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Bergs J, Morr AS, Silva RV, Infante-Duarte C, Sack I. The Networking Brain: How Extracellular Matrix, Cellular Networks, and Vasculature Shape the In Vivo Mechanical Properties of the Brain. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2402338. [PMID: 38874205 DOI: 10.1002/advs.202402338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/22/2024] [Indexed: 06/15/2024]
Abstract
Mechanically, the brain is characterized by both solid and fluid properties. The resulting unique material behavior fosters proliferation, differentiation, and repair of cellular and vascular networks, and optimally protects them from damaging shear forces. Magnetic resonance elastography (MRE) is a noninvasive imaging technique that maps the mechanical properties of the brain in vivo. MRE studies have shown that abnormal processes such as neuronal degeneration, demyelination, inflammation, and vascular leakage lead to tissue softening. In contrast, neuronal proliferation, cellular network formation, and higher vascular pressure result in brain stiffening. In addition, brain viscosity has been reported to change with normal blood perfusion variability and brain maturation as well as disease conditions such as tumor invasion. In this article, the contributions of the neuronal, glial, extracellular, and vascular networks are discussed to the coarse-grained parameters determined by MRE. This reductionist multi-network model of brain mechanics helps to explain many MRE observations in terms of microanatomical changes and suggests that cerebral viscoelasticity is a suitable imaging marker for brain disease.
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Affiliation(s)
- Judith Bergs
- Department of Radiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Anna S Morr
- Department of Radiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Rafaela V Silva
- Experimental and Clinical Research Center, a cooperation between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité - Universitätsmedizin Berlin, Lindenberger Weg 80, 13125, Berlin, Germany
- Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, ECRC Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Carmen Infante-Duarte
- Experimental and Clinical Research Center, a cooperation between the Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité - Universitätsmedizin Berlin, Lindenberger Weg 80, 13125, Berlin, Germany
- Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, ECRC Experimental and Clinical Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
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2
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Hong J, Kirkland JM, Acheta J, Marziali LN, Beck B, Jeanette H, Bhatia U, Davis G, Herron J, Roué C, Abi-Ghanem C, Feltri ML, Zuloaga K, Bechler ME, Poitelon Y, Belin S. YAP and TAZ regulate remyelination in the central nervous system. Glia 2024; 72:156-166. [PMID: 37724047 PMCID: PMC10659087 DOI: 10.1002/glia.24467] [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: 10/21/2022] [Revised: 08/19/2023] [Accepted: 08/26/2023] [Indexed: 09/20/2023]
Abstract
Myelinating cells are sensitive to mechanical stimuli from their extracellular matrix. Ablation of YAP and TAZ mechanotransducers in Schwann cells abolishes the axon-Schwann cell recognition, myelination, and remyelination in the peripheral nervous system. It was unknown if YAP and TAZ are also required for myelination and remyelination in the central nervous system. Here we define the importance of oligodendrocyte (OL) YAP and TAZ in vivo, by specific deletion in oligodendroglial cells in adult OLs during myelin repair. Blocking YAP and TAZ expression in OL lineage cells did not affect animal viability or any major defects on OL maturation and myelination. However, using a mouse model of demyelination/remyelination, we demonstrate that YAP and TAZ modulate the capacity of OLs to remyelinate axons, particularly during the early stage of the repair process, when OL proliferation is most important. These results indicate that YAP and TAZ signaling is necessary for effective remyelination of the mouse brain.
