1
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Pan T, Yang B, Yao S, Wang R, Zhu Y. Exploring the multifaceted role of adenosine nucleotide translocase 2 in cellular and disease processes: A comprehensive review. Life Sci 2024; 351:122802. [PMID: 38857656 DOI: 10.1016/j.lfs.2024.122802] [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: 03/07/2024] [Revised: 05/04/2024] [Accepted: 06/04/2024] [Indexed: 06/12/2024]
Abstract
Adenosine nucleotide translocases (ANTs) are a family of proteins abundant in the inner mitochondrial membrane, primarily responsible for shuttling ADP and ATP across the mitochondrial membrane. Additionally, ANTs are key players in balancing mitochondrial energy metabolism and regulating cell death. ANT2 isoform, highly expressed in undifferentiated and proliferating cells, is implicated in the development and drug resistance of various tumors. We conduct a detailed analysis of the potential mechanisms by which ANT2 may influence tumorigenesis and drug resistance. Notably, the significance of ANT2 extends beyond oncology, with roles in non-tumor cell processes including blood cell development, gastrointestinal motility, airway hydration, nonalcoholic fatty liver disease, obesity, chronic kidney disease, and myocardial development, making it a promising therapeutic target for multiple pathologies. To better understand the molecular mechanisms of ANT2, this review summarizes the structural properties, expression patterns, and basic functions of the ANT2 protein. In particular, we review and analyze the controversy surrounding ANT2, focusing on its role in transporting ADP/ATP across the inner mitochondrial membrane, its involvement in the composition of the mitochondrial permeability transition pore, and its participation in apoptosis.
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Affiliation(s)
- Tianhui Pan
- Laboratory of Gastroenterology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, PR China
| | - Bin Yang
- Laboratory of Gastroenterology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, PR China
| | - Sheng Yao
- Laboratory of Gastroenterology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, PR China
| | - Rui Wang
- Laboratory of Gastroenterology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, PR China
| | - Yongliang Zhu
- Laboratory of Gastroenterology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, PR China.
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2
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Bround MJ, Havens JR, York AJ, Sargent MA, Karch J, Molkentin JD. ANT-dependent MPTP underlies necrotic myofiber death in muscular dystrophy. SCIENCE ADVANCES 2023; 9:eadi2767. [PMID: 37624892 PMCID: PMC10456852 DOI: 10.1126/sciadv.adi2767] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023]
Abstract
Mitochondrial permeability transition pore (MPTP) formation contributes to ischemia-reperfusion injury in the heart and several degenerative diseases, including muscular dystrophy (MD). MD is a family of genetic disorders characterized by progressive muscle necrosis and premature death. It has been proposed that the MPTP has two molecular components, the adenine nucleotide translocase (ANT) family of proteins and an unknown component that requires the chaperone cyclophilin D (CypD) to activate. This model was examined in vivo by deleting the gene encoding ANT1 (Slc25a4) or CypD (Ppif) in a δ-sarcoglycan (Sgcd) gene-deleted mouse model of MD, revealing that dystrophic mice lacking Slc25a4 were partially protected from cell death and MD pathology. Dystrophic mice lacking both Slc25a4 and Ppif together were almost completely protected from necrotic cell death and MD disease. This study provides direct evidence that ANT1 and CypD are required MPTP components governing in vivo cell death, suggesting a previously unrecognized therapeutic approach in MD and other necrotic diseases.
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Affiliation(s)
- Michael J. Bround
- Department of Pediatrics, Cincinnati Children's Hospital and the University of Cincinnati, Cincinnati, OH, USA
| | - Julian R. Havens
- Department of Pediatrics, Cincinnati Children's Hospital and the University of Cincinnati, Cincinnati, OH, USA
| | - Allen J. York
- Department of Pediatrics, Cincinnati Children's Hospital and the University of Cincinnati, Cincinnati, OH, USA
| | - Michelle A. Sargent
- Department of Pediatrics, Cincinnati Children's Hospital and the University of Cincinnati, Cincinnati, OH, USA
| | - Jason Karch
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, USA
| | - Jeffery D. Molkentin
- Department of Pediatrics, Cincinnati Children's Hospital and the University of Cincinnati, Cincinnati, OH, USA
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3
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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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4
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Chapa-Dubocq XR, Rodríguez-Graciani KM, Escobales N, Javadov S. Mitochondrial Volume Regulation and Swelling Mechanisms in Cardiomyocytes. Antioxidants (Basel) 2023; 12:1517. [PMID: 37627512 PMCID: PMC10451443 DOI: 10.3390/antiox12081517] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/24/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
Mitochondrion, known as the "powerhouse" of the cell, regulates ion homeostasis, redox state, cell proliferation and differentiation, and lipid synthesis. The inner mitochondrial membrane (IMM) controls mitochondrial metabolism and function. It possesses high levels of proteins that account for ~70% of the membrane mass and are involved in the electron transport chain, oxidative phosphorylation, energy transfer, and ion transport, among others. The mitochondrial matrix volume plays a crucial role in IMM remodeling. Several ion transport mechanisms, particularly K+ and Ca2+, regulate matrix volume. Small increases in matrix volume through IMM alterations can activate mitochondrial respiration, whereas excessive swelling can impair the IMM topology and initiates mitochondria-mediated cell death. The opening of mitochondrial permeability transition pores, the well-characterized phenomenon with unknown molecular identity, in low- and high-conductance modes are involved in physiological and pathological increases of matrix volume. Despite extensive studies, the precise mechanisms underlying changes in matrix volume and IMM structural remodeling in response to energy and oxidative stressors remain unknown. This review summarizes and discusses previous studies on the mechanisms involved in regulating mitochondrial matrix volume, IMM remodeling, and the crosstalk between these processes.
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Affiliation(s)
| | | | | | - Sabzali Javadov
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR 00936-5067, USA; (X.R.C.-D.); (K.M.R.-G.); (N.E.)
