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Hakanen J, Parmentier N, Sommacal L, Garcia-Sanchez D, Aittaleb M, Vertommen D, Zhou L, Ruiz-Reig N, Tissir F. The Celsr3-Kif2a axis directs neuronal migration in the postnatal brain. Prog Neurobiol 2021; 208:102177. [PMID: 34582949 DOI: 10.1016/j.pneurobio.2021.102177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 08/12/2021] [Accepted: 09/20/2021] [Indexed: 12/27/2022]
Abstract
The tangential migration of immature neurons in the postnatal brain involves consecutive migration cycles and depends on constant remodeling of the cell cytoskeleton, particularly in the leading process (LP). Despite the identification of several proteins with permissive and empowering functions, the mechanisms that specify the direction of migration remain largely unknown. Here, we report that planar cell polarity protein Celsr3 orients neuroblasts migration from the subventricular zone (SVZ) to olfactory bulb (OB). In Celsr3-forebrain conditional knockout mice, neuroblasts loose directionality and few can reach the OB. Celsr3-deficient neuroblasts exhibit aberrant branching of LP, de novo LP formation, and decreased growth rate of microtubules (MT). Mechanistically, we show that Celsr3 interacts physically with Kif2a, a MT depolymerizing protein and that conditional inactivation of Kif2a in the forebrain recapitulates the Celsr3 knockout phenotype. Our findings provide evidence that Celsr3 and Kif2a cooperatively specify the directionality of neuroblasts tangential migration in the postnatal brain.
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Affiliation(s)
- Janne Hakanen
- Université catholique de Louvain, Institute of Neuroscience, Developmental Neurobiology, Brussels, Belgium
| | - Nicolas Parmentier
- Université catholique de Louvain, Institute of Neuroscience, Developmental Neurobiology, Brussels, Belgium
| | - Leonie Sommacal
- Université catholique de Louvain, Institute of Neuroscience, Developmental Neurobiology, Brussels, Belgium
| | - Dario Garcia-Sanchez
- Université catholique de Louvain, Institute of Neuroscience, Developmental Neurobiology, Brussels, Belgium
| | - Mohamed Aittaleb
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Didier Vertommen
- Université catholique de Louvain, de Duve Institute, Massprot Platform, Brussels, Belgium
| | - Libing Zhou
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, PR China
| | - Nuria Ruiz-Reig
- Université catholique de Louvain, Institute of Neuroscience, Developmental Neurobiology, Brussels, Belgium
| | - Fadel Tissir
- Université catholique de Louvain, Institute of Neuroscience, Developmental Neurobiology, Brussels, Belgium; College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
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2
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Regulation of Synaptic Development by Astrocyte Signaling Factors and Their Emerging Roles in Substance Abuse. Cells 2020; 9:cells9020297. [PMID: 31991879 PMCID: PMC7072591 DOI: 10.3390/cells9020297] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/20/2020] [Accepted: 01/20/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes have critical functions throughout the central nervous system (CNS) and have emerged as regulators of synaptic development and function. With their highly complex morphologies, they are able to interact with thousands of synapses via peripheral astrocytic processes (PAPs), ensheathing neuronal axons and dendrites to form the tripartite synapse. In this way, astrocytes engage in crosstalk with neurons to mediate a variety of CNS processes including the regulation of extracellular matrix protein signaling, formation and maintenance of the blood-brain barrier (BBB), axon growth and guidance, homeostasis of the synaptic microenvironment, synaptogenesis, and the promotion of synaptic diversity. In this review, we discuss several key astrocyte signaling factors (thrombospondins, netrins, apolipoproteins, neuregulins, bone morphogenetic proteins, and neuroligins) in the maintenance and regulation of synapse formation. We also explore how these astrocyte signaling factors are impacted by and contribute to substance abuse, particularly alcohol and cocaine use.
