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Leterrier C. Stress balls for the brain: How beading protects axons from mechanical damage. J Cell Biol 2024; 223:e202407024. [PMID: 38985206 PMCID: PMC11233989 DOI: 10.1083/jcb.202407024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024] Open
Abstract
The slender shape of axons makes them uniquely susceptible to mechanical stress. In this issue, Pan, Hu et al. (https://doi.org/10.1083/jcb.202206046) use a microfluidic axon-on-chip device to reveal how actomyosin protects axons from mild mechanical stress, by transiently adopting a beaded shape that helps limit the spread of damaging calcium waves.
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2
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Ghisleni A, Bonilla-Quintana M, Crestani M, Lavagnino Z, Galli C, Rangamani P, Gauthier NC. Mechanically induced topological transition of spectrin regulates its distribution in the mammalian cell cortex. Nat Commun 2024; 15:5711. [PMID: 38977673 PMCID: PMC11231315 DOI: 10.1038/s41467-024-49906-6] [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: 01/24/2024] [Accepted: 06/24/2024] [Indexed: 07/10/2024] Open
Abstract
The cell cortex is a dynamic assembly formed by the plasma membrane and underlying cytoskeleton. As the main determinant of cell shape, the cortex ensures its integrity during passive and active deformations by adapting cytoskeleton topologies through yet poorly understood mechanisms. The spectrin meshwork ensures such adaptation in erythrocytes and neurons by adopting different organizations. Erythrocytes rely on triangular-like lattices of spectrin tetramers, whereas in neurons they are organized in parallel, periodic arrays. Since spectrin is ubiquitously expressed, we exploited Expansion Microscopy to discover that, in fibroblasts, distinct meshwork densities co-exist. Through biophysical measurements and computational modeling, we show that the non-polarized spectrin meshwork, with the intervention of actomyosin, can dynamically transition into polarized clusters fenced by actin stress fibers that resemble periodic arrays as found in neurons. Clusters experience lower mechanical stress and turnover, despite displaying an extension close to the tetramer contour length. Our study sheds light on the adaptive properties of spectrin, which participates in the protection of the cell cortex by varying its densities in response to key mechanical features.
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Affiliation(s)
- Andrea Ghisleni
- IFOM ETS, The AIRC Institute of Molecular Oncology, Milan, Italy
| | - Mayte Bonilla-Quintana
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA
| | - Michele Crestani
- IFOM ETS, The AIRC Institute of Molecular Oncology, Milan, Italy
- Laboratory of Applied Mechanobiology, Department for Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Zeno Lavagnino
- IFOM ETS, The AIRC Institute of Molecular Oncology, Milan, Italy
| | - Camilla Galli
- IFOM ETS, The AIRC Institute of Molecular Oncology, Milan, Italy
- Humanitas Cardio Center, IRCCS Humanitas Research Hospital, Rozzano (Milan, Italy
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA.
| | - Nils C Gauthier
- IFOM ETS, The AIRC Institute of Molecular Oncology, Milan, Italy.
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3
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Martin CG, Bent JS, Hill T, Topalidou I, Singhvi A. Epithelial UNC-23 limits mechanical stress to maintain glia-neuron architecture in C. elegans. Dev Cell 2024; 59:1668-1688.e7. [PMID: 38670103 PMCID: PMC11233253 DOI: 10.1016/j.devcel.2024.04.005] [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: 11/23/2022] [Revised: 12/23/2023] [Accepted: 04/03/2024] [Indexed: 04/28/2024]
Abstract
For an organ to maintain correct architecture and function, its diverse cellular components must coordinate their size and shape. Although cell-intrinsic mechanisms driving homotypic cell-cell coordination are known, it is unclear how cell shape is regulated across heterotypic cells. We find that epithelial cells maintain the shape of neighboring sense-organ glia-neuron units in adult Caenorhabditis elegans (C. elegans). Hsp co-chaperone UNC-23/BAG2 prevents epithelial cell shape from deforming, and its loss causes head epithelia to stretch aberrantly during animal movement. In the sense-organ glia, amphid sheath (AMsh), this causes progressive fibroblast growth factor receptor (FGFR)-dependent disruption of the glial apical cytoskeleton. Resultant glial cell shape alteration causes concomitant shape change in glia-associated neuron endings. Epithelial UNC-23 maintenance of glia-neuron shape is specific both spatially, within a defined anatomical zone, and temporally, in a developmentally critical period. As all molecular components uncovered are broadly conserved across central and peripheral nervous systems, we posit that epithelia may similarly regulate glia-neuron architecture cross-species.
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Affiliation(s)
- Cecilia G Martin
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - James S Bent
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Tyler Hill
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Irini Topalidou
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
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4
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Shiomi A, Kaneko T, Nishikawa K, Tsuchida A, Isoshima T, Sato M, Toyooka K, Doi K, Nishikii H, Shintaku H. High-throughput mechanical phenotyping and transcriptomics of single cells. Nat Commun 2024; 15:3812. [PMID: 38760380 PMCID: PMC11101642 DOI: 10.1038/s41467-024-48088-5] [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: 07/11/2023] [Accepted: 04/22/2024] [Indexed: 05/19/2024] Open
Abstract
The molecular system regulating cellular mechanical properties remains unexplored at single-cell resolution mainly due to a limited ability to combine mechanophenotyping with unbiased transcriptional screening. Here, we describe an electroporation-based lipid-bilayer assay for cell surface tension and transcriptomics (ELASTomics), a method in which oligonucleotide-labelled macromolecules are imported into cells via nanopore electroporation to assess the mechanical state of the cell surface and are enumerated by sequencing. ELASTomics can be readily integrated with existing single-cell sequencing approaches and enables the joint study of cell surface mechanics and underlying transcriptional regulation at an unprecedented resolution. We validate ELASTomics via analysis of cancer cell lines from various malignancies and show that the method can accurately identify cell types and assess cell surface tension. ELASTomics enables exploration of the relationships between cell surface tension, surface proteins, and transcripts along cell lineages differentiating from the haematopoietic progenitor cells of mice. We study the surface mechanics of cellular senescence and demonstrate that RRAD regulates cell surface tension in senescent TIG-1 cells. ELASTomics provides a unique opportunity to profile the mechanical and molecular phenotypes of single cells and can dissect the interplay among these in a range of biological contexts.
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Affiliation(s)
- Akifumi Shiomi
- Cluster for Pioneering Research, RIKEN, Saitama, Japan
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | | | | | | | | | - Mayuko Sato
- Center for Sustainable Resource Science, RIKEN, Yokohama, Japan
| | | | - Kentaro Doi
- Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, Japan
| | | | - Hirofumi Shintaku
- Cluster for Pioneering Research, RIKEN, Saitama, Japan.
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan.
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5
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Buhlan M, Ljaschenko D, Scholz N, Langenhan T. Experimental modulation of physiological force application on leg joint neurons in intact Drosophila melanogaster. Nat Protoc 2024; 19:113-126. [PMID: 37945792 DOI: 10.1038/s41596-023-00907-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/25/2023] [Indexed: 11/12/2023]
Abstract
The study of how mechanical forces affect biological events in living tissue is important for the understanding of a multitude of physiogical and pathophysiological phenomena. However, these investigations are often impeded by insufficient knowledge about force parameters, inadequate experimental administration of force stimuli and lack of noninvasive means to record their molecular and cellular effects. We therefore introduced a procedure to study the impact of force stimulation on adhesion G-protein-coupled receptor dissociation in mechanosensory neurons. Here, we detail a procedure to harness the mechanical force spectrum that emerges during the natural flexion-extension cycle of the femorotibial joint of adult fruit flies (Drosophila melanogaster). Mechanical load generated during the joint's motion is transmitted to specialized mechanosensory neurons residing close to the joint axis, which serve as proprioceptive sensors in the peripheral nervous system of the animal. Temporary immobilization of the joint by a restraint made of a human hair allows for the observation of transgenic mechanosensitive reporters by using fluorescent readout in the neurons before, during and after cessation of mechanical stimulation. The assay harnesses physiologically adequate stimuli for joint flexion and extension, can be conducted noninvasively in live specimens and is compatible with various transgenic reporter systems beyond the initially conceived strategy and mechanobiological hypotheses tested. The application of the protocol requires knowledge in Drosophila genetics, husbandry and fluorescence imaging and micromanipulation skills. The experimental procedure can be completed in 10 h and requires an additional 30 min in advance for fly fixation and leg immobilization. The apple agar cooking and heptane glue preparation requires a maximum of 30 min on the day before the experiment is conducted.
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Affiliation(s)
- Max Buhlan
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Dmitrij Ljaschenko
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Nicole Scholz
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany.
| | - Tobias Langenhan
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany.
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6
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Sanfeliu-Cerdán N, Català-Castro F, Mateos B, Garcia-Cabau C, Ribera M, Ruider I, Porta-de-la-Riva M, Canals-Calderón A, Wieser S, Salvatella X, Krieg M. A MEC-2/stomatin condensate liquid-to-solid phase transition controls neuronal mechanotransduction during touch sensing. Nat Cell Biol 2023; 25:1590-1599. [PMID: 37857834 PMCID: PMC10635833 DOI: 10.1038/s41556-023-01247-0] [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: 07/22/2022] [Accepted: 09/01/2023] [Indexed: 10/21/2023]
Abstract
A growing body of work suggests that the material properties of biomolecular condensates ensuing from liquid-liquid phase separation change with time. How this aging process is controlled and whether the condensates with distinct material properties can have different biological functions is currently unknown. Using Caenorhabditis elegans as a model, we show that MEC-2/stomatin undergoes a rigidity phase transition from fluid-like to solid-like condensates that facilitate transport and mechanotransduction, respectively. This switch is triggered by the interaction between the SH3 domain of UNC-89 (titin/obscurin) and MEC-2. We suggest that this rigidity phase transition has a physiological role in frequency-dependent force transmission in mechanosensitive neurons during body wall touch. Our data demonstrate a function for the liquid and solid phases of MEC-2/stomatin condensates in facilitating transport or mechanotransduction, and a previously unidentified role for titin homologues in neurons.
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Affiliation(s)
- Neus Sanfeliu-Cerdán
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Frederic Català-Castro
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Borja Mateos
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Carla Garcia-Cabau
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Maria Ribera
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Iris Ruider
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Montserrat Porta-de-la-Riva
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Adrià Canals-Calderón
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Stefan Wieser
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Xavier Salvatella
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- ICREA, Barcelona, Spain.
| | - Michael Krieg
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain.
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Aydın MŞ, Bay S, Yiğit EN, Özgül C, Oğuz EK, Konuk EY, Ayşit N, Cengiz N, Erdoğan E, Him A, Koçak M, Eroglu E, Öztürk G. Active shrinkage protects neurons following axonal transection. iScience 2023; 26:107715. [PMID: 37701578 PMCID: PMC10493506 DOI: 10.1016/j.isci.2023.107715] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 07/31/2023] [Accepted: 08/22/2023] [Indexed: 09/14/2023] Open
Abstract
Trauma, vascular events, or neurodegenerative processes can lead to axonal injury and eventual transection (axotomy). Neurons can survive axotomy, yet the underlying mechanisms are not fully understood. Excessive water entry into injured neurons poses a particular risk due to swelling and subsequent death. Using in vitro and in vivo neurotrauma model systems based on laser transection and surgical nerve cut, we demonstrated that axotomy triggers actomyosin contraction coupled with calpain activity. As a consequence, neurons shrink acutely to force water out through aquaporin channels preventing swelling and bursting. Inhibiting shrinkage increased the probability of neuronal cell death by about 3-fold. These studies reveal a previously unrecognized cytoprotective response mechanism to neurotrauma and offer a fresh perspective on pathophysiological processes in the nervous system.
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Affiliation(s)
- Mehmet Şerif Aydın
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
| | - Sadık Bay
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
| | - Esra Nur Yiğit
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
| | - Cemil Özgül
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
| | - Elif Kaval Oğuz
- Department of Science Education, Faculty of Education, Yüzüncü Yıl University, Van 65080, Türkiye
| | - Elçin Yenidünya Konuk
- Department of Medical Biology, School of Medicine, Bakırçay University, İzmir 35665, Türkiye
| | - Neşe Ayşit
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
- Department of Medical Biology and Genetics, School of Medicine, Istanbul Medipol University, Istanbul 34810, Türkiye
| | - Nureddin Cengiz
- Department of Histology and Embryology, School of Medicine, Bandırma Onyedi Eylül University, Bandırma, Balıkesir 10200, Türkiye
| | - Ender Erdoğan
- Department of Histology and Embryology, School of Medicine, Selçuk University, Konya 42130, Türkiye
| | - Aydın Him
- Department of Physiology, School of Medicine, Bolu Abant İzzet Baysal University, Bolu 14030, Türkiye
| | - Mehmet Koçak
- Biostatistics and Bioinformatics Analysis Unit, Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
- Department of Biostatistics and Medical Informatics, International School of Medicine, Istanbul Medipol University, Istanbul 34810, Türkiye
| | - Emrah Eroglu
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
| | - Gürkan Öztürk
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul 34810, Türkiye
- Department of Physiology, International School of Medicine, Istanbul Medipol University, Istanbul 34810, Türkiye
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8
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Glomb O, Swaim G, Munoz LLancao P, Lovejoy C, Sutradhar S, Park J, Wu Y, Cason SE, Holzbaur ELF, Hammarlund M, Howard J, Ferguson SM, Gramlich MW, Yogev S. A kinesin-1 adaptor complex controls bimodal slow axonal transport of spectrin in Caenorhabditis elegans. Dev Cell 2023; 58:1847-1863.e12. [PMID: 37751746 PMCID: PMC10574138 DOI: 10.1016/j.devcel.2023.08.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 08/18/2023] [Accepted: 08/30/2023] [Indexed: 09/28/2023]
Abstract
An actin-spectrin lattice, the membrane periodic skeleton (MPS), protects axons from breakage. MPS integrity relies on spectrin delivery via slow axonal transport, a process that remains poorly understood. We designed a probe to visualize endogenous spectrin dynamics at single-axon resolution in vivo. Surprisingly, spectrin transport is bimodal, comprising fast runs and movements that are 100-fold slower than previously reported. Modeling and genetic analysis suggest that the two rates are independent, yet both require kinesin-1 and the coiled-coil proteins UNC-76/FEZ1 and UNC-69/SCOC, which we identify as spectrin-kinesin adaptors. Knockdown of either protein led to disrupted spectrin motility and reduced distal MPS, and UNC-76 overexpression instructed excessive transport of spectrin. Artificially linking spectrin to kinesin-1 drove robust motility but inefficient MPS assembly, whereas impairing MPS assembly led to excessive spectrin transport, suggesting a balance between transport and assembly. These results provide insight into slow axonal transport and MPS integrity.
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Affiliation(s)
- Oliver Glomb
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Grace Swaim
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Pablo Munoz LLancao
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Christopher Lovejoy
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Sabyasachi Sutradhar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Junhyun Park
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Youjun Wu
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Sydney E Cason
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marc Hammarlund
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA; Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Quantitative Biology Institute, Yale University, New Haven, CT 06510, USA
| | - Shawn M Ferguson
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | | | - Shaul Yogev
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA.
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9
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张 强, Godfred GKT, 张 艳, 卫 小, 陈 维, 张 全. [Research progress of chondrocyte mechanotransduction mediated by TRPV4 and PIEZOs]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2023; 40:638-644. [PMID: 37666753 PMCID: PMC10477401 DOI: 10.7507/1001-5515.202301029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/08/2023] [Indexed: 09/06/2023]
Abstract
Mechanical signal transduction are crucial for chondrocyte in response to mechanical cues during the growth, development and osteoarthritis (OA) of articular cartilage. Extracellular matrix (ECM) turnover regulates the matrix mechanical microenvironment of chondrocytes. Thus, understanding the mechanotransduction mechanisms during chondrocyte sensing the matrix mechanical microenvironment can develop effective targeted therapy for OA. In recent decades, growing evidences are rapidly advancing our understanding of the mechanical force-dependent cartilage remodeling and injury responses mediated by TRPV4 and PIEZOs. In this review, we highlighted the mechanosensing mechanism mediated by TRPV4 and PIEZOs during chondrocytes sensing mechanical microenvironment of the ECM. Additionally, the latest progress in the regulation of OA by inflammatory signals mediated by TRPV4 and PIEZOs was also introduced. These recent insights provide the potential mechanotheraputic strategies to target these channels and prevent cartilage degeneration associated with OA. This review will shed light on the pathogenesis of articular cartilage, searching clinical targeted therapies, and designing cell-induced biomaterials.
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Affiliation(s)
- 强 张
- 太原理工大学 生物医学工程学院(太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
| | - Godfred K Tawiah Godfred
- 太原理工大学 生物医学工程学院(太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
| | - 艳君 张
- 太原理工大学 生物医学工程学院(太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
- 山西医科大学 第二临床医院 骨与软骨组织损伤修复山西省重点实验室(太原 030001)Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, the Second Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan 030001, P. R. China
| | - 小春 卫
- 太原理工大学 生物医学工程学院(太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
| | - 维毅 陈
- 太原理工大学 生物医学工程学院(太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
| | - 全有 张
- 太原理工大学 生物医学工程学院(太原 030024)College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
- 山西医科大学 第二临床医院 骨与软骨组织损伤修复山西省重点实验室(太原 030001)Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, the Second Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan 030001, P. R. China
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10
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Sadhanasatish T, Augustin K, Windgasse L, Chrostek-Grashoff A, Rief M, Grashoff C. A molecular optomechanics approach reveals functional relevance of force transduction across talin and desmoplakin. SCIENCE ADVANCES 2023; 9:eadg3347. [PMID: 37343090 DOI: 10.1126/sciadv.adg3347] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 05/17/2023] [Indexed: 06/23/2023]
Abstract
Many mechanobiological processes that govern development and tissue homeostasis are regulated on the level of individual molecular linkages, and a number of proteins experiencing piconewton-scale forces in cells have been identified. However, under which conditions these force-bearing linkages become critical for a given mechanobiological process is often still unclear. Here, we established an approach to revealing the mechanical function of intracellular molecules using molecular optomechanics. When applied to the integrin activator talin, the technique provides direct evidence that its role as a mechanical linker is indispensable for the maintenance of cell-matrix adhesions and overall cell integrity. Applying the technique to desmoplakin shows that mechanical engagement of desmosomes to intermediate filaments is expendable under homeostatic conditions yet strictly required for preserving cell-cell adhesion under stress. These results reveal a central role of talin and desmoplakin as mechanical linkers in cell adhesion structures and demonstrate that molecular optomechanics is a powerful tool to investigate the molecular details of mechanobiological processes.
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Affiliation(s)
- Tanmay Sadhanasatish
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
| | - Katharina Augustin
- Center for Protein Assemblies and Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
| | - Lukas Windgasse
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
| | - Anna Chrostek-Grashoff
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
| | - Matthias Rief
- Center for Protein Assemblies and Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
| | - Carsten Grashoff
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
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11
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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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12
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Porta-de-la-Riva M, Gonzalez AC, Sanfeliu-Cerdán N, Karimi S, Malaiwong N, Pidde A, Morales-Curiel LF, Fernandez P, González-Bolívar S, Hurth C, Krieg M. Neural engineering with photons as synaptic transmitters. Nat Methods 2023; 20:761-769. [PMID: 37024651 DOI: 10.1038/s41592-023-01836-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 03/03/2023] [Indexed: 04/08/2023]
Abstract
Neuronal computation is achieved through connections of individual neurons into a larger network. To expand the repertoire of endogenous cellular communication, we developed a synthetic, photon-assisted synaptic transmission (PhAST) system. PhAST is based on luciferases and channelrhodopsins that enable the transmission of a neuronal state across space, using photons as neurotransmitters. PhAST overcomes synaptic barriers and rescues the behavioral deficit of a glutamate mutant with conditional, calcium-triggered photon emission between two neurons of the Caenorhabditis elegans nociceptive avoidance circuit. To demonstrate versatility and flexibility, we generated de novo synaptic transmission between two unconnected cells in a sexually dimorphic neuronal circuit, suppressed endogenous nocifensive response through activation of an anion channelrhodopsin and switched attractive to aversive behavior in an olfactory circuit. Finally, we applied PhAST to dissect the calcium dynamics of the temporal pattern generator in a motor circuit for ovipositioning. In summary, we established photon-based synaptic transmission that facilitates the modification of animal behavior.
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Affiliation(s)
| | | | | | - Shadi Karimi
- Institut de Ciències Fotòniques, Castelldefels, Spain
| | | | | | | | | | | | - Cedric Hurth
- Institut de Ciències Fotòniques, Castelldefels, Spain
| | - Michael Krieg
- Institut de Ciències Fotòniques, Castelldefels, Spain.
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13
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Fok A, Brissette B, Hallacy T, Ahamed H, Ho E, Ramanathan S, Ringstad N. High-fidelity encoding of mechanostimuli by tactile food-sensing neurons requires an ensemble of ion channels. Cell Rep 2023; 42:112452. [PMID: 37119137 DOI: 10.1016/j.celrep.2023.112452] [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: 02/15/2022] [Revised: 02/07/2023] [Accepted: 04/14/2023] [Indexed: 04/30/2023] Open
Abstract
The nematode C. elegans uses mechanosensitive neurons to detect bacteria, which are food for worms. These neurons release dopamine to suppress foraging and promote dwelling. Through a screen of genes highly expressed in dopaminergic food-sensing neurons, we identify a K2P-family potassium channel-TWK-2-that damps their activity. Strikingly, loss of TWK-2 restores mechanosensation to neurons lacking the NOMPC-like channel transient receptor potential 4 (TRP-4), which was thought to be the primary mechanoreceptor for tactile food sensing. The alternate mechanoreceptor mechanism uncovered by TWK-2 mutation requires three Deg/ENaC channel subunits: ASIC-1, DEL-3, and UNC-8. Analysis of cell-physiological responses to mechanostimuli indicates that TRP and Deg/ENaC channels work together to set the range of analog encoding of stimulus intensity and to improve signal-to-noise characteristics and temporal fidelity of food-sensing neurons. We conclude that a specialized mechanosensory modality-tactile food sensing-emerges from coordination of distinct force-sensing mechanisms housed in one type of sensory neuron.
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Affiliation(s)
- Alice Fok
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, and Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
| | - Benjamin Brissette
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, and Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
| | - Tim Hallacy
- Harvard University, Departments of Molecular and Cell Biology, Stem Cell and Regenerative Biology and Applied Physics, Cambridge, MA 10238, USA
| | - Hassan Ahamed
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, and Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
| | - Elver Ho
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, and Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA
| | - Sharad Ramanathan
- Harvard University, Departments of Molecular and Cell Biology, Stem Cell and Regenerative Biology and Applied Physics, Cambridge, MA 10238, USA
| | - Niels Ringstad
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, and Neuroscience Institute, NYU School of Medicine, New York, NY 10016, USA.
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14
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Chai Z, Gu S, Lykotrafitis G. Dynamics of the axon plasma membrane skeleton. SOFT MATTER 2023; 19:2514-2528. [PMID: 36939651 DOI: 10.1039/d2sm01602h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
It was recently revealed via super-resolution microscopy experiments that the axon plasma membrane skeleton (APMS) comprises a series of periodically arranged azimuthal actin rings connected via longitudinal spectrin filaments forming an orthotropic network. The common perception is that APMS enhances structural stability of the axon but its impact on axon deformation is unknown. To investigate the response of the APMS to extension, we introduce a coarse-grain molecular dynamics model consisting of actin particles forming rings and chains of particles representing spectrin tetramers with repeats than can unfold. We observe that the shape of force-extension curve is initially linear and the force level depends on the extension rate. Even during the initial deformation stage, unfolding of spectrin repeats occurs, but the saw-tooth shape of the corresponding force-extension curve observed in the case of one spectrin tetramer does not appear in the case of the entire APMS. The reason is that spectrin unfolding is not synchronized across filaments during extension. If actin-spectrin associations remain intact, the force-extension response reaches a perfectly plastic region because of increased spectrin unfolding frequency. However, when actin-spectrin links dissociate, which can happen at moderate and high extension rates, APMS softens and the resistance force decreases linearly as the axon elongates until it reaches a point where the APMS is completely severed. Furthermore, when the ring-to-ring distance is maintained fixed under stretch, the resistance force relaxes exponentially as a function of time due to additional unfolding of spectrin tetramers following the Kelvin-Voigt representation of the Zener model.
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Affiliation(s)
- Zhaojie Chai
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA.
| | - Shiju Gu
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - George Lykotrafitis
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA.
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA
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15
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Tao A, LaCroix AS, Shoyer TC, Venkatraman V, Xu KL, Feiger B, Hoffman BD. Identifying constitutive and context-specific molecular-tension-sensitive protein recruitment within focal adhesions. Dev Cell 2023; 58:522-534.e7. [PMID: 36924770 PMCID: PMC10080727 DOI: 10.1016/j.devcel.2023.02.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/28/2022] [Accepted: 02/20/2023] [Indexed: 03/17/2023]
Abstract
Mechanosensitive processes often rely on adhesion structures to strengthen, or mature, in response to applied loads. However, a limited understanding of how the molecular tensions that are experienced by a particular protein affect the recruitment of other proteins represents a major obstacle in the way of deciphering molecular mechanisms that underlie mechanosensitive processes. Here, we describe an imaging-based technique, termed fluorescence-tension co-localization (FTC), for studying molecular-tension-sensitive protein recruitment inside cells. Guided by discrete time Markov chain simulations of protein recruitment, we integrate immunofluorescence labeling, molecular tension sensors, and machine learning to determine the sensitivity, specificity, and context dependence of molecular-tension-sensitive protein recruitment. The application of FTC to the mechanical linker protein vinculin in mouse embryonic fibroblasts reveals constitutive and context-specific molecular-tension-sensitive protein recruitment that varies with adhesion maturation. FTC overcomes limitations associated with the alteration of numerous proteins during the manipulation of cell contractility, providing molecularly specific insights into tension-sensitive protein recruitment.
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Affiliation(s)
- Arnold Tao
- Biomedical Engineering, Duke University, Durham, NC, USA
| | | | | | | | - Karen L Xu
- Biomedical Engineering, Duke University, Durham, NC, USA
| | - Bradley Feiger
- Biomedical Engineering, Duke University, Durham, NC, USA
| | - Brenton D Hoffman
- Biomedical Engineering, Duke University, Durham, NC, USA; Cell Biology, Duke University, Durham, NC, USA.
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16
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Nunes Vicente F, Chen T, Rossier O, Giannone G. Novel imaging methods and force probes for molecular mechanobiology of cytoskeleton and adhesion. Trends Cell Biol 2023; 33:204-220. [PMID: 36055943 DOI: 10.1016/j.tcb.2022.07.008] [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: 05/06/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 12/01/2022]
Abstract
Detection and conversion of mechanical forces into biochemical signals is known as mechanotransduction. From cells to tissues, mechanotransduction regulates migration, proliferation, and differentiation in processes such as immune responses, development, and cancer progression. Mechanosensitive structures such as integrin adhesions, the actin cortex, ion channels, caveolae, and the nucleus sense and transmit forces. In vitro approaches showed that mechanosensing is based on force-dependent protein deformations and reorganizations. However, the mechanisms in cells remained unclear since cell imaging techniques lacked molecular resolution. Thanks to recent developments in super-resolution microscopy (SRM) and molecular force sensors, it is possible to obtain molecular insight of mechanosensing in live cells. We discuss how understanding of molecular mechanotransduction was revolutionized by these innovative approaches, focusing on integrin adhesions, actin structures, and the plasma membrane.
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Affiliation(s)
- Filipe Nunes Vicente
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France; Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Tianchi Chen
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Olivier Rossier
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Grégory Giannone
- University Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France.
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17
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Sanfeliu-Cerdán N, Lin LC, Dunn AR, Goodman MB, Krieg M. Visualizing Neurons Under Tension In Vivo with Optogenetic Molecular Force Sensors. Methods Mol Biol 2023; 2600:239-266. [PMID: 36587102 DOI: 10.1007/978-1-0716-2851-5_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The visualization of mechanical stress distribution in specific molecular networks within a living and physiologically active cell or animal remains a formidable challenge in mechanobiology. The advent of fluorescence-resonance energy transfer (FRET)-based molecular tension sensors overcame a significant hurdle that now enables us to address previously technically limited questions. Here, we describe a method that uses genetically encoded FRET tension sensors to visualize the mechanics of cytoskeletal networks in neurons of living animals with sensitized emission FRET and confocal scanning light microscopy. This method uses noninvasive immobilization of living animals to image neuronal β-spectrin cytoskeleton at the diffraction limit, and leverages multiple imaging controls to verify and underline the quality of the measurements. In combination with a semiautomated machine-vision algorithm to identify and trace individual neurites, our analysis performs simultaneous calculation of FRET efficiencies and visualizes statistical uncertainty on a pixel by pixel basis. Our approach is not limited to genetically encoded spectrin tension sensors, but can also be used for any kind of ratiometric imaging in neuronal cells both in vivo and in vitro.
