Regulation of GSK3beta by Intercellular Localization.

通过细胞间定位调节 GSK3beta。

• 批准号: 6855688
• 负责人: GAUTAM N BIJUR
• 金额: $ 23.47万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-15 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6855688
• 关键词: apoptosis; biological signal transduction; cAMP response element binding protein; camptothecin; cell component structure /function; cerebral ischemia /hypoxia; enzyme activity; laboratory mouse; laboratory rat; mitochondria; neural plasticity; neurotoxicology; phosphatidylinositol 3 kinase; protein localization; pyruvate dehydrogenase; serine threonine protein kinase; thapsigargin; tissue /cell culture; transcription factor

DESCRIPTION (provided by applicant): Glycogen synthase kinase-3beta (GSKbeta) is a key component of numerous cell signaling cascades, affecting many fundamental cellular functions associated with neural plasticity. Furthermore, GSK3beta is being recognized as an important mediator of apoptosis, a process of cell death that may contribute to neuronal loss following brain injury due to cerebral ischemia, and in certain types of neurodegenerative diseases. GSK3beta is known to exist in at least three cellular compartments, the cytosol, the nucleus and mitochondria. The activities of GSK3beta in these three compartments was measured in SHSY5Y cells following activation of proapoptotic signaling with thapsigargin, an agent which causes endoplasmic reticulum (ER) stress. Neuronal death in cerebral ischemia is believed to be due to increased intracellular calcium from ER stress. Thapsigargin treatment selectively increased GSK3b activity in the nucleus and the mitochondria, but cytosolic GSK3beta activity was not increased. To test if other apoptotic stimuli could also activate nuclear and mitochondrial GSK3beta, cells were treated with camptothecin, an agent that causes genotoxic stress. Camptothecin also activated GSK3beta in the nucleus and mitochondria, but not in the cytosol. The selective activation of GSK3beta in the nuclear and mitochondrial compartments is likely a major factor in the proapoptotic actions of GSK3beta. The goal of Specific Aim 1 is to examine if nuclear GSK plays a role in apoptosis and test the effects of modulating nuclear GSK3beta on two transcription factors, camp response element binding protein (CREB) and heat shock factor-1 (HSF1), which are critical for maintaining neural plasticity and cell survival, and whose actions are known to be impaired by increased GSK3beta activity. The goal of Specific Aim 2 is to selectively modulate the activity of mitochondrial GSK3beta, and test if increased mitochondria GSK3beta contributes to apoptotic signaling and inhibits the activity of the key metabolic enzyme pyruvate dehydrogenase, and impairs mitochondrial function. The goal of Specific Aim 3 is to test if GSK3beta plays a deleterious role in the generation of neuronal damage following NMDA treatment and in a model of transient focal cerebral ischemia, and if inhibition of GSK3beta has the potential to provide significant therapeutic neuronal protection from both insults. Overall, these aims will identify the mechanisms by which GSK3beta activity is regulated and the relative contributions of distinct pools of GSK3beta in impairing neural plasticity.

描述（由申请人提供）：糖原合成酶激酶 3beta (GSKbeta) 是众多细胞信号级联的关键组成部分，影响与神经可塑性相关的许多基本细胞功能。此外，GSK3beta 被认为是细胞凋亡的重要介质，细胞凋亡是一种细胞死亡过程，可能导致脑缺血引起的脑损伤后以及某些类型的神经退行性疾病中的神经元损失。已知 GSK3beta 存在于至少三个细胞区室中：细胞质、细胞核和线粒体。在用毒胡萝卜素激活促凋亡信号后，在 SHSY5Y 细胞中测量这三个区室中 GSK3β 的活性，毒胡萝卜素是一种引起内质网 (ER) 应激的药物。脑缺血中的神经元死亡被认为是由于内质网应激导致细胞内钙增加所致。毒胡萝卜素处理选择性增加细胞核和线粒体中的 GSK3b 活性，但胞质 GSK3β 活性并未增加。为了测试其他细胞凋亡刺激是否也可以激活核和线粒体 GSK3β，用喜树碱（一种引起基因毒性应激的物质）处理细胞。喜树碱还激活细胞核和线粒体中的 GSK3β，但不激活细胞质中的 GSK3beta。 GSK3beta 在核和线粒体区室中的选择性激活可能是 GSK3beta 促凋亡作用的主要因素。具体目标 1 的目标是检查核 GSK 是否在细胞凋亡中发挥作用，并测试调节核 GSK3β 对两种转录因子：camp 反应元件结合蛋白 (CREB) 和热休克因子-1 (HSF1) 的影响，这两个转录因子是对于维持神经可塑性和细胞存活至关重要，并且已知 GSK3beta 活性增加会损害其作用。具体目标 2 的目标是选择性调节线粒体 GSK3β 的活性，并测试线粒体 GSK3β 的增加是否有助于细胞凋亡信号传导、抑制关键代谢酶丙酮酸脱氢酶的活性，并损害线粒体功能。具体目标 3 的目标是测试 GSK3beta 是否在 NMDA 治疗后和短暂性局灶性脑缺血模型中的神经元损伤的产生中发挥有害作用，以及抑制 GSK3beta 是否有可能提供显着的治疗性神经元保护，使其免受这两种损伤的影响。侮辱。总体而言，这些目标将确定 GSK3beta 活性的调节机制以及不同 GSK3beta 池在损害神经可塑性方面的相对贡献。