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Dumoulin A, Wilson NH, Tucker KL, Stoeckli ET. A cell-autonomous role for primary cilium-mediated signaling in long-range commissural axon guidance. Development 2024; 151:dev202788. [PMID: 39157903 PMCID: PMC11423920 DOI: 10.1242/dev.202788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 08/08/2024] [Indexed: 08/20/2024]
Abstract
Ciliopathies are characterized by the absence or dysfunction of primary cilia. Despite the fact that cognitive impairments are a common feature of ciliopathies, how cilia dysfunction affects neuronal development has not been characterized in detail. Here, we show that primary cilium-mediated signaling is required cell-autonomously by neurons during neural circuit formation. In particular, a functional primary cilium is crucial during axonal pathfinding for the switch in responsiveness of axons at a choice point or intermediate target. Using different animal models and in vivo, ex vivo and in vitro experiments, we provide evidence for a crucial role of primary cilium-mediated signaling in long-range axon guidance. The primary cilium on the cell body of commissural neurons transduces long-range guidance signals sensed by growth cones navigating an intermediate target. In extension of our finding that Shh is required for the rostral turn of post-crossing commissural axons, we suggest a model implicating the primary cilium in Shh signaling upstream of a transcriptional change of axon guidance receptors, which in turn mediate the repulsive response to floorplate-derived Shh shown by post-crossing commissural axons.
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Affiliation(s)
- Alexandre Dumoulin
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Nicole H Wilson
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Kerry L Tucker
- University of New England, College of Osteopathic Medicine, Department of Biomedical Sciences, Center for Excellence in the Neurosciences, Biddeford, ME 04005, USA
| | - Esther T Stoeckli
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- University Research Priority Program 'Adaptive Brain Circuits in Development and Learning' (URPP AdaBD), University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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2
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Hu L, Liu XY, Zhao L, Hu ZB, Li ZX, Liu WT, Song NN, Hu YQ, Jiang LP, Zhang L, Tao YC, Zhang Q, Chen JY, Lang B, Wang YB, Yue L, Ding YQ. Ventricular Netrin-1 deficiency leads to defective pyramidal decussation and mirror movement in mice. Cell Death Dis 2024; 15:343. [PMID: 38760361 PMCID: PMC11101614 DOI: 10.1038/s41419-024-06719-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 04/27/2024] [Accepted: 05/03/2024] [Indexed: 05/19/2024]
Abstract
The corticospinal tract (CST) is the principal neural pathway responsible for conducting voluntary movement in the vertebrate nervous system. Netrin-1 is a well-known guidance molecule for midline crossing of commissural axons during embryonic development. Families with inherited Netrin-1 mutations display congenital mirror movements (CMM), which are associated with malformations of pyramidal decussation in most cases. Here, we investigated the role of Netrin-1 in CST formation by generating conditional knockout (CKO) mice using a Gfap-driven Cre line. A large proportion of CST axons spread laterally in the ventral medulla oblongata, failed to decussate and descended in the ipsilateral spinal white matter of Ntn1Gfap CKO mice. Netrin-1 mRNA was expressed in the ventral ventricular zone (VZ) and midline, while Netrin-1 protein was transported by radial glial cells to the ventral medulla, through which CST axons pass. The level of transported Netrin-1 protein was significantly reduced in Ntn1Gfap CKO mice. In addition, Ntn1Gfap CKO mice displayed increased symmetric movements. Our findings indicate that VZ-derived Netrin-1 deletion leads to an abnormal trajectory of the CST in the spinal cord due to the failure of CST midline crossing and provides novel evidence supporting the idea that the Netrin-1 signalling pathway is involved in the pathogenesis of CMM.
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Affiliation(s)
- Ling Hu
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China.
| | - Xi-Yue Liu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Li Zhao
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China
| | - Zhi-Bin Hu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Ze-Xuan Li
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China
| | - Wei-Tang Liu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Ning-Ning Song
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China
| | - Yun-Qing Hu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Luo-Peng Jiang
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China
| | - Lei Zhang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Yun-Chao Tao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Qiong Zhang
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China
| | - Jia-Yin Chen
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China
| | - Bing Lang
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, 410083, China
| | - Yu-Bing Wang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Lei Yue
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, and Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai, 200092, China
| | - Yu-Qiang Ding
- Department of Laboratory Animal Science, Fudan University, Shanghai, 200032, China.
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
- Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai, 200032, China.
