氧化应激在全氟辛烷磺酰基化合物诱导人胚胎肝细胞凋亡中的作用

目的探讨全氟辛烷磺酰基化合物(PFOS)致人胚胎肝(L-02)细胞凋亡的作用及其机制。方法将处于对数生长期的L-02细胞分别暴露于终浓度为0(对照)、50、100、150、200μmol/L的PFOS溶液培养24 h。采用MTT法检测细胞活性,采用流式细胞术检测细胞凋亡率,并测定细胞线粒体内活性氧(ROS)、谷胱甘肽(GSH)、丙二醛(MDA)和超氧化物歧化酶(SOD)的水平及线粒体膜电位,采用q RT-PCR法检测凋亡相关基因caspase-3、caspase-9、bax、bcl-2 m RNA的表达水平。结果与对照组比较,150、200μmol/L PFOS染毒L-02细胞的存活率均降低,而100、150、200μmol/L PFOS染毒组L-02细胞的凋亡率均增加,差异均有统计学意义(P0.05);且随着PFOS染毒浓度的升高,L-02细胞的存活率呈下降趋势,而凋亡率呈上升趋势。与对照组比较,各浓度PFOS染毒组L-02细胞内ROS和MDA水平均增加,而各浓度PFOS染毒组L-02细胞内SOD水平和100、150、200μmol/L PFOS染毒组L-02细胞内GSH水平和线粒体膜电位均较低,差异均有统计学意义(P0.05);且随着PFOS染毒浓度的升高,L-02细胞内ROS和MDA水平均呈上升趋势,而SOD、GSH水平和线粒体膜电位均呈下降趋势。与对照组比较,各浓度PFOS染毒组L-02细胞中caspase-3、caspase-9、Bax m RNA的表达水平均较高,而bcl-2、bcl-2/bax值均较低,除50μmol/L PFOS染毒组caspase-9外,差异均有统计学意义(P0.05﹚。结论在本实验剂量下,PFOS暴露可引起L-02细胞凋亡,其机制与PFOS诱导的氧化损伤和线粒体凋亡途径有关。

Effect of oxidative stress in apoptosis of L-02 cells induced by PFOS

Objective To understand the effect of oxidative stress on the apoptosis of L-02 cells induced by PFOS.Methods L-02 cells were exposed to 0,50,100,150 and 200 μmol/L of PFOS for 24 h.MTT method was used to measure the survival of L-02 cells,the cell apoptosis was measured by flow cytometry,the L-02 cells homogenates were prepared to detect the levels of reactive oxygen species(ROS),malondialdehyde(MDA),superoxide dismutase(SOD) and glutathione hormone(GSH) in spectrophotometric assay.Rhodamine 123 fluorescent probe was used to detect the mitochondrial membrane potential altering in L-02 cells.The expression levels of caspase-3,caspase-9,bcl-2 and bax mRNA were examined by qRT-PCR.Results Compared with the control group,the livability of L-02 cells decreased significantly in 150,200 μmol/L PFOS-treated groups (P＜0.05),the percentage of apoptosis increased significantly in 100,150 and 200 μmol/L PFOS-treated groups (P＜0.05),the livability tendency of L-02 cells decreased as the dose of PFOS increased,and the apoptosis rates in L-02 cells showed an increasing tendency.Compared with the control group,the levels of ROS and MDA increased significantly in PFOS-exposed groups (P＜ 0.05),the levels of SOD decreased significantly in PFOS-exposed groups,the levels of GSH and MMP decreased significantly in 100,150 and 200 μmol/L PFOS-treated groups (P＜0.05),as the concentrations of PFOS increased and the levels of ROS and MDA showed an increased trend and the levels of SOD,GSH showed a declining trend.Compared with the control groups,except the level of caspase-9 in 50 μmol/L PFOS-treated groups,the levels of caspase-3,caspase-9,bax mRNA increased significantly in PFOS-exposed groups (P＜0.05),the levels of bcl-2 mRNA and the bcl mRNA/bax mRNA value in PFOS-exposed groups were significantly lower (P＜0.05).Conclusion At the dose of PFOS exposed in the present study,PFOS can induce the L-02 cell apoptosis,and mitochondria mediated signaling pathway may be involved in it.