1
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Feltri ML, Weaver MR, Belin S, Poitelon Y. The Hippo pathway: Horizons for innovative treatments of peripheral nerve diseases. J Peripher Nerv Syst 2021; 26:4-16. [PMID: 33449435 DOI: 10.1111/jns.12431] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/16/2020] [Accepted: 12/20/2020] [Indexed: 12/19/2022]
Abstract
Initially identified in Drosophila, the Hippo signaling pathway regulates how cells respond to their environment by controlling proliferation, migration and differentiation. Many recent studies have focused on characterizing Hippo pathway function and regulation in mammalian cells. Here, we present a brief overview of the major components of the Hippo pathway, as well as their regulation and function. We comprehensively review the studies that have contributed to our understanding of the Hippo pathway in the function of the peripheral nervous system and in peripheral nerve diseases. Finally, we discuss innovative approaches that aim to modulate Hippo pathway components in diseases of the peripheral nervous system.
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Affiliation(s)
- M Laura Feltri
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA.,Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Michael R Weaver
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Sophie Belin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
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2
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Diaz Vera D, Soucy JR, Lee A, Koppes RA, Koppes AN. Light irradiation of peripheral nerve cells: Wavelength impacts primary sensory neuron outgrowth in vitro. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 215:112105. [PMID: 33406470 DOI: 10.1016/j.jphotobiol.2020.112105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 12/07/2020] [Accepted: 12/17/2020] [Indexed: 12/19/2022]
Abstract
The expansion of optogenetics via the development and application of new opsins has opened a new world of possibilities as a research and therapeutic tool. Nevertheless, it has also raised questions about the innocuity of using light irradiation on tissues and cells such as those from the Peripheral Nervous System (PNS). Thus, to investigate the potential of PNS being affected by optogenetic light irradiation, rat dorsal root ganglion neurons and Schwann cells were isolated and their response to light irradiation examined in vitro. Light irradiation was delivered as millisecond pulses at wavelengths in the visible spectrum between 627 and 470 nm, with doses ranging between 4.5 and 18 J/cm2 at an irradiance value of 1 mW/mm2. Results show that compared to cultures kept in dark conditions, light irradiation at 470 nm reduced neurite outgrowth in dissociated dorsal root neurons in a dose dependent manner while higher wavelengths had no effect on neuron morphology. Although neurite outgrowth was limited by light irradiation, no signs of cell death or apoptosis were found. On the other hand, peripheral glia, Schwann cells, were insensitive to light irradiation with metabolism, proliferation, and RNA levels of transcription factors c-Jun and krox-20 remaining unaltered following stimulation. As the fields of photostimulation and optogenetics expand, these results indicate the need for consideration to cell type response and stimulation parameters for applications in vitro and further investigation on specific mechanisms driving response.
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Affiliation(s)
- David Diaz Vera
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA.
| | - Jonathan R Soucy
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA.
| | - Audrey Lee
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA.
| | - Ryan A Koppes
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA.
| | - Abigail N Koppes
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA; Department of Biology, Northeastern University, Boston, MA, USA.
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3
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Abstract
Hypomyelinating leukodystrophies constitute a subset of genetic white matter disorders characterized by a primary lack of myelin deposition. Most patients with severe hypomyelination present in infancy or early childhood and develop severe neurological deficits, but the clinical presentation can also be mild with onset of symptoms in adolescence or adulthood. MRI can be used to visualize the process of myelination in detail, and MRI pattern recognition can provide a clinical diagnosis in many patients. Next-generation sequencing provides a definitive diagnosis in 80-90% of patients. Genes associated with hypomyelination include those that encode structural myelin proteins but also many that encode proteins involved in RNA translation and some lysosomal proteins. The precise pathomechanisms remain to be elucidated. Improved understanding of the process of myelination, the metabolic axonal support functions of myelin and the proposed contribution of myelin to CNS plasticity provide possible explanations as to why almost all patients with hypomyelination experience slow clinical decline after a long phase of stability. In this Review, we provide an overview of the hypomyelinating leukodystrophies, the advances in our understanding of myelin biology and of the genes involved in these disorders, and the insights these advances have provided into their clinical presentations and evolution.
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Bretaud S, Guillon E, Karppinen SM, Pihlajaniemi T, Ruggiero F. Collagen XV, a multifaceted multiplexin present across tissues and species. Matrix Biol Plus 2020; 6-7:100023. [PMID: 33543021 PMCID: PMC7852327 DOI: 10.1016/j.mbplus.2020.100023] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/06/2020] [Accepted: 01/06/2020] [Indexed: 01/09/2023] Open
Abstract
Type XV collagen is a non-fibrillar collagen that is associated with basement membranes and belongs to the multiplexin subset of the collagen superfamily. Collagen XV was initially studied because of its sequence homology with collagen XVIII/endostatin whose anti-angiogenic and anti-tumorigenic properties were subjects of wide interest in the past years. But during the last fifteen years, collagen XV has gained growing attention with increasing number of studies that have attributed new functions to this widely distributed collagen/proteoglycan hybrid molecule. Despite the cumulative evidence of its functional pleiotropy and its evolutionary conserved function, no review compiling the current state of the art about collagen XV is currently available. Here, we thus provide the first comprehensive view of the knowledge gathered so far on the molecular structure, tissue distribution and functions of collagen XV in development, tissue homeostasis and disease with an evolutionary perspective. We hope that our review will open new roads for promising research on collagen XV in the coming years. Type XV collagen belongs to the multiplexin subset of the collagen superfamily. It is evolutionarily conserved collagen and associated with basement membranes. This collagen/proteoglycan hybrid molecule contains an anti-angiogenic restin domain. It has important functions in the cardiovascular and the neuromuscular systems. Its expression is dysregulated in various diseases including cancers.
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Key Words
- Animal models
- BM, basement membrane
- BMZ, basement membrane zone
- COL, collagenous domain
- CS, chondroitin sulfate
- CSPG, chondroitin sulfate proteoglycan
- Collagen-related disease
- Collagens
- Development
- ECM, extracellular matrix
- Evolution
- Extracellular matrix
- GAG, glycosaminoglycan
- HFD, High fat diet
- HS, heparan sulfate
- HSPG, heparan sulfate proteoglycan
- Multiplexin
- NC, non-collagenous domain
- TD, trimerization domain
- TSPN, Thrombospondin-1 N-terminal like domain
- dpf, day post-fertilization
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Affiliation(s)
- Sandrine Bretaud
- Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, UMR CNRS 5242, University of Lyon, Lyon 69364, France
| | - Emilie Guillon
- Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, UMR CNRS 5242, University of Lyon, Lyon 69364, France
| | - Sanna-Maria Karppinen
- Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7C, FI-90230 Oulu, Finland
| | - Taina Pihlajaniemi
- Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Aapistie 7C, FI-90230 Oulu, Finland
| | - Florence Ruggiero
- Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, UMR CNRS 5242, University of Lyon, Lyon 69364, France
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5
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Torii T, Miyamoto Y, Yamauchi J. Cellular Signal-Regulated Schwann Cell Myelination and Remyelination. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1190:3-22. [PMID: 31760634 DOI: 10.1007/978-981-32-9636-7_1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Increasing studies have demonstrated multiple signaling molecules responsible for oligodendrocytes and Schwann cells development such as migration, differentiation, myelination, and axo-glial interaction. However, complicated roles in these events are still poorly understood. This chapter focuses on well established intracellular signaling transduction and recent topics that control myelination and are elucidated from accumulating evidences. The underlying molecular mechanisms, which involved in membrane trafficking through small GTPase Arf6 and its activator cytohesins, demonstrate the crosstalk between well established intracellular signaling transduction and a new finding signaling pathway in glial cells links to physiological phenotype and essential role in peripheral nerve system (PNS). Since Arf family proteins affect the expression levels of myelin protein zero (MPZ) and Krox20, which is a transcription factor regulatory factor in early developmental stages of Schwann cells, Arf proteins likely to be key regulator for Schwann cells development. Herein, we discuss how intracellular signaling transductions in Schwann cells associate with myelination in CNS and PNS.
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Affiliation(s)
- Tomohiro Torii
- Graduate School of Brain Science, Doshisha University, Kyotanabe-shi, Kyoto, Japan
| | - Yuki Miyamoto
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan.
