Dissect the mechanisms underlying interspecies pluripotent stem cell competition

剖析种间多能干细胞竞争的机制

• 批准号: 10364140
• 负责人: Jun Wu
• 金额: $ 35.26万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-18 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10364140
• 关键词: Animals; Apoptosis; Attention; Automobile Driving; Cell Death; Cell Survival; Cells; Chemicals; Chimera organism; Chimerism; Coculture Techniques; Competence; Complement; Complex; Data; Development; Disabled Persons; Distant; Embryo; Embryonic Heart; Endogenous Retroviruses; Endothelium; Ensure; Generations; Genes; Genetic; Growth; Homeostasis; Human; In Vitro; Innate Immune Response; Inner Cell Mass; Kidney; Knockout Mice; Macaca mulatta; Medical; Molecular; Mus; Nature; Organ; Organ Donor; Organ Transplantation; Organogenesis; Pancreas; Play; Pluripotent Stem Cells; Process; RELA gene; Rattus; Research; Research Personnel; Rhesus; Role; Shapes; Signal Transduction; Source; Sum; System; TP53 gene; Thymus Gland; Tissues; Transmission Electron Microscopy; Work; base; blastocyst; comparative; fetal; fitness; human pluripotent stem cell; hypoxia inducible factor 1; implantation; improved; in vitro Model; in vivo; innovation; p53 Signaling Pathway; pluripotency; single-cell RNA sequencing; success; transcriptome; transcriptome sequencing

PROJECT SUMMARY/ABSTRACT Shortage of organs for transplantation is one of the largest unmet medical needs. Researchers are currently working on a variety of ways to increase the number of organs available. Recently, the prospect of producing human organs in animals via interspecies blastocyst complementation has raised important attention and may constitute an innovative approach to overcome the worldwide shortage of donor organs. Interspecies blastocyst complementation works by injecting donor pluripotent stem cells (PSCs) from one species into the organogenesis-disabled blastocyst of a different species. The growing host embryo can provide an emptied developmental organ niche for donor cells to occupy. Despite the potential, however, recent work revealed that although donor PSCs can initially engraft to inner cell mass (ICM) of blastocysts from distantly related host species, their chimeric contribution to early post-implantation stages is low. These results suggest the existence of embryonic xenogeneic barriers between evolutionarily distant species. Unlike chimera formation within the same species, a multitude of factors can differ significantly between species, which preclude robust chimerism. Cell competition, a conserved fitness-sensing process during which fitter cells eliminate neighboring less-fit but viable cells, has been proposed as a surveillance mechanism to ensure normal development and tissue homeostasis, and has also been suggested to act as a barrier to interspecies chimerism. During chimera formation, xenogeneic donor PSCs may be treated as unfit or aberrant cells and targeted for elimination. Most recently, we developed an interspecies PSC co-culture strategy and discovered a previously unknown mode of cell competition between species. Interspecies competition between PSCs occurred in primed but not naive pluripotent cells, and between evolutionarily distant species. By comparative transcriptome analysis, we found that genes related to the NF-κB and p53 signaling pathways, among others, were upregulated in less-fit ‘loser’ human cells. Genetic inactivation of TP53, a core component (P65, also known as RELA) and an upstream regulator (MYD88) of the NF-κB complex in human PSCs could overcome their competitive elimination by co- cultured mouse PSCs, thereby improving the survival and chimerism of human cells in early mouse embryos. Based on extensive preliminary results, in this proposal, we will further dissect the mechanisms underlying interspecies primed PSC competition in both loser and winner cells. And, by suppressing interspecies PSC competition, we aim to improve chimerism and provide the proof-of-concept of interspecies blastocyst complementation from donor PSCs of rhesus monkey, our close kin, in distantly related mouse host.

项目概要/摘要 移植器官短缺是最大的未满足的医疗需求之一。研究人员目前正在 研究各种方法来增加可用器官的数量。近期生产前景 动物的人体器官通过种间囊胚互补引起了人们的广泛关注，并可能 是克服全球捐赠器官短缺问题的创新方法。种间囊胚 互补作用是通过将一个物种的供体多能干细胞 (PSC) 注射到 不同物种的器官发生障碍的囊胚。生长中的宿主胚胎可以提供一个空的 供体细胞占据的发育器官生态位。然而，尽管有潜力，但最近的研究表明 尽管供体 PSC 最初可以植入远亲宿主囊胚的内细胞团 (ICM) 物种，它们的嵌合体对植入后早期阶段的贡献很低。这些结果表明存在 进化上遥远的物种之间的胚胎异种屏障。与内嵌合体的形成不同 同一物种中，物种之间的多种因素可能存在显着差异，从而排除了强大的嵌合现象。 细胞竞争，一种保守的适应度感知过程，在此过程中，适应度较高的细胞会淘汰邻近的适应度较低但适应度较低的细胞。 活细胞，已被提议作为一种监视机制，以确保正常发育和组织 体内平衡，也被认为可以作为种间嵌合的屏障。嵌合期间 当异种供体 PSC 形成时，可将其视为不合格或异常细胞并进行消除。最多 最近，我们开发了一种跨物种 PSC 共培养策略，并发现了一种以前未知的模式 物种之间的细胞竞争。 PSC 之间的种间竞争发生在启动期而非幼稚期 多能细胞，以及进化上遥远的物种之间。通过比较转录组分析，我们发现 与 NF-κB 和 p53 信号通路等相关的基因在不太健康的“失败者”中表达上调 人体细胞。核心成分（P65，也称为 RELA）和上游基因 TP53 的基因失活 人类 PSC 中 NF-κB 复合物的调节因子 (MYD88) 可以通过共同克服其竞争性消除 培养小鼠 PSC，从而提高早期小鼠胚胎中人类细胞的存活率和嵌合性。 基于广泛的初步结果，在本提案中，我们将进一步剖析其背后的机制 种间在失败者和获胜者细胞中引发了 PSC 竞争。并且，通过抑制种间 PSC 竞争，我们的目标是改善嵌合并提供种间囊胚的概念验证 来自我们的近亲恒河猴的供体 PSC 在远亲小鼠宿主中的互补。