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Vilca S, Wahlestedt C, Izenwasser S, Gainetdinov RR, Pardo M. Dopamine Transporter Knockout Rats Display Epigenetic Alterations in Response to Cocaine Exposure. Biomolecules 2023; 13:1107. [PMID: 37509143 PMCID: PMC10377455 DOI: 10.3390/biom13071107] [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: 06/05/2023] [Revised: 06/22/2023] [Accepted: 07/08/2023] [Indexed: 07/30/2023] Open
Abstract
(1) Background: There is an urgent need for effective treatments for cocaine use disorder (CUD), and new pharmacological approaches targeting epigenetic mechanisms appear to be promising options for the treatment of this disease. Dopamine Transporter (DAT) transgenic rats recently have been proposed as a new animal model for studying susceptibility to CUD. (2) Methods: DAT transgenic rats were treated chronically with cocaine (10 mg/kg) for 8 days, and the expression of epigenetic modulators, Lysine Demethylase 6B (KDM6B) and Bromodomain-containing protein 4 (BRD4), was examined in the prefrontal cortex (PFC). (3) Results: We show that only full knockout (KO) of DAT impacts basal levels of KDM6B in females. Additionally, cocaine altered the expression of both epigenetic markers in a sex- and genotype-dependent manner. In response to chronic cocaine, KDM6B expression was decreased in male rats with partial DAT mutation (HET), while no changes were observed in wild-type (WT) or KO rats. Indeed, while HET male rats have reduced KDM6B and BRD4 expression, HET female rats showed increased KDM6B and BRD4 expression levels, highlighting the impact of sex on epigenetic mechanisms in response to cocaine. Finally, both male and female KO rats showed increased expression of BRD4, but only KO females exhibited significantly increased KDM6B expression in response to cocaine. Additionally, the magnitude of these effects was bigger in females when compared to males for both epigenetic enzymes. (4) Conclusions: This preliminary study provides additional support that targeting KDM6B and/or BRD4 may potentially be therapeutic in treating addiction-related behaviors in a sex-dependent manner.
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Affiliation(s)
- Samara Vilca
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.V.); (C.W.); (S.I.)
- Center for Therapeutic Innovation, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Claes Wahlestedt
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.V.); (C.W.); (S.I.)
- Center for Therapeutic Innovation, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Sari Izenwasser
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (S.V.); (C.W.); (S.I.)
| | - Raul R. Gainetdinov
- Institute of Translational Biomedicine, St. Petersburg University Hospital, St. Petersburg State University, Universitetskaya Emb. 7-9, 199034 St. Petersburg, Russia;
| | - Marta Pardo
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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2
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The dopamine transporter gene SLC6A3: multidisease risks. Mol Psychiatry 2022; 27:1031-1046. [PMID: 34650206 PMCID: PMC9008071 DOI: 10.1038/s41380-021-01341-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 09/28/2021] [Accepted: 10/01/2021] [Indexed: 02/02/2023]
Abstract
The human dopamine transporter gene SLC6A3 has been consistently implicated in several neuropsychiatric diseases but the disease mechanism remains elusive. In this risk synthesis, we have concluded that SLC6A3 represents an increasingly recognized risk with a growing number of familial mutants associated with neuropsychiatric and neurological disorders. At least five loci were related to common and severe diseases including alcohol use disorder (high activity variant), attention-deficit/hyperactivity disorder (low activity variant), autism (familial proteins with mutated networking) and movement disorders (both regulatory variants and familial mutations). Association signals depended on genetic markers used as well as ethnicity examined. Strong haplotype selection and gene-wide epistases support multimarker assessment of functional variations and phenotype associations. Inclusion of its promoter region's functional markers such as DNPi (rs67175440) and 5'VNTR (rs70957367) may help delineate condensate-based risk action, testing a locus-pathway-phenotype hypothesis for one gene-multidisease etiology.
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3
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Synaptic Zn 2+ potentiates the effects of cocaine on striatal dopamine neurotransmission and behavior. Transl Psychiatry 2021; 11:570. [PMID: 34750356 PMCID: PMC8575899 DOI: 10.1038/s41398-021-01693-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 12/12/2022] Open
Abstract
Cocaine binds to the dopamine (DA) transporter (DAT) to regulate cocaine reward and seeking behavior. Zinc (Zn2+) also binds to the DAT, but the in vivo relevance of this interaction is unknown. We found that Zn2+ concentrations in postmortem brain (caudate) tissue from humans who died of cocaine overdose were significantly lower than in control subjects. Moreover, the level of striatal Zn2+ content in these subjects negatively correlated with plasma levels of benzoylecgonine, a cocaine metabolite indicative of recent use. In mice, repeated cocaine exposure increased synaptic Zn2+ concentrations in the caudate putamen (CPu) and nucleus accumbens (NAc). Cocaine-induced increases in Zn2+ were dependent on the Zn2+ transporter 3 (ZnT3), a neuronal Zn2+ transporter localized to synaptic vesicle membranes, as ZnT3 knockout (KO) mice were insensitive to cocaine-induced increases in striatal Zn2+. ZnT3 KO mice showed significantly lower electrically evoked DA release and greater DA clearance when exposed to cocaine compared to controls. ZnT3 KO mice also displayed significant reductions in cocaine locomotor sensitization, conditioned place preference (CPP), self-administration, and reinstatement compared to control mice and were insensitive to cocaine-induced increases in striatal DAT binding. Finally, dietary Zn2+ deficiency in mice resulted in decreased striatal Zn2+ content, cocaine locomotor sensitization, CPP, and striatal DAT binding. These results indicate that cocaine increases synaptic Zn2+ release and turnover/metabolism in the striatum, and that synaptically released Zn2+ potentiates the effects of cocaine on striatal DA neurotransmission and behavior and is required for cocaine-primed reinstatement. In sum, these findings reveal new insights into cocaine's pharmacological mechanism of action and suggest that Zn2+ may serve as an environmentally derived regulator of DA neurotransmission, cocaine pharmacodynamics, and vulnerability to cocaine use disorders.
