1
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Shrestha RK, Founds MW, Shepard SJ, Rothrock MM, Defnet AE, Steed PR. Mutational analysis of a conserved positive charge in the c-ring of E. coli ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148962. [PMID: 36822493 PMCID: PMC9998364 DOI: 10.1016/j.bbabio.2023.148962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/25/2023] [Accepted: 02/13/2023] [Indexed: 02/25/2023]
Abstract
F1Fo ATP synthase is a ubiquitous molecular motor that utilizes a rotary mechanism to synthesize adenosine triphosphate (ATP), the fundamental energy currency of life. The membrane-embedded Fo motor converts the electrochemical gradient of protons into rotation, which is then used to drive the conformational changes in the soluble F1 motor that catalyze ATP synthesis. In E. coli, the Fo motor is composed of a c10 ring (rotor) alongside subunit a (stator), which together provide two aqueous half channels that facilitate proton translocation. Previous work has suggested that Arg50 and Thr51 on the cytoplasmic side of each subunit c are involved in the proton translocation process, and positive charge is conserved in this region of subunit c. To further investigate the role of these residues and the chemical requirements for activity at these positions, we generated 13 substitution mutants and assayed their in vitro ATP synthesis, H+ pumping, and passive H+ permeability activities, as well as the ability of mutants to carry out oxidative phosphorylation in vivo. While polar and hydrophobic mutations were generally tolerated in either position, introduction of negative charge or removal of polarity caused a substantial defect. We discuss the possible effects of altered electrostatics on the interaction between the rotor and stator, water structure in the aqueous channel, and interaction of the rotor with cardiolipin.
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Affiliation(s)
- Rashmi K Shrestha
- Department of Chemistry & Biochemistry, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, United States of America
| | - Michael W Founds
- Department of Chemistry & Biochemistry, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, United States of America
| | - Sam J Shepard
- Department of Chemistry & Biochemistry, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, United States of America
| | - Mallory M Rothrock
- Department of Chemistry & Biochemistry, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, United States of America
| | - Amy E Defnet
- Department of Chemistry & Biochemistry, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, United States of America
| | - P Ryan Steed
- Department of Chemistry & Biochemistry, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, United States of America.
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2
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Targeting mitochondrial impairment for the treatment of cardiovascular diseases: From hypertension to ischemia-reperfusion injury, searching for new pharmacological targets. Biochem Pharmacol 2023; 208:115405. [PMID: 36603686 DOI: 10.1016/j.bcp.2022.115405] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023]
Abstract
Mitochondria and mitochondrial proteins represent a group of promising pharmacological target candidates in the search of new molecular targets and drugs to counteract the onset of hypertension and more in general cardiovascular diseases (CVDs). Indeed, several mitochondrial pathways result impaired in CVDs, showing ATP depletion and ROS production as common traits of cardiac tissue degeneration. Thus, targeting mitochondrial dysfunction in cardiomyocytes can represent a successful strategy to prevent heart failure. In this context, the identification of new pharmacological targets among mitochondrial proteins paves the way for the design of new selective drugs. Thanks to the advances in omics approaches, to a greater availability of mitochondrial crystallized protein structures and to the development of new computational approaches for protein 3D-modelling and drug design, it is now possible to investigate in detail impaired mitochondrial pathways in CVDs. Furthermore, it is possible to design new powerful drugs able to hit the selected pharmacological targets in a highly selective way to rescue mitochondrial dysfunction and prevent cardiac tissue degeneration. The role of mitochondrial dysfunction in the onset of CVDs appears increasingly evident, as reflected by the impairment of proteins involved in lipid peroxidation, mitochondrial dynamics, respiratory chain complexes, and membrane polarization maintenance in CVD patients. Conversely, little is known about proteins responsible for the cross-talk between mitochondria and cytoplasm in cardiomyocytes. Mitochondrial transporters of the SLC25A family, in particular, are responsible for the translocation of nucleotides (e.g., ATP), amino acids (e.g., aspartate, glutamate, ornithine), organic acids (e.g. malate and 2-oxoglutarate), and other cofactors (e.g., inorganic phosphate, NAD+, FAD, carnitine, CoA derivatives) between the mitochondrial and cytosolic compartments. Thus, mitochondrial transporters play a key role in the mitochondria-cytosol cross-talk by leading metabolic pathways such as the malate/aspartate shuttle, the carnitine shuttle, the ATP export from mitochondria, and the regulation of permeability transition pore opening. Since all these pathways are crucial for maintaining healthy cardiomyocytes, mitochondrial carriers emerge as an interesting class of new possible pharmacological targets for CVD treatments.
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3
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Johns A, Higuchi-Sanabria R, Thorwald MA, Vilchez D. A tale of two pathways: Regulation of proteostasis by UPR mt and MDPs. Curr Opin Neurobiol 2023; 78:102673. [PMID: 36621224 PMCID: PMC9845188 DOI: 10.1016/j.conb.2022.102673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/28/2022] [Accepted: 12/08/2022] [Indexed: 01/07/2023]
Abstract
Mitochondrial fitness is critical to organismal health and its impairment is associated with aging and age-related diseases. As such, numerous quality control mechanisms exist to preserve mitochondrial stability, including the unfolded protein response of the mitochondria (UPRmt). The UPRmt is a conserved mechanism that drives the transcriptional activation of mitochondrial chaperones, proteases, autophagy (mitophagy), and metabolism to promote restoration of mitochondrial function under stress conditions. UPRmt has direct ramifications in aging, and its activation is often ascribed to improve health whereas its dysfunction tends to correlate with disease. This review pairs a description of the most recent findings within the field of UPRmt with a more poorly understood field: mitochondria-derived peptides (MDPs). Similar to UPRmt, MDPs are microproteins derived from the mitochondria that can impact organismal health and longevity. We then highlight a tantalizing interconnection between UPRmt and MDPs wherein both mechanisms may be efficiently coordinated to maintain organismal health.
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Affiliation(s)
- Angela Johns
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany. https://twitter.com/AngyJohns
| | - Ryo Higuchi-Sanabria
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089, USA.
| | - Max A Thorwald
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089, USA.
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Institute for Genetics, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Faculty of Medicine, University Hospital Cologne, Cologne, Germany.
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4
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Feng X, Cheng XT, Zheng P, Li Y, Hakim J, Zhang SQ, Anderson SM, Linask K, Prestil R, Zou J, Sheng ZH, Blackstone C. Ligand-free mitochondria-localized mutant AR-induced cytotoxicity in spinal bulbar muscular atrophy. Brain 2023; 146:278-294. [PMID: 35867854 DOI: 10.1093/brain/awac269] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 06/12/2022] [Accepted: 07/03/2022] [Indexed: 01/11/2023] Open
Abstract
Spinal bulbar muscular atrophy (SBMA), the first identified CAG-repeat expansion disorder, is an X-linked neuromuscular disorder involving CAG-repeat-expansion mutations in the androgen receptor (AR) gene. We utilized CRISPR-Cas9 gene editing to engineer novel isogenic human induced pluripotent stem cell (hiPSC) models, consisting of isogenic AR knockout, control and disease lines expressing mutant AR with distinct repeat lengths, as well as control and disease lines expressing FLAG-tagged wild-type and mutant AR, respectively. Adapting a small-molecule cocktail-directed approach, we differentiate the isogenic hiPSC models into motor neuron-like cells with a highly enriched population to uncover cell-type-specific mechanisms underlying SBMA and to distinguish gain- from loss-of-function properties of mutant AR in disease motor neurons. We demonstrate that ligand-free mutant AR causes drastic mitochondrial dysfunction in neurites of differentiated disease motor neurons due to gain-of-function mechanisms and such cytotoxicity can be amplified upon ligand (androgens) treatment. We further show that aberrant interaction between ligand-free, mitochondria-localized mutant AR and F-ATP synthase is associated with compromised mitochondrial respiration and multiple other mitochondrial impairments. These findings counter the established notion that androgens are requisite for mutant AR-induced cytotoxicity in SBMA, reveal a compelling mechanistic link between ligand-free mutant AR, F-ATP synthase and mitochondrial dysfunction, and provide innovative insights into motor neuron-specific therapeutic interventions for SBMA.
