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Lewis GR, Marshall WF. Mitochondrial networks through the lens of mathematics. Phys Biol 2023; 20:051001. [PMID: 37290456 PMCID: PMC10347554 DOI: 10.1088/1478-3975/acdcdb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 06/10/2023]
Abstract
Mitochondria serve a wide range of functions within cells, most notably via their production of ATP. Although their morphology is commonly described as bean-like, mitochondria often form interconnected networks within cells that exhibit dynamic restructuring through a variety of physical changes. Further, though relationships between form and function in biology are well established, the extant toolkit for understanding mitochondrial morphology is limited. Here, we emphasize new and established methods for quantitatively describing mitochondrial networks, ranging from unweighted graph-theoretic representations to multi-scale approaches from applied topology, in particular persistent homology. We also show fundamental relationships between mitochondrial networks, mathematics, and physics, using ideas of graph planarity and statistical mechanics to better understand the full possible morphological space of mitochondrial network structures. Lastly, we provide suggestions for how examination of mitochondrial network form through the language of mathematics can inform biological understanding, and vice versa.
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Affiliation(s)
- Greyson R Lewis
- Biophysics Graduate Program, University of California—San Francisco, San Francisco, CA, United States of America
- NSF Center for Cellular Construction, Department of Biochemistry and Biophysics, UCSF, 600 16th St., San Francisco, CA, United States of America
- Department of Biochemistry and Biophysics, Center for Cellular Construction, University of California San Francisco, San Francisco, CA, United States of America
| | - Wallace F Marshall
- NSF Center for Cellular Construction, Department of Biochemistry and Biophysics, UCSF, 600 16th St., San Francisco, CA, United States of America
- Department of Biochemistry and Biophysics, Center for Cellular Construction, University of California San Francisco, San Francisco, CA, United States of America
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2
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Wang Z, Natekar P, Tea C, Tamir S, Hakozaki H, Schöneberg J. MitoTNT: Mitochondrial Temporal Network Tracking for 4D live-cell fluorescence microscopy data. PLoS Comput Biol 2023; 19:e1011060. [PMID: 37083820 PMCID: PMC10184899 DOI: 10.1371/journal.pcbi.1011060] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 05/15/2023] [Accepted: 03/29/2023] [Indexed: 04/22/2023] Open
Abstract
Mitochondria form a network in the cell that rapidly changes through fission, fusion, and motility. Dysregulation of this four-dimensional (4D: x,y,z,time) network is implicated in numerous diseases ranging from cancer to neurodegeneration. While lattice light-sheet microscopy has recently made it possible to image mitochondria in 4D, quantitative analysis methods for the resulting datasets have been lacking. Here we present MitoTNT, the first-in-class software for Mitochondrial Temporal Network Tracking in 4D live-cell fluorescence microscopy data. MitoTNT uses spatial proximity and network topology to compute an optimal tracking assignment. To validate the accuracy of tracking, we created a reaction-diffusion simulation to model mitochondrial network motion and remodeling events. We found that our tracking is >90% accurate for ground-truth simulations and agrees well with published motility results for experimental data. We used MitoTNT to quantify 4D mitochondrial networks from human induced pluripotent stem cells. First, we characterized sub-fragment motility and analyzed network branch motion patterns. We revealed that the skeleton node motion is correlated along branch nodes and is uncorrelated in time. Second, we identified fission and fusion events with high spatiotemporal resolution. We found that mitochondrial skeleton nodes near the fission/fusion sites move nearly twice as fast as random skeleton nodes and that microtubules play a role in mediating selective fission/fusion. Finally, we developed graph-based transport simulations that model how material would distribute on experimentally measured mitochondrial temporal networks. We showed that pharmacological perturbations increase network reachability but decrease network resilience through a combination of altered mitochondrial fission/fusion dynamics and motility. MitoTNT's easy-to-use tracking module, interactive 4D visualization capability, and powerful post-tracking analyses aim at making temporal network tracking accessible to the wider mitochondria research community.
