Cell Non-Autonomous nature of the Heat Shock Response

描述（由申请人提供）：组织或生物体中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有可能影响整个生物体的内稳态。有时，这些信号可能是破坏性的：例如，在许多年龄性神经退行性疾病中，在特定的神经元亚群中出现功能障碍，随后在周围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，并以协调保护生物体而告终。道格拉斯博士发现了一种源于神经系统的转导信号成分，它可以保护远端相关组织免受压力。初步研究表明，一个组成激活的表达

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.