REGULATION OF ETHANOL-INDUCIBLE CYTOCHROME P450 GENE

乙醇诱导细胞色素 P450 基因的调控

• 批准号: 3801921
• 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/3801921
• 关键词: alcoholism /alcohol abuse; aniline; cytochrome P450; enzyme induction /repression; enzyme mechanism; enzyme structure; enzyme substrate; ethanol; free radicals; genetic transcription; human tissue; isozymes; ketone body; laboratory rat; lymphocyte; messenger RNA; posttranslational modifications; 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 (P450IIE) of both rat and human. We have also demonstrated three distinct types of regulation of P450IIE. The mechanism of P450IIE mRNA stabilization was further studied to identify intermediary metabolites responsible for the mRNA stabilization. The level of two ketone bodies (~-hydroxybutyrate and acetoacetate) positively correlated with the elevated level of P450IIE mRNA. In addition, the molecular mechanism of P450IIE reduction by CCl4, was also examined. Aniline hydroxylase and the amounts of immunoreactive P450IIE were rapidly decreased in a time-dependent manner after CCl4 injection. These declines were not accompanied by the changes in the level of P450IIE mRNA and transcriptional activity, indicating a post-translational inhibition by CCl probably due to specific destruction of P450IIE by locally generated free radical metabolites. In contrast, the amounts of immunoreactive other P450s such as P450IA and P450IIC did not appear to be affected by CCl4, indicating a specific destruction of P450IIE by its substrate. A method for the measurement of P450IIE in easily obtainable human tissues was also established. P450IIE1 expressed in cultured lymphocytes could be easily detected by specific antibody to P450IIE. The induction of lymphocyte P450IIE was observed in both human and rat lymphocytes. The levels of P450IIE in lymphocytes from alcoholic patients at admission and discharge are being studied.

作为一个持续进行的项目， P450 IIE的进一步研究。我们之前已经确认， 确定了乙醇诱导的细胞色素P450的结构 （P450 IIE）的表达。 我们还展示了三个 P450 IIE的不同类型的调节。P450 IIE mRNA的作用机制 进一步研究了稳定性以鉴定中间代谢物 负责mRNA的稳定。 两种酮体水平 （~-羟基丁酸和乙酰乙酸）与 P450 IIE mRNA水平升高。此外，还探讨了 还检查了CCl_4对P450 IIE的还原作用。 苯胺羟化酶和 免疫反应性P450 IIE的量在一个 注射CCl 4后呈时间依赖性。这些下降并不是 并伴有P450 IIE mRNA水平的变化， 转录活性，表明CCl的翻译后抑制 可能是由于P450 IIE被局部产生的 自由基代谢物相反，免疫反应性的量 其他P450，如P450 IA和P450 IIC，似乎没有受到影响 CCl 4，表明P450 IIE被其底物特异性破坏。 一种简便的人P450 IIE测定方法 组织也建立了。 P450 IIE 1在培养的 P450 IIE特异性抗体可检测到淋巴细胞。 在人和小鼠淋巴细胞中均观察到P450 IIE的诱导作用。 大鼠淋巴细胞 酗酒者淋巴细胞中P450 IIE的水平 正在研究入院和出院时的患者。