Mechanisms Governing Expansion of Embryonic Progenitor Cells (EPCs) inMetaplasia

摘要/摘要 这个应用程序总体目标是确定共享的、保守的机制，这些机制可以 癌前病变，如化生。我们的初步和公布的数据表明，假幽门或左右- 胃中称为SPEM类型的化生是一种保守的再生程序的表现，由 大规模的伤害。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志物，这些标志物会增殖以修复组织损伤。我们 假设化生/再生过程是由胚胎样细胞种群的扩张推动的 祖细胞(EPC)。内皮祖细胞在很大程度上是由成熟的分泌物产生的，这些分泌物通过以下方式成为祖细胞样细胞 一种循序渐进的、保守的细胞程序，我们称之为“掌状症”。 在这里，我们将展示河马通过Nf2(Merlin)和下游转录因子传递信号的初步数据 YAP1/TAZ可能是EPC扩增的一个关键的、保守的调节子。在目标1中，我们将测试必要性/充分性 Nf2和YAP1/Taz在小鼠胃化生模型以及人和小鼠器官中的表达。我们将表演 基于发现的RNA-Seq实验，以发现调节内皮祖细胞和化生的新河马靶标。在AIM 2我们将看看这些河马途径成分如何与我们所患的掌症的不同阶段相互作用 它们是否能够克服阶段1和阶段2之间以及阶段2和阶段2之间的分子检查点 3.我们还将确定河马信号如何与保守的掌叶虫病专用基因Ifrd1相互作用， 我们将展示，当细胞上调mTORC1以重新进入细胞周期3期时，需要它来抑制P53 手掌症。在目标3中，我们将测试是否通过河马途径增加EPC的形成和化生 通过将河马突变体与：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- 致病细菌幽门螺杆菌。 实验的设计是为了与我们的生物统计学家严燕博士合作提供适当的动力。 最先进的成像技术(例如，AiryScan活细胞，共聚焦于有机物；FIB-SEM三维超微结构 纳米断层扫描)将与詹姆斯·菲茨帕特里克博士一起在我们的机构成像核心进行；有机支持， 基因编辑将与布莱尔·麦迪逊博士和我们共享的有机核心合作；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波博士的合作进行，张波博士是 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.