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Affiliation(s)
- Jiayue Hong
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Jules M Kirkland
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Jenica Acheta
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Leandro N Marziali
- Institute for Myelin and Glia Exploration, Dept. Biochemistry, University at Buffalo, Buffalo, NY, 14203, USA
| | - Brianna Beck
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Haley Jeanette
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Urja Bhatia
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Grace Davis
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Jacob Herron
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Clémence Roué
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Charly Abi-Ghanem
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - M Laura Feltri
- Institute for Myelin and Glia Exploration, Dept. Biochemistry, University at Buffalo, Buffalo, NY, 14203, USA
- Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, 14203, USA
| | - Kristen Zuloaga
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Marie E Bechler
- Department of Cell and Developmental Biology, and Department of Neuroscience and Physiology State University of New York Upstate Medical University, Syracuse, NY, 13210, USA
| | - Yannick Poitelon
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
| | - Sophie Belin
- Albany Medical College, Department of Neuroscience and Experimental Therapeutics, Albany, NY, 12208, USA
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3
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Jagielska A, Radzwill K, Espinosa-Hoyos D, Yang M, Kowsari K, Farley JE, Giera S, Byrne A, Sheng G, Fang NX, Dodge JC, Pedraza CE, Van Vliet KJ. Artificial axons as a biomimetic 3D myelination platform for the discovery and validation of promyelinating compounds. Sci Rep 2023; 13:19529. [PMID: 37945646 PMCID: PMC10636046 DOI: 10.1038/s41598-023-44675-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 10/11/2023] [Indexed: 11/12/2023] Open
Abstract
Multiple sclerosis (MS), a chronic neurodegenerative disease driven by damage to the protective myelin sheath, is currently incurable. Today, all clinically available treatments modulate the immune-mediated symptoms of the disease but they fail to stop neurodegeneration in many patients. Remyelination, the regenerative process of myelin repair by oligodendrocytes, which is considered a necessary step to protect demyelinated axons and stop neuronal death, is impaired in MS patients. One of the major obstacles to finding effective remyelinating drugs is the lack of biomimetic drug screening platforms that enable quantification of compounds' potential to stimulate 3D myelination in the physiologically relevant axon-like environment. To address this need, we built a unique myelination drug discovery platform, by expanding our previously developed technology, artificial axons (AAs), which enables 3D-printing of synthetic axon mimics with the geometry and mechanical properties closely resembling those of biological axons. This platform allows for high-throughput phenotypic myelination assay based on quantification of 3D wrapping of myelin membrane around axons in response to compounds. Here, we demonstrate quantification of 3D myelin wrapping by rat oligodendrocytes around the axon mimics in response to a small library of known pro-myelinating compounds. This assay shows pro-myelinating activity for all tested compounds consistent with the published in vitro and in vivo data, demonstrating predictive power of AA platform. We find that stimulation of myelin wrapping by these compounds is dose-dependent, providing a facile means to quantify the compounds' potency and efficacy in promoting myelin wrapping. Further, the ranking of relative efficacy among these compounds differs in this 3D axon-like environment as compared to a traditional oligodendrocyte 2D differentiation assay quantifying area of deposited myelin membrane. Together, we demonstrate that the artificial axons platform and associated phenotypic myelin wrapping assay afford direct evaluation of myelin wrapping by oligodendrocytes in response to soluble compounds in an axon-like environment, providing a predictive tool for the discovery of remyelinating therapies.
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Affiliation(s)
- Anna Jagielska
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Artificial Axon Labs, Boston, MA, USA.
| | | | - Daniela Espinosa-Hoyos
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Sanofi, Cambridge, MA, USA
| | - Mingyu Yang
- Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kavin Kowsari
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Merck, Rahway, NJ, USA
| | - Jonathan E Farley
- Sanofi, Cambridge, MA, USA
- Alnylam Pharmaceuticals, Cambridge, MA, USA
| | | | | | | | - Nicholas X Fang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- The University of Hong Kong, Hong Kong, China
| | | | | | - Krystyn J Van Vliet
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Cornell University, Ithaca, NY, USA.