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3
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Sullivan KG, Bashaw GJ. Commissureless acts as a substrate adapter in a conserved Nedd4 E3 ubiquitin ligase pathway to promote axon growth across the midline. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.13.562283. [PMID: 37905056 PMCID: PMC10614773 DOI: 10.1101/2023.10.13.562283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
In both vertebrates and invertebrates, commissural neurons prevent premature responsiveness to the midline repellant Slit by downregulating surface levels of its receptor Roundabout1 (Robo1). In Drosophila, Commissureless (Comm) plays a critical role in this process; however, there is conflicting data on the underlying molecular mechanism. Here, we demonstrate that the conserved PY motifs in the cytoplasmic domain of Comm are required allow the ubiquitination and lysosomal degradation of Robo1. Disruption of these motifs prevents Comm from localizing to Lamp1 positive late endosomes and to promote axon growth across the midline in vivo. In addition, we conclusively demonstrate a role for Nedd4 in midline crossing. Genetic analysis shows that nedd4 mutations result in midline crossing defects in the Drosophila embryonic nerve cord, which can be rescued by introduction of exogenous Nedd4. Biochemical evidence shows that Nedd4 incorporates into a three-member complex with Comm and Robo in a PY motif-dependent manner. Finally, we present genetic evidence that Nedd4 acts with Comm in the embryonic nerve cord to downregulate Robo1 levels. Taken together, these findings demonstrate that Comm promotes midline crossing in the nerve cord by facilitating Robo ubiquitination by Nedd4, ultimately leading to its degradation.
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Affiliation(s)
- Kelly G. Sullivan
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd., Philadelphia, PA, 19104, USA
| | - Greg J. Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd., Philadelphia, PA, 19104, USA
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Sullivan KG, Bashaw GJ. Intracellular Trafficking Mechanisms that Regulate Repulsive Axon Guidance. Neuroscience 2023; 508:123-136. [PMID: 35863679 PMCID: PMC9839465 DOI: 10.1016/j.neuroscience.2022.07.012] [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: 03/31/2022] [Revised: 07/01/2022] [Accepted: 07/13/2022] [Indexed: 01/17/2023]
Abstract
Friedrich Bonhoeffer made seminal contributions to the study of axon guidance in the developing nervous system. His discoveries of key cellular and molecular mechanisms that dictate wiring specificity laid the foundation for countless investigators who have followed in his footsteps. Perhaps his most significant contribution was the cloning and characterization of members of the conserved ephrin family of repulsive axon guidance cues. In this review, we highlight the major contributions that Bonhoeffer and his colleagues made to the field of axon guidance, and discuss ongoing investigations into the diverse array of mechanisms that ensure that axon repulsion is precisely regulated to allow for accurate pathfinding. Specifically, we focus our discussion on the post-translational regulation of two major families of repulsive axon guidance factors: ephrin ligands and their Eph receptors, and slit ligands and their Roundabout (Robo) receptors. We will give special emphasis to the ways in which regulated endocytic trafficking events allow navigating axons to adjust their responses to repellant signals and how these trafficking events are intimately related to receptor signaling. By highlighting parallels and differences between the regulation of these two important repulsive axon guidance pathways, we hope to identify key outstanding questions for future investigation.
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Affiliation(s)
- Kelly G Sullivan
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, United States
| | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, United States.
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Ding Z, Zhang J, Hu Y, Li N, Yu S, Zheng L, Lin L. Effects of PI3K/AKT/mTOR pathway regulation of HIF-1α on Lanthanum-induced neurotoxicity in rats. Brain Res 2021; 1761:147400. [PMID: 33705787 DOI: 10.1016/j.brainres.2021.147400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/30/2021] [Accepted: 02/27/2021] [Indexed: 10/22/2022]
Abstract
This study examined the effects of the AKT/mTOR/HIF-1α signaling pathway on learning and memory in offspring rats induced by lanthanum from neuroethology and molecular biology perspectives. 32 pregnant adult Wistar rats were divided into four groups randomly: control group (NC), 0.25%, 0.5% and 1.0% LaCl3 groups (n = 8). All rats were poisoned through free drinking from day 0 of pregnancy to postnatal day 21 (suckling period). All offspring rats were poisoned through free drinking from delactation to postnatal day 48. Offspring rats aged 49-days-old were used as sampling objects to construct an LaCl3 poisoning model of offspring rats. Changes in hippocampal neurons, apoptosis of hippocampal neurons, learning and memory abilities of LaCl3-poisoned animals were measured by Nissl staining, TUNEL method and the shuttle box test, respectively. Expressions of PI3K, AKT, and mTOR, HIF-1α, and VEGF in the hippocampus were tested by qPCR and Western blot. Distributions of PI3K and p-AKT in hippocampal neurons were observed through the immunohistochemical method. With increasing LaCl3 dose, lightning strike time and active avoidance incubation period of offspring rats in the different LaCl3 groups were significantly prolonged. The Nissl body positive neurons of hippocampal neurons gradually declined while apoptosis in cells increased. The expressions of both mRNA (PI3K, AKT, mTOR, HIF-1α, VEGF) and proteins (PI3K, p-AKT, p-mTOR, HIF-1α, VEGF) in the hippocampus of the LaCl3 groups were significantly lower than those of NC group (p < 0.05). LaCl3 poisoning can induce developmental injuries in hippocampal neurons and can increase cell apoptosis. As a result, learning and memory abilities of offspring rats, as well as the expressions of PI3K/AKT/mTOR, are decreased, thus inhibiting activation of HIF-1α and influencing the expression of the downstream VEGF gene.
