scholarly journals The Regulation of Non-Specific Membrane Permeability Transition in Yeast Mitochondria under Oxidative Stress

2021 ◽  
Vol 12 (2) ◽  
pp. 419-439
Author(s):  
Elena P. Isakova ◽  
Olga I. Klein ◽  
Yulia I. Deryabina
Keyword(s):  
Oxidative Stress ◽  
Membrane Permeability ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Permeability Transition ◽  
Yeast Mitochondria ◽  
Membrane Pore ◽  
Saccharomyces Cerevisiae Mitochondria ◽  
Specific Membrane

In this study, the mechanism of non-specific membrane permeability (yPTP) in the Endomyces magnusii yeast mitochondria under oxidative stress due to blocking the key antioxidant enzymes has been investigated. We used monitoring the membrane potential at the cellular (potential-dependent staining) and mitochondrial levels and mitochondria ultra-structural images with transmission electron microscopy (TEM) to demonstrate the mitochondrial permeability transition induction due to the pore opening. Analysis of the yPTP opening upon respiring different substrates showed that NAD(P)H completely blocked the development of the yPTP. The yPTP opening was inhibited by 5–20 mM Pi, 5 mM Mg2+, adenine nucleotides (AN), 5 mM GSH, the inhibitor of the Pi transporter (PiC), 100 μM mersalyl, the blockers of the adenine nucleotide transporter (ANT) carboxyatractyloside (CATR), and bongkrekic acid (BA). We concluded that the non-specific membrane permeability pore opens in the E. magnusii mitochondria under oxidative stress, and the ANT and PiC are involved in its formation. The crucial role of the Ca2+ ions in the process has not been confirmed. We showed that the Ca2+ ions affected the yPTP both with and without the Ca2+ ionophore ETH129 application insignificantly. This phenomenon in the E. magnusii yeast unites both mitochondrial unselective channel (ScMUC) features in the Saccharomyces cerevisiae mitochondria and the classical membrane pore in the mammalian ones (mPTP).

scholarly journals Cyclophilin-D promotes the mitochondrial permeability transition but has opposite effects on apoptosis and necrosis

2004 ◽  
Vol 383 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Yanmin LI ◽  
Nicholas JOHNSON ◽  
Michela CAPANO ◽  
Mina EDWARDS ◽  
Martin CROMPTON
Keyword(s):  
Oxidative Stress ◽  
Cell Injury ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition ◽  
Cyclophilin D ◽  
Intact Cells ◽  
Inner Membrane ◽  
Mitochondrial Permeability ◽  
Apoptosis And Necrosis

Cyclophilin-D is a peptidylprolyl cis–trans isomerase of the mitochondrial matrix. It is involved in mitochondrial permeability transition, in which the adenine nucleotide translocase of the inner membrane is transformed from an antiporter to a non-selective pore. The permeability transition has been widely considered as a mechanism in both apoptosis and necrosis. The present study examines the effects of cyclophilin-D on the permeability transition and lethal cell injury, using a neuronal (B50) cell line stably overexpressing cyclophilin-D in mitochondria. Cyclophilin-D overexpression rendered isolated mitochondria far more susceptible to the permeability transition induced by Ca2+ and oxidative stress. Similarly, cyclophilin-D overexpression brought forward the onset of the permeability transition in intact cells subjected to oxidative stress. In addition, in the absence of stress, the mitochondria of cells overexpressing cyclophilin-D maintained a lower inner-membrane potential than those of normal cells. All these effects of cyclophilin-D overexpression were abolished by cyclosporin A. It is concluded that cyclophilin-D promotes the permeability transition in B50 cells. However, cyclophilin-D overexpression had opposite effects on apoptosis and necrosis; whereas NO-induced necrosis was promoted, NO- and staurosporine-induced apoptosis were inhibited. These findings indicate that the permeability transition leads to cell necrosis, but argue against its involvement in apoptosis.

