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Asad A, Shahidan NO, de la Vega de León A, Wiggin GR, Whitfield TT, Baxendale S. A screen of pharmacologically active compounds to identify modulators of the Adgrg6/Gpr126 signalling pathway in zebrafish embryos. Basic Clin Pharmacol Toxicol 2023; 133:364-377. [PMID: 37394692 PMCID: PMC10952222 DOI: 10.1111/bcpt.13923] [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: 04/06/2023] [Revised: 06/20/2023] [Accepted: 06/27/2023] [Indexed: 07/04/2023]
Abstract
Adhesion G protein-coupled receptors (GPCRs) are an underrepresented class of GPCRs in drug discovery. We previously developed an in vivo drug screening pipeline to identify compounds with agonist activity for Adgrg6 (Gpr126), an adhesion GPCR required for myelination of the peripheral nervous system in vertebrates. The screening assay tests for rescue of an ear defect found in adgrg6tb233c-/- hypomorphic homozygous mutant zebrafish, using the expression of versican b (vcanb) mRNA as an easily identifiable phenotype. In the current study, we used the same assay to screen a commercially available library of 1280 diverse bioactive compounds (Sigma LOPAC). Comparison with published hits from two partially overlapping compound collections (Spectrum, Tocris) confirms that the screening assay is robust and reproducible. Using a modified counter screen for myelin basic protein (mbp) gene expression, we have identified 17 LOPAC compounds that can rescue both inner ear and myelination defects in adgrg6tb233c-/- hypomorphic mutants, three of which (ebastine, S-methylisothiourea hemisulfate, and thapsigargin) are new hits. A further 25 LOPAC hit compounds were effective at rescuing the otic vcanb expression but not mbp. Together, these and previously identified hits provide a wealth of starting material for the development of novel and specific pharmacological modulators of Adgrg6 receptor activity.
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Affiliation(s)
- Anzar Asad
- School of BiosciencesUniversity of SheffieldSheffieldUK
| | | | | | | | | | - Sarah Baxendale
- School of BiosciencesUniversity of SheffieldSheffieldUK
- Sheffield Zebrafish Screening Facility, School of BiosciencesUniversity of SheffieldSheffieldUK
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2
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Fazal SV, Mutschler C, Chen CZ, Turmaine M, Chen CY, Hsueh YP, Ibañez-Grau A, Loreto A, Casillas-Bajo A, Cabedo H, Franklin RJM, Barker RA, Monk KR, Steventon BJ, Coleman MP, Gomez-Sanchez JA, Arthur-Farraj P. SARM1 detection in myelinating glia: sarm1/ Sarm1 is dispensable for PNS and CNS myelination in zebrafish and mice. Front Cell Neurosci 2023; 17:1158388. [PMID: 37091921 PMCID: PMC10113485 DOI: 10.3389/fncel.2023.1158388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/14/2023] [Indexed: 04/08/2023] Open
Abstract
Since SARM1 mutations have been identified in human neurological disease, SARM1 inhibition has become an attractive therapeutic strategy to preserve axons in a variety of disorders of the peripheral (PNS) and central nervous system (CNS). While SARM1 has been extensively studied in neurons, it remains unknown whether SARM1 is present and functional in myelinating glia? This is an important question to address. Firstly, to identify whether SARM1 dysfunction in other cell types in the nervous system may contribute to neuropathology in SARM1 dependent diseases? Secondly, to ascertain whether therapies altering SARM1 function may have unintended deleterious impacts on PNS or CNS myelination? Surprisingly, we find that oligodendrocytes express sarm1 mRNA in the zebrafish spinal cord and that SARM1 protein is readily detectable in rodent oligodendrocytes in vitro and in vivo. Furthermore, activation of endogenous SARM1 in cultured oligodendrocytes induces rapid cell death. In contrast, in peripheral glia, SARM1 protein is not detectable in Schwann cells and satellite glia in vivo and sarm1/Sarm1 mRNA is detected at very low levels in Schwann cells, in vivo, in zebrafish and mouse. Application of specific SARM1 activators to cultured mouse Schwann cells does not induce cell death and nicotinamide adenine dinucleotide (NAD) levels remain unaltered suggesting Schwann cells likely contain no functionally relevant levels of SARM1. Finally, we address the question of whether SARM1 is required for myelination or myelin maintenance. In the zebrafish and mouse PNS and CNS, we show that SARM1 is not required for initiation of myelination and myelin sheath maintenance is unaffected in the adult mouse nervous system. Thus, strategies to inhibit SARM1 function to treat neurological disease are unlikely to perturb myelination in humans.
