title: Role of α-toxin-induced apoptosis of umbilical vein endothelial cells in vertical infection of Staphylococcus aureus L-form.
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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Bengbu Medical College, Bangpu, China. gjc-2003@sohu.com
authors.forename: Junchang
authors.initials: J
authors.lastname: Guan
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhu
authors.forename: Fengling
authors.initials: F
authors.lastname: Yu
authors.forename: Wenxuan
authors.initials: W
authors.lastname: Yang
authors.forename: Tingting
authors.initials: T
authors.lastname: Liu
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Na
authors.initials: N
authors.lastname: Lin
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Congsen
authors.initials: C
authors.lastname: Liu
mesh_terms: D017209:Apoptosis; D001427:Bacterial Toxins / Q000633:toxicity*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D002478:Cells, Cultured; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology*; D006801:Humans; D007740:L Forms; D013203:Staphylococcal Infections; D013211:Staphylococcus aureus; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D014409:Tumor Necrosis Factor-alpha; C036117:staphylotoxin; C505407:CASP3 protein, human; C505530:CASP8 protein, human; D053148:Caspase 3; D053181:Caspase 8