scholarly journals The Mitochondrial Permeability Transition Regulates Cytochrome c Release for Apoptosis during Endoplasmic Reticulum Stress by Remodeling the Cristae Junction

2007 ◽  
Vol 283 (6) ◽  
pp. 3476-3486 ◽  
Author(s):  
Dawei Zhang ◽  
Chao Lu ◽  
Matthew Whiteman ◽  
Britton Chance ◽  
Jeffrey S. Armstrong
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome C ◽  
Endoplasmic Reticulum Stress ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Cytochrome C Release ◽  
Mitochondrial Permeability

scholarly journals Metformin inhibits mitochondrial permeability transition and cell death: a pharmacological in vitro study

2004 ◽  
Vol 382 (3) ◽  
pp. 877-884 ◽  
Author(s):  
Bruno GUIGAS ◽  
Dominique DETAILLE ◽  
Christiane CHAUVIN ◽  
Cécile BATANDIER ◽  
Frédéric De OLIVEIRA ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Cytochrome C Release ◽  
Intact Cells ◽  
Human Carcinoma ◽  
Butyl Hydroperoxide ◽  
Mitochondrial Permeability ◽  
New Findings

Metformin, a drug widely used in the treatment of Type II diabetes, has recently received attention owing to new findings regarding its mitochondrial and cellular effects. In the present study, the effects of metformin on respiration, complex 1 activity, mitochondrial permeability transition, cytochrome c release and cell death were investigated in cultured cells from a human carcinoma-derived cell line (KB cells). Metformin significantly decreased respiration both in intact cells and after permeabilization. This was due to a mild and specific inhibition of the respiratory chain complex 1. In addition, metformin prevented to a significant extent mitochondrial permeability transition both in permeabilized cells, as induced by calcium, and in intact cells, as induced by the glutathione-oxidizing agent t-butyl hydroperoxide. This effect was equivalent to that of cyclosporin A, the reference inhibitor. Finally, metformin impaired the t-butyl hydroperoxide-induced cell death, as judged by Trypan Blue exclusion, propidium iodide staining and cytochrome c release. We propose that metformin prevents the permeability transition-related commitment to cell death in relation to its mild inhibitory effect on complex 1, which is responsible for a decreased probability of mitochondrial permeability transition.

scholarly journals Bax-induced Cytochrome C Release from Mitochondria Is Independent of the Permeability Transition Pore but Highly Dependent on Mg2+ Ions

1998 ◽  
Vol 143 (1) ◽  
pp. 217-224 ◽  
Author(s):  
Robert Eskes ◽  
Bruno Antonsson ◽  
Astrid Osen-Sand ◽  
Sylvie Montessuit ◽  
Christoph Richter ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cyclosporin A ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Cytochrome C Release ◽  
Mitochondrial Permeability ◽  
Isolated Mitochondria ◽  
Mammalian Homologue

Bcl-2 family members either promote or repress programmed cell death. Bax, a death-promoting member, is a pore-forming, mitochondria-associated protein whose mechanism of action is still unknown. During apoptosis, cytochrome C is released from the mitochondria into the cytosol where it binds to APAF-1, a mammalian homologue of Ced-4, and participates in the activation of caspases. The release of cytochrome C has been postulated to be a consequence of the opening of the mitochondrial permeability transition pore (PTP). We now report that Bax is sufficient to trigger the release of cytochrome C from isolated mitochondria. This pathway is distinct from the previously described calcium-inducible, cyclosporin A–sensitive PTP. Rather, the cytochrome C release induced by Bax is facilitated by Mg2+ and cannot be blocked by PTP inhibitors. These results strongly suggest the existence of two distinct mechanisms leading to cytochrome C release: one stimulated by calcium and inhibited by cyclosporin A, the other Bax dependent, Mg2+ sensitive but cyclosporin insensitive.

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