In vivo mechanisms of amyloid-induced pancreatic islet dysfunction in type 2 diabetes

淀粉样蛋白诱导的 2 型糖尿病胰岛功能障碍的体内机制

基本信息

批准号：
10588374
负责人：
Jordan James Wright
金额：
--
依托单位：
VETERANS HEALTH ADMINISTRATION
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-07-01 至 2028-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10588374
关键词：
Affect Alpha Cell Alzheimer&apos s Disease Amputation Amyloid Apoptosis Area Behavior Beta Cell Binding Bioinformatics Biology Blindness Blood Vessels Cell Death Cell Membrane Permeability Cell Survival Cells Cellular biology Communication Data Science Deposition Development Development Plans Developmental Biology Diabetes Mellitus Disease Education Etiology Foundations Functional disorder Gene Expression Gene Expression Profile Genetic Transcription Glucagon Health Human Hyperglycemia Imaging Techniques Immunoglobulins Immunology In Vitro Individual Inflammation Inflammatory Insulin Insulin Resistance International Islet Cell Islets of Langerhans Kidney Failure Knockout Mice Knowledge Laboratories Ligands Measurement Measures Mediating Mentors Mentorship Methodology Methods Modeling Molecular Monitor Mus Myocardial Infarction National Institute of Diabetes and Digestive and Kidney Diseases Non-Insulin-Dependent Diabetes Mellitus Nuclear Nuclear RNA Oxidative Stress Pathogenesis Pattern recognition receptor Physiology Process Reagent Receptor Activation Reporting Research Research Design Risk Rodent Rodent Model Role Signal Pathway Signal Transduction Structure Structure of alpha Cell of islet Techniques Technology Testing Time Toxic effect Training Transgenic Mice Transplantation Veterans Viral Visualization Work amylin receptor amyloid formation anterior chamber career development cell type collaborative environment cost diabetes pathogenesis endoplasmic reticulum stress experimental study extracellular eye chamber genetic manipulation human tissue improved in vivo innovation insulin secretion intravital imaging islet islet amyloid polypeptide knock-down longitudinal analysis member mouse model multidisciplinary novel novel strategies prevent programs protein aggregation receptor receptor binding receptor for advanced glycation endproducts receptor-mediated signaling response skills small hairpin RNA transcriptome sequencing transcriptomic profiling

项目摘要

PROJECT SUMMARY / ABSTRACT Type 2 diabetes (T2D) affects 20% of veterans and costs the VA almost $1.5 billion annually. In addition to insulin resistance, the hyperglycemia that defines T2D is caused by insufficient insulin secretion and dysregulated glucagon secretion from the β and α cells of pancreatic islets. T2D islets are also characterized by changes in vasculature, increased inflammation, and deposition of insoluble amyloid, composed primarily of islet amyloid polypeptide (IAPP). Soluble IAPP oligomers, rather than the amyloid itself, are toxic to β cells, through various postulated mechanisms including ER stress, oxidative stress, membrane permeabilization, and receptor-mediated signaling. The receptor for advanced glycation endproducts (RAGE), which binds several extracellular ligands and activates intracellular inflammatory signaling pathways, was recently shown to bind IAPP oligomers and mediate IAPP oligomer-induced toxicity in β cells using cell and islet culture models and transgenic mouse models. However, it is unknown if IAPP-RAGE signaling occurs in human islets, if such signaling occurs in non-β islet cells including α cells, what effect IAPP-RAGE signaling in specific cell types has on human islet function, and what specific RAGE signaling pathways are activated in human islet cells. I hypothesize that IAPP oligomer-induced activation of RAGE receptors on β and ⍺ cells modulates human islet function and health in vitro and in vivo. To test my hypothesis and fill these knowledge gaps, I will leverage four new experimental techniques to study primary human islet cells: 1) recently developed pseudoislet methodology that allows efficient cell-specific genetic manipulation of human islets; 2) transplantation of human pseudoislets into mice to enable longitudinal analysis of structure and function in vivo; 3) modified intravital imaging techniques to visualize amyloid formation and cell death longitudinally; 4) single nuclear isolation and sequencing technologies to detect changes in gene expression in transduced pseudoislets. In Aim 1, I will test the hypothesis that RAGE mediates IAPP oligomer-induced β cell dysfunction in human islets in vitro and in vivo. In Aim 2, I will test the hypothesis that IAPP-RAGE signaling in ⍺ cells causes dysregulated glucagon secretion in human islets in vitro and in vivo. These experiments will clarify fundamental processes in T2D pathogenesis and help identify novel targets to treat and prevent T2D. I will complete these aims as part of an intensive supervised career development plan with oversight and guidance from an expert multi-disciplinary mentoring committee. I will receive formal and informal training in five fundamental areas: 1) new and emerging experimental techniques; 2) scientific education; 3) presentation and communication skills; 4) professional development; and 5) laboratory management. These skills and the results of my proposed experiments will form a strong foundation for my independent research program as I work to improve the understanding and treatment of diabetes mellitus. Project Summary-Page 1

