In vivo systems to discover mechanisms regulating human islet alpha cell function

体内系统发现调节人类胰岛α细胞功能的机制

• 批准号: 10228762
• 负责人: Seung K Kim
• 金额: $ 53.9万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-04 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10228762
• 关键词: Address; Affect; Alpha Cell; Architecture; B-Lymphocytes; Beta Cell; Biological Assay; Biological Models; Biology; Cell physiology; Cells; Cellular biology; Chromatin; Coupled; Diabetes Mellitus; Disease; Electrophysiology (science); Environment; Exons; Functional disorder; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genetic study; Genomic approach; Genomics; Glucagon; Glucose; Health; Hormonal; Hormones; Human; Hyperglycemia; Impairment; In Vitro; Insulin; Insulin Resistance; Insulin-Dependent Diabetes Mellitus; Investigation; Islet Cell; Islets of Langerhans; Lead; Lipids; Measurement; Measures; Medical; Metabolic; Methods; Modernization; Molecular; Mus; Non-Insulin-Dependent Diabetes Mellitus; Organ; Organelles; Output; Pancreatic Diseases; Pathologic; Pathology; Phenotype; Physiological; Physiology; Population; Production; Property; Regulation; Research; Research Personnel; Resolution; Risk; Rodent; Role; Signal Transduction; Structural Protein; System; Testing; Time; Toxic effect; Transplantation; Visual; Work; base; diabetes pathogenesis; diabetes risk; diabetic; diet-induced obesity; disease phenotype; flexibility; gene function; genetic approach; in vitro Assay; in vivo; islet; novel; preproglucagons; reconstitution; response; tool; transcription factor; transcriptome

Type 1 and Type 2 diabetes mellitus are recognized as bi-hormonal diseases reflecting pathology in both insulin-producing islet b-cells and glucagon-producing islet a-cells. While intensive global efforts have focused on b-cell biology and replacement, little is known about the genetic or molecular effectors of a-cell activity in health or in diabetes, especially in human islets. Discovery of molecular mechanisms that govern human a-cell gene regulation and physiological functions like glucagon output are urgently needed. We have generated new tools to measure human a-cell function and regulation in vivo, and at single-cell resolution. We propose the following scientifically-timely and medically-relevant Aims that will define regulators of human a-cells: 1. Identify mechanisms regulating human a-cell function. To enable unprecedented studies of human glucagon secretion and regulation, we generated NOD.Cg-Prkdc scidIl2rgtm1WjlSz mice (NSG) with an in-frame deletion of preproglucagon exon 3 that encodes Glucagon 1-29; termed GKO-NSG. These mice permit quantification of regulated glucagon secretion from transplanted human a-cells. Genetic, physiological, and genomic approaches in vitro and in vivo will be used to identify mechanisms governing human a-cell function. Specifically, we will analyze how a-cells are impacted by transcription factors, MAFB and RFX6, which our analysis indicates are enriched in a distinct, functionally active cell population. 2. Investigate the role of lipid droplets in human a-cell adaptive responses to lipotoxicity. Lipotoxicity and accompanying insulin resistance is an established risk for diabetes pathogenesis in humans. We will use genetic approaches and physiological assays in vitro and in vivo to identify mechanisms governing accumulation of lipid droplets (LDs), an organelle in human islets. These studies will test the hypothesis that LDs regulate function of human a-cells challenged by lipotoxicity and insulin resistance. This work allows previously unattainable investigation of physiological mechanisms governing and regulating human a-cells. A fundamental advance in diabetes and islet biology research would be the identification and characterization of factors that lead to decreased islet cell function in those with diabetes, or at risk for developing diabetes. Mechanisms governing function of human islet a-cells should be revealed by the studies proposed here. Our work should establish paradigms that connect gene transcriptional and organelle regulation to control of key a-cell physiological functions in healthy and diseased pancreatic islets. Appropriately regulated islet a-cell function is an essential feature of health, and our work will have broad impact by describing ways to ameliorate islet a-cell function, in both normal and pathological conditions.

1型和2型糖尿病被认为是反映胰岛素产生胰岛B细胞和产生胰高血糖素的胰岛的双激素疾病。尽管全球强化的努力集中在B细胞生物学和替代方面，但对健康或糖尿病中A细胞活性的遗传或分子效应者知之甚少，尤其是在人类胰岛中。迫切需要发现控制人A细胞基因调节和生理功能（如胰高血糖素输出）的分子机制。我们已经生成了新工具来测量体内和单细胞分辨率的人类A细胞功能和调节。我们提出了以下科学和医学上相关的目标，该目标将定义人类A细胞的调节剂：1。确定调节人A细胞功能的机制。为了实现对人胰高血糖素分泌和调节的前所未有的研究，我们产生了NOD.CG-PRKDC SCIDIL2RGTM1WJLSZ小鼠（NSG），并用pregoglucagon Exon 3的框架缺失编码胰高血糖素1-29；称为GKO-NSG。这些小鼠允许定量从移植的人A细胞中分泌受调节的胰高血糖素分泌。体外和体内的遗传，生理和基因组方法将用于识别有关人A细胞功能的机制。具体而言，我们将分析A细胞如何受到转录因子MAFB和RFX6的影响，我们的分析表明，这表明这些因子富集在独特的功能活性细胞群中。 2。研究脂质液滴在人A细胞自适应反应中对脂毒性的作用。脂肪毒性和随附的胰岛素抵抗是人类糖尿病发病机理的确定风险。我们将在体外和体内使用遗传方法和生理测定，以识别有关人类胰岛中脂质液滴积累（LDS）的积累的机制。这些研究将检验以下假设：LDS调节受脂肪毒性和胰岛素抵抗挑战的人类A细胞的功能。这项工作允许对管理和调节人类A细胞的生理机制进行以前无法实现的研究。糖尿病和胰岛生物学研究的基本进展是鉴定和表征导致糖尿病患者胰岛细胞功能降低或患糖尿病风险的因素。在此提出的研究应揭示有关人类胰岛A细胞功能的机制。我们的工作应建立将基因转录和细胞器调节连接起来，以控制健康和患病胰岛中关键A细胞生理功能的范例。适当调节的胰岛A细胞功能是健康的重要特征，我们的工作将通过描述在正常和病理条件下改善胰岛A细胞功能的方法来产生广泛的影响。