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

摘要：妊娠期糖尿病(GDM)是一种根据发病情况定义的异质性疾病。 糖耐量异常或高血糖在妊娠晚期发生，当胰腺β细胞 当胰岛素抵抗增加时，不能分泌足够的胰岛素。GDM影响约10%的 所有怀孕，并对孕妇及其母亲的短期和长期健康产生负面影响 后代。MicroRNAs(miRNAs，18-25nt)是一类转录后的小非编码RNA 调节基因表达，并已被证明调节β细胞内的几个关键过程。MiRNAs 也被认为是1型糖尿病和2型糖尿病的潜在生物标志物。过去的研究表明 也展示了miRNAs作为GDM生物标记物的潜力，但大多数仅用于 有针对性的方法，没有考虑母亲超重/肥胖的影响。反对这一点 背景：我们采集了登记为未产妇的孕妇的血浆样本。 妊娠结局研究-监测准妈妈(nuMoM2B；NCT01322529)研究以执行无偏见 MiRNA测序。我们的初步数据显示，母亲超重/肥胖状态(定义为体重指数≥25) 影响血浆miRNA特征。与同一BMI类别中的对照相比，我们确定了一组 在后来患上妊娠期糖尿病的孕妇中，miRNAs是不同的。这一结果表明 MiRNA信号在高血糖发病前预测妊娠期糖尿病发病的可能性。有趣的是，我们还 发现miR-517a-3p，一种富含胎盘的miRNA，已知可以促进细胞增殖， 后来患上妊娠期糖尿病的母亲的基因表达下调。在目标1中，我们假设上调 MIR-517A-3P对β细胞的功能和存活有正向调节作用。为了检验这一假设，我们将定义 未报道的miR-517a-3p在INS-1细胞、小鼠胰岛和人胰岛调节β细胞功能中的作用 模型，以及使用最先进的rna-seq方法来揭示调控基因和分子。 小路。在目标2中，我们假设miRNA签名和临床变量的组合将会改善 妊娠糖尿病的预测。这一假说将通过量化这些miRNA的表达水平来检验 使用来自多中心nuMoM2B研究的扩展样本集并使用适当的 与Joanne Daggy博士合作的模型选择方法(印第安纳大学生物统计和健康数据系 科学)。此R01补充资料还将为候选人(Kua博士)提供时间进行实验和 参加培训课程以获得新的研究技能，以追求独立内科科学家的职业生涯。 候选人的培训将包括三个主要目标：(1)获得最先进的miRNA生物学培训 以及它们在调节β细胞功能和妊娠期糖尿病风险中的作用，(2)开发实验工具包以 支持妊娠期糖尿病和子代代谢规划方面的翻译和临床研究，以及(3) 提炼科学传播技能，包括口头陈述和科学写作技能。

ABSTRACT: Gestational diabetes mellitus (GDM) is a heterogenous disease that is defined by the occurrence of glucose intolerance or hyperglycemia during the late second trimester and occurs when pancreatic β cells cannot secrete sufficient insulin when there is increasing insulin resistance. GDM affects approximately 10% of all pregnancies and negatively impacts the short-and long-term health of both pregnant mothers and their offspring. microRNAs (miRNAs, 18-25 nt) are a class of small non-coding RNAs that post transcriptionally modulate gene expression and have been shown to regulate several key processes within the β cell. miRNAs have also been implicated as potential biomarkers for type 1 diabetes, and type 2 diabetes. Past studies have also demonstrated a potential for miRNAs to serve as biomarkers for GDM as well, but most only employed targeted approaches and did not consider the contribution of maternal overweight/obesity. Against this background, we obtained plasma samples collected from pregnant mothers enrolled in the Nulliparous Pregnancy Outcomes Study-Monitoring Mothers-to-be (nuMoM2b; NCT01322529) study to perform unbiased miRNA sequencing. Our preliminary data showed that maternal overweight/obesity status (defined as BMI≥25) influenced plasma miRNA signatures. Compared to controls in the same BMI category, we identified a set of miRNAs that were different in pregnant mothers who subsequently developed GDM. This result indicates the potential of miRNA signatures to predict GDM onset prior to onset of hyperglycemia. Interestingly, we also found that miR-517a-3p, a placental-enriched miRNA that is known to increase cellular proliferation, was downregulated in mothers who subsequently developed GDM. In Aim 1, we hypothesize that the upregulation of miR-517a-3p positively regulates β cell function and survival. To test this hypothesis, we will define the unreported role of miR-517a-3p in regulating β cell function using INS-1 cells, murine islets, and human islet models, as well as using state-of-the-art RNA-seq approach to uncover the modulated genes and molecular pathways. In Aim 2, we hypothesize that a combination of miRNA signatures and clinical variables will improve the prediction of GDM. This hypothesis will be tested by quantifying the expression levels of these miRNA signatures using expanded sample sets from the multi-center nuMoM2b study and analyzed using appropriate model-selection methods in collaboration with Dr. Joanne Daggy (IU Dept of Biostatistics and Health Data Science). This R01 supplement will also support time for the candidate (Dr. Kua) to perform experiments and attend training courses to acquire new research skills to pursue a career as an independent physician scientist. The candidate training will include three main objectives: (1) Obtain state-of-the-art training in miRNA biology and their role in modulating β cell function and gestational diabetes risk, (2) develop experimental toolkits to support translational and clinical studies in gestational diabetes and offspring metabolic programming, and (3) refine scientific dissemination skills, including oral presentation and scientific writing skills.