Li Jin, Su Lei, Gong Ying-Ying, Ding Mei-Lin, Hong Shu-Bin, Yu Shuang, Xiao Hai-Peng
Department of Geriatrics, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, P.R. China.
Department of Endocrinology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, P.R. China.
PLoS One. 2017 Mar 27;12(3):e0173576. doi: 10.1371/journal.pone.0173576. eCollection 2017.
Liraglutide is administered as glucagon-like peptide-1 (GLP-1) receptor agonist for diabetic patients and can protect pancreatic β-cells by inhibiting their apoptosis. MicroRNA-139-5p (miRNA-139-5p) participates in the regulation of cancer cell apoptosis. However, it is not clear whether miR-139-5p contributes to the anti-apoptotic effect of liraglutide in β-cells. The objective of the present study was to investigate the role of miR-139-5p on apoptosis of pancreatic β-cells. MicroRNA levels in pancreatic tissue from diabetic rats and INS-1 cells treated with liraglutide were measured by real-time quantitative RT-PCR. The role of miR-139-5p on apoptosis was studied by transfecting INS-1 cells with miR-139-5p mimics. The mRNA and protein expression of the target gene, insulin receptor substrate-1 (IRS1), were measured by qRT-PCR and Western blot, respectively. Apoptosis in rat pancreatic tissue and INS-1 cells was detected by TUNEL and annexin V/propidium iodide costaining. Apoptosis of pancreatic tissue from diabetic rats and INS-1 cells was decreased by administration of liraglutide. The expression of miR-139-5p increased in the pancreas of diabetic rats and decreased with liraglutide treatment. Incubation with liraglutide (100 nM) for 48 h attenuated the expression of miR-139-5p and increased the mRNA and protein levels of IRS1. Direct regulatory effects of miR-139-5p on IRS1 were found by a dual-luciferase reporter assay. Transfection of INS-1 cells with miR-139-5p mimics led to decreases in the mRNA and protein expression of IRS1. In conclusion, our observations suggest that decreased miR-139-5p expression contributes to the anti-apoptotic effect of liraglutide on the diabetic rat pancreas and INS-1 cells by targeting IRS1.
利拉鲁肽作为胰高血糖素样肽-1（GLP-1）受体激动剂用于糖尿病患者，可通过抑制胰腺β细胞凋亡来保护它们。微小RNA-139-5p（miRNA-139-5p）参与癌细胞凋亡的调控。然而，尚不清楚miR-139-5p是否有助于利拉鲁肽对β细胞的抗凋亡作用。本研究的目的是探讨miR-139-5p在胰腺β细胞凋亡中的作用。通过实时定量逆转录聚合酶链反应（RT-PCR）测定糖尿病大鼠胰腺组织和经利拉鲁肽处理的INS-1细胞中的微小RNA水平。通过用miR-139-5p模拟物转染INS-1细胞来研究miR-139-5p对凋亡的作用。分别通过qRT-PCR和蛋白质免疫印迹法测定靶基因胰岛素受体底物-1（IRS1）的mRNA和蛋白质表达。通过TUNEL法和膜联蛋白V/碘化丙啶共染色检测大鼠胰腺组织和INS-1细胞中的凋亡情况。给予利拉鲁肽可降低糖尿病大鼠胰腺组织和INS-1细胞的凋亡。糖尿病大鼠胰腺中miR-139-5p的表达增加，而利拉鲁肽治疗后其表达降低。用100 nM利拉鲁肽孵育48小时可减弱miR-139-5p的表达，并增加IRS1的mRNA和蛋白质水平。通过双荧光素酶报告基因检测发现miR-139-5p对IRS1有直接调控作用。用miR-139-5p模拟物转染INS-1细胞导致IRS1的mRNA和蛋白质表达降低。总之，我们的观察结果表明，miR-139-5p表达降低通过靶向IRS1有助于利拉鲁肽对糖尿病大鼠胰腺和INS-1细胞的抗凋亡作用。
