Rictor/mTORC2在小鼠胚胎植入中的作用

Role of Rictor/mTORC2 in mouse embryo implantation

摘要:

目的：通过研究mTOR配体之一———Rictor基因在早孕小鼠中的表达规律，以及对胚胎植入的影响，为最终阐明其在胚胎植入中的作用和相关机制奠定基础。方法：构建小鼠早孕和子宫内膜条件敲除Rictor基因的动物模型。结果：免疫组化结果表明，Rictor基因在小鼠早孕期D1至D4表达于腔和腺上皮，以及胚胎植入后着床点附近的蜕膜组织区。成功繁殖了基因型为Rictorfl/flCre+/-的条件性敲除小鼠。免疫组化、Western blot及RT-qPCR结果表明小鼠子宫中Rictor表达降低，提示Rictor子宫条件敲除小鼠模型构建成功。相比对照鼠，敲除鼠的子宫体积和重量都明显降低（P<0.01）；敲除鼠孕5 d子宫外观显示无可见胚胎植入位点，且腔上皮细胞中增生标志物Ki67和子宫内膜容受性标志物MUC1表达均升高。结论：子宫内膜条件敲除Rictor后，由于容受性的降低导致胚胎的植入率明显下降。

Abstract:

Objective：To investigate the expression of the Rictor gene，an ligand for mTOR，in mice in early pregnancy and its effect on embryo implantation，and to lay a foundation for further research on the role and mechanism of the Rictor gene in mouse embryo implantation. Methods：The mouse model of early pregnancy and uterine-specific knockout of the Rictor gene was established. Results：Immunohistochemistry showed that the Rictor gene was mainly expressed in the luminal and glandular epithelium on days 1-4 of pregnancy and the decidual tissue near the implantation site after embryo implantation. The conditional-knockout mice with genotype Rictorfl/flCre+/- were successfully propagated. Immunohistochemistry，Western blot，and RT-qPCR showed that the expression of the Rictor gene was reduced in mouse uterus，suggesting that a mouse model of conditional knockout of the Rictor gene in the uterus was successfully established. Compared with the control mice，the knockout mice had significantly lower volume and weight of the uterus （P<0.01）. On day 5 of pregnancy，the knockout mice had no embryo implantation sites in the uterus and had significant increases in the expression of Ki67（a marker for proliferation） and MUC1（a marker for endometrial receptivity） in the luminal epithelial cells. Conclusion：There is a significant reduction in embryo implantation rate due to impaired receptivity after conditional knockout of the Rictor gene.