GSK3b mediates radiation-induced cytotoxicity in hippocampal neurons

GSK3b 介导海马神经元辐射诱导的细胞毒性

• 批准号: 8337105
• 负责人: Fen Xia
• 金额: $ 38.75万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-12 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8337105
• 关键词: Affect; Apoptosis; Attenuated; Biochemical; Biological; Brain; Brain Neoplasms; Cells; Cephalic; Child; Cognitive; Core Protein; Cranial Irradiation; DNA Double Strand Break; Data; Double Strand Break Repair; Exhibits; Figs - dietary; Functional disorder; Genetic; Genetic Transcription; Glycogen Synthase Kinases; Goals; Hippocampus (Brain); In Vitro; Ionizing radiation; Laboratories; Malignant - descriptor; Malignant neoplasm of brain; Maps; Mediating; Mediator of activation protein; Metabolic; Modeling; Molecular; Neurocognitive; Neurons; Nonhomologous DNA End Joining; PIK3CG gene; Pathway interactions; Patients; Phosphorylation; Phosphorylation Inhibition; Phosphorylation Site; Phosphotransferases; Play; Prevention; Process; Protein Kinase; Proteins; Proto-Oncogene Proteins c-akt; Quality of life; Radiation; Radiation Protection; Radioprotection; Regulation; Resistance; Role; Series; Signal Pathway; Signal Transduction; Testing; Toxic effect; Up-Regulation; Work; biological adaptation to stress; brain tissue; cancer cell; cell injury; cognitive function; cytotoxicity; improved; in vivo; irradiation; neoplastic cell; neuron apoptosis; neuroprotection; neurotoxicity; novel; prophylactic; repaired; research study; tumor

DESCRIPTION (provided by applicant): A formidable challenge in the treatment of primary and metastatic brain cancers, especially in children, is the long-term neurocognitive deficiencies resulting from cranial irradiation (IR)-induced hippocampal neuronal apoptosis. Our laboratory has discovered a novel functional connection between the metabolic kinase GSK3¿ and the Non- homologous End-joining (NHEJ) pathway that repair DNA double-strand breaks (DSBs). Furthermore, our preliminary data revealed that the NHEJ mediator 53BP1 is directly phosphorylated by GSK3¿; meanwhile, increased expression of the classic GSK3¿ substrate ¿-catenin is associated with enhanced repair of IR-induced DSBs and survival in hippocampal neurons. Thus, we hypothesize that GSK3¿ regulates NHEJ-mediated repair of DSBs and determines neuron cytotoxicity following IR via suppression of 53BP1 and ¿-catenin function. In addition, tumor cells which contain abnormal GSK3 ¿ activity will not exhibit GSK3¿-mediated protection from IR-induced cytotoxicity. A series of in vitro and in vivo experiments are proposed to test our hypotheses: Aim 1 will identify the GSK3 ¿ phosphorylation sites in 53BP1 and determine whether GSK3 ¿ -specific phosphorylation direct 53BP1 function in NHEJ and in survival of irradiated hippocampal neurons. Aim 2 will determine whether GSK3 ¿ regulates 53BP1 through suppressing ¿ - catenin that may promote NHEJ activity by increasing 53BP1 transcription, or by directly interacts with 53BP1. Aim 3 will determine if abnormal GSK3 ¿ activity determine brain tumor cell resistance to the prophylactic GSK3 ¿ -inhibition mediated protection from radiation induced cytotoxicity. PUBLIC HEALTH RELEVANCE: In an effort to decrease neurotoxicity and improve patient quality of life, pharmacologic agents which exhibit neuroprotective effects are being rigorously investigated. Thus, the goal of this proposal is to determine the mechanisms of action that protect neurons from irradiation-induced hippocampal neuronal apoptosis with a view toward prevention of neurocognitive toxicity from cranial IR.

描述（由申请人提供）：治疗原发性和转移性脑癌（尤其是儿童）的一个巨大挑战是由颅脑照射（IR）诱导的海马神经元凋亡导致的长期神经认知缺陷。我们的实验室发现了代谢激酶GSK 3？与修复DNA双链断裂（DSB）的非同源末端连接（NHEJ）途径之间的新功能联系。此外，我们的初步数据显示，NHEJ介体53 BP 1被GSK 3直接磷酸化;同时，经典的GSK 3底物连环蛋白的表达增加与IR诱导的DSB的修复增强和海马神经元的存活有关。因此，我们假设GSK 3通过抑制53 BP 1和<$-连环蛋白功能调节NHEJ介导的DSB修复并决定IR后的神经元细胞毒性。此外，含有异常GSK 3活性的肿瘤细胞不会表现出GSK 3介导的对IR诱导的细胞毒性的保护作用。提出了一系列体外和体内实验来验证我们的假设：目的1将确定53 BP 1中的GSK 3磷酸化位点，并确定GSK 3特异性磷酸化是否指导53 BP 1在NHEJ中的功能和辐射海马神经元的存活。目的2将确定GSK 3是否通过抑制可能通过增加53 BP 1转录或直接与53 BP 1相互作用促进NHEJ活性的β-连环蛋白来调节53 BP 1。目的3将确定是否异常的GSK 3？活性决定脑肿瘤细胞对预防性GSK 3？抑制介导的辐射诱导细胞毒性保护的抗性。 公共卫生相关性：为了减少神经毒性和改善患者的生活质量，正在严格研究表现出神经保护作用的药理学试剂。因此，本提案的目标是确定保护神经元免受辐射诱导的海马神经元凋亡的作用机制，以期预防颅IR的神经认知毒性。