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5
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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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6
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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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7
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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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8
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Bernardi P, Carraro M, Lippe G. The mitochondrial permeability transition: Recent progress and open questions. FEBS J 2022; 289:7051-7074. [PMID: 34710270 PMCID: PMC9787756 DOI: 10.1111/febs.16254] [Citation(s) in RCA: 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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9
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Chapa-Dubocq XR, Garcia-Baez JF, Bazil JN, Javadov S. Crosstalk between adenine nucleotide transporter and mitochondrial swelling: experimental and computational approaches. Cell Biol Toxicol 2022:10.1007/s10565-022-09724-2. [PMID: 35606662 DOI: 10.1007/s10565-022-09724-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/10/2022] [Indexed: 11/30/2022]
Abstract
Mitochondrial metabolism and function are modulated by changes in matrix Ca2+. Small increases in the matrix Ca2+ stimulate mitochondrial bioenergetics, whereas excessive Ca2+ leads to cell death by causing massive matrix swelling and impairing the structural and functional integrity of mitochondria. Sustained opening of the non-selective mitochondrial permeability transition pores (PTP) is the main mechanism responsible for mitochondrial Ca2+ overload that leads to mitochondrial dysfunction and cell death. Recent studies suggest the existence of two or more types of PTP, and adenine nucleotide translocator (ANT) and FOF1-ATP synthase were proposed to form the PTP independent of each other. Here, we elucidated the role of ANT in PTP opening by applying both experimental and computational approaches. We first developed and corroborated a detailed model of the ANT transport mechanism including the matrix (ANTM), cytosolic (ANTC), and pore (ANTP) states of the transporter. Then, the ANT model was incorporated into a simple, yet effective, empirical model of mitochondrial bioenergetics to ascertain the point when Ca2+ overload initiates PTP opening via an ANT switch-like mechanism activated by matrix Ca2+ and is inhibited by extra-mitochondrial ADP. We found that encoding a heterogeneous Ca2+ response of at least three types of PTPs, weakly, moderately, and strongly sensitive to Ca2+, enabled the model to simulate Ca2+ release dynamics observed after large boluses were administered to a population of energized cardiac mitochondria. Thus, this study demonstrates the potential role of ANT in PTP gating and proposes a novel mechanism governing the cryptic nature of the PTP phenomenon.
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Affiliation(s)
- Xavier R Chapa-Dubocq
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, 00936-5067, USA
| | - Jorge F Garcia-Baez
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, 00936-5067, USA
| | - Jason N Bazil
- Department of Physiology, Michigan State University, East Lansing, MI, 48824-1046, USA
| | - Sabzali Javadov
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR, 00936-5067, USA.
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10
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Patel P, Mendoza A, Robichaux DJ, Wang MC, Wehrens XHT, Karch J. Inhibition of the Anti-Apoptotic Bcl-2 Family by BH3 Mimetics Sensitize the Mitochondrial Permeability Transition Pore Through Bax and Bak. Front Cell Dev Biol 2021; 9:765973. [PMID: 34926454 PMCID: PMC8672142 DOI: 10.3389/fcell.2021.765973] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/12/2021] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial permeability transition pore (MPTP)-dependent necrosis contributes to numerous pathologies in the heart, brain, and skeletal muscle. The MPTP is a non-selective pore in the inner mitochondrial membrane that is triggered by high levels of matrix Ca2+, and sustained opening leads to mitochondrial dysfunction. Although the MPTP is defined by an increase in inner mitochondrial membrane permeability, the expression of pro-apoptotic Bcl-2 family members, Bax and Bak localization to the outer mitochondrial membrane is required for MPTP-dependent mitochondrial dysfunction and subsequent necrotic cell death. Contrary to the role of Bax and Bak in apoptosis, which is dependent on their oligomerization, MPTP-dependent necrosis does not require oligomerization as monomeric/inactive forms of Bax and Bak can facilitate mitochondrial dysfunction. However, the relationship between Bax and Bak activation/oligomerization and MPTP sensitization remains to be explored. Here, we use a combination of in vitro and ex vivo approaches to determine the role of the anti-apoptotic Bcl-2 family members, which regulate Bax/Bak activity, in necrotic cell death and MPTP sensitivity. To study the role of each predominantly expressed anti-apoptotic Bcl-2 family member (i.e., Mcl-1, Bcl-2, and Bcl-xL) in MPTP regulation, we utilize various BH3 mimetics that specifically bind to and inhibit each. We determined that the inhibition of each anti-apoptotic Bcl-2 family member lowers mitochondrial calcium retention capacity and sensitizes MPTP opening. Furthermore, the inhibition of each Bcl-2 family member exacerbates both apoptotic and necrotic cell death in vitro in a Bax/Bak-dependent manner. Our findings suggests that mitochondrial Ca2+ retention capacity and MPTP sensitivity is influenced by Bax/Bak activation/oligomerization on the outer mitochondrial membrane, providing further evidence of the crosstalk between the apoptotic and necrotic cell death pathways.
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Affiliation(s)
- Pooja Patel
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
| | - Arielys Mendoza
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
| | - Dexter J Robichaux
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
| | - Meng C Wang
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, United States
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
| | - Jason Karch
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States
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11
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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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12
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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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13
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Li A, Li X, Yi J, Ma J, Zhou J. Butyrate Feeding Reverses CypD-Related Mitoflash Phenotypes in Mouse Myofibers. Int J Mol Sci 2021; 22:7412. [PMID: 34299032 PMCID: PMC8304904 DOI: 10.3390/ijms22147412] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/05/2021] [Accepted: 07/08/2021] [Indexed: 12/12/2022] Open
Abstract
Mitoflashes are spontaneous transients of the biosensor mt-cpYFP. In cardiomyocytes, mitoflashes are associated with the cyclophilin D (CypD) mediated opening of mitochondrial permeability transition pore (mPTP), while in skeletal muscle they are considered hallmarks of mitochondrial respiration burst under physiological conditions. Here, we evaluated the potential association between mitoflashes and the mPTP opening at different CypD levels and phosphorylation status by generating three CypD derived fusion constructs with a red shifted, pH stable Ca2+ sensor jRCaMP1b. We observed perinuclear mitochondrial Ca2+ efflux accompanying mitoflashes in CypD and CypDS42A (a phosphor-resistant mutation at Serine 42) overexpressed myofibers but not the control myofibers expressing the mitochondria-targeting sequence of CypD (CypDN30). Assisted by a newly developed analysis program, we identified shorter, more frequent mitoflash activities occurring over larger areas in CypD and CypDS42A overexpressed myofibers than the control CypDN30 myofibers. These observations provide an association between the elevated CypD expression and increased mitoflash activities in hindlimb muscles in an amyotrophic lateral sclerosis (ALS) mouse model previously observed. More importantly, feeding the mice with sodium butyrate reversed the CypD-associated mitoflash phenotypes and protected against ectopic upregulation of CypD, unveiling a novel molecular mechanism underlying butyrate mediated alleviation of ALS progression in the mouse model.
