Crohn's disease-associated mucosal factors regulate the expression of TNF-like cytokine 1A and its receptors in primary subepithelial intestinal myofibroblasts and intestinal epithelial cells

Intestinal subepithelial myofibroblasts (SEMFs) exert a profibrotic role in Crohn's disease (CD). Tumor necrosis factor-like cytokine 1A (TL1A) and its receptors, death-domain receptor 3 (DR3) and decoy receptor 3 (DcR3), are mucosal factors with significant involvement in experimental inflammation and CD. We aimed to determine the regulation of expression of this system of proteins in SEMFs and intestinal epithelial cells. The relative amount of mRNA transcripts for TL1A, DR3, and DcR3 was measured by real-time reverse transcription polymerase chain reaction in cultured primary SEMFs, colonic myofibroblast cell line 18CO, and epithelial cell line HT29. Protein expression was determined by immunofluorescence. The effect of various proinflammatory stimuli in mRNA and protein expression was studied. TL1A mRNA and protein expression in primary SEMFs (and 18CO cells) was significantly upregulated after stimulation with interleukin 1-alpha and/or tumor necrosis factor alpha (TNF-α) (32- to 44-fold increase, P