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4
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Koijam AS, Hijam AC, Singh AS, Jaiswal P, Mukhopadhyay K, Rajamma U, Haobam R. Association of Dopamine Transporter Gene with Heroin Dependence in an Indian Subpopulation from Manipur. J Mol Neurosci 2020; 71:122-136. [PMID: 32557146 DOI: 10.1007/s12031-020-01633-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 06/11/2020] [Indexed: 01/11/2023]
Abstract
Dopamine transporter (DAT) or solute carrier family 6 member 3 (SLC6A3) is a transmembrane protein regulating dopaminergic neurotransmission. It has been implicated in playing important roles in the dopaminergic reward pathways, and thus, DAT1 is a strong candidate gene for association studies with heroin dependence. A case-control study involving 279 individuals (147 controls and 132 heroin-dependent cases) was conducted. Ten polymorphisms of the DAT1 (SLC6A3) gene were analysed for its association with heroin dependence. Following the Hardy-Weinberg equilibrium (HWE) test, genetic association analyses were performed for the study groups. The post hoc statistical power of the study was 0.655 (65.5%). Single-nucleotide polymorphism (SNP) rs246997 was found to be significantly associated with heroin dependence at allelic, genotypic, and haplotypic levels. A significant difference in the distribution of 11R allele and 10R/11R genotype of rs28363170 between heroin-dependent cases and controls was also observed. Nominal significance at degrees of freedom (df) = 5 was also observed for rs28363170. Five bimarker-based haplotype combinations were also found to be associated with heroin dependence. For the first time, 13R allele (7R/13R genotype) and 14R allele (7R/14R genotype) were identified for rs3836790 in the population. The study also reports that the 11R allele and 10R/11R genotype of rs28363170 is associated with protection against heroin dependence. 7R and 6R alleles were also found to be the common alleles of rs3836790 in the study population. The study provides evidence for the association of polymorphisms of DAT1 (SLC6A3) with heroin dependence.
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Affiliation(s)
- Arunkumar Singh Koijam
- Department of Biotechnology, Manipur University, Canchipur, Imphal, Manipur, 795003, India
| | - Aruna Chanu Hijam
- Department of Biotechnology, Manipur University, Canchipur, Imphal, Manipur, 795003, India
| | - Asem Surindro Singh
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, USA
| | - Preeti Jaiswal
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, West Bengal, India
| | - Kanchan Mukhopadhyay
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, West Bengal, India
| | - Usha Rajamma
- Manovikas Biomedical Research & Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector-J, EM Bypass, Kolkata, West Bengal, India.,Centre for Development & Aging Research, Inter University Centre for Biomedical Research & Super Speciality Hospital, MG University Campus, Thalappady, Rubber Board PO, Kottayam, Kerala, India
| | - Reena Haobam
- Department of Biotechnology, Manipur University, Canchipur, Imphal, Manipur, 795003, India.
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5
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Zhao J, Chen C, Bell RL, Qing H, Lin Z. Identification of HIVEP2 as a dopaminergic transcription factor related to substance use disorders in rats and humans. Transl Psychiatry 2019; 9:247. [PMID: 31586043 PMCID: PMC6778090 DOI: 10.1038/s41398-019-0573-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 05/30/2019] [Accepted: 06/20/2019] [Indexed: 12/27/2022] Open
Abstract
Playing an important role in the etiology of substance use disorder (SUD), dopamine (DA) neurons are subject to various regulations but transcriptional regulations are largely understudied. For the first time, we report here that the Human Immunodeficiency Virus Type I Enhancer Binding Protein 2 (HIVEP2) is a dopaminergic transcriptional regulator. HIVEP2 is expressed in both the cytoplasm and nuclei of DA neurons. Therein, HIVEP2 can target the intronic sequence GTGGCTTTCT of SLC6A3 and thereby activate the gene. In naive rats from the bi-directional selectively bred substance-preferring P vs -nonpreferring NP rat model of substance abuse vulnerability, increased gene activity in males was associated with the vulnerability, whereas decreased gene activity in the females was associated with the same vulnerability. In clinical subjects, extensive and significant HIVEP2-SLC6A3 interactions were observed for SUD. Collectively, HIVEP2-mediated transcriptional mechanisms are implicated in dopaminergic pathophysiology of SUD.
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Affiliation(s)
- Juan Zhao
- 0000 0000 8841 6246grid.43555.32School of Life Science, Beijing Institute of Technology, 100081 Beijing, China ,0000 0000 8795 072Xgrid.240206.2Laboratory of Psychiatric Genomics, McLean Hospital, Belmont, MA 02478 USA
| | - Chunnuan Chen
- 0000 0000 8795 072Xgrid.240206.2Laboratory of Psychiatric Genomics, McLean Hospital, Belmont, MA 02478 USA ,Department of Neurology, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province, P. R. China
| | - Richard L. Bell
- 0000 0001 2287 3919grid.257413.6Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana 46202 USA
| | - Hong Qing
- 0000 0000 8841 6246grid.43555.32School of Life Science, Beijing Institute of Technology, 100081 Beijing, China
| | - Zhicheng Lin
- Laboratory of Psychiatric Genomics, McLean Hospital, Belmont, MA, 02478, USA.
