702 Transient Receptor Potential Ankyrin-1 (TRPA1) Has a Major Role in Visceral Pain

Abstract

Introduction Hypertrophic mesenteric adipose tissue enwrapping the intestine has been considered as a specific sign of Crohn's disease (CD). The role of this “creeping fat” in CD is unknown. Cartonectin (collagenous repeat-containing sequence of 26 kDa protein, CORS26) is a newly identified secretory protein produced by adipocytes with yet unclear function. Intestinal fibroblasts play an important role in the stricturing and inflammatory process of CD. Aim of this study was to investigate the in-vitro effect of Cartonectin on primary human colonic lamina propria fibroblasts (CLPF) from CD tissue. Materials and Methods: CLPF were isolated from strictured and non-strictured colonic specimens of CD and control patients. For CLPF stimulation increasing concentrations of recombinant human Cartonectin (10, to 500ng/ml) were used alone or for costimulation with LPS or TNF. IL-6, IL-8 and TGF-β in supernatants were quantified by ELISA. mRNA levels of collagen 1, collagen 3 and connective tissue growth factor (CTGF) were detected by real-time PCR. Results: LPSinduced IL-8 secretion fromnormal CLPFwas suppressed by Cartonectin in a dose-dependent fashion (200 ng/ml: p=0.0002 at 8h; p<0.0001 at 48h). However, LPS-induced IL-6 secretion was not affected. This was true as well for strictured CLPF for up to 48h (p=0.004) but not in “non-strictured” CLPF from CD patients. Only after treatment with high doses of Cartonectin (500 ng/ml) LPS-induced IL-8 secretion was significantly suppressed in non-strictured CLPF (p=0.02). TNF-induced inflammatory cytokine production could not be suppressed by Cartonectin neither in normal nor in CD (strictured and non-strictured) CLPF. Spontaneous TGF-β1 production of stricture CLPF was significantly suppressed by Cartonectin at a concentration of 500ng/ml at 48 hours (112 ± 17.8 vs 69 ±15 pg/ml; p=0.01). This effect was not observed in non-strictured CLPF. Interestingly, Cartonectin reduced collagen 1 and 3 as well as CTGF mRNA production in CLPF from strictured CD tissue. Conclusion: Cartonectin exerts anti-inflammatory effects on primary human CLPF both from CD patients and normal controls. Cartonectin suppresses profibrotic activity in CLPF isolated from strictures. Cartonectin may therefore be able to modulate both inflammatory and profibrotic responses of CLPF in CD.