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6
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Stadelmann C, Timmler S, Barrantes-Freer A, Simons M. Myelin in the Central Nervous System: Structure, Function, and Pathology. Physiol Rev 2019; 99:1381-1431. [PMID: 31066630 DOI: 10.1152/physrev.00031.2018] [Citation(s) in RCA: 292] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Oligodendrocytes generate multiple layers of myelin membrane around axons of the central nervous system to enable fast and efficient nerve conduction. Until recently, saltatory nerve conduction was considered the only purpose of myelin, but it is now clear that myelin has more functions. In fact, myelinating oligodendrocytes are embedded in a vast network of interconnected glial and neuronal cells, and increasing evidence supports an active role of oligodendrocytes within this assembly, for example, by providing metabolic support to neurons, by regulating ion and water homeostasis, and by adapting to activity-dependent neuronal signals. The molecular complexity governing these interactions requires an in-depth molecular understanding of how oligodendrocytes and axons interact and how they generate, maintain, and remodel their myelin sheaths. This review deals with the biology of myelin, the expanded relationship of myelin with its underlying axons and the neighboring cells, and its disturbances in various diseases such as multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Furthermore, we will highlight how specific interactions between astrocytes, oligodendrocytes, and microglia contribute to demyelination in hereditary white matter pathologies.
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Affiliation(s)
- Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Sebastian Timmler
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Alonso Barrantes-Freer
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Mikael Simons
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
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7
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Prior R, Van Helleputte L, Klingl YE, Van Den Bosch L. HDAC6 as a potential therapeutic target for peripheral nerve disorders. Expert Opin Ther Targets 2018; 22:993-1007. [DOI: 10.1080/14728222.2018.1541235] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Robert Prior
- Department of Neurosciences, KU Leuven - University of Leuven, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium
- Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
| | - Lawrence Van Helleputte
- Department of Neurosciences, KU Leuven - University of Leuven, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium
- Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
| | - Yvonne Eileen Klingl
- Department of Neurosciences, KU Leuven - University of Leuven, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium
- Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
| | - Ludo Van Den Bosch
- Department of Neurosciences, KU Leuven - University of Leuven, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium
- Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
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8
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Wrobel MR, Sundararaghavan HG. Biomaterial Cues to Direct a Pro-regenerative Phenotype in Macrophages and Schwann Cells. Neuroscience 2018; 376:172-187. [DOI: 10.1016/j.neuroscience.2018.02.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/23/2018] [Accepted: 02/09/2018] [Indexed: 12/11/2022]
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9
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Abstract
Our understanding of the processes controlling peripheral nervous system myelination have been significantly benefited by the development of an in vitro myelinating culture system in which primary Schwann cells are cocultured together with primary sensory neurons. In this chapter, we describe the protocol currently used in our laboratories to establish Schwann cells neuronal myelinating cocultures. We also include a detailed description of the various substrates that can be used to establish it.
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Affiliation(s)
- Carla Taveggia
- Division of Neuroscience and INSPE, San Raffaele Scientific Institute, Milan, Italy.
| | - Alessandra Bolino
- Division of Neuroscience and INSPE, San Raffaele Scientific Institute, Milan, Italy.
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10
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Belin S, Zuloaga KL, Poitelon Y. Influence of Mechanical Stimuli on Schwann Cell Biology. Front Cell Neurosci 2017; 11:347. [PMID: 29209171 PMCID: PMC5701625 DOI: 10.3389/fncel.2017.00347] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/19/2017] [Indexed: 12/05/2022] Open
Abstract
Schwann cells are the glial cells of the peripheral nervous system (PNS). They insulate axons by forming a specialized extension of plasma membrane called the myelin sheath. The formation of myelin is essential for the rapid saltatory propagation of action potentials and to maintain the integrity of axons. Although both axonal and extracellular matrix (ECM) signals are necessary for myelination to occur, the cellular and molecular mechanisms regulating myelination continue to be elucidated. Schwann cells in peripheral nerves are physiologically exposed to mechanical stresses (i.e., tensile, compressive and shear strains), occurring during development, adulthood and injuries. In addition, there is a growing body of evidences that Schwann cells are sensitive to the stiffness of their environment. In this review, we detail the mechanical constraints of Schwann cells and peripheral nerves. We explore the regulation of Schwann cell signaling pathways in response to mechanical stimulation. Finally, we provide a comprehensive overview of the experimental studies addressing the mechanobiology of Schwann cells. Understanding which mechanical properties can interfere with the cellular and molecular biology of Schwann cell during development, myelination and following injuries opens new insights in the regulation of PNS development and treatment approaches in peripheral neuropathies.
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Affiliation(s)
- Sophie Belin
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
| | - Kristen L. Zuloaga
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
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11
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Melfi S, Montt Guevara MM, Bonalume V, Ruscica M, Colciago A, Simoncini T, Magnaghi V. Src and phospho-FAK kinases are activated by allopregnanolone promoting Schwann cell motility, morphology and myelination. J Neurochem 2017; 141:165-178. [PMID: 28072455 DOI: 10.1111/jnc.13951] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 12/19/2016] [Accepted: 12/30/2016] [Indexed: 01/11/2023]
Abstract
Schwann cells' (SCs) development and maturation require coordinate and complementary activation of several signals and intracellular pathways. Among factors controlling these processes, the signalling intermediates Src tyrosine kinase and focal adhesion kinase (FAK) are relevant for SCs', participating in regulation of their adhesion, motility and migration. Recently, the progesterone metabolite allopregnanolone (ALLO) was proved to be synthesized by SCs, whereas it acts autocrinally on SCs motility and proliferation, which are crucial processes for nerve development, maturation and regeneration. Herein, we investigate the hypothesis that the molecular mechanisms behind the ALLO's action on SCs involve the signalling intermediates Src and FAK. We first demonstrated that ALLO 10-6 M regulates SCs morphology, motility and myelination, also increasing the internode distance in the in vitro myelination model of neuron/SCs co-culture. ALLO's actions were mediated by the modulation of Src/FAK pathway, since they were counteracted by PP2 10-5 M, a selective inhibitor of Src kinase. Then, we proved that Src/FAK activation in SCs involves GABA-A dependent mechanisms and actin re-arrangements. In conclusion, our findings are the first to corroborate the importance of the neuroactive steroid ALLO in regulating SCs development and maturation via the Src and phospho-FAK signalling activation. Cover Image for this issue: doi: 10.1111/jnc.13795.
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Affiliation(s)
- Simona Melfi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | | | - Veronica Bonalume
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Massimiliano Ruscica
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Alessandra Colciago
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Tommaso Simoncini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Valerio Magnaghi
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
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12
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Herbert AL, Monk KR. Advances in myelinating glial cell development. Curr Opin Neurobiol 2017; 42:53-60. [PMID: 27930937 PMCID: PMC5316316 DOI: 10.1016/j.conb.2016.11.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/07/2016] [Accepted: 11/13/2016] [Indexed: 12/31/2022]
Abstract
In the vertebrate nervous system, the fast conduction of action potentials is potentiated by the myelin sheath, a multi-lamellar, lipid-rich structure that also provides vital trophic and metabolic support to axons. Myelin is elaborated by the plasma membrane of specialized glial cells, oligodendrocytes in the central nervous system (CNS) and Schwann cells (SCs) in the peripheral nervous system (PNS). The diseases that result from damage to myelin or glia, including multiple sclerosis and Charcot-Marie-Tooth disease, underscore the importance of these cells for human health. Therefore, an understanding of glial development and myelination is crucial in addressing the etiology of demyelinating diseases and developing patient therapies. In this review, we discuss new insights into the roles of mechanotransduction and cytoskeletal rearrangements as well as activity dependent myelination and axonal maintenance by glia. Together, these discoveries advance our knowledge of myelin and glia in nervous system health and plasticity throughout life.
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Affiliation(s)
- Amy L Herbert
- Department of Developmental Biology, Washington University School of Medicine, 660 South Euclid Ave., Saint Louis, MO 63110, USA
| | - Kelly R Monk
- Department of Developmental Biology, Washington University School of Medicine, 660 South Euclid Ave., Saint Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, 660 South Euclid Ave., Saint Louis, MO 63110, USA.
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13
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Abstract
The mechanisms that drive the spiral wrapping of the myelin sheath around axons are poorly understood. Two papers in this issue of Developmental Cell demonstrate that actin disassembly, rather than actin assembly, predominates during oligodendrocyte maturation and is critical for the genesis of the central myelin sheath.
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Affiliation(s)
- Jayshree Samanta
- New York University Neuroscience Institute, Departments of Physiology and Neuroscience, NYU School of Medicine, New York, NY 10016, USA
| | - James L Salzer
- New York University Neuroscience Institute, Departments of Physiology and Neuroscience, NYU School of Medicine, New York, NY 10016, USA.
