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.

项目摘要 干细胞增殖在这一过程中被精确控制的分子机制 人们对再生的认识还很少。也就是说，受损的组织如何感觉到何时终止 再生过程，抑制干细胞有丝分裂活性，并组织ECM完整性仍然是基本的 悬而未决的问题。干细胞在再生组织中的不受控制的增殖可能导致肿瘤 队形。果蝇中肠干细胞(ISC)最近成为一个有吸引力的模型 研究组织动态平衡和再生的系统。这是由于基因控制方面惊人的相似之处。 以及果蝇和哺乳动物消化系统之间的细胞组成，以及强大的基因 此模型中提供的工具。重要的是，果蝇ISC的增殖被促进以响应组织 损伤刺激组织修复。利用这一模型系统，已经进行了许多研究，以 揭示激活ISC增殖的途径。 尽管有丰富的关于激活干细胞增殖能力的知识，但在很大程度上 未知组织如何在再生结束时适当地下调干细胞增殖，以及如何 这一过程与上皮重塑有关。我们最近建立了果蝇ISCs作为一种优秀的 模型来研究终止再生的分子基础。使用RNA-seq，我们确定了几组 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)基因沉默复合体的一种成分，是 适当终止再生过程。进一步分析确定的直接靶向mRNAs 含有dMOV10的miRISC，包括狒狒(激活素信号的I型受体)和两个主要的非 整合素ECM受体、Syndecan(一种跨膜型硫酸乙酰肝素蛋白多糖)和Dystroglan(An 肌营养不良蛋白-糖蛋白复合体的整体膜成分)。除了识别出 DMOV10作为终止期特异性基因，同样的RNA-seq分析表明，关键成分 对于间隔连接，和肌动蛋白调节器在再生和返回到 后期处于正常水平。 在这项提案中，我们将在以下位置定义干细胞失活和细胞外基质重塑的关键分子 果蝇中肠再生的终止期有以下几个具体目标。目标1。 确定间隔连接成分在中肠再生中的作用。目标2.确定SDC的角色 和DG参与ECM重塑。目标3.定义miRNA介导的网络的全球格局。