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Ritz NL, Bastiaanssen TFS, Cowan CSM, Smith L, Theune N, Brocka M, Myers EM, Moloney RD, Moloney GM, Shkoporov AN, Draper LA, Hill C, Dinan TG, Slattery DA, Cryan JF. Social fear extinction susceptibility is associated with Microbiota-Gut-Brain axis alterations. Brain Behav Immun 2024; 120:315-326. [PMID: 38852762 DOI: 10.1016/j.bbi.2024.06.009] [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: 11/21/2023] [Revised: 06/06/2024] [Accepted: 06/06/2024] [Indexed: 06/11/2024] Open
Abstract
Social anxiety disorder is a common psychiatric condition that severely affects quality of life of individuals and is a significant societal burden. Although many risk factors for social anxiety exist, it is currently unknown how social fear sensitivity manifests biologically. Furthermore, since some individuals are resilient and others are susceptible to social fear, it is important to interrogate the mechanisms underpinning individual response to social fear situations. The microbiota-gut-brain axis has been associated with social behaviour, has recently been linked with social anxiety disorder, and may serve as a therapeutic target for modulation. Here, we assess the potential of this axis to be linked with social fear extinction processes in a murine model of social anxiety disorder. To this end, we correlated differential social fear responses with microbiota composition, central gene expression, and immune responses. Our data provide evidence that microbiota variability is strongly correlated with alterations in social fear behaviour. Moreover, we identified altered gene candidates by amygdalar transcriptomics that are linked with social fear sensitivity. These include genes associated with social behaviour (Armcx1, Fam69b, Kcnj9, Maoa, Serinc5, Slc6a17, Spata2, and Syngr1), inflammation and immunity (Cars, Ckmt1, Klf5, Maoa, Map3k12, Pex5, Serinc5, Sidt1, Spata2), and microbe-host interaction (Klf5, Map3k12, Serinc5, Sidt1). Together, these data provide further evidence for a role of the microbiota-gut-brain axis in social fear responses.
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Affiliation(s)
- Nathaniel L Ritz
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Thomaz F S Bastiaanssen
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Caitlin S M Cowan
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Linda Smith
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; School of Microbiology, University College Cork, Cork, T12K8AF, Ireland
| | - Nigel Theune
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Marta Brocka
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Eibhlís M Myers
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Rachel D Moloney
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Gerard M Moloney
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland
| | - Andrey N Shkoporov
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; School of Microbiology, University College Cork, Cork, T12K8AF, Ireland
| | - Lorraine A Draper
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; School of Microbiology, University College Cork, Cork, T12K8AF, Ireland
| | - Colin Hill
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; School of Microbiology, University College Cork, Cork, T12K8AF, Ireland
| | - Timothy G Dinan
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Psychiatry and Neurobehavioural Science, University College Cork, Cork T12YT20, Ireland
| | - David A Slattery
- Dept. of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, Frankfurt 60528, Germany
| | - John F Cryan
- APC Microbiome Ireland, University College Cork, Cork T12YT20, Ireland; Dept. of Anatomy and Neuroscience, University College Cork, Cork T12YT20, Ireland.
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Nguyen H, Glaaser IW, Slesinger PA. Direct modulation of G protein-gated inwardly rectifying potassium (GIRK) channels. Front Physiol 2024; 15:1386645. [PMID: 38903913 PMCID: PMC11187414 DOI: 10.3389/fphys.2024.1386645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/08/2024] [Indexed: 06/22/2024] Open
Abstract
Ion channels play a pivotal role in regulating cellular excitability and signal transduction processes. Among the various ion channels, G-protein-coupled inwardly rectifying potassium (GIRK) channels serve as key mediators of neurotransmission and cellular responses to extracellular signals. GIRK channels are members of the larger family of inwardly-rectifying potassium (Kir) channels. Typically, GIRK channels are activated via the direct binding of G-protein βγ subunits upon the activation of G-protein-coupled receptors (GPCRs). GIRK channel activation requires the presence of the lipid signaling molecule, phosphatidylinositol 4,5-bisphosphate (PIP2). GIRK channels are also modulated by endogenous proteins and other molecules, including RGS proteins, cholesterol, and SNX27 as well as exogenous compounds, such as alcohol. In the last decade or so, several groups have developed novel drugs and small molecules, such as ML297, GAT1508 and GiGA1, that activate GIRK channels in a G-protein independent manner. Here, we aim to provide a comprehensive overview focusing on the direct modulation of GIRK channels by G-proteins, PIP2, cholesterol, and novel modulatory compounds. These studies offer valuable insights into the underlying molecular mechanisms of channel function, and have potential implications for both basic research and therapeutic development.
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Affiliation(s)
| | | | - Paul A. Slesinger
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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Popova D, Sun J, Chow HM, Hart RP. A critical review of ethanol effects on neuronal firing: A metabolic perspective. ALCOHOL, CLINICAL & EXPERIMENTAL RESEARCH 2024; 48:450-458. [PMID: 38217065 DOI: 10.1111/acer.15266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/14/2024]
Abstract
Ethanol metabolism is relatively understudied in neurons, even though changes in neuronal metabolism are known to affect their activity. Recent work demonstrates that ethanol is preferentially metabolized over glucose as a source of carbon and energy, and it reprograms neurons to a state of reduced energy potential and diminished capacity to utilize glucose once ethanol is exhausted. Ethanol intake has been associated with changes in neuronal firing and specific brain activity (EEG) patterns have been linked with risk for alcohol use disorder (AUD). Furthermore, a haplotype of the inwardly rectifying potassium channel subunit, GIRK2, which plays a critical role in regulating excitability of neurons, has been linked with AUD and shown to be directly regulated by ethanol. At the same time, overexpression of GIRK2 prevents ethanol-induced metabolic changes. Based on the available evidence, we conclude that the mechanisms underlying the effects of ethanol on neuronal metabolism are a novel target for developing therapies for AUD.
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Affiliation(s)
- Dina Popova
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey, USA
| | - Jacquelyne Sun
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Hei-Man Chow
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, Hong Kong
- Gerald Choa Neuroscience Institute, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Ronald P Hart
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey, USA
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Silva-Cardoso GK, N'Gouemo P. Influence of Inherited Seizure Susceptibility on Intermittent Voluntary Alcohol Consumption and Alcohol Withdrawal Seizures in Genetically Epilepsy-Prone Rats (GEPR-3s). Brain Sci 2024; 14:188. [PMID: 38391762 PMCID: PMC10886844 DOI: 10.3390/brainsci14020188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 02/10/2024] [Accepted: 02/15/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND The link between epilepsy and alcohol consumption is complex, with conflicting reports. To enhance our understanding of this link, we conducted a study to determine how inherited seizure susceptibility affects voluntary alcohol consumption and influences alcohol withdrawal seizures in male and female genetically epilepsy-prone rats (GEPR-3s) compared to Sprague Dawley (SD) rats. METHODS In the first experiment, animals were given access to two bottles simultaneously, one containing water and the other 7.5%, 15%, or 30% (v/v) alcohol three times a week for each dose after acclimation to drinking water. In a second experiment, animals were tested for acoustically evoked alcohol seizures 24 h after the last session of voluntary alcohol consumption. RESULTS Analysis revealed that GEPR-3s (males and females) had lower alcohol intake and preference than SD rats, particularly at lower alcohol concentrations. However, female GEPR-3s consumed more alcohol and had a higher alcohol preference than males. Furthermore, withdrawal from voluntary alcohol consumption facilitated the onset and duration of seizures in GEPR-3s. CONCLUSIONS Our study suggests that genetic seizure susceptibility in GEPR-3s is negatively associated with alcohol consumption. However, withdrawal from low to moderate amounts of alcohol intake can promote epileptogenesis in the epileptic GEPR-3s.
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Affiliation(s)
- Gleice Kelli Silva-Cardoso
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA
| | - Prosper N'Gouemo
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA
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Marron Fernandez de Velasco E, Tipps ME, Haider B, Souders A, Aguado C, Rose TR, Vo BN, DeBaker MC, Luján R, Wickman K. Ethanol-Induced Suppression of G Protein-Gated Inwardly Rectifying K +-Dependent Signaling in the Basal Amygdala. Biol Psychiatry 2023; 94:863-874. [PMID: 37068702 PMCID: PMC10576835 DOI: 10.1016/j.biopsych.2023.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 04/05/2023] [Accepted: 04/05/2023] [Indexed: 04/19/2023]
Abstract
BACKGROUND The basolateral amygdala (BLA) regulates mood and associative learning and has been linked to the development and persistence of alcohol use disorder. The GABABR (gamma-aminobutyric acid B receptor) is a promising therapeutic target for alcohol use disorder, and previous work suggests that exposure to ethanol and other drugs can alter neuronal GABABR-dependent signaling. The effect of ethanol on GABABR-dependent signaling in the BLA is unknown. METHODS GABABR-dependent signaling in the mouse BLA was examined using slice electrophysiology following repeated ethanol exposure. Neuron-specific viral genetic manipulations were then used to understand the relevance of ethanol-induced neuroadaptations in the basal amygdala subregion (BA) to mood-related behavior. RESULTS The somatodendritic inhibitory effect of GABABR activation on principal neurons in the basal but not the lateral subregion of the BLA was diminished following ethanol exposure. This adaptation was attributable to the suppression of GIRK (G protein-gated inwardly rectifying K+) channel activity and was mirrored by a redistribution of GABABR and GIRK channels from the surface membrane to internal sites. While GIRK1 and GIRK2 subunits are critical for GIRK channel formation in BA principal neurons, GIRK3 is necessary for the ethanol-induced neuroadaptation. Viral suppression of GIRK channel activity in BA principal neurons from ethanol-naïve mice recapitulated some mood-related behaviors observed in C57BL/6J mice during ethanol withdrawal. CONCLUSIONS The ethanol-induced suppression of GIRK-dependent signaling in BA principal neurons contributes to some of the mood-related behaviors associated with ethanol withdrawal in mice. Approaches designed to prevent this neuroadaptation and/or strengthen GIRK-dependent signaling may prove useful for the treatment of alcohol use disorder.
