亚硒酸钠对神经皮质细胞氧化损伤作用

Sodium selenite induced oxidative damage in cultured cortical neurons

目的研究不同剂量亚硒酸钠对小鼠大脑皮层神经皮质细胞的损伤作用。方法选用24h龄ICR小鼠,培养大脑神经皮质细胞,48h后加入不同浓度的亚硒酸钠(0.004,0.020,0.100,0.500μmol/L),四甲基偶氮噻唑蓝试验检测细胞活性、激光共聚焦显微镜检测线粒体膜电位,慧星试验检测细胞DNA损伤。结果高剂量亚硒酸钠(0.1和0.5μmol/L)明显抑制皮质神经细胞生长、降低线粒体膜电位、并严重损伤DNA,且呈现剂量效应关系(P<0.05)。与对照组比较,低剂量亚硒酸钠(0.004和0.020μmol/L)虽然呈现一定毒性作用,但差异无统计学意义(P>0.05)。结论高浓度亚硒酸钠可引起细胞损伤,降低细胞活力,其机制可能与细胞线粒体结构和功能改变以及DNA结构损伤有关。

Objective To observe the damage of sodium selenite on cultured cortical neurons and its mechanism. Methods Sodium selenite was added to neuronal after two days cultured in vitro with different concentrations （0.000, 0.004, 0.020, 0.100, and 0. 500 μmol/L）. Mitochondrial membrane potential （confocal microscopy through focusing, CMTF） and MTT were performed to investigate the alterations of mitochondrial structure and functions; DNA damage was measured by single cell gel electrophoresis（SCGE）. Each experiment was repeated at least 3 times. Results High concentration of sodium selenite（0. 100 - 0,500 μmol/L） could cause significant damage of cultured cortical neurons, whereas low concentration of sodium selenite（0-0. 020μmol/L） had no effect on the activity of the cells. Conclusion Our data demonstrated that high concentration of sodium selenite could damage the cultured neurons. The alterations of mitochondrial structure and functions and DNA damage played important roles in neurotoxic mechanism induced by sodium selenite.