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Affiliation(s)
- Xia Feng
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Cell Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.,Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Xiu-Tang Cheng
- Synaptic Function Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Pengli Zheng
- Cell Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Yan Li
- Protein/Peptide Sequencing Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Jill Hakim
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | | | - Stacie M Anderson
- Flow Cytometry Core, National Human Genome Research Institute, National Institute of Health, Bethesda, MD, USA
| | - Kaari Linask
- iPSC Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ryan Prestil
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Jizhong Zou
- iPSC Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zu-Hang Sheng
- Synaptic Function Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Craig Blackstone
- Cell Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.,MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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5
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Ley-Ngardigal S, Bertolin G. Approaches to monitor ATP levels in living cells: where do we stand? FEBS J 2022; 289:7940-7969. [PMID: 34437768 DOI: 10.1111/febs.16169] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/30/2021] [Accepted: 08/25/2021] [Indexed: 01/14/2023]
Abstract
ATP is the most universal and essential energy molecule in cells. This is due to its ability to store cellular energy in form of high-energy phosphate bonds, which are extremely stable and readily usable by the cell. This energy is key for a variety of biological functions such as cell growth and division, metabolism, and signaling, and for the turnover of biomolecules. Understanding how ATP is produced and hydrolyzed with a spatiotemporal resolution is necessary to understand its functions both in physiological and in pathological contexts. In this review, first we will describe the organization of the electron transport chain and ATP synthase, the main molecular motor for ATP production in mitochondria. Second, we will review the biochemical assays currently available to estimate ATP quantities in cells, and we will compare their readouts, strengths, and weaknesses. Finally, we will explore the palette of genetically encoded biosensors designed for microscopy-based approaches, and show how their spatiotemporal resolution opened up the possibility to follow ATP levels in living cells.
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Affiliation(s)
- Seyta Ley-Ngardigal
- CNRS, Univ Rennes, IGDR (Genetics and Development Institute of Rennes), Rennes, France.,LVMH Research Perfumes and Cosmetics, Saint-Jean-de-Braye, France
| | - Giulia Bertolin
- CNRS, Univ Rennes, IGDR (Genetics and Development Institute of Rennes), Rennes, France
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6
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Peterson AA, Rangwala AM, Thakur MK, Ward PS, Hung C, Outhwaite IR, Chan AI, Usanov DL, Mootha VK, Seeliger MA, Liu DR. Discovery and molecular basis of subtype-selective cyclophilin inhibitors. Nat Chem Biol 2022; 18:1184-1195. [PMID: 36163383 PMCID: PMC9596378 DOI: 10.1038/s41589-022-01116-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/19/2022] [Indexed: 11/25/2022]
Abstract
Although cyclophilins are attractive targets for probing biology and therapeutic intervention, no subtype-selective cyclophilin inhibitors have been described. We discovered novel cyclophilin inhibitors from the in vitro selection of a DNA-templated library of 256,000 drug-like macrocycles for cyclophilin D (CypD) affinity. Iterated macrocycle engineering guided by ten X-ray co-crystal structures yielded potent and selective inhibitors (half maximal inhibitory concentration (IC50) = 10 nM) that bind the active site of CypD and also make novel interactions with non-conserved residues in the S2 pocket, an adjacent exo-site. The resulting macrocycles inhibit CypD activity with 21- to >10,000-fold selectivity over other cyclophilins and inhibit mitochondrial permeability transition pore opening in isolated mitochondria. We further exploited S2 pocket interactions to develop the first cyclophilin E (CypE)-selective inhibitor, which forms a reversible covalent bond with a CypE S2 pocket lysine, and exhibits 30- to >4,000-fold selectivity over other cyclophilins. These findings reveal a strategy to generate isoform-selective small-molecule cyclophilin modulators, advancing their suitability as targets for biological investigation and therapeutic development.
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Affiliation(s)
- Alexander A Peterson
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Aziz M Rangwala
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Manish K Thakur
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Patrick S Ward
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Howard Hughes Medical Institute and Departments of Molecular Biology and Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Christie Hung
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Ian R Outhwaite
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Alix I Chan
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Dmitry L Usanov
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Vamsi K Mootha
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Howard Hughes Medical Institute and Departments of Molecular Biology and Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - Markus A Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA.
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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7
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Liu S, Liu S, Jiang H. Multifaceted roles of mitochondrial stress responses under ETC dysfunction - repair, destruction and pathogenesis. FEBS J 2022; 289:6994-7013. [PMID: 34918460 DOI: 10.1111/febs.16323] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 01/13/2023]
Abstract
Electron transport chain (ETC) dysfunction is a common feature of mitochondrial diseases and induces severe cellular stresses, including mitochondrial membrane potential (Δψm ) reduction, mitochondrial matrix acidification, metabolic derangements and proteostatic stresses. Extensive studies of ETC dysfunction in yeast, Caenorhabditis elegans, cultured cells and mouse models have revealed multiple mitochondrial stress response pathways. Here, we summarise the current understanding of the triggers, sensors, signalling mechanisms and the functional outcomes of mitochondrial stress responses in different species. We highlight Δψm reduction as a major trigger of stress responses in different species, but the responses are species-specific and the outcomes are context-dependent. ETC dysfunction elicits a mitochondrial unfolded protein response (UPRmt ) to repair damaged mitochondria in C. elegans, and activates a global adaptive programme to maintain Δψm in yeast. Yeast and C. elegans responses are remarkably similar at the downstream responses, although they are activated by different signalling mechanisms. UPRmt generally protects ETC-defective worms, but its constitutive activation is toxic for wildtype worms and worms carrying mutant mtDNA. In contrast to lower organisms, ETC dysfunction in mammals mainly activates a mitochondrial integrated stress response (ISRmt ) to reprogramme metabolism and a PINK1-Parkin mitophagy pathway to degrade damaged mitochondria. Accumulating in vivo results suggest that the ATF4 branch of ISRmt exacerbates metabolic derangements to accelerate mitochondrial disease progression. The in vivo roles of mitophagy in mitochondrial diseases are also context-dependent. These results thus reveal the common and unique aspects of mitochondrial stress responses in different species and highlight their multifaceted roles in mitochondrial diseases.
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Affiliation(s)
- Shanshan Liu
- National Institute of Biological Sciences, Beijing, China.,Beijing Key Laboratory of Cell Biology for Animal Aging, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Siqi Liu
- National Institute of Biological Sciences, Beijing, China.,Beijing Key Laboratory of Cell Biology for Animal Aging, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Hui Jiang
- National Institute of Biological Sciences, Beijing, China.,Beijing Key Laboratory of Cell Biology for Animal Aging, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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8
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Ocampo-Hernández B, Gutiérrez Mireles ER, Gutiérrez-Aguilar M. Morphology and permeability transitions in plant mitochondria: Different aspects of the same event? BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148586. [PMID: 35772521 DOI: 10.1016/j.bbabio.2022.148586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
Plant mitochondria are sensitive organelles affected by changing environmental stressors. Upon heat shock or the presence of reactive oxygen species, plant mitochondria undergo in vivo morphological derangements associated with the extensively characterized opening of the mitochondrial permeability transition pore. Nevertheless, the classic mitochondrial permeability transition is known to be triggered by calcium overload causing mitochondrial swelling and dysfunction. Here we review evidence concerning calcium handling, permeability transition and mitochondrial impairments in plants, supporting the notion that the mitochondrial morphology transition is an in vivo indicator of the permeability transition.
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Affiliation(s)
- Bryan Ocampo-Hernández
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, México
| | - Emilia R Gutiérrez Mireles
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, México
| | - Manuel Gutiérrez-Aguilar
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, México.
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9
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The Joint Influence of Tl+ and Thiol-Modifying Agents on Rat Liver Mitochondrial Parameters In Vitro. Int J Mol Sci 2022; 23:ijms23168964. [PMID: 36012228 PMCID: PMC9409397 DOI: 10.3390/ijms23168964] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 08/02/2022] [Accepted: 08/03/2022] [Indexed: 11/17/2022] Open
Abstract
Recent data have shown that the mitochondrial permeability transition pore (MPTP) is the complex of the Ca2+-modified adenine nucleotide translocase (ANT) and the Ca2+-modified ATP synthase. We found in a previous study that ANT conformational changes may be involved in Tl+-induced MPTP opening in the inner membrane of Ca2+-loaded rat liver mitochondria. In this study, the effects of thiol-modifying agents (eosin-5-maleimide (EMA), fluorescein isothiocyanate (FITC), Cu(o-phenanthroline)2 (Cu(OP)2), and embelin (Emb)), and MPTP inhibitors (ADP, cyclosporine A (CsA), n-ethylmaleimide (NEM), and trifluoperazine (TFP)) on MPTP opening were tested simultaneously with increases in swelling, membrane potential (ΔΨmito) decline, decreases in state 3, 4, and 3UDNP (2,4-dinitrophenol-uncoupled) respiration, and changes in the inner membrane free thiol group content. The effects of these thiol-modifying agents on the studied mitochondrial characteristics were multidirectional and showed a clear dependence on their concentration. This research suggests that Tl+-induced MPTP opening in the inner membrane of calcium-loaded mitochondria may be caused by the interaction of used reagents (EMA, FITC, Emb, Cu(OP)2) with active groups of ANT, the mitochondrial phosphate carrier (PiC) and the mitochondrial respiratory chain complexes. This study provides further insight into the causes of thallium toxicity and may be useful in the development of new treatments for thallium poisoning.
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10
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Nath S. Novel molecular insights into ATP synthesis in oxidative phosphorylation based on the principle of least action. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139561] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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11
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Abstract
Significance: Aging is a natural process that affects most living organisms, resulting in increased mortality. As the world population ages, the prevalence of age-associated diseases, and their associated health care costs, has increased sharply. A better understanding of the molecular mechanisms that lead to cellular dysfunction may provide important targets for interventions to prevent or treat these diseases. Recent Advances: Although the mitochondrial theory of aging had been proposed more than 40 years ago, recent new data have given stronger support for a central role for mitochondrial dysfunction in several pathways that are deregulated during normal aging and age-associated disease. Critical Issues: Several of the experimental evidence linking mitochondrial alterations to age-associated loss of function are correlative and mechanistic insights are still elusive. Here, we review how mitochondrial dysfunction may be involved in many of the known hallmarks of aging, and how these pathways interact in an intricate net of molecular relationships. Future Directions: As it has become clear that mitochondrial dysfunction plays causative roles in normal aging and age-associated diseases, it is necessary to better define the molecular interactions and the temporal and causal relationship between these changes and the relevant phenotypes seen during the aging process. Antioxid. Redox Signal. 36, 824-843.
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Affiliation(s)
- Caio M P F Batalha
- Lab. Genética Mitocondrial, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Anibal Eugênio Vercesi
- Departamento de Patologia Clínica, Faculdade de Medicina, Universidade de Campinas, Campinas, Brazil
| | - Nadja C Souza-Pinto
- Lab. Genética Mitocondrial, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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12
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Serrat R, Oliveira-Pinto A, Marsicano G, Pouvreau S. Imaging mitochondrial calcium dynamics in the central nervous system. J Neurosci Methods 2022; 373:109560. [PMID: 35320763 DOI: 10.1016/j.jneumeth.2022.109560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 03/04/2022] [Accepted: 03/06/2022] [Indexed: 12/28/2022]
Abstract
Mitochondrial calcium handling is a particularly active research area in the neuroscience field, as it plays key roles in the regulation of several functions of the central nervous system, such as synaptic transmission and plasticity, astrocyte calcium signaling, neuronal activity… In the last few decades, a panel of techniques have been developed to measure mitochondrial calcium dynamics, relying mostly on photonic microscopy, and including synthetic sensors, hybrid sensors and genetically encoded calcium sensors. The goal of this review is to endow the reader with a deep knowledge of the historical and latest tools to monitor mitochondrial calcium events in the brain, as well as a comprehensive overview of the current state of the art in brain mitochondrial calcium signaling. We will discuss the main calcium probes used in the field, their mitochondrial targeting strategies, their key properties and major drawbacks. In addition, we will detail the main roles of mitochondrial calcium handling in neuronal tissues through an extended report of the recent studies using mitochondrial targeted calcium sensors in neuronal and astroglial cells, in vitro and in vivo.
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Affiliation(s)
- Roman Serrat
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Alexandre Oliveira-Pinto
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Giovanni Marsicano
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Sandrine Pouvreau
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France.
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13
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Boyenle ID, Oyedele AK, Ogunlana AT, Adeyemo AF, Oyelere FS, Akinola OB, Adelusi TI, Ehigie LO, Ehigie AF. Targeting the mitochondrial permeability transition pore for drug discovery: Challenges and opportunities. Mitochondrion 2022; 63:57-71. [PMID: 35077882 DOI: 10.1016/j.mito.2022.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/22/2021] [Accepted: 01/17/2022] [Indexed: 12/29/2022]
Abstract
Several drug targets have been amenable to drug discovery pursuit not until the characterization of the mitochondrial permeability transition pore (MPTP), a pore with an undefined molecular identity that forms on the inner mitochondrial membrane upon mitochondrial permeability transition (MPT) under the influence of calcium overload and oxidative stress. The opening of the pore which is presumed to cause cell death in certain human diseases also has implications under physiological parlance. Different models for this pore have been postulated following its first identification in the last six decades. The mitochondrial community has witnessed many protein candidates such as; voltage-dependent anion channel (VDAC), adenine nucleotide translocase (ANT), Mitochondrial phosphate carrier (PiC), Spastic Paralegin (SPG7), disordered proteins, and F1Fo ATPase. However, genetic studies have cast out most of these candidates with only F1Fo ATPase currently under intense argument. Cyclophilin D (CyPD) remains the widely accepted positive regulator of the MPTP known to date, but no drug candidate has emerged as its inhibitor, raising concern issues for therapeutics. Thus, in this review, we discuss various models of MPTP reported with the hope of stimulating further research in this field. We went beyond the classical description of the MPTP to ascribe a 'two-edged sword property' to the pore for therapeutic function in human disease because its inhibition and activation have pharmacological relevance. We suggested putative proteins upstream to CyPD that can regulate its activity and prevent cell deaths in neurodegenerative disease and ischemia-reperfusion injury.