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Affiliation(s)
- Zichen Wang
- Department of Pharmacology, University of California, San Diego, San Diego, California, United States of America
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California, United States of America
| | - Parth Natekar
- Department of Pharmacology, University of California, San Diego, San Diego, California, United States of America
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California, United States of America
| | - Challana Tea
- Department of Pharmacology, University of California, San Diego, San Diego, California, United States of America
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California, United States of America
| | - Sharon Tamir
- Department of Pharmacology, University of California, San Diego, San Diego, California, United States of America
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California, United States of America
| | - Hiroyuki Hakozaki
- Department of Pharmacology, University of California, San Diego, San Diego, California, United States of America
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California, United States of America
| | - Johannes Schöneberg
- Department of Pharmacology, University of California, San Diego, San Diego, California, United States of America
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California, United States of America
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3
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Automated analysis of mitochondrial dimensions in mesenchymal stem cells: Current methods and future perspectives. Heliyon 2023; 9:e12987. [PMID: 36711314 PMCID: PMC9873686 DOI: 10.1016/j.heliyon.2023.e12987] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/03/2023] [Accepted: 01/11/2023] [Indexed: 01/20/2023] Open
Abstract
As centre of energy production and key regulators of metabolic and cellular signaling pathways, the integrity of mitochondria is essential for mesenchymal stem cell function in tissue regeneration. Alterations in the size, shape and structural organization of mitochondria are correlated with the physiological state of the cell and its environment and could be used as diagnostic biomarkers. Therefore, high-throughput experimental and computational techniques are crucial to ensure adequate correlations between mitochondrial function and disease phenotypes. The emerge of microfluidic technologies can address the shortcomings of traditional methods to determine mitochondrial dimensions for diagnostic and therapeutic use. This review discusses optical detection methods compatible with microfluidics to measure mitochondrial dynamics and their potential for clinical stem cell research targeting mitochondrial dysfunction.
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4
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Universal dynamics of mitochondrial networks: a finite-size scaling analysis. Sci Rep 2022; 12:17074. [PMID: 36224243 PMCID: PMC9556628 DOI: 10.1038/s41598-022-14946-9] [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] [Received: 11/04/2021] [Accepted: 06/15/2022] [Indexed: 01/04/2023] Open
Abstract
Evidence from models and experiments suggests that the networked structure observed in mitochondria emerges at the critical point of a phase transition controlled by fission and fusion rates. If mitochondria are poised at criticality, the relevant network quantities should scale with the system's size. However, whether or not the expected finite-size effects take place has not been demonstrated yet. Here, we first provide a theoretical framework to interpret the scaling behavior of mitochondrial network quantities by analyzing two conceptually different models of mitochondrial dynamics. Then, we perform a finite-size scaling analysis of real mitochondrial networks extracted from microscopy images and obtain scaling exponents comparable with critical exponents from models and theory. Overall, we provide a universal description of the structural phase transition in mammalian mitochondria.
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5
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Fractured Symmetries: Information and Control Theory Perspectives on Mitochondrial Dysfunction. Acta Biotheor 2021; 69:277-301. [PMID: 32725452 DOI: 10.1007/s10441-020-09387-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022]
Abstract
Mitochondrial dysfunction underlies a vast array of chronic disorders across the life span. The asymptotic limit theorems of information and control theories, supplemented by symmetry-breaking phase transition arguments adapted from physical theory, give deep insight into canonical mechanisms of cognition and regulation associated with such dysfunction. The probability models studied here can provide a foundation for the development of statistical tools useful in clinical and public health address of those disorders.
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6
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Cavinato M, Madreiter-Sokolowski CT, Büttner S, Schosserer M, Zwerschke W, Wedel S, Grillari J, Graier WF, Jansen-Dürr P. Targeting cellular senescence based on interorganelle communication, multilevel proteostasis, and metabolic control. FEBS J 2020; 288:3834-3854. [PMID: 33200494 PMCID: PMC7611050 DOI: 10.1111/febs.15631] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/02/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023]
Abstract
Cellular senescence, a stable cell division arrest caused by severe damage and stress, is a hallmark of aging in vertebrates including humans. With progressing age, senescent cells accumulate in a variety of mammalian tissues, where they contribute to tissue aging, identifying cellular senescence as a major target to delay or prevent aging. There is an increasing demand for the discovery of new classes of small molecules that would either avoid or postpone cellular senescence by selectively eliminating senescent cells from the body (i.e., ‘senolytics’) or inactivating/switching damage‐inducing properties of senescent cells (i.e., ‘senostatics/senomorphics’), such as the senescence‐associated secretory phenotype. Whereas compounds with senolytic or senostatic activity have already been described, their efficacy and specificity has not been fully established for clinical use yet. Here, we review mechanisms of senescence that are related to mitochondria and their interorganelle communication, and the involvement of proteostasis networks and metabolic control in the senescent phenotype. These cellular functions are associated with cellular senescence in in vitro and in vivo models but have not been fully exploited for the search of new compounds to counteract senescence yet. Therefore, we explore possibilities to target these mechanisms as new opportunities to selectively eliminate and/or disable senescent cells with the aim of tissue rejuvenation. We assume that this research will provide new compounds from the chemical space which act as mimetics of caloric restriction, modulators of calcium signaling and mitochondrial physiology, or as proteostasis optimizers, bearing the potential to counteract cellular senescence, thereby allowing healthy aging.
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Affiliation(s)
- Maria Cavinato
- Institute for Biomedical Aging Research, Leopold-Franzens Universität Innsbruck, Austria.,Center for Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens Universität Innsbruck, Austria
| | - Corina T Madreiter-Sokolowski
- Department of Health Sciences and Technology, Institute of Translational Medicine, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Austria
| | - Sabrina Büttner
- Institute of Molecular Biosciences, University of Graz, Austria.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Sweden
| | - Markus Schosserer
- Christian Doppler Laboratory for Skin Multimodal Analytical Imaging of Aging and Senescence, Institute of Molecular Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria.,Austrian Cluster for Tissue Regeneration, Medical University of Vienna, Austria
| | - Werner Zwerschke
- Institute for Biomedical Aging Research, Leopold-Franzens Universität Innsbruck, Austria.,Center for Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens Universität Innsbruck, Austria
| | - Sophia Wedel
- Institute for Biomedical Aging Research, Leopold-Franzens Universität Innsbruck, Austria.,Center for Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens Universität Innsbruck, Austria
| | - Johannes Grillari
- Christian Doppler Laboratory for Skin Multimodal Analytical Imaging of Aging and Senescence, Institute of Molecular Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria.,Austrian Cluster for Tissue Regeneration, Medical University of Vienna, Austria.,Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Vienna, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Austria.,BioTechMed Graz, Austria
| | - Pidder Jansen-Dürr
- Institute for Biomedical Aging Research, Leopold-Franzens Universität Innsbruck, Austria.,Center for Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens Universität Innsbruck, Austria
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7
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Li W, Zhang S, Yang G. Dynamic organization of intracellular organelle networks. WIREs Mech Dis 2020; 13:e1505. [PMID: 32865347 DOI: 10.1002/wsbm.1505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/06/2020] [Accepted: 07/09/2020] [Indexed: 01/07/2023]
Abstract
