MECHANISMS OF CHIEF CELL DEDIFFERENTIATION

主要细胞去分化的机制

• 批准号: 10020395
• 负责人: Jason C Mills
• 金额: $ 44.14万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10020395
• 关键词: 3-Dimensional; Address; Apoptosis; Applications Grants; Architecture; Automobile Driving; Autophagocytosis; Award; Back; Bacteria; Binding; Cell Cycle; Cell Cycle Stage; Cell Differentiation process; Cells; Cellular Stress; Cellular Structures; Cessation of life; ChIP-seq; Chief Cell; Chronic; Chronic Disease; Clustered Regularly Interspaced Short Palindromic Repeats; Complex; Data; Development; Disease; Disease model; Dysplasia; Electron Microscopy; Enzymes; Epitopes; Event; Future; Gene Expression; Genes; Genetic; Genetic Transcription; Goals; Helicobacter pylori; Human; Hyperactive behavior; Infection; Inflammation; Initiator tRNA; Injury; Knockout Mice; Knowledge; Lesion; Malignant Neoplasms; Messenger RNA; Metaplasia; Mitosis; Modeling; Molecular; Mus; Mutagenesis; Natural regeneration; Organ; Organoids; Output; Pathway interactions; Patients; Pharmacology; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiological; Process; Proteins; Repression; Research; Resistance; Ribosomes; Risk; Role; S Phase; Sampling; Scaffolding Protein; Secretory Vesicles; Stomach; Stress; Techniques; Testing; Tissue Microarray; Tissues; Translating; Translations; activating transcription factor 3; adult stem cell; biological adaptation to stress; cancer risk; cell dedifferentiation; chronic infection; disease phenotype; experimental study; gastric tumorigenesis; genetic manipulation; human disease; human tissue; in vivo; malignant stomach neoplasm; mouse model; new therapeutic target; overexpression; paligenosis; polyposis; progenitor; programs; protein complex; recruit; repaired; response; scaffold; spasmolytic polypeptide; transcription factor; transcriptome sequencing; translation factor; tumorigenesis

PROJECT SUMMARY We study how injury and inflammation induce mature cells like the digestive-enzyme-secreting zymogenic chief cell (ZC) to disassemble their complex cell architecture and re-enter the cell cycle. We previously showed that ZCs become proliferative via a sequence of molecular-cellular events conserved across many tissues and species in scenarios where mature cells are recruited back into the cell cycle in response to tissue damage. Thus, cells have an evolutionarily conserved program for this reprogramming, as they do for death (apoptosis) and division (mitosis). We call this program paligenosis and showed that mature cells: first degrade/recycle their differentiated cell components (Stage 1), then induce expression of progenitor-like genes (eg. Sox9 = Stage 2), and finally re-enter the cell cycle (Stage 3). Paligenotic ZCs convert to cells that can be seen histopathologically as the type of metaplasia that occurs in stomach during long-term infection with the bacterium Helicobacter pylori: pseudopyloric or Spasmolytic Polypeptide Expressing Metaplasia (SPEM). Metaplasia can either resolve as tissue is repaired or become chronic and increase risk for progression to dysplasia and cancer. We have shown that paligenosis is governed by dynamic changes in mTORC1, the cellular translation control protein complex. mTORC1 is elevated at baseline in ZCs to drive translation of digestive enzymes, it shuts off at Stage 1, and reactivates at Stage 3. Without mTORC1, paligenosis stops at Stage 2 with cells looking metaplastic, but unable to enter S-phase. Here, we explore the mechanisms that induce and promote paligenosis. We show preliminary data implicating the Integrated Stress Response (ISR) pathway as a central paligenosis hub with a particular role for the transcription factor Atf3, which is associated with the ISR, and another gene which we hypothesize is a target of ATF3: Ifrd1, a multifunctional scaffolding protein. We hypothesize that the stress of large-scale tissue damage and/or inflammation triggers ISR hyperactivity, which leads to greatly increased ATF3 and IFRD1, to help push cells back into the cell cycle. In the absence of Atf3 or Ifrd1, we show paligenosis is defective. Our Specific Aims will be: 1) to confirm and further characterize at which stages ISR is active and confirm and characterize the role for ATF3 using, in part Atf3−/− mice; 2) to identify additional genes involved in the ISR and paligenosis by confirming the role of IFRD1 with Ifrd1−/− mice, probe relative contributions of ATF3 and IFRD1 by characterizing double knockout mice, and finally to perform ChIP- and RNA- Seq during paligenosis ±ATF3; 3) to test known ATF3 and ISR genes and new targets developed in Aim 2 in a pipeline of more physiological disease models (eg chronic infection of mice with H pylori), human translational samples (Tissue Microarray and additional human samples of metaplasia and cancer with nearly a 1000 patients), and in a mouse model of tumorigenesis ±ATF3. Together, the experiments may help us understand fundamental mechanisms cells use in regeneration and tumorigenesis that apply not just to the stomach but potentially other organs as well.

