酒精对雄鼠精液质量及植入前胚胎全基因组DNA甲基化的影响

Chronic Alcohol Ingestion Influences Sperm Semen Quality and Global DNA Methylation in Pre-implantation Embryos

采用HE染色法、精子活力与形态学分析技术以及免疫荧光技术分别检测酒精对小鼠肝组织、精子的活力及形态、精子和植入前各时期胚胎的DNA甲基化的影响。HE染色结果表明,与对照组(生理盐水处理45 d)相比,实验组I(20%酒精灌胃30 d,生理盐水处理15 d)及实验组II(20%酒精灌胃45 d)小鼠肝脏出现不同程度的损害;精子活力与形态学分析发现,与对照组相比,实验组I和II精子活力明显降低,但实验组I精子活力高于实验组II,且对照组的精子正常形态精子率高于实验组I和II;免疫荧光结果显示,实验组精子DNA甲基化水平低于对照组,并且实验组I高于实验组II;植入前胚胎的2-细胞、4-细胞期,对照组DNA甲基化水平明显高于实验组,且实验组I高于实验组II,8-细胞期以后,对照组与实验组I无显著性差异,而实验组II却在8-细胞和桑椹胚期低于对照组,到囊胚期,对照组与实验组均无明显差异。酒精对雄鼠精子的破坏作用可能是导致植入前胚胎表观遗传异常的直接原因,且停止酒精摄入后可在一定程度上缓解其带来的一些不利影响。

Hematoxylin-eosin staining, sperm motility and morphology analysis technology, immuno- fluorescence technique were used to investigate adverse effects of alcohol on hepatic tissue of mice, semen qual- ity, genome-wide DNA methylation of sperm and pre-implantation embryos from different groups. HE staining results indicated that in this experiment, different degree of damage in liver were detected from treatment group I with a gastric injection with 4-5 g/kg modified alcohol solution for 30 d and treatment group II with injection for 45 d. The measurement of sperm motility results suggested that the main parameters were associated with a sig- nificantly reduction in treatment group I and II, meanwhile treatment group I was significantly greater than treatmentgroup II. There were significant decreases in the rate of normal sperms morphology in treatment groups. Mice in chronic alcohol ingestion had a significant decrease in semi-quantification of genome-wide DNA methylation levels, compared with the animal without treatment, and treatment group I was significantly greater than treatment group II. In 2-cell and 4-cell stage of preimplantation embryo, DNA methylation level in the control was significantly greater than the treatment groups, and treatment group I was significantly higher than treatment group II. After 8-cell stage, there was no significant difference between treatment group I and control, but treatment group II significantly lower than control from stages of 8-cell and morula. In the period of blastocyst, no obvious difference was found between each other. Taken together, our results suggested that alcohol on male mice sperm damage may be the direct reason of epigenetic abnormalities in mice pre-implantation embryo, and stopping alcohol intake could alleviate some of its negative effects.