1
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Gerle C, Jiko C, Nakano A, Yokoyama K, Gopalasingam CC, Shigematsu H, Abe K. Human F-ATP synthase as a drug target. Pharmacol Res 2024:107423. [PMID: 39303772 DOI: 10.1016/j.phrs.2024.107423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 09/14/2024] [Accepted: 09/16/2024] [Indexed: 09/22/2024]
Abstract
Practical and conceptual barriers have kept human F-ATP synthase out of reach as a target for the treatment of human diseases. Although this situation has persisted for decades, it may change in the near future. In this review the principal functionalities of human F-ATP synthase--proton motive force / ATP interconversion, membrane bending and mitochondrial permeability transition--are surveyed in the context of their respective potential for pharmaceutical intervention. Further, the technical requirements necessary to allow drug designs that are effective at the multiple levels of functionality and modality of human F-ATP synthase are discussed. The structure-based development of gastric proton pump inhibitors is used to exemplify what might be feasible for human F-ATP synthase. And finally, four structural regions of the human F-ATP synthase are examined as potential sites for the development of structure based drug development.
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Affiliation(s)
- Christoph Gerle
- Life Science Research Infrastructure Group, RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 1-1-1, Japan.
| | - Chimari Jiko
- Division of Radiation Life Science, Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Atsuki Nakano
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
| | - Ken Yokoyama
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto 603-8555, Japan
| | - Chai C Gopalasingam
- Life Science Research Infrastructure Group, RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 1-1-1, Japan
| | - Hideki Shigematsu
- Structural Biology Division, Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo, Japan
| | - Kazuhiro Abe
- Molecular Biochemistry Lab, Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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2
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Bertero E, Popoiu TA, Maack C. Mitochondrial calcium in cardiac ischemia/reperfusion injury and cardioprotection. Basic Res Cardiol 2024; 119:569-585. [PMID: 38890208 PMCID: PMC11319510 DOI: 10.1007/s00395-024-01060-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/31/2024] [Accepted: 06/01/2024] [Indexed: 06/20/2024]
Abstract
Mitochondrial calcium (Ca2+) signals play a central role in cardiac homeostasis and disease. In the healthy heart, mitochondrial Ca2+ levels modulate the rate of oxidative metabolism to match the rate of adenosine triphosphate consumption in the cytosol. During ischemia/reperfusion (I/R) injury, pathologically high levels of Ca2+ in the mitochondrial matrix trigger the opening of the mitochondrial permeability transition pore, which releases solutes and small proteins from the matrix, causing mitochondrial swelling and ultimately leading to cell death. Pharmacological and genetic approaches to tune mitochondrial Ca2+ handling by regulating the activity of the main Ca2+ influx and efflux pathways, i.e., the mitochondrial Ca2+ uniporter and sodium/Ca2+ exchanger, represent promising therapeutic strategies to protect the heart from I/R injury.
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Affiliation(s)
- Edoardo Bertero
- Department of Translational Research, Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Am Schwarzenberg 15, Haus A15, 97078, Würzburg, Germany
- Chair of Cardiovascular Disease, Department of Internal Medicine and Specialties (Di.M.I.), University of Genoa, Genoa, Italy
| | - Tudor-Alexandru Popoiu
- Department of Translational Research, Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Am Schwarzenberg 15, Haus A15, 97078, Würzburg, Germany
- "Victor Babes" University of Medicine and Pharmacy, Timisoara, Romania
| | - Christoph Maack
- Department of Translational Research, Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Am Schwarzenberg 15, Haus A15, 97078, Würzburg, Germany.
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3
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Ge WD, Du TT, Wang CY, Sun LN, Wang YQ. Calcium signaling crosstalk between the endoplasmic reticulum and mitochondria, a new drug development strategies of kidney diseases. Biochem Pharmacol 2024; 225:116278. [PMID: 38740223 DOI: 10.1016/j.bcp.2024.116278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/25/2024] [Accepted: 05/10/2024] [Indexed: 05/16/2024]
Abstract
Calcium (Ca2+) acts as a second messenger and constitutes a complex and large information exchange system between the endoplasmic reticulum (ER) and mitochondria; this process is involved in various life activities, such as energy metabolism, cell proliferation and apoptosis. Increasing evidence has suggested that alterations in Ca2+ crosstalk between the ER and mitochondria, including alterations in ER and mitochondrial Ca2+ channels and related Ca2+ regulatory proteins, such as sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), inositol 1,4,5-trisphosphate receptor (IP3R), and calnexin (CNX), are closely associated with the development of kidney disease. Therapies targeting intracellular Ca2+ signaling have emerged as an emerging field in the treatment of renal diseases. In this review, we focused on recent advances in Ca2+ signaling, ER and mitochondrial Ca2+ monitoring methods and Ca2+ homeostasis in the development of renal diseases and sought to identify new targets and insights for the treatment of renal diseases by targeting Ca2+ channels or related Ca2+ regulatory proteins.
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Affiliation(s)
- Wen-Di Ge
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Tian-Tian Du
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Cao-Yang Wang
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Lu-Ning Sun
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China.
| | - Yong-Qing Wang
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China.
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4
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Pekson R, Liang FG, Axelrod JL, Lee J, Qin D, Wittig AJH, Paulino VM, Zheng M, Peixoto PM, Kitsis RN. The mitochondrial ATP synthase is a negative regulator of the mitochondrial permeability transition pore. Proc Natl Acad Sci U S A 2023; 120:e2303713120. [PMID: 38091291 PMCID: PMC10743364 DOI: 10.1073/pnas.2303713120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 10/24/2023] [Indexed: 12/18/2023] Open
Abstract
The mitochondrial permeability transition pore (mPTP) is a channel in the inner mitochondrial membrane whose sustained opening in response to elevated mitochondrial matrix Ca2+ concentrations triggers necrotic cell death. The molecular identity of mPTP is unknown. One proposed candidate is the mitochondrial ATP synthase, whose canonical function is to generate most ATP in multicellular organisms. Here, we present mitochondrial, cellular, and in vivo evidence that, rather than serving as mPTP, the mitochondrial ATP synthase inhibits this pore. Our studies confirm previous work showing persistence of mPTP in HAP1 cell lines lacking an assembled mitochondrial ATP synthase. Unexpectedly, however, we observe that Ca2+-induced pore opening is markedly sensitized by loss of the mitochondrial ATP synthase. Further, mPTP opening in cells lacking the mitochondrial ATP synthase is desensitized by pharmacological inhibition and genetic depletion of the mitochondrial cis-trans prolyl isomerase cyclophilin D as in wild-type cells, indicating that cyclophilin D can modulate mPTP through substrates other than subunits in the assembled mitochondrial ATP synthase. Mitoplast patch clamping studies showed that mPTP channel conductance was unaffected by loss of the mitochondrial ATP synthase but still blocked by cyclophilin D inhibition. Cardiac mitochondria from mice whose heart muscle cells we engineered deficient in the mitochondrial ATP synthase also demonstrate sensitization of Ca2+-induced mPTP opening and desensitization by cyclophilin D inhibition. Further, these mice exhibit strikingly larger myocardial infarctions when challenged with ischemia/reperfusion in vivo. We conclude that the mitochondrial ATP synthase does not function as mPTP and instead negatively regulates this pore.