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14
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Tonazzini I, Jacchetti E, Meucci S, Beltram F, Cecchini M. Schwann Cell Contact Guidance versus Boundary -Interaction in Functional Wound Healing along Nano and Microstructured Membranes. Adv Healthc Mater 2015; 4:1849-60. [PMID: 26097140 DOI: 10.1002/adhm.201500268] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/27/2015] [Indexed: 01/09/2023]
Abstract
Peripheral nerve transection is often encountered after trauma and can lead to long-term/permanent loss of sensor/motor functionality. Here, the effect of pure contact interaction of nano/microgrooved substrates on Schwann cells (SCs) is studied in view of their possible use for nerve-repair applications. Elastomeric gratings (GRs; i.e., alternating lines of ridges and grooves) are developed with different lateral periods (1-20 μm) and depths (0.3-2.5 μm), leading to two distinct cell-material interaction regimes: contact guidance (grating period < cell body diameter) and boundary guidance (grating period ≥ cell body diameter). Here, it is shown that boundary guidance leads to the best single-cell polarization, actin organization, and single-cell directional migration. Remarkably, contact guidance is instead more effective in driving collective SC migration and improves functional wound healing. It is also demonstrated that this behavior is linked to the properties of the SC monolayers on different GRs. SCs on large-period GRs are characterized by N-Cadherin downregulation and enhanced single-cell scattering into the wound with respect to SCs on small-period GRs, indicating a less compact monolayer characterized by looser cell-cell junctions in the boundary guidance regime. The present results provide information on the impact of specific sub-micrometer topographical elements on SC functional response, which can be exploited for nerve-regeneration applications.
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Affiliation(s)
- Ilaria Tonazzini
- NEST, Scuola Normale Superiore; Piazza San Silvestro 12 Pisa 56127 Italy
- NEST, Istituto Nanoscienze-CNR; Piazza San Silvestro 12 Pisa 56127 Italy
- Fondazione Umberto Veronesi; Piazza Velasca 5 Milano 20122 Italy
| | - Emanuela Jacchetti
- NEST, Scuola Normale Superiore; Piazza San Silvestro 12 Pisa 56127 Italy
- NEST, Istituto Nanoscienze-CNR; Piazza San Silvestro 12 Pisa 56127 Italy
| | - Sandro Meucci
- NEST, Scuola Normale Superiore; Piazza San Silvestro 12 Pisa 56127 Italy
- NEST, Istituto Nanoscienze-CNR; Piazza San Silvestro 12 Pisa 56127 Italy
| | - Fabio Beltram
- NEST, Scuola Normale Superiore; Piazza San Silvestro 12 Pisa 56127 Italy
- NEST, Istituto Nanoscienze-CNR; Piazza San Silvestro 12 Pisa 56127 Italy
| | - Marco Cecchini
- NEST, Scuola Normale Superiore; Piazza San Silvestro 12 Pisa 56127 Italy
- NEST, Istituto Nanoscienze-CNR; Piazza San Silvestro 12 Pisa 56127 Italy
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15
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Roos A, Weis J, Korinthenberg R, Fehrenbach H, Häusler M, Züchner S, Mache C, Hubmann H, Auer-Grumbach M, Senderek J. Inverted formin 2-related Charcot-Marie-Tooth disease: extension of the mutational spectrum and pathological findings in Schwann cells and axons. J Peripher Nerv Syst 2015; 20:52-9. [DOI: 10.1111/jns.12106] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 01/22/2015] [Accepted: 02/07/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Andreas Roos
- Institute of Neuropathology; RWTH Aachen University Hospital; Aachen Germany
- Department of Bioanalytics; Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V. Dortmund; Dortmund Germany
| | - Joachim Weis
- Institute of Neuropathology; RWTH Aachen University Hospital; Aachen Germany
| | | | | | - Martin Häusler
- Department of Pediatrics; RWTH Aachen University Hospital; Aachen Germany
| | - Stephan Züchner
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics; University of Miami Miller School of Medicine; Miami FL USA
| | - Christoph Mache
- Department of Pediatrics; Medical University Graz; Graz Austria
| | - Holger Hubmann
- Department of Pediatrics; Medical University Graz; Graz Austria
| | | | - Jan Senderek
- Friedrich-Baur Institute, Department of Neurology; Ludwig-Maximilians University Munich; Munich Germany
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16
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Ohashi K. Roles of cofilin in development and its mechanisms of regulation. Dev Growth Differ 2015; 57:275-90. [DOI: 10.1111/dgd.12213] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 02/06/2023]
Affiliation(s)
- Kazumasa Ohashi
- Department of Biomolecular Sciences; Graduate School of Life Sciences; Tohoku University; Sendai Miyagi 980-8578 Japan
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17
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Pooya S, Liu X, Kumar VBS, Anderson J, Imai F, Zhang W, Ciraolo G, Ratner N, Setchell KDR, Yoshida Y, Yutaka Y, Jankowski MP, Dasgupta B. The tumour suppressor LKB1 regulates myelination through mitochondrial metabolism. Nat Commun 2014; 5:4993. [PMID: 25256100 DOI: 10.1038/ncomms5993] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 08/14/2014] [Indexed: 01/04/2023] Open
Abstract
A prerequisite to myelination of peripheral axons by Schwann cells (SCs) is SC differentiation, and recent evidence indicates that reprogramming from a glycolytic to oxidative metabolism occurs during cellular differentiation. Whether this reprogramming is essential for SC differentiation, and the genes that regulate this critical metabolic transition are unknown. Here we show that the tumour suppressor Lkb1 is essential for this metabolic transition and myelination of peripheral axons. Hypomyelination in the Lkb1-mutant nerves and muscle atrophy lead to hindlimb dysfunction and peripheral neuropathy. Lkb1-null SCs failed to optimally activate mitochondrial oxidative metabolism during differentiation. This deficit was caused by Lkb1-regulated diminished production of the mitochondrial Krebs cycle substrate citrate, a precursor to cellular lipids. Consequently, myelin lipids were reduced in Lkb1-mutant mice. Restoring citrate partially rescued Lkb1-mutant SC defects. Thus, Lkb1-mediated metabolic shift during SC differentiation increases mitochondrial metabolism and lipogenesis, necessary for normal myelination.
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Affiliation(s)
- Shabnam Pooya
- Department of Oncology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Xiaona Liu
- Department of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - V B Sameer Kumar
- Department of Oncology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Jane Anderson
- Department of Oncology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Fumiyasu Imai
- Department of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Wujuan Zhang
- Department of Pathology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Georgianne Ciraolo
- Department of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Nancy Ratner
- Department of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Kenneth D R Setchell
- Department of Pathology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | | | - Yoshida Yutaka
- Department of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Michael P Jankowski
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Biplab Dasgupta
- Department of Oncology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
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18
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Schmid D, Zeis T, Sobrio M, Schaeren-Wiemers N. MAL overexpression leads to disturbed expression of genes that influence cytoskeletal organization and differentiation of Schwann cells. ASN Neuro 2014; 6:1759091414548916. [PMID: 25290060 PMCID: PMC4187015 DOI: 10.1177/1759091414548916] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In the developing peripheral nervous system, a coordinated reciprocal signaling between Schwann cells and axons is crucial for accurate myelination. The myelin and lymphocyte protein MAL is a component of lipid rafts that is important for targeting proteins and lipids to distinct domains. MAL overexpression impedes peripheral myelinogenesis, which is evident by a delayed onset of myelination and reduced expression of the myelin protein zero (Mpz/P0) and the low-affinity neurotrophin receptor p75(NTR). This study shows that MAL overexpression leads to a significant reduction of Mpz and p75(NTR) expression in primary mouse Schwann cell cultures, which was already evident before differentiation, implicating an effect of MAL in early Schwann cell development. Their transcription was robustly reduced, despite normal expression of essential transcription factors and receptors. Further, the cAMP response element-binding protein (CREB) and phosphoinositide 3-kinase signaling pathways important for Schwann cell differentiation were correctly induced, highlighting that other so far unknown rate limiting factors do exist. We identified novel genes expressed by Schwann cells in a MAL-dependent manner in vivo and in vitro. A number of those, including S100a4, RhoU and Krt23, are implicated in cytoskeletal organization and plasma membrane dynamics. We showed that S100a4 is predominantly expressed by nonmyelinating Schwann cells, whereas RhoU was localized within myelin membranes, and Krt23 was detected in nonmyelinating as well as in myelinating Schwann cells. Their differential expression during early peripheral nerve development further underlines their possible role in influencing Schwann cell differentiation and myelination.