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Affiliation(s)
- Ibrahim Damilare Boyenle
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria; Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Abdulquddus Kehinde Oyedele
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Abdeen Tunde Ogunlana
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Aishat Folashade Adeyemo
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | | | - Olateju Balikis Akinola
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Temitope Isaac Adelusi
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Leonard Ona Ehigie
- Computational Biology/Drug Discovery Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
| | - Adeola Folasade Ehigie
- Membrane Biochemistry and Biophysics Research Laboratory, Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
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14
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He J, Rössner N, Hoang MTT, Alejandro S, Peiter E. Transport, functions, and interaction of calcium and manganese in plant organellar compartments. PLANT PHYSIOLOGY 2021; 187:1940-1972. [PMID: 35235665 PMCID: PMC8890496 DOI: 10.1093/plphys/kiab122] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/02/2021] [Indexed: 05/05/2023]
Abstract
Calcium (Ca2+) and manganese (Mn2+) are essential elements for plants and have similar ionic radii and binding coordination. They are assigned specific functions within organelles, but share many transport mechanisms to cross organellar membranes. Despite their points of interaction, those elements are usually investigated and reviewed separately. This review takes them out of this isolation. It highlights our current mechanistic understanding and points to open questions of their functions, their transport, and their interplay in the endoplasmic reticulum (ER), vesicular compartments (Golgi apparatus, trans-Golgi network, pre-vacuolar compartment), vacuoles, chloroplasts, mitochondria, and peroxisomes. Complex processes demanding these cations, such as Mn2+-dependent glycosylation or systemic Ca2+ signaling, are covered in some detail if they have not been reviewed recently or if recent findings add to current models. The function of Ca2+ as signaling agent released from organelles into the cytosol and within the organelles themselves is a recurrent theme of this review, again keeping the interference by Mn2+ in mind. The involvement of organellar channels [e.g. glutamate receptor-likes (GLR), cyclic nucleotide-gated channels (CNGC), mitochondrial conductivity units (MCU), and two-pore channel1 (TPC1)], transporters (e.g. natural resistance-associated macrophage proteins (NRAMP), Ca2+ exchangers (CAX), metal tolerance proteins (MTP), and bivalent cation transporters (BICAT)], and pumps [autoinhibited Ca2+-ATPases (ACA) and ER Ca2+-ATPases (ECA)] in the import and export of organellar Ca2+ and Mn2+ is scrutinized, whereby current controversial issues are pointed out. Mechanisms in animals and yeast are taken into account where they may provide a blueprint for processes in plants, in particular, with respect to tunable molecular mechanisms of Ca2+ versus Mn2+ selectivity.
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Affiliation(s)
- Jie He
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Nico Rössner
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Minh T T Hoang
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Santiago Alejandro
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
| | - Edgar Peiter
- Faculty of Natural Sciences III, Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany
- Author for communication:
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15
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Lushchak VI, Duszenko M, Gospodaryov DV, Garaschuk O. Oxidative Stress and Energy Metabolism in the Brain: Midlife as a Turning Point. Antioxidants (Basel) 2021; 10:1715. [PMID: 34829586 PMCID: PMC8614699 DOI: 10.3390/antiox10111715] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/23/2021] [Accepted: 10/25/2021] [Indexed: 01/10/2023] Open
Abstract
Neural tissue is one of the main oxygen consumers in the mammalian body, and a plentitude of metabolic as well as signaling processes within the brain is accompanied by the generation of reactive oxygen (ROS) and nitrogen (RNS) species. Besides the important signaling roles, both ROS and RNS can damage/modify the self-derived cellular components thus promoting neuroinflammation and oxidative stress. While previously, the latter processes were thought to progress linearly with age, newer data point to midlife as a critical turning point. Here, we describe (i) the main pathways leading to ROS/RNS generation within the brain, (ii) the main defense systems for their neutralization and (iii) summarize the recent literature about considerable changes in the energy/ROS homeostasis as well as activation state of the brain's immune system at midlife. Finally, we discuss the role of calorie restriction as a readily available and cost-efficient antiaging and antioxidant lifestyle intervention.
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Affiliation(s)
- Volodymyr I. Lushchak
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., 76018 Ivano-Frankivsk, Ukraine; (V.I.L.); (D.V.G.)
- Department of Medical Biochemistry, I. Horbachevsky Ternopil National Medical University, 46002 Ternopil, Ukraine
- Research and Development University, 13a Shota Rustaveli Str., 76018 Ivano-Frankivsk, Ukraine
| | - Michael Duszenko
- Department of Neurophysiology, Institute of Physiology, University of Tübingen, 72074 Tübingen, Germany;
| | - Dmytro V. Gospodaryov
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., 76018 Ivano-Frankivsk, Ukraine; (V.I.L.); (D.V.G.)
| | - Olga Garaschuk
- Department of Neurophysiology, Institute of Physiology, University of Tübingen, 72074 Tübingen, Germany;
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16
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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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17
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Amodeo GF, Krilyuk N, Pavlov EV. Formation of High-Conductive C Subunit Channels upon Interaction with Cyclophilin D. Int J Mol Sci 2021; 22:ijms222011022. [PMID: 34681682 PMCID: PMC8538490 DOI: 10.3390/ijms222011022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/05/2021] [Accepted: 10/10/2021] [Indexed: 12/25/2022] Open
Abstract
The c subunit of the ATP synthase is an inner mitochondrial membrane (IMM) protein. Besides its role as the main component of the rotor of the ATP synthase, c subunit from mammalian mitochondria exhibits ion channel activity. In particular, c subunit may be involved in one of the pathways leading to the formation of the permeability transition pore (PTP) during mitochondrial permeability transition (PT), a phenomenon consisting of the permeabilization of the IMM due to high levels of calcium. Our previous study on the synthetic c subunit showed that high concentrations of calcium induce misfolding into cross-β oligomers that form low-conductance channels in model lipid bilayers of about 400 pS. Here, we studied the effect of cyclophilin D (CypD), a mitochondrial chaperone and major regulator of PTP, on the electrophysiological activity of the c subunit to evaluate its role in the functional properties of c subunit. Our study shows that in presence of CypD, c subunit exhibits a larger conductance, up to 4 nS, that could be related to its potential role in mitochondrial toxicity. Further, our results suggest that CypD is necessary for the formation of c subunit induced PTP but may not be an integral part of the pore.
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18
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Mitochondrial Permeability Transition Causes Mitochondrial Reactive Oxygen Species- and Caspase 3-Dependent Atrophy of Single Adult Mouse Skeletal Muscle Fibers. Cells 2021; 10:cells10102586. [PMID: 34685566 PMCID: PMC8534155 DOI: 10.3390/cells10102586] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/16/2021] [Accepted: 09/25/2021] [Indexed: 02/03/2023] Open
Abstract
Elevated mitochondrial reactive oxygen species (mROS) and an increase in caspase-3 activity are established mechanisms that lead to skeletal muscle atrophy via the upregulation of protein degradation pathways. However, the mechanisms upstream of an increase in mROS and caspase-3 activity in conditions of muscle atrophy have not been identified. Based upon knowledge that an event known as mitochondrial permeability transition (MPT) causes an increase in mROS emission and the activation of caspase-3 via mitochondrial release of cytochrome c, as well as the circumstantial evidence for MPT in some muscle atrophy conditions, we tested MPT as a mechanism of atrophy. Briefly, treating cultured single mouse flexor digitorum brevis (FDB) fibers from adult mice with a chemical inducer of MPT (Bz423) for 24 h caused an increase in mROS and caspase-3 activity that was accompanied by a reduction in muscle fiber diameter that was able to be prevented by inhibitors of MPT, mROS, or caspase-3 (p < 0.05). Similarly, a four-day single fiber culture as a model of disuse caused atrophy that could be prevented by inhibitors of MPT, mROS, or activated caspase-3. As such, our results identify MPT as a novel mechanism of skeletal muscle atrophy that operates through mROS emission and caspase-3 activation.