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Affiliation(s)
- Zhe Ding
- Institute of Molecular Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China; Department of Nursing, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China.
| | - Jinhui Zhang
- Institute of Molecular Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China; Department of Nursing, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China.
| | - Yuqian Hu
- Institute of Molecular Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China; Department of Clinical Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China.
| | - Nan Li
- Institute of Molecular Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China; Department of Nursing, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China.
| | - Shengjin Yu
- Institute of Molecular Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China; Department of Basic Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China.
| | - Linlin Zheng
- Institute of Molecular Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China; Department of Nursing, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China.
| | - Lijuan Lin
- Institute of Molecular Medicine, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China; Department of Nursing, School of Medicine, Eastern Liaoning University, Dandong 118003, Liaoning, People's Republic of China.
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6
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Belin S, Nawabi H. CNS Disease and Regeneration: When Growing Is Not Enough. SYSTEMS MEDICINE 2021. [DOI: 10.1016/b978-0-12-801238-3.11529-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Ducuing H, Gardette T, Pignata A, Kindbeiter K, Bozon M, Thoumine O, Delloye-Bourgeois C, Tauszig-Delamasure S, Castellani V. SlitC-PlexinA1 mediates iterative inhibition for orderly passage of spinal commissural axons through the floor plate. eLife 2020; 9:e63205. [PMID: 33345773 PMCID: PMC7775108 DOI: 10.7554/elife.63205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/18/2020] [Indexed: 12/12/2022] Open
Abstract
Spinal commissural axon navigation across the midline in the floor plate requires repulsive forces from local Slit repellents. The long-held view is that Slits push growth cones forward and prevent them from turning back once they became sensitized to these cues after midline crossing. We analyzed with fluorescent reporters Slits distribution and FP glia morphology. We observed clusters of Slit-N and Slit-C fragments decorating a complex architecture of glial basal process ramifications. We found that PC2 proprotein convertase activity contributes to this pattern of ligands. Next, we studied Slit-C acting via PlexinA1 receptor shared with another FP repellent, the Semaphorin3B, through generation of a mouse model baring PlexinA1Y1815F mutation abrogating SlitC but not Sema3B responsiveness, manipulations in the chicken embryo, and ex vivo live imaging. This revealed a guidance mechanism by which SlitC constantly limits growth cone exploration, imposing ordered and forward-directed progression through aligned corridors formed by FP basal ramifications.
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Affiliation(s)
- Hugo Ducuing
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
| | - Thibault Gardette
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
| | - Aurora Pignata
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
| | - Karine Kindbeiter
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
| | - Muriel Bozon
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
| | - Olivier Thoumine
- Interdisciplinary Institute for Neuroscience, UMR CNRS 5297 - University of BordeauxBordeauxFrance
| | - Céline Delloye-Bourgeois
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
| | - Servane Tauszig-Delamasure
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
| | - Valerie Castellani
- Institut NeuroMyoGène - CNRS UMR 5310 - INSERM U1217 de Lyon- UCBL Lyon 1, Faculté de Médecine et de PharmacieLyonFrance
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Pasterkamp RJ, Burk K. Axon guidance receptors: Endocytosis, trafficking and downstream signaling from endosomes. Prog Neurobiol 2020; 198:101916. [PMID: 32991957 DOI: 10.1016/j.pneurobio.2020.101916] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/06/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023]
Abstract
During the development of the nervous system, axons extend through complex environments. Growth cones at the axon tip allow axons to find and innervate their appropriate targets and form functional synapses. Axon pathfinding requires axons to respond to guidance signals and these cues need to be detected by specialized receptors followed by intracellular signal integration and translation. Several downstream signaling pathways have been identified for axon guidance receptors and it has become evident that these pathways are often initiated from intracellular vesicles called endosomes. Endosomes allow receptors to traffic intracellularly, re-locating receptors from one cellular region to another. The localization of axon guidance receptors to endosomal compartments is crucial for their function, signaling output and expression levels. For example, active receptors within endosomes can recruit downstream proteins to the endosomal membrane and facilitate signaling. Also, endosomal trafficking can re-locate receptors back to the plasma membrane to allow re-activation or mediate downregulation of receptor signaling via degradation. Accumulating evidence suggests that axon guidance receptors do not follow a pre-set default trafficking route but may change their localization within endosomes. This re-routing appears to be spatially and temporally regulated, either by expression of adaptor proteins or co-receptors. These findings shed light on how signaling in axon guidance is regulated and diversified - a mechanism which explains how a limited set of guidance cues can help to establish billions of neuronal connections. In this review, we summarize and discuss our current knowledge of axon guidance receptor trafficking and provide directions for future research.