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Affiliation(s)
- Shaline V. Fazal
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Clara Mutschler
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom
| | - Civia Z. Chen
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Mark Turmaine
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Chiung-Ya Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Andrea Ibañez-Grau
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández, Alicante, Spain
| | - Andrea Loreto
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom
| | - Angeles Casillas-Bajo
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández, Alicante, Spain
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), Alicante, Spain
| | - Hugo Cabedo
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández, Alicante, Spain
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), Alicante, Spain
| | - Robin J. M. Franklin
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
- Altos Labs - Cambridge Institute of Science, Cambridge, United Kingdom
| | - Roger A. Barker
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Kelly R. Monk
- Vollum Institute, Oregon Health & Science University, Portland, OR, United States
| | | | - Michael P. Coleman
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom
| | - Jose A. Gomez-Sanchez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández, Alicante, Spain
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), Alicante, Spain
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Peter Arthur-Farraj
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom
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3
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Arena KA, Zhu Y, Kucenas S. Transforming growth factor-beta signaling modulates perineurial glial bridging following peripheral spinal motor nerve injury in zebrafish. Glia 2022; 70:1826-1849. [PMID: 35616185 PMCID: PMC9378448 DOI: 10.1002/glia.24220] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/06/2022] [Accepted: 05/11/2022] [Indexed: 11/12/2022]
Abstract
Spinal motor nerves are necessary for organismal locomotion and survival. In zebrafish and most vertebrates, these peripheral nervous system structures are composed of bundles of axons that naturally regenerate following injury. However, the cellular and molecular mechanisms that mediate this process are still only partially understood. Perineurial glia, which form a component of the blood-nerve barrier, are necessary for the earliest regenerative steps by establishing a glial bridge across the injury site as well as phagocytosing debris. Without perineurial glial bridging, regeneration is impaired. In addition to perineurial glia, Schwann cells, the cells that ensheath and myelinate axons within the nerve, are essential for debris clearance and axon guidance. In the absence of Schwann cells, perineurial glia exhibit perturbed bridging, demonstrating that these two cell types communicate during the injury response. While the presence and importance of perineurial glial bridging is known, the molecular mechanisms that underlie this process remain a mystery. Understanding the cellular and molecular interactions that drive perineurial glial bridging is crucial to unlocking the mechanisms underlying successful motor nerve regeneration. Using laser axotomy and in vivo imaging in zebrafish, we show that transforming growth factor-beta (TGFβ) signaling modulates perineurial glial bridging. Further, we identify connective tissue growth factor-a (ctgfa) as a downstream effector of TGF-β signaling that works in a positive feedback loop to mediate perineurial glial bridging. Together, these studies present a new signaling pathway involved in the perineurial glial injury response and further characterize the dynamics of the perineurial glial bridge.
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Affiliation(s)
- Kimberly A. Arena
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
- Program in Fundamental NeuroscienceUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Yunlu Zhu
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Sarah Kucenas
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
- Program in Fundamental NeuroscienceUniversity of VirginiaCharlottesvilleVirginiaUSA
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4
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Brown RI, Kawakami K, Kucenas S. A novel gene trap line for visualization and manipulation of erbb3b + neural crest and glial cells in zebrafish. Dev Biol 2022; 482:114-123. [PMID: 34932993 DOI: 10.1016/j.ydbio.2021.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/08/2021] [Accepted: 12/16/2021] [Indexed: 12/22/2022]
Abstract
Glia are a diverse and essential cell type in the vertebrate nervous system. Transgenic tools and fluorescent reporter lines are critical resources to investigate how glial subtypes develop and function. However, despite the many lines available in zebrafish, the community still lacks the ability to label all unique stages of glial development and specific subpopulations of cells. To address this issue, we screened zebrafish gene and enhancer trap lines to find a novel reporter for peripheral glial subtypes. From these, we generated the gSAIzGFFD37A transgenic line that expresses GFP in neural crest cells and central and peripheral glia. We found that the gene trap construct is located within an intron of erbb3b, a gene essential for glial development. Additionally, we confirmed that GFP+ cells express erbb3b along with sox10, a known glial marker. From our screen, we have identified the gSAIzGFFD37A line as a novel and powerful tool for studying glia in the developing zebrafish, as well as a new resource to manipulate erbb3b+ cells.
