3种纳米颗粒对BGC-823细胞线粒体膜电位及细胞内活性氧水平的影响

目的探讨不同化学组成的纳米颗粒对人胃癌BGC-823细胞线粒体膜电位（mitochondrial membrane potential,MMP）及细胞内活性氧（reactive oxygen species,ROS）水平的影响。方法将不同浓度纳米活性炭（activated carbon nanoparticles,ACNP）、纳米二氧化硅（SiO2）、纳米二氧化钛（TiO2）作用于BGC-823细胞24h后,用流式细胞仪以罗丹明123（Rh123）作为荧光指示剂检测细胞MMP;用ROS捕获剂双氢罗丹明123孵育细胞,通过检测细胞内Rh123的平均荧光强度而测得细胞内ROS水平。结果经ACNP、纳米SiO2、纳米TiO2作用24h后,BGC-823细胞MMP呈剂量依赖性降低。0.1,0.2mg/mlACNP组细胞内ROS水平高于对照组（P〈0.05）;0.1,0.2,0.4mg/ml纳米SiO2组细胞内ROS水平呈剂量依赖性降低;0.1,0.2mg/ml纳米TiO2组细胞内ROS水平高于对照组（P〈0.05）。结论 ACNP诱导细胞发生氧化应激,生成ROS,可能进一步通过活化线粒体信号转导途径诱导细胞凋亡;化学活性较强的纳米SiO2和纳米TiO2在含水介质中能够产生大量ROS,作用于细胞后能直接引起膜脂质过氧化,导致细胞膜破裂,细胞坏死。

Effects of three kinds of nanoparticles on the mitochondrial membrane potential and level of reactive oxygen species in human gastric carcinoma cell line BGC-823

Objective Using the activated carbon nanoparticles （ACNP）,silicon dioxide nanoparticles （nano-SiO2） and titanium dioxide nanoparticles （nano-TiO2） to investigate the effect of nanoparticles of different chemical compositions on the mitochondrial membrane potential （MMP） and level of reactive oxygen species （ROS） in human gastric carcinoma cell line BGC-823 in vitro.Methods BGC-823 cells were treated with ACNP,nano-SiO2 and nano-TiO2 at various concentrations for 24 hours.Mitochondrial membrane potential（MMP）was labeled by rhodamine123 （Rh123） and examined by flow cytometry （FCM）.Dihydrorhodamine123 （DHR123） was used as an ROS capturer.The mean fluorescent intensity of Rh123 which was the product of intracellular oxidation was examined by FCM,and the level of ROS was thus measured.Results After treatment with 0.1,0.2 and 0.4 mg/ml ACNP,nano-SiO2 or nano-TiO2 for 24 hours,the MMP of BGC-823 cells decreased in a dose-dependent manner.The cellular ROS levels of the 0.1 and 0.2 mg/ml ACNP groups were significantly higher than those of the control group （P0.05）.The cellular ROS levels of the nano-SiO2 groups decreased in a dose-dependent manner.The cellular ROS levels of the 0.1 and 0.2 mg/ml nano-TiO2 groups were higher than those of the control group （P0.05）.Conclusion ACNP may induce oxidative stress in BGC-823 cells by overproduction of ROS,and then induce apoptosis of BGC-823 cells by activating the mitochondrial signal transduction pathway.Nano-SiO2 and nano-TiO2 could produce ROS in aqueous medium and directly induce necrosis of BGC-823 cells via disintegrating plasma membranes.