Heat shock proteins in the nervous system

在应激刺激下，细胞激活一种高度保守的热休克反应，在这种反应中，一组应激蛋白（称为“热休克蛋白”或“Hsps”）被诱导，在细胞修复和保护中发挥作用。我们之前的研究表明，这种细胞应激反应与生理相关，因为热休克蛋白在神经系统中被迅速诱导，以响应温度升高和组织损伤。热休克蛋白是“蛋白质修复剂”，为细胞应激和神经退行性疾病期间积累的错误折叠、容易聚集的蛋白质提供一道防线。HSPA是一个多基因家族，包括由HSPA1A基因编码的应激诱导型Hsp70-1和由HSPA6基因编码的应激诱导型Hsp70B'，但目前对其关注较少。这项研究计划的愿景是将细胞应激反应的神经生物学带入一个新时代。即，在组织培养中生长的神经元细胞的细胞应激反应的实时成像，除此之外，在完整的哺乳动物大脑中进行高分辨率的实时成像，重点是Hsp70B'。本课题组是目前唯一报道Hsp70B'在神经系统中的表达的实验室。2014年10月，我们报道了Hsp70-1未观察到的Hsp70B'的新作用。在神经细胞从应激诱导的转录抑制中恢复过程中，Hsp70B'与核斑的外围短暂结合，核斑是转录位点。我们现在将确定应激后的转录恢复是否依赖于Hsp70B'的诱导，以及这种现象是否仅针对神经元细胞。通过旋转圆盘显微镜和多光子显微镜对培养的神经细胞和完整脑中的hsp70进行实时图像定位，确定应激敏感的细胞内位点。这些研究将有助于神经系统中细胞应激反应的实时分析。我们新颖的神经蛋白错误折叠多靶点调节剂的神经保护特性将利用最新的多光子进展进入活体大脑分析的新领域。参与该项目的受训者将从细胞应激反应的新方面和2009-2014年期间获得的一系列先进技术中受益，CFI/ORF基础设施主要奖励580万美元给多伦多大学斯卡伯勒分校生物科学系应激神经生物学中心。

In response to stressful stimuli, cells activate a highly conserved heat shock response in which a set of stress proteins (termed `heat shock proteins' or `Hsps') are induced that play roles in cellular repair and protection. Our previous studies have shown that this cellular stress response is physiologically relevant as Hsps are rapidly induced in the nervous system in response to temperature elevation and tissue injury. Hsps are `protein repair agents' that provide a line of defense against misfolded, aggregation-prone proteins that accumulated following cellular stress and during neurodegenerative disorders. HSPA is a multigene family that includes i) stress-inducible Hsp70-1 encoded by the HSPA1A gene and ii) stress-inducible Hsp70B' encoded by HSPA6 that has received comparatively little attention. The vision of this research proposal is to move the neurobiology of the cellular stress response into a new era. Namely, live imaging of the cellular stress response in neuronal cells grown in tissue culture and, beyond that, to high resolution live imaging in the intact mammalian brain, with a focus on Hsp70B'. Our research group is presently the only laboratory that has reported on expression of Hsp70B' in neural systems. In October 2014, we reported a novel role of Hsp70B' that is not observed for Hsp70-1. Hsp70B' transiently associates with the periphery of nuclear speckles that are sites of transcription during the recovery of neuronal cells from stress-induced transcriptional inhibition. We will now determine if transcriptional recovery after stress is dependent on induction of Hsp70B' and if the phenomenon is specific to neuronal cells. Stress-sensitive intracellular sites will be identified by live image localization of Hsp70s in cultured neuronal cells by spinning disk microscopy and in the intact brain by multiphoton microscopy. These studies will facilitate real time analysis of the cellular stress response in neural systems. Neuroprotective features of our novel multitarget modulators of neural protein misfolding will be moved into a new realm of analysis in the living brain using the latest multiphoton advances. Trainees participating in the program will benefit from working on novel aspects of the cellular stress response and from the array of advanced technology acquired over the period 2009-2014 with a major CFI/ORF infrastructure award of $5.8 million to the Center for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough.