1
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Cifuentes LP, Athamneh AIM, Efremov Y, Raman A, Kim T, Suter DM. A modified motor-clutch model reveals that neuronal growth cones respond faster to soft substrates. Mol Biol Cell 2024; 35:ar47. [PMID: 38354034 PMCID: PMC11064671 DOI: 10.1091/mbc.e23-09-0364] [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: 09/13/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/27/2024] Open
Abstract
Neuronal growth cones sense a variety of cues including chemical and mechanical ones to establish functional connections during nervous system development. Substrate-cytoskeletal coupling is an established model for adhesion-mediated growth cone advance; however, the detailed molecular and biophysical mechanisms underlying the mechanosensing and mechanotransduction process remain unclear. Here, we adapted a motor-clutch model to better understand the changes in clutch and cytoskeletal dynamics, traction forces, and substrate deformation when a growth cone interacts with adhesive substrates of different stiffnesses. Model parameters were optimized using experimental data from Aplysia growth cones probed with force-calibrated glass microneedles. We included a reinforcement mechanism at both motor and clutch level. Furthermore, we added a threshold for retrograde F-actin flow that indicates when the growth cone is strongly coupled to the substrate. Our modeling results are in strong agreement with experimental data with respect to the substrate deformation and the latency time after which substrate-cytoskeletal coupling is strong enough for the growth cone to advance. Our simulations show that it takes the shortest time to achieve strong coupling when substrate stiffness was low at 4 pN/nm. Taken together, these results suggest that Aplysia growth cones respond faster and more efficiently to soft than stiff substrates.
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Affiliation(s)
| | | | - Yuri Efremov
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907
- Institute for Regenerative Medicine, Sechenov University, Moscow 119991, Russia
| | - Arvind Raman
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907
| | - Taeyoon Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907
| | - Daniel M. Suter
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907
- Purdue Institute for Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47907
- Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907
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2
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Gui J, Zhou H, Wan H, Yang D, Liu Q, Zhu L, Mi Y. The Role of Vasodilator-stimulated Phosphoproteins in the Development of Malignant Tumors. Curr Cancer Drug Targets 2024; 24:477-489. [PMID: 37962042 PMCID: PMC11092557 DOI: 10.2174/0115680096262439231023110106] [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: 05/15/2023] [Revised: 08/06/2023] [Accepted: 09/06/2023] [Indexed: 11/15/2023]
Abstract
Vasodilator-stimulated phosphoprotein (VASP) is an actin-binding protein that includes three structural domains: Enabled/VASP homolog1 (EVH1), EVH2, and proline-rich (PRR). VASP plays an important role in various cellular behaviors related to cytoskeletal regulation. More importantly, VASP plays a key role in the progression of several malignant tumors and is associated with malignant cell proliferation, invasion, and metastasis. Here, we have summarized current studies on the impact of VASP on the development of several malignant tumors and their mechanisms. This study provides a new theoretical basis for clinical molecular diagnosis and molecular targeted therapy.
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Affiliation(s)
- Jiandong Gui
- Wuxi School of Medicine, Jiangnan University, 1800 Lihudadao, Wuxi, 214122, Jiangsu Province, China
- Department of Urology, Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214122, Jiangsu Province, China
| | - Hangsheng Zhou
- Wuxi School of Medicine, Jiangnan University, 1800 Lihudadao, Wuxi, 214122, Jiangsu Province, China
- Department of Urology, Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214122, Jiangsu Province, China
| | - Hongyuan Wan
- Wuxi School of Medicine, Jiangnan University, 1800 Lihudadao, Wuxi, 214122, Jiangsu Province, China
- Department of Urology, Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214122, Jiangsu Province, China
| | - Dongjie Yang
- Department of Urology, Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214122, Jiangsu Province, China
| | - Qing Liu
- Department of Urology, Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214122, Jiangsu Province, China
- Huadong Sanatorium, 67 Dajishan, Wuxi 214122, Jiangsu Province, China
| | - Lijie Zhu
- Department of Urology, Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214122, Jiangsu Province, China
| | - Yuanyuan Mi
- Department of Urology, Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214122, Jiangsu Province, China
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3
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Atkins M, Nicol X, Fassier C. Microtubule remodelling as a driving force of axon guidance and pruning. Semin Cell Dev Biol 2023; 140:35-53. [PMID: 35710759 DOI: 10.1016/j.semcdb.2022.05.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/26/2022] [Accepted: 05/31/2022] [Indexed: 01/28/2023]
Abstract
The establishment of neuronal connectivity relies on the microtubule (MT) cytoskeleton, which provides mechanical support, roads for axonal transport and mediates signalling events. Fine-tuned spatiotemporal regulation of MT functions by tubulin post-translational modifications and MT-associated proteins is critical for the coarse wiring and subsequent refinement of neuronal connectivity. The defective regulation of these processes causes a wide range of neurodevelopmental disorders associated with connectivity defects. This review focuses on recent studies unravelling how MT composition, post-translational modifications and associated proteins influence MT functions in axon guidance and/or pruning to build functional neuronal circuits. We here summarise experimental evidence supporting the key role of this network as a driving force for growth cone steering and branch-specific axon elimination. We further provide a global overview of the MT-interactors that tune developing axon behaviours, with a special emphasis on their emerging versatility in the regulation of MT dynamics/structure. Recent studies establishing the key and highly selective role of the tubulin code in the regulation of MT functions in axon pathfinding are also reported. Finally, our review highlights the emerging molecular links between these MT regulation processes and guidance signals that wire the nervous system.
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Affiliation(s)
- Melody Atkins
- INSERM, UMR-S 1270, Institut du Fer à Moulin, Sorbonne Université, F-75005 Paris, France
| | - Xavier Nicol
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, F-75012 Paris, France
| | - Coralie Fassier
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, F-75012 Paris, France.
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4
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Schneider F, Metz I, Rust MB. Regulation of actin filament assembly and disassembly in growth cone motility and axon guidance. Brain Res Bull 2023; 192:21-35. [PMID: 36336143 DOI: 10.1016/j.brainresbull.2022.10.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022]
Abstract
Directed outgrowth of axons is fundamental for the establishment of neuronal networks. Axon outgrowth is guided by growth cones, highly motile structures enriched in filamentous actin (F-actin) located at the axons' distal tips. Growth cones exploit F-actin-based protrusions to scan the environment for guidance cues, and they contain the sensory apparatus to translate guidance cue information into intracellular signaling cascades. These cascades act upstream of actin-binding proteins (ABP) and thereby control assembly and disassembly of F-actin. Spatiotemporally controlled F-actin dis-/assembly in growth cones steers the axon towards attractants and away from repellents, and it thereby navigates the axon through the developing nervous system. Hence, ABP that control F-actin dynamics emerged as critical regulators of neuronal network formation. In the present review article, we will summarize and discuss current knowledge of the mechanisms that control remodeling of the actin cytoskeleton in growth cones, focusing on recent progress in the field. Further, we will introduce tools and techniques that allow to study actin regulatory mechanism in growth cones.
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Affiliation(s)
- Felix Schneider
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany; DFG Research Training Group 'Membrane Plasticity in Tissue Development and Remodeling', GRK 2213, Philipps-University of Marburg, 35032 Marburg, Germany; Molecular Urooncology, Department of Urology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Isabell Metz
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany; DFG Research Training Group 'Membrane Plasticity in Tissue Development and Remodeling', GRK 2213, Philipps-University of Marburg, 35032 Marburg, Germany
| | - Marco B Rust
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany; DFG Research Training Group 'Membrane Plasticity in Tissue Development and Remodeling', GRK 2213, Philipps-University of Marburg, 35032 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032 Marburg, Germany.
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5
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Schelski M, Bradke F. Microtubule retrograde flow retains neuronal polarization in a fluctuating state. SCIENCE ADVANCES 2022; 8:eabo2336. [PMID: 36332023 PMCID: PMC9635824 DOI: 10.1126/sciadv.abo2336] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
In developing vertebrate neurons, a neurite is formed by more than a hundred microtubules. While individual microtubules are dynamic, the microtubule array has been regarded as stationary. Using live-cell imaging of neurons in culture or in brain slices, combined with photoconversion techniques and pharmacological manipulations, we uncovered that the microtubule array flows retrogradely within neurites to the soma. This flow drives cycles of microtubule density, a hallmark of the fluctuating state before axon formation, thereby inhibiting neurite growth. The motor protein dynein fuels this process. Shortly after axon formation, microtubule retrograde flow slows down in the axon, reducing microtubule density cycles and enabling axon extension. Thus, keeping neurites short is an active process. Microtubule retrograde flow is a previously unknown type of cytoskeletal dynamics, which changes the hitherto axon-centric view of neuronal polarization.
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Affiliation(s)
- Max Schelski
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
- International Max Planck Research School for Brain and Behavior, University of Bonn, Bonn, Germany
| | - Frank Bradke
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
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6
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Chen C, Chu CH, Chu Y, Chang TY, Chen SW, Liang SY, Tsai YC, Chen BC, Tu HL, Cheng PL. Neuronal paxillin and drebrin mediate BDNF-induced force transduction and growth cone turning in a soft-tissue-like environment. Cell Rep 2022; 40:111188. [PMID: 35977504 DOI: 10.1016/j.celrep.2022.111188] [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: 09/12/2021] [Revised: 03/23/2022] [Accepted: 07/20/2022] [Indexed: 11/26/2022] Open
Abstract
Soft tissue environments govern neuronal morphogenesis. However, the precise molecular mechanisms underlying chemotropism-directed axonal growth cone movement in extremely soft environments remain unclear. Here, we show that drebrin, a growth cone T-zone protein, modulates growth cone turning in response to brain-derived neurotrophic factor (BDNF) coated on a soft substrate. Structurally, axonal growth cones of rodent hippocampal neurons grown on 0.1 kPa hydrogels possess an expanded T zone in which drebrin is highly integrated with both F-actin and microtubules. Biochemically, we identify paxillin as interacting with drebrin in cells grown on 0.1 kPa hydrogels but not on glass coverslips. When grown on 0.1 kPa substrates, growth cones asymmetrically exposed to BDNF-bound stripes exhibit enhanced paxillin-drebrin interaction on the side facing the stripes, an activity that is PKA and AAK1 dependent but independent of Src kinase. Functionally, we show that BDNF-induced growth cone turning and force generation on soft substrates require drebrin phosphorylation and paxillin-drebrin association.
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Affiliation(s)
- Chen Chen
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Chien-Hsin Chu
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Ying Chu
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Ting-Ya Chang
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Sheng-Wen Chen
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Shu-Yang Liang
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Yun-Chi Tsai
- Research Center for Applied Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Bi-Chang Chen
- Research Center for Applied Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Pei-Lin Cheng
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan.
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7
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Costa AC, Sousa MM. The Role of Spastin in Axon Biology. Front Cell Dev Biol 2022; 10:934522. [PMID: 35865632 PMCID: PMC9294387 DOI: 10.3389/fcell.2022.934522] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/07/2022] [Indexed: 12/05/2022] Open
Abstract
Neurons are highly polarized cells with elaborate shapes that allow them to perform their function. In neurons, microtubule organization—length, density, and dynamics—are essential for the establishment of polarity, growth, and transport. A mounting body of evidence shows that modulation of the microtubule cytoskeleton by microtubule-associated proteins fine tunes key aspects of neuronal cell biology. In this respect, microtubule severing enzymes—spastin, katanin and fidgetin—a group of microtubule-associated proteins that bind to and generate internal breaks in the microtubule lattice, are emerging as key modulators of the microtubule cytoskeleton in different model systems. In this review, we provide an integrative view on the latest research demonstrating the key role of spastin in neurons, specifically in the context of axonal cell biology. We focus on the function of spastin in the regulation of microtubule organization, and axonal transport, that underlie its importance in the intricate control of axon growth, branching and regeneration.
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Affiliation(s)
- Ana Catarina Costa
- Nerve Regeneration Group, Instituto de Biologia Molecular e Celular (IBMC), Instituto de Investigação e Inovação Em Saúde (i3S), University of Porto, Porto, Portugal
- Graduate Program in Molecular and Cell Biology, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- *Correspondence: Ana Catarina Costa, ; Monica Mendes Sousa,
| | - Monica Mendes Sousa
- Nerve Regeneration Group, Instituto de Biologia Molecular e Celular (IBMC), Instituto de Investigação e Inovação Em Saúde (i3S), University of Porto, Porto, Portugal
- *Correspondence: Ana Catarina Costa, ; Monica Mendes Sousa,
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8
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Atherton J, Stouffer M, Francis F, Moores CA. Visualising the cytoskeletal machinery in neuronal growth cones using cryo-electron tomography. J Cell Sci 2022; 135:274968. [PMID: 35383828 PMCID: PMC9016625 DOI: 10.1242/jcs.259234] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 03/02/2022] [Indexed: 12/12/2022] Open
Abstract
Neurons extend axons to form the complex circuitry of the mature brain. This depends on the coordinated response and continuous remodelling of the microtubule and F-actin networks in the axonal growth cone. Growth cone architecture remains poorly understood at nanoscales. We therefore investigated mouse hippocampal neuron growth cones using cryo-electron tomography to directly visualise their three-dimensional subcellular architecture with molecular detail. Our data showed that the hexagonal arrays of actin bundles that form filopodia penetrate and terminate deep within the growth cone interior. We directly observed the modulation of these and other growth cone actin bundles by alteration of individual F-actin helical structures. Microtubules with blunt, slightly flared or gently curved ends predominated in the growth cone, frequently contained lumenal particles and exhibited lattice defects. Investigation of the effect of absence of doublecortin, a neurodevelopmental cytoskeleton regulator, on growth cone cytoskeleton showed no major anomalies in overall growth cone organisation or in F-actin subpopulations. However, our data suggested that microtubules sustained more structural defects, highlighting the importance of microtubule integrity during growth cone migration. Summary: Cryo-electron tomographic reconstruction of neuronal growth cone subdomains reveals distinctive F-actin and microtubule cytoskeleton architectures and modulation at molecular detail.
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Affiliation(s)
- Joseph Atherton
- Randall Centre for Cell and Molecular Biophysics, King's College, London SE1 1YR, UK.,Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
| | - Melissa Stouffer
- INSERM UMR-S 1270, 17 Rue du Fer à Moulin, 75005 Paris, France.,Sorbonne University UMR-S 1270, 4 Place Jussieu, 75005 Paris, France.,Institut du Fer à Moulin, 17 Rue du Fer à Moulin, 75005 Paris, France.,Institute of Science and Technology Austria, Am campus 1, 3400 Klosterneuberg, Austria
| | - Fiona Francis
- INSERM UMR-S 1270, 17 Rue du Fer à Moulin, 75005 Paris, France.,Sorbonne University UMR-S 1270, 4 Place Jussieu, 75005 Paris, France.,Institut du Fer à Moulin, 17 Rue du Fer à Moulin, 75005 Paris, France
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London WC1E 7HX, UK
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9
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Danastas K, Larsen A, Jobson S, Guo G, Cunningham AL, Miranda-Saksena M. Herpes simplex virus-1 utilizes the host actin cytoskeleton for its release from axonal growth cones. PLoS Pathog 2022; 18:e1010264. [PMID: 35073379 PMCID: PMC8812851 DOI: 10.1371/journal.ppat.1010264] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 02/03/2022] [Accepted: 01/10/2022] [Indexed: 11/19/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) has evolved mechanisms to exploit the host cytoskeleton during entry, replication and exit from cells. In this study, we determined the role of actin and the molecular motor proteins, myosin II and myosin V, in the transport and release of HSV-1 from axon termini, or growth cones. Using compartmentalized neuronal devices, we showed that inhibition of actin polymerization, but not actin branching, significantly reduced the release of HSV-1 from axons. Furthermore, we showed that inhibition of myosin V, but not myosin II, also significantly reduced the release of HSV-1 from axons. Using confocal and electron microscopy, we determined that viral components are transported along axons to growth cones, despite actin or myosin inhibition. Overall, our study supports the role of actin in virus release from axonal growth cones and suggests myosin V as a likely candidate involved in this process. Herpes simplex virus type 1 (HSV-1) is a ubiquitous human pathogen causing cold sores and genital herpes. HSV-1 infects sensory neurons of the peripheral nervous system where it establishes a lifelong infection and cannot be cured. Reactivation is common, with the virus transported back along sensory nerves, forming new lesions, or is shed asymptomatically. Antiviral resistance is emerging to current antivirals that target viral replication, indicating the need to identify new targets for future treatment. The host cell cytoskeleton plays an important role during transport of the virus. HSV-1 is transported along axons via microtubules; however, how the virus is released from axon termini, where actin predominates, is unknown. Here we show that an intact actin cytoskeleton is required for efficient virus release from axon termini. Furthermore, we show that myosin V, an actin based molecular motor that drives transport, is essential in virus release from axon termini. Together, this study defines the mechanisms behind HSV-1 release from axon termini which will guide future directions in identifying possible therapeutic targets for HSV-1.
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Affiliation(s)
- Kevin Danastas
- Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Australia
| | - Ava Larsen
- Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Australia
| | - Sophie Jobson
- Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Australia
| | - Gerry Guo
- Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Australia
| | - Anthony L. Cunningham
- Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Australia
- * E-mail: (ALC); (MM-S)
| | - Monica Miranda-Saksena
- Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, Australia
- * E-mail: (ALC); (MM-S)
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10
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Sánchez-Huertas C, Herrera E. With the Permission of Microtubules: An Updated Overview on Microtubule Function During Axon Pathfinding. Front Mol Neurosci 2021; 14:759404. [PMID: 34924953 PMCID: PMC8675249 DOI: 10.3389/fnmol.2021.759404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/01/2021] [Indexed: 01/27/2023] Open
Abstract
During the establishment of neural circuitry axons often need to cover long distances to reach remote targets. The stereotyped navigation of these axons defines the connectivity between brain regions and cellular subtypes. This chemotrophic guidance process mostly relies on the spatio-temporal expression patterns of extracellular proteins and the selective expression of their receptors in projection neurons. Axon guidance is stimulated by guidance proteins and implemented by neuronal traction forces at the growth cones, which engage local cytoskeleton regulators and cell adhesion proteins. Different layers of guidance signaling regulation, such as the cleavage and processing of receptors, the expression of co-receptors and a wide variety of intracellular cascades downstream of receptors activation, have been progressively unveiled. Also, in the last decades, the regulation of microtubule (MT) assembly, stability and interactions with the submembranous actin network in the growth cone have emerged as crucial effector mechanisms in axon pathfinding. In this review, we will delve into the intracellular signaling cascades downstream of guidance receptors that converge on the MT cytoskeleton of the growing axon. In particular, we will focus on the microtubule-associated proteins (MAPs) network responsible of MT dynamics in the axon and growth cone. Complementarily, we will discuss new evidences that connect defects in MT scaffold proteins, MAPs or MT-based motors and axon misrouting during brain development.
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Affiliation(s)
- Carlos Sánchez-Huertas
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Alicante, Spain
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11
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Zhovmer AS, Manning A, Smith C, Hayes JB, Burnette DT, Wang J, Cartagena-Rivera AX, Dokholyan NV, Singh RK, Tabdanov ED. Mechanical Counterbalance of Kinesin and Dynein Motors in a Microtubular Network Regulates Cell Mechanics, 3D Architecture, and Mechanosensing. ACS NANO 2021; 15:17528-17548. [PMID: 34677937 PMCID: PMC9291236 DOI: 10.1021/acsnano.1c04435] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Microtubules (MTs) and MT motor proteins form active 3D networks made of unstretchable cables with rod-like bending mechanics that provide cells with a dynamically changing structural scaffold. In this study, we report an antagonistic mechanical balance within the dynein-kinesin microtubular motor system. Dynein activity drives the microtubular network inward compaction, while isolated activity of kinesins bundles and expands MTs into giant circular bands that deform the cell cortex into discoids. Furthermore, we show that dyneins recruit MTs to sites of cell adhesion, increasing the topographic contact guidance of cells, while kinesins antagonize it via retraction of MTs from sites of cell adhesion. Actin-to-microtubule translocation of septin-9 enhances kinesin-MT interactions, outbalances the activity of kinesins over that of dyneins, and induces the discoid architecture of cells. These orthogonal mechanisms of MT network reorganization highlight the existence of an intricate mechanical balance between motor activities of kinesins and dyneins that controls cell 3D architecture, mechanics, and cell-microenvironment interactions.
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Affiliation(s)
- Alexander S. Zhovmer
- Center
for Biologics Evaluation and Research, U.S.
Food and Drug Administration, Silver Spring, Maryland 20903, United States
- . Tel: 1-301-402-1606
| | - Alexis Manning
- Center
for Biologics Evaluation and Research, U.S.
Food and Drug Administration, Silver Spring, Maryland 20903, United States
| | - Chynna Smith
- Section
on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - James B. Hayes
- Department
of Cell and Developmental Biology, Vanderbilt Medical Center, University of Vanderbilt, Nashville, Tennessee 37232, United States
| | - Dylan T. Burnette
- Department
of Cell and Developmental Biology, Vanderbilt Medical Center, University of Vanderbilt, Nashville, Tennessee 37232, United States
| | - Jian Wang
- Department
of Pharmacology, Penn State College of Medicine, Pennsylvania State University, Hummelstown, Pennsylvania 17036, United States
| | - Alexander X. Cartagena-Rivera
- Section
on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
- . Tel: 1-301-503-4033
| | - Nikolay V. Dokholyan
- Department
of Pharmacology, Penn State College of Medicine, Pennsylvania State University, Hummelstown, Pennsylvania 17036, United States
- Department
of Biochemistry & Molecular Biology, Penn State College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033, United States
- . Tel: 1-717-531-5177
| | - Rakesh K. Singh
- Department
of Obstetrics and Gynecology, University
of Rochester Medical Center, Rochester, New York 14620, United States
- . Tel: 1-585-276-6281
| | - Erdem D. Tabdanov
- Department
of Pharmacology, Penn State College of Medicine, Pennsylvania State University, Hummelstown, Pennsylvania 17036, United States
- . Tel: 1-717-531-0003 Ext: 4430
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12
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Leterrier C. A Pictorial History of the Neuronal Cytoskeleton. J Neurosci 2021; 41:11-27. [PMID: 33408133 PMCID: PMC7786211 DOI: 10.1523/jneurosci.2872-20.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 11/21/2022] Open
Affiliation(s)
- Christophe Leterrier
- Aix Marseille Université, Centre National de la Recherche Scientifique, INP Unité Mixte de Recherche 7051, NeuroCyto, Marseille 13005, France
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13
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Gallo G. The bioenergetics of neuronal morphogenesis and regeneration: Frontiers beyond the mitochondrion. Dev Neurobiol 2020; 80:263-276. [PMID: 32750228 DOI: 10.1002/dneu.22776] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/29/2020] [Accepted: 07/29/2020] [Indexed: 12/27/2022]
Abstract
The formation of axons and dendrites during development, and their regeneration following injury, are energy intensive processes. The underlying assembly and dynamics of the cytoskeleton, axonal transport mechanisms, and extensive signaling networks all rely on ATP and GTP consumption. Cellular ATP is generated through oxidative phosphorylation (OxP) in mitochondria, glycolysis and "regenerative" kinase systems. Recent investigations have focused on the role of the mitochondrion in axonal development and regeneration emphasizing the importance of this organelle and OxP in axon development and regeneration. In contrast, the understanding of alternative sources of ATP in neuronal morphogenesis and regeneration remains largely unexplored. This review focuses on the current state of the field of neuronal bioenergetics underlying morphogenesis and regeneration and considers the literature on the bioenergetics of non-neuronal cell motility to emphasize the potential contributions of non-mitochondrial energy sources.
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Affiliation(s)
- Gianluca Gallo
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Shriners Hospitals Pediatric Research Center, Temple University, Philadelphia, PA, USA
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14
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Mikhaylova M, Rentsch J, Ewers H. Actomyosin Contractility in the Generation and Plasticity of Axons and Dendritic Spines. Cells 2020; 9:cells9092006. [PMID: 32882840 PMCID: PMC7565476 DOI: 10.3390/cells9092006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/19/2020] [Accepted: 08/25/2020] [Indexed: 12/15/2022] Open
Abstract
Actin and non-muscle myosins have long been known to play important roles in growth cone steering and neurite outgrowth. More recently, novel functions for non-muscle myosin have been described in axons and dendritic spines. Consequently, possible roles of actomyosin contraction in organizing and maintaining structural properties of dendritic spines, the size and location of axon initial segment and axonal diameter are emerging research topics. In this review, we aim to summarize recent findings involving myosin localization and function in these compartments and to discuss possible roles for actomyosin in their function and the signaling pathways that control them.
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Affiliation(s)
- Marina Mikhaylova
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, 10115 Berlin, Germany
- DFG Emmy Noether Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Correspondence: (M.M.); (H.E.); Tel.: +49-4074-1055-815 (M.M.); +49-30-838-60644 (H.E.)
| | - Jakob Rentsch
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
| | - Helge Ewers
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
- Correspondence: (M.M.); (H.E.); Tel.: +49-4074-1055-815 (M.M.); +49-30-838-60644 (H.E.)
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15
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Costa AR, Sousa MM. Non-Muscle Myosin II in Axonal Cell Biology: From the Growth Cone to the Axon Initial Segment. Cells 2020; 9:cells9091961. [PMID: 32858875 PMCID: PMC7563147 DOI: 10.3390/cells9091961] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 08/21/2020] [Accepted: 08/21/2020] [Indexed: 12/14/2022] Open
Abstract
By binding to actin filaments, non-muscle myosin II (NMII) generates actomyosin networks that hold unique contractile properties. Their dynamic nature is essential for neuronal biology including the establishment of polarity, growth cone formation and motility, axon growth during development (and axon regeneration in the adult), radial and longitudinal axonal tension, and synapse formation and function. In this review, we discuss the current knowledge on the spatial distribution and function of the actomyosin cytoskeleton in different axonal compartments. We highlight some of the apparent contradictions and open questions in the field, including the role of NMII in the regulation of axon growth and regeneration, the possibility that NMII structural arrangement along the axon shaft may control both radial and longitudinal contractility, and the mechanism and functional purpose underlying NMII enrichment in the axon initial segment. With the advances in live cell imaging and super resolution microscopy, it is expected that in the near future the spatial distribution of NMII in the axon, and the mechanisms by which it participates in axonal biology will be further untangled.
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16
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Conventional and Non-Conventional Roles of Non-Muscle Myosin II-Actin in Neuronal Development and Degeneration. Cells 2020; 9:cells9091926. [PMID: 32825197 PMCID: PMC7566000 DOI: 10.3390/cells9091926] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/13/2022] Open
Abstract
Myosins are motor proteins that use chemical energy to produce mechanical forces driving actin cytoskeletal dynamics. In the brain, the conventional non-muscle myosin II (NMII) regulates actin filament cytoskeletal assembly and contractile forces during structural remodeling of axons and dendrites, contributing to morphology, polarization, and migration of neurons during brain development. NMII isoforms also participate in neurotransmission and synaptic plasticity by driving actin cytoskeletal dynamics during synaptic vesicle release and retrieval, and formation, maturation, and remodeling of dendritic spines. NMIIs are expressed differentially in cerebral non-neuronal cells, such as microglia, astrocytes, and endothelial cells, wherein they play key functions in inflammation, myelination, and repair. Besides major efforts to understand the physiological functions and regulatory mechanisms of NMIIs in the nervous system, their contributions to brain pathologies are still largely unclear. Nonetheless, genetic mutations or deregulation of NMII and its regulatory effectors are linked to autism, schizophrenia, intellectual disability, and neurodegeneration, indicating non-conventional roles of NMIIs in cellular mechanisms underlying neurodevelopmental and neurodegenerative disorders. Here, we summarize the emerging biological roles of NMIIs in the brain, and discuss how actomyosin signaling contributes to dysfunction of neurons and glial cells in the context of neurological disorders. This knowledge is relevant for a deep understanding of NMIIs on the pathogenesis and therapeutics of neuropsychiatric and neurodegenerative diseases.
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17
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Rodemer W, Gallo G, Selzer ME. Mechanisms of Axon Elongation Following CNS Injury: What Is Happening at the Axon Tip? Front Cell Neurosci 2020; 14:177. [PMID: 32719586 PMCID: PMC7347967 DOI: 10.3389/fncel.2020.00177] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
After an injury to the central nervous system (CNS), functional recovery is limited by the inability of severed axons to regenerate and form functional connections with appropriate target neurons beyond the injury. Despite tremendous advances in our understanding of the mechanisms of axon growth, and of the inhibitory factors in the injured CNS that prevent it, disappointingly little progress has been made in restoring function to human patients with CNS injuries, such as spinal cord injury (SCI), through regenerative therapies. Clearly, the large number of overlapping neuron-intrinsic and -extrinsic growth-inhibitory factors attenuates the benefit of neutralizing any one target. More daunting is the distances human axons would have to regenerate to reach some threshold number of target neurons, e.g., those that occupy one complete spinal segment, compared to the distances required in most experimental models, such as mice and rats. However, the difficulties inherent in studying mechanisms of axon regeneration in the mature CNS in vivo have caused researchers to rely heavily on extrapolation from studies of axon regeneration in peripheral nerve, or of growth cone-mediated axon development in vitro and in vivo. Unfortunately, evidence from several animal models, including the transected lamprey spinal cord, has suggested important differences between regeneration of mature CNS axons and growth of axons in peripheral nerve, or during embryonic development. Specifically, long-distance regeneration of severed axons may not involve the actin-myosin molecular motors that guide embryonic growth cones in developing axons. Rather, non-growth cone-mediated axon elongation may be required to propel injured axons in the mature CNS. If so, it may be necessary to use other experimental models to promote regeneration that is sufficient to contact a critical number of target neurons distal to a CNS lesion. This review examines the cytoskeletal underpinnings of axon growth, focusing on the elongating axon tip, to gain insights into how CNS axons respond to injury, and how this might affect the development of regenerative therapies for SCI and other CNS injuries.
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Affiliation(s)
- William Rodemer
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Gianluca Gallo
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States.,Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States.,Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
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18
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Abstract
The intracellular transport system in neurons is specialized to an extraordinary degree, enabling the delivery of critical cargo to sites in axons or dendrites that are far removed from the cell center. Vesicles formed in the cell body are actively transported by kinesin motors along axonal microtubules to presynaptic sites that can be located more than a meter away. Both growth factors and degradative vesicles carrying aged organelles or aggregated proteins take the opposite route, driven by dynein motors. Distance is not the only challenge; precise delivery of cargos to sites of need must also be accomplished. For example, localized delivery of presynaptic components to hundreds of thousands of "en passant" synapses distributed along the length of a single axon in some neuronal subtypes provides a layer of complexity that must be successfully navigated to maintain synaptic transmission. We review recent advances in the field of axonal transport, with a focus on conceptual developments, and highlight our growing quantitative understanding of neuronal trafficking and its role in maintaining the synaptic function that underlies higher cognitive processes such as learning and memory.
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Affiliation(s)
- Pedro Guedes-Dias
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Institute of Neuronal Cell Biology, Technische Universität München, 80802 Munich, Germany
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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19
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Meka DP, Scharrenberg R, Calderon de Anda F. Emerging roles of the centrosome in neuronal development. Cytoskeleton (Hoboken) 2020; 77:84-96. [DOI: 10.1002/cm.21593] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/16/2019] [Accepted: 01/04/2020] [Indexed: 12/24/2022]
Affiliation(s)
- Durga Praveen Meka
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH)University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Robin Scharrenberg
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH)University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Froylan Calderon de Anda
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH)University Medical Center Hamburg‐Eppendorf Hamburg Germany
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20
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Law S, Stout M, Rensch A, Rowsell JM. Expression of MYOSIN VIIA in developing mouse cochleovestibular ganglion neurons. Gene Expr Patterns 2020; 35:119092. [PMID: 31918020 DOI: 10.1016/j.gep.2019.119092] [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: 08/21/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 10/25/2022]
Abstract
Myosins make up a large super family of motor proteins responsible for actin-based motility in most eukaryotic cells. Myosin VIIA is essential for the development and function of sensory hair cells in the inner ear. The role of Myosin VIIA in the development of cochleovestibular ganglion (CVG) neurons in the mouse is largely unknown. Neurons of the CVG innervate sensory hair cells of the cochlea and vestibular organs to transmit hearing and balance information respectively to the brain. The aim of this study was to characterize the expression of MYOSIN VIIA in the CVG of mouse embryos. Spatiotemporal expression of MYOSIN VIIA was characterized in embryonic (E) mouse inner ear neurons from E9.5 to postnatal (P) day 0. At early stages, when otic neurons begin to delaminate to form the CVG, MYOSIN VIIA was co-expressed with TuJ1, ISLET1 and NEUROD in the otic epithelium and CVG. When CVG neurons were migrating and exiting mitosis, MYSOSIN VIIA was downregulated in a subset of neurons, which were NEUROD-negative and GATA3-positive. After segregation of the CVG, MYOSIN VIIA was observed in a subset of vestibular neurons marked by TUJ1 and absent in cochlear neurons, marked by GATA3. The differential expression of MYOSIN VIIA may indicate a role in inner ear neuron migration and specific labeling of vestibular neurons.
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Affiliation(s)
- Sarah Law
- Department of Biology, Saint Mary's College, Notre Dame, IN, 46556, USA.
| | - Molly Stout
- Department of Biology, Saint Mary's College, Notre Dame, IN, 46556, USA.
| | - Amanda Rensch
- Department of Biology, Saint Mary's College, Notre Dame, IN, 46556, USA.
| | - Jennifer M Rowsell
- Department of Biology, Saint Mary's College, Notre Dame, IN, 46556, USA.
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21
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Microtubule-Actomyosin Mechanical Cooperation during Contact Guidance Sensing. Cell Rep 2019; 25:328-338.e5. [PMID: 30304674 PMCID: PMC6226003 DOI: 10.1016/j.celrep.2018.09.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/20/2018] [Accepted: 09/07/2018] [Indexed: 01/14/2023] Open
Abstract
Cancer cell migration through and away from tumors is driven in part by migration along aligned extracellular matrix, a process known as contact guidance (CG). To concurrently study the influence of architectural and mechanical regulators of CG sensing, we developed a set of CG platforms. Using flat and nanotextured substrates with variable architectures and stiffness, we show that CG sensing is regulated by substrate stiffness and define a mechanical role for microtubules and actomyosin-microtubule interactions during CG sensing. Furthermore, we show that Arp2/3-dependent lamellipodia dynamics can compete with aligned protrusions to diminish the CG response and define Arp2/3- and Formins-dependent actin architectures that regulate microtu-bule-dependent protrusions, which promote the CG response. Thus, our work represents a comprehen-sive examination of the physical mechanisms influ-encing CG sensing. Aligned extracellular matrix architectures in tumors direct migration of invasive cancer cells. Tabdanov et al. show that the mechanical properties of aligned extracellular matrix environments influence invasive cell behavior and define a mechanical role for microtubules and actomyosin-microtubule interactions during sensing of contact guidance cues that arise from aligned extracellular matrix.
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22
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McKenzie AJ, Svec KV, Williams TF, Howe AK. Protein kinase A activity is regulated by actomyosin contractility during cell migration and is required for durotaxis. Mol Biol Cell 2019; 31:45-58. [PMID: 31721649 PMCID: PMC6938270 DOI: 10.1091/mbc.e19-03-0131] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Dynamic subcellular regulation of protein kinase A (PKA) activity is important for the motile behavior of many cell types, yet the mechanisms governing PKA activity during cell migration remain largely unknown. The motility of SKOV-3 epithelial ovarian cancer (EOC) cells has been shown to be dependent both on localized PKA activity and, more recently, on mechanical reciprocity between cellular tension and extracellular matrix rigidity. Here, we investigated the possibility that PKA is regulated by mechanical signaling during migration. We find that localized PKA activity in migrating cells rapidly decreases upon inhibition of actomyosin contractility (specifically, of myosin ATPase, Rho kinase, or myosin light-chain kinase activity). Moreover, PKA activity is spatially and temporally correlated with cellular traction forces in migrating cells. Additionally, PKA is rapidly and locally activated by mechanical stretch in an actomyosin contractility-dependent manner. Finally, inhibition of PKA activity inhibits mechanically guided migration, also known as durotaxis. These observations establish PKA as a locally regulated effector of cellular mechanotransduction and as a regulator of mechanically guided cell migration.
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Affiliation(s)
- Andrew J McKenzie
- Department of Pharmacology.,University of Vermont Cancer Center, and
| | - Kathryn V Svec
- Department of Pharmacology.,University of Vermont Cancer Center, and
| | - Tamara F Williams
- Department of Pharmacology.,University of Vermont Cancer Center, and
| | - Alan K Howe
- Department of Pharmacology.,University of Vermont Cancer Center, and.,Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
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23
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Dupraz S, Hilton BJ, Husch A, Santos TE, Coles CH, Stern S, Brakebusch C, Bradke F. RhoA Controls Axon Extension Independent of Specification in the Developing Brain. Curr Biol 2019; 29:3874-3886.e9. [PMID: 31679934 DOI: 10.1016/j.cub.2019.09.040] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/22/2019] [Accepted: 09/16/2019] [Indexed: 12/22/2022]
Abstract
The specification of an axon and its subsequent outgrowth are key steps during neuronal polarization, a prerequisite to wire the brain. The Rho-guanosine triphosphatase (GTPase) RhoA is believed to be a central player in these processes. However, its physiological role has remained undefined. Here, genetic loss- and gain-of-function experiments combined with time-lapse microscopy, cell culture, and in vivo analysis show that RhoA is not involved in axon specification but confines the initiation of neuronal polarization and axon outgrowth during development. Biochemical analysis and super-resolution microscopy together with molecular and pharmacological manipulations reveal that RhoA restrains axon growth by activating myosin-II-mediated actin arc formation in the growth cone to prevent microtubules from protruding toward the leading edge. Through this mechanism, RhoA regulates the duration of axon growth and pause phases, thus controlling the tightly timed extension of developing axons. Thereby, this work unravels physiologically relevant players coordinating actin-microtubule interactions during axon growth.
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Affiliation(s)
- Sebastian Dupraz
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Brett J Hilton
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Andreas Husch
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Telma E Santos
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Charlotte H Coles
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Sina Stern
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany
| | - Cord Brakebusch
- Biotech Research & Innovation Centre, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark
| | - Frank Bradke
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, Building 99, 53127 Bonn, Germany.
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24
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Meka DP, Scharrenberg R, Zhao B, Kobler O, König T, Schaefer I, Schwanke B, Klykov S, Richter M, Eggert D, Windhorst S, Dotti CG, Kreutz MR, Mikhaylova M, Calderon de Anda F. Radial somatic F-actin organization affects growth cone dynamics during early neuronal development. EMBO Rep 2019; 20:e47743. [PMID: 31650708 PMCID: PMC6893363 DOI: 10.15252/embr.201947743] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 09/06/2019] [Accepted: 09/27/2019] [Indexed: 11/16/2022] Open
Abstract
The centrosome is thought to be the major neuronal microtubule‐organizing center (MTOC) in early neuronal development, producing microtubules with a radial organization. In addition, albeit in vitro, recent work showed that isolated centrosomes could serve as an actin‐organizing center, raising the possibility that neuronal development may, in addition, require a centrosome‐based actin radial organization. Here, we report, using super‐resolution microscopy and live‐cell imaging of cultured rodent neurons, F‐actin organization around the centrosome with dynamic F‐actin aster‐like structures with F‐actin fibers extending and retracting actively. Photoactivation/photoconversion experiments and molecular manipulations of F‐actin stability reveal a robust flux of somatic F‐actin toward the cell periphery. Finally, we show that somatic F‐actin intermingles with centrosomal PCM‐1 (pericentriolar material 1 protein) satellites. Knockdown of PCM‐1 and disruption of centrosomal activity not only affect F‐actin dynamics near the centrosome but also in distal growth cones. Collectively, the data show a radial F‐actin organization during early neuronal development, which might be a cellular mechanism for providing peripheral regions with a fast and continuous source of actin polymers, hence sustaining initial neuronal development.
