1
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Koren SA, Ahmed Selim N, De la Rosa L, Horn J, Farooqi MA, Wei AY, Müller-Eigner A, Emerson J, Johnson GVW, Wojtovich AP. All-optical spatiotemporal mapping of ROS dynamics across mitochondrial microdomains in situ. Nat Commun 2023; 14:6036. [PMID: 37758713 PMCID: PMC10533892 DOI: 10.1038/s41467-023-41682-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Hydrogen peroxide (H2O2) functions as a second messenger to signal metabolic distress through highly compartmentalized production in mitochondria. The dynamics of reactive oxygen species (ROS) generation and diffusion between mitochondrial compartments and into the cytosol govern oxidative stress responses and pathology, though these processes remain poorly understood. Here, we couple the H2O2 biosensor, HyPer7, with optogenetic stimulation of the ROS-generating protein KillerRed targeted into multiple mitochondrial microdomains. Single mitochondrial photogeneration of H2O2 demonstrates the spatiotemporal dynamics of ROS diffusion and transient hyperfusion of mitochondria due to ROS. This transient hyperfusion phenotype required mitochondrial fusion but not fission machinery. Measurement of microdomain-specific H2O2 diffusion kinetics reveals directionally selective diffusion through mitochondrial microdomains. All-optical generation and detection of physiologically-relevant concentrations of H2O2 between mitochondrial compartments provide a map of mitochondrial H2O2 diffusion dynamics in situ as a framework to understand the role of ROS in health and disease.
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Affiliation(s)
- Shon A Koren
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Nada Ahmed Selim
- University of Rochester Medical Center, Department of Pharmacology and Physiology, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Lizbeth De la Rosa
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Jacob Horn
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - M Arsalan Farooqi
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Alicia Y Wei
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Annika Müller-Eigner
- Research Group Epigenetics, Metabolism and Longevity, Research Institute for Farm Animal Biology (FBN), Dummerstorf, 18196, Germany
| | - Jacen Emerson
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Gail V W Johnson
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Andrew P Wojtovich
- University of Rochester Medical Center, Department of Anesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA.
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2
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Duarte FV, Ciampi D, Duarte CB. Mitochondria as central hubs in synaptic modulation. Cell Mol Life Sci 2023; 80:173. [PMID: 37266732 DOI: 10.1007/s00018-023-04814-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 06/03/2023]
Abstract
Mitochondria are present in the pre- and post-synaptic regions, providing the energy required for the activity of these very specialized neuronal compartments. Biogenesis of synaptic mitochondria takes place in the cell body, and these organelles are then transported to the synapse by motor proteins that carry their cargo along microtubule tracks. The transport of mitochondria along neurites is a highly regulated process, being modulated by the pattern of neuronal activity and by extracellular cues that interact with surface receptors. These signals act by controlling the distribution of mitochondria and by regulating their activity. Therefore, mitochondria activity at the synapse allows the integration of different signals and the organelles are important players in the response to synaptic stimulation. Herein we review the available evidence regarding the regulation of mitochondrial dynamics by neuronal activity and by neuromodulators, and how these changes in the activity of mitochondria affect synaptic communication.
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Affiliation(s)
- Filipe V Duarte
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- III - Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Daniele Ciampi
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
| | - Carlos B Duarte
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
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3
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Monzel AS, Enríquez JA, Picard M. Multifaceted mitochondria: moving mitochondrial science beyond function and dysfunction. Nat Metab 2023; 5:546-562. [PMID: 37100996 PMCID: PMC10427836 DOI: 10.1038/s42255-023-00783-1] [Citation(s) in RCA: 105] [Impact Index Per Article: 105.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 03/10/2023] [Indexed: 04/28/2023]
Abstract
Mitochondria have cell-type specific phenotypes, perform dozens of interconnected functions and undergo dynamic and often reversible physiological recalibrations. Given their multifunctional and malleable nature, the frequently used terms 'mitochondrial function' and 'mitochondrial dysfunction' are misleading misnomers that fail to capture the complexity of mitochondrial biology. To increase the conceptual and experimental specificity in mitochondrial science, we propose a terminology system that distinguishes between (1) cell-dependent properties, (2) molecular features, (3) activities, (4) functions and (5) behaviours. A hierarchical terminology system that accurately captures the multifaceted nature of mitochondria will achieve three important outcomes. It will convey a more holistic picture of mitochondria as we teach the next generations of mitochondrial biologists, maximize progress in the rapidly expanding field of mitochondrial science, and also facilitate synergy with other disciplines. Improving specificity in the language around mitochondrial science is a step towards refining our understanding of the mechanisms by which this unique family of organelles contributes to cellular and organismal health.
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Affiliation(s)
- Anna S Monzel
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - José Antonio Enríquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
- CIBER de Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain
| | - Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, NY, USA.
- Department of Neurology, H. Houston Merritt Center, Columbia Translational Neuroscience Initiative, Columbia University Irving Medical Center, New York, NY, USA.
- New York State Psychiatric Institute, New York, NY, USA.
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4
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Quintana-Cabrera R, Scorrano L. Determinants and outcomes of mitochondrial dynamics. Mol Cell 2023; 83:857-876. [PMID: 36889315 DOI: 10.1016/j.molcel.2023.02.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/13/2023] [Accepted: 02/13/2023] [Indexed: 03/09/2023]
Abstract
Mitochondria are not only central organelles in metabolism and energy conversion but are also platforms for cellular signaling cascades. Classically, the shape and ultrastructure of mitochondria were depicted as static. The discovery of morphological transitions during cell death and of conserved genes controlling mitochondrial fusion and fission contributed to establishing the concept that mitochondrial morphology and ultrastructure are dynamically regulated by mitochondria-shaping proteins. These finely tuned, dynamic changes in mitochondrial shape can in turn control mitochondrial function, and their alterations in human diseases suggest that this space can be explored for drug discovery. Here, we review the basic tenets and molecular mechanisms of mitochondrial morphology and ultrastructure, describing how they can coordinately define mitochondrial function.
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Affiliation(s)
| | - Luca Scorrano
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; Department of Biology, University of Padova, Via U. Bassi 58B, 35121 Padova, Italy.
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5
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Park M, Sunwoo K, Kim YJ, Won M, Xu Y, Kim J, Pu Z, Li M, Kim JY, Seo JH, Kim JS. Cutting Off H + Leaks on the Inner Mitochondrial Membrane: A Proton Modulation Approach to Selectively Eradicate Cancer Stem Cells. J Am Chem Soc 2023; 145:4647-4658. [PMID: 36745678 DOI: 10.1021/jacs.2c12587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cancer stem cells (CSCs) are associated with the invasion and metastatic relapse of various cancers. However, current cancer therapies are limited to targeting the bulk of primary tumor cells while remaining the CSCs untouched. Here, we report a new proton (H+) modulation approach to selectively eradicate CSCs via cutting off the H+ leaks on the inner mitochondrial membrane (IMM). Based on the fruit extract of Gardenia jasminoides, a multimodal molecule channel blocker with high biosafety, namely, Bo-Mt-Ge, is developed. Importantly, in this study, we successfully identify that mitochondrial uncoupling protein UCP2 is closely correlated with the stemness of CSCs, which may offer a new perspective for selective CSC drug discovery. Mechanistic studies show that Bo-Mt-Ge can specifically inhibit the UCP2 activities, decrease the H+ influx in the matrix, regulate the electrochemical gradient, and deplete the endogenous GSH, which synergistically constitute a unique MoA to active apoptotic CSC death. Intriguingly, Bo-Mt-Ge also counteracts the therapeutic resistance via a two-pronged tactic: drug efflux pump P-glycoprotein downregulation and antiapoptotic factor (e.g., Bcl-2) inhibition. With these merits, Bo-Mt-Ge proved to be one of the safest and most efficacious anti-CSC agents, with ca. 100-fold more potent than genipin alone in vitro and in vivo. This study offers new insights and promising solutions for future CSC therapies in the clinic.
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Affiliation(s)
- Minsu Park
- Division of Medical Oncology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 02841, Korea.,Brain Korea 21 Program for Biomedical Science, Korea University College of Medicine, Korea University, Seoul 02841, Korea.,Department of Biomedical Research Center, Korea University Guro Hospital, Korea University, Seoul 08308, Korea
| | - Kyoung Sunwoo
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Yoon-Jae Kim
- Division of Medical Oncology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 02841, Korea.,Brain Korea 21 Program for Biomedical Science, Korea University College of Medicine, Korea University, Seoul 02841, Korea.,Department of Biomedical Research Center, Korea University Guro Hospital, Korea University, Seoul 08308, Korea
| | - Miae Won
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Yunjie Xu
- Department of Chemistry, Korea University, Seoul 02841, Korea.,Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, P. R. China
| | - Jaewon Kim
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Zhongji Pu
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311200, P. R. China
| | - Mingle Li
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Ji Young Kim
- Division of Medical Oncology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 02841, Korea.,Department of Biomedical Research Center, Korea University Guro Hospital, Korea University, Seoul 08308, Korea
| | - Jae Hong Seo
- Division of Medical Oncology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 02841, Korea.,Brain Korea 21 Program for Biomedical Science, Korea University College of Medicine, Korea University, Seoul 02841, Korea.,Department of Biomedical Research Center, Korea University Guro Hospital, Korea University, Seoul 08308, Korea
| | - Jong Seung Kim
- Department of Chemistry, Korea University, Seoul 02841, Korea
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6
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Burtscher J, Soltany A, Visavadiya NP, Burtscher M, Millet GP, Khoramipour K, Khamoui AV. Mitochondrial stress and mitokines in aging. Aging Cell 2023; 22:e13770. [PMID: 36642986 PMCID: PMC9924952 DOI: 10.1111/acel.13770] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/08/2022] [Accepted: 12/20/2022] [Indexed: 01/17/2023] Open
Abstract
Mitokines are signaling molecules that enable communication of local mitochondrial stress to other mitochondria in distant cells and tissues. Among those molecules are FGF21, GDF15 (both expressed in the nucleus) and several mitochondrial-derived peptides, including humanin. Their responsiveness to mitochondrial stress induces mitokine-signaling in response for example to exercise, following mitochondrial challenges in skeletal muscle. Such signaling is emerging as an important mediator of exercise-derived and dietary strategy-related molecular and systemic health benefits, including healthy aging. A compensatory increase in mitokine synthesis and secretion could preserve mitochondrial function and overall cellular vitality. Conversely, resistance against mitokine actions may also develop. Alterations of mitokine-levels, and therefore of mitokine-related inter-tissue cross talk, are associated with general aging processes and could influence the development of age-related chronic metabolic, cardiovascular and neurological diseases; whether these changes contribute to aging or represent "rescue factors" remains to be conclusively shown. The aim of the present review is to summarize the expanding knowledge on mitokines, the potential to modulate them by lifestyle and their involvement in aging and age-related diseases. We highlight the importance of well-balanced mitokine-levels, the preventive and therapeutic properties of maintaining mitokine homeostasis and sensitivity of mitokine signaling but also the risks arising from the dysregulation of mitokines. While reduced mitokine levels may impair inter-organ crosstalk, also excessive mitokine concentrations can have deleterious consequences and are associated with conditions such as cancer and heart failure. Preservation of healthy mitokine signaling levels can be achieved by regular exercise and is associated with an increased lifespan.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport SciencesUniversity of LausanneLausanneSwitzerland,Department of Biomedical SciencesUniversity of LausanneLausanneSwitzerland
| | - Afsaneh Soltany
- Department of Biology, Faculty of ScienceUniversity of ShirazShirazIran
| | - Nishant P. Visavadiya
- Department of Exercise Science and Health PromotionFlorida Atlantic UniversityBoca RatonFloridaUSA
| | - Martin Burtscher
- Department of Sport ScienceUniversity of InnsbruckInnsbruckAustria
| | - Grégoire P. Millet
- Institute of Sport SciencesUniversity of LausanneLausanneSwitzerland,Department of Biomedical SciencesUniversity of LausanneLausanneSwitzerland
| | - Kayvan Khoramipour
- Department of Physiology and Pharmacology, Neuroscience Research Center, Institute of Neuropharmacology, and Afzalipour School of MedicineKerman University of Medical SciencesKermanIran
| | - Andy V. Khamoui
- Department of Exercise Science and Health PromotionFlorida Atlantic UniversityBoca RatonFloridaUSA
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7
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Yoon Y, Lee H, Federico M, Sheu SS. Non-conventional mitochondrial permeability transition: Its regulation by mitochondrial dynamics. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148914. [PMID: 36063902 PMCID: PMC9729414 DOI: 10.1016/j.bbabio.2022.148914] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/21/2022] [Accepted: 08/29/2022] [Indexed: 11/21/2022]
Abstract
Mitochondrial permeability transition (MPT) is a phenomenon that the inner mitochondrial membrane (IMM) loses its selective permeability, leading to mitochondrial dysfunction and cell injury. Electrophysiological evidence indicates the presence of a mega-channel commonly called permeability transition pore (PTP) whose opening is responsible for MPT. However, the molecular identity of the PTP is still under intensive investigations and debates, although cyclophilin D that is inhibited by cyclosporine A (CsA) is the established regulatory component of the PTP. PTP can also open transiently and functions as a rapid mitochondrial Ca2+ releasing mechanism. Mitochondrial fission and fusion, the main components of mitochondrial dynamics, control the number and size of mitochondria, and have been shown to play a role in regulating MPT directly or indirectly. Studies by us and others have indicated the potential existence of a form of transient MPT that is insensitive to CsA. This "non-conventional" MPT is regulated by mitochondrial dynamics and may serve a protective role possibly by decreasing the susceptibility for a frequent or sustained PTP opening; hence, it may have a therapeutic value in many disease conditions involving MPT.