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Affiliation(s)
- Robin Isadora Brown
- Department of Biology, University of Virginia, Charlottesville, VA, 22904, USA; Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, 22904, USA
| | - Koichi Kawakami
- Laboratory of Molecular and Developmental Biology, National Institute of Genetics, and Department of Genetics, SOKENDAI The Graduate University for Advanced Studies, Mishima, Shizuoka, 444-8540, Japan
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, VA, 22904, USA; Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, 22904, USA.
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5
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Petersen SC. Open-Ended Inquiry into Zebrafish Nerve Development Using Image Analysis. JOURNAL OF UNDERGRADUATE NEUROSCIENCE EDUCATION : JUNE : A PUBLICATION OF FUN, FACULTY FOR UNDERGRADUATE NEUROSCIENCE 2021; 20:A73-A82. [PMID: 35540941 PMCID: PMC9053433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/07/2021] [Accepted: 09/20/2021] [Indexed: 06/14/2023]
Abstract
Open-ended laboratory projects increase student success and retention in the sciences. However, developing organismal-based research projects is a challenge for students with restricted laboratory access, such as those attending courses remotely. Here I describe the use of image analysis of zebrafish neural development for authentic research projects in an introductory biology laboratory course. Zebrafish are a vertebrate model that produce large numbers of externally and rapidly developing embryos. Because zebrafish larvae are transparent, fluorescent reporters marking nervous system structures can be imaged over time and analyzed by undergraduate scientists. In the pilot of this project, remote first-year college students independently developed biological questions based on an image collection comparing zebrafish mutants and wild-type siblings. Students created and mastered techniques to analyze position, organization, and other morphological features of developing neurons and glia in the images to directly test their biological questions. At the end of the course, students communicated their project results in journal article format and oral presentations. Students were able to hone skills in organismal observation and data collection while studying remotely, and they reported excitement at applying lecture-based knowledge to their own independent questions. This module can be adapted by other instructors for both students on- and off-campus to teach principles of neural development, data collection, data analysis, and scientific communication.
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Affiliation(s)
- Sarah C Petersen
- Department of Neuroscience and Department of Biology, Kenyon College, Gambier, OH 43022
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6
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Neely SA, Lyons DA. Insights Into Central Nervous System Glial Cell Formation and Function From Zebrafish. Front Cell Dev Biol 2021; 9:754606. [PMID: 34912801 PMCID: PMC8666443 DOI: 10.3389/fcell.2021.754606] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/05/2021] [Indexed: 12/23/2022] Open
Abstract
The term glia describes a heterogenous collection of distinct cell types that make up a large proportion of our nervous system. Although once considered the glue of the nervous system, the study of glial cells has evolved significantly in recent years, with a large body of literature now highlighting their complex and diverse roles in development and throughout life. This progress is due, in part, to advances in animal models in which the molecular and cellular mechanisms of glial cell development and function as well as neuron-glial cell interactions can be directly studied in vivo in real time, in intact neural circuits. In this review we highlight the instrumental role that zebrafish have played as a vertebrate model system for the study of glial cells, and discuss how the experimental advantages of the zebrafish lend themselves to investigate glial cell interactions and diversity. We focus in particular on recent studies that have provided insight into the formation and function of the major glial cell types in the central nervous system in zebrafish.
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Affiliation(s)
- Sarah A. Neely
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - David A. Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
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7
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Small molecule screening as an approach to encounter inefficient myelin repair. Curr Opin Pharmacol 2021; 61:127-135. [PMID: 34753035 DOI: 10.1016/j.coph.2021.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/20/2022]
Abstract
While current multiple sclerosis therapies are focused on immunomodulation, thereby slowing down disease progression, scientific interest has nowadays been shifted toward regenerative therapies aiming at reversing already existing deficits. The application of chemical compounds was proven to be valuable for the understanding of oligodendrogenesis and for exposing mechanisms that can boost remyelination. However, sufficient myelin repair has not been achieved yet, thus underscoring the need for more studies toward this unmet clinical goal. In this regard, many research groups have significantly contributed to the field via developing compound screening approaches or using single substances. We, here, present an overview of recent studies addressing the identification of myelin repair drugs and provide insights into technical aspects and identified substances.