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19
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Nirody JA, Budin I, Rangamani P. ATP synthase: Evolution, energetics, and membrane interactions. J Gen Physiol 2021; 152:152111. [PMID: 32966553 PMCID: PMC7594442 DOI: 10.1085/jgp.201912475] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 08/24/2020] [Indexed: 12/24/2022] Open
Abstract
The synthesis of ATP, life’s “universal energy currency,” is the most prevalent chemical reaction in biological systems and is responsible for fueling nearly all cellular processes, from nerve impulse propagation to DNA synthesis. ATP synthases, the family of enzymes that carry out this endless task, are nearly as ubiquitous as the energy-laden molecule they are responsible for making. The F-type ATP synthase (F-ATPase) is found in every domain of life and has facilitated the survival of organisms in a wide range of habitats, ranging from the deep-sea thermal vents to the human intestine. Accordingly, there has been a large amount of work dedicated toward understanding the structural and functional details of ATP synthases in a wide range of species. Less attention, however, has been paid toward integrating these advances in ATP synthase molecular biology within the context of its evolutionary history. In this review, we present an overview of several structural and functional features of the F-type ATPases that vary across taxa and are purported to be adaptive or otherwise evolutionarily significant: ion channel selectivity, rotor ring size and stoichiometry, ATPase dimeric structure and localization in the mitochondrial inner membrane, and interactions with membrane lipids. We emphasize the importance of studying these features within the context of the enzyme’s particular lipid environment. Just as the interactions between an organism and its physical environment shape its evolutionary trajectory, ATPases are impacted by the membranes within which they reside. We argue that a comprehensive understanding of the structure, function, and evolution of membrane proteins—including ATP synthase—requires such an integrative approach.
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Affiliation(s)
- Jasmine A Nirody
- Center for Studies in Physics and Biology, The Rockefeller University, New York, NY.,All Souls College, University of Oxford, Oxford, UK
| | - Itay Budin
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA
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20
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Angeli S, Foulger A, Chamoli M, Peiris TH, Gerencser A, Shahmirzadi AA, Andersen J, Lithgow G. The mitochondrial permeability transition pore activates the mitochondrial unfolded protein response and promotes aging. eLife 2021; 10:63453. [PMID: 34467850 PMCID: PMC8410078 DOI: 10.7554/elife.63453] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 08/15/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial activity determines aging rate and the onset of chronic diseases. The mitochondrial permeability transition pore (mPTP) is a pathological pore in the inner mitochondrial membrane thought to be composed of the F-ATP synthase (complex V). OSCP, a subunit of F-ATP synthase, helps protect against mPTP formation. How the destabilization of OSCP may contribute to aging, however, is unclear. We have found that loss OSCP in the nematode Caenorhabditis elegans initiates the mPTP and shortens lifespan specifically during adulthood, in part via initiation of the mitochondrial unfolded protein response (UPRmt). Pharmacological or genetic inhibition of the mPTP inhibits the UPRmt and restores normal lifespan. Loss of the putative pore-forming component of F-ATP synthase extends adult lifespan, suggesting that the mPTP normally promotes aging. Our findings reveal how an mPTP/UPRmt nexus may contribute to aging and age-related diseases and how inhibition of the UPRmt may be protective under certain conditions.
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Affiliation(s)
- Suzanne Angeli
- Buck Institute for Research on Aging, Novato, United States
| | - Anna Foulger
- Buck Institute for Research on Aging, Novato, United States
| | - Manish Chamoli
- Buck Institute for Research on Aging, Novato, United States
| | | | - Akos Gerencser
- Buck Institute for Research on Aging, Novato, United States
| | - Azar Asadi Shahmirzadi
- Buck Institute for Research on Aging, Novato, United States.,USC Leonard Davis School of Gerontology, University of Southern California, Los Angeles, United States
| | - Julie Andersen
- Buck Institute for Research on Aging, Novato, United States.,USC Leonard Davis School of Gerontology, University of Southern California, Los Angeles, United States
| | - Gordon Lithgow
- Buck Institute for Research on Aging, Novato, United States.,USC Leonard Davis School of Gerontology, University of Southern California, Los Angeles, United States
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21
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Masgras I, Laquatra C, Cannino G, Serapian SA, Colombo G, Rasola A. The molecular chaperone TRAP1 in cancer: From the basics of biology to pharmacological targeting. Semin Cancer Biol 2021; 76:45-53. [PMID: 34242740 DOI: 10.1016/j.semcancer.2021.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/25/2021] [Accepted: 07/02/2021] [Indexed: 12/22/2022]
Abstract
TRAP1, the mitochondrial component of the Hsp90 family of molecular chaperones, displays important bioenergetic and proteostatic functions. In tumor cells, TRAP1 contributes to shape metabolism, dynamically tuning it with the changing environmental conditions, and to shield from noxious insults. Hence, TRAP1 activity has profound effects on the capability of neoplastic cells to evolve towards more malignant phenotypes. Here, we discuss our knowledge on the biochemical functions of TRAP1 in the context of a growing tumor mass, and we analyze the possibility of targeting its chaperone functions for developing novel anti-neoplastic approaches.
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Affiliation(s)
- Ionica Masgras
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy; Istituto di Neuroscienze, Consiglio Nazionale Delle Ricerche (CNR), Padova, Italy
| | - Claudio Laquatra
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Giuseppe Cannino
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | | | | | - Andrea Rasola
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy.
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22
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The Regulation of Non-Specific Membrane Permeability Transition in Yeast Mitochondria under Oxidative Stress. MICROBIOLOGY RESEARCH 2021. [DOI: 10.3390/microbiolres12020029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this study, the mechanism of non-specific membrane permeability (yPTP) in the Endomyces magnusii yeast mitochondria under oxidative stress due to blocking the key antioxidant enzymes has been investigated. We used monitoring the membrane potential at the cellular (potential-dependent staining) and mitochondrial levels and mitochondria ultra-structural images with transmission electron microscopy (TEM) to demonstrate the mitochondrial permeability transition induction due to the pore opening. Analysis of the yPTP opening upon respiring different substrates showed that NAD(P)H completely blocked the development of the yPTP. The yPTP opening was inhibited by 5–20 mM Pi, 5 mM Mg2+, adenine nucleotides (AN), 5 mM GSH, the inhibitor of the Pi transporter (PiC), 100 μM mersalyl, the blockers of the adenine nucleotide transporter (ANT) carboxyatractyloside (CATR), and bongkrekic acid (BA). We concluded that the non-specific membrane permeability pore opens in the E. magnusii mitochondria under oxidative stress, and the ANT and PiC are involved in its formation. The crucial role of the Ca2+ ions in the process has not been confirmed. We showed that the Ca2+ ions affected the yPTP both with and without the Ca2+ ionophore ETH129 application insignificantly. This phenomenon in the E. magnusii yeast unites both mitochondrial unselective channel (ScMUC) features in the Saccharomyces cerevisiae mitochondria and the classical membrane pore in the mammalian ones (mPTP).
