1
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Bouchard EL, Meireles AM, Talbot WS. Oligodendrocyte development and myelin sheath formation are regulated by the antagonistic interaction between the Rag-Ragulator complex and TFEB. Glia 2024; 72:289-299. [PMID: 37767930 PMCID: PMC10841052 DOI: 10.1002/glia.24473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/11/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023]
Abstract
Myelination by oligodendrocytes is critical for fast axonal conduction and for the support and survival of neurons in the central nervous system. Recent studies have emphasized that myelination is plastic and that new myelin is formed throughout life. Nonetheless, the mechanisms that regulate the number, length, and location of myelin sheaths formed by individual oligodendrocytes are incompletely understood. Previous work showed that the lysosomal transcription factor TFEB represses myelination by oligodendrocytes and that the RagA GTPase inhibits TFEB, but the step or steps of myelination in which TFEB plays a role have remained unclear. Here, we show that TFEB regulates oligodendrocyte differentiation and also controls the length of myelin sheaths formed by individual oligodendrocytes. In the dorsal spinal cord of tfeb mutants, individual oligodendrocytes produce myelin sheaths that are longer than those produced by wildtype cells. Transmission electron microscopy shows that there are more myelinated axons in the dorsal spinal cord of tfeb mutants than in wildtype animals, but no significant change in axon diameter. In contrast to tfeb mutants, oligodendrocytes in rraga mutants produce shorter myelin sheaths. The sheath length in rraga; tfeb double mutants is not significantly different from wildtype, consistent with the antagonistic interaction between RagA and TFEB. Finally, we find that the GTPase activating protein Flcn and the RagCa and RagCb GTPases are also necessary for myelination by oligodendrocytes. These findings demonstrate that TFEB coordinates myelin sheath length and number during myelin formation in the central nervous system.
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Affiliation(s)
- Ellen L. Bouchard
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ana M. Meireles
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - William S. Talbot
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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2
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Park S, Jo Y, Kang M, Hong JH, Ko S, Kim S, Park S, Park HC, Shim SH, Choi W. Label-free adaptive optics single-molecule localization microscopy for whole zebrafish. Nat Commun 2023; 14:4185. [PMID: 37443177 PMCID: PMC10344925 DOI: 10.1038/s41467-023-39896-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
Specimen-induced aberration has been a major factor limiting the imaging depth of single-molecule localization microscopy (SMLM). Here, we report the application of label-free wavefront sensing adaptive optics to SMLM for deep-tissue super-resolution imaging. The proposed system measures complex tissue aberrations from intrinsic reflectance rather than fluorescence emission and physically corrects the wavefront distortion more than three-fold stronger than the previous limit. This enables us to resolve sub-diffraction morphologies of cilia and oligodendrocytes in whole zebrafish as well as dendritic spines in thick mouse brain tissues at the depth of up to 102 μm with localization number enhancement by up to 37 times and localization precision comparable to aberration-free samples. The proposed approach can expand the application range of SMLM to whole zebrafish that cause the loss of localization number owing to severe tissue aberrations.
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Affiliation(s)
- Sanghyeon Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Republic of Korea
- Department of Physics, Korea University, Seoul, Republic of Korea
| | - Yonghyeon Jo
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Republic of Korea
- Department of Physics, Korea University, Seoul, Republic of Korea
| | - Minsu Kang
- Department of Chemistry, Korea University, Seoul, Republic of Korea
| | - Jin Hee Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Republic of Korea
| | - Sangyoon Ko
- Department of Chemistry, Korea University, Seoul, Republic of Korea
| | - Suhyun Kim
- Department of Biomedical Sciences, Korea University, Ansan, Republic of Korea
| | - Sangjun Park
- Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Biomedicine and Health Sciences, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hae Chul Park
- Department of Biomedical Sciences, Korea University, Ansan, Republic of Korea
| | - Sang-Hee Shim
- Department of Chemistry, Korea University, Seoul, Republic of Korea.
| | - Wonshik Choi
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Republic of Korea.
- Department of Physics, Korea University, Seoul, Republic of Korea.
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3
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Kim Y, Kim SS, Park BH, Hwang KS, Bae MA, Cho SH, Kim S, Park HC. Mechanism of Bisphenol F Affecting Motor System and Motor Activity in Zebrafish. TOXICS 2023; 11:477. [PMID: 37368577 DOI: 10.3390/toxics11060477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023]
Abstract
Bisphenol F (BPF; 4,4'-dihydroxydiphenylmethane) is one of the most frequently used compounds in the manufacture of plastics and epoxy resins. Previous studies have demonstrated that BPF affects locomotor behavior, oxidative stress, and neurodevelopment in zebrafish. However, its neurotoxic effects are controversial, and the underlying mechanisms are unclear. In order to determine whether BPF affects the motor system, we exposed zebrafish embryos to BPF and assessed behavioral, histological, and neurochemical changes. Spontaneous locomotor behavior and startle response were significantly decreased in BPF-treated zebrafish larvae compared with control larvae. BPF induced motor degeneration and myelination defects in zebrafish larvae. In addition, embryonic exposure to BPF resulted in altered metabolic profiles of neurochemicals, including neurotransmitters and neurosteroids, which may impact locomotion and motor function. In conclusion, exposure to BPF has the potential to affect survival, motor axon length, locomotor activity, myelination, and neurochemical levels of zebrafish larvae.
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Affiliation(s)
- Yeonhwa Kim
- Zebrafish Translational Medical Research Center, Korea University, Ansan 15588, Republic of Korea
| | - Seong Soon Kim
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34141, Republic of Korea
| | - Byeong Heon Park
- Medical Science Research Center, Ansan Hospital, Korea University, Ansan 15588, Republic of Korea
| | - Kyu-Seok Hwang
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34141, Republic of Korea
| | - Myung Ae Bae
- Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34141, Republic of Korea
| | - Sung-Hee Cho
- Chemical Analysis Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Suhyun Kim
- Zebrafish Translational Medical Research Center, Korea University, Ansan 15588, Republic of Korea
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul 04763, Republic of Korea
| | - Hae-Chul Park
- Zebrafish Translational Medical Research Center, Korea University, Ansan 15588, Republic of Korea
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul 04763, Republic of Korea
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4
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Masson MA, Nait-Oumesmar B. Emerging concepts in oligodendrocyte and myelin formation, inputs from the zebrafish model. Glia 2023; 71:1147-1163. [PMID: 36645033 DOI: 10.1002/glia.24336] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/20/2022] [Accepted: 12/29/2022] [Indexed: 01/17/2023]
Abstract
Oligodendrocytes (OLs) are the myelinating cells of the central nervous system (CNS), which are derived from OL precursor cells. Myelin insulates axons allowing the saltatory conduction of action potentials and also provides trophic and metabolic supports to axons. Interestingly, oligodendroglial cells have the capacity to sense neuronal activity, which regulates myelin sheath formation via the vesicular release of neurotransmitters. Neuronal activity-dependent regulation of myelination is mediated by specialized interaction between axons and oligodendroglia, involving both synaptic and extra-synaptic modes of communications. The zebrafish has provided key advantages for the study of the myelination process in the CNS. External development and transparent larval stages of this vertebrate specie combined with the existence of several transgenic reporter lines provided key advances in oligodendroglial cell biology, axo-glial interactions and CNS myelination. In this publication, we reviewed and discussed the most recent knowledge on OL development and myelin formation, with a focus on mechanisms regulating these fundamental biological processes in the zebrafish. Especially, we highlighted the critical function of axons and oligodendroglia modes of communications and calcium signaling in myelin sheath formation and growth. Finally, we reviewed the relevance of these knowledge's in demyelinating diseases and drug discovery of pharmacological compounds favoring myelin regeneration.
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Affiliation(s)
- Mary-Amélie Masson
- Sorbonne Université, Institut du Cerveau, Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Brahim Nait-Oumesmar
- Sorbonne Université, Institut du Cerveau, Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié-Salpêtrière, Paris, France
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5
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Baraban M, Gordillo Pi C, Bonnet I, Gilles JF, Lejeune C, Cabrera M, Tep F, Breau MA. Actomyosin contractility in olfactory placode neurons opens the skin epithelium to form the zebrafish nostril. Dev Cell 2023; 58:361-375.e5. [PMID: 36841243 PMCID: PMC10023511 DOI: 10.1016/j.devcel.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 12/07/2022] [Accepted: 02/02/2023] [Indexed: 02/27/2023]
Abstract
Despite their barrier function, epithelia can locally lose their integrity to create physiological openings during morphogenesis. The mechanisms driving the formation of these epithelial breaks are only starting to be investigated. Here, we study the formation of the zebrafish nostril (the olfactory orifice), which opens in the skin epithelium to expose the olfactory neurons to external odorant cues. Combining live imaging, drug treatments, laser ablation, and tissue-specific functional perturbations, we characterize a mechanical interplay between olfactory placode neurons and the skin, which plays a crucial role in the formation of the orifice: the neurons pull on the overlying skin cells in an actomyosin-dependent manner which, in combination with a local reorganization of the skin epithelium, triggers the opening of the orifice. This work identifies an original mechanism to break an epithelial sheet, in which an adjacent group of cells mechanically assists the epithelium to induce its local rupture.
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Affiliation(s)
- Marion Baraban
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, 75005 Paris, France; Laboratoire Jean Perrin, 75005 Paris, France.
| | - Clara Gordillo Pi
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, 75005 Paris, France
| | - Isabelle Bonnet
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR168, Laboratoire Physico Chimie Curie, 75005 Paris, France
| | | | - Camille Lejeune
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, 75005 Paris, France
| | - Mélody Cabrera
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, 75005 Paris, France
| | - Florian Tep
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, 75005 Paris, France
| | - Marie Anne Breau
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, 75005 Paris, France; Laboratoire Jean Perrin, 75005 Paris, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France.
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6
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Choi EK, Choi BM, Cho Y, Kim S. Myelin toxicity of chlorhexidine in zebrafish larvae. Pediatr Res 2023; 93:845-851. [PMID: 35854088 DOI: 10.1038/s41390-022-02186-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 04/27/2022] [Accepted: 06/07/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Chlorhexidine gluconate (CHG) is a topical antiseptic solution recommended for skin preparation before central venous catheter placement and maintenance in adults and children. Although CHG is not recommended for use in children aged <2 months owing to limited safety data, it is commonly used in neonatal intensive care units worldwide. We used zebrafish model to verify the effects of early-life exposure to CHG on the developing nervous system, highlighting its impact on oligodendrocyte development and myelination. METHODS Zebrafish embryos were exposed to different concentrations of CHG from 4 h post fertilization to examine developmental toxicity. The hatching rate, mortality, and malformation of the embryos/larvae were monitored. Oligodendrocyte lineage in transgenic zebrafish embryos was used to investigate defects in oligodendrocytes and myelin. Myelin structure, locomotor behavior, and expression levels of genes involved in myelination were investigated. RESULTS Exposure to CHG significantly induced oligodendrocyte defects in the central nervous system, delayed myelination, and locomotor alterations. Ultra-microstructural changes with splitting and fluid-accumulated vacuoles between the myelin sheaths were found. Embryonic exposure to CHG decreased myelination, in association with downregulated mbpa, plp1b, and scrt2 gene expression. CONCLUSION Our results suggest that CHG has a potential for myelin toxicity in the developing brain. IMPACT To date, the neurodevelopmental toxicity of chlorhexidine gluconate (CHG) exposure on the developing brains of infants remains unknown. We demonstrated that CHG exposure to zebrafish larvae resulted in significant defects in oligodendrocytes and myelin sheaths. These CHG-exposed zebrafish larvae exhibited structural changes and locomotor alterations. Given the increased CHG use in neonates, this study is the first to identify the risk of early-life CHG exposure on the developing nervous system.
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Affiliation(s)
- Eui Kyung Choi
- Department of Pediatrics, College of Medicine, Korea University, Seoul, Republic of Korea
- Division of Neonatology, Department of Pediatrics, Korea University Guro Hospital, Ulsan, Gyeonggi-do, Republic of Korea
| | - Byung Min Choi
- Department of Pediatrics, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Yuji Cho
- Core Research & Development Center, Korea University Ansan Hospital, Ansan, Gyeonggi-do, Republic of Korea
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Suhyun Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea.