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Xu Z, Wang W, Ren Y, Zhang W, Fang P, Huang L, Wang X, Shi P. Regeneration of cortical tissue from brain injury by implantation of defined molecular gradient of semaphorin 3A. Biomaterials 2018; 157:125-135. [DOI: 10.1016/j.biomaterials.2017.12.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 12/04/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
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Kim M, Bjorke B, Mastick GS. Motor neuron migration and positioning mechanisms: New roles for guidance cues. Semin Cell Dev Biol 2017; 85:78-83. [PMID: 29141180 DOI: 10.1016/j.semcdb.2017.11.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/10/2017] [Indexed: 11/24/2022]
Abstract
Motor neurons differentiate from progenitor cells and cluster as motor nuclei, settling next to the floor plate in the brain stem and spinal cord. Although precise positioning of motor neurons is critical for their functional input and output, the molecular mechanisms that guide motor neurons to their proper positions remain poorly understood. Here, we review recent evidence of motor neuron positioning mechanisms, highlighting situations in which motor neuron cell bodies can migrate, and experiments that show that their migration is regulated by axon guidance cues. The view that emerges is that motor neurons are actively trapped or restricted in static positions, as the cells balance a push in the dorsal direction by repulsive Slit/Robo cues and a pull in the ventral direction by attractive Netrin-1/DCC cues. These new functions of guidance cues are necessary fine-tuning to set up patterns of motor neurons at their proper positions in the neural tube during embryogenesis.
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Affiliation(s)
- Minkyung Kim
- Department of Biology, University of Nevada, Reno, NV 89557, USA.
| | - Brielle Bjorke
- Neuroscience Program, Carleton College, Northfield, MN 55057, USA
| | - Grant S Mastick
- Department of Biology, University of Nevada, Reno, NV 89557, USA
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Hakanen J, Salminen M. Defects in neural guidepost structures and failure to remove leptomeningeal cells from the septal midline behind the interhemispheric fusion defects in Netrin1 deficient mice. Int J Dev Neurosci 2015; 47:206-15. [PMID: 26397040 DOI: 10.1016/j.ijdevneu.2015.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 08/19/2015] [Accepted: 08/19/2015] [Indexed: 11/18/2022] Open
Abstract
Corpus callosum (CC) is the largest commissural tract in mammalian brain and it acts to coordinate information between the two cerebral hemispheres. During brain development CC forms at the boundary area between the cortex and the septum and special transient neural and glial guidepost structures in this area are thought to be critical for CC formation. In addition, it is thought that the fusion of the two hemispheres in the septum area is a prerequisite for CC formation. However, very little is known of the molecular mechanisms behind the fusion of the two hemispheres. Netrin1 (NTN1) acts as an axon guidance molecule in the developing central nervous system and Ntn1 deficiency leads to the agenesis of CC in mouse. Here we have analyzed Ntn1 deficient mice to better understand the reasons behind the observed lack of CC. We show that Ntn1 deficiency leads to defects in neural, but not in glial guidepost structures that may contribute to the agenesis of CC. In addition, Nnt1 was expressed by the leptomeningeal cells bordering the two septal walls prior to fusion. Normally these cells are removed when the septal fusion occurs. At the same time, the Laminin containing basal lamina produced by the leptomeningeal cells is disrupted in the midline area to allow the cells to mix and the callosal axons to cross. In Ntn1 deficient embryos however, the leptomeninges and the basal lamina were not removed properly from the midline area and the septal fusion did not occur. Thus, NTN1 contributes to the formation of the CC by promoting the preceding removal of the midline leptomeningeal cells and interhemispheric fusion.
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Affiliation(s)
- Janne Hakanen
- Department of Veterinary Biosciences, University of Helsinki, Finland.
| | - Marjo Salminen
- Department of Veterinary Biosciences, University of Helsinki, Finland.
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Xu CJ, Wang JL, Jin WL. The Neural Stem Cell Microenvironment: Focusing on Axon Guidance Molecules and Myelin-Associated Factors. J Mol Neurosci 2015; 56:887-897. [PMID: 25757451 DOI: 10.1007/s12031-015-0538-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 02/27/2015] [Indexed: 12/20/2022]
Abstract
Neural stem cells (NSCs) could produce various cell phenotypes in the subventricular zone (SVZ) and dentate gyrus of the hippocampus in the central nervous system (CNS), where neurogenesis has been determined to occur. The extracellular microenvironment also influences the behaviors of NSCs during development and at CNS injury sites. Our previous study indicates that myelin, a component of the CNS, could regulate the differentiation of NSCs in vitro. Recent reports have implicated three myelin-derived inhibitors, NogoA, myelin-associated glycoprotein (MAG), and oligodendrocyte-myelin glycoprotein (OMgp), as well as several axon guidance molecules as regulators of NSC survival, proliferation, migration, and differentiation. However, the molecular mechanisms underlying the behavior of NSCs are not fully understood. In this study, we summarize the current literature on the effects of different extrinsic factors on NSCs and discuss possible mechanisms, as well as future possible clinical applications.
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Affiliation(s)
- Chao-Jin Xu
- Department of Histology and Embryology, Institute of Neuroscience, Wenzhou Medical University, University town, Cha Shan, Zhejiang, 325035, China.
| | - Jun-Ling Wang
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Wei-Lin Jin
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education, School of Electronic Information and Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China. .,School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, China.
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O'Leary CJ, Bradford D, Chen M, White A, Blackmore DG, Cooper HM. The Netrin/RGM Receptor, Neogenin, Controls Adult Neurogenesis by Promoting Neuroblast Migration and Cell Cycle Exit. Stem Cells 2015; 33:503-14. [DOI: 10.1002/stem.1861] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 07/31/2014] [Accepted: 09/06/2014] [Indexed: 01/16/2023]
Affiliation(s)
- Conor J. O'Leary
- The University of Queensland, Queensland Brain Institute; Brisbane Queensland Australia
| | - DanaKai Bradford
- The University of Queensland, Queensland Brain Institute; Brisbane Queensland Australia
| | - Min Chen
- The University of Queensland, Queensland Brain Institute; Brisbane Queensland Australia
| | - Amanda White
- The University of Queensland, Queensland Brain Institute; Brisbane Queensland Australia
| | - Daniel G. Blackmore
- The University of Queensland, Queensland Brain Institute; Brisbane Queensland Australia
| | - Helen M. Cooper
- The University of Queensland, Queensland Brain Institute; Brisbane Queensland Australia
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Cuccioli V, Bueno C, Belvindrah R, Lledo PM, Martinez S. Attractive action of FGF-signaling contributes to the postnatal developing hippocampus. Hippocampus 2014; 25:486-99. [DOI: 10.1002/hipo.22386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2014] [Indexed: 12/31/2022]
Affiliation(s)
- V. Cuccioli
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández (CSIC-UMH); Sant Joan d'Alacant 03550 Spain
| | - C. Bueno
- Faculty of Medicine; Department of Human Anatomy and Psychobiology; IMIB-Arrixaca and CIBERSAM (Centro Investigación Biomedica en Red Salud Mental), University of Murcia E-30071; Murcia Spain
| | - R. Belvindrah
- Laboratory for Perception and Memory; Institut Pasteur; F-75015 Paris France
- Centre National de la Recherche Scientifique (CNRS); Unité Mixte de Recherche 3571 F-75015 Paris France
| | - P.-M. Lledo
- Laboratory for Perception and Memory; Institut Pasteur; F-75015 Paris France
- Centre National de la Recherche Scientifique (CNRS); Unité Mixte de Recherche 3571 F-75015 Paris France
| | - S. Martinez
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández (CSIC-UMH); Sant Joan d'Alacant 03550 Spain
- Faculty of Medicine; Department of Human Anatomy and Psychobiology; IMIB-Arrixaca and CIBERSAM (Centro Investigación Biomedica en Red Salud Mental), University of Murcia E-30071; Murcia Spain
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Identification of a microRNA regulator for axon guidance in the olfactory bulb of adult mice. Gene 2014; 547:319-28. [PMID: 24992028 DOI: 10.1016/j.gene.2014.06.063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 01/09/2023]
Abstract
