Molecular Mechanisms of Regeneration Termination

再生终止的分子机制

• 批准号: 10408258
• 负责人: Hiroshi Nakato
• 金额: $ 32.94万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10408258
• 关键词: Actins; Activins; Address; Affect; Bacterial Infections; Biological Models; Cells; Complex; Data; Drosophila genus; Dystroglycan; Dystrophin; ECM receptor; Epithelial; Extracellular Matrix; Failure; Filopodia; Foundations; Future; Gene Silencing; Genes; Genetic; Glycoproteins; Heparan Sulfate Proteoglycan; High-Risk Cancer; Homeostasis; Integrins; Intestines; Knowledge; Link; Mediating; Membrane; Messenger RNA; MicroRNAs; Midgut; Mitotic Activity; Modeling; Molecular; Natural regeneration; Nature; Order Coleoptera; Organ Size; Papio; Pathway interactions; Phase; Process; Role; Septate; Signal Transduction; Stem Cell Development; Testing; Tissues; Type I Activin Receptors; design; gastrointestinal system; gliotactin; helicase; member; regenerative tissue; response; stem cell function; stem cell model; stem cell proliferation; stem cell therapy; stem cells; syndecan; targeted cancer therapy; tissue regeneration; tissue repair; tool; transcriptome sequencing; tumor

Project Summary The molecular mechanisms by which stem cell proliferation is precisely controlled during the course of regeneration are poorly understood. Namely, how a damaged tissue senses when to terminate the regeneration process, inactivates stem cell mitotic activity, and organizes ECM integrity remain fundamental unanswered questions. Uncontrolled proliferation of stem cells in regenerative tissues can result in tumor formation. The Drosophila midgut intestinal stem cell (ISC) has recently emerged as an attractive model system to study tissue homeostasis and regeneration. This is due to striking similarities in genetic control and cellular composition between the Drosophila and mammalian digestive systems, and powerful genetic tools available in this model. Importantly, Drosophila ISC proliferation is promoted in response to tissue damage to stimulate tissue repair. Using this model system, a number of studies have been conducted to reveal the pathways that activate ISC proliferation. Despite a wealth of knowledge on the activation of proliferative capacity of stem cells, it is largely unknown how the tissue properly down-regulates stem cell proliferation at the end of regeneration and how this process is linked to epithelial remodeling. We recently established the Drosophila ISCs as an excellent model to study the molecular basis for regeneration termination. Using RNA-seq, we identified sets of genes and pathways that are up/down-regulated at different phases of regeneration. Among these, we found that dMOV10, a component of the microRNA (miRNA) gene silencing complex, is required for the proper termination of the regeneration process. Further analyses identified direct target mRNAs of dMOV10-containing miRISC, including baboon (the Type I receptor of activin signaling) and two major non- integrin ECM receptors, Syndecan (a transmembrane heparan sulfate proteoglycan) and Dystroglycan (an integral membrane component of the dystrophin-glycoprotein complex). In addition to the identification of dMOV10 as a termination stage-specific gene, this same RNA-seq analysis showed that key components for septate junctions, and actin regulators are specifically upregulated during regeneration and return to normal level at a late stage. In this proposal, we will define these key molecules in stem cell inactivation and ECM remodeling at the termination stage of Drosophila midgut regeneration through the following Specific Aims. Aim 1. Determine the role of septate junction components in midgut regeneration. Aim 2. Define the role of Sdc and Dg in ECM remodeling. Aim 3. Define the global landscape of the miRNA-mediated network.

项目概要 干细胞增殖过程中精确控制的分子机制 对再生的了解还很有限。也就是说，受损组织如何感知何时终止 再生过程、使干细胞有丝分裂活性失活并组织 ECM 完整性仍然是基础 未解答的问题。再生组织中干细胞不受控制的增殖可能导致肿瘤 形成。果蝇中肠肠干细胞（ISC）最近成为一种有吸引力的模型 研究组织稳态和再生的系统。这是由于基因控制方面的惊人相似性 果蝇和哺乳动物消化系统之间的细胞组成和强大的遗传 该模型中可用的工具。重要的是，果蝇 ISC 增殖因组织反应而得到促进 损伤以刺激组织修复。使用该模型系统进行了多项研究 揭示激活 ISC 增殖的途径。 尽管关于干细胞增殖能力激活的知识很丰富，但很大程度上 未知组织如何在再生结束时正确下调干细胞增殖以及如何 这一过程与上皮重塑有关。我们最近建立了果蝇 ISC 作为优秀的 模型来研究再生终止的分子基础。使用 RNA-seq，我们确定了一组 在再生的不同阶段上调/下调的基因和途径。其中，我们 发现 dMOV10 是 microRNA (miRNA) 基因沉默复合物的一个组成部分，是 正确终止再生过程。进一步分析确定了直接靶标 mRNA 含有 dMOV10 的 miRISC，包括狒狒（激活素信号传导的 I 型受体）和两种主要的非 整合素 ECM 受体、Syndecan（一种跨膜硫酸乙酰肝素蛋白聚糖）和 Dystroglycan（一种 肌营养不良蛋白-糖蛋白复合物的完整膜成分）。除了识别 dMOV10 作为终止阶段特异性基因，同样的 RNA-seq 分析表明关键成分 对于隔膜连接，肌动蛋白调节剂在再生和返回过程中特别上调 后期正常水平。 在本提案中，我们将在干细胞失活和 ECM 重塑中定义这些关键分子 通过以下具体目标实现果蝇中肠再生的终止阶段。目标1。 确定隔膜连接成分在中肠再生中的作用。目标 2. 定义 Sdc 的角色 和 ECM 重塑中的 Dg。目标 3. 定义 miRNA 介导的网络的全球格局。