女性肥胖对玻璃化冷冻解冻后胚胎移植出生子代脂质代谢的影响及机制研究

Obesity has become a global epidemic, vitrification is a common way to save embryos in assisted reproductive therapy, and whether women's obesity aggravates the vitrification injury is unclear. We had found that the lipid content of embryos in maternal obesity group was significantly increased, after vitrification, the stress gene sustained a high expression level. During the early embryonic development after fertilization, the epigenetic modification of the whole genome changed dramatically. This provides a critical window period that the epigenetic genome may be highly sensitive to environmental stress. During this period, the pressure of the external environment may affect the embryonic epigenetic modification, which in turn affects the phenotype of the offspring. We hypothesized that the high stress in the embryo after vitrification may affect the genetic modification of lipid metabolism-related genes and change their expressions, which may affect the occurrence of metabolic diseases. To confirm this hypothesis, we will use diet-induced mouse obesity model, using gene sequencing and in vivo transplantation of embryos and other techniques to study the effect of obesity on the lipid metabolism related gene epigenetic modification of the offspring after the post-vitrification embryo transferred, and the mechanisms and consequences. This study will elucidate the effect of obesity on the metabolic diseases of the offspring of transferred embryos after vitrification and provide a new therapeutic target for the prevention of the impact of obesity on offspring.

肥胖已成为全球性流行性疾病，玻璃化冷冻是辅助生殖治疗中保存胚胎的常见方式，女性肥胖是否加重其冷冻损伤至今不清。课题组研究发现母源性小鼠肥胖组胚胎内脂滴含量明显升高，玻璃化冷冻复苏后，其应激基因持续高表达。在受精后的早期胚胎发育期间，全基因组的表观遗传修饰发生巨大的改变。这提供了一个表观基因组对环境压力高度敏感的关键窗口期。在这一时期，外界环境的压力会影响胚胎表观遗传学的修饰，进而影响子代的表型。我们推测复苏后胚胎内高应激状态可能会影响脂质代谢基因表观遗传修饰的变化，使其表达发生变化，进而影响出生子代代谢性疾病的发生。为证实这一假说，我们将使用饮食诱导的小鼠肥胖模型，采用基因测序及胚胎体内移植等技术，研究肥胖对复苏后胚胎移植出生子代脂质代谢相关基因表观遗传修饰的影响、机制及后果。本课题将阐明肥胖对玻璃化冷冻解冻后胚胎移植出生子代代谢性疾病的影响及机制，为预防肥胖对子代的影响提供新的治疗靶点。

肥胖已成为全球性流行性疾病，玻璃化冷冻是辅助生殖治疗中保存胚胎的常见方式，而女性肥胖是否加重其冷冻损伤以及对其子代健康的影响至今不清。本研究从临床以及动物实验验证肥胖对胚胎玻璃化冷冻复苏及其子代健康的影响，并通过多组学测序分析寻找肥胖对囊胚及其子代健康影响的关键基因。临床实验结果可见女性肥胖可降低促排卵过程中卵巢的反应性,但并不影响胚胎质量及妊娠结局，超重/肥胖并不加重胚胎玻璃化冷冻损伤。动物实验证明母性肥胖不影响胚胎质量及鲜胚移植妊娠结局，且肥胖导致新鲜胚胎脂滴含量增加，抵消胚胎玻璃化冷冻解冻造成的脂滴损失，有利于妊娠结局；单纯母代肥胖不影响子代的体重及代谢情况，玻璃化冷冻解冻过程可影响子代的体重及代谢情况。进一步对小鼠体外培养囊胚及其移植后形成的子代肝脏进行全基因组甲基化测序和转录组测序结合双重联合分析得出，肥胖可能通过Tcf7l2、Acot1、Abcc8、Hspd1、Pten 、Fasn及Agpat2等基因DNA甲基化水平与转录组水平的改变影响囊胚及子代糖脂代谢的病理生理过程。本研究从临床到动物实验系统验证了肥胖对胚胎发育、胚胎玻璃化冷冻、胚胎移植以及子代健康的影响，并通过多组学测序寻找肥胖对胚胎及子代健康影响的关键基因，为预防肥胖对子代的影响提供新的治疗靶点。