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Affiliation(s)
- Ang Li
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, TX 76010, USA; (X.L.); (J.Y.)
| | - Xuejun Li
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, TX 76010, USA; (X.L.); (J.Y.)
| | - Jianxun Yi
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, TX 76010, USA; (X.L.); (J.Y.)
| | - Jianjie Ma
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA;
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, TX 76010, USA; (X.L.); (J.Y.)
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14
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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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15
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Bernardi P. Looking Back to the Future of Mitochondrial Research. Front Physiol 2021; 12:682467. [PMID: 33995132 PMCID: PMC8119648 DOI: 10.3389/fphys.2021.682467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 04/12/2021] [Indexed: 12/03/2022] Open
Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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16
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Mitochondrial Dysfunction and Permeability Transition in Neonatal Brain and Lung Injuries. Cells 2021; 10:cells10030569. [PMID: 33807810 PMCID: PMC7999701 DOI: 10.3390/cells10030569] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 01/16/2023] Open
Abstract
This review discusses the potential mechanistic role of abnormally elevated mitochondrial proton leak and mitochondrial bioenergetic dysfunction in the pathogenesis of neonatal brain and lung injuries associated with premature birth. Providing supporting evidence, we hypothesized that mitochondrial dysfunction contributes to postnatal alveolar developmental arrest in bronchopulmonary dysplasia (BPD) and cerebral myelination failure in diffuse white matter injury (WMI). This review also analyzes data on mitochondrial dysfunction triggered by activation of mitochondrial permeability transition pore(s) (mPTP) during the evolution of perinatal hypoxic-ischemic encephalopathy. While the still cryptic molecular identity of mPTP continues to be a subject for extensive basic science research efforts, the translational significance of mitochondrial proton leak received less scientific attention, especially in diseases of the developing organs. This review is focused on the potential mechanistic relevance of mPTP and mitochondrial dysfunction to neonatal diseases driven by developmental failure of organ maturation or by acute ischemia-reperfusion insult during development.
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17
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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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18
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Moon SH, Dilthey BG, Liu X, Guan S, Sims HF, Gross RW. High-fat diet activates liver iPLA 2γ generating eicosanoids that mediate metabolic stress. J Lipid Res 2021; 62:100052. [PMID: 33636162 PMCID: PMC8010217 DOI: 10.1016/j.jlr.2021.100052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 12/18/2022] Open
Abstract
High-fat (HF) diet-induced obesity precipitates multiple metabolic disorders including insulin resistance, glucose intolerance, oxidative stress, and inflammation, resulting in the initiation of cell death programs. Previously, we demonstrated murine germline knockout of calcium-independent phospholipase A2γ (iPLA2γ) prevented HF diet-induced weight gain, attenuated insulin resistance, and decreased mitochondrial permeability transition pore (mPTP) opening leading to alterations in bioenergetics. To gain insight into the specific roles of hepatic iPLA2γ in mitochondrial function and cell death under metabolic stress, we generated a hepatocyte-specific iPLA2γ-knockout (HEPiPLA2γKO). Using this model, we compared the effects of an HF diet on wild-type versus HEPiPLA2γKO mice in eicosanoid production and mitochondrial bioenergetics. HEPiPLA2γKO mice exhibited higher glucose clearance rates than WT controls. Importantly, HF-diet induced the accumulation of 12-hydroxyeicosatetraenoic acid (12-HETE) in WT liver which was decreased in HEPiPLA2γKO. Furthermore, HF-feeding markedly increased Ca2+ sensitivity and resistance to ADP-mediated inhibition of mPTP opening in WT mice. In contrast, ablation of iPLA2γ prevented the HF-induced hypersensitivity of mPTP opening to calcium and maintained ADP-mediated resistance to mPTP opening. Respirometry revealed that ADP-stimulated mitochondrial respiration was significantly reduced by exogenous 12-HETE. Finally, HEPiPLA2γKO hepatocytes were resistant to calcium ionophore-induced lipoxygenase-mediated lactate dehydrogenase release. Collectively, these results demonstrate that an HF diet increases iPLA2γ-mediated hepatic 12-HETE production leading to mitochondrial dysfunction and hepatic cell death.
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Affiliation(s)
- Sung Ho Moon
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - Beverly Gibson Dilthey
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - Xinping Liu
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - Shaoping Guan
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - Harold F Sims
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - Richard W Gross
- Division of Bioorganic Chemistry and Molecular Pharmacology, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA; Department of Developmental Biology, Washington University School of Medicine, Saint Louis, MO, USA; Center for Cardiovascular Research, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA; Department of Chemistry, Washington University, Saint Louis, MO, USA.
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19
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Kent AC, El Baradie KBY, Hamrick MW. Targeting the Mitochondrial Permeability Transition Pore to Prevent Age-Associated Cell Damage and Neurodegeneration. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6626484. [PMID: 33574977 PMCID: PMC7861926 DOI: 10.1155/2021/6626484] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 02/07/2023]
Abstract
The aging process is associated with significant alterations in mitochondrial function. These changes in mitochondrial function are thought to involve increased production of reactive oxygen species (ROS), which over time contribute to cell death, senescence, tissue degeneration, and impaired tissue repair. The mitochondrial permeability transition pore (mPTP) is likely to play a critical role in these processes, as increased ROS activates mPTP opening, which further increases ROS production. Injury and inflammation are also thought to increase mPTP opening, and chronic, low-grade inflammation is a hallmark of aging. Nicotinamide adenine dinucleotide (NAD+) can suppress the frequency and duration of mPTP opening; however, NAD+ levels are known to decline with age, further stimulating mPTP opening and increasing ROS release. Research on neurodegenerative diseases, particularly on Parkinson's disease (PD) and Alzheimer's disease (AD), has uncovered significant findings regarding mPTP openings and aging. Parkinson's disease is associated with a reduction in mitochondrial complex I activity and increased oxidative damage of DNA, both of which are linked to mPTP opening and subsequent ROS release. Similarly, AD is associated with increased mPTP openings, as evidenced by amyloid-beta (Aβ) interaction with the pore regulator cyclophilin D (CypD). Targeted therapies that can reduce the frequency and duration of mPTP opening may therefore have the potential to prevent age-related declines in cell and tissue function in various systems including the central nervous system.
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Affiliation(s)
- Andrew C. Kent
- Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- University of Georgia, Athens, GA, USA
| | | | - Mark W. Hamrick
- Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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20
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Koushi M, Asakai R. Bisindolylpyrrole Induces a Cpr3- and Porin1/2-Dependent Transition in Yeast Mitochondrial Permeability in a Low Conductance State via the AACs-Associated Pore. Int J Mol Sci 2021; 22:ijms22031212. [PMID: 33530556 PMCID: PMC7865566 DOI: 10.3390/ijms22031212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/17/2021] [Accepted: 01/22/2021] [Indexed: 02/07/2023] Open
Abstract
Although the mitochondrial permeability transition pore (PTP) is presumably formed by either ATP synthase or the ATP/ADP carrier (AAC), little is known about their differential roles in PTP activation. We explored the role of AAC and ATP synthase in PTP formation in Saccharomyces cerevisiae using bisindolylpyrrole (BP), an activator of the mammalian PTP. The yeast mitochondrial membrane potential, as indicated by tetramethylrhodamine methyl ester signals, dissipated over 2–4 h after treatment of cells with 5 μM BP, which was sensitive to cyclosporin A (CsA) and Cpr3 deficiency and blocked by porin1/2 deficiency. The BP-induced depolarization was inhibited by a specific AAC inhibitor, bongkrekate, and consistently blocked in a yeast strain lacking all three AACs, while it was not affected in the strain with defective ATP synthase dimerization, suggesting the involvement of an AAC-associated pore. Upon BP treatment, isolated yeast mitochondria underwent CsA- and bongkrekate-sensitive depolarization without affecting the mitochondrial calcein signals, indicating the induction of a low conductance channel. These data suggest that, upon BP treatment, yeast can form a porin1/2- and Cpr3-regulated PTP, which is mediated by AACs but not by ATP synthase dimers. This implies that yeast may be an excellent tool for the screening of PTP modulators.
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Affiliation(s)
| | - Rei Asakai
- Correspondence: ; Tel.: +81-475-53-4588; Fax: +81-475-53-4556
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21
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Brustovetsky N. The Role of Adenine Nucleotide Translocase in the Mitochondrial Permeability Transition. Cells 2020; 9:E2686. [PMID: 33333766 PMCID: PMC7765165 DOI: 10.3390/cells9122686] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/10/2020] [Accepted: 12/12/2020] [Indexed: 12/30/2022] Open
Abstract
The mitochondrial permeability transition, a Ca2+-induced significant increase in permeability of the inner mitochondrial membrane, plays an important role in various pathologies. The mitochondrial permeability transition is caused by induction of the permeability transition pore (PTP). Despite significant effort, the molecular composition of the PTP is not completely clear and remains an area of hot debate. The Ca2+-modified adenine nucleotide translocase (ANT) and F0F1 ATP synthase are the major contenders for the role of pore in the PTP. This paper briefly overviews experimental results focusing on the role of ANT in the mitochondrial permeability transition and proposes that multiple molecular entities might be responsible for the conductance pathway of the PTP. Consequently, the term PTP cannot be applied to a single specific protein such as ANT or a protein complex such as F0F1 ATP synthase, but rather should comprise a variety of potential contributors to increased permeability of the inner mitochondrial membrane.
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Affiliation(s)
- Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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22
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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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23
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A systematic review of post-translational modifications in the mitochondrial permeability transition pore complex associated with cardiac diseases. Biochim Biophys Acta Mol Basis Dis 2020; 1867:165992. [PMID: 33091565 DOI: 10.1016/j.bbadis.2020.165992] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/23/2020] [Accepted: 10/08/2020] [Indexed: 12/28/2022]
Abstract
The mitochondrial permeability transition pore (mPTP) opening is involved in the pathophysiology of multiple cardiac diseases, such as ischemia/reperfusion injury and heart failure. A growing number of evidence provided by proteomic screening techniques has demonstrated the role of post-translational modifications (PTMs) in several key components of the pore in response to changes in the extra/intracellular environment and bioenergetic demand. This could lead to a fine, complex regulatory mechanism that, under pathological conditions, can shift the state of mitochondrial functions and, thus, the cell's fate. Understanding the complex relationship between these PTMs is still under investigation and can provide new, promising therapeutic targets and treatment approaches. This review, using a systematic review of the literature, presents the current knowledge on PTMs of the mPTP and their role in health and cardiac disease.
