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Grandi M, Fabbian S, Solaini G, Baracca A, Bellanda M, Giorgio V. Peptides Targeting the IF1-ATP Synthase Complex Modulate the Permeability Transition Pore in Cancer HeLa Cells. Int J Mol Sci 2024; 25:4655. [PMID: 38731874 PMCID: PMC11083241 DOI: 10.3390/ijms25094655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/19/2024] [Accepted: 04/21/2024] [Indexed: 05/13/2024] Open
Abstract
The mitochondrial protein IF1 is upregulated in many tumors and acts as a pro-oncogenic protein through its interaction with the ATP synthase and the inhibition of apoptosis. We have recently characterized the molecular nature of the IF1-Oligomycin Sensitivity Conferring Protein (OSCP) subunit interaction; however, it remains to be determined whether this interaction could be targeted for novel anti-cancer therapeutic intervention. We generated mitochondria-targeting peptides to displace IF1 from the OSCP interaction. The use of one selective peptide led to displacement of the inhibitor IF1 from ATP synthase, as shown by immunoprecipitation. NMR spectroscopy analysis, aimed at clarifying whether these peptides were able to directly bind to the OSCP protein, identified a second peptide which showed affinity for the N-terminal region of this subunit overlapping the IF1 binding region. In situ treatment with the membrane-permeable derivatives of these peptides in HeLa cells, that are silenced for the IF1 inhibitor protein, showed significant inhibition in mitochondrial permeability transition and no effects on mitochondrial respiration. These peptides mimic the effects of the IF1 inhibitor protein in cancer HeLa cells and confirm that the IF1-OSCP interaction inhibits apoptosis. A third peptide was identified which counteracts the anti-apoptotic role of IF1, showing that OSCP is a promising target for anti-cancer therapies.
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Affiliation(s)
- Martina Grandi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
| | - Simone Fabbian
- Department of Chemical Science, University of Padova, 35121 Padova, Italy
| | - Giancarlo Solaini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
| | - Alessandra Baracca
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
| | - Massimo Bellanda
- Department of Chemical Science, University of Padova, 35121 Padova, Italy
- Institute of Biomolecular Chemistry of National Research Council of Italy (CNR), 35131 Padova, Italy
| | - Valentina Giorgio
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
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2
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Bernardi P, Gerle C, Halestrap AP, Jonas EA, Karch J, Mnatsakanyan N, Pavlov E, Sheu SS, Soukas AA. Identity, structure, and function of the mitochondrial permeability transition pore: controversies, consensus, recent advances, and future directions. Cell Death Differ 2023; 30:1869-1885. [PMID: 37460667 PMCID: PMC10406888 DOI: 10.1038/s41418-023-01187-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 06/15/2023] [Accepted: 06/23/2023] [Indexed: 07/22/2023] Open
Abstract
The mitochondrial permeability transition (mPT) describes a Ca2+-dependent and cyclophilin D (CypD)-facilitated increase of inner mitochondrial membrane permeability that allows diffusion of molecules up to 1.5 kDa in size. It is mediated by a non-selective channel, the mitochondrial permeability transition pore (mPTP). Sustained mPTP opening causes mitochondrial swelling, which ruptures the outer mitochondrial membrane leading to subsequent apoptotic and necrotic cell death, and is implicated in a range of pathologies. However, transient mPTP opening at various sub-conductance states may contribute several physiological roles such as alterations in mitochondrial bioenergetics and rapid Ca2+ efflux. Since its discovery decades ago, intensive efforts have been made to identify the exact pore-forming structure of the mPT. Both the adenine nucleotide translocase (ANT) and, more recently, the mitochondrial F1FO (F)-ATP synthase dimers, monomers or c-subunit ring alone have been implicated. Here we share the insights of several key investigators with different perspectives who have pioneered mPT research. We critically assess proposed models for the molecular identity of the mPTP and the mechanisms underlying its opposing roles in the life and death of cells. We provide in-depth insights into current controversies, seeking to achieve a degree of consensus that will stimulate future innovative research into the nature and role of the mPTP.
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Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Christoph Gerle
- Laboratory of Protein Crystallography, Institute for Protein Research, Osaka University, Suita, Japan
| | - Andrew P Halestrap
- School of Biochemistry and Bristol Heart Institute, University of Bristol, Bristol, UK
| | - Elizabeth A Jonas
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Jason Karch
- Department of Integrative Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Nelli Mnatsakanyan
- Department of Cellular and Molecular Physiology, College of Medicine, Penn State University, State College, PA, USA
| | - Evgeny Pavlov
- Department of Molecular Pathobiology, New York University, New York, NY, USA
| | - Shey-Shing Sheu
- Department of Medicine, Center for Translational Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
| | - Alexander A Soukas
- Department of Medicine, Diabetes Unit and Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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3
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Neginskaya MA, Pavlov EV. Investigation of Properties of the Mitochondrial Permeability Transition Pore Using Whole-Mitoplast Patch-Clamp Technique. DNA Cell Biol 2023; 42:481-487. [PMID: 37311169 PMCID: PMC10460960 DOI: 10.1089/dna.2023.0171] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 06/15/2023] Open
Abstract
The mitochondrial permeability transition pore (mPTP) is a channel in the mitochondrial inner membrane that is activated by excessive calcium uptake. In this study, we used a whole-mitoplast patch-clamp approach to investigate the ionic currents associated with mPTP at the level of the whole single mitochondrion. The whole-mitoplast conductance was at the level of 5 to 7 nS, which is consistent with the presence of three to six single mPTP channels per mitochondrion. We found that mPTP currents are voltage dependent and inactivate at negative potential. The currents were inhibited by cyclosporine A and adenosine diphosphate. When mPTP was induced by oxidative stress, currents were partially blocked by the adenine nucleotide translocase inhibitor bongkrekic acid. Our data suggest that the whole-mitoplast patch-clamp approach is a useful method for investigating the biophysical properties and regulation of the mPTP.
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Affiliation(s)
- Maria A. Neginskaya
- Department of Molecular Pathobiology, New York University, New York, New York, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Evgeny V. Pavlov
- Department of Molecular Pathobiology, New York University, New York, New York, USA
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4
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Szabo I, Szewczyk A. Mitochondrial Ion Channels. Annu Rev Biophys 2023; 52:229-254. [PMID: 37159294 DOI: 10.1146/annurev-biophys-092622-094853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Mitochondria are involved in multiple cellular tasks, such as ATP synthesis, metabolism, metabolite and ion transport, regulation of apoptosis, inflammation, signaling, and inheritance of mitochondrial DNA. The majority of the correct functioning of mitochondria is based on the large electrochemical proton gradient, whose component, the inner mitochondrial membrane potential, is strictly controlled by ion transport through mitochondrial membranes. Consequently, mitochondrial function is critically dependent on ion homeostasis, the disturbance of which leads to abnormal cell functions. Therefore, the discovery of mitochondrial ion channels influencing ion permeability through the membrane has defined a new dimension of the function of ion channels in different cell types, mainly linked to the important tasks that mitochondrial ion channels perform in cell life and death. This review summarizes studies on animal mitochondrial ion channels with special focus on their biophysical properties, molecular identity, and regulation. Additionally, the potential of mitochondrial ion channels as therapeutic targets for several diseases is briefly discussed.
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Affiliation(s)
- Ildiko Szabo
- Department of Biology, University of Padova, Italy;
| | - Adam Szewczyk
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland;
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5
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Galber C, Fabbian S, Gatto C, Grandi M, Carissimi S, Acosta MJ, Sgarbi G, Tiso N, Argenton F, Solaini G, Baracca A, Bellanda M, Giorgio V. The mitochondrial inhibitor IF1 binds to the ATP synthase OSCP subunit and protects cancer cells from apoptosis. Cell Death Dis 2023; 14:54. [PMID: 36690622 PMCID: PMC9870916 DOI: 10.1038/s41419-023-05572-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 12/29/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023]
Abstract
The mitochondrial protein IF1 binds to the catalytic domain of the ATP synthase and inhibits ATP hydrolysis in ischemic tissues. Moreover, IF1 is overexpressed in many tumors and has been shown to act as a pro-oncogenic protein, although its mechanism of action is still debated. Here, we show that ATP5IF1 gene disruption in HeLa cells decreases colony formation in soft agar and tumor mass development in xenografts, underlining the role of IF1 in cancer. Notably, the lack of IF1 does not affect proliferation or oligomycin-sensitive mitochondrial respiration, but it sensitizes the cells to the opening of the permeability transition pore (PTP). Immunoprecipitation and proximity ligation analysis show that IF1 binds to the ATP synthase OSCP subunit in HeLa cells under oxidative phosphorylation conditions. The IF1-OSCP interaction is confirmed by NMR spectroscopy analysis of the recombinant soluble proteins. Overall, our results suggest that the IF1-OSCP interaction protects cancer cells from PTP-dependent apoptosis under normoxic conditions.
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Affiliation(s)
- Chiara Galber
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, I-40126, Italy
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, I-35121, Italy
| | - Simone Fabbian
- Department of Chemical Science, University of Padova, Padova, I-35121, Italy
| | - Cristina Gatto
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, I-40126, Italy
| | - Martina Grandi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, I-40126, Italy
| | - Stefania Carissimi
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, I-35121, Italy
| | - Manuel Jesus Acosta
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, I-35121, Italy
| | - Gianluca Sgarbi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, I-40126, Italy
| | - Natascia Tiso
- Department of Biology, University of Padova, Padova, I-35131, Italy
| | | | - Giancarlo Solaini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, I-40126, Italy
| | - Alessandra Baracca
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, I-40126, Italy
| | - Massimo Bellanda
- Department of Chemical Science, University of Padova, Padova, I-35121, Italy
- Consiglio Nazionale delle Ricerche Institute of Biomolecular Chemistry, Padova, I-35131, Italy
| | - Valentina Giorgio
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, I-40126, Italy.
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, I-35121, Italy.
