Targeted Genetic Analysis of T2D and Quantitative Traits

 描述（由申请人提供）：2型糖尿病（T2 D）是美国和全球发病率和死亡率的主要原因。鉴定增加T2 D易感性的基因将通过提供有关T2 D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来显著影响公众健康。我们的总体目标是确定负责T2 D和糖尿病相关的数量性状（QT）关联信号的功能变体，靶基因和机制。以前，我们已经使用低频和常见变体鉴定了T2 D和QT的新基因座。我们开发了注释调控变体的策略，并在几个位点定义了变体和变体等位基因结合转录调控因子并增加或减少特定靶基因表达的机制。在这项提案中，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，并评估数百种特定血浆代谢产物对QT变异和T2 D风险的贡献。具体而言，在基因型、调控元件活性和染色质结构与表达水平相关的调控元件和资源的实验证据的指导下，我们将测试变体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，鉴定转录调控因子，并验证原代细胞、模型生物中的瞬时表达和人类细胞系中的基因组编辑结果。对于胰岛素加工和分泌位点，我们已经涉及到单一变异体，我们将进行基因及其编码蛋白质的详细表征，并确定参考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，我们将测试 基因变异与>700种代谢物的关联，确定它们在T2 D风险和QT变异中的作用，并评估未受影响的高危个体未来T2 D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，并评估对使用来自20年芬兰美国NIDDM遗传学调查（FUSION）研究的资源预测T2 D风险的模型的贡献。这些目标的成功完成将把T2 D相关信号转化为生物学见解和潜在的治疗靶点。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将被确定，指导评估新疗法和干预高危个体以预防疾病的研究。研究人员的富有成效和长期合作使这些目标的实现变得可行，并可能对T2 D造成的公共卫生危机提供高度信息。

 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.