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4
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Rocha DN, Carvalho ED, Pires LR, Gardin C, Zanolla I, Szewczyk PK, Machado C, Fernandes R, Stachewicz U, Zavan B, Relvas JB, Pêgo AP. It takes two to remyelinate: A bioengineered platform to study astrocyte-oligodendrocyte crosstalk and potential therapeutic targets in remyelination. BIOMATERIALS ADVANCES 2023; 151:213429. [PMID: 37148597 DOI: 10.1016/j.bioadv.2023.213429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 03/21/2023] [Accepted: 04/12/2023] [Indexed: 05/08/2023]
Abstract
The loss of the myelin sheath insulating axons is the hallmark of demyelinating diseases. These pathologies often lead to irreversible neurological impairment and patient disability. No effective therapies are currently available to promote remyelination. Several elements contribute to the inadequacy of remyelination, thus understanding the intricacies of the cellular and signaling microenvironment of the remyelination niche might help us to devise better strategies to enhance remyelination. Here, using a new in vitro rapid myelinating artificial axon system based on engineered microfibres, we investigated how reactive astrocytes influence oligodendrocyte (OL) differentiation and myelination ability. This artificial axon culture system enables the effective uncoupling of molecular cues from the biophysical properties of the axons, allowing the detailed study of the astrocyte-OL crosstalk. Oligodendrocyte precursor cells (OPCs) were cultured on poly(trimethylene carbonate-co-ε-caprolactone) copolymer electrospun microfibres that served as surrogate axons. This platform was then combined with a previously established tissue engineered glial scar model of astrocytes embedded in 1 % (w/v) alginate matrices, in which astrocyte reactive phenotype was acquired using meningeal fibroblast conditioned medium. OPCs were shown to adhere to uncoated engineered microfibres and differentiate into myelinating OL. Reactive astrocytes were found to significantly impair OL differentiation ability, after six and eight days in a co-culture system. Differentiation impairment was seen to be correlated with astrocytic miRNA release through exosomes. We found significantly reduction on the expression of pro-myelinating miRNAs (miR-219 and miR-338) and an increase in anti-myelinating miRNA (miR-125a-3p) content between reactive and quiescent astrocytes. Additionally, we show that OPC differentiation inhibition could be reverted by rescuing the activated astrocytic phenotype with ibuprofen, a chemical inhibitor of the small rhoGTPase RhoA. Overall, these findings show that modulating astrocytic function might be an interesting therapeutic avenue for demyelinating diseases. The use of these engineered microfibres as an artificial axon culture system will enable the screening for potential therapeutic agents that promote OL differentiation and myelination while providing valuable insight on the myelination/remyelination processes.
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Affiliation(s)
- Daniela N Rocha
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Faculdade de Engenharia da Universidade do Porto (FEUP), 4200-465 Porto, Portugal
| | - Eva D Carvalho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Faculdade de Engenharia da Universidade do Porto (FEUP), 4200-465 Porto, Portugal
| | - Liliana R Pires
- Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Faculdade de Engenharia da Universidade do Porto (FEUP), 4200-465 Porto, Portugal
| | - Chiara Gardin
- Maria Cecilia Hospital, GVM Care & Research, Cotignola, 48033 Ravenna, Italy
| | - Ilaria Zanolla
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Piotr K Szewczyk
- Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland
| | - Cláudia Machado
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Rui Fernandes
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Urszula Stachewicz
- Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland
| | - Barbara Zavan
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - João B Relvas
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal; Department of Biomedicine, Faculty of Medicine, Universidade do Porto, 4200-319 Porto, Portugal
| | - Ana P Pêgo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-343 Porto, Portugal.