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Affiliation(s)
- Daniela Schmid
- Department of Biomedicine, University Hospital Basel, University of Basel, Switzerland
| | - Thomas Zeis
- Department of Biomedicine, University Hospital Basel, University of Basel, Switzerland
| | - Monia Sobrio
- Department of Biomedicine, University Hospital Basel, University of Basel, Switzerland
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19
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Povarova OI, Uversky VN, Kuznetsova IM, Turoverov KK. Actinous enigma or enigmatic actin: Folding, structure, and functions of the most abundant eukaryotic protein. INTRINSICALLY DISORDERED PROTEINS 2014; 2:e34500. [PMID: 28232879 PMCID: PMC5314930 DOI: 10.4161/idp.34500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 08/12/2014] [Accepted: 08/13/2014] [Indexed: 02/06/2023]
Abstract
Being the most abundant protein of the eukaryotic cell, actin continues to keep its secrets for more than 60 years. Everything about this protein, its structure, functions, and folding, is mysteriously counterintuitive, and this review represents an attempt to solve some of the riddles and conundrums commonly found in the field of actin research. In fact, actin is a promiscuous binder with a wide spectrum of biological activities. It can exist in at least three structural forms, globular, fibrillar, and inactive (G-, F-, and I-actin, respectively). G-actin represents a thermodynamically instable, quasi-stationary state, which is formed in vivo as a result of the energy-intensive, complex posttranslational folding events controlled and driven by cellular folding machinery. The G-actin structure is dependent on the ATP and Mg2+ binding (which in vitro is typically substituted by Ca2+) and protein is easily converted to the I-actin by the removal of metal ions and by action of various denaturing agents (pH, temperature, and chemical denaturants). I-actin cannot be converted back to the G-form. Foldable and “natively folded” forms of actin are always involved in interactions either with the specific protein partners, such as Hsp70 chaperone, prefoldin, and the CCT chaperonin during the actin folding in vivo or with Mg2+ and ATP as it takes place in the G-form. We emphasize that the solutions for the mysteries of actin multifunctionality, multistructurality, and trapped unfolding can be found in the quasi-stationary nature of this enigmatic protein, which clearly possesses many features attributed to both globular and intrinsically disordered proteins.
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Affiliation(s)
- Olga I Povarova
- Laboratory of structural dynamics, stability, and folding of proteins; Institute of Cytology; Russian Academy of Sciences; St. Petersburg, Russia
| | - Vladimir N Uversky
- Laboratory of structural dynamics, stability, and folding of proteins; Institute of Cytology; Russian Academy of Sciences; St. Petersburg, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute; Morsani College of Medicine; University of South Florida; Tampa, FL USA; Institute for Biological Instrumentation; Russian Academy of Sciences; Pushchino, Russia; Biology Department; Faculty of Science; King Abdulaziz University; Jeddah, Kingdom of Saudi Arabia
| | - Irina M Kuznetsova
- Laboratory of structural dynamics, stability, and folding of proteins; Institute of Cytology; Russian Academy of Sciences; St. Petersburg, Russia; St. Petersburg State Polytechnical University; St. Petersburg, Russia
| | - Konstantin K Turoverov
- Laboratory of structural dynamics, stability, and folding of proteins; Institute of Cytology; Russian Academy of Sciences; St. Petersburg, Russia; St. Petersburg State Polytechnical University; St. Petersburg, Russia
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20
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Shakhbazau A, Archibald SJ, Shcharbin D, Bryszewska M, Midha R. Aligned collagen-GAG matrix as a 3D substrate for Schwann cell migration and dendrimer-based gene delivery. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:1979-1989. [PMID: 24801062 DOI: 10.1007/s10856-014-5224-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 04/21/2014] [Indexed: 06/03/2023]
Abstract
The development of artificial off-the-shelf conduits that facilitate effective nerve regeneration and recovery after repair of traumatic nerve injury gaps is of fundamental importance. Collagen-glycosaminoglycan (GAG) matrix mimicking Schwann cell (SC) basal lamina has been proposed as a suitable and biologically rational substrate for nerve regeneration. In the present study, we have focused on the permissiveness of this matrix type for SC migration and repopulation, as these events play an essential role in nerve remodeling. We have also demonstrated that SCs cultured within collagen-GAG matrix are compatible with non-viral dendrimer-based gene delivery, that may allow conditioning of matrix-embedded cells for future gene therapy applications.
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Affiliation(s)
- Antos Shakhbazau
- Department of Clinical Neuroscience, Faculty of Medicine, University of Calgary, HMRB 109-3330 Hospital Drive NW, Calgary, AB, T2N4N1, Canada,
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21
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Gesellchen F, Bernassau AL, Déjardin T, Cumming DRS, Riehle MO. Cell patterning with a heptagon acoustic tweezer--application in neurite guidance. LAB ON A CHIP 2014; 14:2266-75. [PMID: 24817215 DOI: 10.1039/c4lc00436a] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Accurate control over positioning of cells is a highly desirable feature in tissue engineering applications since it allows, for example, population of substrates in a controlled fashion, rather than relying on random seeding. Current methods to achieve a differential distribution of cells mostly use passive patterning methods to change chemical, mechanical or topographic properties of surfaces, making areas differentially permissive to the adhesion of cells. However, these methods have no ad hoc control over the actual deposition of cells. Direct patterning methods like bioprinting offer good control over cell position, but require sophisticated instrumentation and are often cost- and time-intensive. Here, we present a novel electronically controlled method of generating dynamic cell patterns by acoustic trapping of cells at a user-determined position, with a heptagonal acoustic tweezer device. We demonstrate the capability of the device to create complex patterns of cells using the device's ability to re-position acoustic traps by using a phase shift in the acoustic wave, and by switching the configuration of active piezoelectric transducers. Furthermore, we show that by arranging Schwann cells from neonatal rats in a linear pattern we are able to create Bands of Büngner-like structures on a non-structured surface and demonstrate that these features are able to guide neurite outgrowth from neonatal rat dorsal root ganglia.
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Affiliation(s)
- F Gesellchen
- Centre for Cell Engineering, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK.
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22
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Neuropathologic Characterization ofINF2-Related Charcot-Marie-Tooth Disease: Evidence for a Schwann Cell Actinopathy. J Neuropathol Exp Neurol 2014; 73:223-33. [DOI: 10.1097/nen.0000000000000047] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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23
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Uggenti C, De Stefano ME, Costantino M, Loreti S, Pisano A, Avallone B, Talora C, Magnaghi V, Tata AM. M2 muscarinic receptor activation regulates Schwann cell differentiation and myelin organization. Dev Neurobiol 2014; 74:676-91. [PMID: 24403178 DOI: 10.1002/dneu.22161] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 12/14/2013] [Accepted: 12/15/2013] [Indexed: 01/01/2023]
Abstract
Glial cells express acetylcholine receptors. In particular, rat Schwann cells express different muscarinic receptor subtypes, the most abundant of which is the M2 subtype. M2 receptor activation causes a reversible arrest of the cell cycle. This negative effect on Schwann cell proliferation suggests that these cells may possibly progress into a differentiating program. In this study we analyzed the in vitro modulation, by the M2 agonist arecaidine, of transcription factors and specific signaling pathways involved in Schwann cell differentiation. The arecaidine-induced M2 receptor activation significantly upregulates transcription factors involved in the promyelinating phase (e.g., Sox10 and Krox20) and downregulates proteins involved in the maintenance of the undifferentiated state (e.g., c-jun, Notch-1, and Jagged-1). Furthermore, arecaidine stimulation significantly increases the expression of myelin proteins, which is accompanied by evident changes in cell morphology, as indicated by electron microscopy analysis, and by substantial cellular re-distribution of actin and cell adhesion molecules. Moreover, ultrastructural and morphometric analyses on sciatic nerves of M2/M4 knockout mice show numerous degenerating axons and clear alterations in myelin organization compared with wild-type mice. Therefore, our data demonstrate that acetylcholine mediates axon-glia cross talk, favoring Schwann cell progression into a differentiated myelinating phenotype and contributing to compact myelin organization.
