Detailing the role of Bax translocation, cytochrome c release, and perinuclear clustering of the mitochondria in the killing of HeLa cells by TNF.
Induction of cell death in HeLa cells with TNF and cycloheximide (CHX) required an adequate ATP supply and was accompanied by decrease in intracellular pH, translocation of Bax, perinuclear clustering of the mitochondria, and cytochrome c release. The chloride channel inhibitor furosemide prevented the intracellular acidification, the translocation of Bax and the cell death. Cyclosporin A (CyA) or bongkrekic acid (BK) inhibited the induction of the MPT, the release of cytochrome c and the cell death without affecting the perinuclear clustering of the mitochondria or the translocation of Bax. Energy depletion with the ATP synthase inhibitor oligomycin or the uncoupler FCCP in the presence of 2-deoxy-glucose prevented the perinuclear clustering of the mitochondria and the cell killing. However, mitochondrial translocation of Bax was still observed. By contrast, cytochrome c was released in the oligomycin-treated cells but not in the same cells treated with FCCP. The data demonstrate that apoptosis in HeLa cells is ATP dependent and requires the translocation of Bax. The movement of Bax to the mitochondria occurs before and during the perinuclear clustering of these organelles and does not require the presence of ATP. The release of cytochrome c depends on the induction of the mitochondrial permeability transition but not ATP content.
Pucci
Bruna
B
Department of Cellular and Molecular Pathology, IRCCS San Raffaele Pisana, Rome, Italy.
Bertani
Francesca
F
Karpinich
Natalie O
NO
Indelicato
Manuela
M
Russo
Matteo A
MA
Farber
John L
JL
Tafani
Marco
M
D000255:Adenosine Triphosphate / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D001865:Bongkrekic Acid / Q000494:pharmacology; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002470:Cell Survival; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D003513:Cycloheximide / Q000633:toxicity; D016572:Cyclosporine / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005665:Furosemide / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008928:Mitochondria / Q000201:enzymology* / Q000473:pathology; D033681:Mitochondrial Membrane Transport Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000201:enzymology; D000083162:Mitochondrial Permeability Transition Pore; D009840:Oligomycins / Q000494:pharmacology; D010539:Permeability; D021381:Protein Transport; D014268:Trifluoperazine / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D014475:Uncoupling Agents / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
C494826:BAX protein, human; D018118:Chloride Channels; D004791:Enzyme Inhibitors; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D009840:Oligomycins; D014409:Tumor Necrosis Factor-alpha; D014475:Uncoupling Agents; D051028:bcl-2-Associated X Protein; D001865:Bongkrekic Acid; D014268:Trifluoperazine; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D005665:Furosemide; D016572:Cyclosporine; D000255:Adenosine Triphosphate; D045304:Cytochromes c; D003513:Cycloheximide