项目概要/摘要 20% 的退伍军人患有 2 型糖尿病 (T2D)，每年给退伍军人管理局造成近 15 亿美元的损失。胰岛素抵抗，定义 T2D 的高血糖是由胰岛素分泌不足引起的 T2D 胰岛 β 和 α 细胞的胰高血糖素分泌失调也具有特征。通过脉管系统的变化、炎症的增加和不溶性淀粉样蛋白的沉积，淀粉样蛋白主要由可溶性 IAPP 寡聚体而非淀粉样蛋白本身对 β 细胞具有毒性。通过各种假设的机制，包括内质网应激、氧化应激、膜透化和受体介导的信号传导。晚期糖基化终产物 (RAGE) 的受体，可结合多种物质。细胞外配体并激活细胞内炎症信号传导途径，最近被证明可以结合 IAPP 寡聚物并使用细胞和胰岛培养模型介导 IAPP 寡聚物诱导的 β 细胞毒性然而，尚不清楚 IAPP-RAGE 信号是否发生在人类胰岛中（如果存在）。信号传导发生在包括 α 细胞在内的非 β 胰岛细胞中，对特定细胞类型中的 IAPP-RAGE 信号传导有何影响对人类胰岛功能的影响，以及在人类胰岛细胞中哪些特定的 RAGE 信号通路被激活。保持 IAPP 寡聚体诱导的 β 和 ⍺ 细胞上 RAGE 受体的激活调节为了检验我的假设并填补这些知识空白，我在体外和体内研究了人类胰岛的功能和健康。将利用四种新的实验技术来研究原代人类胰岛细胞：1）最近开发的伪胰岛方法允许对人类胰岛进行有效的细胞特异性遗传操作2) 将人类伪胰岛移植到小鼠体内，以实现结构和功能的纵向分析体内；3) 改良活体成像技术以纵向观察淀粉样蛋白的形成和细胞死亡；单核分离和测序技术检测转导基因表达的变化在目标 1 中，我将检验 RAGE 介导 IAPP 寡聚物诱导的 β 细胞的假设。在目标 2 中，我将测试 IAPP-RAGE 信号传导的假设。 ⍺ 细胞在体外和体内引起人胰岛胰高血糖素分泌失调。阐明 T2D 发病机制的基本过程，并帮助确定治疗和预防 T2D I 的新靶点。将完成这些目标，作为强化监督的职业发展计划的一部分，并受到监督和我将接受多学科专家指导委员会的指导。五个基本领域：1）新兴实验技术；2）科学教育；和沟通技巧；4) 专业发展；5) 实验室管理。我提出的实验结果将为我的独立研究计划奠定坚实的基础，因为我致力于提高对糖尿病的认识和治疗。项目摘要-第1页