Circulating miRNA Signatures of Beta-Cell Response to Metformin or Insulin in Youth with Dysglycemia

摘要 患有糖尿病前期(糖耐量受损)或2型糖尿病(T2D)的年轻人体验相对较快 一种不能被二甲双胍或胰岛素预防或延迟的β细胞衰竭。潜在的机制 T2D的暴发性病程以及二甲双胍和胰岛素在青年中缺乏预防益处 未知。表观遗传生物标记物，如microRNAs(MiRNAs)，调节在葡萄糖和 胰岛素代谢，并可能在调节对二甲双胍或胰岛素的反应中发挥作用。MiRNAs是 短的非编码RNA，调节对葡萄糖稳态重要的基因的表达，但它们在 对二甲双胍和胰岛素的全身反应知之甚少，特别是在年轻人。我们的目标是 发现与胰岛素抵抗和β细胞衰竭相关的循环miRNAs，尽管药物治疗 青春年华。为了实现这一目标，我们建议对恢复的胰岛素分泌(RISE)进行二次分析 甘精胰岛素与二甲双胍联合应用的随机对照研究 在10-19岁患有血糖障碍的青年中单独使用二甲双胍。我们将使用RNA检测循环中的miRNAs 排序(在基线和12个月干预结束时)和匹配回归(逻辑和 广义线性)模型来识别与二甲双胍和胰岛素反应相关的miRNAs。最重要的是 这一应用的假设是循环miRNA图谱(反映组织特异性miRNA变化) 在二甲双胍和/或治疗期间导致胰岛细胞衰竭和胰岛素抵抗的进展 血糖异常的青年患者的胰岛素。我们将测试以下目标：(1)识别基线循环 与β细胞功能改善或恶化相关的miRNAs(胰岛素敏感性- 调整的稳态C-肽和最高血糖时精氨酸对急性C-肽的反应 增强[ACPRmax])和胰岛素敏感性(平均葡萄糖输注率除以 青年糖尿病前期或早期T2D患者12个月时的稳态血浆胰岛素浓度[M/I] 经过12个月的干预后，使用甘精氨酸二甲双胍或单独使用二甲双胍(n=32)和(2)以确定 与改善或改善有关的循环miRNAs的变化(基线至12个月) 患有糖尿病前期或糖尿病前期的青年患者12个月时β细胞功能和胰岛素敏感性恶化 在12个月的干预后早期T2D，或单独使用二甲双胍(n=32)。 拟议工作的成功完成将确定与Beta进展相关的循环miRNAs- 青年时期的细胞衰竭和胰岛素抵抗。此外，它还将提供必要的试点数据，以便 设计更大规模的研究，以确定有助于β细胞进展的表观遗传机制 青年糖尿病前期患者应用胰岛素和/或二甲双胍治疗失败和胰岛素抵抗 早期T2D。确定二甲双胍和胰岛素衰竭的表观遗传学机制是关键的下一步 开发新的治疗方法来预防儿童T2D或诱导糖尿病前期的缓解。

ABSTRACT Youth with prediabetes (impaired glucose tolerance) or type 2 diabetes (T2D) experience relatively rapid beta-cell failure that is not prevented or delayed by metformin or insulin. Mechanisms underlying the fulminant course of T2D and the lack of preventive benefit from metformin and insulin in youth are unknown. Epigenetic biomarkers such as microRNAs (miRNAs) regulate genes important in glucose and insulin metabolism and may play a role in mediating responsiveness to metformin or insulin. miRNAs are short non-coding RNAs that regulate expression of genes important to glucose homeostasis, but their role in systemic responses to metformin and insulin is poorly understood, especially in youth. Our objective is to identify circulating miRNAs related to insulin resistance and beta-cell failure despite pharmacotherapy in youth. To achieve this goal, we propose a secondary analysis of the Restoring Insulin Secretion (RISE) Pediatric Mediation Study, a randomized controlled trial of glargine insulin followed by metformin or metformin alone in youth ages 10–19 with dysglycemia. We will assay circulating miRNAs using RNA sequencing (at baseline and at the end of the 12-month intervention) and fit regression (logistic and generalized linear) models to identify miRNAs related to metformin and insulin response. The overarching hypothesis of this application is that circulating miRNA profiles (reflecting tissue-specific miRNA changes) contribute to progression of beta-cell failure and insulin resistance during treatment with metformin and/or insulin in youth with dysglycemia. We will test the following aims: (1) To identify baseline circulating miRNAs associated with improvement or worsening in beta-cell function (insulin sensitivity- adjusted steady-state C-peptide and acute C-peptide response to arginine at maximal glycemic potentiation [ACPRmax]) and insulin sensitivity (mean glucose infusion rate divided by mean steady-state plasma insulin concentration [M/I]) at 12 months in youth with prediabetes or early T2D after a 12-month intervention with glargine + metformin or metformin alone (n=32) and (2) to identify changes in circulating miRNAs (between baseline and month 12) associated with improvement or worsening in beta-cell function and insulin sensitivity at 12 months in youth with prediabetes or early T2D after a 12-month intervention with glargine + metformin or metformin alone (n=32). Successful completion of the proposed work will identify circulating miRNAs related to progression of beta- cell failure and insulin resistance in youth. In addition, it will provide necessary pilot data that will inform design of larger studies to determine the epigenetic mechanisms contributing to progression of beta-cell failure and insulin resistance despite treatment with insulin and/or metformin in youth with prediabetes and early T2D. Identifying epigenetic mechanisms of metformin and insulin failure is a critical next step in the development of novel treatments to prevent pediatric T2D or induce remission of prediabetes.