REGULATION OF ETHANOL-INDUCIBLE CYTOCHROME P450 GENE

乙醇诱导细胞色素 P450 基因的调控

• 批准号: 3808628
• 负责人: B J SONG
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3808628
• 关键词: alcoholism /alcohol abuse; antibody formation; carbon tetrachloride; complementary DNA; cytochrome P450; diabetes mellitus genetics; enzyme induction /repression; enzyme mechanism; enzyme structure; enzyme substrate; ethanol; gene expression; genetic mapping; genetic regulation; genetic transcription; hormone regulation /control mechanism; human tissue; isozymes; laboratory rat; lymphocyte; messenger RNA; molecular cloning; molecular genetics; nucleic acid hybridization; nucleic acid sequence; pregnancy; tissue /cell culture; western blottings

As a continuous ongoing project, the molecular regulatory mechanism of P450IIE was further investigated. We have previously identified and determined the structures of the ethanol-inducible cytochrome P450 (P450IIEI) of both rat and human. We have also demonstrated three distinct types of regulation of P450IIE1 in rat. The three types of up-regulation of P450IIE appeared to be present in liver, lung, and kidney tissues. The mechanism of a negative effect of CCl4 on P450IIE was further examined. The administration of CCl4 not only reduced the level of P450IIE associated enzyme activity and the amount of immunoreactive P450llE, but also caused rapid decline in its mRNA indicating a pretranslational reduction of P450IIE by its own substrate. In contrast, other major classes of P450 did not appear to be affected by CCl4, indicating a specific reduction of P450IIE. In a collaboratory project with Dr. Casazza, a pretranslational reduction of P450IIE during pregnancy was also observed indicating a negative hormonal control mechanism in P450IIE regulation. The two specific down-regulations of P450IIE by CCl4 and hormones during pregnancy along with three types of up-regulatory mechanism of P450IIE thus provide an unique example of multiple modes of regulation among the classes of P450, most of which are activated by transcriptional activation. A method for the measurement of P450IIE1 in easily obtainable human tissues was also established. By immunoblot analysis, P450IIE1 expressed in cultured lymphocytes could be easily detected by specific antibody to P450IIE1. The levels of P450IIE in lymphocytes from poorly controlled diabetic children are elevated four to ten fold over those of the corresponding control subjects. The induced levels of P450IIEI determined by the density of immunoreactive bands highly correlated with those of hemoglobin Alc with a correlationship coefficient of 0.87. The levels of P450IIE in lymphocytes from alcoholic patients at admission and discharge were determined by the immunoblot analyses: the levels of P450IIE in alcoholics were four to five folds higher than those found in the voluntary control group.

作为一个持续正在进行的项目，分子调节机制 P450IIE进一步研究了。我们以前已经确定了 确定乙醇诱导的细胞色素P450的结构 （P450IIEI）的大鼠和人。我们还展示了三个不同的 大鼠P450IIE1的调节类型。三种类型的上调 P450IIE似乎存在于肝脏，肺和肾脏组织中。这 进一步研究了CCL4对P450IIE的负面影响的机制。这 CCL4的给药不仅降低了P450IIE相关的水平 酶活性和免疫反应性P450LLE的量，但也引起 它的mRNA迅速下降，表明预后减少 P450IIE通过其自己的基材。相比之下，其他主要类P450确实 似乎不受CCL4的影响，表明 P450IIE。在与预后的Casazza博士合作项目中 还观察到怀孕期间P450IIE的减少，表明 P450IIE调节中的负激素控制机制。这两个具体 CCL4的P450IIE下调和怀孕期间的激素 因此，P450IIE的三种类型的上调机制提供了一个 P450类中多种调节模式的独特示例， 其中大多数是通过转录激活激活的。 一种在易于获得的人体组织中测量P450IIE1的方法 也建立了。通过免疫印迹分析，P450IIE1在 特异性抗体可以轻松检测到培养的淋巴细胞 P450IIE1。淋巴细胞中P450IIE的水平不良。 糖尿病儿童高于四到十倍 相应的控制对象。诱导的P450IIEI水平确定 通过免疫反应带的密度高度相关 血红蛋白ALC的相关系数为0.87。水平 入院和出院时酒精患者的淋巴细胞中的P450IIE 通过免疫印迹分析确定：P450IIE的水平 酗酒者比自愿中的酗酒者高四到五倍 对照组。