Transport of gene silencing between cells during RNA interference

描述（由申请人提供）：RNA干扰（RNAi）是一种保守的机制，通过该机制，双链RNA可以特异性地干扰匹配序列的基因。RNA干扰技术是从一个获得诺贝尔奖的简单蠕虫C. elegans到一个治疗方法沉默人类致病基因，缺乏常规药物。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。对模式生物C. elegans是强调的事实，即人类对应的RNA通道，进口RNA到C。在RNAi过程中，线虫细胞是将基于RNAi的药物导入人类细胞所必需的。候选人提出了一个5年的职业发展计划，旨在使用C。elegans获得在RNA干扰过程中RNA在细胞之间转运的基本见解，同时在研究型大学建立独立的学术生涯。候选人将在遗传学和生物化学的坚实基础上，在动物细胞之间RNA转运研究的先驱和领导者克雷格亨特博士的指导下，发展成为RNA转运的独立研究人员。该计划将在现代生物学的领先机构哈佛大学的分子生物学系进行。导师实验室的研究发现了保守的RNA通道SID-1，该通道是RNAi介导的沉默信号的输入和组织内细胞之间信号的运输所必需的。在最近的一份出版物中，这位候选人报告了一个发现，即从C. elegans组织通过受调节的SID-1非依赖性机制发生。在指导阶段，候选人将：1）使用先进的显微镜解剖组织内细胞之间的SID-1依赖的RNA转运，并检查SID-1独立的RNA从组织的输出是如何由sid-3介导的，sid-3是这种输出所需的基因;和2）检查细胞内RNAi途径蛋白在产生从该细胞转运的RNA中的作用。除了导师的实验室外，Aim 1的先进显微镜将在候选人的合作者Xiaowei Zhuang博士的实验室进行，他是超分辨率显微镜的先驱。在该奖项的独立阶段，候选人将分析sexd-1和sexd-2的作用，这是候选人发现的组织间输出所需的另外两个基因，并将使用在指导阶段获得的方法和技术来定义输出的基本分子途径。和生物化学的方法，同时执行上述研究计划将装备候选人建立一个多方面的和丰富的研究计划，作为一个独立的研究者。此外，拟议的研究将揭示在C. elegans，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的药物可以特异性靶向目前没有常规药物的致病基因。但是，将药物特异性和有效地递送到患病细胞和组织中是RNA治疗的主要障碍。了解控制RNAi介导的沉默信号从细胞中输出的机制以及这种输出对这些细胞内RNAi的影响，在C. elegans将提供有价值的见解，以克服这些障碍，在人类治疗RNAi。

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.