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Ghose A, Pullarkat P. The role of mechanics in axonal stability and development. Semin Cell Dev Biol 2023; 140:22-34. [PMID: 35786351 PMCID: PMC7615100 DOI: 10.1016/j.semcdb.2022.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/05/2022] [Accepted: 06/13/2022] [Indexed: 01/28/2023]
Abstract
Much of the focus of neuronal cell biology has been devoted to growth cone guidance, synaptogenesis, synaptic activity, plasticity, etc. The axonal shaft too has received much attention, mainly for its astounding ability to transmit action potentials and the transport of material over long distances. For these functions, the axonal cytoskeleton and membrane have been often assumed to play static structural roles. Recent experiments have changed this view by revealing an ultrastructure much richer in features than previously perceived and one that seems to be maintained at a dynamic steady state. The role of mechanics in this is only beginning to be broadly appreciated and appears to involve passive and active modes of coupling different biopolymer filaments, filament turnover dynamics and membrane biophysics. Axons, being unique cellular processes in terms of high aspect ratios and often extreme lengths, also exhibit unique passive mechanical properties that might have evolved to stabilize them under mechanical stress. In this review, we summarize the experiments that have exposed some of these features. It is our view that axonal mechanics deserves much more attention not only due to its significance in the development and maintenance of the nervous system but also due to the susceptibility of axons to injury and neurodegeneration.
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Affiliation(s)
- Aurnab Ghose
- Indian Institute of Science Education and Research, Pune 411 008, India.
| | - Pramod Pullarkat
- Raman Research Institute, C. V. Raman Avenue, Bengaluru 560 080, India.
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2
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Bernal R, Van Hemelryck M, Gurchenkov B, Cuvelier D. Actin Stress Fibers Response and Adaptation under Stretch. Int J Mol Sci 2022; 23:ijms23095095. [PMID: 35563485 PMCID: PMC9101353 DOI: 10.3390/ijms23095095] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 02/04/2023] Open
Abstract
One of the many effects of soft tissues under mechanical solicitation in the cellular damage produced by highly localized strain. Here, we study the response of peripheral stress fibers (SFs) to external stretch in mammalian cells, plated onto deformable micropatterned substrates. A local fluorescence analysis reveals that an adaptation response is observed at the vicinity of the focal adhesion sites (FAs) due to its mechanosensor function. The response depends on the type of mechanical stress, from a Maxwell-type material in compression to a complex scenario in extension, where a mechanotransduction and a self-healing process takes place in order to prevent the induced severing of the SF. A model is proposed to take into account the effect of the applied stretch on the mechanics of the SF, from which relevant parameters of the healing process are obtained. In contrast, the repair of the actin bundle occurs at the weak point of the SF and depends on the amount of applied strain. As a result, the SFs display strain-softening features due to the incorporation of new actin material into the bundle. In contrast, the response under compression shows a reorganization with a constant actin material suggesting a gliding process of the SFs by the myosin II motors.
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Affiliation(s)
- Roberto Bernal
- Cellular Mechanics Laboratory, Physics Department, SMAT-C, Universidad de Santiago de Chile, Santiago 9170124, Chile;
- Correspondence: (R.B.); (D.C.)
| | - Milenka Van Hemelryck
- Cellular Mechanics Laboratory, Physics Department, SMAT-C, Universidad de Santiago de Chile, Santiago 9170124, Chile;
| | - Basile Gurchenkov
- Institut du Cerveau et de la Moelle Épinière, Hôpital Pitié Salpêtrière, 47 bd de l’Hôpital, 75013 Paris, France;
| | - Damien Cuvelier
- Sorbonne Université, Faculté des Sciences et Ingénierie, UFR 926 Chemistry, 75005 Paris, France
- Institut Pierre Gilles de Gennes, Paris Sciences et Lettres Research University, 75005 Paris, France
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, UMR 144, 75248 Paris, France
- Correspondence: (R.B.); (D.C.)
