Maternal Programming Gene Expression DNA Methylation

母体编程 基因表达 DNA 甲基化

• 批准号: 7020116
• 负责人: Michael Joseph Meaney
• 金额: $ 22.41万
• 依托单位: MCGILL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7020116
• 关键词: CpG islands; DNA methylation; behavioral /social science research tag; cell line; chromatin immunoprecipitation; corticosteroid receptors; developmental genetics; epigenetics; functional /structural genomics; gene environment interaction; gene expression; genetic promoter element; hippocampus; hypothalamic pituitary adrenal axis; intermolecular interaction; laboratory rat; maternal behavior; nerve growth factors; neurogenetics; serotonin; stress; tissue /cell culture

DESCRIPTION (provided by applicant): Maternal care of pups influences the development of hypothalamic-pituitary-adrenal (HPA) responses to stress in the rat. Thus, the adult offspring of mothers that naturally show an increased frequency of pup licking/grooming and arched back nursing (ie, High LG-ABN mothers) show more modest HPA responses to stress. These effects are, in part, mediated by changes in hippocampal glucocorticoid receptor (GR) gene expression. We propose a working model describing the cellular and molecular basis for this maternal effect. The changes in maternal care increase serotonin (5-HT) turnover in the hippocampus which, in turn, activates cAMP formation via a 5-HT7 receptor and to increase protein kinase A activity and increased expression of activator protein-2 (AP-2) and NGFI-A which transactivate GR gene transcription via direct interaction with relevant GR gene promoter sequences. The critical questions concern the apparent permanence of these effects: How might maternal care program differences in gene expression over the lifespan of the offspring? Our studies are designed to examine the hypothesis that such effects are mediated by structural changes in DNA sequences located at specific sites within the promoter region of the GR gene. These studies use both in vivo and in vitro approaches to examine how maternal care alters DNA methylation and the relationship between such chemical alterations of the DNA, chromatin structure, gene expression and physiology. The methods include analysis of single nucleotide methylation using sodium bisulfite mapping, histone modifications and DNA-protein interactions with chromatin immunoprecipitation assays. We believe that these studies hold the possibility of providing a clear description of the mechanisms by which maternal care exerts long-term effects over gene expression in the brain and thus of phenotypic development. In essence, these studies directly examine gene X environment interactions in relation to specific, functional trait. Finally, although normally loath to use such descriptions, to the best of our knowledge these studies potentially provide the first description of structural changes in DNA in response to a post-mitotic, environmental event, and may ultimately provide the initial studies of environmentally-induced plasticity in DNA methyation and chromatin structure over the lifespan.

描述（由申请人提供）：幼崽的孕产妇护理会影响下丘脑 - 垂体 - 肾上腺（HPA）对大鼠压力的反应。因此，母亲的成年后代自然显示出幼犬舔/修饰和拱形疗养的频率增加（即高LG-ABN母亲）表现出对压力的更适中的HPA反应。这些作用部分是由海马糖皮质激素受体（GR）基因表达的变化介导的。我们提出了一个工作模型，描述了这种母体效应的细胞和分子基础。孕产妇护理的变化增加了海马中的5-羟色胺（5-HT）周转率，这反过来又通过5-HT7受体激活cAMP形成，并增加蛋白激酶A的活性并增加激活剂蛋白-2（AP-2）和NGFI-A的表达，从而通过与相关GR基因促销序列直接相互作用进行反式GR基因转录。关键问题涉及这些影响的明显永久性：在后代的寿命中，孕产妇护理计划在基因表达中如何差异？我们的研究旨在研究以下假设：这种效应是由位于GR基因启动子区域内特定位点的DNA序列的结构变化介导的。这些研究都使用体内和体外方法来检查母体护理如何改变DNA甲基化以及DNA的这种化学改变，染色质结构，基因表达和生理学之间的关系。该方法包括使用Bisulfite钠映射，组蛋白修饰和DNA-蛋白质与染色质免疫沉淀测定法分析单核苷酸甲基化。我们认为，这些研究具有清晰的描述，说明母亲护理对大脑中基因表达以及表型发育产生长期影响的机制。从本质上讲，这些研究直接检查了基因X环境相互作用与特定功能性状有关。最后，尽管通常不愿意使用此类描述，但据我们所知，这些研究可能会对DNA的结构变化进行首次描述，以响应有丝分裂后的环境事件，并最终可能提供对寿命中DNA甲基化和染色质结构中环境诱导的可塑性的初步研究。