[Study of trichloroethylene-induced apoptosis in normal human epidermis keratinocytes in vitro].
OBJECTIVE
To investigate the apoptosis-inducing effect of trichloroethylene (TCE) on cultured normal human epidermis keratinocytes (NHEK) in vitro.


METHODS
NR(50) 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
NR(50) 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-G(1) 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%).


CONCLUSIONS
TCE may induce apoptosis of cultured NHEK in vitro, and inhibit cell proliferation through lipid peroxidation and oxidative stress.
Shen
Tong
T
Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China.
Ma
Tai
T
Ding
Rui
R
Tu
Deng-yun
DY
Zhu
Qi-xing
QX
D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects*; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D014241:Trichloroethylene / Q000633:toxicity*
D014241:Trichloroethylene