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8
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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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9
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Li M, Zhu Y, Tang L, Xu H, Zhong J, Peng W, Yuan Y, Gu X, Wang H. Protective effects and molecular mechanisms of Achyranthes bidentata polypeptide k on Schwann cells. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:381. [PMID: 33842602 PMCID: PMC8033397 DOI: 10.21037/atm-20-2900] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Background Achyranthes bidentata polypeptide k (ABPPk) is an active ingredient used in traditional Chinese medicine separated from Achyranthes bidentata polypeptides. So far, the role of ABPPk in peripheral nerve protection has not been comprehensively studied. Methods In this study, primary Schwann cells exposed to serum deprivation were treated with ABPPk or nerve growth factor (NGF) in vitro. Cell viability, cell apoptosis, apoptosis-related protein expression, and antioxidant enzyme activity were analyzed. To further explore the underlying molecular mechanisms and key regulatory molecules involved in the effects of ABPPk, integrative and dynamic bioinformatics analysis at different time points was carried out following RNA-seq of Schwann cells subjected to serum deprivation. Results We found that ABPPk could effectively reduce Schwann cell apoptosis caused by serum deprivation, which was comparable to NGF’s anti-apoptotic effects. ABPPk had the largest number of upregulated and downregulated differential expression genes at the earliest 0.5 h time, while NGF had fewer differential expression genes at this early stage. The significant difference at this time point between the two groups was also displayed in heatmaps. The molecular regulation of diseases and functions and canonical pathways revealed that ABPPk had more participation and advantages in the vasculature and immune system areas, especially angiogenesis regulation. Also, ABPPk demonstrated an earlier start in these molecular regulations than NGF. Furthermore, the analysis of transcription factors also illustrated that ABPPk not only had more key initial regulatory factors participating in vascular-related processes, but these also remained for a longer period. There was no significant difference in neural-related molecular regulation between the two groups. Conclusions Using high-throughput sequencing technology, our work unveiled the protective effects of ABPPk on Schwann cells after serum deprivation in a more comprehensive manner. These results further enrich the positive functions and molecular mechanisms of ABPPk and traditional Chinese medicine and benefit the discovery of novel therapeutic targets for peripheral nerve regeneration.
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Affiliation(s)
- Meiyuan Li
- Key Laboratory of Neuroregeneration of Jiangsu, Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Ye Zhu
- Key Laboratory of Neuroregeneration of Jiangsu, Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Leili Tang
- Key Laboratory of Neuroregeneration of Jiangsu, Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Hua Xu
- Department of Orthopedics, Affiliated Hospital of Nantong University, Nantong, China
| | | | - Wenqiang Peng
- Key Laboratory of Neuroregeneration of Jiangsu, Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Ying Yuan
- Key Laboratory of Neuroregeneration of Jiangsu, Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xiaosong Gu
- Key Laboratory of Neuroregeneration of Jiangsu, Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Hongkui Wang
- Key Laboratory of Neuroregeneration of Jiangsu, Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
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10
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Wang M, Kleele T, Xiao Y, Plucinska G, Avramopoulos P, Engelhardt S, Schwab MH, Kneussel M, Czopka T, Sherman DL, Brophy PJ, Misgeld T, Brill MS. Completion of neuronal remodeling prompts myelination along developing motor axon branches. J Cell Biol 2021; 220:211755. [PMID: 33538762 PMCID: PMC7868780 DOI: 10.1083/jcb.201911114] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 11/20/2020] [Accepted: 01/04/2021] [Indexed: 12/20/2022] Open
Abstract
Neuronal remodeling and myelination are two fundamental processes during neurodevelopment. How they influence each other remains largely unknown, even though their coordinated execution is critical for circuit function and often disrupted in neuropsychiatric disorders. It is unclear whether myelination stabilizes axon branches during remodeling or whether ongoing remodeling delays myelination. By modulating synaptic transmission, cytoskeletal dynamics, and axonal transport in mouse motor axons, we show that local axon remodeling delays myelination onset and node formation. Conversely, glial differentiation does not determine the outcome of axon remodeling. Delayed myelination is not due to a limited supply of structural components of the axon–glial unit but rather is triggered by increased transport of signaling factors that initiate myelination, such as neuregulin. Further, transport of promyelinating signals is regulated via local cytoskeletal maturation related to activity-dependent competition. Our study reveals an axon branch–specific fine-tuning mechanism that locally coordinates axon remodeling and myelination.