Abstract P237: Exercise Training Prevents Hypercholesterolemia-Induced Cardiac Mitochondrial Dysfunction

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Allison M McGee ◽  
Kyle S McCommis ◽  
M H Laughlin ◽  
Douglas K Bowles ◽  
Christopher P Baines
Keyword(s):  
Oxidative Stress ◽  
Exercise Training ◽  
Manganese Superoxide Dismutase ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition ◽  
Exercise Group ◽  
Ros Generation ◽  
Cyclophilin D ◽  
Negative Effects

Hypercholesterolemia has been suggested to have direct negative effects on myocardial function due to increased reactive oxygen species (ROS) generation and increased myocyte death. Mitochondrial permeability transition (MPT) is a significant mediator of cell death, which is enhanced by ROS generation and attenuated by exercise training. The purpose of this study was to investigate the effect of hypercholesterolemia on the MPT response of cardiac mitochondria. We hypothesized that familial hypercholesterolemic (FH) pigs would have an enhanced MPT response, and that exercise training could reverse this phenotype. FH pigs were obtained from the University of Wisconsin. Control, normolipidemic farm pigs were maintained on standard pig chow. After 4 months on a high-fat diet, the FH pigs were switched to the standard pig chow, and randomized to sedentary or exercise groups. The exercise group underwent a progressive treadmill-based training program for 4 months. At the end of the training protocol the animals were sacrificed and the heart removed. MPT was assessed by mitochondrial swelling in response to Ca2+. Protein nitrotyrosylation, GSH levels, and antioxidant enzyme expression were also examined. FH pigs did show an increased MPT response despite no change in the expression of putative MPT pore components adenine nucleotide translocase (ANT), mitochondrial phosphate carrier (PiC), and cyclophilin-D (CypD). FH also caused increased oxidative stress, depicted by increased protein nitrotyrosylation and decreased GSH levels. This was associated with concomitant decreases in the expression of mitochondrial antioxidant enzymes manganese superoxide dismutase (MnSOD) and thioredoxin-2 (Trx2). However, chronic exercise training was able to normalize the MPT response in FH pigs, reduce oxidative stress, and increase MnSOD expression. We conclude that hypercholesterolemia causes increased oxidative stress and enhances the MPT response in the porcine myocardium, and that exercise training can correct for both the increased oxidative stress and MPT alterations observed with hypercholesterolemia.

The mitochondrial permeability transition pore

1999 ◽  
Vol 66 ◽  
pp. 167-179 ◽  
Author(s):  
Martin Crompton ◽  
Sukaina Virji ◽  
Veronica Doyle ◽  
Nicholas Johnson ◽  
John M. Ward
Keyword(s):  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition Pore ◽  
Anion Channel ◽  
Permeability Transition ◽  
Adenine Nucleotide Translocase ◽  
Voltage Dependent Anion Channel ◽  
Inner Membrane ◽  
Membrane Pore ◽  
Voltage Dependent

This chapter reviews recent advances in the identification of the structural elements of the permeability transition pore. The discovery that cyclosporin A (CsA) inhibits the pore proved instrumental. Various approaches indicate that CsA blocks the pore by binding to cyclophilin (CyP)-D. In particular, covalent labelling of CyP-D in situ by a photoactive CsA derivative has shown that pore ligands have the same effects on the degree to which CsA both blocks the pore and binds to CyP-D. The recognition that CyP-D is a key component has enabled the other constituents to be resolved. Use of a CyP-D fusion protein as affinity matrix has revealed that CyP-D binds very strongly to 1:1 complexes of the voltage-dependent anion channel (from the outer membrane) and adenine nucleotide translocase (inner membrane). Our current model envisages that the pore arises as a complex between these three components at contact sites between the mitochondrial inner and outer membranes. This is in line with recent reconstitutions of pore activity from protein fractions containing these proteins. The strength of interaction between these proteins suggests that it may be a permanent feature rather than assembled only under pathological conditions. Calcium, the key activator of the pore, does not appear to affect pore assembly; rather, an allosteric action allowing pore flicker into an open state is indicated. CsA inhibits pore flicker and lowers the binding affinity for calcium. Whether adenine nucleotide translocase or the voltage-dependent anion channel (via inner membrane insertion) provides the inner membrane pore has not been settled, and data relevant to this issue are also documented.

