Submitted to: Hepatology Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/11/2012
Publication Date: 1/3/2013
Citation: Ye, Q., Wang, X., Wang, Q., Xia, M., Zhu, Y., Lian, F., Ling, W. 2013. Cytochrome P4502E1 inhibitor, chlormethiazole, decreases lipopolysaccharide-induced inflammation in rat Kupffer cells with ethanol treatment. Hepatology Research. 43:1-9. Interpretive Summary: Chronic abuse of ethanol in humans causes a number of physiological and biochemical changes to liver that may lead to the progression of alcoholic liver disease. In this study, we carried out both an animal and a cell culture study to determine whether the alcohol induced inflammation contributes to liver disease. We demonstrated that an enzyme inhibitor called chlormenthizaole can block alcohol induced damage and inflammation; there by decreasing the liver’s injury. This result could provide a basis for developing dietary strategies to prevent liver disease amongst chronic alcohol users.
Technical Abstract: To investigate the role of Cytochrome P4502E1 in sensitizing Kupffer cells to lipopolysaccharide (LPS)-mediated inflammation after ethanol induction. Sprague-Dawley rats were fed a liquid ethanol diet, control diet or ethanol diet supplemented with CYP2E1 inhibitor, chlormethiazole (CMZ), for 4'weeks. Hepatic CYP2E1 protein, nuclear factor-kappa B (NF-KB) p65 protein and tumor necrosis factor (TNF)-alpha mRNA were measured. In vitro, isolated Kupffer cells from control rats were exposed to ethanol with different CMZ concentration; CYP2E1 expression and reactive oxygen species (ROS) generation were compared. The identified CMZ concentration was further utilized to evaluate the role of CYP2E1 on the sensitization of ethanol-induced Kupffer cell to LPS. The effect of LPS alone was tested in controlled Kupffer cells without ethanol. TNF-alpha, nuclear NF-KB p65 and cytoplasm IKB-alpha were monitored for all groups. Ethanol feeding increased hepatic CYP2E1 level, nuclear accumulation of NF-KB p65 and TNF-alpha expression in rats. These changes were inhibited by CMZ supplementation. In cultured Kupffer cells, increased CYP2E1 content and ROS production by in vitro ethanol induction were dose-dependently inhibited by CMZ. Compared with LPS alone, the ethanol induction group produced significantly more TNF-alpha, nuclear NF-KB p65 and less cytoplasm I'B-a under LPS stimuli. CMZ abolished the effects of ethanol on LPS-stimulated NF-'B translocation and TNF-alpha generation in Kupffer cells. In cultured Kupffer cell, using CMZ as inhibitor, ethanol-induced CYP2E1 overexpression was proved to contribute to the sensitization of Kupffer cells to LPS stimuli, with amplification of ROS production and activation of NF-KB, resulting in increased TNF-alpha production.