Semaphorin3A (sema3a), mainly localized in the olfactory neuron layer and periglomerular layer, is essential for the normal arrangement of axons in the olfactory bulb both in embryonic and adult mice functioning through its dynamic spatiotemporal expression. The regulators that can modulate the expression of sema3a by direct interaction, however, are unknown. In order to find the regulators of sema3a in the olfactory bulb, we focused on microRNAs, well-known post-transcriptional regulators. We found that axon guidance is the main molecular and biological process ongoing in the steady-state olfactory bulb of the adult mouse by screening the abundant microRNAs and exploring their functions in the olfactory bulb via our customized microRNA arrays, Gene Ontology and Kyoto Encyclopedia of Genes annotation. Furthermore, we traced the expression of three candidate regulators (miR-30c, miR-200b, and miR-429) and sema3a by the quantitative real-time polymerase chain reaction and immunohistochemistry. The results showed that only miR-30c expression corresponded inversely with sema3a. Finally, miR-30c was verified to be a specific regulator of sema3a by dual luciferase reporter assay in vitro. Taken together, our results suggested that miR-30c is a potential regulator in axon-guidance by suppressing the expression of sema3a, which will give new insights in elucidating the mechanism of architectonic and functional maintenance of the olfactory bulb.
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Winkle CC, McClain LM, Valtschanoff JG, Park CS, Maglione C, Gupton SL. A novel Netrin-1-sensitive mechanism promotes local SNARE-mediated exocytosis during axon branching. ACTA ACUST UNITED AC 2014; 205:217-32. [PMID: 24778312 PMCID: PMC4003241 DOI: 10.1083/jcb.201311003] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Localized plasma membrane expansion during axon branching mediated by Netrin-1 occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion. Developmental axon branching dramatically increases synaptic capacity and neuronal surface area. Netrin-1 promotes branching and synaptogenesis, but the mechanism by which Netrin-1 stimulates plasma membrane expansion is unknown. We demonstrate that SNARE-mediated exocytosis is a prerequisite for axon branching and identify the E3 ubiquitin ligase TRIM9 as a critical catalytic link between Netrin-1 and exocytic SNARE machinery in murine cortical neurons. TRIM9 ligase activity promotes SNARE-mediated vesicle fusion and axon branching in a Netrin-dependent manner. We identified a direct interaction between TRIM9 and the Netrin-1 receptor DCC as well as a Netrin-1–sensitive interaction between TRIM9 and the SNARE component SNAP25. The interaction with SNAP25 negatively regulates SNARE-mediated exocytosis and axon branching in the absence of Netrin-1. Deletion of TRIM9 elevated exocytosis in vitro and increased axon branching in vitro and in vivo. Our data provide a novel model for the spatial regulation of axon branching by Netrin-1, in which localized plasma membrane expansion occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion.
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Affiliation(s)
- Cortney C Winkle
- Neuroscience Center and Curriculum in Neurobiology, 2 Department of Cell Biology and Physiology, and 3 Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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Achim K, Salminen M, Partanen J. Mechanisms regulating GABAergic neuron development. Cell Mol Life Sci 2014; 71:1395-415. [PMID: 24196748 PMCID: PMC11113277 DOI: 10.1007/s00018-013-1501-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 10/10/2013] [Accepted: 10/14/2013] [Indexed: 12/17/2022]
Abstract
Neurons using gamma-aminobutyric acid (GABA) as their neurotransmitter are the main inhibitory neurons in the mature central nervous system (CNS) and show great variation in their form and function. GABAergic neurons are produced in all of the main domains of the CNS, where they develop from discrete regions of the neuroepithelium. Here, we review the gene expression and regulatory mechanisms controlling the main steps of GABAergic neuron development: early patterning of the proliferative neuroepithelium, production of postmitotic neural precursors, establishment of their identity and migration. By comparing the molecular regulation of these events across CNS, we broadly identify three regions utilizing distinct molecular toolkits for GABAergic fate determination: telencephalon-anterior diencephalon (DLX2 type), posterior diencephalon-midbrain (GATA2 type) and hindbrain-spinal cord (PTF1A and TAL1 types). Similarities and differences in the molecular regulatory mechanisms reveal the core determinants of a GABAergic neuron as well as provide insights into generation of the vast diversity of these neurons.