Intracellular organelles are membrane-bound and biochemically distinct compartments constructed to serve specialized functions in eukaryotic cells. Through extensive interactions, they form networks to coordinate and integrate their specialized functions for cell physiology. A fundamental property of these organelle networks is that they constantly undergo dynamic organization via membrane fusion and fission to remodel their internal connections and to mediate direct material exchange between compartments. The dynamic organization not only enables them to serve critical physiological functions adaptively but also differentiates them from many other biological networks such as gene regulatory networks and cell signaling networks. This review examines this fundamental property of the organelle networks from a systems point of view. The focus is exclusively on homotypic networks formed by mitochondria, lysosomes, endosomes, and the endoplasmic reticulum, respectively. First, key mechanisms that drive the dynamic organization of these networks are summarized. Then, several distinct organizational properties of these networks are highlighted. Next, spatial properties of the dynamic organization of these networks are emphasized, and their functional implications are examined. Finally, some representative molecular machineries that mediate the dynamic organization of these networks are surveyed. Overall, the dynamic organization of intracellular organelle networks is emerging as a fundamental and unifying paradigm in the internal organization of eukaryotic cells. This article is categorized under: Metabolic Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Wenjing Li
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Shuhao Zhang
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, Nankai University, Tianjin, China
| | - Ge Yang
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China.,Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.,Department of Computational Biology, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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8
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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: 31] [Impact Index Per Article: 7.8] [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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9
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Torres MJ, McLaughlin KL, Renegar RH, Valsaraj S, Whitehurst KS, Sharaf OM, Sharma UM, Horton JL, Sarathy B, Parks JC, Brault JJ, Fisher-Wellman KH, Neufer PD, Virag JAI. Intracardiac administration of ephrinA1-Fc preserves mitochondrial bioenergetics during acute ischemia/reperfusion injury. Life Sci 2019; 239:117053. [PMID: 31733316 DOI: 10.1016/j.lfs.2019.117053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/06/2019] [Accepted: 11/08/2019] [Indexed: 12/18/2022]
Abstract
AIMS Intracardiac injection of recombinant EphrinA1-Fc immediately following coronary artery ligation in mice reduces infarct size in both reperfused and non-reperfused myocardium, but the cellular alterations behind this phenomenon remain unknown. MAIN METHODS Herein, 10 wk-old B6129SF2/J male mice were exposed to acute ischemia/reperfusion (30minI/24hrsR) injury immediately followed by intracardiac injection of either EphrinA1-Fc or IgG-Fc. After 24 h of reperfusion, sections of the infarct margin in the left ventricle were imaged via transmission electron microscopy, and mitochondrial function was assessed in both permeabilized fibers and isolated mitochondria, to examine mitochondrial structure, function, and energetics in the early stages of repair. KEY FINDINGS At a structural level, EphrinA1-Fc administration prevented the I/R-induced loss of sarcomere alignment and mitochondrial organization along the Z disks, as well as disorganization of the cristae and loss of inter-mitochondrial junctions. With respect to bioenergetics, loss of respiratory function induced by I/R was prevented by EphrinA1-Fc. Preservation of cardiac bioenergetics was not due to changes in mitochondrial JH2O2 emitting potential, membrane potential, ADP affinity, efficiency of ATP production, or activity of the main dehydrogenase enzymes, suggesting that EphrinA1-Fc indirectly maintains respiratory function via preservation of the mitochondrial network. Moreover, these protective effects were lost in isolated mitochondria, further emphasizing the importance of the intact cardiomyocyte ultrastructure in mitochondrial energetics. SIGNIFICANCE Collectively, these data suggest that intracardiac injection of EphrinA1-Fc protects cardiac function by preserving cardiomyocyte structure and mitochondrial bioenergetics, thus emerging as a potential therapeutic strategy in I/R injury.
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Affiliation(s)
- Maria J Torres
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA
| | - Kelsey L McLaughlin
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Randall H Renegar
- Dept of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Smrithi Valsaraj
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - K'Shylah S Whitehurst
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Omar M Sharaf
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Uma M Sharma
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Julie L Horton
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Brinda Sarathy
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Justin C Parks
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Jeffrey J Brault
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA; Dept of Kinesiology, College of Health and Human Performance, East Carolina University, Greenville, NC, 27834, USA
| | - Kelsey H Fisher-Wellman
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, 27834, USA; Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA
| | - Jitka A I Virag
- Dept of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, 27834, USA.
