Temporal Lobe Epilepsy and Retrotransposons

颞叶癫痫和逆转录转座子

• 批准号: 9064579
• 负责人: Wade H Berrettini
• 金额: $ 25.05万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9064579
• 关键词: Address; Affect; Antibodies; Anticonvulsants; Brain; Brain Diseases; Cell Nucleus; Cell Separation; Cell physiology; Central Nervous System Diseases; Chromatin Structure; Chronic; Chronic Disease; Cloning; Complex; Craniotomy; Cryptogenic Epilepsies; DNA; DNA Sequence; Data; Daughter; Detection; Development; Disease; Electroencephalography; Elements; Embryonic Development; Epilepsy; Event; Excision; Family Study; Fluorescence; Gene Expression; Gene Frequency; Genes; Genetic; Genetic Risk; Genetic Transcription; Genome; Genomic Segment; Goals; High-Throughput Nucleotide Sequencing; Human Genome; Image; Infection; Inherited; Introns; Junk DNA; L1 Elements; Label; Mediating; Morbidity - disease rate; Mosaicism; Mutation; Neuronal Differentiation; Neurons; Nuclear; Organism; Partial Epilepsies; Paste substance; Patients; Pharmaceutical Preparations; Pharmacotherapy; Play; Population; Procedures; Public Health; RNA; RNA Polymerase II; RNA-Directed DNA Polymerase; Regimen; Retrotransposon; Risk; Role; Sampling; Secondary to; Seizures; Sequence Alignment; Site; Staining method; Stains; Temporal Lobe; Temporal Lobe Epilepsy; Testing; Therapeutic; Tissues; Traumatic CNS injury; Twin Studies; Variant; base; brain cell; case control; digital; endonuclease; improved; malformation; mortality; public health relevance; risk variant; success; transposon/insertion element; tumor

 DESCRIPTION (provided by applicant): Idiopathic (cryptogenic) epilepsy is a common, chronic group of brain disorders, affecting 1-2% of the US population, creating a significant public health problem because of the associated morbidity and mortality. One subtype of this complex group of brain disorders, temporal lobe epilepsy (TLE), is particularly burdensome, because a substantial fraction of patients do not respond to anticonvulsant medications. If the seizure focus can be localized by imaging and/or EEG, the TLE patient often elects to have a partial resection of the affected temporal lobe, because they have daily seizures, despite multiple pharmacotherapy regimens. Although genetic risk is thought to play a role in TLE, identification of common risk alleles has had limited success. In the past 5 years, data have accumulated to prove that neuronal embryogenesis is accompanied by activation of LINE1 (L1) retrotransposons (RTPs) to an unexpected degree, such that developing neurons may accumulate de novo L1s insertions. This results in a substantial mosaicism within populations of CNS neurons. While most of these somatic de novo L1s will have little effect on neuronal function (perhaps because they occur in gene deserts or in large introns or in genes not required for that cell's function), some may interfere with normal neuronal activity because they have inserted into a gene needed by that particular neuron for normal function. If one or more functional de novo L1s occur early in CNS development, all the daughter neurons that derive from that neuronal precursor will also carry the L1 insertion, perhaps leading to a dysfunctional population of neurons destined to become an epileptic focus. This proposal will leverage CNS tissue (obtained at craniotomy) from patients with intractable TLE, who have undergone a therapeutic partial resection of one temporal lobe. Using fluorescence-assisted cell sorting of temporal lobe neuronal nuclei, followed by high-throughput sequencing and alignment to the reference genome, detection of de novo L1s will be done. The allele frequencies in neuronal DNA of selected de novo intragenic L1s will be determined by droplet digital PCR. In this manner, it is expected that de novo intragenic L1s, contributing to idiopathic TLE, will be discovered.

 描述（由申请人提供）：特发性（隐源性）癫痫是一种常见的慢性脑部疾病，影响1-2%的美国人口，由于相关的发病率和死亡率，造成了严重的公共卫生问题。颞叶癫痫（TLE）是这组复杂的脑部疾病的一个亚型，特别是负担，因为相当一部分患者对抗惊厥药物没有反应。如果癫痫灶可以通过成像和/或EEG定位，TLE患者通常选择部分切除受影响的颞叶，因为他们每天都有癫痫发作，尽管有多种药物治疗方案。虽然遗传风险被认为在TLE中发挥作用，但常见风险等位基因的鉴定成功有限。 在过去的5年中，积累的数据证明，神经元胚胎发生伴随着LINE 1（L1）反转录转座子（RTPs）的激活，达到了意想不到的程度，使得发育中的神经元可能会积累从头L1插入。这导致CNS神经元群体内的大量镶嵌现象。虽然这些体细胞的新生L1对神经元功能几乎没有影响（可能是因为它们出现在基因沙漠或大内含子中，或者是细胞功能不需要的基因中），但有些可能会干扰正常的神经元活动，因为它们插入了特定神经元正常功能所需的基因。如果一个或多个功能性的新生L1在CNS发育的早期出现，那么从该神经元前体衍生的所有子神经元也将携带L1插入，可能导致注定成为癫痫病灶的神经元功能失调。该提案将利用来自顽固性TLE患者的CNS组织（在开颅手术中获得），这些患者接受了一侧颞叶的治疗性部分切除术。使用颞叶神经元细胞核的荧光辅助细胞分选，然后进行高通量测序并与参考基因组比对，将进行新生L1的检测。将通过液滴数字PCR确定所选从头基因内L1的神经元DNA中的等位基因频率。以这种方式，预计将发现导致特发性TLE的新生基因内L1。