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Affiliation(s)
- R J Pasterkamp
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, 3584 CG Utrecht, the Netherlands.
| | - K Burk
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; Center for Biostructural Imaging of Neurodegeneration, 37075 Göttingen, Germany.
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Kaneyama T, Shirasaki R. Post-crossing segment of dI1 commissural axons forms collateral branches to motor neurons in the developing spinal cord. J Comp Neurol 2019; 526:1943-1961. [PMID: 29752714 DOI: 10.1002/cne.24464] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/30/2018] [Accepted: 05/03/2018] [Indexed: 11/09/2022]
Abstract
The dI1 commissural axons in the developing spinal cord, upon crossing the midline through the floor plate, make a sharp turn to grow rostrally. These post-crossing axons initially just extend adjacent to the floor plate without entering nearby motor columns. However, it remains poorly characterized how these post-crossing dI1 axons behave subsequently to this process. In the present study, to address this issue, we examined in detail the behavior of post-crossing dI1 axons in mice, using the Atoh1 enhancer-based conditional expression system that enables selective and sparse labeling of individual dI1 axons, together with Hb9 and ChAT immunohistochemistry for precise identification of spinal motor neurons (MNs). We found unexpectedly that the post-crossing segment of dI1 axons later gave off collateral branches that extended laterally to invade motor columns. Interestingly, these collateral branches emerged at around the time when their primary growth cones initiated invasion into motor columns. In addition, although the length of the laterally growing collateral branches increased with age, the majority of them remained within motor columns. Strikingly, these collateral branches further gave rise to multiple secondary branches in the region of MNs that innervate muscles close to the body axis. Moreover, these axonal branches formed presynaptic terminals on MNs. These observations demonstrate that dI1 commissural neurons develop axonal projection to spinal MNs via collateral branches arising later from the post-crossing segment of these axons. Our findings thus reveal a previously unrecognized projection of dI1 commissural axons that may contribute directly to generating proper motor output.
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Affiliation(s)
- Takeshi Kaneyama
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Ryuichi Shirasaki
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
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Zhuang M, Li X, Zhu J, Zhang J, Niu F, Liang F, Chen M, Li D, Han P, Ji SJ. The m6A reader YTHDF1 regulates axon guidance through translational control of Robo3.1 expression. Nucleic Acids Res 2019; 47:4765-4777. [PMID: 30843071 PMCID: PMC6511866 DOI: 10.1093/nar/gkz157] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 02/25/2019] [Accepted: 02/27/2019] [Indexed: 12/02/2022] Open
Abstract
N 6-Methyladenosine (m6A) is a dynamic mRNA modification which regulates protein expression in various posttranscriptional levels. Functional studies of m6A in nervous system have focused on its writers and erasers so far, whether and how m6A readers mediate m6A functions through recognizing and binding their target mRNA remains poorly understood. Here, we find that the expression of axon guidance receptor Robo3.1 which plays important roles in midline crossing of spinal commissural axons is regulated precisely at translational level. The m6A reader YTHDF1 binds to and positively regulates translation of m6A-modified Robo3.1 mRNA. Either mutation of m6A sites in Robo3.1 mRNA or YTHDF1 knockdown or knockout leads to dramatic reduction of Robo3.1 protein without affecting Robo3.1 mRNA level. Specific ablation of Ythdf1 in spinal commissural neurons results in pre-crossing axon guidance defects. Our findings identify a mechanism that YTHDF1-mediated translation of m6A-modified Robo3.1 mRNA controls pre-crossing axon guidance in spinal cord.
