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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Di X, Gao X, Peng L, Ai J, Jin X, Qi S, Li H, Wang K, Luo D. Cellular mechanotransduction in health and diseases: from molecular mechanism to therapeutic targets. Signal Transduct Target Ther 2023; 8:282. [PMID: 37518181 PMCID: PMC10387486 DOI: 10.1038/s41392-023-01501-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 08/01/2023] Open
Abstract
Cellular mechanotransduction, a critical regulator of numerous biological processes, is the conversion from mechanical signals to biochemical signals regarding cell activities and metabolism. Typical mechanical cues in organisms include hydrostatic pressure, fluid shear stress, tensile force, extracellular matrix stiffness or tissue elasticity, and extracellular fluid viscosity. Mechanotransduction has been expected to trigger multiple biological processes, such as embryonic development, tissue repair and regeneration. However, prolonged excessive mechanical stimulation can result in pathological processes, such as multi-organ fibrosis, tumorigenesis, and cancer immunotherapy resistance. Although the associations between mechanical cues and normal tissue homeostasis or diseases have been identified, the regulatory mechanisms among different mechanical cues are not yet comprehensively illustrated, and no effective therapies are currently available targeting mechanical cue-related signaling. This review systematically summarizes the characteristics and regulatory mechanisms of typical mechanical cues in normal conditions and diseases with the updated evidence. The key effectors responding to mechanical stimulations are listed, such as Piezo channels, integrins, Yes-associated protein (YAP) /transcriptional coactivator with PDZ-binding motif (TAZ), and transient receptor potential vanilloid 4 (TRPV4). We also reviewed the key signaling pathways, therapeutic targets and cutting-edge clinical applications of diseases related to mechanical cues.
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Affiliation(s)
- Xingpeng Di
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Xiaoshuai Gao
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Liao Peng
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Jianzhong Ai
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Xi Jin
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Shiqian Qi
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Hong Li
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China
| | - Kunjie Wang
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China.
| | - Deyi Luo
- Department of Urology and Institute of Urology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, P.R. China.
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3
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Alfadil E, Bradke F. Moving through the crowd. Where are we at understanding physiological axon growth? Semin Cell Dev Biol 2023; 140:63-71. [PMID: 35817655 DOI: 10.1016/j.semcdb.2022.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 01/28/2023]
Abstract
Axon growth enables the rapid wiring of the central nervous system. Understanding this process is a prerequisite to retriggering it under pathological conditions, such as a spinal cord injury, to elicit axon regeneration. The last decades saw progress in understanding the mechanisms underlying axon growth. Most of these studies employed cultured neurons grown on flat surfaces. Only recently studies on axon growth were performed in 3D. In these studies, physiological environments exposed more complex and dynamic aspects of axon development. Here, we describe current views on axon growth and highlight gaps in our knowledge. We discuss how axons interact with the extracellular matrix during development and the role of the growth cone and its cytoskeleton within. Finally, we propose that the time is ripe to study axon growth in a more physiological setting. This will help us uncover the physiologically relevant mechanisms underlying axon growth, and how they can be reactivated to induce axon regeneration.
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Affiliation(s)
- Eissa Alfadil
- Laboratory of Axon Growth and Regeneration, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, Building 99, 53127, Bonn, Germany.
| | - Frank Bradke
- Laboratory of Axon Growth and Regeneration, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, Building 99, 53127, Bonn, Germany
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4
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Abstract
Recently, substrate stiffness has been involved in the physiology and pathology of the nervous system. However, the role and function of substrate stiffness remain unclear. Here, we review known effects of substrate stiffness on nerve cell morphology and function in the central and peripheral nervous systems and their involvement in pathology. We hope this review will clarify the research status of substrate stiffness in nerve cells and neurological disorder.
