THE EFFECTS OF HYPERTHERMIA ON THE NEUROEPITHELIAL CELLS IN PRIMARY CULTURE / 神经解剖学杂志

ABSTRACT

The animal experiment studies have demonstrated that hyperthermia is a strong teratogen to many kinds of animal with high incidence of neural tube defects(NTD).Epidermiological investigation showed that hyperthermia was closely related to the acencephaly and excenphaly in human being,but little was known about the distinct mechanism of NTD induced by hyperthermia.In order to study the developmental mechanism of NTD induced by hyperthermia,we observed the effects of hyperthermia on the neuroepithelial cells in primary culture.The neural tubes of the hamster embryos on 10 d after fertilization were obtained.the neuroepithelia were dissociated and then seeded at the density of 1×106 cells per well.The cells were divided into experimental and control groups randomly.The experimental groups were exposed to 42 C for 20 min,whereas groups exposed to 37 Cserved as control.After treatment of hyperthermia,the cells were incubated continuously at 37 C in a 95%air/5%CO2 humidified incubator,the culture was terminated after different intervals.Phase-contrast microscopy.scanning electron microscopy.transmission electron microscopy,MTT assay,agarose gel electrophoresis analysis,TUNEL detection,immunocytochemistryand image analysis were made.The results of the experimental groups indicated that the floating cells and apoptotic cells increased in number,the neurites of the cells were shortened even disappeared,the survival cells decreased in number,the ultrastructure of the cells demonstrated distinct abnormal changes,the function of mitochondria was impaired,the expressions of both bcl-2 and bax were abnormal.The above results suggest that hyperthermia may induce apoptosis of neuroepithelial cells,duringwhich bcl-2 and bax genes may play important regulatory roles.