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6
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Yoon Y, Lee H, Federico M, Sheu SS. Non-conventional mitochondrial permeability transition: Its regulation by mitochondrial dynamics. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148914. [PMID: 36063902 PMCID: PMC9729414 DOI: 10.1016/j.bbabio.2022.148914] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/21/2022] [Accepted: 08/29/2022] [Indexed: 11/21/2022]
Abstract
Mitochondrial permeability transition (MPT) is a phenomenon that the inner mitochondrial membrane (IMM) loses its selective permeability, leading to mitochondrial dysfunction and cell injury. Electrophysiological evidence indicates the presence of a mega-channel commonly called permeability transition pore (PTP) whose opening is responsible for MPT. However, the molecular identity of the PTP is still under intensive investigations and debates, although cyclophilin D that is inhibited by cyclosporine A (CsA) is the established regulatory component of the PTP. PTP can also open transiently and functions as a rapid mitochondrial Ca2+ releasing mechanism. Mitochondrial fission and fusion, the main components of mitochondrial dynamics, control the number and size of mitochondria, and have been shown to play a role in regulating MPT directly or indirectly. Studies by us and others have indicated the potential existence of a form of transient MPT that is insensitive to CsA. This "non-conventional" MPT is regulated by mitochondrial dynamics and may serve a protective role possibly by decreasing the susceptibility for a frequent or sustained PTP opening; hence, it may have a therapeutic value in many disease conditions involving MPT.
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Affiliation(s)
- Yisang Yoon
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta 30912, GA, USA.
| | - Hakjoo Lee
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta 30912, GA, USA
| | - Marilen Federico
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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7
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Dumbali SP, Wenzel PL. Mitochondrial Permeability Transition in Stem Cells, Development, and Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1409:1-22. [PMID: 35739412 DOI: 10.1007/5584_2022_720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The mitochondrial permeability transition (mPT) is a process that permits rapid exchange of small molecules across the inner mitochondrial membrane (IMM) and thus plays a vital role in mitochondrial function and cellular signaling. Formation of the pore that mediates this flux is well-documented in injury and disease but its regulation has also emerged as critical to the fate of stem cells during embryonic development. The precise molecular composition of the mPTP has been enigmatic, with far more genetic studies eliminating molecular candidates than confirming them. Rigorous studies in the recent decade have implicated central involvement of the F1Fo ATP synthase, or complex V of the electron transport chain, and continue to confirm a regulatory role for Cyclophilin D (CypD), encoded by Ppif, in modulating the sensitivity of the pore to opening. A host of endogenous molecules have been shown to trigger flux characteristic of mPT, including positive regulators such as calcium ions, reactive oxygen species, inorganic phosphate, and fatty acids. Conductance of the pore has been described as low or high, and reversibility of pore opening appears to correspond with the relative abundance of negative regulators of mPT such as adenine nucleotides, hydrogen ion, and divalent cations that compete for calcium-binding sites in the mPTP. Current models suggest that distinct pores could be responsible for differing reversibility and conductance depending upon cellular context. Indeed, irreversible propagation of mPT inevitably leads to collapse of transmembrane potential, arrest of ATP synthesis, mitochondrial swelling, and cell death. Future studies should clarify ambiguities in mPTP structure and reveal new roles for mPT in dictating specialized cellular functions beyond cell survival that are tied to mitochondrial fitness including stem cell self-renewal and fate. The focus of this review is to describe contemporary models of the mPTP and highlight how pore activity impacts stem cells and development.
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Affiliation(s)
- Sandeep P Dumbali
- Department of Integrative Biology & Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Pamela L Wenzel
- Department of Integrative Biology & Pharmacology, The University of Texas Health Science Center at Houston, Houston, TX, USA.
- Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA.
- Immunology Program, The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA.
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8
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Bernardi P, Carraro M, Lippe G. The mitochondrial permeability transition: Recent progress and open questions. FEBS J 2022; 289:7051-7074. [PMID: 34710270 PMCID: PMC9787756 DOI: 10.1111/febs.16254] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 10/27/2021] [Indexed: 01/13/2023]
Abstract
Major progress has been made in defining the basis of the mitochondrial permeability transition, a Ca2+ -dependent permeability increase of the inner membrane that has puzzled mitochondrial research for almost 70 years. Initially considered an artefact of limited biological interest by most, over the years the permeability transition has raised to the status of regulator of mitochondrial ion homeostasis and of druggable effector mechanism of cell death. The permeability transition is mediated by opening of channel(s) modulated by matrix cyclophilin D, the permeability transition pore(s) (PTP). The field has received new impulse (a) from the hypothesis that the PTP may originate from a Ca2+ -dependent conformational change of F-ATP synthase and (b) from the reevaluation of the long-standing hypothesis that it originates from the adenine nucleotide translocator (ANT). Here, we provide a synthetic account of the structure of ANT and F-ATP synthase to discuss potential and controversial mechanisms through which they may form high-conductance channels; and review some intriguing findings from the wealth of early studies of PTP modulation that still await an explanation. We hope that this review will stimulate new experiments addressing the many outstanding problems, and thus contribute to the eventual solution of the puzzle of the permeability transition.
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Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences and CNR Neuroscience InstituteUniversity of PadovaItaly
| | - Michela Carraro
- Department of Biomedical Sciences and CNR Neuroscience InstituteUniversity of PadovaItaly
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9
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Hakiminia B, Alikiaii B, Khorvash F, Mousavi S. Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities. Fundam Clin Pharmacol 2022; 36:612-662. [PMID: 35118714 DOI: 10.1111/fcp.12767] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/15/2022] [Accepted: 02/02/2022] [Indexed: 02/07/2023]
Abstract
Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.
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Affiliation(s)
- Bahareh Hakiminia
- Department of Clinical Pharmacy and Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Babak Alikiaii
- Department of Anesthesiology and Intensive Care, Alzahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fariborz Khorvash
- Department of Neurology, Alzahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sarah Mousavi
- Department of Clinical Pharmacy and Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
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10
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Melatonin-Induced Postconditioning Suppresses NMDA Receptor through Opening of the Mitochondrial Permeability Transition Pore via Melatonin Receptor in Mouse Neurons. Int J Mol Sci 2022; 23:ijms23073822. [PMID: 35409182 PMCID: PMC8998233 DOI: 10.3390/ijms23073822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 03/02/2022] [Accepted: 03/28/2022] [Indexed: 12/29/2022] Open
Abstract
Mitochondrial membrane potential regulation through the mitochondrial permeability transition pore (mPTP) is reportedly involved in the ischemic postconditioning (PostC) phenomenon. Melatonin is an endogenous hormone that regulates circadian rhythms. Its neuroprotective effects via mitochondrial melatonin receptors (MTs) have recently attracted attention. However, details of the neuroprotective mechanisms associated with PostC have not been clarified. Using hippocampal CA1 pyramidal cells from C57BL mice, we studied the involvement of MTs and the mPTP in melatonin-induced PostC mechanisms similar to those of ischemic PostC. We measured changes in spontaneous excitatory postsynaptic currents (sEPSCs), intracellular calcium concentration, mitochondrial membrane potential, and N-methyl-D-aspartate receptor (NMDAR) currents after ischemic challenge, using the whole-cell patch-clamp technique. Melatonin significantly suppressed increases in sEPSCs and intracellular calcium concentrations. The NMDAR currents were significantly suppressed by melatonin and the MT agonist, ramelteon. However, this suppressive effect was abolished by the mPTP inhibitor, cyclosporine A, and the MT antagonist, luzindole. Furthermore, both melatonin and ramelteon potentiated depolarization of mitochondrial membrane potentials, and luzindole suppressed depolarization of mitochondrial membrane potentials. This study suggests that melatonin-induced PostC via MTs suppressed the NMDAR that was induced by partial depolarization of mitochondrial membrane potential by opening the mPTP, reducing excessive release of glutamate and inducing neuroprotection against ischemia-reperfusion injury.
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11
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Vlasov AV, Osipov SD, Bondarev NA, Uversky VN, Borshchevskiy VI, Yanyushin MF, Manukhov IV, Rogachev AV, Vlasova AD, Ilyinsky NS, Kuklin AI, Dencher NA, Gordeliy VI. ATP synthase F OF 1 structure, function, and structure-based drug design. Cell Mol Life Sci 2022; 79:179. [PMID: 35253091 PMCID: PMC11072866 DOI: 10.1007/s00018-022-04153-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/26/2021] [Accepted: 01/14/2022] [Indexed: 11/30/2022]
Abstract
ATP synthases are unique rotatory molecular machines that supply biochemical reactions with adenosine triphosphate (ATP)-the universal "currency", which cells use for synthesis of vital molecules and sustaining life. ATP synthases of F-type (FOF1) are found embedded in bacterial cellular membrane, in thylakoid membranes of chloroplasts, and in mitochondrial inner membranes in eukaryotes. The main functions of ATP synthases are control of the ATP synthesis and transmembrane potential. Although the key subunits of the enzyme remain highly conserved, subunit composition and structural organization of ATP synthases and their assemblies are significantly different. In addition, there are hypotheses that the enzyme might be involved in the formation of the mitochondrial permeability transition pore and play a role in regulation of the cell death processes. Dysfunctions of this enzyme lead to numerous severe disorders with high fatality levels. In our review, we focus on FOF1-structure-based approach towards development of new therapies by using FOF1 structural features inherited by the representatives of this enzyme family from different taxonomy groups. We analyzed and systematized the most relevant information about the structural organization of FOF1 to discuss how this approach might help in the development of new therapies targeting ATP synthases and design tools for cellular bioenergetics control.