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24
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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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25
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Carraro M, Jones K, Sartori G, Schiavone M, Antonucci S, Kucharczyk R, di Rago JP, Franchin C, Arrigoni G, Forte M, Bernardi P. The Unique Cysteine of F-ATP Synthase OSCP Subunit Participates in Modulation of the Permeability Transition Pore. Cell Rep 2020; 32:108095. [DOI: 10.1016/j.celrep.2020.108095] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/13/2020] [Accepted: 08/10/2020] [Indexed: 12/31/2022] Open
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26
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Structural and functional properties of plant mitochondrial F-ATP synthase. Mitochondrion 2020; 53:178-193. [DOI: 10.1016/j.mito.2020.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/25/2020] [Accepted: 06/08/2020] [Indexed: 12/13/2022]
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27
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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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28
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Dubinin MV, Talanov EY, Tenkov KS, Starinets VS, Mikheeva IB, Belosludtsev KN. Transport of Ca 2+ and Ca 2+-dependent permeability transition in heart mitochondria in the early stages of Duchenne muscular dystrophy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148250. [PMID: 32569663 DOI: 10.1016/j.bbabio.2020.148250] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/05/2020] [Accepted: 06/12/2020] [Indexed: 01/01/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a progressive skeletal muscle disease that is associated with severe cardiac complications in the late stages. Significant mitochondrial dysfunction is reportedly responsible for the development of cardiomyopathy with age. At the same time, adaptive changes in mitochondrial metabolism in cardiomyocytes were identified in the early stages of DMD. In this work, we evaluate the functioning of calcium transport systems (MCU and NCLX), and MPT pore in the heart mitochondria of young dystrophin-deficient mice. As compared to wild-type animals, heart mitochondria of mdx mice have been found to be more efficient both in respect to Ca2+ uniport and Na+-dependent Ca2+ efflux. The data obtained indicate that the increased rate of Ca2+ uptake by heart mitochondria of mdx mice may be due to an increase in the ratio of MCU and MCUb subunits. In turn, an increase in the rate of Ca2+ efflux from organelles in DMD may be the result of a significant increase in the level of NCLX. Moreover, the heart mitochondria of mdx mice were more resistant to MPT pore opening, which may be due to an increase in the microviscosity of mitochondrial membranes of DMD mice. At the same time, the level of putative MPT pore proteins did not change. The paper discusses the effect of rearrangements of the mitochondrial proteome involved in the transport and accumulation of calcium on the adaptation of this organ to DMD.
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Affiliation(s)
- Mikhail V Dubinin
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia.
| | - Eugeny Yu Talanov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Kirill S Tenkov
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia
| | - Vlada S Starinets
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Irina B Mikheeva
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - Konstantin N Belosludtsev
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow Region 142290, Russia
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29
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Bround MJ, Bers DM, Molkentin JD. A 20/20 view of ANT function in mitochondrial biology and necrotic cell death. J Mol Cell Cardiol 2020; 144:A3-A13. [PMID: 32454061 DOI: 10.1016/j.yjmcc.2020.05.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/16/2020] [Accepted: 05/20/2020] [Indexed: 12/25/2022]
Abstract
The adenosine nucleotide translocase (ANT) family of proteins are inner mitochondrial membrane proteins involved in energy homeostasis and cell death. The primary function of ANT proteins is to exchange cytosolic ADP with matrix ATP, facilitating the export of newly synthesized ATP to the cell while providing new ADP substrate to the mitochondria. As such, the ANT proteins are central to maintaining energy homeostasis in all eukaryotic cells. Evidence also suggests that the ANTs constitute a pore-forming component of the mitochondrial permeability transition pore (MPTP), a structure that forms in the inner mitochondrial membrane that is thought to underlie regulated necrotic cell death. Additionally, emerging studies suggest that ANT proteins are also critical for mitochondrial uncoupling and for promoting mitophagy. Thus, the ANTs are multifunctional proteins that are poised to participate in several aspects of mitochondrial biology and the greater regulation of cell death, which will be discussed here.
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Affiliation(s)
- Michael J Bround
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Jeffery D Molkentin
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA; Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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30
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Mechanisms for Ca 2+-dependent permeability transition in mitochondria. Proc Natl Acad Sci U S A 2020; 117:2743-2744. [PMID: 31992648 DOI: 10.1073/pnas.1921035117] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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31
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Patel P, Karch J. Regulation of cell death in the cardiovascular system. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 353:153-209. [PMID: 32381175 DOI: 10.1016/bs.ircmb.2019.11.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The adult heart is a post-mitotic terminally differentiated organ; therefore, beyond development, cardiomyocyte cell death is maladaptive. Heart disease is the leading cause of death in the world and aberrant cardiomyocyte cell death is the underlying problem for most cardiovascular-related diseases and fatalities. In this chapter, we will discuss the different cell death mechanisms that engage during normal cardiac development, aging, and disease states. The most abundant loss of cardiomyocytes occurs during a myocardial infarction, when the blood supply to the heart is obstructed, and the affected myocardium succumbs to cell death. Originally, this form of cell death was considered to be unregulated; however, research from the last half a century clearly demonstrates that this form of cell death is multifaceted and employees various degrees of regulation. We will explore all of the cell death pathways that have been implicated in this disease state and the potential interplay between them. Beyond myocardial infarction, we also explore the role and mechanisms of cardiomyocyte cell death in heart failure, myocarditis, and chemotherapeutic-induced cardiotoxicity. Inhibition of cardiomyocyte cell death has extensive therapeutic potential that will increase the longevity and health of the human heart.
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Affiliation(s)
- Pooja Patel
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States
| | - Jason Karch
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, United States.
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32
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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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33
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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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34
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Karch J, Bround MJ, Khalil H, Sargent MA, Latchman N, Terada N, Peixoto PM, Molkentin JD. Inhibition of mitochondrial permeability transition by deletion of the ANT family and CypD. SCIENCE ADVANCES 2019; 5:eaaw4597. [PMID: 31489369 PMCID: PMC6713508 DOI: 10.1126/sciadv.aaw4597] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 07/25/2019] [Indexed: 05/19/2023]
Abstract
The mitochondrial permeability transition pore (MPTP) has resisted molecular identification. The original model of the MPTP that proposed the adenine nucleotide translocator (ANT) as the inner membrane pore-forming component was challenged when mitochondria from Ant1/2 double null mouse liver still had MPTP activity. Because mice express three Ant genes, we reinvestigated whether the ANTs comprise the MPTP. Liver mitochondria from Ant1, Ant2, and Ant4 deficient mice were highly refractory to Ca2+-induced MPTP formation, and when also given cyclosporine A (CsA), the MPTP was completely inhibited. Moreover, liver mitochondria from mice with quadruple deletion of Ant1, Ant2, Ant4, and Ppif (cyclophilin D, target of CsA) lacked Ca2+-induced MPTP formation. Inner-membrane patch clamping in mitochondria from Ant1, Ant2, and Ant4 triple null mouse embryonic fibroblasts showed a loss of MPTP activity. Our findings suggest a model for the MPTP consisting of two distinct molecular components: The ANTs and an unknown species requiring CypD.