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Affiliation(s)
- Carolina Uggenti
- Dipartmento di Biologia e Biotecnologie "Charles Darwin,", "Sapienza" Università di Roma, Roma, Italy; Centro di ricerca in Neurobiologia "Daniel Bovet,", "Sapienza" Università di Roma, Roma, Italy
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24
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CHANG CHENGTAO, LIN CHOUCHINGK, JU MINGSHAUNG. COMBINED ATOMIC FORCE AND FLUORESCENCE MICROSCOPIES TO MEASURE SUBCELLULAR MECHANICAL PROPERTIES OF LIVE CELLS. J MECH MED BIOL 2013. [DOI: 10.1142/s0219519413500577] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Atomic force microscopy (AFM) has been widely applied to study cellular functions;however, the relationship between cellular elasticity and ultrastructure density of a live cell remains to be discovered. The objective of this study was thus to extend our previous method of integrating AFM and immunofluorescence imaging to measure the ultrastructure distribution-related local mechanical properties of live cells. First, the morphology of a live cell was obtained by AFM. Second, the indentation sites were selected and flexible force volume indentation was performed. Third, the immunofluorescence image of the cell was obtained. The last was the mapping of the indentation site to the immunofluorescence image and obtaining the relationship between the local elastic properties and cytoskeleton density. The results on differentiated rat Schwann cells (RSCs) showed that the elastic modulus of stress fibers is higher than those of the nucleus and cytosol. The local elastic modulus of the live RSCs is correlated to the actin density, and the stress fiber that behaves like a pretension beam can give RSCs enough strength to envelop axons during myelination. In particular, the elastic properties of the live RSCs were twofold lower than those of the fixed. The results demonstrated the integrated method's applicability for a live cell.
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Affiliation(s)
- CHENG-TAO CHANG
- Department of Mechanical Engineering, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan
| | - CHOU-CHING K. LIN
- Department of Neurology, University Hospital, College of Medicine, National Cheng Kung University, 138 Sheng Li Road, Tainan 701, Taiwan
| | - MING-SHAUNG JU
- Department of Mechanical Engineering, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan
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25
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Abstract
The fundamental roles of Schwann cells during peripheral nerve formation and regeneration have been recognized for more than 100 years, but the cellular and molecular mechanisms that integrate Schwann cell and axonal functions continue to be elucidated. Derived from the embryonic neural crest, Schwann cells differentiate into myelinating cells or bundle multiple unmyelinated axons into Remak fibers. Axons dictate which differentiation path Schwann cells follow, and recent studies have established that axonal neuregulin1 signaling via ErbB2/B3 receptors on Schwann cells is essential for Schwann cell myelination. Extracellular matrix production and interactions mediated by specific integrin and dystroglycan complexes are also critical requisites for Schwann cell-axon interactions. Myelination entails expansion and specialization of the Schwann cell plasma membrane over millimeter distances. Many of the myelin-specific proteins have been identified, and transgenic manipulation of myelin genes have provided novel insights into myelin protein function, including maintenance of axonal integrity and survival. Cellular events that facilitate myelination, including microtubule-based protein and mRNA targeting, and actin based locomotion, have also begun to be understood. Arguably, the most remarkable facet of Schwann cell biology, however, is their vigorous response to axonal damage. Degradation of myelin, dedifferentiation, division, production of axonotrophic factors, and remyelination all underpin the substantial regenerative capacity of the Schwann cells and peripheral nerves. Many of these properties are not shared by CNS fibers, which are myelinated by oligodendrocytes. Dissecting the molecular mechanisms responsible for the complex biology of Schwann cells continues to have practical benefits in identifying novel therapeutic targets not only for Schwann cell-specific diseases but other disorders in which axons degenerate.
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Affiliation(s)
- Grahame J Kidd
- Department of Neuroscience, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
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26
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Wang Y, Teng HL, Huang ZH. Intrinsic migratory properties of cultured Schwann cells based on single-cell migration assay. PLoS One 2012; 7:e51824. [PMID: 23251634 PMCID: PMC3522601 DOI: 10.1371/journal.pone.0051824] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 11/06/2012] [Indexed: 11/18/2022] Open
Abstract
The migration of Schwann cells is critical for development of peripheral nervous system and is essential for regeneration and remyelination after nerve injury. Although several factors have been identified to regulate Schwann cell migration, intrinsic migratory properties of Schwann cells remain elusive. In this study, based on time-lapse imaging of single isolated Schwann cells, we examined the intrinsic migratory properties of Schwann cells and the molecular cytoskeletal machinery of soma translocation during migration. We found that cultured Schwann cells displayed three motile phenotypes, which could transform into each other spontaneously during their migration. Local disruption of F-actin polymerization at leading front by a Cytochalasin D or Latrunculin A gradient induced collapse of leading front, and then inhibited soma translocation. Moreover, in migrating Schwann cells, myosin II activity displayed a polarized distribution, with the leading process exhibiting higher expression than the soma and trailing process. Decreasing this front-to-rear difference of myosin II activity by frontal application of a ML-7 or BDM (myosin II inhibitors) gradient induced the collapse of leading front and reversed soma translocation, whereas, increasing this front-to-rear difference of myosin II activity by rear application of a ML-7 or BDM gradient or frontal application of a Caly (myosin II activator) gradient accelerated soma translocation. Taken together, these results suggest that during migration, Schwann cells display malleable motile phenotypes and the extension of leading front dependent on F-actin polymerization pulls soma forward translocation mediated by myosin II activity.
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Affiliation(s)
- Ying Wang
- School of Laboratory Medicine and Life Science, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Institute of Hypoxia Medicine and Institute of Neuroscience, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Hong-Lin Teng
- Department of Spine Surgery, the First Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Zhi-hui Huang
- Institute of Hypoxia Medicine and Institute of Neuroscience, Wenzhou Medical College, Wenzhou, Zhejiang, China
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27
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Love JM, Pathak GK, Chetta J, Shah SB. Variability in Membrane Continuity Between Schwann Cells and Neurons. Cell Mol Bioeng 2012. [DOI: 10.1007/s12195-012-0250-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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28
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Negative Regulators of Schwann Cell Differentiation—Novel Targets for Peripheral Nerve Therapies? J Clin Immunol 2012; 33 Suppl 1:S18-26. [DOI: 10.1007/s10875-012-9786-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 08/27/2012] [Indexed: 01/01/2023]
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29
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Heinen A, Tzekova N, Graffmann N, Torres KJ, Uhrberg M, Hartung HP, Küry P. Histone methyltransferase enhancer of zeste homolog 2 regulates Schwann cell differentiation. Glia 2012; 60:1696-708. [DOI: 10.1002/glia.22388] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 05/31/2012] [Accepted: 06/19/2012] [Indexed: 01/05/2023]
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30
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Bernard F, Moreau-Fauvarque C, Heitz-Marchaland C, Zagar Y, Dumas L, Fouquet S, Lee X, Shao Z, Mi S, Chédotal A. Role of transmembrane semaphorin Sema6A in oligodendrocyte differentiation and myelination. Glia 2012; 60:1590-604. [DOI: 10.1002/glia.22378] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 06/05/2012] [Indexed: 11/09/2022]
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31
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Goebbels S, Oltrogge JH, Wolfer S, Wieser GL, Nientiedt T, Pieper A, Ruhwedel T, Groszer M, Sereda MW, Nave KA. Genetic disruption of Pten in a novel mouse model of tomaculous neuropathy. EMBO Mol Med 2012; 4:486-99. [PMID: 22488882 PMCID: PMC3443946 DOI: 10.1002/emmm.201200227] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 02/16/2012] [Accepted: 02/17/2012] [Indexed: 01/01/2023] Open
Abstract
‘Tomacula’ and myelin outfoldings are striking neuropathological features of a diverse group of inherited demyelinating neuropathies. Whereas the underlying genetic defects are well known, the molecular mechanisms of tomacula formation have remained obscure. We hypothesized that they are caused by uncontrolled, excessive myelin membrane growth, a process, which is regulated in normal development by neuregulin-1/ErbB2, PI3 Kinase signalling and ERK/MAPK signalling. Here, we demonstrate by targeted disruption of Pten in Schwann cells that hyperactivation of the endogenous PI3 Kinase pathway causes focal hypermyelination, myelin outfoldings and tomacula, even when induced in adult animals by tamoxifen, and is associated with progressive peripheral neuropathy. Activated AKT kinase is associated with PtdIns(3,4,5)P3 at paranodal loops and Schmidt–Lanterman incisures. This striking myelin pathology, with features of human CMT type 4B1 and HNPP, is dependent on AKT/mTOR signalling, as evidenced by a significant amelioration of the pathology in mice treated with rapamycin. We suggest that regions of non-compact myelin are under lifelong protection by PTEN against abnormal membrane outgrowth, and that dysregulated phosphoinositide levels play a critical role in the pathology of tomaculous neuropathies.
