南方医科大学学报

南方医科大学学报 ›› 2013, Vol. 33 ›› Issue (05): 619-.

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Role of α-toxin-induced apoptosis of umbilical vein endothelial cells in vertical infection of Staphylococcus aureus L-form

管俊昌，朱翔，余峰玲，杨文选，刘婷婷，张涛，林娜，刘勇，刘从森   

  • 出版日期:2013-05-20 发布日期:2013-05-20

α-毒素诱导的脐静脉内皮细胞凋亡在金葡菌L型垂直感染中的作用

  • Online:2013-05-20 Published:2013-05-20

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摘要： 目的 确定α-毒素诱导脐静脉内皮细胞（HUV-EC-C）的凋亡在金葡菌L型垂直感染中的作用。方法在培养的HUV-EC-C
细胞中加入不同浓度（0、10、30、90、270 ng/ml）的金葡菌α-毒素，处理不同时间（0、2、4、6、8 h）后经Annexin V-PI染色，流式细胞
仪检测HUV-EC-C 细胞的凋亡率。通过ELISA 检测α肿瘤坏死因子（TNF-α）、caspase-3 与caspase-8 的表达量，并观察加入
TNF-α中和抗体、caspases-3抑制剂zDEVD-FMK、caspase-8抑制剂zIETD-fmk对α-毒素诱导HUV-EC-C细胞凋亡的影响。结
果α-毒素能够诱导HUV-EC-C 细胞凋亡并表现为时间、剂量依赖性，明显增加HUV-EC-C 细胞中TNF-α 、caspase-3 与
caspase-8 的表达；在加入TNF-α中和抗体、zDEVD-FMK、zIETD-fmk 后可部分阻断α-毒素能够诱导的HUV-EC-C 细胞凋亡。
结论α-毒素通过TNF-α 及caspase-8介导的外源性死亡途径诱导HUV-EC-C细胞凋亡，表明α-毒素诱导内皮细胞凋亡是金葡菌
L型垂直感染影响胎儿发育的主要机制之一。

Abstract: Objective To investigate α-toxin-induced apoptosis of umbilical vein endothelial cells and explore its role in vertical
infection of Staphylococcus aureus L-form. Methods HUV-EC-C cells exposed to different concentrations (0, 10, 30, 90, and 270
ng/ml) of α-toxin for different time lengths (0, 2, 4, 6, and 8 h) were examined for apoptosis using flow cytometry with
Annexin V-PI staining. The levels of tumor necrosis factor-α (TNF-α) and the activities of, caspase-3 and caspase-8 in the cell
culture were detected by ELISA and colorimetric method, respectively. α-Toxin-induced cell apoptosis was also analyzed in
HUV-EC-C cells treated with a neutralizing antibody of TNF-α or with the inhibitory peptides of caspase-3 (zDEVD-FMK) and
caspase-8 (zIETD-fmk). Results α-Toxin induced apoptosis of HUV-EC-C cells in a dose- and time-dependent manner and
caused significantly enhanced expression of TNF-α and the activation of both caspase-3 and caspase-8. Inhibition of TNF-α
with its neutralizing antibody and the inhibitory peptides of caspase-3 or -8 all significantly decreased α-toxin-induced cell
apoptosis, and the caspase-3 inhibitor completely blocked α-toxin-induced cell apoptosis. Conclusion α-Toxin-induced
apoptosis is partially mediated by the extrinsic cell death pathway of TNF-α and caspase-8 and plays an important role in the
vertical infection of S. aureus L-form to affect fetal growth and development.