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Affiliation(s)
- Jason Karch
- Department of Pediatrics, Cincinnati Children's Hospital and University of Cincinnati, Cincinnati, OH, USA
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, Baylor College of Medicine, Houston TX, USA
| | - Michael J. Bround
- Department of Pediatrics, Cincinnati Children's Hospital and University of Cincinnati, Cincinnati, OH, USA
| | - Hadi Khalil
- Department of Pediatrics, Cincinnati Children's Hospital and University of Cincinnati, Cincinnati, OH, USA
| | - Michelle A. Sargent
- Department of Pediatrics, Cincinnati Children's Hospital and University of Cincinnati, Cincinnati, OH, USA
| | - Nadina Latchman
- Baruch College and Graduate Center of City University of New York, NY, USA
| | - Naohiro Terada
- Department of Pathology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Pablo M. Peixoto
- Baruch College and Graduate Center of City University of New York, NY, USA
| | - Jeffery D. Molkentin
- Department of Pediatrics, Cincinnati Children's Hospital and University of Cincinnati, Cincinnati, OH, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
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35
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Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy.
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36
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Carraro M, Checchetto V, Szabó I, Bernardi P. F‐ATPsynthase and the permeability transition pore: fewer doubts, more certainties. FEBS Lett 2019; 593:1542-1553. [DOI: 10.1002/1873-3468.13485] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Michela Carraro
- Department of Biomedical Sciences University of Padova Italy
| | | | - Ildikó Szabó
- Department of Biology University of Padova Italy
| | - Paolo Bernardi
- Department of Biomedical Sciences University of Padova Italy
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37
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Molecular Identities and ATP Release Activities of Two Types of Volume-Regulatory Anion Channels, VSOR and Maxi-Cl. CURRENT TOPICS IN MEMBRANES 2018; 81:125-176. [PMID: 30243431 DOI: 10.1016/bs.ctm.2018.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An elaborate volume regulation system based on interplay of ion channels and transporters was evolved to cope with constant osmotic challenges caused by intensive metabolism, transport and other physiological/pathophysiological events. In animal cells, two types of anion channels are directly activated by cell swelling and involved in the regulatory volume decrease (RVD): volume-sensitive outwardly rectifying anion channel (VSOR), also called volume-regulated anion channel (VRAC), and Maxi-Cl which is the most major type of maxi-anion channel (MAC). These two channels have very different biophysical profiles and exhibit opposite dependence on intracellular ATP. After several decades of verifying many false-positive candidates for VSOR and Maxi-Cl, LRRC8 family proteins emerged as major VSOR components, and SLCO2A1 protein as a core of Maxi-Cl. Still, neither of these proteins alone can fully reproduce the native channel phenotypes suggesting existence of missing components. Although both VSOR and Maxi-Cl have pores wide enough to accommodate bulky ATP4- and MgATP2- anions, evidence accumulated hitherto, based on pharmacological and gene silencing experiments, suggests that Maxi-Cl, but not VSOR, serves as one of the major pathways for the release of ATP from swollen and ischemic/hypoxic cells. Relations of VSOR and Maxi-Cl with diseases and their selective pharmacology are the topics promoted by recent advance in molecular identification of the two volume-activated, volume-regulatory anion channels.
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38
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Baines CP, Gutiérrez-Aguilar M. The still uncertain identity of the channel-forming unit(s) of the mitochondrial permeability transition pore. Cell Calcium 2018; 73:121-130. [PMID: 29793100 PMCID: PMC5993635 DOI: 10.1016/j.ceca.2018.05.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/07/2018] [Accepted: 05/12/2018] [Indexed: 10/16/2022]
Abstract
Mitochondria from different organisms can undergo a sudden process of inner membrane unselective leakiness to molecules known as the mitochondrial permeability transition (MPT). This process has been studied for nearly four decades and several proteins have been claimed to constitute, or at least regulate the usually inactive pore responsible for this transition. However, no protein candidate proposed as the actual pore-forming unit has passed rigorous gain- or loss-of-function genetic tests. Here we review evidence for -and against- putative channel-forming components of the MPT pore. We conclude that the structure of the MPT pore still remains largely undefined and suggest that future studies should follow established technical considerations to unambiguously consolidate the channel forming constituent(s) of the MPT pore.
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Affiliation(s)
- Christopher P Baines
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211, USA; Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, MO 65211, USA; Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, MO 65211, USA.
| | - Manuel Gutiérrez-Aguilar
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, Mexico.
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39
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Karch J, Molkentin JD. Identity of the elusive mitochondrial permeability transition pore: what it might be, what it was, and what it still could be. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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40
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Amodeo GF, Solesio ME, Pavlov EV. From ATP synthase dimers to C-ring conformational changes: unified model of the mitochondrial permeability transition pore. Cell Death Dis 2017; 8:1. [PMID: 29233966 PMCID: PMC5839071 DOI: 10.1038/s41419-017-0042-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 08/11/2017] [Accepted: 10/06/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Giuseppe Federico Amodeo
- Department of Basic Sciences, New York University, College of Dentistry, 345 East 24th Street, New York, NY, 10010, USA
| | - Maria E Solesio
- Department of Basic Sciences, New York University, College of Dentistry, 345 East 24th Street, New York, NY, 10010, USA
| | - Evgeny V Pavlov
- Department of Basic Sciences, New York University, College of Dentistry, 345 East 24th Street, New York, NY, 10010, USA.
