Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany.
German Center for Diabetes Research (DZD), München-Neuherberg, Germany.
Acta Physiol (Oxf). 2021 Aug;232(4):e13693. doi: 10.1111/apha.13693. Epub 2021 Jun 29.
MicroRNAs play an important role in the maintenance of cellular functions by fine-tuning gene expression levels. The aim of the current study was to identify genetically caused changes in microRNA expression which associate with islet dysfunction in diabetic mice.
To identify novel microRNAs involved in islet dysfunction, transcriptome and miRNome analyses were performed in islets of obese, diabetes-susceptible NZO and diabetes-resistant B6-ob/ob mice and results combined with quantitative trait loci (QTL) and functional in vitro analysis.
In islets of NZO and B6-ob/ob mice, 94 differentially expressed microRNAs were detected, of which 11 are located in diabetes QTL. Focusing on conserved microRNAs exhibiting the strongest expression difference and which have not been linked to islet function, miR-205-5p was selected for further analysis. According to transcriptome data and target prediction analyses, miR-205-5p affects genes involved in Wnt and calcium signalling as well as insulin secretion. Over-expression of miR-205-5p in the insulinoma cell line INS-1 increased insulin expression, left-shifted the glucose-dependence of insulin secretion and supressed the expression of the diabetes gene TCF7L2. The interaction between miR-205-5p and TCF7L2 was confirmed by luciferase reporter assay.
MiR-205-5p was identified as relevant microRNA involved in islet dysfunction by interacting with TCF7L2.
微小 RNA 通过精细调节基因表达水平，在维持细胞功能方面发挥着重要作用。本研究旨在鉴定与糖尿病小鼠胰岛功能障碍相关的遗传引起的微小 RNA 表达变化。
为了鉴定与胰岛功能障碍相关的新的微小 RNA，对肥胖、易患糖尿病的 NZO 和糖尿病抗性 B6-ob/ob 小鼠的胰岛进行了转录组和 miRNome 分析，并将结果与数量性状基因座 (QTL) 和功能体外分析相结合。
在 NZO 和 B6-ob/ob 小鼠的胰岛中，检测到 94 个差异表达的微小 RNA，其中 11 个位于糖尿病 QTL 中。关注表现出最强表达差异且与胰岛功能无关的保守微小 RNA，选择 miR-205-5p 进行进一步分析。根据转录组数据和靶标预测分析，miR-205-5p 影响涉及 Wnt 和钙信号以及胰岛素分泌的基因。在胰岛素瘤细胞系 INS-1 中转录物表达 miR-205-5p 增加了胰岛素的表达，左移了胰岛素分泌对葡萄糖的依赖性，并抑制了糖尿病基因 TCF7L2 的表达。miR-205-5p 与 TCF7L2 之间的相互作用通过荧光素酶报告基因检测得到证实。
miR-205-5p 通过与 TCF7L2 相互作用，被鉴定为与胰岛功能障碍相关的相关微小 RNA。
