Modifiers of Proinsulin Influence T2D Susceptibility

胰岛素原调节剂影响 T2D 易感性

基本信息

批准号：
9351508
负责人：
PETER ARVAN
金额：
$ 100.88万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-12 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9351508
关键词：
20 year old Address Adult Amino Acid Substitution Beta Cell Biochemistry Biogenesis Bioinformatics C57BL/6 Mouse Cell physiology Cellular biology Complement Defect Development Diabetes Mellitus Diet Disease Disease Progression Endoplasmic Reticulum Ensure Environmental Risk Factor Exhibits Failure Foundations Gene-Modified Genes Genetic Genetic Models Genetic Polymorphism Goals Grant Health High Fat Diet Human Individual Insulin Insulin Resistance Intervention Lead Mass Spectrum Analysis Measurement Measures Methods Minor Mission Modality Molecular Molecular Chaperones Molecular Conformation Monoclonal Antibody R24 Mus National Institute of Diabetes and Digestive and Kidney Diseases Nature Non obese Non-Insulin-Dependent Diabetes Mellitus Obesity Pathogenesis Pathogenicity Pathway interactions Patients Pattern Pharmacology Phenotype Population Predisposition Process Production Prognostic Marker Proinsulin Proteins Proteome Proteomics Reporting Research Personnel Resistance development Specificity Testing Therapeutic Intervention Time Wolcott-Rallison syndrome Work biological adaptation to stress diabetic disulfide bond endoplasmic reticulum stress genetic approach genome wide association study improved insight insulin secretion islet mouse model non-diabetic novel novel diagnostics novel marker novel strategies novel therapeutics pressure proteostasis small molecule trafficking

项目摘要

PROJECT SUMMARY Type 2 diabetes (T2D) is caused by a failure of beta cells to produce sufficient insulin to maintain euglycemia. As a consequence of genetic/environmental factors, insulin resistance develops that pressures beta cells to increase insulin production. Although beta cells have some capacity to compensate for the demand, by approximately one-third of ~600 million individuals with obesity in the world develop go on to develop diabetes. The factors that lead to beta cell failure are unknown. Due to the polygenic nature of the disease, it is likely many genes modify beta cell function, and polymorphisms in any single gene would not be detected because they present minor contributions. Our underlying hypothesis is that multiple genes impact the efficiency of proinsulin folding in the endoplasmic reticulum (ER) and modify the progression of T2D. Significantly, our preliminary studies show that a high fat diet is sufficient to cause proinsulin misfolding well before diabetes development in C57BL/6 mice. In addition, we have identified genetic modifiers that exacerbate proinsulin misfolding and beta cell failure. We hypothesize that the fundamental cause of beta cell failure in T2D is a breakdown at the level of the ER with failure to efficiently fold excessive amounts of proinsulin and resulting consequences on downstream processing and secretion. To test our hypothesis, we have established a team of outstanding investigators to work together to identify critical proteins that modify proinsulin folding using state-of-the-art proteomics, biochemistry, cell biology, murine genetics and bioinformatics. In preliminary studies we developed methods to differentiate between specific disulfide bond defects and other misfolded conformations of proinsulin, generated all of the necessary murine strains and validated the proteomic mass spectrometry approach for proinsulin interactions using human islets. We have also demonstrated the potential of small molecules to improve proinsulin production in challenged islets. We expect our novel approach will identify distinct defects in the proinsulin folding pathway that represent the earliest changes leading to beta cell demise in both murine models and humans. The three aims of our R24 grant focus on defining how proinsulin folding patterns change when islets are challenged, and to identify how protein interactions with proinsulin may predict the efficiency of proinsulin trafficking through the secretory pathway, impacting islet health. Aim 1 will quantify the folded and unfolded state of proinsulin by measuring intermediates in the folding process in normal and diseased islets from well-characterized murine models. Aim 2 will define how the proteins that interact with proinsulin change during progression from normal, obese non-diabetic to T2D islets from human donors. Aim 3 will elucidate what interventions and chaperone functions may preserve productive proinsulin folding and restore an efficient proinsulin “proteostasis” network. Collectively, our proposed studies may identify novel biomarkers and avenues for therapeutic intervention in T2D, and therefore are of paramount importance to the mission of NIDDK.

项目概要 2 型糖尿病 (T2D) 是由于 β 细胞无法产生足够的胰岛素来维持血糖正常而引起的。由于遗传/环境因素，胰岛素抵抗的发展迫使β细胞尽管β细胞有一定的能力来补偿胰岛素的需求，但世界上约 6 亿肥胖者中约有三分之一发展为糖尿病。由于该疾病的多基因性质，导致 β 细胞衰竭的因素尚不清楚。许多基因都会改变β细胞的功能，并且任何单个基因的多态性都不会被检测到，因为我们的基本假设是多个基因影响效率。内质网 (ER) 中的胰岛素原折叠并显着改变 T2D 的进展。初步研究表明，高脂肪饮食足以在糖尿病发生之前就导致胰岛素原错误折叠此外，我们还发现了可加剧胰岛素原的基因修饰。我们勇敢地承认，T2D 中 β 细胞衰竭的根本原因是 ER 水平的分解，无法有效折叠过量的胰岛素原，并导致为了检验我们的假设，我们建立了一个团队。杰出的研究人员共同努力，使用以下方法识别改变胰岛素原折叠的关键蛋白质最先进的蛋白质组学、生物化学、细胞生物学、小鼠遗传学和生物信息学。通过研究，我们开发了区分特定二硫键缺陷和其他错误折叠的方法胰岛素原的构象，生成所有必需的鼠科菌株并验证蛋白质组质量我们还展示了使用人类胰岛进行胰岛素原相互作用的光谱测定方法。我们期望我们的新方法能够改善受挑战的胰岛中的胰岛素原生产。识别胰岛素原折叠途径中的明显缺陷，该缺陷代表导致β细胞的最早变化我们 R24 的三个目标重点是定义胰岛素原如何死亡。当胰岛受到挑战时，折叠模式会发生变化，并确定蛋白质与胰岛素原的相互作用如何可能预测胰岛素原通过分泌途径运输的效率，从而影响胰岛健康。通过测量正常情况下折叠过程中的中间体来量化胰岛素原的折叠和展开状态目标 2 将定义蛋白质如何相互作用。人类供体的胰岛从正常肥胖非糖尿病进展为 T2D 过程中胰岛素原发生变化。将阐明哪些干预措施和伴侣功能可以保持有效的胰岛素原折叠和总的来说，我们提出的研究可能会发现新的机制。 T2D 的生物标志物和治疗干预途径，因此对于 NIDDK 的使命。