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23
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C subunit of the ATP synthase is an amyloidogenic calcium dependent channel-forming peptide with possible implications in mitochondrial permeability transition. Sci Rep 2021; 11:8744. [PMID: 33888826 PMCID: PMC8062469 DOI: 10.1038/s41598-021-88157-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/06/2021] [Indexed: 01/18/2023] Open
Abstract
The c subunit is an inner mitochondrial membrane (IMM) protein encoded by three nuclear genes. Best known as an integral part of the F0 complex of the ATP synthase, the c subunit is also present in other cytoplasmic compartments in ceroid lipofuscinoses. Under physiological conditions, this 75 residue-long peptide folds into an α-helical hairpin and forms oligomers spanning the lipid bilayer. In addition to its physiological role, the c subunit has been proposed as a key participant in stress-induced IMM permeabilization by the mechanism of calcium-induced permeability transition. However, the molecular mechanism of the c subunit participation in IMM permeabilization is not completely understood. Here we used fluorescence spectroscopy, atomic force microscopy and black lipid membrane methods to gain insights into the structural and functional properties of unmodified c subunit protein that might make it relevant to mitochondrial toxicity. We discovered that c subunit is an amyloidogenic peptide that can spontaneously fold into β-sheets and self-assemble into fibrils and oligomers in a Ca2+-dependent manner. C subunit oligomers exhibited ion channel activity in lipid membranes. We propose that the toxic effects of c subunit might be linked to its amyloidogenic properties and are driven by mechanisms similar to those of neurodegenerative polypeptides such as Aβ and α-synuclein.
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24
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Agnetti G, Herrmann H, Cohen S. New roles for desmin in the maintenance of muscle homeostasis. FEBS J 2021; 289:2755-2770. [PMID: 33825342 DOI: 10.1111/febs.15864] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 02/06/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022]
Abstract
Desmin is the primary intermediate filament (IF) of cardiac, skeletal, and smooth muscle. By linking the contractile myofibrils to the sarcolemma and cellular organelles, desmin IF contributes to muscle structural and cellular integrity, force transmission, and mitochondrial homeostasis. Mutations in desmin cause myofibril misalignment, mitochondrial dysfunction, and impaired mechanical integrity leading to cardiac and skeletal myopathies in humans, often characterized by the accumulation of protein aggregates. Recent evidence indicates that desmin filaments also regulate proteostasis and cell size. In skeletal muscle, changes in desmin filament dynamics can facilitate catabolic events as an adaptive response to a changing environment. In addition, post-translational modifications of desmin and its misfolding in the heart have emerged as key determinants of homeostasis and disease. In this review, we provide an overview of the structural and cellular roles of desmin and propose new models for its novel functions in preserving the homeostasis of striated muscles.
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Affiliation(s)
- Giulio Agnetti
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.,DIBINEM, University of Bologna, Italy
| | - Harald Herrmann
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Shenhav Cohen
- Faculty of Biology, Technion Institute of Technology, Haifa, Israel
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25
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Gutiérrez-Aguilar M. Mitochondrial calcium transport and permeability transition as rational targets for plant protection. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148288. [PMID: 32800781 DOI: 10.1016/j.bbabio.2020.148288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/23/2020] [Accepted: 08/03/2020] [Indexed: 12/28/2022]
Abstract
The mitochondrial permeability transition (MPT) is a death-inducing mechanism that collapses electrochemical gradients across inner mitochondrial membranes. Several studies in model plants have detailed potential MPT-dependent cell death upon abiotic stress in response to heat shock, ultraviolet radiation, heavy metal toxicity and waterlogging. However, the molecular specifics of the MPT and its possible role on plant cell death remain controversial. This review addresses previous and recent developments on the role(s) of the MPT in plants. Considering these advances, MPT targeting can constitute a plausible strategy to ameliorate cell death in plants upon abiotic stress.
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Affiliation(s)
- Manuel Gutiérrez-Aguilar
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México City, Mexico.
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26
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Ohwada W, Tanno M, Yano T, Ong SB, Abe K, Sato T, Kuno A, Miki T, Sugawara H, Igaki Y, Miura T. Distinct intra-mitochondrial localizations of pro-survival kinases and regulation of their functions by DUSP5 and PHLPP-1. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165851. [PMID: 32480039 DOI: 10.1016/j.bbadis.2020.165851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/14/2020] [Accepted: 05/26/2020] [Indexed: 01/03/2023]
Abstract
ERK and Akt have been shown to regulate cell sensitivity to death-inducing stress by phosphorylating GSK-3β, a major modulator of the threshold for mitochondrial permeability transition. Here we examined intra-mitochondrial localization of the pro-survival kinases and their regulation by phosphatases. Stepwise trypsin digestion of mitochondria isolated from HEK293 or H9c2 cells was performed, and immunoblotting revealed that GSK-3β and ERK localized dominantly in the outer membrane (OM), while Akt resided at comparable levels in OM, the inner membrane (IM) and the matrix. Treatment with IGF-1 increased the protein level of Akt in the matrix, while ERK and GSK-3β protein levels were increased in OM. Simultaneously, IGF-1 treatment elevated the level of Thr202/Tyr204-phospho-ERK in IM and matrix and levels of Ser473-phospho-Akt and Ser9-phospho-GSK-3β in OM, IM and matrix. Exposing cells to reactive oxygen species (ROS) by using antimycin A increased the levels of DUSP5 and PHLPP-1 mainly in OM and induced dephosphorylation of Akt, ERK and GSK-3β. The mitochondrial localization of DUSP5 was confirmed by experiments with mitochondria purified by Percoll gradient centrifugation and by transfection of cells with GFP-tagged DUSP5. Knockdown of either DUSP5 or PHLPP-1 increased the levels of both Thr202/Tyr204-phospho-ERK and Ser473-phospho-Akt in mitochondria. Cell death induced by antimycin A was suppressed by siRNA-mediated knockdown of DUSP5. The results suggest that Akt and ERK in mitochondria show distinct intra-mitochondrial localization and crosstalk in GSK-3β regulation and that recruitment of DUSP5 as well as PHLPP-1 to mitochondria contributes to ROS-induced termination of the protective signaling.
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Affiliation(s)
- Wataru Ohwada
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masaya Tanno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Toshiyuki Yano
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Sang-Bing Ong
- Signature Research Program in Cardiovascular & Metabolic Diseases, Duke-NUS Medical School, Singapore
| | - Koki Abe
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tatsuya Sato
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Cellular Physiology and Signal Transduction, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Atsushi Kuno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Pharmacology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takayuki Miki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hirohito Sugawara
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yusuke Igaki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
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27
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Cryo-EM structure of the entire mammalian F-type ATP synthase. Nat Struct Mol Biol 2020; 27:1077-1085. [DOI: 10.1038/s41594-020-0503-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/06/2020] [Indexed: 02/07/2023]
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28
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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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Carraro M, Carrer A, Urbani A, Bernardi P. Molecular nature and regulation of the mitochondrial permeability transition pore(s), drug target(s) in cardioprotection. J Mol Cell Cardiol 2020; 144:76-86. [DOI: 10.1016/j.yjmcc.2020.05.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/28/2020] [Accepted: 05/20/2020] [Indexed: 12/12/2022]
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30
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Hausenloy DJ, Schulz R, Girao H, Kwak BR, De Stefani D, Rizzuto R, Bernardi P, Di Lisa F. Mitochondrial ion channels as targets for cardioprotection. J Cell Mol Med 2020; 24:7102-7114. [PMID: 32490600 PMCID: PMC7339171 DOI: 10.1111/jcmm.15341] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/31/2020] [Accepted: 04/12/2020] [Indexed: 12/14/2022] Open
Abstract
Acute myocardial infarction (AMI) and the heart failure (HF) that often result remain the leading causes of death and disability worldwide. As such, new therapeutic targets need to be discovered to protect the myocardium against acute ischaemia/reperfusion (I/R) injury in order to reduce myocardial infarct (MI) size, preserve left ventricular function and prevent the onset of HF. Mitochondrial dysfunction during acute I/R injury is a critical determinant of cell death following AMI, and therefore, ion channels in the inner mitochondrial membrane, which are known to influence cell death and survival, provide potential therapeutic targets for cardioprotection. In this article, we review the role of mitochondrial ion channels, which are known to modulate susceptibility to acute myocardial I/R injury, and we explore their potential roles as therapeutic targets for reducing MI size and preventing HF following AMI.
