title: Silencing of caspase-8 and caspase-3 by RNA interference prevents vascular endothelial cell injury in mice with endotoxic shock.
abstract: OBJECTIVE
  Septic shock and sequential multiple organ failure remain the cause of death in septic patients. Vascular endothelial cell apoptosis may play a role in the pathogenesis of the septic syndrome. Caspase-8 is presumed to be the apex of the death receptor-mediated apoptosis pathway, whereas caspase-3 belongs to the "effector" protease in the apoptosis cascade. Synthetic small interfering RNAs (siRNAs) specifically suppress gene expression by RNA interference. Therefore, we evaluated the therapeutic efficacy of caspase-8/caspase-3 siRNAs in a murine model of polymicrobial endotoxic shock.
  
  
  METHODS
  Polymicrobial endotoxic shock was induced by cecal ligation and puncture (CLP) in BALB/c mice. In vivo delivery of siRNAs was performed by using a transfection reagent (Lipofectamine 2000) at 10 h after CLP. As a negative control, animals received non-sense (scrambled) siRNA.
  
  
  RESULTS
  Marked increases in caspase-8 and caspase-3 protein expression in CLP aortic tissues were strongly suppressed by treatment with caspase-8/caspase-3 siRNAs. This siRNA treatment prevented DNA ladder formation and less phosphorylation of the pro-apoptotic protein Bad seen in CLP aortic tissues. Transferase-mediated dUTP nick end labeling (TUNEL) revealed that the appearance of apoptosis in aortic endothelium after CLP was eliminated by this siRNA treatment. Although all of the control animals subjected to CLP died within 2 days, administration of caspase-8/caspase-3 siRNAs indefinitely (>7 days) improved the survival of CLP mice.
  
  
  CONCLUSIONS
  Gene silencing of caspase-8 and caspase-3 with siRNAs provided profound protection against polymicrobial endotoxic shock. The prevention of vascular endothelial cell apoptosis appears to be, at least in part, responsible for their beneficial effects in endotoxic shock.
authors.affiliation: Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Matsuda
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takano
authors.forename: Shun-Ichiro
authors.initials: S
authors.lastname: Kageyama
authors.forename: Noboru
authors.initials: N
authors.lastname: Hatakeyama
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Shakunaga
authors.forename: Isao
authors.initials: I
authors.lastname: Kitajima
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hattori
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western / Q000379:methods; D053148:Caspase 3 / Q000235:genetics*; D053181:Caspase 8 / Q000235:genetics*; D042783:Endothelial Cells / Q000201:enzymology / Q000473:pathology; D020868:Gene Silencing; D015316:Genetic Therapy / Q000379:methods*; D008055:Lipids / Q000008:administration & dosage; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010766:Phosphorylation; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage; D012772:Shock, Septic / Q000201:enzymology / Q000473:pathology / Q000628:therapy*; D014162:Transfection / Q000379:methods; D051025:bcl-Associated Death Protein / Q000378:metabolism
chemical_list: C494821:Bad protein, rat; D008055:Lipids; C086724:Lipofectamine; D034741:RNA, Small Interfering; D051025:bcl-Associated Death Protein; D053148:Caspase 3; D053181:Caspase 8