title: [TcpC induces apoptosis of human vascular endothelial cells and its mechanisms].
abstract: OBJECTIVE
  To investigate the effects of TcpC on human umbilical vascular endothelial cells (HUVECs) and its mechanisms.
  
  
  METHODS
  HUVECs were co-cultured with TcpC secreting wild-type E. coli strain CFT073 (TcpC(wt)) or tcpc gene-deleted CFT073 mutant strain (TcpC(mut)) in transwell system,respectively. Apoptosis of HUVECs was analyzed by Annexin-V/PI double staining. Mitochondrial membrane depolarization was detected by JC-1 staining. Expression of apoptosis-related proteins in HUVECs was determined by Western blot.
  
  
  RESULTS
  HUVECs showed morphological changes after co-cultured with TcpC(wt) for 24 h: the cells became detached and cell debris increased,and cell number was also decreased when compared to HUVECs co-cultured with TcpC(mut). The apoptosis of HUVEC cells co-cultured with TcpC(wt) for 24 h significantly increased,compared to that of control group and TcpC(mut) group (60.1% 9.7% compared with 9.0% 1.3% and 16.9% 0.4%,respectively, P<0.05); meanwhile the mitochondrial depolarization of HUVECs co-cultured with TcpC(wt) was significantly increased,compared to that in control and TcpC(mut) groups (64.5% 0.9% compared with 14.5% 2.1% and 15.6% 3.3%, respectively,P<0.05). Cleavage of PARP and inhibition of Mcl-1 and XIAP expression were seen in HUVECs co-cultured with TcpC(wt),but not in groups of control and TcpC(mut).
  
  
  CONCLUSIONS
  TcpC secreted from CFT073 can induce apoptosis of HUVECs through mitochondrial pathway, in which PARP is cleaved and Mcl-1 and XIAP expressions are inhibited.
authors.affiliation: Department of Medicine, Zhejiang University City College School of Medicine, Hangzhou 310015, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
authors.forename: Jia-le
authors.initials: JL
authors.lastname: Zhou
authors.forename: Jie
authors.initials: J
authors.lastname: Fang
authors.forename: Da-Yong
authors.initials: DY
authors.lastname: Zhang
authors.forename: Bao-Ming
authors.initials: BM
authors.lastname: Wang
authors.forename: Rui-Ling
authors.initials: RL
authors.lastname: Chen
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Pan
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000473:pathology*; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D064549:Myeloid Cell Leukemia Sequence 1 Protein / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D037521:Virulence Factors / Q000494:pharmacology*; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; C579095:MCL1 protein, human; D064549:Myeloid Cell Leukemia Sequence 1 Protein; C549538:TcpC protein, E coli; D037521:Virulence Factors; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D011065:Poly(ADP-ribose) Polymerases