- Zebrafish Translational Medical Research Center, Korea University, Ansan, Gyeonggi-do, Republic of Korea.
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7
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Santos-Ledo A, Pérez-Montes C, DeOliveira-Mello L, Arévalo R, Velasco A. Oligodendrocyte origin and development in the zebrafish visual system. J Comp Neurol 2023; 531:515-527. [PMID: 36477827 PMCID: PMC10107312 DOI: 10.1002/cne.25440] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 09/19/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022]
Abstract
Oligodendrocytes are the myelinating cells in the central nervous system. In birds and mammals, the oligodendrocyte progenitor cells (OPCs) originate in the preoptic area (POA) of the hypothalamus. However, it remains unclear in other vertebrates such as fish. Thus, we have studied the early progression of OPCs during zebrafish visual morphogenesis from 2 days post fertilization (dpf) until 11 dpf using the olig2:EGFP transgenic line; and we have analyzed the differential expression of transcription factors involved in oligodendrocyte differentiation: Sox2 (using immunohistochemistry) and Sox10 (using the transgenic line sox10:tagRFP). The first OPCs (olig2:EGFP/Sox2) were found at 2 dpf in the POA. From 3 dpf onwards, these olig2:EGFP/Sox2 cells migrate to the optic chiasm, where they invade the optic nerve (ON), extending toward the retina. At 5 dpf, olig2:EGFP/Sox2 cells in the ON also colocalize with sox10:tagRFP. When olig2:EGFP cells differentiate and present more projections, they become positive only for sox10:tagRFP. olig2:EGFP/sox10: tagRFP cells ensheath the ON by 5 dpf when they also become positive for a myelin marker, based on the mbpa:tagRFPt transgenic line. We also found olig2:EGFP cells in other regions of the visual system. In the central retina at 2 dpf, they are positive for Sox2 but later become restricted to the proliferative germinal zone without this marker. In the ventricular areas of the optic tectum, olig2:EGFP cells present Sox2 but arborized ones sox10:tagRFP instead. Our data matches with other models, where OPCs are specified in the POA and migrate to the ON through the optic chiasm.
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Affiliation(s)
- Adrián Santos-Ledo
- Department of Cell Biology and Pathology, Instituto de NeurocienciasdeCastilla y León (INCyL), Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Cristina Pérez-Montes
- Department of Cell Biology and Pathology, Instituto de NeurocienciasdeCastilla y León (INCyL), Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Laura DeOliveira-Mello
- Department of Cell Biology and Pathology, Instituto de NeurocienciasdeCastilla y León (INCyL), Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Rosario Arévalo
- Department of Cell Biology and Pathology, Instituto de NeurocienciasdeCastilla y León (INCyL), Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Almudena Velasco
- Department of Cell Biology and Pathology, Instituto de NeurocienciasdeCastilla y León (INCyL), Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
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8
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Impact of the Voltage-Gated Calcium Channel Antagonist Nimodipine on the Development of Oligodendrocyte Precursor Cells. Int J Mol Sci 2023; 24:ijms24043716. [PMID: 36835129 PMCID: PMC9960570 DOI: 10.3390/ijms24043716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). While most of the current treatment strategies focus on immune cell regulation, except for the drug siponimod, there is no therapeutic intervention that primarily aims at neuroprotection and remyelination. Recently, nimodipine showed a beneficial and remyelinating effect in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Nimodipine also positively affected astrocytes, neurons, and mature oligodendrocytes. Here we investigated the effects of nimodipine, an L-type voltage-gated calcium channel antagonist, on the expression profile of myelin genes and proteins in the oligodendrocyte precursor cell (OPC) line Oli-Neu and in primary OPCs. Our data indicate that nimodipine does not have any effect on myelin-related gene and protein expression. Furthermore, nimodipine treatment did not result in any morphological changes in these cells. However, RNA sequencing and bioinformatic analyses identified potential micro (mi)RNA that could support myelination after nimodipine treatment compared to a dimethyl sulfoxide (DMSO) control. Additionally, we treated zebrafish with nimodipine and observed a significant increase in the number of mature oligodendrocytes (* p≤ 0.05). Taken together, nimodipine seems to have different positive effects on OPCs and mature oligodendrocytes.
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9
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Spencer SA, Suárez-Pozos E, Verdugo JS, Wang H, Afshari FS, Li G, Manam S, Yasuda D, Ortega A, Lister JA, Ishii S, Zhang Y, Fuss B. Lysophosphatidic acid signaling via LPA 6 : A negative modulator of developmental oligodendrocyte maturation. J Neurochem 2022; 163:478-499. [PMID: 36153691 PMCID: PMC9772207 DOI: 10.1111/jnc.15696] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 01/14/2023]
Abstract
The developmental process of central nervous system (CNS) myelin sheath formation is characterized by well-coordinated cellular activities ultimately ensuring rapid and synchronized neural communication. During this process, myelinating CNS cells, namely oligodendrocytes (OLGs), undergo distinct steps of differentiation, whereby the progression of earlier maturation stages of OLGs represents a critical step toward the timely establishment of myelinated axonal circuits. Given the complexity of functional integration, it is not surprising that OLG maturation is controlled by a yet fully to be defined set of both negative and positive modulators. In this context, we provide here first evidence for a role of lysophosphatidic acid (LPA) signaling via the G protein-coupled receptor LPA6 as a negative modulatory regulator of myelination-associated gene expression in OLGs. More specifically, the cell surface accessibility of LPA6 was found to be restricted to the earlier maturation stages of differentiating OLGs, and OLG maturation was found to occur precociously in Lpar6 knockout mice. To further substantiate these findings, a novel small molecule ligand with selectivity for preferentially LPA6 and LPA6 agonist characteristics was functionally characterized in vitro in primary cultures of rat OLGs and in vivo in the developing zebrafish. Utilizing this approach, a negative modulatory role of LPA6 signaling in OLG maturation could be corroborated. During development, such a functional role of LPA6 signaling likely serves to ensure timely coordination of circuit formation and myelination. Under pathological conditions as seen in the major human demyelinating disease multiple sclerosis (MS), however, persistent LPA6 expression and signaling in OLGs can be seen as an inhibitor of myelin repair. Thus, it is of interest that LPA6 protein levels appear elevated in MS brain samples, thereby suggesting that LPA6 signaling may represent a potential new druggable pathway suitable to promote myelin repair in MS.
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Affiliation(s)
- Samantha A Spencer
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Edna Suárez-Pozos
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Jazmín Soto Verdugo
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del IPN, Ciudad de México, México
| | - Huiqun Wang
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia, USA
| | - Fatemah S Afshari
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Guo Li
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia, USA
| | - Susmita Manam
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Daisuke Yasuda
- Department of Immunology, Akita University Graduate School of Medicine, Akita, Japan
| | - Arturo Ortega
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del IPN, Ciudad de México, México
| | - James A Lister
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Satoshi Ishii
- Department of Immunology, Akita University Graduate School of Medicine, Akita, Japan
| | - Yan Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia, USA
| | - Babette Fuss
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
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10
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Lysko DE, Talbot WS. Unmyelinated sensory neurons use Neuregulin signals to promote myelination of interneurons in the CNS. Cell Rep 2022; 41:111669. [PMID: 36384112 PMCID: PMC9719401 DOI: 10.1016/j.celrep.2022.111669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 09/06/2022] [Accepted: 10/25/2022] [Indexed: 11/17/2022] Open
Abstract
The signaling mechanisms neurons use to modulate myelination of circuits in the central nervous system (CNS) are only partly understood. Through analysis of isoform-specific neuregulin1 (nrg1) mutants in zebrafish, we demonstrate that nrg1 type II is an important regulator of myelination of two classes of spinal cord interneurons. Surprisingly, nrg1 type II expression is prominent in unmyelinated Rohon-Beard sensory neurons, whereas myelination of neighboring interneurons is reduced in nrg1 type II mutants. Cell-type-specific loss-of-function studies indicate that nrg1 type II is required in Rohon-Beard neurons to signal to other neurons, not oligodendrocytes, to modulate spinal cord myelination. Together, our data support a model in which unmyelinated neurons express Nrg1 type II proteins to regulate myelination of neighboring neurons, a mode of action that may coordinate the functions of unmyelinated and myelinated neurons in the CNS.
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Affiliation(s)
- Daniel E Lysko
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - William S Talbot
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA.
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11
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Tamalin Function Is Required for the Survival of Neurons and Oligodendrocytes in the CNS. Int J Mol Sci 2022; 23:ijms232113395. [PMID: 36362204 PMCID: PMC9654138 DOI: 10.3390/ijms232113395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/30/2022] [Accepted: 10/30/2022] [Indexed: 11/06/2022] Open
Abstract
Tamalin is a post-synaptic scaffolding protein that interacts with group 1 metabotropic glutamate receptors (mGluRs) and several other proteins involved in protein trafficking and cytoskeletal events, including neuronal growth and actin reorganization. It plays an important role in synaptic plasticity in vitro by controlling the ligand-dependent trafficking of group 1 mGluRs. Abnormal regulation of mGluRs in the central nervous system (CNS) is associated with glutamate-mediated neurodegenerative disorders. However, the pathological consequences of tamalin deficiency in the CNS are unclear. In this study, tamalin knockout (KO) zebrafish and mice exhibited neurodegeneration along with oligodendrocyte degeneration in the post-embryonic CNS to adulthood without any developmental defects, thus suggesting the function of tamalin is more important in the postnatal stage to adulthood than that in CNS development. Interestingly, hypomyelination was independent of axonal defects in the CNS of tamalin knockout zebrafish and mice. In addition, the loss of Arf6, a downstream signal of tamalin scaffolding protein, synergistically induced neurodegeneration in tamalin KO zebrafish even in the developing CNS. Furthermore, tamalin KO zebrafish displayed increased mGluR5 expression. Taken together, tamalin played an important role in neuronal and oligodendrocyte survival and myelination through the regulation of mGluR5 in the CNS.
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12
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Hossainian D, Shao E, Jiao B, Ilin VA, Parris RS, Zhou Y, Bai Q, Burton EA. Quantification of functional recovery in a larval zebrafish model of spinal cord injury. J Neurosci Res 2022; 100:2044-2054. [PMID: 35986577 PMCID: PMC10695274 DOI: 10.1002/jnr.25118] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/19/2022] [Accepted: 08/01/2022] [Indexed: 11/12/2023]
Abstract
Human spinal cord injury (SCI) is characterized by permanent loss of damaged axons, resulting in chronic disability. In contrast, zebrafish can regenerate axonal projections following central nervous system injury and re-establish synaptic contacts with distant targets; elucidation of the underlying molecular events is an important goal with translational potential for improving outcomes in SCI patients. We generated transgenic zebrafish with GFP-labeled axons and transected their spinal cords at 10 days post-fertilization. Intravital confocal microscopy revealed robust axonal regeneration following the procedure, with abundant axons bridging the transection site by 48 h post-injury. In order to analyze neurological function in this model, we developed and validated new open-source software to measure zebrafish lateral trunk curvature during propulsive and turning movements at high temporal resolution. Immediately following spinal cord transection, axial movements were dramatically decreased caudal to the lesion site, but preserved rostral to the injury, suggesting the induction of motor paralysis below the transection level. Over the subsequent 96 h, the magnitude of movements caudal to the lesion recovered to baseline, but the rate of change of truncal curvature did not fully recover, suggesting incomplete restoration of caudal strength over this time course. Quantification of both morphological and functional recovery following SCI will be important for the analysis of axonal regeneration and downstream events necessary for restoration of motor function. An extensive array of genetic and pharmacological interventions can be deployed in the larval zebrafish model to investigate the underlying molecular mechanisms.
