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Jeanne E Savage
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Zoe Neale
- Department of Psychology, Virginia Commonwealth UniversityRichmond, VA, USA; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Seung B Cho
- Department of Psychology, Virginia Commonwealth UniversityRichmond, VA, USA; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Danielle M Dick
- Department of Human and Molecular Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychology, Virginia Commonwealth UniversityRichmond, VA, USA; Department of African-American Studies, Virginia Commonwealth UniversityRichmond, VA, USA; College Behavioral and Emotional Health Institute, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Kenneth S Kendler
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth UniversityRichmond, VA, USA; Department of Psychiatry, Virginia Commonwealth UniversityRichmond, VA, USA
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Alcohol and nicotine codependence-associated DNA methylation changes in promoter regions of addiction-related genes. Sci Rep 2017; 7:41816. [PMID: 28165486 PMCID: PMC5292964 DOI: 10.1038/srep41816] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 12/28/2016] [Indexed: 01/19/2023] Open
Abstract
Altered DNA methylation in addiction-related genes may modify the susceptibility to alcohol or drug dependence (AD or ND). We profiled peripheral blood DNA methylation levels of 384 CpGs in promoter regions of 82 addiction-related genes in 256 African Americans (AAs) (117 cases with AD-ND codependence and 139 controls) and 196 European Americans (103 cases with AD-ND codependence and 93 controls) using Illumina's GoldenGate DNA methylation array assays. AD-ND codependence-associated DNA methylation changes were analyzed using linear mixed-effects models with consideration of batch effects and covariates age, sex, and ancestry proportions. Seventy CpGs (in 41 genes) showed nominally significant associations (P < 0.05) with AD-ND codependence in both AAs and EAs. One CpG (HTR2B cg27531267) was hypomethylated in AA cases (P = 7.2 × 10-5), while 17 CpGs in 16 genes (including HTR2B cg27531267) were hypermethylated in EA cases (5.6 × 10-9 ≤ P ≤ 9.5 × 10-5). Nevertheless, 13 single nucleotide polymorphisms (SNPs) nearby HTR2B cg27531267 and the interaction of these SNPs and cg27531267 did not show significant effects on AD-ND codependence in either AAs or EAs. Our study demonstrated that DNA methylation changes in addiction-related genes could be potential biomarkers for AD-ND co-dependence. Future studies need to explore whether DNA methylation alterations influence the risk of AD-ND codependence or the other way around.
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Rinker JA, Fulmer DB, Trantham-Davidson H, Smith ML, Williams RW, Lopez MF, Randall PK, Chandler LJ, Miles MF, Becker HC, Mulholland PJ. Differential potassium channel gene regulation in BXD mice reveals novel targets for pharmacogenetic therapies to reduce heavy alcohol drinking. Alcohol 2017; 58:33-45. [PMID: 27432260 DOI: 10.1016/j.alcohol.2016.05.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 04/12/2016] [Accepted: 05/03/2016] [Indexed: 12/22/2022]
Abstract
Alcohol (ethanol) dependence is a chronic relapsing brain disorder partially influenced by genetics and characterized by an inability to regulate harmful levels of drinking. Emerging evidence has linked genes that encode KV7, KIR, and KCa2 K+ channels with variation in alcohol-related behaviors in rodents and humans. This led us to experimentally test relations between K+ channel genes and escalation of drinking in a chronic-intermittent ethanol (CIE) exposure model of dependence in BXD recombinant inbred strains of mice. Transcript levels for K+ channel genes in the prefrontal cortex (PFC) and nucleus accumbens (NAc) covary with voluntary ethanol drinking in a non-dependent cohort. Transcripts that encode KV7 channels covary negatively with drinking in non-dependent BXD strains. Using a pharmacological approach to validate the genetic findings, C57BL/6J mice were allowed intermittent access to ethanol to establish baseline consumption before they were treated with retigabine, an FDA-approved KV7 channel positive modulator. Systemic administration significantly reduced drinking, and consistent with previous evidence, retigabine was more effective at reducing voluntary consumption in high-drinking than low-drinking subjects. We evaluated the specific K+ channel genes that were most sensitive to CIE exposure and identified a gene subset in the NAc and PFC that were dysregulated in the alcohol-dependent BXD cohort. CIE-induced modulation of nine genes in the NAc and six genes in the PFC covaried well with the changes in drinking induced by ethanol dependence. Here we identified novel candidate genes in the NAc and PFC that are regulated by ethanol dependence and correlate with voluntary drinking in non-dependent and dependent BXD mice. The findings that Kcnq expression correlates with drinking and that retigabine reduces consumption suggest that KV7 channels could be pharmacogenetic targets to treat individuals with alcohol addiction.
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Reilly MT, Noronha A, Goldman D, Koob GF. Genetic studies of alcohol dependence in the context of the addiction cycle. Neuropharmacology 2017; 122:3-21. [PMID: 28118990 DOI: 10.1016/j.neuropharm.2017.01.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/13/2017] [Accepted: 01/19/2017] [Indexed: 12/16/2022]
Abstract
Family, twin and adoption studies demonstrate clearly that alcohol dependence and alcohol use disorders are phenotypically complex and heritable. The heritability of alcohol use disorders is estimated at approximately 50-60% of the total phenotypic variability. Vulnerability to alcohol use disorders can be due to multiple genetic or environmental factors or their interaction which gives rise to extensive and daunting heterogeneity. This heterogeneity makes it a significant challenge in mapping and identifying the specific genes that influence alcohol use disorders. Genetic linkage and (candidate gene) association studies have been used now for decades to map and characterize genomic loci and genes that underlie the genetic vulnerability to alcohol use disorders. These approaches have been moderately successful in identifying several genes that contribute to the complexity of alcohol use disorders. Recently, genome-wide association studies have become one of the major tools for identifying genes for alcohol use disorders by examining correlations between millions of common single-nucleotide polymorphisms with diagnosis status. Genome-wide association studies are just beginning to uncover novel biology; however, the functional significance of results remains a matter of extensive debate and uncertainty. In this review, we present a select group of genome-wide association studies of alcohol dependence, as one example of a way to generate functional hypotheses, within the addiction cycle framework. This analysis may provide novel directions for validating the functional significance of alcohol dependence candidate genes. This article is part of the Special Issue entitled "Alcoholism".
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Affiliation(s)
- Matthew T Reilly
- National Institutes of Health (NIH), National Institute on Alcohol Abuse and Alcoholism (NIAAA), Division of Neuroscience and Behavior, 5635 Fishers Lane, Bethesda, MD 20852, USA.
| | - Antonio Noronha
- National Institutes of Health (NIH), National Institute on Alcohol Abuse and Alcoholism (NIAAA), Division of Neuroscience and Behavior, 5635 Fishers Lane, Bethesda, MD 20852, USA
| | - David Goldman
- National Institutes of Health (NIH), National Institute on Alcohol Abuse and Alcoholism (NIAAA), Chief, Laboratory of Neurogenetics, 5635 Fishers Lane, Bethesda, MD 20852, USA
| | - George F Koob
- National Institutes of Health (NIH), National Institute on Alcohol Abuse and Alcoholism (NIAAA), Director NIAAA, 5635 Fishers Lane, Bethesda, MD 20852, USA
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Voltage-Sensitive Potassium Channels of the BK Type and Their Coding Genes Are Alcohol Targets in Neurons. Handb Exp Pharmacol 2017; 248:281-309. [PMID: 29204711 DOI: 10.1007/164_2017_78] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Among all members of the voltage-gated, TM6 ion channel superfamily, the proteins that constitute calcium- and voltage-gated potassium channels of large conductance (BK) and their coding genes are unique for their involvement in ethanol-induced disruption of normal physiology and behavior. Moreover, in vitro studies document that BK activity is modified by ethanol with an EC50~23 mM, which is near blood alcohol levels considered legal intoxication in most states of the USA (0.08 g/dL = 17.4 mM). Following a succinct introduction to our current understanding of BK structure and function in central neurons, with a focus on neural circuits that contribute to the neurobiology of alcohol use disorders (AUD), we review the modifications in organ physiology by alcohol exposure via BK and the different molecular elements that determine the ethanol response of BK in alcohol-naïve systems, including the role of an ethanol-recognizing site in the BK-forming slo1 protein, modulation of accessory BK subunits, and their coding genes. The participation of these and additional elements in determining the response of a system or an organism to protracted ethanol exposure is consequently analyzed, with insights obtained from invertebrate and vertebrate models. Particular emphasis is put on the role of BK and coding genes in different forms of tolerance to alcohol exposure. We finally discuss genetic results on BK obtained in invertebrate organisms and rodents in light of possible extrapolation to human AUD.
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Nixon SJ, Prather R, Lewis B. Sex differences in alcohol-related neurobehavioral consequences. HANDBOOK OF CLINICAL NEUROLOGY 2016; 125:253-72. [PMID: 25307580 DOI: 10.1016/b978-0-444-62619-6.00016-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
In this chapter, we review existing research regarding sex differences in alcohol's effects on neurobehavioral functions/processes. Drawn largely from laboratory studies, literature regarding acute alcohol administration and chronic alcohol misuse is explored focusing on commonly employed neuropsychologic domains (e.g., executive function, visuospatial skills, learning and memory, gait and balance), neurophysiologic measures (e.g., electroencephalography and event-related potentials), and structural and functional neuroimaging (e.g., magnetic resonance imaging (MRI), functional MRI, diffusion tensor imaging, positron emission tomography, and magnetic resonance spectroscopy). To provide a historical perspective on the development of these questions, we have included reference to early and more recent research. Additionally, specific biases, knowledge gaps, and continuing controversies are noted.
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Affiliation(s)
- Sara Jo Nixon
- Department of Psychiatry, University of Florida, Gainesville, FL, USA; Department of Psychology, University of Florida, Gainesville, FL, USA.
| | - Robert Prather
- Department of Psychiatry, University of Florida, Gainesville, FL, USA
| | - Ben Lewis
- Department of Psychiatry, University of Florida, Gainesville, FL, USA
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