Use of lymphocytes for assessing ethanol-mediated alterations in the expression of hepatic cytochrome P4502E1.
Use of lymphocytes for assessing ethanol-mediated alterations in the expression of hepatic cytochrome P4502E1.
复制标题
使用淋巴细胞评估乙醇介导的肝细胞色素 P4502E1 表达的变化。
DOI：
10.1111/j.1530-0277.1995.tb00994.x
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Carpenter,SP
中科院分区：
文献类型：
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作者：
Raucy,JL;Curley,G;Carpenter,SP
乙醇诱导的细胞色素P4502E1 （2E1）参与了许多肝毒素和肝癌原的生物活化。由于高水平的表达可能会增加暴露于由该酶代谢的化学物质的肝毒性的程度和严重性，因此一种相对非侵入性的方法来区分那些表现出高浓度2E1的个体可能是有用的。考虑到这一点，我们研究了乙醇暴露是否会以类似的方式改变兔白细胞和肝脏中的2E1。用新鲜分离的微粒体制备，而不是培养的细胞，用于免疫化学检测2E1。这种酶存在于淋巴细胞和中性粒细胞中。淋巴细胞是兔白细胞群的主要组成部分，我们监测了乙醇暴露后2E1蛋白水平的变化，并将其与肝酶的变化进行了比较。本研究结果表明，淋巴细胞和肝脏中2E1表达的增强程度取决于酒精暴露的时间和剂量。事实上，血液酒精浓度与淋巴细胞（r= 0.65,p< 0.01）和肝脏（r= 0.60,p< 0.01）中的2E1含量之间存在相关性。在15%乙醇剂量下治疗12天，肝脏和淋巴细胞中2E1的最大增加（6 - 10倍）。无论从处理过的兔子身上取血并与未处理的兔子进行比较，还是在乙醇暴露前后从同一只动物身上取白细胞，这种诱导都是明显的。后者的研究结果表明，兔淋巴细胞2E1的变化是由乙醇暴露引起的，而不是由酶表达的变异性引起的。有趣的是，在10%的剂量下，2E1的升高早在第3天就被注意到，在第6天下降，在第12和24天恢复到略高于3天暴露期的水平。在肝脏和淋巴细胞中都观察到这种2E1升高的模式，事实上，在所有暴露时期和两种剂量的酒精检查中，淋巴细胞和肝脏2E1含量之间存在相关性（r= 0.70,p< 0.01）。总的来说，这些研究表明2E1在淋巴细胞和肝脏中的诱导是平行发生的。此外，研究结果表明，人类血液中2E1可能被用作异种生物促进肝酶表达改变的表型标记物。这些发现应该对P450酶的体内监测产生重大影响。
The ethanol‐inducible cytochrome P4502E1 (2E1) is involved in the bioactivation of numerous hepatotoxins and hepatocarcinogens. Because high levels of expression may enhance the degree and severity of hepatotoxicity from exposure to chemicals metabolized by this enzyme, a relatively noninvasive method to phenotypically distinguish those individuals exhibiting elevated concentrations of 2E1 may be useful. With this in mind, we examined whether ethanol exposure could alter 2E1 in rabbit white blood cells and liver in a similar manner. Microsomes prepared from freshly isolated, rather than cultured cells, were used to immunochemically detect 2E1. The enzyme was found in lymphocytes and neutrophils. Lymphocytes, which comprise the majority of the white cell population in rabbits, were monitored for changes in 2E1 protein levels after ethanol exposure and compared with alterations of the hepatic enzyme. Results presented herein demonstrate that the degree of enhancement in 2E1 expression of lymphocytes and liver was dependent on the length and dose of alcohol exposure. Indeed, correlations were observed between blood alcohol concentrations and 2E1 content in lymphocytes (r= 0.65,p< 0.01) and liver (r= 0.60,p< 0.01). The greatest increase in 2E1 (6‐ to 10‐fold) occurred in both liver and lymphocytes at a dose of 15% ethanol for 12 days of treatment. This induction was evident regardless of whether blood was taken from treated and compared with untreated rabbits or if white cells were obtained from the same animal before and after ethanol exposure. The latter findings demonstrate that changes in lymphocyte 2E1 were caused by ethanol exposure and not to variability in enzyme expression among rabbits. Interestingly, at the 10% dose, elevation of 2E1 was noted as early as 3 days, declined at 6 days, and at 12 and 24 days returned to slightly higher levels than those seen at the 3‐day exposure period. This pattern of 2E1 elevation was observed in both the liver and lymphocytes, in fact, at all exposure periods and at the two doses of alcohol examined, a correlation (r= 0.70,p< 0.01) was observed between lymphocyte and liver 2E1 content. Collectively, these studies show that induction of 2E1 in lymphocytes and liver occurs in a parallel fashion. Furthermore, results suggest that blood 2E1 may be used in humans as a phenotypic marker for xenobiotic‐promoted alterations in the expression of the liver enzyme. These findings should have a significant impact on in vivo monitoring of this P450 enzyme.