Signaling-regulated establishment of pluripotency in vivo

体内多能性的信号调节建立

• 批准号: 10583972
• 负责人: Amy Ralston
• 金额: $ 51.67万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10583972
• 关键词: Binding Sites; Cell Nucleus; Cells; Child Development; Chromatin; Chromatin Remodeling Factor; Collaborations; Compensation; Complex; Defect; Development; Embryo; Embryonic Development; Endowment; Ensure; Epiblast; Exhibits; Family; Fetus; Gene Expression; Genes; Genetic Transcription; Genomics; Human; Knock-out; Knowledge; Mammals; Methods; Modeling; Molecular; Mothers; Mus; NuRD complex; Oocytes; Pattern; Placenta; Pregnancy; Process; Publishing; Repression; Role; SOX15 gene; SOX21 gene; Series; Signal Transduction; Specific qualifier value; Surface; Testing; Time; Transcription Coactivator; Work; blastomere structure; cell fate specification; cofactor; embryo cell; embryonic stem cell; experimental study; fetus cell; gene repression; genome editing; healthy pregnancy; implantation; in vivo; interest; member; mouse model; novel; pluripotency; pluripotency factor; recruit; single cell analysis; transcription factor

PROJECT SUMMARY The first priority of the mammalian embryo is to establish its own placenta, which will eventually be recognized and accepted by the mother. At the same time, the embryo must reserve fetal cells by endowing some with pluripotency. Decades of rigorous study have revealed the molecular mechanism that partly explains this first cell fate decision. Around the 16-cell stage, when the embryo is still a ball of cells, cells on the outer surface polarize and repress Hippo signaling. As a consequence of Hippo repression, transcription factors YAP and TAZ (WWTR1) enter the nuclei of the outer cells, where they partner with TEAD4 to promote expression of key regulators of placental (trophectoderm) fate. Excitingly, this mechanism, which we helped discover in mice, is conserved in humans, highlighting the utility of the mouse model as a discovery platform. Yet, a major mystery remained unsolved: how are the pluripotent cells specified? Are they pluripotent by virtue of being non- trophectoderm? Or is there a more active mechanism? Our lab discovered that the pluripotency factor SOX2 exhibits a unique expression pattern at the 16-cell stage. That is, when other pluripotency factors, such as OCT4 and NANOG are expressed in both inside and outside cells of the embryo, SOX2 is detected only in inside cells. This observation suggests that SOX2 helps actively specify the earliest stages of pluripotency. Through a series of experiments, we subsequently showed that SOX2 expression pattern is dependent on the YAP/TAZ/TEAD transcriptional complex, indicating that trophectoderm and pluripotency are regulated by Hippo signaling in parallel, starting at the 16-cell stage. We now seek to discover: 1) Does the SOX2 pattern provide the positional information to restrict the activity of other pluripotency factors to the inside cells of the embryo? 2) Do Sox2 paralogues work with SOX2 or other factors to promote the pluripotency of inside cells? 3) How do YAP/TAZ/TEAD mechanistically repress expression of Sox2 while promoting expression of trophectoderm genes in outer cells? Our team brings together expertise in high throughput genome editing, time-resolved analysis of single cell gene expression, and ultra-low input genomics, which are all needed to make the major mechanistic advances envisioned here. These studies will help reveal the generalizable principles of mammalian embryonic development that are fundamental to ensuring healthy pregnancy and child development.

项目摘要 哺乳动物胚胎的首要任务是建立自己的胎盘，最终会被识别 并被母亲接受。与此同时，胚胎必须保留胎儿细胞， 多能性。几十年的严格研究揭示了部分解释这一现象的分子机制 细胞命运的决定大约在16细胞阶段，当胚胎仍然是一个细胞球时，外表面的细胞 抑制河马信号。作为Hippo阻遏的结果，转录因子雅普和 TAZ（WWTR 1）进入外细胞的细胞核，在那里它们与TEAD 4合作促进关键蛋白的表达。 胎盘（滋养外胚层）命运的调节因子。令人兴奋的是，我们帮助在小鼠中发现的这种机制， 在人类中保守，突出了小鼠模型作为发现平台的实用性。然而，一个主要的谜团 仍然没有解决：多能细胞是如何指定的？他们是不是因为没有能力而具有多能性？ 滋养外胚层是否有更积极的机制？我们的实验室发现多能性因子SOX 2 在16-细胞阶段表现出独特的表达模式。也就是说，当其他多能性因子，如 OCT 4和NANOG在胚胎的内部和外部细胞中表达，SOX 2仅在胚胎的细胞中检测到。 在细胞内。这一观察结果表明，SOX 2有助于积极指定多能性的最早阶段。 通过一系列的实验，我们随后发现SOX 2的表达模式依赖于 雅普/TAZ/TEAD转录复合物，表明滋养外胚层和多能性受 海马信号并行，从16细胞阶段开始。我们现在寻求发现：1）SOX 2模式是否 提供位置信息以将其它多能性因子的活性限制到细胞的内部， 胚胎？2)Sox 2旁系同源物是否与Sox 2或其他因子一起促进细胞内的多能性？ 3)雅普/TAZ/TEAD如何在促进Sox 2表达的同时， 滋养外胚层基因在外层细胞中我们的团队汇集了高通量基因组编辑方面的专业知识， 单细胞基因表达的时间分辨分析和超低输入基因组学，这些都是需要的， 实现了这里所设想的主要机械进步。这些研究将有助于揭示 哺乳动物胚胎发育的基本原则，以确保健康的怀孕和孩子 发展