Short-fiber protein of ad40 confers enteric tropism and protection against acidic gastrointestinal conditions.

The lack of vectors for selective gene delivery to the intestine has hampered the development of gene therapy strategies for intestinal diseases. We hypothesized that chimeric adenoviruses of Ad5 (species C) displaying proteins of the naturally enteric Ad40 (species F) might hold the intestinal tropism of the species F and thus be useful for gene delivery to the intestine. As oral-fecal dissemination of enteric adenovirus must withstand the conditions encountered in the gastrointestinal tract, we studied the resistance of chimeric Ad5 carrying the short-fiber protein of Ad40 to acid milieu and proteases and found that the Ad40 short fiber confers resistance to inactivation in acidic conditions and that AdF/40S was further activated upon exposure to low pH. In contrast, the chimeric AdF/40S exhibited only a slightly higher protease resistance compared with Ad5 to proteases present in simulated gastric juice. Then, the biodistribution of different chimeric adenoviruses by oral, rectal, and intravenous routes was tested. Expression of reporter ß-galactosidase was measured in extracts of 15 different organs 3 days after administration. Our results indicate that among the chimeric viruses, only intrarectally given AdF/40S infected the colon (preferentially enteroendocrine cells and macrophages) and to a lesser extent, the small intestine, whereas Ad5 infectivity was very poor in all tissues. Additional in vitro experiments showed improved infectivity of AdF/40S also in different human epithelial cell lines. Therefore, our results point at the chimeric adenovirus AdF/40S as an interesting vector for selective gene delivery to treat intestinal diseases.

Functionally enhanced siRNA targeting TNFα attenuates DSS-induced colitis and TLR-mediated immunostimulation in mice.

Tumor necrosis factor (TNFα) is a proinflammatory cytokine involved in the pathogenesis of inflammatory bowel disease (IBD). Although TNFα has been extensively targeted using systemic drugs, the use of antisense and small interfering RNA (siRNA) to drive down its expression at the site of inflammation should provide important advantages. In this study, native and chemically modified siRNA against TNFα was developed and characterized using a murine model of IBD. siRNA with 2'-O-methyl and propanediol modifications (siTNF-OMe-P) were resistant to nuclease degradation and provided better silencing efficacy in vitro as compared to unmodified siRNA. Every modification reduced nonspecific Toll-like receptor (TLR)-mediated immunomodulation in human peripheral blood mononuclear cells (PBMC) cells. Intrarectal administration of siTNF-OMe-P significantly ameliorated the clinical endpoints and histopathological severity in 5% dextran sulphate sodium (DSS)-treated mice as compared to unmodified and other chemically modified siRNAs. Differential gene expression assessed in siTNF-OMe-P-treated animals correlated with improved colon integrity and reduced TLR activation as compared to all treatment groups. All in all, this study demonstrates that propanediol and 2'-O-methyl modifications have profound functional consequences for siRNA efficacy in vivo. Consequently, this strategy has potential implications for therapeutic intervention in IBD and other diseases.

Once-daily, high-concentration MMX mesalamine in active ulcerative colitis.

BACKGROUND & AIMS: SPD476 (LIALDA in the US; MEZAVANT in the EU; otherwise known as MMX mesalamine; Shire Pharmaceuticals Inc., Wayne, PA, under license from Giuliani SpA, Milan, Italy) is a novel, once-daily, high-strength (1.2 g/tablet) formulation of mesalamine, utilizing MMX Multi Matrix System (MMX) technology designed to deliver the active drug throughout the colon. We performed a double-blind, multicenter study, comparing MMX mesalamine vs placebo for the treatment of active ulcerative colitis. A delayed-release oral mesalamine (ASACOL; Procter & Gamble, Cincinnati, OH) reference arm was included. METHODS: Three hundred forty-three patients with active, mild-to-moderate ulcerative colitis received MMX mesalamine 2.4 g/day or 4.8 g/day given once daily, ASACOL 2.4 g/day given in 3 divided doses, or placebo for 8 weeks. The primary end point was the proportion of patients in clinical and endoscopic remission (modified ulcerative colitis disease activity index of < or =1 with rectal bleeding and stool frequency scores of 0, no mucosal friability, and a > or =1-point reduction in sigmoidoscopy score from baseline). RESULTS: A significantly greater proportion of patients receiving MMX mesalamine 2.4 g/day given once daily (40.5%; P = .01) and 4.8 g/day given once daily (41.2%; P = .007) achieved clinical and endoscopic remission at week 8, vs placebo (22.1%). The clinical and endoscopic remission rate for ASACOL (32.6%; P = .124) was not significantly superior to placebo. All active treatments were well-tolerated. CONCLUSIONS: Once-daily MMX mesalamine was efficacious and well-tolerated for the induction of clinical and endoscopic remission. MMX mesalamine offers effective and convenient mesalamine therapy, potentially improving treatment compliance.

Impact of periampullary duodenal diverticula at endoscopic retrograde cholangiopancreatography: a proposed classification of periampullary duodenal diverticula.

BACKGROUND/AIMS: To propose a classification schema to describe periampullary duodenal diverticula (PDD) found at endoscopic retrograde cholangiopancreatography (ERCP), and to study the characteristics of these diverticula. MATERIALS AND METHODS: Among 400 consecutive patients in whom an ERCP was performed, PDD were present in 131 (32.8%), being these patients significantly older than the remaining, served as controls. RESULTS: PDD were classified in 3 different types according to the position of the major duodenal papilla: type I (16.3%), inside the diverticulum; type II (10.2%), in the margin of the diverticulum; and type III (6.5%), near the diverticulum. PDD were not associated with a more difficult cannulation of the biliary tract. CONCLUSIONS: PDD are common, especially in older patients, and do not significantly increase the difficulty of deep cannulation.