The mitochondrial permeability transition: its molecular mechanism and role in reperfusion injury

1999 ◽  
Vol 66 ◽  
pp. 181-203 ◽  
Author(s):  
Andrew P. Halestrap
Keyword(s):  
Oxidative Stress ◽  
Cyclosporin A ◽  
Reperfusion Injury ◽  
Molecular Mechanism ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Apoptotic Cell ◽  
Heart Function ◽  
Permeability Transition ◽  
Mitochondrial Permeability

The mitochondrial permeability transition (mPT) involves the opening of a non-specific pore in the inner membrane of mitochondria, converting them from organelles whose production of ATP sustains the cell, to instruments of death. Here, I first summarize the evidence in favour of our model for the molecular mechanism of the mPT. It is proposed that the adenine nucleotide translocase (ANT) is converted into a non-specific pore through a calcium-mediated conformational change. This requires the binding of a unique cyclophilin (cyclophilin-D, CyP-D) to the ANT, except when matrix [Ca2+] is very high. Binding of CyP-D is increased in response to oxidative stress and some thiol reagents which sensitize the mPT to [Ca2+]. Matrix adenine nucleotides decrease the sensitivity of the mPT to [Ca2+] by binding to the ANT. This is antagonized by carboxyatractyloside (an inhibitor of the ANT) and by modification of specific thiol groups on the ANT by oxidative stress or thiol reagents; such treatments thus enhance the mPT. In contrast, decreasing intracellular pH below 7.0 greatly desensitizes the mPT to [Ca2+]. Conditions which sensitize the mPT towards [Ca2+] are found in hearts reperfused after a period of ischaemia, a process that may irreversibly damage the heart (reperfusion injury). We have demonstrated directly that mPT pores open during reperfusion (but not ischaemia) using a technique that involves entrapment of [3H]deoxyglucose in mitochondria that have undergone the mPT. The mPT may subsequently reverse in hearts that recover from ischaemia/reperfusion, the extent of resealing correlating with recovery of heart function. A variety of agents that antagonize the mPT protect the heart from reperfusion injury, including cyclosporin A, pyruvate and propofol. Mitochondria that undergo the mPT and then reseal may cause cytochrome c release and thus initiate apoptosis in cells subjected to stresses less severe than those causing necrosis. An example is the apoptotic cell death in the hippocampus that occurs several days after insulin-induced hypoglycaemia, and can be prevented by prior treatment with cyclosporin A.

scholarly journals Inhibition of mitochondrial permeability transition by deletion of the ANT family and CypD

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw4597 ◽  
Author(s):  
Jason Karch ◽  
Michael J. Bround ◽  
Hadi Khalil ◽  
Michelle A. Sargent ◽  
Nadina Latchman ◽  
...  
Keyword(s):  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Liver Mitochondria ◽  
Null Mouse ◽  
Cyclophilin D ◽  
Inner Membrane ◽  
Membrane Pore ◽  
Mitochondrial Permeability

The mitochondrial permeability transition pore (MPTP) has resisted molecular identification. The original model of the MPTP that proposed the adenine nucleotide translocator (ANT) as the inner membrane pore-forming component was challenged when mitochondria from Ant1/2 double null mouse liver still had MPTP activity. Because mice express three Ant genes, we reinvestigated whether the ANTs comprise the MPTP. Liver mitochondria from Ant1, Ant2, and Ant4 deficient mice were highly refractory to Ca2+-induced MPTP formation, and when also given cyclosporine A (CsA), the MPTP was completely inhibited. Moreover, liver mitochondria from mice with quadruple deletion of Ant1, Ant2, Ant4, and Ppif (cyclophilin D, target of CsA) lacked Ca2+-induced MPTP formation. Inner-membrane patch clamping in mitochondria from Ant1, Ant2, and Ant4 triple null mouse embryonic fibroblasts showed a loss of MPTP activity. Our findings suggest a model for the MPTP consisting of two distinct molecular components: The ANTs and an unknown species requiring CypD.

Permeability transition in rat liver mitochondria is modulated by the ATP-Mg/Pi carrier

2003 ◽  
Vol 285 (2) ◽  
pp. G274-G281 ◽  
Author(s):  
Thilo Hagen ◽  
Christopher J. Lagace ◽  
Josephine S. Modica-Napolitano ◽  
June R. Aprille
Keyword(s):  
Rat Liver ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Permeability Transition ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Mitochondrial Permeability ◽  
Nucleotide Content ◽  
Adenine Nucleotide Pool

