REGULATION OF ETHANOL-INDUCIBLE CYTOCHROME P450 GENE

作为一个持续进行的项目，分子调控机制 对P450IIE进行了进一步研究。我们之前已经确定和 乙醇诱导的细胞色素P450的结构测定 (P450IIEI)。我们还展示了三个不同的 P450IIE1在大鼠体内的调节类型。三种类型的上调 P450IIE在肝、肺、肾组织中均有表达。这个 进一步探讨了CCl4对P450IIE产生负性作用的机制。这个 CCl4的应用不仅降低了P450IIE相关的水平 酶活性和免疫活性P450llE的量，还会引起 其mRNA的快速下降表明翻译前的减少 P450IIE由其自身底物合成。相比之下，P450的其他主要类别做到了 似乎不受CCl4的影响，表明特定的减少 P450 IIE。在与Casazza博士的合作项目中，一名翻译前 妊娠期间P450IIE的减少也被观察到，表明 P450IIE调节中的负性激素调控机制。这两个具体的 妊娠期CCl4和激素对P450IIE的下调作用 通过P450IIE的三种上调机制，从而提供了一种 P450级中多种调节模式的独特范例， 其中大部分是通过转录激活来激活的。 一种测定易得人体组织中P450IIE1的方法 也成立了。经免疫印迹分析，P450IIE1在 培养的淋巴细胞可被特异性抗体检测到 P450IIE1。控制不良患者淋巴细胞中P450IIE的水平 糖尿病儿童的体重比正常儿童高4到10倍 相应的对照受试者。P450IIEI诱导水平的测定 通过免疫反应条带的密度与那些 血红蛋白Alc的相关系数为0.87。的水平 酒精中毒患者入院和出院时淋巴细胞中P450IIE的表达 通过免疫印迹分析确定：P450IIE水平 酗酒者比自愿酗酒者高出四到五倍。 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.