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Affiliation(s)
- Weijin Si
- Key Laboratory of Cognitive Science, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central Minzu University, Wuhan 430074, China
| | - Jihong Gong
- Key Laboratory of Cognitive Science, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central Minzu University, Wuhan 430074, China
| | - Xiaofei Yang
- Key Laboratory of Cognitive Science, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis & Treatment, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central Minzu University, Wuhan 430074, China
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5
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Züger F, Berner N, Gullo MR. Towards a Novel Cost-Effective and Versatile Bioink for 3D-Bioprinting in Tissue Engineering. Biomimetics (Basel) 2023; 8:biomimetics8010027. [PMID: 36648813 PMCID: PMC9844313 DOI: 10.3390/biomimetics8010027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/16/2022] [Accepted: 01/03/2023] [Indexed: 01/11/2023] Open
Abstract
3D-bioprinting for tissue regeneration relies on, among other things, hydrogels with favorable rheological properties. These include shear thinning for cell-friendly extrusion, post-printing structural stability as well as physiologically relevant elastic moduli needed for optimal cell attachment, proliferation, differentiation and tissue maturation. This work introduces a cost-efficient gelatin-methylcellulose based hydrogel whose rheological properties can be independently optimized for optimal printability and tissue engineering. Hydrogel viscosities were designed to present three different temperature regimes: low viscosity for eased cell suspension and printing with minimal shear stress, form fidelity directly after printing and long term structural stability during incubation. Enzymatically crosslinked hydrogel scaffolds with stiffnesses ranging from 5 to 50 kPa were produced, enabling the hydrogel to biomimic cell environments for different types of tissues. The bioink showed high intrinsic cytocompatibility and tissues fabricated by embedding and bioprinting NIH 3T3 fibroblasts showed satisfactory viability. This novel hydrogel uses robust and inexpensive technology, which can be adjusted for implementation in tissue regeneration, e.g., in myocardial or neural tissue engineering.
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Affiliation(s)
- Fabian Züger
- Institute for Medical Engineering and Medical Informatics, University of Applied Sciences and Arts Northwestern Switzerland, Hofackerstrasse 30, CH-4312 Muttenz, Switzerland
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Natascha Berner
- Institute for Medical Engineering and Medical Informatics, University of Applied Sciences and Arts Northwestern Switzerland, Hofackerstrasse 30, CH-4312 Muttenz, Switzerland
| | - Maurizio R. Gullo
- Institute for Medical Engineering and Medical Informatics, University of Applied Sciences and Arts Northwestern Switzerland, Hofackerstrasse 30, CH-4312 Muttenz, Switzerland
- Correspondence: ; Tel.: +41-61-228-53-31
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6
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Ros O, Nicol X. Axon pathfinding and targeting: (R)evolution of insights from in vitro assays. Neuroscience 2023; 508:110-122. [PMID: 36096337 DOI: 10.1016/j.neuroscience.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 01/17/2023]
Abstract
Investigating axonal behaviors while neurons are connecting with each other has been a challenge since the early studies on nervous system development. While molecule-driven axon pathfinding has been theorized by observing neurons at different developmental stages in vivo, direct observation and measurements of axon guidance behaviors required the invention of in vitro systems enabling to test the impact of molecules or cellular extracts on axons growing in vitro. With time, the development of novel in vivo approaches has confirmed the mechanisms highlighted in culture and has led in vitro systems to be adapted for cellular processes that are still inaccessible in intact organisms. We here review the evolution of these in vitro assays, which started with crucial contributions from the Bonhoeffer lab.
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Affiliation(s)
- Oriol Ros
- Universitat de Barcelona, Department of Cell Biology, Physiology and Immunology, Avinguda Diagonal 643, 08028 Barcelona, Catalonia, Spain
| | - Xavier Nicol
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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7
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Castillo Ransanz L, Van Altena PFJ, Heine VM, Accardo A. Engineered cell culture microenvironments for mechanobiology studies of brain neural cells. Front Bioeng Biotechnol 2022; 10:1096054. [PMID: 36588937 PMCID: PMC9794772 DOI: 10.3389/fbioe.2022.1096054] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/29/2022] [Indexed: 12/15/2022] Open
Abstract
The biomechanical properties of the brain microenvironment, which is composed of different neural cell types, the extracellular matrix, and blood vessels, are critical for normal brain development and neural functioning. Stiffness, viscoelasticity and spatial organization of brain tissue modulate proliferation, migration, differentiation, and cell function. However, the mechanical aspects of the neural microenvironment are largely ignored in current cell culture systems. Considering the high promises of human induced pluripotent stem cell- (iPSC-) based models for disease modelling and new treatment development, and in light of the physiological relevance of neuromechanobiological features, applications of in vitro engineered neuronal microenvironments should be explored thoroughly to develop more representative in vitro brain models. In this context, recently developed biomaterials in combination with micro- and nanofabrication techniques 1) allow investigating how mechanical properties affect neural cell development and functioning; 2) enable optimal cell microenvironment engineering strategies to advance neural cell models; and 3) provide a quantitative tool to assess changes in the neuromechanobiological properties of the brain microenvironment induced by pathology. In this review, we discuss the biological and engineering aspects involved in studying neuromechanobiology within scaffold-free and scaffold-based 2D and 3D iPSC-based brain models and approaches employing primary lineages (neural/glial), cell lines and other stem cells. Finally, we discuss future experimental directions of engineered microenvironments in neuroscience.
