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: 9054081
• 负责人: Fen Xia
• 金额: $ 3.44万
• 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 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9054081
• 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 Kinase 3; 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; 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; p53-binding protein 1; 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）：在原发性和转移性脑癌的治疗中，特别是在儿童中，一个巨大的挑战是颅照射（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GSK3 -与修复DNA双链断裂（DSBs）的非同源末端连接（NHEJ）途径之间的一种新的功能联系。此外，我们的初步数据显示，NHEJ中介53BP1被GSK3直接磷酸化；同时，经典GSK3“底物”-catenin的表达增加与ir诱导的dsb修复和海马神经元存活增强有关。因此，我们假设GSK3调节nhej介导的dsb修复，并通过抑制53BP1和-catenin功能决定IR后神经元的细胞毒性。此外，含有异常GSK3活性的肿瘤细胞不会表现出GSK3介导的对ir诱导的细胞毒性的保护作用。我们提出了一系列体外和体内实验来验证我们的假设：Aim 1将确定53BP1中GSK3的磷酸化位点，并确定GSK3特异性磷酸化是否直接影响53BP1在NHEJ和辐射海马神经元存活中的功能。Aim 2将确定GSK3是通过抑制catenin调控53BP1， catenin可能通过增加53BP1转录来促进NHEJ活性，还是直接与53BP1相互作用。目的3将确定异常的GSK3活性是否决定脑肿瘤细胞对预防性GSK3抑制介导的辐射诱导细胞毒性保护的抗性。