Probing the Protective Role of EZH2 in Epilepsy

探讨 EZH2 在癫痫中的保护作用

• 批准号: 10398140
• 负责人: RAYMOND J DINGLEDINE
• 金额: $ 50.7万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10398140
• 关键词: Alzheimer' s Disease; Amygdaloid structure; Anticonvulsants; Antiepileptogenic; Appearance; Binding; Biochemical; Bioinformatics; Blood - brain barrier anatomy; Brain; Cell Death; Cell Nucleus; Cells; Cellular Assay; Chromatin; Chronic; Complex; Convulsants; Data; Data Set; Disease; Disease Progression; Dose; EZH2 gene; Epilepsy; Epileptogenesis; Gene Expression; Generations; Genes; Genetic Models; Genetic Transcription; Hippocampus (Brain); Histones; Immunohistochemistry; Incidence; Individual; Inflammation; Institution; Life; Measures; Messenger RNA; Methylation; Methyltransferase; Migraine; Modeling; Molecular Biology; Molecular Genetics; Mus; Nerve Degeneration; Neurons; Outcome Measure; Output; Pathologic; Patients; Persons; Pharmaceutical Preparations; Pharmacology; Polycomb; Population; Prosencephalon; Proteins; Publishing; Rattus; Recurrence; Resected; Ribosomes; Role; Seizures; Status Epilepticus; Stimulus; Temporal Lobe Epilepsy; Testing; Time; Transcript; Up-Regulation; Work; antagonist; axonal sprouting; bioinformatics tool; dravet syndrome; epigenetic silencing; experimental study; follow-up; gene repression; genetic approach; genetic corepressor; genome-wide; granule cell; inhibitor; kainate; mRNA Expression; nervous system disorder; neurogenesis; novel; post stroke; programs; protein complex; response; stoichiometry; transcription factor; transcriptome sequencing; virtual; whole genome

Project Summary/Abstract Epilepsy is the 4th most prevalent neurological disorder after stroke, Alzheimer’s and migraine with an incidence of 1 in 26 individuals. Though there are a number of anti-convulsant drugs available, there are no anti-epileptogenic drugs that mitigate the progression of the disease. Using novel bioinformatic approaches, we have identified an endogenous, protective program launched by the brain after a prolonged seizure that functions to mitigate pathological changes. Epileptogenesis is associated with a plethora of changes in the brain including alterations in plasticity, cell death, neurogenesis, inflammation and axonal sprouting. These changes occur over timescales ranging from many minutes to years, but the orchestrating mechanisms are virtually unknown. Long-term changes in gene expression that are associated with epileptogenesis imply that one or more master regulators of transcription may be coordinating the brain alterations. In order to uncover these transcriptional mechanisms, we turned to our recently published genome-wide expression datasets generated by the Epilepsy Microarray Consortium (EMC). The datasets consist of mRNA expression profiles of rat dentate granule cells assayed at various time points after Status Epilepticus (SE). Using a novel bioinformatic tool that integrates whole genome transcription factor binding data with gene expression profiles, we analyzed datasets derived from brains induced by 3 different convulsant stimuli, each in 2 independent labs, and at various time-points. This analysis projected that Polycomb target genes represent the majority of chronically altered genes during epileptogenesis. REST targets represent a second, overlapping, group of repressed genes. Polycomb is a well-known driver of life-long changes in gene expression that works by epigenetically silencing genes across the phyla. Our data shows an extremely robust induction of EZH2 protein (the catalytic methylase subunit of Polycomb) over a 20 day window post SE in neurons. Further, we find that antagonizing EZH2 shortly after SE robustly accelerates the onset of spontaneous recurrent seizures in mice, suggesting a protective rather than pathological role for EZH2. How antagonism of EZH2 later after SE remains to be determined. In this project, we will test the hypothesis that an alteration in Polycomb output is a principal modifier of epileptogenesis. We will ascertain whether EZH2 upregulation is always protective or whether its role evolves during the latent period. We will test the effect of an order-of-magnitude change in EZH2 levels on corepressor function to see whether such upregulation augments or hampers the repressive abilities of two major EZH2 containing complexes: Polycomb and REST. We anticipate that these studies will establish Polycomb as a major orchestrator of the long-term changes associated with epileptogenesis. If so, approaches that modulate Polycomb function may be of benefit to the 65 million people world-wide that live with epilepsy.

项目总结/摘要 癫痫是继中风、阿尔茨海默病和偏头痛之后第四大最常见的神经系统疾病， 发病率为1/26。虽然有一些抗惊厥药物，但没有 抗癫痫药物，减缓疾病的进展。使用新的生物信息学方法， 我们已经确定了一个内源性的，在长时间癫痫发作后由大脑启动的保护程序， 减轻病理变化的功能。 癫痫发生与大脑的大量变化有关，包括可塑性的改变， 细胞死亡、神经发生、炎症和轴突发芽。这些变化发生的时间范围 从几分钟到几年，但协调机制几乎是未知的。的长期变化 与癫痫发生相关的基因表达暗示一个或多个癫痫的主调节因子， 转录可能是协调大脑的变化。为了揭示这些转录机制， 我们转向我们最近发表的癫痫微阵列产生的全基因组表达数据集， Consortium（EMC）.数据集由在200 ℃下测定的大鼠齿状颗粒细胞的mRNA表达谱组成。 癫痫持续状态（SE）后的不同时间点。使用一种新的生物信息学工具， 基因组转录因子结合数据与基因表达谱，我们分析了来自 由3种不同的惊厥刺激诱导的大脑，每种在2个独立的实验室中，在不同的时间点。这 分析预测，Polycomb靶基因代表了大多数慢性改变的基因， 癫痫发生REST靶标代表了第二组重叠的受抑制基因。Polycomb是一个 基因表达终身变化的众所周知的驱动因素，通过表观遗传学沉默基因来起作用。 门我们的数据显示了EZH 2蛋白（EZH 2蛋白的催化甲基化酶亚基）的极其稳健的诱导。 Polycomb）在神经元中SE后20天窗口内的变化。此外，我们发现，拮抗EZH 2后不久， SE强烈地加速小鼠自发性复发性癫痫发作，这表明其具有保护作用， 而不是病理作用。SE后EZH 2的拮抗作用如何仍有待确定。 在这个项目中，我们将测试一个假设，即改变Polycomb输出是一个主要的修改器， 癫痫发生我们将确定EZH 2上调是否总是保护性的，或者它的作用是否会演变。 在潜伏期。我们将测试EZH 2水平的数量级变化对辅阻遏物的影响。 功能，以了解这种上调是否增强或阻碍两种主要EZH 2的抑制能力。 包含复合物：Polycomb和REST。我们预计，这些研究将建立Polycomb作为 癫痫发生相关的长期变化的主要协调者。如果是这样， 调节Polycomb功能可能对全世界6500万患有 癫痫