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Affiliation(s)
- Kaia Achim
- EMBL Heidelberg, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Marjo Salminen
- Department of Veterinary Biosciences, University of Helsinki, Agnes Sjobergin katu 2, PO Box 66, 00014 Helsinki, Finland
| | - Juha Partanen
- Department of Biosciences, University of Helsinki, Viikinkaari 5, PO Box 56, 00014 Helsinki, Finland
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Bhojwani D, Sabin ND, Pei D, Yang JJ, Khan RB, Panetta JC, Krull KR, Inaba H, Rubnitz JE, Metzger ML, Howard SC, Ribeiro RC, Cheng C, Reddick WE, Jeha S, Sandlund JT, Evans WE, Pui CH, Relling MV. Methotrexate-induced neurotoxicity and leukoencephalopathy in childhood acute lymphoblastic leukemia. J Clin Oncol 2014; 32:949-59. [PMID: 24550419 DOI: 10.1200/jco.2013.53.0808] [Citation(s) in RCA: 230] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Methotrexate (MTX) can cause significant clinical neurotoxicity and asymptomatic leukoencephalopathy. We sought to identify clinical, pharmacokinetic, and genetic risk factors for these MTX-related toxicities during childhood acute lymphoblastic leukemia (ALL) therapy and provide data on safety of intrathecal and high-dose MTX rechallenge in patients with neurotoxicity. PATIENTS AND METHODS Prospective brain magnetic resonance imaging was performed at four time points for 369 children with ALL treated in a contemporary study that included five courses of high-dose MTX and 13 to 25 doses of triple intrathecal therapy. Logistic regression modeling was used to evaluate clinical and pharmacokinetic factors, and a genome-wide association study (GWAS) was performed to identify germline polymorphisms for their association with neurotoxicities. RESULTS Fourteen patients (3.8%) developed MTX-related clinical neurotoxicity. Of 13 patients rechallenged with intrathecal and/or high-dose MTX, 12 did not experience recurrence of neurotoxicity. Leukoencephalopathy was found in 73 (20.6%) of 355 asymptomatic patients and in all symptomatic patients and persisted in 74% of asymptomatic and 58% of symptomatic patients at the end of therapy. A high 42-hour plasma MTX to leucovorin ratio (measure of MTX exposure) was associated with increased risk of leukoencephalopathy in multivariable analysis (P = .038). GWAS revealed polymorphisms in genes enriched for neurodevelopmental pathways with plausible mechanistic roles in neurotoxicity. CONCLUSION MTX-related clinical neurotoxicity is transient, and most patients can receive subsequent MTX without recurrence of acute or subacute symptoms. All symptomatic patients and one in five asymptomatic patients develop leukoencephalopathy that can persist until the end of therapy. Polymorphisms in genes related to neurogenesis may contribute to susceptibility to MTX-related neurotoxicity.