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Affiliation(s)
- Sandra Goebbels
- Max-Planck-Institute of Experimental Medicine, Göttingen, Germany.
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32
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Pereira JA, Lebrun-Julien F, Suter U. Molecular mechanisms regulating myelination in the peripheral nervous system. Trends Neurosci 2011; 35:123-34. [PMID: 22192173 DOI: 10.1016/j.tins.2011.11.006] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 12/21/2022]
Abstract
Glial cells and neurons are engaged in a continuous and highly regulated bidirectional dialog. A remarkable example is the control of myelination. Oligodendrocytes in the central nervous system (CNS) and Schwann cells (SCs) in the peripheral nervous system (PNS) wrap their plasma membranes around axons to organize myelinated nerve fibers that allow rapid saltatory conduction. The functionality of this system is critical, as revealed by numerous neurological diseases that result from deregulation of the system, including multiple sclerosis and peripheral neuropathies. In this review we focus on PNS myelination and present a conceptual framework that integrates crucial signaling mechanisms with basic SC biology. We will highlight signaling hubs and overarching molecular mechanisms, including genetic, epigenetic, and post-translational controls, which together regulate the interplay between SCs and axons, extracellular signals, and the transcriptional network.
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Affiliation(s)
- Jorge A Pereira
- Institute of Cell Biology, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
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33
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Jin F, Dong B, Georgiou J, Jiang Q, Zhang J, Bharioke A, Qiu F, Lommel S, Feltri ML, Wrabetz L, Roder JC, Eyer J, Chen X, Peterson AC, Siminovitch KA. N-WASp is required for Schwann cell cytoskeletal dynamics, normal myelin gene expression and peripheral nerve myelination. Development 2011; 138:1329-37. [PMID: 21385763 DOI: 10.1242/dev.058677] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Schwann cells elaborate myelin sheaths around axons by spirally wrapping and compacting their plasma membranes. Although actin remodeling plays a crucial role in this process, the effectors that modulate the Schwann cell cytoskeleton are poorly defined. Here, we show that the actin cytoskeletal regulator, neural Wiskott-Aldrich syndrome protein (N-WASp), is upregulated in myelinating Schwann cells coincident with myelin elaboration. When N-WASp is conditionally deleted in Schwann cells at the onset of myelination, the cells continue to ensheath axons but fail to extend processes circumferentially to elaborate myelin. Myelin-related gene expression is also severely reduced in the N-WASp-deficient cells and in vitro process and lamellipodia formation are disrupted. Although affected mice demonstrate obvious motor deficits these do not appear to progress, the mutant animals achieving normal body weights and living to advanced age. Our observations demonstrate that N-WASp plays an essential role in Schwann cell maturation and myelin formation.
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Affiliation(s)
- Fuzi Jin
- Department of Haematology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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34
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Abstract
During peripheral nerve development, Schwann cells ensheathe axons and form myelin to enable rapid and efficient action potential propagation. Although myelination requires profound changes in Schwann cell shape, how neuron-glia interactions converge on the Schwann cell cytoskeleton to induce these changes is unknown. Here, we demonstrate that the submembranous cytoskeletal proteins αII and βII spectrin are polarized in Schwann cells and colocalize with signaling molecules known to modulate myelination in vitro. Silencing expression of these spectrins inhibited myelination in vitro, and remyelination in vivo. Furthermore, myelination was disrupted in motor nerves of zebrafish lacking αII spectrin. Finally, we demonstrate that loss of spectrin significantly reduces both F-actin in the Schwann cell cytoskeleton and the Nectin-like protein, Necl4, at the contact site between Schwann cells and axons. Therefore, we propose αII and βII spectrin in Schwann cells integrate the neuron-glia interactions mediated by membrane proteins into the actin-dependent cytoskeletal rearrangements necessary for myelination.
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35
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Novak N, Bar V, Sabanay H, Frechter S, Jaegle M, Snapper SB, Meijer D, Peles E. N-WASP is required for membrane wrapping and myelination by Schwann cells. ACTA ACUST UNITED AC 2011; 192:243-50. [PMID: 21263026 PMCID: PMC3172181 DOI: 10.1083/jcb.201010013] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
N-WASP–deficient Schwann cells sort and ensheath axons but arrest at the promyelinating stage. During peripheral nerve myelination, Schwann cells sort larger axons, ensheath them, and eventually wrap their membrane to form the myelin sheath. These processes involve extensive changes in cell shape, but the exact mechanisms involved are still unknown. Neural Wiskott–Aldrich syndrome protein (N-WASP) integrates various extracellular signals to control actin dynamics and cytoskeletal reorganization through activation of the Arp2/3 complex. By generating mice lacking N-WASP in myelinating Schwann cells, we show that N-WASP is crucial for myelination. In N-WASP–deficient nerves, Schwann cells sort and ensheath axons, but most of them fail to myelinate and arrest at the promyelinating stage. Yet, a limited number of Schwann cells form unusually short internodes, containing thin myelin sheaths, with the occasional appearance of myelin misfoldings. These data suggest that regulation of actin filament nucleation in Schwann cells by N-WASP is crucial for membrane wrapping, longitudinal extension, and myelination.
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Affiliation(s)
- Nurit Novak
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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Wicklow DT, Rogers KD, Dowd PF, Gloer JB. Bioactive metabolites from Stenocarpella maydis, a stalk and ear rot pathogen of maize. Fungal Biol 2010; 115:133-42. [PMID: 21315311 DOI: 10.1016/j.funbio.2010.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/22/2010] [Accepted: 11/23/2010] [Indexed: 10/18/2022]
Abstract
Stenocarpella maydis is a fungal pathogen of major importance that causes a dry-rot of maize ears and is associated with a neuromycotoxicosis in cattle grazing harvested maize fields in southern Africa and Argentina. In an effort to investigate the potential roles of S. maydis metabolites in the fungal disease cycle, ethyl acetate extracts of solid-substrate fermentations of several S. maydis isolates from maize grown in the United States were found to exhibit significant phytotoxic, antifungal, and antiinsectan activity. Chemical investigations of extracts of S. maydis isolates from Illinois and Nebraska led to the isolation or detection of the known metabolites diplodiatoxin, chaetoglobosins K and L, and (all-E)-trideca-4,6,10,12-tetraene-2,8-diol as major components. A culture of Stenocarpella macrospora from maize grown in Zambia produced diplosporin and chaetoglobosins K and L as major components that were isolated. Diplodiatoxin produced significant lesions in a maize leaf puncture wound assay. Diplosporin and chaetoglobosin K displayed moderate antiinsectan activity in dietary assays against the fall armyworm Spodoptera frugiperda, while chaetoglobosin K exhibited significant antifungal activity against Aspergillus flavus and Fusarium verticillioides. Using LC-ESIMS and (1)H NMR data, diplodiatoxin was detected as a major component in S. maydis-rotted grain, stalks, and stalk residues. This constitutes the first report of chaetoglobosins K and L from S. maydis, of (all-E)-trideca-4,6,10,12-tetraene-2,8-diol from Stenocarpella, and the first reported detection of diplodiatoxin, or any other Stenocarpella metabolite, in diseased maize seeds and stalk tissues.
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Affiliation(s)
- Donald T Wicklow
- Bacterial Food Pathogens and Mycology, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, Peoria, IL 61604, USA.
