Reversible Effect Of Dextran Sodium Sulfate On Mucus Secreting Intestinal Epithelial Cells

Development of animal models of inflammatory bowel disease (IBD) is important to provide insights into the pathogenesis of IBD and to evaluate modalities to prevent or ameliorate inflammation or enhance mucosal healing. However, the use of in vitro models of the inflamed gastrointestinal tract can provide valuable insight into a possible mechanism for dextran sodium sulfate (DSS)-induced colitis of importance for the design of subsequent in vivo studies. To develop a new in vitro IBD model with DSS-induced inflammation in human mucus-secreting intestinal epithelial cells (HT29-MTX-E12), we first investigated effects of increasing doses of DSS on viability and integrity of these intestinal epithelial cells. For cell viability studies, cells were treated with DSS solutions for 24 or 48 h and viability was measured fluorometrically by PicoGreen double-stranded DNA quantitation. HT29-MTX-E12 cells were differentiated in trans-well inserts and DSS solutions were added for 6 d before measuring integrity by transepithelial electrical resistance (TEER) and the permeability to fluorescein isothiocyanate (FITC)-dextran. Then, medium with 10% fetal calf serum (FCS) was added and TEER and FITC-dextran permeability were measured after 8 d of treatment. A biphasic response in cell viability was observed with increased viability at low doses and decreased viability at high doses of DSS. Viability was decreased to 29% at the highest dose of DSS (10% vol/wt) for 48 h (P < 0.001). Dextran sodium sulfate significantly decreased the TEER of the intestinal epithelial cells to 59% and increased the permeability to FITC-dextran by 70% (P < 0.001). However, the integrity of the intestinal epithelium could be fully restored at all DSS doses by subsequent treatment with medium containing 10% FCS for 8 d. In conclusion, DSS affects the viability and disrupts the intestinal barrier function of HT29-MTX-E12 monolayers, a main feature observed in IBD. Furthermore, the harmful effect of DSS is reversible, suggesting that recovery of intestinal integrity after DSS treatment by potential therapeutic drugs can be studied in vitro.