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Affiliation(s)
- Mengru Zhuang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- SUSTech-HKUST Joint PhD Program, Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xinbei Li
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Junda Zhu
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Jian Zhang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Fugui Niu
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- SUSTech-HIT Joint Graduate Program, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Fanghao Liang
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- SUSTech-HIT Joint Graduate Program, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Mengxian Chen
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Duo Li
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Peng Han
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Sheng-Jian Ji
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Institute of Neuroscience, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
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11
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Martin-Lopez E, Meller SJ, Greer CA. Development of piriform cortex interhemispheric connections via the anterior commissure: progressive and regressive strategies. Brain Struct Funct 2018; 223:4067-4085. [PMID: 30141078 DOI: 10.1007/s00429-018-1741-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/21/2018] [Indexed: 12/27/2022]
Abstract
The anterior commissure (AC) is a phylogenetically conserved inter-hemispheric connection found among vertebrates with bilateral symmetry. The AC connects predominantly olfactory areas but many aspects of its development and structure are unknown. To fill this gap, we investigated the embryonic and postnatal development of the AC by tracing axons with DiI and the piggyback transposon multicolor system. With this strategy, we show that axon growth during establishment of the AC follows a strictly regulated timeline of events that include waiting periods ("regressive strategies") as well as periods of active axon outgrowth ("progressive strategies"). We also provide evidence that these processes may be regulated in the midline via overexpression of chondroitin sulfate proteoglycans. Additionally, we demonstrate that the ipsi- and contralateral innervation of piriform cortex occurs simultaneously. Morphologically, we found that 20% of axons were myelinated by postnatal day (P) 22, in a process that occurred fundamentally around P14. By immunohistochemistry, we described the presence of glial cells and two new subtypes of neurons: one expressing a calretinin (CR)-/MAP2+ phenotype, distributed homogeneously inside the AC; and the other expressing a CR+/MAP2+ phenotype that lies beneath the bed nucleus of the stria terminalis. Our results are consistent with the notion that the AC follows a strictly regulated program during the embryonic and postnatal development similarly to other distal targeting axonal tracts.
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Affiliation(s)
- Eduardo Martin-Lopez
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.,Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Sarah J Meller
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.,Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Charles A Greer
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA. .,Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA. .,The Interdepartmental Neuroscience Graduate Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.
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12
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Bonneaud N, Layalle S, Colomb S, Jourdan C, Ghysen A, Severac D, Dantec C, Nègre N, Maschat F. Control of nerve cord formation by Engrailed and Gooseberry-Neuro: A multi-step, coordinated process. Dev Biol 2017; 432:273-285. [PMID: 29097190 DOI: 10.1016/j.ydbio.2017.10.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 10/06/2017] [Accepted: 10/24/2017] [Indexed: 01/05/2023]
Abstract
One way to better understand the molecular mechanisms involved in the construction of a nervous system is to identify the downstream effectors of major regulatory proteins. We previously showed that Engrailed (EN) and Gooseberry-Neuro (GsbN) transcription factors act in partnership to drive the formation of posterior commissures in the central nervous system of Drosophila. In this report, we identified genes regulated by both EN and GsbN through chromatin immunoprecipitation ("ChIP on chip") and transcriptome experiments, combined to a genetic screen relied to the gene dose titration method. The genomic-scale approaches allowed us to define 175 potential targets of EN-GsbN regulation. We chose a subset of these genes to examine ventral nerve cord (VNC) defects and found that half of the mutated targets show clear VNC phenotypes when doubly heterozygous with en or gsbn mutations, or when homozygous. This strategy revealed new groups of genes never described for their implication in the construction of the nerve cord. Their identification suggests that, to construct the nerve cord, EN-GsbN may act at three levels, in: (i) sequential control of the attractive-repulsive signaling that ensures contralateral projection of the commissural axons, (ii) temporal control of the translation of some mRNAs, (iii) regulation of the capability of glial cells to act as commissural guideposts for developing axons. These results illustrate how an early, coordinated transcriptional control may orchestrate the various mechanisms involved in the formation of stereotyped neuronal networks. They also validate the overall strategy to identify genes that play crucial role in axonal pathfinding.
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Affiliation(s)
- Nathalie Bonneaud
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France; CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France
| | - Sophie Layalle
- CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France; CNRS - INSERM - Université de Montpellier, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34094, France
| | - Sophie Colomb
- CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France
| | - Christophe Jourdan
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France
| | - Alain Ghysen
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France
| | - Dany Severac
- MGX - Montpellier GenomiX, Institut de Génomique Fonctionnelle, Montpellier F-34094, France
| | - Christelle Dantec
- MGX - Montpellier GenomiX, Institut de Génomique Fonctionnelle, Montpellier F-34094, France
| | - Nicolas Nègre
- DGIMI, INRA, Université de Montpellier, 34095 Montpellier, France; Institut Universitaire de France (IUF), Paris, France
| | - Florence Maschat
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France; CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France.
