Mouse model for neuroprotection

描述（由申请人提供）：Ca2+稳态紊乱是短暂性缺血和一些神经退行性疾病（如阿尔茨海默病（AD）、多谷氨酰胺病和帕金森病）中神经元损伤的主要原因。内质网（ER）是Ca2+储存的主要细胞器。内质网通过Ca2+信号传导调节多种细胞功能，并为跨膜和腔内蛋白的翻译后折叠和成熟提供专门的环境。细胞内Ca2+储存的损失导致细胞质Ca2+的升高，这可能导致神经元易感性，导致内在细胞死亡途径的激活。此外，由于蛋白伴侣使用Ca2+作为辅助因子，ER Ca2+的释放也会通过错误折叠蛋白的积累导致细胞损伤。扰乱内质网功能的生理、病理和实验条件会导致内质网内错误折叠蛋白的积累，并作为随后的内质网应激的结果，激活代偿性信号通路，统称为未折叠蛋白反应（UPR）。在本提案中，我们概述了我们的策略，以开发基于STC2过表达的神经保护小鼠模型，以对抗Ca2+放松管制。我们最近发现STC2是由哺乳动物UPR、缺氧和脑缺血诱导的基因。我们进一步证明，在培养细胞中，STC2的表达是必要的，足以提供细胞保护，防止ER Ca2+稳态破坏引起的细胞死亡。STC2是一种在鱼类和哺乳动物中高度保守的分泌糖蛋白激素。我们假设STC2在哺乳动物中具有独特的功能，作为UPR的关键存活成分，在病理条件下保护细胞免受Ca2+稳态破坏引起的损伤。这一建议的具体目标如下：目标1。目的：制备STC2表达时空调控的转基因小鼠。目标2。目的探讨STC2的神经保护功能。我们的研究将为科学界开发有价值的资源-具有空间和时间控制STC2表达的转基因小鼠，并进行体外和体内可行性研究，这将为证明STC2对Ca2+稳态失调引发的细胞死亡的神经保护特性提供原理证明。我们的研究结果将对未来开发基于STC2的治疗策略来预防神经元死亡至关重要。

DESCRIPTION (provided by applicant): Disturbance of Ca2+ homeostasis is a major cause of neuronal injury in transient ischemia and several neurodegenerative disorders such as Alzheimer's disease (AD), polyglutamine diseases, and Parkinson's disease. The endoplasmic reticulum (ER) is a major organelle for Ca2+ storage. The ER regulates multiple cellular functions through Ca2+ signaling, and provides a specialized environment for post-translational folding and maturation of transmembrane and luminal proteins. Loss of Ca2+ from intracellular stores causes elevation of cytosolic Ca2+, which can lead to neuronal vulnerability resulting from activation of intrinsic cell death pathways. In addition, since protein chaperones use Ca2+ as a cofactor, release of ER Ca2+ also causes cell injury through an accumulation of misfolded proteins. Physiological, pathological and experimental conditions that perturb ER function cause accumulation of misfolded proteins within the ER, and as a result of the ensuing ER stress, activate compensatory signaling pathways collectively known as the unfolded protein response (UPR). In this proposal we outline our strategy to develop a mouse model for neuroprotection against Ca2+ deregulation, based on overexpression of stanniocalcin 2 (STC2). We recently identified STC2 as a gene induced by the mammalian UPR, hypoxia, and cerebral ischemia. We further demonstrated that in cultured cells expression of STC2 is essential and sufficient to offer cytoprotection against cell death induced by disruption of ER Ca2+ homeostasis. STC2 is a secreted glycoprotein hormone highly conserved in fish and mammals. We postulate that STC2 carries out a distinct function in mammals as a critical survival component of the UPR, defending cells from injury caused by disruption of Ca2+ homeostasis under pathological conditions. The following are the specific aims of this proposal: Aim 1. To generate transgenic mice with spatial/temporal control of STC2 expression. Aim 2. To characterize the neuroprotective function of STC2. Our investigation will develop a valuable resource for the scientific community - transgenic mice with spatial and temporal control of STC2 expression, and perform in vitro and in vivo feasibility studies that will provide the proof of principle to demonstrate neuroprotective properties of STC2 against cell death initiated by deregulation of Ca2+ homeostasis. Outcome of our investigation will be critical for the future development of STC2 based therapeutic strategy to prevent neuronal death.