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Hossain S, Fragoso G, Mushynski WE, Almazan G. Regulation of peripheral myelination by Src-like kinases. Exp Neurol 2010; 226:47-57. [DOI: 10.1016/j.expneurol.2010.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 07/13/2010] [Accepted: 08/02/2010] [Indexed: 01/06/2023]
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Meng J, Xia W, Tang J, Tang BL, Liang F. Dephosphorylation-dependent inhibitory activity of juxtanodin on filamentous actin disassembly. J Biol Chem 2010; 285:28838-49. [PMID: 20610382 DOI: 10.1074/jbc.m110.117887] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the vertebrate central nervous system, maturation of oligodendrocytes is accompanied by a dramatic transformation of cell morphology. Juxtanodin (JN) is an actin cytoskeleton-related oligodendroglial protein that promotes arborization of cultured oligodendrocytes. We performed in vitro and in culture experiments to further elucidate the biochemical effects, molecular interactions, and activity regulation of JN. Pulldown and co-sedimentation assays confirmed JN binding to filamentous but not globular beta-actin largely through a C-terminal domain of 14 amino acid residues. JN had much lower affinity to F-alpha-actin than to F-beta-actin. Bundling and actin polymerization assays revealed no JN influence on F-beta-actin cross-linking or G-beta-actin polymerization. Sedimentation assay, however, demonstrated that JN slowed the rate of F-beta-actin disassembly induced by dilution with F-actin depolymerization buffer. JN-S278E mutant, a mimic of phosphorylated JN at serine 278, exhibited a much diminished affinity/stabilizing effect on F-beta-actin. Immunoblotting revealed both phosphorylated and dephosphorylated native JN of the brain, with the former migrating slightly slower than the latter and becoming undetectable when brain lysate was subjected to in vitro dephosphorylation prior to being loaded for electrophoresis. In cultured OLN-93 cells, overexpression of JN promoted the formation of actin fibers and inhibited F-actin disassembly induced by latrunculin A. S278E phosphomimetic mutation resulted in loss of JN activity in cultured cells, whereas S278A, T258A, and T258E dephospho-/phosphomimetic mutations did not. These findings establish JN as an actin cytoskeleton-stabilizing protein that may play active roles in oligodendroglial differentiation and myelin formation. Specific phosphorylation of JN might serve as an important mechanism regulating JN functions.
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Affiliation(s)
- Jun Meng
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Gonçalves AF, Dias NG, Moransard M, Correia R, Pereira JA, Witke W, Suter U, Relvas JB. Gelsolin is required for macrophage recruitment during remyelination of the peripheral nervous system. Glia 2010; 58:706-15. [PMID: 20014276 DOI: 10.1002/glia.20956] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Reorganization of the actin cytoskeleton is necessary for Schwann cell proliferation, migration and for the morphological changes associated with sorting, ensheathing and myelination of axons. Such reorganization requires regulated severing and depolymerization of actin filaments. Gelsolin is an actin filament severing protein expressed in many cell types including Schwann cells. Using Gelsolin knockout mice, we investigated the role of this protein in the myelination and remyelination of the peripheral nervous system. Our results show that although gelsolin is not necessary for developmental myelination, it is required for timely remyelination of the sciatic nerve following crush injury. Gelsolin is necessary for macrophage motility in culture, and its absence is likely to impair the recruitment of macrophages to the injury site.
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Affiliation(s)
- Ana Filipa Gonçalves
- Institute of Cell Biology, Department of Biology, ETH Zurich, Zurich, Switzerland
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Haber M, Vautrin S, Fry EJ, Murai KK. Subtype-specific oligodendrocyte dynamics in organotypic culture. Glia 2009; 57:1000-13. [DOI: 10.1002/glia.20824] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Wang H, Tewari A, Einheber S, Salzer JL, Melendez-Vasquez CV. Myosin II has distinct functions in PNS and CNS myelin sheath formation. ACTA ACUST UNITED AC 2008; 182:1171-84. [PMID: 18794332 PMCID: PMC2542477 DOI: 10.1083/jcb.200802091] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The myelin sheath forms by the spiral wrapping of a glial membrane around the axon. The mechanisms responsible for this process are unknown but are likely to involve coordinated changes in the glial cell cytoskeleton. We have found that inhibition of myosin II, a key regulator of actin cytoskeleton dynamics, has remarkably opposite effects on myelin formation by Schwann cells (SC) and oligodendrocytes (OL). Myosin II is necessary for initial interactions between SC and axons, and its inhibition or down-regulation impairs their ability to segregate axons and elongate along them, preventing the formation of a 1:1 relationship, which is critical for peripheral nervous system myelination. In contrast, OL branching, differentiation, and myelin formation are potentiated by inhibition of myosin II. Thus, by controlling the spatial and localized activation of actin polymerization, myosin II regulates SC polarization and OL branching, and by extension their ability to form myelin. Our data indicate that the mechanisms regulating myelination in the peripheral and central nervous systems are distinct.
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Affiliation(s)
- Haibo Wang
- Department of Biological Sciences, Hunter College, City University of New York, New York, NY 10065, USA
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The cyclin-dependent kinase inhibitor p57kip2 is a negative regulator of Schwann cell differentiation and in vitro myelination. Proc Natl Acad Sci U S A 2008; 105:8748-53. [PMID: 18550808 DOI: 10.1073/pnas.0802659105] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The p57kip2 gene encodes a member of the cyclin-dependent kinase inhibitor family, proteins known to block G(1)/S transition during the mammalian cell cycle. We observed that expression of p57kip2 in Schwann cells of the developing and injured adult peripheral nervous system is dynamically regulated. Using gene knockdown by means of vector-based RNA interference in cultured primary Schwann cells we found that reduced levels of p57kip2 lead to cell cycle exit, actin filament stabilization, altered cell morphology and growth, and down-regulation of promyelinating markers as well as induction of myelin genes and proteins. In addition, we could demonstrate that in vitro myelination is enhanced by p57kip2-suppressed Schwann cells. Using microarray technology we found that these cellular reactions are specific to lowered p57kip2 expression levels and detected a shift of the transcriptional expression program toward the pattern known from Schwann cells in developing peripheral nerves. Because in the absence of axons primary Schwann cells normally do not display differentiation-associated reactions, we conclude that we have identified a mechanism and an important intrinsic negative regulator of myelinating glia differentiation.
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Yu WM, Yu H, Chen ZL. Laminins in peripheral nerve development and muscular dystrophy. Mol Neurobiol 2008; 35:288-97. [PMID: 17917117 DOI: 10.1007/s12035-007-0026-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 11/30/1999] [Accepted: 11/28/2006] [Indexed: 12/14/2022]
Abstract
Laminins are extracellular matrix (ECM) proteins that play an important role in cellular function and tissue morphogenesis. In the peripheral nervous system (PNS), laminins are expressed in Schwann cells and participate in their development. Mutations in laminin subunits expressed in the PNS and in skeleton muscle may cause peripheral neuropathies and muscular dystrophy in both humans and mice. Recent studies using gene knockout technology, such as cell-type specific gene targeting techniques, revealed that laminins and their receptors mediate Schwann cell and axon interactions. Schwann cells with disrupted laminin expression exhibit impaired proliferation and differentiation and also undergo apoptosis. In this review, we focus on the potential molecular mechanisms by which laminins participate in the development of Schwann cells.
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Affiliation(s)
- Wei-Ming Yu
- Laboratory of Neurobiology and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10021, USA
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Berti C, Nodari A, Wrabetz L, Feltri ML. Role of integrins in peripheral nerves and hereditary neuropathies. Neuromolecular Med 2007; 8:191-204. [PMID: 16775376 DOI: 10.1385/nmm:8:1-2:191] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 11/18/2005] [Accepted: 11/30/2005] [Indexed: 01/11/2023]
Abstract
Interactions between Schwann cells and extracellular matrix on one surface, and axons on the other, are required for correct myelination in the developing peripheral nervous system. Integrins are transmembrane proteins that mediate the former in association with other surface receptors. This review focuses on the role that integrins play in the development of the peripheral nervous system, and in inherited human peripheral neuropathies. Here we describe recent findings on integrin signaling to different intracellular pathways, focusing on cell adhesion, migration, and polarization. Then we use information derived from recent experiments of targeted mutagenesis in mice to show that, consistent with temporally regulated expression, different integrins serve multiple roles in developing nerve.
