Department of Endocrinology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, 1665, Kong Jiang Road, Shanghai, 200092, China.
Diabetes Metab. 2012 Jun;38(3):250-7. doi: 10.1016/j.diabet.2012.01.003. Epub 2012 Mar 3.
This study evaluated the direct effects of advanced glycation end-products (AGEs) on pancreatic β cells, including cellular viability, generation of reactive oxygen species (ROS) and insulin secretion, and also looked for the main source of ROS in INS-1 cells and the possible molecular mechanism(s) of cell injury by AGEs.
INS-1 cells were cultured with 100, 200 and 500 mg/L of AGEs for specific periods of time. Cell apoptosis was determined by ELISA and real-time PCR assays. ROS were detected by DCFH-DA and MitoSOX Red probes with a flow cytometer, NADPH oxidase activity was measured by lucigenin chemiluminescence and MAPK phosphorylation was measured by Western blot tests.
Both cell apoptosis and ROS generation increased in AGE-treated cells in a dose-dependent way, and both the mitochondrial electron transport chain and NADPH oxidase pathway participated in ROS generation, although the role of the mitochondrial pathway was earlier and more important. AGEs exerted a toxic effect on insulin secretion that could be largely reversed by inhibiting ROS.
AGEs injured INS-1 cells by oxidative stress mainly through the mitochondrial pathway, although the JNK and p38 MAPK signaling pathways were also key modulators in ROS-mediated β-cell death.
本研究评估了晚期糖基化终产物（AGEs）对胰腺β细胞的直接作用，包括细胞活力、活性氧（ROS）生成和胰岛素分泌，并寻找 INS-1 细胞中 ROS 的主要来源和 AGEs 引起细胞损伤的可能分子机制。
用 100、200 和 500mg/L 的 AGEs 分别培养 INS-1 细胞特定时间。通过 ELISA 和实时 PCR 检测细胞凋亡。用 DCFH-DA 和 MitoSOX Red 探针通过流式细胞仪检测 ROS，用荧光素化学发光法测定 NADPH 氧化酶活性，用 Western blot 检测 MAPK 磷酸化。
AGE 处理的细胞中细胞凋亡和 ROS 生成均呈剂量依赖性增加，线粒体电子传递链和 NADPH 氧化酶途径均参与 ROS 生成，尽管线粒体途径的作用更早且更重要。AGEs 通过氧化应激对胰岛素分泌产生毒性作用，该作用可通过抑制 ROS 而得到很大程度的逆转。
AGEs 通过氧化应激主要通过线粒体途径损伤 INS-1 细胞，尽管 JNK 和 p38 MAPK 信号通路也是 ROS 介导的β细胞死亡的关键调节剂。
