Identification of Genes Influencing Total Antioxidant Status

描述（由申请人提供）：该项目将采用一种新的方法来经验性地鉴定影响总抗氧化状态的候选基因，这是一种与心血管疾病风险相关的氧化应激指数。使用现有的定量转录谱从淋巴细胞样本从1,240个墨西哥裔美国人的圣安东尼奥家庭心脏研究，我们已经确定了约1,400个成绩单，表现出高度显着的证据，顺式调节推断定量连锁分析。这些顺式调节的转录本已被检查与TAS水平的关联。利用这个大规模的全基因组表达数据，我们发现了大约150个顺式调节基因，这些基因也与TAS水平显著相关。拟议的项目将利用这种全基因组表达为基础的信息，以快速识别影响这些新的候选基因的转录水平的调控序列变异，并评估其对人类血浆总抗氧化状态的影响。为了确定与心血管疾病风险相关的氧化应激相关基因，我们将研究75个新的候选基因。我们先前的顺式作用序列变异的证据可以作为一个概率因果锚，以最大限度地提高我们的机会，找到所选基因的近端启动子内的功能变异。对于每个基因，我们将（1）在182个创始者个体中对推定的启动子区域的大约两个DNA酶进行重测序以鉴定启动子变体;（2）对我们具有转录谱的1，240个SAFHS样品中所有检测到的启动子变体进行基因分型;（3）测试启动子序列变体是否与适当候选基因的基因表达水平相关;（4）检测启动子序列变异体与血浆总抗氧化剂水平之间的关联;（5）在墨西哥裔美国人家庭的独立样本中确认观察到的与总抗氧化剂水平的关联;以及（6）对影响TAS水平的启动子变异体进行初步功能分析。拟议的研究应该加快发现新基因的步伐，这些基因是人类在调节与CVD风险相关的氧化应激方面的变化的基础。通过关注转录本显示顺式调节变异和与抗氧化状态密切相关的基因，我们应该最大限度地提高发现影响CVD风险的因果遗传变异的可能性。 公共卫生相关性：动脉粥样硬化是北美死亡率的主要原因，预计在未来20年内在全球范围内将达到类似的区别。在这个项目中，我们将采用一种新的策略，该策略将加快发现与心脏病风险有关的基因的步伐。对这种疾病易感性相关基因的了解将有助于我们了解动脉粥样硬化的原因，并可能加快寻找新的治疗方法。

DESCRIPTION (provided by applicant): This project will employ a novel approach to the empirical identification of candidate genes influencing total antioxidant status, an index of oxidative stress that is related to cardiovascular disease risk. Using existing quantitative transcriptional profiles obtained from lymphocyte samples from 1,240 Mexican American individuals in the San Antonio Family Heart Study, we have identified approximately 1,400 transcripts that exhibit highly significant evidence for cis-regulation as inferred from quantitative linkage analysis. Each of these cis-regulated transcripts has been examined for association with TAS levels. Using this large-scale genome-wide expression data, we have discovered approximately 150 cis-regulated genes that also are significantly correlated with TAS levels. The proposed project will exploit this genome-wide expression-based information to rapidly identify regulatory sequence variants that influence transcriptional levels of these novel empirically-chosen candidate genes and to assess their influence on human plasma total antioxidant status. In order to identify genes involved in oxidative stress that are relevant to cardiovascular disease risk, we will examine 75 novel empirically-chosen candidates. Our prior evidence for cis-acting sequence variation can be exploited as a probabilistic causal anchor to maximize our chance for finding functional variation within the proximal promoters of the chosen genes. For each gene, we will (1) resequence approximately two kilobases of putative promoter region in 182 founder individuals to identify promoter variants; (2) genotype all detected promoter variation in the 1,240 SAFHS samples for which we have transcriptional profiles; (3) test whether promoter sequence variants are associated with gene expression levels of the appropriate candidate gene; (4) test for associations between promoter sequence variants and plasma total antioxidant levels; (5) confirm observed associations with total antioxidant levels in an independent sample of Mexican American families; and (6) perform preliminary functional analyses of promoter variants influencing TAS levels. The proposed research should increase the pace of discovery of novel genes underlying human variation in accommodation of oxidative stress in relation to CVD risk. By focusing on genes whose transcripts show evidence for both cis-regulatory variation and a strong relationship with antioxidant status, we should maximize our probability for finding causal genetic variants influencing CVD risk. PUBLIC HEALTH RELEVANCE: Atherosclerosis is the leading cause of mortality in North America and is predicted to attain a similar distinction on a global scale within the next twenty years. In this project, we will employ a novel strategy that should increase the pace of discovery of genes that are involved in heart disease risk. Such knowledge of some of the genes involved in susceptibility to this disease will contribute to our understanding of the causes of atherosclerosis and potentially speed the search for new treatments.