Queens College and Graduate Center, City University of New York, 65-30 Kissena Blvd, NSB E143, Flushing, NY, 11367, USA.
Present Address: Chancellor's Office, Leeward Community College, Pearl City, HI, USA.
Cell Commun Signal. 2020 Jul 11;18(1):111. doi: 10.1186/s12964-020-00616-8.
Cells taken from mouse embryos before sex differentiation respond to insults according to their chromosomal sex, a difference traceable to differential methylation. We evaluated the mechanism for this difference in the controlled situation of their response to ethanol.
We evaluated the expression of mRNA for alcohol dehydrogenase (ADH), aldehyde dehyrogenases (ALDH), and a cytochrome P450 isoenzyme (Cyp2e1) in male and female mice, comparing the expressions to toxicity under several experimental conditions evaluating redox and other states.
Females are more sensitive to ethanol. Disulfiram, which inhibits alcohol dehydrogenase (ADH), increases cell death in males, eliminating the sex dimorphism. The expressions ADH Class 1 to 4 and ALDH Class 1 and 2 do not differ by sex. However, females express approximately 8X more message for Cyp2e1, an enzyme in the non-canonical pathway. Female cells produce approximately 15% more ROS (reactive oxygen species) than male cells, but male cells contain approximately double the concentration of GSH, a ROS scavenger. Scavenging ROS with N-acetyl cysteine reduces cell death and eliminates sex dimorphism. Finally, since many of the differences in gene expression derive from methylation of DNA, we exposed cells to the methyltransferase inhibitor 5-aza- 2-deoxycytidine; blocking methylation eliminates both the difference in expression of Cyp2e1 and cell death.
We conclude that the sex-differential cell death caused by ethanol derives from sex dimorphic methylation of Cyp2e1 gene, resulting in generation of more ROS.
在性别分化之前从老鼠胚胎中提取的细胞会根据其染色体性别对刺激做出反应，这种差异可追溯到差异甲基化。我们在其对乙醇的反应的受控情况下评估了这种差异的机制。
我们评估了雄性和雌性小鼠中酒精脱氢酶 (ADH)、醛脱氢酶 (ALDH) 和细胞色素 P450 同工酶 (Cyp2e1) 的 mRNA 表达，比较了在评估氧化还原和其他状态的几种实验条件下的表达与毒性。
雌性对乙醇更敏感。抑制酒精脱氢酶 (ADH) 的戒酒硫增加了雄性细胞的死亡，消除了性别二态性。ADH 类 1 至 4 和 ALDH 类 1 和 2 的表达不因性别而异。然而，雌性表达大约 8 倍更多的 Cyp2e1 信使，这是一种非典型途径中的酶。雌性细胞产生的 ROS（活性氧）比雄性细胞多约 15%，但雄性细胞中含有大约两倍的 GSH，一种 ROS 清除剂。用 N-乙酰半胱氨酸清除 ROS 可减少细胞死亡并消除性别二态性。最后，由于基因表达的许多差异源于 DNA 的甲基化，我们将细胞暴露于甲基转移酶抑制剂 5-氮杂-2-脱氧胞苷；阻断甲基化消除了 Cyp2e1 的表达差异和细胞死亡。
我们得出结论，乙醇引起的性别差异细胞死亡源自 Cyp2e1 基因的性别二态性甲基化，导致产生更多的 ROS。