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6
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Abstract
The human dopamine transporter gene SLC6A3 is involved in substance use disorders (SUDs) among many other common neuropsychiatric illnesses but allelic association results including those with its classic genetic markers 3'VNTR or Int8VNTR remain mixed and unexplainable. To better understand the genetics for reproducible association signals, we report the presence of recombination hotspots based on sequencing of the entire 5' promoter regions in two small SUDs cohorts, 30 African Americans (AAs) and 30 European Americans (EAs). Recombination rate was the highest near the transcription start site (TSS) in both cohorts. In addition, each cohort carried 57 different promoter haplotypes out of 60 and no haplotypes were shared between the two ethnicities. A quarter of the haplotypes evolved in an ethnicity-specific manner. Finally, analysis of five hundred subjects of European ancestry, from the 1000 Genome Project, confirmed the promoter recombination hotspots and also revealed several additional ones in non-coding regions only. These findings provide an explanation for the mixed results as well as guidance for selection of effective markers to be used in next generation association validation (NGAV), facilitating the delineation of pathogenic variation in this critical neuropsychiatric gene.
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7
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Grünblatt E, Werling AM, Roth A, Romanos M, Walitza S. Association study and a systematic meta-analysis of the VNTR polymorphism in the 3'-UTR of dopamine transporter gene and attention-deficit hyperactivity disorder. J Neural Transm (Vienna) 2019; 126:517-529. [PMID: 30923918 PMCID: PMC6456487 DOI: 10.1007/s00702-019-01998-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/24/2019] [Indexed: 01/21/2023]
Abstract
Attention-deficit hyperactivity disorder (ADHD) has been postulated to associate with dopaminergic dysfunction, including the dopamine transporter (DAT1). Several meta-analyses showed small but significant association between the 10-repeat allele in the DAT1 gene in 3'-untranslated region variant number tandem repeat polymorphism and child and adolescent ADHD, whereas in adult ADHD the 9-repeat allele was suggested to confer as risk allele. Interestingly, recent evidence indicated that the long-allele variants (10 repeats and longer) might confer to lower expression of the transporter in comparison to the short-allele. Therefore, we assessed here the association in samples consisting of families with child and adolescent ADHD as well as a case-control sample, using either the 10- versus 9-repeat or the long- versus short-allele approach. Following, we conducted a systematic review and meta-analysis, including family and case-control studies, using the two aforementioned approaches as well as stratifying to age and ethnicity. The first approach (10-repeat) resulted in nominal significant association in child and adolescent ADHD (OR 1.1050 p = 0.0128), that became significant stratifying to European population (OR 1.1301 p = 0.0085). The second approach (long-allele) resulted in significant association with the whole ADHD population (OR 1.1046 p = 0.0048), followed by significant association for child and adolescent ADHD (OR 1.1602 p = 0.0006) and in Caucasian and in European child and adolescent ADHD (OR 1.1310 p = 0.0114; OR 1.1661 p = 0.0061; respectively). We were not able to confirm the association reported in adults using both approaches. In conclusion, we found further indication for a possible DAT1 gene involvement; however, further studies should be conducted with stringent phenotyping to reduce heterogeneity, a limitation observed in most included studies.
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Affiliation(s)
- Edna Grünblatt
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
- Translational Molecular Psychiatry, Department of Child and Adolescent Psychiatry and Psychotherapy, Centre for Child and Adolescent Psychiatry Research, University Hospital of Psychiatry Zurich, Wagistrasse 12, 8952, Schlieren, Switzerland.
| | - Anna Maria Werling
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Alexander Roth
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Marcel Romanos
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Hospital of Wuerzburg, Würzburg, Germany
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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8
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Saad MH, Rumschlag M, Guerra MH, Savonen CL, Jaster AM, Olson PD, Alazizi A, Luca F, Pique-Regi R, Schmidt CJ, Bannon MJ. Differentially expressed gene networks, biomarkers, long noncoding RNAs, and shared responses with cocaine identified in the midbrains of human opioid abusers. Sci Rep 2019; 9:1534. [PMID: 30733491 PMCID: PMC6367337 DOI: 10.1038/s41598-018-38209-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/21/2018] [Indexed: 12/21/2022] Open
Abstract
Opioid abuse is now the most common cause of accidental death in the US. Although opioids and most other drugs of abuse acutely increase signaling mediated by midbrain dopamine (DA)-synthesizing neurons, little is known about long-lasting changes in DA cells that may contribute to continued opioid abuse, craving, and relapse. A better understanding of the molecular and cellular bases of opioid abuse could lead to advancements in therapeutics. This study comprises, to our knowledge, the first unbiased examination of genome-wide changes in midbrain gene expression associated with human opioid abuse. Our analyses identified differentially expressed genes and distinct gene networks associated with opioid abuse, specific genes with predictive capability for subject assignment to the opioid abuse cohort, and genes most similarly affected in chronic opioid and cocaine abusers. We also identified differentially expressed long noncoding RNAs capable of regulating known drug-responsive protein-coding genes. Opioid-regulated genes identified in this study warrant further investigation as potential biomarkers and/or therapeutic targets for human substance abuse.