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Affiliation(s)
- Alexey V Vlasov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Joint Institute for Nuclear Research, 141980, Dubna, Russia
| | - Stepan D Osipov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
| | - Nikolay A Bondarev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
| | - Vladimir N Uversky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Valentin I Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52425, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Mikhail F Yanyushin
- Institute of Basic Biological Problems, Russian Academy of Sciences, 142290, Pushchino, Moscow region, Russia
| | - Ilya V Manukhov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
| | - Andrey V Rogachev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Joint Institute for Nuclear Research, 141980, Dubna, Russia
| | - Anastasiia D Vlasova
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
| | - Nikolay S Ilyinsky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
| | - Alexandr I Kuklin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Joint Institute for Nuclear Research, 141980, Dubna, Russia
| | - Norbert A Dencher
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia
- Physical Biochemistry, Department Chemistry, Technische Universität Darmstadt, Alarich-Weiss-Straße 4, 64287, Darmstadt, Germany
| | - Valentin I Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Russia.
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52425, Jülich, Germany.
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428, Jülich, Germany.
- Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, 38027, Grenoble, France.
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12
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Boyenle ID, Oyedele AK, Ogunlana AT, Adeyemo AF, Oyelere FS, Akinola OB, Adelusi TI, Ehigie LO, Ehigie AF. Targeting the mitochondrial permeability transition pore for drug discovery: Challenges and opportunities. Mitochondrion 2022; 63:57-71. [PMID: 35077882 DOI: 10.1016/j.mito.2022.01.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/22/2021] [Accepted: 01/17/2022] [Indexed: 12/29/2022]
Abstract
Several drug targets have been amenable to drug discovery pursuit not until the characterization of the mitochondrial permeability transition pore (MPTP), a pore with an undefined molecular identity that forms on the inner mitochondrial membrane upon mitochondrial permeability transition (MPT) under the influence of calcium overload and oxidative stress. The opening of the pore which is presumed to cause cell death in certain human diseases also has implications under physiological parlance. Different models for this pore have been postulated following its first identification in the last six decades. The mitochondrial community has witnessed many protein candidates such as; voltage-dependent anion channel (VDAC), adenine nucleotide translocase (ANT), Mitochondrial phosphate carrier (PiC), Spastic Paralegin (SPG7), disordered proteins, and F1Fo ATPase. However, genetic studies have cast out most of these candidates with only F1Fo ATPase currently under intense argument. Cyclophilin D (CyPD) remains the widely accepted positive regulator of the MPTP known to date, but no drug candidate has emerged as its inhibitor, raising concern issues for therapeutics. Thus, in this review, we discuss various models of MPTP reported with the hope of stimulating further research in this field. We went beyond the classical description of the MPTP to ascribe a 'two-edged sword property' to the pore for therapeutic function in human disease because its inhibition and activation have pharmacological relevance. We suggested putative proteins upstream to CyPD that can regulate its activity and prevent cell deaths in neurodegenerative disease and ischemia-reperfusion injury.
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Affiliation(s)
- Ibrahim Damilare Boyenle
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria; Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Abdulquddus Kehinde Oyedele
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Abdeen Tunde Ogunlana
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Aishat Folashade Adeyemo
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | | | - Olateju Balikis Akinola
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Temitope Isaac Adelusi
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Leonard Ona Ehigie
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Adeola Folasade Ehigie
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
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13
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Methods of Measuring Mitochondrial Potassium Channels: A Critical Assessment. Int J Mol Sci 2022; 23:ijms23031210. [PMID: 35163132 PMCID: PMC8835872 DOI: 10.3390/ijms23031210] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 12/22/2022] Open
Abstract
In this paper, the techniques used to study the function of mitochondrial potassium channels are critically reviewed. The majority of these techniques have been known for many years as a result of research on plasma membrane ion channels. Hence, in this review, we focus on the critical evaluation of techniques used in the studies of mitochondrial potassium channels, describing their advantages and limitations. Functional analysis of mitochondrial potassium channels in comparison to that of plasmalemmal channels presents additional experimental challenges. The reliability of functional studies of mitochondrial potassium channels is often affected by the need to isolate mitochondria and by functional properties of mitochondria such as respiration, metabolic activity, swelling capacity, or high electrical potential. Three types of techniques are critically evaluated: electrophysiological techniques, potassium flux measurements, and biochemical techniques related to potassium flux measurements. Finally, new possible approaches to the study of the function of mitochondrial potassium channels are presented. We hope that this review will assist researchers in selecting reliable methods for studying, e.g., the effects of drugs on mitochondrial potassium channel function. Additionally, this review should aid in the critical evaluation of the results reported in various articles on mitochondrial potassium channels.
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14
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Martens MD, Karch J, Gordon JW. The molecular mosaic of regulated cell death in the cardiovascular system. Biochim Biophys Acta Mol Basis Dis 2021; 1868:166297. [PMID: 34718119 DOI: 10.1016/j.bbadis.2021.166297] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 10/07/2021] [Accepted: 10/22/2021] [Indexed: 12/11/2022]
Abstract
Cell death is now understood to be a highly regulated process that contributes to normal development and tissue homeostasis, alongside its role in the etiology of various pathological conditions. Through detailed molecular analysis, we have come to know that all cells do not always die in the same way, and that there are at least 7 processes involved, including: apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, and autophagy-mediated cell death. These processes act as pieces in the mosaic of cardiomyocyte cell death, which come together depending on context and stimulus. This review details each individual process, as well as highlights how they come together to produce various cardiac pathologies. By knowing how the pieces go together we can aim towards the development of efficacious therapeutics, which will enable us to prevent cardiomyocyte loss in the face of stress, both reducing mortality and improving quality of life.
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Affiliation(s)
- Matthew D Martens
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Science, University of Manitoba, Winnipeg, Manitoba, Canada; The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, Canada
| | - Jason Karch
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
| | - Joseph W Gordon
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Science, University of Manitoba, Winnipeg, Manitoba, Canada; College of Nursing, Rady Faculty of Health Science, University of Manitoba, Winnipeg, Manitoba, Canada; The Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme of the Children's Hospital Research Institute of Manitoba, Canada.
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15
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Carrer A, Laquatra C, Tommasin L, Carraro M. Modulation and Pharmacology of the Mitochondrial Permeability Transition: A Journey from F-ATP Synthase to ANT. Molecules 2021; 26:molecules26216463. [PMID: 34770872 PMCID: PMC8587538 DOI: 10.3390/molecules26216463] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/21/2021] [Accepted: 10/23/2021] [Indexed: 12/22/2022] Open
Abstract
The permeability transition (PT) is an increased permeation of the inner mitochondrial membrane due to the opening of the PT pore (PTP), a Ca2+-activated high conductance channel involved in Ca2+ homeostasis and cell death. Alterations of the PTP have been associated with many pathological conditions and its targeting represents an incessant challenge in the field. Although the modulation of the PTP has been extensively explored, the lack of a clear picture of its molecular nature increases the degree of complexity for any target-based approach. Recent advances suggest the existence of at least two mitochondrial permeability pathways mediated by the F-ATP synthase and the ANT, although the exact molecular mechanism leading to channel formation remains elusive for both. A full comprehension of this to-pore conversion will help to assist in drug design and to develop pharmacological treatments for a fine-tuned PT regulation. Here, we will focus on regulatory mechanisms that impinge on the PTP and discuss the relevant literature of PTP targeting compounds with particular attention to F-ATP synthase and ANT.
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16
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Carrer A, Tommasin L, Šileikytė J, Ciscato F, Filadi R, Urbani A, Forte M, Rasola A, Szabò I, Carraro M, Bernardi P. Defining the molecular mechanisms of the mitochondrial permeability transition through genetic manipulation of F-ATP synthase. Nat Commun 2021; 12:4835. [PMID: 34376679 PMCID: PMC8355262 DOI: 10.1038/s41467-021-25161-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/26/2021] [Indexed: 12/13/2022] Open
Abstract
F-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.
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Affiliation(s)
- Andrea Carrer
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ludovica Tommasin
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Justina Šileikytė
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Francesco Ciscato
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Riccardo Filadi
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Consiglio Nazionale delle Ricerche Neuroscience Institute, Padova, Italy
| | - Andrea Urbani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Michael Forte
- Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Andrea Rasola
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ildikò Szabò
- Consiglio Nazionale delle Ricerche Neuroscience Institute, Padova, Italy.,Department of Biology, University of Padova, Padova, Italy
| | - Michela Carraro
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
| | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy. .,Consiglio Nazionale delle Ricerche Neuroscience Institute, Padova, Italy.
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Rigotto G, Zentilin L, Pozzan T, Basso E. Effects of Mild Excitotoxic Stimulus on Mitochondria Ca 2+ Handling in Hippocampal Cultures of a Mouse Model of Alzheimer's Disease. Cells 2021; 10:cells10082046. [PMID: 34440815 PMCID: PMC8394681 DOI: 10.3390/cells10082046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/02/2021] [Accepted: 08/06/2021] [Indexed: 01/19/2023] Open
Abstract
In Alzheimer’s disease (AD), the molecular mechanisms involved in the neurodegeneration are still incompletely defined, though this aspect is crucial for a better understanding of the malady and for devising effective therapies. Mitochondrial dysfunctions and altered Ca2+ signaling have long been implicated in AD, though it is debated whether these events occur early in the course of the pathology, or whether they develop at late stages of the disease and represent consequences of different alterations. Mitochondria are central to many aspects of cellular metabolism providing energy, lipids, reactive oxygen species, signaling molecules for cellular quality control, and actively shaping intracellular Ca2+ signaling, modulating the intensity and duration of the signal itself. Abnormalities in the ability of mitochondria to take up and subsequently release Ca2+ could lead to changes in the metabolism of the organelle, and of the cell as a whole, that eventually result in cell death. We sought to investigate the role of mitochondria and Ca2+ signaling in a model of Familial Alzheimer’s disease and found early alterations in mitochondria physiology under stressful condition, namely, reduced maximal respiration, decreased ability to sustain membrane potential, and a slower return to basal matrix Ca2+ levels after a mild excitotoxic stimulus. Treatment with an inhibitor of the permeability transition pore attenuated some of these mitochondrial disfunctions and may represent a promising tool to ameliorate mitochondria and cellular functioning in AD and prevent or slow down cell loss in the disease.