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Affiliation(s)
- Ryan Pekson
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY10461
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
| | - Felix G. Liang
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY10461
| | - Joshua L. Axelrod
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY10461
| | - Jaehoon Lee
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY10461
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
| | - Dongze Qin
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY10461
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
| | - Andre J. H. Wittig
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY10461
| | - Victor M. Paulino
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY10461
| | - Min Zheng
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY10461
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
| | - Pablo M. Peixoto
- Department of Natural Sciences, Baruch College and Program in Molecular, Cellular, and Developmental Biology, Graduate Center, City University of New York, New York, NY10010
| | - Richard N. Kitsis
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY10461
- Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY10461
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5
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Nikiforova AB, Baburina YL, Borisova MP, Surin AK, Kharechkina ES, Krestinina OV, Suvorina MY, Kruglova SA, Kruglov AG. Mitochondrial F-ATP Synthase Co-Migrating Proteins and Ca 2+-Dependent Formation of Large Channels. Cells 2023; 12:2414. [PMID: 37830628 PMCID: PMC10572550 DOI: 10.3390/cells12192414] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/18/2023] [Accepted: 10/02/2023] [Indexed: 10/14/2023] Open
Abstract
Monomers, dimers, and individual FOF1-ATP synthase subunits are, presumably, involved in the formation of the mitochondrial permeability transition pore (PTP), whose molecular structure, however, is still unknown. We hypothesized that, during the Ca2+-dependent assembly of a PTP complex, the F-ATP synthase (subunits) recruits mitochondrial proteins that do not interact or weakly interact with the F-ATP synthase under normal conditions. Therefore, we examined whether the PTP opening in mitochondria before the separation of supercomplexes via BN-PAGE will increase the channel stability and channel-forming capacity of isolated F-ATP synthase dimers and monomers in planar lipid membranes. Additionally, we studied the specific activity and the protein composition of F-ATP synthase dimers and monomers from rat liver and heart mitochondria before and after PTP opening. Against our expectations, preliminary PTP opening dramatically suppressed the high-conductance channel activity of F-ATP synthase dimers and monomers and decreased their specific "in-gel" activity. The decline in the channel-forming activity correlated with the reduced levels of as few as two proteins in the bands: methylmalonate-semialdehyde dehydrogenase and prohibitin 2. These results indicate that proteins co-migrating with the F-ATP synthase may be important players in PTP formation and stabilization.
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Affiliation(s)
- Anna B. Nikiforova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia; (A.B.N.); (Y.L.B.); (M.P.B.); (E.S.K.); (O.V.K.)
| | - Yulia L. Baburina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia; (A.B.N.); (Y.L.B.); (M.P.B.); (E.S.K.); (O.V.K.)
| | - Marina P. Borisova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia; (A.B.N.); (Y.L.B.); (M.P.B.); (E.S.K.); (O.V.K.)
| | - Alexey K. Surin
- Branch of the Shemyakin—Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Prospekt Nauki 6, 142290 Pushchino, Russia;
- State Research Centre for Applied Microbiology and Biotechnology, 142279 Obolensk, Russia
- Institute of Protein Research, Russian Academy of Sciences, Institutskaya 4, 142290 Pushchino, Russia;
| | - Ekaterina S. Kharechkina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia; (A.B.N.); (Y.L.B.); (M.P.B.); (E.S.K.); (O.V.K.)
| | - Olga V. Krestinina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia; (A.B.N.); (Y.L.B.); (M.P.B.); (E.S.K.); (O.V.K.)
| | - Maria Y. Suvorina
- Institute of Protein Research, Russian Academy of Sciences, Institutskaya 4, 142290 Pushchino, Russia;
| | - Svetlana A. Kruglova
- Institute of Basic Biological Problems, Russian Academy of Sciences, Institutskaya 2, 142290 Pushchino, Russia;
| | - Alexey G. Kruglov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia; (A.B.N.); (Y.L.B.); (M.P.B.); (E.S.K.); (O.V.K.)
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6
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Kumari A, Nguyen DM, Garg V. Patch-clamp technique to study mitochondrial membrane biophysics. J Gen Physiol 2023; 155:e202313347. [PMID: 37347216 PMCID: PMC10287547 DOI: 10.1085/jgp.202313347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/12/2023] [Accepted: 06/08/2023] [Indexed: 06/23/2023] Open
Abstract
Mitochondria are double-membrane organelles crucial for oxidative phosphorylation, enabling efficient ATP synthesis by eukaryotic cells. Both of the membranes, the highly selective inner mitochondrial membrane (IMM) and a relatively porous outer membrane (OMM), harbor a number of integral membrane proteins that help in the transport of biological molecules. These transporters are especially enriched in the IMM, where they help maintain transmembrane gradients for H+, K+, Ca2+, PO43-, and metabolites like ADP/ATP, citrate, etc. Impaired activity of these transporters can affect the efficiency of energy-transducing processes and can alter cellular redox state, leading to activation of cell-death pathways or metabolic syndromes in vivo. Although several methodologies are available to study ion flux through membrane proteins, the patch-clamp technique remains the gold standard for quantitatively analyzing electrogenic ion exchange across membranes. Direct patch-clamp recordings of mitoplasts (mitochondria devoid of outer membrane) in different modes, such as whole-mitoplast or excised-patch mode, allow researchers the opportunity to study the biophysics of mitochondrial transporters in the native membrane, in real time, in isolation from other fluxes or confounding factors due to changes in ion gradients, pH, or mitochondrial potential (ΔΨ). Here, we summarize the use of patch clamp to investigate several membrane proteins of mitochondria. We demonstrate how this technique can be reliably applied to record whole-mitoplast Ca2+ currents mediated via mitochondrial calcium uniporter or H+ currents mediated by uncoupling protein 1 and discuss critical considerations while recording currents from these small vesicles of the IMM (mitoplast diameter = 2-5 µm).
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Affiliation(s)
- Anshu Kumari
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, USA
| | - Dung M. Nguyen
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, USA
| | - Vivek Garg
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, USA
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7
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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: 63] [Impact Index Per Article: 63.0] [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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8
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Neginskaya MA, Morris SE, Pavlov EV. Refractive Index Imaging Reveals That Elimination of the ATP Synthase C Subunit Does Not Prevent the Adenine Nucleotide Translocase-Dependent Mitochondrial Permeability Transition. Cells 2023; 12:1950. [PMID: 37566029 PMCID: PMC10417283 DOI: 10.3390/cells12151950] [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: 06/07/2023] [Revised: 07/19/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023] Open
Abstract
The mitochondrial permeability transition pore (mPTP) is a large, weakly selective pore that opens in the mitochondrial inner membrane in response to the pathological increase in matrix Ca2+ concentration. mPTP activation has been implicated as a key factor contributing to stress-induced necrotic and apoptotic cell death. The molecular identity of the mPTP is not completely understood. Both ATP synthase and adenine nucleotide translocase (ANT) have been described as important components of the mPTP. Using a refractive index (RI) imaging approach, we recently demonstrated that the removal of either ATP synthase or ANT eliminates the Ca2+-induced mPTP in experiments with intact cells. These results suggest that mPTP formation relies on the interaction between ATP synthase and ANT protein complexes. To gain further insight into this process, we used RI imaging to investigate mPTP properties in cells with a genetically eliminated C subunit of ATP synthase. These cells also lack ATP6, ATP8, 6.8PL subunits and DAPIT but, importantly, have a vestigial ATP synthase complex with assembled F1 and peripheral stalk domains. We found that these cells can still undergo mPTP activation, which can be blocked by the ANT inhibitor bongkrekic acid. These results suggest that ANT can form the pore independently from the C subunit but still requires the presence of other components of ATP synthase.
