The role of endometrial gland derived extracellular vesicles in mediating an optimal uterine environment.

基本原理：对于人类和家畜的成功怀孕，子宫内膜(子宫的内层)必须为植入胚胎创造合适的环境。子宫内膜腺分泌物，包括细胞外小泡，创造了这种环境。细胞外小泡是一种膜结合的小泡，含有microRNA和蛋白质，被靶细胞摄取并改变其功能。使用新的3D超微结构成像方法，我们已经显示ECV形成于子宫内膜腺微绒毛的顶端(图1)。这是一个新发现，因为ECV被认为是以一种非常不同的方式形成的。我们现在需要了解子宫内膜腺中ECV是如何形成的，并确定激素和营养因素是如何调节这一过程的。我们需要确定子宫内膜上皮细胞含有什么microRNAs和蛋白质，它们是否与子宫内膜表型有关，以及这些microRNAs可能对胚胎中的基因表达途径产生什么影响。项目计划：1)研究人子宫内膜腺中ECV的形成，并确定激素或营养刺激是否能改变这种情况。2)确定子宫内膜内皮细胞的特征，包括其microRNA含量，并确定这种变化是否会因激素或营养刺激而改变。3)进行电子计算机分析以确定ECV microRNAs的目标基因，并试图在胚胎细胞系中测试这些预测。在南安普敦建立了子宫内膜腺分离和3D成像方法。苏塞克斯和南安普顿的团队在分离ECV、从人和动物组织和血清中提取microRNA-seq以及生物信息学分析方面拥有专业知识。这项工作的影响将来自于对ECV的生理作用及其调节的更好理解，以及应用这些发现来提高人类和家畜育种项目中自然受孕和辅助受孕的成功。

Rationale: For successful pregnancy in humans and livestock, the endometrium (the lining of the womb) must create the right environment for the implanting embryo. Endometrial gland secretions, which include extracellular vesicles, create this environment. Extracellular vesicles (ECVs) are membrane bound vesicles containing microRNA and proteins, which are taken up by target cells and change their function. Using novel 3D ultrastructural imaging approaches, we have shown that ECVs form on the tips of endometrial gland microvilli (Fig 1). This is a novel finding as ECVs had been thought to form in a very different manner. We now need to understand how the ECVs are formed in endometrial glands and determine how this can be regulated by hormonal and nutritional factors. We need to establish what microRNAs and proteins the endometrial ECVs contain, whether these relate to endometrial phenotype, and what effects these microRNAs could have on gene expression pathways in the embryo. Project plan: 1) To study the formation of ECVs in isolated human endometrial glands and establish whether this can be altered by hormonal or nutritional stimuli. 2) To characterise endometrial ECVs including their microRNA content and establish whether this changes in response to hormonal or nutritional stimuli. 3) To perform an in-silico analysis to determine the target genes of the ECV microRNAs and seek to test these predictions in an embryonic cell line. Endometrial gland isolation and 3D imaging approaches are established in Southampton. The Sussex and Southampton teams have expertise in isolation of ECVs, microRNA-seq from human and animal tissue and serum, and expertise in bioinformatic analyses. The impact of this work will come from an improved understanding of the physiological role of ECVs and their regulation and from the application of these findings to improve the success of natural and assisted conception in humans and livestock breeding programs.