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Affiliation(s)
- Mengzhe Wang
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Tatjana Kleele
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Yan Xiao
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Gabriela Plucinska
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Petros Avramopoulos
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany.,German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Stefan Engelhardt
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany.,German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Markus H Schwab
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Matthias Kneussel
- University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology (ZMNH), Institute for Molecular Neurogenetics, Hamburg, Germany
| | - Tim Czopka
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Diane L Sherman
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Monika S Brill
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
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11
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Muppirala AN, Limbach LE, Bradford EF, Petersen SC. Schwann cell development: From neural crest to myelin sheath. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 10:e398. [PMID: 33145925 DOI: 10.1002/wdev.398] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/16/2022]
Abstract
Vertebrate nervous system function requires glial cells, including myelinating glia that insulate axons and provide trophic support that allows for efficient signal propagation by neurons. In vertebrate peripheral nervous systems, neural crest-derived glial cells known as Schwann cells (SCs) generate myelin by encompassing and iteratively wrapping membrane around single axon segments. SC gliogenesis and neurogenesis are intimately linked and governed by a complex molecular environment that shapes their developmental trajectory. Changes in this external milieu drive developing SCs through a series of distinct morphological and transcriptional stages from the neural crest to a variety of glial derivatives, including the myelinating sublineage. Cues originate from the extracellular matrix, adjacent axons, and the developing SC basal lamina to trigger intracellular signaling cascades and gene expression changes that specify stages and transitions in SC development. Here, we integrate the findings from in vitro neuron-glia co-culture experiments with in vivo studies investigating SC development, particularly in zebrafish and mouse, to highlight critical factors that specify SC fate. Ultimately, we connect classic biochemical and mutant studies with modern genetic and visualization tools that have elucidated the dynamics of SC development. This article is categorized under: Signaling Pathways > Cell Fate Signaling Nervous System Development > Vertebrates: Regional Development.
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Affiliation(s)
- Anoohya N Muppirala
- Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neuroscience, Kenyon College, Gambier, Ohio, USA
| | | | | | - Sarah C Petersen
- Department of Neuroscience, Kenyon College, Gambier, Ohio, USA.,Department of Biology, Kenyon College, Gambier, Ohio, USA
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12
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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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13
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Bradley EC, Cunningham RL, Wilde C, Morgan RK, Klug EA, Letcher SM, Schöneberg T, Monk KR, Liebscher I, Petersen SC. In vivo identification of small molecules mediating Gpr126/Adgrg6 signaling during Schwann cell development. Ann N Y Acad Sci 2019; 1456:44-63. [PMID: 31529518 DOI: 10.1111/nyas.14233] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/30/2019] [Accepted: 08/26/2019] [Indexed: 12/13/2022]
Abstract
Gpr126/Adgrg6, an adhesion family G protein-coupled receptor (aGPCR), is required for the development of myelinating Schwann cells in the peripheral nervous system. Myelin supports and insulates vertebrate axons to permit rapid signal propagation throughout the nervous system. In mammals and zebrafish, mutations in Gpr126 arrest Schwann cells at early developmental stages. We exploited the optical and pharmacological tractability of larval zebrafish to uncover drugs that mediate myelination by activating Gpr126 or functioning in parallel. Using a fluorescent marker of mature myelinating glia (Tg[mbp:EGFP-CAAX]), we screened hypomorphic gpr126 mutant larvae for restoration of myelin basic protein (mbp) expression along peripheral nerves following small molecule treatment. Our screens identified five compounds sufficient to promote mbp expression in gpr126 hypomorphs. Using an allelic series of gpr126 mutants, we parsed the ability of small molecules to restore mbp, suggesting differences in drug efficacy dependent on Schwann cell developmental state. Finally, we identify apomorphine hydrochloride as a direct small molecule activator of Gpr126 using combined in vivo/in vitro assays and show that aporphine class compounds promote Schwann cell development in vivo. Our results demonstrate the utility of in vivo screening for aGPCR modulators and identify small molecules that interact with the gpr126-mediated myelination program.
