title: Differential potassium channel gene regulation in BXD mice reveals novel targets for pharmacogenetic therapies to reduce heavy alcohol drinking.
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.
authors.affiliation: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Rinker
authors.affiliation: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: Diana B
authors.initials: DB
authors.lastname: Fulmer
authors.affiliation: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: Heather
authors.initials: H
authors.lastname: Trantham-Davidson
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
authors.forename: Maren L
authors.initials: ML
authors.lastname: Smith
authors.affiliation: Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Williams
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Lopez
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Randall
authors.affiliation: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: L Judson
authors.initials: LJ
authors.lastname: Chandler
authors.affiliation: Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Miles
authors.affiliation: Department of Psychiatry & Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC 29425, USA; Ralph H. Johnson VA Medical Center, Charleston, SC 29425, USA.
authors.forename: Howard C
authors.initials: HC
authors.lastname: Becker
authors.affiliation: Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Psychiatry & Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC 29425, USA. Electronic address: mulholl@musc.edu.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Mulholland
mesh_terms: D000428:Alcohol Drinking / Q000235:genetics* / Q000378:metabolism / Q000517:prevention & control*; D000818:Animals; D002219:Carbamates / Q000627:therapeutic use; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D049990:Membrane Transport Modulators / Q000627:therapeutic use; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D010597:Pharmacogenetics / Q000379:methods*; D010655:Phenylenediamines / Q000627:therapeutic use; D015221:Potassium Channels / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D002219:Carbamates; D049990:Membrane Transport Modulators; D010655:Phenylenediamines; D015221:Potassium Channels; C101866:ezogabine
keywords: Alcohol use disorder; BXD mice; K(+) channels; Nucleus accumbens; Pharmacogenetics; Prefrontal cortex