Production of a cytochrome P450 2E1 transgenic mouse and initial evaluation of alcoholic liver damage

Abstract

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. (HEPATOLOGY 2002; 36:122-134.)

Ethanol‐induced cytochrome P4502E1 causes carcinogenic etheno‐DNA lesions in alcoholic liver disease†‡

“…14 Hepatic injury was found strikingly increased in transgenic mice overexpressing CYP2E1. 26 In line with these data, there were fewer oxidized DNA products in CYP2E1 knockout compared with wild-type mice after challenge with ethanol, and CYP2E1-null or 1-aminobenzotriazole-treated mice were completely protected from ethanol-induced DNA damage. 14 The fact that CYP2E1-null mice also developed liver injury was attributed to compensatory mechanisms, including the induction of CYP4A isozymes.…”

CYP2E1 and oxidative liver injury by alcohol

“…Recently, A CYP2E1 transgenic mouse model was developed that overexpressed CYP2E1. When treated with ethanol, the CYP2E1 overexpressing mice displayed higher transaminase levels and histological features of liver injury compared with the control mice (130). We developed an adenoviral vector which expresses human CYP2E1 and showed that infection of HepG2 cells with this adenovirus potentiated acetaminophen toxicity as compared to HepG2 cells infected with a LacZ expressing adenovirus (131).…”

Risk factors and mechanisms of hepatocarcinogenesis with special emphasis on alcohol and oxidative stress

“…The role of CYP2E1 induction and cell injury has been studied in detail in the liver. For example, oxidized DNA products have been found to be lower in CYP2E1 knockout mice compared to wild-type mice (Bardag-Gorce et al, 2000;Bradford et al, 2005), whereas more pronounced hepatic damage was observed in transgenic mice overexpressing CYP2E1 (Morgan et al, 2002).…”