Expression of trefoil factor genes in the duodenum and colon of dogs with inflammatory bowel disease and healthy dogs.

Trefoil factors (TFF) are small peptides produced by goblet cells, which are crucial for epithelial restitution. In humans with inflammatory bowel disease (IBD), TFF expression is up-regulated as part of an unspecific repair mechanism. The goal of this study was to assess TFF gene expression in the gastrointestinal tract from dogs with IBD compared to healthy controls. Preliminary assessment by PCR revealed TFF1 and 3 expression in the small and large intestine, whereas TFF2 was amplified only in the stomach. Subsequent RT-qPCR (with relative quantification against 3 reference genes) on endoscopic duodenal (IBD n=22, healthy controls n=18) and colonic (IBD n=12, controls n=11) biopsies revealed that TFF1 expression was significantly up-regulated in the duodenum from IBD dogs (Mann-Whitney p=0.001), whereas TFF3 expression was significantly lower in IBD colon compared to controls (t-test p=0.018). This study demonstrates evidence for dysregulation of TFF gene expression in canine IBD. Up-regulation of TFF1 could signify ectopic expression as a compensatory repair-mechanism, whereas down-regulation of TFF3 could contribute to defective epithelial barrier function, respectively. Whether this is a cause or consequence of IBD could not be established.