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Affiliation(s)
- Manal H Saad
- Wayne State University School of Medicine, Department of Pharmacology, Detroit, MI, 48201, USA
| | - Matthew Rumschlag
- Wayne State University School of Medicine, Department of Pharmacology, Detroit, MI, 48201, USA
| | - Michael H Guerra
- Wayne State University School of Medicine, Department of Pharmacology, Detroit, MI, 48201, USA
| | - Candace L Savonen
- Wayne State University School of Medicine, Department of Pharmacology, Detroit, MI, 48201, USA
| | - Alaina M Jaster
- Wayne State University School of Medicine, Department of Pharmacology, Detroit, MI, 48201, USA
| | - Philip D Olson
- Wayne State University School of Medicine, Department of Pharmacology, Detroit, MI, 48201, USA
| | - Adnan Alazizi
- Wayne State University School of Medicine, Center for Molecular Medicine & Genetics, Detroit, MI, 48201, USA.,Wayne State University School of Medicine, Department of Obstetrics and Gynecology, Detroit, MI, 48201, USA
| | - Francesca Luca
- Wayne State University School of Medicine, Center for Molecular Medicine & Genetics, Detroit, MI, 48201, USA.,Wayne State University School of Medicine, Department of Obstetrics and Gynecology, Detroit, MI, 48201, USA
| | - Roger Pique-Regi
- Wayne State University School of Medicine, Center for Molecular Medicine & Genetics, Detroit, MI, 48201, USA.,Wayne State University School of Medicine, Department of Obstetrics and Gynecology, Detroit, MI, 48201, USA
| | - Carl J Schmidt
- University of Michigan School of Medicine, Department of Pathology, Detroit, MI, 48109, USA
| | - Michael J Bannon
- Wayne State University School of Medicine, Department of Pharmacology, Detroit, MI, 48201, USA.
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9
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Zhao Y, Yu J, Zhao J, Chen X, Xiong N, Wang T, Qing H, Lin Z. Intragenic Transcriptional cis-Antagonism Across SLC6A3. Mol Neurobiol 2018; 56:4051-4060. [PMID: 30259411 DOI: 10.1007/s12035-018-1357-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/18/2018] [Indexed: 12/29/2022]
Abstract
A promoter can be regulated by various cis-acting elements so that delineation of the regulatory modes among them may help understand developmental, environmental and genetic mechanisms in gene activity. Here we report that the human dopamine transporter gene SLC6A3 carries a 5' distal 5-kb super enhancer (5KSE) which upregulated the promoter by 5-fold. Interestingly, 5KSE is able to prevent 3' downstream variable number tandem repeats (3'VNTRs) from silencing the promoter. This new enhancer consists of a 5'VNTR and three repetitive sub-elements that are conserved in primates. Two of 5KSE's sub-elements, E-9.7 and E-8.7, upregulate the promoter, but only the later could continue doing so in the presence of 3'VNTRs. Finally, E-8.7 is activated by novel dopaminergic transcription factors including SRP54 and Nfe2l1. Together, these results reveal a multimodal regulatory mechanism in SLC6A3.
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Affiliation(s)
- Ying Zhao
- Laboratory of Psychiatric Neurogenomics, Basic Neuroscience Division, McLean Hospital, Belmont, MA, 02478, USA.,School of Pharmacy, Xinxiang Medical University, Xinxiang, 453003, China
| | - Jinlong Yu
- Laboratory of Psychiatric Neurogenomics, Basic Neuroscience Division, McLean Hospital, Belmont, MA, 02478, USA
| | - Juan Zhao
- Laboratory of Psychiatric Neurogenomics, Basic Neuroscience Division, McLean Hospital, Belmont, MA, 02478, USA.,College of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Xiaowu Chen
- Laboratory of Psychiatric Neurogenomics, Basic Neuroscience Division, McLean Hospital, Belmont, MA, 02478, USA.,Department of Neurology, Shenzhen University General Hospital, Shenzhen, Guangzhou, 518060, China
| | - Nian Xiong
- Laboratory of Psychiatric Neurogenomics, Basic Neuroscience Division, McLean Hospital, Belmont, MA, 02478, USA.,Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tao Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong Qing
- College of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Zhicheng Lin
- Laboratory of Psychiatric Neurogenomics, Basic Neuroscience Division, McLean Hospital, Belmont, MA, 02478, USA.
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10
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Salatino-Oliveira A, Rohde LA, Hutz MH. The dopamine transporter role in psychiatric phenotypes. Am J Med Genet B Neuropsychiatr Genet 2018; 177:211-231. [PMID: 28766921 DOI: 10.1002/ajmg.b.32578] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 06/26/2017] [Accepted: 07/18/2017] [Indexed: 01/06/2023]
Abstract
The dopamine transporter (DAT) is one of the most relevant and investigated neurotransmitter transporters. DAT is a plasma membrane protein which plays a homeostatic role, controlling both extracellular and intracellular concentrations of dopamine (DA). Since unbalanced DA levels are known to be involved in numerous mental disorders, a wealth of investigations has provided valuable insights concerning DAT role into normal brain functioning and pathological processes. Briefly, this extensive but non-systematic review discusses what is recently known about the role of SLC6A3 gene which encodes the dopamine transporter in psychiatric phenotypes. DAT protein, SLC6A3 gene, animal models, neuropsychology, and neuroimaging investigations are also concisely discussed. To conclude, current challenges are reviewed in order to provide perspectives for future studies.