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Tsytsarev V, Arakawa H, Zhao S, Chédotal A, Erzurumlu RS. Behavioral Consequences of a Bifacial Map in the Mouse Somatosensory Cortex. J Neurosci 2017; 37:7209-7218. [PMID: 28663199 PMCID: PMC5546400 DOI: 10.1523/jneurosci.0598-17.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/14/2017] [Accepted: 06/19/2017] [Indexed: 02/04/2023] Open
Abstract
The whisker system is an important sensory organ with extensive neural representations in the brain of the mouse. Patterned neural modules (barrelettes) in the ipsilateral principal sensory nucleus of the trigeminal nerve (PrV) correspond to the whiskers. Axons of the PrV barrelette neurons cross the midline and confer the whisker-related patterning to the contralateral ventroposteromedial nucleus of the thalamus, and subsequently to the cortex. In this way, specific neural modules called barreloids and barrels in the contralateral thalamus and cortex represent each whisker. Partial midline crossing of the PrV axons, in a conditional Robo3 mutant (Robo3R3-5cKO) mouse line, leads to the formation of bilateral whisker maps in the ventroposteromedial, as well as the barrel cortex. We used voltage-sensitive dye optical imaging and somatosensory and motor behavioral tests to characterize the consequences of bifacial maps in the thalamocortical system. Voltage-sensitive dye optical imaging verified functional, bilateral whisker representation in the barrel cortex and activation of distinct cortical loci following ipsilateral and contralateral stimulation of the specific whiskers. The mutant animals were comparable with the control animals in sensorimotor tests. However, they showed noticeable deficits in all of the whisker-dependent or -related tests, including Y-maze exploration, horizontal surface approach, bridge crossing, gap crossing, texture discrimination, floating in water, and whisking laterality. Our results indicate that bifacial maps along the thalamocortical system do not offer a functional advantage. Instead, they lead to impairments, possibly due to the smaller size of the whisker-related modules and interference between the ipsilateral and contralateral whisker representations in the same thalamus and cortex.SIGNIFICANCE STATEMENT The whisker sensory system plays a quintessentially important role in exploratory behavior of mice and other nocturnal rodents. Here, we studied a novel mutant mouse line, in which the projections from the brainstem to the thalamus are disrupted. This led to formation of bilateral whisker maps in both the thalamus and the cortex. The two whisker maps crowd in a space normally devoted to the contralateral map alone and in a nonoverlapping fashion. Stimulation of the whiskers on either side activates the corresponding region of the map. Mice with bilateral whisker maps perform well in general sensorimotor tasks but show poor performance in specific tests that require whisker-dependent tactile discrimination. These observations indicate that contralateral, instead of bilateral, representation of the sensory space plays a critical role in acuity and fine discrimination during somesthesis.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Hiroyuki Arakawa
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Shuxin Zhao
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Alain Chédotal
- Centre de Recherche Institut de la Vision, Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S968, 75012 Paris, France
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
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14
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Welniarz Q, Morel MP, Pourchet O, Gallea C, Lamy JC, Cincotta M, Doulazmi M, Belle M, Méneret A, Trouillard O, Ruiz M, Brochard V, Meunier S, Trembleau A, Vidailhet M, Chédotal A, Dusart I, Roze E. Non cell-autonomous role of DCC in the guidance of the corticospinal tract at the midline. Sci Rep 2017; 7:410. [PMID: 28341853 PMCID: PMC5428661 DOI: 10.1038/s41598-017-00514-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 02/28/2017] [Indexed: 11/13/2022] Open
Abstract
DCC, a NETRIN-1 receptor, is considered as a cell-autonomous regulator for midline guidance of many commissural populations in the central nervous system. The corticospinal tract (CST), the principal motor pathway for voluntary movements, crosses the anatomic midline at the pyramidal decussation. CST fails to cross the midline in Kanga mice expressing a truncated DCC protein. Humans with heterozygous DCC mutations have congenital mirror movements (CMM). As CMM has been associated, in some cases, with malformations of the pyramidal decussation, DCC might also be involved in this process in human. Here, we investigated the role of DCC in CST midline crossing both in human and mice. First, we demonstrate by multimodal approaches, that patients with CMM due to DCC mutations have an increased proportion of ipsilateral CST projections. Second, we show that in contrast to Kanga mice, the anatomy of the CST is not altered in mice with a deletion of DCC in the CST. Altogether, these results indicate that DCC controls CST midline crossing in both humans and mice, and that this process is non cell-autonomous in mice. Our data unravel a new level of complexity in the role of DCC in CST guidance at the midline.