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Affiliation(s)
- Yisang Yoon
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta 30912, GA, USA.
| | - Hakjoo Lee
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta 30912, GA, USA
| | - Marilen Federico
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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8
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Abstract
The analogy of mitochondria as powerhouses has expired. Mitochondria are living, dynamic, maternally inherited, energy-transforming, biosynthetic, and signaling organelles that actively transduce biological information. We argue that mitochondria are the processor of the cell, and together with the nucleus and other organelles they constitute the mitochondrial information processing system (MIPS). In a three-step process, mitochondria (1) sense and respond to both endogenous and environmental inputs through morphological and functional remodeling; (2) integrate information through dynamic, network-based physical interactions and diffusion mechanisms; and (3) produce output signals that tune the functions of other organelles and systemically regulate physiology. This input-to-output transformation allows mitochondria to transduce metabolic, biochemical, neuroendocrine, and other local or systemic signals that enhance organismal adaptation. An explicit focus on mitochondrial signal transduction emphasizes the role of communication in mitochondrial biology. This framework also opens new avenues to understand how mitochondria mediate inter-organ processes underlying human health.
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Affiliation(s)
- Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Neurology, H. Houston Merritt Center, Columbia Translational Neuroscience Initiative, Columbia University Irving Medical Center, New York, NY 10032, USA; New York State Psychiatric Institute, New York, NY 10032, USA.
| | - Orian S Shirihai
- Department of Medicine, Endocrinology, and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Metabolism Theme, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
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9
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Chustecki JM, Etherington RD, Gibbs DJ, Johnston IG. Altered collective mitochondrial dynamics in the Arabidopsis msh1 mutant compromising organelle DNA maintenance. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5428-5439. [PMID: 35662332 PMCID: PMC9467644 DOI: 10.1093/jxb/erac250] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/01/2022] [Indexed: 05/19/2023]
Abstract
Mitochondria form highly dynamic populations in the cells of plants (and almost all eukaryotes). The characteristics and benefits of this collective behaviour, and how it is influenced by nuclear features, remain to be fully elucidated. Here, we use a recently developed quantitative approach to reveal and analyse the physical and collective 'social' dynamics of mitochondria in an Arabidopsis msh1 mutant where the organelle DNA maintenance machinery is compromised. We use a newly created line combining the msh1 mutant with mitochondrially targeted green fluorescent protein (GFP), and characterize mitochondrial dynamics with a combination of single-cell time-lapse microscopy, computational tracking, and network analysis. The collective physical behaviour of msh1 mitochondria is altered from that of the wild type in several ways: mitochondria become less evenly spread, and networks of inter-mitochondrial encounters become more connected, with greater potential efficiency for inter-organelle exchange-reflecting a potential compensatory mechanism for the genetic challenge to the mitochondrial DNA population, supporting more inter-organelle exchange. We find that these changes are similar to those observed in friendly, where mitochondrial dynamics are altered by a physical perturbation, suggesting that this shift to higher connectivity may reflect a general response to mitochondrial challenges, where physical dynamics of mitochondria may be altered to control the genetic structure of the mtDNA population.
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Affiliation(s)
| | | | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Birmingham, UK
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10
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Harbauer AB, Schneider A, Wohlleber D. Analysis of Mitochondria by Single-Organelle Resolution. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2022; 15:1-16. [PMID: 35303775 DOI: 10.1146/annurev-anchem-061020-111722] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cellular organelles are highly specialized compartments with distinct functions. With the increasing resolution of detection methods, it is becoming clearer that same organelles may have different functions or properties not only within different cell populations of a tissue but also within the same cell. Dysfunction or altered function affects the organelle itself and may also lead to malignancies or undesirable cell death. To understand cellular function or dysfunction, it is therefore necessary to analyze cellular components at the single-organelle level. Here, we review the recent advances in analyzing cellular function at single-organelle resolution using high-parameter flow cytometry or multicolor confocal microscopy. We focus on the analysis of mitochondria, as they are organelles at the crossroads of various cellular signaling pathways and functions. However, most of the applied methods/technologies are transferable to any other organelle, such as the endoplasmic reticulum, lysosomes, or peroxisomes.
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Affiliation(s)
- Angelika B Harbauer
- Max Planck Institute of Neurobiology, Martinsried, Germany;
- Institute of Neuronal Cell Biology, TUM School of Medicine, Technical University of Munich, Munich, Germany
- Munich Cluster for Systems Neurology, Munich, Germany
| | - Annika Schneider
- Institute of Molecular Immunology and Experimental Oncology, TUM School of Medicine, Technical University of Munich, Munich, Germany; ,
| | - Dirk Wohlleber
- Institute of Molecular Immunology and Experimental Oncology, TUM School of Medicine, Technical University of Munich, Munich, Germany; ,
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11
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Lara-Rojas F, Juárez-Verdayes M, Wu HM, Cheung AY, Montiel J, Pascual-Morales E, Ryken SE, Bezanilla M, Cardenas L. Using Hyper as a molecular probe to visualize hydrogen peroxide in living plant cells: An updated method. Methods Enzymol 2022; 683:265-289. [PMID: 37087192 DOI: 10.1016/bs.mie.2022.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Reactive oxygen species (ROS) are highly reactive reduced oxygen molecules that play a myriad of roles in animal and plant cells. In plant cells the production of ROS results from aerobic metabolism during respiration and photosynthesis. Therefore mitochondria, chloroplasts, and peroxisomes constitute an important source of ROS. However, ROS can also be produced in response to many physiological stimuli such as pathogen attack, hormone signaling, abiotic stresses or during cell wall organization and plant morphogenesis. The study of ROS in plant cells has been limited to biochemical assays and use of fluorescent probes, however, the irreversible oxidation of the fluorescent dyes prevents the visualization of dynamic changes. We have previously reported that Hyper 1 is a biosensor for H2O2 and consists of a circularly permutated YFP (cpYFP) inserted into the regulatory domain of the Escherichia coli hydrogen peroxide (H2O2) sensor protein OxyR rendering it an H2O2-specific quantitative probe (Bilan & Belousov, 2018; Hernandez-Barrera et al., 2015). Herein we describe an updated protocol for using the improved new version of Hyper 2 and Hyper 3 as a dynamic biosensor for H2O2 in Arabidopsis with virtually unlimited potential to detect H2O2 throughout the plant and under a broad range of developmental and environmental conditions (Bilan et al., 2013).
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12
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Garagounis C, Delkis N, Papadopoulou KK. Unraveling the roles of plant specialized metabolites: using synthetic biology to design molecular biosensors. THE NEW PHYTOLOGIST 2021; 231:1338-1352. [PMID: 33997999 DOI: 10.1111/nph.17470] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/16/2021] [Indexed: 05/25/2023]
Abstract
Plants are a rich source of specialized metabolites with a broad range of bioactivities and many applications in human daily life. Over the past decades significant progress has been made in identifying many such metabolites in different plant species and in elucidating their biosynthetic pathways. However, the biological roles of plant specialized metabolites remain elusive and proposed functions lack an identified underlying molecular mechanism. Understanding the roles of specialized metabolites frequently is hampered by their dynamic production and their specific spatiotemporal accumulation within plant tissues and organs throughout a plant's life cycle. In this review, we propose the employment of strategies from the field of Synthetic Biology to construct and optimize genetically encoded biosensors that can detect individual specialized metabolites in a standardized and high-throughput manner. This will help determine the precise localization of specialized metabolites at the tissue and single-cell levels. Such information will be useful in developing complete system-level models of specialized plant metabolism, which ultimately will demonstrate how the biosynthesis of specialized metabolites is integrated with the core processes of plant growth and development.
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Affiliation(s)
- Constantine Garagounis
- Department of Biochemistry and Biotechnology, Plant and Environmental Biotechnology Laboratory, University of Thessaly, Larissa, 41500, Greece
| | - Nikolaos Delkis
- Department of Biochemistry and Biotechnology, Plant and Environmental Biotechnology Laboratory, University of Thessaly, Larissa, 41500, Greece
| | - Kalliope K Papadopoulou
- Department of Biochemistry and Biotechnology, Plant and Environmental Biotechnology Laboratory, University of Thessaly, Larissa, 41500, Greece
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13
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Weissman D, Maack C. Redox signaling in heart failure and therapeutic implications. Free Radic Biol Med 2021; 171:345-364. [PMID: 34019933 DOI: 10.1016/j.freeradbiomed.2021.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/17/2021] [Accepted: 05/03/2021] [Indexed: 12/13/2022]
Abstract
Heart failure is a growing health burden worldwide characterized by alterations in excitation-contraction coupling, cardiac energetic deficit and oxidative stress. While current treatments are mostly limited to antagonization of neuroendocrine activation, more recent data suggest that also targeting metabolism may provide substantial prognostic benefit. However, although in a broad spectrum of preclinical models, oxidative stress plays a causal role for the development and progression of heart failure, no treatment that targets reactive oxygen species (ROS) directly has entered the clinical arena yet. In the heart, ROS derive from various sources, such as NADPH oxidases, xanthine oxidase, uncoupled nitric oxide synthase and mitochondria. While mitochondria are the primary source of ROS in the heart, communication between different ROS sources may be relevant for physiological signalling events as well as pathologically elevated ROS that deteriorate excitation-contraction coupling, induce hypertrophy and/or trigger cell death. Here, we review the sources of ROS in the heart, the modes of pathological activation of ROS formation as well as therapeutic approaches that may target ROS specifically in mitochondria.
