Fig. 1

PCDH20 was decreased in the colon epithelium of Crohn’s disease patients and mice colitis models. a Venn diagram showing the intersection of cadherins using two different algorithms (top panel). The mRNA expression heatmap of cadherins in colonic epithelium of CD patients (bottom panel). Each group n = 8. b Representative sections from colonic epithelium of patients with CD (n = 19), and HC (n = 15) were stained for PCDH20 by using immunohistochemistry. c Semi-quantified score of PCDH20 stained by immunohistochemistry in different disease behaviors of CD patients. B1 n = 8, B2/3 n = 11. d Immunoblots of PCDH20 protein in the colonic mucosa of CD patients. CD n = 8, HC n = 8, representative image. e RT-qPCR detection of PCDH20 mRNA expression in colon biopsy samples. CD n = 43, and HC n = 42. f Correlation between PCDH20 mRNA expression and CDAI in patients with CD (n = 43). g–i Immunohistochemistry staining (g), RT-qPCR (h), and immunoblots (i) for PCDH20 levels in colonic epithelium of TNBS-induced colitis mice model. Each group n = 3 (g, i). TNBS n = 16, control n = 11 (h). Representative images for immunohistochemistry staining. j–l Immunohistochemistry staining (j), RT-qPCR (k), and immunoblots (l) for PCDH20 levels in colonic epithelium of DSS-induced colitis mice models. Each group n = 3 (j, l), DSS n = 11, control n = 5 (k); representative images for immunohistochemistry staining. The data in c, e, h, k were presented as mean ± SEM. * p < 0.05, **p < 0.01 vs. Control, ***p < 0.001 vs Control. Magnification × 200 (top in b) and × 400 (bottom in b, g, j). Scale bars = 100 μm (top in b) and 5 μm (bottom in b, g, j). # Gene expression in qPCR was normalized to beta-actin in each group. Abbreviations: Crohn’s disease, CD; healthy control, HC; non-stricture, non-penetrating behavior, B1; stricture behavior, B2; penetrating behavior, B3; Crohn’s disease activity index, CDAI