Ontology highlight
ABSTRACT: Background
One of the most challenging conditions in Crohn's disease (CD) patients is the treatment of perianal fistulae. We have recently shown that epithelial-to-mesenchymal transition (EMT) plays a crucial role during CD-fistulae development. Dickkopf-homolog 1 (DKK-1) is known to play a key role during EMT. Here, we investigated a role for DKK-1 in the pathogenesis of CD-associated fistulae.Methods
Dkk-1 protein expression in CD-fistula specimens were investigated by immunohistochemistry. Colonic lamina propria fibroblasts (CLPF) were obtained from either non-IBD control patients or patients with fistulizing CD. HT-29 intestinal epithelial cells (IEC) were either grown as monolayers or spheroids. Cells were treated with either TNF-?, TGF-? or IL-13. Knock-down of DKK-1 or ?-Catenin was induced in HT-29-IEC by siRNA technique. mRNA expression was determined by real-time-PCR.Results
Dkk-1 protein was specifically expressed in transitional cells lining the fistula tracts. TGF-? induced DKK-1 mRNA expression in HT-29-IEC, but decreased it in fistula CLPF. On a functional level, DKK-1 knock-down prevented TGF-?-induced IL-13 mRNA expression in HT-29-IEC. Further, loss of ?-Catenin was accompanied by reduced levels of DKK-1 and, again, IL-13 in IEC in response to TGF-?. In turn, treatment of HT-29-IEC as well as fistula CLPF with IL-13 resulted in decreased levels of DKK-1 mRNA. Treatment with TNF-? or the bacterial wall component, muramyl-dipeptide, decreased DKK-1 mRNA levels in HT-29-IEC, but enhanced it in fistula CLPF.Discussion
We demonstrate that DKK-1 is strongly expressed in cells lining the CD-fistula tracts and regulates factors involved in EMT initiation. These data provide evidence for a role of DKK-1 in the pathogenesis of CD-associated perianal fistulae.
SUBMITTER: Frei SM
PROVIDER: S-EPMC3826763 | biostudies-literature | 2013
REPOSITORIES: biostudies-literature
PloS one 20131108 11
<h4>Background</h4>One of the most challenging conditions in Crohn's disease (CD) patients is the treatment of perianal fistulae. We have recently shown that epithelial-to-mesenchymal transition (EMT) plays a crucial role during CD-fistulae development. Dickkopf-homolog 1 (DKK-1) is known to play a key role during EMT. Here, we investigated a role for DKK-1 in the pathogenesis of CD-associated fistulae.<h4>Methods</h4>Dkk-1 protein expression in CD-fistula specimens were investigated by immunohi ...[more]