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Affiliation(s)
| | - Luis A Rohde
- Division of Child and Adolescent Psychiatry, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Institute for Developmental Psychiatry for Children and Adolescents, São Paulo, Brazil
| | - Mara H Hutz
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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11
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Liu K, Yu J, Zhao J, Zhou Y, Xiong N, Xu J, Wang T, Bell RL, Qing H, Lin Z. AZI23'UTR Is a New SLC6A3 Downregulator Associated with an Epistatic Protection Against Substance Use Disorders. Mol Neurobiol 2017; 55:5611-5622. [PMID: 28983843 DOI: 10.1007/s12035-017-0781-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 09/19/2017] [Indexed: 11/29/2022]
Abstract
Regulated activity of SLC6A3, which encodes the human dopamine transporter (DAT), contributes to diseases such as substance abuse disorders (SUDs); however, the exact transcription mechanism remains poorly understood. Here, we used a common genetic variant of the gene, intron 1 DNP1B sequence, as bait to screen and clone a new transcriptional activity, AZI23'UTR, for SLC6A3. AZI23'UTR is a 3' untranslated region (3'UTR) of the human 5-Azacytidine Induced 2 gene (AZI2) but appeared to be transcribed independently of AZI2. Found to be present in both human cell nuclei and dopamine neurons, this RNA was shown to downregulate promoter activity through a variant-dependent mechanism in vitro. Both reduced RNA density ratio of AZI23'UTR/AZI2 and increased DAT mRNA levels were found in ethanol-naive alcohol-preferring rats. Secondary analysis of dbGaP GWAS datasets (Genome-Wide Association Studies based on the database of Genotypes and Phenotypes) revealed significant interactions between regions upstream of AZI23'UTR and SLC6A3 in SUDs. Jointly, our data suggest that AZI23'UTR confers variant-dependent transcriptional regulation of SLC6A3, a potential risk factor for SUDs.
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Affiliation(s)
- Kefu Liu
- Laboratory of Psychiatric Neurogenomics, Division of Basic Neuroscience, Mailman Neuroscience Research Center, McLean Hospital, Belmont, MA, 02478, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, 02478, USA.,School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Jinlong Yu
- Laboratory of Psychiatric Neurogenomics, Division of Basic Neuroscience, Mailman Neuroscience Research Center, McLean Hospital, Belmont, MA, 02478, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, 02478, USA
| | - Juan Zhao
- Laboratory of Psychiatric Neurogenomics, Division of Basic Neuroscience, Mailman Neuroscience Research Center, McLean Hospital, Belmont, MA, 02478, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, 02478, USA.,School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Yanhong Zhou
- Laboratory of Psychiatric Neurogenomics, Division of Basic Neuroscience, Mailman Neuroscience Research Center, McLean Hospital, Belmont, MA, 02478, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, 02478, USA
| | - Nian Xiong
- Laboratory of Psychiatric Neurogenomics, Division of Basic Neuroscience, Mailman Neuroscience Research Center, McLean Hospital, Belmont, MA, 02478, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, 02478, USA.,Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Jie Xu
- Department of Computer Information Systems, Bentley University, Waltham, MA, 02452, USA
| | - Tao Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Richard L Bell
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Hong Qing
- School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Zhicheng Lin
- Laboratory of Psychiatric Neurogenomics, Division of Basic Neuroscience, Mailman Neuroscience Research Center, McLean Hospital, Belmont, MA, 02478, USA. .,Department of Psychiatry, Harvard Medical School, Boston, MA, 02478, USA.
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12
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Green AL, Zhan L, Eid A, Zarbl H, Guo GL, Richardson JR. Valproate increases dopamine transporter expression through histone acetylation and enhanced promoter binding of Nurr1. Neuropharmacology 2017; 125:189-196. [PMID: 28743636 DOI: 10.1016/j.neuropharm.2017.07.020] [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: 02/06/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 12/19/2022]
Abstract
The dopamine transporter (DAT) is the key regulator of dopaminergic transmission and is a target of several xenobiotics, including pesticides and pharmacological agents. Previously, we identified a prominent role for histone deacetylases in the regulation of DAT expression. Here, we utilized a rat dopaminergic cell line (N27) to probe the responsiveness of DAT mRNA expression to inhibitors of histone acetylation. Inhibition of histone deacetylases (HDACs) by valproate, butyrate and Trichostatin A led to a 3-10-fold increase in DAT mRNA expression, a 50% increase in protein levels, which were accompanied by increased H3 acetylation levels. To confirm the mechanism of valproate-mediated increase in DAT mRNA, chromatin immunoprecipitation (ChIP) assays were used and demonstrated a significant increase in enrichment of acetylation of histone 3 on lysines 9 and 14 (H3K9/K14ac) in the DAT promoter. Expression of Nurr1 and Pitx3, key regulators of DAT expression, were increased following valproate treatment and Nurr1 binding was enriched in the DAT promoter. Together, these results indicate that histone acetylation and subsequent enhancement of transcription factor binding are plausible mechanisms for DAT regulation by valproate and, perhaps, by other xenobiotics.
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Affiliation(s)
- Ashley L Green
- Environmental and Occupational Health Sciences Institute, Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Le Zhan
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University Piscataway, NJ, USA
| | - Aseel Eid
- Department of Pharmaceutical Sciences, Center for Neurodegenerative Disease and Aging, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Helmut Zarbl
- Environmental and Occupational Health Sciences Institute, Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Grace L Guo
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University Piscataway, NJ, USA
| | - Jason R Richardson
- Environmental and Occupational Health Sciences Institute, Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA; Department of Pharmaceutical Sciences, Center for Neurodegenerative Disease and Aging, Northeast Ohio Medical University, Rootstown, OH, USA.
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13
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Vallender EJ, Goswami DB, Shinday NM, Westmoreland SV, Yao WD, Rowlett JK. Transcriptomic profiling of the ventral tegmental area and nucleus accumbens in rhesus macaques following long-term cocaine self-administration. Drug Alcohol Depend 2017; 175:9-23. [PMID: 28376414 PMCID: PMC5693237 DOI: 10.1016/j.drugalcdep.2017.01.030] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 01/18/2017] [Accepted: 01/18/2017] [Indexed: 01/23/2023]
Abstract
BACKGROUND The behavioral consequences associated with addiction are thought to arise from drug-induced neuroadaptation. The mesolimbic system plays an important initial role in this process, and while the dopaminergic system specifically has been strongly interrogated, a complete understanding of the broad transcriptomic effects associated with cocaine use remains elusive. METHODS Using next generation sequencing approaches, we performed a comprehensive evaluation of gene expression differences in the ventral tegmental area and nucleus accumbens of rhesus macaques that had self-administered cocaine for roughly 100days and saline-yoked controls. During self-administration, the monkeys increased daily consumption of cocaine until almost the maximum number of injections were taken within the first 15min of the one hour session for a total intake of 3mg/kg/day. RESULTS We confirm the centrality of dopaminergic differences in the ventral tegmental area, but in the nucleus accumbens we see the strongest evidence for an inflammatory response and large scale chromatin remodeling. CONCLUSIONS These findings suggest an expanded understanding of the pathology of cocaine addiction with the potential to lead to the development of alternative treatment strategies.
