Cell Non-Autonomous nature of the Heat Shock Response

描述(申请人提供)：组织或生物体内不同细胞类型之间的同步通讯以实现正常功能的了解甚少。在离散的组织中产生的各种分泌的细胞外信号往往有可能影响整个生物体的动态平衡。有时，这些信号可能是破坏性的：例如，在许多年龄起病的神经退行性疾病中，特定的神经元子集出现功能障碍，随后在周围组织中启动退行性级联反应。然而，从一个组织到另一个组织的信号也可以是建设性的，最终是对有机体的协调保护。道格拉斯博士发现了一种起源于神经系统的转导信号成分，可以在远端相关组织中提供抵御压力的保护。初步研究表明，一种结构性激活的基因表达 热休克转录因子，HSF-1，仅在线虫神经系统中存在：(1)保护线虫免受热应激；(2)延缓衰老；(3)解毒远端组织中的模型病蛋白质。由分泌的HSF-1信号提供的热保护需要一个功能正常的热感觉神经回路和RNA转运体，这表明它的传播需要一个假定的RNA信号。相反，长寿和蛋白质解毒表型需要不同的信号通路才能繁殖，涉及胰岛素/IGF-1转录因子DAF-16。因此，神经系统中HSF-1激活的位置和性质指定了其针对不同应激源的保护模式。在这项研究中，道格拉斯博士将描述这些细胞外信号事件在一个活的、完整的有机体中的产生、传播和最终接收。在目标1中，他将确定能够分泌保护性HSF-1信号的关键神经元，并定义这些选定神经元中的参与机制。在目标2中，将发现每个发散信号的身份。在目标3中，将在受体组织中识别识别不同HSF-1信号并启动保护计划所需的细胞因子。指导阶段的培训将使道格拉斯博士准备好领导一个独立的实验室，利用线虫发达和易驯化的遗传学、神经生物学和生物化学来解决新的生物学重要性问题。该奖项下的培训将包括：学习利用线虫神经系统研究完整动物中神经出生的细胞外信号事件；定量蛋白质组学中的质谱学技术，这是识别相关信号分子和相关机制所必需的；小RNA图谱和组织特异性核糖体图谱所必需的生物信息学技术；在以下领域的新研究方法 蛋白质动态平衡和衰老；以及指导技能，如教学和拨款撰写。这些都将极大地促进道格拉斯博士作为一名独立研究员的过渡和成功。

DESCRIPTION (provided by applicant): The synchronous communication among different cell types within a tissue or organism to achieve normal function is poorly understood. A variety of secreted extracellular signals that are generated in discrete tissues often have the potential to impact homeostasis throughout the entire organism. Occasionally, these signals can be destructive: in numerous age-onset neurodegenerative diseases, for example, dysfunction arises in a defined subset of neurons and subsequently initiates a degenerative cascade in peripheral tissues. Yet, signals from one tissue to another can also be constructive and end in the coordinate protection of the organism. Dr. Douglas has identified a transduction signaling component that originates in the nervous system and can confer protection against stress in distally associated tissues. Preliminary studies show that expression of a constitutively-activated Heat Shock transcription Factor, HSF-1, exclusively in the nervous system of the nematode C. elegans: (1) protects against heat stress; (2) slows aging; and (3) detoxifies model-disease proteins in distal tissues. Heat-protection conferred by secreted HSF-1 signals requires a functional thermo- sensory neural circuit and RNA transporters, suggesting that a putative RNA signal is required for its propagation. In contrast, long-lifespan and proteo-detoxification phenotypes require a distinct signaling pathway for their propagation involving the insulin/IGF-1 transcription factor DAF-16. Thus the site and nature of HSF-1 activation in the nervous system specifies its mode of protection against different stressors. In this study, Dr. Douglas will characterize the generation, propagation and ultimate receipt of these extracellular signaling events in a living, intact organism. In Aim 1, he will identify key neurons which are capable of secreting protective HSF-1 signals and define the participating machinery within those select neurons. In Aim 2, the identity of each divergent signal will be uncovered. In Aim 3, cellular factors will be identified within recipient tissues which are required to recognize the different HSF-1 signals and initiate protective programs. Training in the mentored phase will prepare Dr. Douglas to direct an independent lab using the well developed and tractable genetics, neurobiology, and biochemistry of C. elegans to address new questions of biological importance. Training under this award will include: learning to utilize the C. elegans nervous system to study neural-born extracellular signaling events in the intact animal; mass spectrometry techniques in quantitative proteomics which are necessary to identify pertinent signaling molecules and associated machinery; bioinformatic techniques necessary for small RNA profiling and tissue-specific ribosomal profiling; new investigational methods in the fields of protein homeostasis and aging; and mentorship skills such as teaching and grant writing. These will greatly facilitate Dr. Douglas' transition and success as an independent investigator.