The overexpression of Bax produces cell death upon induction of the mitochondrial permeability transition.
Stably transfected Jurkat T cells were produced in which Bax expression is inducible by muristerone A. The cell death resulting from induction of the overexpression of Bax was prevented by inhibition of the mitochondrial permeability transition (MPT) with cyclosporin A (CyA) in combination with the phospholipase A2 inhibitor aristolochic acid (ArA). The caspase-3 inhibitor Z-Asp-Glu-Val aspartic acid fluoromethylketone (Z-DEVD-FMK) had no effect on the loss of viability. The MPT was measured as the CyA plus ArA-preventable loss of the mitochondrial membrane potential (DeltaPsim). The MPT was accompanied by the release of cytochrome c from the mitochondria, caspase-3 activation in the cytosol, cleavage of the nuclear enzyme poly(ADP-ribose)polymerase (PARP), and DNA fragmentation, all of which were inhibited by CyA plus ArA. Z-DEVD-FMK had no effect on the loss of DeltaPsim and the redistribution of cytochrome c but did prevent caspase-3 activation, PARP cleavage, and DNA fragmentation. It is concluded that Bax induces the MPT, a critical event in the loss of cell viability. In addition to the cell death, the MPT mediates other typical manifestations of apoptosis in this model, namely release of cytochrome c, caspase activation with PARP cleavage, and DNA fragmentation.
Pastorino
J G
JG
Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Chen
S T
ST
Tafani
M
M
Snyder
J W
JW
Farber
J L
JL
D017209:Apoptosis; D034341:Aristolochic Acids; D053148:Caspase 3; D020169:Caspases; D016572:Cyclosporine / Q000494:pharmacology; D003546:Cysteine Endopeptidases / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D053938:DNA Fragmentation; D004441:Ecdysterone / Q000031:analogs & derivatives / Q000494:pharmacology; D004789:Enzyme Activation; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D019169:Jurkat Cells; D008928:Mitochondria / Q000502:physiology*; D009842:Oligopeptides / Q000494:pharmacology; D010539:Permeability; D010616:Phenanthrenes / Q000494:pharmacology; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2; D014162:Transfection; D051028:bcl-2-Associated X Protein
D034341:Aristolochic Acids; C494826:BAX protein, human; D015853:Cysteine Proteinase Inhibitors; D003574:Cytochrome c Group; D009842:Oligopeptides; D010616:Phenanthrenes; D011506:Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C055348:muristerone A; D004441:Ecdysterone; D016572:Cyclosporine; C000228:aristolochic acid I; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D010741:Phospholipases A; D054467:Phospholipases A2; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases