酒精对小鼠NIT-1细胞氧化损伤及凋亡的影响

目的　研究酒精能否诱导小鼠胰岛素瘤细胞(NIT -1)凋亡,初步探讨凋亡发生机制。方法　体外培养的小鼠NIT- 1细胞用不同浓度酒精处理后,采用DNA琼脂糖凝胶电泳法观察酒精对小鼠NIT- 1细胞凋亡的影响;测定细胞丙二醛(MDA)和谷胱甘肽(GSH)的含量以及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH- Px ,GPX)的活性以判断细胞氧化程度;采用比色法测定Caspase 3酶活性。结果　酒精导致NIT 1细胞琼脂糖凝胶电泳显示典型的梯状凋亡条带。与对照组比,剂量组MDA生成增多,SOD、GSH -Px活性下降,GSH含量下降。酒精作用后NIT 1细胞caspase- 3活性升高,升高程度与作用时间及剂量有关。结论　提示高浓度酒精可导致体外培养的小鼠NIT- 1胰岛β细胞氧化抗氧化失衡,氧化应激诱导细胞发生凋亡,凋亡的发生很可能与Caspase- 3激活有关。

Oxidative damage and apoptosis in NIT-1 cells induced by ethanol

OBJECTIVE: To decide whether ethanol induce apoptosis in mouse insulinoma cells (NIT-1) and the potential mechanism involved. METHODS: After NIT-1 cells were exposed to various concentrations of ethanol, agarose gel electrophoresis was used to detected DNA fragmentation. malondialdehyde (MDA) content, glutathione (GSH) level, superoxide dismutase(SOD) and glutathione peroxidase (GSH-Px) were measured in NIT-1 cells to evaluate the oxidative damage degree. Caspase-3 relative activity was determined by colorimetric assay. RESULTS: The results showed a "DNA ladder" pattern after treated with ethanol in NIT-1 cells. The MDA content was higher, the SOD activity, GSH-Px activity and GSH content were lower in ethanol group than those of control group. Ethanol increased the caspase-3 activity by a dose and time dependent manner. CONCLUSION: Higher concentration of ethanol induces imbalance of oxidation and antioxidative ability in NIT-1 cells, and oxidative stress further leads to apoptosis which may be related to the increased caspase-3 activity.