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Affiliation(s)
| | - Megan E Tipps
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Bushra Haider
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Anna Souders
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Carolina Aguado
- Departmento de Ciencias Médicas, Facultad de Medicina, Universidad Castilla La Mancha, Campus Biosanitario, La Mancha, Albacete, Spain
| | - Timothy R Rose
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Baovi N Vo
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Margot C DeBaker
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota
| | - Rafael Luján
- Departmento de Ciencias Médicas, Facultad de Medicina, Universidad Castilla La Mancha, Campus Biosanitario, La Mancha, Albacete, Spain
| | - Kevin Wickman
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
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Zhang T, Rao Q, Dai M, Wu ZE, Zhao Q, Li F. Tripterygium wilfordii protects against an animal model of autoimmune hepatitis. JOURNAL OF ETHNOPHARMACOLOGY 2023; 309:116365. [PMID: 36907478 DOI: 10.1016/j.jep.2023.116365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/22/2023] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tripterygium wilfordii tablets (TWT) is widely used to treat autoimmune diseases such as rheumatoid arthritis. Celastrol, one main active ingredient in TWT, has been shown to produce a variety of beneficial effects, including anti-inflammatory, anti-obesity, anti-cancer, and immunomodulatory. However, whether TWT could protect against Concanavalin A (Con A)-induced hepatitis remains unclear. THE AIM OF THE STUDY This study aims to investigate the protective effect of TWT against Con A-induced hepatitis and elucidate the underlying mechanism. MATERIALS AND METHODS Metabolomic analysis, pathological analysis, biochemical analysis, qPCR and Western blot analysis and the Pxr-null mice were used in this study. RESULTS The results indicated that TWT and its active ingredient celastrol could protect against Con A-induced acute hepatitis. Plasma metabolomics analysis revealed that metabolic perturbations related to bile acid and fatty acid metabolism induced by Con A were reversed by celastrol. The level of itaconate in the liver was increased by celastrol and speculated as an active endogenous compound mediating the protective effect of celastrol. Administration of 4-octanyl itaconate (4-OI) as a cell-permeable itaconate mimicker was found to attenuate Con A-induced liver injury through activation of the pregnane X receptor (PXR) and enhancement of the transcription factor EB (TFEB)-mediated autophagy. CONCLUSIONS Celastrol increased itaconate and 4-OI promoted activation of TFEB-mediated lysosomal autophagy to protect against Con A-induced liver injury in a PXR-dependent manner. Our study reported a protective effect of celastrol against Con A-induced AIH via an increased production of itaconate and upregulation of TFEB. The results highlighted that PXR and TFEB-mediated lysosomal autophagic pathway may offer promising therapeutic target for the treatment of autoimmune hepatitis.
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Affiliation(s)
- Ting Zhang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Laboratory of Metabolomics and Drug-induced Liver Injury, Sichuan University-Oxford University Huaxi Gastrointestinal Cancer Centre, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Qianru Rao
- Laboratory of Metabolomics and Drug-induced Liver Injury, Sichuan University-Oxford University Huaxi Gastrointestinal Cancer Centre, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Manyun Dai
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Laboratory of Metabolomics and Drug-induced Liver Injury, Sichuan University-Oxford University Huaxi Gastrointestinal Cancer Centre, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Zhanxuan E Wu
- Laboratory of Metabolomics and Drug-induced Liver Injury, Sichuan University-Oxford University Huaxi Gastrointestinal Cancer Centre, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Qi Zhao
- Laboratory of Metabolomics and Drug-induced Liver Injury, Sichuan University-Oxford University Huaxi Gastrointestinal Cancer Centre, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Fei Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; Laboratory of Metabolomics and Drug-induced Liver Injury, Sichuan University-Oxford University Huaxi Gastrointestinal Cancer Centre, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, 610041, China; Department of Pharmacy, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
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Gimenez-Gomez P, Le T, Martin GE. Modulation of neuronal excitability by binge alcohol drinking. Front Mol Neurosci 2023; 16:1098211. [PMID: 36866357 PMCID: PMC9971943 DOI: 10.3389/fnmol.2023.1098211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/19/2023] [Indexed: 02/16/2023] Open
Abstract
Drug use poses a serious threat to health systems throughout the world. The number of consumers rises every year being alcohol the drug of abuse most consumed causing 3 million deaths (5.3% of all deaths) worldwide and 132.6 million disability-adjusted life years. In this review, we present an up-to-date summary about what is known regarding the global impact of binge alcohol drinking on brains and how it affects the development of cognitive functions, as well as the various preclinical models used to probe its effects on the neurobiology of the brain. This will be followed by a detailed report on the state of our current knowledge of the molecular and cellular mechanisms underlying the effects of binge drinking on neuronal excitability and synaptic plasticity, with an emphasis on brain regions of the meso-cortico limbic neurocircuitry.
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Affiliation(s)
- Pablo Gimenez-Gomez
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, United States
- The Brudnick Neuropsychiatric Research Institute, Worcester, MA, United States
| | - Timmy Le
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, United States
- The Brudnick Neuropsychiatric Research Institute, Worcester, MA, United States
- Graduate Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA, United States
| | - Gilles E. Martin
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, United States
- The Brudnick Neuropsychiatric Research Institute, Worcester, MA, United States
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Campos-Ríos A, Rueda-Ruzafa L, Lamas JA. The Relevance of GIRK Channels in Heart Function. MEMBRANES 2022; 12:1119. [PMID: 36363674 PMCID: PMC9698958 DOI: 10.3390/membranes12111119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/06/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
Among the large number of potassium-channel families implicated in the control of neuronal excitability, G-protein-gated inwardly rectifying potassium channels (GIRK/Kir3) have been found to be a main factor in heart control. These channels are activated following the modulation of G-protein-coupled receptors and, although they have been implicated in different neurological diseases in both human and animal studies of the central nervous system, the therapeutic potential of different subtypes of these channel families in cardiac conditions has remained untapped. As they have emerged as a promising potential tool to treat a variety of conditions that disrupt neuronal homeostasis, many studies have started to focus on these channels as mediators of cardiac dynamics, thus leading to research into their implication in cardiovascular conditions. Our aim is to review the latest advances in GIRK modulation in the heart and their role in the cardiovascular system.
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Affiliation(s)
- Ana Campos-Ríos
- CINBIO, Laboratory of Neuroscience, University of Vigo, 36310 Vigo, Spain
- Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), 15706 Vigo, Spain
| | - Lola Rueda-Ruzafa
- Department of Nursing Science, Physiotherapy and Medicine, Faculty of Health Sciences, University of Almeria, 04120 Almeria, Spain
| | - José Antonio Lamas
- CINBIO, Laboratory of Neuroscience, University of Vigo, 36310 Vigo, Spain
- Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), 15706 Vigo, Spain
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GIRK Channels as Candidate Targets for the Treatment of Substance Use Disorders. Biomedicines 2022; 10:biomedicines10102552. [PMID: 36289814 PMCID: PMC9599444 DOI: 10.3390/biomedicines10102552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/05/2022] [Accepted: 10/09/2022] [Indexed: 11/16/2022] Open
Abstract
Substance use disorders (SUDs) are chronic, lifelong disorders that have serious consequences. Repeated substance use alters brain function. G-protein-activated inwardly rectifying potassium (GIRK) channels are expressed widely in the brain, including the reward system, and regulate neuronal excitability. Functional GIRK channels are identified as heterotetramers of GIRK subunits (GIRK1–4). The GIRK1, GIRK2, and GIRK3 subunits are mainly expressed in rodent brain regions, and various addictive substances act on the brain through GIRK channels. Studies with animals (knockout and missense mutation animals) and humans have demonstrated the involvement of GIRK channels in the effects of addictive substances. Additionally, GIRK channel blockers affect behavioral responses to addictive substances. Thus, GIRK channels play a key role in SUDs, and GIRK channel modulators may be candidate medications. Ifenprodil is a GIRK channel blocker that does not have serious side effects. Two clinical trials were conducted to investigate the effects of ifenprodil in patients with alcohol or methamphetamine use disorder. Although the number of participants was relatively low, evidence of its safety and efficacy was found. The present review discusses the potential of GIRK channel modulators as possible medications for addiction. Therapeutic agents that target GIRK channels may be promising for the treatment of SUDs.
