Regulation of the human taurine transporter by TNF‐α and an anti‐inflammatory function of taurine in human intestinal Caco‐2− cells

Abstract We investigated whether or not the inflammatory cytokines affect the activity of taurine transporter (TAUT) in human intestinal Caco‐2 − cells. Among the cytokines, tumor necrosis factor α(TNF‐α) markedly augmented the TAUT activity. A kinetic analysis of the TAUT activity in TNF‐α‐treated Caco‐2 cells suggests that this up‐regulation was associated with both an increase in the amount of TAUT and an increase in its affinity. Considering these results, it seems that intracellular taurine plays a role in the intestinal epithelial cells under such an inflammatory condition as that caused by an excessive amount of TNF‐α secreted by macrophages. To verify this hypothesis, we examined the effect of taurine on inflamed intestinal cells by using a co‐culture system of Caco‐2 cells with human macrophage‐like THP‐1 cells. The result shows that taurine significantly repressed the damage to Caco‐2 cells caused by TNF‐α secreted by THP‐1 cells. Thus, taurine may be a useful substance against intestinal inflammation.