Description
Background:The intestinal mucus layer is an essential component of innate defense against invasive pathogens or commensal bacteria that drive inflammation. The mucus layer is made up of soluble gel-forming mucins and epithelial transmembrane (TM) mucins. TM mucins form a barrier for invasion, but also have crucial signaling functions that are not well understood. Our aim is to investigate the function of most abundant intestinal TM mucin MUC13 during bacterial infection and inflammation.
Methods:
We used intestinal epithelial cells that highly express MUC13 and can be grown as a confluent monolayer to mimic the intestinal barrier. Using CRISPR/Cas9 genome editing technology, we generated MUC13 knockout cells. Different proliferation, barrier formation, migration, wound healing assays and advanced confocal microscopy were performed to investigate the function of MUC13.
Results:
The MUC13 knockout cells grew slower than the wild type cells and had an altered morphology. In the absence of MUC13, occludin was highly upregulated resulting in monolayers with very strong tight junctions as measured by trans epithelial electrical resistance (TEER). We demonstrated that MUC13 localizes to the actin arc of growing and migrating cells and MUC13 knockout cells had a significant defect in wound healing. We found that MUC13 can be cleaved by proteases of pathogenic bacteria and are currently investigating the effect of these proteases on MUC13 downstream signaling.
Conclusion:
The intestinal TM mucin MUC13 is a central regulator of epithelial barrier formation and wound healing in the intestinal tract that might be utilized by pathogenic bacteria to establish infection.
Societal impact:
TM mucins play important roles in defense against bacterial infection such as Salmonella enterica and Campylobacter jejuni that are the most common causes of human gastroenteritis. Mutations in TM mucins are associated with inflammatory bowel disease (IBD) that affects 1 in 200 people in the Netherlands and is also prevalent in dogs.
| Period | 15 Nov 2018 |
|---|---|
| Event title | "Making a Difference" - Veterinary Science Day 2018 |
| Event type | Conference |
| Location | Bunnik, NetherlandsShow on map |