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Affiliation(s)
- David Weissman
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany; Department of Internal Medicine 1, University Clinic Würzburg, Würzburg, Germany.
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14
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Booth DM, Várnai P, Joseph SK, Hajnóczky G. Oxidative bursts of single mitochondria mediate retrograde signaling toward the ER. Mol Cell 2021; 81:3866-3876.e2. [PMID: 34352204 DOI: 10.1016/j.molcel.2021.07.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 05/14/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
The emerging role of mitochondria as signaling organelles raises the question of whether individual mitochondria can initiate heterotypic communication with neighboring organelles. Using fluorescent probes targeted to the endoplasmic-reticulum-mitochondrial interface, we demonstrate that single mitochondria generate oxidative bursts, rapid redox oscillations, confined to the nanoscale environment of the interorganellar contact sites. Using probes fused to inositol 1,4,5-trisphosphate receptors (IP3Rs), we show that Ca2+ channels directly sense oxidative bursts and respond with Ca2+ transients adjacent to active mitochondria. Application of specific mitochondrial stressors or apoptotic stimuli dramatically increases the frequency and amplitude of the oxidative bursts by enhancing transient permeability transition pore openings. Conversely, blocking interface Ca2+ transport via elimination of IP3Rs or mitochondrial calcium uniporter channels suppresses ER-mitochondrial Ca2+ feedback and cell death. Thus, single mitochondria initiate local retrograde signaling by miniature oxidative bursts and, upon metabolic or apoptotic stress, may also amplify signals to the rest of the cell.
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Affiliation(s)
- David M Booth
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Péter Várnai
- Department of Physiology, Semmelweis University, Faculty of Medicine, 1444 Budapest, Hungary
| | - Suresh K Joseph
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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15
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Mukherjee I, Ghosh M, Meinecke M. MICOS and the mitochondrial inner membrane morphology - when things get out of shape. FEBS Lett 2021; 595:1159-1183. [PMID: 33837538 DOI: 10.1002/1873-3468.14089] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 12/21/2022]
Abstract
Mitochondria play a key role in cellular signalling, metabolism and energetics. Proper architecture and remodelling of the inner mitochondrial membrane are essential for efficient respiration, apoptosis and quality control in the cell. Several protein complexes including mitochondrial contact site and cristae organizing system (MICOS), F1 FO -ATP synthase, and Optic Atrophy 1 (OPA1), facilitate formation, maintenance and stability of cristae membranes. MICOS, the F1 FO -ATP synthase, OPA1 and inner membrane phospholipids such as cardiolipin and phosphatidylethanolamine interact with each other to organize the inner membrane ultra-structure and remodel cristae in response to the cell's demands. Functional alterations in these proteins or in the biosynthesis pathway of cardiolipin and phosphatidylethanolamine result in an aberrant inner membrane architecture and impair mitochondrial function. Mitochondrial dysfunction and abnormalities hallmark several human conditions and diseases including neurodegeneration, cardiomyopathies and diabetes mellitus. Yet, they have long been regarded as secondary pathological effects. This review discusses emerging evidence of a direct relationship between protein- and lipid-dependent regulation of the inner mitochondrial membrane morphology and diseases such as fatal encephalopathy, Leigh syndrome, Parkinson's disease, and cancer.
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Affiliation(s)
- Indrani Mukherjee
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany
| | - Mausumi Ghosh
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany.,Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, Göttingen, Germany
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16
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Aklima J, Onojima T, Kimura S, Umiuchi K, Shibata T, Kuraoka Y, Oie Y, Suganuma Y, Ohta Y. Effects of Matrix pH on Spontaneous Transient Depolarization and Reactive Oxygen Species Production in Mitochondria. Front Cell Dev Biol 2021; 9:692776. [PMID: 34277637 PMCID: PMC8278022 DOI: 10.3389/fcell.2021.692776] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/26/2021] [Indexed: 01/28/2023] Open
Abstract
Reactive oxygen species (ROS) oxidize surrounding molecules and thus impair their functions. Since mitochondria are a major source of ROS, suppression of ROS overproduction in the mitochondria is important for cells. Spontaneous transient depolarization of individual mitochondria is a physiological phenomenon widely observed from plants to mammals. Mitochondrial uncoupling can reduce ROS production; therefore, it is conceivable that transient depolarization could reduce ROS production. However, transient depolarization has been observed with increased ROS production. Therefore, the exact contribution of transient depolarization to ROS production has not been elucidated. In this study, we examined how the spontaneous transient depolarization occurring in individual mitochondria affected ROS production. When the matrix pH increased after the addition of malate or exposure of the isolated mitochondria to a high-pH buffer, transient depolarization was stimulated. Similar stimulation by an increased matrix pH was also observed in the mitochondria in intact H9c2 cells. Modifying the mitochondrial membrane potential and matrix pH by adding K+ in the presence of valinomycin, a K+ ionophore, clarified that an increase in the matrix pH is a major cause of ROS generation. When we added ADP in the presence of oligomycin to suppress the transient depolarization without decreasing the matrix pH, we observed the suppression of mitochondrial respiration, increased matrix pH, and enhanced ROS production. Based on these results, we propose a model where spontaneous transient depolarization occurs during increased proton influx through proton channels opened by increased matrix pH, leading to the suppression of ROS production. This study improves our understanding of mitochondrial behavior.
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Affiliation(s)
- Jannatul Aklima
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan.,Department of Biochemistry and Molecular Biology, University of Chittagong, Chittagong, Bangladesh
| | - Takumi Onojima
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Sawako Kimura
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Kanji Umiuchi
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Takahiro Shibata
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Yusho Kuraoka
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Yoshiki Oie
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Yoshiki Suganuma
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Yoshihiro Ohta
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Japan
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17
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Pedersen SF, Flinck M, Pardo LA. The Interplay between Dysregulated Ion Transport and Mitochondrial Architecture as a Dangerous Liaison in Cancer. Int J Mol Sci 2021; 22:ijms22105209. [PMID: 34069047 PMCID: PMC8156689 DOI: 10.3390/ijms22105209] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 02/06/2023] Open
Abstract
Transport of ions and nutrients is a core mitochondrial function, without which there would be no mitochondrial metabolism and ATP production. Both ion homeostasis and mitochondrial phenotype undergo pervasive changes during cancer development, and both play key roles in driving the malignancy. However, the link between these events has been largely ignored. This review comprehensively summarizes and critically discusses the role of the reciprocal relationship between ion transport and mitochondria in crucial cellular functions, including metabolism, signaling, and cell fate decisions. We focus on Ca2+, H+, and K+, which play essential and highly interconnected roles in mitochondrial function and are profoundly dysregulated in cancer. We describe the transport and roles of these ions in normal mitochondria, summarize the changes occurring during cancer development, and discuss how they might impact tumorigenesis.
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Affiliation(s)
- Stine F. Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark;
- Correspondence: (S.F.P.); (L.A.P.)
| | - Mette Flinck
- Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark;
| | - Luis A. Pardo
- Oncophysiology Group, Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
- Correspondence: (S.F.P.); (L.A.P.)
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18
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Quintana-Cabrera R, Manjarrés-Raza I, Vicente-Gutiérrez C, Corrado M, Bolaños JP, Scorrano L. Opa1 relies on cristae preservation and ATP synthase to curtail reactive oxygen species accumulation in mitochondria. Redox Biol 2021; 41:101944. [PMID: 33780775 PMCID: PMC8039725 DOI: 10.1016/j.redox.2021.101944] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/26/2021] [Accepted: 03/10/2021] [Indexed: 12/21/2022] Open
Abstract
Reactive oxygen species (ROS) are a common product of active mitochondrial respiration carried in mitochondrial cristae, but whether cristae shape influences ROS levels is unclear. Here we report that the mitochondrial fusion and cristae shape protein Opa1 requires mitochondrial ATP synthase oligomers to reduce ROS accumulation. In cells fueled with galactose to force ATP production by mitochondria, cristae are enlarged, ATP synthase oligomers destabilized, and ROS accumulate. Opa1 prevents both cristae remodeling and ROS generation, without impinging on levels of mitochondrial antioxidant defense enzymes that are unaffected by Opa1 overexpression. Genetic and pharmacologic experiments indicate that Opa1 requires ATP synthase oligomerization and activity to reduce ROS levels upon a blockage of the electron transport chain. Our results indicate that the converging effect of Opa1 and mitochondrial ATP synthase on mitochondrial ultrastructure regulate ROS abundance to sustain cell viability.
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Affiliation(s)
- Rubén Quintana-Cabrera
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain; Department of Biochemistry and Molecular Biology, University of Salamanca, Spain.
| | - Israel Manjarrés-Raza
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain; Department of Biochemistry and Molecular Biology, University of Salamanca, Spain
| | - Carlos Vicente-Gutiérrez
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Mauro Corrado
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg Im Breisgau, Germany
| | - Juan P Bolaños
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain; Department of Biochemistry and Molecular Biology, University of Salamanca, Spain
| | - Luca Scorrano
- Veneto Institute of Molecular Medicine, Padova, Italy; Department of Biology, University of Padova, Padova, Italy.
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19
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The redox language in neurodegenerative diseases: oxidative post-translational modifications by hydrogen peroxide. Cell Death Dis 2021; 12:58. [PMID: 33431811 PMCID: PMC7801447 DOI: 10.1038/s41419-020-03355-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/07/2020] [Indexed: 01/29/2023]
Abstract
Neurodegenerative diseases, a subset of age-driven diseases, have been known to exhibit increased oxidative stress. The resultant increase in reactive oxygen species (ROS) has long been viewed as a detrimental byproduct of many cellular processes. Despite this, therapeutic approaches using antioxidants were deemed unsuccessful in circumventing neurodegenerative diseases. In recent times, it is widely accepted that these toxic by-products could act as secondary messengers, such as hydrogen peroxide (H2O2), to drive important signaling pathways. Notably, mitochondria are considered one of the major producers of ROS, especially in the production of mitochondrial H2O2. As a secondary messenger, cellular H2O2 can initiate redox signaling through oxidative post-translational modifications (oxPTMs) on the thiol group of the amino acid cysteine. With the current consensus that cellular ROS could drive important biological signaling pathways through redox signaling, researchers have started to investigate the role of cellular ROS in the pathogenesis of neurodegenerative diseases. Moreover, mitochondrial dysfunction has been linked to various neurodegenerative diseases, and recent studies have started to focus on the implications of mitochondrial ROS from dysfunctional mitochondria on the dysregulation of redox signaling. Henceforth, in this review, we will focus our attention on the redox signaling of mitochondrial ROS, particularly on mitochondrial H2O2, and its potential implications with neurodegenerative diseases.
