Science and Education Office, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
Department of Internal Medicine, South China Normal University Hospital, Guangzhou 510630, China.
Biomed Res Int. 2021 Apr 5;2021:6662612. doi: 10.1155/2021/6662612. eCollection 2021.
miRNAs pose a good prospect in the diagnosis and treatment of type 2 diabetes (T2D). This study is aimed at investigating whether miR-720 targets Rab35 to regulate insulin secretion in MIN6 cells and its molecular mechanism and the clinical value of miR-720 as a specific biomarker of T2D. Fifty-five samples of new diagnosis T2D patients and normal control were collected. Levels of miR-720, fasting blood glucose, insulin, and other indicators of glucose and lipid metabolism were determined. We increased and decreased the miR-720 expression using miR-720 mimic and inhibitor to identify the effect of miR-720 on insulin secretion in MIN6 cells, respectively. Then, we used miR-720 mimic, miR-720 inhibitor, and dual luciferase reporter gene assays to prove miR-720 which regulates insulin secretion by targeting Rab35 in MIN6 cells. In addition, we overexpressed and silenced the Rab35 gene to detect the expression of PI3K, Akt, and mTOR in MIN6 cells by RT-PCR and western blot. In this study, circulating miR-720 was significantly higher in the T2D group than the control group, and miR-270 was positive correlated with FBG, while negatively correlated with FINS. The overexpression of miR-720 inhibited insulin secretion, and miR-720 downregulation promoted insulin secretion. miR-720 regulated insulin secretion by targeting Rab35 in MIN6 cells. Compared with the control group, the expression of PI3K, Akt, and mTOR was significantly decreased by the overexpression of the Rab35 gene, while the silencing Rab35 gene could induce the expression of PI3K, Akt, and mTOR. Furthermore, miR-720 mimic could activate the PI3K pathway. We conclude that miR-720 may be a potential biomarker for the diagnosis of T2D. Increase of miR-720 reduced the Rab35 expression then activate the PI3K/Akt/mTOR signal pathway, thus inhibiting insulin secretion.
miRNAs 在 2 型糖尿病（T2D）的诊断和治疗中具有广阔的前景。本研究旨在探讨 miR-720 是否通过靶向 Rab35 调节 MIN6 细胞胰岛素分泌及其分子机制，以及 miR-720 作为 T2D 特异性生物标志物的临床价值。收集了 55 例新诊断的 T2D 患者和正常对照组的样本。测定 miR-720 水平、空腹血糖、胰岛素及其他糖脂代谢指标。分别采用 miR-720 模拟物和抑制剂增加和减少 miR-720 的表达，以确定 miR-720 对 MIN6 细胞胰岛素分泌的影响。然后，我们采用 miR-720 模拟物、miR-720 抑制剂和双荧光素酶报告基因实验证实 miR-720 通过靶向 Rab35 调节 MIN6 细胞胰岛素分泌。此外，我们过表达和沉默 Rab35 基因，通过 RT-PCR 和 Western blot 检测 MIN6 细胞中 PI3K、Akt 和 mTOR 的表达。在这项研究中，T2D 组循环 miR-720 明显高于对照组，miR-270 与 FBG 呈正相关，与 FINS 呈负相关。miR-720 的过表达抑制胰岛素分泌，miR-720 的下调促进胰岛素分泌。miR-720 通过靶向 MIN6 细胞中的 Rab35 调节胰岛素分泌。与对照组相比，Rab35 基因过表达可显著降低 PI3K、Akt 和 mTOR 的表达，而沉默 Rab35 基因可诱导 PI3K、Akt 和 mTOR 的表达。此外，miR-720 模拟物可激活 PI3K 通路。综上所述，miR-720 可能是 T2D 诊断的潜在生物标志物。miR-720 的增加降低了 Rab35 的表达，进而激活了 PI3K/Akt/mTOR 信号通路，从而抑制了胰岛素的分泌。
