title: Hippocampal betaine/GABA transporter mRNA expression is not regulated by inflammation or dehydration post-status epilepticus.
abstract: Seizure activity can alter GABA transporter and osmoprotective gene expression, which may be involved in the pathogenesis of epilepsy. However, the response of the betaine/GABA transporter (BGT1) is unknown. The goal of the present study was to compare the expression of BGT1 mRNA to that of other osmoprotective genes and GABA transporters following status epilepticus (SE). The possible contributory role of dehydration and inflammation was also investigated because both have been shown to be involved in the regulation of GABA transporter and/or osmoprotective gene expression. BGT1 mRNA was increased 24 h post-SE, as were osmoprotective genes. BGT1 was decreased 72 h and 4 weeks post-SE, as were the GABA transporter mRNAs. The mRNA values for osmoprotective genes following 24-h water withdrawal were significantly lower than the values obtained 24 h post-SE despite similarities in their plasma osmolality values. BGT1 mRNA was not altered by lipopolysaccharide-induced inflammation while the transcription factor tonicity-responsive enhancer binding protein and the GABA transporters 1 and 3 were. These results suggest that neither plasma osmolality nor inflammation fully account for the changes seen in BGT1 mRNA expression post-SE. However, it is evident that BGT1 mRNA expression is altered by SE and displays a temporal pattern with similarities to both GABA and osmolyte transporters. Further investigation of BGT1 regulation in the brain is warranted.
authors.affiliation: Anticonvulsant Drug Development Program, Department of Pharmacology Toxicology, University of Utah, Salt Lake City, Utah 84108, USA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Rowley
authors.forename: Misty D
authors.initials: MD
authors.lastname: Smith
authors.forename: John G
authors.initials: JG
authors.lastname: Lamb
authors.forename: Arne
authors.initials: A
authors.lastname: Schousboe
authors.forename: H Steve
authors.initials: HS
authors.lastname: White
mesh_terms: D000818:Animals; D001622:Betaine / Q000378:metabolism*; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics*; D003681:Dehydration / Q000209:etiology / Q000235:genetics* / Q000378:metabolism; D050485:GABA Plasma Membrane Transport Proteins / Q000096:biosynthesis; D005786:Gene Expression Regulation; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D018836:Inflammation Mediators / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000096:biosynthesis*; D013226:Status Epilepticus / Q000150:complications / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D050485:GABA Plasma Membrane Transport Proteins; D018836:Inflammation Mediators; D012333:RNA, Messenger; C072207:betaine plasma membrane transport proteins; D001622:Betaine