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41
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Mitochondrial Calcium Uptake in Activation of the Permeability Transition Pore and Cell Death. MOLECULAR BASIS FOR MITOCHONDRIAL SIGNALING 2017. [DOI: 10.1007/978-3-319-55539-3_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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42
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Konstantinov YM, Dietrich A, Weber-Lotfi F, Ibrahim N, Klimenko ES, Tarasenko VI, Bolotova TA, Koulintchenko MV. DNA import into mitochondria. BIOCHEMISTRY (MOSCOW) 2016; 81:1044-1056. [DOI: 10.1134/s0006297916100035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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43
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Quantification of active mitochondrial permeability transition pores using GNX-4975 inhibitor titrations provides insights into molecular identity. Biochem J 2016; 473:1129-40. [PMID: 26920024 PMCID: PMC4845862 DOI: 10.1042/bcj20160070] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/24/2016] [Indexed: 01/11/2023]
Abstract
The molecular identity of the mitochondrial permeability transition pore (MPTP), a key player in cell death, remains controversial. Here we use a novel MPTP inhibitor to demonstrate that formation of the pore involves native mitochondrial membrane proteins adopting novel conformations. Inhibition of the mitochondrial permeability transition pore (MPTP) by the novel inhibitor GNX-4975 was characterized. Titration of MPTP activity in de-energized rat liver mitochondria allowed determination of the number of GNX-4975-binding sites and their dissociation constant (Ki). Binding sites increased in number when MPTP opening was activated by increasing [Ca2+], phenylarsine oxide (PAO) or KSCN, and decreased when MPTP opening was inhibited with bongkrekic acid (BKA) or ADP. Values ranged between 9 and 50 pmol/mg of mitochondrial protein, but the Ki remained unchanged at ∼1.8 nM when the inhibitor was added before Ca2+. However, when GNX-4975 was added after Ca2+ it was much less potent with a Ki of ∼140 nM. These data imply that a protein conformational change is required to form the MPTP complex and generate the GNX-4975-binding site. Occupation of the latter with GNX-4975 prevents the Ca2+ binding that triggers pore opening. We also demonstrated that GNX-4975 stabilizes an interaction between the adenine nucleotide translocase (ANT), held in its ‘c’ conformation with carboxyatractyloside (CAT), and the phosphate carrier (PiC) bound to immobilized PAO. No components of the F1Fo-ATP synthase bound significantly to immobilized PAO. Our data are consistent with our previous proposal that the MPTP may form at an interface between the PiC and ANT (or other similar mitochondrial carrier proteins) when they adopt novel conformations induced by factors that sensitize the MPTP to [Ca2+]. We propose that GNX-4975 binds to this interface preventing a calcium-triggered event that opens the interface into a pore.
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44
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Sabirov RZ, Merzlyak PG, Islam MR, Okada T, Okada Y. The properties, functions, and pathophysiology of maxi-anion channels. Pflugers Arch 2016; 468:405-20. [DOI: 10.1007/s00424-015-1774-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/11/2015] [Accepted: 12/15/2015] [Indexed: 01/19/2023]
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45
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Nucleic acid import into mitochondria: New insights into the translocation pathways. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3165-81. [DOI: 10.1016/j.bbamcr.2015.09.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 08/16/2015] [Accepted: 09/10/2015] [Indexed: 11/18/2022]
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46
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Todisco S, Di Noia MA, Onofrio A, Parisi G, Punzi G, Redavid G, De Grassi A, Pierri CL. Identification of new highly selective inhibitors of the human ADP/ATP carriers by molecular docking and in vitro transport assays. Biochem Pharmacol 2015; 100:112-32. [PMID: 26616220 DOI: 10.1016/j.bcp.2015.11.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 11/18/2015] [Indexed: 12/16/2022]
Abstract
Mitochondrial carriers are proteins that shuttle a variety of metabolites, nucleotides and coenzymes across the inner mitochondrial membrane. The mitochondrial ADP/ATP carriers (AACs) specifically translocate the ATP synthesized within mitochondria to the cytosol in exchange for the cytosolic ADP, playing a key role in energy production, in promoting cell viability and regulating mitochondrial permeability transition pore opening. In Homo sapiens four genes code for AACs with different tissue distribution and expression patterns. Since AACs are dysregulated in several cancer types, the employment of known and new AAC inhibitors might be crucial for inducing mitochondrial-mediated apoptosis in cancer cells. Albeit carboxyatractyloside (CATR) and bongkrekic acid (BKA) are known to be powerful and highly selective AAC inhibitors, able to induce mitochondrial dysfunction at molecular level and poisoning at physiological level, we estimated here for the first time their affinity for the human recombinant AAC2 by in vitro transport assays. We found that the inhibition constants of CATR and BKA are 4 nM and 2.0 μM, respectively. For finding new AAC inhibitors we also performed a docking-based virtual screening of an in-house developed chemical library and we identified about 100 ligands showing high affinity for the AAC2 binding region. By testing 13 commercially available molecules, out of the 100 predicted candidates, we found that 2 of them, namely suramin and chebulinic acid, are competitive AAC2 inhibitors with inhibition constants 0.3 μM and 2.1 μM, respectively. We also demonstrated that chebulinic acid and suramin are "highly selective" AAC2 inhibitors, since they poorly inhibit other human mitochondrial carriers (namely ORC1, APC1 and AGC1).
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Affiliation(s)
- Simona Todisco
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy; Department of Sciences, University of Basilicata, Via N. Sauro 85, 85100 Potenza, Italy
| | - Maria Antonietta Di Noia
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Angelo Onofrio
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Giovanni Parisi
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Giuseppe Punzi
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Giandomenico Redavid
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Anna De Grassi
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Ciro Leonardo Pierri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy.
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47
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Bernardi P, Rasola A, Forte M, Lippe G. The Mitochondrial Permeability Transition Pore: Channel Formation by F-ATP Synthase, Integration in Signal Transduction, and Role in Pathophysiology. Physiol Rev 2015; 95:1111-55. [PMID: 26269524 DOI: 10.1152/physrev.00001.2015] [Citation(s) in RCA: 420] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The mitochondrial permeability transition (PT) is a permeability increase of the inner mitochondrial membrane mediated by a channel, the permeability transition pore (PTP). After a brief historical introduction, we cover the key regulatory features of the PTP and provide a critical assessment of putative protein components that have been tested by genetic analysis. The discovery that under conditions of oxidative stress the F-ATP synthases of mammals, yeast, and Drosophila can be turned into Ca(2+)-dependent channels, whose electrophysiological properties match those of the corresponding PTPs, opens new perspectives to the field. We discuss structural and functional features of F-ATP synthases that may provide clues to its transition from an energy-conserving into an energy-dissipating device as well as recent advances on signal transduction to the PTP and on its role in cellular pathophysiology.
