摘要
目的检测三氯乙烯(TCE)对人表皮角质形成细胞(NHEK)的凋亡诱导作用,探讨TCE皮肤毒性的作用靶。方法采用中性红吸附试验测定TCE对体外无血清培养的NHEK的中性红吸附减少50%的浓度(NR50值),确定TCE染毒剂量;测定丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力反映细胞脂质过氧化作用和氧化状态;用透射电子显微镜(TEM)和流式细胞仪(FCM)观察细胞凋亡形态学改变和测定细胞DNA含量,计算凋亡发生率及增殖指数(PI)。结果TCE对NHEK的NR50值为4.53(3.92～5.13)mmol/L;TCE处理NHEK4h后,MDA含量的增加和SOD活力的抑制均具有剂量-效应关系(r=0.98,r=0.93,P<0.01);TEM观察显示,与对照相比,TCE处理组细胞可见明显凋亡改变;FCM测定显示,DNA含量直方图中G1期前可见明显的凋亡峰,与对照组相比,TCE处理组细胞凋亡率明显增高(空白对照及TCE0.125、0.500、2.000mmol/L组分别为18.42%、31.83%、38.63%、44.35%),而PI则明显降低(空白对照及TCE0.125、0.500、2.000mmol/L组分别为4.99%、3.26%、2.48%、2.07%)。结论在体外培养条件下,TCE可通过脂质过氧化和氧化应激作用诱导NHEK凋亡,抑制其增殖。
Objective To investigate the apoptosis-inducing effect of trichloroethylene（TCE） on cultured normal human epidermis keratinocytes（NHEK） in vitro. Methods NR50 values（the concentration of neutral red absorbed is reduced to 50% ） of TCE on NHEK were assayed by neutral red uptake（NRU）,and the administered dose of TCE was determined. Lipid peroxidation（LPO） and oxidative stress were assessed by measurement of malondialdehyde（MDA） contens and superoxide dismutase（SOD） activity. Transmission electron microscope （TEM） were used to observe morphologic changes,flow cytometer（FCM） was used to measure DNA contents and calculate cell apoptosis rate and proliferation index （PI）. Results NR50 values of TCE on NHEK was found to be 4.53 mmol/L（95 % CI：3.92 - 5.13 mmol/L）. The increase in MDA content and inhibition of SOD activity in a concentration-dependent manner were shown after NHEK was treated with a series of dose of TCE 4 h later, and typical morphologic changes of apoptosis were also observed by TEM examination. FCM analysis revealed a sub-G1 peak in the apoptotic cells. The apoptotic rate in TCE 0. 125,0. 500,2. 000 mmol/L exposed groups （31.83 %, 38.63 %, 44.35% ,respectively） were significantly higher than that in blank control（ 18.42% ）, while PI in TCE 0. 125, 0.500,2.000 mmol/L group（3.26% ,2.48% ,2.07% ,respectively） were significantly lower than that in blank control（4.99% ）. Conclusion TCE may induce apoptosis of cultured NHEK in vitro, and inhibit cell proliferation through lipid peroxidation and oxidative stress.
出处
《中华劳动卫生职业病杂志》
CAS
CSCD
北大核心
2005年第5期347-350,共4页
Chinese Journal of Industrial Hygiene and Occupational Diseases
基金
国家自然科学基金资助项目(30471469)
安徽省自然科学基金资助项目(03043801)
安徽省教育厅自然科学重点科研项目(2003KJ036ZD)
