title: Regulation of CART peptide expression by CREB in the rat nucleus accumbens in vivo.
abstract: Production of mRNA from the cocaine- and amphetamine-regulated transcript (CART) gene is regulated by cocaine and other drugs of abuse in the nucleus accumbens (NAc), a brain reward region. Current hypotheses postulate that CART peptides there oppose the rewarding actions of cocaine by opposing the effects of dopaminergic transmission. Since over expression of CREB was shown to decrease cocaine-mediated reward, we hypothesized that CART could be a target gene for CREB in the NAc and that over expression of CREB would increase CART peptide levels. Transcription factor (TF) binding to DNA is influenced by sequences adjacent to consensus TF binding sites and other factors. We thus examined CREB binding to a 27mer oligonucleotide containing the CRE sequence from the CART gene proximal promoter. Using electrophoretic mobility shift assays and TF-antibody super shift assays, CREB was found to bind to the CRE sequence from the CART promoter. To test if over expression of CREB in the NAc affected CART peptide levels, Herpes simplex virus-1 vectors over expressing CREB (HSV-CREB), or a vector that expressed LacZ (HSV-LacZ) as a control, were injected into the NAc of rats. Western blotting and in situ hybridization showed that HSV-CREB injections increased CART mRNA and peptide levels. Injections of a dominant negative CREB mutant (HSV-mCREB) did not alter either CART mRNA or peptide levels. The finding that CREB can regulate the levels of CART mRNA and peptides in vivo in the NAc supports a role for CART peptides in psychostimulant-induced reward and reinforcement.
authors.affiliation: Division of Neuroscience, Yerkes National Primate Research Center of Emory University, Yerkes Primate Center, 954 Gatewood Rd NE, Atlanta, GA 30329, USA. grogge2002@yahoo.com
authors.forename: George A
authors.initials: GA
authors.lastname: Rogge
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Jones
authors.forename: Thomas
authors.initials: T
authors.lastname: Green
authors.forename: Eric
authors.initials: E
authors.lastname: Nestler
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kuhar
mesh_terms: D000818:Animals; D001483:Base Sequence / Q000235:genetics; D001665:Binding Sites / Q000235:genetics; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D005822:Genetic Vectors / Q000235:genetics; D018259:Herpesvirus 1, Human / Q000235:genetics; D007763:Lac Operon / Q000235:genetics; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
chemical_list: D000697:Central Nervous System Stimulants; D017362:Cyclic AMP Response Element-Binding Protein; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein