title: [Cathepsin B promoted the apoptosis of vascular smooth muscle cells as induced by tumor necrosis factor-α].
abstract: OBJECTIVE
  To establish the cathepsin B over-expression group and cathepsin B gene-silencing group so as to investigate whether cathepsin B was capable of promoting the apoptosis of VSMC (vascular smooth muscle cell) induced by TNF-α/act D.
  
  
  METHODS
  Human aortic smooth muscle cell (HA-VSMC) was transfected with pcDNA3.1-cathepsin B and pSilencer2.1-cathepsin B plasmids by lipofection to establish the over-expression and gene-silencing groups. Through TNF-α induced apoptosis, the cell viability was observed by MTT assay, morphological observation and assays of apoptotic proteins as indicators of apoptosis.
  
  
  RESULTS
  The cathepsin B over-expression and gene-silencing group were successfully established. MTT assay showed no significant difference between the transfected cell and blank control. After the intervention of TNF-α, the HA-VSMC viability decreased significantly. As compared with control group, the over-expression group significantly decreased (9.98% ± 1.04% vs 14.60% ± 1.34%). As compared with the over-expression group, the E64d and CA-074ME groups (18.23% ± 1.05%, 17.40% ± 1.03%) increased significantly while the silent group (21.30% ± 2.37%) significantly increased. The analysis of acridine orange/ethidium bromide staining showed similar results. Western blot showed the Bcl-2 protein were significantly higher in the silent group than that in the control group. And the over-expression group was significantly lower than the control group. The E64d and CA-074ME groups were significantly higher than that in the over-expression group. But the Bax protein level had no significant difference among all groups.
  
  
  CONCLUSIONS
  The over-expression of cathepsin B promotes TNF-α-induced VSMC apoptosis while Cathepsin B gene silencing and the addition of cathepsin inhibitor in over-expression group inhibit the TNF-α induced VSMC apoptosis.
authors: Department of Cardiology, Wuxi People's Hospital, Nanjing Medical University, Wuxi 214320, China.
authors: Tao
authors: T
authors: Zhang
authors: Zhen-yu
authors: ZY
authors: Yang
authors: Xiao-ping
authors: XP
authors: Bo
authors: Xiao-qing
authors: XQ
authors: Wu
authors: Zong-bin
authors: ZB
authors: Li
authors: Su-xia
authors: SX
authors: Guo