β cell miRNAs Function as Molecular Hubs of Type 1 Diabetes Pathogenesis

β 细胞 miRNA 作为 1 型糖尿病发病机制的分子中心

基本信息

批准号：
10615586
负责人：
Carmella Evans-Molina
金额：
$ 42.82万
依托单位：
INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-05-01 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10615586
关键词：
3&apos Untranslated Regions Address Autoantibodies Autoimmunity Beta Cell Binding Biological Markers Cell Death Cell Survival Cell physiology Cells Cellular Stress Childhood Chronic Clinical Complex Cues Data Data Set Detection Development Diabetes Mellitus Disease Evolution Exhibits Exposure to Female Fluorescent in Situ Hybridization Functional disorder Gene Expression Genetic Transcription Goals High Fat Diet Homicide Human Immune Immune system Inflammatory Insulin Insulin-Dependent Diabetes Mellitus Interferon Type II Interleukin-1 beta Invaded Islets of Langerhans Knowledge Measures Mediating Mediator Messenger RNA Metabolic Diseases MicroRNAs Modeling Molecular Mus Non-Insulin-Dependent Diabetes Mellitus Organ Donor Pancreas Pancreatic Injury Pathogenesis Pathway interactions Pattern Phenotype Plasma Play Porifera Process Quantitative Reverse Transcriptase PCR Research Role Signal Pathway Small RNA Streptozocin Stress Testing Therapeutic Intervention Tissues Untranslated RNA Up-Regulation Validation Work chemokine clinical biomarkers cytokine diabetes pathogenesis diabetes risk experimental study extracellular vesicles imaging approach immune cell infiltrate injured insulin dependent diabetes mellitus onset insulin secretion intercellular communication islet mRNA Transcript Degradation mRNA Translation male mouse model non-diabetic novel overexpression posttranscriptional programs response sexual dimorphism single molecule transcriptome sequencing

项目摘要

Type 1 diabetes (T1D) is a chronic metabolic disorder that is characterized by immune-mediated β cell destruction, resulting in the lifelong need for exogenous insulin therapy. Historically, T1D has been considered a disease of β cell homicide. However, recent evidence suggests that the β cell actively contributes to its own demise in T1D through engagement of cell intrinsic stress pathways that both hasten cell death and exacerbate autoimmunity. microRNAs (miRNAs, 18-25 nt) are a class of small non-coding RNAs that post transcriptionally modulate gene expression by binding the 3’untranslated region of a target mRNA to either inhibit mRNA translation or cause mRNA degradation. In addition to these regulatory roles within their cells of origin, miRNAs can be packaged and released within extracellular vesicles (EVs), which can be transferred to recipient cells to both facilitate intercellular communication and promote disease pathogenesis. While miRNAs have been shown to regulate several key processes within the β cell and have been implicated as potential mediators of a dialogue between the immune system and the β cell in diabetes, a full understanding of the role of miRNAs in T1D pathophysiology remains elusive. To this end, we profiled changes in miRNA expression patterns in human islets and islet-derived extracellular vesicles (EV’s) in response to IL-1β and IFN-γ, two cytokines selected to model the inflammatory intra-islet milieu observed in T1D. Our initial small RNA sequencing and additional preliminary data has shown that islet miRNA expression patterns are responsive to inflammatory extrinsic cues and that miRNAs appear to be selectively packaged into islet-derived EV’s in response to cytokine treatment. Moreover, islet and islet-derived EV miRNAs exhibited striking sexually dimorphic expression patterns under basal conditions and following cytokine treatment. Interestingly, miR-155-5p and miR-146-5p were the only two miRNAs that were coordinately upregulated in cytokine-treated islets and islet-derived EVs from both male and female donors, and upregulation of these miRNAs was associated with detrimental changes in β cell function and survival. Based on these findings, we hypothesize that β cell miR-155-5p and miR-146-5p function as key molecular hubs during the evolution of T1D, playing a role in disease pathogenesis, while also having potential utility as diabetes biomarkers. To test this hypothesis, we aim to: 1) define how miRNA signatures change in human β cells during T1D progression using state-of-the art smFISH imaging approaches, focused on miR-155 and 146 and a panel of additional miRNAs predicted to have either common or distinct expression patterns in males and females; 2) elucidate the mechanisms underlying miR-155-5p and miR-146-5p upregulation under inflammatory conditions; 3) define how miR-146 and miR-155 regulate β cell function and survival, leveraging both ex vivo human islet models and novel mouse models of β cell specific deletion of miR-155; and 4) test the utility of EV miRNA signatures informed from islet RNA sequencing as clinical biomarkers using plasma EVs and β cell enriched plasma EVs collected from pediatric subjects with recent onset T1D or autoantibody positivity.

1型糖尿病（T1D）是一种以免疫介导的β细胞为特征的慢性代谢疾病破坏，导致对外源胰岛素治疗的终生需求。从历史上看，T1D被认为是β细胞杀人剂的疾病。然而，最近的证据表明，β细胞通过参与细胞固有的应激途径而在T1D中积极造成自身的灭亡，既加速细胞死亡又加剧自身免疫性。 microRNA（miRNA，18-25 NT）是一类小型非编码RNA，通过结合靶mRNA的3'untranslated区域来抑制mRNA翻译或引起mRNA降解，从而在转录后调节基因表达。除了它们在其原产细胞中的这些调节作用外，可以将miRNA包装在细胞外蔬菜（EV）中，它们可以转移到受体细胞中，以促进细胞间交流并促进疾病发病机理。尽管已显示miRNA可以调节β细胞内的几个关键过程，并被视为对话的潜在介体在糖尿病中免疫系统和β细胞之间，对miRNA在T1D病理生理学中的作用的全面了解仍然难以捉摸。为此，我们介绍了人类胰岛和胰岛衍生的细胞外蔬菜（EV）中的miRNA表达模式的变化，以响应IL-1β和IFN-γ，选择了两种细胞因子，以模拟T1D中观察到的炎症性内在环境。我们最初的小RNA测序和其他初步数据表明，胰岛miRNA表达模式对炎症外在提示有反应，并且MiRNA似乎被选择地包装到胰岛衍生的EV中，以响应细胞因子治疗。此外，在基本条件和细胞因子治疗后，胰岛和胰岛衍生的EV miRNA暴露于性二态表达模式。有趣的是，miR-155-5p和miR-146-5p是仅有的两个miRNA，在细胞因子处理的胰岛和胰岛衍生的evs中均协调上调的miRNA。女性捐助者和这些miRNA的上调与β细胞功能和存活率的有害变化有关。基于这些发现，我们假设β细胞miR-155-5p和miR-146-5p在T1D演变过程中起关键分子枢纽的功能，在疾病发病机理中发挥了作用，同时也具有潜在的效用作为糖尿病生物标志物。为了检验这一假设，我们的目的是：1）定义miRNA特征在T1D进展过程中使用最先进的Smfish成像方法在T1D进展过程中如何变化，该方法集中在miR-155和146上，以及预测的其他miRNA，预计在男性和女性中具有常见或独特的表达模式； 2）阐明miR-155-5p和miR-146-5p上调的机制在炎症条件下上调； 3）定义miR-146和miR-155如何调节β细胞功能和生存，利用MiR-155的β细胞特异性缺失的外体胰岛模型和新型小鼠模型； 4）测试使用等离子体EV和从最近发作T1D或自身抗体阳性的儿科受试者收集的β细胞富集的血浆EV。