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10
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Madreiter-Sokolowski CT, Ramadani-Muja J, Ziomek G, Burgstaller S, Bischof H, Koshenov Z, Gottschalk B, Malli R, Graier WF. Tracking intra- and inter-organelle signaling of mitochondria. FEBS J 2019; 286:4378-4401. [PMID: 31661602 PMCID: PMC6899612 DOI: 10.1111/febs.15103] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/19/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Mitochondria are as highly specialized organelles and masters of the cellular energy metabolism in a constant and dynamic interplay with their cellular environment, providing adenosine triphosphate, buffering Ca2+ and fundamentally contributing to various signaling pathways. Hence, such broad field of action within eukaryotic cells requires a high level of structural and functional adaptation. Therefore, mitochondria are constantly moving and undergoing fusion and fission processes, changing their shape and their interaction with other organelles. Moreover, mitochondrial activity gets fine-tuned by intra- and interorganelle H+ , K+ , Na+ , and Ca2+ signaling. In this review, we provide an up-to-date overview on mitochondrial strategies to adapt and respond to, as well as affect, their cellular environment. We also present cutting-edge technologies used to track and investigate subcellular signaling, essential to the understanding of various physiological and pathophysiological processes.
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Affiliation(s)
- Corina T Madreiter-Sokolowski
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach, Switzerland
| | - Jeta Ramadani-Muja
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Gabriela Ziomek
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Sandra Burgstaller
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Zhanat Koshenov
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Benjamin Gottschalk
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
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11
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Mironov AA, Dimov ID, Beznoussenko GV. Role of Intracellular Transport in the Centriole-Dependent Formation of Golgi Ribbon. Results Probl Cell Differ 2019; 67:49-79. [PMID: 31435792 DOI: 10.1007/978-3-030-23173-6_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The intracellular transport is the most confusing issue in the field of cell biology. The Golgi complex (GC) is the central station along the secretory pathway. It contains Golgi glycosylation enzymes, which are responsible for protein and lipid glycosylation, and in many cells, it is organized into a ribbon. Position and structure of the GC depend on the position and function of the centriole. Here, we analyze published data related to the role of centriole and intracellular transport (ICT) for the formation of Golgi ribbon and specifically stress the importance of the delivery of membranes containing cargo and membrane proteins to the cell centre where centriole/centrosome is localized. Additionally, we re-examined the formation of Golgi ribbon from the point of view of different models of ICT.
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Affiliation(s)
| | - Ivan D Dimov
- Department of Anatomy, Saint Petersburg State Paediatric Medical University, Saint Petersburg, Russia
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12
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Moore AS, Holzbaur ELF. Mitochondrial-cytoskeletal interactions: dynamic associations that facilitate network function and remodeling. CURRENT OPINION IN PHYSIOLOGY 2018; 3:94-100. [PMID: 30555978 PMCID: PMC6289269 DOI: 10.1016/j.cophys.2018.03.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Mitochondria are dynamic organelles that can form complex networks in the cell. These networks can be rapidly remodeled in response to environmental changes or to support cellular needs. Mitochondrial dynamics are dependent on interactions with the cellular cytoskeleton - both microtubules and actin filaments. Mitochondrial-cytoskeletal interactions have a well-established role in mitochondrial motility. Recent progress indicates that these interactions also regulate the balance of mitochondrial fission/fusion, as well as mitochondria turnover and mitochondrial inheritance during cell division. We review these advances, and how this work has deepened our understanding of mitochondrial dynamics in the cell.
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Affiliation(s)
- Andrew S Moore
- Department of Physiology, University of Pennsylvania Perelman School of Medicine 638A Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA 19104-6085
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine 638A Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA 19104-6085
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13
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Mitochondrial network complexity emerges from fission/fusion dynamics. Sci Rep 2018; 8:363. [PMID: 29321534 PMCID: PMC5762699 DOI: 10.1038/s41598-017-18351-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 12/06/2017] [Indexed: 12/03/2022] Open
Abstract
Mitochondrial networks exhibit a variety of complex behaviors, including coordinated cell-wide oscillations of energy states as well as a phase transition (depolarization) in response to oxidative stress. Since functional and structural properties are often interwinded, here we characterized the structure of mitochondrial networks in mouse embryonic fibroblasts using network tools and percolation theory. Subsequently we perturbed the system either by promoting the fusion of mitochondrial segments or by inducing mitochondrial fission. Quantitative analysis of mitochondrial clusters revealed that structural parameters of healthy mitochondria laid in between the extremes of highly fragmented and completely fusioned networks. We confirmed our results by contrasting our empirical findings with the predictions of a recently described computational model of mitochondrial network emergence based on fission-fusion kinetics. Altogether these results offer not only an objective methodology to parametrize the complexity of this organelle but also support the idea that mitochondrial networks behave as critical systems and undergo structural phase transitions.
