Targeted Genetic Analysis of T2D and Quantitative Traits

 描述(申请人提供)：2型糖尿病(T2D)是美国和世界范围内发病率和死亡率的主要原因。通过提供有关T2D的发展和治疗的生物学和临床数据，以及建议高危个体改变生活方式，识别增加T2D易感性的基因将极大地影响公众健康。我们的总体目标是确定T2D和糖尿病相关数量性状(QT)关联信号的功能变异、靶基因和机制。在此之前，我们已经使用低频和常见的变异体确定了T2D和QTS的新基因座。我们开发了注释调控变异的策略，并在几个基因座上定义了变异以及变异等位基因结合转录调控因子和增加或减少特定靶基因表达的机制。在这项建议中，我们扩展了这些先前的成功，以进一步确定分子和生物学机制，并评估数百种特定的血浆代谢物对QT变异和T2D风险的贡献。具体地说，在调节元件和资源与基因、调节元件活性和染色质结构与表达水平相关的实验证据的指导下，我们将测试变种在转录活性和蛋白质-DNA相互作用中的等位基因特异性差异，识别转录调节因子，并验证在原代细胞中的结果，在模式生物中的瞬时表达，以及在人类细胞系中的基因组编辑。对于我们已经发现的单个变异的胰岛素加工和分泌基因，我们将对这些基因及其编码的蛋白质进行详细的表征，并确定参考等位基因和替代等位基因对基础和葡萄糖刺激的胰岛素原和胰岛素分泌的影响。此外，我们还将测试 基因变异与&gt；700代谢物的关联，确定它们在T2D风险和QT变异中的作用，并评估未受影响的高危个体未来T2D的预测。我们将使用代谢物关联来注释基因座，通过孟德尔随机化确定因果贡献，并使用20年来芬兰美国NIDDM遗传学研究(FUMP)研究的资源来评估对预测T2D风险的模型的贡献。这些目标的成功完成将把T2D关联信号转化为生物学见解和潜在的治疗目标。将确定风险变异、它们影响基因功能的机制以及它们对疾病过程的病理影响，指导评估新疗法和干预高危个体以预防疾病的研究。研究人员的卓有成效和长期的合作使这些目标的实现是可行的，并可能对T2D造成的公共健康危机具有很高的信息量。

 DESCRIPTION (provided by applicant): Type 2 diabetes (T2D) is a major cause of morbidity and mortality in the USA and worldwide. Identification of genes increasing susceptibility to T2D would substantially affect the public health by providing biological and clinical data about development and treatment of T2D and by advising lifestyle changes in at-risk individuals. Our overall goal is to identify the functional variants, target genes, and mechanisms responsible for T2D and diabetes-related quantitative trait (QT) association signals. Previously, we have identified novel loci for T2D and QTs using both low-frequency and common variants. We developed strategies to annotate regulatory variants and, at several loci, defined variants and the mechanisms by which variant alleles bind transcriptional regulators and increase or decrease expression of specific target genes. In this proposal, we extend these previous successes to further define molecular and biological mechanisms and assess the contribution of hundreds of specific plasma metabolites to QT variation and T2D risk. Specifically, guided by experimental evidence of regulatory elements and resources correlating genotype, regulatory element activity, and chromatin structure with expression level, we will test variants for allele-specific differences in transcriptional activity and protein-DNA interactions, identify transcriptional regulators, and validate results in primary cells, transient expression in model organisms, and genome editing in human cell lines. For insulin processing and secretion loci at which we have already implicated single variants, we will perform detailed characterization of the genes and their encoded proteins and determine the effects of the reference and alternate alleles on basal and glucose-stimulated proinsulin and insulin secretion. In addition, we will test association of genetic variants with >700 metabolites, determine their role in T2D risk and QT variation, and assess prediction of future T2D in unaffected at-risk individuals. We will use metabolite associations to annotate loci, identify causal contributions by Mendelian randomization, and assess the contribution to models that predict T2D risk using resources from the 20-year Finland United States Investigation of NIDDM Genetics (FUSION) study. Successful completion of these aims will translate T2D association signals into biological insights and potential therapeutic targets. Risk variants, the mechanisms by which they affect gene function, and their pathological effects on disease processes will be determined, guiding studies that evaluate novel therapies and intervene in at-risk individuals to prevent disease. The productive and longstanding collaboration of the investigators make achievement of these aims feasible and likely highly informative to the public health crisis posed by T2D.