REGULATION OF ETHANOL-INDUCIBLE CYTOCHROME P450 GENE

作为一个持续进行的项目，分子调控机制 P450IIE 被进一步研究。我们之前已经确定并 确定了乙醇诱导的细胞色素 P450 的结构 (P450IIEI) 大鼠和人类。我们还展示了三种不同的 大鼠中 P450IIE1 的调节类型。上调的三种类型 P450IIE 似乎存在于肝、肺和肾组织中。的 进一步研究了 CCl4 对 P450IIE 的负面影响的机制。的 CCl4 的施用不仅降低了相关 P450IIE 的水平 酶活性和免疫反应性P450llE的量，也引起 其 mRNA 的快速下降表明翻译前的减少 P450IIE采用自己的基板。相比之下，P450 的其他主要类别则没有 似乎不受 CCl4 的影响，表明具体减少 P450IIE。在与 Casazza 博士的一个合作项目中， 还观察到妊娠期间 P450IIE 的减少，表明 P450IIE 调节中的负性激素控制机制。这两个具体 妊娠期间 CCl4 和激素对 P450IIE 的下调 具有 P450IIE 的三种上调机制，从而提供 P450 类别中多种调节模式的独特示例， 其中大部分是通过转录激活而激活的。 一种在易于获得的人体组织中测量 P450IIE1 的方法 也成立了。通过免疫印迹分析，P450IIE1 表达于 培养的淋巴细胞可以通过特异性抗体轻松检测到 P450IIE1。控制不良的淋巴细胞中 P450IIE 水平 糖尿病儿童的发病率是正常儿童的四到十倍 相应的控制对象。测定 P450IIIEI 的诱导水平 通过与免疫反应带的密度高度相关的 血红蛋白 Alc 的相关系数为 0.87。的水平 酒精患者入院和出院时淋巴细胞中的 P450IIE 通过免疫印迹分析确定：P450IIE 的水平 酗酒者的比例是自愿者的四到五倍 对照组。

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.