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Blum K, Brodie MS, Pandey SC, Cadet JL, Gupta A, Elman I, Thanos PK, Gondre-Lewis MC, Baron D, Kazmi S, Bowirrat A, Febo M, Badgaiyan RD, Braverman ER, Dennen CA, Gold MS. Researching Mitigation of Alcohol Binge Drinking in Polydrug Abuse: KCNK13 and RASGRF2 Gene(s) Risk Polymorphisms Coupled with Genetic Addiction Risk Severity (GARS) Guiding Precision Pro-Dopamine Regulation. J Pers Med 2022; 12:jpm12061009. [PMID: 35743793 PMCID: PMC9224860 DOI: 10.3390/jpm12061009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/12/2022] [Accepted: 06/16/2022] [Indexed: 11/22/2022] Open
Abstract
Excessive alcohol intake, e.g., binge drinking, is a serious and mounting public health problem in the United States and throughout the world. Hence the need for novel insights into the underlying neurobiology that may help improve prevention and therapeutic strategies. Therefore, our group employed a darkness-induced alcohol intake protocol to define the reward deficiency domains of alcohol and other substance use disorders in terms of reward pathways' reduced dopamine signaling and its restoration via specifically-designed therapeutic compounds. It has been determined that KCNK13 and RASGRF2 genes, respectively, code for potassium two pore domain channel subfamily K member 13 and Ras-specific guanine nucleotide-releasing factor 2, and both genes have important dopamine-related functions pertaining to alcohol binge drinking. We present a hypothesis that identification of KCNK13 and RASGRF2 genes' risk polymorphism, coupled with genetic addiction risk score (GARS)-guided precision pro-dopamine regulation, will mitigate binge alcohol drinking. Accordingly, we review published reports on the benefits of this unique approach and provide data on favorable outcomes for both binge-drinking animals and drunk drivers, including reductions in alcohol intake and prevention of relapse to drinking behavior. Since driving under the influence of alcohol often leads to incarceration rather than rehabilitation, there is converging evidence to support the utilization of GARS with or without KCNK13 and RASGRF2 risk polymorphism in the legal arena, whereby the argument that "determinism" overrides the "free will" account may be a plausible defense strategy. Obviously, this type of research is tantamount to helping resolve a major problem related to polydrug abuse.
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Affiliation(s)
- Kenneth Blum
- The Kenneth Blum Behavioral & Neurogenetic Institute, Austin, TX 78701, USA; (E.R.B.); (C.A.D.)
- Division of Addiction Research & Education, Center for Psychiatry, Medicine & Primary Care (Office of Provost), Western University Health Sciences, Pomona, CA 91766, USA; (D.B.); (M.F.)
- Institute of Psychology, ELTE Eötvös Loránd University, Egyetem tér 1-3, 1053 Budapest, Hungary
- Department of Psychiatry, School of Medicine, University of Vermont, Burlington, VT 05405, USA
- Department of Psychiatry, Wright State University Boonshoft School of Medicine and Dayton VA Medical Centre, Dayton, OH 45324, USA
- Correspondence:
| | - Mark S. Brodie
- Center for Alcohol Research in Epigenetics, Departments of Physiology and Biophysics, and Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (M.S.B.); (S.C.P.)
| | - Subhash C. Pandey
- Center for Alcohol Research in Epigenetics, Departments of Physiology and Biophysics, and Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (M.S.B.); (S.C.P.)
| | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Ashim Gupta
- Future Biologics, Lawrenceville, GA 30043, USA;
| | - Igor Elman
- Center for Pain and the Brain (P.A.I.N Group), Department of Anesthesiology, Critical Care & Pain Medicine, Boston Children’s Hospital, Boston, MA 02115, USA;
| | - Panayotis K. Thanos
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biosciences, State University of New York at Buffalo, Buffalo, NY 14203, USA;
- Department of Psychology, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Marjorie C. Gondre-Lewis
- Neuropsychopharmacology Laboratory, Department of Anatomy, Howard University College of Medicine, Washington, DC 20059, USA;
| | - David Baron
- Division of Addiction Research & Education, Center for Psychiatry, Medicine & Primary Care (Office of Provost), Western University Health Sciences, Pomona, CA 91766, USA; (D.B.); (M.F.)
| | - Shan Kazmi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA;
| | - Abdalla Bowirrat
- Department of Molecular Biology and Adelson School of Medicine, Ariel University, Ariel 40700, Israel;
| | - Marcelo Febo
- Division of Addiction Research & Education, Center for Psychiatry, Medicine & Primary Care (Office of Provost), Western University Health Sciences, Pomona, CA 91766, USA; (D.B.); (M.F.)
| | - Rajendra D. Badgaiyan
- Department of Psychiatry, South Texas Veteran Health Care System, Audie L. Murphy Memorial VA Hospital, Long School of Medicine, University of Texas Medical Center, San Antonio, TX 78229, USA;
| | - Eric R. Braverman
- The Kenneth Blum Behavioral & Neurogenetic Institute, Austin, TX 78701, USA; (E.R.B.); (C.A.D.)
| | - Catherine A. Dennen
- The Kenneth Blum Behavioral & Neurogenetic Institute, Austin, TX 78701, USA; (E.R.B.); (C.A.D.)
| | - Mark S. Gold
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA;
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11
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Luo H, Marron Fernandez de Velasco E, Wickman K. Neuronal G protein-gated K + channels. Am J Physiol Cell Physiol 2022; 323:C439-C460. [PMID: 35704701 PMCID: PMC9362898 DOI: 10.1152/ajpcell.00102.2022] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
G protein-gated inwardly rectifying K+ (GIRK/Kir3) channels exert a critical inhibitory influence on neurons. Neuronal GIRK channels mediate the G protein-dependent, direct/postsynaptic inhibitory effect of many neurotransmitters including γ-aminobutyric acid (GABA), serotonin, dopamine, adenosine, somatostatin, and enkephalin. In addition to their complex regulation by G proteins, neuronal GIRK channel activity is sensitive to PIP2, phosphorylation, regulator of G protein signaling (RGS) proteins, intracellular Na+ and Ca2+, and cholesterol. The application of genetic and viral manipulations in rodent models, together with recent progress in the development of GIRK channel modulators, has increased our understanding of the physiological and behavioral impact of neuronal GIRK channels. Work in rodent models has also revealed that neuronal GIRK channel activity is modified, transiently or persistently, by various stimuli including exposure drugs of abuse, changes in neuronal activity patterns, and aversive experience. A growing body of preclinical and clinical evidence suggests that dysregulation of GIRK channel activity contributes to neurological diseases and disorders. The primary goals of this review are to highlight fundamental principles of neuronal GIRK channel biology, mechanisms of GIRK channel regulation and plasticity, the nascent landscape of GIRK channel pharmacology, and the potential relevance of GIRK channels to the pathophysiology and treatment of neurological diseases and disorders.
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Affiliation(s)
- Haichang Luo
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, United States
| | | | - Kevin Wickman
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, United States
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12
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Monroy-Jaramillo N, Martínez-Magaña JJ, Pérez-Aldana BE, Ortega-Vázquez A, Montalvo-Ortiz J, López-López M. The role of alcohol intake in the pharmacogenetics of treatment with clozapine. Pharmacogenomics 2022; 23:371-392. [PMID: 35311547 DOI: 10.2217/pgs-2022-0006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Clozapine (CLZ) is an atypical antipsychotic reserved for patients with refractory psychosis, but it is associated with a significant risk of severe adverse reactions (ADRs) that are potentiated with the concomitant use of alcohol. Additionally, pharmacogenetic studies have explored the influence of several genetic variants in CYP450, receptors and transporters involved in the interindividual response to CLZ. Herein, we systematically review the current multiomics knowledge behind the interaction between CLZ and alcohol intake, and how its concomitant use might modulate the pharmacogenetics. CYP1A2*1F, *1C and other alleles not yet discovered could support a precision medicine approach for better therapeutic effects and fewer CLZ ADRs. CLZ monitoring systems should be amended and include alcohol intake to protect patients from severe CLZ ADRs.
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Affiliation(s)
- Nancy Monroy-Jaramillo
- Department of Genetics, National Institute of Neurology & Neurosurgery, Manuel Velasco Suárez, La Fama, Tlalpan, Mexico City, 14269, Mexico
| | - José Jaime Martínez-Magaña
- Department of Psychiatry, Division of Human Genetics, Yale University School of Medicine, Orange, West Haven, CT 06477, USA
| | - Blanca Estela Pérez-Aldana
- Doctorado en Ciencias Biológicas y de la Salud, Metropolitan Autonomous University, Campus Xochimilco, Villa Quietud, Coyoacán, Mexico City, 04960, Mexico
| | - Alberto Ortega-Vázquez
- Metropolitan Autonomous University, Campus Xochimilco, Villa Quietud, Coyoacán, Mexico City, 04960, Mexico
| | - Janitza Montalvo-Ortiz
- Department of Psychiatry, Division of Human Genetics, Yale University School of Medicine, Orange, West Haven, CT 06477, USA
| | - Marisol López-López
- Metropolitan Autonomous University, Campus Xochimilco, Villa Quietud, Coyoacán, Mexico City, 04960, Mexico
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13
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Niedzwiedz-Massey VM, Douglas JC, Rafferty T, Wight PA, Kane CJM, Drew PD. Ethanol modulation of hippocampal neuroinflammation, myelination, and neurodevelopment in a postnatal mouse model of fetal alcohol spectrum disorders. Neurotoxicol Teratol 2021; 87:107015. [PMID: 34256161 PMCID: PMC8440486 DOI: 10.1016/j.ntt.2021.107015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/24/2021] [Accepted: 07/08/2021] [Indexed: 01/15/2023]
Abstract
Fetal alcohol spectrum disorders (FASD) are alarmingly common and result in significant personal and societal loss. Neuropathology of the hippocampus is common in FASD leading to aberrant cognitive function. In the current study, we evaluated the effects of ethanol on the expression of a targeted set of molecules involved in neuroinflammation, myelination, neurotransmission, and neuron function in the developing hippocampus in a postnatal model of FASD. Mice were treated with ethanol from P4-P9, hippocampi were isolated 24 h after the final treatment at P10, and mRNA levels were quantitated by qRT-PCR. We evaluated the effects of ethanol on both pro-inflammatory and anti-inflammatory molecules in the hippocampus and identified novel mechanisms by which ethanol induces neuroinflammation. We further demonstrated that ethanol decreased expression of molecules associated with mature oligodendrocytes and greatly diminished expression of a lacZ reporter driven by the first half of the myelin proteolipid protein (PLP) gene (PLP1). In addition, ethanol caused a decrease in genes expressed in oligodendrocyte progenitor cells (OPCs). Together, these studies suggest ethanol may modulate pathogenesis in the developing hippocampus through effects on cells of the oligodendrocyte lineage, resulting in altered oligodendrogenesis and myelination. We also observed differential expression of molecules important in synaptic plasticity, neurogenesis, and neurotransmission. Collectively, the molecules evaluated in these studies may play a role in ethanol-induced pathology in the developing hippocampus and contribute to cognitive impairment associated with FASD. A better understanding of these molecules and their effects on the developing hippocampus may lead to novel treatment strategies for FASD.
