中文摘要：

目的：探讨强力霉素（doxycycline,Dox）保护胸腺上皮细胞的作用及其机制,为进一步研究Dox的免疫调节作用奠定基础。方法：利用光学显微镜观察Dox对丝裂霉素（mitomycin,MMC）诱导MTEC1凋亡的影响,同时采用Hochest33342、PI单染、Annexin V和PI双染确认其作用,最后利用表面加强激光解析电离飞行时间质谱技术分析了SAX2芯片捕获的Dox作用前后的差异蛋白质。结果：通过形态学观察、Hochest33342、PI单染及Annexin V和PI双染发现Dox确实能保护MTEC1抵抗丝裂霉素诱导的细胞凋亡。随后采用表面加强激光解析电离飞行时间质谱技术分析SAX2芯片捕获蛋白,发现Dox能调控15种蛋白,其中上调8种,下调7种。结论：Dox具有保护MTEC1,抑制MMC诱导的细胞凋亡作用,并对MTEC1的蛋白表达有调控作用。

英文摘要：

Objective： To expose the molecular mechanism of doxycycline （Dox） that protects the mouse thymic epithelial cell line（ MTEC1 ） free from apoptosis which induced by mitomycin（ MMC ）. Methods： The effect of Dox protects the MTEC1 cells anti-apoptosis against the MMC induced was observed under an optical microscope, and confirmed by Hochest33342 stain, PI single stain, Annexin V and PI double stain, and observed by fluorescence microscope or flow cytometer. Furthermore, SELDI Protein Chip was used to analyze the profile proteomics of MTEC1 cell which treated by doxycycline or not. Results： Dox was found to protect the MTEC1 free from cell apoptosis not only morphology observed with optical microscope but also detected by Hochest33342 stain, PI single stain, Annexin V and PI double stain. Proteomics assay by sur- face-enhanced laser desorption/ionization time-of-flight mass spectrometry （SELDI-TOF-MS） disclosed that the Dox can up-regulate 8 proteins expressions and down-regulate 7 protein expressions. Conclusion： Dox protects MTEC1 against the apoptosis induced by mitomycin and regulated the proteins expressions in MTEC1. It will contribute to the further exploration of the mechanisms of Dox on MTEC1.