摘要
目的探讨N-乙酰半胱氨酸(NAC)在有或无caspase抑制条件下,对Cr(Ⅵ)诱导的肝细胞线粒体依赖性凋亡的拮抗作用。方法将L-02肝细胞随机分成对照组、Cr(Ⅵ)处理组、Z-VAD-fmk预处理组[Z-VAD-fmk预处理细胞1h,加入Cr(Ⅵ)]、NAC预处理组[NAC预处理细胞1h,加入Cr(Ⅵ)]、联合预处理组[Z-VAD-fmk和NAC分别预处理细胞1h,加入Cr(Ⅵ)],Cr(Ⅵ)终浓度为20μmol/L,处理6h。流式细胞仪检测细胞凋亡率,荧光分光光度法检测线粒体膜电位(△ψm)和通透性转运孔(PTP)的改变,单细胞凝胶电泳法观察细胞凋亡形态及细胞DNA损伤情况。结果终浓度20μmol/L的Cr(Ⅵ),处理6h,可诱导细胞凋亡,在有或无caspase抑制条件下,NAC均明显减轻了Cr(Ⅵ)引起的肝细胞线粒体膜电位下降及PTP孔开放(P<0.05),使细胞DNA损伤程度减轻(P<0.05),从而对细胞凋亡有明显拮抗作用(P<0.05),但与非caspase抑制条件下相比,caspase抑制条件下NAC的保护效果有明显降低(P<0.05)。结论在有或无caspase抑制条件下,NAC对Cr(Ⅵ)诱导的L-02肝细胞凋亡具有重要拮抗作用,caspase在该凋亡过程中不起决定性作用。
Objective To explore the antagonistic effect of N-acetylcysteine（NAC） on hexevalent chromium（Cr（Ⅵ））-induced apoptosis in L-02 hepatocytes with or without caspase inhibitors.Methods L-02 hepatocytes were randomly divided into a control group,and Cr（Ⅵ）,Z-VAD-fmk＋Cr（Ⅵ）,NAC＋Cr（Ⅵ）,Z-VAD-fmk＋NAC＋Cr（Ⅵ） four treatment groups,in which L-02 hepatocytes were cultured with Cr（Ⅵ） at the dose of 20μmol /L for 6h.The rates of apoptosis in all groups were detected by flow cytometry（FC） after staining with propidium iodide（PI）.The changes of mitochondrial emberane potential（△ψm） and permeability transition pore（PTP） were determined by fluorescent spectrometer.The DNA damages in hepatocytes were observed by the single cell gel electrophoresiss（SCGE）.Results Cr（Ⅵ） significantly induced apoptosis of L-02 hepatocytes at the dose of 20μmol/L for 6 hours（P0.05）.However,NAC significantly decreased the rates of apoptosis of L-02 hepatocytes and alleviated the damages to mitochondria and DNA caused by Cr（Ⅵ） in L-02 hepatocytes with or without caspase（P 0.05）.However,in comparition with the non caspase-inhibited group,the protective effects of NAC decreased in the caspase-inhibited group（P 0.05）.Conclusion NAC could protect the apoptosis of L-02 hepatocyte induced with Cr（Ⅵ） with or without caspase inhibitor,and caspase could not play a decisive role in this process.
出处
《卫生研究》
CAS
CSCD
北大核心
2010年第6期678-681,共4页
Journal of Hygiene Research
基金
国家自然科学基金项目(No.30671776)