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Affiliation(s)
- Lucía Castillo Ransanz
- Department of Child and Adolescence Psychiatry, Amsterdam Neuroscience, Emma Children’s Hospital, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Pieter F. J. Van Altena
- Department of Precision and Microsystems Engineering, Delft University of Technology, Delft, Netherlands
| | - Vivi M. Heine
- Department of Child and Adolescence Psychiatry, Amsterdam Neuroscience, Emma Children’s Hospital, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands,Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Department of Complex Trait Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, Netherlands,*Correspondence: Vivi M. Heine, ; Angelo Accardo,
| | - Angelo Accardo
- Department of Precision and Microsystems Engineering, Delft University of Technology, Delft, Netherlands,*Correspondence: Vivi M. Heine, ; Angelo Accardo,
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8
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Goncalves KE, Phillips S, Shah DSH, Athey D, Przyborski SA. Application of biomimetic surfaces and 3D culture technology to study the role of extracellular matrix interactions in neurite outgrowth and inhibition. BIOMATERIALS ADVANCES 2022; 144:213204. [PMID: 36434926 DOI: 10.1016/j.bioadv.2022.213204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/10/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022]
Abstract
The microenvironment that cells experience during in vitro culture can often be far removed from the native environment they are exposed to in vivo. To recreate the physiological environment that developing neurites experience in vivo, we combine a well-established model of human neurite development with, functionalisation of both 2D and 3D growth substrates with specific extracellular matrix (ECM) derived motifs displayed on engineered scaffold proteins. Functionalisation of growth substrates provides biochemical signals more reminiscent of the in vivo environment and the combination of this technology with 3D cell culture techniques, further recapitulates the native cellular environment by providing a more physiologically relevant geometry for neurites to develop. This biomaterials approach was used to study interactions between the ECM and developing neurites, along with the identification of specific motifs able to enhance neuritogenesis within this model. Furthermore, this technology was employed to study the process of neurite inhibition that has a detrimental effect on neuronal connectivity following injury to the central nervous system (CNS). Growth substrates were functionalised with inhibitory peptides released from damaged myelin within the injured spinal cord (Nogo & OMgp). This model was then utilised to study the underlying molecular mechanisms that govern neurite inhibition in addition to potential mechanisms of recovery.
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Affiliation(s)
- K E Goncalves
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - S Phillips
- Orla Protein Technologies Ltd, (now part of Porvair Sciences Ltd), 73 Clywedog Road East, Wrexham Industrial Estate, Wrexham LL13 9XS, UK
| | - D S H Shah
- Orla Protein Technologies Ltd, (now part of Porvair Sciences Ltd), 73 Clywedog Road East, Wrexham Industrial Estate, Wrexham LL13 9XS, UK
| | - D Athey
- Orla Protein Technologies Ltd, (now part of Porvair Sciences Ltd), 73 Clywedog Road East, Wrexham Industrial Estate, Wrexham LL13 9XS, UK
| | - S A Przyborski
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; Reprocell Europe Ltd, NETPark Incubator, Thomas Wright Way, Sedgefield TS21 3FD, UK.
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9
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Burute M, Jansen KI, Mihajlovic M, Vermonden T, Kapitein LC. Local changes in microtubule network mobility instruct neuronal polarization and axon specification. SCIENCE ADVANCES 2022; 8:eabo2343. [PMID: 36332030 PMCID: PMC9635826 DOI: 10.1126/sciadv.abo2343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
The polarization of neurons into axons and dendrites depends on extracellular cues, intracellular signaling, cytoskeletal rearrangements, and polarized transport, but the interplay between these processes during polarization remains unresolved. Here, we show that axon specification is determined by differences in microtubule network mobility between neurites, regulated by Rho guanosine triphosphatases (GTPases) and extracellular cues. In developing neurons, retrograde microtubule flow prevents the entry of the axon-selective motor protein Kinesin-1 into most neurites. Using inducible assays to control microtubule network flow, we demonstrate that local inhibition of microtubule mobility is sufficient to guide Kinesin-1 into a specific neurite, whereas long-term global inhibition induces the formation of multiple axons. We furthermore show that extracellular mechanical cues and intracellular Rho GTPase signaling control the local differences in microtubule network flow. These results reveal a novel cytoskeletal mechanism for neuronal polarization.