项目概要 我们研究损伤和炎症如何诱导成熟细胞，例如分泌消化酶的酶原负责人 细胞（ZC）分解其复杂的细胞结构并重新进入细胞周期。我们之前表明 ZC 通过一系列在许多组织中保守的分子细胞事件而增殖 成熟细胞因组织损伤而被招募回细胞周期的情况下的物种。 因此，细胞对于这种重编程有一个进化上保守的程序，就像它们对于死亡（细胞凋亡）所做的那样 和分裂（有丝分裂）。我们将这个程序称为“paligenosis”，并表明成熟细胞：首先降解/回收 它们分化的细胞成分（第 1 阶段），然后诱导祖细胞样基因的表达（例如 Sox9 = 第2阶段），最后重新进入细胞周期（第3阶段）。异质 ZC 转化为可见细胞 组织病理学上称为长期感染胃中发生的化生类型 幽门螺杆菌：假幽门或解痉多肽表达化生 (SPEM)。 化生可以随着组织修复而消退，也可以变成慢性并增加进展的风险 发育不良和癌症。我们已经证明，多变性是由 mTORC1 的动态变化控制的，mTORC1 是 细胞翻译控制蛋白复合物。 mTORC1 在 ZC 中基线升高以驱动翻译 消化酶，它在第 1 阶段关闭，并在第 3 阶段重新激活。如果没有 mTORC1，多变性会停止在 第 2 阶段，细胞看起来化生，但无法进入 S 期。 在这里，我们探索诱导和促进异变的机制。我们展示初步数据 暗示综合应激反应（ISR）途径作为一个中央异变枢纽，对 与 ISR 相关的转录因子 Atf3，以及我们假设的另一个基因 ATF3 的靶点：Ifrd1，一种多功能支架蛋白。我们假设大尺度组织的应力 损伤和/或炎症会触发 ISR 过度活跃，从而导致 ATF3 和 IFRD1 大大增加，从而 帮助将细胞推回细胞周期。在缺乏 Atf3 或 Ifrd1 的情况下，我们表明 paligenosis 是有缺陷的。我们的 具体目标是： 1) 确认并进一步描述情监侦处于活跃状态并确认和 部分使用 Atf3−/− 小鼠来描述 ATF3 的作用； 2) 鉴定与 ISR 相关的其他基因 通过确认 IFRD1 对 Ifrd1−/− 小鼠的作用，探讨 ATF3 和 IFRD1 的相对贡献 通过表征双基因敲除小鼠，最后在异变±ATF3期间进行 ChIP 和 RNA 测序； 3) 在更多生理学管道中测试已知的 ATF3 和 ISR 基因以及 Aim 2 中开发的新靶标 疾病模型（例如幽门螺杆菌慢性感染小鼠）、人类转化样本（组织微阵列） 以及近 1000 名患者的化生和癌症的其他人类样本），以及在小鼠模型中 肿瘤发生±ATF3。总之，这些实验可以帮助我们了解细胞使用的基本机制 再生和肿瘤发生不仅适用于胃，也可能适用于其他器官。