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Affiliation(s)
- Victoria M Niedzwiedz-Massey
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - James C Douglas
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Tonya Rafferty
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Patricia A Wight
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Cynthia J M Kane
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Paul D Drew
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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14
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You C, Vandegrift BJ, Brodie MS. KCNK13 potassium channels in the ventral tegmental area of rats are important for excitation of ventral tegmental area neurons by ethanol. Alcohol Clin Exp Res 2021; 45:1348-1358. [PMID: 33960499 DOI: 10.1111/acer.14630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Alcohol excites neurons of the ventral tegmental area (VTA) and the release of dopamine from these neurons is a key event in ethanol (EtOH)-induced reward and reinforcement. Many mechanisms have been proposed to explain EtOH's actions on neurons of the VTA, but antagonists generally do not eliminate the EtOH-induced excitation of VTA neurons. We have previously demonstrated that the ion channel KCNK13 plays an important role in the EtOH-related excitation of mouse VTA neurons. Here, we elaborate on that finding and further assess the importance of KCNK13 in rats. METHODS Rats (Sprague-Dawley and Fisher 344) were used in these studies. In addition to single-unit electrophysiology in brain slices, we used quantitative PCR and immunohistochemistry to discern the effects of EtOH and the brain slice preparation method on the expression levels of the Kcnk13 gene and KCNK13 protein. RESULTS Immunohistochemistry demonstrated that the levels of KCNK13 were significantly reduced during procedures normally used to prepare brain slices for electrophysiology, with a reduction of about 75% in KCNK13 protein at the time that electrophysiological recordings would normally be made. Extracellular recordings demonstrated that EtOH-induced excitation of VTA neurons was reduced after knockdown of Kcnk13 using a small interfering RNA (siRNA) delivered via the recording micropipette. Real-time PCR demonstrated that the expression of Kcnk13 was altered in a time-dependent manner after alcohol withdrawal. CONCLUSIONS KCNK13 plays an important role in EtOH-induced stimulation of rat VTA neurons and is dynamically regulated by cell damage and EtOH exposure, and during withdrawal. KCNK13 is a novel alcohol-sensitive protein, and further investigation of this channel may offer new avenues for the development of agents useful in altering the rewarding effect of alcohol.
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Affiliation(s)
- Chang You
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA.,Department of Psychiatry, Center for Alcohol Research in Epigenetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Bertha J Vandegrift
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA.,Department of Psychiatry, Center for Alcohol Research in Epigenetics, University of Illinois at Chicago, Chicago, IL, USA
| | - Mark S Brodie
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA.,Department of Psychiatry, Center for Alcohol Research in Epigenetics, University of Illinois at Chicago, Chicago, IL, USA
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15
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McCoy MT, Jayanthi S, Cadet JL. Potassium Channels and Their Potential Roles in Substance Use Disorders. Int J Mol Sci 2021; 22:1249. [PMID: 33513859 PMCID: PMC7865894 DOI: 10.3390/ijms22031249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/12/2023] Open
Abstract
Substance use disorders (SUDs) are ubiquitous throughout the world. However, much remains to be done to develop pharmacotherapies that are very efficacious because the focus has been mostly on using dopaminergic agents or opioid agonists. Herein we discuss the potential of using potassium channel activators in SUD treatment because evidence has accumulated to support a role of these channels in the effects of rewarding drugs. Potassium channels regulate neuronal action potential via effects on threshold, burst firing, and firing frequency. They are located in brain regions identified as important for the behavioral responses to rewarding drugs. In addition, their expression profiles are influenced by administration of rewarding substances. Genetic studies have also implicated variants in genes that encode potassium channels. Importantly, administration of potassium agonists have been shown to reduce alcohol intake and to augment the behavioral effects of opioid drugs. Potassium channel expression is also increased in animals with reduced intake of methamphetamine. Together, these results support the idea of further investing in studies that focus on elucidating the role of potassium channels as targets for therapeutic interventions against SUDs.
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Affiliation(s)
| | | | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program, Baltimore, MD 21224, USA; (M.T.M.); (S.J.)
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16
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Therapeutic potential of targeting G protein-gated inwardly rectifying potassium (GIRK) channels in the central nervous system. Pharmacol Ther 2021; 223:107808. [PMID: 33476640 DOI: 10.1016/j.pharmthera.2021.107808] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/05/2021] [Indexed: 12/15/2022]
Abstract
G protein-gated inwardly rectifying potassium channels (Kir3/GirK) are important for maintaining resting membrane potential, cell excitability and inhibitory neurotransmission. Coupled to numerous G protein-coupled receptors (GPCRs), they mediate the effects of many neurotransmitters, neuromodulators and hormones contributing to the general homeostasis and particular synaptic plasticity processes, learning, memory and pain signaling. A growing number of behavioral and genetic studies suggest a critical role for the appropriate functioning of the central nervous system, as well as their involvement in many neurologic and psychiatric conditions, such as neurodegenerative diseases, mood disorders, attention deficit hyperactivity disorder, schizophrenia, epilepsy, alcoholism and drug addiction. Hence, GirK channels emerge as a very promising tool to be targeted in the current scenario where these conditions already are or will become a global public health problem. This review examines recent findings on the physiology, function, dysfunction, and pharmacology of GirK channels in the central nervous system and highlights the relevance of GirK channels as a worthful potential target to improve therapies for related diseases.
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17
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Zhao Y, Gameiro-Ros I, Glaaser IW, Slesinger PA. Advances in Targeting GIRK Channels in Disease. Trends Pharmacol Sci 2021; 42:203-215. [PMID: 33468322 DOI: 10.1016/j.tips.2020.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/30/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022]
Abstract
G protein-gated inwardly rectifying potassium (GIRK) channels are essential regulators of cell excitability in the brain. While they are implicated in a variety of neurological diseases in both human and animal model studies, their therapeutic potential has been largely untapped. Here, we review recent advances in the development of small molecule compounds that specifically modulate GIRK channels and compare them with first-generation compounds that exhibit off-target activity. We describe the method of discovery of these small molecule modulators, their chemical features, and their effects in vivo. These studies provide a promising outlook on the future development of subunit-specific GIRK modulators to regulate neuronal excitability in a brain region-specific manner.
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Affiliation(s)
- Yulin Zhao
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Isabel Gameiro-Ros
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ian W Glaaser
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Paul A Slesinger
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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18
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Li DL, Hu L, Wang L, Chen CL. Permeation mechanisms through the selectivity filter and the open helix bundle crossing gate of GIRK2. Comput Struct Biotechnol J 2020; 18:3950-3958. [PMID: 33335691 PMCID: PMC7734222 DOI: 10.1016/j.csbj.2020.11.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 12/01/2022] Open
Abstract
G protein-gated inwardly rectifying potassium channels (GIRK) are essential for the regulation of cellular excitability, a physiological function that relies critically on the conduction of K+ ions, which is dependent on two molecular mechanisms, namely selectivity and gating. Molecular Dynamics (MD) studies have shown that K+ conduction remains inefficient even with open channel gates, therefore further detailed study on the permeation events is required. In this study, all-atom MD simulations were employed to investigate the permeation mechanism through the GIRK2 selectivity filter (SF) and its open helix bundle crossing (HBC) gate. Our results show that it is the SF rather than the HBC or the G-loop gate that determines the permeation efficiency upon activation of the channel. SF-permeation is accomplished by a water-K+ coupled mechanism and the entry to the S1 coordination site is likely affected by a SF tilt. Moreover, we show that a 4-K+ occupancy in the SF-HBC cavity is required for the permeation through an open HBC, where three K+ ions around E152 help to abolish the unfavorable cation-dipole interactions that function as an energy barrier, while the fourth K+ located near the HBC allows for the inward transport. These findings facilitate further understanding of the dynamic permeation mechanisms through GIRK2 and potentially provide an alternative regulatory approach for the Kir3 family given the overall high evolutionary residue conservation.