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Affiliation(s)
- Mithila Burute
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Klara I. Jansen
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Marko Mihajlovic
- Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences (UIPS), Science for Life, Utrecht University, Universiteitsweg 99, 3508 TB Utrecht, Netherlands
| | - Tina Vermonden
- Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences (UIPS), Science for Life, Utrecht University, Universiteitsweg 99, 3508 TB Utrecht, Netherlands
| | - Lukas C. Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
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10
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Kong L, Gao X, Qian Y, Sun W, You Z, Fan C. Biomechanical microenvironment in peripheral nerve regeneration: from pathophysiological understanding to tissue engineering development. Am J Cancer Res 2022; 12:4993-5014. [PMID: 35836812 PMCID: PMC9274750 DOI: 10.7150/thno.74571] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/11/2022] [Indexed: 01/12/2023] Open
Abstract
Peripheral nerve injury (PNI) caused by trauma, chronic disease and other factors may lead to partial or complete loss of sensory, motor and autonomic functions, as well as neuropathic pain. Biological activities are always accompanied by mechanical stimulation, and biomechanical microenvironmental homeostasis plays a complicated role in tissue repair and regeneration. Recent studies have focused on the effects of biomechanical microenvironment on peripheral nervous system development and function maintenance, as well as neural regrowth following PNI. For example, biomechanical factors-induced cluster gene expression changes contribute to formation of peripheral nerve structure and maintenance of physiological function. In addition, extracellular matrix and cell responses to biomechanical microenvironment alterations after PNI directly trigger a series of cascades for the well-organized peripheral nerve regeneration (PNR) process, where cell adhesion molecules, cytoskeletons and mechanically gated ion channels serve as mechanosensitive units, mechanical effector including focal adhesion kinase (FAK) and yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) as mechanotransduction elements. With the rapid development of tissue engineering techniques, a substantial number of PNR strategies such as aligned nerve guidance conduits, three-dimensional topological designs and piezoelectric scaffolds emerge expected to improve the neural biomechanical microenvironment in case of PNI. These tissue engineering nerve grafts display optimized mechanical properties and outstanding mechanomodulatory effects, but a few bottlenecks restrict their application scenes. In this review, the current understanding in biomechanical microenvironment homeostasis associated with peripheral nerve function and PNR is integrated, where we proposed the importance of balances of mechanosensitive elements, cytoskeletal structures, mechanotransduction cascades, and extracellular matrix components; a wide variety of promising tissue engineering strategies based on biomechanical modulation are introduced with some suggestions and prospects for future directions.
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Affiliation(s)
- Lingchi Kong
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.,Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai, 200233, China.,Youth Science and Technology Innovation Studio of Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China
| | - Xin Gao
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-dimension Materials, College of Materials Science and Engineering, Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai, 201620, China
| | - Yun Qian
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.,Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai, 200233, China.,Youth Science and Technology Innovation Studio of Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.,✉ Corresponding authors: Yun Qian, E-mail: ; Wei Sun, E-mail: ; Zhengwei You, E-mail: ; Cunyi Fan, E-mail:
| | - Wei Sun
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-dimension Materials, College of Materials Science and Engineering, Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai, 201620, China.,✉ Corresponding authors: Yun Qian, E-mail: ; Wei Sun, E-mail: ; Zhengwei You, E-mail: ; Cunyi Fan, E-mail:
| | - Zhengwei You
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-dimension Materials, College of Materials Science and Engineering, Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, Shanghai, 201620, China.,✉ Corresponding authors: Yun Qian, E-mail: ; Wei Sun, E-mail: ; Zhengwei You, E-mail: ; Cunyi Fan, E-mail:
| | - Cunyi Fan
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.,Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration, Shanghai, 200233, China.,Youth Science and Technology Innovation Studio of Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.,✉ Corresponding authors: Yun Qian, E-mail: ; Wei Sun, E-mail: ; Zhengwei You, E-mail: ; Cunyi Fan, E-mail:
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11
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Zhang SY, Zhao J, Ni JJ, Li H, Quan ZZ, Qing H. Application and prospects of high-throughput screening for in vitro neurogenesis. World J Stem Cells 2022; 14:393-419. [PMID: 35949394 PMCID: PMC9244953 DOI: 10.4252/wjsc.v14.i6.393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 04/07/2022] [Accepted: 05/28/2022] [Indexed: 02/06/2023] Open
Abstract
Over the past few decades, high-throughput screening (HTS) has made great contributions to new drug discovery. HTS technology is equipped with higher throughput, minimized platforms, more automated and computerized operating systems, more efficient and sensitive detection devices, and rapid data processing systems. At the same time, in vitro neurogenesis is gradually becoming important in establishing models to investigate the mechanisms of neural disease or developmental processes. However, challenges remain in generating more mature and functional neurons with specific subtypes and in establishing robust and standardized three-dimensional (3D) in vitro models with neural cells cultured in 3D matrices or organoids representing specific brain regions. Here, we review the applications of HTS technologies on in vitro neurogenesis, especially aiming at identifying the essential genes, chemical small molecules and adaptive microenvironments that hold great prospects for generating functional neurons or more reproductive and homogeneous 3D organoids. We also discuss the developmental tendency of HTS technology, e.g., so-called next-generation screening, which utilizes 3D organoid-based screening combined with microfluidic devices to narrow the gap between in vitro models and in vivo situations both physiologically and pathologically.