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Affiliation(s)
- Darius Hossainian
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Enhua Shao
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Tsinghua University Medical School, Beijing, China
| | - Binxuan Jiao
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Tsinghua University Medical School, Beijing, China
| | - Vladimir A. Ilin
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Ritika S. Parris
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Yangzhong Zhou
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Tsinghua University Medical School, Beijing, China
| | - Qing Bai
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Edward A. Burton
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Geriatric Research, Education and Clinical Center, Pittsburgh VA Healthcare System, Pittsburgh, PA, 15213, USA
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13
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Lam M, Takeo K, Almeida RG, Cooper MH, Wu K, Iyer M, Kantarci H, Zuchero JB. CNS myelination requires VAMP2/3-mediated membrane expansion in oligodendrocytes. Nat Commun 2022; 13:5583. [PMID: 36151203 PMCID: PMC9508103 DOI: 10.1038/s41467-022-33200-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 09/07/2022] [Indexed: 11/08/2022] Open
Abstract
Myelin is required for rapid nerve signaling and is emerging as a key driver of CNS plasticity and disease. How myelin is built and remodeled remains a fundamental question of neurobiology. Central to myelination is the ability of oligodendrocytes to add vast amounts of new cell membrane, expanding their surface areas by many thousand-fold. However, how oligodendrocytes add new membrane to build or remodel myelin is not fully understood. Here, we show that CNS myelin membrane addition requires exocytosis mediated by the vesicular SNARE proteins VAMP2/3. Genetic inactivation of VAMP2/3 in myelinating oligodendrocytes caused severe hypomyelination and premature death without overt loss of oligodendrocytes. Through live imaging, we discovered that VAMP2/3-mediated exocytosis drives membrane expansion within myelin sheaths to initiate wrapping and power sheath elongation. In conjunction with membrane expansion, mass spectrometry of oligodendrocyte surface proteins revealed that VAMP2/3 incorporates axon-myelin adhesion proteins that are collectively required to form nodes of Ranvier. Together, our results demonstrate that VAMP2/3-mediated membrane expansion in oligodendrocytes is indispensable for myelin formation, uncovering a cellular pathway that could sculpt myelination patterns in response to activity-dependent signals or be therapeutically targeted to promote regeneration in disease.
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Affiliation(s)
- Mable Lam
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Koji Takeo
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
- Pharmaceutical Research Laboratories, Toray Industries, Inc., Kamakura, Kanagawa, Japan
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Madeline H Cooper
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Kathryn Wu
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Manasi Iyer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Husniye Kantarci
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - J Bradley Zuchero
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.
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14
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Humanized zebrafish as a tractable tool for in vivo evaluation of pro-myelinating drugs. Cell Chem Biol 2022; 29:1541-1555.e7. [PMID: 36126653 DOI: 10.1016/j.chembiol.2022.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/25/2022] [Accepted: 08/24/2022] [Indexed: 12/14/2022]
Abstract
Therapies that promote neuroprotection and axonal survival by enhancing myelin regeneration are an unmet need to prevent disability progression in multiple sclerosis. Numerous potentially beneficial compounds have originated from phenotypic screenings but failed in clinical trials. It is apparent that current cell- and animal-based disease models are poor predictors of positive treatment options, arguing for novel experimental approaches. Here we explore the experimental power of humanized zebrafish to foster the identification of pro-remyelination compounds via specific inhibition of GPR17. Using biochemical and imaging techniques, we visualize the expression of zebrafish (zf)-gpr17 during the distinct stages of oligodendrocyte development, thereby demonstrating species-conserved expression between zebrafish and mammals. We also demonstrate species-conserved function of zf-Gpr17 using genetic loss-of-function and rescue techniques. Finally, using GPR17-humanized zebrafish, we provide proof of principle for in vivo analysis of compounds acting via targeted inhibition of human GPR17. We anticipate that GPR17-humanized zebrafish will markedly improve the search for effective pro-myelinating pharmacotherapies.
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15
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Suzzi S, Ahrendt R, Hans S, Semenova SA, Chekuru A, Wirsching P, Kroehne V, Bilican S, Sayed S, Winkler S, Spieß S, Machate A, Kaslin J, Panula P, Brand M. Deletion of lrrk2 causes early developmental abnormalities and age-dependent increase of monoamine catabolism in the zebrafish brain. PLoS Genet 2021; 17:e1009794. [PMID: 34516550 PMCID: PMC8459977 DOI: 10.1371/journal.pgen.1009794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 09/23/2021] [Accepted: 08/24/2021] [Indexed: 12/12/2022] Open
Abstract
LRRK2 gain-of-function is considered a major cause of Parkinson's disease (PD) in humans. However, pathogenicity of LRRK2 loss-of-function in animal models is controversial. Here we show that deletion of the entire zebrafish lrrk2 locus elicits a pleomorphic transient brain phenotype in maternal-zygotic mutant embryos (mzLrrk2). In contrast to lrrk2, the paralog gene lrrk1 is virtually not expressed in the brain of both wild-type and mzLrrk2 fish at different developmental stages. Notably, we found reduced catecholaminergic neurons, the main target of PD, in specific cell populations in the brains of mzLrrk2 larvae, but not adult fish. Strikingly, age-dependent accumulation of monoamine oxidase (MAO)-dependent catabolic signatures within mzLrrk2 brains revealed a previously undescribed interaction between LRRK2 and MAO biological activities. Our results highlight mzLrrk2 zebrafish as a tractable tool to study LRRK2 loss-of-function in vivo, and suggest a link between LRRK2 and MAO, potentially of relevance in the prodromic stages of PD.
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Affiliation(s)
- Stefano Suzzi
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Reiner Ahrendt
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Stefan Hans
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Svetlana A. Semenova
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Avinash Chekuru
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Paul Wirsching
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Volker Kroehne
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Saygın Bilican
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Shady Sayed
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Sylke Winkler
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany
| | - Sandra Spieß
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Anja Machate
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Jan Kaslin
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
| | - Pertti Panula
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Michael Brand
- Center for Molecular and Cellular Bioengineering (CMCB), Center for Regenerative Therapies Dresden (CRTD), Technische Universität (TU) Dresden, Dresden, Germany
- * E-mail:
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16
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Turan F, Yilmaz Ö, Schünemann L, Lindenberg TT, Kalanithy JC, Harder A, Ahmadi S, Duman T, MacDonald RB, Winter D, Liu C, Odermatt B. Effect of modulating glutamate signaling on myelinating oligodendrocytes and their development-A study in the zebrafish model. J Neurosci Res 2021; 99:2774-2792. [PMID: 34520578 DOI: 10.1002/jnr.24940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 07/12/2021] [Accepted: 07/21/2021] [Indexed: 01/02/2023]
Abstract
Myelination is crucial for the development and maintenance of axonal integrity, especially fast axonal action potential conduction. There is increasing evidence that glutamate signaling and release through neuronal activity modulates the myelination process. In this study, we examine the effect of manipulating glutamate signaling on myelination of oligodendrocyte (OL) lineage cells and their development in zebrafish (zf). We use the "intensity-based glutamate-sensing fluorescent reporter" (iGluSnFR) in the zf model (both sexes) to address the hypothesis that glutamate is implicated in regulation of myelinating OLs. Our results show that glial iGluSnFR expression significantly reduces OL lineage cell number and the expression of myelin markers in larvae (zfl) and adult brains. The specific glutamate receptor agonist, L-AP4, rescues this iGluSnFR effect by significantly increasing the expression of the myelin-related genes, plp1b and mbpa, and enhances myelination in L-AP4-injected zfl compared to controls. Furthermore, we demonstrate that degrading glutamate using Glutamat-Pyruvate Transaminase (GPT) or the blockade of glutamate reuptake by L-trans-pyrrolidine-2,4-dicarboxylate (PDC) significantly decreases myelin-related genes and drastically declines myelination in brain ventricle-injected zfl. Moreover, we found that myelin-specific ClaudinK (CldnK) and 36K protein expression is significantly decreased in iGluSnFR-expressing zfl and adult brains compared to controls. Taken together, this study confirms that glutamate signaling is directly required for the preservation of myelinating OLs and for the myelination process itself. These findings further suggest that glutamate signaling may provide novel targets to therapeutically boost remyelination in several demyelinating diseases of the CNS.
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Affiliation(s)
- Funda Turan
- Medical Faculty, Institute of Neuroanatomy, University of Bonn, Bonn, Germany.,Faculty of Science, Biology Department, Ankara University, Ankara, Turkey
| | - Öznur Yilmaz
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Lena Schünemann
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Tobias T Lindenberg
- Medical Faculty, Institute of Neuroanatomy, University of Bonn, Bonn, Germany
| | - Jeshurun C Kalanithy
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Alexander Harder
- Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany
| | - Shiva Ahmadi
- Medical Faculty, Institute for Biochemistry and Molecular Biology (IBMB), University of Bonn, Bonn, Germany
| | - Türker Duman
- Faculty of Science, Biology Department, Ankara University, Ankara, Turkey
| | - Ryan B MacDonald
- Institute of Ophthalmology, University College London, London, UK
| | - Dominic Winter
- Medical Faculty, Institute for Biochemistry and Molecular Biology (IBMB), University of Bonn, Bonn, Germany
| | - Changsheng Liu
- Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
| | - Benjamin Odermatt
- Medical Faculty, Institute of Neuroanatomy, University of Bonn, Bonn, Germany.,Medical Faculty, Institute of Anatomy and Cell-Biology, University of Bonn, Bonn, Germany
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17
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Zou S, Hu B. In vivo imaging reveals mature Oligodendrocyte division in adult Zebrafish. CELL REGENERATION (LONDON, ENGLAND) 2021; 10:16. [PMID: 34075520 PMCID: PMC8169745 DOI: 10.1186/s13619-021-00079-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Whether mature oligodendrocytes (mOLs) participate in remyelination has been disputed for several decades. Recently, some studies have shown that mOLs participate in remyelination by producing new sheaths. However, whether mOLs can produce new oligodendrocytes by asymmetric division has not been proven. Zebrafish is a perfect model to research remyelination compared to other species. In this study, optic nerve crushing did not induce local mOLs death. After optic nerve transplantation from olig2:eGFP fish to AB/WT fish, olig2+ cells from the donor settled and rewrapped axons in the recipient. After identifying these rewrapping olig2+ cells as mOLs at 3 months posttransplantation, in vivo imaging showed that olig2+ cells proliferated. Additionally, in vivo imaging of new olig2+ cell division from mOLs was also captured within the retina. Finally, fine visual function was renewed after the remyelination program was completed. In conclusion, our in vivo imaging results showed that new olig2+ cells were born from mOLs by asymmetric division in adult zebrafish, which highlights the role of mOLs in the progression of remyelination in the mammalian CNS.
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Affiliation(s)
- Suqi Zou
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
- School of Life Sciences, Nanchang University, Nanchang, Jiangxi, 330031, P. R. China.
| | - Bing Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
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18
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Marshall-Phelps KLH, Kegel L, Baraban M, Ruhwedel T, Almeida RG, Rubio-Brotons M, Klingseisen A, Benito-Kwiecinski SK, Early JJ, Bin JM, Suminaite D, Livesey MR, Möbius W, Poole RJ, Lyons DA. Neuronal activity disrupts myelinated axon integrity in the absence of NKCC1b. J Cell Biol 2021; 219:151733. [PMID: 32364583 PMCID: PMC7337504 DOI: 10.1083/jcb.201909022] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 03/09/2020] [Accepted: 04/07/2020] [Indexed: 02/07/2023] Open
Abstract
Through a genetic screen in zebrafish, we identified a mutant with disruption to myelin in both the CNS and PNS caused by a mutation in a previously uncharacterized gene, slc12a2b, predicted to encode a Na+, K+, and Cl- (NKCC) cotransporter, NKCC1b. slc12a2b/NKCC1b mutants exhibited a severe and progressive pathology in the PNS, characterized by dysmyelination and swelling of the periaxonal space at the axon-myelin interface. Cell-type-specific loss of slc12a2b/NKCC1b in either neurons or myelinating Schwann cells recapitulated these pathologies. Given that NKCC1 is critical for ion homeostasis, we asked whether the disruption to myelinated axons in slc12a2b/NKCC1b mutants is affected by neuronal activity. Strikingly, we found that blocking neuronal activity completely prevented and could even rescue the pathology in slc12a2b/NKCC1b mutants. Together, our data indicate that NKCC1b is required to maintain neuronal activity-related solute homeostasis at the axon-myelin interface, and the integrity of myelinated axons.
