Mechanisms Governing Expansion of Embryonic Progenitor Cells (EPCs) inMetaplasia

摘要/总结 该应用程序的总体目标是识别诱导的共享的、保守的机制 癌前病变如化生。我们的初步和公布的数据表明，假幽门或类似的 胃中被称为 SPEM 型化生的现象是由以下因素诱导的保守再生程序的表现： 大规模伤害。化生细胞本身的特征是“去分化”表型，其中 它们表达类似胚胎或早期发育的标记物，这些标记物可以增殖以修复组织损伤。我们 假设化生/再生过程是由类胚胎群体的扩张推动的 祖细胞（EPC）。 EPC 很大程度上源自成熟的分泌，通过以下方式变得类似祖细胞： 一个逐步的、保守的细胞程序，我们称之为“paligenosis”。 在这里，我们将展示 Hippo 通过 Nf2 (Merlin) 和下游转录因子进行信号传导的初步数据 YAP1/TAZ 可能是 EPC 扩展的关键、保守调节剂。在目标 1 中，我们将测试必要性/充分性 Nf2 和 Yap1/Taz 在小鼠模型以及人和小鼠类器官胃化生中的作用。我们将表演 基于发现的 RNA-Seq 实验发现调节 EPC 和化生的新 Hippo 靶标。瞄准 2 我们将研究这些 Hippo 通路成分如何与我们所拥有的 paligenosis 阶段相互作用 表征，它们是否可以克服第 1 阶段和第 2 阶段以及第 2 阶段和第 2 阶段之间的分子检查点 3. 我们还将确定 Hippo 信号传导如何与保守的、古变专用基因 Ifrd1 相互作用， 我们将证明，当细胞上调 mTORC1 以重新进入第 3 阶段的细胞周期时，需要抑制 p53 异变病。在目标 3 中，我们将测试是否通过 Hippo 途径增加 EPC 形成和化生 通过将 Hippo 突变体与以下物质结合来增加肿瘤发生： 1) 诱变剂 MNU；或 2) 额外的胃癌- 相关突变等位基因 p53 和 Cdh1；或3）通过增加人类胃癌的慢性炎症- 诱发幽门螺杆菌。 我们与生物统计学家 Yan Yan 博士合作，设计了适当的实验。 最先进的成像（例如 AiryScan 活细胞、类器官共聚焦；FIB-SEM 3-D 超微结构 纳米断层扫描）将由 James Fitzpatrick 博士在我们的机构成像核心进行；类器官支持， 基因编辑将与 Blair Madison 博士和我们共享的类器官核心合作；生物信息学 分析（包括与数据存储库的协同作用）将通过我们与张博博士的合作进行，张博博士是该项目的负责人。 再生医学中心的机构生物信息学核心。

ABSTRACT/SUMMARY The Overall Goal of this application is to identify shared, conserved mechanisms that induce precancerous lesions like metaplasia. Our preliminary and published data indicate that pseudopyloric or so- called SPEM-type metaplasia in stomach is the manifestation of a conserved regeneration program induced by large-scale injury. The metaplastic cells themselves are characterized by a “dedifferentiated” phenotype wherein they express embryonic-like or early developmental markers that proliferate to repair the tissue damage. We hypothesize that the metaplastic/regenerative process is fueled by expansion of a population of embryonic-like progenitor cells (EPCs). EPCs arise in large part from mature secretory that become progenitor-like by following a stepwise, conserved cellular program we call “paligenosis”. Here, we will show preliminary data that Hippo signaling via Nf2 (Merlin) and downstream transcription factors YAP1/TAZ may be a critical, conserved modulator of EPC expansion. In Aim 1, we will test necessity/sufficiency of Nf2 and Yap1/Taz in gastric metaplasia in mouse models and in human and mouse organoids. We will perform discovery based RNA-Seq experiments to uncover new Hippo targets modulating EPCs and metaplasia. In Aim 2 we will look at how these Hippo pathway components interact with the stages of paligenosis we have characterized, whether they can overcome molecular checkpoints between Stages 1 and 2 and between 2 and 3. We will also determine how Hippo signaling interacts with the conserved, paligenosis-dedicated gene Ifrd1, which we will show is required to suppress p53 as cells upregulate mTORC1 to reenter the cell cycle in Stage 3 paligenosis. In Aim 3, we will test whether increasing EPC formation and metaplasia via the Hippo pathway increases tumorigenesis by combining Hippo mutants with: 1) the mutagen MNU; or 2) additional gastric-cancer- related mutant alleles p53 and Cdh1; or 3) by increasing chronic inflammation with the human gastric-cancer- predisposing bacterium H pylori. Experiments were designed to be appropriately powered in collaboration with our biostatistician, Dr. Yan Yan. State-of-the-art imaging (eg. AiryScan live-cell, confocal on organoids; FIB-SEM 3-D ultrastructural nanotomography) will be performed with Dr. James Fitzpatrick in our institutional imaging core; organoid support, and gene editing will be in collaboration with Dr. Blair Madison and our shared organoid core; bioinformatic analysis including synergy with data repositories will be via our collaboration with Dr. Bo Zhang, who directs the institutional bioinformatics core for the Center for Regenerative Medicine.