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Affiliation(s)
- Shu-Yuan Zhang
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Juan Zhao
- Aerospace Medical Center, Aerospace Center Hospital, Beijing 100049, China
| | - Jun-Jun Ni
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Hui Li
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Zhen-Zhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing 100081, China
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12
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Rempel SK, Welch MJ, Ludwig AL, Phillips MJ, Kancherla Y, Zack DJ, Gamm DM, Gómez TM. Human photoreceptors switch from autonomous axon extension to cell-mediated process pulling during synaptic marker redistribution. Cell Rep 2022; 39:110827. [PMID: 35584680 DOI: 10.1016/j.celrep.2022.110827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/18/2022] [Accepted: 04/26/2022] [Indexed: 11/19/2022] Open
Abstract
Photoreceptors (PRs) are the primary visual sensory cells, and their loss leads to blindness that is currently incurable. Although cell replacement therapy holds promise, success is hindered by our limited understanding of PR axon growth during development and regeneration. Here, we generate retinal organoids from human pluripotent stem cells to study the mechanisms of PR process extension. We find that early-born PRs exhibit autonomous axon extension from dynamic terminals. However, as PRs age from 40 to 80 days of differentiation, they lose dynamic terminals on 2D substrata and in 3D retinal organoids. Interestingly, PRs without motile terminals are still capable of extending axons but only by process stretching via attachment to motile non-PR cells. Immobile PR terminals of late-born PRs have fewer and less organized actin filaments but more synaptic proteins compared with early-born PR terminals. These findings may help inform the development of PR transplantation therapies.
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Affiliation(s)
- Sarah K Rempel
- Department of Neuroscience, University of Wisconsin - Madison, Madison, WI 53706, USA; McPherson Eye Research Institute, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Madalynn J Welch
- Department of Neuroscience, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Allison L Ludwig
- Department of Ophthalmology and Visual Sciences, University of Wisconsin - Madison, Madison, WI 53705, USA; McPherson Eye Research Institute, University of Wisconsin - Madison, Madison, WI 53706, USA; Waisman Center, University of Wisconsin - Madison, Madison, WI 53705, USA
| | - M Joseph Phillips
- McPherson Eye Research Institute, University of Wisconsin - Madison, Madison, WI 53706, USA; Waisman Center, University of Wisconsin - Madison, Madison, WI 53705, USA
| | - Yochana Kancherla
- Department of Neuroscience, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Donald J Zack
- Department of Ophthalmology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - David M Gamm
- Department of Ophthalmology and Visual Sciences, University of Wisconsin - Madison, Madison, WI 53705, USA; McPherson Eye Research Institute, University of Wisconsin - Madison, Madison, WI 53706, USA; Waisman Center, University of Wisconsin - Madison, Madison, WI 53705, USA
| | - Timothy M Gómez
- Department of Neuroscience, University of Wisconsin - Madison, Madison, WI 53706, USA; McPherson Eye Research Institute, University of Wisconsin - Madison, Madison, WI 53706, USA.
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13
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Wang Q, Xie J, Zhou C, Lai W. Substrate stiffness regulates the differentiation profile and functions of osteoclasts via cytoskeletal arrangement. Cell Prolif 2021; 55:e13172. [PMID: 34953003 PMCID: PMC8780927 DOI: 10.1111/cpr.13172] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 11/24/2021] [Accepted: 11/26/2021] [Indexed: 02/05/2023] Open
Abstract
Objectives Aging and common diseases alter the stiffness of bone tissue, causing changes to the microenvironment of the mechanosensitive bone cells. Osteoclasts, the sole bone‐resorbing cells, play a vital role in bone remodeling. This study was performed to elucidate the mechanism through which osteoclasts sense and react to substrate stiffness signals. Materials and methods We fabricated polydimethylsiloxane (PDMS) substrates of different stiffness degrees for osteoclast formation progressed from osteoclast precursors including bone marrow‐derived macrophages (BMMs) and RAW264.7 monocytes. Osteoclast differentiation in response to the stiffness signals was determined by examining the cell morphology, fusion/fission activities, transcriptional profile, and resorption function. Cytoskeletal changes and mechanosensitive adhesion molecules were also assessed. Results Stiffer PDMS substrates accelerated osteoclast differentiation, firstly observed by variations in their morphology and fusion/fission activities. Upregulation of canonical osteoclast markers (Nfatc1, Acp5, Ctsk, Camk2a, Mmp9, Rela, and Traf6) and the fusion master regulator DC‐stamp were detected on stiffer substrates, with similar increases in their bone resorption functions. Additionally, the activation of cytoskeleton‐associated adhesion molecules, including fibronectin and integrin αvβ3, followed by biochemical signaling cascades of paxillin, FAK, PKC, and RhoA, was detected on the stiffer substrates. Conclusions This is the first study to provide evidence proving that extracellular substrate stiffness is a strong determinant of osteoclast differentiation and functions. Higher stiffness upregulated the differentiation profile and activity of osteoclasts, revealing the mechanical regulation of osteoclast activity in bone homeostasis and diseases.
