权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Fetal DNA oxidation and repair in neurodegeneration

神经退行性疾病中胎儿 DNA 氧化和修复

基本信息

批准号：
7229998
负责人：
PETER G WELLS
金额：
$ 13.11万
依托单位：
UNIVERSITY OF TORONTO
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-01-01 至 2008-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7229998
关键词：
8-Oxo-2&apos -Deoxyguanosine 8-hydroxyguanosine 8-oxoguanine Brain Cockayne Syndrome DNA DNA Repair DNA lesion Defect Detection Development Dose Engineering Enzymes Excision Exposure to Fetal Development Fetus Gene Expression Gene Expression Microarray Analysis Gene Targeting Genes Genetic Transcription High Pressure Liquid Chromatography Human Ingestion Knock-out Knockout Mice Ligands Mediating Methylmercury Compounds Modeling Mus Mutation Nerve Degeneration Neuraxis Neurodevelopmental Deficit Pathologic Pathology Pathway interactions Pattern Perinatal Exposure Polymerase Chain Reaction Predisposition Proteins Reactive Oxygen Species Regulator Genes Regulatory Element Risk Risk Factors Role Seafood Testing Toxic Environmental Substances Toxic effect Transcription-Coupled Repair Transgenic Mice base behavior test catalase environmental agent environmental chemical fetal in utero in vivo insight mouse model oxidation oxidative DNA damage postnatal prenatal repaired

项目摘要

DESCRIPTION (provided by applicant): Methylmercury (MeHg) is an environmental agent introduced to humans primarily via the ingestion of contaminated seafood. Prenatal MeHg exposure induces neurodevelopmental deficits, at doses below those causing systemic toxicity. One potential toxicological mechanism for this and other environmental chemicals likely involves reactive oxygen species (ROS) formation, as the fetus has low antioxidative protection. This toxicity may involve oxidative DNA lesions, the most prominent of which is 8-oxoguanine (8-oxoG), which can result in mutations or altered gene transcription. The latter is potentially relevant to developmental pathologies. Repair of 8-oxoG is carried out by the base excision (BER) and transcription-coupled (TCR) repair pathways. We hypothesize that ROS-mediated oxidative DNA damage in fetal brain modifies specific gene expression levels, contributing to postnatal neurodevelopmental deficits. The progeny of mouse models with genetic alterations in 8-oxoG repair activity will be assessed for neurodevelopmental deficits after in utero exposure to MeHg. Oxoguanine glycosylase 1 (ogg1) knockout (BER-deficient) and Cockayne syndrome B (CSB) knockout (TCR-deficient) mice will be tested as repair-deficient models, while transgenic mice expressing highly active bacterial formamidopyrimidine glycosylase (Fpg) will be genetically engineered and employed as a BER-enhanced model. Fetal ROS and 8-oxoG, specific gene regulatory targets for oxidation and associated gene expression changes in utero will be analyzed in the same fetal brains, and assessed with respect to postnatal CMS pathologies in the progeny. 8-OxoG will be quantified by HPLC with electrochemical detection, oxidation of target gene regulatory elements will be characterized by ligand- mediated PCR, gene expression by microarray analysis, and neurodevelopmental deficits by behavioral tests. These studies will provide mechanistic insight into the fetal origin of environmentally-induced neurodevelopmental defects, and the role of DNA repair activity as a risk factor.

描述（由申请人提供）：甲基汞 (MeHg) 是一种环境因子，主要通过摄入受污染的海鲜而引入人类。产前接触甲基汞会导致神经发育缺陷，剂量低于引起全身毒性的剂量。这种化学物质和其他环境化学物质的一种潜在毒理学机制可能涉及活性氧（ROS）的形成，因为胎儿的抗氧化保护能力较低。这种毒性可能涉及 DNA 氧化损伤，其中最突出的是 8-氧代鸟嘌呤 (8-oxoG)，它可能导致突变或基因转录改变。后者可能与发育病理学相关。 8-oxoG 的修复是通过碱基切除 (BER) 和转录偶联 (TCR) 修复途径进行的。我们假设胎儿大脑中 ROS 介导的氧化 DNA 损伤会改变特定的基因表达水平，从而导致出生后神经发育缺陷。 8-oxoG 修复活性基因改变的小鼠模型的后代将在子宫内暴露于甲基汞后评估神经发育缺陷。氧鸟嘌呤糖基化酶 1 (ogg1) 敲除（BER 缺陷）和科凯恩综合征 B (CSB) 敲除（TCR 缺陷）小鼠将作为修复缺陷模型进行测试，而表达高活性细菌甲酰胺嘧啶糖基化酶 (Fpg) 的转基因小鼠将经过基因工程改造并用作 BER 增强模型。胎儿 ROS 和 8-oxoG、子宫内氧化的特定基因调控靶点和相关基因表达变化将在同一胎儿大脑中进行分析，并根据后代的出生后 CMS 病理进行评估。 8-OxoG 将通过 HPLC 和电化学检测进行定量，靶基因调控元件的氧化将通过配体介导的 PCR 进行表征，基因表达通过微阵列分析进行表征，神经发育缺陷通过行为测试进行表征。这些研究将为环境引起的神经发育缺陷的胎儿起源以及 DNA 修复活性作为危险因素的作用提供机制上的见解。