P005 Establishing a porcine model to translate anorectal stem cell organoid models to elucidate the aetiology of perianal Crohn's fistulae
Adegbola S.*1, Moore J.2, Sahnan K.1, Tozer P.1, Phillips R.1, Warusavitarne J.3, Faiz O.1, Hart A.4
1St Mark's Academic Institute, Surgery, London, United Kingdom 2Curileum Discovery Ltd, Northwick Park Institute of Medical Research/St Mark's Hospital Site, London, United Kingdom 3St Mark's Hospital, London, London, United Kingdom 4St Mark's Academic Institute, Gastroenterology, London, United Kingdom
Perianal fistulising Crohn's disease remains an extremely challenging medical problem as many fistulas do not respond to available treatments. A regenerative medicine approach is showing promise: injecting allogeneic adipose-derived mesenchymal stem cells in and around complex fistulas improves healing similar to surgery in a recent Phase 3 randomised trial (TiGenix, Cx601) .
Organoid-based technologies may expand the understanding of ineffective endogenous stem cell response to tissue damage in Crohn's fistulas and offer a range of new therapeutic targets. Organoids are
Anal tissue, including the anorectal transition zone (ATZ), was resected from healthy Landrace/Cross pigs (females, aged 4–6months) within one hour of termination. Biopsies taken from anal, ATZ and rectal tissue were transferred to petri-dishes, where they were washed/minced. Stem cells were isolated from tissues using a modified protocol developed for mice . Tissues were exposed to enzymatic digestion (collagenase/dispase, Sigma) at 37C for 1–2 hours on a shaker to release non-adherent cells from the mucosal tissue layer; tissue fragments were then removed by sequential filtering and centrifugation. Porcine cells were cultured in human organoid medium .
Ring structures, characteristic of developing 3D
Here we describe for the first time the ability to establish porcine anorectal organoid models using modifications of established techniques. The porcine model provides a valuable model to establish methodologies and characterise anorectal organoid biology to translate to Crohn's patients
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