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Affiliation(s)
- Quentin Welniarz
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de Biologie Paris Seine, Neuroscience Paris Seine, F-75005, Paris, France
| | - Marie-Pierre Morel
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de Biologie Paris Seine, Neuroscience Paris Seine, F-75005, Paris, France
| | - Oriane Pourchet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de Biologie Paris Seine, Neuroscience Paris Seine, F-75005, Paris, France
| | - Cécile Gallea
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France
| | - Jean-Charles Lamy
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France
| | - Massimo Cincotta
- Unità Operativa di Neurologia-Firenze, Azienda USL Toscana Centro, Ospedale San Giovanni di Dio, 50143, Firenze, Italy
| | - Mohamed Doulazmi
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de Biologie Paris Seine, Adaptation Biologique et vieillissement, F-75005, Paris, France
| | - Morgane Belle
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Aurélie Méneret
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France.,Département de Neurologie, AP-HP, Hôpital Pitié Salpêtrière, Paris, France
| | - Oriane Trouillard
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France
| | - Marta Ruiz
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France
| | - Vanessa Brochard
- Centre d'Investigation Clinique 14-22, INSERM/AP-HP, Paris, France
| | - Sabine Meunier
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France
| | - Alain Trembleau
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de Biologie Paris Seine, Neuroscience Paris Seine, F-75005, Paris, France
| | - Marie Vidailhet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France.,Département de Neurologie, AP-HP, Hôpital Pitié Salpêtrière, Paris, France
| | - Alain Chédotal
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, F-75012, Paris, France
| | - Isabelle Dusart
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de Biologie Paris Seine, Neuroscience Paris Seine, F-75005, Paris, France
| | - Emmanuel Roze
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, F-75013, Paris, France. .,Département de Neurologie, AP-HP, Hôpital Pitié Salpêtrière, Paris, France.
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15
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Abstract
Contactin-2/transiently expressed axonal surface glycoprotein-1 (TAG-1) is a cell adhesion molecule belonging to the immunoglobulin superfamily (IgSF). It has six immunoglobulin-like extracellular domains and four fibronectin III-like ones, with anchoring to the cell membrane through glycosylphosphatidyl inositol. Contactin-2/TAG-1 is expressed in specific neurons transiently on the axonal surface during the fetal period. In postnatal stages, Contactin-2/TAG-1 is expressed in cerebellar granule cells, hippocampal pyramidal cells, and the juxtaparanodal regions of myelinated nerve fibers. In the embryonic nervous system, Contactin-2/TAG-1 plays important roles in axonal elongation, axonal guidance, and cellular migration. In the postnatal nervous system, it also plays an essential role in the formation of myelinated nerve fibers. Moreover, Contactin-2/TAG-1 has been linked to autoimmune diseases of the human nervous system. Taken together, Contactin-2/TAG-1 plays a central role in a variety of functions from development to disease.
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Affiliation(s)
- Tomoyuki Masuda
- a Doctoral and Master's Programs in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba , Ibaraki , Japan.,b Department of Neurology , Faculty of Medicine, University of Tsukuba , Ibaraki , Japan.,c Department of Neurobiology , Faculty of Medicine, University of Tsukuba , Ibaraki , Japan
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16
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Early Commissural Diencephalic Neurons Control Habenular Axon Extension and Targeting. Curr Biol 2017; 27:270-278. [PMID: 28065605 DOI: 10.1016/j.cub.2016.11.038] [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: 06/01/2016] [Revised: 10/07/2016] [Accepted: 11/16/2016] [Indexed: 01/19/2023]
Abstract
Most neuronal populations form on both the left and right sides of the brain. Their efferent axons appear to grow synchronously along similar pathways on each side, although the neurons or their environment often differ between the two hemispheres [1-4]. How this coordination is controlled has received little attention. Frequently, neurons establish interhemispheric connections, which can function to integrate information between brain hemispheres (e.g., [5]). Such commissures form very early, suggesting their potential developmental role in coordinating ipsilateral axon navigation during embryonic development [4]. To address the temporal-spatial control of bilateral axon growth, we applied long-term time-lapse imaging to visualize the formation of the conserved left-right asymmetric habenular neural circuit in the developing zebrafish embryo [6]. Although habenular neurons are born at different times across brain hemispheres [7], we found that elongation of habenular axons occurs synchronously. The initiation of axon extension is not controlled within the habenular network itself but through an early developing proximal diencephalic network. The commissural neurons of this network influence habenular axons both ipsilaterally and contralaterally. Their unilateral absence impairs commissure formation and coordinated habenular axon elongation and causes their subsequent arrest on both sides of the brain. Thus, habenular neural circuit formation depends on a second intersecting commissural network, which facilitates the exchange of information between hemispheres required for ipsilaterally projecting habenular axons. This mechanism of network formation may well apply to other circuits, and has only remained undiscovered due to technical limitations.
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17
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Delloye-Bourgeois C, Moret F, Castellani V. Performing Axon Orientation Assays with Secreted Semaphorins and Other Guidance Cues. Methods Mol Biol 2017; 1493:237-246. [PMID: 27787855 DOI: 10.1007/978-1-4939-6448-2_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The guidance of axons within the developing nervous system is orchestrated by a variety of cues that successively and complementary attract or repel axons to achieve a stereotyped wiring of neural circuits. Here we present a version of a method that has been widely used to identify and characterize the effect of guidance cues on the orientation of axons. We describe the coculture, within a three-dimensional environment, of dorsal spinal cord explants together with a cell aggregate secreting a candidate cue and the method to quantify the effect of this cue on axon orientation.