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Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
| | - Andrea Rasola
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
| | - Michael Forte
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
| | - Giovanna Lippe
- Department of Biomedical Sciences and Consiglio Nazionale delle Ricerche Neuroscience Institute, University of Padova, Padova, Italy; Vollum Institute, Oregon Health and Sciences University, Portland, Oregon; and Department of Food Science, University of Udine, Udine, Italy
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48
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Kwong JQ, Molkentin JD. Physiological and pathological roles of the mitochondrial permeability transition pore in the heart. Cell Metab 2015; 21:206-214. [PMID: 25651175 PMCID: PMC4616258 DOI: 10.1016/j.cmet.2014.12.001] [Citation(s) in RCA: 305] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Prolonged mitochondrial permeability transition pore (MPTP) opening results in mitochondrial energetic dysfunction, organelle swelling, rupture, and typically a type of necrotic cell death. However, acute opening of the MPTP has a critical physiologic role in regulating mitochondrial Ca(2+) handling and metabolism. Despite the physiological and pathological roles that the MPTP orchestrates, the proteins that comprise the pore itself remain an area of ongoing investigation. Here, we will discuss the molecular composition of the MPTP and its role in regulating cardiac physiology and disease. A better understanding of MPTP structure and function will likely suggest novel cardioprotective therapeutic approaches.
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Affiliation(s)
- Jennifer Q Kwong
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Jeffery D Molkentin
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA; Howard Hughes Medical Institute, Cincinnati, OH 45229, USA.
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49
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Jonas EA, Porter GA, Alavian KN. Bcl-xL in neuroprotection and plasticity. Front Physiol 2014; 5:355. [PMID: 25278904 PMCID: PMC4166110 DOI: 10.3389/fphys.2014.00355] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 09/02/2014] [Indexed: 01/14/2023] Open
Abstract
Accepted features of neurodegenerative disease include mitochondrial and protein folding dysfunction and activation of pro-death factors. Neurons that experience high metabolic demand or those found in organisms with genetic mutations in proteins that control cell stress may be more susceptible to aging and neurodegenerative disease. In neurons, events that normally promote growth, synapse formation, and plasticity are also often deployed to control neurotoxicity. Such protective strategies are coordinated by master stress-fighting proteins. One such specialized protein is the anti-cell death Bcl-2 family member Bcl-xL, whose myriad death-protecting functions include enhancement of bioenergetic efficiency, prevention of mitochondrial permeability transition channel activity, protection from mitochondrial outer membrane permeabilization (MOMP) to pro-apoptotic factors, and improvement in the rate of vesicular trafficking. Synapse formation and normal neuronal activity provide protection from neuronal death. Therefore, Bcl-xL brings about synapse formation as a neuroprotective strategy. In this review we will consider how this multi-functional master regulator protein uses many strategies to enhance synaptic and neuronal function and thus counteracts neurodegenerative stimuli.
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Affiliation(s)
- Elizabeth A Jonas
- Section of Endocrinology, Department of Internal Medicine, Yale University New Haven, CT, USA ; Department of Neurobiology, Yale University New Haven, CT, USA
| | - George A Porter
- Departments of Pediatrics (Cardiology), University of Rochester Medical Center Rochester, NY, USA ; Internal Medicine (Aab Cardiovascular Research Institute), University of Rochester Medical Center Rochester, NY, USA ; Department of Pharmacology and Physiology, University of Rochester Medical Center Rochester, NY, USA
| | - Kambiz N Alavian
- Division of Brain Sciences, Department of Medicine, Imperial College London London, UK
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Halestrap AP, Richardson AP. The mitochondrial permeability transition: a current perspective on its identity and role in ischaemia/reperfusion injury. J Mol Cell Cardiol 2014; 78:129-41. [PMID: 25179911 DOI: 10.1016/j.yjmcc.2014.08.018] [Citation(s) in RCA: 310] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 08/21/2014] [Accepted: 08/24/2014] [Indexed: 12/29/2022]
Abstract
The mitochondrial permeability transition pore (MPTP) is a non-specific pore that opens in the inner mitochondrial membrane (IMM) when matrix [Ca(2+)] is high, especially when accompanied by oxidative stress, high [Pi] and adenine nucleotide depletion. Such conditions occur during ischaemia and subsequent reperfusion, when MPTP opening is known to occur and cause irreversible damage to the heart. Matrix cyclophilin D facilitates MPTP opening and is the target of its inhibition by cyclosporin A that is cardioprotective. Less certainty exists over the composition of the pore itself, with structural and/or regulatory roles proposed for the adenine nucleotide translocase, the phosphate carrier and the FoF1 ATP synthase. Here we critically review the supporting data for the role of each and suggest that they may interact with each other through their bound cardiolipin to form the ATP synthasome. We propose that under conditions favouring MPTP opening, calcium-triggered conformational changes in these proteins may perturb the interface between them generating the pore. Proteins associated with the outer mitochondrial membrane (OMM), such as members of the Bcl-2 family and hexokinase (HK), whilst not directly involved in pore formation, may regulate MPTP opening through interactions between OMM and IMM proteins at "contact sites". Recent evidence suggests that cardioprotective protocols such as preconditioning inhibit MPTP opening at reperfusion by preventing the loss of mitochondrial bound HK2 that stabilises these contact sites. Contact site breakage both sensitises the MPTP to [Ca(2+)] and facilitates cytochrome c loss from the intermembrane space leading to greater ROS production and further MPTP opening. This article is part of a Special Issue entitled "Mitochondria: From Basic Mitochondrial Biology to Cardiovascular Disease".
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Affiliation(s)
- Andrew P Halestrap
- School of Biochemistry and Bristol CardioVascular, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK.
| | - Andrew P Richardson
- School of Biochemistry and Bristol CardioVascular, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
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