The function of germ granules in maintaining pluripotency in the C. elegans germline

胚芽颗粒在维持线虫种系多能性中的功能

• 批准号: 9023577
• 负责人: Dustin Lynn Updike
• 金额: $ 33.3万
• 依托单位: MOUNT DESERT ISLAND BIOLOGICAL LAB
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9023577
• 关键词: Adult; Affinity; Animal Model; Binding; Caenorhabditis elegans; Cell Nucleus; Cells; Complex; Cytoplasm; Cytoplasmic Granules; Data; Disease; Event; Exhibits; Genetic; Genetic Models; Genetic Transcription; Germ; Germ Cells; Goals; Health; Human; Meiosis; Messenger RNA; Methods; Modeling; Molecular; Mutation; Pathway interactions; Patients; Phenocopy; Post-Transcriptional Regulation; Process; Property; Proteins; RNA; RNA-Binding Proteins; Regenerative Medicine; Repression; Research; Ribonucleoproteins; Role; Small Interfering RNA; Somatic Cell; Spermatogenesis; Stem cells; Structure; Surveys; Techniques; Testing; Time; Transcript; Translating; Translations; cell type; cofactor; epigenetic memory; improved; innovation; mRNA Expression; mutant; neuronal cell body; novel strategies; patient safety; pluripotency; protein expression; self-renewal; sex determination; sperm cell; stemness; translation factor

 DESCRIPTION (provided by applicant): Stem cells are defined by their pluripotent and self-renewing properties. A significant amount of research is focused on unlocking these properties in differentiated cells in order to create patient-derived stem cells that can be used to treat disease. However, the process of creating patient-derived stem cells relies heavily on expressing pluripotency factors within the nucleus; using techniques that often render stem cells too dangerous for regenerative medicine. This proposal takes a unique approach to understand how cytoplasmic components called germ granules regulate cellular "stemness". The ultimate goal is to be able to manipulate germ-granule pluripotency factors within the cytoplasm to improve the quality and safety of patient-derived stem cells. Germ granules are a heterogeneous mix of RNA and RNA-binding proteins, and they are conserved in the germline from worms to humans. The transparency and sophisticated genetics of C. elegans offers an opportunity to study germ-granule function in a way that is not feasible in more complex model organisms. Our recent studies have shown that germ-granules create a cytoplasmic microenvironment that facilitates post- transcriptional regulation events that are central to the pluripotent and self-renewing properties of the germline. We have also shown that depleting germ granules causes germ cells to lose pluripotency, initiate somatic differentiation, and express transcripts associated with spermatogenesis. Our preliminary data suggests that germ granules maintain pluripotency by 1) silencing somatic mRNAs that are stochastically expressed in the germline, and 2) repressing the function of associated proteins required for sperm-specific mRNA expression. We will test these ideas by inducing the expression of mRNAs that exhibit high germ-granule affinity, and then we will compare changes in their distribution, accumulation, and translation in the presence and absence of germ granules (Aim 1). We will also determine how and which sperm-promoting pathways are negatively regulated by germ granules (Aim 2). And finally, we examine a specific germ-granule protein, CSR-1, that has the capacity to recognize and promote the expression of germline mRNAs, and will determine how it and its cofactors function in germ granules to promote germ-cell pluripotency (Aim 3). These findings will provide new approaches to safely induce cellular pluripotency when it is needed and shut off pluripotency when it is not.

 描述（由适用提供）：干细胞由它们的多能和自我更新特性定义。大量研究集中在解锁分化细胞中的这些特性，以创建可用于治疗疾病的患者衍生的干细胞。但是，创建患者衍生的干细胞的过程在很大程度上依赖于表达细胞核内的多能分因素。使用通常使干细胞对再生医学太危险的技术。该提议采用了一种独特的方法来了解称为胚芽颗粒的细胞质成分如何调节细胞“茎”。最终目标是能够操纵细胞质中的生殖颗粒多能因素，以提高患者衍生的干细胞的质量和安全性。胚芽颗粒是RNA和RNA结合蛋白的异质混合物，它们在从蠕虫到人类的生殖线中保守。秀丽隐杆线虫的透明度和复杂的遗传学提供了一个机会，以一种在更复杂的模型生物中不可行的方式研究生殖颗粒功能的机会。我们最近的研究表明，生殖细胞生成的细胞质微环境促进了转录后调节事件，这对种系的多能和自我更新性质至关重要。我们还表明，耗尽的生殖颗粒会导致生殖细胞失去多能性，启动躯体分化和与精子发生相关的表达转录本。我们的初步数据表明，生殖颗粒通过1）沉默在生殖线中随机表达的体细胞mRNA，以及2）反映精子特异性mRNA表达所需的相关蛋白的功能。我们将通过诱导暴露高生殖颗粒亲和力的mRNA的表达来测试这些思想，然后我们将在存在和不存在菌粒颗粒的情况下比较它们的分布，积累和翻译的变化（AIM 1）。我们还将确定细菌颗粒对促进精子的方式和哪些促进途径的调节（AIM 2）。最后，我们检查了一种特定的生殖颗粒蛋白CSR-1，该蛋白具有识别和促进种系mRNA的表达的能力，并将确定其及其辅助因子在生殖颗粒中的作用。种系多能性（AIM 3）。这些发现将提供新的方法，以便在需要时安全地诱导细胞多能力，并在不需要时关闭多功能。