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5
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Carvalho E, Morais M, Ferreira H, Silva M, Guimarães S, Pêgo A. A paradigm shift: Bioengineering meets mechanobiology towards overcoming remyelination failure. Biomaterials 2022; 283:121427. [DOI: 10.1016/j.biomaterials.2022.121427] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 01/31/2022] [Accepted: 02/17/2022] [Indexed: 12/14/2022]
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6
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Liu Z, Wang J, Chen H, Zhang G, Lv Z, Li Y, Zhao S, Li W. Coaxial Electrospun PLLA Fibers Modified with Water-Soluble Materials for Oligodendrocyte Myelination. Polymers (Basel) 2021; 13:polym13203595. [PMID: 34685353 PMCID: PMC8537353 DOI: 10.3390/polym13203595] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/15/2022] Open
Abstract
Myelin sheaths are essential in maintaining the integrity of axons. Development of the platform for in vitro myelination would be especially useful for demyelinating disease modeling and drug screening. In this study, a fiber scaffold with a core-shell structure was prepared in one step by the coaxial electrospinning method. A high-molecular-weight polymer poly-L-lactic acid (PLLA) was used as the core, while the shell was a natural polymer material such as hyaluronic acid (HA), sodium alginate (SA), or chitosan (CS). The morphology, differential scanning calorimetry (DSC), Fourier transform infrared spectra (FTIR), contact angle, viability assay, and in vitro myelination by oligodendrocytes were characterized. The results showed that such fibers are bead-free and continuous, with an average size from 294 ± 53 to 390 ± 54 nm. The DSC and FTIR curves indicated no changes in the phase state of coaxial brackets. Hyaluronic acid/PLLA coaxial fibers had the minimum contact angle (53.1° ± 0.24°). Myelin sheaths were wrapped around a coaxial electrospun scaffold modified with water-soluble materials after a 14-day incubation. All results suggest that such a scaffold prepared by coaxial electrospinning potentially provides a novel platform for oligodendrocyte myelination.
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Affiliation(s)
- Zhepeng Liu
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; (J.W.); (H.C.); (Y.L.); (S.Z.)
- Correspondence: (Z.L.); (W.L.)
| | - Jing Wang
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; (J.W.); (H.C.); (Y.L.); (S.Z.)
| | - Haini Chen
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; (J.W.); (H.C.); (Y.L.); (S.Z.)
| | - Guanyu Zhang
- Department of Cell Biology, Second Military Medical University, Shanghai 200433, China; (G.Z.); (Z.L.)
| | - Zhuman Lv
- Department of Cell Biology, Second Military Medical University, Shanghai 200433, China; (G.Z.); (Z.L.)
| | - Yijun Li
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; (J.W.); (H.C.); (Y.L.); (S.Z.)
| | - Shoujin Zhao
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; (J.W.); (H.C.); (Y.L.); (S.Z.)
| | - Wenlin Li
- Department of Cell Biology, Second Military Medical University, Shanghai 200433, China; (G.Z.); (Z.L.)
- Correspondence: (Z.L.); (W.L.)
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7
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Cayre M, Falque M, Mercier O, Magalon K, Durbec P. Myelin Repair: From Animal Models to Humans. Front Cell Neurosci 2021; 15:604865. [PMID: 33935649 PMCID: PMC8079744 DOI: 10.3389/fncel.2021.604865] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 03/15/2021] [Indexed: 12/20/2022] Open
Abstract
It is widely thought that brain repair does not occur, but myelin regeneration provides clear evidence to the contrary. Spontaneous remyelination may occur after injury or in multiple sclerosis (MS). However, the efficiency of remyelination varies considerably between MS patients and between the lesions of each patient. Myelin repair is essential for optimal functional recovery, so a profound understanding of the cells and mechanisms involved in this process is required for the development of new therapeutic strategies. In this review, we describe how animal models and modern cell tracing and imaging methods have helped to identify the cell types involved in myelin regeneration. In addition to the oligodendrocyte progenitor cells identified in the 1990s as the principal source of remyelinating cells in the central nervous system (CNS), other cell populations, including subventricular zone-derived neural progenitors, Schwann cells, and even spared mature oligodendrocytes, have more recently emerged as potential contributors to CNS remyelination. We will also highlight the conditions known to limit endogenous repair, such as aging, chronic inflammation, and the production of extracellular matrix proteins, and the role of astrocytes and microglia in these processes. Finally, we will present the discrepancies between observations in humans and in rodents, discussing the relationship of findings in experimental models to myelin repair in humans. These considerations are particularly important from a therapeutic standpoint.
