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: 8509634
• 负责人: Fen Xia
• 金额: $ 37.19万
• 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/8509634
• 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.

描述（由申请人提供）：原发性和转移性脑癌（尤其是儿童）治疗中的一个巨大挑战是颅内辐射（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 GSK3 与修复 DNA 双链断裂 (DSB) 的非同源末端连接 (NHEJ) 途径之间的新型功能连接。此外，我们的初步数据显示 NHEJ 介质 53BP1 直接被 GSK3¿ 磷酸化；同时，经典 GSK3¿ 底物 β-连环蛋白表达的增加与 IR 诱导的 DSB 修复增强和海马神经元存活相关。因此，我们假设 GSK3¿ 调节 NHEJ 介导的 DSB 修复，并通过抑制 53BP1 和 ¡-连环蛋白功能来确定 IR 后的神经元细胞毒性。此外，含有异常 GSK3 活性的肿瘤细胞不会表现出 GSK3 介导的针对 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检验我们的假设：目标 1 将鉴定 53BP1 中的 GSK3 ¿ 磷酸化位点，并确定 GSK3 ¿ 特异性磷酸化是否指导 53BP1 在 NHEJ 中和受辐射海马神经元的存活中发挥作用。目标 2 将确定 GSK3 是否通过抑制 ¿ - 连环蛋白（可能通过增加 53BP1 转录或直接与 53BP1 相互作用来促进 NHEJ 活性）来调节 53BP1。目标 3 将确定异常的 GSK3 ¿ 活性是否决定脑肿瘤细胞对预防性 GSK3 ¿ 抑制介导的针对辐射诱导的细胞毒性的保护的抵抗力。