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Affiliation(s)
- Caterina Berti
- San Raffaele Scientific Institute, DIBIT, Via Olgettina 58, 20132 Milano, Italy
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Bacon C, Lakics V, Machesky L, Rumsby M. N-WASP regulates extension of filopodia and processes by oligodendrocyte progenitors, oligodendrocytes, and Schwann cells—implications for axon ensheathment at myelination. Glia 2007; 55:844-58. [PMID: 17405146 DOI: 10.1002/glia.20505] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The molecular mechanisms used by oligodendrocyte precursor cells (OPCs), oligodendrocytes (OLs), and Schwann cells (SCs) to advance processes for motility in the developing nervous system and to ensheath axons at myelination are currently not well defined. Here we demonstrate that OPCs, OLs, and SCs express the major proteins involved in actin polymerization-driven protrusion; these key proteins including F-actin, the Arp2/3 complex, neural-Wiskott Aldrich Syndrome protein (N-WASP) and WAVE proteins, and the RhoGTPases Rac and Cdc42 are present at the leading edges of processes being extended by OPCs, OLs, and SCs. We reveal by real-time PCR that OLs and SCs have different dominant WAVE isoforms. Inhibition of the WASP/WAVE protein, N-WASP, with wiskostatin that prevents activation of the Arp2/3 complex, blocks process extension by OPCs and SCs. Inhibition of N-WASP also causes OPC and SC process retraction, which is preceded by retraction of filopodia. This implicates filopodia in OPC and SC process stability and also of N-WASP in OPC and SC process dynamics. We also demonstrate that p34 (a component of the Arp2/3 complex), WASP/WAVE proteins, actin, alpha-tubulin, Rac, Cdc42, vinculin, and focal adhesion kinase are detected in water-shocked myelin purified from brain. Inhibition of N-WASP with wiskostatin decreases the number of axons undergoing initial ensheathment in intact optic nerve samples and reduces the Po content of dorsal root ganglia:SC co-cultures. Our findings indicate that OPCs, OLs, and SCs extend processes using actin polymerization-driven protrusion dependent on N-WASP. We hypothesize that inner mesaxons of OLs and SCs use the same mechanism to ensheath axons at myelination.
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Affiliation(s)
- Claire Bacon
- Department of Biology, University of York, York, United Kingdom
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Thaxton C, Lopera J, Bott M, Baldwin ME, Kalidas P, Fernandez-Valle C. Phosphorylation of the NF2 tumor suppressor in Schwann cells is mediated by Cdc42-Pak and requires paxillin binding. Mol Cell Neurosci 2006; 34:231-42. [PMID: 17175165 DOI: 10.1016/j.mcn.2006.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 10/28/2006] [Accepted: 11/07/2006] [Indexed: 11/22/2022] Open
Abstract
Mutations in the Neurofibromatosis type 2 tumor suppressor gene that encodes Schwannomin causes formation of benign schwannomas. Schwannoma cells lose their characteristic bipolar shape and become rounded with excessive ruffling membranes. Schwannomin is phosphorylated at serine 518 (S518) by p21 activated kinase (Pak). Unphosphorylated schwannomin is associated with growth inhibition but little is known about the function of the phosphorylated form, or the molecular events leading to its phosphorylation. Here, we report in SCs that schwannomin S518 phosphorylation requires binding to paxillin and targeting to the plasma membrane. Phospho-S518-schwannomin is enriched in the peripheral-most aspects of membrane specializations where paxillin, activated Pak, Cdc42 but not Rac are highly expressed. Schwannomin and Pak phosphorylation levels are not reduced in response to lowering Rac-GTP levels with NSC23766. Expression of schwannomin S518A/D-GFP variants each distinctively altered Schwann cell shape and polarity. These results are consistent with tight spatial regulation of S518 phosphorylation at the plasma membrane in a paxillin and Cdc42-Pak dependent manner that leads to local reorganization of the SC cytoskeleton.
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Affiliation(s)
- Courtney Thaxton
- Biomolecular Research Annex, Department of Molecular Biology and Microbiology, University of Central Florida, Orlando, FL 32826, USA
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Abstract
This selective review of Schwann cell biology focuses on questions relating to the origins, development and differentiation of Schwann cells and the signals that control these processes. The importance of neuregulins and their receptors in controlling Schwann cell precursor survival and generation of Schwann cells, and the role of these molecules in Schwann cell biology is addressed. The reciprocal signalling between peripheral glial cells and neurons in development and adult life revealed in recent years is highlighted, and the profound change in survival regulation from neuron-dependent Schwann cell precursors to adult Schwann cells that depend on autocrine survival signals is discussed. Besides providing neuronal and autocrine signals, Schwann cells signal to mesenchymal cells and influence the development of the connective tissue sheaths of peripheral nerves. The importance of Desert Hedgehog in this process is described. The control of gene expression during Schwann cell development and differentiation by transcription factors is reviewed. Knockout of Oct-6 and Krox-20 leads to delay or absence of myelination, and these results are related to morphological or physiological observations on knockout or mutation of myelin-related genes. Finally, the relationship between selected extracellular matrix components, integrins and the cytoskeleton is explored and related to disease.
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Affiliation(s)
- R Mirsky
- Department of Anatomy and Developmental Biology, University College London, UK.
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D'Antonio M, Michalovich D, Paterson M, Droggiti A, Woodhoo A, Mirsky R, Jessen KR. Gene profiling and bioinformatic analysis of Schwann cell embryonic development and myelination. Glia 2006; 53:501-15. [PMID: 16369933 DOI: 10.1002/glia.20309] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
To elucidate the molecular mechanisms involved in Schwann cell development, we profiled gene expression in the developing and injured rat sciatic nerve. The genes that showed significant changes in expression in developing and dedifferentiated nerve were validated with RT-PCR, in situ hybridisation, Western blot and immunofluorescence. A comprehensive approach to annotating micro-array probes and their associated transcripts was performed using Biopendium, a database of sequence and structural annotation. This approach significantly increased the number of genes for which a functional insight could be found. The analysis implicates agrin and two members of the collapsin response-mediated protein (CRMP) family in the switch from precursors to Schwann cells, and synuclein-1 and alphaB-crystallin in peripheral nerve myelination. We also identified a group of genes typically related to chondrogenesis and cartilage/bone development, including type II collagen, that were expressed in a manner similar to that of myelin-associated genes. The comprehensive function annotation also identified, among the genes regulated during nerve development or after nerve injury, proteins belonging to high-interest families, such as cytokines and kinases, and should therefore provide a uniquely valuable resource for future research.
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Affiliation(s)
- Maurizio D'Antonio
- Department of Anatomy and Developmental Biology, University College London, London, United Kingdom
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Clardy SL, Wang X, Zhao W, Liu W, Chase GA, Beard JL, True Felt B, Connor JR. Acute and chronic effects of developmental iron deficiency on mRNA expression patterns in the brain. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2006:173-96. [PMID: 17447428 DOI: 10.1007/978-3-211-33328-0_19] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Because of the multiple biochemical pathways that require iron, iron deficiency can impact brain metabolism in many ways. The goal of this study was to identify a molecular footprint associated with ongoing versus long term consequences of iron deficiency using microarray analysis. Rats were born to iron-deficient mothers, and were analyzed at two different ages: 21 days, while weaning and iron-deficient; and six months, after a five month iron-sufficient recovery period. Overall, the data indicate that ongoing iron deficiency impacts multiple pathways, whereas the long term consequences of iron deficiency on gene expression are more limited. These data suggest that the gene array profiles obtained at postnatal day 21 reflect a brain under development in a metabolically compromised setting that given appropriate intervention is mostly correctable. There are, however, long term consequences to the developmental iron deficiency that could underlie the neurological deficits reported for iron deficiency.
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Affiliation(s)
- S L Clardy
- Department of Neurosurgery, M.S. Hershey Medical Center, Hershey, USA
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50
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Bermingham JR, Shearin H, Pennington J, O'Moore J, Jaegle M, Driegen S, van Zon A, Darbas A, Ozkaynak E, Ryu EJ, Milbrandt J, Meijer D. The claw paw mutation reveals a role for Lgi4 in peripheral nerve development. Nat Neurosci 2005; 9:76-84. [PMID: 16341215 DOI: 10.1038/nn1598] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Accepted: 10/18/2005] [Indexed: 12/24/2022]
Abstract
Peripheral nerve development results from multiple cellular interactions between axons, Schwann cells and the surrounding mesenchymal tissue. The delayed axonal sorting and hypomyelination throughout the peripheral nervous system of claw paw (clp) mutant mice suggest that the clp gene product is critical for these interactions. Here we identify the clp mutation as a 225-bp insertion in the Lgi4 gene. Lgi4 encodes a secreted and glycosylated leucine-rich repeat protein and is expressed in Schwann cells. The clp mutation affects Lgi4 mRNA splicing, resulting in a mutant protein that is retained in the cell. Additionally, siRNA-mediated downregulation of Lgi4 in wild-type neuron-Schwann cell cocultures inhibits myelination, whereas exogenous Lgi4 restores myelination in clp/clp cultures. Thus, the abnormalities observed in clp mice are attributable to the loss of Lgi4 function, and they identify Lgi4 as a new component of Schwann cell signaling pathway(s) that controls axon segregation and myelin formation.
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Affiliation(s)
- John R Bermingham
- McLaughlin Research Institute, 1520 23rd Street South, Great Falls, Montana 59405, USA.
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