title: Gene silencing of TNF-alpha in a murine model of acute colitis using a modified cyclodextrin delivery system.
abstract: Inflammatory bowel disease (IBD) is a chronic relapsing inflammation of the gastrointestinal tract. The cytokine TNF-alpha (TNF-α) plays a pivotal role in mediating this inflammatory response. RNA interference (RNAi) holds great promise for the specific and selective silencing of aberrantly expressed genes, such as TNF-α in IBD. The aim of this study was to investigate the efficacy of an amphiphilic cationic cyclodextrin (CD) vector for effective TNF-α siRNA delivery to macrophage cells and to mice with induced acute-colitis. The stability of CD.siRNA was examined by gel electrophoresis in biorelevant media reflecting colonic fluids. RAW264.7 cells were transfected with CD.TNF-α siRNA, stimulated with lipopolysaccharide (LPS) and TNF-α and IL-6 responses were measured by PCR and ELISA. Female C57BL/6 mice were exposed to dextran sodium sulphate (DSS) and treated by intrarectal administration with either CD.siRNA TNF-α or a control solution. In vitro, siRNA in CD nanocomplexes remained intact and stable in both fed and fasted simulated colonic fluids. RAW264.7 cells transfected with CD.TNF-α siRNA and stimulated with LPS displayed a significant reduction in both gene and protein levels of TNF-α and IL-6. CD.TNF-α siRNA-treated mice revealed a mild amelioration in clinical signs of colitis, but significant reductions in total colon weight and colonic mRNA expression of TNF-α and IL-6 compared to DSS-control mice were detected. This data indicates the clinical potential of a local CD-based TNF-α siRNA delivery system for the treatment of IBD.
authors.affiliation: Pharmacodelivery Group, School of Pharmacy, University College Cork, Cork, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: McCarthy
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Neill
authors.forename: L
authors.initials: L
authors.lastname: Bourre
authors.forename: D
authors.initials: D
authors.lastname: Walsh
authors.forename: A
authors.initials: A
authors.lastname: Quinlan
authors.forename: G
authors.initials: G
authors.lastname: Hurley
authors.forename: J
authors.initials: J
authors.lastname: Ogier
authors.forename: F
authors.initials: F
authors.lastname: Shanahan
authors.forename: S
authors.initials: S
authors.lastname: Melgar
authors.forename: R
authors.initials: R
authors.lastname: Darcy
authors.forename: C M
authors.initials: CM
authors.lastname: O'Driscoll
mesh_terms: D000818:Animals; D002460:Cell Line; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D016264:Dextran Sulfate; D004195:Disease Models, Animal; D005260:Female; D020868:Gene Silencing; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides; D051379:Mice; D008810:Mice, Inbred C57BL; D011094:Polyethyleneimine / Q000737:chemistry; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D015850:Interleukin-6; D008070:Lipopolysaccharides; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; D047392:beta-Cyclodextrins; D011094:Polyethyleneimine; D016264:Dextran Sulfate; C031215:betadex