The Role of Uterine Glycogen in Establishing a Successful Pregnancy

项目摘要 不孕不育是一个重大的公共卫生问题，具有巨大的医疗、心理和经济成本。 女性的最高生育率为每周期30%。在大多数情况下，卵母细胞是受精的，但产生的胚胎 在植入前或植入期间死亡。在此期间，胚胎依赖于葡萄糖分泌进入子宫 流明。从受精到桑拿期，葡萄糖摄取量都很低。当胚胎接近囊胚时 阶段，葡萄糖摄取量增加50倍。同样，子宫内膜蜕膜化是一个葡萄糖密集型的过程。 抑制磷酸戊糖途径会损害蜕膜化并减少产仔数。之后 蜕膜化时，子宫内膜切换到Warburg新陈代谢，以产生ATP。葡萄糖中的缺陷 分泌物进入子宫腔或蜕膜摄取与妊娠并发症有关。子宫是如何 满足胚胎和子宫内膜对葡萄糖时空变化的需求很差 明白了。我们的初步数据显示，子宫内膜可以储存葡萄糖作为大分子。 小鼠体内的糖原。我们发现子宫上皮细胞中的糖原储备在发情前期和 在植入前阶段下降。子宫上皮细胞表达葡萄糖-6-磷酸酶，这是 从糖原中释放出的葡萄糖所必需的部分。相反，间质中的糖原含量 从发情前期到发情后日间(DPC)为3.5，为低水平。在DPC 5.5，糖原含量 种植部位的间质增加了7倍，但种植间的间质仍然很低。我们确认了 蜕膜通过诱导人工蜕膜形成来储存大量的糖原。这些数据表明 子宫内膜储存了两个不同的糖原池，它们可能是葡萄糖的主要来源 在怀孕期间。因此，这个项目的目标1是确定储存在子宫内膜中的糖原是否 对于一个成功的怀孕来说是必不可少的。使用糖原合成酶1(GYS1)的小鼠，我们将敲除 用孕酮受体(PRCre)Cre小鼠子宫糖原合成酶。在确认成功后 GYS1基因敲除和相应的糖原减少，我们将确定这些小鼠是否有规律 生殖周期和葡萄糖耐量。接下来，我们将评估它们的生育力，并确定是否缺乏 子宫糖原合成酶会损害胚胎成功怀孕的能力。怀孕的事- 子宫上皮糖原含量的依赖性变化提示卵巢激素调节 这个组织中的糖原。我们已经证明了雌激素刺激的IGF1诱导糖生成。 体外培养子宫上皮细胞。我们的初步数据表明，黄体酮直接刺激糖原 通过细胞膜上的孕激素受体分解。目标2将阐明激活的途径 膜孕酮受体导致糖原分解。然后我们将确认雌二醇和 去卵巢小鼠的黄体酮。总而言之，这项研究将确定子宫内膜糖原是否储存 并评估子宫上皮中糖原的激素调节。

Project Summary Infertility is a significant public health problem with substantial medical, psychosocial, and economic costs. Maximal fertility in women is 30% per cycle. In most cases, the oocyte is fertilized, but the resulting embryo dies before or during implantation. During this time, embryos depend on glucose secretions into the uterine lumen. From fertilization until the morula stage, glucose uptake is low. As embryos approach the blastocyst stage, glucose uptake increases 50-fold. Similarly, endometrial decidualization is a glucose-intense process. Inhibition of the pentose phosphate pathway impairs decidualization and reduces litter size. After decidualization, the endometrium switches to Warburg metabolism to generate ATP. Defects in glucose secretion into the lumen or uptake by the decidua are linked to pregnancy complications. How the uterus meets the changing needs of the embryos and endometrium for glucose in a spatiotemporal manner is poorly understood. Our preliminary data show that the uterine endometrium can store glucose as the macromolecule glycogen in the mouse. We show that glycogen reserves in the uterine epithelium peak at proestrus and decline during the preimplantation period. The uterine epithelium expressed glucose-6-phosphatase, which is necessary for the section of glucose released from glycogen. Conversely, the glycogen content of the stroma was low and unchanging from proestrus to day post coitum (DPC) 3.5. At DPC 5.5, the glycogen content of the stroma increased 7-fold at the implantation site but remained low at the inter-implantation site. We confirmed that the decidua stores large amounts of glycogen by inducing artificial decidualization. These data indicate that the endometrium stores two distinct pools of glycogen that may serve as essential sources of glucose during pregnancy. Therefore, Aim 1 of this project is to determine if glycogen stored in the endometrium is necessary for a successful pregnancy. Using glycogen synthase 1 (GYS1) floxed mice, we will knock out glycogen synthase in the uterus using progesterone receptor (PRCre) Cre mice. After confirming a successful knockout of GYS1 and a corresponding decrease in glycogen, we will determine if these mice have regular reproductive cycles and glucose tolerance. Next, we will evaluate their fertility and determine if the lack of uterine glycogen synthase impairs the embryo's ability to establish a successful pregnancy. The pregnancy- dependent changes in glycogen content of the uterine epithelium suggest that ovarian hormones regulate glycogen in this tissue. We have already shown that estradiol-stimulated IGF1 induces glycogenesis in the uterine epithelium in vitro. Our preliminary data indicate that progesterone directly stimulates glycogen breakdown via membrane progesterone receptors. Aim 2 will elucidate the pathway by which activation of membrane progesterone receptors leads to glycogenolysis. We will then confirm the effects of estradiol and progesterone in ovariectomized mice. In summary, this research will determine if endometrial glycogen stores are required during pregnancy and assess the hormonal regulation of glycogen in the uterine epithelium.