Mechanisms Governing Expansion of Embryonic Progenitor Cells (EPCs) inMetaplasia

摘要/总结 该应用程序的总体目标是确定共同的、保守的机制， 癌前病变如化生。我们的初步数据和发表的数据表明假幽门或- 胃中的所谓SPEM型化生是由 大规模的伤害。化生细胞本身的特征在于“去分化”表型，其中 它们表达增殖以修复组织损伤的胚胎样或早期发育标记。我们 假设化生/再生过程是由胚胎样细胞群的扩增所推动的， 祖细胞（EPCs）。EPCs在很大程度上来源于成熟的分泌细胞，它们通过以下方式变成祖细胞样： 一个逐步的，保守的细胞程序，我们称之为“paligenosis”。 在这里，我们将展示通过Nf 2（Merlin）和下游转录因子的Hippo信号传导的初步数据， YAP 1/TAZ可能是EPC扩增的关键、保守的调节剂。在目标1中，我们将测试必要性/充分性 Nf 2和Yap 1/Taz在小鼠模型以及人类和小鼠类器官中的胃化生中的作用。我们将执行 基于发现的RNA-Seq实验，以发现新的Hippo靶点调节EPCs和化生。在Aim中 我们将研究这些Hippo通路组分如何与我们所患的paligenosis阶段相互作用。 表征，它们是否可以克服阶段1和2之间以及阶段2和2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Paligenosis专用基因Ifrd 1相互作用， 当细胞上调mTORC 1重新进入第3阶段的细胞周期时， 苍白病在目标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增加肿瘤发生：1）诱变剂MNU;或2）额外的胃癌- 相关的突变等位基因p53和Cdh 1;或3）通过增加人胃癌的慢性炎症， 诱发细菌幽门螺杆菌。 与我们的生物统计学家Yan Yan博士合作设计了适当的实验。 最先进的成像技术（例如，AiryScan活细胞，类器官共聚焦; FB-SEM 3-D超微结构 纳米断层摄影术）将在我们的机构成像中心与詹姆斯菲茨帕特里克博士一起进行;类器官支持， 基因编辑将与布莱尔麦迪逊博士和我们共同的类器官核心合作;生物信息学 包括与数据存储库的协同作用在内的分析将通过我们与张波博士的合作进行，他负责 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.