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Affiliation(s)
| | - Linde Kegel
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Marion Baraban
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Torben Ruhwedel
- Electron Microscopy Core Unit, Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Anna Klingseisen
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Jason J Early
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Jenea M Bin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Daumante Suminaite
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Matthew R Livesey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Wiebke Möbius
- Electron Microscopy Core Unit, Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Richard J Poole
- Department of Cell and Developmental Biology, University College London, London, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
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19
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Kim S, Lee DW, Schachner M, Park HC. Small compounds mimicking the adhesion molecule L1 improve recovery in a zebrafish demyelination model. Sci Rep 2021; 11:5878. [PMID: 33723325 PMCID: PMC7960995 DOI: 10.1038/s41598-021-85412-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 03/01/2021] [Indexed: 02/05/2023] Open
Abstract
Demyelination leads to a loss of neurons, which results in, among other consequences, a severe reduction in locomotor function, and underlies several diseases in humans including multiple sclerosis and polyneuropathies. Considerable clinical progress has been made in counteracting demyelination. However, there remains a need for novel methods that reduce demyelination while concomitantly achieving remyelination, thus complementing the currently available tools to ameliorate demyelinating diseases. In this study, we used an established zebrafish demyelination model to test selected compounds, following a screening in cell culture experiments and in a mouse model of spinal cord injury that was aimed at identifying beneficial functions of the neural cell adhesion molecule L1. In comparison to mammalian nervous system disease models, the zebrafish allows testing of potentially promotive compounds more easily than what is possible in mammals. We found that our selected compounds tacrine and duloxetine significantly improved remyelination in the peripheral and central nervous system of transgenic zebrafish following pharmacologically induced demyelination. Given that both molecules are known to positively affect functions other than those related to L1 and in other disease contexts, we propose that their combined beneficial function raises hope for the use of these compounds in clinical settings.
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Affiliation(s)
- Suhyun Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, 15335, Republic of Korea
| | - Dong-Won Lee
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, 15335, Republic of Korea
| | - Melitta Schachner
- Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08554, USA.
- Center for Neuroscience, Shantou University Medical College, Shantou, 515041, Guangdong, China.
| | - Hae-Chul Park
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, 15335, Republic of Korea.
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20
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Abstract
Myelination of axons provides the structural basis for rapid saltatory impulse propagation along vertebrate fiber tracts, a well-established neurophysiological concept. However, myelinating oligodendrocytes and Schwann cells serve additional functions in neuronal energy metabolism that are remarkably similar to those of axon-ensheathing glial cells in unmyelinated invertebrates. Here we discuss myelin evolution and physiological glial functions, beginning with the role of ensheathing glia in preventing ephaptic coupling, axoglial metabolic support, and eliminating oxidative radicals. In both vertebrates and invertebrates, axoglial interactions are bidirectional, serving to regulate cell fate, nerve conduction, and behavioral performance. One key step in the evolution of compact myelin in the vertebrate lineage was the emergence of the open reading frame for myelin basic protein within another gene. Several other proteins were neofunctionalized as myelin constituents and help maintain a healthy nervous system. Myelination in vertebrates became a major prerequisite of inhabiting new ecological niches.
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Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
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21
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Won SY, Kwon S, Jeong HS, Chung KW, Choi B, Chang JW, Lee JE. Fibulin 5, a human Wharton's jelly-derived mesenchymal stem cells-secreted paracrine factor, attenuates peripheral nervous system myelination defects through the Integrin-RAC1 signaling axis. Stem Cells 2020; 38:1578-1593. [PMID: 33107705 PMCID: PMC7756588 DOI: 10.1002/stem.3287] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 04/25/2023]
Abstract
In the peripheral nervous system (PNS), proper development of Schwann cells (SCs) contributing to axonal myelination is critical for neuronal function. Impairments of SCs or neuronal axons give rise to several myelin-related disorders, including dysmyelinating and demyelinating diseases. Pathological mechanisms, however, have been understood at the elementary level and targeted therapeutics has remained undeveloped. Here, we identify Fibulin 5 (FBLN5), an extracellular matrix (ECM) protein, as a key paracrine factor of human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) to control the development of SCs. We show that co-culture with WJ-MSCs or treatment of recombinant FBLN5 promotes the proliferation of SCs through ERK activation, whereas FBLN5-depleted WJ-MSCs do not. We further reveal that during myelination of SCs, FBLN5 binds to Integrin and modulates actin remodeling, such as the formation of lamellipodia and filopodia, through RAC1 activity. Finally, we show that FBLN5 effectively restores the myelination defects of SCs in the zebrafish model of Charcot-Marie-Tooth (CMT) type 1, a representative demyelinating disease. Overall, our data propose human WJ-MSCs or FBLN5 protein as a potential treatment for myelin-related diseases, including CMT.
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Affiliation(s)
- So Yeon Won
- Department of Health Sciences and TechnologySamsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan UniversitySeoulSouth Korea
| | - Soojin Kwon
- Stem Cell & Regenerative Medicine Institute, Samsung Medical CenterSeoulSouth Korea
- Stem Cell Institute, ENCell Co. LtdSeoulSouth Korea
| | - Hui Su Jeong
- Department of Health Sciences and TechnologySamsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan UniversitySeoulSouth Korea
| | - Ki Wha Chung
- Department of Biological SciencesKongju National UniversityKongjuSouth Korea
| | - Byung‐Ok Choi
- Department of NeurologySungkyunkwan University School of MedicineSeoulSouth Korea
| | - Jong Wook Chang
- Stem Cell & Regenerative Medicine Institute, Samsung Medical CenterSeoulSouth Korea
- Stem Cell Institute, ENCell Co. LtdSeoulSouth Korea
| | - Ji Eun Lee
- Department of Health Sciences and TechnologySamsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan UniversitySeoulSouth Korea
- Samsung Biomedical Research Institute, Samsung Medical CenterSeoulSouth Korea
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22
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Vanhunsel S, Beckers A, Moons L. Designing neuroreparative strategies using aged regenerating animal models. Ageing Res Rev 2020; 62:101086. [PMID: 32492480 DOI: 10.1016/j.arr.2020.101086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/13/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022]
Abstract
In our ever-aging world population, the risk of age-related neuropathies has been increasing, representing both a social and economic burden to society. Since the ability to regenerate in the adult mammalian central nervous system is very limited, brain trauma and neurodegeneration are often permanent. As a consequence, novel scientific challenges have emerged and many research efforts currently focus on triggering repair in the damaged or diseased brain. Nevertheless, stimulating neuroregeneration remains ambitious. Even though important discoveries have been made over the past decades, they did not translate into a therapy yet. Actually, this is not surprising; while these disorders mainly manifest in aged individuals, most of the research is being performed in young animal models. Aging of neurons and their environment, however, greatly affects the central nervous system and its capacity to repair. This review provides a detailed overview of the impact of aging on central nervous system functioning and regeneration potential, both in non-regenerating and spontaneously regenerating animal models. Additionally, we highlight the need for aging animal models with regenerative capacities in the search for neuroreparative strategies.
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Affiliation(s)
- Sophie Vanhunsel
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - An Beckers
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lieve Moons
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium.
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23
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Lee DW, Kim E, Jeong I, Kim HK, Kim S, Park HC. Schwann cells selectively myelinate primary motor axons via neuregulin-ErbB signaling. Glia 2020; 68:2585-2600. [PMID: 32589818 DOI: 10.1002/glia.23871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 05/20/2020] [Accepted: 05/26/2020] [Indexed: 11/06/2022]
Abstract
Spinal motor neurons project their axons out of the spinal cord via the motor exit point (MEP) and regulate their target muscle fibers for diverse behaviors. Several populations of glial cells including Schwann cells, MEP glia, and perineurial glia are tightly associated with spinal motor axons in nerve fascicles. Zebrafish have two types of spinal motor neurons, primary motor neurons (PMNs) and secondary motor neurons (SMNs). PMNs are implicated in the rapid response, whereas SMNs are implicated in normal and slow movements. However, the precise mechanisms mediating the distinct functions of PMNs and SMNs in zebrafish are unclear. In this study, we found that PMNs were myelinated by MEP glia and Schwann cells, whereas SMNs remained unmyelinated at the examined stages. Immunohistochemical analysis revealed that myelinated PMNs solely innervated fast muscle through a distributed neuromuscular junction (NMJ), whereas unmyelinated SMNs innervated both fast and slow muscle through distributed and myoseptal NMJs, respectively, indicating that myelinated PMNs could provide rapid responses for startle and escape movements, while unmyelinated SMNs regulated normal, slow movement. Further, we demonstrate that neuregulin 1 (Nrg1) type III-ErbB signaling provides a key instructive signal that determines the myelination of primary motor axons by MEP glia and Schwann cells. Perineurial glia ensheathed unmyelinated secondary motor axons and myelinated primary motor nerves. Ensheathment required interaction with both MEP glia and Schwann cells. Collectively, these data suggest that primary and secondary motor neurons contribute to the regulation of movement in zebrafish with distinct patterns of myelination.
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Affiliation(s)
- Dong-Won Lee
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Eunmi Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Inyoung Jeong
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Hwan-Ki Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Suhyun Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Hae-Chul Park
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
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24
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Schwarzer S, Asokan N, Bludau O, Chae J, Kuscha V, Kaslin J, Hans S. Neurogenesis in the inner ear: the zebrafish statoacoustic ganglion provides new neurons from a Neurod/Nestin-positive progenitor pool well into adulthood. Development 2020; 147:dev.176750. [PMID: 32165493 DOI: 10.1242/dev.176750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 02/25/2020] [Indexed: 01/13/2023]
Abstract
The vertebrate inner ear employs sensory hair cells and neurons to mediate hearing and balance. In mammals, damaged hair cells and neurons are not regenerated. In contrast, hair cells in the inner ear of zebrafish are produced throughout life and regenerate after trauma. However, it is unknown whether new sensory neurons are also formed in the adult zebrafish statoacoustic ganglion (SAG), the sensory ganglion connecting the inner ear to the brain. Using transgenic lines and marker analysis, we identify distinct cell populations and anatomical landmarks in the juvenile and adult SAG. In particular, we analyze a Neurod/Nestin-positive progenitor pool that produces large amounts of new neurons at juvenile stages, which transitions to a quiescent state in the adult SAG. Moreover, BrdU pulse chase experiments reveal the existence of a proliferative but otherwise marker-negative cell population that replenishes the Neurod/Nestin-positive progenitor pool at adult stages. Taken together, our study represents the first comprehensive characterization of the adult zebrafish SAG showing that zebrafish, in sharp contrast to mammals, display continued neurogenesis in the SAG well beyond embryonic and larval stages.
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Affiliation(s)
- Simone Schwarzer
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Nandini Asokan
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Oliver Bludau
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Jeongeun Chae
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Veronika Kuscha
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Jan Kaslin
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Stefan Hans
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
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25
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Tian W, Czopka T, López-Schier H. Systemic loss of Sarm1 protects Schwann cells from chemotoxicity by delaying axon degeneration. Commun Biol 2020; 3:49. [PMID: 32001778 PMCID: PMC6992705 DOI: 10.1038/s42003-020-0776-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/09/2020] [Indexed: 12/11/2022] Open
Abstract
Protecting the nervous system from chronic effects of physical and chemical stress is a pressing clinical challenge. The obligate pro-degenerative protein Sarm1 is essential for Wallerian axon degeneration. Thus, blocking Sarm1 function is emerging as a promising neuroprotective strategy with therapeutic relevance. Yet, the conditions that will most benefit from inhibiting Sarm1 remain undefined. Here we combine genome engineering, pharmacology and high-resolution intravital videmicroscopy in zebrafish to show that genetic elimination of Sarm1 increases Schwann-cell resistance to toxicity by diverse chemotherapeutic agents after axonal injury. Synthetic degradation of Sarm1-deficient axons reversed this effect, suggesting that glioprotection is a non-autonomous effect of delayed axon degeneration. Moreover, loss of Sarm1 does not affect macrophage recruitment to nerve-wound microenvironment, injury resolution, or neural-circuit repair. These findings anticipate that interventions aimed at inhibiting Sarm1 can counter heightened glial vulnerability to chemical stressors and may be an effective strategy to reduce chronic consequences of neurotrauma.
