Glutathione S‐Transferase 8‐8 Expression Is Lower in Alcohol‐Preferring Than in Alcohol‐Nonpreferring Rats

Abstract

Objective-A primary focus of alcohol research is to provide novel targets for alcohol treatment by identifying genes that predispose individuals to drink alcohol. Animal models of alcoholism developed by selective breeding are invaluable tools to elucidate both the genetic nature and the underlying biological mechanisms that contribute to alcohol dependence. These selected lines (high alcohol preferring and low alcohol preferring) display phenotypic and genetic differences that can be studied to further our understanding of alcohol preference and related genetic traits. By combining molecular techniques, genetic and physiological factors that underlie the cause of alcoholism can be identified.Methods-Total gene expression analysis was used to identify genes that are differentially expressed in specific brain regions between alcohol-naïve, inbred alcohol-preferring (iP) andnonpreferring (iNP) rats. Quantitative reverse transcriptase-polymerase chain reaction, in situ hybridization, Western blot, and sequence analysis were used to further characterize rat glutathione S-transferase .Results-Lower expression of rGST 8-8 mRNA was observed in discrete brain regions of iP compared with iNP animals, and these expression differences were confirmed. To determine additional expression patterns of rGST 8-8, we used in situ hybridization. Rat GST 8-8 was highly expressed in hippocampus, the choroid plexus of the dorsal third ventricle and the lateral ventricle, and ependymal cells along the dorsal third ventricle and the third ventricle. Western blot analysis showed that rGST 8-8 protein levels were lower in the hippocampus and the amygdala of iP compared with iNP. A silent single-nucleotide polymorphism in the coding region and three single-nucleotide polymorphisms in the 3′-UTR were identified in the rGST 8-8 cDNA.Conclusion-There is regional variation of rGST 8-8 expression in the brain, at both the mRNA and protein level, and the iP strain has lower innate rGST 8-8 levels than the iNP strain in discrete brain regions. Alcoholism is a complex disorder influenced by both environmental and genetic factors. The genetic contribution to alcoholism likely results from the action of multiple, possibly interacting genes. Identification of the genes that influence alcohol drinking is an important area of research in the alcohol field and has involved several strategies, including the use of human studies and the development of genetic animal models of alcoholism. Sequencing of the rat genome has revealed that most human genes have counterparts in the rat (Rat Genome Sequencing Project Consortium, 2004). Thus, identification of interesting genes in a rat model can provide candidate genes for specific diseases that can be evaluated further in humans. HHS Public AccessAnimal models of alcohol preference have been used to identify both chromosomal loci and candidate genes that may influence alcohol-drinking behavior Foroud et al., 2000;Grisel et al., 2002;Liang et al., 2003). The alcohol-preferring (P) andnonpreferring (NP) ...

Glutathione S-transferases Detoxify Endogenous and Exogenous Toxic Agents- Minireview

“…The transferases can reduce cholesterylhydroperoxides [20], fatty acid hydroperoxides, (S)-9-hydroproxy-10, 12-octodecadieonic acid and (S)-13-hydroperoxy-9, 11-octadecadieonic acid [21]. That the lipid peroxidation end products like 2-alkenals acrolein, crotonaldedyde and 4-hydroxy-2-alkenals are conjugate with GSH by GSTs [21].…”

Glutathione S Transferases: Biochemistry, Polymorphism and Role in Colorectal Carcinogenesis

“…The transferases can also reduce cholesteryl hydroperoxides [21] and fatty acid hydroperoxides, including (S)-9-hydroperoxy-10,12-octadecadieonic acid and (S)-13-hydroperoxy-9,11-octadecadieonic acid [20]. Among the end-products of lipid peroxidation, GSTs conjugate GSH with the 2-alkenals acrolein and crotonaldehyde, as well as 4-hydroxy-2-alkenals of between 6 and 15 carbon atoms in length [22]. Further, GSTs catalyze the conjugation of cholesterol-5,6-oxide,epoxyeicosatrienoic acid, and 9,10-epoxystearic acid with GSH indicating its role in cellular protection against a range of harmful electrophiles of oxidative stress [2].…”

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“…All equipment used to obtain tissue was treated with RNaseZap (Ambion Inc., Austin, TX) to prevent RNA degradation. The nucleus accumbens, caudate putamen, frontal cortex, hippocampus, and amygdala were dissected as described previously (Liang et al, 2004).…”