HEAT SHOCK PROTEINS IN SPINAL CORD NEURAL SURVIVAL

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。脊髓损伤（SCI）和随后的继发性细胞死亡部分涉及缺血成分。少突胶质细胞和星形胶质细胞的存活对于维持白色物质中的细胞相互作用和限制继发性损伤是至关重要的。本研究的目的是研究缺氧/缺血暴露的少突胶质细胞和星形胶质细胞中热休克蛋白（hsps）的诱导和相互作用，并确定与更高的缺血耐受性相关的分子和信号通路。应激诱导的热休克蛋白参与蛋白质的重折叠和修复，并与脑和脊髓的细胞缺血耐受有关。我们将测试的假设，SCI后，热休克蛋白表达的诱导调节神经胶质细胞的生存信号通路，以保持少突胶质细胞/星形胶质细胞的完整性和与神经元的相互作用。该提案的具体目标是：1.目的：研究热休克蛋白在培养的缺氧缺血少突胶质细胞和星形胶质细胞中的表达，以及在脊髓挫伤中的表达。2.探讨热休克蛋白对缺氧缺血损伤和脊髓损伤后少突胶质细胞和星形胶质细胞存活的影响。3.探讨脊髓损伤后热休克蛋白相关的细胞保护机制，以及热休克蛋白结合蛋白在缺氧/缺血存活途径和细胞死亡中的作用。使用胚胎少突胶质细胞前体（OPC）分化为少突胶质细胞或星形胶质细胞，并暴露于缺氧/缺血，我们将评估热休克蛋白的表达在细胞模型和相关的HSP表达水平与细胞存活。此外，我们将描述啮齿动物脊髓中SCI诱导的hsps的特征。将确定hsp基因过表达或沉默对细胞缺氧/缺血的少突胶质细胞/星形胶质细胞存活和对SCI诱导的延迟损伤的影响，以及在整个动物中实验性hsp诱导对SCI后继发性损伤诱导的损伤的影响。最后，我们将使用蛋白质组学的方法来确定蛋白质-蛋白质相互作用与hsps诱导的缺氧/缺血寡树突细胞和星形胶质细胞，并在脊髓损伤后的差异受损地区。因此，我们将表征细胞对缺氧/缺血的差异敏感性的信号通路，并确定SCI中潜在的干预靶点。这些研究将确定新的治疗方法，以保持少突胶质细胞的支持，在受伤的脊髓，抑制细胞凋亡，并减少迟发性白色物质损伤。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Spinal cord injury (SCI) and subsequent secondary cell death partially involves an ischemic component. Oligodendrocytes and astrocytes survival is critical to maintain cellular interactions in the white matter and limit secondary injury damage. The purpose of this proposal is to study heat shock proteins (hsps) induction and interactions in hypoxia/ischemia-exposed oligodendrocytes and astrocytes and identify molecules and signaling pathways associated with higher tolerance to ischemia. Hsps induced by various stresses are involved in protein refolding and repair, and have been implicated in cellular ischemic tolerance in brain and in spinal cord. We will test the hypothesis that after SCI, induction of hsp expression modulates glial cell survival signaling pathways to preserve oligodendrocyte / astrocyte integrity and interactions with neurons. The specific aims of this proposal are: 1. To examine the expression profile of heat shock proteins induced in hypoxic/ischemic oligodendrocytes and astrocytes in culture, and in contused spinal cord. 2. To determine the effect of hsp on oligodendrocytes and astrocytes survival to hypoxia/ ischemic injury and after SCI. 3. To determine the mechanism(s) of hsp-related cell protection and the role of hsp binding proteins in hypoxia/ ischemia survival pathways and in cell death after SCI. Using embryonic oligodendrocyte precursors (OPCs) differentiated to either oligodendrocytes or astrocytes and exposed to hypoxia/ischemia, we will assess heat shock proteins expression in a cellular model and correlate the levels of hsp expression with cell survival. In addition, we will characterize the profile of hsps induced by SCI in rodent spinal cord. The effect of hsp gene overexpression or silencing on oligodendrocytes/astrocytes survival to cellular hypoxia/ ischemia and on SCI-induced delayed injury will be determined, as well as the effect of experimental hsp induction in the whole animal on secondary injury-induced damage after SCI. Finally, we will use proteomic approaches to identify protein-protein interactions with hsps induced by hypoxia/ischemia in oligodendro- cytes and in astrocytes, and in differentially damaged areas of the spinal cord after SCI. Thus, we will characterize signaling pathways underlying cellular differential sensitivity to hypoxia/ischemia and identify potential intervention targets in SCI. These studies will identify novel therapeutic approaches to preserve oligodendroglial support in injured spinal cord, inhibit apoptosis, and reduce delayed white matter injury.