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14
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Huang ZN, Chung HM, Fang SC, Her LS. Adhesion Regulating Molecule 1 Mediates HAP40 Overexpression-Induced Mitochondrial Defects. Int J Biol Sci 2017; 13:1420-1437. [PMID: 29209146 PMCID: PMC5715525 DOI: 10.7150/ijbs.20742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 09/10/2017] [Indexed: 12/29/2022] Open
Abstract
Striatal neuron death in Huntington's disease is associated with abnormal mitochondrial dynamics and functions. However, the mechanisms for this mitochondrial dysregulation remain elusive. Increased accumulation of Huntingtin-associated protein 40 (HAP40) has been shown to be associated with Huntington's disease. However, the link between increased HAP40 and Huntington's disease remains largely unknown. Here we show that HAP40 overexpression causes mitochondrial dysfunction and reduces cell viability in the immortalized mouse striatal neurons. HAP40-associated mitochondrial dysfunction is associated with reduction of adhesion regulating molecule 1 (ADRM1) protein. Consistently, depletion of ADRM1 by shRNAs impaired mitochondrial functions and increased mitochondrial fragmentation in mouse striatal cells. Moreover, reducing ADRM1 levels enhanced activity of fission factor dynamin-related GTPase protein 1 (Drp1) via increased phosphorylation at serine 616 of Drp1 (Drp1Ser616). Restoring ADRM1 protein levels was able to reduce HAP40-induced ROS levels and mitochondrial fragmentation and improved mitochondrial functions and cell viability. Moreover, reducing Drp1 activity by Drp1 inhibitor, Mdivi-1, ameliorates both HAP40 overexpression- and ADRM1 depletion-induced mitochondrial dysfunction. Taken together, our studies suggest that HAP40-mediated reduction of ADRM1 alters the mitochondrial fission activity and results in mitochondrial fragmentation and mitochondrial dysfunction.
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Affiliation(s)
- Zih-Ning Huang
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan
| | - Her Min Chung
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan
| | - Su-Chiung Fang
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan 741, Taiwan.,Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Lu-Shiun Her
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan
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15
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Regulation of Mitochondrial Structure and Dynamics by the Cytoskeleton and Mechanical Factors. Int J Mol Sci 2017; 18:ijms18081812. [PMID: 28825689 PMCID: PMC5578198 DOI: 10.3390/ijms18081812] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/09/2017] [Accepted: 08/18/2017] [Indexed: 12/21/2022] Open
Abstract
Mitochondria supply cells with energy in the form of ATP, guide apoptosis, and contribute to calcium buffering and reactive oxygen species production. To support these diverse functions, mitochondria form an extensive network with smaller clusters that are able to move along microtubules aided by motor proteins. Mitochondria are also associated with the actin network, which is involved in cellular responses to various mechanical factors. In this review, we discuss mitochondrial structure and function in relation to the cytoskeleton and various mechanical factors influencing cell functions. We first summarize the morphological features of mitochondria with an emphasis on fission and fusion as well as how network properties govern function. We then review the relationship between the mitochondria and the cytoskeletal structures, including mechanical interactions. We also discuss how stretch and its dynamic pattern affect mitochondrial structure and function. Finally, we present preliminary data on how extracellular matrix stiffness influences mitochondrial morphology and ATP generation. We conclude by discussing the more general role that mitochondria may play in mechanobiology and how the mechanosensitivity of mitochondria may contribute to the development of several diseases and aging.