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Affiliation(s)
- Weili Tian
- Sensory Biology & Organogenesis, Helmholtz Zentrum Munich, Munich, Germany
| | - Tim Czopka
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
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26
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Oosterhof N, Kuil LE, van der Linde HC, Burm SM, Berdowski W, van Ijcken WFJ, van Swieten JC, Hol EM, Verheijen MHG, van Ham TJ. Colony-Stimulating Factor 1 Receptor (CSF1R) Regulates Microglia Density and Distribution, but Not Microglia Differentiation In Vivo. Cell Rep 2019; 24:1203-1217.e6. [PMID: 30067976 DOI: 10.1016/j.celrep.2018.06.113] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/23/2018] [Accepted: 06/27/2018] [Indexed: 01/02/2023] Open
Abstract
Microglia are brain-resident macrophages with trophic and phagocytic functions. Dominant loss-of-function mutations in a key microglia regulator, colony-stimulating factor 1 receptor (CSF1R), cause adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP), a progressive white matter disorder. Because it remains unclear precisely how CSF1R mutations affect microglia, we generated an allelic series of csf1r mutants in zebrafish to identify csf1r-dependent microglia changes. We found that csf1r mutations led to aberrant microglia density and distribution and regional loss of microglia. The remaining microglia still had a microglia-specific gene expression signature, indicating that they had differentiated normally. Strikingly, we also observed lower microglia numbers and widespread microglia depletion in postmortem brain tissue of ALSP patients. Both in zebrafish and in human disease, local microglia loss also presented in regions without obvious pathology. Together, this implies that CSF1R mainly regulates microglia density and that early loss of microglia may contribute to ALSP pathogenesis.
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Affiliation(s)
- Nynke Oosterhof
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Laura E Kuil
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Herma C van der Linde
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Saskia M Burm
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Woutje Berdowski
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Wilfred F J van Ijcken
- Center for Biomics, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - John C van Swieten
- Department of Neurology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands; Department of Clinical Genetics, VU Medical Center, Amsterdam, the Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands; Department of Neuroimmunology, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
| | - Mark H G Verheijen
- Department of Molecular and Cellular Neurobiology, CNCR, Amsterdam Neuroscience, VU University, Amsterdam, the Netherlands
| | - Tjakko J van Ham
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands.
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27
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Klingseisen A, Ristoiu AM, Kegel L, Sherman DL, Rubio-Brotons M, Almeida RG, Koudelka S, Benito-Kwiecinski SK, Poole RJ, Brophy PJ, Lyons DA. Oligodendrocyte Neurofascin Independently Regulates Both Myelin Targeting and Sheath Growth in the CNS. Dev Cell 2019; 51:730-744.e6. [PMID: 31761670 PMCID: PMC6912162 DOI: 10.1016/j.devcel.2019.10.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/10/2019] [Accepted: 10/17/2019] [Indexed: 01/06/2023]
Abstract
Selection of the correct targets for myelination and regulation of myelin sheath growth are essential for central nervous system (CNS) formation and function. Through a genetic screen in zebrafish and complementary analyses in mice, we find that loss of oligodendrocyte Neurofascin leads to mistargeting of myelin to cell bodies, without affecting targeting to axons. In addition, loss of Neurofascin reduces CNS myelination by impairing myelin sheath growth. Time-lapse imaging reveals that the distinct myelinating processes of individual oligodendrocytes can engage in target selection and sheath growth at the same time and that Neurofascin concomitantly regulates targeting and growth. Disruption to Caspr, the neuronal binding partner of oligodendrocyte Neurofascin, also impairs myelin sheath growth, likely reflecting its association in an adhesion complex at the axon-glial interface with Neurofascin. Caspr does not, however, affect myelin targeting, further indicating that Neurofascin independently regulates distinct aspects of CNS myelination by individual oligodendrocytes in vivo. Single oligodendrocytes coordinate myelin targeting and growth at the same time Oligodendrocyte Neurofascin prevents myelination of cell bodies Oligodendrocyte Neurofascin promotes myelin sheath growth The neuronal binding partner of Neurofascin, Caspr, promotes myelin sheath growth
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Affiliation(s)
- Anna Klingseisen
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Ana-Maria Ristoiu
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Linde Kegel
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Diane L Sherman
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Maria Rubio-Brotons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Sigrid Koudelka
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | | | - Richard J Poole
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK.
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28
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Nagarajan B, Harder A, Japp A, Häberlein F, Mingardo E, Kleinert H, Yilmaz Ö, Zoons A, Rau B, Christ A, Kubitscheck U, Eiberger B, Sandhoff R, Eckhardt M, Hartmann D, Odermatt B. CNS myelin protein 36K regulates oligodendrocyte differentiation through Notch. Glia 2019; 68:509-527. [PMID: 31702067 DOI: 10.1002/glia.23732] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022]
Abstract
In contrast to humans and other mammals, zebrafish can successfully regenerate and remyelinate central nervous system (CNS) axons following injury. In addition to common myelin proteins found in mammalian myelin, 36K protein is a major component of teleost fish CNS myelin. Although 36K is one of the most abundant proteins in zebrafish brain, its function remains unknown. Here we investigate the function of 36K using translation-blocking Morpholinos. Morphant larvae showed fewer dorsally migrated oligodendrocyte precursor cells as well as upregulation of Notch ligand. A gamma secretase inhibitor, which prevents activation of Notch, could rescue oligodendrocyte precursor cell numbers in 36K morphants, suggesting that 36K regulates initial myelination through inhibition of Notch signaling. Since 36K like other short chain dehydrogenases might act on lipids, we performed thin layer chromatography and mass spectrometry of lipids and found changes in lipid composition in 36K morphant larvae. Altogether, we suggest that during early development 36K regulates membrane lipid composition, thereby altering the amount of transmembrane Notch ligands and the efficiency of intramembrane gamma secretase processing of Notch and thereby influencing oligodendrocyte precursor cell differentiation and further myelination. Further studies on the role of 36K short chain dehydrogenase in oligodendrocyte precursor cell differentiation during remyelination might open up new strategies for remyelination therapies in human patients.
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Affiliation(s)
- Bhuvaneswari Nagarajan
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany
| | - Alexander Harder
- Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany
| | - Anna Japp
- Institute of Neuropathology, University Clinics, University of Bonn, Bonn, Germany
| | - Felix Häberlein
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany.,Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Enrico Mingardo
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany
| | - Henning Kleinert
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany
| | - Öznur Yilmaz
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany
| | - Angelika Zoons
- Institute of Anatomy, Division of Neuroanatomy, University Clinics, University of Bonn, Bonn, Germany
| | - Birgit Rau
- Institute of Anatomy, Division of Neuroanatomy, University Clinics, University of Bonn, Bonn, Germany
| | - Andrea Christ
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany
| | - Ulrich Kubitscheck
- Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany
| | - Britta Eiberger
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany
| | - Roger Sandhoff
- Lipid Pathobiochemistry Group, German Cancer Research Centre, Heidelberg, Germany
| | - Matthias Eckhardt
- Institute of Biochemistry and Molecular Biology, University Clinics, University of Bonn, Bonn, Germany
| | - Dieter Hartmann
- Institute of Anatomy, Division of Neuroanatomy, University Clinics, University of Bonn, Bonn, Germany
| | - Benjamin Odermatt
- Institute of Anatomy, Division of Anatomy and Cell Biology, University Clinics, University of Bonn, Bonn, Germany.,Institute of Anatomy, Division of Neuroanatomy, University Clinics, University of Bonn, Bonn, Germany
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29
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Reinhardt L, Kordes S, Reinhardt P, Glatza M, Baumann M, Drexler HCA, Menninger S, Zischinsky G, Eickhoff J, Fröb C, Bhattarai P, Arulmozhivarman G, Marrone L, Janosch A, Adachi K, Stehling M, Anderson EN, Abo-Rady M, Bickle M, Pandey UB, Reimer MM, Kizil C, Schöler HR, Nussbaumer P, Klebl B, Sterneckert JL. Dual Inhibition of GSK3β and CDK5 Protects the Cytoskeleton of Neurons from Neuroinflammatory-Mediated Degeneration In Vitro and In Vivo. Stem Cell Reports 2019; 12:502-517. [PMID: 30773488 PMCID: PMC6409486 DOI: 10.1016/j.stemcr.2019.01.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammation is a hallmark of neurological disorders and is accompanied by the production of neurotoxic agents such as nitric oxide. We used stem cell-based phenotypic screening and identified small molecules that directly protected neurons from neuroinflammation-induced degeneration. We demonstrate that inhibition of CDK5 is involved in, but not sufficient for, neuroprotection. Instead, additional inhibition of GSK3β is required to enhance the neuroprotective effects of CDK5 inhibition, which was confirmed using short hairpin RNA-mediated knockdown of CDK5 and GSK3β. Quantitative phosphoproteomics and high-content imaging demonstrate that neurite degeneration is mediated by aberrant phosphorylation of multiple microtubule-associated proteins. Finally, we show that our hit compound protects neurons in vivo in zebrafish models of motor neuron degeneration and Alzheimer's disease. Thus, we demonstrate an overlap of CDK5 and GSK3β in mediating the regulation of the neuronal cytoskeleton and that our hit compound LDC8 represents a promising starting point for neuroprotective drugs. Phenotypic screening identifies CDK inhibitors protecting neurons from inflammation Inhibition of CDK5 is involved in neuroprotection but is not sufficient Dual inhibition of CDK5 and GSK3β is neuroprotective in vitro and in vivo Quantitative phosphoproteomics links neuroprotection to microtubule dynamics
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Affiliation(s)
- Lydia Reinhardt
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany; Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Susanne Kordes
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany; Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Peter Reinhardt
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany; Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Michael Glatza
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany; Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Matthias Baumann
- Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Hannes C A Drexler
- Bioanalytical Mass Spectrometry, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Sascha Menninger
- Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Gunther Zischinsky
- Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Jan Eickhoff
- Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Claudia Fröb
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany
| | - Prabesh Bhattarai
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany; German Center for Neurodegenerative Diseases (DZNE) within the Helmholtz Association, Tatzberg 41, 01307 Dresden, Germany
| | - Guruchandar Arulmozhivarman
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany
| | - Lara Marrone
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany
| | - Antje Janosch
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Kenjiro Adachi
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Martin Stehling
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Eric N Anderson
- Department of Pediatrics, Division of Child Neurology, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA; Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA 15261, USA
| | - Masin Abo-Rady
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany
| | - Marc Bickle
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Udai Bhan Pandey
- Department of Pediatrics, Division of Child Neurology, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA; Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA 15261, USA; Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Michell M Reimer
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany
| | - Caghan Kizil
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany; German Center for Neurodegenerative Diseases (DZNE) within the Helmholtz Association, Tatzberg 41, 01307 Dresden, Germany
| | - Hans R Schöler
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany; University of Münster, Medical Faculty, Domagkstrasse 3, 48149 Münster, Germany
| | - Peter Nussbaumer
- Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Bert Klebl
- Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, 44227 Dortmund, Germany
| | - Jared L Sterneckert
- Technische Universität Dresden, DFG-Research Center for Regenerative Therapies Dresden (CRTD), Fetscherstrasse 105, 01307 Dresden, Germany; Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany.
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30
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Tsarouchas TM, Wehner D, Cavone L, Munir T, Keatinge M, Lambertus M, Underhill A, Barrett T, Kassapis E, Ogryzko N, Feng Y, van Ham TJ, Becker T, Becker CG. Dynamic control of proinflammatory cytokines Il-1β and Tnf-α by macrophages in zebrafish spinal cord regeneration. Nat Commun 2018; 9:4670. [PMID: 30405119 PMCID: PMC6220182 DOI: 10.1038/s41467-018-07036-w] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 10/12/2018] [Indexed: 12/22/2022] Open
Abstract
Spinal cord injury leads to a massive response of innate immune cells in non-regenerating mammals, but also in successfully regenerating zebrafish. However, the role of the immune response in successful regeneration is poorly defined. Here we show that inhibiting inflammation reduces and promoting it accelerates axonal regeneration in spinal-lesioned zebrafish larvae. Mutant analyses show that peripheral macrophages, but not neutrophils or microglia, are necessary for repair. Macrophage-less irf8 mutants show prolonged inflammation with elevated levels of Tnf-α and Il-1β. Inhibiting Tnf-α does not rescue axonal growth in irf8 mutants, but impairs it in wildtype animals, indicating a pro-regenerative role of Tnf-α. In contrast, decreasing Il-1β levels or number of Il-1β+ neutrophils rescue functional regeneration in irf8 mutants. However, during early regeneration, interference with Il-1β function impairs regeneration in irf8 and wildtype animals. Hence, inflammation is dynamically controlled by macrophages to promote functional spinal cord regeneration in zebrafish. While proinflammatory signalling is preventive to axon regrowth, activated macrophages can be beneficial, for example by limiting the inflammation. This study uses mutant zebrafish lines that lack macrophages and/or microglia to show that peripheral macrophages are necessary in axon regrowth following complete transection of spinal cord.