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Affiliation(s)
- Myriam Cayre
- Aix Marseille Université, Centre National de la Recherche Scientifique (CNRS), Institut de Biologie du Développement de Marseille (IBDM-UMR 7288), Marseille, France
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8
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Balestri S, Del Giovane A, Sposato C, Ferrarelli M, Ragnini-Wilson A. The Current Challenges for Drug Discovery in CNS Remyelination. Int J Mol Sci 2021; 22:ijms22062891. [PMID: 33809224 PMCID: PMC8001072 DOI: 10.3390/ijms22062891] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
The myelin sheath wraps around axons, allowing saltatory currents to be transmitted along neurons. Several genetic, viral, or environmental factors can damage the central nervous system (CNS) myelin sheath during life. Unless the myelin sheath is repaired, these insults will lead to neurodegeneration. Remyelination occurs spontaneously upon myelin injury in healthy individuals but can fail in several demyelination pathologies or as a consequence of aging. Thus, pharmacological intervention that promotes CNS remyelination could have a major impact on patient’s lives by delaying or even preventing neurodegeneration. Drugs promoting CNS remyelination in animal models have been identified recently, mostly as a result of repurposing phenotypical screening campaigns that used novel oligodendrocyte cellular models. Although none of these have as yet arrived in the clinic, promising candidates are on the way. Many questions remain. Among the most relevant is the question if there is a time window when remyelination drugs should be administrated and why adult remyelination fails in many neurodegenerative pathologies. Moreover, a significant challenge in the field is how to reconstitute the oligodendrocyte/axon interaction environment representative of healthy as well as disease microenvironments in drug screening campaigns, so that drugs can be screened in the most appropriate disease-relevant conditions. Here we will provide an overview of how the field of in vitro models developed over recent years and recent biological findings about how oligodendrocytes mature after reactivation of their staminal niche. These data have posed novel questions and opened new views about how the adult brain is repaired after myelin injury and we will discuss how these new findings might change future drug screening campaigns for CNS regenerative drugs.
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9
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Keating CE, Cullen DK. Mechanosensation in traumatic brain injury. Neurobiol Dis 2020; 148:105210. [PMID: 33259894 DOI: 10.1016/j.nbd.2020.105210] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/10/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) is distinct from other neurological disorders because it is induced by a discrete event that applies extreme mechanical forces to the brain. This review describes how the brain senses, integrates, and responds to forces under both normal conditions and during injury. The response to forces is influenced by the unique mechanical properties of brain tissue, which differ by region, cell type, and sub-cellular structure. Elements such as the extracellular matrix, plasma membrane, transmembrane receptors, and cytoskeleton influence its properties. These same components also act as force-sensors, allowing neurons and glia to respond to their physical environment and maintain homeostasis. However, when applied forces become too large, as in TBI, these components may respond in an aberrant manner or structurally fail, resulting in unique pathological sequelae. This so-called "pathological mechanosensation" represents a spectrum of cellular responses, which vary depending on the overall biomechanical parameters of the injury and may be compounded by repetitive injuries. Such aberrant physical responses and/or damage to cells along with the resulting secondary injury cascades can ultimately lead to long-term cellular dysfunction and degeneration, often resulting in persistent deficits. Indeed, pathological mechanosensation not only directly initiates secondary injury cascades, but this post-physical damage environment provides the context in which these cascades unfold. Collectively, these points underscore the need to use experimental models that accurately replicate the biomechanics of TBI in humans. Understanding cellular responses in context with injury biomechanics may uncover therapeutic targets addressing various facets of trauma-specific sequelae.
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Affiliation(s)
- Carolyn E Keating
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA
| | - D Kacy Cullen
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA.
