Molecular mechanisms of cell death: central implication of ATP synthase in mitochondrial permeability transition

AbstractF-ATP synthase is a leading candidate as the mitochondrial permeability transition pore (PTP) but the mechanism(s) leading to channel formation remain undefined. Here, to shed light on the structural requirements for PTP formation, we test cells ablated for g, OSCP and b subunits, and ρ0 cells lacking subunits a and A6L. Δg cells (that also lack subunit e) do not show PTP channel opening in intact cells or patch-clamped mitoplasts unless atractylate is added. Δb and ΔOSCP cells display currents insensitive to cyclosporin A but inhibited by bongkrekate, suggesting that the adenine nucleotide translocator (ANT) can contribute to channel formation in the absence of an assembled F-ATP synthase. Mitoplasts from ρ0 mitochondria display PTP currents indistinguishable from their wild-type counterparts. In this work, we show that peripheral stalk subunits are essential to turn the F-ATP synthase into the PTP and that the ANT provides mitochondria with a distinct permeability pathway.

Download Full-text

Faculty Opinions recommendation of Loss of cyclophilin D reveals a critical role for mitochondrial permeability transition in cell death.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1025130.301711 ◽

2005 ◽

Author(s):

Atan Gross

Keyword(s):

Cell Death ◽

Mitochondrial Permeability Transition ◽

Critical Role ◽

Permeability Transition ◽

Cyclophilin D ◽

Mitochondrial Permeability

Download Full-text

Faculty Opinions recommendation of Loss of cyclophilin D reveals a critical role for mitochondrial permeability transition in cell death.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1025130.297852 ◽

2005 ◽

Author(s):

Robert Sapolsky

Keyword(s):

Cell Death ◽

Mitochondrial Permeability Transition ◽

Critical Role ◽

Permeability Transition ◽

Cyclophilin D ◽

Mitochondrial Permeability

Download Full-text

Metformin induces apoptosis via uterus mitochondrial permeability transition pore opening and protects against estradiol benzoate-induced uterine defect and associated pathophysiological disorder in female Wistar rats

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00562-6 ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Adeola Oluwakemi Olowofolahan ◽

Obinna Matthew Paulinus ◽

Heritage Mojisola Dare ◽

Olufunso Olabode Olorunsogo

Keyword(s):

Cell Death ◽

Cytochrome C ◽

Mitochondrial Permeability Transition ◽

Permeability Transition ◽

Estradiol Benzoate ◽

Histological Evaluation ◽

Mitochondrial Atpase ◽

Rat Uterus ◽

Mitochondrial Permeability ◽

Pore Opening

Abstract Background Some antitumor or anticancer agents have been shown to execute cell death by induction of mitochondrial permeability transition (mPT) pore opening in order to elicit their chemotherapeutic effect. Therefore, this study investigated the effect of metformin on cell death via rat uterus mPT pore and estradiol benzoate-induced uterine defect and associated pathophysiological disorder in female rat. Mitochondria were isolated using differential centrifugation. The mPT pore opening, cytochrome c release and mitochondrial ATPase activity were determined spectrophotometrically. Caspases 9 and 3 activities, MDA and estradiol levels and SOD, GSH activities, were determined using ELISA technique. Histological and histochemical assessments of the uterine section were carried out using standard methods. Results Metformin at concentrations 10–90 μg/mL, showed no significant effect on mPT pore opening, mATPase activity and release of cytochrome c. However, oral administration of metformin caused mPT pore opening, enhancement of mATPase activity and activation of caspases 9 and 3 significantly at 300 and 400 mg/kg. Metformin protected against estradiol benzoate (EB)-induced uterine defect and other associated pathophysiological disorder. It also improved the antioxidant defense system. The histological evaluation revealed the protective effect of metformin on the cellular architecture of the uterus while the histochemical examination showed severe hyperplasia in the uterine section of EB-treated rats, remarkably reversed by metformin co-treatment. Conclusion This study suggests that metformin at high doses induces apoptosis via rat uterus mPT pore opening and protects against EB-induced uterine defect (hyperplasia) and associated pathophysiological disorder.

Download Full-text

Prerequisites for ubiquinone analogs to prevent mitochondrial permeability transition-induced cell death

Journal of Bioenergetics and Biomembranes ◽

10.1007/s10863-012-9406-7 ◽

2012 ◽

Vol 44 (1) ◽

pp. 207-212 ◽

Cited By ~ 12

Author(s):

Julie Belliere ◽

Flavien Devun ◽

Cécile Cottet-Rousselle ◽

Cécile Batandier ◽

Xavier Leverve ◽

...

Keyword(s):

Cell Death ◽

Mitochondrial Permeability Transition ◽

Permeability Transition ◽

Mitochondrial Permeability

Download Full-text

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

Biochemical Journal ◽

10.1042/bj20040885 ◽

2004 ◽

Vol 382 (3) ◽

pp. 877-884 ◽

Cited By ~ 102

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.

Download Full-text