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Affiliation(s)
- Maria A. Neginskaya
- Department of Molecular Pathobiology, New York University, 345 East 24th Street, New York, NY 10010, USA; (S.E.M.); (E.V.P.)
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave, New York, NY 10461, USA
| | - Sally E. Morris
- Department of Molecular Pathobiology, New York University, 345 East 24th Street, New York, NY 10010, USA; (S.E.M.); (E.V.P.)
| | - Evgeny V. Pavlov
- Department of Molecular Pathobiology, New York University, 345 East 24th Street, New York, NY 10010, USA; (S.E.M.); (E.V.P.)
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9
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Domínguez-Zorita S, Cuezva JM. The Mitochondrial ATP Synthase/IF1 Axis in Cancer Progression: Targets for Therapeutic Intervention. Cancers (Basel) 2023; 15:3775. [PMID: 37568591 PMCID: PMC10417293 DOI: 10.3390/cancers15153775] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/18/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023] Open
Abstract
Cancer poses a significant global health problem with profound personal and economic implications on National Health Care Systems. The reprograming of metabolism is a major trait of the cancer phenotype with a clear potential for developing effective therapeutic strategies to combat the disease. Herein, we summarize the relevant role that the mitochondrial ATP synthase and its physiological inhibitor, ATPase Inhibitory Factor 1 (IF1), play in metabolic reprogramming to an enhanced glycolytic phenotype. We stress that the interplay in the ATP synthase/IF1 axis has additional functional roles in signaling mitohormetic programs, pro-oncogenic or anti-metastatic phenotypes depending on the cell type. Moreover, the same axis also participates in cell death resistance of cancer cells by restrained mitochondrial permeability transition pore opening. We emphasize the relevance of the different post-transcriptional mechanisms that regulate the specific expression and activity of ATP synthase/IF1, to stimulate further investigations in the field because of their potential as future targets to treat cancer. In addition, we review recent findings stressing that mitochondria metabolism is the primary altered target in lung adenocarcinomas and that the ATP synthase/IF1 axis of OXPHOS is included in the most significant signature of metastatic disease. Finally, we stress that targeting mitochondrial OXPHOS in pre-clinical mouse models affords a most effective therapeutic strategy in cancer treatment.
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Affiliation(s)
- Sonia Domínguez-Zorita
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049 Madrid, Spain;
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, 28029 Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, 28041 Madrid, Spain
| | - José M. Cuezva
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049 Madrid, Spain;
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) ISCIII, 28029 Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre, Universidad Autónoma de Madrid, 28041 Madrid, Spain
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10
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Frigo E, Tommasin L, Lippe G, Carraro M, Bernardi P. The Haves and Have-Nots: The Mitochondrial Permeability Transition Pore across Species. Cells 2023; 12:1409. [PMID: 37408243 PMCID: PMC10216546 DOI: 10.3390/cells12101409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 07/07/2023] Open
Abstract
The demonstration that F1FO (F)-ATP synthase and adenine nucleotide translocase (ANT) can form Ca2+-activated, high-conductance channels in the inner membrane of mitochondria from a variety of eukaryotes led to renewed interest in the permeability transition (PT), a permeability increase mediated by the PT pore (PTP). The PT is a Ca2+-dependent permeability increase in the inner mitochondrial membrane whose function and underlying molecular mechanisms have challenged scientists for the last 70 years. Although most of our knowledge about the PTP comes from studies in mammals, recent data obtained in other species highlighted substantial differences that could be perhaps attributed to specific features of F-ATP synthase and/or ANT. Strikingly, the anoxia and salt-tolerant brine shrimp Artemia franciscana does not undergo a PT in spite of its ability to take up and store Ca2+ in mitochondria, and the anoxia-resistant Drosophila melanogaster displays a low-conductance, selective Ca2+-induced Ca2+ release channel rather than a PTP. In mammals, the PT provides a mechanism for the release of cytochrome c and other proapoptotic proteins and mediates various forms of cell death. In this review, we cover the features of the PT (or lack thereof) in mammals, yeast, Drosophila melanogaster, Artemia franciscana and Caenorhabditis elegans, and we discuss the presence of the intrinsic pathway of apoptosis and of other forms of cell death. We hope that this exercise may help elucidate the function(s) of the PT and its possible role in evolution and inspire further tests to define its molecular nature.
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Affiliation(s)
- Elena Frigo
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Via Ugo Bassi 58/B, I-35131 Padova, Italy; (E.F.); (L.T.); (M.C.)
| | - Ludovica Tommasin
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Via Ugo Bassi 58/B, I-35131 Padova, Italy; (E.F.); (L.T.); (M.C.)
| | - Giovanna Lippe
- Department of Medicine, University of Udine, Piazzale Kolbe 4, I-33100 Udine, Italy;
| | - Michela Carraro
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Via Ugo Bassi 58/B, I-35131 Padova, Italy; (E.F.); (L.T.); (M.C.)
| | - Paolo Bernardi
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Via Ugo Bassi 58/B, I-35131 Padova, Italy; (E.F.); (L.T.); (M.C.)
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11
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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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12
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Carraro M, Bernardi P. The mitochondrial permeability transition pore in Ca 2+ homeostasis. Cell Calcium 2023; 111:102719. [PMID: 36963206 DOI: 10.1016/j.ceca.2023.102719] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 03/26/2023]
Abstract
The mitochondrial Permeability Transition Pore (PTP) can be defined as a Ca2+ activated mega-channel involved in mitochondrial damage and cell death, making its inhibition a hallmark for therapeutic purposes in many PTP-related paradigms. Although long-lasting PTP openings have been widely studied, the physiological implications of transient openings (also called "flickering" behavior) are still poorly understood. The flickering activity was suggested to play a role in the regulation of Ca2+ and ROS homeostasis, and yet this hypothesis did not reach general consensus. This state of affairs might arise from the lack of unquestionable experimental evidence, due to limitations of the available techniques for capturing transient PTP activity and to a still partial understanding of its molecular identity. In this review we will focus on possible implications of the PTP in physiology, in particular its role as a Ca2+ release pathway, discussing the consequences of its forced inhibition. We will also consider the recent hypothesis of the existence of more permeability pathways and their potential involvement in mitochondrial physiology.
