Altered Structural Expression and Enzymatic Activity Parameters in Quiescent Ulcerative Colitis: Are These Potential Normalization Criteria?

• DOI: 10.3390/ijms21051887
• Publication Date: 2020-03-10T15:59:36Z
• Authors: Sebastian Kjærgaard; Morten M. B. Damm; Joan Chang; Lene B. Riis; Hanne B. Rasmussen; Rasmus Hytting-An...; Susanne M. Krug; Jörg-Dieter Schulzke; Niels Bindslev; Mark Berner Hansen
• Keywords: Occludin; Claudin

Mucosal healing determined by endoscopy is currently the remission standard for ulcerative colitis (UC). However, new criteria are emerging, such as histologic normalization, which appears to correlate better risk of relapse. Here, we study mucosal on a molecular and functional level in quiescent UC. We obtained endoscopic biopsies from 33 UC patients 17 controls. Histology was assessed using Geboes score. Protein mRNA levels were evaluated tight junction proteins claudin-2, claudin-4, occludin, tricellulin, well Cl−/HCO3− exchanger DRA, cyclo-oxygenase enzymes (COX-1, COX-2). The activity COX-1 COX-2 modified Ussing chambers, measuring electrogenic ion transport (short-circuit current, SCC). Chronic inflammation present most patients. protein claudin-4 reduced, while mRNA-levels claudin-2 upregulated Surprisingly, downregulated, but unaltered COX-2. Basal not affected, inhibition induced two-fold larger decrease SCC Despite being clinical remission, demonstrated abnormal barrier properties at level. Further exploration signature revision current standards should be considered.