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Affiliation(s)
- Giulia Rigotto
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (G.R.); (T.P.)
| | - Lorena Zentilin
- International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy;
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (G.R.); (T.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
- Venetian Institute of Molecular Medicine (VIMM), 35131 Padua, Italy
| | - Emy Basso
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (G.R.); (T.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
- Correspondence:
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18
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NAD(H) Regulates the Permeability Transition Pore in Mitochondria through an External Site. Int J Mol Sci 2021; 22:ijms22168560. [PMID: 34445270 PMCID: PMC8395297 DOI: 10.3390/ijms22168560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/28/2021] [Accepted: 08/05/2021] [Indexed: 11/17/2022] Open
Abstract
The opening of the permeability transition pore (mPTP) in mitochondria initiates cell death in numerous diseases. The regulation of mPTP by NAD(H) in the mitochondrial matrix is well established; however, the role of extramitochondrial (cytosolic) NAD(H) is still unclear. We studied the effect of added NADH and NAD+ on: (1) the Ca2+-retention capacity (CRC) of isolated rat liver, heart, and brain mitochondria; (2) the Ca2+-dependent mitochondrial swelling in media whose particles can (KCl) or cannot (sucrose) be extruded from the matrix by mitochondrial carriers; (3) the Ca2+-dependent mitochondrial depolarization and the release of entrapped calcein from mitochondria of permeabilized hepatocytes; and (4) the Ca2+-dependent mitochondrial depolarization and subsequent repolarization. NADH and NAD+ increased the CRC of liver, heart, and brain mitochondria 1.5-2.5 times, insignificantly affecting the rate of Ca2+-uptake and the free Ca2+ concentration in the medium. NAD(H) suppressed the Ca2+-dependent mitochondrial swelling both in KCl- and sucrose-based media but did not induce the contraction and repolarization of swollen mitochondria. By contrast, EGTA caused mitochondrial repolarization in both media and the contraction in KCl-based medium only. NAD(H) delayed the Ca2+-dependent depolarization and the release of calcein from individual mitochondria in hepatocytes. These data unambiguously demonstrate the existence of an external NAD(H)-dependent site of mPTP regulation.
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19
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Kruglov AG, Kharechkina ES, Nikiforova AB, Odinokova IV, Kruglova SA. Dynamics of the permeability transition pore size in isolated mitochondria and mitoplasts. FASEB J 2021; 35:e21764. [PMID: 34245631 DOI: 10.1096/fj.202100596r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/28/2021] [Accepted: 06/14/2021] [Indexed: 11/11/2022]
Abstract
The size of the permeability transition pore (PTP) is accepted to be ≤1.5 kDa. However, different authors reported values from 650 to 4000 Da. The present study is focused on the variability of the average PTP size in and between mitochondrial samples, its reasons and relations with PTP dynamics. Measurement of PTP size by the standard method revealed its 500 Da-range variability between mitochondrial samples. Sequential measurements in the same sample showed that the PTP size tends to grow with time and Ca2+ concentration. Selective damage to the mitochondrial outer membrane (MOM) reduced the apparent PTP size by ~200-300 Da. Hypotonic and hypertonic osmotic shock and partial removal of the MOM with the preservation of the mitochondrial inner membrane intactness decreased the apparent PTP size by ~50%. We developed an approach to continuous monitoring of the PTP size that revealed the existence of stable PTP states with different pore sizes (~700, 900-1000, ~1350, 1700-1800, and 2100-2200 Da) and transitions between them. The transitions were accelerated by elevating the Ca2+ concentration, temperature, and osmotic pressure, which demonstrates an increased capability of PTP to accommodate to large molecules (plasticity). Cyclosporin A inhibited the transitions between states. The analysis of PTP size dynamics in osmotically shocked mitochondria and mitoplasts confirmed the importance of the MOM for the stabilization of PTP structure. Thus, this approach provides a new tool for PTP studies and the opportunity to reconcile data on the PTP size and mitochondrial megachannel conductance.
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Affiliation(s)
- Alexey G Kruglov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Ekaterina S Kharechkina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Anna B Nikiforova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Irina V Odinokova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Svetlana A Kruglova
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Russia
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20
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Morciano G, Naumova N, Koprowski P, Valente S, Sardão VA, Potes Y, Rimessi A, Wieckowski MR, Oliveira PJ. The mitochondrial permeability transition pore: an evolving concept critical for cell life and death. Biol Rev Camb Philos Soc 2021; 96:2489-2521. [PMID: 34155777 DOI: 10.1111/brv.12764] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023]
Abstract
In this review, we summarize current knowledge of perhaps one of the most intriguing phenomena in cell biology: the mitochondrial permeability transition pore (mPTP). This phenomenon, which was initially observed as a sudden loss of inner mitochondrial membrane impermeability caused by excessive calcium, has been studied for almost 50 years, and still no definitive answer has been provided regarding its mechanisms. From its initial consideration as an in vitro artifact to the current notion that the mPTP is a phenomenon with physiological and pathological implications, a long road has been travelled. We here summarize the role of mitochondria in cytosolic calcium control and the evolving concepts regarding the mitochondrial permeability transition (mPT) and the mPTP. We show how the evolving mPTP models and mechanisms, which involve many proposed mitochondrial protein components, have arisen from methodological advances and more complex biological models. We describe how scientific progress and methodological advances have allowed milestone discoveries on mPTP regulation and composition and its recognition as a valid target for drug development and a critical component of mitochondrial biology.
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Affiliation(s)
- Giampaolo Morciano
- Maria Cecilia Hospital, GVM Care & Research, Via Corriera 1, Cotignola, Ravenna, 48033, Italy.,Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara, 44121, Italy
| | - Natalia Naumova
- Department of Cardiac Thoracic and Vascular Sciences and Public Health, University of Padua Medical School, Via Giustiniani 2, Padova, 35128, Italy
| | - Piotr Koprowski
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Sara Valente
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
| | - Vilma A Sardão
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
| | - Yaiza Potes
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Alessandro Rimessi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara, 44121, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Paulo J Oliveira
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
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21
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Galber C, Minervini G, Cannino G, Boldrin F, Petronilli V, Tosatto S, Lippe G, Giorgio V. The f subunit of human ATP synthase is essential for normal mitochondrial morphology and permeability transition. Cell Rep 2021; 35:109111. [PMID: 33979610 DOI: 10.1016/j.celrep.2021.109111] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/11/2021] [Accepted: 04/20/2021] [Indexed: 01/03/2023] Open
Abstract
The f subunit is localized at the base of the ATP synthase peripheral stalk. Its function in the human enzyme is poorly characterized. Because full disruption of its ATP5J2 gene with the CRISPR-Cas9 strategy in the HAP1 human model has been shown to cause alterations in the amounts of other ATP synthase subunits, here we investigated the role of the f subunit in HeLa cells by regulating its levels through RNA interference. We confirm the role of the f subunit in ATP synthase dimer stability and observe that its downregulation per se does not alter the amounts of the other enzyme subunits or ATP synthase synthetic/hydrolytic activity. We show that downregulation of the f subunit causes abnormal crista organization and decreases permeability transition pore (PTP) size, whereas its re-expression in f subunit knockdown cells rescues mitochondrial morphology and PTP-dependent swelling.
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Affiliation(s)
- Chiara Galber
- Department of Biomedical Sciences, University of Padova, Padova 35121, Italy; Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova 35121, Italy
| | - Giovanni Minervini
- Department of Biomedical Sciences, University of Padova, Padova 35121, Italy
| | - Giuseppe Cannino
- Department of Biomedical Sciences, University of Padova, Padova 35121, Italy
| | | | - Valeria Petronilli
- Department of Biomedical Sciences, University of Padova, Padova 35121, Italy; Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova 35121, Italy
| | - Silvio Tosatto
- Department of Biomedical Sciences, University of Padova, Padova 35121, Italy
| | - Giovanna Lippe
- Department of Medicine, University of Udine, Udine 33100, Italy
| | - Valentina Giorgio
- Department of Biomedical Sciences, University of Padova, Padova 35121, Italy; Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova 35121, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40126, Italy.
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22
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Ho KL, Karwi QG, Wagg C, Zhang L, Vo K, Altamimi T, Uddin GM, Ussher JR, Lopaschuk GD. Ketones can become the major fuel source for the heart but do not increase cardiac efficiency. Cardiovasc Res 2021; 117:1178-1187. [PMID: 32402081 PMCID: PMC7982999 DOI: 10.1093/cvr/cvaa143] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 04/16/2020] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
AIMS Ketones have been proposed to be a 'thrifty' fuel for the heart and increasing cardiac ketone oxidation can be cardioprotective. However, it is unclear how much ketone oxidation can contribute to energy production in the heart, nor whether increasing ketone oxidation increases cardiac efficiency. Therefore, our goal was to determine to what extent high levels of the ketone body, β-hydroxybutyrate (βOHB), contributes to cardiac energy production, and whether this influences cardiac efficiency. METHODS AND RESULTS Isolated working mice hearts were aerobically perfused with palmitate (0.8 mM or 1.2 mM), glucose (5 mM) and increasing concentrations of βOHB (0, 0.6, 2.0 mM). Subsequently, oxidation of these substrates, cardiac function, and cardiac efficiency were assessed. Increasing βOHB concentrations increased myocardial ketone oxidation rates without affecting glucose or fatty acid oxidation rates where normal physiological levels of glucose (5 mM) and fatty acid (0.8 mM) are present. Notably, ketones became the major fuel source for the heart at 2.0 mM βOHB (at both low or high fatty acid concentrations), with the elevated ketone oxidation rates markedly increasing tricarboxylic acid (TCA) cycle activity, producing a large amount of reducing equivalents and finally, increasing myocardial oxygen consumption. However, the marked increase in ketone oxidation at high concentrations of βOHB was not accompanied by an increase in cardiac work, suggesting that a mismatch between excess reduced equivalents production from ketone oxidation and cardiac adenosine triphosphate production. Consequently, cardiac efficiency decreased when the heart was exposed to higher ketone levels. CONCLUSIONS We demonstrate that while ketones can become the major fuel source for the heart, they do not increase cardiac efficiency, which also underscores the importance of recognizing ketones as a major fuel source for the heart in times of starvation, consumption of a ketogenic diet or poorly controlled diabetes.
