中文摘要：

目的观察tBHQ对内源性线粒体凋亡通路和凋亡相关蛋白Bel-2等蛋白表达的影响，探讨tBHQ在无机砷诱导HaCaT细胞凋亡过程中的作用。方法采用分光光度法检测Caspase-3蛋白活力；Westernblot法分析细胞内Caspase-3、CytC、Bcl-2和Bax蛋白表达水平。结果NaAsO2单独作用于HaCaT细胞24h，线粒体中CytC蛋白表达降低，而胞浆中CytC蛋白表达则随染砷剂量的增加而明显升高。tBHQ预处理12h后再分别暴露于NaAsO2，线粒体中CytC蛋白表达明显恢复，胞浆中CytC蛋白表达则随tBHQ剂量的增加而明显回落。此外，NaAsO。单独作用于HaCaT细胞24h，Procaspase-3蛋白表达降低，而Caspase-3活化程度均显著高于对照组（P〈0．01），tBHQ预处理12h后再暴露于NaAsO2，Procaspase-3蛋白表达均明显高于相同浓度砷单独作用组，而且Caspase-3酶活力得到明显抑制，差异均具有统计学意义（P〈0．05）。NaAsO：单独作用于HaCaT细胞24h，与对照组相比Bcl-2蛋白表达降低，而Bax蛋白表达明显升高。tBHQ预处理12h后再分别暴露于NaAsO2，Bcl-2蛋白表达明显恢复，而Bax蛋白表达则随tBHQ剂量的增加而减少。结论tBHQ能够影响线粒体凋亡途径拮抗NaAsO2诱导的人皮肤角质细胞凋亡；tBHQ能够诱导调控凋亡相关蛋白Bcl-2／Bax从而发挥抗凋亡作用。

英文摘要：

Objectives TO observe the effect of tBHQ on endogenous mitochondrial apoptotic pathways and influence on the ex- pression of apoptosis protein Bcl-2 family proteins. To study the role of tBHQ in the process of HaCaT cells apoptosis induced by inorganic arsenic. Methods Spectrophotometric method was used to detect the protein activity of Caspase-3 ; Western blot a- nalysis was employed to detect the protein expression levels of Caspase-3, Cytochrome C, Bcl-2 and Bax in cells. Results The HaCaT cells were exposed to NaAsO2for 24 h, protein expression of Cytochrome C in mitochondrial declined and protein ex- pression of Cytochrome C in endoehylema was elevated with arsenic increased. After tBHQ pretreatment for 12h, Cytochrome C in mitochondrial and endochylema were exposed to NaAsO2respectively, protein expression of Cytoehrome C in mitochondrial was significantly restored and protein expression of Cytochrome C in endochylema fell back with the dose of tBHQ increased. In addi- tion, cells were exposed to NaAsO2for 24 h, protein expression of proeaspase-3 declined and activation level of Caspase-3 were significantly higher than the control group（ P 〈0.01）. After tBHQ pretreatment for 12 h, the protein expression of procaspase- 3 significantly higher than the control group with same arsenic exposure and enzyme activity of Caspase-3 significantly inhibited （ P 〈0.05）. The cells were exposed to NaAsO2alone for 24 h, protein expression of Bcl-2 was lower than the control group, and protein expression of Bax was significantly higher. After tBHQ pretreatment for 12 h, Bel-2 and Bax were separately exposed to NaAsO2, the expression of Bcl-2 protein was restored and protein expression of Bax fell back significantly with the dose of tBHQ increased. Conclusion tBHQ can influence mitochondrial apoptosis pathway on human skin keratinocytes apoptosis induced by NaAsO2 ; tBHQ can induce regulated apoptosis related to protein of Bcl-2 or Bax so as to play its anti-apoptosis role.