FIGURE 5.

Caspase 1 is required for beclin 1 up-regulation after HS/R and hypoxia/reoxygenation. A, Atg7, Atg12-Atg5 conjugate, and Atg3 expression in WT and caspase 1^−/− hepatocytes cultured under normoxia or hypoxia for 2, 6, and 18 h was assessed by Western blot analysis (left panel). The expression of Atg12-Atg5 in WT and caspase 1^−/− hepatocytes treated with LPS for 6 h was shown in the right as a positive control. Images are representative of at least three independent experiments. B, representative Western blot analysis of beclin 1 in WT and caspase 1^−/− hepatocytes cultured under normoxia or hypoxia for 2, 6, and 18 h. C, representative Western blot analysis of beclin 1 in WT hepatocytes treated with control siRNA or caspase 1 siRNA after normoxia or hypoxia for 2 and 6 h. D, representative Western blot analysis of beclin 1 in caspase 1^−/− hepatocytes transfected with vector or mouse caspase 1 plasmid after normoxia or hypoxia for 2 and 6 h. E, beclin1 mRNA levels in hepatocytes after normoxia or 6 h of hypoxia. Data are mean ± S.E., n = 3. *, p < 0.05; ns, not significant. F, beclin 1 expression in WT hepatocytes transfected with siControl (C) or sibeclin1 (b) for 24 h before they were subjected to 6 h of hypoxia. G, mitochondrial (left panel) and cytosolic H₂O₂ (right panel) production in WT hepatocytes transfected with control siRNA (siCtrl) or siRNA targeting beclin 1 (sibeclin1) and 6 h of hypoxia/1 h of reoxygenation. Data are mean ± S.E. #, p < 0.05, hypoxia-reoxygenation versus normoxia; **, p < 0.01, siCtrl versus sibeclin1.