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3
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Membrane Homeostasis: The Role of Actin Cytoskeleton. J Indian Inst Sci 2021. [DOI: 10.1007/s41745-020-00217-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Biswas A, Kashyap P, Datta S, Sengupta T, Sinha B. Cholesterol Depletion by MβCD Enhances Cell Membrane Tension and Its Variations-Reducing Integrity. Biophys J 2019; 116:1456-1468. [PMID: 30979551 PMCID: PMC6486507 DOI: 10.1016/j.bpj.2019.03.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 01/22/2019] [Accepted: 03/14/2019] [Indexed: 11/23/2022] Open
Abstract
Cholesterol depletion by methyl-β-cyclodextrin (MβCD) remodels the plasma membrane’s mechanics in cells and its interactions with the underlying cytoskeleton, whereas in red blood cells, it is also known to cause lysis. Currently it’s unclear if MβCD alters membrane tension or only enhances membrane-cytoskeleton interactions—and how this relates to cell lysis. We map membrane height fluctuations in single cells and observe that MβCD reduces temporal fluctuations robustly but flattens spatial membrane undulations only slightly. Utilizing models explicitly incorporating membrane confinement besides other viscoelastic factors, we estimate membrane mechanical parameters from the fluctuations’ frequency spectrum. This helps us conclude that MβCD enhances membrane tension and does so even on ATP-depleted cell membranes where this occurs despite reduction in confinement. Additionally, on cholesterol depletion, cell membranes display higher intracellular heterogeneity in the amplitude of spatial undulations and membrane tension. MβCD also has a strong impact on the cell membrane’s tenacity to mechanical stress, making cells strongly prone to rupture on hypo-osmotic shock with larger rupture diameters—an effect not hindered by actomyosin perturbations. Our study thus demonstrates that cholesterol depletion increases membrane tension and its variability, making cells prone to rupture independent of the cytoskeletal state of the cell.
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Affiliation(s)
- Arikta Biswas
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
| | - Purba Kashyap
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
| | - Sanchari Datta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
| | - Titas Sengupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
| | - Bidisha Sinha
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India.
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Gallardo MJ, Suwalsky M, Ramírez D, Tapia J, Sepulveda B. Antioxidant effect of resveratrol in single red blood cells measured by thermal fluctuation spectroscopy. Arch Biochem Biophys 2019; 665:30-35. [PMID: 30796890 DOI: 10.1016/j.abb.2019.02.011] [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] [Received: 12/09/2018] [Revised: 02/14/2019] [Accepted: 02/16/2019] [Indexed: 01/29/2023]
Abstract
The human red blood cell (RBC) membrane has significant elastic capabilities which can be described measuring typical membrane edge fluctuations and mechanical properties by optical techniques. The RBC elastic properties can be affected by changes in the surrounding media. In an attempt to elucidate the molecular mechanisms of the interaction of resveratrol with the red cell membrane and of its antioxidant capacity the changes in mechanical properties of the RBC membrane were analyzed. These studies were carried out through measurements of RBC membrane fluctuations in the presence of the oxidant agent HClO using thermal fluctuation spectroscopy (TFS). The observed results showed that the elastic capabilities of RBC changed with low concentration of hypochlorous acid but without morphological changes. However, in the presence of resveratrol the deformation and decrease of elastic capabilities induced by HClO on RBC decreased. These in vitro results demonstrated the protective effect of RV against the detrimental effects triggered by HClO upon human erythrocytes.
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Affiliation(s)
| | - Mario Suwalsky
- Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile.
| | - Diego Ramírez
- Centro de Óptica y Fotónica, Universidad de Concepción, Concepción, Chile; Departmento de Física, Universidad de Concepción, Concepción, Chile; Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Concepción, Chile
| | - Jorge Tapia
- Centro de Óptica y Fotónica, Universidad de Concepción, Concepción, Chile; Departmento de Física, Universidad de Concepción, Concepción, Chile
| | - Benjamín Sepulveda
- Centro de Óptica y Fotónica, Universidad de Concepción, Concepción, Chile; Departmento de Física, Universidad de Concepción, Concepción, Chile
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Miller KE, Suter DM. An Integrated Cytoskeletal Model of Neurite Outgrowth. Front Cell Neurosci 2018; 12:447. [PMID: 30534055 PMCID: PMC6275320 DOI: 10.3389/fncel.2018.00447] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/07/2018] [Indexed: 12/27/2022] Open
Abstract
Neurite outgrowth underlies the wiring of the nervous system during development and regeneration. Despite a significant body of research, the underlying cytoskeletal mechanics of growth and guidance are not fully understood, and the relative contributions of individual cytoskeletal processes to neurite growth are controversial. Here, we review the structural organization and biophysical properties of neurons to make a semi-quantitative comparison of the relative contributions of different processes to neurite growth. From this, we develop the idea that neurons are active fluids, which generate strong contractile forces in the growth cone and weaker contractile forces along the axon. As a result of subcellular gradients in forces and material properties, actin flows rapidly rearward in the growth cone periphery, and microtubules flow forward in bulk along the axon. With this framework, an integrated model of neurite outgrowth is proposed that hopefully will guide new approaches to stimulate neuronal growth.
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Affiliation(s)
- Kyle E Miller
- Department of Integrative Biology, Michigan State University, East Lansing, MI, United States
| | - Daniel M Suter
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States.,Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, United States.,Bindley Bioscience Center, Purdue University, West Lafayette, IN, United States.,Birck Nanotechnology Center, Purdue University, West Lafayette, IN, United States
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