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20
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Weissert V, Rieger B, Morris S, Arroum T, Psathaki OE, Zobel T, Perkins G, Busch KB. Inhibition of the mitochondrial ATPase function by IF1 changes the spatiotemporal organization of ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2021; 1862:148322. [PMID: 33065099 PMCID: PMC7718977 DOI: 10.1016/j.bbabio.2020.148322] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/11/2020] [Accepted: 09/29/2020] [Indexed: 01/20/2023]
Abstract
• Mitochondrial F1FO ATP synthase is the key enzyme for mitochondrial bioenergetics. Dimeric F1FO-ATP synthase, is preferentially located at the edges of the cristae and its oligomerization state determines mitochondrial ultrastructure. The ATP synthase inhibitor protein IF1 modulates not only ATP synthase activity but also regulates both the structure and function of mitochondria. In order to understand this in more detail, we have investigated the effect of IF1 on the spatiotemporal organization of the ATP synthase. Stable cell lines were generated that overexpressed IF1 and constitutively active IF1-H49K. The expression of IF1-H49K induced a change in the localization and mobility of the ATP synthase as analyzed by single molecule tracking and localization microscopy (TALM). In addition, the ultrastructure and function of mitochondria in cells with higher levels of active IF1 displayed a gradual alteration. In state III, cristae structures were significantly altered. The inhibition of the hydrolase activity of the F1FO-ATP synthase by IF1 together with altered inner mitochondrial membrane caused re-localization and altered mobility of the enzyme.
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Affiliation(s)
- Verena Weissert
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, 49076 Osnabrück, Lower Saxony, Germany
| | - Bettina Rieger
- Institute of Molecular Cell Biology, Department of Biology, University of Muenster, 48149 Muenster, Germany
| | - Silke Morris
- Institute of Molecular Cell Biology, Department of Biology, University of Muenster, 48149 Muenster, Germany
| | - Tasnim Arroum
- Institute of Molecular Cell Biology, Department of Biology, University of Muenster, 48149 Muenster, Germany
| | - Olympia Ekaterini Psathaki
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, 49076 Osnabrück, Lower Saxony, Germany
| | - Thomas Zobel
- Imaging Network, Cells in Motion Interfaculty Centre, University of Muenster, 48149 Muenster, Germany
| | - Guy Perkins
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA, USA
| | - Karin B Busch
- Institute of Molecular Cell Biology, Department of Biology, University of Muenster, 48149 Muenster, Germany.
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21
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Heine KB, Justyn NM, Hill GE, Hood WR. Ultraviolet irradiation alters the density of inner mitochondrial membrane and proportion of inter-mitochondrial junctions in copepod myocytes. Mitochondrion 2020; 56:82-90. [PMID: 33220503 DOI: 10.1016/j.mito.2020.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 10/18/2020] [Accepted: 11/02/2020] [Indexed: 01/11/2023]
Abstract
The efficient production of energy via oxidative phosphorylation is essential to the growth, survival, and reproduction of eukaryotes. The behavior (position of, and communication between, mitochondria) and morphology of mitochondria play key roles in efficient energy production and are influenced by oxidative stressors such as ultraviolet (UV) radiation. We tested the hypothesis that mitochondria change their behavior and morphology to meet energetic demands of responding to changes in oxidative stress. Specifically, we predicted that UV irradiation would increase the density of inner mitochondrial membrane and proportion of inter-mitochondrial junctions to influence whole-animal metabolic rate. Using transmission electron microscopy, we found that both three and six hours of UV-A/B irradiation (0.5 W/m2) increased the proportion of inter-mitochondrial junctions (with increasing mitochondrial aspect ratio) and the density of inner mitochondrial membrane in myocytes of Tigriopus californicus copepods. Mitochondrial density increased following both irradiation treatments, but mitochondrial size decreased under the six hour treatment. Metabolic rate was maintained under three hours of irradiation but decreased following six hours of exposure. These observations demonstrate that the density of inner mitochondrial membrane and proportion of inter-mitochondrial junctions can play formative roles in maintaining whole-animal metabolic rate, and ultimately organismal performance, under exposure to an oxidative stressor.
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Affiliation(s)
- Kyle B Heine
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA.
| | - Nicholas M Justyn
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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22
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Van Wijk R, Van Wijk EP, Pang J, Yang M, Yan Y, Han J. Integrating Ultra-Weak Photon Emission Analysis in Mitochondrial Research. Front Physiol 2020; 11:717. [PMID: 32733265 PMCID: PMC7360823 DOI: 10.3389/fphys.2020.00717] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/29/2020] [Indexed: 12/11/2022] Open
Abstract
Once regarded solely as the energy source of the cell, nowadays mitochondria are recognized to perform multiple essential functions in addition to energy production. Since the discovery of pathogenic mitochondrial DNA defects in the 1980s, research advances have revealed an increasing number of common human diseases, which share an underlying pathogenesis involving mitochondrial dysfunction. A major factor in this dysfunction is reactive oxygen species (ROS), which influence the mitochondrial-nuclear crosstalk and the link with the epigenome, an influence that provides explanations for pathogenic mechanisms. Regarding these mechanisms, we should take into account that mitochondria produce the majority of ultra-weak photon emission (UPE), an aspect that is often ignored - this type of emission may serve as assay for ROS, thus providing new opportunities for a non-invasive diagnosis of mitochondrial dysfunction. In this article, we overviewed three relevant areas of mitochondria-related research over the period 1960-2020: (a) respiration and energy production, (b) respiration-related production of free radicals and other ROS species, and (c) ultra-weak photon emission in relation to ROS and stress. First, we have outlined how these research areas initially developed independently of each other - following that, our review aims to show their stepwise integration during later stages of development. It is suggested that a further stimulation of research on UPE may have the potential to enhance the progress of modern mitochondrial research and its integration in medicine.
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Affiliation(s)
- Roeland Van Wijk
- Meluna Research, Department of Biophotonics, Geldermalsen, Netherlands
| | | | - Jingxiang Pang
- Key Laboratory for Biotech-Drugs of National Health Commission, Shandong Medicinal Biotechnology Center, Jinan, China
- Shandong First Medical University, Jinan, China
- Shandong Academy of Medical Sciences, Jinan, China
| | - Meina Yang
- Key Laboratory for Biotech-Drugs of National Health Commission, Shandong Medicinal Biotechnology Center, Jinan, China
- Shandong First Medical University, Jinan, China
- Shandong Academy of Medical Sciences, Jinan, China
| | - Yu Yan
- Meluna Research, Department of Biophotonics, Geldermalsen, Netherlands
| | - Jinxiang Han
- Key Laboratory for Biotech-Drugs of National Health Commission, Shandong Medicinal Biotechnology Center, Jinan, China
- Shandong First Medical University, Jinan, China
- Shandong Academy of Medical Sciences, Jinan, China
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23
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Picard M, Sandi C. The social nature of mitochondria: Implications for human health. Neurosci Biobehav Rev 2020; 120:595-610. [PMID: 32651001 DOI: 10.1016/j.neubiorev.2020.04.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 12/15/2022]
Abstract
Sociality has profound evolutionary roots and is observed from unicellular organisms to multicellular animals. In line with the view that social principles apply across levels of biological complexity, a growing body of data highlights the remarkable social nature of mitochondria - life-sustaining endosymbiotic organelles with their own genome that populate the cell cytoplasm. Here, we draw from organizing principles of behavior in social organisms to reveal that similar to individuals among social networks, mitochondria communicate with each other and with the cell nucleus, exhibit group formation and interdependence, synchronize their behaviors, and functionally specialize to accomplish specific functions within the organism. Mitochondria are social organelles. The extension of social principles across levels of biological complexity is a theoretical shift that emphasizes the role of communication and interdependence in cell biology, physiology, and neuroscience. With the help of emerging computational methods capable of capturing complex dynamic behavioral patterns, the implementation of social concepts in mitochondrial biology may facilitate cross-talk across disciplines towards increasingly holistic and accurate models of human health.
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Affiliation(s)
- Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, NY, USA; Department of Neurology, H. Houston Merritt Center, Columbia Translational Neuroscience Initiative, Columbia University Irving Medical Center, New York, NY, USA; New York State Psychiatric Institute, New York, NY, USA.
| | - Carmen Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, Swiss Federal Institute of Technology Lausanne (EPFL), Switzerland
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24
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Berry BJ, Trewin AJ, Milliken AS, Baldzizhar A, Amitrano AM, Lim Y, Kim M, Wojtovich AP. Optogenetic control of mitochondrial protonmotive force to impact cellular stress resistance. EMBO Rep 2020; 21:e49113. [PMID: 32043300 PMCID: PMC7132214 DOI: 10.15252/embr.201949113] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/26/2019] [Accepted: 01/15/2020] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial respiration generates an electrochemical proton gradient across the mitochondrial inner membrane called protonmotive force (PMF) to drive diverse functions and synthesize ATP. Current techniques to manipulate the PMF are limited to its dissipation; yet, there is no precise and reversible method to increase the PMF. To address this issue, we aimed to use an optogenetic approach and engineered a mitochondria-targeted light-activated proton pump that we name mitochondria-ON (mtON) to selectively increase the PMF in Caenorhabditis elegans. Here we show that mtON photoactivation increases the PMF in a dose-dependent manner, supports ATP synthesis, increases resistance to mitochondrial toxins, and modulates energy-sensing behavior. Moreover, transient mtON activation during hypoxic preconditioning prevents the well-characterized adaptive response of hypoxia resistance. Our results show that optogenetic manipulation of the PMF is a powerful tool to modulate metabolism and cell signaling.
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Affiliation(s)
- Brandon J Berry
- Department of Pharmacology and PhysiologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Adam J Trewin
- Department of Anesthesiology and Perioperative MedicineUniversity of Rochester Medical CenterRochesterNYUSA
| | - Alexander S Milliken
- Department of Pharmacology and PhysiologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Aksana Baldzizhar
- Department of Anesthesiology and Perioperative MedicineUniversity of Rochester Medical CenterRochesterNYUSA
| | - Andrea M Amitrano
- Department of PathologyUniversity of Rochester Medical CenterRochesterNYUSA
- Department of Microbiology and ImmunologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Yunki Lim
- Nephrology DivisionDepartment of MedicineSchool of Medicine and DentistryUniversity of Rochester Medical CenterRochesterNYUSA
| | - Minsoo Kim
- Department of PathologyUniversity of Rochester Medical CenterRochesterNYUSA
- Department of Microbiology and ImmunologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Andrew P Wojtovich
- Department of Pharmacology and PhysiologyUniversity of Rochester Medical CenterRochesterNYUSA
- Department of Anesthesiology and Perioperative MedicineUniversity of Rochester Medical CenterRochesterNYUSA
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25
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Kanemaru K, Suzuki J, Taiko I, Iino M. Red fluorescent CEPIA indicators for visualization of Ca 2+ dynamics in mitochondria. Sci Rep 2020; 10:2835. [PMID: 32071363 PMCID: PMC7029041 DOI: 10.1038/s41598-020-59707-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/04/2020] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial Ca2+ dynamics are involved in the regulation of multifarious cellular processes, including intracellular Ca2+ signalling, cell metabolism and cell death. Use of mitochondria-targeted genetically encoded Ca2+ indicators has revealed intercellular and subcellular heterogeneity of mitochondrial Ca2+ dynamics, which are assumed to be determined by distinct thresholds of Ca2+ increases at each subcellular mitochondrial domain. The balance between Ca2+ influx through the mitochondrial calcium uniporter and extrusion by cation exchangers across the inner mitochondrial membrane may define the threshold; however, the precise mechanisms remain to be further explored. We here report the new red fluorescent genetically encoded Ca2+ indicators, R-CEPIA3mt and R-CEPIA4mt, which are targeted to mitochondria and their Ca2+ affinities are engineered to match the intramitochondrial Ca2+ concentrations. They enable visualization of mitochondrial Ca2+ dynamics with high spatiotemporal resolution in parallel with the use of green fluorescent probes and optogenetic tools. Thus, R-CEPIA3mt and R-CEPIA4mt are expected to be a useful tool for elucidating the mechanisms of the complex mitochondrial Ca2+ dynamics and their functions.
