Transport of gene silencing between cells during RNA interference

描述(申请人提供)：RNA干扰(RNAi)是一种保守的机制，通过它双链RNA可以特异性地使匹配序列的基因失活。RNAi已经从在简单线虫中获得诺贝尔奖的发现迅速发展到一种治疗方法，以沉默缺乏传统药物的人类致病基因。然而，RNAi的基本方面仍然不清楚，需要了解它们以确保安全有效的RNAi治疗。在RNAi过程中将RNA输入线虫细胞的RNA通道的人类对应物对于将基于RNAi的药物输入人类细胞是必需的，这一事实突显了对模式生物线虫的研究的持续相关性和重要性。应聘者提出了一项为期5年的职业发展计划，旨在利用线虫对RNA干扰过程中细胞之间的RNA运输获得基本见解，同时在研究型大学建立独立的学术生涯。这位候选人将在他雄厚的遗传学和生物化学基础上，在克雷格·亨特博士的指导下发展成为RNA运输的独立研究员。亨特博士是研究动物细胞之间RNA运输的先驱和领导者。该计划将在哈佛大学分子生物学系实施，该系是现代生物学领域的领军机构。导师实验室的研究导致发现了保守的RNA通道SID-1，它是RNAi介导的沉默信号的输入和组织内细胞之间信号传输所必需的。在最近的一篇论文中，这位候选人报告了一项发现，即线虫组织中的RNA输出是通过受调控的SID-1独立机制进行的。在指导阶段，候选人将：1)用先进的显微镜分析组织内细胞之间SID-1依赖的RNA运输，并研究SID-1独立的组织RNA输出是如何由SID-3介导的，sid-3是这种输出所需的基因；2)研究细胞内RNAi途径蛋白在产生从该细胞运输的RNA中的作用。除了导师的实验室外，Aim1的高级显微镜将在候选人的合作者庄晓伟博士的实验室进行，庄晓伟博士是超分辨率显微镜的先驱。在奖项的独立阶段，候选人将分析候选人发现的另外两个基因Sexd-1和Sexd-2的作用，这两个基因是组织间输出所必需的，并将使用在辅导性阶段培训中获得的方法和技术，在补充细胞生物学、遗传学和生化方法方面确定用于输出的基本分子途径，同时执行上述研究计划，将使候选人作为独立研究人员建立一个多方面和丰富的研究计划。此外，拟议的研究将揭示线虫RNAi过程中RNA运输的基本方面，这将影响治疗人类疾病的RNAi方法的设计。 公共卫生相关性：基于RNAi的药物可以专门针对目前没有常规药物可用的致病基因。但是，将药物特异性和高效地输送到病变细胞和组织中是RNA治疗的主要障碍。了解控制RNAi介导的沉默信号从细胞输出的机制以及这种输出对线虫这些细胞内RNAi的影响将为克服人类治疗性RNAi的这些障碍提供有价值的见解。

DESCRIPTION (provided by applicant): RNA interference (RNAi) is a conserved mechanism by which double-stranded RNA can specifically inactivate genes of matching sequence. RNAi has rapidly developed from a Nobel-prize winning discovery in the simple worm C. elegans to a therapeutic approach to silence human disease-causing genes that lack conventional medicines. However, fundamental aspects of RNAi remain unclear and they need to be understood to ensure safe and efficacious RNAi therapy. The continued relevance and significance of studies in the model organism C. elegans is underscored by the fact that the human counterpart of an RNA channel that imports RNA into C. elegans cells during RNAi is required for the import of RNAi-based drugs into human cells. The candidate presents a 5-year career development plan that aims to use C. elegans to gain fundamental insights into the transport of RNA between cells during RNA interference, while establishing an independent academic career at a research university. The candidate will build on his strong foundation in genetics and biochemistry to develop into an independent researcher in RNA transport under the mentorship of Dr. Craig Hunter, a pioneer and leader in the study of RNA transport between animal cells. The plan will be carried out in the Department of Molecular Biology at Harvard University, a leading institution in modern biology. Research in the mentor's lab led to the discovery of the conserved RNA channel SID-1 that is required for the import of RNAi-mediated silencing signals and the transport of signals between cells within a tissue. In a recent publication, the candidate reported the discovery that export of RNA from C. elegans tissues occurs through a regulated SID-1 independent mechanism. During the mentored phase, the candidate will: 1) Dissect the SID-1 dependent transport of RNA between cells within a tissue using advanced microscopy and examine how the SID-1 independent export of RNA from tissues is mediated by sid-3, a gene required for such export; and 2) examine the role of RNAi pathway proteins within a cell in generating RNAs transported from that cell. In addition to the mentor's laboratory, advanced microscopy for Aim1 will be carried out in the lab of the candidate's collaborator Dr. Xiaowei Zhuang, who is a pioneer in super-resolution microscopy. During the independent phase of the award, the candidate will analyze the roles of sexd-1 and sexd-2, two other genes discovered by the candidate that are required for inter-tissue export and will define a basic molecular pathway for export using the approaches and techniques acquired during the mentored phase Training in the complementary cell biological, genetic, and biochemical approaches while executing the above research plan will equip the candidate to establish a multi-faceted and rich research program as an independent investigator. Further, the proposed studies will reveal fundamental aspects of RNA transport during RNAi in C. elegans, which will impact the design of therapeutic RNAi approaches to human diseases. Public Health Relevance: Relevance RNAi-based drugs can specifically target disease-causing genes for which no conventional medicines are currently available. But, delivery of the drugs specifically and efficiently into diseased cells and tissues is a major barrier to RNA therapy. Understanding the mechanisms that control export of RNAi-mediated silencing signals from cells and the effect of such export on RNAi within these cells in C. elegans will provide valuable insights to overcome these barriers to therapeutic RNAi in humans.