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10
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Espinosa-Hoyos D, Burstein SR, Cha J, Jain T, Nijsure M, Jagielska A, Fossati V, Van Vliet KJ. Mechanosensitivity of Human Oligodendrocytes. Front Cell Neurosci 2020; 14:222. [PMID: 32848617 PMCID: PMC7420028 DOI: 10.3389/fncel.2020.00222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 06/22/2020] [Indexed: 12/28/2022] Open
Abstract
Oligodendrocytes produce and repair myelin, which is critical for the integrity and function of the central nervous system (CNS). Oligodendrocyte and oligodendrocyte progenitor cell (OPC) biology is modulated in vitro by mechanical cues within the magnitudes observed in vivo. In some cases, these cues are sufficient to accelerate or inhibit terminal differentiation of murine oligodendrocyte progenitors. However, our understanding of oligodendrocyte lineage mechanobiology has been restricted primarily to animal models to date, due to the inaccessibility and challenges of human oligodendrocyte cell culture. Here, we probe the mechanosensitivity of human oligodendrocyte lineage cells derived from human induced pluripotent stem cells. We target phenotypically distinct stages of the human oligodendrocyte lineage and quantify the effect of substratum stiffness on cell migration and differentiation, within the range documented in vivo. We find that human oligodendrocyte lineage cells exhibit mechanosensitive migration and differentiation. Further, we identify two patterns of human donor line-dependent mechanosensitive differentiation. Our findings illustrate the variation among human oligodendrocyte responses, otherwise not captured by animal models, that are important for translational research. Moreover, these findings highlight the importance of studying glia under conditions that better approximate in vivo mechanical cues. Despite significant progress in human oligodendrocyte derivation methodology, the extended duration, low yield, and low selectivity of human-induced pluripotent stem cell-derived oligodendrocyte protocols significantly limit the scale-up and implementation of these cells and protocols for in vivo and in vitro applications. We propose that mechanical modulation, in combination with traditional soluble and insoluble factors, provides a key avenue to address these challenges in cell production and in vitro analysis.
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Affiliation(s)
- Daniela Espinosa-Hoyos
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Suzanne R. Burstein
- The New York Stem Cell Foundation Research Institute, New York, NY, United States
| | - Jaaram Cha
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Tanya Jain
- The New York Stem Cell Foundation Research Institute, New York, NY, United States
| | - Madhura Nijsure
- The New York Stem Cell Foundation Research Institute, New York, NY, United States
| | - Anna Jagielska
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
- Critical Analytics for Manufacturing Personalized-Medicine (CAMP) Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology (SMART) CREATE, Singapore, Singapore
| | - Valentina Fossati
- The New York Stem Cell Foundation Research Institute, New York, NY, United States
| | - Krystyn J. Van Vliet
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
- Critical Analytics for Manufacturing Personalized-Medicine (CAMP) Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology (SMART) CREATE, Singapore, Singapore
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
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Du X, Zhang Z, Zhou H, Zhou J. Differential Modulators of NG2-Glia Differentiation into Neurons and Glia and Their Crosstalk. Cell Mol Neurobiol 2020; 41:1-15. [PMID: 32285247 DOI: 10.1007/s10571-020-00843-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/06/2020] [Indexed: 02/08/2023]
Abstract
As the fifth main cell population in the brain, NG2-glia are also known as oligodendrocyte precursor cells. NG2-glia express receptors and ion channels for fast modulation of neuronal activities and signaling with neuronal synapses, which are of functional significance in both physiological and pathological states. NG2-glia also participate in fast signaling with peripheral neurons via direct synaptic contacts in the brain. These distinctive glia have the unique capability of proliferating and differentiating into oligodendrocytes, which are critical for axonal myelination in the early developing brain. In neurodegenerative diseases, NG2-glia play an important role and undergo morphological modification, adapt the expression of their membrane receptors and ion channels, and display gene-modulated cell reprogramming and excitotoxicity-caused cell death. These modifications directly and indirectly influence populations of neurons and other glial cells. NG2-glia regulate their action and dynamics in response to neuronal behavior and disease, indicating a critical function to preserve and remodel myelin in physiological states and to repair it in pathological states. Here, we review in detail the differential modulators of NG2-glia into neurons and astrocytes, as well as interactions of NG2-glia with neurons, astrocytes, and microglia. We will also summarize a future potential exploitation of NG2-glia.
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Affiliation(s)
- Xiaohuang Du
- Department of Scientific Research, Army Medical University, Chongqing, 400037, China
| | - Zuo Zhang
- National Drug Clinical Trial Institution, Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Hongli Zhou
- National Drug Clinical Trial Institution, Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China
| | - Jiyin Zhou
- National Drug Clinical Trial Institution, Second Affiliated Hospital, Army Medical University, Chongqing, 400037, China.
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