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Affiliation(s)
- Michela Carraro
- Department of Biomedical Sciences, University of Padova and CNR Neuroscience Institute, Via Ugo Bassi 58/B, I-35131 Padova, Italy.
| | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padova and CNR Neuroscience Institute, Via Ugo Bassi 58/B, I-35131 Padova, Italy
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13
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Kumar S, Choudhary N, Faruq M, Kumar A, Saran RK, Indercanti PK, Singh V, Sait H, Jaitley S, Valis M, Kuca K, Polipalli SK, Kumar M, Singh T, Suravajhala P, Sharma R, Kapoor S. Anastrozole-mediated modulation of mitochondrial activity by inhibition of mitochondrial permeability transition pore opening: an initial perspective. J Biomol Struct Dyn 2023; 41:14063-14079. [PMID: 36815262 DOI: 10.1080/07391102.2023.2176927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/31/2023] [Indexed: 02/24/2023]
Abstract
The mitochondrial permeability transition pore (mtPTP) plays a vital role in altering the structure and function of mitochondria. Cyclophilin D (CypD) is a mitochondrial protein that regulates mtPTP function and a known drug target for therapeutic studies involving mitochondria. While the effect of aromatase inhibition on the mtPTP has been studied previously, the effect of anastrozole on the mtPTP has not been completely elucidated. The role of anastrozole in modulating the mtPTP was evaluated by docking, molecular dynamics and network-guided studies using human CypD data. The peripheral blood mononuclear cells (PBMCs) of patients with mitochondrial disorders and healthy controls were treated with anastrozole and evaluated for mitochondrial permeability transition pore (mtPTP) function and apoptosis using a flow cytometer. Spectrophotometry was employed for estimating total ATP levels. The anastrozole-CypD complex is more stable than cyclosporin A (CsA)-CypD. Anastrozole performed better than cyclosporine in inhibiting mtPTP. Additional effects included inducing mitochondrial membrane depolarization and a reduction in mitochondrial swelling and superoxide generation, intrinsic caspase-3 activity and cellular apoptosis, along with an increase in ATP levels. Anastrozole may serve as a potential therapeutic agent for mitochondrial disorders and ameliorate the clinical phenotype by regulating the activity of mtPTP. However, further studies are required to substantiate our preliminary findings.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Somesh Kumar
- Pediatrics Genetics & Research Laboratory, Department of Pediatrics, Maulana Azad Medical College & Associated LN Hospital, Delhi, India
| | - Neha Choudhary
- Centre for Computational Biology and Bioinformatics, Central University of Himachal Pradesh, Dharamsala, India
| | - Mohammed Faruq
- Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research (CSIR), Delhi, India
| | - Arun Kumar
- Department of Emergency Medicine, All India Institute of Medical Sciences (AIIMS), New Delhi, India
- Department of Zoology, Kirori Mal College, University of Delhi, Delhi, India
| | - Ravindra K Saran
- Department of Pathology, Govind Ballabh Pant Institute of Postgraduate Medical Education and Research, Delhi, India
| | | | - Vikram Singh
- Centre for Computational Biology and Bioinformatics, Central University of Himachal Pradesh, Dharamsala, India
| | - Haseena Sait
- Pediatrics Genetics & Research Laboratory, Department of Pediatrics, Maulana Azad Medical College & Associated LN Hospital, Delhi, India
| | - Sunita Jaitley
- Department of Biomedical Sciences, Acharya Narendra Dev College, University of Delhi, Delhi, India
| | - Martin Valis
- Department of Neurology of the Medical Faculty of Charles University and University Hospital in Hradec Králové, Hradec Králové, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Sunil K Polipalli
- Pediatrics Genetics & Research Laboratory, Department of Pediatrics, Maulana Azad Medical College & Associated LN Hospital, Delhi, India
| | - Manoj Kumar
- Department of Emergency Medicine, All India Institute of Medical Sciences (AIIMS), New Delhi, India
- Department of Microbiology, World College of Medical Science and Research, Jhajjar, Haryana, India
| | - Tejveer Singh
- Molecular Oncology Laboratory, Department of Zoology, University of Delhi, Delhi, India
| | | | - Rohit Sharma
- Department of Rasa Shastra and Bhaishajya Kalpana, Faculty of Ayurveda, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Seema Kapoor
- Pediatrics Genetics & Research Laboratory, Department of Pediatrics, Maulana Azad Medical College & Associated LN Hospital, Delhi, India
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14
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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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15
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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: 71] [Impact Index Per Article: 35.5] [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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16
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Mitochondrial ATP synthase c-subunit leak channel triggers cell death upon loss of its F 1 subcomplex. Cell Death Differ 2022; 29:1874-1887. [PMID: 35322203 PMCID: PMC9433415 DOI: 10.1038/s41418-022-00972-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/16/2022] [Accepted: 02/28/2022] [Indexed: 02/03/2023] Open
Abstract
Mitochondrial ATP synthase is vital not only for cellular energy production but also for energy dissipation and cell death. ATP synthase c-ring was suggested to house the leak channel of mitochondrial permeability transition (mPT), which activates during excitotoxic ischemic insult. In this present study, we purified human c-ring from both eukaryotic and prokaryotic hosts to biophysically characterize its channel activity. We show that purified c-ring forms a large multi-conductance, voltage-gated ion channel that is inhibited by the addition of ATP synthase F1 subcomplex. In contrast, dissociation of F1 from FO occurs during excitotoxic neuronal death suggesting that the F1 constitutes the gate of the channel. mPT is known to dissipate the osmotic gradient across the inner membrane during cell death. We show that ATP synthase c-subunit knock down (KD) prevents the osmotic change in response to high calcium and eliminates large conductance, Ca2+ and CsA sensitive channel activity of mPT. These findings elucidate the gating mechanism of the ATP synthase c-subunit leak channel (ACLC) and suggest how ACLC opening is regulated by cell stress in a CypD-dependent manner.
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17
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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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18
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Amodeo GF, Krilyuk N, Pavlov EV. Formation of High-Conductive C Subunit Channels upon Interaction with Cyclophilin D. Int J Mol Sci 2021; 22:ijms222011022. [PMID: 34681682 PMCID: PMC8538490 DOI: 10.3390/ijms222011022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/05/2021] [Accepted: 10/10/2021] [Indexed: 12/25/2022] Open
Abstract
The c subunit of the ATP synthase is an inner mitochondrial membrane (IMM) protein. Besides its role as the main component of the rotor of the ATP synthase, c subunit from mammalian mitochondria exhibits ion channel activity. In particular, c subunit may be involved in one of the pathways leading to the formation of the permeability transition pore (PTP) during mitochondrial permeability transition (PT), a phenomenon consisting of the permeabilization of the IMM due to high levels of calcium. Our previous study on the synthetic c subunit showed that high concentrations of calcium induce misfolding into cross-β oligomers that form low-conductance channels in model lipid bilayers of about 400 pS. Here, we studied the effect of cyclophilin D (CypD), a mitochondrial chaperone and major regulator of PTP, on the electrophysiological activity of the c subunit to evaluate its role in the functional properties of c subunit. Our study shows that in presence of CypD, c subunit exhibits a larger conductance, up to 4 nS, that could be related to its potential role in mitochondrial toxicity. Further, our results suggest that CypD is necessary for the formation of c subunit induced PTP but may not be an integral part of the pore.
