Heat shock proteins in the nervous system

在对应激刺激的反应中，细胞激活高度保守的热休克反应，其中诱导一组应激蛋白（称为“热休克蛋白”或“HSP”），其在细胞修复和保护中起作用。我们以前的研究表明，这种细胞应激反应是生理相关的，因为热休克蛋白在神经系统中迅速诱导，以响应温度升高和组织损伤。热休克蛋白是“蛋白质修复剂”，提供了一条防线，防止错误折叠，聚集倾向的蛋白质积累后，细胞的压力和神经退行性疾病。HSPA是一个多基因家族，包括i）由HSPA 1A基因编码的应激诱导型Hsp 70 -1和ii）由HSPA 6编码的应激诱导型Hsp 70 B '，其受到的关注相对较少。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，在组织培养物中生长的神经元细胞中的细胞应激反应的实时成像，以及除此之外，在完整的哺乳动物脑中的高分辨率实时成像，重点是Hsp 70 B '。 本课题组是目前国内唯一报道Hsp 70 B '在神经系统表达的实验室。在2014年10月，我们报道了Hsp 70 -1没有观察到的Hsp 70 B '的新作用。热休克蛋白70 B '瞬时与核斑点的周边相关联，核斑点是神经元细胞从应激诱导的转录抑制中恢复期间的转录位点。我们现在将确定应激后转录恢复是否依赖于Hsp 70 B '的诱导，以及这种现象是否是神经元细胞特有的。将通过旋转圆盘显微镜在培养的神经元细胞中和通过多光子显微镜在完整脑中对Hsp 70的实时图像定位来鉴定应激敏感的细胞内位点。这些研究将有助于神经系统细胞应激反应的真实的实时分析。我们的新的神经蛋白质错误折叠的多靶点调节剂的神经保护功能将被移动到一个新的领域，在活的大脑中使用最新的多光子进展的分析。参加该计划的学员将受益于细胞应激反应的新方面的工作，并从2009-2014年期间获得的一系列先进技术中受益，其中CFI/ORF基础设施奖为多伦多斯卡伯勒大学生物科学系应激神经生物学中心580万美元。

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.