Cell Non-Autonomous nature of the Heat Shock Response

描述（由申请人提供）：对组织或生物体内不同细胞类型之间实现正常功能的同步通信知之甚少。在离散组织中产生的各种分泌的细胞外信号通常具有影响整个生物体的稳态的潜力。有时，这些信号可能是破坏性的：例如，在许多年龄发作的神经退行性疾病中，功能障碍出现在一个确定的神经元子集中，随后在外周组织中引发退行性级联反应。然而，从一个组织到另一个组织的信号也可以是建设性的，并最终协调保护生物体。 道格拉斯博士已经确定了一种起源于神经系统的转导信号成分，可以保护远端相关组织免受压力。初步研究表明，组成性激活的 热休克转录因子1（Heat Shock Transcription Factor，HSF-1）是线虫C. elegans：（1）保护免受热应激;（2）减缓衰老;（3）解毒远端组织中的模型疾病蛋白。由分泌的HSF-1信号赋予的热保护需要功能性热感觉神经回路和RNA转运蛋白，这表明其繁殖需要推定的RNA信号。相比之下，长寿命和蛋白解毒表型需要一个独特的信号通路，其传播涉及胰岛素/IGF-1转录因子β-16。因此，神经系统中HSF-1激活的位点和性质规定了其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活的、完整的生物体中的产生、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内的参与机制。在目标2中，将揭示每个发散信号的身份。在目标3中，将在受体组织内鉴定识别不同HSF-1信号并启动保护程序所需的细胞因子。 在指导阶段的培训将准备道格拉斯博士指导一个独立的实验室使用发达和易于处理的遗传学，神经生物学，和生物化学的C。elegans来解决新的生物学重要性问题。该奖项下的培训将包括：学习使用C。elegans神经系统研究神经出生的细胞外信号事件在完整的动物;质谱技术在定量蛋白质组学是必要的，以确定相关的信号分子和相关的机制;生物信息学技术所需的小RNA分析和组织特异性核糖体分析;新的调查方法领域的 蛋白质稳态和衰老;以及指导技能，如教学和拨款写作。这些将极大地促进道格拉斯博士作为一名独立研究者的过渡和成功。

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.