Figure 1

Differential response of McNtcp.24 cells to bile acid treatment. (A) Cells were treated with bile acids (50 μM) for 1 h, and caspase 8 activity was assayed in cell extracts using the fluorogenic substrate, Z-IETD-AFC, as described in the Materials and Methods. Only GCDCA was able to activate caspase 8 in McNtpc.24 cells consistent with its role in the induction of apoptosis. The values shown are mean ± SD (n = 3). (B) Genomic DNA fragmentation in bile acid-treated cells. The cells were incubated with 50 μM bile acids for 3 h and genomic DNA was isolated as described in the Materials and Methods. Glycine-conjugated bile acids induced the DNA laddering pattern indicative of apoptosis. GCA, glycocholic acid; GCDCA, glycochenodeoxycholic acid; GDCA, glycodeoxycholic acid; TCA, taurocholic acid; TCDCA, taurochenodeoxycholic acid; TDCA, taurodeoxycholic acid. The experiments in (A) and (B) were repeated four times with similar results.