中波紫外线诱导HaCaT细胞凋亡的研究

目的以不同剂量的中波紫外线(UVB)诱导体外培养的人永生化角质形成细胞(HaCaT细胞)凋亡,探讨肿瘤坏死因子-α(TNF-α)是否参与凋亡过程。方法取对数生长期的HaCaT细胞,分别用10 mJ/cm2,15 J/cm2,20 J/cm2,25 J/cm2,30 J/cm2的UVB照射,并于照射24 h后检测HaCaT细胞的增殖活性,分析HaCaT细胞的凋亡率,测定HaCaT细胞上清液中TNF-α的水平,观察细胞形态及凋亡细胞特征。结果在10~30 mJ/cm2的UVB照射下,随照射剂量的增大,细胞的增殖活性逐渐下降,而细胞的凋亡率逐渐增加,当剂量达30 J/cm2时,细胞凋亡率最大,细胞的增殖活性和凋亡率呈直线负相关;随UVB照射剂量的增大,TNF-α的分泌量增加,细胞上清液中TNF-α的分泌量和凋亡率呈直线正相关;倒置显微镜及透射电镜进一步从形态学上证实了细胞的凋亡改变。结论UVB可诱导细胞凋亡,且呈剂量依赖性;照射产生的TNF-α可能参与了其凋亡过程。

The Study of Apoptosis Induced by Ultraviolet B Radiation on HaCat Cells

Objective To investigate the effect of apoptosis of HaCat cells irradiated by UVB in different doses and its mechanism.Methods MTT assay was used to test the viability of HaCat cells,flow cytometry to measure apoptosis rate,a specific ELISA to detect the concentration of tumor necrosis factor-α,and light and transmission electron microscope to observe the ultrastructure of HaCaT cells.Results It was found that 10-30 mJ/cm2 UVB irradiation could induce apoptosis of cultured HaCat cells,which was observed by transmission electron microscope and also examined by flow cytometry.The increasing secrete content of TNF-αin cultured medium of HaCat cells was tested after irradiation.Conclusion UVB can induce apoptosis in HaCat cells,and TNF-α may contribute to the induction of apoptosis.