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Affiliation(s)
- Qingxuan Wang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Chenchen Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Wenli Lai
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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14
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Abe K, Baba K, Huang L, Wei KT, Okano K, Hosokawa Y, Inagaki N. Mechanosensitive axon outgrowth mediated by L1-laminin clutch interface. Biophys J 2021; 120:3566-3576. [PMID: 34384760 PMCID: PMC8456307 DOI: 10.1016/j.bpj.2021.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/28/2021] [Accepted: 08/04/2021] [Indexed: 11/11/2022] Open
Abstract
Mechanical properties of the extracellular environment modulate axon outgrowth. Growth cones at the tip of extending axons generate traction force for axon outgrowth by transmitting the force of actin filament retrograde flow, produced by actomyosin contraction and F-actin polymerization, to adhesive substrates through clutch and cell adhesion molecules. A molecular clutch between the actin filament flow and substrate is proposed to contribute to cellular mechanosensing. However, the molecular identity of the clutch interface responsible for mechanosensitive growth cone advance is unknown. We previously reported that mechanical coupling between actin filament retrograde flow and adhesive substrates through the clutch molecule shootin1a and the cell adhesion molecule L1 generates traction force for axon outgrowth and guidance. Here, we show that cultured mouse hippocampal neurons extend longer axons on stiffer substrates under elastic conditions that correspond to the soft brain environments. We demonstrate that this stiffness-dependent axon outgrowth requires actin-adhesion coupling mediated by shootin1a, L1, and laminin on the substrate. Speckle imaging analyses showed that L1 at the growth cone membrane switches between two adhesive states: L1 that is immobilized and that undergoes retrograde movement on the substrate. The duration of the immobilized phase was longer on stiffer substrates; this was accompanied by increases in actin-adhesion coupling and in the traction force exerted on the substrate. These data suggest that the interaction between L1 and laminin is enhanced on stiffer substrates, thereby promoting force generation for axon outgrowth.
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Affiliation(s)
- Kouki Abe
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Kentarou Baba
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Liguo Huang
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Koay Teng Wei
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Kazunori Okano
- Bio-processing Engineering Laboratory, Division of Materials Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Yoichiroh Hosokawa
- Bio-processing Engineering Laboratory, Division of Materials Science, Nara Institute of Science and Technology, Ikoma, Japan
| | - Naoyuki Inagaki
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Japan.
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15
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Powell R, Eleftheriadou D, Kellaway S, Phillips JB. Natural Biomaterials as Instructive Engineered Microenvironments That Direct Cellular Function in Peripheral Nerve Tissue Engineering. Front Bioeng Biotechnol 2021; 9:674473. [PMID: 34113607 PMCID: PMC8185204 DOI: 10.3389/fbioe.2021.674473] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/16/2021] [Indexed: 12/25/2022] Open
Abstract
Nerve tissue function and regeneration depend on precise and well-synchronised spatial and temporal control of biological, physical, and chemotactic cues, which are provided by cellular components and the surrounding extracellular matrix. Therefore, natural biomaterials currently used in peripheral nerve tissue engineering are selected on the basis that they can act as instructive extracellular microenvironments. Despite emerging knowledge regarding cell-matrix interactions, the exact mechanisms through which these biomaterials alter the behaviour of the host and implanted cells, including neurons, Schwann cells and immune cells, remain largely unclear. Here, we review some of the physical processes by which natural biomaterials mimic the function of the extracellular matrix and regulate cellular behaviour. We also highlight some representative cases of controllable cell microenvironments developed by combining cell biology and tissue engineering principles.
