Prdx Ⅴ在链脲佐菌霉素诱导MIN6细胞凋亡过程中的调控作用

Regulatory Effect of Prdx Ⅴ on Streptozotocin-Induced Apoptosis in MIN6 Cells

Prdx Ⅴ(peroxiredoxin Ⅴ)是过氧化物还原酶家族中一员,可有效地保护细胞免受氧化应激造成的氧化损伤。该文主要阐明了链脲佐菌霉素(streptozotocin,STZ)诱导MIN6小鼠胰岛瘤细胞凋亡的分子机制及Prdx Ⅴ在这一过程中的调控作用。该研究利用STZ处理MIN6小鼠胰岛瘤细胞,通过MTT法、荧光显微镜照相、流式细胞术、蛋白质免疫印迹分析等方法检测细胞存活率、细胞内活性氧类(reactive oxygen species,ROS)及细胞凋亡水平、一氧化氮(nitric oxide,NO)含量、凋亡相关蛋白质及相关信号通路蛋白质水平。结果表明,STZ主要通过激活p38信号通路调控NO的生成,引起MIN6细胞发生凋亡,而与细胞内增加的ROS无内在联系。与此同时,STZ可致使细胞内Prdx Ⅴ蛋白质水平明显上升,当Prdx Ⅴ基因沉默之后,发现STZ诱导的Prdx Ⅴ缺失型MIN6细胞凋亡率明显高于对照组,提示Prdx Ⅴ对STZ诱导MIN6细胞凋亡过程具有一定的调控作用。该研究结果揭示了STZ诱导MIN6细胞凋亡分子机制,同时初步探析了Prdx Ⅴ对STZ引起MIN6胰岛细胞凋亡的调控作用,为研究氧化应激引起胰岛细胞损伤及死亡机制提供了一定的理论基础。

Peroxiredoxin Ⅴ（Prdx Ⅴ） is a thioredoxin peroxidase involved in peroxiredoxins family, which can effectively protect cells against oxidative damage caused by oxidative stress. This study is aimed to explore the molecular mechanism of STZ-induced apoptosis in MIN6 cells and the regulatory function of Prdx Ⅴ during the process. We used the MTT assay, fluorescence microscopy, flow cytometry and Western blot assay for analyzing the cell viability, the cellular ROS levels, nitric oxide production and apoptosis-related-proteinslevels in STZ-treated MIN6 cells, respectively. The results showed that the STZ-induced MIN6 cell apoptosis was mainly resulted in NO production regulated by p38 signaling pathway, and the Prdx Ⅴ protein levels were also increased during the process. Furthermore, knockdown the Prdx Ⅴ gene expressions with Lenti-virus, resulted in decreasing of the cell viability and increasing the cell apoptosis in STZ-treated MIN6 cells. Our findings provide a theoretical basis for the study of the mechanism of oxidative stress caused islet cell damage and death.