Genes Regulated By Abused Drugs

滥用药物会通过生化机制对行为产生长期的改变，而这些机制在很大程度上是未知的。药物改变了大脑中特定基因表达的变化，可以为成瘾的可能生化基础提供一个主要窗口。为了进一步探索这一领域，我们现在越来越多地关注阵列杂交技术，该技术已经允许鉴定数十种不同的cdna，这些cdna对应于大脑中表达的候选药物调节基因。在这一年中，我们加强了候选基因的表征，这些基因的表达受安非他明、可卡因和吗啡的调节。在本实验室的人类基因组扫描研究中，我们已经确定了吗啡调节基因NrCAM的人类单倍型，该基因与人类药物滥用脆弱性有关。在这一年中，我们报道了KEPI基因。我们还发现了这个初始吗啡上调基因的一个亲戚，KEPI，我们称之为“GBPI”，作为第二种蛋白激酶c依赖性磷酸化蛋白，其磷酸化使其成为蛋白磷酸酶1活性的强大抑制剂，并在肠道和大脑中表达。利用微阵列技术，我们已经能够从大约38%的寡核苷酸DNA微阵列基因中检测到可重复的阳性杂交信号，并鉴定出大约1-2%的基因通过敲除或药物可重复调节2倍以上。在今年接受发表的工作中，我们将安非他明引起的变化描述为一些基因急剧上调和长期下调。这些数据为进一步研究人类药物滥用脆弱性基因组扫描和成瘾神经生物学机制提供了强有力的基础。

Abused drugs produce long-lasting changes in behaviors via biochemical mechanisms that are largely unknown. Drug-altered changes in expression of specific genes in the brain can provide a major window on possible biochemical substrates for ddiction. To further explore this area, we are now increasingly focused on array hybridization techniques that has allow identification of dozens of distinct cDNAs that correspond to candidate drug- regulated genes expressed in brain. During this year, we have enhanced characterization of candidate genes whose expression is regulated by amphetamine, cocaine and morphine. We have identified a human haplotype in the morphine-regulated gene, NrCAM, that is associated with human substance abuse vulnerability in human genome scanning studies from this laboratory. During this year, we have reported the KEPI gene. We have also identified a relative of this initial morphine-upregulated gene, KEPI, that we have termed "GBPI" as a second protein-kinase-C dependent phosphoprotein whose phosphorylation causes it to become a powerful inhibitor of protein phosphatase 1 activity and is expressed in gut and in brain. Using microarrays, we have been able to detect reproducible positive hybridization signals from ca 38% of the genes sampled oligonucleotide DNA microarrays, and to identify the ca 1-2% that are reproducibly regulated more than 2-fold by knockouts or drugs. We have characterized amphetamine-induced changes as upregualating a number of genes acutely and downregulating them chronically, in work accepted for publication in this year. These data provide powerful substrates for further convergence with studies of human drug abuse vulnerability genome scans and with studies of mechanisms of addiction neurobiology.