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Affiliation(s)
- Eric J. Vallender
- Harvard Medical School, New England Primate Research Center, Southborough, MA 01772,University of Mississippi Medical Center, Jackson, MS 39216,Tulane National Primate Research Center, Covington, LA 70433
| | - Dharmendra B. Goswami
- Harvard Medical School, New England Primate Research Center, Southborough, MA 01772,Boston University, Boston, MA 02118
| | - Nina M. Shinday
- Harvard Medical School, New England Primate Research Center, Southborough, MA 01772,University of Massachusetts-Amherst, Amherst, MA 01003
| | | | - Wei-Dong Yao
- Harvard Medical School, New England Primate Research Center, Southborough, MA 01772,SUNY Upstate Medical University, Syracuse, NY 13210
| | - James K. Rowlett
- Harvard Medical School, New England Primate Research Center, Southborough, MA 01772,University of Mississippi Medical Center, Jackson, MS 39216,Tulane National Primate Research Center, Covington, LA 70433,University of Massachusetts-Amherst, Amherst, MA 01003
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Kennedy JL, Xiong N, Yu J, Zai CC, Pouget JG, Li J, Liu K, Qing H, Wang T, Martin E, Levy DL, Lin Z. Increased Nigral SLC6A3 Activity in Schizophrenia Patients: Findings From the Toronto-McLean Cohorts. Schizophr Bull 2016; 42:772-81. [PMID: 26707863 PMCID: PMC4838105 DOI: 10.1093/schbul/sbv191] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
SLC6A3, which encodes the primary regulator of extracellular dopamine (DA) concentration, the DA transporter, has been implicated in schizophrenia (SCZ). However, the details of its genetic effect on risk remain largely unknown. The purpose of this candidate gene study was to identify a specificSLC6A3activity associated with SCZ by using functional genetic approaches. We first examined gene activity in DA neurons isolated from case-control postmortem nigral tissue and found that the averageSLC6A3mRNA level in controls was only 0.37-fold of that in cases (P= .0034). To understand this expression difference, we examined the association of 10 genetic markers, mostly located in the promoter region, with SCZ in 1717 subjects collected from Toronto and McLean cohorts, including 881 controls and 836 cases and identified the 5' promoter SNP rs1478435 as having a significant association signal (uncorrectedPvalue: .00462; adjustedPvalue: .0319) in unrelated Caucasians. Allele T was over-represented in controls (OR = .75); T-carrier controls had decreased mRNA levels in nigral DA neurons, contributing to the reduced activity in the controls. In vitro functional analysis confirmed that T carriers displayed attenuated enhancement of promoter activity. These findings collectively suggest that increased nigralSLC6A3activity may be a risk factor for SCZ, and may help to explain high rates of comorbidity with substance abuse.
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Affiliation(s)
- James L. Kennedy
- Neurogenetics Section, Neuroscience Research Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada;,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada;,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Nian Xiong
- Laboratory of Psychiatric Neurogenomics, McLean Hospital, Belmont, MA;,Department of Psychiatry, Harvard Medical School, Boston, MA;,Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jinlong Yu
- Laboratory of Psychiatric Neurogenomics, McLean Hospital, Belmont, MA;,Department of Psychiatry, Harvard Medical School, Boston, MA
| | - Clement C. Zai
- Neurogenetics Section, Neuroscience Research Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada;,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada;,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Jennie G. Pouget
- Neurogenetics Section, Neuroscience Research Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada;,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada;,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Jie Li
- Laboratory of Psychiatric Neurogenomics, McLean Hospital, Belmont, MA;,Department of Psychiatry, Harvard Medical School, Boston, MA;,Institute of Psychiatry, Tianjin Mental Health Center, Tianjin, China
| | - Kefu Liu
- Laboratory of Psychiatric Neurogenomics, McLean Hospital, Belmont, MA;,Department of Psychiatry, Harvard Medical School, Boston, MA;,School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Hong Qing
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Tao Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Eden Martin
- Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL
| | - Deborah L. Levy
- Department of Psychiatry, Harvard Medical School, Boston, MA;,Psychology Research Laboratory, McLean Hospital, Belmont, MA,Joint last author
| | - Zhicheng Lin
- Laboratory of Psychiatric Neurogenomics, McLean Hospital, Belmont, MA; Department of Psychiatry, Harvard Medical School, Boston, MA;
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Li Z, He Y, Tang J, Zong X, Hu M, Chen X. Molecular imaging of striatal dopamine transporters in major depression--a meta-analysis. J Affect Disord 2015; 174:137-43. [PMID: 25497470 DOI: 10.1016/j.jad.2014.11.045] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 11/20/2014] [Accepted: 11/22/2014] [Indexed: 11/25/2022]
Abstract
BACKGROUND Increasing studies have revealed the dopamine transporter (DAT) availability altered in striatum associated with major depression. However, the results remain inconsistent. METHODS To assess the alteration of striatal DAT availability in major depression, we performed a meta-analysis based on 12 case-control molecular imaging studies, including a total of 209 depressed patients and 314 healthy controls. Hedges׳ g and corresponding 95% confidence intervals (CIs) for striatal DAT availability in major depression compared with controls were estimated. RESULTS Our meta-analysis revealed no evidence for the alteration of striatal DAT availability in major depression (Hedges׳ g=0.09, CI 95% from -0.43 to 0.61, P=0.73). Meta-regression analyses suggested that there were no moderating effects for age, gender, year of publication, sample size, medication exposures and severity of depression on the hedges׳g values for striatal DAT availability. LIMITATIONS The results should be treated with caution because of the significant heterogeneity and the potential interference of confounding factors in this meta-analysis. CONCLUSIONS Our results showed no altered striatal DAT availability in major depression and indicated that striatal DAT may not implicated in the pathophysiology of major depression.
