Our study suggests that Bcl-3 may be an effective target for promoting regeneration of the epithelium in the colon. Bcl3−/−C57BL/6 (B6) mice were generated as described previously [15, 16]. All mice were group-housed in individually ventilated cages (IVCs) under specific pathogen-free conditions. Standard mTOR inhibitor housing and environmental conditions were maintained (temperature

21°C, 12 h light/12 h darkness with 50% humidity). Animals were fed sterile standard pellet diet and water ad libitum. Animal husbandry and experimental procedures were approved by the University College Cork Animal Experimentation Ethics Committee (AEEC). Mice were administered 2% DSS (45 kDa; TdB Consultancy, Uppsala, Sweden) ad libitum in their drinking water to induce colitis, as described previously [18]. DSS solutions were prepared freshly

and administered on a daily basis for 6 days. This was followed by water up to day 8 to induce acute disease. Body weight, stool consistency and posture/fur texture were recorded daily to determine the daily disease activity index (DAI). DAI scoring was assessed blinded with a maximum score of 10, as described previously [18, 19]. DAI scoring combined scoring from weight loss (% change) 0–4, stool consistency 0–4 and posture/fur texture 0–2. Briefly, a percentage weight loss score of 0 = no loss, 1 = 1–3% loss, 2 = 3–6% loss, 3 = 6–9% loss and 4 = greater than 9% loss in body mass. A stool

consistency score of 0 = no change, 1 = mild change, 2 = loose stool, 3 = loose stool and rectal bleeding, 4 = diarrhoea and rectal 3-deazaneplanocin A bleeding. A fur and posture score 0 = no change, 1 = mild hunched posture, 2 = hunched posture and reduced movement. Mice were killed at day 8 with colons removed from anus to caecum and washed in phosphate-buffered saline (PBS). Colons were measured and cut longitudinally dividing into the distal and proximal colon. Both proximal and distal colons were weighed and processed for histology, protein and quantitative reverse transcription–polymerase chain reaction (qRT–PCR) Avelestat (AZD9668) analysis. Distal colons (3 cm) were cut longitudinally and into three sections. One section was rolled in a ‘swiss roll’ fashion and frozen in optimal cutting temperature (OCT) tissue-freezing medium (Tissue Tek, Sakura Finetek, Torrance, CA, USA) using liquid nitrogen. Frozen sections (6 μm) were fixed in ice-cold acetone/ethanol 3:1 solution and stained with haematoxylin and eosin (H&E) according to standard histological staining procedures. Stained sections were analysed and scored using a light microscope (Olympus BX51; Olympus, Hamburg, Germany). Images were captured using Cell F software (Olympus). Images captured are representative of greater than seven fields of view at ×20 magnification per mouse. Histological scoring was performed in a blinded fashion.