Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou, China.
Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Department of Toxicology, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, China.
Toxicology. 2019 Jan 15;412:19-28. doi: 10.1016/j.tox.2018.11.011. Epub 2018 Nov 29.
Primary mouse hepatocyte cultures are widely used in toxicological and pharmacological studies. However, the strain differences in alterations of metabolic enzymes and the regulation of gene expression in response to different stimuli remains unclear. To address this issue, we examined the expression of metabolic enzymes and the regulatory role of DNA methylation in the primary hepatocytes of two mouse strains, CD-1 and C57BL/6. Primary culture of mouse hepatocytes was established using collagen sandwich configuration. Analysis of gene expression of 24 phase I, 18 phase II, and 6 phase III metabolic enzymes on 4 consecutive days after cell seeding revealed that the basal levels of most enzymes in primary cultured hepatocytes differed greatly between the two mouse strains. However, the dynamic changes in most genes were identical between the two strains. In addition, treatment with 3-methylcholanthrene, phenobarbital, and rifampin led to the induction of cytochrome P-450 (cyp) 1a1 and cyp1a2, cyp2b10, cyp3a11. However, induction varied in degree between the two types of primary hepatocytes. The dynamic changes in global DNA methylation and the expression of DNA methylation regulatory factors of the two mouse strains were similar. Of the genes down-regulated over the culture period, hypermethylation of cyp2e1 gene appeared in both mouse strains and led to a suppression of gene expression. Taken together, these results demonstrate that the expression of metabolic enzymes and the response to agonists in primary hepatocytes differ between CD-1 and C57BL/6 mouse strains. Epigenetic regulation might be involved in the suppression of cyp 450s' expression.
原代鼠肝细胞培养广泛应用于毒理学和药理学研究。然而，不同刺激下代谢酶的变化和基因表达的调节在两种鼠品系（CD-1 和 C57BL/6）中的差异尚不清楚。为了解决这个问题，我们研究了两种鼠品系（CD-1 和 C57BL/6）原代肝细胞中代谢酶的表达和 DNA 甲基化的调节作用。使用胶原夹层构型建立原代鼠肝细胞培养。分析细胞接种后连续 4 天 24 种 I 相、18 种 II 相和 6 种 III 相代谢酶的基因表达，结果显示两种鼠品系原代培养肝细胞中大多数酶的基础水平差异很大。然而，两种品系的大多数基因的动态变化是相同的。此外，用 3-甲基胆蒽、苯巴比妥和利福平处理导致细胞色素 P-450（cyp）1a1 和 cyp1a2、cyp2b10、cyp3a11 的诱导。然而，两种原代肝细胞的诱导程度不同。两种鼠品系的全基因组 DNA 甲基化和 DNA 甲基化调节因子的表达动态变化相似。在培养期间下调的基因中，cyp2e1 基因在两种鼠品系中均出现超甲基化，导致基因表达受到抑制。综上所述，这些结果表明 CD-1 和 C57BL/6 鼠品系原代肝细胞中代谢酶的表达和对激动剂的反应不同。表观遗传调控可能参与了 CYP450 表达的抑制。