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Affiliation(s)
- Kim L Ho
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Qutuba G Karwi
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
- Department of Pharmacology, College of Medicine, University of Diyala, Diyala, Iraq
| | - Cory Wagg
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Liyan Zhang
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Katherina Vo
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Tariq Altamimi
- Diabetes and Obesity Center, University of Louisville, Louisville, KT, USA
| | - Golam M Uddin
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - John R Ussher
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Gary D Lopaschuk
- Cardiovascular Research Centre Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
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23
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Functional activity of permeability transition pore in energized and deenergized rat liver mitochondria. UKRAINIAN BIOCHEMICAL JOURNAL 2020. [DOI: 10.15407/ubj92.06.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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24
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Brustovetsky N. The Role of Adenine Nucleotide Translocase in the Mitochondrial Permeability Transition. Cells 2020; 9:E2686. [PMID: 33333766 PMCID: PMC7765165 DOI: 10.3390/cells9122686] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/10/2020] [Accepted: 12/12/2020] [Indexed: 12/30/2022] Open
Abstract
The mitochondrial permeability transition, a Ca2+-induced significant increase in permeability of the inner mitochondrial membrane, plays an important role in various pathologies. The mitochondrial permeability transition is caused by induction of the permeability transition pore (PTP). Despite significant effort, the molecular composition of the PTP is not completely clear and remains an area of hot debate. The Ca2+-modified adenine nucleotide translocase (ANT) and F0F1 ATP synthase are the major contenders for the role of pore in the PTP. This paper briefly overviews experimental results focusing on the role of ANT in the mitochondrial permeability transition and proposes that multiple molecular entities might be responsible for the conductance pathway of the PTP. Consequently, the term PTP cannot be applied to a single specific protein such as ANT or a protein complex such as F0F1 ATP synthase, but rather should comprise a variety of potential contributors to increased permeability of the inner mitochondrial membrane.
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Affiliation(s)
- Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Neginskaya MA, Strubbe JO, Amodeo GF, West BA, Yakar S, Bazil JN, Pavlov EV. The very low number of calcium-induced permeability transition pores in the single mitochondrion. J Gen Physiol 2020; 152:e202012631. [PMID: 32810269 PMCID: PMC7537349 DOI: 10.1085/jgp.202012631] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/22/2020] [Accepted: 07/24/2020] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial permeability transition (PT) is a phenomenon of stress-induced increase in nonspecific permeability of the mitochondrial inner membrane that leads to disruption of oxidative phosphorylation and cell death. Quantitative measurement of the membrane permeability increase during PT is critically important for understanding the PT's impact on mitochondrial function. The elementary unit of PT is a PT pore (PTP), a single channel presumably formed by either ATP synthase or adenine nucleotide translocator (ANT). It is not known how many channels are open in a single mitochondrion during PT, which makes it difficult to quantitatively estimate the overall degree of membrane permeability. Here, we used wide-field microscopy to record mitochondrial swelling and quantitatively measure rates of single-mitochondrion volume increase during PT-induced high-amplitude swelling. PT was quantified by calculating the rates of water flux responsible for measured volume changes. The total water flux through the mitochondrial membrane of a single mitochondrion during PT was in the range of (2.5 ± 0.4) × 10-17 kg/s for swelling in 2 mM Ca2+ and (1.1 ± 0.2) × 10-17 kg/s for swelling in 200 µM Ca2+. Under these experimental conditions, a single PTP channel with ionic conductance of 1.5 nS could allow passage of water at the rate of 0.65 × 10-17 kg/s. Thus, we estimate the integral ionic conductance of the whole mitochondrion during PT to be 5.9 ± 0.9 nS for 2 mM concentration of Ca2+ and 2.6 ± 0.4 nS for 200 µM of Ca2+. The number of PTPs per mitochondrion ranged from one to nine. Due to the uncertainties in PTP structure and model parameters, PTP count results may be slightly underestimated. However, taking into account that each mitochondrion has ∼15,000 copies of ATP synthases and ANTs, our data imply that PTP activation is a rare event that occurs only in a small subpopulation of these proteins.
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Affiliation(s)
- Maria A. Neginskaya
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
| | - Jasiel O. Strubbe
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Giuseppe F. Amodeo
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
| | - Benjamin A. West
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Shoshana Yakar
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
| | - Jason N. Bazil
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Evgeny V. Pavlov
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
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The mitochondrial permeability transition pore: Is it formed by the ATP synthase, adenine nucleotide translocators or both? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148249. [DOI: 10.1016/j.bbabio.2020.148249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/06/2020] [Accepted: 06/12/2020] [Indexed: 12/26/2022]
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27
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Mitochondrial F-ATP synthase as the permeability transition pore. Pharmacol Res 2020; 160:105081. [PMID: 32679179 DOI: 10.1016/j.phrs.2020.105081] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 12/27/2022]
Abstract
The current state of research on the mitochondrial permeability transition pore (PTP) can be described in terms of three major problems: molecular identity, atomic structure and gating mechanism. In this review these three problems are discussed in the light of recent findings with special emphasis on the discovery that the PTP is mitochondrial F-ATP synthase (mtFoF1). Novel features of the mitochondrial F-ATP synthase emerging from the success of single particle cryo electron microscopy (cryo-EM) to determine F-ATP synthase structures are surveyed along with their possible involvement in pore formation. Also, current findings from the gap junction field concerning the involvement of lipids in channel closure are examined. Finally, an earlier proposal denoted as the 'Death Finger' is discussed as a working model for PTP gating.
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Mnatsakanyan N, Jonas EA. The new role of F 1F o ATP synthase in mitochondria-mediated neurodegeneration and neuroprotection. Exp Neurol 2020; 332:113400. [PMID: 32653453 DOI: 10.1016/j.expneurol.2020.113400] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/23/2020] [Accepted: 07/07/2020] [Indexed: 02/08/2023]
Abstract
The mitochondrial F1Fo ATP synthase is one of the most abundant proteins of the mitochondrial inner membrane, which catalyzes the final step of oxidative phosphorylation to synthesize ATP from ADP and Pi. ATP synthase uses the electrochemical gradient of protons (ΔμH+) across the mitochondrial inner membrane to synthesize ATP. Under certain pathophysiological conditions, ATP synthase can run in reverse to hydrolyze ATP and build the necessary ΔμH+ across the mitochondrial inner membrane. Tight coupling between these two processes, proton translocation and ATP synthesis, is achieved by the unique rotational mechanism of ATP synthase and is necessary for efficient cellular metabolism and cell survival. The uncoupling of these processes, dissipation of mitochondrial inner membrane potential, elevated levels of ROS, low matrix content of ATP in combination with other cellular malfunction trigger the opening of the mitochondrial permeability transition pore in the mitochondrial inner membrane. In this review we will discuss the new role of ATP synthase beyond oxidative phosphorylation. We will highlight its function as a unique regulator of cell life and death and as a key target in mitochondria-mediated neurodegeneration and neuroprotection.
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Affiliation(s)
- Nelli Mnatsakanyan
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA.
| | - Elizabeth Ann Jonas
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA
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Carraro M, Carrer A, Urbani A, Bernardi P. Molecular nature and regulation of the mitochondrial permeability transition pore(s), drug target(s) in cardioprotection. J Mol Cell Cardiol 2020; 144:76-86. [DOI: 10.1016/j.yjmcc.2020.05.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/28/2020] [Accepted: 05/20/2020] [Indexed: 12/12/2022]
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30
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Mnatsakanyan N, Jonas EA. ATP synthase c-subunit ring as the channel of mitochondrial permeability transition: Regulator of metabolism in development and degeneration. J Mol Cell Cardiol 2020; 144:109-118. [PMID: 32461058 PMCID: PMC7877492 DOI: 10.1016/j.yjmcc.2020.05.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/07/2020] [Accepted: 05/20/2020] [Indexed: 12/29/2022]
Abstract
The mitochondrial permeability transition pore (mPTP) or mitochondrial megachannel is arguably one of the most mysterious phenomena in biology today. mPTP has been at the center of ongoing extensive scientific research for the last several decades. In this review we will discuss recent advances in the field that enhance our understanding of the molecular composition of mPTP, its regulatory mechanisms and its pathophysiological role. We will describe our recent findings on the role of ATP synthase c-subunit ring as a central player in mitochondrial permeability transition and as an important metabolic regulator during development and in degenerative diseases.
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Affiliation(s)
- Nelli Mnatsakanyan
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA.
| | - Elizabeth Ann Jonas
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA.
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31
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Abstract
Adult cardiomyocytes are postmitotic cells that undergo very limited cell division. Thus, cardiomyocyte death as occurs during myocardial infarction has very detrimental consequences for the heart. Mitochondria have emerged as an important regulator of cardiovascular health and disease. Mitochondria are well established as bioenergetic hubs for generating ATP but have also been shown to regulate cell death pathways. Indeed many of the same signals used to regulate metabolism and ATP production, such as calcium and reactive oxygen species, are also key regulators of mitochondrial cell death pathways. It is widely hypothesized that an increase in calcium and reactive oxygen species activate a large conductance channel in the inner mitochondrial membrane known as the PTP (permeability transition pore) and that opening of this pore leads to necroptosis, a regulated form of necrotic cell death. Strategies to reduce PTP opening either by inhibition of PTP or inhibiting the rise in mitochondrial calcium or reactive oxygen species that activate PTP have been proposed. A major limitation of inhibiting the PTP is the lack of knowledge about the identity of the protein(s) that form the PTP and how they are activated by calcium and reactive oxygen species. This review will critically evaluate the candidates for the pore-forming unit of the PTP and discuss recent data suggesting that assumption that the PTP is formed by a single molecular identity may need to be reconsidered.