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Affiliation(s)
- Kazunori Kanemaru
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
| | - Junji Suzuki
- Department of Physiology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Isamu Taiko
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
- Department of Physiology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan.
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26
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Heine KB, Hood WR. Mitochondrial behaviour, morphology, and animal performance. Biol Rev Camb Philos Soc 2020; 95:730-737. [PMID: 32022456 DOI: 10.1111/brv.12584] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 12/14/2022]
Abstract
We have a limited understanding of the proximate mechanisms that are responsible for the development of variation in animal performance and life-history strategies. Provided that components of an organism's successful life history - for example, mate competition, gestation, lactation, etc. - are energetically demanding, increased energy production within mitochondria is likely the foundation from which organisms are able to perform these tasks. Mitochondrial behaviour (positioning within the cell and communication between mitochondria) and morphology affect variation in energy production at the molecular, cellular, and organismal levels. Therefore, adaptations in mitochondrial behaviour and morphology that favour efficient energy production likely influence variation in animal performance. Previous work has linked greater proportions of inter-mitochondrial junctions and density of the inner mitochondrial membrane, among other traits, with increased energetic demand. Future research should focus on how inter-mitochondrial junctions and morphology of the inner mitochondrial membrane, in particular, influence animal performance in accordance with mitochondrial density, fission, and fusion.
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Affiliation(s)
- Kyle B Heine
- Department of Biological Sciences, Auburn University, 101 Rouse Life Sciences Building, Auburn, AL, 36849, U.S.A
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, 101 Rouse Life Sciences Building, Auburn, AL, 36849, U.S.A
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27
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Glancy B. Visualizing Mitochondrial Form and Function within the Cell. Trends Mol Med 2020; 26:58-70. [PMID: 31706841 PMCID: PMC6938546 DOI: 10.1016/j.molmed.2019.09.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/25/2019] [Accepted: 09/25/2019] [Indexed: 12/12/2022]
Abstract
The specific cellular role of mitochondria is influenced by the surrounding environment because effective mitochondrial function requires the delivery of inputs (e.g., oxygen) and export of products (e.g., signaling molecules) to and from other cellular components, respectively. Recent technological developments in mitochondrial imaging have led to a more precise and comprehensive understanding of the spatial relationships governing the function of this complex organelle, opening a new era of mitochondrial research. Here, I highlight current imaging approaches for visualizing mitochondrial form and function within complex cellular environments. Increasing clarity of mitochondrial behavior within cells will continue to lend mechanistic insights into the role of mitochondria under normal and pathological conditions and point to spatially regulated processes that can be targeted to improve cellular function.
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Affiliation(s)
- Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA; National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA.
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28
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Live cell imaging of signaling and metabolic activities. Pharmacol Ther 2019; 202:98-119. [DOI: 10.1016/j.pharmthera.2019.06.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/31/2019] [Indexed: 12/15/2022]
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29
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Wong YC, Peng W, Krainc D. Lysosomal Regulation of Inter-mitochondrial Contact Fate and Motility in Charcot-Marie-Tooth Type 2. Dev Cell 2019; 50:339-354.e4. [PMID: 31231042 DOI: 10.1016/j.devcel.2019.05.033] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 02/25/2019] [Accepted: 05/16/2019] [Indexed: 10/26/2022]
Abstract
Properly regulated mitochondrial networks are essential for cellular function and implicated in multiple diseases. Mitochondria undergo fission and fusion events, but the dynamics and regulation of a third event of inter-mitochondrial contact formation remain unclear. Using super-resolution imaging, we demonstrate that inter-mitochondrial contacts frequently form and play a fundamental role in mitochondrial networks by restricting mitochondrial motility. Inter-mitochondrial contact untethering events are marked and regulated by mitochondria-lysosome contacts, which are modulated by RAB7 GTP hydrolysis. Moreover, inter-mitochondrial contact formation and untethering are further regulated by Mfn1/2 and Drp1 GTP hydrolysis, respectively. Surprisingly, endoplasmic reticulum tubules are also present at inter-mitochondrial contact untethering events, in addition to mitochondrial fission and fusion events. Importantly, we find that multiple Charcot-Marie-Tooth type 2 disease-linked mutations in Mfn2 (CMT2A), RAB7 (CMT2B), and TRPV4 (CMT2C) converge on prolonged inter-mitochondrial contacts and defective mitochondrial motility, highlighting a role for inter-mitochondrial contacts in mitochondrial network regulation and disease.
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Affiliation(s)
- Yvette C Wong
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Wesley Peng
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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30
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Dietz JV, Bohovych I, Viana MP, Khalimonchuk O. Proteolytic regulation of mitochondrial dynamics. Mitochondrion 2019; 49:289-304. [PMID: 31029640 DOI: 10.1016/j.mito.2019.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/19/2019] [Indexed: 12/23/2022]
Abstract
Spatiotemporal changes in the abundance, shape, and cellular localization of the mitochondrial network, also known as mitochondrial dynamics, are now widely recognized to play a key role in mitochondrial and cellular physiology as well as disease states. This process involves coordinated remodeling of the outer and inner mitochondrial membranes by conserved dynamin-like guanosine triphosphatases and their partner molecules in response to various physiological and stress stimuli. Although the core machineries that mediate fusion and partitioning of the mitochondrial network have been extensively characterized, many aspects of their function and regulation are incompletely understood and only beginning to emerge. In the present review we briefly summarize current knowledge about how the key mitochondrial dynamics-mediating factors are regulated via selective proteolysis by mitochondrial and cellular proteolytic machineries.
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Affiliation(s)
- Jonathan V Dietz
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, United States of America
| | - Iryna Bohovych
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, United States of America
| | - Martonio Ponte Viana
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, United States of America
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, United States of America; Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, United States of America; Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, United States of America.
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31
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De la Fuente S, Sheu SS. SR-mitochondria communication in adult cardiomyocytes: A close relationship where the Ca 2+ has a lot to say. Arch Biochem Biophys 2019; 663:259-268. [PMID: 30685253 PMCID: PMC6377816 DOI: 10.1016/j.abb.2019.01.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 01/14/2019] [Accepted: 01/22/2019] [Indexed: 02/07/2023]
Abstract
In adult cardiomyocytes, T-tubules, junctional sarcoplasmic reticulum (jSR), and mitochondria juxtapose each other and form a unique and highly repetitive functional structure along the cell. The close apposition between jSR and mitochondria creates high Ca2+ microdomains at the contact sites, increasing the efficiency of the excitation-contraction-bioenergetics coupling, where the Ca2+ transfer from SR to mitochondria plays a critical role. The SR-mitochondria contacts are established through protein tethers, with mitofusin 2 the most studied SR-mitochondrial "bridge", albeit controversial. Mitochondrial Ca2+ uptake is further optimized with the mitochondrial Ca2+ uniporter preferentially localized in the jSR-mitochondria contact sites and the mitochondrial Na+/Ca2+ exchanger localized away from these sites. Despite all these unique features facilitating the privileged transport of Ca2+ from SR to mitochondria in adult cardiomyocytes, the question remains whether mitochondrial Ca2+ concentrations oscillate in synchronicity with cytosolic Ca2+ transients during heartbeats. Proper Ca2+ transfer controls not only the process of mitochondrial bioenergetics, but also of mitochondria-mediated cell death, autophagy/mitophagy, mitochondrial fusion/fission dynamics, reactive oxygen species generation, and redox signaling, among others. Our review focuses specifically on Ca2+ signaling between SR and mitochondria in adult cardiomyocytes. We discuss the physiological and pathological implications of this SR-mitochondrial Ca2+ signaling, research gaps, and future trends.
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Affiliation(s)
- Sergio De la Fuente
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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32
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Chareyron I, Wall C, Thevenet J, Santo-Domingo J, Wiederkehr A. Cellular stress is a prerequisite for glucose-induced mitochondrial matrix alkalinization in pancreatic β-cells. Mol Cell Endocrinol 2019; 481:71-83. [PMID: 30476561 DOI: 10.1016/j.mce.2018.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 11/20/2018] [Accepted: 11/22/2018] [Indexed: 11/24/2022]
Abstract
Changes in mitochondrial and cytosolic pH alter the chemical gradient across the inner mitochondrial membrane. The proton chemical gradient contributes to mitochondrial ATP synthesis as well as the uptake and release of metabolites and ions from the organelle. Here mitochondrial pH and ΔpH were studied for the first time in human pancreatic β-cells. Adenoviruses were used for rat insulin promoter dependent expression of the pH sensor SypHer targeted to either the mitochondrial matrix or the cytosol. The matrix pH in resting human β-cells is low (pH = 7.50 ± SD 0.17) compared to published values in other cell types. Consequently, the ΔpH of β-cells mitochondria is small. Glucose stimulation consistently resulted in acidification of the matrix pH in INS-1E insulinoma cells and β-cells in intact human islets or islet monolayer cultures. We registered acidification with similar kinetics but of slightly smaller amplitude in the cytosol of β-cells, thus glucose stimulation further reduced the ΔpH. Infection of human islets with high levels of adenoviruses caused the mitochondrial pH to increase. The apoptosis inducer and broad-spectrum kinase inhibitor staurosporine had similar effects on pH homeostasis. Although staurosporine alone does not affect the mitochondrial pH, glucose slightly increases the matrix pH of staurosporine treated cells. These two cellular stressors alter the normal mitochondrial pH response to glucose in pancreatic β-cells.
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Affiliation(s)
- Isabelle Chareyron
- Mitochondrial Function, Nestlé Institute of Health Sciences, 1015, Lausanne, Switzerland
| | - Christopher Wall
- Mitochondrial Function, Nestlé Institute of Health Sciences, 1015, Lausanne, Switzerland
| | - Jonathan Thevenet
- Mitochondrial Function, Nestlé Institute of Health Sciences, 1015, Lausanne, Switzerland
| | - Jaime Santo-Domingo
- Mitochondrial Function, Nestlé Institute of Health Sciences, 1015, Lausanne, Switzerland
| | - Andreas Wiederkehr
- Mitochondrial Function, Nestlé Institute of Health Sciences, 1015, Lausanne, Switzerland.