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Affiliation(s)
- Durga Praveen Meka
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Robin Scharrenberg
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bing Zhao
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kobler
- Combinatorial Neuroimaging Core Facility (CNI), Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Theresa König
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Irina Schaefer
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Birgit Schwanke
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sergei Klykov
- Emmy-Noether Group "Neuronal Protein Transport", Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Melanie Richter
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dennis Eggert
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.,Heinrich Pette Institute-Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carlos G Dotti
- Centro de Biología Molecular "Severo Ochoa", CSIC-UAM, Madrid, Spain
| | - Michael R Kreutz
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Leibniz Guest Group "Dendritic Organelles and Synaptic Function", Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marina Mikhaylova
- Emmy-Noether Group "Neuronal Protein Transport", Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Froylan Calderon de Anda
- RG Neuronal Development, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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25
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Abstract
The spindle segregates chromosomes in cell division and it has long been discussed whether it is microtubules alone that build this fundamental molecular machine. Recent work in mouse oocytes now shows that actin filaments co-assemble with microtubules to promote faithful chromosome segregation.
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26
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Malacrida A, Meregalli C, Rodriguez-Menendez V, Nicolini G. Chemotherapy-Induced Peripheral Neuropathy and Changes in Cytoskeleton. Int J Mol Sci 2019; 20:ijms20092287. [PMID: 31075828 PMCID: PMC6540147 DOI: 10.3390/ijms20092287] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 12/23/2022] Open
Abstract
Despite the different antineoplastic mechanisms of action, peripheral neurotoxicity induced by all chemotherapy drugs (anti-tubulin agents, platinum compounds, proteasome inhibitors, thalidomide) is associated with neuron morphological changes ascribable to cytoskeleton modifications. The “dying back” degeneration of distal terminals (sensory nerves) of dorsal root ganglia sensory neurons, observed in animal models, in in vitro cultures and biopsies of patients is the most evident hallmark of the perturbation of the cytoskeleton. On the other hand, in highly polarized cells like neurons, the cytoskeleton carries out its role not only in axons but also has a fundamental role in dendrite plasticity and in the organization of soma. In the literature, there are many studies focused on the antineoplastic-induced alteration of microtubule organization (and consequently, fast axonal transport defects) while very few studies have investigated the effect of the different classes of drugs on microfilaments, intermediate filaments and associated proteins. Therefore, in this review, we will focus on: (1) Highlighting the fundamental role of the crosstalk among the three filamentous subsystems and (2) investigating pivotal cytoskeleton-associated proteins.
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Affiliation(s)
- Alessio Malacrida
- School of Medicine and Surgery, Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, via Cadore 48, 20900 Monza, MB, Italy.
| | - Cristina Meregalli
- School of Medicine and Surgery, Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, via Cadore 48, 20900 Monza, MB, Italy.
| | - Virginia Rodriguez-Menendez
- School of Medicine and Surgery, Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, via Cadore 48, 20900 Monza, MB, Italy.
| | - Gabriella Nicolini
- School of Medicine and Surgery, Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, via Cadore 48, 20900 Monza, MB, Italy.
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27
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Slater PG, Cammarata GM, Samuelson AG, Magee A, Hu Y, Lowery LA. XMAP215 promotes microtubule-F-actin interactions to regulate growth cone microtubules during axon guidance in Xenopus laevis. J Cell Sci 2019; 132:jcs.224311. [PMID: 30890650 DOI: 10.1242/jcs.224311] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 03/08/2019] [Indexed: 12/24/2022] Open
Abstract
It has long been established that neuronal growth cone navigation depends on changes in microtubule (MT) and F-actin architecture downstream of guidance cues. However, the mechanisms by which MTs and F-actin are dually coordinated remain a fundamentally unresolved question. Here, we report that the well-characterized MT polymerase, XMAP215 (also known as CKAP5), plays an important role in mediating MT-F-actin interaction within the growth cone. We demonstrate that XMAP215 regulates MT-F-actin alignment through its N-terminal TOG 1-5 domains. Additionally, we show that XMAP215 directly binds to F-actin in vitro and co-localizes with F-actin in the growth cone periphery. We also find that XMAP215 is required for regulation of growth cone morphology and response to the guidance cue, Ephrin A5. Our findings provide the first strong evidence that XMAP215 coordinates MT and F-actin interaction in vivo We suggest a model in which XMAP215 regulates MT extension along F-actin bundles into the growth cone periphery and that these interactions may be important to control cytoskeletal dynamics downstream of guidance cues. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Paula G Slater
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | | | | | - Alexandra Magee
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | - Yuhan Hu
- Department of Cell Biology, Yale University, New Haven, CT 06520, USA
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28
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Gadau SD. Tubulin post-translational modifications in developing dog primary neurons obtained with methods according to the 3Rs principles. Res Vet Sci 2018; 122:56-63. [PMID: 30458355 DOI: 10.1016/j.rvsc.2018.11.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 10/19/2018] [Accepted: 11/12/2018] [Indexed: 11/30/2022]
Abstract
Microtubules play a crucial role during neuronal morphogenesis regulating many functions. In the study of these phenomena in vitro cellular models have been employed, mainly resorting to housed experimental animals. Among alternative models in neurobiological study, recently dog caught particular attention. In fact, the complexity of the canine brain, the life long span and the neurodegenerative pathologies render the dog a species more close to humans than rodents. Lately, growing interest in the limitation of the use of experimental animals, has stimulated the search for alternative experimental protocols. Starting from fetal dog brain, obtained by alternative way of sampling, we set neuronal primary cultures. Through immunofluorescence, we examined the presence and the cellular distribution of tubulin post-translational modifications as tyrosinated and acetylated α-tubulin, as markers of dynamic and stable microtubule respectively. In addition, we evaluated the pattern of two associated proteins which may slide on these two tubulin modifications, i.e. CLIP-170 and Kinesin-1. A clear positivity for tyrosinated and acetylated α-tubulin, was found. As far as the motor proteins are concerned, we detected a prevalence of CLIP-170 compared to kinesin-1 with a better overlapping between tyrosinated α-tubulin and CLIP-170. Our findings highlighted some original data about the role of the microtubular network during early phases of canine neuronal morphogenesis. In addition, the experimental protocol underlined the utility of this alternative model that allows to bypass both the scarcity of commercial canine neuronal cell lines and the need to resort to experimental dogs, respecting the 3Rs principles (reduction, refinement, and replacement).
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Affiliation(s)
- Sergio Domenico Gadau
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100, Italy.
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30
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Papandréou MJ, Leterrier C. The functional architecture of axonal actin. Mol Cell Neurosci 2018; 91:151-159. [PMID: 29758267 DOI: 10.1016/j.mcn.2018.05.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/10/2018] [Accepted: 05/11/2018] [Indexed: 11/17/2022] Open
Abstract
The cytoskeleton builds and supports the complex architecture of neurons. It orchestrates the specification, growth, and compartmentation of the axon: axon initial segment, axonal shaft, presynapses. The cytoskeleton must then maintain this intricate architecture for the whole life of its host, but also drive its adaptation to new network demands and changing physiological conditions. Microtubules are readily visible inside axon shafts by electron microscopy, whereas axonal actin study has long been focused on dynamic structures of the axon such as growth cones. Super-resolution microscopy and live-cell imaging have recently revealed new actin-based structures in mature axons: rings, hotspots and trails. This has caused renewed interest for axonal actin, with efforts underway to understand the precise organization and cellular functions of these assemblies. Actin is also present in presynapses, where its arrangement is still poorly defined, and its functions vigorously debated. Here we review the organization of axonal actin, focusing on recent advances and current questions in this rejuvenated field.
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31
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Mortal S, Iseppon F, Perissinotto A, D'Este E, Cojoc D, Napolitano LMR, Torre V. Actin Waves Do Not Boost Neurite Outgrowth in the Early Stages of Neuron Maturation. Front Cell Neurosci 2017; 11:402. [PMID: 29326552 PMCID: PMC5741660 DOI: 10.3389/fncel.2017.00402] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/01/2017] [Indexed: 11/27/2022] Open
Abstract
During neurite development, Actin Waves (AWs) emerge at the neurite base and move up to its tip, causing a transient retraction of the Growth Cone (GC). Many studies have shown that AWs are linked to outbursts of neurite growth and, therefore, contribute to the fast elongation of the nascent axon. Using long term live cell-imaging, we show that AWs do not boost neurite outgrowth and that neurites without AWs can elongate for several hundred microns. Inhibition of Myosin II abolishes the transient GC retraction and strongly modifies the AWs morphology. Super-resolution nanoscopy shows that Myosin IIB shapes the growth cone-like AWs structure and is differently distributed in AWs and GCs. Interestingly, depletion of membrane cholesterol and inhibition of Rho GTPases decrease AWs frequency and velocity. Our results indicate that Myosin IIB, membrane tension, and small Rho GTPases are important players in the regulation of the AW dynamics. Finally, we suggest a role for AWs in maintaining the GCs active during environmental exploration.