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19
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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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20
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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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21
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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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22
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Neginskaya MA, Pavlov EV, Sheu SS. Electrophysiological properties of the mitochondrial permeability transition pores: Channel diversity and disease implication. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2021; 1862:148357. [PMID: 33359307 PMCID: PMC7954400 DOI: 10.1016/j.bbabio.2020.148357] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/26/2020] [Accepted: 12/15/2020] [Indexed: 02/07/2023]
Abstract
The mitochondrial permeability transition pore (mPTP) is a channel that, when open, is responsible for a dramatic increase in the permeability of the mitochondrial inner membrane, a process known as the mitochondrial permeability transition (mPT). mPTP activation during Ca2+ dyshomeostasis and oxidative stress disrupts normal mitochondrial function and induces cell death. mPTP opening has been implicated as a critical event in many diseases, including hypoxic injuries, neurodegeneration, and diabetes. Discoveries of recent years indicate that mPTP demonstrates very complicated behavior and regulation, and depending on specific induction or stress conditions, it can function as a high-conductance pore, a small channel, or a non-specific membrane leak. The focus of this review is to summarize the literature on the electrophysiological properties of the mPTP and to evaluate the evidence that it has multiple molecular identities. This review also provides perspective on how an electrophysiological approach can be used to quantitatively investigate the biophysical properties of the mPTP under physiological, pharmacological, pathophysiological, and disease conditions.
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Affiliation(s)
- M A Neginskaya
- Department of Molecular Pathobiology, New York University, New York, NY, USA.
| | - E V Pavlov
- Department of Molecular Pathobiology, New York University, New York, NY, USA
| | - S-S Sheu
- Department of Medicine, Center for Translational Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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23
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Urbani A, Prosdocimi E, Carrer A, Checchetto V, Szabò I. Mitochondrial Ion Channels of the Inner Membrane and Their Regulation in Cell Death Signaling. Front Cell Dev Biol 2021; 8:620081. [PMID: 33585458 PMCID: PMC7874202 DOI: 10.3389/fcell.2020.620081] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/07/2020] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are bioenergetic organelles with a plethora of fundamental functions ranging from metabolism and ATP production to modulation of signaling events leading to cell survival or cell death. Ion channels located in the outer and inner mitochondrial membranes critically control mitochondrial function and, as a consequence, also cell fate. Opening or closure of mitochondrial ion channels allow the fine-tuning of mitochondrial membrane potential, ROS production, and function of the respiratory chain complexes. In this review, we critically discuss the intracellular regulatory factors that affect channel activity in the inner membrane of mitochondria and, indirectly, contribute to cell death. These factors include various ligands, kinases, second messengers, and lipids. Comprehension of mitochondrial ion channels regulation in cell death pathways might reveal new therapeutic targets in mitochondria-linked pathologies like cancer, ischemia, reperfusion injury, and neurological disorders.
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Affiliation(s)
- Andrea Urbani
- Department of Biomedical Sciences, University of Padova, Padua, Italy
- Department of Biology, University of Padova, Padua, Italy
| | | | - Andrea Carrer
- Department of Biomedical Sciences, University of Padova, Padua, Italy
- Department of Biology, University of Padova, Padua, Italy
| | | | - Ildikò Szabò
- Department of Biology, University of Padova, Padua, Italy
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24
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Amodeo GF, Pavlov EV. Amyloid β, α-synuclein and the c subunit of the ATP synthase: Can these peptides reveal an amyloidogenic pathway of the permeability transition pore? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183531. [PMID: 33309700 DOI: 10.1016/j.bbamem.2020.183531] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/26/2020] [Accepted: 11/09/2020] [Indexed: 01/29/2023]
Abstract
Mitochondrial Permeability Transition (PT) is a phenomenon of increased permeability of the inner mitochondrial membrane in response to high levels of Ca2+ and/or reactive oxygen species (ROS) in the matrix. PT occurs upon the opening of a pore, namely the permeability transition pore (PTP), which dissipates the membrane potential uncoupling the respiratory chain. mPT activation and PTP formation can occur through multiple molecular pathways. The specific focus of this review is to discuss the possible molecular mechanisms of PTP that involve the participation of mitochondrially targeted amyloid peptides Aβ, α-synuclein and c subunit of the ATP synthase (ATPase). As activators of PTP, amyloid peptides are uniquely different from other activators because they are capable of forming channels in lipid bilayers. This property rises the possibility that in this permeabilization pathway the formation of the channel involves the direct participation of peptides, making it uniquely different from other PTP induction mechanisms. In this pathway, a critical step of PTP activation involves the import of amyloidogenic peptides from the cytosol into the matrix. In the matrix these peptides, which would fold into α-helical structure in native conditions, interact with cyclophilin D (CypD) and upon stimulation by elevated ROS and/or the Ca2+ spontaneously misfold into β-sheet ion conducting pores, causing PTP opening.
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Affiliation(s)
- Giuseppe F Amodeo
- Department of Molecular Pathobiology, New York University, United States of America.
| | - Evgeny V Pavlov
- Department of Molecular Pathobiology, New York University, United States of America.
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25
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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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26
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Nath S. A Novel Conceptual Model for the Dual Role of FOF1-ATP Synthase in Cell Life and Cell Death. Biomol Concepts 2020; 11:143-152. [PMID: 32827389 DOI: 10.1515/bmc-2020-0014] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/22/2020] [Indexed: 12/31/2022] Open
Abstract
The mitochondrial permeability transition (MPT) has been one of the longstanding enigmas in biology. Its cause is currently at the center of an extensive scientific debate, and several hypotheses on its molecular nature have been put forward. The present view holds that the transition arises from the opening of a high-conductance channel in the energy-transducing membrane, the permeability transition pore (PTP), also called the mitochondrial megachannel or the multiconductance channel (MMC). Here, the novel hypothesis is proposed that the aqueous access channels at the interface of the c-ring and the a-subunit of FO in the FOF1-ATP synthase are repurposed during induction of apoptosis and constitute the elusive PTP/ MMC. A unifying principle based on regulation by local potentials is advanced to rationalize the action of the myriad structurally and chemically diverse inducers and inhibitors of PTP/MMC. Experimental evidence in favor of the hypothesis and its differences from current models of PTP/MMC are summarized. The hypothesis explains in considerable detail how the binding of Ca2+ to a β-catalytic site (site 3) in the F1 portion of ATP synthase triggers the opening of the PTP/MMC. It is also shown to connect to longstanding proposals within Nath's torsional mechanism of energy transduction and ATP synthesis as to how the binding of MgADP to site 3 does not induce PTP/MMC, but instead catalyzes physiological ATP synthesis in cell life. In the author's knowledge, this is the first model that explains how Ca2+ transforms the FOF1-ATP synthase from an exquisite energy-conserving enzyme in cell life into an energy-dissipating structure that promotes cell death. This has major implications for basic as well as for clinical research, such as for the development of drugs that target the MPT, given the established role of PTP/MMC dysregulation in cancer, ischemia, cardiac hypertrophy, and various neurodegenerative diseases.
