不同价态锰对神经细胞的毒性比较以及硒的保护作用

目的研究不同价态锰化合物对神经母细胞瘤细胞(SH-SY5Y)DNA损伤作用、细胞凋亡和细胞周期的影响,以及抗氧化剂硒的保护作用,从而探讨锰的神经毒作用机制。方法将培养的SH-SY5Y细胞随机分为染毒的二价锰和三价锰化合物(0.5 mmol/L)组、空白对照组、硒干预组。培养24 h后应用单细胞凝胶电泳检测细胞DNA链断裂情况。48 h后用流式细胞仪测定细胞凋亡率、细胞周期分布。结果三价锰组DNA损伤程度比二价锰组严重。二价锰和三价锰组均出现亚二倍体的凋亡峰;细胞周期分布也发生改变,与对照组相比S期细胞明显增多,差异有统计学意义(P<0.01);三价锰比二价锰更易引起细胞凋亡(P<0.01)和细胞周期变化(P<0.05)。硒可降低锰化合物引起的细胞DNA损伤、凋亡率和细胞周期中S期细胞数。结论不同价态锰对神经细胞均有损伤作用,且三价锰大于二价锰。硒对锰致细胞DNA损伤、凋亡和细胞周期改变有一定的保护作用,提示氧化应激可能参与了锰的毒作用。

Neural Toxicity Induced by Divalent and Tetravalent Forms of Manganese and its Protection by Selenium

Objective The neural toxicity induced by manganese with different valence was compared,and the protective effects of selenium was investigated.Methods The SH-SY5Y cells were divided into the following groups: control;Mn~(2+);Mn~(3+);Selenium;Mn~(2+) + Selenium;Mn~(3+) + Selenium.The degree of DNA strand break was determined using a Single Cell Gel Electrophoresis method.Cell apoptosis and cell cycle distribution were determined by flow cytometry. Results Mn~(3+) induced more DNA strand break,apoptosis and S phase accumulation than Mn~(2+).The neural toxicity induced by either Mn~(3+) or Mn~(2+) was reduced by selenium.Conclusion Mn~(3+) exhibits stronger neural toxicity than Mn~(2+).Selenium may be a potential agent to protect neurons from Mn-induced damage.