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Affiliation(s)
- Themistoklis M Tsarouchas
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Daniel Wehner
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.,Technische Universität Dresden, DFG-Center of Regenerative Therapies Dresden, Fetscherstraße 105, Dresden, 01307, Germany
| | - Leonardo Cavone
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Tahimina Munir
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Marcus Keatinge
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Marvin Lambertus
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.,Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, 0316, Oslo, Norway
| | - Anna Underhill
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Thomas Barrett
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Elias Kassapis
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Nikolay Ogryzko
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Yi Feng
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Tjakko J van Ham
- Department of Clinical Genetics, Erasmus University Medical Center, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands
| | - Thomas Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
| | - Catherina G Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
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Meireles AM, Shen K, Zoupi L, Iyer H, Bouchard EL, Williams A, Talbot WS. The Lysosomal Transcription Factor TFEB Represses Myelination Downstream of the Rag-Ragulator Complex. Dev Cell 2018; 47:319-330.e5. [PMID: 30399334 PMCID: PMC6250074 DOI: 10.1016/j.devcel.2018.10.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 08/28/2018] [Accepted: 10/03/2018] [Indexed: 12/30/2022]
Abstract
Myelin allows for fast and efficient axonal conduction, but much remains to be determined about the mechanisms that regulate myelin formation. To investigate the genetic basis of myelination, we carried out a genetic screen using zebrafish. Here, we show that the lysosomal G protein RagA is essential for CNS myelination. In rraga-/- mutant oligodendrocytes, target genes of the lysosomal transcription factor Tfeb are upregulated, consistent with previous evidence that RagA represses Tfeb activity. Loss of Tfeb function is sufficient to restore myelination in RagA mutants, indicating that hyperactive Tfeb represses myelination. Conversely, tfeb-/- single mutants exhibit ectopic myelin, further indicating that Tfeb represses myelination during development. In a mouse model of de- and remyelination, TFEB expression is increased in oligodendrocytes, but the protein is localized to the cytoplasm, and hence inactive, especially during remyelination. These results define essential regulators of myelination and may advance approaches to therapeutic remyelination.
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Affiliation(s)
- Ana M Meireles
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kimberle Shen
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lida Zoupi
- University of Edinburgh/MS Society Centre for MS Research, MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh Bioquarter, 5 Little France Drive, Edinburgh EH16 4UU, UK
| | - Harini Iyer
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ellen L Bouchard
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Anna Williams
- University of Edinburgh/MS Society Centre for MS Research, MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh Bioquarter, 5 Little France Drive, Edinburgh EH16 4UU, UK
| | - William S Talbot
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Garcia-Pradas L, Gleiser C, Wizenmann A, Wolburg H, Mack AF. Glial Cells in the Fish Retinal Nerve Fiber Layer Form Tight Junctions, Separating and Surrounding Axons. Front Mol Neurosci 2018; 11:367. [PMID: 30364233 PMCID: PMC6192225 DOI: 10.3389/fnmol.2018.00367] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 09/18/2018] [Indexed: 02/01/2023] Open
Abstract
In the retina of teleost fish, cell addition continues throughout life involving proliferation and axonal growth. To study how this is achieved in a fully functioning retina, we investigated the nerve fiber layer (NFL) of the cichlid fish Astatotilapia burtoni for components that might regulate the extracellular environment. We hypothesized that growing axons are surrounded by different cell structures than signal conducting axons. Using immunohistochemistry and freeze fracture electron microscopy we found that the endfeet of Müller cells (MCs) expressed aquaporin-4 but not in high densities as in mammals. The presence of this water channel indicates the involvement of MCs in water homeostasis. Remarkably, we discovered conspicuous tight junctions in the retinal NFL. These tight junctions formed branching strands between myelin-like wrappings of ganglion cell axons that differed morphologically from any known myelin, and also an elaborate meshwork on large membrane faces between axons. We speculated that these tight junctions have additional functions than solely facilitating nerve conductance. Immunostainings against the adaptor protein ZO-1 labeled the NFL as did antibodies against the mammalian claudin-1, 3, and 19. Performing PCR analysis, we showed expression of claudin-1, 3, 5a, 5b, 9, 11, and 19 in the fish retina, claudins that typically occur at brain barriers or myelin. We could show by immunostains for doublecortin, a marker for differentiating neurons, that new axons are not surrounded by the myelin-like wrappings but only by the endfeet of MCs. We hypothesize that the tight junctions in the NFL of fish might contribute to the separation of an extracellular space around axons facilitating conductance, from a growth-promoting environment. For a functional test we applied Evans Blue dye to eye cup preparations which showed a retention of the dye in the NFL. This indicates that these remarkable tight junctions can indeed act as a diffusion barrier.
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Affiliation(s)
- Lidia Garcia-Pradas
- Institut für klinische Anatomie und Zellanalytik, Universität Tübingen, Tübingen, Germany
| | - Corinna Gleiser
- Institut für klinische Anatomie und Zellanalytik, Universität Tübingen, Tübingen, Germany
| | - Andrea Wizenmann
- Institut für klinische Anatomie und Zellanalytik, Universität Tübingen, Tübingen, Germany
| | - Hartwig Wolburg
- Institut für Pathologie und Neuropathologie, Universität Tübingen, Tübingen, Germany
| | - Andreas F Mack
- Institut für klinische Anatomie und Zellanalytik, Universität Tübingen, Tübingen, Germany
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Fish Scales Dictate the Pattern of Adult Skin Innervation and Vascularization. Dev Cell 2018; 46:344-359.e4. [PMID: 30032992 DOI: 10.1016/j.devcel.2018.06.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 05/27/2018] [Accepted: 06/22/2018] [Indexed: 11/24/2022]
Abstract
As animals mature from embryonic to adult stages, the skin grows and acquires specialized appendages, like hairs, feathers, and scales. How cutaneous blood vessels and sensory axons adapt to these dramatic changes is poorly understood. By characterizing skin maturation in zebrafish, we discovered that sensory axons are delivered to the adult epidermis in organized nerves patterned by features in bony scales. These nerves associate with blood vessels and osteoblasts above scales. Osteoblasts create paths in scales that independently guide nerves and blood vessels during both development and regeneration. By preventing scale regeneration and examining mutants lacking scales, we found that scales recruit, organize, and polarize axons and blood vessels to evenly distribute them in the skin. These studies uncover mechanisms for achieving comprehensive innervation and vascularization of the adult skin and suggest that scales coordinate a metamorphosis-like transformation of the skin with sensory axon and vascular remodeling.
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Ghosh S, Hui SP. Axonal regeneration in zebrafish spinal cord. REGENERATION (OXFORD, ENGLAND) 2018; 5:43-60. [PMID: 29721326 PMCID: PMC5911453 DOI: 10.1002/reg2.99] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 03/09/2018] [Accepted: 03/13/2018] [Indexed: 12/12/2022]
Abstract
In the present review we discuss two interrelated events-axonal damage and repair-known to occur after spinal cord injury (SCI) in the zebrafish. Adult zebrafish are capable of regenerating axonal tracts and can restore full functionality after SCI. Unlike fish, axon regeneration in the adult mammalian central nervous system is extremely limited. As a consequence of an injury there is very little repair of disengaged axons and therefore functional deficit persists after SCI in adult mammals. In contrast, peripheral nervous system axons readily regenerate following injury and hence allow functional recovery both in mammals and fish. A better mechanistic understanding of these three scenarios could provide a more comprehensive insight into the success or failure of axonal regeneration after SCI. This review summarizes the present understanding of the cellular and molecular basis of axonal regeneration, in both the peripheral nervous system and the central nervous system, and large scale gene expression analysis is used to focus on different events during regeneration. The discovery and identification of genes involved in zebrafish spinal cord regeneration and subsequent functional experimentation will provide more insight into the endogenous mechanism of myelination and remyelination. Furthermore, precise knowledge of the mechanism underlying the extraordinary axonal regeneration process in zebrafish will also allow us to unravel the potential therapeutic strategies to be implemented for enhancing regrowth and remyelination of axons in mammals.
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Affiliation(s)
- Sukla Ghosh
- Department of BiophysicsMolecular Biology and BioinformaticsUniversity of Calcutta92 A. P. C. RoadKolkata 700009India
| | - Subhra Prakash Hui
- Department of BiophysicsMolecular Biology and BioinformaticsUniversity of Calcutta92 A. P. C. RoadKolkata 700009India
- Victor Chang Cardiac Research InstituteLowy Packer Building, 405 Liverpool StDarlinghurstNSW 2010Australia.
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35
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Abstract
The optical transparency of zebrafish larvae enables live imaging. Here we describe the methodology for live imaging and detail how to mount larvae for live imaging of Schwann cell development.
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Affiliation(s)
- Rebecca L Cunningham
- Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Kelly R Monk
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA. .,Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO, USA.
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36
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Abstract
Myelination by oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system is essential for nervous system function and health. Despite its importance, we have a relatively poor understanding of the molecular and cellular mechanisms that regulate myelination in the living animal, particularly in the CNS. This is partly due to the fact that myelination commences around birth in mammals, by which time the CNS is complex and largely inaccessible, and thus very difficult to image live in its intact form. As a consequence, in recent years much effort has been invested in the use of smaller, simpler, transparent model organisms to investigate mechanisms of myelination in vivo. Although the majority of such studies have employed zebrafish, the Xenopus tadpole also represents an important complementary system with advantages for investigating myelin biology in vivo. Here we review how the natural features of zebrafish embryos and larvae and Xenopus tadpoles make them ideal systems for experimentally interrogating myelination by live imaging. We outline common transgenic technologies used to generate zebrafish and Xenopus that express fluorescent reporters, which can be used to image myelination. We also provide an extensive overview of the imaging modalities most commonly employed to date to image the nervous system in these transparent systems, and also emerging technologies that we anticipate will become widely used in studies of zebrafish and Xenopus myelination in the near future.
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Affiliation(s)
- Jenea M Bin
- Centre for Neuroregeneration, MS Society Centre for Translational Research, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, UK
| | - David A Lyons
- Centre for Neuroregeneration, MS Society Centre for Translational Research, Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, Edinburgh, UK
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Tingaud-Sequeira A, Raldúa D, Lavie J, Mathieu G, Bordier M, Knoll-Gellida A, Rambeau P, Coupry I, André M, Malm E, Möller C, Andreasson S, Rendtorff ND, Tranebjærg L, Koenig M, Lacombe D, Goizet C, Babin PJ. Functional validation of ABHD12 mutations in the neurodegenerative disease PHARC. Neurobiol Dis 2016; 98:36-51. [PMID: 27890673 DOI: 10.1016/j.nbd.2016.11.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 10/25/2016] [Accepted: 11/21/2016] [Indexed: 12/13/2022] Open
Abstract
ABHD12 mutations have been linked to neurodegenerative PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and early-onset cataract), a rare, progressive, autosomal, recessive disease. Although ABHD12 is suspected to play a role in the lysophosphatidylserine and/or endocannabinoid pathways, its precise functional role(s) leading to PHARC disease had not previously been characterized. Cell and zebrafish models were designed to demonstrate the causal link between an identified new missense mutation p.T253R, characterized in ABHD12 from a young patient, the previously characterized p.T202I and p.R352* mutations, and the associated PHARC. Measuring ABHD12 monoacylglycerol lipase activity in transfected HEK293 cells demonstrated inhibition with mutated isoforms. Both the expression pattern of zebrafish abhd12 and the phenotype of specific antisense morpholino oligonucleotide gene knockdown morphants were consistent with human PHARC hallmarks. High abhd12 transcript levels were found in the optic tectum and tract, colocalized with myelin basic protein, and in the spinal cord. Morphants have myelination defects and concomitant functional deficits, characterized by progressive ataxia and motor skill impairment. A disruption of retina architecture and retinotectal projections was observed, together with an inhibition of lens clarification and a low number of mechanosensory hair cells in the inner ear and lateral line system. The severe phenotypes in abhd12 knockdown morphants were rescued by introducing wild-type human ABHD12 mRNA, but not by mutation-harboring mRNAs. Zebrafish may provide a suitable vertebrate model for ABHD12 insufficiency and the study of functional impairment and potential therapeutic rescue of this rare, neurodegenerative disease.