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Affiliation(s)
- Sunil Nath
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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27
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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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28
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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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29
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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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30
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ATP Synthase C-Subunit-Deficient Mitochondria Have a Small Cyclosporine A-Sensitive Channel, but Lack the Permeability Transition Pore. Cell Rep 2020; 26:11-17.e2. [PMID: 30605668 PMCID: PMC6521848 DOI: 10.1016/j.celrep.2018.12.033] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/01/2018] [Accepted: 12/06/2018] [Indexed: 01/14/2023] Open
Abstract
Permeability transition (PT) is an increase in mitochondrial inner membrane permeability that can lead to a disruption of mitochondrial function and cell death. PT is responsible for tissue damage in stroke and myocardial infarction. It is caused by the opening of a large conductance (~1.5 nS) channel, the mitochondrial PT pore (mPTP). We directly tested the role of the c-subunit of ATP synthase in mPTP formation by measuring channel activity in c-subunit knockout mitochondria. We found that the classic mPTP conductance was lacking in c-subunit knockout mitochondria, but channels sensitive to the PT inhibitor cyclosporine A could be recorded. These channels had a significantly lower conductance compared with the cyclosporine A-sensitive channels detected in parental cells and were sensitive to the ATP/ADP translocase inhibitor bongkrekic acid. We propose that, in the absence of the c-subunit, mPTP cannot be formed, and a distinct cyclosporine A-sensitive low-conductance channel emerges. Neginskaya et al. report that c-subunit-deficient mitochondria contain a CSA-sensitive channel. This channel is much smaller compared with the wild-type permeability transition pore and is sensitive to inhibitors of adenine nucleotide translocase. This work highlights the importance of the c-subunit in forming the permeability transition pore.
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31
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Wacquier B, Combettes L, Dupont G. Dual dynamics of mitochondrial permeability transition pore opening. Sci Rep 2020; 10:3924. [PMID: 32127570 PMCID: PMC7054270 DOI: 10.1038/s41598-020-60177-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 02/06/2020] [Indexed: 11/09/2022] Open
Abstract
Mitochondria play an essential role in bioenergetics and cellular Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ handling. The mitochondrial permeability transition pore (mPTP) is a non-specific channel located in the inner mitochondrial membrane. Long-lasting openings of the pore allow the rapid passage of ions and large molecules, which can result in cell death. The mPTP also exhibits transient, low conductance openings that contribute to Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ homeostasis. Although many regulators of the pore have been identified, none of them uniquely governs the passage between the two operating modes, which thus probably relies on a still unidentified network of interactions. By developing a core computational model for mPTP opening under the control of mitochondrial voltage and Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+, we uncovered the existence of a positive feedback loop leading to bistability. The characteristics of the two stable steady-states correspond to those of the two opening states. When inserted in a full model of Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ handling by mitochondria, our description of the pore reproduces observations in mitochondrial suspensions. Moreover, the model predicted the occurrence of hysteresis in the switching between the two modes, upon addition and removal of free Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ in the extra-mitochondrial medium. Stochastic simulations then confirmed that the pore can undergo transient openings resembling those observed in intact cells.
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Affiliation(s)
- Benjamin Wacquier
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050, Brussels, Belgium
| | | | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050, Brussels, Belgium.
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32
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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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33
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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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34
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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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35
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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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36
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Boyman L, Coleman AK, Zhao G, Wescott AP, Joca HC, Greiser BM, Karbowski M, Ward CW, Lederer WJ. Dynamics of the mitochondrial permeability transition pore: Transient and permanent opening events. Arch Biochem Biophys 2019; 666:31-39. [PMID: 30930285 PMCID: PMC6538282 DOI: 10.1016/j.abb.2019.03.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/19/2019] [Accepted: 03/26/2019] [Indexed: 12/11/2022]
Abstract
A gentle optical examination of the mitochondrial permeability transition pore (mPTP) opening events was carried out in isolated quiescent ventricular myocytes by tracking the inner membrane potential (ΔΨM) using TMRM (tetramethylrhodamine methyl ester). Zeiss Airyscan 880 ″super-resolution" or "high-resolution" imaging was done with very low levels of illumination (0.009% laser power). In cellular areas imaged every 9 s (ROI or regions of interest), transient depolarizations of variable amplitudes occurred at increasing rates for the first 30 min. The time to first depolarization events was 8.4 min (±1.1 SEM n = 21 cells). At longer times, essentially permanent and irreversible depolarizations occurred at an increasing fraction of all events. In other cellular areas surrounding the ROI, mitochondria were rarely illuminated (once per 5 min) and virtually no permanent depolarization events occurred for over 1 h of imaging. These findings suggest that photon stress due to the imaging itself plays an important role in the generation of both the transient mPTP opening events as well as the permanent mPTP opening events. Consistent with the evidence that photon "stress" in mitochondria loaded with virtually any photon absorbing substance, generates reactive oxygen species (ROS) [1-5], we show that cyclosporine-A (CsA, 10 μM) and the antioxidant n-acetyl cysteine (NAC, 10 mM), reduced the number of events by 80% and 93% respectively. Furthermore, CsA and NAC treatment led to the virtual disappearance of permanent depolarization events. Nevertheless, all transient depolarization events in any condition (control, CsA and NAC) appeared to repolarize with a similar half-time of 30 ± 6 s (n = 478) at 37 °C. Further experiments showed quantitatively similar results in cerebral vascular smooth muscle cells, using a different confocal system, and different photon absorbing reagent (TMRE; tetramethylrhodamine ethyl ester). In these experiments, using modest power (1% laser power) transient depolarization events were seen in only 8 out of 23 cells while with higher power (8%), all cells showed transient events, which align with the level of photon stress being the driver of the effect. Together, our findings suggest that photon-induced ROS is sufficient to cause depolarization events of individual mitochondria in quiescent cells; without electrical or mechanical activity to stimulates mitochondrial metabolism, and without raising the mitochondrial matrix Ca2+. In a broad context, these findings neither support nor deny the relevance or occurrence of ΔΨM depolarization events in specific putatively physiologic mitochondrial behaviors such as MitoFlashes [6,7] or MitoWinks [8]. Instead, our findings raise a caution with regards to the physiological and pathophysiological functions attributed to singular ΔΨM depolarization events when those functions are investigated using photon absorbing substances. Nevertheless, using photon stress as a tool ("Optical Stress-Probe"), we can extract information on the activation, reversibility, permanency and kinetics of mitochondrial depolarization. These data may provide new information on mPTP, help identify the mPTP protein complex, and establish the physiological function of the mPTP protein complex and their links to MitoFlashes and MitoWinks.
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Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA.
| | - Andrew K Coleman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Guiling Zhao
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Andrew P Wescott
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Humberto C Joca
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - B Maura Greiser
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA
| | - Chris W Ward
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - W J Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA; Department of Physiology, University of Maryland School of Medicine, 111 Penn Street, Baltimore, MD, 21201, USA.