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Affiliation(s)
| | - Rebecca L Cunningham
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Caroline Wilde
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Rory K Morgan
- Vollum Institute, Oregon Health & Science University, Portland, Oregon
| | - Emma A Klug
- Department of Neuroscience, Kenyon College, Gambier, Ohio
| | | | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Kelly R Monk
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri.,Vollum Institute, Oregon Health & Science University, Portland, Oregon
| | - Ines Liebscher
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Sarah C Petersen
- Department of Neuroscience, Kenyon College, Gambier, Ohio.,Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
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14
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Zhu XY, Guo SY, Xia B, Li CQ, Wang L, Wang YH. Development of zebrafish demyelination model for evaluation of remyelination compounds and RORγt inhibitors. J Pharmacol Toxicol Methods 2019; 98:106585. [DOI: 10.1016/j.vascn.2019.106585] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 05/08/2019] [Accepted: 05/15/2019] [Indexed: 11/25/2022]
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15
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Won SY, Choi BO, Chung KW, Lee JE. Zebrafish is a central model to dissect the peripheral neuropathy. Genes Genomics 2019; 41:993-1000. [PMID: 31183681 DOI: 10.1007/s13258-019-00838-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 06/01/2019] [Indexed: 02/06/2023]
Abstract
The peripheral nervous system (PNS) is composed with all nerves extended from the brain and spinal cord, which are the central nervous system to other organs of the body. Dysfunctional peripheral motion resulting from the regressive neuronal axons in the defected PNS leads to several peripheral neuropathies including both inherited and non-inherited disorders. Because of poor understanding of cellular and molecular mechanisms involved in the peripheral neuropathy, there is currently non-targeted treatment of the disorder. Basic researches have paid attention to dissect roles of causative genes, identified from the inherited peripheral neuropathies, in PNS development. However, recent studies focusing on investigation of therapeutic targets have suggested that successful regeneration of the impaired peripheral nerves may be most effective treatment. The regeneration studies have been limited in the rodents system due to some of practical and physiological disadvantages until zebrafish model has emerged as an ideal system. Hence, this review aims to provide a comprehensive overview of the advantages of zebrafish as a model for the peripheral neuropathy researches and to suggest the disease genes-involved potential mechanisms targeting the PNS regeneration that may be demonstrated in zebrafish.
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Affiliation(s)
- So Yeon Won
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, South Korea
| | - Byung-Ok Choi
- Department of Neurology, Sungkyunkwan University School of Medicine, Seoul, 06351, South Korea
| | - Ki Wha Chung
- Department of Biological Sciences, Kongju National University, Kongju, 32588, South Korea
| | - Ji Eun Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, South Korea.
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, 06351, South Korea.
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16
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Bremer J, Marsden KC, Miller A, Granato M. The ubiquitin ligase PHR promotes directional regrowth of spinal zebrafish axons. Commun Biol 2019; 2:195. [PMID: 31149640 PMCID: PMC6531543 DOI: 10.1038/s42003-019-0434-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/16/2019] [Indexed: 01/05/2023] Open
Abstract
To reconnect with their synaptic targets, severed axons need to regrow robustly and directionally along the pre-lesional trajectory. While mechanisms directing axonal regrowth are poorly understood, several proteins direct developmental axon outgrowth, including the ubiquitin ligase PHR (Mycbp2). Invertebrate PHR also limits regrowth of injured axons, whereas its role in vertebrate axonal regrowth remains elusive. Here we took advantage of the high regrowth capacity of spinal zebrafish axons and observed robust and directional regrowth following laser transection of spinal Mauthner axons. We found that PHR directs regrowing axons along the pre-lesional trajectory and across the transection site. At the transection site, initial regrowth of wild-type axons was multidirectional. Over time, misdirected sprouts were corrected in a PHR-dependent manner. Ablation of cyfip2, known to promote F-actin-polymerization and pharmacological inhibition of JNK reduced misdirected regrowth of PHR-deficient axons, suggesting that PHR controls directional Mauthner axonal regrowth through cyfip2- and JNK-dependent pathways.