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16
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El Zowalaty AE, Li R, Zheng Y, Lydon JP, DeMayo FJ, Ye X. Deletion of RhoA in Progesterone Receptor-Expressing Cells Leads to Luteal Insufficiency and Infertility in Female Mice. Endocrinology 2017; 158:2168-2178. [PMID: 28498971 PMCID: PMC5505209 DOI: 10.1210/en.2016-1796] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 05/08/2017] [Indexed: 12/22/2022]
Abstract
Ras homolog gene family, member A (RhoA) is widely expressed throughout the female reproductive system. To assess its role in progesterone receptor-expressing cells, we generated RhoA conditional knockout mice RhoAd/d (RhoAf/f-Pgr-Cre+/-). RhoAd/d female mice had comparable mating activity, serum luteinizing hormone, prolactin, and estradiol levels and ovulation with control but were infertile with progesterone insufficiency, indicating impaired steroidogenesis in RhoAd/d corpus luteum (CL). RhoA was highly expressed in wild-type luteal cells and conditionally deleted in RhoAd/d CL. Gestation day 3.5 (D3.5) RhoAd/d ovaries had reduced numbers of CL, less defined corpus luteal cord formation, and disorganized CL collagen IV staining. RhoAd/d CL had lipid droplet and free cholesterol accumulation, indicating the availability of cholesterol for steroidogenesis, but disorganized β-actin and vimentin staining, indicating disrupted cytoskeleton integrity. Cytoskeleton is important for cytoplasmic cholesterol movement to mitochondria and for regulating mitochondria. Dramatically reduced expression of mitochondrial markers heat shock protein 60 (HSP60), voltage-dependent anion channel, and StAR was detected in RhoAd/d CL. StAR carries out the rate-limiting step of steroidogenesis. StAR messenger RNA expression was reduced in RU486-treated D3.5 wild-type CL and tended to be induced in progesterone-treated D3.5 RhoAd/d CL, with parallel changes of HSP60 expression. These data demonstrated the in vivo function of RhoA in CL luteal cell cytoskeleton integrity, cholesterol transport, StAR expression, and progesterone synthesis, and a positive feedback on StAR expression in CL by progesterone signaling. These findings provide insights into mechanisms of progesterone insufficiency.
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Affiliation(s)
- Ahmed E. El Zowalaty
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602
- Interdisciplinary Toxicology Program, University of Georgia, Athens, Georgia 30602
| | - Rong Li
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602
- Interdisciplinary Toxicology Program, University of Georgia, Athens, Georgia 30602
| | - Yi Zheng
- Division of Experimental Hematology and Cancer Biology, Children’s Hospital Research Foundation, Cincinnati, Ohio 45229
| | - John P. Lydon
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Francesco J. DeMayo
- Reproductive and Developmental Biology Laboratory/Pregnancy and Female Reproduction Group, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Xiaoqin Ye
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602
- Interdisciplinary Toxicology Program, University of Georgia, Athens, Georgia 30602
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17
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Abstract
Mitochondria mediate energy metabolism, apoptosis, and aging, while mitochondrial disruption leads to age-related diseases that include age-related macular degeneration. Descriptions of mitochondrial morphology have been non-systematic and qualitative, due to lack of knowledge on the molecular mechanism of mitochondrial dynamics. The current study analyzed mitochondrial size, shape, and position quantitatively in retinal pigment epithelial cells (RPE) using a systematic computational model to suggest mitochondrial trafficking under oxidative environment. Our previous proteomic study suggested that prohibitin is a mitochondrial decay biomarker in the RPE. The current study examined the prohibitin interactome map using immunoprecipitation data to determine the indirect signaling on cytoskeletal changes and transcriptional regulation by prohibitin. Immunocytochemistry and immunoprecipitation demonstrated that there is a positive correlation between mitochondrial changes and altered filaments as well as prohibitin interactions with kinesin and unknown proteins in the RPE. Specific cytoskeletal and nuclear protein-binding mechanisms may exist to regulate prohibitin-mediated reactions as key elements, including vimentin and p53, to control apoptosis in mitochondria and the nucleus. Prohibitin may regulate mitochondrial trafficking through unknown proteins that include 110 kDa protein with myosin head domain and 88 kDa protein with cadherin repeat domain. Altered cytoskeleton may represent a mitochondrial decay signature in the RPE. The current study suggests that mitochondrial dynamics and cytoskeletal changes are critical for controlling mitochondrial distribution and function. Further, imbalance of retrograde versus anterograde mitochondrial trafficking may initiate the pathogenic reaction in adult-onset neurodegenerative diseases.
