Modifiers of Proinsulin Influence T2D Susceptibility

胰岛素原调节剂影响 T2D 易感性

• 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
• 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

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.

项目摘要 2型糖尿病（T2 D）是由β细胞无法产生足够的胰岛素来维持正常血糖引起的。 作为遗传/环境因素的结果，胰岛素抵抗的发展迫使β细胞 增加胰岛素产量。虽然β细胞有一定的能力来弥补需求， 世界上约6亿肥胖个体中的约三分之一继续发展为糖尿病。 导致β细胞衰竭的因素尚不清楚。由于这种疾病的多基因性， 许多基因改变β细胞功能，任何单个基因的多态性都不会被检测到， 他们的贡献很小我们的基本假设是，多个基因影响的效率， 胰岛素原在内质网（ER）中折叠并改变T2 D的进展。值得注意的是，我们 初步研究表明，高脂肪饮食足以导致胰岛素原错误折叠， 在C57 BL/6小鼠中的发育。此外，我们还发现了基因修饰剂，加剧胰岛素原 错误折叠和β细胞衰竭。我们假设T2 D中β细胞衰竭的根本原因是 在ER水平的分解，不能有效地折叠过量的胰岛素原， 对下游加工和分泌的影响。为了验证我们的假设，我们成立了一个小组 杰出的研究人员一起工作，以确定关键的蛋白质，修改胰岛素原折叠使用 最先进的蛋白质组学、生物化学、细胞生物学、鼠遗传学和生物信息学。初步 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，产生了所有必要的小鼠品系，并验证了蛋白质组质量 使用人胰岛的胰岛素原相互作用的光谱方法。我们还展示了 的小分子，以提高胰岛素原生产的挑战胰岛。我们希望我们的新方法 确定胰岛素原折叠途径中的明显缺陷，这些缺陷代表导致β细胞凋亡的最早变化。 小鼠模型和人类中的死亡。我们的R24赠款的三个目标集中在定义胰岛素原如何 当胰岛受到挑战时，折叠模式发生变化，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，影响胰岛健康。目标1将 通过测量正常人胰岛素原折叠过程中的中间产物， 和来自良好表征的鼠模型的患病胰岛。目标2将定义蛋白质如何与 胰岛素原在从正常的、肥胖的非糖尿病的人供体的胰岛进展到T2 D胰岛期间的变化。目标3 将阐明什么样的干预和伴侣蛋白功能可以保持生产性胰岛素原折叠， 恢复一个有效的胰岛素原“蛋白质稳态”网络。总的来说，我们提出的研究可能会发现新的 生物标志物和T2 D治疗干预的途径，因此对T2 D治疗至关重要。 NIDDK的使命。