基于植入前胚胎SLC2As表达和调控，探讨肥胖损伤胚胎发育的机制

Glucose metabolic diseases especially obesity can significantly damage the development of preimplantation embryos, even resulting in infertility, but its mechanism is still unknown. Glucose has special significance to the development of preimplantation embryos, and there are great differences in the requirement of glucose during each stage embryos. Glucose entrying into cells mainly depends on the glucose carrier family SLC2As transport. As a portal to control glucose intake, the precise and orderly expression of SLC2As is crucial to assure on-demand glucose intake of the each stage embryos. However, the expression characteristics and regulatory mechanisms of SLC2As in the preimplantation embryos are still unknown. Our preliminary data have demonstrated that there were 11 kinds of SLC2A expressions in the blastocyst, and P38 participated in the regulation of SLC2A expression. This project will firstly systematically analyse SLC2A expression sequence in the preimplantation each stage embryos, and map the embryo expression profile; then screen out the possibly effective condidate(s) considering the change of SLC2A protein expression level and finally verify the function of these candidate(s) through antisense RNA technology, and the role of P38 in embryo glucose transport and metabolism processes will be investigated through gene expression regulation. On this basis, we will mainly focus on the perspectives of the expression sequence of SLC2As and P38 regulation to analyse the effects of obesity on the glucose uptake, metabolism and development of preimplantation embryos, revealing the mechanism of obesity damage the embryonic development.

代谢性疾病特别是肥胖可显著影响人类的生育能力，其对植入前胚胎代谢和发育的损伤是可能的原因，但具体机制不详。葡萄糖对调控植入前胚胎发育有特殊意义，各期胚胎对其需求存在巨大差别。葡萄糖进入细胞主要依靠糖载体家族SLC2A的运输。作为控制葡萄糖摄入的“门户”，SLC2A“有序”和“恰当”的表达对保证各期胚胎“按需”摄入至关重要，但其在植入前胚胎中的表达和调控特征尚未明了。我们前期发现囊胚中有11种SLC2A表达，且P38参与调控了SLC2A的表达。本项目将系统分析SLC2A在植入前各期胚胎中的表达时序，绘制胚胎表达图谱；结合蛋白表达水平的变化，筛选可能的效应成员，利用反义RNA技术验证其功能；并通过基因上/下调控来明确P38在胚胎糖转运和糖代谢过程中的作用。在此基础上，将重点从SLC2A表达时序和P38调控角度探讨肥胖对植入前胚胎的葡萄糖摄入、代谢和发育的影响，以揭示肥胖损伤生育力的机制。

肥胖可显著影响人类的生育能力，其对植入前胚胎代谢和发育的损伤是可能的原因，但具体机制不详。葡萄糖对调控植入前胚胎发育有特殊意义,葡萄糖进入细胞主要依靠糖载体家族SLC2A的运输。SLC2A“有序”和“恰当”的表达对保证各期胚胎“按需”摄入至关重要，但其在植入前胚胎中的表达和调控特征尚未明了。对此开展了以下研究:1）通过小鼠模型分析肥胖对植入胚胎发育的作用,并探讨了饮食控制的意义；2）从蛋白层面，分析高糖高脂饮食对小鼠卵巢组织SLC2A表达模式的影响；3）分析卵母细胞及植入前胚胎的葡SLC2A的表达差异，并筛选可能的效应型; 4）探讨SLC2A表达调控对胚胎发育的具体影响；5）验证非生理性体外培养对植入前胚胎SLC2A表达的影响；6）通过RNAseq技术分析肥胖小鼠植入前胚胎的表达差异。结果：1）高糖饮食可致小鼠整体葡萄糖代谢失衡，并损伤卵子成熟和胚胎发育；恢复正常饮食可逆转上述影响；2）高糖饮食和HA环境可抑制SLC2A3、4、8的表达；3）植入前胚胎和卵子SLC2A mRNA表达模式有显著差异，SLC2A3、4、8表达最为丰富；4）体外培养可影响SLC2As的表达，可抑制多种SLC2ASs的表达；5）SLC2A模式的改变可影响植入前胚胎的发育；6）肥胖与正常小鼠植入前胚胎RNA表达谱存在差异，25个基因上调，30基因下降，涉及细胞代谢、氧化与抗氧化，细胞调控性死亡等多个方面。结论：1）肥胖可通过葡萄糖代谢通路影响卵子成熟和胚胎发育，恢复正常饮食可以逆转这一效应，提示健康饮食比禁食更有意义；2）肥胖会降低卵巢组织多个SLC2A蛋白表达并影响其定位，提示SLC2A蛋白可能是肥胖影响卵巢功能的重要机制；3）SLC2A在植入前胚胎中表达存在差异，显示植入前胚胎葡萄转运需求和方式存在差异，而调控SLC2A表达可影响胚胎发育；5）非生理的体外操作可影响植入前胚胎的SLC2A表达，优化培养体系有重要意义；6）肥胖对胚胎的影响至少涉及细胞代谢、氧化与抗氧化，以及调控性死亡等多个方面，提示需要开展更多研究。