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Affiliation(s)
- Dai-Lin Li
- Key Laboratory of Environmental Biotechnology (XMUT), Fujian Province University, Xiamen University of Technology, Xiamen 361005, China
| | - Liang Hu
- School of Computer and Information Engineering, Xiamen University of Technology, Xiamen 361005, China
| | - Lei Wang
- Key Laboratory of Environmental Biotechnology (XMUT), Fujian Province University, Xiamen University of Technology, Xiamen 361005, China
| | - Chin-Ling Chen
- School of Computer and Information Engineering, Xiamen University of Technology, Xiamen 361005, China.,School of Information Engineering, Changchun Sci-Tech University, Changchun 130600, China.,Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung 41349, Taiwan
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19
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Ma L, Song J, Sun X, Ding W, Fan K, Qi M, Xu Y, Zhang W. Role of microtubule-associated protein 6 glycosylated with Gal-(β-1,3)-GalNAc in Parkinson's disease. Aging (Albany NY) 2020; 11:4597-4610. [PMID: 31289257 PMCID: PMC6660046 DOI: 10.18632/aging.102072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/28/2019] [Indexed: 12/13/2022]
Abstract
Aberrant glycosylation of proteins has major implications for human diseases. To determine whether protein glycosylation contributes to the pathogenesis of Parkinson’s disease (PD), a mouse model of PD was established by injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Induction of PD-like features was verified by assessing motor impairment and confirming reductions in biological markers, including dopamine, 5-hydroxytryptamine and tyrosine hydroxylase, as well as the aggregation of α-synuclein. Altered glycosylation was detected using biotinylated agaracus bisporus lectin, which specifically binds exposed Gal-(β-1,3)-GalNAc linked to glycoproteins. Subsequent lectin affinity chromatography coupled with mass spectrometry revealed enhanced glycosylation of microtubule-associated protein 6 (MAP6) in PD mice as compared to healthy controls. In situ dual co-immunofluorescence analysis and immunoblotting confirmed that MAP6 is glycosylated with Gal-(β-1,3)-GalNAc oligosaccharides, which in turn alters the distribution and structure of MAP6 complexes within neurons. This is the first study to described MAP6 as a glycoprotein containing Gal-(β-1,3)-GalNAc oligosaccharides and to show that hyperglycosylation of MAP6 is strongly associated with the pathogenesis of PD. These findings provide potentially valuable information for developing new therapeutic targets for the treatment of PD as well as reliably prognostic biomarkers.
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Affiliation(s)
- Li Ma
- Department of Epidemiology, Dalian Medical University, Dalian 116044, China
| | - Jiaxin Song
- Department of Epidemiology, Dalian Medical University, Dalian 116044, China
| | - Xueying Sun
- Department of Epidemiology, Dalian Medical University, Dalian 116044, China
| | - Wenyong Ding
- Biochemistry and Molecular Biology Department of College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Kaiyang Fan
- Medical Administration Department, Affiliated Hospital of Jining Medical University, Jining 272000, China
| | - Minghua Qi
- Biochemistry and Molecular Biology Department of College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Yuefei Xu
- Biochemistry and Molecular Biology Department of College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Wenli Zhang
- Biochemistry and Molecular Biology Department of College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China
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20
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Miguel E, Vekovischeva O, Kuokkanen K, Vesajoki M, Paasikoski N, Kaskinoro J, Myllymäki M, Lainiola M, Janhunen SK, Hyytiä P, Linden A, Korpi ER. GABA B receptor positive allosteric modulators with different efficacies affect neuroadaptation to and self-administration of alcohol and cocaine. Addict Biol 2019; 24:1191-1203. [PMID: 30421860 DOI: 10.1111/adb.12688] [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: 06/25/2018] [Revised: 09/28/2018] [Accepted: 10/04/2018] [Indexed: 01/14/2023]
Abstract
Drugs of abuse induce widespread synaptic adaptations in the mesolimbic dopamine (DA) neurons. Such drug-induced neuroadaptations may constitute an initial cellular mechanism eventually leading to compulsive drug-seeking behavior. To evaluate the impact of GABAB receptors on addiction-related persistent neuroplasticity, we tested the ability of orthosteric agonist baclofen and two positive allosteric modulators (PAMs) of GABAB receptors to suppress neuroadaptations in the ventral tegmental area (VTA) and reward-related behaviors induced by ethanol and cocaine. A novel compound (S)-1-(5-fluoro-2,3-dihydro-1H-inden-2-yl)-4-methyl-6,7,8,9-tetrahydro-[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one (ORM-27669) was found to be a GABAB PAM of low efficacy as agonist, whereas the reference compound (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) had a different allosteric profile being a more potent PAM in the calcium-based assay and an agonist, coupled with potent PAM activity, in the [35 S] GTPγS binding assay in rat and human recombinant receptors. Using autoradiography, the high-efficacy rac-BHFF and the low-efficacy ORM-27669 potentiated the effects of baclofen on [35 S] GTPγS binding with identical brain regional distribution. Treatment of mice with baclofen, rac-BHFF, or ORM-27669 failed to induce glutamate receptor neuroplasticity in the VTA DA neurons. Pretreatment with rac-BHFF at non-sedative doses effectively reversed both ethanol- and cocaine-induced plasticity and attenuated cocaine i.v. self-administration and ethanol drinking. Pretreatment with ORM-27669 only reversed ethanol-induced neuroplasticity and attenuated ethanol drinking but had no effects on cocaine-induced neuroplasticity or self-administration. These findings encourage further investigation of GABAB receptor PAMs with different efficacies in addiction models to develop novel treatment strategies for drug addiction.
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Affiliation(s)
- Elena Miguel
- Department of Pharmacology, Faculty of MedicineUniversity of Helsinki Finland
| | - Olga Vekovischeva
- Department of Pharmacology, Faculty of MedicineUniversity of Helsinki Finland
| | - Katja Kuokkanen
- Research and Development, Orion Pharma, Orion Corporation Finland
| | - Marja Vesajoki
- Research and Development, Orion Pharma, Orion Corporation Finland
| | - Nelli Paasikoski
- Department of Pharmacology, Faculty of MedicineUniversity of Helsinki Finland
| | - Janne Kaskinoro
- Research and Development, Orion Pharma, Orion Corporation Finland
| | - Mikko Myllymäki
- Research and Development, Orion Pharma, Orion Corporation Finland
| | - Mira Lainiola
- Department of Pharmacology, Faculty of MedicineUniversity of Helsinki Finland
| | | | - Petri Hyytiä
- Department of Pharmacology, Faculty of MedicineUniversity of Helsinki Finland
| | - Anni‐Maija Linden
- Department of Pharmacology, Faculty of MedicineUniversity of Helsinki Finland
| | - Esa R. Korpi
- Department of Pharmacology, Faculty of MedicineUniversity of Helsinki Finland
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21
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Ethanol-induced conditioned place preference and aversion differentially alter plasticity in the bed nucleus of stria terminalis. Neuropsychopharmacology 2019; 44:1843-1854. [PMID: 30795004 PMCID: PMC6785142 DOI: 10.1038/s41386-019-0349-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 01/11/2023]
Abstract
Contextual cues associated with drugs of abuse, such as ethanol, can trigger craving and drug-seeking behavior. Pavlovian procedures, such as place conditioning, have been widely used to study the rewarding/aversive properties of drugs and the association between environmental cues and drug seeking. Previous research has shown that ethanol as an unconditioned stimulus can induce a strong conditioned place preference (CPP) or aversion (CPA) in rodents. However, the neural mechanisms underlying ethanol-induced reward and aversion have not been thoroughly investigated. The bed nucleus of the stria terminalis (BNST), an integral part of the extended amygdala, is engaged by both rewarding and aversive stimuli and plays a role in ethanol-seeking behavior. Here, we used ex-vivo slice physiology to probe learning-induced synaptic plasticity in the BNST following ethanol-induced CPP and CPA. Male DBA/2 J mice (2-3 months old) were conditioned using previously reported ethanol-induced CPP/CPA procedures. Ethanol-induced CPP was associated with increased neuronal excitability in the ventral BNST (vBNST). Conversely, ethanol-induced CPA resulted in a significant decrease in spontaneous glutamatergic transmission without alterations in GABAergic signaling. Ethanol-CPA also led to a significant increase in the paired-pulse ratio at excitatory synapses, suggestive of a decrease in presynaptic glutamate release. Collectively, these data demonstrate that the vBNST is involved in the modulation of contextual learning associated with both the rewarding and the aversive properties of ethanol in mice.
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22
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Kozek KA, Du Y, Sharma S, Prael FJ, Spitznagel BD, Kharade SV, Denton JS, Hopkins CR, Weaver CD. Discovery and Characterization of VU0529331, a Synthetic Small-Molecule Activator of Homomeric G Protein-Gated, Inwardly Rectifying, Potassium (GIRK) Channels. ACS Chem Neurosci 2019; 10:358-370. [PMID: 30136838 PMCID: PMC6528656 DOI: 10.1021/acschemneuro.8b00287] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
G protein-gated, inwardly rectifying, potassium (GIRK) channels are important regulators of cellular excitability throughout the body. GIRK channels are heterotetrameric and homotetrameric combinations of the Kir3.1-4 (GIRK1-4) subunits. Different subunit combinations are expressed throughout the central nervous system (CNS) and the periphery, and most of these combinations contain a GIRK1 subunit. For example, the predominance of GIRK channels in the CNS are composed of GIRK1 and GIRK2 subunits, while the GIRK channels in cardiac atrial myocytes are made up mostly of GIRK1 and GIRK4 subunits. Although the vast majority of GIRK channels contain a GIRK1 subunit, discrete populations of cells that express non-GIRK1-containing GIRK (non-GIRK1/X) channels do exist. For instance, dopaminergic neurons in the ventral tegmental area of the brain, associated with addiction and reward, do not express the GIRK1 subunit. Targeting these non-GIRK1/X channels with subunit-selective pharmacological probes could lead to important insights into how GIRK channels are involved in reward and addiction. Such insights may, in turn, reveal therapeutic opportunities for the treatment or prevention of addiction. Previously, our laboratory discovered small molecules that can specifically modulate the activity of GIRK1-containing GIRK channels. However, efforts to generate compounds active on non-GIRK1/X channels from these scaffolds have been unsuccessful. Recently, ivermectin was shown to modulate non-GIRK1/X channels, and historically, ivermectin is known to modulate a wide variety of neuronal channels and receptors. Further, ivermectin is a complex natural product, which makes it a challenging starting point for development of more selective, effective, and potent compounds. Thus, while ivermectin provides proof-of-concept as a non-GIRK1/X channel activator, it is of limited utility. Therefore, we sought to discover a synthetic small molecule that would serve as a starting point for the development of non-GIRK1/X channel modulators. To accomplish this, we used a high-throughput thallium flux assay to screen a 100 000-compound library in search of activators of homomeric GIRK2 channels. Using this approach, we discovered VU0529331, the first synthetic small molecule reported to activate non-GIRK1/X channels, to our knowledge. This discovery represents the first step toward developing potent and selective non-GIRK1/X channel probes. Such molecules will help elucidate the role of GIRK channels in addiction, potentially establishing a foundation for future development of therapies utilizing targeted GIRK channel modulation.
