Background

Iron overload can result in a disorder in glucose metabolism. However, the underlining mechanism through which iron overload induces beta cell death remains unknown.

Methods

According to the concentration of ferric ammonium citrate (FAC) and N-acetylcysteine, INS-1 cells were randomly divided into four groups: normal control (FAC 0 μM) group, FAC 80 μM group, FAC 160 μM group, FAC 160μM + NAC group.. Cell proliferation was assessed by Cell Counting Kit-8. Reactive oxygen species (ROS) level was further evaluated using flow cytometer with a fluorescent probe. The mitochondrial membrane potential was detected by JC-1 kit, and transmission electron microscopy was used to observe the mitochondrial changes. The related protein expressions were detected by western bolt to evaluate mitophagy status.

Results

It was shown that FAC treatment decreased INS-1 cell viability in vitro, resulted in a decline in mitochondrial membrane potential, increased oxidative stress level and suppressed mitophagy. Furthermore, these effects could be alleviated by the ROS scavenger.

Conclusions

We proved that increased iron overload primarily increased oxidative stress and further suppressed mitophagy via PTEN-induced putative kinase 1/Parkin pathway, resulting in cytotoxicity in INS-1 cells.

中文翻译：

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对铁超载诱导的胰腺β细胞中PINK1 / Parkin途径相关的氧化损伤的线粒体反应

背景

铁过载会导致葡萄糖代谢紊乱。但是，铁过载引起β细胞死亡的机制尚不清楚。

方法

根据柠檬酸铁铵（FAC）和N-乙酰半胱氨酸的浓度，将INS-1细胞随机分为四组：正常对照组（FAC 0μM）组，FAC 80μM组，FAC 160μM组，FAC160μM+ NAC通过细胞计数试剂盒8评估细胞增殖。使用带荧光探针的流式细胞仪进一步评估活性氧（ROS）水平。用JC-1试剂盒检测线粒体膜电位，并用透射电镜观察线粒体的变化。Western blot检测相关蛋白的表达，以评价细胞的线粒体状态。

结果

结果表明，FAC处理可降低INS-1细胞的体外活力，导致线粒体膜电位下降，氧化应激水平升高和线粒体抑制。此外，ROS清除剂可以减轻这些影响。

结论

我们证明增加的铁超负荷主要通过PTEN诱导的假定激酶1 / Parkin途径增加氧化应激并进一步抑制线粒体，从而导致INS-1细胞的细胞毒性。