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37
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Bernardi P. Why F-ATP Synthase Remains a Strong Candidate as the Mitochondrial Permeability Transition Pore. Front Physiol 2018; 9:1543. [PMID: 30443222 PMCID: PMC6221903 DOI: 10.3389/fphys.2018.01543] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 10/15/2018] [Indexed: 01/12/2023] Open
Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
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38
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Guo L, Carraro M, Sartori G, Minervini G, Eriksson O, Petronilli V, Bernardi P. Arginine 107 of yeast ATP synthase subunit g mediates sensitivity of the mitochondrial permeability transition to phenylglyoxal. J Biol Chem 2018; 293:14632-14645. [PMID: 30093404 DOI: 10.1074/jbc.ra118.004495] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 07/27/2018] [Indexed: 12/18/2022] Open
Abstract
Modification with arginine-specific glyoxals modulates the permeability transition (PT) of rat liver mitochondria, with inhibitory or inducing effects that depend on the net charge of the adduct(s). Here, we show that phenylglyoxal (PGO) affects the PT in a species-specific manner (inhibition in mouse and yeast, induction in human and Drosophila mitochondria). Following the hypotheses (i) that the effects are mediated by conserved arginine(s) and (ii) that the PT is mediated by the F-ATP synthase, we have narrowed the search to 60 arginines. Most of these residues are located in subunits α, β, γ, ϵ, a, and c and were excluded because PGO modification did not significantly affect enzyme catalysis. On the other hand, yeast mitochondria lacking subunit g or bearing a subunit g R107A mutation were totally resistant to PT inhibition by PGO. Thus, the effect of PGO on the PT is specifically mediated by Arg-107, the only subunit g arginine that has been conserved across species. These findings are evidence that the PT is mediated by F-ATP synthase.
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Affiliation(s)
- Lishu Guo
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Michela Carraro
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Geppo Sartori
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Giovanni Minervini
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Ove Eriksson
- the Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Valeria Petronilli
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
| | - Paolo Bernardi
- From the Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, Padova 35131, Italy and
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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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40
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Abstract
Mitochondrial ATP generation by oxidative phosphorylation combines the stepwise oxidation by the electron transport chain (ETC) of the reducing equivalents NADH and FADH2 with the generation of ATP by the ATP synthase. Recent studies show that the ATP synthase is not only essential for the generation of ATP but may also contribute to the formation of the mitochondrial permeability transition pore (PTP). We present a model, in which the PTP is located within the c-subunit ring in the Fo subunit of the ATP synthase. Opening of the PTP was long associated with uncoupling of the ETC and the initiation of programmed cell death. More recently, it was shown that PTP opening may serve a physiologic role: it can transiently open to regulate mitochondrial signaling in mature cells, and it is open in the embryonic mouse heart. This review will discuss how the ATP synthase paradoxically lies at the center of both ATP generation and cell death.
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41
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Abstract
Current models theorizing on what the mitochondrial permeability transition (mPT) pore is made of, implicate the c-subunit rings of ATP synthase complex. However, two very recent studies, one on atomistic simulations and in the other disrupting all genes coding for the c subunit disproved those models. As a consequence of this, the structural elements of the pore remain unknown. The purpose of the present short-review is to (i) briefly review the latest findings, (ii) serve as an index for more comprehensive reviews regarding mPT specifics, (iii) reiterate on the potential pitfalls while investigating mPT in conjunction to bioenergetics, and most importantly (iv) suggest to those in search of mPT pore identity, to also look elsewhere.
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Affiliation(s)
- Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary; MTA-SE Lendület Neurobiochemistry Research Group, Hungary.
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42
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Giorgio V, Guo L, Bassot C, Petronilli V, Bernardi P. Calcium and regulation of the mitochondrial permeability transition. Cell Calcium 2017; 70:56-63. [PMID: 28522037 DOI: 10.1016/j.ceca.2017.05.004] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 05/05/2017] [Accepted: 05/05/2017] [Indexed: 12/11/2022]
Abstract
Recent years have seen renewed interest in the permeability transition pore, a high conductance channel responsible for permeabilization of the inner mitochondrial membrane, a process that leads to depolarization and Ca2+ release. Transient openings may be involved in physiological Ca2+ homeostasis while long-lasting openings may trigger and/or execute cell death. In this review we specifically focus (i) on the hypothesis that the PTP forms from the F-ATP synthase and (ii) on the mechanisms through which Ca2+ can reversibly switch this energy-conserving nanomachine into an energy-dissipating device.
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Affiliation(s)
- Valentina Giorgio
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Italy
| | - Lishu Guo
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Italy
| | - Claudio Bassot
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Italy
| | - Valeria Petronilli
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Italy
| | - Paolo Bernardi
- Department of Biomedical Sciences and CNR Neuroscience Institute, University of Padova, Italy.
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43
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Bâ A. Alcohol and thiamine deficiency trigger differential mitochondrial transition pore opening mediating cellular death. Apoptosis 2017; 22:741-752. [DOI: 10.1007/s10495-017-1372-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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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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45
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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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46
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Elustondo PA, Nichols M, Negoda A, Thirumaran A, Zakharian E, Robertson GS, Pavlov EV. Mitochondrial permeability transition pore induction is linked to formation of the complex of ATPase C-subunit, polyhydroxybutyrate and inorganic polyphosphate. Cell Death Discov 2016; 2:16070. [PMID: 27924223 PMCID: PMC5137186 DOI: 10.1038/cddiscovery.2016.70] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/10/2016] [Accepted: 08/19/2016] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial permeability transition pore (mPTP) opening allows free movement of ions and small molecules leading to mitochondrial membrane depolarization and ATP depletion that triggers cell death. A multi-protein complex of the mitochondrial ATP synthase has an essential role in mPTP. However, the molecular identity of the central 'pore' part of mPTP complex is not known. A highly purified fraction of mammalian mitochondria containing C-subunit of ATPase (C-subunit), calcium, inorganic polyphosphate (polyP) and polyhydroxybutyrate (PHB) forms ion channels with properties that resemble the native mPTP. We demonstrate here that amount of this channel-forming complex dramatically increases in intact mitochondria during mPTP activation. This increase is inhibited by both Cyclosporine A, an inhibitor of mPTP and Ruthenium Red, an inhibitor of the Mitochondrial Calcium Uniporter. Similar increases in the amount of complex formation occurs in areas of mouse brain damaged by ischemia-reperfusion injury. These findings suggest that calcium-induced mPTP is associated with de novo assembly of a channel comprising C-subunit, polyP and PHB.
