Type 2 diabetes risk variant effects on mitochondrial (patho)physiology

2 型糖尿病风险变异对线粒体（病理）生理学的影响

基本信息

批准号：
10717519
负责人：
Scott Soleimanpour
金额：
$ 78.88万
依托单位：
JACKSON LABORATORY
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：
2023-09-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10717519
关键词：
Affect Beta Cell Binding Bioenergetics Biological Assay Cell Survival Cell physiology Cells Chromatin Clustered Regularly Interspaced Short Palindromic Repeats Compensation Complex DNA Binding DNA Sequence Defect Development Disease Etiology Failure Functional disorder Gene Expression Profile Genes Genetic Diseases Genetic Risk Genetic Transcription Genomic DNA Genomics Health Health system Histone Acetylation Human Immunodeficient Mouse Impairment In Vitro Insulin Insulin Resistance Islet Cell Islets of Langerhans Islets of Langerhans Transplantation Knockout Mice Knowledge Link Medical Metabolic Mitochondria Modification Molecular Non-Insulin-Dependent Diabetes Mellitus Pancreas Patients Peripheral Persons Phenotype Physiology Prediabetes syndrome Public Health Quantitative Trait Loci Regulatory Element Reporter Genes Reporting Single Nucleotide Polymorphism Techniques Testing Untranslated RNA Validation Variant Work diet-induced obesity genome editing genome wide association study genomic locus glycemic control impaired glucose tolerance in vivo innovation islet mitochondrial dysfunction mitochondrial metabolism mouse model new therapeutic target physiologic model pre-clinical prevent risk variant tool trait transcription factor

项目摘要

PROJECT SUMMARY / ABSTRACT Type 2 diabetes (T2D) results when pancreatic islet β-cells fail to secrete sufficient insulin to meet peripheral insulin demand. Mitochondrial bioenergetics is central to the (patho)physiology of β-cell (dys)function, and recent work suggests that β-cell mitochondrial dysfunction precedes the development of T2D in β-cells from donors with impaired glucose tolerance (or pre-diabetes). Mitochondrial defects have been reported in the β-cells of human T2D patients, but the etiology of mitochondrial dysfunction in T2D is unknown. Such mechanistic knowledge is necessary to guide strategies to prevent or treat islet failure and T2D. Importantly, genome-wide association studies (GWAS) link single nucleotide polymorphisms (SNPs) in >500 genetic loci to T2D and islet dysfunction-related metabolic traits. The majority of these SNPs are non-coding and overlap regulatory elements (REs) with broad transcriptional implications for affected cells. In this study, we combine our expertise in the genomics of T2D, (epi)genomic modification, and mitochondrial function in β-cells to bridge the gap from genomic association to mechanistic understanding. We hypothesize that non-coding T2D SNPs cause β-cell dysfunction by altering RE use or activity, thereby changing expression of effector genes that directly impair mitochondrial health. To test this, we propose to use sophisticated (epi)genomic editing tools in human islets and β-cell specific mouse models for physiological relevance and validation in two complementary Aims. In Aim 1, we will test RE– effector gene links in human islets using CRISPR-QTL. In parallel, we will assess T2D risk allele effects on RE chromatin accessibility, activity, transcription factor binding, and β-cell expression of putative mitochondrial T2D effector genes using complementary in vivo (single cell chromatin accessibility, histone acetylation, and expression quantitative trait locus analysis of primary human islets) and in vitro (reporter gene, DNA-binding assay) approaches. Finally, we will determine the consequences of effector gene perturbation on mitochondrial phenotypes, β-cell viability, and insulin content and secretion in human islets and EndoC-βH3 cells. In Aim 2, we harness β-cell-specific knockout mouse models to assign function to two high-priority mitochondrial T2D effector genes in glycemic control, β-cell mass/function, and mitochondrial metabolism. Further, we will address the importance of these mitochondrial T2D effector genes for β-cell compensation to peripheral insulin resistance following diet-induced obesity. Finally, we will use (epi)genomic editing tools in human islets to determine if mitochondrial T2D effector genes impair β-cell function and glycemic control in ex vivo assays as well as after islet transplantation into immunodeficient mice. Completion of this study will generate new variant-to-function connections that assign molecular and cellular functions to T2D risk alleles, identify novel therapeutic targets, and provide important knowledge to guide subsequent strategies to prevent or treat β-cell failure and T2D.

项目概要/摘要当胰岛 β 细胞无法分泌足够的胰岛素以满足外周血需要时，就会导致 2 型糖尿病 (T2D) 线粒体生物能学是 β 细胞（功能障碍）功能的（病理）生理学的核心。研究表明，供体 β 细胞中 β 细胞线粒体功能障碍先于 2 型糖尿病的发生据报道，葡萄糖耐量受损（或糖尿病前期）的β细胞存在线粒体缺陷。人类 T2D 患者，但 T2D 线粒体功能障碍的病因尚不清楚。知识对于指导预防或治疗胰岛衰竭和 T2D 的策略是必要的，重要的是，全基因组。关联研究 (GWAS) 将超过 500 个基因位点的单核苷酸多态性 (SNP) 与 T2D 和胰岛联系起来这些 SNP 中的大多数是非编码且重叠的调控元件。（RE）对受影响的细胞具有广泛的转录影响在这项研究中，我们结合了我们在以下方面的专业知识。 T2D 的基因组学、（表观）基因组修饰和 β 细胞中的线粒体功能，以弥补基因组学的差距我们勇敢地承认非编码 T2D SNP 会导致 β 细胞功能障碍。通过改变 RE 使用或活性，改变效应基因的表达，从而直接损害线粒体为了测试这一点，我们建议在人类胰岛和 β 细胞特异性中使用复杂的（表观）基因组编辑工具。在两个互补目标中的生理相关性和验证的小鼠模型在目标 1 中，我们将测试 RE-。同时，我们将使用 CRISPR-QTL 评估 T2D 风险等位基因对 RE 的影响。假定线粒体 T2D 的染色质可及性、活性、转录因子结合和 β 细胞表达使用互补的体内效应基因（单细胞染色质可及性、组蛋白乙酰化和原代人胰岛的表达数量性状基因座分析）和体外（报告基因、DNA 结合最后，我们将确定效应基因扰动对线粒体的影响。在目标 2 中，人胰岛和 EndoC-βH3 细胞的表型、β 细胞活力以及胰岛素含量和分泌。我们利用 β 细胞特异性敲除小鼠模型为两个高优先级线粒体 T2D 分配功能此外，我们将讨论血糖控制、β细胞质量/功能和线粒体代谢中的效应基因。这些线粒体 T2D 效应基因对于 β 细胞补偿外周胰岛素抵抗的重要性最后，我们将在人类胰岛中使用（表观）基因组编辑工具来确定是否存在饮食引起的肥胖。线粒体 T2D 效应基因在离体试验中以及试验后损害 β 细胞功能和血糖控制胰岛移植到免疫缺陷小鼠中将产生新的功能变异。将分子和细胞功能分配给 T2D 风险等位基因的连接，确定新的治疗靶点，并提供重要知识来指导后续预防或治疗 β 细胞衰竭和 T2D 的策略。