title: Effects of treatment with small interfering RNA on joint inflammation in mice with collagen-induced arthritis.
abstract: OBJECTIVE
  RNA interference is a process in which genes can be silenced sequence-specifically. In mammals, RNA interference can be invoked by introduction of small (19-21-nucleotide) double-stranded RNA molecules known as small interfering RNA (siRNA) into cells. Thereby, siRNA offers promise as a novel therapeutic modality. However, siRNA is a relatively large, highly charged molecule and does not readily enter cells. This study was undertaken to investigate the use of electroporation for in vivo transfection of siRNA into joint tissue in arthritic mice to achieve local RNA interference.
  
  
  METHODS
  Proof of principle that siRNA is able to inhibit gene expression in vivo in the mouse joint was studied by local injection and electroporation of siRNA designed to silence reporter genes. In mice with collagen-induced arthritis (CIA), the disease-modulating activity of siRNA designed to silence tumor necrosis factor alpha (TNFalpha) was investigated.
  
  
  RESULTS
  Luciferase activity could be reduced by >90% with luciferase-specific siRNA as compared with the activity measured after electroporation without siRNA or with irrelevant siRNA. The effect was observed only locally. In mice with CIA, electroporation of siRNA designed to inhibit TNFalpha strongly inhibited joint inflammation, whereas electroporation of irrelevant siRNA or injection of siRNA against TNFalpha without electroporation failed to produce therapeutic effects.
  
  
  CONCLUSIONS
  Local electroporation of siRNA in joint tissue can inhibit CIA in mice. These results offer promise for the use of siRNA as a new strategy for therapeutic intervention in rheumatoid arthritis and may serve as a tool to study arthritis disease pathways through loss-of-function phenotypes.
authors.affiliation: Intradigm Co., Rockville, Maryland, USA. R.M.Schiffelers@pharm.uu.nl
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Schiffelers
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Gert
authors.initials: G
authors.lastname: Storm
authors.forename: Martin C
authors.initials: MC
authors.lastname: Woodle
authors.forename: Puthupparampil V
authors.initials: PV
authors.lastname: Scaria
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000235:genetics / Q000517:prevention & control*; D002460:Cell Line; D003094:Collagen; D004195:Disease Models, Animal; D018274:Electroporation / Q000379:methods; D005260:Female; D020868:Gene Silencing; D018390:Gene Targeting; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007596:Joints / Q000187:drug effects / Q000473:pathology; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000627:therapeutic use*; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; D049452:Green Fluorescent Proteins; D003094:Collagen; D008156:Luciferases