Liang Tiebing, Habegger Kirk, Spence John P, Foroud Tatiana, Ellison Julie A, Lumeng Lawrence, Li Ting-Kai, Carr Lucinda G
Department of Medicine, Indiana University School of Medicine, 975 W. Walnut Street, Indianapolis, IN 46202, USA.
Alcohol Clin Exp Res. 2004 Nov;28(11):1622-8. doi: 10.1097/01.alc.0000145686.79141.57.
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.
Total gene expression analysis was used to identify genes that are differentially expressed in specific brain regions between alcohol-naive, inbred alcohol-preferring (iP) and -nonpreferring (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 8-8 (rGST 8-8).
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.
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.
酒精研究的一个主要重点是通过识别使个体易饮酒的基因，为酒精治疗提供新的靶点。通过选择性育种开发的酒精中毒动物模型是阐明导致酒精依赖的遗传本质和潜在生物学机制的宝贵工具。这些选定品系（高酒精偏好和低酒精偏好）表现出表型和遗传差异，可对其进行研究以加深我们对酒精偏好及相关遗传特征的理解。通过结合分子技术，可确定导致酒精中毒的遗传和生理因素。
采用全基因表达分析来识别在未接触酒精的近交系酒精偏好（iP）和非偏好（iNP）大鼠的特定脑区中差异表达的基因。使用定量逆转录聚合酶链反应、原位杂交、蛋白质印迹和序列分析来进一步表征大鼠谷胱甘肽S -转移酶8 - 8（rGST 8 - 8）。
与iNP动物相比，在iP大鼠的离散脑区中观察到rGST 8 - 8 mRNA表达较低，且这些表达差异得到了证实。为了确定rGST 8 - 8的其他表达模式，我们采用了原位杂交。大鼠GST 8 - 8在海马、背侧第三脑室和侧脑室的脉络丛以及沿背侧第三脑室和第三脑室的室管膜细胞中高度表达。蛋白质印迹分析表明，与iNP相比，iP大鼠海马和杏仁核中的rGST 8 - 8蛋白水平较低。在rGST 8 - 8 cDNA中鉴定出编码区的一个沉默单核苷酸多态性和3' - UTR中的三个单核苷酸多态性。
在大脑中，rGST 8 - 8在mRNA和蛋白质水平均存在区域差异表达，并且在离散脑区中，iP品系的固有rGST 8 - 8水平低于iNP品系。
