Proteomic determinants of direct measures of insulin sensitivity

胰岛素抵抗（IR）的后果不仅包括2型糖尿病，而且还包括一组胰岛素抵抗。 代谢异常会使危及生命的动脉粥样硬化并发症的风险增加一倍 包括心肌梗塞、缺血性中风和外周动脉疾病。IR患病率为 随着西方人口变得更重和更久坐，当一个更 考虑到发展中国家除肥胖症流行外， 在发达国家，IR对全球公共卫生的影响无疑是深远的。很少有药理学 存在改善胰岛素敏感性和降低IR和近期并发症风险的选择。 IR替代测量的基因组研究已经产生了令人失望数量的新线索。此外，委员会认为， 迫切需要开发更准确的基于血液的IR诊断测试。 这项研究的目的是发现和验证新的IR蛋白标志物， 接受过两种“金标准”胰岛素直接测量之一的个体的血液 敏感性：胰岛素抑制试验（IST）或正葡萄糖钳夹试验（EC）。此信息将用于 确定可靶向治疗IR的新分子途径，并开发统计学方法， 与通过胰岛素敏感性的直接测量估计的IR程度高度相关的模型。在aim中 在这项提议中，2100名白色/欧洲受试者的血液在斯坦福大学或 EC在胰岛素敏感性与心血管疾病（RISC）和乌普萨拉之间的关系 成年男性纵向研究（ULSAM）研究将使用一种新的蛋白质来测量981种蛋白质的存在。 新兴的平台，利用称为邻近延伸测定的新技术。这 技术允许精确和可靠地定量血浆中的蛋白质，低至飞摩尔或 阿托摩尔水平。我们将进一步验证这些受试者中确定的最重要信号，在另外约300个非 欧洲受试者和来自斯坦福大学的300名受试者，他们在减肥后接受了第二次IST 或使用噻唑烷二酮。在目标2中，我们将使用 孟德尔随机化的原则，我们将量化验证标志物提供的改善， 在识别IR并发症风险受试者的常规措施中。在目标3中， 在自然界中似乎是因果关系的蛋白质之间的关系将通过基因敲除来进一步研究， 在与IR相关的人细胞系中产生这些蛋白质。这些细胞系将包括脂肪细胞， 肝细胞和骨骼肌细胞。这项研究是最大的血浆蛋白质组研究， 胰岛素敏感性的测量方法。研究结果预计将产生重要的机制见解 IR的分子基础，并为基于血液的诊断测试的开发提供基础 可以非常可靠地检测出IR并发症风险低或高的受试者。

The consequences of insulin resistance (IR) include not only type 2 diabetes mellitus but also a cluster of metabolic abnormalities that double the risk of developing life-threatening complications of atherosclerosis including myocardial infarction, ischemic strokes, and peripheral arterial disease. The prevalence IR is increasing at an alarming rate as western populations become heavier and more sedentary. When one further considers the ongoing epidemiological transitions in developing countries in addition to the obesity epidemic in developed countries, the worldwide public health impact of IR is undoubtedly profound. Few pharmacological options exist that improve one’s insulin sensitivity and decrease the risk of complications from IR and recent genomic studies of surrogate measures of IR have yielded a disappointing number of new leads. Furthermore, a critical need exists for the development of more accurate blood-based diagnostic tests for IR. The long-term objective of the proposed research is to discover and validate novel protein markers of IR circulating in the blood of individuals who have undergone either one of the two ‘gold standard’ direct measures of insulin sensitivity: an insulin suppression test (IST) or a euglycemic clamp (EC). This information will be used to identify novel molecular pathways of IR that can be targeted pharmacologically and to develop statistical models that correlate highly with the degree of IR as estimated by direct measures of insulin sensitivity. In aim 1 of this proposal, the blood of 2100 white/European subjects who have undergone an IST at Stanford or an EC in the Relationship between Insulin Sensitivity and Cardiovascular Disease (RISC) and the Uppsala Longitudinal Study of Adult Men (ULSAM) studies will be measured for the presence of 981 proteins using an emerging platform that leverages novel technology referred to as the proximity extension assay. This technology allows for the accurate and reliable quantification of proteins in plasma down to the femtomolar or attomolar level. We will further validate the top signals identified in these subjects in an additional ~300 non- European subjects and a subset of 300 subjects from Stanford who underwent a second IST after weight loss or use of a thiazolidinedione. In aim 2, we will examine validated signals from Aim 1 for causality using the principal of Mendelian randomization, and we will quantify improvements afforded by validated markers over conventional measures in identifying subjects at risk of complications from IR. In aim 3, validated associations between proteins that appear causal in nature will be further examined through knockdown of the genes producing these proteins in human cell lines relevant to IR. These cell lines will include adipocytes, hepatocytes, and skeletal myocytes. This study is the largest study of the plasma proteome in relation to direct measures of insulin sensitivity ever proposed. Findings are expected to yield important mechanistic insights into the molecular basis of IR and provide the foundation for the development of a blood-based diagnostic test that can very reliably detect subjects at low or high risk of complications from IR.