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18
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Abstract
Keratin 24 (K24) is a new kind of keratin genes, which encodes a novel keratin protein, K24 that bears high similarity to the type I keratins and displays a unique expression profile. However, the role of K24 is incompletely understood. In our study, we investigated the localization of K24 within the epidermis and possible functions. Keratin 24 was found to be modestly overexpressed in senescent keratinocytes and was mainly restricted to the upper stratum spinosum of epidermis. The protein was required for terminal differentiation upon CaCl2-induced differentiation. In vitro results showed that increased K24 in keratinocytes dramatically changed the differentiation of primary keratinocytes. It also inhibited cell survival by G1/S phase cell cycle arrest and induced senescence, autophagy and apoptosis of keratinocytes. In addition, K24 activated PKCδ signal pathway involving in cellular survival. In summary, K24 may be suggested as a potential differentiation marker and anti-proliferative factor in the epidermis.
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Ba Q, Yang G. Intracellular organelle networks: Understanding their organization and communication through systems-level modeling and analysis. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s11515-016-1436-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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20
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Mitochondria, cholesterol and cancer cell metabolism. Clin Transl Med 2016; 5:22. [PMID: 27455839 PMCID: PMC4960093 DOI: 10.1186/s40169-016-0106-5] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/26/2016] [Indexed: 12/15/2022] Open
Abstract
Given the role of mitochondria in oxygen consumption, metabolism and cell death regulation, alterations in mitochondrial function or dysregulation of cell death pathways contribute to the genesis and progression of cancer. Cancer cells exhibit an array of metabolic transformations induced by mutations leading to gain-of-function of oncogenes and loss-of-function of tumor suppressor genes that include increased glucose consumption, reduced mitochondrial respiration, increased reactive oxygen species generation and cell death resistance, all of which ensure cancer progression. Cholesterol metabolism is disturbed in cancer cells and supports uncontrolled cell growth. In particular, the accumulation of cholesterol in mitochondria emerges as a molecular component that orchestrates some of these metabolic alterations in cancer cells by impairing mitochondrial function. As a consequence, mitochondrial cholesterol loading in cancer cells may contribute, in part, to the Warburg effect stimulating aerobic glycolysis to meet the energetic demand of proliferating cells, while protecting cancer cells against mitochondrial apoptosis due to changes in mitochondrial membrane dynamics. Further understanding the complexity in the metabolic alterations of cancer cells, mediated largely through alterations in mitochondrial function, may pave the way to identify more efficient strategies for cancer treatment involving the use of small molecules targeting mitochondria, cholesterol homeostasis/trafficking and specific metabolic pathways.
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21
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Scholkmann F. Long range physical cell-to-cell signalling via mitochondria inside membrane nanotubes: a hypothesis. Theor Biol Med Model 2016; 13:16. [PMID: 27267202 PMCID: PMC4896004 DOI: 10.1186/s12976-016-0042-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 05/27/2016] [Indexed: 02/07/2023] Open
Abstract
Coordinated interaction of single cells by cell-to-cell communication (signalling) enables complex behaviour necessary for the functioning of multicellular organisms. A quite newly discovered cell-to-cell signalling mechanism relies on nanotubular cell-co-cell connections, termed "membrane nanotubes" (MNTs). The present paper presents the hypothesis that mitochondria inside MNTs can form a connected structure (mitochondrial network) which enables the exchange of energy and signals between cells. It is proposed that two modes of energy and signal transmission may occur: electrical/electrochemical and electromagnetic (optical). Experimental work supporting the hypothesis is reviewed, and suggestions for future research regarding the discussed topic are given.
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Affiliation(s)
- Felix Scholkmann
- Biomedical Optics Research Laboratory, Department of Neonatology, University Hospital Zurich, University of Zurich, Frauenklinikstr. 10, 8091, Zurich, Switzerland.
- Research Office for Complex Physical and Biological Systems (ROCoS), Mutschellenstr. 179, 8038, Zurich, Switzerland.
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