Deciphering cellular and molecular pathways controlling invasive trophoblast differentiation

背景：胎盘的正确形成是哺乳动物成功繁殖的最重要决定因素之一。胎盘在母亲和胎儿之间形成机械和生理联系，支持生长发育。如果发育不正常，可能会出现严重的问题，包括母亲和后代的死亡。胚泡中的一组特殊细胞“侵入”子宫壁，附着在胚胎上后，胎盘就形成了。这些细胞被称为滋养层细胞，然后扩大形成细胞结构，使氧气和营养物质在母亲和胎儿之间传递，并进一步指导局部环境对发育中的胎儿的耐受性。尽管胎盘很重要，但我们对其形成的关键早期阶段所涉及的细胞和分子事件的理解仍然很差。最近进展：在过去的五年中，我的实验室已经研究了ADAM蛋白酶和低氧暴露是否控制侵袭性滋养细胞的功能。利用3D胎盘外植体系统再现了胎盘发育过程中发生的许多细胞事件和最先进的单细胞测序，我们发现特异性ADAMs促进滋养细胞侵袭，低氧加速滋养细胞分化为侵袭亚型。目标：我的实验室的长期目标是识别和表征滋养细胞生物学和胎盘发育中重要的新分子和细胞过程，我将通过两个短期目标来推进这一目标：1)测试ADAM蛋白酶是否控制EVT分化；2)确定控制EVT分化的缺氧调控通路。方法：拟进行的研究将验证ADAM蛋白酶和低氧张力促进滋养细胞沿浸润性胞外途径分化的假设。利用滋养细胞类器官培养和3D胎盘外植体系统，我将结合最先进的单细胞测序和基因编辑方法来确定ADAM蛋白酶是否协调滋养细胞分化，并确定缺氧如何驱动侵袭性滋养细胞规范。HQP：我打算在支持期间培训一个由8名HQP组成的多样化小组。在培训这些HQP时，我将实施公平和包容的招聘和指导做法。影响：这些研究将提高我们对滋养细胞生物学和胎盘形成的分子机制的理解，目前对此知之甚少。这项工作还将产生关于ADAM蛋白酶和氧传感系统的新知识，这些系统可能在其他细胞系统和器官中保守，因此可能间接地为干细胞和发育生物学领域做出贡献。

BACKGROUND: Correct formation of the placenta is one of the most important determinants of successful reproduction in mammals. The placenta forms the mechanical and physiologic link between mother and fetus, supporting growth and development. If it does not develop properly, there can be serious problems, including death, for both mother and offspring. The placenta develops after a special group of cells that are part of the blastocyst `invade' into the wall of the uterus, attaching the embryo. These cells, called trophoblasts, then expand to create cellular structures that enable transfer of oxygen and nutrients between mother and fetus, and further instruct a local environment of tolerance towards the developing fetus. Despite the importance of the placenta, we still have a poor understanding of the cellular and molecular events involved in the critical early stages of its formation. RECENT PROGRESS: Over the past five years, my lab has examined if ADAM proteases and exposure to low oxygen control invasive trophoblast functions. Using 3D placental explant systems that recapitulate many of the cellular events occurring during placental development and state-of-the-art single cell sequencing, we show that specific ADAMs promote trophoblast invasion and low oxygen accelerates trophoblast differentiation into invasive subtypes. OBJECTIVES: Building on my laboratory's long-term objective to identify and characterize novel molecular and cellular processes important in trophoblast biology and placental development, I will advance this via two short-term objectives: 1) testing if ADAM proteases control EVT differentiation; and 2) identifying hypoxia-regulated pathways controlling EVT differentiation. METHODOLOGY: The proposed studies will test the hypothesis that ADAM proteases and low O2 tension promote trophoblast differentiation along the invasive extravillous pathway. Using trophoblast organoid cultures and 3D placental explant systems, I will incorporate state-of-the-art single cell sequencing and gene-editing methods to determine if ADAM proteases coordinate trophoblast differentiation and identify how hypoxia drives invasive trophoblast specification. HQP: I intend to train a diverse group of 8 HQP over the timeline of this support. In the training of these HQP, I will implement equitable and inclusive recruitment and mentoring practices. IMPACT: These studies will improve our understanding of the molecular mechanisms involved in trophoblast biology and placental formation, of which there is currently little knowledge. This work will also generate new knowledge about ADAM proteases and oxygen-sensing systems that are likely conserved in other cellular systems and organs, and may therefore indirectly contribute to fields of stem cell and developmental biology.