RT Journal Article
SR Electronic
T1 Fluoxetine and Cocaine Induce the Epigenetic Factors MeCP2 and MBD1 in Adult Rat Brain
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 487
OP 492
DO 10.1124/mol.106.022301
VO 70
IS 2
A1 Cassel, Suzanne
A1 Carouge, Delphine
A1 Gensburger, Claire
A1 Anglard, Patrick
A1 Burgun, Claude
A1 Dietrich, Jean-Bernard
A1 Aunis, Dominique
A1 Zwiller, Jean
YR 2006
UL http://molpharm.aspetjournals.org/content/70/2/487.abstract
AB Once bound to methylated CpG sites, methyl-CpG-binding protein 2 (MeCP2) is thought to silence transcription of downstream genes by recruiting a histone deacetylase (HDAC). Mutations within the MeCP2 gene have been found to cause Rett syndrome, a disorder of arrested neuronal development. Using immunohistochemistry, we found that Mecp2, as well as the methyl-CpG-binding protein MBD1, were significantly induced in normal adult rat brain after repeated injections of fluoxetine or cocaine for 10 days (one injection per day). Mecp2 was not induced by repeated injections of 1-(2-bis(4-fluorphenyl)-methoxy)-ethyl)-4-(3-phenyl-propyl)piperazine (GBR-12909) or nortriptyline. Together, the data indicate that the serotonergic system is predominantly involved. Using real-time reverse transcription-polymerase chain reaction experiments, MBD1 mRNA and both Mecp2_e1 and Mecp2_e2 transcripts were found to be induced by fluoxetine. Induction of the methylbinding proteins was accompanied with enhanced HDAC2 labeling intensity and mRNA synthesis in response to fluoxetine. In tandem, acetylated forms of histone H3 were found to be decreased. The effect was characterized in three serotonin projection areas, the caudate-putamen, the frontal cortex, and the dentate gyrus subregion of hippocampus. Our data highlight GABAergic neurons as major target cells expressing Mecp2 in response to the serotonin-elevating agents and suggest that serotonin signaling enhances gene silencing in postmitotic neurons.