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Affiliation(s)
- Simone Mortal
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Federico Iseppon
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Andrea Perissinotto
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Elisa D'Este
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Dan Cojoc
- Optical Manipulation Lab, Istituto Officina dei Materiali (CNR), Trieste, Italy
| | - Luisa M R Napolitano
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Vincent Torre
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
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32
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Ning G, Liu Y, Xu H, Li Y, Wu H, Wang X, Feng S. Gene silencing NMII promotes axonal regeneration against contusive spinal cord injury in rats. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2017; 10:11345-11352. [PMID: 31966489 PMCID: PMC6965883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/09/2017] [Indexed: 06/10/2023]
Abstract
There are drastic changes that occur in the impaired regions after spinal cord injury (SCI), however, improvement of the detrimental pathological process after injury is limited in the mammalian adult, which is due a large part to the failure of local axons to grow. Non-muscle myosin II (NMII) has been proved having essential role in the regulation of cytoskeletal structure and genetic silencing NMII markedly accelerates axon growth in vitro. Our purpose is to explore the association between phosphorylated NMII expression and axonal regeneration after SCI in rats and determine whether gene silencing NMII can improve the locomotor function in rats with SCI. The results showed that phosphorylated NMII level was up regulated after SCI and may even play important role in inhibiting neuronal survival and axonal regeneration. After silencing NMII, the viability of neurons, proliferation of axons, synaptic connection and locomotor functional recovery were promoted significantly after SCI. Our study provides an effective way by direct regulation of neuron viability, the proliferation of axons and synaptic connection for treating SCI, which may be a novel method for repairing SCI. However, the specific signaling pathway mechanisms about the recovery require further study.
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Affiliation(s)
- Guangzhi Ning
- Department of Orthopedics, Tianjin Medical University General HospitalTianjing, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin CityTianjin, China
| | - Yang Liu
- Department of Orthopedics, Tianjin Medical University General HospitalTianjing, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin CityTianjin, China
| | - Hong Xu
- Department of Orthopedics, Tianjin Medical University General HospitalTianjing, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin CityTianjin, China
| | - Yulin Li
- Department of Orthopedics, Tianjin Medical University General HospitalTianjing, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin CityTianjin, China
| | - Hong Wu
- Department of Orthopedics, Tianjin Medical University General HospitalTianjing, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin CityTianjin, China
| | - Xiaobo Wang
- Department of Orthopedics, Tianjin Medical University General HospitalTianjing, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin CityTianjin, China
| | - Shiqing Feng
- Department of Orthopedics, Tianjin Medical University General HospitalTianjing, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin CityTianjin, China
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33
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Mogessie B, Schuh M. Actin protects mammalian eggs against chromosome segregation errors. Science 2017; 357:357/6353/eaal1647. [DOI: 10.1126/science.aal1647] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 06/28/2017] [Indexed: 11/02/2022]
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Athamneh AIM, He Y, Lamoureux P, Fix L, Suter DM, Miller KE. Neurite elongation is highly correlated with bulk forward translocation of microtubules. Sci Rep 2017; 7:7292. [PMID: 28779177 PMCID: PMC5544698 DOI: 10.1038/s41598-017-07402-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 06/28/2017] [Indexed: 11/09/2022] Open
Abstract
During the development of the nervous system and regeneration following injury, microtubules (MTs) are required for neurite elongation. Whether this elongation occurs primarily through tubulin assembly at the tip of the axon, the transport of individual MTs, or because MTs translocate forward in bulk is unclear. Using fluorescent speckle microscopy (FSM), differential interference contrast (DIC), and phase contrast microscopy, we tracked the movement of MTs, phase dense material, and docked mitochondria in chick sensory and Aplysia bag cell neurons growing rapidly on physiological substrates. In all cases, we find that MTs and other neuritic components move forward in bulk at a rate that on average matches the velocity of neurite elongation. To better understand whether and why MT assembly is required for bulk translocation, we disrupted it with nocodazole. We found this blocked the forward bulk advance of material along the neurite and was paired with a transient increase in axonal tension. This indicates that disruption of MT dynamics interferes with neurite outgrowth, not by disrupting the net assembly of MTs at the growth cone, but rather because it alters the balance of forces that power the bulk forward translocation of MTs.
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Affiliation(s)
- Ahmad I M Athamneh
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Yingpei He
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Phillip Lamoureux
- Department of Integrative Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Lucas Fix
- Department of Integrative Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Daniel M Suter
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA. .,Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA. .,Bindley Bioscience Center, Purdue University, West Lafayette, IN, 47907, USA. .,Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA.
| | - Kyle E Miller
- Department of Integrative Biology, Michigan State University, East Lansing, MI, 48824, USA.
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35
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Omotade OF, Pollitt SL, Zheng JQ. Actin-based growth cone motility and guidance. Mol Cell Neurosci 2017; 84:4-10. [PMID: 28268126 DOI: 10.1016/j.mcn.2017.03.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/27/2017] [Accepted: 03/03/2017] [Indexed: 11/27/2022] Open
Abstract
Nerve growth cones, the dilated tip of developing axons, are equipped with exquisite abilities to sense environmental cues and to move rapidly through complex terrains of developing brain, leading the axons to their specific targets for precise neuronal wiring. The actin cytoskeleton is the major component of the growth cone that powers its directional motility. Past research has provided significant insights into the mechanisms by which growth cones translate extracellular signals into directional migration. In this review, we summarize the actin-based mechanisms underlying directional growth cone motility, examine novel findings, and discuss the outstanding questions concerning the actin-based growth cone behaviors.
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Affiliation(s)
- Omotola F Omotade
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States; Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Stephanie L Pollitt
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States; Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - James Q Zheng
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States; Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, United States.
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36
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Sun X, Zhou Z, Man C, Leung A, Ngan A. Cell-structure specific necrosis by optical-trap induced intracellular nuclear oscillation. J Mech Behav Biomed Mater 2017; 66:58-67. [DOI: 10.1016/j.jmbbm.2016.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 10/25/2016] [Accepted: 10/27/2016] [Indexed: 12/22/2022]
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37
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Katta S, Krieg M, Goodman MB. Feeling force: physical and physiological principles enabling sensory mechanotransduction. Annu Rev Cell Dev Biol 2016; 31:347-71. [PMID: 26566115 DOI: 10.1146/annurev-cellbio-100913-013426] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Organisms as diverse as microbes, roundworms, insects, and mammals detect and respond to applied force. In animals, this ability depends on ionotropic force receptors, known as mechanoelectrical transduction (MeT) channels, that are expressed by specialized mechanoreceptor cells embedded in diverse tissues and distributed throughout the body. These cells mediate hearing, touch, and proprioception and play a crucial role in regulating organ function. Here, we attempt to integrate knowledge about the architecture of mechanoreceptor cells and their sensory organs with principles of cell mechanics, and we consider how engulfing tissues contribute to mechanical filtering. We address progress in the quest to identify the proteins that form MeT channels and to understand how these channels are gated. For clarity and convenience, we focus on sensory mechanobiology in nematodes, fruit flies, and mice. These themes are emphasized: asymmetric responses to applied forces, which may reflect anisotropy of the structure and mechanics of sensory mechanoreceptor cells, and proteins that function as MeT channels, which appear to have emerged many times through evolution.
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Affiliation(s)
- Samata Katta
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305;
| | - Michael Krieg
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305;
| | - Miriam B Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305;
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38
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Pacheco A, Gallo G. Actin filament-microtubule interactions in axon initiation and branching. Brain Res Bull 2016; 126:300-310. [PMID: 27491623 DOI: 10.1016/j.brainresbull.2016.07.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 07/28/2016] [Accepted: 07/30/2016] [Indexed: 10/21/2022]
Abstract
Neurons begin life as spherical cells. A major hallmark of neuronal development is the formation of elongating processes from the cell body which subsequently differentiate into dendrites and the axon. The formation and later development of neuronal processes is achieved through the concerted organization of actin filaments and microtubules. Here, we review the literature regarding recent advances in the understanding of cytoskeletal interactions in neurons focusing on the initiation of processes from neuronal cell bodies and the collateral branching of axons. The complex crosstalk between cytoskeletal elements is mediated by a cohort of proteins that either bind both cytoskeletal systems or allow one to regulate the other. Recent studies have highlighted the importance of microtubule plus-tip proteins in the regulation of the dynamics and organization of actin filaments, while also providing a mechanism for the subcellular capture and guidance of microtubule tips by actin filaments. Although the understanding of cytoskeletal crosstalk and interactions in neuronal morphogenesis has advanced significantly in recent years the appreciation of the neuron as an integrated cytoskeletal system remains a frontier.
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Affiliation(s)
- Almudena Pacheco
- Temple University, Lewis Kats School of Medicine, Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, 3500 North Broad Street, Philadelphia, PA 19140, United States
| | - Gianluca Gallo
- Temple University, Lewis Kats School of Medicine, Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, 3500 North Broad Street, Philadelphia, PA 19140, United States.
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39
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Abstract
UNLABELLED Growth cones interact with the extracellular matrix (ECM) through integrin receptors at adhesion sites termed point contacts. Point contact adhesions link ECM proteins to the actin cytoskeleton through numerous adaptor and signaling proteins. One presumed function of growth cone point contacts is to restrain or "clutch" myosin-II-based filamentous actin (F-actin) retrograde flow (RF) to promote leading edge membrane protrusion. In motile non-neuronal cells, myosin-II binds and exerts force upon actin filaments at the leading edge, where clutching forces occur. However, in growth cones, it is unclear whether similar F-actin-clutching forces affect axon outgrowth and guidance. Here, we show in Xenopus spinal neurons that RF is reduced in rapidly migrating growth cones on laminin (LN) compared with non-integrin-binding poly-d-lysine (PDL). Moreover, acute stimulation with LN accelerates axon outgrowth over a time course that correlates with point contact formation and reduced RF. These results suggest that RF is restricted by the assembly of point contacts, which we show occurs locally by two-channel imaging of RF and paxillin. Further, using micropatterns of PDL and LN, we demonstrate that individual growth cones have differential RF rates while interacting with two distinct substrata. Opposing effects on RF rates were also observed in growth cones treated with chemoattractive and chemorepulsive axon guidance cues that influence point contact adhesions. Finally, we show that RF is significantly attenuated in vivo, suggesting that it is restrained by molecular clutching forces within the spinal cord. Together, our results suggest that local clutching of RF can control axon guidance on ECM proteins downstream of axon guidance cues. SIGNIFICANCE STATEMENT Here, we correlate point contact adhesions directly with clutching of filamentous actin retrograde flow (RF), which our findings strongly suggest guides developing axons. Acute assembly of new point contact adhesions is temporally and spatially linked to attenuation of RF at sites of forward membrane protrusion. Importantly, clutching of RF is modulated by extracellular matrix (ECM) proteins and soluble axon guidance cues, suggesting that it may regulate axon guidance in vivo. Consistent with this notion, we found that RF rates of spinal neuron growth cones were slower in vivo than what was observed in vitro. Together, our study provides the best evidence that growth cone-ECM adhesions clutch RF locally to guide axons in vivo.
