Figure 2.

MMP13 is highly induced in human and murine fibrosis. (A) Bulk RNA sequencing was performed from biopsies taken during routine endoscopy from patients with CD B1 (non-stricturing, non-penetrating, Montreal classification n= 45), with CD B2 (stricturing n= 22) and non-IBD controls (n= 51) within the IBDome cohort. The expression of MMP13 is depicted. (B, C) Colon tissue sections from CD patients with stenosis (IF cohort) (n= 11) and from healthy controls (n= 8) were stained by immunofluorescence for MMP13 or Isotype control. The mean gray values were assessed by Image J. Representative pictures are shown. (D) Wildtype mice received 3 cycles of DSS and animals without treatment were used as control. Gene expression in colon tissue was analyzed at day 63 by qPCR (n= 12-13 per group). (E) Protein lysates (50µg) isolated from colons of untreated wildtype animals and of mice from chronic DSS-induced colitis were used for detection of MMP13 by Western Blot. β-Actin was used as loading control. Quantitative data were analyzed with Wilcoxon-Mann-Whitney test (*p>0.05, **p>0.01, two-tailed) and mean values are shown with standard deviation. Scale bar represents 50µm.