The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, P.R. China.
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
PeerJ. 2022 Aug 10;10:e13849. doi: 10.7717/peerj.13849. eCollection 2022.
Glucotoxicity-induced pancreatic -cell failure contributes to the development of type 2 diabetes mellitus (T2DM). Accumulating evidence reveals that miRNAs play a critical role in regulating pancreatic -cell function and survival. In this study, we employed a self-assembled cell microarray (SAMcell)-based functional screening assay to identify miRNAs that are capable of regulating the dysfunction of -cells induced by glucotoxicity. Among 62 conserved miRNAs we tested, miR-190 was identified as a candidate regulator that could effectively restore insulin expression in NIT-1 cells under high-glucose (HG) stimulation. Further analyses demonstrated that miR-190 was significantly down-regulated in HG-treated NIT-1 cells, as well as in the pancreas of diabetic mice. Mechanistic studies showed that Cybb is the direct target gene of miR-190, which encodes the gp91phox protein, a subunit of the NOX2 complex. Furthermore, both miR-190 overexpression and Cybb knockdown inhibited apoptosis and improved glucose-stimulated insulin secretion (GSIS) in HG-stimulated NIT-1 cells by attenuating the excessive production of reactive oxygen species (ROS). More importantly, a targeted delivery of mPEG-PCL-g-PDMAEMA nanoparticles/miR-190 complexes (PECgD NPs/miR-190) to the pancreas significantly ameliorated hyperglycemia, decreased fasting serum insulin levels, and improved glucose tolerance in diabetic mice. Taken together, our findings suggest that the miR-190/Cybb axis plays an important role in glucotoxicity-induced pancreatic -cell failure. Restoring miR-190 expression levels may be a possible therapeutic strategy to protect -cells in T2DM.
糖毒性诱导的胰岛细胞功能衰竭是 2 型糖尿病（T2DM）发病的重要原因。越来越多的证据表明，miRNA 在调节胰岛细胞功能和存活方面发挥着关键作用。在本研究中，我们采用基于自组装细胞微阵列（SAMcell）的功能筛选检测方法，鉴定了能够调节高糖诱导的β细胞功能障碍的miRNA。在我们检测的 62 个保守 miRNA 中，miR-190 被鉴定为候选调控因子，可在高糖（HG）刺激下有效恢复 NIT-1 细胞中的胰岛素表达。进一步分析表明，miR-190 在 HG 处理的 NIT-1 细胞以及糖尿病小鼠的胰腺中显著下调。机制研究表明，Cybb 是 miR-190 的直接靶基因，其编码 gp91phox 蛋白，是 NOX2 复合物的一个亚基。此外，miR-190 的过表达和 Cybb 的敲低均通过抑制过量的活性氧（ROS）产生来抑制 HG 刺激的 NIT-1 细胞凋亡和改善葡萄糖刺激的胰岛素分泌（GSIS）。更重要的是，靶向递送至胰腺的 mPEG-PCL-g-PDMAEMA 纳米粒/miR-190 复合物（PECgD NPs/miR-190）显著改善了糖尿病小鼠的高血糖，降低了空腹血清胰岛素水平，并改善了葡萄糖耐量。综上所述，我们的研究结果表明，miR-190/Cybb 轴在糖毒性诱导的胰岛细胞功能衰竭中发挥重要作用。恢复 miR-190 的表达水平可能是保护 T2DM 中β细胞的一种可行的治疗策略。