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Affiliation(s)
- Rebecca Powell
- UCL Centre for Nerve Engineering, University College London, London, United Kingdom.,Department of Pharmacology, UCL School of Pharmacy, University College London, London, United Kingdom
| | - Despoina Eleftheriadou
- UCL Centre for Nerve Engineering, University College London, London, United Kingdom.,Department of Pharmacology, UCL School of Pharmacy, University College London, London, United Kingdom.,Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Simon Kellaway
- UCL Centre for Nerve Engineering, University College London, London, United Kingdom.,Department of Pharmacology, UCL School of Pharmacy, University College London, London, United Kingdom
| | - James B Phillips
- UCL Centre for Nerve Engineering, University College London, London, United Kingdom.,Department of Pharmacology, UCL School of Pharmacy, University College London, London, United Kingdom
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16
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Onesto MM, Short CA, Rempel SK, Catlett TS, Gomez TM. Growth Factors as Axon Guidance Molecules: Lessons From in vitro Studies. Front Neurosci 2021; 15:678454. [PMID: 34093120 PMCID: PMC8175860 DOI: 10.3389/fnins.2021.678454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/26/2021] [Indexed: 11/13/2022] Open
Abstract
Growth cones at the tips of extending axons navigate through developing organisms by probing extracellular cues, which guide them through intermediate steps and onto final synaptic target sites. Widespread focus on a few guidance cue families has historically overshadowed potentially crucial roles of less well-studied growth factors in axon guidance. In fact, recent evidence suggests that a variety of growth factors have the ability to guide axons, affecting the targeting and morphogenesis of growth cones in vitro. This review summarizes in vitro experiments identifying responses and signaling mechanisms underlying axon morphogenesis caused by underappreciated growth factors.
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Affiliation(s)
| | | | | | | | - Timothy M. Gomez
- Neuroscience Training Program and Cell and Molecular Biology Program, Department of Neuroscience, University of Wisconsin–Madison, Madison, WI, United States
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17
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Dey K, Roca E, Ramorino G, Sartore L. Progress in the mechanical modulation of cell functions in tissue engineering. Biomater Sci 2021; 8:7033-7081. [PMID: 33150878 DOI: 10.1039/d0bm01255f] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In mammals, mechanics at multiple stages-nucleus to cell to ECM-underlie multiple physiological and pathological functions from its development to reproduction to death. Under this inspiration, substantial research has established the role of multiple aspects of mechanics in regulating fundamental cellular processes, including spreading, migration, growth, proliferation, and differentiation. However, our understanding of how these mechanical mechanisms are orchestrated or tuned at different stages to maintain or restore the healthy environment at the tissue or organ level remains largely a mystery. Over the past few decades, research in the mechanical manipulation of the surrounding environment-known as substrate or matrix or scaffold on which, or within which, cells are seeded-has been exceptionally enriched in the field of tissue engineering and regenerative medicine. To do so, traditional tissue engineering aims at recapitulating key mechanical milestones of native ECM into a substrate for guiding the cell fate and functions towards specific tissue regeneration. Despite tremendous progress, a big puzzle that remains is how the cells compute a host of mechanical cues, such as stiffness (elasticity), viscoelasticity, plasticity, non-linear elasticity, anisotropy, mechanical forces, and mechanical memory, into many biological functions in a cooperative, controlled, and safe manner. High throughput understanding of key cellular decisions as well as associated mechanosensitive downstream signaling pathway(s) for executing these decisions in response to mechanical cues, solo or combined, is essential to address this issue. While many reports have been made towards the progress and understanding of mechanical cues-particularly, substrate bulk stiffness and viscoelasticity-in regulating the cellular responses, a complete picture of mechanical cues is lacking. This review highlights a comprehensive view on the mechanical cues that are linked to modulate many cellular functions and consequent tissue functionality. For a very basic understanding, a brief discussion of the key mechanical players of ECM and the principle of mechanotransduction process is outlined. In addition, this review gathers together the most important data on the stiffness of various cells and ECM components as well as various tissues/organs and proposes an associated link from the mechanical perspective that is not yet reported. Finally, beyond addressing the challenges involved in tuning the interplaying mechanical cues in an independent manner, emerging advances in designing biomaterials for tissue engineering are also explored.
