Altered gene expression in frontal cortex and midbrain of 3,4-methylenedioxymethamphetamine (MDMA) treated mice: differential regulation of GABA transporter subtypes.
Changes in gene expression were examined in the brain of mice treated with a drug of abuse, 3,4-methylenedioxymethamphetamine (MDMA, also called Ecstasy). Frontal cortex and midbrain mRNA, analyzed by differential display polymerase chain reaction (DD-PCR) method, showed an altered expression of several cDNAs, 11 of which were isolated, cloned and sequenced. The sequence of one MDMA-induced mRNA corresponds (99.3%) to the mouse gamma-amino butyric acid (GABA) transporter 1 (mGAT1). The established involvement of GABA neurotransmission in the activity of several abused drugs prompted us to focus herein on MDMA effect on the GABA transporter gene family. Semi-quantitative PCR analysis with primers selective to the reported mGAT1 sequence confirmed that MDMA treatment increased mGAT1 expression. Time-course study of the expression of the three GABA transporter subtypes showed that MDMA induced a differential temporal activation of mGAT1 and mGAT4, but had no effect on mGAT2. Quantitative real-time PCR further proved the increased expression of mGAT1 and mGAT4 upon MDMA treatment. Western immunoblotting with anti-GAT1 antibodies showed that MDMA also increased GAT1 protein levels, suggesting that neurotransmission of GABA was altered. MDMA effect was also verified in serotonin transporter knockout (-/-) mice that are insensitive behaviorally to MDMA; the drug did not increase GAT1 protein level in these mutants. In mice, tiagabine and NO-711, inhibitors of GABA transporters, restrained MDMA-induced acute toxicity and death. These results should facilitate novel approaches to prevent deleterious effects, including fatality, induced by MDMA and similar abused psychostimulants.
Peng
Weiping
W
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
Simantov
Rabi
R
D000818:Animals; D002352:Carrier Proteins / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D003001:Cloning, Molecular; D005625:Frontal Lobe / Q000187:drug effects*; D050485:GABA Plasma Membrane Transport Proteins; D005786:Gene Expression Regulation / Q000187:drug effects*; D008297:Male; D008565:Membrane Proteins / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D026901:Membrane Transport Proteins; D008636:Mesencephalon / Q000187:drug effects*; D051379:Mice; D018345:Mice, Knockout / Q000378:metabolism; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology* / Q000633:toxicity; D009419:Nerve Tissue Proteins / Q000187:drug effects; D009557:Nipecotic Acids / Q000494:pharmacology; D027361:Organic Anion Transporters; D010091:Oximes / Q000494:pharmacology; D020033:Protein Isoforms / Q000187:drug effects; D012333:RNA, Messenger / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012701:Serotonin / Q000235:genetics / Q000378:metabolism; D000078308:Tiagabine; D005680:gamma-Aminobutyric Acid / Q000187:drug effects
D002352:Carrier Proteins; D050485:GABA Plasma Membrane Transport Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D009557:Nipecotic Acids; D027361:Organic Anion Transporters; D010091:Oximes; D020033:Protein Isoforms; D012333:RNA, Messenger; C493414:Slc6a1 protein, mouse; C078793:NNC 711; D012701:Serotonin; D005680:gamma-Aminobutyric Acid; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D000078308:Tiagabine