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Affiliation(s)
- Krystian A. Kozek
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
- vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
- vanderbilt Medical Scientist Training Program, Vanderbilt University, Nashville, Tennessee, USA
| | - Yu Du
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
- vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Swagat Sharma
- Department of Pharmaceutical Sciences, Center for Drug Discovery, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Francis J. Prael
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
- vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Brittany D. Spitznagel
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
- vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Sujay V. Kharade
- Department of Anesthesiology, Vanderbilt University, Nashville, Tennessee, USA
| | - Jerod S. Denton
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Anesthesiology, Vanderbilt University, Nashville, Tennessee, USA
| | - Corey R. Hopkins
- Department of Pharmaceutical Sciences, Center for Drug Discovery, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - C. David Weaver
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
- vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA
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23
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You C, Savarese A, Vandegrift BJ, He D, Pandey SC, Lasek AW, Brodie MS. Ethanol acts on KCNK13 potassium channels in the ventral tegmental area to increase firing rate and modulate binge-like drinking. Neuropharmacology 2019; 144:29-36. [PMID: 30332606 PMCID: PMC6286249 DOI: 10.1016/j.neuropharm.2018.10.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 09/27/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022]
Abstract
Alcohol excitation of the ventral tegmental area (VTA) is important in neurobiological processes related to the development of alcoholism. The ionotropic receptors on VTA neurons that mediate ethanol-induced excitation have not been identified. Quinidine blocks ethanol excitation of VTA neurons, and blockade of two-pore potassium channels is among the actions of quinidine. Therefore two-pore potassium channels in the VTA may be potential targets for the action of ethanol. Here, we explored whether ethanol activation of VTA neurons is mediated by the two-pore potassium channel KCNK13. Extracellular recordings of the response of VTA neurons to ethanol were performed in combination with knockdown of Kcnk13 using a short hairpin RNA (shRNA) in C57BL/6 J mice. Real-time PCR and immunohistochemistry were used to examine expression of this channel in the VTA. Finally, the role of KCNK13 in binge-like drinking was examined in the drinking in the dark test after knockdown of the channel. Kcnk13 expression in the VTA was increased by acute ethanol exposure. Ethanol-induced excitation of VTA neurons was selectively reduced by shRNA targeting Kcnk13. Importantly, knockdown of Kcnk13 in the VTA resulted in increased alcohol drinking. These results are consistent with the idea that ethanol stimulates VTA neurons at least in part by inhibiting KCNK13, a specific two-pore potassium channel, and that KCNK13 can control both VTA neuronal activity and binge drinking. KCNK13 is a novel alcohol-sensitive molecular target and may be amenable to the development of pharmacotherapies for alcoholism treatment.
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Affiliation(s)
- Chang You
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, 60612, USA; Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Antonia Savarese
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Bertha J Vandegrift
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, 60612, USA; Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Donghong He
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Subhash C Pandey
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA; Jesse Brown VA Medical Center, Chicago, IL, 60612, USA
| | - Amy W Lasek
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Mark S Brodie
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, 60612, USA; Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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24
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Sanchez-Roige S, Fontanillas P, Elson SL, Gray JC, de Wit H, Davis LK, MacKillop J, Palmer AA. Genome-wide association study of alcohol use disorder identification test (AUDIT) scores in 20 328 research participants of European ancestry. Addict Biol 2019; 24:121-131. [PMID: 29058377 PMCID: PMC6988186 DOI: 10.1111/adb.12574] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/11/2017] [Accepted: 09/25/2017] [Indexed: 12/26/2022]
Abstract
Genetic factors contribute to the risk for developing alcohol use disorder (AUD). In collaboration with the genetics company 23andMe, Inc., we performed a genome-wide association study of the alcohol use disorder identification test (AUDIT), an instrument designed to screen for alcohol misuse over the past year. Our final sample consisted of 20 328 research participants of European ancestry (55.3% females; mean age = 53.8, SD = 16.1) who reported ever using alcohol. Our results showed that the 'chip-heritability' of AUDIT score, when treated as a continuous phenotype, was 12%. No loci reached genome-wide significance. The gene ADH1C, which has been previously implicated in AUD, was among our most significant associations (4.4 × 10-7 ; rs141973904). We also detected a suggestive association on chromosome 1 (2.1 × 10-7 ; rs182344113) near the gene KCNJ9, which has been implicated in mouse models of high ethanol drinking. Using linkage disequilibrium score regression, we identified positive genetic correlations between AUDIT score, high alcohol consumption and cigarette smoking. We also observed an unexpected positive genetic correlation between AUDIT and educational attainment and additional unexpected negative correlations with body mass index/obesity and attention-deficit/hyperactivity disorder. We conclude that conducting a genetic study using responses to an online questionnaire in a population not ascertained for AUD may represent a cost-effective strategy for elucidating aspects of the etiology of AUD.
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Affiliation(s)
- Sandra Sanchez-Roige
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | | | | | | | - Joshua C. Gray
- Center for Deployment Psychology, Uniformed Services University, Bethesda, MD, 20814
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL 60637, USA
| | - Lea K. Davis
- Vanderbilt Genetics Institute; Division of Genetic Medicine, Department of Medicine, Vanderbilt University, Nashville, TN, USA
| | - James MacKillop
- Peter Boris Centre for Addictions Research, McMaster University/St. Joseph’s Healthcare Hamilton, Hamilton, ON L8N 3K7, Canada; Homewood Research Institute, Guelph, ON N1E 6K9, Canada
| | - Abraham A. Palmer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, USA
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25
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Knockdown of hypocretin attenuates extended access of cocaine self-administration in rats. Neuropsychopharmacology 2018; 43:2373-2382. [PMID: 29703996 PMCID: PMC6180106 DOI: 10.1038/s41386-018-0054-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 03/06/2018] [Accepted: 03/07/2018] [Indexed: 12/22/2022]
Abstract
The hypocretin/orexin (HCRT) neuropeptide system regulates feeding, arousal state, stress responses, and reward, especially under conditions of enhanced motivational relevance. In particular, HCRT neurotransmission facilitates drug-seeking behavior in circumstances that demand increased effort and/or motivation to take the drug. The present study used a shRNA-encoding adeno-associated viral vector to knockdown Hcrt expression throughout the dorsal hypothalamus in adult rats and determine the role of HCRT in cocaine self-administration. Chronic Hcrt silencing did not impact cocaine self-administration under short-access conditions, but robustly attenuated cocaine intake under extended access conditions, a model that mimics key features of compulsive cocaine taking. In addition, Hcrt silencing decreased motivation for both cocaine and a highly palatable food reward (i.e., sweetened condensed milk; SCM) under a progressive ratio schedule of reinforcement, but did not alter responding for SCM under a fixed ratio schedule. Importantly, Hcrt silencing did not affect food or water consumption, and had no consequence for general measures of arousal and stress reactivity. At the molecular level, chronic Hcrt knockdown reduced the number of neurons expressing dynorphin (DYN), and to a smaller extent melanin-concentrating hormone (MCH), in the dorsal hypothalamus. These original findings support the hypothesis that HCRT neurotransmission promotes operant responding for both drug and non-drug rewards, preferentially under conditions requiring a high degree of motivation. Furthermore, the current study provides compelling evidence for the involvement of the HCRT system in cocaine self-administration also under low-effort conditions in rats allowed extended access, possibly via functional interactions with DYN and MCH signaling.
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26
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Morel C, Montgomery S, Han MH. Nicotine and alcohol: the role of midbrain dopaminergic neurons in drug reinforcement. Eur J Neurosci 2018; 50:2180-2200. [PMID: 30251377 DOI: 10.1111/ejn.14160] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/31/2018] [Accepted: 08/20/2018] [Indexed: 12/11/2022]
Abstract
Nicotine and alcohol addiction are leading causes of preventable death worldwide and continue to constitute a huge socio-economic burden. Both nicotine and alcohol perturb the brain's mesocorticolimbic system. Dopamine (DA) neurons projecting from the ventral tegmental area (VTA) to multiple downstream structures, including the nucleus accumbens, prefrontal cortex, and amygdala, are highly involved in the maintenance of healthy brain function. VTA DA neurons play a crucial role in associative learning and reinforcement. Nicotine and alcohol usurp these functions, promoting reinforcement of drug taking behaviors. In this review, we will first describe how nicotine and alcohol individually affect VTA DA neurons by examining how drug exposure alters the heterogeneous VTA microcircuit and network-wide projections. We will also examine how coadministration or previous exposure to nicotine or alcohol may augment the reinforcing effects of the other. Additionally, this review briefly summarizes the role of VTA DA neurons in nicotine, alcohol, and their synergistic effects in reinforcement and also addresses the remaining questions related to the circuit-function specificity of the dopaminergic system in mediating nicotine/alcohol reinforcement and comorbidity.
