Induction of Apoptosis in an Intestinal Epithelial Cell Line, IEC-6

Abstract

IEC-6 is a non-transformed rat small intestinal epithelial cell line with characteristics of crypt epithelial cells. We have already reported that, in FCS culture, these cells exhibited signs of differentiation after reaching confluence, represented by the induction of alkaline phosphatase (ALP) activity. The IEC-6 cells then became detached from the culture plates, apoptosis being induced in the cells. The sequential events in in vitro culture of IEC-6 cells closely resemble the in vivo differentiation of small intestinal epithelial cells. In this study, we examined the nature of the signals involved in the induction of apoptosis in IEC-6 cells. Apoptosis was induced in an IEC-6 culture by stimulating with ionomycin. The addition of TPA inhibited apoptosis, inducing a proliferate response. However, TPA enhanced the induction of apoptosis when added together with ionomycin. The effects of other reagents were also examined, and the results suggest that the stimuli inducing apoptosis and those inducing proliferation were closely related.