Gene silencing of TNF-alpha in a murine model of acute colitis using a modified cyclodextrin delivery system

• Published in: Journal of controlled release Vol. 168; no. 1; pp. 28 - 34
• Main Authors: McCarthy, J., O'Neill, M.J., Bourre, L., Walsh, D., Quinlan, A., Hurley, G., Ogier, J., Shanahan, F., Melgar, S., Darcy, R., O'Driscoll, C.M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 28.05.2013
• Subjects: animal models; Animals; beta-Cyclodextrins - chemistry; Cell Line; colitis; Colitis - chemically induced; Colitis - drug therapy; Colitis - metabolism; colon; Cyclodextrin; cyclodextrins; dextran; Dextran Sulfate; Disease Models, Animal; enzyme-linked immunosorbent assay; Female; gel electrophoresis; gene expression; Gene Silencing; genes; inflammation; Inflammatory bowel disease; interleukin-6; Interleukin-6 - metabolism; Intrarectal administration; Lipopolysaccharides; macrophages; messenger RNA; Mice; Mice, Inbred C57BL; Murine model of acute-colitis; Polyethyleneimine - chemistry; polymerase chain reaction; RNA interference; RNA, Small Interfering - administration & dosage; RNA, Small Interfering - chemistry; siRNA delivery; small interfering RNA; sodium sulfate; TNF-α; tumor necrosis factor-alpha; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; CD; RT; Intrarectal administration; DSS; MR; Murine model of acute-colitis; IBD; siRNA; UC; LPS; Inflammatory bowel disease; Cyclodextrin; SF; TNF-α; pDNA; PEI; siRNA delivery
• ISSN: 0168-3659; 1873-4995
• DOI: 10.1016/j.jconrel.2013.03.004

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.