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Affiliation(s)
- Carole Morel
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah Montgomery
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ming-Hu Han
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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27
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GIRK currents in VTA dopamine neurons control the sensitivity of mice to cocaine-induced locomotor sensitization. Proc Natl Acad Sci U S A 2018; 115:E9479-E9488. [PMID: 30228121 PMCID: PMC6176583 DOI: 10.1073/pnas.1807788115] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
GABABR-dependent activation of G protein-gated inwardly rectifying potassium channels (GIRK or KIR3) provides a well-known source of inhibition in the brain, but the details on how this important inhibitory pathway affects neural circuits are lacking. We used sorting nexin 27 (SNX27), an endosomal adaptor protein that associates with GIRK2c and GIRK3 subunits, to probe the role of GIRK channels in reward circuits. A conditional knockout of SNX27 in both substantia nigra pars compacta and ventral tegmental area (VTA) dopamine neurons leads to markedly smaller GABABR- and dopamine D2R-activated GIRK currents, as well as to suprasensitivity to cocaine-induced locomotor sensitization. Expression of the SNX27-insensitive GIRK2a subunit in SNX27-deficient VTA dopamine neurons restored GIRK currents and GABABR-dependent inhibition of spike firing, while also resetting the mouse's sensitivity to cocaine-dependent sensitization. These results establish a link between slow inhibition mediated by GIRK channels in VTA dopamine neurons and cocaine addiction, revealing a therapeutic target for treating addiction.
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28
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Kozell LB, Denmark DL, Walter NAR, Buck KJ. Distinct Roles for Two Chromosome 1 Loci in Ethanol Withdrawal, Consumption, and Conditioned Place Preference. Front Genet 2018; 9:323. [PMID: 30210527 PMCID: PMC6120100 DOI: 10.3389/fgene.2018.00323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/30/2018] [Indexed: 11/18/2022] Open
Abstract
We previously identified a region on chromosome 1 that harbor quantitative trait loci (QTLs) with large effects on alcohol withdrawal risk using both chronic and acute models in mice. Here, using newly created and existing QTL interval-specific congenic (ISC) models, we report the first evidence that this region harbors two distinct alcohol withdrawal QTLs (Alcw11and Alcw12), which underlie 13% and 3–6%, respectively, of the genetic variance in alcohol withdrawal severity measured using the handling-induced convulsion. Our results also precisely localize Alcw11 and Alcw12 to discreet chromosome regions (syntenic with human 1q23.1–23.3) that encompass a limited number of genes with validated genotype-dependent transcript expression and/or non-synonymous sequence variation that may underlie QTL phenotypic effects. ISC analyses also implicate Alcw11and Alcw12 in withdrawal-induced anxiety-like behavior, representing the first evidence for their broader roles in alcohol withdrawal beyond convulsions; but detect no evidence for Alcw12 involvement in ethanol conditioned place preference (CPP) or consumption. Our data point to high-quality candidates for Alcw12, including genes involved in mitochondrial respiration, spatial buffering, and neural plasticity, and to Kcnj9 as a high-quality candidate for Alcw11. Our studies are the first to show, using two null mutant models on different genetic backgrounds, that Kcnj9−/− mice demonstrate significantly less severe alcohol withdrawal than wildtype littermates using acute and repeated exposure paradigms. We also demonstrate that Kcnj9−/− voluntarily consume significantly more alcohol (20%, two-bottle choice) than wildtype littermates. Taken together with evidence implicating Kcnj9 in ethanol CPP, our results support a broad role for this locus in ethanol reward and withdrawal phenotypes. In summary, our results demonstrate two distinct chromosome 1 QTLs that significantly affect risk for ethanol withdrawal, and point to their distinct unique roles in alcohol reward phenotypes.
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Affiliation(s)
- Laura B Kozell
- Department of Behavioral Neuroscience, Portland Veterans Affairs Medical Center and School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Deaunne L Denmark
- Department of Behavioral Neuroscience, Portland Veterans Affairs Medical Center and School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Nicole A R Walter
- Department of Behavioral Neuroscience, Portland Veterans Affairs Medical Center and School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Kari J Buck
- Department of Behavioral Neuroscience, Portland Veterans Affairs Medical Center and School of Medicine, Oregon Health and Science University, Portland, OR, United States
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29
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Neurobiological Effects of Binge Drinking Help in Its Detection and Differential Diagnosis from Alcohol Dependence. DISEASE MARKERS 2018; 2018:5623683. [PMID: 30069273 PMCID: PMC6057287 DOI: 10.1155/2018/5623683] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/12/2018] [Indexed: 02/07/2023]
Abstract
The prevalence of binge drinking in the general population is 3-4 times higher than that of alcohol dependence. Neuroimaging studies show that binge drinking in adolescence impairs brain development and white matter integrity. Regions with reduced functional activity include the limbic system, ventral diencephalon, frontal lobe, and middle and inferior temporal lobes, whereas the right superior frontal and parietal lobes are typically hyperactivated. The observed activation of the frontoparietal areas might reflect the alternative memory system operating, whereas the reduced occipito-hippocampal response is associated with impaired visual and linguistic processing/learning. Some other findings from literature research include a decrease of N-acetylaspartate (NAA) in the frontal lobe and its increase in the parietal lobes, as well as the reduced components of event-related potentials, reflecting deficit in attention, working memory, inhibition, and executive functioning. Animal studies show that even a single day of binge drinking results in a neurodegeneration and reactive gliosis in the limbic cortex as well as in gene expression dysregulation and histone acetylation. Another biological evidence on binge drinking effect include inflammatory response, oxidative stress, formation of toxic ceramides, activation of caspase 3, and secretion of corticoliberin. Some of the binge drinking-induced cognitive abnormalities can be reversible after three weeks of abstinence. Although binge drinkers have a similar pattern of neuropsychological deficits with chronic alcohol consumers (mainly memory deficits), binge drinkers have prominent impairment of inhibitory control, which may be a marker of binge pattern of alcohol drinking. The optimal therapeutic strategies should target the inhibitory control processes to facilitate discontinuation of alcohol consumption and to block its possible progression to the alcohol dependence syndrome.
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30
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Regulatory Effect of General Anesthetics on Activity of Potassium Channels. Neurosci Bull 2018; 34:887-900. [PMID: 29948841 PMCID: PMC6129254 DOI: 10.1007/s12264-018-0239-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/12/2018] [Indexed: 12/19/2022] Open
Abstract
General anesthesia is an unconscious state induced by anesthetics for surgery. The molecular targets and cellular mechanisms of general anesthetics in the mammalian nervous system have been investigated during past decades. In recent years, K+ channels have been identified as important targets of both volatile and intravenous anesthetics. This review covers achievements that have been made both on the regulatory effect of general anesthetics on the activity of K+ channels and their underlying mechanisms. Advances in research on the modulation of K+ channels by general anesthetics are summarized and categorized according to four large K+ channel families based on their amino-acid sequence homology. In addition, research achievements on the roles of K+ channels in general anesthesia in vivo, especially with regard to studies using mice with K+ channel knockout, are particularly emphasized.
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31
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You C, Vandegrift B, Brodie MS. Ethanol actions on the ventral tegmental area: novel potential targets on reward pathway neurons. Psychopharmacology (Berl) 2018; 235:1711-1726. [PMID: 29549390 PMCID: PMC5949141 DOI: 10.1007/s00213-018-4875-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/06/2018] [Indexed: 12/14/2022]
Abstract
The ventral tegmental area (VTA) evaluates salience of environmental stimuli and provides dopaminergic innervation to many brain areas affected by acute and chronic ethanol exposure. While primarily associated with rewarding and reinforcing stimuli, recent evidence indicates a role for the VTA in aversion as well. Ethanol actions in the VTA may trigger neuroadaptation resulting in reduction of the aversive responses to alcohol and a relative increase in the rewarding responses. In searching for effective pharmacotherapies for the treatment of alcohol abuse and alcoholism, recognition of this imbalance may reveal novel strategies. In addition to conventional receptor/ion channel pharmacotherapies, epigenetic factors that control neuroadaptation to chronic ethanol treatment can be targeted as an avenue for development of therapeutic approaches to restore the balance. Furthermore, when exploring therapies to address reward/aversion imbalance in the action of alcohol in the VTA, sex differences have to be taken into account to ensure effective treatment for both men and women. These principles apply to a VTA-centric approach to therapies, but should hold true when thinking about the overall approach in the development of neuroactive drugs to treat alcohol use disorders. Although the functions of the VTA itself are complex, it is a useful model system to evaluate the reward/aversion imbalance that occurs with ethanol exposure and could be used to provide new leads in the efforts to develop novel drugs to treat alcoholism.
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Affiliation(s)
- Chang You
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Bertha Vandegrift
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Mark S Brodie
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 S. Wolcott Ave, Room E-202, M/C 901, Chicago, IL, 60612, USA.
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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32
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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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33
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Abrahao KP, Salinas AG, Lovinger DM. Alcohol and the Brain: Neuronal Molecular Targets, Synapses, and Circuits. Neuron 2017; 96:1223-1238. [PMID: 29268093 PMCID: PMC6566861 DOI: 10.1016/j.neuron.2017.10.032] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/30/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
Ethanol is one of the most commonly abused drugs. Although environmental and genetic factors contribute to the etiology of alcohol use disorders, it is ethanol's actions in the brain that explain (1) acute ethanol-related behavioral changes, such as stimulant followed by depressant effects, and (2) chronic changes in behavior, including escalated use, tolerance, compulsive seeking, and dependence. Our knowledge of ethanol use and abuse thus relies on understanding its effects on the brain. Scientists have employed both bottom-up and top-down approaches, building from molecular targets to behavioral analyses and vice versa, respectively. This review highlights current progress in the field, focusing on recent and emerging molecular, cellular, and circuit effects of the drug that impact ethanol-related behaviors. The focus of the field is now on pinpointing which molecular effects in specific neurons within a brain region contribute to behavioral changes across the course of acute and chronic ethanol exposure.
