title: Role of Growth Arrest and DNA Damage-Inducible, Beta in Alcohol-Drinking Behaviors.
abstract: BACKGROUND
  The contribution of epigenetic factors, such as histone acetylation and DNA methylation, to the regulation of alcohol-drinking behavior has been increasingly recognized over the last several years. GADD45b is a protein demonstrated to be involved in DNA demethylation at neurotrophic factor gene promoters, including at brain-derived neurotrophic factor (Bdnf) which has been highly implicated in alcohol-drinking behavior.
  
  
  METHODS
  DNA methyltransferase-1 (Dnmt1), 3a, and 3b, and Gadd45a, b, and g mRNA were measured in the nucleus accumbens (NAc) and ventral tegmental areas of high ethanol (EtOH) consuming C57BL/6J (C57) and low alcohol consuming DBA/2J (DBA) mice using quantitative reverse transcriptase polymerase chain reaction (PCR). In the NAc, GADD45b protein was measured via immunohistochemistry and Bdnf9a mRNA using in situ PCR. Bdnf9a promoter histone H3 acetylated at lysines 9 and 14 (H3K9,K14ac) was measured using chromatin immunoprecipitation, and 5-methylcytosine (5MC) and 5-hydroxymethylcytosine (5HMC) using methylated DNA immunoprecipitation. Alcohol-drinking behavior was evaluated in Gadd45b haplodeficient (+/-) and null mice (-/-) utilizing drinking-in-the-dark (DID) and 2-bottle free-choice paradigms.
  
  
  RESULTS
  C57 mice had lower levels of Gadd45b and g mRNA and GADD45b protein in the NAc relative to the DBA strain. C57 mice had lower NAc shell Bdnf9a mRNA levels, Bdnf9a promoter H3K9,K14ac, and higher Bdnf9a promoter 5HMC and 5MC. Acute EtOH increased GADD45b protein, Bdnf9a mRNA, and histone acetylation and decreased 5HMC in C57 mice. Gadd45b +/- mice displayed higher drinking behavior relative to wild-type littermates in both DID and 2-bottle free-choice paradigms.
  
  
  CONCLUSIONS
  These data indicate the importance of the DNA demethylation pathway and its interactions with histone posttranslational modifications in alcohol-drinking behavior. Further, we suggest that lower DNA demethylation protein GADD45b levels may affect Bdnf expression possibly leading to altered alcohol-drinking behavior.
authors: Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.|Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.
authors: David P
authors: DP
authors: Gavin
authors: Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.|Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.
authors: Handojo
authors: H
authors: Kusumo
authors: Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.|Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.
authors: Huaibo
authors: H
authors: Zhang
authors: Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.
authors: Alessandro
authors: A
authors: Guidotti
authors: Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.|Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.
authors: Subhash C
authors: SC
authors: Pandey
mesh_terms: D000428:Alcohol Drinking / Q000503:physiopathology*; D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis / Q000502:physiology*; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism / Q000502:physiology; D044127:Epigenesis, Genetic; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D018345:Mice, Knockout; D009714:Nucleus Accumbens / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000097642:GADD45 Proteins
chemical_list: D000943:Antigens, Differentiation; D019208:Brain-Derived Neurotrophic Factor; C490125:Gadd45b protein, mouse; D000097642:GADD45 Proteins
keywords: Alcoholism; Bdnf; DNA Methylation; GADD45b; Histone; Nucleus Accumbens