title: Silencing of fas-associated death domain protects mice from septic lung inflammation and apoptosis.
abstract: BACKGROUND
  A better understanding of the molecular mechanisms involved in the pathogenesis of sepsis and its resultant organ failure and new therapeutic approaches and targets are urgently needed. Accumulating evidence suggests that apoptosis plays an important role in the pathophysiology of sepsis and that apoptosis may be detrimental in septic acute lung injury (ALI).
  
  
  OBJECTIVE
  We tested the hypothesis that systemic administration of small interfering RNA (siRNA) targeting Fas-associated death domain (FADD), which recruits procaspase-8 into the death-inducing signaling complex, may be protective in septic ALI and mortality.
  
  
  METHODS
  Polymicrobial sepsis was induced by cecal ligation and puncture (CLP) in BALB/c mice. In vivo delivery of siRNA was performed by using a transfection reagent at 10 hours after CLP. As a negative control, animals received nonsense (scrambled) siRNA.
  
  
  RESULTS
  In CLP-induced septic mice, surface expression of death receptors was up-regulated, and FADD was highly expressed. DNA fragmentation ladder and transferase-mediated dUTP nick end labeling assays showed that treatment with FADD siRNA suppressed apoptosis induction in septic lungs. This siRNA treatment prevented the ALI development in CLP mice, as indicated by the findings that blood-gas derangements, histologic lung damage, and increased pulmonary inflammatory cells were greatly improved. Finally, FADD siRNA administration dramatically improved the survival of CLP mice.
  
  
  CONCLUSIONS
  These results indicate the pathophysiologic significance of the death receptor apoptotic pathway, including FADD, in septic ALI and the potential usefulness of FADD siRNA for gene therapy of the septic syndrome.
authors.affiliation: Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Matsuda
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Takano
authors.forename: Shun-Ichiro
authors.initials: S
authors.lastname: Kageyama
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kurobe
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Yoshihara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takano
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hattori
mesh_terms: D055371:Acute Lung Injury / Q000473:pathology*; D000818:Animals; D017209:Apoptosis; D053181:Caspase 8 / Q000378:metabolism; D053200:Fas-Associated Death Domain Protein / Q000235:genetics* / Q000378:metabolism; D020868:Gene Silencing; D006863:Hydrogen-Ion Concentration; D020287:In Situ Nick-End Labeling; D008168:Lung / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism; D018805:Sepsis / Q000473:pathology*; D013154:Spleen / Q000473:pathology; D053199:TNF Receptor-Associated Death Domain Protein / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D053200:Fas-Associated Death Domain Protein; D034741:RNA, Small Interfering; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053199:TNF Receptor-Associated Death Domain Protein; C481226:Tradd protein, mouse; D014409:Tumor Necrosis Factor-alpha; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D053181:Caspase 8