Figure 2
Ex vivo colonic biopsy model. Endoscopic pinch biopsies taken from the sigmoid colon were used in an ex vivo biopsy model. Images (A–C) show hematoxylin and eosin staining of biopsies from healthy controls following 24 h in basal medium. Image (D) shows a biopsy from quiescent UC (Mayo score ≤ 2) stimulated with IFN-gamma 100 ng/ml for 24 h in the basal medium. Immunoenzymatic staining confirms a strong signal of pSTAT1 (brown) in the epithelial border confirming good uptake of IFN-gamma to the epithelium. In image (E) the proliferative cell marker Ki67 (brown) was detected with immunostaining in healthy controls at baseline and following 24 h with no significant change in expression shown in graph (H). In image (F) dual-staining for IL-33 (red) and Ki67 (green) revealed IL-33 presence also in Ki67 positive cells (yellow). RT-qPCR was performed for IL33 and TNF in healthy controls comparing baseline (0 h) with 24 h incubation in basal medium. No significant differences were seen (IL33 p-value = 0.3, TNF p-value = 0.8) shown in graph G. Scale bars = 50 µm.