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Affiliation(s)
- Zongchang Li
- Institute of Mental Health, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China; Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ying He
- Institute of Mental Health, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jinsong Tang
- Institute of Mental Health, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - Xiaofen Zong
- Institute of Mental Health, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Maolin Hu
- Institute of Mental Health, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiaogang Chen
- Institute of Mental Health, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China; Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, Hunan, China; The State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China; National Technology of Institute of Psychiatry, Central South University, Changsha, Hunan, China.
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16
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Bannon MJ, Savonen CL, Hartley ZJ, Johnson MM, Schmidt CJ. Investigating the potential influence of cause of death and cocaine levels on the differential expression of genes associated with cocaine abuse. PLoS One 2015; 10:e0117580. [PMID: 25658879 PMCID: PMC4319936 DOI: 10.1371/journal.pone.0117580] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/28/2014] [Indexed: 01/27/2023] Open
Abstract
The development of new therapeutic strategies for the treatment of complex brain disorders such as drug addiction is likely to be advanced by a more complete understanding of the underlying molecular pathophysiology. Although the study of postmortem human brain represents a unique resource in this regard, it can be challenging to disentangle the relative contribution of chronic pathological processes versus perimortem events to the observed changes in gene expression. To begin to unravel this issue, we analyzed by quantitative PCR the midbrain expression of numerous candidate genes previously associated with cocaine abuse. Data obtained from chronic cocaine abusers (and matched control subjects) dying of gunshot wounds were compared with a prior study of subjects with deaths directly attributable to cocaine abuse. Most of the genes studied (i.e., tyrosine hydroxylase, dopamine transporter, forkhead box A2, histone variant H3 family 3B, nuclear factor kappa B inhibitor alpha, growth arrest and DNA damage-inducible beta) were found to be differentially expressed in chronic cocaine abusers irrespective of immediate cause of death or perimortem levels of cocaine, suggesting that these may represent core pathophysiological changes arising with chronic drug abuse. On the other hand, chemokine C-C motif ligand 2 and jun proto-oncogene expression were unaffected in cocaine-abusing subjects dying of gunshot wounds, in contrast to the differential expression previously reported in cocaine-related fatalities. The possible influence of cause of death and other factors on the cocaine-responsiveness of these genes is discussed.
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Affiliation(s)
- Michael J. Bannon
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
| | - Candace L. Savonen
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Zachary J. Hartley
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Magen M. Johnson
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Carl J. Schmidt
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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A molecular profile of cocaine abuse includes the differential expression of genes that regulate transcription, chromatin, and dopamine cell phenotype. Neuropsychopharmacology 2014; 39:2191-9. [PMID: 24642598 PMCID: PMC4104338 DOI: 10.1038/npp.2014.70] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/19/2014] [Accepted: 03/09/2014] [Indexed: 02/07/2023]
Abstract
Chronic drug abuse, craving, and relapse are thought to be linked to long-lasting changes in neural gene expression arising through transcriptional and chromatin-related mechanisms. The key contributions of midbrain dopamine (DA)-synthesizing neurons throughout the addiction process provide a compelling rationale for determining the drug-induced molecular changes that occur in these cells. Yet our understanding of these processes remains rudimentary. The postmortem human brain constitutes a unique resource that can be exploited to gain insights into the pathophysiology of complex disorders such as drug addiction. In this study, we analyzed the profiles of midbrain gene expression in chronic cocaine abusers and well-matched drug-free control subjects using microarray and quantitative PCR. A small number of genes exhibited robust differential expression; many of these are involved in the regulation of transcription, chromatin, or DA cell phenotype. Transcript abundances for approximately half of these differentially expressed genes were diagnostic for assigning subjects to the cocaine-abusing vs control cohort. Identification of a molecular signature associated with pathophysiological changes occurring in cocaine abusers' midbrains should contribute to the development of biomarkers and novel therapeutic targets for drug addiction.
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18
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Functional effects of dopamine transporter gene genotypes on in vivo dopamine transporter functioning: a meta-analysis. Mol Psychiatry 2014; 19:880-9. [PMID: 24061496 DOI: 10.1038/mp.2013.126] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 12/20/2022]
Abstract
Much psychiatric genetic research has focused on a 40-base pair variable number of tandem repeats (VNTR) polymorphism located in the 3'-untranslated region (3'UTR) of the dopamine active transporter (DAT) gene (SLC6A3). This variant produces two common alleles with 9- and 10-repeats (9R and 10R). Studies associating this variant with in vivo DAT activity in humans have had mixed results. We searched for studies using positron emission tomography (PET) or single-photon emission computed tomography (SPECT) to evaluate this association. Random effects meta-analyses assessed the association of the 3'UTR variant with DAT activity. We also evaluated heterogeneity among studies and evidence for publication bias. We found twelve studies comprising 511 subjects, 125 from PET studies and 386 from SPECT studies. The PET studies provided highly significant evidence that the 9R allele was associated with increased DAT activity in human adults. The SPECT studies were highly heterogeneous. As a group, they suggested no association between the 3'UTR polymorphism and DAT activity. When the analysis was limited to the most commonly used ligand, [123I]β-CIT, stratification by affection status dramatically reduced heterogeneity and revealed a significant association of the 9R allele with increased DAT activity for healthy subjects. In humans, the 9R allele of the 3'UTR polymorphism of SLC6A3 regulates dopamine activity in the striatal brain regions independent of the presence of neuropsychiatric illness. Differences in study methodology account for the heterogeneous results across individual studies.
