[Apoptosis of cultured human trophoblasts induced by tumor necrosis factor-alpha and interferon-gamma].
OBJECTIVE
To investigate the potential role of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in inducing apoptosis of human trophoblast during early pregnancy and its mechanism.


METHODS
Human trophoblast of early gestation were cultured in vitro. Having cultured with TNF-alpha and IFN-gamma for 36 hours, their cytotoxic activity was determined by viable cell calculation. Apoptotic morphology was observed under light and electronic microscope. DNA fragment pattern and apoptotic index were analysed by agarose gel electrophoresis and flow cytometer assay (FCM) respectively. Adherent cell analysis and sorting interactive laser cytometer was used to examine the changes of cellular reactive oxygen species (ROS) caused by TNF-alpha.


RESULTS
TNF-alpha alone significantly decreased the number of viable cells at the concentration of 1,000, 3,000 and 5,000 U/ml (P < 0.05). While combined with IFN-gamma, TNF-alpha decreased the number of viable cells more markedly. Electronic microscopic examination showed chromatin aggregating beneath the nuclear envelope, nuclear contraction and apoptotic bodies. Agarose gel electrophoresis of fragmented DNA showed a ladder-like pattern. FCM showed that the apoptotic index of trophoblasts was TNF-alpha concentration dependent. Cellular ROS was increased by TNF-alpha.


CONCLUSIONS
TNF-alpha and IFN-gamma could induce apoptosis of human trophoblasts during early pregnancy, partly through the mechanism of ROS.
Xing
F
F
Nanfang Hospital, First Military Medical University, Guangzhou 510515.
Kong
L
L
Chen
S
S
D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D017382:Reactive Oxygen Species / Q000378:metabolism; D014327:Trophoblasts / Q000166:cytology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma