葡萄球菌肠毒素B诱导脐静脉内皮细胞凋亡机制的探讨

目的探讨金黄色葡萄球菌(金葡菌)肠毒素B诱导脐静脉内皮细胞凋亡的机制。方法将不同浓度金葡菌肠毒素B感染脐静脉内皮细胞8 h后,用流式细胞术检测细胞凋亡率,同时用比色法检测TNF-α、caspase-3及caspase-8的产生量,并检测加入TNF-α抗体、caspase-3和caspase-8抑制剂后的细胞凋亡率。结果不同浓度肠毒素B作用脐静脉内皮细胞8 h后均可诱导细胞凋亡,且TNF-α、caspase-3和caspase-8的产生量均高于对照组(P0.01);而加入TNF-α抗体、caspase-3和caspase-8抑制剂后凋亡率明显降低。结论金葡菌肠毒素B可以诱导脐静脉内皮细胞凋亡,其凋亡机制可能是通过TNF-α介导的caspase-8及caspase-3激活的外源性死亡因子受体途径。

Mechanisms of apoptosis in human umbilical vein endothelial cells by Staphylococcal enterotoxin B

Objective To study the mechanisms of apoptosis in human umbilical vein endothelial cells induced by Staphylococcal entertoxin B（SEB）.Method For 8 hours after human umbilical vein endothelial cells（HUVEC） were infected by SEB,the apoptosis rate of HUVEC was determined by flow cytometry,and the productions of TNF-α,caspase 3 and caspase 8 in the HUVEC were detected by colorimetric assay.Meanwhile,SEB-induced apoptosis was also determined by flow cytometry after the antibody against TNF-α,inhibitor of caspase 3 or caspase 8 was added,prior to SEB respectively in the HUVEC.Result SEB significantly induced the apoptosis of HUVEC,accompanied with the significant increase in the production of TNF-α,caspase 3 and caspase 8.But the apoptosis rates of HUVEC were significantly inhibited by antibody against TNF-α,inhibitor of caspase 3 or caspase 8,respectively.Conclusion SEB is a mediator of staphylococcus aureus inducing the apoptosis of HUVEC and can activate caspases via the extrinsic death pathway mediated by TNF-α.