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Affiliation(s)
- Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - Armando G Salinas
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA.
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34
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Rifkin RA, Moss SJ, Slesinger PA. G Protein-Gated Potassium Channels: A Link to Drug Addiction. Trends Pharmacol Sci 2017; 38:378-392. [PMID: 28188005 DOI: 10.1016/j.tips.2017.01.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/08/2017] [Accepted: 01/10/2017] [Indexed: 11/29/2022]
Abstract
G protein-gated inwardly rectifying potassium (GIRK) channels are regulators of neuronal excitability in the brain. Knockout mice lacking GIRK channels display altered behavioral responses to multiple addictive drugs, implicating GIRK channels in addictive behaviors. Here, we review the effects of GIRK subunit deletions on the behavioral response to psychostimulants, such as cocaine and methamphetamine. Additionally, exposure of mice to psychostimulants produces alterations in the surface expression of GIRK channels in multiple types of neurons within the reward system of the brain. Thus, we compare the subcellular mechanisms by which drug exposure appears to alter GIRK expression in multiple cell types and provide an outlook on future studies examining the role of GIRK channels in addiction. A greater understanding of how GIRK channels are regulated by addictive drugs may enable the development of therapies to prevent or treat drug abuse.
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Affiliation(s)
- Robert A Rifkin
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Stephen J Moss
- Dept of Neuroscience, Tufts University School of Medicine, Boston, MA 02155, USA; Dept of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK
| | - Paul A Slesinger
- Fishberg 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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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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A Role for the GIRK3 Subunit in Methamphetamine-Induced Attenuation of GABAB Receptor-Activated GIRK Currents in VTA Dopamine Neurons. J Neurosci 2016; 36:3106-14. [PMID: 26985023 DOI: 10.1523/jneurosci.1327-15.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
UNLABELLED Repeated exposure to psychostimulants induces locomotor sensitization and leads to persistent changes in the circuitry of the mesocorticolimbic dopamine (DA) system. G-protein-gated inwardly rectifying potassium (GIRK; also known as Kir3) channels mediate a slow IPSC and control the excitability of DA neurons. Repeated 5 d exposure to psychostimulants decreases the size of the GABAB receptor (GABABR)-activated GIRK currents (IBaclofen) in ventral tegmental area (VTA) DA neurons of mice, but the mechanism underlying this plasticity is poorly understood. Here, we show that methamphetamine-dependent attenuation of GABABR-GIRK currents in VTA DA neurons required activation of both D1R-like and D2R-like receptors. The methamphetamine-dependent decrease in GABABR-GIRK currents in VTA DA neurons did not depend on a mechanism of dephosphorylation of the GABAB R2 subunit found previously for other neurons in the reward pathway. Rather, the presence of the GIRK3 subunit appeared critical for the methamphetamine-dependent decrease of GABABR-GIRK current in VTA DA neurons. Together, these results highlight different regulatory mechanisms in the learning-evoked changes that occur in the VTA with repeated exposure to psychostimulants. SIGNIFICANCE STATEMENT Exposure to addictive drugs such as psychostimulants produces persistent adaptations in inhibitory circuits within the mesolimbic dopamine system, suggesting that addictive behaviors are encoded by changes in the reward neural circuitry. One form of neuroadaptation that occurs with repeated exposure to psychostimulants is a decrease in slow inhibition, mediated by a GABAB receptor and a potassium channel. Here, we examine the subcellular mechanism that links psychostimulant exposure with changes in slow inhibition and reveal that one type of potassium channel subunit is important for mediating the effect of repeated psychostimulant exposure. Dissecting out the components of drug-dependent plasticity and uncovering novel protein targets in the reward circuit may lead to the development of new therapeutics for treating addiction.
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Tipps ME, Raybuck JD, Kozell LB, Lattal KM, Buck KJ. G Protein-Gated Inwardly Rectifying Potassium Channel Subunit 3 Knock-Out Mice Show Enhanced Ethanol Reward. Alcohol Clin Exp Res 2016; 40:857-64. [PMID: 27012303 PMCID: PMC4820358 DOI: 10.1111/acer.13012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 01/07/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND G protein-gated inwardly rectifying potassium (GIRK) channels contribute to the effects of a number of drugs of abuse, including ethanol. However, the roles of individual subunits in the rewarding effects of ethanol are poorly understood. METHODS We compare conditioned place preference (CPP) in GIRK3 subunit knock-out (GIRK3(-/-)), heterozygote (GIRK3(+/-)), and wild-type (WT) mice. In addition, the development of locomotor tolerance/sensitization and the effects of EtOH intoxication on associative learning (fear conditioning) are also assessed. RESULTS Our data show significant EtOH CPP in GIRK3(-/-) and GIRK3(+/-) mice, but not in the WT littermates. In addition, we demonstrate that these effects are not due to differences in EtOH metabolism, the development of EtOH tolerance/sensitivity, or associative learning abilities. While there were no consistent genotype differences in the fear conditioning assay, our data do show a selective sensitization of the impairing effects of EtOH intoxication on contextual learning, but no effect on cued learning. CONCLUSIONS These findings suggest that GIRK3 plays a role in EtOH reward. Furthermore, the selectivity of this effect suggests that GIRK channels could be an effective therapeutic target for the prevention and/or treatment of alcoholism.
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Affiliation(s)
- Megan E. Tipps
- Portland Alcohol Research Center; Portland VA Medical Center, 3710 SW US Veterans Hospital Rd., Bldg 104, Portland, OR 97239-3098, USA
- Department of Behavioral Neuroscience; Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239-3098, USA
| | - Jonathan D. Raybuck
- Department of Behavioral Neuroscience; Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239-3098, USA
| | - Laura B. Kozell
- Portland Alcohol Research Center; Portland VA Medical Center, 3710 SW US Veterans Hospital Rd., Bldg 104, Portland, OR 97239-3098, USA
- Department of Behavioral Neuroscience; Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239-3098, USA
| | - K. Matthew Lattal
- Department of Behavioral Neuroscience; Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239-3098, USA
| | - Kari J. Buck
- Portland Alcohol Research Center; Portland VA Medical Center, 3710 SW US Veterans Hospital Rd., Bldg 104, Portland, OR 97239-3098, USA
- Department of Behavioral Neuroscience; Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239-3098, USA
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Mayfield J, Arends MA, Harris RA, Blednov YA. Genes and Alcohol Consumption: Studies with Mutant Mice. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 126:293-355. [PMID: 27055617 PMCID: PMC5302130 DOI: 10.1016/bs.irn.2016.02.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test.
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Affiliation(s)
- J Mayfield
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, United States
| | - M A Arends
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, United States
| | - R A Harris
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, United States.
| | - Y A Blednov
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, United States
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Gold MS, Badgaiyan RD, Blum K. A Shared Molecular and Genetic Basis for Food and Drug Addiction: Overcoming Hypodopaminergic Trait/State by Incorporating Dopamine Agonistic Therapy in Psychiatry. Psychiatr Clin North Am 2015; 38:419-62. [PMID: 26300032 DOI: 10.1016/j.psc.2015.05.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This article focuses on the shared molecular and neurogenetics of food and drug addiction tied to the understanding of reward deficiency syndrome. Reward deficiency syndrome describes a hypodopaminergic trait/state that provides a rationale for commonality in approaches for treating long-term reduced dopamine function across the reward brain regions. The identification of the role of DNA polymorphic associations with reward circuitry has resulted in new understanding of all addictive behaviors.
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Affiliation(s)
- Mark S Gold
- Departments of Psychiatry & Behavioral Sciences, Keck School of Medicine, University of Southern California, 1975 Zonal Avenue, Los Angeles, CA 90033, USA; Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Rivermend Health Scientific Advisory Board, 2300 Windy Ridge Parkway South East, Suite 210S, Atlanta, GA 30339, USA; Drug Enforcement Administration (DEA) Educational Foundation, Washington, DC, USA.
| | - Rajendra D Badgaiyan
- Laboratory of Advanced Radiochemistry and Molecular and Functioning Imaging, Department of Psychiatry, College of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Kenneth Blum
- Department of Psychiatry, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL, USA; Department of Psychiatry, Center for Clinical & Translational Science, Community Mental Health Institute, University of Vermont College of Medicine, University of Vermont, Burlington, VT, USA; Division of Applied Clinical Research, Dominion Diagnostics, LLC, 211 Circuit Drive, North Kingstown, RI 02852, USA; Rivermend Health Scientific Advisory Board, Atlanta, GA, USA
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Mayfield J, Blednov YA, Harris RA. Behavioral and Genetic Evidence for GIRK Channels in the CNS: Role in Physiology, Pathophysiology, and Drug Addiction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 123:279-313. [PMID: 26422988 DOI: 10.1016/bs.irn.2015.05.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G protein-coupled inwardly rectifying potassium (GIRK) channels are widely expressed throughout the brain and mediate the inhibitory effects of many neurotransmitters. As a result, these channels are important for normal CNS function and have also been implicated in Down syndrome, Parkinson's disease, psychiatric disorders, epilepsy, and drug addiction. Knockout mouse models have provided extensive insight into the significance of GIRK channels under these conditions. This review examines the behavioral and genetic evidence from animal models and genetic association studies in humans linking GIRK channels with CNS disorders. We further explore the possibility that subunit-selective modulators and other advanced research tools will be instrumental in establishing the role of individual GIRK subunits in drug addiction and other relevant CNS diseases and in potentially advancing treatment options for these disorders.
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Affiliation(s)
- Jody Mayfield
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA.
| | - Yuri A Blednov
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA
| | - R Adron Harris
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, Texas, USA
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