Organoid systems to identify endometrial origins of pre-eclampsia

怀孕期间的疾病会严重影响母亲和婴儿的健康，甚至在轻微的情况下，也会给生命中最快乐的事情之一蒙上阴影。先兆子痫（PE）是一种常见病，发生率高达5%，它可以有严重和较轻微的形式。PE在妊娠34周之前表现为最严重的，尽管这种早发型的疾病研究得最多，但我们仍然不知道根本原因是什么。我们确实知道，是胎盘功能不正常导致了危险的高血压和PE特有的肾脏症状，但我们知道如何阻止疾病发展的唯一方法就是分娩，通常是在婴儿准备好之前。如果我们了解为什么胎盘在PE中出现故障，那么我们就可以设计更好的治疗方法，甚至在疾病发展之前识别出那些有疾病风险的人。本项目旨在重建胎盘关键部分的形成，并提出是否正是母亲的子宫引发了一系列事件，导致PE中胎盘功能障碍的问题。胎盘在怀孕期间与婴儿一起发育，作为营养和废物处理的中间人，让婴儿成长。当受精卵植入子宫时，胎盘就开始形成，并形成一种叫做胎盘绒毛的结构，这种结构深入子宫内膜，获取动脉血液，作为婴儿生长的营养来源。在早发性PE中，正是胎盘与母体动脉的这种界面不能正常形成，导致婴儿生长不良，母亲心血管系统失衡，最终导致危及生命的症状。在过去的十年里，一系列独立的研究发现，患有PE的母亲或那些经常患有PE的母亲的子宫组织中存在细微的异常。这些大多是观察性研究表明，在早发性PE中，子宫在受精前后都没有为怀孕做好适当的准备；这个过程叫做去个性化。最近我们对细胞如何协同作用形成组织和器官的理解取得了进展，这使我们能够在实验室中培育出完整的子宫和胎盘组织。研究这些胎盘和子宫“类器官”是如何共同发育的，将有助于我们首次确定子宫是如何引发早发性PE的胎盘畸形的。在我们位于曼彻斯特的临床研究中心，复发性早发性PE患者已经慷慨地同意在怀孕之外进行子宫活检。子宫细胞和类器官可以从这些活组织组织中发育出来，并在培养皿中重新组合，形成一个“个体生态位”。标准化细胞形成的胎盘类器官可以在PE蜕膜生态位中发育，并与健康妊娠妇女活检形成的蜕膜生态位中发育的类器官进行比较。这种比较将采用一种称为单细胞转录组学的技术对类器官进行极高分辨率的分析；本质上是根据类器官中每个细胞表达的基因来描述它们的特征，从而定义不同的细胞类型以及它们之间的关系。胎盘类器官包含侵入和进入子宫动脉的细胞类型，因此PE蜕膜生态位对这些关键细胞的影响将通过单细胞转录组学来检测。通过比较150多个PE胎盘的转录组，可以验证蜕膜PE相对于实际PE疾病状态的影响。此外，单细胞转录组方法结合计算模型将允许识别驱动胎盘畸形的蜕膜PE的确切信号。了解这一点将为未来的药物靶向治疗提供信息，并可能导致在怀孕前发现那些有发生PE风险的人。

Diseases of pregnancy can have serious affects on both mother and baby's health, and even in mild cases can overshadow what is supposed to be one of life's most joyous events. Pre-eclampsia (PE) is a common disease occurring in up to 5% of all pregnancies and it can have both severe and more mild forms. PE is most serious when it manifests before 34 weeks of pregnancy, and although this early-onset type of the disease is the most well studied we still do not understand what the root cause is. We do know that it is the placenta not functioning properly that causes the dangerous high blood pressure and kidney symptoms characteristic of PE, but the only way we know how to stop progression of the disease is to deliver the baby, often before it is ready. If we understand why the placenta malfunctions in PE then we may be able to design better treatments and even recognise those at risk of disease before it develops.This project aims to reconstruct the formation of key parts of the placenta and ask the question whether it is the mother's womb that initiates a chain of events leading to placental malfunction in PE. The placenta develops alongside the baby during pregnancy, acting as the go-between for nutrient and waste handling to allow baby to grow. It begins to form right as the fertilised egg implants into the womb and builds structures called placental villi that invade deep into the womb lining to access arterial blood as the nutrient source for baby's growth. It is this placental interface with maternal arteries that doesn't form properly in early-onset PE, leading to poor growth for the baby and imbalances in the mother's cardiovascular system that can eventually lead to life-threatening symptoms. A series of independent studies over the last decade detected subtle abnormalities in the womb tissue of mothers with PE or those that have had it recurrently. These mostly observational studies suggest that in early-onset PE the womb doesn't properly prepare for pregnancy prior to and after fertilisation; a process called decidualisation. Recent advances in our understanding of how cells work together to form tissues and organs has led us to be able to grow whole pieces of womb and placental tissue in the lab. Investigating how these placental and womb 'organoids' develop together will help us identify for the first time how the womb triggers malformation of the placenta in early-onset PE. At our clinical research centre in Manchester, sufferers of recurrent early-onset PE have graciously consented to womb biopsies outside of pregnancy. Womb cells and organoids can be developed from these biopsies and re-combined to configure a 'decidual niche' in a petri dish. Placental organoids formed from standardised cells can then be developed within this PE decidual niche and compared to organoids developed in a decidual niche made with biopsies from women who have had healthy pregnancies. This comparison will take the form of extremely high resolution analysis of the organoids using a technique called single cell transcriptomics; essentially characterising each cell in the organoid based on the genes they express and so defining different cell types and their relationships with one another. Placental organoids contain the cell types that invade and access womb arteries and so the effects of the PE decidual niche on these crucial cells will be detected by single cell transcriptomics. Validation of the effects of PE decidua relative to actual PE disease state can be made through comparison to transcriptomes from of more than 150 PE placentas. Moreover, the single cell transcriptome approach combined with computational modelling will allow the identification of the exact signals from PE decidua that drive placental malformation. Understanding this will inform future drug targeting for treatment and may lead to detection of those at risk of developing PE before pregnancy.