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Affiliation(s)
- Derek J. Hausenloy
- Cardiovascular & Metabolic Disorders ProgramDuke‐National University of Singapore Medical SchoolSingaporeSingapore
- National Heart Research Institute SingaporeNational Heart CentreSingaporeSingapore
- Yong Loo Lin School of MedicineNational University SingaporeSingaporeSingapore
- The Hatter Cardiovascular InstituteUniversity College LondonLondonUK
- Cardiovascular Research CenterCollege of Medical and Health SciencesAsia UniversityTaichung CityTaiwan
| | - Rainer Schulz
- Institute of PhysiologyJustus‐Liebig University GiessenGiessenGermany
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of MedicineUniversity of CoimbraCoimbraPortugal
- Center for Innovative Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
- Clinical Academic Centre of CoimbraCACCCoimbraPortugal
| | - Brenda R. Kwak
- Department of Pathology and ImmunologyUniversity of GenevaGenevaSwitzerland
| | - Diego De Stefani
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Rosario Rizzuto
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Paolo Bernardi
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
| | - Fabio Di Lisa
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
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31
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18-kDa translocator protein association complexes in the brain: From structure to function. Biochem Pharmacol 2020; 177:114015. [PMID: 32387458 DOI: 10.1016/j.bcp.2020.114015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/04/2020] [Indexed: 12/14/2022]
Abstract
The outer mitochondrial membrane 18-kDa translocator protein (TSPO) is highly conserved in organisms of different species and ubiquitously expressed throughout tissues, including the nervous system. In the healthy adult brain, TSPO expression levels are low and promptly modulated under different pathological conditions, such as cancer, inflammatory states, and neurological and psychiatric disorders. Not surprisingly, several endogenous and synthetic molecules capable of binding TSPO have been proposed as drugs or diagnostic tools for brain diseases. The most studied biochemical function of TSPO is cholesterol translocation into mitochondria, which in turn affects the synthesis of steroids in the periphery and neurosteroids in the brain. In the last 30 years, roles for TSPO have also been suggested in other cellular processes, such as heme synthesis, apoptosis, autophagy, calcium signalling and reactive oxygen species production. Herein, we provide an overview of TSPO associations with different proteins, focusing particular attention on their related functions. Furthermore, recent TSPO-targeted therapeutic interventions are explored and discussed as prospect for innovative treatments in mental and brain diseases.
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32
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Zemanova L, Vaskova M, Schmidt M, Roubalova J, Haleckova A, Benek O, Musilek K. RNase T1 Refolding Assay for Determining Mitochondrial Cyclophilin D Activity: A Novel In Vitro Method Applicable in Drug Research and Discovery. Biochemistry 2020; 59:1680-1687. [PMID: 32275395 DOI: 10.1021/acs.biochem.9b01025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human cyclophilin D is a mitochondrial peptidyl-prolyl isomerase that plays a role in regulating the opening of the mitochondrial permeability transition pore. It is considered a viable and promising molecular target for the treatment of diseases for which disease development is associated with pore opening, e.g., Alzheimer's disease or ischemia/reperfusion injury. Currently available and widely used in vitro methods based on Kofron's assay for determining cyclophilin D activity suffer from serious drawbacks and limitations. In this study, a completely novel approach for an in vitro assay of cyclophilin D activity using RNase T1 refolding is introduced. The method is simple and is more in line with the presumed physiological role of cyclophilin D in protein folding than Kofron's assay, which relies on a peptide substrate. The method is applicable for identifying novel inhibitors of cyclophilin D as potential drugs for the treatment of the diseases mentioned above. Moreover, the description of CypD activity in the in vitro RNase T1 refolding assay reveals new possibilities for investigating the role of cyclophilin D in protein folding in cells and may lead to a better understanding of its pathological and physiological roles.
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Affiliation(s)
- Lucie Zemanova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Michaela Vaskova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Monika Schmidt
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Jana Roubalova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Annamaria Haleckova
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Ondrej Benek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
| | - Kamil Musilek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
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33
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Wacquier B, Combettes L, Dupont G. Dual dynamics of mitochondrial permeability transition pore opening. Sci Rep 2020; 10:3924. [PMID: 32127570 PMCID: PMC7054270 DOI: 10.1038/s41598-020-60177-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 02/06/2020] [Indexed: 11/09/2022] Open
Abstract
Mitochondria play an essential role in bioenergetics and cellular Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ handling. The mitochondrial permeability transition pore (mPTP) is a non-specific channel located in the inner mitochondrial membrane. Long-lasting openings of the pore allow the rapid passage of ions and large molecules, which can result in cell death. The mPTP also exhibits transient, low conductance openings that contribute to Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ homeostasis. Although many regulators of the pore have been identified, none of them uniquely governs the passage between the two operating modes, which thus probably relies on a still unidentified network of interactions. By developing a core computational model for mPTP opening under the control of mitochondrial voltage and Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+, we uncovered the existence of a positive feedback loop leading to bistability. The characteristics of the two stable steady-states correspond to those of the two opening states. When inserted in a full model of Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ handling by mitochondria, our description of the pore reproduces observations in mitochondrial suspensions. Moreover, the model predicted the occurrence of hysteresis in the switching between the two modes, upon addition and removal of free Ca\documentclass[12pt]{minimal}
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\begin{document}$${}^{2+}$$\end{document}2+ in the extra-mitochondrial medium. Stochastic simulations then confirmed that the pore can undergo transient openings resembling those observed in intact cells.
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Affiliation(s)
- Benjamin Wacquier
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050, Brussels, Belgium
| | | | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Faculté des Sciences, Université Libre de Bruxelles (ULB) CP231, B1050, Brussels, Belgium.
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34
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Oliveira HCF, Vercesi AE. Mitochondrial bioenergetics and redox dysfunctions in hypercholesterolemia and atherosclerosis. Mol Aspects Med 2019; 71:100840. [PMID: 31882067 DOI: 10.1016/j.mam.2019.100840] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 12/12/2022]
Abstract
In the first part of this review, we summarize basic mitochondrial bioenergetics concepts showing that mitochondria are critical regulators of cell life and death. Until a few decades ago, mitochondria were considered to play essential roles only in respiration, ATP formation, non-shivering thermogenesis and a variety of metabolic pathways. However, the concept presented by Peter Mitchell regarding coupling between electron flow and ATP synthesis through the intermediary of a H+ electrochemical potential leads to the recognition that the proton-motive force also regulates a series of relevant cell signalling processes, such as superoxide generation, redox balance and Ca2+ handling. Alterations in these processes lead to cell death and disease states. In the second part of this review, we discuss the role of mitochondrial dysfunctions in the specific context of hypercholesterolemia-induced atherosclerosis. We provide a literature analysis that indicates a decisive role of mitochondrial redox dysfunction in the development of atherosclerosis and discuss the underlying molecular mechanisms. Finally, we highlight the potential mitochondrial-targeted therapeutic strategies that are relevant for atherosclerosis.
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Affiliation(s)
- Helena C F Oliveira
- Department of Structural and Functional Biology, Biology Institute, State University of Campinas, Campinas, SP, Brazil.
| | - Anibal E Vercesi
- Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil.
