5-氮杂胞苷对小鼠体外培养胚胎组蛋白H3K27乙酰化模式的影响

Effects of 5-Azacytidine on H3K27 Acetylation Patterns in Preimplantation Mouse Embryos Cultured In Vitro

目的:探讨5-氮杂胞苷(5-azacytidine,5-AzaC)对胚胎体外发育过程中异常表观修饰的修正作用。方法:取小鼠体内自然受精原核胚和孤雌激活原核胚分别用不同浓度的5-AzaC(0.1μmol/L、0.01μmol/L、空白对照)处理24 h后在体外进行培养,然后采用间接免疫荧光法检测分析不同发育时期的胚胎组蛋白H3K27乙酰化模式。结果:5-AzaC对体内受精的2-细胞期和4-细胞期胚胎的组蛋白H3K27乙酰化模式有比较明显的影响,较低浓度的5-AzaC能使胚胎体外发育率有所提高,但差异无统计学意义(P>0.05);5-AzaC对孤雌激活囊胚组蛋白H3K27异常的乙酰化模式有明显影响,但是不同浓度之间差异无统计学意义(P>0.05)。结论:5-AzaC可能通过修正胚胎异常的H3K27乙酰化模式而提高孤雌胚的体外发育及着床能力,在改善胚胎的体外培养条件方面具有潜在的应用前景。

Objective： To explore the effects of DNA methylation inhibitor 5-azacytidine（5-AzaC） on the correction of abnormal epigenetic modifications. Methods： Prokaryotic embryos in vivo and parthenogenetic prokaryotic embryos, treated with different concentrations of 5-AzaC for 24 h, were cultured. Then different developmental stage embryos were collected in corresponding period. Embryonic H3K27 acetylation patterns in every group were detected by immunofluorescence method. Results： In 2-cell and 4-cell stages, the H3K27 acetylation levels of prokaryotic embryos in vivo followed by cultured in vitro were obviously affected by the treatment of inhibitors. The difference of H3K27 acetylation is not obvious or gradually eliminates in the latter period. The developmental rate of prokaryotic embryos cultured in vitro was improved in lower concentrations of inhibitors, however, the diffience was not statistically significant. 5-AzaC could modify abnormal patterns of H3K27 acetylation in parthenogenetic embryos especially the blastocyst stage, but the differences in concentrations of 5-AzaC were not statistically significant. Conclusion： Abnormal H3K27 acetylation patterns of parthenogenetic embryos were corrected by 5-AzaC to a certain extent. It could provide some significances to improve the implantation capacity of pathenogenetic embryos, developmental ability and culture conditions in vitro.