title: RNA interference inhibits high mobility group box 1 by lipopolysaccharide-activated murine macrophage RAW 264.7 secretion.
abstract: BACKGROUND
  This study aims to evaluate the influence of RNA interference (RNAi) on the high mobility group box 1 (HMGB-1) in the lipopolysaccharide (LPS)-induced murine macrophage cell line RAW 264.7.
  
  
  METHODS
  In order to observe the effect of RNAi on HMGB-1, tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and transforming growth factor β (TGF-β) levels, the RAW 264.7 cell line was divided into five treatment groups to measure separately as a function of time of negative control, LPS stimulation only, LPS + HMGB-1 short interfering RNAs (siRNAs), LPS + negative control siRNAs (siNC), and LPS + nafamostat mesilate (NM).
  
  
  RESULTS
  Measurement does show HMGB-1 expression in the LPS-activated macrophages in an explicit time-dependent manner. The HMGB-1 cellular level is consistently knocked down 80%∼85% by the siRNA; TNF-α, IL-6, and TGF-β levels in turn significantly decrease following siRNA delivery to the inflammatory response. HMGB-1 expression is lower in the LPS + NM group than the LPS + HMGB-1 siRNA group at the initial stage, however, a significantly lower level of HMGB-1 in the siRNA group is observed 48 h later. The decrease of TNF-α, IL-6, and TGF-β levels in the LPS-induced inflammatory response is also observed in both groups.
  
  
  CONCLUSIONS
  Our results demonstrate that HMGB-1 RNAi treatment of LPS-stimulated macrophages inhibit HMGB-1 and remarkably reduce the LPS-induced inflammatory responses. Hence, RNAi is highly recommended as a potential candidate for a new therapeutic strategy to minimize or, to a lesser extent, prevent the LPS-induced inflammatory injury.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, LinKou, Taiwan.
authors.forename: Han-Chung
authors.initials: HC
authors.lastname: Hu
authors.forename: Ting-Ya
authors.initials: TY
authors.lastname: Wang
authors.forename: Yung-Che
authors.initials: YC
authors.lastname: Chen
authors.forename: Chin-Chou
authors.initials: CC
authors.lastname: Wang
authors.forename: Meng-Chih
authors.initials: MC
authors.lastname: Lin
mesh_terms: D000818:Animals; D001550:Benzamidines; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D015536:Down-Regulation; D006146:Guanidines / Q000494:pharmacology / Q000627:therapeutic use; D024243:HMGB1 Protein / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007249:Inflammation / Q000378:metabolism* / Q000628:therapy*; D008070:Lipopolysaccharides; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D034622:RNA Interference; D034741:RNA, Small Interfering; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D001550:Benzamidines; D016207:Cytokines; D006146:Guanidines; D024243:HMGB1 Protein; D008070:Lipopolysaccharides; D034741:RNA, Small Interfering; D015842:Serine Proteinase Inhibitors; C032855:nafamostat