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Affiliation(s)
- Tyler M Bauer
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
| | - Elizabeth Murphy
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
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OPA1 regulates respiratory supercomplexes assembly: The role of mitochondrial swelling. Mitochondrion 2019; 51:30-39. [PMID: 31870826 DOI: 10.1016/j.mito.2019.11.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/08/2019] [Accepted: 11/22/2019] [Indexed: 12/30/2022]
Abstract
Optic atrophy type 1 protein (OPA1), a dynamin-related GTPase, that, in addition to mitochondrial fusion, plays an important role in maintaining the structural organization and integrity of the inner mitochondrial membrane (IMM). OPA1 exists in two forms: IMM-bound long-OPA1 (L-OPA1) and soluble short-OPA1 (S-OPA1), a product of L-OPA1 proteolytic cleavage localized in the intermembrane space. In addition to OPA1, the structural and functional integrity of IMM can be regulated by changes in the matrix volume due to the opening/closure of permeability transition pores (PTP). Herein, we investigated the crosstalk between the PTP and OPA1 to clarify whether PTP opening is involved in OPA1-mediated regulation of respiratory chain supercomplexes (RCS) assembly using cardiac mitochondria and cell line. We found that: 1) Proteolytic cleavage of L-OPA1 is stimulated by PTP-induced mitochondrial swelling, 2) OPA1 knockdown reduces PTP-induced mitochondrial swelling but enhances ROS production, 3) OPA1 deficiency impairs the RCS assembly associated with diminished ETC activity and oxidative phosphorylation, 4) OPA1 has no physical interaction with phospholipid scramblase 3 although OPA1 downregulation increases expression of the scramblase. Thus, this study demonstrates that L-OPA1 cleavage depends on the PTP-induced mitochondrial swelling suggesting a regulatory role of the PTP-OPA1 axis in RCS assembly and mitochondrial bioenergetics.
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Mnatsakanyan N, Llaguno MC, Yang Y, Yan Y, Weber J, Sigworth FJ, Jonas EA. A mitochondrial megachannel resides in monomeric F 1F O ATP synthase. Nat Commun 2019; 10:5823. [PMID: 31862883 PMCID: PMC6925261 DOI: 10.1038/s41467-019-13766-2] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 11/25/2019] [Indexed: 11/08/2022] Open
Abstract
Purified mitochondrial ATP synthase has been shown to form Ca2+-activated, large conductance channel activity similar to that of mitochondrial megachannel (MMC) or mitochondrial permeability transition pore (mPTP) but the oligomeric state required for channel formation is being debated. We reconstitute purified monomeric ATP synthase from porcine heart mitochondria into small unilamellar vesicles (SUVs) with the lipid composition of mitochondrial inner membrane and analyze its oligomeric state by electron cryomicroscopy. The cryo-EM density map reveals the presence of a single ATP synthase monomer with no density seen for a second molecule tilted at an 86o angle relative to the first. We show that this preparation of SUV-reconstituted ATP synthase monomers, when fused into giant unilamellar vesicles (GUVs), forms voltage-gated and Ca2+-activated channels with the key features of mPTP. Based on our findings we conclude that the ATP synthase monomer is sufficient, and dimer formation is not required, for mPTP activity.
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Affiliation(s)
- Nelli Mnatsakanyan
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA.
| | - Marc C Llaguno
- Center for Cellular and Molecular Imaging, Yale University, New Haven, CT, USA
| | - Youshan Yang
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Yangyang Yan
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Joachim Weber
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, USA
| | - Fred J Sigworth
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Elizabeth A Jonas
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT, USA.
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34
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Carraro M, Bernardi P. Measurement of membrane permeability and the mitochondrial permeability transition. Methods Cell Biol 2019; 155:369-379. [PMID: 32183968 DOI: 10.1016/bs.mcb.2019.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mitochondrial permeability transition (PT) is an increase in the inner membrane permeability caused by the opening of a Ca2+-activated high-conductance channel, the so-called PT pore (PTP) or mitochondrial megachannel (MMC). Recent data indicate that F-ATP synthase contributes substantially to the generation of the PTP, yet this hypothesis is the matter of controversy. In this chapter, we will describe an approach to study the pore, i.e., the evaluation of mitochondrial swelling by means of a decrease in the absorbance at 540nm. This method should be useful to resolve apparent discrepancies in the literature and help solve emerging issues on the identity of mitochondrial pores.
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Affiliation(s)
- Michela Carraro
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
| | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
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35
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Purified F-ATP synthase forms a Ca 2+-dependent high-conductance channel matching the mitochondrial permeability transition pore. Nat Commun 2019; 10:4341. [PMID: 31554800 PMCID: PMC6761146 DOI: 10.1038/s41467-019-12331-1] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 08/29/2019] [Indexed: 12/20/2022] Open
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. The molecular identity of the mitochondrial megachannel (MMC)/permeability transition pore (PTP), a key effector of cell death, remains controversial. Here authors demonstrate that the membrane embedded bovine F-ATP synthase elicits Ca2 + -dependent currents matching those of the MMC/PTP.
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36
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Carraro M, Checchetto V, Szabó I, Bernardi P. F‐ATPsynthase and the permeability transition pore: fewer doubts, more certainties. FEBS Lett 2019; 593:1542-1553. [DOI: 10.1002/1873-3468.13485] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Michela Carraro
- Department of Biomedical Sciences University of Padova Italy
| | | | - Ildikó Szabó
- Department of Biology University of Padova Italy
| | - Paolo Bernardi
- Department of Biomedical Sciences University of Padova Italy
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37
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Contribution of Mitochondrial Ion Channels to Chemo-Resistance in Cancer Cells. Cancers (Basel) 2019; 11:cancers11060761. [PMID: 31159324 PMCID: PMC6627730 DOI: 10.3390/cancers11060761] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 05/16/2019] [Accepted: 05/23/2019] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial ion channels are emerging oncological targets, as modulation of these ion-transporting proteins may impact on mitochondrial membrane potential, efficiency of oxidative phosphorylation and reactive oxygen production. In turn, these factors affect the release of cytochrome c, which is the point of no return during mitochondrial apoptosis. Many of the currently used chemotherapeutics induce programmed cell death causing damage to DNA and subsequent activation of p53-dependent pathways that finally leads to cytochrome c release from the mitochondrial inter-membrane space. The view is emerging, as summarized in the present review, that ion channels located in this organelle may account in several cases for the resistance that cancer cells can develop against classical chemotherapeutics, by preventing drug-induced apoptosis. Thus, pharmacological modulation of these channel activities might be beneficial to fight chemo-resistance of different types of cancer cells.
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38
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MacDougall G, Anderton RS, Mastaglia FL, Knuckey NW, Meloni BP. Mitochondria and neuroprotection in stroke: Cationic arginine-rich peptides (CARPs) as a novel class of mitochondria-targeted neuroprotective therapeutics. Neurobiol Dis 2018; 121:17-33. [PMID: 30218759 DOI: 10.1016/j.nbd.2018.09.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/26/2018] [Accepted: 09/11/2018] [Indexed: 01/11/2023] Open
Abstract
Stroke is the second leading cause of death globally and represents a major cause of devastating long-term disability. Despite sustained efforts to develop clinically effective neuroprotective therapies, presently there is no clinically available neuroprotective agent for stroke. As a central mediator of neurodamaging events in stroke, mitochondria are recognised as a critical neuroprotective target, and as such, provide a focus for developing mitochondrial-targeted therapeutics. In recent years, cationic arginine-rich peptides (CARPs) have been identified as a novel class of neuroprotective agent with several demonstrated mechanisms of action, including their ability to target mitochondria and exert positive effects on the organelle. This review provides an overview on neuronal mitochondrial dysfunction in ischaemic stroke pathophysiology and highlights the potential beneficial effects of CARPs on mitochondria in the ischaemic brain following stroke.
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Affiliation(s)
- Gabriella MacDougall
- Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, Australia; Perron Institute for Neurological and Translational Science, Nedlands, Australia; School of Heath Sciences, and Institute for Health Research, The University Notre Dame Australia, Fremantle, Australia.
| | - Ryan S Anderton
- Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, Australia; Perron Institute for Neurological and Translational Science, Nedlands, Australia; School of Heath Sciences, and Institute for Health Research, The University Notre Dame Australia, Fremantle, Australia
| | - Frank L Mastaglia
- Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, Australia; Perron Institute for Neurological and Translational Science, Nedlands, Australia
| | - Neville W Knuckey
- Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, Australia; Perron Institute for Neurological and Translational Science, Nedlands, Australia; Department of Neurosurgery, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Bruno P Meloni
- Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, Australia; Perron Institute for Neurological and Translational Science, Nedlands, Australia; Department of Neurosurgery, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Western Australia, Australia
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39
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Briston T, Hicks AR. Mitochondrial dysfunction and neurodegenerative proteinopathies: mechanisms and prospects for therapeutic intervention. Biochem Soc Trans 2018; 46:829-842. [PMID: 29986938 PMCID: PMC6103456 DOI: 10.1042/bst20180025] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/10/2018] [Accepted: 05/21/2018] [Indexed: 12/22/2022]
Abstract
Neurodegenerative proteinopathies are a group of pathologically similar, progressive disorders of the nervous system, characterised by structural alterations within and toxic misfolding of susceptible proteins. Oligomerisation of Aβ, tau, α-synuclein and TDP-43 leads to a toxin gain- or loss-of-function contributing to the phenotype observed in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and frontotemporal dementia. Misfolded proteins can adversely affect mitochondria, and post-mitotic neurones are especially sensitive to metabolic dysfunction. Misfolded proteins impair mitochondrial dynamics (morphology and trafficking), preventing functional mitochondria reaching the synapse, the primary site of ATP utilisation. Furthermore, a direct association of misfolded proteins with mitochondria may precipitate or augment dysfunctional oxidative phosphorylation and mitochondrial quality control, causing redox dyshomeostasis observed in disease. As such, a significant interest lies in understanding mechanisms of mitochondrial toxicity in neurodegenerative disorders and in dissecting these mechanisms with a view of maintaining mitochondrial homeostasis in disease. Recent advances in understanding mitochondrially controlled cell death pathways and elucidating the mitochondrial permeability pore bioarchitecture are beginning to present new avenues to target neurodegeneration. Novel mitochondrial roles of deubiquitinating enzymes are coming to light and present an opportunity for a new class of proteins to target therapeutically with the aim of promoting mitophagy and the ubiquitin-proteasome system. The brain is enormously metabolically active, placing a large emphasis on maintaining ATP supply. Therefore, identifying mechanisms to sustain mitochondrial function may represent a common intervention point across all proteinopathies.