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19
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Zhao Y, Xiong N, Liu Y, Zhou Y, Li N, Qing H, Lin Z. Human dopamine transporter gene: differential regulation of 18-kb haplotypes. Pharmacogenomics 2014; 14:1481-94. [PMID: 24024899 DOI: 10.2217/pgs.13.141] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
AIM Since previous functional studies of short haplotypes and polymorphic sites of SLC6A3 have shown variant-dependent and drug-sensitive promoter activity, this study aimed to understand whether a large SLC6A3 regulatory region, containing these small haplotypes and polymorphic sites, can display haplotype-dependent promoter activity in a drug-sensitive and pathway-related manner. MATERIALS & METHODS By creating and using a single copy number luciferase-reporter vector, we examined regulation of two different SLC6A3 haplotypes (A and B) of the 5´ 18-kb promoter and two known downstream regulatory variable number tandem repeats by 17 drugs in four different cellular models. RESULTS The two regulatory haplotypes displayed up to 3.2-fold difference in promoter activity. The regulations were drug selective (37.5% of the drugs showed effects), and both haplotype and cell type dependent. Pathway analysis revealed at least 13 main signaling hubs targeting SLC6A3, including histone deacetylation, AKT, PKC and CK2 α-chains. CONCLUSION SLC6A3 may be regulated via either its promoter or the variable number tandem repeats independently by specific signaling pathways and in a haplotype-dependent manner. Furthermore, we have developed the first pathway map for SLC6A3 regulation. These findings provide a framework for understanding complex and variant-dependent regulations of SLC6A3.
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Affiliation(s)
- Ying Zhao
- Department of Psychiatry, Harvard Medical School & Laboratory of Psychiatric Neurogenomics, Division of Alcohol & Drug Abuse, McLean Hospital, Mailstop 318, 115 Mill Street, Belmont, MA 02478, USA
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Velázquez-Sánchez C, Ferragud A, Ramos-Miguel A, García-Sevilla JA, Canales JJ. Substituting a long-acting dopamine uptake inhibitor for cocaine prevents relapse to cocaine seeking. Addict Biol 2013; 18:633-43. [PMID: 22741574 DOI: 10.1111/j.1369-1600.2012.00458.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The treatment of cocaine addiction remains a challenge. The dopamine replacement approach in cocaine addiction involves the use of a competing dopaminergic agonist that might suppress withdrawal and drug craving in abstinent individuals. Although it has long been postulated that such an approach may be therapeutically successful, preclinical or clinical evidence showing its effectiveness to prevent relapse is scant. We used in rats a procedure that involved substitution of the N-substituted benztropine analog 3α-[bis(4'-fluorophenyl)methoxy]-tropane (AHN-1055), a long-acting dopamine uptake inhibitor (DUI), for cocaine. Maintenance treatment was self-administered. After extinction, reinstatement of drug seeking was induced by cocaine priming. We measured the contents of brain-derived neurotrophic factor (BDNF), c-Fos and Fas-associated death domain (FADD) proteins in the medial prefrontal cortex (mPFC) following reinstatement. DUI, but not amphetamine, substitution led to extinction of active lever presses, as did saline substitution. DUI substitution significantly reduced cocaine-induced reinstatement of drug-seeking behavior, which was strongly elicited after saline substitution. Rats passively yoked to DUI also showed reduced cocaine-primed reinstatement. Reductions in drug seeking during reinstatement were matched by downward shifts in the contents of BDNF, c-Fos and FADD proteins in the mPFC, which were elevated in relapsing rats. These data indicate that DUI substitution not only leads to extinction of self-administration behavior but also prevents reinstatement of drug seeking induced by cocaine re-exposure. Thus, DUI substitution therapy using compounds with low abuse potential, even if received passively in the context previously paired with drug taking, may provide an effective treatment for stimulant addiction.
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Johnson MM, David JA, Michelhaugh SK, Schmidt CJ, Bannon MJ. Increased heat shock protein 70 gene expression in the brains of cocaine-related fatalities may be reflective of postdrug survival and intervention rather than excited delirium. J Forensic Sci 2012; 57:1519-23. [PMID: 22803793 DOI: 10.1111/j.1556-4029.2012.02212.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cocaine-related fatalities can pose forensic challenges, particularly when accompanied by excited delirium (ED) syndrome and interventions by law enforcement and medical personnel. A recent report concluded that elevated heat shock protein 70 (HSP70) expression in autopsy brain samples constitutes a reliable forensic biomarker for the identification of ED as a cause of death. The present study quantified the abundance of both HSPA1A and HSPA1B gene (HSP70-encoding) transcripts in midbrain specimens from a series of cocaine-related fatalities and matched drug-free control subjects. HSP70 expression was increased significantly in cocaine abusers as a group compared to control subjects, irrespective of the presence or absence of ED. Furthermore, elevated HSP70 expression was predictive of a period of survival between cocaine use and death that included medical and/or police intervention. The present data do not support the assertion that HSP70 expression is a reliable brain biomarker for identifying ED as a cause of death.
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Affiliation(s)
- Magen M Johnson
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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