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Affiliation(s)
- Juliane Bremer
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA USA
| | - Kurt C. Marsden
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA USA
- Present Address: Department of Biological Sciences, North Carolina State University, Raleigh, 27607 NC USA
| | - Adam Miller
- Institute of Neuroscience, University of Oregon, Eugene, 97405 OR USA
| | - Michael Granato
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA USA
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17
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Preston MA, Finseth LT, Bourne JN, Macklin WB. A novel myelin protein zero transgenic zebrafish designed for rapid readout of in vivo myelination. Glia 2019; 67:650-667. [PMID: 30623975 PMCID: PMC6555554 DOI: 10.1002/glia.23559] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 10/11/2018] [Accepted: 10/16/2018] [Indexed: 12/14/2022]
Abstract
Demyelination occurs following many neurological insults, most notably in multiple sclerosis (MS). Therapeutics that promote remyelination could slow the neurological decline associated with chronic demyelination; however, in vivo testing of candidate small molecule drugs and signaling cascades known to impact myelination is expensive and labor intensive. Here, we describe the development of a novel zebrafish line which uses the putative promoter of Myelin Protein Zero (mpz), a major structural protein in myelin, to drive expression of Enhanced Green Fluorescent Protein (mEGFP) specifically in the processes and nascent internodes of myelinating glia. We observe that changes in fluorescence intensity in Tg(mpz:mEGFP) larvae are a reliable surrogate for changes in myelin membrane production per se in live larvae following bath application of drugs. These changes in fluorescence are strongly predictive of changes in myelin-specific mRNAs [mpz, 36K and myelin basic protein (mbp)] and protein production (Mbp). Finally, we observe that certain drugs alter nascent internode number and length, impacting the overall amount of myelin membrane synthesized and a number of axons myelinated without significantly changing the number of myelinating oligodendrocytes. These studies demonstrate that the Tg(mpz:mEGFP) reporter line responds effectively to positive and negative small molecule regulators of myelination, and could be useful for identifying candidate drugs that specifically target myelin membrane production in vivo. Combined with high throughput cell-based screening of large chemical libraries and automated imaging systems, this transgenic line is useful for rapid large scale whole animal screening to identify novel myelinating small molecule compounds in vivo.
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Affiliation(s)
- Marnie A Preston
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Lisbet T Finseth
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Jennifer N Bourne
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
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18
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Manipulating Neuronal Activity in the Developing Zebrafish Spinal Cord to Investigate Adaptive Myelination. Methods Mol Biol 2019; 1936:211-225. [PMID: 30820901 DOI: 10.1007/978-1-4939-9072-6_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In the central nervous system, oligodendrocyte-lineage cells and myelination can adapt to physiological brain activity. Since myelin can in turn regulate neuronal function, such "adaptive" myelination has been proposed as a form of nervous system plasticity, implicated in learning and cognition. The molecular and cellular mechanisms underlying adaptive myelination and its functional consequences remain to be fully defined, partly because it remains challenging to manipulate activity and monitor myelination over time in vivo at single-cell resolution, in a model that would also allow examination of the functional output of individual neurons and circuits. Here, we describe a workflow to manipulate neuronal activity and to assess oligodendrocyte-lineage cell dynamics and myelination in larval zebrafish, a vertebrate animal model that is ideal for live imaging and amenable to genetic discovery, and that has well-characterized neuronal circuits with myelinated axons.
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19
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Treichel AJ, Hines JH. Development of an Embryonic Zebrafish Oligodendrocyte-Neuron Mixed Coculture System. Zebrafish 2018; 15:586-596. [PMID: 30300571 DOI: 10.1089/zeb.2018.1625] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
During vertebrate neural development, oligodendrocytes insulate nerve axons with myelin sheaths. Zebrafish (Danio rerio) has emerged as a useful model organism for studying oligodendrocyte development. However, the absence of an in vitro culture system necessitates in vivo manipulations and analyses, which, in some instances, limits the questions that can be addressed. To fill this gap we developed a mixed coculture system for embryonic zebrafish neurons and oligodendrocyte-lineage cells. Cultures harvested from embryos ≥30 hours postfertilization (hpf) yielded oligodendrocyte progenitor cells (OPCs) positive for olig2 and sox10 transgenic reporters. Cultured OPCs exhibited dynamic, exploratory membrane processes, and cell morphologies resembled those established in vivo. Cells harvested from advanced stage embryos possessed more arborized processes than those from early stage embryos. Advanced stage (>60 hpf) embryo culture produced differentiated, mbp+ oligodendrocytes. Genetically tractable neuron subtypes extended neurites when harvested from embryos ≥19 hpf. Coculture produced juxtaposed oligodendrocytes and neurons, demonstrating the practical usefulness of this technique for future studies examining axon-oligodendrocyte interactions under defined conditions. We expect that zebrafish oligodendrocyte culture will complement existing in vivo strengths and may facilitate future studies elucidating the mechanisms of oligodendrocyte specification, proliferation, differentiation, motility, and axon-oligodendrocyte interactions that shape adult myelination patterns.