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Affiliation(s)
- Thomas Briston
- Neurology Innovation Centre, Hatfield Research Laboratories, Eisai Ltd, Hatfield, U.K.
| | - Amy R Hicks
- Neurology Innovation Centre, Hatfield Research Laboratories, Eisai Ltd, Hatfield, U.K
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40
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Kamei Y, Koushi M, Aoyama Y, Asakai R. The yeast mitochondrial permeability transition is regulated by reactive oxygen species, endogenous Ca 2+ and Cpr3, mediating cell death. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1313-1326. [PMID: 30031690 DOI: 10.1016/j.bbabio.2018.07.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 11/29/2022]
Abstract
We investigated the properties of the permeability transition pore (PTP) in Saccharomyces cerevisiae in agar-embedded mitochondria (AEM) and agar-embedded cells (AEC) and its role in yeast death. In AEM, ethanol-induced pore opening, as indicated by the release of calcein and mitochondrial membrane depolarization, can be inhibited by CsA, by Cpr3 deficiency, and by the antioxidant glutathione. Notably, the pore opening is inhibited, when mitochondria are preloaded by EGTA or Fluo3 to chelate matrix Ca2+, or are pretreated with 4-Br A23187 to extract matrix Ca2+, prior to agar-embedding, or when pore opening is induced in the presence of EGTA; opened pores are re-closed by sequential treatment with CsA, 4-Br A23187 plus EGTA and NADH, indicating endogenous matrix Ca2+ involvement. CsA also inhibits the pore opening with low conductance triggered by exogenous Ca2+ transport with ETH129. In AEC, the treatment of tert-butylhydroperoxide, a pro-oxidant that triggers transient pore opening in high conductance in AEM, induces yeast death, which is also dependent on CsA and Cpr3. Furthermore, AEMs from mutants lacking three ADP/ATP carrier (AAC) isoforms and with defective ATP synthase dimerization exhibit high and low conductance pore openings with CsA sensitivity, respectively. Collectively, these data show that the yeast PTP is regulated by Cpr3, endogenous matrix Ca2+, and reactive oxygen species, and that it is involved in yeast death; furthermore, ATP synthase dimers play a key role in CsA-sensitive pore formation, while AACs are dispensable.
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Affiliation(s)
- Yoshiko Kamei
- Department of Morphophysiology, Faculty of Pharmaceutical Sciences, Josai International University, 1 Gumyo, Togane, Chiba 283-8555, Japan
| | - Masami Koushi
- Department of Morphophysiology, Faculty of Pharmaceutical Sciences, Josai International University, 1 Gumyo, Togane, Chiba 283-8555, Japan
| | - Yasunori Aoyama
- Department of Morphophysiology, Faculty of Pharmaceutical Sciences, Josai International University, 1 Gumyo, Togane, Chiba 283-8555, Japan
| | - Rei Asakai
- Department of Morphophysiology, Faculty of Pharmaceutical Sciences, Josai International University, 1 Gumyo, Togane, Chiba 283-8555, Japan.
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41
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Nesci S, Trombetti F, Ventrella V, Pagliarani A. From the Ca 2+-activated F 1F O-ATPase to the mitochondrial permeability transition pore: an overview. Biochimie 2018; 152:85-93. [PMID: 29964086 DOI: 10.1016/j.biochi.2018.06.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/26/2018] [Indexed: 01/02/2023]
Abstract
Based on recent advances on the Ca2+-activated F1FO-ATPase features, a novel multistep mechanism involving the mitochondrial F1FO complex in the formation and opening of the still enigmatic mitochondrial permeability transition pore (MPTP), is proposed. MPTP opening makes the inner mitochondrial membrane (IMM) permeable to ions and solutes and, through cascade events, addresses cell fate to death. Since MPTP forms when matrix Ca2+ concentration rises and ATP is hydrolyzed by the F1FO-ATPase, conformational changes, triggered by Ca2+ insertion in F1, may be transmitted to FO and locally modify the IMM curvature. These events would cause F1FO-ATPase dimer dissociation and MPTP opening.
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Affiliation(s)
- Salvatore Nesci
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Fabiana Trombetti
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Vittoria Ventrella
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Alessandra Pagliarani
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy.
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42
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Channel formation by F-ATP synthase and the permeability transition pore: an update. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2017.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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43
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Makarov VI, Khmelinskii I, Javadov S. Computational Modeling of In Vitro Swelling of Mitochondria: A Biophysical Approach. Molecules 2018; 23:molecules23040783. [PMID: 29597314 PMCID: PMC5901922 DOI: 10.3390/molecules23040783] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/12/2018] [Accepted: 03/27/2018] [Indexed: 11/17/2022] Open
Abstract
Swelling of mitochondria plays an important role in the pathogenesis of human diseases by stimulating mitochondria-mediated cell death through apoptosis, necrosis, and autophagy. Changes in the permeability of the inner mitochondrial membrane (IMM) of ions and other substances induce an increase in the colloid osmotic pressure, leading to matrix swelling. Modeling of mitochondrial swelling is important for simulation and prediction of in vivo events in the cell during oxidative and energy stress. In the present study, we developed a computational model that describes the mechanism of mitochondrial swelling based on osmosis, the rigidity of the IMM, and dynamics of ionic/neutral species. The model describes a new biophysical approach to swelling dynamics, where osmotic pressure created in the matrix is compensated for by the rigidity of the IMM, i.e., osmotic pressure induces membrane deformation, which compensates for the osmotic pressure effect. Thus, the effect is linear and reversible at small membrane deformations, allowing the membrane to restore its normal form. On the other hand, the membrane rigidity drops to zero at large deformations, and the swelling becomes irreversible. As a result, an increased number of dysfunctional mitochondria can activate mitophagy and initiate cell death. Numerical modeling analysis produced results that reasonably describe the experimental data reported earlier.
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Affiliation(s)
- Vladimir I Makarov
- Department of Physics, University of Puerto Rico, Rio Piedras Campus, San Juan, PR 00931-3343, USA.
| | - Igor Khmelinskii
- Faculty of Sciences and Technology, Department of Chemistry and Pharmacy, and Interdisciplinary Centre of Chemistry of Algarve, University of Algarve, 8005-139 Faro, Portugal.
| | - Sabzali Javadov
- Department of Physiology and Biophysics, University of Puerto Rico, Medical Sciences Campus, San Juan, PR 00936-5067, USA.
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Antoniel M, Jones K, Antonucci S, Spolaore B, Fogolari F, Petronilli V, Giorgio V, Carraro M, Di Lisa F, Forte M, Szabó I, Lippe G, Bernardi P. The unique histidine in OSCP subunit of F-ATP synthase mediates inhibition of the permeability transition pore by acidic pH. EMBO Rep 2018; 19:257-268. [PMID: 29217657 PMCID: PMC5797955 DOI: 10.15252/embr.201744705] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 11/09/2017] [Accepted: 11/14/2017] [Indexed: 01/19/2023] Open
Abstract
The permeability transition pore (PTP) is a Ca2+-dependent mitochondrial channel whose opening causes a permeability increase in the inner membrane to ions and solutes. The most potent inhibitors are matrix protons, with channel block at pH 6.5. Inhibition is reversible, mediated by histidyl residue(s), and prevented by their carbethoxylation by diethylpyrocarbonate (DPC), but their assignment is unsolved. We show that PTP inhibition by H+ is mediated by the highly conserved histidyl residue (H112 in the human mature protein) of oligomycin sensitivity conferral protein (OSCP) subunit of mitochondrial F1FO (F)-ATP synthase, which we also show to undergo carbethoxylation after reaction of mitochondria with DPC. Mitochondrial PTP-dependent swelling cannot be inhibited by acidic pH in H112Q and H112Y OSCP mutants, and the corresponding megachannels (the electrophysiological counterpart of the PTP) are insensitive to inhibition by acidic pH in patch-clamp recordings of mitoplasts. Cells harboring the H112Q and H112Y mutations are sensitized to anoxic cell death at acidic pH. These results demonstrate that PTP channel formation and its inhibition by H+ are mediated by the F-ATP synthase.
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Affiliation(s)
- Manuela Antoniel
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Kristen Jones
- Vollum Institute, Oregon Health and Sciences University, Portland, OR, USA
| | - Salvatore Antonucci
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Barbara Spolaore
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Federico Fogolari
- Department of Mathematics, Computer Sciences and Physics, University of Udine, Udine, Italy
| | - Valeria Petronilli
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Valentina Giorgio
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Michela Carraro
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Fabio Di Lisa
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Michael Forte
- Vollum Institute, Oregon Health and Sciences University, Portland, OR, USA
| | - Ildikó Szabó
- Department of Biology, University of Padova, Padova, Italy
| | - Giovanna Lippe
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Paolo Bernardi
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padova, Italy
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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45
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Mitochondrial permeability transition pore: sensitivity to opening and mechanistic dependence on substrate availability. Sci Rep 2017; 7:10492. [PMID: 28874733 PMCID: PMC5585167 DOI: 10.1038/s41598-017-10673-8] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/11/2017] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial Ca2+ uptake has a key role in cellular Ca2+ homeostasis. Excessive matrix Ca2+ concentrations, especially when coincident with oxidative stress, precipitate opening of an inner mitochondrial membrane, high-conductance channel: the mitochondrial permeability transition pore (mPTP). mPTP opening has been implicated as a final cell death pathway in numerous diseases and therefore understanding conditions dictating mPTP opening is crucial for developing targeted therapies. Here, we have investigated the impact of mitochondrial metabolic state on the probability and consequences of mPTP opening. Isolated mitochondria were energised using NADH- or FADH2-linked substrates. The functional consequences of Ca2+-induced mPTP opening were assessed by Ca2+ retention capacity, using fluorescence-based analysis, and simultaneous measurements of mitochondrial Ca2+ handling, membrane potential, respiratory rate and production of reactive oxygen species (ROS). Succinate-induced, membrane potential-dependent reverse electron transfer sensitised mitochondria to mPTP opening. mPTP-induced depolarisation under succinate subsequently inhibited reverse electron transfer. Complex I-driven respiration was reduced after mPTP opening but sustained in the presence of complex II-linked substrates, consistent with inhibition of complex I-supported respiration by leakage of matrix NADH. Additionally, ROS generated at complex III did not sensitise mitochondria to mPTP opening. Thus, cellular metabolic fluxes and metabolic environment dictate mitochondrial functional response to Ca2+ overload.
