Genes Regulated By Abused Drugs

滥用药物通过在很大程度上不为人所知的生化机制，在行为上产生长期的变化。药物改变大脑中特定基因的表达变化，可以为吸毒的可能生化底物提供一个主要窗口。为了进一步探索这一领域，我们现在越来越关注阵列杂交技术，它可以识别数十个与大脑中表达的候选药物调控基因相对应的不同的cDNA。在这一年里，我们加强了候选基因的特征，这些基因的表达受到苯丙胺、可卡因和吗啡的调控。在本实验室的人类基因组扫描研究中，我们已经在吗啡调节基因NrCAM中发现了一种人类单倍型，它与人类物质滥用的脆弱性有关。在这一年里，我们已经报道了Kepi基因。我们还鉴定了这个最初的吗啡上调基因kepi的一个相关基因，我们将其命名为GBPI，它是一种依赖于蛋白激酶C的第二种磷酸化蛋白，它的磷酸化使其成为蛋白磷酸酶1活性的强大抑制因子，并在肠道和脑中表达。使用微阵列，我们已经能够从抽样的寡核苷酸DNA微阵列中检测到约38%的可重复的阳性杂交信号，并识别出被敲除或药物重复调控2倍以上的约1-2%的基因。在今年接受发表的工作中，我们将苯丙胺引起的变化描述为急剧上调一些基因，并长期下调它们。这些数据为进一步与人类药物滥用脆弱性的研究、基因组扫描和成瘾神经生物学机制的研究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.