Mitochondrial permeability transition, due to opening of the permeability transition pore (PTP), is triggered by Ca2+ in conjunction with an inducing agent such as phosphate. However, incubation of rat liver mitochondria in the presence of low micromolar concentrations of Ca2+ and millimolar concentrations of phosphate is known to also cause net efflux of matrix adenine nucleotides via the ATP-Mg/Pi carrier. This raises the possibility that adenine nucleotide depletion through this mechanism contributes to mitochondrial permeability transition. Results of this study show that phosphate-induced opening of the mitochondrial PTP is, at least in part, secondary to depletion of the intramitochondrial adenine nucleotide content via the ATP-Mg/Pi carrier. Delaying net adenine nucleotide efflux from mitochondria also delays the onset of phosphate-induced PTP opening. Moreover, mitochondria that are depleted of matrix adenine nucleotides via the ATP-Mg/Pi carrier show highly increased susceptibility to swelling induced by high Ca2+ concentration, atractyloside, and the prooxidant tert-butylhydroperoxide. Thus the ATPMg/Pi carrier, by regulating the matrix adenine nucleotide content, can modulate the sensitivity of rat liver mitochondria to undergo permeability transition. This has important implications for hepatocytes under cellular conditions in which the intramitochondrial adenine nucleotide pool size is depleted, such as in hypoxia or ischemia, or during reperfusion when the mitochondria are exposed to increased oxidative stress.

scholarly journals Inhibition of mitochondrial permeability transition by deletion of the ANT family and CypD

2018 ◽  
Author(s):  
Jason Karch ◽  
Michael J. Bround ◽  
Hadi Khalil ◽  
Michelle A. Sargent ◽  
Nadina Latchman ◽  
...  
Keyword(s):  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Liver Mitochondria ◽  
Null Mouse ◽  
Inner Membrane ◽  
Membrane Pore ◽  
Mitochondrial Permeability

AbstractThe mitochondrial permeability transition pore (MPTP) has resisted molecular identification for decades. The original model of the MPTP had the adenine nucleotide translocator (ANT) as the inner membrane pore-forming component. Indeed, reconstitution experiments showed that recombinant or purified ANT generates MPTP-like pores in lipid bilayers. This model was challenged when mitochondria from Ant1/2 double null mouse liver still showed MPTP activity. Because mice contain and express 3 Ant genes, here we reinvestigated the genetic basis for the ANTs as comprising the MPTP. Liver mitochondria from Ant1, Ant2, and Ant4 deficient mice were highly refractory to Ca2+-induced MPT, and when also given cyclosporine A, MPT was completely inhibited. Moreover, liver mitochondria from mice with quadruple deletion of Ant1, Ant2, Ant4 and Ppif (cyclophilin D, target of CsA) lacked Ca2+-induced MPT. Finally, inner membrane patch clamping in mitochondria from Ant1, Ant2 and Ant4 triple null mouse embryonic fibroblasts (MEFs) showed a loss of MPT-like pores. Our findings suggest a new model of MPT consisting of two distinct molecular components, one of which is the ANTs and the other of which is unknown but requires CypD.One Sentence SummaryGenetic deletion of Ant1/2/4 and Ppif in mice fully inhibits the mitochondrial permeability transition pore

scholarly journals Purified F-ATP synthase forms a Ca2+-dependent high-conductance channel matching the mitochondrial permeability transition pore

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Andrea Urbani ◽  
Valentina Giorgio ◽  
Andrea Carrer ◽  
Cinzia Franchin ◽  
Giorgio Arrigoni ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Atp Synthase ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Permeability Transition Pore ◽  
Anion Channel ◽  
Permeability Transition ◽  
Channel Activity ◽  
Voltage Dependent Anion Channel

Abstract The molecular identity of the mitochondrial megachannel (MMC)/permeability transition pore (PTP), a key effector of cell death, remains controversial. By combining highly purified, fully active bovine F-ATP synthase with preformed liposomes we show that Ca2+ dissipates the H+ gradient generated by ATP hydrolysis. After incorporation of the same preparation into planar lipid bilayers Ca2+ elicits currents matching those of the MMC/PTP. Currents were fully reversible, were stabilized by benzodiazepine 423, a ligand of the OSCP subunit of F-ATP synthase that activates the MMC/PTP, and were inhibited by Mg2+ and adenine nucleotides, which also inhibit the PTP. Channel activity was insensitive to inhibitors of the adenine nucleotide translocase (ANT) and of the voltage-dependent anion channel (VDAC). Native gel-purified oligomers and dimers, but not monomers, gave rise to channel activity. These findings resolve the long-standing mystery of the MMC/PTP and demonstrate that Ca2+ can transform the energy-conserving F-ATP synthase into an energy-dissipating device.

Sign in / Sign up

Export Citation Format

Share Document