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Affiliation(s)
- Angèle Tingaud-Sequeira
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France
| | | | - Julie Lavie
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France
| | - Guilaine Mathieu
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France
| | - Magali Bordier
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France; CHU Bordeaux, Hôpital Pellegrin, Service de Génétique Médicale, Bordeaux, France
| | - Anja Knoll-Gellida
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France
| | - Pierre Rambeau
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France
| | - Isabelle Coupry
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France
| | - Michèle André
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France
| | - Eva Malm
- Department of Ophthalmology, Lund University Hospital, Lund, Sweden
| | - Claes Möller
- School of Medicine and Health, Örebro University, Sweden
| | - Sten Andreasson
- Department of Ophthalmology, Lund University Hospital, Lund, Sweden
| | - Nanna D Rendtorff
- Department Audiology, Bispebjerg Hospital/Rigshospitalet, Department of Clinical Genetics, Rigshospitalet/The Kennedy Center, University of Copenhagen, Institute for Clinical Medicine Copenhagen, Denmark
| | - Lisbeth Tranebjærg
- Department Audiology, Bispebjerg Hospital/Rigshospitalet, Department of Clinical Genetics, Rigshospitalet/The Kennedy Center, University of Copenhagen, Institute for Clinical Medicine Copenhagen, Denmark
| | - Michel Koenig
- Laboratoire de Génétique Moléculaire et unité INSERM UMR_S827, IURC, Montpellier, France
| | - Didier Lacombe
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France; CHU Bordeaux, Hôpital Pellegrin, Service de Génétique Médicale, Bordeaux, France
| | - Cyril Goizet
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France; CHU Bordeaux, Hôpital Pellegrin, Service de Génétique Médicale, Bordeaux, France
| | - Patrick J Babin
- Univ. Bordeaux, INSERM U1211, Maladies Rares: Génétique et Métabolisme (MRGM), F-33076 Bordeaux, France.
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Abstract
Myelin is a lipid-rich sheath formed by the spiral wrapping of specialized glial cells around axon segments. Myelinating glia allow for rapid transmission of nerve impulses and metabolic support of axons, and the absence of or disruption to myelin results in debilitating motor, cognitive, and emotional deficits in humans. Because myelin is a jawed vertebrate innovation, zebrafish are one of the simplest vertebrate model systems to study the genetics and development of myelinating glia. The morphogenetic cellular movements and genetic program that drive myelination are conserved between zebrafish and mammals, and myelin develops rapidly in zebrafish larvae, within 3-5days postfertilization. Myelin ultrastructure can be visualized in the zebrafish from larval to adult stages via transmission electron microscopy, and the dynamic development of myelinating glial cells may be observed in vivo via transgenic reporter lines in zebrafish larvae. Zebrafish are amenable to genetic and pharmacological screens, and screens for myelinating glial phenotypes have revealed both genes and drugs that promote myelin development, many of which are conserved in mammalian glia. Recently, zebrafish have been employed as a model to understand the complex dynamics of myelinating glia during development and regeneration. In this chapter, we describe these key methodologies and recent insights into mechanisms that regulate myelination using the zebrafish model.
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Affiliation(s)
- M D'Rozario
- Washington University School of Medicine, St. Louis, MO, United States
| | - K R Monk
- Washington University School of Medicine, St. Louis, MO, United States; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States
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Parrilla M, León-Lobera F, Lillo C, Arévalo R, Aijón J, Lara JM, Velasco A. Sox10 Expression in Goldfish Retina and Optic Nerve Head in Controls and after the Application of Two Different Lesion Paradigms. PLoS One 2016; 11:e0154703. [PMID: 27149509 PMCID: PMC4858161 DOI: 10.1371/journal.pone.0154703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/18/2016] [Indexed: 12/24/2022] Open
Abstract
The mammalian central nervous system (CNS) is unable to regenerate. In contrast, the CNS of fish, including the visual system, is able to regenerate after damage. Moreover, the fish visual system grows continuously throughout the life of the animal, and it is therefore an excellent model to analyze processes of myelination and re-myelination after an injury. Here we analyze Sox10+ oligodendrocytes in the goldfish retina and optic nerve in controls and after two kinds of injuries: cryolesion of the peripheral growing zone and crushing of the optic nerve. We also analyze changes in a major component of myelin, myelin basic protein (MBP), as a marker for myelinated axons. Our results show that Sox10+ oligodendrocytes are located in the retinal nerve fiber layer and along the whole length of the optic nerve. MBP was found to occupy a similar location, although its loose appearance in the retina differed from the highly organized MBP+ axon bundles in the optic nerve. After optic nerve crushing, the number of Sox10+ cells decreased in the crushed area and in the optic nerve head. Consistent with this, myelination was highly reduced in both areas. In contrast, after cryolesion we did not find changes in the Sox10+ population, although we did detect some MBP- degenerating areas. We show that these modifications in Sox10+ oligodendrocytes are consistent with their role in oligodendrocyte identity, maintenance and survival, and we propose the optic nerve head as an excellent area for research aimed at better understanding of de- and remyelination processes.
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Affiliation(s)
- Marta Parrilla
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
| | - Fernando León-Lobera
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- IBSAL, Salamanca, Spain
| | - Concepción Lillo
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- IBSAL, Salamanca, Spain
| | - Rosario Arévalo
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- IBSAL, Salamanca, Spain
| | - José Aijón
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- IBSAL, Salamanca, Spain
| | - Juan Manuel Lara
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- IBSAL, Salamanca, Spain
| | - Almudena Velasco
- Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Salamanca, Spain
- IBSAL, Salamanca, Spain
- * E-mail:
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40
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Abstract
In the nervous system, axons transmit information in the form of electrical impulses over long distances. The speed of impulse conduction is enhanced by myelin, a lipid-rich membrane that wraps around axons. Myelin also is required for the long-term health of axons by providing metabolic support. Accordingly, myelin deficiencies are implicated in a wide range of neurodevelopmental and neuropsychiatric disorders, intellectual disabilities, and neurodegenerative conditions. Central nervous system myelin is formed by glial cells called oligodendrocytes. During development, oligodendrocyte precursor cells migrate from their origins to their target axons, extend long membrane processes that wrap axons, and produce the proteins and lipids that provide myelin membrane with its unique characteristics. Myelination is a dynamic process that involves intricate interactions between multiple cell types. Therefore, an in vivo myelination model, such as the zebrafish, which allows for live observation of cell dynamics and cell-to-cell interactions, is well suited for investigating oligodendrocyte development. Zebrafish offer several advantages to investigating myelination, including the use of transgenic reporter lines, live imaging, forward genetic screens, chemical screens, and reverse genetic approaches. This chapter will describe how these tools and approaches have provided new insights into the regulatory mechanisms that guide myelination.
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Affiliation(s)
- E S Mathews
- University of Colorado School of Medicine, Aurora, CO, United States
| | - B Appel
- University of Colorado School of Medicine, Aurora, CO, United States
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41
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Shen K, Sidik H, Talbot WS. The Rag-Ragulator Complex Regulates Lysosome Function and Phagocytic Flux in Microglia. Cell Rep 2016; 14:547-559. [PMID: 26774477 PMCID: PMC4731305 DOI: 10.1016/j.celrep.2015.12.055] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/24/2015] [Accepted: 12/09/2015] [Indexed: 01/07/2023] Open
Abstract
Microglia are resident macrophages of the CNS that are essential for phagocytosis of apoptotic neurons and weak synapses during development. We show that RagA and Lamtor4, two components of the Rag-Ragulator complex, are essential regulators of lysosomes in microglia. In zebrafish lacking RagA function, microglia exhibit an expanded lysosomal compartment, but they are unable to properly digest apoptotic neuronal debris. Previous biochemical studies have placed the Rag-Ragulator complex upstream of mTORC1 activation in response to cellular nutrient availability. Nonetheless, RagA and mTOR mutant zebrafish have distinct phenotypes, indicating that the Rag-Ragulator complex has functions independent of mTOR signaling. Our analysis reveals an essential role of the Rag-Ragulator complex in proper lysosome function and phagocytic flux in microglia.
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Affiliation(s)
- Kimberle Shen
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Harwin Sidik
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - William S Talbot
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Hu X, Fan Q, Hou H, Yan R. Neurological dysfunctions associated with altered BACE1-dependent Neuregulin-1 signaling. J Neurochem 2016; 136:234-49. [PMID: 26465092 PMCID: PMC4833723 DOI: 10.1111/jnc.13395] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 01/09/2023]
Abstract
Inhibition of BACE1 is being pursued as a therapeutic target to treat patients suffering from Alzheimer's disease because BACE1 is the sole β-secretase that generates β-amyloid peptide. Knowledge regarding other cellular functions of BACE1 is therefore critical for the safe use of BACE1 inhibitors in human patients. Neuregulin-1 (Nrg1) is a BACE1 substrate and BACE1 cleavage of Nrg1 is critical for signaling functions in myelination, remyelination, synaptic plasticity, normal psychiatric behaviors, and maintenance of muscle spindles. This review summarizes the most recent discoveries associated with BACE1-dependent Nrg1 signaling in these areas. This body of knowledge will help to provide guidance for preventing unwanted Nrg1-based side effects following BACE1 inhibition in humans. To initiate its signaling cascade, membrane anchored Neuregulin (Nrg), mainly type I and III β1 Nrg1 isoforms and Nrg3, requires ectodomain shedding. BACE1 is one of such indispensable sheddases to release the functional Nrg signaling fragment. The dependence of Nrg on the cleavage by BACE1 is best manifested by disrupting the critical role of Nrg in the control of axonal myelination, schizophrenic behaviors as well as the formation and maintenance of muscle spindles.
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Affiliation(s)
- Xiangyou Hu
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Qingyuan Fan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Hailong Hou
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
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43
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The Autotaxin-Lysophosphatidic Acid Axis Modulates Histone Acetylation and Gene Expression during Oligodendrocyte Differentiation. J Neurosci 2015; 35:11399-414. [PMID: 26269646 DOI: 10.1523/jneurosci.0345-15.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED During development, oligodendrocytes (OLGs), the myelinating cells of the CNS, undergo a stepwise progression during which OLG progenitors, specified from neural stem/progenitor cells, differentiate into fully mature myelinating OLGs. This progression along the OLG lineage is characterized by well synchronized changes in morphology and gene expression patterns. The latter have been found to be particularly critical during the early stages of the lineage, and they have been well described to be regulated by epigenetic mechanisms, especially by the activity of the histone deacetylases HDAC1 and HDAC2. The data presented here identify the extracellular factor autotaxin (ATX) as a novel upstream signal modulating HDAC1/2 activity and gene expression in cells of the OLG lineage. Using the zebrafish as an in vivo model system as well as rodent primary OLG cultures, this functional property of ATX was found to be mediated by its lysophospholipase D (lysoPLD) activity, which has been well characterized to generate the lipid signaling molecule lysophosphatidic acid (LPA). More specifically, the lysoPLD activity of ATX was found to modulate HDAC1/2 regulated gene expression during a time window coinciding with the transition from OLG progenitor to early differentiating OLG. In contrast, HDAC1/2 regulated gene expression during the transition from neural stem/progenitor to OLG progenitor appeared unaffected by ATX and its lysoPLD activity. Thus, together, our data suggest that an ATX-LPA-HDAC1/2 axis regulates OLG differentiation specifically during the transition from OLG progenitor to early differentiating OLG and via a molecular mechanism that is evolutionarily conserved from at least zebrafish to rodent. SIGNIFICANCE STATEMENT The formation of the axon insulating and supporting myelin sheath by differentiating oligodendrocytes (OLGs) in the CNS is considered an essential step during vertebrate development. In addition, loss and/or dysfunction of the myelin sheath has been associated with a variety of neurologic diseases in which repair is limited, despite the presence of progenitor cells with the potential to differentiate into myelinating OLGs. This study characterizes the autotaxin-lysophosphatidic acid signaling axis as a modulator of OLG differentiation in vivo in the developing zebrafish and in vitro in rodent OLGs in culture. These findings provide novel insight into the regulation of developmental myelination, and they are likely to lead to advancing studies related to the stimulation of myelin repair under pathologic conditions.