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40
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Zou Y, Qin J, Huang Z, Yin G, Pu X, He D. Fabrication of Aligned Conducting PPy-PLLA Fiber Films and Their Electrically Controlled Guidance and Orientation for Neurites. ACS APPLIED MATERIALS & INTERFACES 2016; 8:12576-82. [PMID: 27172537 DOI: 10.1021/acsami.6b00957] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Electrically conductive biomaterial scaffolds have great potential in neural tissue regeneration. In this work, an aligned conductive fibrous scaffold was prepared by electrospinning PLLA on rotating collector and chemical oxidation polymerization of pyrrole (PPy) codoped with poly(glutamic acid)/dodecyl benzenesulfonic acid sodium. The characterization results of composition, structure and mechanics of fiber films show that the existence of weak polar van der Waals' force between PPy coating and PLLA fibers. The resistivity of aligned rough PPy-PLLA fiber film (about 800 nm of fiber diameter) at the perpendicular and parallel directions is 0.971 and 0.874 Ω m, respectively. Aligned rough PPy-PLLA fiber film could guide the extension of 68% PC12 neurites along the direction of fiber axis. Under electrostimulation (ES) of 100, 200, and 400 mV/cm, median neurite lengths of differentiated PC12 on aligned fiber-films are 128, 149, and 141 μm, respectively. Furthermore, under ES of 100, 200, and 400 mV/cm, the alignment rate of neurite along the electropotential direction (angle between neurite and electropotential direction ≤10°) on random fibers film are 17, 23, and 28%, respectively, and the alignment rate of neurites along the fiber axis (angle between neurite and fiber axis ≤10°) on aligned fibers film reach to 76, 83, and 79%, respectively, indicating that the combination of ES and rough conducting aligned structure could adjust the alignment of cellular neurites along the direction of the fiber axis or electropotential.
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Affiliation(s)
- Yuanwen Zou
- College of Materials Science and Engineering, Sichuan University , Chengdu 610065, China
| | - Jiabang Qin
- College of Materials Science and Engineering, Sichuan University , Chengdu 610065, China
| | - Zhongbing Huang
- College of Materials Science and Engineering, Sichuan University , Chengdu 610065, China
| | - Guangfu Yin
- College of Materials Science and Engineering, Sichuan University , Chengdu 610065, China
| | - Ximing Pu
- College of Materials Science and Engineering, Sichuan University , Chengdu 610065, China
| | - Da He
- College of Materials Science and Engineering, Sichuan University , Chengdu 610065, China
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41
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Abstract
The growth and migration of neurons require continuous remodelling of the neuronal cytoskeleton, providing a versatile cellular framework for force generation and guided movement, in addition to structural support. Actin filaments and microtubules are central to the dynamic action of the cytoskeleton and rapid advances in imaging technologies are enabling ever more detailed visualisation of the dynamic intracellular networks that they form. However, these filaments do not act individually and an expanding body of evidence emphasises the importance of actin-microtubule crosstalk in orchestrating cytoskeletal dynamics. Here, we summarise our current understanding of the structure and dynamics of actin and microtubules in isolation, before reviewing both the mechanisms and the molecular players involved in mediating actin-microtubule crosstalk in neurons.
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Affiliation(s)
- Charlotte H Coles
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
| | - Frank Bradke
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
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42
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Winkle CC, Taylor KL, Dent EW, Gallo G, Greif KF, Gupton SL. Beyond the cytoskeleton: The emerging role of organelles and membrane remodeling in the regulation of axon collateral branches. Dev Neurobiol 2016; 76:1293-1307. [PMID: 27112549 DOI: 10.1002/dneu.22398] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/11/2016] [Accepted: 04/21/2016] [Indexed: 12/19/2022]
Abstract
The generation of axon collateral branches is a fundamental aspect of the development of the nervous system and the response of axons to injury. Although much has been discovered about the signaling pathways and cytoskeletal dynamics underlying branching, additional aspects of the cell biology of axon branching have received less attention. This review summarizes recent advances in our understanding of key factors involved in axon branching. This article focuses on how cytoskeletal mechanisms, intracellular organelles, such as mitochondria and the endoplasmic reticulum, and membrane remodeling (exocytosis and endocytosis) contribute to branch initiation and formation. Together this growing literature provides valuable insight as well as a platform for continued investigation into how multiple aspects of axonal cell biology are spatially and temporally orchestrated to give rise to axon branches. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1293-1307, 2016.
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Affiliation(s)
- Cortney C Winkle
- Neurobiology Curriculum, University of North Carolina, Chapel Hill, North Carolina, 27599
| | - Kendra L Taylor
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, Wisconsin, 53705
| | - Erik W Dent
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, 53705
| | - Gianluca Gallo
- Lewis Katz School of Medicine, Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Temple University, Philadelphia, Pennsylvania, 19140
| | - Karen F Greif
- Department of Biology, Bryn Mawr College, Bryn Mawr, Pennsylvania, 19010
| | - Stephanie L Gupton
- Department of Cell Biology and Physiology, Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina, 27599
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43
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Increase in Growth Cone Size Correlates with Decrease in Neurite Growth Rate. Neural Plast 2016; 2016:3497901. [PMID: 27274874 PMCID: PMC4870373 DOI: 10.1155/2016/3497901] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/03/2016] [Indexed: 11/18/2022] Open
Abstract
Several important discoveries in growth cone cell biology were made possible by the use of growth cones derived from cultured Aplysia bag cell neurons, including the characterization of the organization and dynamics of the cytoskeleton. The majority of these Aplysia studies focused on large growth cones induced by poly-L-lysine substrates at early stages in cell culture. Under these conditions, the growth cones are in a steady state with very little net advancement. Here, we offer a comprehensive cellular analysis of the motile behavior of Aplysia growth cones in culture beyond this pausing state. We found that average growth cone size decreased with cell culture time whereas average growth rate increased. This inverse correlation of growth rate and growth cone size was due to the occurrence of large growth cones with a peripheral domain larger than 100 μm(2). The large pausing growth cones had central domains that were less consistently aligned with the direction of growth and could be converted into smaller, faster-growing growth cones by addition of a three-dimensional collagen gel. We conclude that the significant lateral expansion of lamellipodia and filopodia as observed during these culture conditions has a negative effect on neurite growth.
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44
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De La Cruz EM, Martiel JL, Blanchoin L. Mechanical heterogeneity favors fragmentation of strained actin filaments. Biophys J 2016; 108:2270-81. [PMID: 25954884 DOI: 10.1016/j.bpj.2015.03.058] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/19/2015] [Accepted: 03/02/2015] [Indexed: 10/23/2022] Open
Abstract
We present a general model of actin filament deformation and fragmentation in response to compressive forces. The elastic free energy density along filaments is determined by their shape and mechanical properties, which were modeled in terms of bending, twisting, and twist-bend coupling elasticities. The elastic energy stored in filament deformation (i.e., strain) tilts the fragmentation-annealing reaction free-energy profile to favor fragmentation. The energy gradient introduces a local shear force that accelerates filament intersubunit bond rupture. The severing protein, cofilin, renders filaments more compliant in bending and twisting. As a result, filaments that are partially decorated with cofilin are mechanically heterogeneous (i.e., nonuniform) and display asymmetric shape deformations and energy profiles distinct from mechanically homogenous (i.e., uniform), bare actin, or saturated cofilactin filaments. The local buckling strain depends on the relative size of the compliant segment as well as the bending and twisting rigidities of flanking regions. Filaments with a single bare/cofilin-decorated boundary localize energy and force adjacent to the boundary, within the compliant cofilactin segment. Filaments with small cofilin clusters were predicted to fragment within the compliant cofilactin rather than at boundaries. Neglecting contributions from twist-bend coupling elasticity underestimates the energy density and gradients along filaments, and thus the net effects of filament strain to fragmentation. Spatial confinement causes compliant cofilactin segments and filaments to adopt higher deformation modes and store more elastic energy, thereby promoting fragmentation. The theory and simulations presented here establish a quantitative relationship between actin filament fragmentation thermodynamics and elasticity, and reveal how local discontinuities in filament mechanical properties introduced by regulatory proteins can modulate both the severing efficiency and location along filaments. The emergent behavior of mechanically heterogeneous filaments, particularly under confinement, emphasizes that severing in cells is likely to be influenced by multiple physical and chemical factors.