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Affiliation(s)
- Neus Sanfeliu-Cerdán
- Neurophotonics and Mechanical Systems Biology, ICFO, Institut de Ciències Fotòniques, ICFO, Castelldefels, Spain
| | - Li-Chun Lin
- Neurophotonics and Mechanical Systems Biology, ICFO, Institut de Ciències Fotòniques, ICFO, Castelldefels, Spain
| | - Alexander R Dunn
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
| | - Miriam B Goodman
- Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Michael Krieg
- Neurophotonics and Mechanical Systems Biology, ICFO, Institut de Ciències Fotòniques, ICFO, Castelldefels, Spain.
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18
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Windgasse L, Grashoff C. Multiplexed Molecular Tension Sensor Measurements Using PIE-FLIM. Methods Mol Biol 2023; 2600:221-237. [PMID: 36587101 DOI: 10.1007/978-1-0716-2851-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Genetically encoded Förster Resonance Energy Transfer (FRET)-based tension sensors were developed to enable the quantification of piconewton (pN)-scale forces that act across distinct proteins in living cells and organisms. An important extension of this technology is the multiplexing of tension sensors to monitor several independent FRET probes in parallel. Here we describe how pulsed interleaved excitation (PIE)-fluorescence lifetime imaging microscopy (FLIM) can be implemented to enable the analysis of two co-expressed tension sensor constructs. Our protocol covers all essential steps from biosensor expression and live cell PIE image acquisition to lifetime calculations.
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Affiliation(s)
- Lukas Windgasse
- Department of Quantitative Cell Biology, Institute of Integrative Cell Biology and Physiology, University of Münster, Münster, Germany
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Integrative Cell Biology and Physiology, University of Münster, Münster, Germany.
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19
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Wang LM, Goodman MB, Kuhl E. Image-based axon model highlights heterogeneity in initiation of damage. Biophys J 2023; 122:9-19. [PMID: 36461640 PMCID: PMC9822833 DOI: 10.1016/j.bpj.2022.11.2946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/29/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
Head injury simulations predict the occurrence of traumatic brain injury by placing a threshold on the calculated strains for axon tracts within the brain. However, a current roadblock to accurate injury prediction is the selection of an appropriate axon damage threshold. While several computational studies have used models of the axon cytoskeleton to investigate damage initiation, these models all employ an idealized, homogeneous axonal geometry. This homogeneous geometry with regularly spaced microtubules, evenly distributed throughout the model, overestimates axon strength because, in reality, the axon cytoskeleton is heterogeneous. In the heterogeneous cytoskeleton, the weakest cross section determines the initiation of failure, but these weak spots are not present in a homogeneous model. Addressing one source of heterogeneity in the axon cytoskeleton, we present a new semiautomated image analysis pipeline for using serial-section transmission electron micrographs to reconstruct the microtubule geometry of an axon. The image analysis procedure locates microtubules within the images, traces them throughout the image stack, and reconstructs the microtubule structure as a finite element mesh. We demonstrate the image analysis approach using a C. elegans touch receptor neuron due to the availability of high-quality serial-section transmission electron micrograph data sets. The results of the analysis highlight the heterogeneity of the microtubule structure in the spatial variation of both microtubule number and length. Simulations comparing this image-based geometry with homogeneous geometries show that structural heterogeneity in the image-based model creates significant spatial variation in deformation. The homogeneous geometries, on the other hand, deform more uniformly. Since no single homogeneous model can replicate the mechanical behavior of the image-based model, our results argue that heterogeneity in axon microtubule geometry should be considered in determining accurate axon failure thresholds.
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Affiliation(s)
- Lucy M Wang
- Department of Mechanical Engineering, Stanford University, Stanford, California.
| | - Miriam B Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California
| | - Ellen Kuhl
- Department of Mechanical Engineering, Stanford University, Stanford, California
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20
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Ghisleni A, Bonilla-Quintana M, Crestani M, Fukuzawa A, Rangamani P, Gauthier N. Mechanically induced topological transition of spectrin regulates its distribution in the mammalian cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.02.522381. [PMID: 36712133 PMCID: PMC9881866 DOI: 10.1101/2023.01.02.522381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The cell cortex is a dynamic assembly that ensures cell integrity during passive deformation or active response by adapting cytoskeleton topologies with poorly understood mechanisms. The spectrin meshwork ensures such adaptation in erythrocytes and neurons. Erythrocytes rely on triangular-like lattices of spectrin tetramers, which in neurons are organized in periodic arrays. We exploited Expansion Microscopy to discover that these two distinct topologies can co-exist in other mammalian cells such as fibroblasts. We show through biophysical measurements and computational modeling that spectrin provides coverage of the cortex and, with the intervention of actomyosin, erythroid-like lattices can dynamically transition into condensates resembling neuron-like periodic arrays fenced by actin stress fibers. Spectrin condensates experience lower mechanical stress and turnover despite displaying an extension close to the contour length of the tetramer. Our study sheds light on the adaptive properties of spectrin, which ensures protection of the cortex by undergoing mechanically induced topological transitions.
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21
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Falconieri A, De Vincentiis S, Cappello V, Convertino D, Das R, Ghignoli S, Figoli S, Luin S, Català-Castro F, Marchetti L, Borello U, Krieg M, Raffa V. Axonal plasticity in response to active forces generated through magnetic nano-pulling. Cell Rep 2022; 42:111912. [PMID: 36640304 PMCID: PMC9902337 DOI: 10.1016/j.celrep.2022.111912] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 11/16/2022] [Accepted: 12/12/2022] [Indexed: 12/30/2022] Open
Abstract
Mechanical force is crucial in guiding axon outgrowth before and after synapse formation. This process is referred to as "stretch growth." However, how neurons transduce mechanical input into signaling pathways remains poorly understood. Another open question is how stretch growth is coupled in time with the intercalated addition of new mass along the entire axon. Here, we demonstrate that active mechanical force generated by magnetic nano-pulling induces remodeling of the axonal cytoskeleton. Specifically, the increase in the axonal density of microtubules induced by nano-pulling leads to an accumulation of organelles and signaling vesicles, which, in turn, promotes local translation by increasing the probability of assembly of the "translation factories." Modulation of axonal transport and local translation sustains enhanced axon outgrowth and synapse maturation.
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Affiliation(s)
| | - Sara De Vincentiis
- Department of Biology, Università di Pisa, 56127 Pisa, Italy,The Barcelona Institute of Science and Technology, Institut de Ciències Fotòniques, ICFO, 08860 Castelldefels, Spain
| | - Valentina Cappello
- Center for Materials Interfaces, Istituto Italiano di Tecnologia, 56025 Pontedera, Italy
| | - Domenica Convertino
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, 56127 Pisa, Italy
| | - Ravi Das
- The Barcelona Institute of Science and Technology, Institut de Ciències Fotòniques, ICFO, 08860 Castelldefels, Spain
| | | | - Sofia Figoli
- Department of Biology, Università di Pisa, 56127 Pisa, Italy
| | - Stefano Luin
- National Enterprise for NanoScience and NanoTechnology (NEST) Laboratory, Scuola Normale Superiore, 56127 Pisa, Italy
| | - Frederic Català-Castro
- The Barcelona Institute of Science and Technology, Institut de Ciències Fotòniques, ICFO, 08860 Castelldefels, Spain
| | - Laura Marchetti
- Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, 56127 Pisa, Italy,Department of Pharmacy, Università di Pisa, 56126 Pisa, Italy
| | - Ugo Borello
- Department of Biology, Università di Pisa, 56127 Pisa, Italy
| | - Michael Krieg
- The Barcelona Institute of Science and Technology, Institut de Ciències Fotòniques, ICFO, 08860 Castelldefels, Spain
| | - Vittoria Raffa
- Department of Biology, Università di Pisa, 56127 Pisa, Italy.
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22
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Synaptic branch stability is mediated by non-enzymatic functions of MEC-17/αTAT1 and ATAT-2. Sci Rep 2022; 12:14003. [PMID: 35977998 PMCID: PMC9385713 DOI: 10.1038/s41598-022-18333-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/09/2022] [Indexed: 11/08/2022] Open
Abstract
Microtubules are fundamental elements of neuronal structure and function. They are dynamic structures formed from protofilament chains of α- and β-tubulin heterodimers. Acetylation of the lysine 40 (K40) residue of α-tubulin protects microtubules from mechanical stresses by imparting structural elasticity. The enzyme responsible for this acetylation event is MEC-17/αTAT1. Despite its functional importance, however, the consequences of altered MEC-17/αTAT1 levels on neuronal structure and function are incompletely defined. Here we demonstrate that overexpression or loss of MEC-17, or of its functional paralogue ATAT-2, causes a delay in synaptic branch extension, and defective synaptogenesis in the mechanosensory neurons of Caenorhabditis elegans. Strikingly, by adulthood, the synaptic branches in these animals are lost, while the main axon shaft remains mostly intact. We show that MEC-17 and ATAT-2 regulate the stability of the synaptic branches largely independently from their acetyltransferase domains. Genetic analyses reveals novel interactions between both mec-17 and atat-2 with the focal adhesion gene zyx-1/Zyxin, which has previously been implicated in actin remodelling. Together, our results reveal new, acetylation-independent roles for MEC-17 and ATAT-2 in the development and maintenance of neuronal architecture.
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23
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Leterrier C, Pullarkat PA. Mechanical role of the submembrane spectrin scaffold in red blood cells and neurons. J Cell Sci 2022; 135:276327. [PMID: 35972759 DOI: 10.1242/jcs.259356] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spectrins are large, evolutionarily well-conserved proteins that form highly organized scaffolds on the inner surface of eukaryotic cells. Their organization in different cell types or cellular compartments helps cells withstand mechanical challenges with unique strategies depending on the cell type. This Review discusses our understanding of the mechanical properties of spectrins, their very distinct organization in red blood cells and neurons as two examples, and the contribution of the scaffolds they form to the mechanical properties of these cells.
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Affiliation(s)
- Christophe Leterrier
- Aix Marseille Université, CNRS, INP UMR 7051, NeuroCyto, Marseille 13005, France
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24
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Mechanosensitive body–brain interactions in Caenorhabditis elegans. Curr Opin Neurobiol 2022; 75:102574. [DOI: 10.1016/j.conb.2022.102574] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 03/30/2022] [Accepted: 05/06/2022] [Indexed: 12/13/2022]
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25
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Shah P, Bao Z, Zaidel-Bar R. Visualizing and quantifying molecular and cellular processes in C. elegans using light microscopy. Genetics 2022; 221:6619563. [PMID: 35766819 DOI: 10.1093/genetics/iyac068] [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: 12/11/2021] [Accepted: 04/14/2022] [Indexed: 11/14/2022] Open
Abstract
Light microscopes are the cell and developmental biologists' "best friend", providing a means to see structures and follow dynamics from the protein to the organism level. A huge advantage of C. elegans as a model organism is its transparency, which coupled with its small size means that nearly every biological process can be observed and measured with the appropriate probe and light microscope. Continuous improvement in microscope technologies along with novel genome editing techniques to create transgenic probes have facilitated the development and implementation of a dizzying array of methods for imaging worm embryos, larvae and adults. In this review we provide an overview of the molecular and cellular processes that can be visualized in living worms using light microscopy. A partial inventory of fluorescent probes and techniques successfully used in worms to image the dynamics of cells, organelles, DNA, and protein localization and activity is followed by a practical guide to choosing between various imaging modalities, including widefield, confocal, lightsheet, and structured illumination microscopy. Finally, we discuss the available tools and approaches, including machine learning, for quantitative image analysis tasks, such as colocalization, segmentation, object tracking, and lineage tracing. Hopefully, this review will inspire worm researchers who have not yet imaged their worms to begin, and push those who are imaging to go faster, finer, and longer.
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Affiliation(s)
- Pavak Shah
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles 90095, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Ronen Zaidel-Bar
- Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
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26
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Zhou R, Han B, Nowak R, Lu Y, Heller E, Xia C, Chishti AH, Fowler VM, Zhuang X. Proteomic and functional analyses of the periodic membrane skeleton in neurons. Nat Commun 2022; 13:3196. [PMID: 35680881 PMCID: PMC9184744 DOI: 10.1038/s41467-022-30720-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 05/09/2022] [Indexed: 12/29/2022] Open
Abstract
Actin, spectrin, and associated molecules form a membrane-associated periodic skeleton (MPS) in neurons. The molecular composition and functions of the MPS remain incompletely understood. Here, using co-immunoprecipitation and mass spectrometry, we identified hundreds of potential candidate MPS-interacting proteins that span diverse functional categories. We examined representative proteins in several of these categories using super-resolution imaging, including previously unknown MPS structural components, as well as motor proteins, cell adhesion molecules, ion channels, and signaling proteins, and observed periodic distributions characteristic of the MPS along the neurites for ~20 proteins. Genetic perturbations of the MPS and its interacting proteins further suggested functional roles of the MPS in axon-axon and axon-dendrite interactions and in axon diameter regulation, and implicated the involvement of MPS interactions with cell adhesion molecules and non-muscle myosin in these roles. These results provide insights into the interactome of the MPS and suggest previously unknown functions of the MPS in neurons.
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Affiliation(s)
- Ruobo Zhou
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, 02138, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA.
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Boran Han
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - Roberta Nowak
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92307, USA
| | - Yunzhe Lu
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Evan Heller
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - Chenglong Xia
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - Athar H Chishti
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Velia M Fowler
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92307, USA
- Department of Biological Sciences, The University of Delaware, Newark, DE, 19716, USA
| | - Xiaowei Zhuang
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, 02138, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA.
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27
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Bonacossa-Pereira I, Coakley S, Hilliard MA. Neuron-epidermal attachment protects hyper-fragile axons from mechanical strain. Cell Rep 2022; 38:110501. [PMID: 35263583 DOI: 10.1016/j.celrep.2022.110501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 12/06/2021] [Accepted: 02/15/2022] [Indexed: 11/03/2022] Open
Abstract
Axons experience significant strain caused by organismal development and movement. A combination of intrinsic mechanical resistance and external shielding by surrounding tissues prevents axonal damage, although the precise mechanisms are unknown. Here, we reveal a neuroprotective function of neuron-epidermal attachment in Caenorhabditis elegans. We show that a gain-of-function mutation in the epidermal hemidesmosome component LET-805/myotactin, in combination with a loss-of-function mutation in UNC-70/β-spectrin, disrupts the uniform attachment and subsequent embedment of sensory axons within the epidermis during development. This generates regions of high tension within axons, leading to spontaneous axonal breaks and degeneration. Completely preventing attachment, by disrupting HIM-4/hemicentin or MEC-5/collagen, eliminates tension and alleviates damage. Finally, we demonstrate that progressive neuron-epidermal attachment via LET-805/myotactin is induced by the axon during development, as well as during regeneration after injury. Together, these results reveal that establishment of uniform neuron-epidermal attachment is critical to protect axons from mechanical strain during development.
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Affiliation(s)
- Igor Bonacossa-Pereira
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Sean Coakley
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Massimo A Hilliard
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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28
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Sun W, Gao X, Lei H, Wang W, Cao Y. Biophysical Approaches for Applying and Measuring Biological Forces. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105254. [PMID: 34923777 PMCID: PMC8844594 DOI: 10.1002/advs.202105254] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 05/13/2023]
Abstract
Over the past decades, increasing evidence has indicated that mechanical loads can regulate the morphogenesis, proliferation, migration, and apoptosis of living cells. Investigations of how cells sense mechanical stimuli or the mechanotransduction mechanism is an active field of biomaterials and biophysics. Gaining a further understanding of mechanical regulation and depicting the mechanotransduction network inside cells require advanced experimental techniques and new theories. In this review, the fundamental principles of various experimental approaches that have been developed to characterize various types and magnitudes of forces experienced at the cellular and subcellular levels are summarized. The broad applications of these techniques are introduced with an emphasis on the difficulties in implementing these techniques in special biological systems. The advantages and disadvantages of each technique are discussed, which can guide readers to choose the most suitable technique for their questions. A perspective on future directions in this field is also provided. It is anticipated that technical advancement can be a driving force for the development of mechanobiology.
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Affiliation(s)
- Wenxu Sun
- School of SciencesNantong UniversityNantong226019P. R. China
| | - Xiang Gao
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
| | - Hai Lei
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
- Chemistry and Biomedicine Innovation CenterNanjing UniversityNanjing210023P. R. China
| | - Wei Wang
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
| | - Yi Cao
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
- MOE Key Laboratory of High Performance Polymer Materials and TechnologyDepartment of Polymer Science & EngineeringCollege of Chemistry & Chemical EngineeringNanjing UniversityNanjing210023P. R. China
- Chemistry and Biomedicine Innovation CenterNanjing UniversityNanjing210023P. R. China
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29
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JIP3 links lysosome transport to regulation of multiple components of the axonal cytoskeleton. Commun Biol 2022; 5:5. [PMID: 35013510 PMCID: PMC8748971 DOI: 10.1038/s42003-021-02945-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 12/02/2021] [Indexed: 12/11/2022] Open
Abstract
Lysosome axonal transport is important for the clearance of cargoes sequestered by the endocytic and autophagic pathways. Building on observations that mutations in the JIP3 (MAPK8IP3) gene result in lysosome-filled axonal swellings, we analyzed the impact of JIP3 depletion on the cytoskeleton of human neurons. Dynamic focal lysosome accumulations were accompanied by disruption of the axonal periodic scaffold (spectrin, F-actin and myosin II) throughout each affected axon. Additionally, axonal microtubule organization was locally disrupted at each lysosome-filled swelling. This local axonal microtubule disorganization was accompanied by accumulations of both F-actin and myosin II. These results indicate that transport of axonal lysosomes is functionally interconnected with mechanisms that control the organization and maintenance of the axonal cytoskeleton. They have potential relevance to human neurological disease arising from JIP3 mutations as well as for neurodegenerative diseases associated with the focal accumulations of lysosomes within axonal swellings such as Alzheimer’s disease. Rafiq et al. report that disruption of JIP3-dependent control of axonal lysosome transport in human neurons results in unexpected changes to the organization of multiple cytoskeletal proteins. This study provides new insights that improve our understanding of intellectual disabilities caused by mutations in JIP3, and are relevant for neurodegenerative diseases associated with accumulations of lysosomes such as the Alzheimer’s disease
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30
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Sobral AF, Chan FY, Norman MJ, Osório DS, Dias AB, Ferreira V, Barbosa DJ, Cheerambathur D, Gassmann R, Belmonte JM, Carvalho AX. Plastin and spectrin cooperate to stabilize the actomyosin cortex during cytokinesis. Curr Biol 2021; 31:5415-5428.e10. [PMID: 34666005 PMCID: PMC8699742 DOI: 10.1016/j.cub.2021.09.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/22/2021] [Accepted: 09/21/2021] [Indexed: 11/16/2022]
Abstract
Cytokinesis, the process that partitions the mother cell into two daughter cells, requires the assembly and constriction of an equatorial actomyosin network. Different types of non-motor F-actin crosslinkers localize to the network, but their functional contribution remains poorly understood. Here, we describe a synergy between the small rigid crosslinker plastin and the large flexible crosslinker spectrin in the C. elegans one-cell embryo. In contrast to single inhibitions, co-inhibition of plastin and the βH-spectrin (SMA-1) results in cytokinesis failure due to progressive disorganization and eventual collapse of the equatorial actomyosin network. Cortical localization dynamics of non-muscle myosin II in co-inhibited embryos mimic those observed after drug-induced F-actin depolymerization, suggesting that the combined action of plastin and spectrin stabilizes F-actin in the contractile ring. An in silico model predicts that spectrin is more efficient than plastin at stabilizing the ring and that ring formation is relatively insensitive to βH-spectrin length, which is confirmed in vivo with a sma-1 mutant that lacks 11 of its 29 spectrin repeats. Our findings provide the first evidence that spectrin contributes to cytokinesis and highlight the importance of crosslinker interplay for actomyosin network integrity.
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Affiliation(s)
- Ana Filipa Sobral
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Fung-Yi Chan
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Michael J Norman
- Department of Physics, North Carolina State University, Raleigh, NC 27695, USA; Quantitative and Computational Developmental Biology Cluster, North Carolina State University, Raleigh, NC 27695, USA
| | - Daniel S Osório
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana Beatriz Dias
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Vanessa Ferreira
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Daniel J Barbosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Dhanya Cheerambathur
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Reto Gassmann
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Julio Monti Belmonte
- Department of Physics, North Carolina State University, Raleigh, NC 27695, USA; Quantitative and Computational Developmental Biology Cluster, North Carolina State University, Raleigh, NC 27695, USA
| | - Ana Xavier Carvalho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
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31
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Pan J, Kmieciak T, Liu YT, Wildenradt M, Chen YS, Zhao Y. Quantifying molecular- to cellular-level forces in living cells. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2021; 54:483001. [PMID: 34866655 PMCID: PMC8635116 DOI: 10.1088/1361-6463/ac2170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mechanical cues have been suggested to play an important role in cell functions and cell fate determination, however, such physical quantities are challenging to directly measure in living cells with single molecule sensitivity and resolution. In this review, we focus on two main technologies that are promising in probing forces at the single molecule level. We review their theoretical fundamentals, recent technical advancements, and future directions, tailored specifically for interrogating mechanosensitive molecules in live cells.
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Affiliation(s)
- Jason Pan
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Tommy Kmieciak
- Department of Engineering Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Yen-Ting Liu
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Matthew Wildenradt
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Yun-Sheng Chen
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Yang Zhao
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, 208 N. Wright Street, Urbana, IL 61801, United States of America
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32
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Das R, Lin LC, Català-Castro F, Malaiwong N, Sanfeliu-Cerdán N, Porta-de-la-Riva M, Pidde A, Krieg M. An asymmetric mechanical code ciphers curvature-dependent proprioceptor activity. SCIENCE ADVANCES 2021; 7:eabg4617. [PMID: 34533987 PMCID: PMC8448456 DOI: 10.1126/sciadv.abg4617] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 07/27/2021] [Indexed: 05/07/2023]
Abstract
A repetitive gait cycle is an archetypical component within the behavioral repertoire of many animals including humans. It originates from mechanical feedback within proprioceptors to adjust the motor program during locomotion and thus leads to a periodic orbit in a low-dimensional space. Here, we investigate the mechanics, molecules, and neurons responsible for proprioception in Caenorhabditis elegans to gain insight into how mechanosensation shapes the orbital trajectory to a well-defined limit cycle. We used genome editing, force spectroscopy, and multiscale modeling and found that alternating tension and compression with the spectrin network of a single proprioceptor encodes body posture and informs TRP-4/NOMPC and TWK-16/TREK2 homologs of mechanosensitive ion channels during locomotion. In contrast to a widely accepted model of proprioceptive “stretch” reception, we found that proprioceptors activated locally under compressive stresses in-vivo and in-vitro and propose that this property leads to compartmentalized activity within long axons delimited by curvature-dependent mechanical stresses.
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33
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Modeling links softening of myelin and spectrin scaffolds of axons after a concussion to increased vulnerability to repeated injuries. Proc Natl Acad Sci U S A 2021; 118:2024961118. [PMID: 34234016 DOI: 10.1073/pnas.2024961118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Damage to the microtubule lattice, which serves as a rigid cytoskeletal backbone for the axon, is a hallmark mechanical initiator of pathophysiology after concussion. Understanding the mechanical stress transfer from the brain tissue to the axonal cytoskeleton is essential to determine the microtubule lattice's vulnerability to mechanical injury. Here, we develop an ultrastructural model of the axon's cytoskeletal architecture to identify the components involved in the dynamic load transfer during injury. Corroborative in vivo studies were performed using a gyrencephalic swine model of concussion via single and repetitive head rotational acceleration. Computational analysis of the load transfer mechanism demonstrates that the myelin sheath and the actin/spectrin cortex play a significant role in effectively shielding the microtubules from tissue stress. We derive failure maps in the space spanned by tissue stress and stress rate to identify physiological conditions in which the microtubule lattice can rupture. We establish that a softer axonal cortex leads to a higher susceptibility of the microtubules to failure. Immunohistochemical examination of tissue from the swine model of single and repetitive concussion confirms the presence of postinjury spectrin degradation, with more extensive pathology observed following repetitive injury. Because the degradation of myelin and spectrin occurs over weeks following the first injury, we show that softening of the myelin layer and axonal cortex exposes the microtubules to higher stress during repeated incidences of traumatic brain injuries. Our predictions explain how mechanical injury predisposes axons to exacerbated responses to repeated injuries, as observed in vitro and in vivo.
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34
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Costa AR, Sousa MM. The role of the membrane-associated periodic skeleton in axons. Cell Mol Life Sci 2021; 78:5371-5379. [PMID: 34085116 PMCID: PMC11071922 DOI: 10.1007/s00018-021-03867-x] [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: 02/06/2021] [Revised: 05/14/2021] [Accepted: 05/27/2021] [Indexed: 11/24/2022]
Abstract
The identification of the membrane periodic skeleton (MPS), composed of a periodic lattice of actin rings interconnected by spectrin tetramers, was enabled by the development of super-resolution microscopy, and brought a new exciting perspective to our view of neuronal biology. This exquisite cytoskeleton arrangement plays an important role on mechanisms regulating neuronal (dys)function. The MPS was initially thought to provide mainly for axonal mechanical stability. Since its discovery, the importance of the MPS in multiple aspects of neuronal biology has, however, emerged. These comprise its capacity to act as a signaling platform, regulate axon diameter-with important consequences on the efficiency of axonal transport and electrophysiological properties- participate in the assembly and function of the axon initial segment, and control axon microtubule stability. Recently, MPS disassembly has also surfaced as an early player in the course of axon degeneration. Here, we will discuss the current knowledge on the role of the MPS in axonal physiology and disease.
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Affiliation(s)
- Ana Rita Costa
- Nerve Regeneration Group, IBMC- Instituto de Biologia Molecular e Celular and i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal
| | - Monica Mendes Sousa
- Nerve Regeneration Group, IBMC- Instituto de Biologia Molecular e Celular and i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal.
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35
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Lavrenyuk K, Conway D, Dahl KN. Imaging methods in mechanosensing: a historical perspective and visions for the future. Mol Biol Cell 2021; 32:842-854. [PMID: 33788578 PMCID: PMC8108522 DOI: 10.1091/mbc.e20-10-0671] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Over the past three decades, as mechanobiology has become a distinct area of study, researchers have developed novel imaging tools to discover the pathways of biomechanical signaling. Early work with substrate engineering and particle tracking demonstrated the importance of cell–extracellular matrix interactions on the cell cycle as well as the mechanical flux of the intracellular environment. Most recently, tension sensor approaches allowed directly measuring tension in cell–cell and cell–substrate interactions. We retrospectively analyze how these various optical techniques progressed the field and suggest our vision forward for a unified theory of cell mechanics, mapping cellular mechanosensing, and novel biomedical applications for mechanobiology.
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Affiliation(s)
- Kirill Lavrenyuk
- Carnegie Mellon University, College of Engineering, Pittsburgh, PA 15213
| | - Daniel Conway
- Virginia Commonwealth University, College of Engineering, Richmond, VA 23284
| | - Kris Noel Dahl
- Carnegie Mellon University, College of Engineering, Pittsburgh, PA 15213
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36
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Fischer LS, Rangarajan S, Sadhanasatish T, Grashoff C. Molecular Force Measurement with Tension Sensors. Annu Rev Biophys 2021; 50:595-616. [PMID: 33710908 DOI: 10.1146/annurev-biophys-101920-064756] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ability of cells to generate mechanical forces, but also to sense, adapt to, and respond to mechanical signals, is crucial for many developmental, postnatal homeostatic, and pathophysiological processes. However, the molecular mechanisms underlying cellular mechanotransduction have remained elusive for many decades, as techniques to visualize and quantify molecular forces across individual proteins in cells were missing. The development of genetically encoded molecular tension sensors now allows the quantification of piconewton-scale forces that act upon distinct molecules in living cells and even whole organisms. In this review, we discuss the physical principles, advantages, and limitations of this increasingly popular method. By highlighting current examples from the literature, we demonstrate how molecular tension sensors can be utilized to obtain access to previously unappreciated biophysical parameters that define the propagation of mechanical forces on molecular scales. We discuss how the methodology can be further developed and provide a perspective on how the technique could be applied to uncover entirely novel aspects of mechanobiology in the future.
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Affiliation(s)
- Lisa S Fischer
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Srishti Rangarajan
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Tanmay Sadhanasatish
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
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37
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Wang C, Xia C, Zhu Y, Zhang H. Innovative fluorescent probes for in vivo visualization of biomolecules in living Caenorhabditis elegans. Cytometry A 2021; 99:560-574. [PMID: 33638604 DOI: 10.1002/cyto.a.24325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/02/2021] [Accepted: 02/15/2021] [Indexed: 12/16/2022]
Abstract
Caenorhabditis elegans (C. elegans) as a well-established multicellular model organism has been widely used in the biological field for half a century. Its numerous advantages including small body size, rapid life cycle, high-reproductive rate, well-defined anatomy, and conserved genome, has made C. elegans one of the most successful multicellular model organisms. Discoveries obtained from the C. elegans model have made great contributions to research fields such as development, aging, biophysics, immunology, and neuroscience. Because of its transparent body and giant cell size, C. elegans is also an ideal subject for high resolution and high-throughput optical imaging and analysis. During the past decade, great advances have been made to develop biomolecule-targeting techniques for noninvasive optical imaging. These novel technologies expanded the toolbox for qualitative and quantitative analysis of biomolecules in C. elegans. In this review, we summarize recently developed fluorescent probes or labeling techniques for visualizing biomolecules at the cellular, subcellular or molecular scale by using C. elegans as the major model organism or designed specifically for the applications in C. elegans. Combining the technological advantages of the C. elegans model with the novel fluorescent labeling techniques will provide new horizons for high-efficiency quantitative optical analysis in live organisms.
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Affiliation(s)
- Chunxia Wang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Chujie Xia
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Yi Zhu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Huimin Zhang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
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38
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Putting the axonal periodic scaffold in order. Curr Opin Neurobiol 2021; 69:33-40. [PMID: 33450534 DOI: 10.1016/j.conb.2020.12.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/01/2023]
Abstract
Neurons rely on a unique organization of their cytoskeleton to build, maintain and transform their extraordinarily intricate shapes. After decades of research on the neuronal cytoskeleton, it is exciting that novel assemblies are still discovered thanks to progress in cellular imaging methods. Indeed, super-resolution microscopy has revealed that axons are lined with a periodic scaffold of actin rings, spaced every 190nm by spectrins. Determining the architecture, composition, dynamics, and functions of this membrane-associated periodic scaffold is a current conceptual and technical challenge, as well as a very active area of research. This short review aims at summarizing the latest research on the axonal periodic scaffold, highlighting recent progress and open questions.
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39
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Kalichamy SS, Alcantara AV, Kim BS, Park J, Yoon KH, Lee JI. Muscle and epidermal contributions of the structural protein β-spectrin promote hypergravity-induced motor neuron axon defects in C. elegans. Sci Rep 2020; 10:21214. [PMID: 33273580 PMCID: PMC7713079 DOI: 10.1038/s41598-020-78414-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 11/23/2020] [Indexed: 11/09/2022] Open
Abstract
Biology is adapted to Earth's gravity force, and the long-term effects of varying gravity on the development of animals is unclear. Previously, we reported that high gravity, called hypergravity, increases defects in the development of motor neuron axons in the nematode Caenorhabditis elegans. Here, we show that a mutation in the unc-70 gene that encodes the cytoskeletal β-spectrin protein suppresses hypergravity-induced axon defects. UNC-70 expression is required in both muscle and epidermis to promote the axon defects in high gravity. We reveal that the location of axon defects is correlated to the size of the muscle cell that the axon traverses. We also show that mutations that compromise key proteins of hemidesmosomal structures suppress hypergravity-induced axon defects. These hemidesmosomal structures play a crucial role in coupling mechanical force between the muscle, epidermis and the external cuticle. We speculate a model in which the rigid organization of muscle, epidermal and cuticular layers under high gravity pressure compresses the narrow axon migration pathways in the extracellular matrix hindering proper axon pathfinding of motor neurons.
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Affiliation(s)
- Saraswathi S Kalichamy
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Mirae Campus 304, 1 Yonseidae-gil, Wonju, Gangwon-do, 26493, South Korea
| | - Alfredo V Alcantara
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Mirae Campus 304, 1 Yonseidae-gil, Wonju, Gangwon-do, 26493, South Korea
| | - Ban-Seok Kim
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Mirae Campus 304, 1 Yonseidae-gil, Wonju, Gangwon-do, 26493, South Korea
| | - Junsoo Park
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Mirae Campus 304, 1 Yonseidae-gil, Wonju, Gangwon-do, 26493, South Korea
| | - Kyoung-Hye Yoon
- Department of Physiology, Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Gangwon-do, 26426, South Korea.
| | - Jin I Lee
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Mirae Campus 304, 1 Yonseidae-gil, Wonju, Gangwon-do, 26493, South Korea.
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40
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Ferreira Castro A, Baltruschat L, Stürner T, Bahrami A, Jedlicka P, Tavosanis G, Cuntz H. Achieving functional neuronal dendrite structure through sequential stochastic growth and retraction. eLife 2020; 9:e60920. [PMID: 33241995 PMCID: PMC7837678 DOI: 10.7554/elife.60920] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/15/2020] [Indexed: 02/06/2023] Open
Abstract
Class I ventral posterior dendritic arborisation (c1vpda) proprioceptive sensory neurons respond to contractions in the Drosophila larval body wall during crawling. Their dendritic branches run along the direction of contraction, possibly a functional requirement to maximise membrane curvature during crawling contractions. Although the molecular machinery of dendritic patterning in c1vpda has been extensively studied, the process leading to the precise elaboration of their comb-like shapes remains elusive. Here, to link dendrite shape with its proprioceptive role, we performed long-term, non-invasive, in vivo time-lapse imaging of c1vpda embryonic and larval morphogenesis to reveal a sequence of differentiation stages. We combined computer models and dendritic branch dynamics tracking to propose that distinct sequential phases of stochastic growth and retraction achieve efficient dendritic trees both in terms of wire and function. Our study shows how dendrite growth balances structure-function requirements, shedding new light on general principles of self-organisation in functionally specialised dendrites.
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Affiliation(s)
- André Ferreira Castro
- Frankfurt Institute for Advanced StudiesFrankfurt am MainGermany
- Ernst Strüngmann Institute (ESI) for Neuroscience in cooperation with Max Planck SocietyFrankfurt am MainGermany
- Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | | | - Tomke Stürner
- Center for Neurodegenerative Diseases (DZNE)BonnGermany
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | | | - Peter Jedlicka
- Frankfurt Institute for Advanced StudiesFrankfurt am MainGermany
- Faculty of Medicine, ICAR3R – Interdisciplinary Centre for 3Rs in Animal Research, Justus Liebig University GiessenGiessenGermany
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe UniversityFrankfurt am MainGermany
| | - Gaia Tavosanis
- Center for Neurodegenerative Diseases (DZNE)BonnGermany
- LIMES Institute, University of BonnBonnGermany
| | - Hermann Cuntz
- Frankfurt Institute for Advanced StudiesFrankfurt am MainGermany
- Ernst Strüngmann Institute (ESI) for Neuroscience in cooperation with Max Planck SocietyFrankfurt am MainGermany
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Zhou H, Huang B, Qu K, Liu J, Zhang J, Lei C. The distribution of four missense mutations in SPTBN5 gene across native Chinese breeds. Anim Biotechnol 2020; 33:796-800. [PMID: 33063596 DOI: 10.1080/10495398.2020.1831521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Modern cattle belong to two subspecies, Bos taurus and Bos indicus. Since divergence, cattle types have accumulated different genetic variations, which have contributed to highly differentiated phenotypes. The mammalian inner ear possesses functional and morphological innovations that contribute to its unique hearing capacities. The spectrin beta, non-erythrocytic 5 (SPTBN5) gene has been shown to play an important function in the inner ear. Four missense mutations: rs522333459 (c.7232G > C:p.Cys2411Ser), rs718838405 (c.6568A > C:p.Met2190Leu), rs516536785 (c.6283C > T:p.Leu2095Phe) and rs480278206 (c.4201T > C:p.Cys1401Arg) were identified in the bovine SPTBN5 gene by whole genome resequencing (http://animal.nwsuaf.edu.cn/code/index.php/BosVar), which might be candidate mutations related with hearing of both taurine and indicine cattle. In our study, PCR and DNA sequencing were used to explore the allele frequencies of four mutations of 971 individuals belonging to 38 native Chinese cattle breeds. We find that four mutant alleles showing strong geographic distribution, consisting with the ancestry distribution of taurine and indicine in China. In addition, we identified four mutations of SPTBN5 were diverged in taurine and indicine cattle showing signatures of adaptive evolution in two subspecies, which might participate in bovine inner ear development.
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Affiliation(s)
- Hongchao Zhou
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Bizhi Huang
- Yunnan Academy of Grassland Animal Science, Kunming, China
| | - Kaixing Qu
- Yunnan Academy of Grassland Animal Science, Kunming, China
| | - Jianyong Liu
- Yunnan Academy of Grassland Animal Science, Kunming, China
| | - Jicai Zhang
- Yunnan Academy of Grassland Animal Science, Kunming, China
| | - Chuzhao Lei
- College of Animal Science and Technology, Northwest A&F University, Yangling, China
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Complementary mesoscale dynamics of spectrin and acto-myosin shape membrane territories during mechanoresponse. Nat Commun 2020; 11:5108. [PMID: 33037189 PMCID: PMC7547731 DOI: 10.1038/s41467-020-18825-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 09/11/2020] [Indexed: 11/08/2022] Open
Abstract
The spectrin-based membrane skeleton is a major component of the cell cortex. While expressed by all metazoans, its dynamic interactions with the other cortex components, including the plasma membrane or the acto-myosin cytoskeleton, are poorly understood. Here, we investigate how spectrin re-organizes spatially and dynamically under the membrane during changes in cell mechanics. We find spectrin and acto-myosin to be spatially distinct but cooperating during mechanical challenges, such as cell adhesion and contraction, or compression, stretch and osmolarity fluctuations, creating a cohesive cortex supporting the plasma membrane. Actin territories control protrusions and contractile structures while spectrin territories concentrate in retractile zones and low-actin density/inter-contractile regions, acting as a fence that organize membrane trafficking events. We unveil here the existence of a dynamic interplay between acto-myosin and spectrin necessary to support a mesoscale organization of the lipid bilayer into spatially-confined cortical territories during cell mechanoresponse.
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43
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Applications of atomic force microscopy in immunology. Front Med 2020; 15:43-52. [PMID: 32820379 DOI: 10.1007/s11684-020-0769-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/04/2020] [Indexed: 01/20/2023]
Abstract
Cellular mechanics, a major regulating factor of cellular architecture and biological functions, responds to intrinsic stresses and extrinsic forces exerted by other cells and the extracellular matrix in the microenvironment. Cellular mechanics also acts as a fundamental mediator in complicated immune responses, such as cell migration, immune cell activation, and pathogen clearance. The principle of atomic force microscopy (AFM) and its three running modes are introduced for the mechanical characterization of living cells. The peak force tapping mode provides the most delicate and desirable virtues to collect high-resolution images of morphology and force curves. For a concrete description of AFM capabilities, three AFM applications are discussed. These applications include the dynamic progress of a neutrophil-extracellular-trap release by neutrophils, the immunological functions of macrophages, and the membrane pore formation mediated by perforin, streptolysin O, gasdermin D, or membrane attack complex.
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Hassan A, Sapir L, Nitsan I, Greenblatt Ben-El RT, Halachmi N, Salzberg A, Tzlil S. A Change in ECM Composition Affects Sensory Organ Mechanics and Function. Cell Rep 2020; 27:2272-2280.e4. [PMID: 31116974 DOI: 10.1016/j.celrep.2019.04.092] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 02/12/2019] [Accepted: 04/18/2019] [Indexed: 11/26/2022] Open
Abstract
Proprioception requires the transduction of muscle-generated deformations into sensory neuronal impulses. In proprioceptive organs, the mechanical coupling between the sensory neuron and the muscle is mediated by a connective structure composed of accessory cells and an extracellular matrix (ECM). Here, we use the fly chordotonal organ (ChO) to investigate how the mechanical properties of the connective element affect mechanosensing. We show that the loss of Pericardin, a major constituent of the ChO ECM, alters the mechanical properties of the ChO resulting in short-wavelength buckling of the accessory cells upon muscle contraction and low compressive strain within the organ. We explain these results using a simplified theoretical model of an elastic beam interacting with an elastic network under a compressive force. We further demonstrate that the transition from compression to bending interferes with the ability of the accessory cells to propagate muscle-generated deformations correctly to the neuron and hence with proper sensing.
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Affiliation(s)
- Abeer Hassan
- Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Liel Sapir
- Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Ido Nitsan
- Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Rina T Greenblatt Ben-El
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa 3109601, Israel
| | - Naomi Halachmi
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa 3109601, Israel
| | - Adi Salzberg
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa 3109601, Israel
| | - Shelly Tzlil
- Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
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Abstract
The brain is our most complex organ. During development, neurons extend axons, which may grow over long distances along well-defined pathways to connect to distant targets. Our current understanding of axon pathfinding is largely based on chemical signaling by attractive and repulsive guidance cues. These cues instruct motile growth cones, the leading tips of growing axons, where to turn and where to stop. However, it is not chemical signals that cause motion-motion is driven by forces. Yet our current understanding of the mechanical regulation of axon growth is very limited. In this review, I discuss the origin of the cellular forces controlling axon growth and pathfinding, and how mechanical signals encountered by growing axons may be integrated with chemical signals. This mechanochemical cross talk is an important but often overlooked aspect of cell motility that has major implications for many physiological and pathological processes involving neuronal growth.
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Affiliation(s)
- Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom;
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Nekimken AL, Pruitt BL, Goodman MB. Touch-induced mechanical strain in somatosensory neurons is independent of extracellular matrix mutations in Caenorhabditis elegans. Mol Biol Cell 2020; 31:1735-1743. [PMID: 32579427 PMCID: PMC7521855 DOI: 10.1091/mbc.e20-01-0049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cutaneous mechanosensory neurons are activated by mechanical loads applied to the skin, and these stimuli are proposed to generate mechanical strain within sensory neurons. Using a microfluidic device to deliver controlled stimuli to intact animals and large, immobile, and fluorescent protein-tagged mitochondria as fiducial markers in the touch receptor neurons (TRNs), we visualized and measured touch-induced mechanical strain in Caenorhabditis elegans worms. At steady state, touch stimuli sufficient to activate TRNs induce an average strain of 3.1% at the center of the actuator and this strain decays to near zero at the edges of the actuator. We also measured strain in animals carrying mutations affecting links between the extracellular matrix (ECM) and the TRNs but could not detect any differences in touch-induced mechanical strain between wild-type and mutant animals. Collectively, these results demonstrate that touching the skin induces local mechanical strain in intact animals and suggest that a fully intact ECM is not essential for transmitting mechanical strain from the skin to cutaneous mechanosensory neurons.
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Affiliation(s)
- Adam L Nekimken
- Departments of Mechanical Engineering, Stanford University, Stanford, CA 94305.,Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
| | - Beth L Pruitt
- Departments of Mechanical Engineering, Stanford University, Stanford, CA 94305.,Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305.,Mechanical Engineering and Biomolecular Science and Engineering, University of California, Santa Barbara, CA 93106
| | - Miriam B Goodman
- Departments of Mechanical Engineering, Stanford University, Stanford, CA 94305.,Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
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48
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Li X, Wang J. Mechanical tumor microenvironment and transduction: cytoskeleton mediates cancer cell invasion and metastasis. Int J Biol Sci 2020; 16:2014-2028. [PMID: 32549750 PMCID: PMC7294938 DOI: 10.7150/ijbs.44943] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/15/2020] [Indexed: 12/13/2022] Open
Abstract
Metastasis is a complicated, multistep process that is responsible for over 90% of cancer-related death. Metastatic disease or the movement of cancer cells from one site to another requires dramatic remodeling of the cytoskeleton. The regulation of cancer cell migration is determined not only by biochemical factors in the microenvironment but also by the biomechanical contextual information provided by the extracellular matrix (ECM). The responses of the cytoskeleton to chemical signals are well characterized and understood. However, the mechanisms of response to mechanical signals in the form of externally applied force and forces generated by the ECM are still poorly understood. Furthermore, understanding the way cellular mechanosensors interact with the physical properties of the microenvironment and transmit the signals to activate the cytoskeletal movements may help identify an effective strategy for the treatment of cancer. Here, we will discuss the role of tumor microenvironment during cancer metastasis and how physical forces remodel the cytoskeleton through mechanosensing and transduction.
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Affiliation(s)
- Xingchen Li
- Department of Obstetrics and Gynecology, Peking University People's Hospital, Beijing, 100044, China
| | - Jianliu Wang
- Department of Obstetrics and Gynecology, Peking University People's Hospital, Beijing, 100044, China
- Beijing Key Laboratory of Female Pelvic Floor Disorders Diseases, Beijing, 100044, China
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49
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Dubey S, Bhembre N, Bodas S, Veer S, Ghose A, Callan-Jones A, Pullarkat P. The axonal actin-spectrin lattice acts as a tension buffering shock absorber. eLife 2020; 9:51772. [PMID: 32267230 PMCID: PMC7190353 DOI: 10.7554/elife.51772] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 04/06/2020] [Indexed: 12/11/2022] Open
Abstract
Axons span extreme distances and are subject to significant stretch deformations during limb movements or sudden head movements, especially during impacts. Yet, axon biomechanics, and its relation to the ultrastructure that allows axons to withstand mechanical stress, is poorly understood. Using a custom developed force apparatus, we demonstrate that chick dorsal root ganglion axons exhibit a tension buffering or strain-softening response, where its steady state elastic modulus decreases with increasing strain. We then explore the contributions from the various cytoskeletal components of the axon to show that the recently discovered membrane-associated actin-spectrin scaffold plays a prominent mechanical role. Finally, using a theoretical model, we argue that the actin-spectrin skeleton acts as an axonal tension buffer by reversibly unfolding repeat domains of the spectrin tetramers to release excess mechanical stress. Our results revise the current viewpoint that microtubules and their associated proteins are the only significant load-bearing elements in axons.
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Affiliation(s)
| | | | - Shivani Bodas
- Indian Institute of Science Education and Research, Pune, India
| | - Sukh Veer
- Raman Research Institute, Bangalore, India
| | - Aurnab Ghose
- Indian Institute of Science Education and Research, Pune, India
| | - Andrew Callan-Jones
- Laboratory of Complex Materials Systems, Paris Diderot University, Paris, France
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50
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Venkatesh K, Mathew A, Koushika SP. Role of actin in organelle trafficking in neurons. Cytoskeleton (Hoboken) 2020; 77:97-109. [DOI: 10.1002/cm.21580] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/14/2019] [Accepted: 11/05/2019] [Indexed: 01/29/2023]
Affiliation(s)
- Keertana Venkatesh
- Department of Biological SciencesTata Institute of Fundamental Research Mumbai India
| | - Amal Mathew
- Department of Biological SciencesTata Institute of Fundamental Research Mumbai India
| | - Sandhya P. Koushika
- Department of Biological SciencesTata Institute of Fundamental Research Mumbai India
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