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Kim S, Lee YI, Chang KY, Lee DW, Cho SC, Ha YW, Na JE, Rhyu IJ, Park SC, Park HC. Promotion of Remyelination by Sulfasalazine in a Transgenic Zebrafish Model of Demyelination. Mol Cells 2015; 38:1013-21. [PMID: 26549504 PMCID: PMC4673405 DOI: 10.14348/molcells.2015.0246] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/11/2015] [Accepted: 10/13/2015] [Indexed: 12/19/2022] Open
Abstract
Most of the axons in the vertebrate nervous system are surrounded by a lipid-rich membrane called myelin, which promotes rapid conduction of nerve impulses and protects the axon from being damaged. Multiple sclerosis (MS) is a chronic demyelinating disease of the CNS characterized by infiltration of immune cells and progressive damage to myelin and axons. One potential way to treat MS is to enhance the endogenous remyelination process, but at present there are no available treatments to promote remyelination in patients with demyelinating diseases. Sulfasalazine is an anti-inflammatory and immune-modulating drug that is used in rheumatology and inflammatory bowel disease. Its anti-inflammatory and immunomodulatory properties prompted us to test the ability of sulfasalazine to promote remyelination. In this study, we found that sulfasalazine promotes remyelination in the CNS of a transgenic zebrafish model of NTR/MTZ-induced demyelination. We also found that sulfasalazine treatment reduced the number of macrophages/microglia in the CNS of demyelinated zebrafish larvae, suggesting that the acceleration of remyelination is mediated by the immunomodulatory function of sulfasalazine. Our data suggest that temporal modulation of the immune response by sulfasalazine can be used to overcome MS by enhancing myelin repair and remyelination in the CNS.
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Affiliation(s)
- Suhyun Kim
- Department of Biomedical Sciences, Korea University, Ansan 425-707,
Korea
| | - Yun-Il Lee
- Well Aging Research Center, Samsung Advanced Institute of Technology (SAIT), Suwon 443-803,
Korea
| | - Ki-Young Chang
- Well Aging Research Center, Samsung Advanced Institute of Technology (SAIT), Suwon 443-803,
Korea
| | - Dong-Won Lee
- Department of Biomedical Sciences, Korea University, Ansan 425-707,
Korea
| | - Sung Chun Cho
- Well Aging Research Center, Samsung Advanced Institute of Technology (SAIT), Suwon 443-803,
Korea
| | - Young Wan Ha
- Well Aging Research Center, Samsung Advanced Institute of Technology (SAIT), Suwon 443-803,
Korea
| | - Ji Eun Na
- Department of Anatomy, College of Medicine, Korea University, Seoul 136-705,
Korea
| | - Im Joo Rhyu
- Department of Anatomy, College of Medicine, Korea University, Seoul 136-705,
Korea
| | - Sang Chul Park
- Well Aging Research Center, Samsung Advanced Institute of Technology (SAIT), Suwon 443-803,
Korea
| | - Hae-Chul Park
- Department of Biomedical Sciences, Korea University, Ansan 425-707,
Korea
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The scales and tales of myelination: using zebrafish and mouse to study myelinating glia. Brain Res 2015; 1641:79-91. [PMID: 26498880 DOI: 10.1016/j.brainres.2015.10.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 10/01/2015] [Accepted: 10/05/2015] [Indexed: 01/06/2023]
Abstract
Myelin, the lipid-rich sheath that insulates axons to facilitate rapid conduction of action potentials, is an evolutionary innovation of the jawed-vertebrate lineage. Research efforts aimed at understanding the molecular mechanisms governing myelination have primarily focused on rodent models; however, with the advent of the zebrafish model system in the late twentieth century, the use of this genetically tractable, yet simpler vertebrate for studying myelination has steadily increased. In this review, we compare myelinating glial cell biology during development and regeneration in zebrafish and mouse and enumerate the advantages and disadvantages of using each model to study myelination. This article is part of a Special Issue entitled SI: Myelin Evolution.
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Sidik H, Talbot WS. A zinc finger protein that regulates oligodendrocyte specification, migration and myelination in zebrafish. Development 2015; 142:4119-28. [PMID: 26459222 DOI: 10.1242/dev.128215] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/01/2015] [Indexed: 12/21/2022]
Abstract
Precise control of oligodendrocyte migration and development is crucial for myelination of axons in the central nervous system (CNS), but important questions remain unanswered about the mechanisms controlling these processes. In a zebrafish screen for myelination mutants, we identified a mutation in zinc finger protein 16-like (znf16l). znf16l mutant larvae have reduced myelin basic protein (mbp) expression and reduced CNS myelin. Marker, time-lapse and ultrastructural studies indicated that oligodendrocyte specification, migration and myelination are disrupted in znf16l mutants. Transgenic studies indicated that znf16l acts autonomously in oligodendrocytes. Expression of Zfp488 from mouse rescued mbp expression in znf16l mutants, indicating that these homologs have overlapping functions. Our results defined the function of a new zinc finger protein with specific function in oligodendrocyte specification, migration and myelination in the developing CNS.
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Affiliation(s)
- Harwin Sidik
- Department of Developmental Biology, Stanford University, CA 94305, USA
| | - William S Talbot
- Department of Developmental Biology, Stanford University, CA 94305, USA
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Czopka T. Insights into mechanisms of central nervous system myelination using zebrafish. Glia 2015; 64:333-49. [PMID: 26250418 DOI: 10.1002/glia.22897] [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: 04/29/2015] [Revised: 07/14/2015] [Accepted: 07/15/2015] [Indexed: 12/12/2022]
Abstract
Myelin is the multi-layered membrane that surrounds most axons and is produced by oligodendrocytes in the central nervous system (CNS). In addition to its important role in enabling rapid nerve conduction, it has become clear in recent years that myelin plays additional vital roles in CNS function. Myelinating oligodendrocytes provide metabolic support to axons and active myelination is even involved in regulating forms of learning and memory formation. However, there are still large gaps in our understanding of how myelination by oligodendrocytes is regulated. The small tropical zebrafish has become an increasingly popular model organism to investigate many aspects of nervous system formation, function, and regeneration. This is mainly due to two approaches for which the zebrafish is an ideally suited vertebrate model--(1) in vivo live cell imaging using vital dyes and genetically encoded reporters, and (2) gene and target discovery using unbiased screens. This review summarizes how the use of zebrafish has helped understand mechanisms of oligodendrocyte behavior and myelination in vivo and discusses the potential use of zebrafish to shed light on important future questions relating to myelination in the context of CNS development, function and repair.
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Affiliation(s)
- Tim Czopka
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
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48
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Diekmann H, Kalbhen P, Fischer D. Characterization of optic nerve regeneration using transgenic zebrafish. Front Cell Neurosci 2015; 9:118. [PMID: 25914619 PMCID: PMC4391235 DOI: 10.3389/fncel.2015.00118] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/16/2015] [Indexed: 11/13/2022] Open
Abstract
In contrast to the adult mammalian central nervous system (CNS), fish are able to functionally regenerate severed axons upon injury. Although the zebrafish is a well-established model vertebrate for genetic and developmental studies, its use for anatomical studies of axon regeneration has been hampered by the paucity of appropriate tools to visualize re-growing axons in the adult CNS. On this account, we used transgenic zebrafish that express enhanced green fluorescent protein (GFP) under the control of a GAP-43 promoter. In adult, naïve retinae, GFP was restricted to young retinal ganglion cells (RGCs) and their axons. Within the optic nerve, these fluorescent axons congregated in a distinct strand at the nerve periphery, indicating age-related order. Upon optic nerve crush, GFP expression was markedly induced in RGC somata and intra-retinal axons at 4 to at least 14 days post injury. Moreover, individual axons were visualized in their natural environment of the optic nerve using wholemount tissue clearing and confocal microscopy. With this novel approach, regenerating axons were clearly detectable beyond the injury site as early as 2 days after injury and grew past the optic chiasm by 4 days. Regenerating axons in the entire optic nerve were labeled from 6 to at least 14 days after injury, thereby allowing detailed visualization of the complete regeneration process. Therefore, this new approach could now be used in combination with expression knockdown or pharmacological manipulations to analyze the relevance of specific proteins and signaling cascades for axonal regeneration in vivo. In addition, the RGC-specific GFP expression facilitated accurate evaluation of neurite growth in dissociated retinal cultures. This fast in vitro assay now enables the screening of compound and expression libraries. Overall, the presented methodologies provide exciting possibilities to investigate the molecular mechanisms underlying successful CNS regeneration in zebrafish.
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Affiliation(s)
- Heike Diekmann
- Division of Experimental Neurology, Department of Neurology, Heinrich-Heine-University of Düsseldorf Düsseldorf, Germany
| | - Pascal Kalbhen
- Division of Experimental Neurology, Department of Neurology, Heinrich-Heine-University of Düsseldorf Düsseldorf, Germany
| | - Dietmar Fischer
- Division of Experimental Neurology, Department of Neurology, Heinrich-Heine-University of Düsseldorf Düsseldorf, Germany
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Xiao Y, Faucherre A, Pola-Morell L, Heddleston JM, Liu TL, Chew TL, Sato F, Sehara-Fujisawa A, Kawakami K, López-Schier H. High-resolution live imaging reveals axon-glia interactions during peripheral nerve injury and repair in zebrafish. Dis Model Mech 2015; 8:553-64. [PMID: 26035865 PMCID: PMC4457030 DOI: 10.1242/dmm.018184] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 03/24/2015] [Indexed: 12/22/2022] Open
Abstract
Neural damage is a devastating outcome of physical trauma. The glia are one of the main effectors of neuronal repair in the nervous system, but the dynamic interactions between peripheral neurons and Schwann cells during injury and regeneration remain incompletely characterized. Here, we combine laser microsurgery, genetic analysis, high-resolution intravital imaging and lattice light-sheet microscopy to study the interaction between Schwann cells and sensory neurons in a zebrafish model of neurotrauma. We found that chronic denervation by neuronal ablation leads to Schwann-cell death, whereas acute denervation by axonal severing does not affect the overall complexity and architecture of the glia. Neuronal-circuit regeneration begins when Schwann cells extend bridging processes to close the injury gap. Regenerating axons grow faster and directionally after the physiological clearing of distal debris by the Schwann cells. This might facilitate circuit repair by ensuring that axons are guided through unoccupied spaces within bands of Büngner towards their original peripheral target. Accordingly, in the absence of Schwann cells, regenerating axons are misrouted, impairing the re-innervation of sensory organs. Our results indicate that regenerating axons use haptotaxis as a directional cue during the reconstitution of a neural circuit. These findings have implications for therapies aimed at neurorepair, which will benefit from preserving the architecture of the peripheral glia during periods of denervation. Summary: Schwann cells are important components of the peripheral glia. We use microsurgery and high-resolution live imaging to show how Schwann cells control the regeneration of a sensorineural circuit.
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Affiliation(s)
- Yan Xiao
- Research Unit Sensory Biology & Organogenesis, Helmholtz Zentrum München, 85764 Munich, Germany
| | - Adèle Faucherre
- Cell & Developmental Biology, Centre for Genomic Regulation, 08003 Barcelona, Spain
| | - Laura Pola-Morell
- Cell & Developmental Biology, Centre for Genomic Regulation, 08003 Barcelona, Spain
| | - John M Heddleston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Tsung-Li Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Teng-Leong Chew
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Fuminori Sato
- Institute for Frontier Medical Sciences, Kyoto University, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Atsuko Sehara-Fujisawa
- Institute for Frontier Medical Sciences, Kyoto University, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, The Graduate University for Advanced Studies (Sokendai), 1111 Yata, Mishima, Shizuoka 411-8540, Japan Department of Genetics, The Graduate University for Advanced Studies (Sokendai), 1111 Yata, Mishima, Shizuoka 411-8540, Japan
| | - Hernán López-Schier
- Research Unit Sensory Biology & Organogenesis, Helmholtz Zentrum München, 85764 Munich, Germany Cell & Developmental Biology, Centre for Genomic Regulation, 08003 Barcelona, Spain
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