Department of Obstetrics and Gynecology, Columbia University College of Physicians and Surgeons, New York, USA.
Reprod Sci. 2010 Apr;17(4):384-90. doi: 10.1177/1933719109356984. Epub 2010 Feb 2.
Alcohol consumption causes cellular injury and excessive cell death. Recent studies indicate that ethanol can induce epigenetic alterations, particularly acetylation and methylation of histones and hypomethylation and hypermethylation of DNA. In the current study, we tested the hypothesis that acute exposure of pregnant mice to alcohol during mid-gestation can induce apoptosis and increase histone H3K9/18 acetylation in the fetal lung. The increased expression of histone H3K9/18 acetylation could alter the expression of genes that induce apoptosis.
C57BL/6J mice at day 13.5 of gestation were injected intraperitoneally with 2 doses of 25% ethanol (experimental) or Ringer solution (control) at 4-hour intervals. The fetuses were retrieved at 1, 3, 12, and 24 hours after alcohol exposure. The lungs were processed for detection of apoptosis by the terminal deoxynucleotidyl transferase biotin- deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) assay and for levels of acetylated histone H3K9/18 by immunohistochemistry.
In the control lungs, apoptosis was observed in 0.22% and 0.25% of the mesenchymal and epithelial cells, respectively. In contrast, at 24 hours after alcohol injection at E13.5, 3.4% of the mesenchymal and 4.0% of the epithelial cells in the lung were undergoing apoptosis (TUNEL-positive; P < .005). The number of positively stained cells and levels of acetylated histone H3K9/18 staining significantly increased 1 hour after alcohol injection (P < .05) and returned to basal levels after 12 hours.
Acute alcohol exposure of pregnant mice at mid-gestation results in increased apoptosis in the fetal lung, and elevated levels of acetylated histone H3K9/18 precede the observation of apoptosis.
饮酒会导致细胞损伤和细胞死亡过多。最近的研究表明，乙醇可以诱导表观遗传改变，特别是组蛋白的乙酰化和甲基化以及 DNA 的低甲基化和高甲基化。在本研究中，我们检验了这样一个假设，即在妊娠中期，急性暴露于酒精的孕鼠会诱导胎肺细胞凋亡，并增加组蛋白 H3K9/18 的乙酰化。组蛋白 H3K9/18 乙酰化的增加表达可能会改变诱导细胞凋亡的基因的表达。
妊娠第 13.5 天的 C57BL/6J 小鼠每隔 4 小时接受 2 次 25%乙醇（实验组）或林格溶液（对照组）的腹腔内注射。在酒精暴露后 1、3、12 和 24 小时，取出胎儿。通过末端脱氧核苷酸转移酶生物素-dUTP 缺口末端标记（TUNEL）检测法检测凋亡，通过免疫组织化学法检测乙酰化组蛋白 H3K9/18 的水平，对肺进行处理。
在对照组肺中，间充质细胞和上皮细胞的凋亡率分别为 0.22%和 0.25%。相比之下，在妊娠第 13.5 天注射酒精后 24 小时，肺中的间充质细胞和上皮细胞分别有 3.4%和 4.0%发生凋亡（TUNEL 阳性；P <.005）。在酒精注射后 1 小时，阳性染色细胞的数量和乙酰化组蛋白 H3K9/18 的水平显著增加（P <.05），12 小时后恢复到基础水平。
妊娠中期孕鼠急性酒精暴露会导致胎肺细胞凋亡增加，并且在观察到凋亡之前，组蛋白 H3K9/18 的乙酰化水平升高。
