Figure 6.
BSIA depends on intracellular calcium stores. (A) H69 cholangiocytes were loaded with increasing concentrations of 1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetraacetic acid (BAPTA) and then treated with either vehicle or 750 μM NaCDC for 1 hour. Caspase 3/7 activities were determined. One‐way ANOVA, P < 0.0001. (B) MCU was knocked down by lentivirus‐mediated shRNA interference. Knockdown was confirmed by RT‐qPCR. Two‐tailed Student t test, P < 0.0001. (C) MCU knockdown was confirmed by immunoblotting. (D) Short hairpin control and MCU knockdown H69 cholangiocytes were treated with 1 mM NaCDC‐induced apoptosis in the absence or presence of sAC‐specific inhibitor KH7. One‐way ANOVA, P < 0.0001. (E) H69 cholangiocytes were incubated with 750 μM NaCDC in normal or Ca2+‐free medium. One‐way ANOVA, P < 0.0001. (F) H69 cholangiocytes were pretreated with or without 50 nM thapsigargin for 15 minutes and then with 0 μM or 750 μM NaCDC. The figure shows a representative experiment from a series with similar results. ***P < 0.001. Abbreviations: ATP1A1, adenosine triphosphatase, sodium/potassium transporting, alpha 1 polypeptide; BAPTA, 1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetraacetic acid; DMEM, Dulbecco's modified Eagle's medium; DMSO, dimethyl sulfoxide; KD, knockdown; n.s., not significant.