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35
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Ure DR, Trepanier DJ, Mayo PR, Foster RT. Cyclophilin inhibition as a potential treatment for nonalcoholic steatohepatitis (NASH). Expert Opin Investig Drugs 2019; 29:163-178. [DOI: 10.1080/13543784.2020.1703948] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Daren R. Ure
- Hepion Pharmaceuticals Inc, Edmonton, AB, Canada
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36
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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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37
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Boyman L, Karbowski M, Lederer WJ. Regulation of Mitochondrial ATP Production: Ca 2+ Signaling and Quality Control. Trends Mol Med 2019; 26:21-39. [PMID: 31767352 DOI: 10.1016/j.molmed.2019.10.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/16/2019] [Accepted: 10/23/2019] [Indexed: 02/06/2023]
Abstract
Cardiac ATP production primarily depends on oxidative phosphorylation in mitochondria and is dynamically regulated by Ca2+ levels in the mitochondrial matrix as well as by cytosolic ADP. We discuss mitochondrial Ca2+ signaling and its dysfunction which has recently been linked to cardiac pathologies including arrhythmia and heart failure. Similar dysfunction in other excitable and long-lived cells including neurons is associated with neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Central to this new understanding is crucial Ca2+ regulation of both mitochondrial quality control and ATP production. Mitochondria-associated membrane (MAM) signaling from the sarcoplasmic reticulum (SR) and the endoplasmic reticulum (ER) to mitochondria is discussed. We propose future research directions that emphasize a need to define quantitatively the physiological roles of MAMs, as well as mitochondrial quality control and ATP production.
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Affiliation(s)
- Liron Boyman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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38
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Myocardial Adaptation in Pseudohypoxia: Signaling and Regulation of mPTP via Mitochondrial Connexin 43 and Cardiolipin. Cells 2019; 8:cells8111449. [PMID: 31744200 PMCID: PMC6912244 DOI: 10.3390/cells8111449] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 11/15/2019] [Indexed: 12/26/2022] Open
Abstract
Therapies intended to mitigate cardiovascular complications cannot be applied in practice without detailed knowledge of molecular mechanisms. Mitochondria, as the end-effector of cardioprotection, represent one of the possible therapeutic approaches. The present review provides an overview of factors affecting the regulation processes of mitochondria at the level of mitochondrial permeability transition pores (mPTP) resulting in comprehensive myocardial protection. The regulation of mPTP seems to be an important part of the mechanisms for maintaining the energy equilibrium of the heart under pathological conditions. Mitochondrial connexin 43 is involved in the regulation process by inhibition of mPTP opening. These individual cardioprotective mechanisms can be interconnected in the process of mitochondrial oxidative phosphorylation resulting in the maintenance of adenosine triphosphate (ATP) production. In this context, the degree of mitochondrial membrane fluidity appears to be a key factor in the preservation of ATP synthase rotation required for ATP formation. Moreover, changes in the composition of the cardiolipin’s structure in the mitochondrial membrane can significantly affect the energy system under unfavorable conditions. This review aims to elucidate functional and structural changes of cardiac mitochondria subjected to preconditioning, with an emphasis on signaling pathways leading to mitochondrial energy maintenance during partial oxygen deprivation.
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39
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Makarov VI, Khmelinskii I, Khuchua Z, Javadov S. In silico simulation of reversible and irreversible swelling of mitochondria: The role of membrane rigidity. Mitochondrion 2019; 50:71-81. [PMID: 31669621 DOI: 10.1016/j.mito.2019.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 08/07/2019] [Accepted: 09/23/2019] [Indexed: 01/24/2023]
Abstract
Mitochondria have been widely accepted as the main source of ATP in the cell. The inner mitochondrial membrane (IMM) is important for the maintenance of ATP production and other functions of mitochondria. The electron transport chain (ETC) generates an electrochemical gradient of protons known as the proton-motive force across the IMM and thus produces the mitochondrial membrane potential that is critical to ATP synthesis. One of the main factors regulating the structural and functional integrity of the IMM is the changes in the matrix volume. Mild (reversible) swelling regulates mitochondrial metabolism and function; however, excessive (irreversible) swelling causes mitochondrial dysfunction and cell death. The central mechanism of mitochondrial swelling includes the opening of non-selective channels known as permeability transition pores (PTPs) in the IMM by high mitochondrial Ca2+ and reactive oxygen species (ROS). The mechanisms of reversible and irreversible mitochondrial swelling and transition between these two states are still unknown. The present study elucidates an upgraded biophysical model of reversible and irreversible mitochondrial swelling dynamics. The model provides a description of the PTP regulation dynamics using an additional differential equation. The rigidity tensor was used in numerical simulations of the mitochondrial parameter dynamics with different initial conditions defined by Ca2+ concentration in the sarco/endoplasmic reticulum. We were able to estimate the values of the IMM rigidity tensor components by fitting the model to the previously reported experimental data. Overall, the model provides a better description of the reversible and irreversible mitochondrial swelling dynamics.
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Affiliation(s)
- Vladimir I Makarov
- Department of Physics, University of Puerto Rico Rio Piedras Campus, San Juan, USA
| | - Igor Khmelinskii
- Faculty of Science and Technology, Department of Chemistry and Pharmacy, and Center of Electronics, Optoelectronics and Telecommunications, University of Algarve, Portugal
| | - Zaza Khuchua
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Biochemistry, Sechenov Moscow State Medical University, Moscow, Russia
| | - Sabzali Javadov
- Department of Physiology and Biophysics, University of Puerto Rico Medical Sciences Campus, San Juan, PR, USA.
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40
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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: 128] [Impact Index Per Article: 25.6] [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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41
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Paradies G, Paradies V, Ruggiero FM, Petrosillo G. Role of Cardiolipin in Mitochondrial Function and Dynamics in Health and Disease: Molecular and Pharmacological Aspects. Cells 2019; 8:cells8070728. [PMID: 31315173 PMCID: PMC6678812 DOI: 10.3390/cells8070728] [Citation(s) in RCA: 224] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/12/2019] [Accepted: 07/14/2019] [Indexed: 12/12/2022] Open
Abstract
In eukaryotic cells, mitochondria are involved in a large array of metabolic and bioenergetic processes that are vital for cell survival. Phospholipids are the main building blocks of mitochondrial membranes. Cardiolipin (CL) is a unique phospholipid which is localized and synthesized in the inner mitochondrial membrane (IMM). It is now widely accepted that CL plays a central role in many reactions and processes involved in mitochondrial function and dynamics. Cardiolipin interacts with and is required for optimal activity of several IMM proteins, including the enzyme complexes of the electron transport chain (ETC) and ATP production and for their organization into supercomplexes. Moreover, CL plays an important role in mitochondrial membrane morphology, stability and dynamics, in mitochondrial biogenesis and protein import, in mitophagy, and in different mitochondrial steps of the apoptotic process. It is conceivable that abnormalities in CL content, composition and level of oxidation may negatively impact mitochondrial function and dynamics, with important implications in a variety of pathophysiological situations and diseases. In this review, we focus on the role played by CL in mitochondrial function and dynamics in health and diseases and on the potential of pharmacological modulation of CL through several agents in attenuating mitochondrial dysfunction.
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Affiliation(s)
- Giuseppe Paradies
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70125 Bari, Italy.
| | | | - Francesca M Ruggiero
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70125 Bari, Italy
| | - Giuseppe Petrosillo
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), 70126 Bari, Italy.
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42
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Wieland F. The 44th FEBS Congress in Krakow: celebrating the multidisciplinarity of biological research. FEBS Lett 2019; 593:1413-1414. [PMID: 31222735 DOI: 10.1002/1873-3468.13503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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