Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA.
Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, USA.
Alcohol Clin Exp Res. 2022 Dec;46(12):2163-2176. doi: 10.1111/acer.14954. Epub 2022 Oct 25.
The chronic-plus-binge model of ethanol consumption, where chronically (8-week) ethanol-fed mice are gavaged a single dose of ethanol (E8G1), is known to induce steatohepatitis in mice. However, how chronically ethanol-fed mice respond to multiple binges of ethanol remains unknown.
We extended the E8G1 model to three gavages of ethanol (E8G3) spaced 24 h apart, sacrificed each group 9 h after the final gavage, analyzed liver injury, and examined gene expression changes using microarray analyses in each group to identify mechanisms contributing to liver responses to binge ethanol.
Surprisingly, E8G3 treatment induced lower levels of liver injury, steatosis, inflammation, and fibrosis as compared to mice after E8G1 treatment. Microarray analyses identified several pathways that may contribute to the reduced liver injury after E8G3 treatment compared to E8G1 treatment. The gene encoding cytochrome P450 2B10 (Cyp2b10) was one of the top upregulated genes in the E8G1 group and was further upregulated in the E8G3 group, but only moderately induced after chronic ethanol consumption, as confirmed by RT-qPCR and western blot analyses. Genetic disruption of Cyp2b10 worsened liver injury in E8G1 and E8G3 mice with higher blood ethanol levels compared to wild-type control mice, while in vitro experiments revealed that CYP2b10 did not directly promote ethanol metabolism. Metabolomic analyses revealed significant differences in hepatic metabolites from E8G1-treated Cyp2b10 knockout and WT mice, and these metabolic alterations may contribute to the reduced liver injury in Cyp2b10 knockout mice.
Hepatic Cyp2b10 expression is highly induced after ethanol binge, and such upregulation reduces acute-on-chronic ethanol-induced liver injury via the indirect modification of ethanol metabolism.
慢性加 binge 型乙醇消耗模型，即慢性（8 周）乙醇喂养的小鼠给予单次乙醇灌胃（E8G1），已知可诱导小鼠脂肪性肝炎。然而，慢性乙醇喂养的小鼠对多次乙醇 binge 的反应如何仍不清楚。
我们将 E8G1 模型扩展为三次乙醇灌胃（E8G3），间隔 24 小时，最后一次灌胃后 9 小时处死每组小鼠，分析肝损伤，并使用微阵列分析检测每组基因表达变化，以鉴定参与 binge 乙醇诱导肝反应的机制。
令人惊讶的是，与 E8G1 处理组相比，E8G3 处理组的肝损伤、脂肪变性、炎症和纤维化程度较低。微阵列分析确定了几个可能有助于 E8G3 处理组比 E8G1 处理组肝损伤降低的途径。细胞色素 P450 2B10（Cyp2b10）基因是 E8G1 组上调最明显的基因之一，在 E8G3 组中进一步上调，但在慢性乙醇消耗后仅适度诱导，RT-qPCR 和 Western blot 分析证实了这一点。Cyp2b10 的基因敲除加重了 E8G1 和 E8G3 小鼠的肝损伤，其血乙醇水平高于野生型对照小鼠，而体外实验表明 CYP2b10 并未直接促进乙醇代谢。代谢组学分析显示，E8G1 处理的 Cyp2b10 敲除和 WT 小鼠的肝内代谢物存在显著差异，这些代谢改变可能导致 Cyp2b10 敲除小鼠肝损伤减轻。
乙醇 binge 后肝 Cyp2b10 表达高度诱导，这种上调通过间接改变乙醇代谢减轻慢性乙醇诱导的急性肝损伤。