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Affiliation(s)
- Kamol Dey
- Department of Applied Chemistry and Chemical Engineering, Faculty of Science, University of Chittagong, Bangladesh
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18
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RHOA signaling defects result in impaired axon guidance in iPSC-derived neurons from patients with tuberous sclerosis complex. Nat Commun 2021; 12:2589. [PMID: 33972524 PMCID: PMC8110792 DOI: 10.1038/s41467-021-22770-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/26/2021] [Indexed: 11/30/2022] Open
Abstract
Patients with Tuberous Sclerosis Complex (TSC) show aberrant wiring of neuronal connections formed during development which may contribute to symptoms of TSC, such as intellectual disabilities, autism, and epilepsy. Yet models examining the molecular basis for axonal guidance defects in developing human neurons have not been developed. Here, we generate human induced pluripotent stem cell (hiPSC) lines from a patient with TSC and genetically engineer counterparts and isogenic controls. By differentiating hiPSCs, we show that control neurons respond to canonical guidance cues as predicted. Conversely, neurons with heterozygous loss of TSC2 exhibit reduced responses to several repulsive cues and defective axon guidance. While TSC2 is a known key negative regulator of MTOR-dependent protein synthesis, we find that TSC2 signaled through MTOR-independent RHOA in growth cones. Our results suggest that neural network connectivity defects in patients with TSC may result from defects in RHOA-mediated regulation of cytoskeletal dynamics during neuronal development. Patients with Tuberous Sclerosis Complex (TSC) show aberrant wiring of neuronal connections. Here, the authors generate iPSC-derived neurons from patients with TSC. TSC2 +/− neurons show impaired mTOR-independent RhoA signaling-mediated axon guidance.
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19
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Axon Growth of CNS Neurons in Three Dimensions Is Amoeboid and Independent of Adhesions. Cell Rep 2021; 32:107907. [PMID: 32698008 DOI: 10.1016/j.celrep.2020.107907] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/26/2020] [Accepted: 06/23/2020] [Indexed: 01/01/2023] Open
Abstract
During development of the central nervous system (CNS), neurons polarize and rapidly extend their axons to assemble neuronal circuits. The growth cone leads the axon to its target and drives axon growth. Here, we explored the mechanisms underlying axon growth in three dimensions. Live in situ imaging and super-resolution microscopy combined with pharmacological and molecular manipulations as well as biophysical force measurements revealed that growth cones extend CNS axons independent of pulling forces on their substrates and without the need for adhesions in three-dimensional (3D) environments. In 3D, microtubules grow unrestrained from the actomyosin cytoskeleton into the growth cone leading edge to enable rapid axon extension. Axons extend and polarize even in adhesion-inert matrices. Thus, CNS neurons use amoeboid mechanisms to drive axon growth. Together with our understanding that adult CNS axons regenerate by reactivating developmental processes, our findings illuminate how cytoskeletal manipulations enable axon regeneration in the adult CNS.
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20
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Javier-Torrent M, Zimmer-Bensch G, Nguyen L. Mechanical Forces Orchestrate Brain Development. Trends Neurosci 2020; 44:110-121. [PMID: 33203515 DOI: 10.1016/j.tins.2020.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/05/2020] [Accepted: 10/26/2020] [Indexed: 02/06/2023]
Abstract
During brain development, progenitors generate successive waves of neurons that populate distinct cerebral regions, where they settle and differentiate within layers or nuclei. While migrating and differentiating, neurons are subjected to mechanical forces arising from the extracellular matrix, and their interaction with neighboring cells. Changes in brain biomechanical properties, during its formation or aging, are converted in neural cells by mechanotransduction into intracellular signals that control key neurobiological processes. Here, we summarize recent findings that support the contribution of mechanobiology to neurodevelopment, with focus on the cerebral cortex. Also discussed are the existing toolbox and emerging technologies made available to assess and manipulate the physical properties of neurons and their environment.
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Affiliation(s)
- Míriam Javier-Torrent
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, CHU Sart Tilman, Liège 4000, Belgium
| | | | - Laurent Nguyen
- GIGA Stem Cells, GIGA-Neurosciences, University of Liège, CHU Sart Tilman, Liège 4000, Belgium.
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21
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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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22
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Abstract
The brain is our most complex organ. During development, neurons extend axons, which may grow over long distances along well-defined pathways to connect to distant targets. Our current understanding of axon pathfinding is largely based on chemical signaling by attractive and repulsive guidance cues. These cues instruct motile growth cones, the leading tips of growing axons, where to turn and where to stop. However, it is not chemical signals that cause motion-motion is driven by forces. Yet our current understanding of the mechanical regulation of axon growth is very limited. In this review, I discuss the origin of the cellular forces controlling axon growth and pathfinding, and how mechanical signals encountered by growing axons may be integrated with chemical signals. This mechanochemical cross talk is an important but often overlooked aspect of cell motility that has major implications for many physiological and pathological processes involving neuronal growth.
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Affiliation(s)
- Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom;
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