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46
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The Involvement of Mg 2+ in Regulation of Cellular and Mitochondrial Functions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:6797460. [PMID: 28757913 PMCID: PMC5516748 DOI: 10.1155/2017/6797460] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 05/31/2017] [Indexed: 12/11/2022]
Abstract
Mg2+ is an essential mineral with pleotropic impacts on cellular physiology and functions. It acts as a cofactor of several important enzymes, as a regulator of ion channels such as voltage-dependent Ca2+ channels and K+ channels and on Ca2+-binding proteins. In general, Mg2+ is considered as the main intracellular antagonist of Ca2+, which is an essential secondary messenger initiating or regulating a great number of cellular functions. This review examines the effects of Mg2+ on mitochondrial functions with a particular focus on energy metabolism, mitochondrial Ca2+ handling, and apoptosis.
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47
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Wang X, Zhang X, Huang Z, Wu D, Liu B, Zhang R, Yin R, Hou T, Jian C, Xu J, Zhao Y, Wang Y, Gao F, Cheng H. Protons Trigger Mitochondrial Flashes. Biophys J 2017; 111:386-394. [PMID: 27463140 DOI: 10.1016/j.bpj.2016.05.052] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 05/06/2016] [Accepted: 05/31/2016] [Indexed: 12/22/2022] Open
Abstract
Emerging evidence indicates that mitochondrial flashes (mitoflashes) are highly conserved elemental mitochondrial signaling events. However, which signal controls their ignition and how they are integrated with other mitochondrial signals and functions remain elusive. In this study, we aimed to further delineate the signal components of the mitoflash and determine the mitoflash trigger mechanism. Using multiple biosensors and chemical probes as well as label-free autofluorescence, we found that the mitoflash reflects chemical and electrical excitation at the single-organelle level, comprising bursting superoxide production, oxidative redox shift, and matrix alkalinization as well as transient membrane depolarization. Both electroneutral H(+)/K(+) or H(+)/Na(+) antiport and matrix proton uncaging elicited immediate and robust mitoflash responses over a broad dynamic range in cardiomyocytes and HeLa cells. However, charge-uncompensated proton transport, which depolarizes mitochondria, caused the opposite effect, and steady matrix acidification mildly inhibited mitoflashes. Based on a numerical simulation, we estimated a mean proton lifetime of 1.42 ns and diffusion distance of 2.06 nm in the matrix. We conclude that nanodomain protons act as a novel, to our knowledge, trigger of mitoflashes in energized mitochondria. This finding suggests that mitoflash genesis is functionally and mechanistically integrated with mitochondrial energy metabolism.
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Affiliation(s)
- Xianhua Wang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China.
| | - Xing Zhang
- Department of Aerospace Medicine, The Fourth Military Medical University, Xi'an, China
| | - Zhanglong Huang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Di Wu
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Beibei Liu
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Rufeng Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Rongkang Yin
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Tingting Hou
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Chongshu Jian
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Jiejia Xu
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Yan Zhao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Yanru Wang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Feng Gao
- Department of Aerospace Medicine, The Fourth Military Medical University, Xi'an, China
| | - Heping Cheng
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China.
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48
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Giorgio V, Burchell V, Schiavone M, Bassot C, Minervini G, Petronilli V, Argenton F, Forte M, Tosatto S, Lippe G, Bernardi P. Ca 2+ binding to F-ATP synthase β subunit triggers the mitochondrial permeability transition. EMBO Rep 2017; 18:1065-1076. [PMID: 28507163 DOI: 10.15252/embr.201643354] [Citation(s) in RCA: 161] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 04/02/2017] [Accepted: 04/05/2017] [Indexed: 01/28/2023] Open
Abstract
F-ATP synthases convert the electrochemical energy of the H+ gradient into the chemical energy of ATP with remarkable efficiency. Mitochondrial F-ATP synthases can also undergo a Ca2+-dependent transformation to form channels with properties matching those of the permeability transition pore (PTP), a key player in cell death. The Ca2+ binding site and the mechanism(s) through which Ca2+ can transform the energy-conserving enzyme into a dissipative structure promoting cell death remain unknown. Through in vitro, in vivo and in silico studies we (i) pinpoint the "Ca2+-trigger site" of the PTP to the catalytic site of the F-ATP synthase β subunit and (ii) define a conformational change that propagates from the catalytic site through OSCP and the lateral stalk to the inner membrane. T163S mutants of the β subunit, which show a selective decrease in Ca2+-ATP hydrolysis, confer resistance to Ca2+-induced, PTP-dependent death in cells and developing zebrafish embryos. These findings are a major advance in the molecular definition of the transition of F-ATP synthase to a channel and of its role in cell death.
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Affiliation(s)
- Valentina Giorgio
- Department of Biomedical Sciences, University of Padova, Padova, Italy .,Consiglio Nazionale delle Ricerche Neuroscience Institute, Padova, Italy
| | - Victoria Burchell
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marco Schiavone
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Claudio Bassot
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Valeria Petronilli
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Consiglio Nazionale delle Ricerche Neuroscience Institute, Padova, Italy
| | | | - Michael Forte
- Vollum Institute, Oregon Health and Sciences University, Portland, OR, USA
| | - Silvio Tosatto
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Consiglio Nazionale delle Ricerche Neuroscience Institute, Padova, Italy
| | - Giovanna Lippe
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy .,Consiglio Nazionale delle Ricerche Neuroscience Institute, Padova, Italy
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49
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Mnatsakanyan N, Beutner G, Porter GA, Alavian KN, Jonas EA. Physiological roles of the mitochondrial permeability transition pore. J Bioenerg Biomembr 2017; 49:13-25. [PMID: 26868013 PMCID: PMC4981558 DOI: 10.1007/s10863-016-9652-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/04/2016] [Indexed: 01/01/2023]
Abstract
Neurons experience high metabolic demand during such processes as synaptic vesicle recycling, membrane potential maintenance and Ca2+ exchange/extrusion. The energy needs of these events are met in large part by mitochondrial production of ATP through the process of oxidative phosphorylation. The job of ATP production by the mitochondria is performed by the F1FO ATP synthase, a multi-protein enzyme that contains a membrane-inserted portion, an extra-membranous enzymatic portion and an extensive regulatory complex. Although required for ATP production by mitochondria, recent findings have confirmed that the membrane-confined portion of the c-subunit of the ATP synthase also houses a large conductance uncoupling channel, the mitochondrial permeability transition pore (mPTP), the persistent opening of which produces osmotic dysregulation of the inner mitochondrial membrane, uncoupling of oxidative phosphorylation and cell death. Recent advances in understanding the molecular components of mPTP and its regulatory mechanisms have determined that decreased uncoupling occurs in states of enhanced mitochondrial efficiency; relative closure of mPTP therefore contributes to cellular functions as diverse as cardiac development and synaptic efficacy.
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Affiliation(s)
- Nelli Mnatsakanyan
- Department Internal Medicine, Section of Endocrinology, Yale University, New Haven, CT, USA
| | - Gisela Beutner
- Department of Pediatrics (Cardiology), University of Rochester Medical Center, Rochester, NY, USA
| | - George A Porter
- Department of Pediatrics (Cardiology), University of Rochester Medical Center, Rochester, NY, USA
| | - Kambiz N Alavian
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK
| | - Elizabeth A Jonas
- Department Internal Medicine, Section of Endocrinology, Yale University, New Haven, CT, USA.
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50
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Hurst S, Hoek J, Sheu SS. Mitochondrial Ca 2+ and regulation of the permeability transition pore. J Bioenerg Biomembr 2017; 49:27-47. [PMID: 27497945 PMCID: PMC5393273 DOI: 10.1007/s10863-016-9672-x] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 07/31/2016] [Indexed: 02/06/2023]
Abstract
The mitochondrial permeability transition pore was originally described in the 1970's as a Ca2+ activated pore and has since been attributed to the pathogenesis of many diseases. Here we evaluate how each of the current models of the pore complex fit to what is known about how Ca2+ regulates the pore, and any insight that provides into the molecular identity of the pore complex. We also discuss the central role of Ca2+ in modulating the pore's open probability by directly regulating processes, such as ATP/ADP balance through the tricarboxylic acid cycle, electron transport chain, and mitochondrial membrane potential. We review how Ca2+ influences second messengers such as reactive oxygen/nitrogen species production and polyphosphate formation. We discuss the evidence for how Ca2+ regulates post-translational modification of cyclophilin D including phosphorylation by glycogen synthase kinase 3 beta, deacetylation by sirtuins, and oxidation/ nitrosylation of key residues. Lastly we introduce a novel view into how Ca2+ activated proteolysis through calpains in the mitochondria may be a driver of sustained pore opening during pathologies such as ischemia reperfusion injury.
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Affiliation(s)
- Stephen Hurst
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Suite 543D, Philadelphia, PA, 19107, USA
| | - Jan Hoek
- Mitocare Center for Mitochondria Research, Department of Pathology Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Suite 543D, Philadelphia, PA, 19107, USA.
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