氢醌对人白血病细胞凋亡及相关蛋白Bcl-2、Bax及Caspase-3表达的影响

目的 研究氢醌对白血病细胞株U937细胞凋亡及相关蛋白Bcl-2、Bax及Caspase-3表达的影响。方法 用不同浓度的氢醌处理U937细胞24 h、48 h后,采用MTT法来检测细胞增殖抑制率;经瑞-吉染色后,观察细胞形态变化;采用流式细胞仪检测细胞凋亡;采用免疫印迹法检测Bcl-2、Bax及Caspase-3蛋白表达。结果 (1)U937细胞的增殖抑制率随氢醌作用时间及浓度的增加而增加,呈时间-剂量依赖性(P<0.05);(2)氢醌作用后,部分细胞体积增大,胞浆中有空泡,胞核发生畸形;(3)流式细胞术结果显示,细胞凋亡率随着氢醌作用时间及浓度的增加而增加,呈时间-剂量依赖性(P<0.05);(4)免疫印迹结果显示,与空白组相比较,染毒48h时,细胞Bax蛋白的表达量增加(P<0.05),而Bcl-2蛋白表达量减少(P<0.05),Bcl-2/Bax比值下降(P<0.05),染毒24 h时,细胞Caspase-3蛋白的表达量增加(P<0.05);与染毒24 h各组相比较,染毒48 h时细胞Caspase-3蛋白的表达量随时间延长呈增加趋势(P<0.05)。结论 氢醌可以诱导U937细胞凋亡,其机制可能与调控凋亡相关蛋白Bcl-2、Bax及Caspase-3的表达有关。

Effects of hydroquinone on apoptosis and expression of Bcl-2,Bax and Caspase-3 in human leukemia cells

Objective To investigate the effects of benzene metabolite hydroquinone on inducing apoptosis of U937 cells and the expression of Bcl-2,Bax and Caspase-3. Methods U937 cells were treated with low,medium,high dose hydroquinone for 24h and 48h.We determined the effects of hydroquinone on inhibiting the proliferation and inducing the apoptosis of U937 cells using MTT and flow cytometry(FCM),respectively.The changes of cell morphology were observed under a microscope after Wright′s staining.The expression of apoptosis-related proteins Bax,Bcl-2,Caspase-3 were detected by western blot. Results MTT results showed that hydroquinone significantly inhibited the proliferation of the U937 cells in a time-dose dependent manner(P<0.05). Wright′s stain showed that after the action of hydroquinone,the volume of some cells increased,with vacuoles in the cytoplasm and deformity of the nucleus.The results of flow cytometry showed that the apoptotic rate was significantly increased with the increase of hydroquinone concentration and time,and in a time-dose dependent manner(P<0.05).Western blot showed that compared with the control group,expression of Bax protein increased(P<0.05),Bcl-2 protein decreased(P<0.05)and the ratio of Bcl-2/Bax decreased at 48h.The expression of Caspase-3 protein increased(P<0.05)at 24h.Compared with 24h,the expression of Caspase-3 protein increased with time(P<0.05)at 48h. Conclusion Hydroquinone can induce the apoptosis of U937 cells,and its mechanism may be related to the regulation of Bax,Bcl-2 and Caspase-3 protein expression.