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Affiliation(s)
- P A Elustondo
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University , Halifax, NS, B3H 4R2 Canada
| | - M Nichols
- Departments of Psychiatry and Pharmacology, Brain Repair Centre, Faculty of Medicine Dalhousie University , Halifax, NS, B3H 4R2f Canada
| | - A Negoda
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University , Halifax, NS, B3H 4R2 Canada
| | - A Thirumaran
- Departments of Psychiatry and Pharmacology, Brain Repair Centre, Faculty of Medicine Dalhousie University , Halifax, NS, B3H 4R2f Canada
| | - E Zakharian
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine , 1 Illini Drive, Peoria, IL 61605, USA
| | - G S Robertson
- Departments of Psychiatry and Pharmacology, Brain Repair Centre, Faculty of Medicine Dalhousie University , Halifax, NS, B3H 4R2f Canada
| | - E V Pavlov
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, NS, B3H 4R2 Canada; Department of Basic Sciences, New York University, College of Dentistry, 345 East 24th Street, New York, NY 10010, USA
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47
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Yan S, Du F, Wu L, Zhang Z, Zhong C, Yu Q, Wang Y, Lue LF, Walker DG, Douglas JT, Yan SS. F1F0 ATP Synthase-Cyclophilin D Interaction Contributes to Diabetes-Induced Synaptic Dysfunction and Cognitive Decline. Diabetes 2016; 65:3482-3494. [PMID: 27554467 PMCID: PMC5079631 DOI: 10.2337/db16-0556] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/09/2016] [Indexed: 02/03/2023]
Abstract
Mitochondrial abnormalities are well known to cause cognitive decline. However, the underlying molecular basis of mitochondria-associated neuronal and synaptic dysfunction in the diabetic brain remains unclear. Here, using a mitochondrial single-channel patch clamp and cyclophilin D (CypD)-deficient mice (Ppif -/-) with streptozotocin-induced diabetes, we observed an increase in the probability of Ca2+-induced mitochondrial permeability transition pore (mPTP) opening in brain mitochondria of diabetic mice, which was further confirmed by mitochondrial swelling and cytochrome c release induced by Ca2+ overload. Diabetes-induced elevation of CypD triggers enhancement of F1F0 ATP synthase-CypD interaction, which in turn leads to mPTP opening. Indeed, in patients with diabetes, brain cypD protein levels were increased. Notably, blockade of the F1F0 ATP synthase-CypD interaction by CypD ablation protected against diabetes-induced mPTP opening, ATP synthesis deficits, oxidative stress, and mitochondria dysfunction. Furthermore, the absence of CypD alleviated deficits in synaptic plasticity, learning, and memory in diabetic mice. Thus, blockade of ATP synthase interaction with CypD provides a promising new target for therapeutic intervention in diabetic encephalopathy.
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Affiliation(s)
- Shijun Yan
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Fang Du
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Long Wu
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Zhihua Zhang
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Changjia Zhong
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Qing Yu
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Yongfu Wang
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Lih-Fen Lue
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ
| | - Douglas G Walker
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ
| | - Justin T Douglas
- Nuclear Magnetic Resonance Laboratory, Molecular Structures Group, School of Pharmacy, University of Kansas, Lawrence, KS
| | - Shirley ShiDu Yan
- Department of Pharmacology & Toxicology and Higuchi Bioscience Center, School of Pharmacy, University of Kansas, Lawrence, KS
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48
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Zulian A, Schiavone M, Giorgio V, Bernardi P. Forty years later: Mitochondria as therapeutic targets in muscle diseases. Pharmacol Res 2016; 113:563-573. [PMID: 27697642 DOI: 10.1016/j.phrs.2016.09.043] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 09/29/2016] [Indexed: 11/22/2022]
Abstract
The hypothesis that mitochondrial dysfunction can be a general mechanism for cell death in muscle diseases is 40 years old. The key elements of the proposed pathogenetic sequence (cytosolic Ca2+ overload followed by excess mitochondrial Ca2+ uptake, functional and then structural damage of mitochondria, energy shortage, worsened elevation of cytosolic Ca2+ levels, hypercontracture of muscle fibers, cell necrosis) have been confirmed in amazing detail by subsequent work in a variety of models. The explicit implication of the hypothesis was that it "may provide the basis for a more rational treatment for some conditions even before their primary causes are known" (Wrogemann and Pena, 1976, Lancet, 1, 672-674). This prediction is being fulfilled, and the potential of mitochondria as pharmacological targets in muscle diseases may soon become a reality, particularly through inhibition of the mitochondrial permeability transition pore and its regulator cyclophilin D.
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Affiliation(s)
- Alessandra Zulian
- CNR Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marco Schiavone
- CNR Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Valentina Giorgio
- CNR Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Paolo Bernardi
- CNR Neuroscience Institute and Department of Biomedical Sciences, University of Padova, Padova, Italy.
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49
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Peruzzo R, Biasutto L, Szabò I, Leanza L. Impact of intracellular ion channels on cancer development and progression. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2016; 45:685-707. [PMID: 27289382 PMCID: PMC5045486 DOI: 10.1007/s00249-016-1143-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 05/13/2016] [Accepted: 05/17/2016] [Indexed: 12/13/2022]
Abstract
Cancer research is nowadays focused on the identification of possible new targets in order to try to develop new drugs for curing untreatable tumors. Ion channels have emerged as "oncogenic" proteins, since they have an aberrant expression in cancers compared to normal tissues and contribute to several hallmarks of cancer, such as metabolic re-programming, limitless proliferative potential, apoptosis-resistance, stimulation of neo-angiogenesis as well as cell migration and invasiveness. In recent years, not only the plasma membrane but also intracellular channels and transporters have arisen as oncological targets and were proposed to be associated with tumorigenesis. Therefore, the research is currently focusing on understanding the possible role of intracellular ion channels in cancer development and progression on one hand and, on the other, on developing new possible drugs able to modulate the expression and/or activity of these channels. In a few cases, the efficacy of channel-targeting drugs in reducing tumors has already been demonstrated in vivo in preclinical mouse models.
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Affiliation(s)
| | - Lucia Biasutto
- CNR Institute of Neuroscience, Padua, Italy
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Ildikò Szabò
- Department of Biology, University of Padua, Padua, Italy
- CNR Institute of Neuroscience, Padua, Italy
| | - Luigi Leanza
- Department of Biology, University of Padua, Padua, Italy.
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50
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Gerle C. On the structural possibility of pore-forming mitochondrial FoF1 ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:1191-1196. [PMID: 26968896 DOI: 10.1016/j.bbabio.2016.03.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 02/23/2016] [Accepted: 03/01/2016] [Indexed: 12/31/2022]
Abstract
The mitochondrial permeability transition is an inner mitochondrial membrane event involving the opening of the permeability transition pore concomitant with a sudden efflux of matrix solutes and breakdown of membrane potential. The mitochondrial F(o)F(1) ATP synthase has been proposed as the molecular identity of the permeability transition pore. The likeliness of potential pore-forming sites in the mitochondrial F(o)F(1) ATP synthase is discussed and a new model, the death finger model, is described. In this model, movement of a p-side density that connects the lipid-plug of the c-ring with the distal membrane bending Fo domain allows reversible opening of the c-ring and structural cross-talk with OSCP and the catalytic (αβ)(3) hexamer. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Christoph Gerle
- Picobiology Institute, Department of Life Science, Graduate School of Life Science, University of Hyogo, Kamigori, Japan; Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan.
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