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33
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Nietzel T, Elsässer M, Ruberti C, Steinbeck J, Ugalde JM, Fuchs P, Wagner S, Ostermann L, Moseler A, Lemke P, Fricker MD, Müller-Schüssele SJ, Moerschbacher BM, Costa A, Meyer AJ, Schwarzländer M. The fluorescent protein sensor roGFP2-Orp1 monitors in vivo H 2 O 2 and thiol redox integration and elucidates intracellular H 2 O 2 dynamics during elicitor-induced oxidative burst in Arabidopsis. THE NEW PHYTOLOGIST 2019; 221:1649-1664. [PMID: 30347449 DOI: 10.1111/nph.15550] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 10/13/2018] [Indexed: 05/04/2023]
Abstract
Hydrogen peroxide (H2 O2 ) is ubiquitous in cells and at the centre of developmental programmes and environmental responses. Its chemistry in cells makes H2 O2 notoriously hard to detect dynamically, specifically and at high resolution. Genetically encoded sensors overcome persistent shortcomings, but pH sensitivity, silencing of expression and a limited concept of sensor behaviour in vivo have hampered any meaningful H2 O2 sensing in living plants. We established H2 O2 monitoring in the cytosol and the mitochondria of Arabidopsis with the fusion protein roGFP2-Orp1 using confocal microscopy and multiwell fluorimetry. We confirmed sensor oxidation by H2 O2 , show insensitivity to physiological pH changes, and demonstrated that glutathione dominates sensor reduction in vivo. We showed the responsiveness of the sensor to exogenous H2 O2 , pharmacologically-induced H2 O2 release, and genetic interference with the antioxidant machinery in living Arabidopsis tissues. Monitoring intracellular H2 O2 dynamics in response to elicitor exposure reveals the late and prolonged impact of the oxidative burst in the cytosol that is modified in redox mutants. We provided a well defined toolkit for H2 O2 monitoring in planta and showed that intracellular H2 O2 measurements only carry meaning in the context of the endogenous thiol redox systems. This opens new possibilities to dissect plant H2 O2 dynamics and redox regulation, including intracellular NADPH oxidase-mediated ROS signalling.
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Affiliation(s)
- Thomas Nietzel
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
| | - Marlene Elsässer
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
- Institute for Cellular and Molecular Botany (IZMB), University of Bonn, Kirschallee 1, D-53115, Bonn, Germany
| | - Cristina Ruberti
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
| | - Janina Steinbeck
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
| | - José Manuel Ugalde
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
| | - Philippe Fuchs
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
| | - Stephan Wagner
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
| | - Lara Ostermann
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
- BioSC, c/o Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Anna Moseler
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
| | - Philipp Lemke
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
| | - Mark D Fricker
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Stefanie J Müller-Schüssele
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
| | - Bruno M Moerschbacher
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
| | - Alex Costa
- Dipartimento di Bioscienze, Università degli Studi di Milano, I-20133, Milano, Italy
| | - Andreas J Meyer
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
- BioSC, c/o Forschungszentrum Jülich, D-52425, Jülich, Germany
| | - Markus Schwarzländer
- Institute for Biology and Biotechnology of Plants, University of Münster, Schlossplatz 8, D-48143, Münster, Germany
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113, Bonn, Germany
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34
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Abstract
Cell-to-cell heterogeneity drives a range of (patho)physiologically important phenomena, such as cell fate and chemotherapeutic resistance. The role of metabolism, and particularly of mitochondria, is increasingly being recognized as an important explanatory factor in cell-to-cell heterogeneity. Most eukaryotic cells possess a population of mitochondria, in the sense that mitochondrial DNA (mtDNA) is held in multiple copies per cell, where the sequence of each molecule can vary. Hence, intra-cellular mitochondrial heterogeneity is possible, which can induce inter-cellular mitochondrial heterogeneity, and may drive aspects of cellular noise. In this review, we discuss sources of mitochondrial heterogeneity (variations between mitochondria in the same cell, and mitochondrial variations between supposedly identical cells) from both genetic and non-genetic perspectives, and mitochondrial genotype-phenotype links. We discuss the apparent homeostasis of mtDNA copy number, the observation of pervasive intra-cellular mtDNA mutation (which is termed "microheteroplasmy"), and developments in the understanding of inter-cellular mtDNA mutation ("macroheteroplasmy"). We point to the relationship between mitochondrial supercomplexes, cristal structure, pH, and cardiolipin as a potential amplifier of the mitochondrial genotype-phenotype link. We also discuss mitochondrial membrane potential and networks as sources of mitochondrial heterogeneity, and their influence upon the mitochondrial genome. Finally, we revisit the idea of mitochondrial complementation as a means of dampening mitochondrial genotype-phenotype links in light of recent experimental developments. The diverse sources of mitochondrial heterogeneity, as well as their increasingly recognized role in contributing to cellular heterogeneity, highlights the need for future single-cell mitochondrial measurements in the context of cellular noise studies.
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Affiliation(s)
- Juvid Aryaman
- Department of Mathematics, Imperial College London, London, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Iain G. Johnston
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- EPSRC Centre for the Mathematics of Precision Healthcare, Imperial College London, London, United Kingdom
| | - Nick S. Jones
- Department of Mathematics, Imperial College London, London, United Kingdom
- EPSRC Centre for the Mathematics of Precision Healthcare, Imperial College London, London, United Kingdom
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35
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McBride S, Wei-LaPierre L, McMurray F, MacFarlane M, Qiu X, Patten DA, Dirksen RT, Harper ME. Skeletal muscle mitoflashes, pH, and the role of uncoupling protein-3. Arch Biochem Biophys 2019; 663:239-248. [PMID: 30659802 DOI: 10.1016/j.abb.2019.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/28/2018] [Accepted: 01/15/2019] [Indexed: 01/03/2023]
Abstract
Mitochondrial reactive oxygen species (ROS) are important cellular signaling molecules, but can cause oxidative damage if not kept within tolerable limits. An important proximal form of ROS in mitochondria is superoxide. Its production is thought to occur in regulated stochastic bursts, but current methods using mitochondrial targeted cpYFP to assess superoxide flashes are confounded by changes in pH. Accordingly, these flashes are generally referred to as 'mitoflashes'. Here we provide regulatory insights into mitoflashes and pH fluctuations in skeletal muscle, and the role of uncoupling protein-3 (UCP3). Using quantitative confocal microscopy of mitoflashes in intact muscle fibers, we show that the mitoflash magnitude significantly correlates with the degree of mitochondrial inner membrane depolarization and ablation of UCP3 did not affect this correlation. We assessed the effects of the absence of UCP3 on mitoflash activity in intact skeletal muscle fibers, and found no effects on mitoflash frequency, amplitude or duration, with a slight reduction in the average size of mitoflashes. We further investigated the regulation of pH flashes (pHlashes, presumably a component of mitoflash) by UCP3 using mitochondrial targeted SypHer (mt-SypHer) in skeletal muscle fibers. The frequency of pHlashes was significantly reduced in the absence of UCP3, without changes in other flash properties. ROS scavenger, tiron, did not alter pHlash frequency in either WT or UCP3KO mice. High resolution respirometry revealed that in the absence of UCP3 there is impaired proton leak and Complex I-driven respiration and maximal coupled respiration. Total cellular production of hydrogen peroxide (H2O2) as detected by Amplex-UltraRed was unaffected. Altogether, we demonstrate a correlation between mitochondrial membrane potential and mitoflash magnitude in skeletal muscle fibers that is independent of UCP3, and a role for UCP3 in the control of pHlash frequency and of proton leak- and Complex I coupled-respiration in skeletal muscle fibers. The differential regulation of mitoflashes and pHlashes by UCP3 and tiron also indicate that the two events, though may be related, are not identical events.
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Affiliation(s)
- S McBride
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON, K1H 8M5, Canada
| | - L Wei-LaPierre
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY, 14642-8711, USA
| | - F McMurray
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON, K1H 8M5, Canada
| | - M MacFarlane
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON, K1H 8M5, Canada
| | - X Qiu
- Department of Biostatistics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY, 14642-8711, USA
| | - D A Patten
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON, K1H 8M5, Canada
| | - R T Dirksen
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY, 14642-8711, USA
| | - M-E Harper
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON, K1H 8M5, Canada.
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36
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Rosselin M, Nunes-Hasler P, Demaurex N. Ultrastructural Characterization of Flashing Mitochondria. ACTA ACUST UNITED AC 2018; 1:1-14. [PMID: 30406212 PMCID: PMC6217927 DOI: 10.1177/2515256418801423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mitochondria undergo spontaneous transient elevations in matrix pH associated with drops in mitochondrial membrane potential. These mitopHlashes require a functional respiratory chain and the profusion protein optic atrophy 1, but their mechanistic basis is unclear. To gain insight on the origin of these dynamic events, we resolved the ultrastructure of flashing mitochondria by correlative light and electron microscopy. HeLa cells expressing the matrix-targeted pH probe mitoSypHer were screened for mitopHlashes and fixed immediately after the occurrence of a flashing event. The cells were then processed for imaging by serial block face scanning electron microscopy using a focused ion beam to generate ~1,200 slices of 10 nm thickness from a 28 μm × 15 μm cellular volume. Correlation of live/fixed fluorescence and electron microscopy images allowed the unambiguous identification of flashing and nonflashing mitochondria. Three-dimensional reconstruction and surface mapping revealed that each tomogram contained two flashing mitochondria of unequal sizes, one being much larger than the average mitochondrial volume. Flashing mitochondria were 10-fold larger than silent mitochondria but with a surface to volume ratio and a cristae volume similar to nonflashing mitochondria. Flashing mitochondria were connected by tubular structures, formed more membrane contact sites, and a constriction was observed at a junction between a flashing mitochondrion and a nonflashing mitochondrion. These data indicate that flashing mitochondria are structurally preserved and bioenergetically competent but form numerous membrane contact sites and are connected by tubular structures, consistent with our earlier suggestion that mitopHlashes might be triggered by the opening of fusion pores between contiguous mitochondria.
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Affiliation(s)
- Manon Rosselin
- Department of Cell Physiology and Metabolism, University of Geneva, Switzerland
| | - Paula Nunes-Hasler
- Department of Cell Physiology and Metabolism, University of Geneva, Switzerland
| | - Nicolas Demaurex
- Department of Cell Physiology and Metabolism, University of Geneva, Switzerland
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37
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Quintana-Cabrera R, Quirin C, Glytsou C, Corrado M, Urbani A, Pellattiero A, Calvo E, Vázquez J, Enríquez JA, Gerle C, Soriano ME, Bernardi P, Scorrano L. The cristae modulator Optic atrophy 1 requires mitochondrial ATP synthase oligomers to safeguard mitochondrial function. Nat Commun 2018; 9:3399. [PMID: 30143614 PMCID: PMC6109181 DOI: 10.1038/s41467-018-05655-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/18/2018] [Indexed: 12/16/2022] Open
Abstract
It is unclear how the mitochondrial fusion protein Optic atrophy 1 (OPA1), which inhibits cristae remodeling, protects from mitochondrial dysfunction. Here we identify the mitochondrial F1Fo-ATP synthase as the effector of OPA1 in mitochondrial protection. In OPA1 overexpressing cells, the loss of proton electrochemical gradient caused by respiratory chain complex III inhibition is blunted and this protection is abolished by the ATP synthase inhibitor oligomycin. Mechanistically, OPA1 and ATP synthase can interact, but recombinant OPA1 fails to promote oligomerization of purified ATP synthase reconstituted in liposomes, suggesting that OPA1 favors ATP synthase oligomerization and reversal activity by modulating cristae shape. When ATP synthase oligomers are genetically destabilized by silencing the key dimerization subunit e, OPA1 is no longer able to preserve mitochondrial function and cell viability upon complex III inhibition. Thus, OPA1 protects mitochondria from respiratory chain inhibition by stabilizing cristae shape and favoring ATP synthase oligomerization. Mitochondrial cristae shape influences apoptosis and respiration. Here the authors show that the mitochondrial fusion protein OPA1 protects mitochondria from dysfunction by promoting ATP synthase oligomerization and reversal activity.
