Morgan Kengathevy, French Samuel W, Morgan Timothy R
VA Medical Center, 5901 E Seventh Street, Long Beach, CA 90822, USA.
Hepatology. 2002 Jul;36(1):122-34. doi: 10.1053/jhep.2002.33720.
Hepatic metabolism of ethanol by cytochrome P450 2E1 (CYP2E1) is believed to contribute to alcoholic liver damage. To further evaluate CYP2E1 in alcoholic liver disease, we created a transgenic mouse containing human CYP2E1 complementary DNA (cDNA) under the control of mouse albumin enhancer-promoter. Two experiments were performed. In the first experiment, transgenic and nontransgenic mice were fed normal chow. In the second experiment, transgenic and nontransgenic mice were pair fed a nutritionally complete liquid diet for 16 weeks. The liquid diet contained 30% of calories as ethanol (or dextrose) and 25% of calories as corn oil. Liver damage was assessed by measuring serum alanine aminotransferase (ALT) levels and examining liver histology. Transgenic animals reproduced and were phenotypically normal. Hepatic levels of CYP2E1 messenger RNA (mRNA), protein, and enzyme activity did not differ between chow-fed transgenic and nontransgenic mice. Livers from transgenic mice fed the alcohol diet contained significantly more CYP2E1 protein and enzyme activity than livers from nontransgenic mice fed the same diet. Transgenic mice receiving the alcohol diet had significantly higher serum ALT levels than nontransgenic mice. Histologic examination of the livers showed higher histologic scores in transgenic mice fed ethanol compared with nontransgenic mice fed ethanol. Ballooning hepatocytes were seen in livers from transgenic mice fed ethanol. Apoptosis, as determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay, did not differ between groups. In conclusion, we have produced a transgenic mouse that expresses human CYP2E1 in the liver. When fed a nutritionally complete alcohol diet, transgenic mice develop more liver damage than nontransgenic mice.
细胞色素P450 2E1（CYP2E1）介导的乙醇肝脏代谢被认为与酒精性肝损伤有关。为了进一步评估酒精性肝病中的CYP2E1，我们构建了一种转基因小鼠，其在小鼠白蛋白增强子-启动子的控制下含有人类CYP2E1互补DNA（cDNA）。进行了两项实验。在第一个实验中，给转基因和非转基因小鼠喂食正常食物。在第二个实验中，将转基因和非转基因小鼠配对，喂食营养完全的液体饮食16周。该液体饮食含有30%的热量来自乙醇（或葡萄糖），25%的热量来自玉米油。通过测量血清丙氨酸转氨酶（ALT）水平和检查肝脏组织学来评估肝损伤。转基因动物能够繁殖且表型正常。在喂食普通食物的转基因和非转基因小鼠之间，肝脏中CYP2E1信使RNA（mRNA）、蛋白质和酶活性水平没有差异。喂食酒精饮食的转基因小鼠的肝脏比喂食相同饮食的非转基因小鼠的肝脏含有显著更多的CYP2E1蛋白质和酶活性。接受酒精饮食的转基因小鼠的血清ALT水平显著高于非转基因小鼠。肝脏组织学检查显示，与喂食乙醇的非转基因小鼠相比，喂食乙醇的转基因小鼠的组织学评分更高。在喂食乙醇的转基因小鼠的肝脏中可见气球样肝细胞。通过末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记（TUNEL）分析确定的细胞凋亡在各组之间没有差异。总之，我们制备了一种在肝脏中表达人类CYP2E1的转基因小鼠。当喂食营养完全的酒精饮食时，转基因小鼠比非转基因小鼠发生更严重的肝损伤。