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Affiliation(s)
| | - Jacob H Hines
- Department of Biology, Winona State University , Winona, Minnesota
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20
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Campi G, Di Gioacchino M, Poccia N, Ricci A, Burghammer M, Ciasca G, Bianconi A. Nanoscale Correlated Disorder in Out-of-Equilibrium Myelin Ultrastructure. ACS NANO 2018; 12:729-739. [PMID: 29281257 DOI: 10.1021/acsnano.7b07897] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ultrastructural fluctuations at nanoscale are fundamental to assess properties and functionalities of advanced out-of-equilibrium materials. We have taken myelin as a model of supramolecular assembly in out-of-equilibrium living matter. Myelin sheath is a simple stable multilamellar structure of high relevance and impact in biomedicine. Although it is known that myelin has a quasi-crystalline ultrastructure, there is no information on its fluctuations at nanoscale in different states due to limitations of the available standard techniques. To overcome these limitations, we have used scanning micro X-ray diffraction, which is a unique non-invasive probe of both reciprocal and real space to visualize statistical fluctuations of myelin order of the sciatic nerve of Xenopus laevis. The results show that the ultrastructure period of the myelin is stabilized by large anticorrelated fluctuations at nanoscale, between hydrophobic and hydrophilic layers. The ratio between the total thickness of hydrophilic and hydrophobic layers defines the conformational parameter, which describes the different states of myelin. Our key result is that myelin in its out-of-equilibrium functional state fluctuates point-to-point between different conformations showing a correlated disorder described by a Levy distribution. As the system approaches the thermodynamic equilibrium in an aged state, the disorder loses its correlation degree and the structural fluctuation distribution changes to Gaussian. In a denatured state at low pH, it changes to a completely disordered stage. Our results aim to clarify the degradation mechanism in biological systems by associating these states with ultrastructural dynamic fluctuations at nanoscale.
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Affiliation(s)
- Gaetano Campi
- Institute of Crystallography, CNR , via Salaria, Km 29.300, 00015 Monterotondo Roma, Italy
| | - Michael Di Gioacchino
- Institute of Crystallography, CNR , via Salaria, Km 29.300, 00015 Monterotondo Roma, Italy
- Rome International Center for Materials Science Superstripes (RICMASS) , Via dei Sabelli 119A, 00185 Roma, Italy
- Department of Science, Nanoscience section, Roma Tre University , Via della Vasca Navale 84, 00146 Roma, Italy
| | - Nicola Poccia
- Department of Physics, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Alessandro Ricci
- Rome International Center for Materials Science Superstripes (RICMASS) , Via dei Sabelli 119A, 00185 Roma, Italy
| | - Manfred Burghammer
- European Synchrotron Radiation Facility , 6 Rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
| | - Gabriele Ciasca
- Physics Institute, Catholic University of Sacred Heart , Largo F. Vito 1, 00168 Rome, Italy
| | - Antonio Bianconi
- Institute of Crystallography, CNR , via Salaria, Km 29.300, 00015 Monterotondo Roma, Italy
- Rome International Center for Materials Science Superstripes (RICMASS) , Via dei Sabelli 119A, 00185 Roma, Italy
- National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) , Kashirskoe shosse 31, 115409 Moscow, Russia
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21
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Cunningham RL, Monk KR. Transmission Electron Microscopy for Zebrafish Larvae and Adult Lateral Line Nerve. Methods Mol Biol 2018; 1739:385-400. [PMID: 29546722 DOI: 10.1007/978-1-4939-7649-2_26] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Transmission electron microscopy (TEM) enables visualization of the ultrastructure of the myelin sheath. Schwann cells on the posterior lateral line nerves and motor nerves can be imaged by TEM. Here, we detail the multiday processing of larval trunks and dissected posterior lateral line for TEM, as well as how to trim embedded samples, section, and stain grids for imaging.
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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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