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Affiliation(s)
- Rubén Quintana-Cabrera
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,University of Salamanca, Consejo Superior de Investigaciones Científicas CSIC, Institute of Functional Biology and Genomics, Salamanca, 37007, Spain.,Institute of Biomedical Research of Salamanca, University Hospital of Salamanca, University of Salamanca, CSIC, 37007, Salamanca, Spain.,CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Charlotte Quirin
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy
| | - Christina Glytsou
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,Department of Pathology, NYU School of Medicine, 10016, New York, NY, USA
| | - Mauro Corrado
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,Max Planck Institute of Immunology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Andrea Urbani
- Department of Biomedical Sciences, University of Padua, Padua, 35121, Italy
| | - Anna Pellattiero
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy
| | - Enrique Calvo
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain
| | - Jesús Vázquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain
| | - José Antonio Enríquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain.,CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Christoph Gerle
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan
| | | | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padua, Padua, 35121, Italy.,Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Padua, Italy
| | - Luca Scorrano
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy. .,Department of Biology, University of Padua, 35121, Padua, Italy.
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38
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Chen W, Luo S, Xie P, Hou T, Yu T, Fu X. Overexpressed UCP2 regulates mitochondrial flashes and reverses lipopolysaccharide-induced cardiomyocytes injury. Am J Transl Res 2018; 10:1347-1356. [PMID: 29887950 PMCID: PMC5992536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Background: Mitochondrial flashes (mitoflashes) are transient signals from transient bursts of reactive oxygen species (ROS) and changes in pH that occur in certain physiological or pathological conditions. Mitoflashes are closely related to metabolism, cell differentiation, stress response, diseases, and aging. Sepsis can trigger mitochondrial dysfunction in myocardial cells, which leads to ROS overproduction, while uncoupling protein 2 (UCP2) can reduce ROS production. This study aims to observe whether UCP2 overexpression can regulate the frequency of mitoflashes in cardiomyocytes during sepsis and thereby play a protective role. Methods: A cell model for sepsis-induced myocardial damage was established using lipopolysaccharide (LPS). UCP2 overexpression in cardiomyocytes was achieved by adenovirus transfection. Creatinine kinase (CK), lactate dehydrogenase (LDH), tumor necrosis factor (TNF-α), and interleukin (IL-6) activities were detected, and mitochondrial membrane potentials (MMP) were measured. The frequency of mitoflashes in cardiomyocytes was observed. Results: With LPS stimulation, mitoflashes in cardiomyocytes increased significantly, and the MMP was damaged. Additionally, significant increases in CK, LDH, TNF-α, and IL-6 expression levels were observed. UCP2 overexpression can significantly reverse myocardial cell injuries that result from LPS stimulation. Compared with the LPS group, the LPS+UCP2 overexpression group showed a decrease in mitoflash frequency, an improved MMP, and decreases in CK, LDH, TNF-α, and IL-6 expression levels. Conclusion: This study is the first to demonstrate the function of UCP2 overexpression in protecting the myocardium by regulating mitoflash frequency and reversing sepsis-induced myocardial injuries.
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Affiliation(s)
- Wenbo Chen
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
| | - Shiyu Luo
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
| | - Peng Xie
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
| | - Tingting Hou
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking UniversityBeijing 100871, China
| | - Tian Yu
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical UniversityZunyi, Guizhou, China
| | - Xiaoyun Fu
- Department of Critical Care Medicine, The First Affiliated Hospital of Zunyi Medical UniversityZunyi, Guizhou, China
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39
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OPA1: How much do we know to approach therapy? Pharmacol Res 2018; 131:199-210. [PMID: 29454676 DOI: 10.1016/j.phrs.2018.02.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/12/2018] [Accepted: 02/12/2018] [Indexed: 01/01/2023]
Abstract
OPA1 is a GTPase that controls several functions, such as mitochondrial dynamics and energetics, mtDNA maintenance and cristae integrity. In the last years, there have been described other cellular pathways and mechanisms involving OPA1 directly or through its interaction. All this new information, by implementing our knowledge on OPA1 is instrumental to elucidating the pathogenic mechanisms of OPA1 mutations. Indeed, these are associated with dominant optic atrophy (DOA), one of the most common inherited optic neuropathies, and with an increasing number of heterogeneous neurodegenerative disorders. In this review, we overview all recent findings on OPA1 protein functions, on its dysfunction and related clinical phenotypes, focusing on the current therapeutic options and future perspectives to treat DOA and the other associated neurological disorders due to OPA1 mutations.
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40
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Eight human OPA1 isoforms, long and short: What are they for? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:263-269. [PMID: 29382469 DOI: 10.1016/j.bbabio.2018.01.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/17/2018] [Accepted: 01/21/2018] [Indexed: 12/31/2022]
Abstract
OPA1 is a dynamin-related GTPase that controls mitochondrial dynamics, cristae integrity, energetics and mtDNA maintenance. The exceptional complexity of this protein is determined by the presence, in humans, of eight different isoforms that, in turn, are proteolytically cleaved into combinations of membrane-anchored long forms and soluble short forms. Recent advances highlight how each OPA1 isoform is able to fulfill "essential" mitochondrial functions, whereas only some variants carry out "specialized" features. Long forms determine fusion, long or short forms alone build cristae, whereas long and short forms together tune mitochondrial morphology. These findings offer novel challenging therapeutic potential to gene therapy.
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41
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Kurz FT, Aon MA, O'Rourke B, Armoundas AA. Assessing Spatiotemporal and Functional Organization of Mitochondrial Networks. Methods Mol Biol 2018; 1782:383-402. [PMID: 29851013 PMCID: PMC7003721 DOI: 10.1007/978-1-4939-7831-1_23] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
The functional and spatiotemporal organization of mitochondrial redox signaling networks can be studied in detail in cardiac myocytes and neurons by assessing the time-resolved signaling traits of their individual mitochondrial components. Perturbations of the mitochondrial network through oxidative stress can lead to coordinated, cluster-bound behavior in the form of synchronized limit-cycle oscillations of mitochondrial inner membrane potentials. These oscillations are facilitated by both structural coupling through changes in the local redox balance and signaling microdomains and functional coupling that is yet poorly understood. Thus, quantifiable measures of both coupling mechanisms, local dynamic mitochondrial coupling constants and functional clustering coefficients, are likely to offer valuable information on mitochondrial network organization. We provide step-by-step methodologies on how to acquire and assess these measures for inner membrane potential fluorescence fluctuations in laser-scanning two-photon microscope recordings of cardiac myocytes and neurons, that can be applied to other tissues as well.
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MESH Headings
- Animals
- Cluster Analysis
- Fluorescent Dyes/chemistry
- Guinea Pigs
- Image Processing, Computer-Assisted/instrumentation
- Image Processing, Computer-Assisted/methods
- Membrane Potential, Mitochondrial
- Microscopy, Confocal/instrumentation
- Microscopy, Confocal/methods
- Microscopy, Fluorescence/instrumentation
- Microscopy, Fluorescence/methods
- Mitochondria, Heart/metabolism
- Mitochondrial Dynamics
- Models, Biological
- Myocytes, Cardiac/cytology
- Neurons
- Reactive Oxygen Species/metabolism
- Signal Transduction
- Software
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Affiliation(s)
- Felix T Kurz
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany.
| | - Miguel A Aon
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Brian O'Rourke
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Antonis A Armoundas
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
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42
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Burke PJ. Mitochondria, Bioenergetics and Apoptosis in Cancer. Trends Cancer 2017; 3:857-870. [PMID: 29198441 PMCID: PMC5957506 DOI: 10.1016/j.trecan.2017.10.006] [Citation(s) in RCA: 269] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 10/12/2017] [Accepted: 10/19/2017] [Indexed: 10/18/2022]
Abstract
Until recently, the dual roles of mitochondria in ATP production (bioenergetics) and apoptosis (cell life/death decision) were thought to be separate. New evidence points to a more intimate link between these two functions, mediated by the remodeling of the mitochondrial ultrastructure during apoptosis. While most of the key molecular players that regulate this process have been identified (primarily membrane proteins), the exact mechanisms by which they function are not yet understood. Because resistance to apoptosis is a hallmark of cancer, and because ultimately all chemotherapies are believed to result directly or indirectly in induction of apoptosis, a better understanding of the biophysical processes involved may lead to new avenues for therapy.
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Affiliation(s)
- Peter J Burke
- Department of Electrical Engineering and Computer Science, University of California, Irvine, Irvine, CA, USA; Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA, USA; Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA.
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43
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Bilan DS, Belousov VV. New tools for redox biology: From imaging to manipulation. Free Radic Biol Med 2017; 109:167-188. [PMID: 27939954 DOI: 10.1016/j.freeradbiomed.2016.12.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 12/02/2016] [Accepted: 12/03/2016] [Indexed: 12/12/2022]
Abstract
Redox reactions play a key role in maintaining essential biological processes. Deviations in redox pathways result in the development of various pathologies at cellular and organismal levels. Until recently, studies on transformations in the intracellular redox state have been significantly hampered in living systems. The genetically encoded indicators, based on fluorescent proteins, have provided new opportunities in biomedical research. The existing indicators already enable monitoring of cellular redox parameters in different processes including embryogenesis, aging, inflammation, tissue regeneration, and pathogenesis of various diseases. In this review, we summarize information about all genetically encoded redox indicators developed to date. We provide the description of each indicator and discuss its advantages and limitations, as well as points that need to be considered when choosing an indicator for a particular experiment. One chapter is devoted to the important discoveries that have been made by using genetically encoded redox indicators.
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Affiliation(s)
- Dmitry S Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
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44
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Fu ZX, Tan X, Fang H, Lau PM, Wang X, Cheng H, Bi GQ. Dendritic mitoflash as a putative signal for stabilizing long-term synaptic plasticity. Nat Commun 2017; 8:31. [PMID: 28652625 PMCID: PMC5484698 DOI: 10.1038/s41467-017-00043-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 04/28/2017] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial flashes (mitoflashes) are recently discovered excitable mitochondrial events in many cell types. Here we investigate their occurrence in the context of structural long-term potentiation (sLTP) at hippocampal synapses. At dendritic spines stimulated by electric pulses, glycine, or targeted glutamate uncaging, induction of sLTP is associated with a phasic occurrence of local, quantized mitochondrial activity in the form of one or a few mitoflashes, over a 30-min window. Low-dose nigericin or photoactivation that elicits mitoflashes stabilizes otherwise short-term spine enlargement into sLTP. Meanwhile, scavengers of reactive oxygen species suppress mitoflashes while blocking sLTP. With targeted photoactivation of mitoflashes, we further show that the stabilization of sLTP is effective within the critical 30-min time-window and a spatial extent of ~2 μm, similar to that of local diffusive reactive oxygen species. These findings indicate a potential signaling role of dendritic mitochondria in synaptic plasticity, and provide new insights into the cellular function of mitoflashes. Mitoflashes are dynamic events in mitochondria, associated with depolarization and release of reactive oxygen species, and have been associated with several cellular functions. The authors now show that in neurons, dendritic mitoflashes are involved in structural postsynaptic changes during LTP.