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Affiliation(s)
- Enrique M De La Cruz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut.
| | - Jean-Louis Martiel
- Physics of the Cytoskeleton and Morphogenesis Group, Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire de Physiologie Cellulaire et Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Énergie Atomique et aux Énergies Alternatives/Institut National de la Recherche Agronomique/Université Joseph Fourier, Grenoble, France.
| | - Laurent Blanchoin
- Physics of the Cytoskeleton and Morphogenesis Group, Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire de Physiologie Cellulaire et Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Énergie Atomique et aux Énergies Alternatives/Institut National de la Recherche Agronomique/Université Joseph Fourier, Grenoble, France
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45
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Antoine-Bertrand J, Fu M, Lamarche-Vane N. Direct measurement of oscillatory RhoA activity in embryonic cortical neurons stimulated with the axon guidance cue netrin-1 using fluorescence resonance energy transfer. Biol Cell 2016; 108:115-26. [PMID: 26787017 DOI: 10.1111/boc.201500077] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 01/15/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND INFORMATION Rho GTPases play an essential role during the development of the nervous system. They induce cytoskeletal rearrangements that are critical for the regulation of axon outgrowth and guidance. It is generally accepted that Rac1 and Cdc42 are positive regulators of axon outgrowth and guidance, whereas RhoA is a negative regulator. However, spatiotemporal control of their activity can modify the function of Rho GTPases during axonal morphogenesis. Signalling downstream of the axon guidance cue netrin-1 and its receptor deleted in colorectal cancer (DCC) triggers the activation of Rac1 and the inhibition of RhoA to promote axon outgrowth. However, our previous work also suggests that netrin-1/DCC signalling can activate RhoA in a time- and region-specific manner. RESULTS Here, we visualised RhoA activation in response to netrin-1 in live embryonic cortical neurons using fluorescence resonance energy transfer. RhoA activity oscillated in unstimulated neurons and netrin-1 increased the amplitude of the oscillations in growth cones after 5 min of stimulation. Within this period of time, netrin-1 transiently increased RhoA activity and modulated the pattern of RhoA oscillations. We found that the timing of netrin-1-induced RhoA activation was different in whole neurons, cell bodies and growth cones. CONCLUSIONS We conclude that netrin-1 modulates the spatiotemporal activation of RhoA in embryonic cortical neurons. SIGNIFICANCE This study demonstrates for the first time the short-term localised activation of RhoA in neuronal growth cones by the axon guidance cue netrin-1.
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Affiliation(s)
- Judith Antoine-Bertrand
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.,Cancer Research Program, Research Institute of the McGill University Health Centre (RI-MUHC), Montreal, Quebec, Canada
| | - Min Fu
- Cancer Research Program, Research Institute of the McGill University Health Centre (RI-MUHC), Montreal, Quebec, Canada
| | - Nathalie Lamarche-Vane
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.,Cancer Research Program, Research Institute of the McGill University Health Centre (RI-MUHC), Montreal, Quebec, Canada
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Turney SG, Ahmed M, Chandrasekar I, Wysolmerski RB, Goeckeler ZM, Rioux RM, Whitesides GM, Bridgman PC. Nerve growth factor stimulates axon outgrowth through negative regulation of growth cone actomyosin restraint of microtubule advance. Mol Biol Cell 2016; 27:500-17. [PMID: 26631553 PMCID: PMC4751601 DOI: 10.1091/mbc.e15-09-0636] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 01/19/2023] Open
Abstract
Nerve growth factor (NGF) promotes growth, differentiation, and survival of sensory neurons in the mammalian nervous system. Little is known about how NGF elicits faster axon outgrowth or how growth cones integrate and transform signal input to motor output. Using cultured mouse dorsal root ganglion neurons, we found that myosin II (MII) is required for NGF to stimulate faster axon outgrowth. From experiments inducing loss or gain of function of MII, specific MII isoforms, and vinculin-dependent adhesion-cytoskeletal coupling, we determined that NGF causes decreased vinculin-dependent actomyosin restraint of microtubule advance. Inhibition of MII blocked NGF stimulation, indicating the central role of restraint in directed outgrowth. The restraint consists of myosin IIB- and IIA-dependent processes: retrograde actin network flow and transverse actin bundling, respectively. The processes differentially contribute on laminin-1 and fibronectin due to selective actin tethering to adhesions. On laminin-1, NGF induced greater vinculin-dependent adhesion-cytoskeletal coupling, which slowed retrograde actin network flow (i.e., it regulated the molecular clutch). On fibronectin, NGF caused inactivation of myosin IIA, which negatively regulated actin bundling. On both substrates, the result was the same: NGF-induced weakening of MII-dependent restraint led to dynamic microtubules entering the actin-rich periphery more frequently, giving rise to faster elongation.
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Affiliation(s)
- Stephen G Turney
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138
| | - Mostafa Ahmed
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
| | - Indra Chandrasekar
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
| | - Robert B Wysolmerski
- Department of Neurobiology and Anatomy, West Virginia University School of Medicine, Morgantown, WV 26506
| | - Zoe M Goeckeler
- Department of Neurobiology and Anatomy, West Virginia University School of Medicine, Morgantown, WV 26506
| | - Robert M Rioux
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
| | - George M Whitesides
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
| | - Paul C Bridgman
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110
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47
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Miyagi T, Tanaka S, Hide I, Shirafuji T, Sakai N. The Subcellular Dynamics of the Gs-Linked Receptor GPR3 Contribute to the Local Activation of PKA in Cerebellar Granular Neurons. PLoS One 2016; 11:e0147466. [PMID: 26800526 PMCID: PMC4723318 DOI: 10.1371/journal.pone.0147466] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/03/2016] [Indexed: 12/12/2022] Open
Abstract
G-protein-coupled receptor (GPR) 3 is a member of the GPR family that constitutively activates adenylate cyclase. We have reported that the expression of GPR3 in cerebellar granular neurons (CGNs) contributes to neurite outgrowth and modulates neuronal proliferation and survival. To further identify its role, we have analyzed the precise distribution and local functions of GPR3 in neurons. The fluorescently tagged GPR3 protein was distributed in the plasma membrane, the Golgi body, and the endosomes. In addition, we have revealed that the plasma membrane expression of GPR3 functionally up-regulated the levels of PKA, as measured by a PKA FRET indicator. Next, we asked if the PKA activity was modulated by the expression of GPR3 in CGNs. PKA activity was highly modulated at the neurite tips compared to the soma. In addition, the PKA activity at the neurite tips was up-regulated when GPR3 was transfected into the cells. However, local PKA activity was decreased when endogenous GPR3 was suppressed by a GPR3 siRNA. Finally, we determined the local dynamics of GPR3 in CGNs using time-lapse analysis. Surprisingly, the fluorescent GPR3 puncta were transported along the neurite in both directions over time. In addition, the anterograde movements of the GPR3 puncta in the neurite were significantly inhibited by actin or microtubule polymerization inhibitors and were also disturbed by the Myosin II inhibitor blebbistatin. Moreover, the PKA activity at the tips of the neurites was decreased when blebbistatin was administered. These results suggested that GPR3 was transported along the neurite and contributed to the local activation of PKA in CGN development. The local dynamics of GPR3 in CGNs may affect local neuronal functions, including neuronal differentiation and maturation.
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Affiliation(s)
- Tatsuhiro Miyagi
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Shigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Izumi Hide
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Toshihiko Shirafuji
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
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48
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O'Toole M, Lamoureux P, Miller KE. Measurement of subcellular force generation in neurons. Biophys J 2016; 108:1027-37. [PMID: 25762315 DOI: 10.1016/j.bpj.2015.01.021] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 01/19/2015] [Accepted: 01/23/2015] [Indexed: 11/24/2022] Open
Abstract
Forces are important for neuronal outgrowth during the initial wiring of the nervous system and after trauma, yet subcellular force generation over the microtubule-rich region at the rear of the growth cone and along the axon has never, to our knowledge, been directly measured. Because previous studies have indicated microtubule polymerization and the microtubule-associated proteins Kinesin-1 and dynein all generate forces that push microtubules forward, a major question is whether the net forces in these regions are contractile or expansive. A challenge in addressing this is that measuring local subcellular force generation is difficult. Here we develop an analytical mathematical model that describes the relationship between unequal subcellular forces arranged in series within the neuron and the net overall tension measured externally. Using force-calibrated towing needles to measure and apply forces, in combination with docked mitochondria to monitor subcellular strain, we then directly measure force generation over the rear of the growth cone and along the axon of chick sensory neurons. We find the rear of the growth cone generates 2.0 nN of contractile force, the axon generates 0.6 nN of contractile force, and that the net overall tension generated by the neuron is 1.3 nN. This work suggests that the forward bulk flow of the cytoskeletal framework that occurs during axonal elongation and growth-cone pauses arises because strong contractile forces in the rear of the growth cone pull material forward.
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Affiliation(s)
- Matthew O'Toole
- Department of Mathematics, Kettering University, Flint, Michigan
| | - Phillip Lamoureux
- Department of Zoology, Michigan State University, East Lansing, Michigan
| | - Kyle E Miller
- Department of Zoology, Michigan State University, East Lansing, Michigan.
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Michalski JP, Cummings SE, O'Meara RW, Kothary R. Integrin-linked kinase regulates oligodendrocyte cytoskeleton, growth cone, and adhesion dynamics. J Neurochem 2016; 136:536-49. [DOI: 10.1111/jnc.13446] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/15/2015] [Accepted: 11/20/2015] [Indexed: 01/28/2023]
Affiliation(s)
- John-Paul Michalski
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
| | - Sarah E. Cummings
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
| | - Ryan W. O'Meara
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
| | - Rashmi Kothary
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
- Department of Medicine; University of Ottawa; Ottawa Ontario Canada
- University of Ottawa Centre for Neuromuscular Disease; Ottawa Ontario Canada
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50
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Menon S, Gupton SL. Building Blocks of Functioning Brain: Cytoskeletal Dynamics in Neuronal Development. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 322:183-245. [PMID: 26940519 PMCID: PMC4809367 DOI: 10.1016/bs.ircmb.2015.10.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neural connectivity requires proper polarization of neurons, guidance to appropriate target locations, and establishment of synaptic connections. From when neurons are born to when they finally reach their synaptic partners, neurons undergo constant rearrangment of the cytoskeleton to achieve appropriate shape and polarity. Of particular importance to neuronal guidance to target locations is the growth cone at the tip of the axon. Growth-cone steering is also dictated by the underlying cytoskeleton. All these changes require spatiotemporal control of the cytoskeletal machinery. This review summarizes the proteins that are involved in modulating the actin and microtubule cytoskeleton during the various stages of neuronal development.
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Affiliation(s)
- Shalini Menon
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, United States of America
| | - Stephanie L Gupton
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, United States of America; Neuroscience Center and Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC, United States of America; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States of America.
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