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Affiliation(s)
- Deepa Bhojwani
- All authors: St Jude Children's Research Hospital; and Deepa Bhojwani, Jun J. Yang, Hiroto Inaba, Jeffrey E. Rubnitz, Monika L. Metzger, Scott C. Howard, Raul C. Ribeiro, Sima Jeha, John T. Sandlund, and Ching-Hon Pui, University of Tennessee Health Sciences Center, College of Medicine, Memphis, TN
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Cayre M, Courtès S, Martineau F, Giordano M, Arnaud K, Zamaron A, Durbec P. Netrin 1 contributes to vascular remodeling in the subventricular zone and promotes progenitor emigration after demyelination. Development 2013; 140:3107-17. [PMID: 23824572 DOI: 10.1242/dev.092999] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Neural stem cells are maintained in the adult brain, sustaining structural and functional plasticity and to some extent participating in brain repair. A thorough understanding of the mechanisms and factors involved in endogenous stem/progenitor cell mobilization is a major challenge in the promotion of spontaneous brain repair. The main neural stem cell niche in the adult brain is the subventricular zone (SVZ). Following demyelination insults, SVZ-derived progenitors act in concert with oligodendrocyte precursors to repopulate the lesion and replace lost oligodendrocytes. Here, we showed robust vascular reactivity within the SVZ after focal demyelination of the corpus callosum in adult mice, together with a remarkable physical association between these vessels and neural progenitors exiting from their niche. Endogenous progenitor cell recruitment towards the lesion was significantly reduced by inhibiting post-lesional angiogenesis in the SVZ using anti-VEGF blocking antibody injections, suggesting a facilitating role of blood vessels for progenitor cell migration towards the lesion. We identified netrin 1 (NTN1) as a key factor upregulated within the SVZ after demyelination and involved in local angiogenesis and progenitor cell migration. Blocking NTN1 expression using a neutralizing antibody inhibited both lesion-induced vascular reactivity and progenitor cell recruitment at the lesion site. We propose a model in which SVZ progenitors respond to a demyelination lesion by NTN1 secretion that both directly promotes cell emigration and contributes to local angiogenesis, which in turn indirectly facilitates progenitor cell emigration from the niche.
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Affiliation(s)
- Myriam Cayre
- Aix-Marseille Université, IBDM-UMR7288, 13288 Marseille, France.
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Plexin-B2 regulates the proliferation and migration of neuroblasts in the postnatal and adult subventricular zone. J Neurosci 2013; 32:16892-905. [PMID: 23175841 DOI: 10.1523/jneurosci.0344-12.2012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In the postnatal forebrain, the subventricular zone (SVZ) contains a pool of undifferentiated cells, which proliferate and migrate along the rostral migratory stream (RMS) to the olfactory bulb and differentiate into granule cells and periglomerular cells. Plexin-B2 is a semaphorin receptor previously known to act on neuronal proliferation in the embryonic brain and neuronal migration in the cerebellum. We show here that, in the postnatal and adult CNS, Plexin-B2 is expressed in the subventricular zone lining the telencephalic ventricles and in the rostral migratory stream. We analyzed Plxnb2(-/-) mice and found that there is a marked reduction in the proliferation of SVZ cells in the mutant. Plexin-B2 expression is downregulated in the olfactory bulb as interneurons initiate radial migration. BrdU labeling and GFP electroporation into postnatal SVZ, in addition to time-lapse videomicroscopy, revealed that neuroblasts deficient for Plexin-B2 migrate faster than control ones and leave the RMS more rapidly. Overall, these results show that Plexin-B2 plays a role in postnatal neurogenesis and in the migration of SVZ-derived neuroblasts.
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Abstract
AbstractThe olfactory system represents a perfect model to study the interactions between the central and peripheral nervous systems in order to establish a neural circuit during early embryonic development. In addition, another important feature of this system is the capability to integrate new cells generated in two neurogenic zones: the olfactory epithelium in the periphery and the wall of the lateral ventricles in the CNS, both during development and adulthood. In all these processes the combination and sequence of specific molecular signals plays a critical role in the wiring of the olfactory axons, as well as the precise location of the incoming cell populations to the olfactory bulb. The purpose of this review is to summarize recent insights into the cellular and molecular events that dictate cell settling position and axonal trajectories from their origin in the olfactory placode to the formation of synapses in the olfactory bulb to ensure rapid and reliable transmission of olfactory information from the nose to the brain.
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