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Affiliation(s)
- Zhong-Xiao Fu
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230027, China.,School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.,State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.,Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Xiao Tan
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.,State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.,Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.,CAS Key Laboratory of Brain Function and Disease, University of Science and Technology of China, Hefei, 230027, China
| | - Huaqiang Fang
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.,Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Pak-Ming Lau
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.,CAS Key Laboratory of Brain Function and Disease, University of Science and Technology of China, Hefei, 230027, China
| | - Xianhua Wang
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China. .,Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
| | - Heping Cheng
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China. .,Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
| | - Guo-Qiang Bi
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230027, China. .,School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China. .,CAS Center for Excellence in Brain Science and Intelligence Technology, University of Science and Technology of China, Hefei, 230027, China. .,Innovation Center for Cell Signaling Network, University of Science and Technology of China, Hefei, 230027, China.
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45
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Wang X, Zhang X, Huang Z, Wu D, Liu B, Zhang R, Yin R, Hou T, Jian C, Xu J, Zhao Y, Wang Y, Gao F, Cheng H. Protons Trigger Mitochondrial Flashes. Biophys J 2017; 111:386-394. [PMID: 27463140 DOI: 10.1016/j.bpj.2016.05.052] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 05/06/2016] [Accepted: 05/31/2016] [Indexed: 12/22/2022] Open
Abstract
Emerging evidence indicates that mitochondrial flashes (mitoflashes) are highly conserved elemental mitochondrial signaling events. However, which signal controls their ignition and how they are integrated with other mitochondrial signals and functions remain elusive. In this study, we aimed to further delineate the signal components of the mitoflash and determine the mitoflash trigger mechanism. Using multiple biosensors and chemical probes as well as label-free autofluorescence, we found that the mitoflash reflects chemical and electrical excitation at the single-organelle level, comprising bursting superoxide production, oxidative redox shift, and matrix alkalinization as well as transient membrane depolarization. Both electroneutral H(+)/K(+) or H(+)/Na(+) antiport and matrix proton uncaging elicited immediate and robust mitoflash responses over a broad dynamic range in cardiomyocytes and HeLa cells. However, charge-uncompensated proton transport, which depolarizes mitochondria, caused the opposite effect, and steady matrix acidification mildly inhibited mitoflashes. Based on a numerical simulation, we estimated a mean proton lifetime of 1.42 ns and diffusion distance of 2.06 nm in the matrix. We conclude that nanodomain protons act as a novel, to our knowledge, trigger of mitoflashes in energized mitochondria. This finding suggests that mitoflash genesis is functionally and mechanistically integrated with mitochondrial energy metabolism.
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Affiliation(s)
- Xianhua Wang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China.
| | - Xing Zhang
- Department of Aerospace Medicine, The Fourth Military Medical University, Xi'an, China
| | - Zhanglong Huang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Di Wu
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Beibei Liu
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Rufeng Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Rongkang Yin
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Tingting Hou
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Chongshu Jian
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Jiejia Xu
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Yan Zhao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Yanru Wang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Feng Gao
- Department of Aerospace Medicine, The Fourth Military Medical University, Xi'an, China
| | - Heping Cheng
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China.
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46
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Jian C, Xu F, Hou T, Sun T, Li J, Cheng H, Wang X. Deficiency of PHB complex impairs respiratory supercomplex formation and activates mitochondrial flashes. J Cell Sci 2017. [PMID: 28630166 DOI: 10.1242/jcs.198523] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Prohibitins (PHBs; prohibitin 1, PHB1 or PHB, and prohibitin 2, PHB2) are evolutionarily conserved and ubiquitously expressed mitochondrial proteins. PHBs form multimeric ring complexes acting as scaffolds in the inner mitochondrial membrane. Mitochondrial flashes (mitoflashes) are newly discovered mitochondrial signaling events that reflect electrical and chemical excitations of the organelle. Here, we investigate the possible roles of PHBs in the regulation of mitoflash signaling. Downregulation of PHBs increases mitoflash frequency by up to 5.4-fold due to elevated basal reactive oxygen species (ROS) production in the mitochondria. Mechanistically, PHB deficiency impairs the formation of mitochondrial respiratory supercomplexes (RSCs) without altering the abundance of individual respiratory complex subunits. These impairments induced by PHB deficiency are effectively rescued by co-expression of PHB1 and PHB2, indicating that the multimeric PHB complex acts as the functional unit. Furthermore, downregulating other RSC assembly factors, including SCAFI (also known as COX7A2L), RCF1a (HIGD1A), RCF1b (HIGD2A), UQCC3 and SLP2 (STOML2), all activate mitoflashes through elevating mitochondrial ROS production. Our findings identify the PHB complex as a new regulator of RSC formation and mitoflash signaling, and delineate a general relationship among RSC formation, basal ROS production and mitoflash biogenesis.
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Affiliation(s)
- Chongshu Jian
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Fengli Xu
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Tingting Hou
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Tao Sun
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Jinghang Li
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Heping Cheng
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xianhua Wang
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
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47
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Constriction of the mitochondrial inner compartment is a priming event for mitochondrial division. Nat Commun 2017; 8:15754. [PMID: 28598422 PMCID: PMC5472732 DOI: 10.1038/ncomms15754] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 04/26/2017] [Indexed: 02/02/2023] Open
Abstract
Mitochondrial division is critical for the maintenance and regulation of mitochondrial function, quality and distribution. This process is controlled by cytosolic actin-based constriction machinery and dynamin-related protein 1 (Drp1) on mitochondrial outer membrane (OMM). Although mitochondrial physiology, including oxidative phosphorylation, is also important for efficient mitochondrial division, morphological alterations of the mitochondrial inner-membrane (IMM) have not been clearly elucidated. Here we report spontaneous and repetitive constriction of mitochondrial inner compartment (CoMIC) associated with subsequent division in neurons. Although CoMIC is potentiated by inhibition of Drp1 and occurs at the potential division spots contacting the endoplasmic reticulum, it appears on IMM independently of OMM. Intra-mitochondrial influx of Ca2+ induces and potentiates CoMIC, and leads to K+-mediated mitochondrial bulging and depolarization. Synergistically, optic atrophy 1 (Opa1) also regulates CoMIC via controlling Mic60-mediated OMM-IMM tethering. Therefore, we propose that CoMIC is a priming event for efficient mitochondrial division.
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48
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Bak DW, Pizzagalli MD, Weerapana E. Identifying Functional Cysteine Residues in the Mitochondria. ACS Chem Biol 2017; 12:947-957. [PMID: 28157297 DOI: 10.1021/acschembio.6b01074] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The mitochondria are dynamic organelles that regulate oxidative metabolism and mediate cellular redox homeostasis. Proteins within the mitochondria are exposed to large fluxes in the surrounding redox environment. In particular, cysteine residues within mitochondrial proteins sense and respond to these redox changes through oxidative modifications of the cysteine thiol group. These oxidative modifications result in a loss in cysteine reactivity, which can be monitored using cysteine-reactive chemical probes and quantitative mass spectrometry (MS). Analysis of cell lysates treated with cysteine-reactive probes enable the identification of hundreds of cysteine residues, however, the mitochondrial proteome is poorly represented (<10% of identified peptides), due to the low abundance of mitochondrial proteins and suppression of mitochondrial peptide MS signals by highly abundant cytosolic peptides. Here, we apply a mitochondrial isolation and purification protocol to substantially increase coverage of the mitochondrial cysteine proteome. Over 1500 cysteine residues from ∼450 mitochondrial proteins were identified, thereby enabling interrogation of an unprecedented number of mitochondrial cysteines. Specifically, these mitochondrial cysteines were ranked by reactivity to identify hyper-reactive cysteines with potential catalytic and regulatory functional roles. Furthermore, analyses of mitochondria exposed to nitrosative stress revealed previously uncharacterized sites of protein S-nitrosation on mitochondrial proteins. Together, the mitochondrial cysteine enrichment strategy presented herein enables detailed characterization of protein modifications that occur within the mitochondria during (patho)physiological fluxes in the redox environment.
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Affiliation(s)
- Daniel W. Bak
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Mattia D. Pizzagalli
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Eranthie Weerapana
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
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49
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Rosselin M, Santo-Domingo J, Bermont F, Giacomello M, Demaurex N. L-OPA1 regulates mitoflash biogenesis independently from membrane fusion. EMBO Rep 2017; 18:451-463. [PMID: 28174208 PMCID: PMC5331265 DOI: 10.15252/embr.201642931] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 12/19/2016] [Accepted: 12/21/2016] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial flashes mediated by optic atrophy 1 (OPA1) fusion protein are bioenergetic responses to stochastic drops in mitochondrial membrane potential (Δψm) whose origin is unclear. Using structurally distinct genetically encoded pH‐sensitive probes, we confirm that flashes are matrix alkalinization transients, thereby establishing the pH nature of these events, which we renamed “mitopHlashes”. Probes located in cristae or intermembrane space as verified by electron microscopy do not report pH changes during Δψm drops or respiratory chain inhibition. Opa1 ablation does not alter Δψm fluctuations but drastically decreases the efficiency of mitopHlash/Δψm coupling, which is restored by re‐expressing fusion‐deficient OPA1K301A and preserved in cells lacking the outer‐membrane fusion proteins MFN1/2 or the OPA1 proteases OMA1 and YME1L, indicating that mitochondrial membrane fusion and OPA1 proteolytic processing are dispensable. pH/Δψm uncoupling occurs early during staurosporine‐induced apoptosis and is mitigated by OPA1 overexpression, suggesting that OPA1 maintains mitopHlash competence during stress conditions. We propose that OPA1 stabilizes respiratory chain supercomplexes in a conformation that enables respiring mitochondria to compensate a drop in Δψm by an explosive matrix pH flash.
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Affiliation(s)
- Manon Rosselin
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Jaime Santo-Domingo
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Flavien Bermont
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | | | - Nicolas Demaurex
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
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50
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Feng G, Liu B, Hou T, Wang X, Cheng H. Mitochondrial Flashes: Elemental Signaling Events in Eukaryotic Cells. Handb Exp Pharmacol 2017; 240:403-422. [PMID: 28233181 DOI: 10.1007/164_2016_129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Mitochondrial flashes (mitoflashes) are recently discovered mitochondrial activity which reflects chemical and electrical excitation of the organelle. Emerging evidence indicates that mitoflashes represent highly regulated, elementary signaling events that play important roles in physiological and pathophysiological processes in eukaryotes. Furthermore, they are regulated by mitochondrial ROS, Ca2+, and protons, and are intertwined with mitochondrial metabolic processes. As such, targeting mitoflash activity may provide a novel means for the control of mitochondrial metabolism and signaling in health and disease. In this brief review, we summarize salient features and mechanisms of biogenesis of mitoflashes, and synthesize data on mitoflash biology in the context of metabolism, cell differentiation, stress response, disease, and ageing.
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Affiliation(s)
- Gaomin Feng
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China
| | - Beibei Liu
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China
| | - Tingting Hou
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China
| | - Xianhua Wang
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China
| | - Heping Cheng
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China.
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