1. F A C U L T Y O F H E A L T H A N D M E D I C A L S C I E N C E S U N I V E R S I T Y O F C O P E N H A G E N An oxazolone zebrafish model for inflammatory bowel disease (IBD): preliminary results Simon Haarder 1, 3, Per Kania 1, Poul Hyttel 2, Thomas Lindebo Holm 3 and Kurt Buchmann 1 1 Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark 2 Department of Basic Animal and Veterinary Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark 3 Department of Immunopharmacology, Novo Nordisk A/S, Denmark References: - Brugmann et al. (2009): Oxazolone-Induced Enterocolitis in Zebrafish Depends on the Composition of the Intestinal Microbiota. Gastroenterology, 137, 1757-1767 pp. - Xu et al. (2013): Teleost skin, an ancient mucosal surface that elicits gut-like immune responses. PNAS, 110 (32), 13097-13102 pp. References: - Brugmann et al. (2009): Oxazolone-Induced Enterocolitis in Zebrafish Depends on the Composition of the Intestinal Microbiota. Gastroenterology, 137, 1757-1767 pp. - Xu et al. (2013): Teleost skin, an ancient mucosal surface that elicits gut-like immune responses. PNAS, 110 (32), 13097-13102 pp. BACKGROUND AND AIM OXAZOLONE CHALLENGE GOBLET CELL COUNTS Control Day 03 dpi Wild-type zebrafish were anaesthetized with MS-222 (200 mg/L) and weighed. Fish were then challenged with oxazolone (0.2, 0.6%, 1.0%, 5 fish per group, in 50% ethanol (solvent)). Control fish were given 50% ethanol. Fish were euthanized 3 days post challenge (overdose MS- 222, 500 mg/L) and weighed. Scale dyed with Alcian Blue Control 0.2 %0.6 %1.0 % OxaControlOxaControlOxaKontrol No. Goblet cells * 216254160259129235 Oxazolone Day 0 3 dpi CONCLUSIONS HISTOLOGY Oxazolone * Pooled from 5 different scales, Alcian blue staining Results indicate that goblet cells from fish scales are affected by oxazolone. Future zebrafish IBD models should include this parameter in association with the traditional intestinal goblet cells counts. Histology data was inconclusive. Currently, alternative approaches are being investigated (e.g. whole-fish sectioning). Other methods are also performed on fish tissue: optimal projection tomography (OPT) and qPCR. Control Mid-intestine sections stained with Alcian Blue Goblet cells depletion seen in both groups Oxazolone The zebrafish (Danio rerio) is an popular animal model, increasingly used to investigate basal pathogenesis of a variety of human diseases. Here, we use the zebrafish as a model for inflammatory bowel disease (IBD), a chronic condition associated with the gastrointestinal system. Like other vertebrates, fish are equipped with a mucosal immune system in the skin (SALT). It has recently been demonstrated that the immune response seen in fish skin in many aspects resembles immune reactions in the fish gut. Hence, we wanted to clarify whether goblet cells found in the epidermis (the outer part of the fish scale) were affected in the same way as intestinal goblet cells are in zebrafish IBD models (depletion). If so, this parameter could be included as a part of the overall disease model evaluation. inner outer