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Affiliation(s)
- Céline Delloye-Bourgeois
- University of Lyon, University Claude Bernard Lyon 1, NeuroMyoGene Insitute (INMG) CNRS UMR5310-INSERM U1217, 16 rue Raphaël Dubois, Lyon 69000, France
| | - Frédéric Moret
- University of Lyon, University Claude Bernard Lyon 1, NeuroMyoGene Insitute (INMG) CNRS UMR5310-INSERM U1217, 16 rue Raphaël Dubois, Lyon 69000, France
| | - Valérie Castellani
- University of Lyon, University Claude Bernard Lyon 1, NeuroMyoGene Insitute (INMG) CNRS UMR5310-INSERM U1217, 16 rue Raphaël Dubois, Lyon 69000, France.
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18
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Planar cell polarity genes Frizzled3a, Vangl2, and Scribble are required for spinal commissural axon guidance. BMC Neurosci 2016; 17:83. [PMID: 27955617 PMCID: PMC5154073 DOI: 10.1186/s12868-016-0318-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/29/2016] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND A fundamental feature of early nervous system development is the guidance of axonal projections to their targets in order to assemble neural circuits that control behavior. Spinal commissural neurons are an attractive model to investigate the multiple guidance cues that control growth cone navigation both pre- and post-midline crossing, as well as along both the dorsal-ventral (D-V) and anterior-posterior (A-P) axes. Accumulating evidence suggests that guidance of spinal commissural axons along the A-P axis is dependent on components of the planar cell polarity (PCP) signaling pathway. In the zebrafish, the earliest born spinal commissural neuron to navigate the midline and turn rostrally is termed commissural primary ascending (CoPA). Unlike mammalian systems, CoPA axons cross the midline as a single axon and allow an analysis of the role of PCP components in anterior pathfinding in single pioneering axons. RESULTS Here, we establish CoPA cells in the zebrafish spinal cord as a model system for investigating the molecular function of planar cell polarity signaling in axon guidance. Using mutant analysis, we show that the functions of Fzd3a and Vangl2 in the anterior turning of commissural axons are evolutionarily conserved in teleosts. We extend our findings to reveal a role for the PCP gene scribble in the anterior guidance of CoPA axons. Analysis of single CoPA axons reveals that these commissural axons become responsive to PCP-dependent anterior guidance cues even prior to midline crossing. When midline crossing is prevented by dcc gene knockdown, ipsilateral CoPA axons still extend axons anteriorly in response to A-P guidance cues. We show that this ipsilateral anterior pathfinding that occurs in the absence of midline crossing is dependent on PCP signaling. CONCLUSION Our results demonstrate that anterior guidance decisions by CoPA axons are dependent on the function of planar cell polarity genes both prior to and after midline crossing.
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19
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Stanic K, Saldivia N, Förstera B, Torrejón M, Montecinos H, Caprile T. Expression Patterns of Extracellular Matrix Proteins during Posterior Commissure Development. Front Neuroanat 2016; 10:89. [PMID: 27733818 PMCID: PMC5039192 DOI: 10.3389/fnana.2016.00089] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/12/2016] [Indexed: 11/13/2022] Open
Abstract
Extracellular matrix (ECM) molecules are pivotal for central nervous system (CNS) development, facilitating cell migration, axonal growth, myelination, dendritic spine formation, and synaptic plasticity, among other processes. During axon guidance, the ECM not only acts as a permissive or non-permissive substrate for navigating axons, but also modulates the effects of classical guidance cues, such as netrin or Eph/ephrin family members. Despite being highly important, little is known about the expression of ECM molecules during CNS development. Therefore, this study assessed the molecular expression patterns of tenascin, HNK-1, laminin, fibronectin, perlecan, decorin, and osteopontin along chick embryo prosomere 1 during posterior commissure development. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. Located in the dorso-caudal portion of prosomere 1, posterior commissure axons primarily arise from the neurons of basal pretectal nuclei that run dorsally to the roof plate midline, where some turn toward the ipsilateral side. Expressional analysis of ECM molecules in this area these revealed to be highly arranged, and molecule interactions with axon fascicles suggested involvement in processes other than structural support. In particular, tenascin and the HNK-1 epitope extended in ventro-dorsal columns and enclosed axons during navigation to the roof plate. Laminin and osteopontin were expressed in the midline, very close to axons that at this point must decide between extending to the contralateral side or turning to the ipsilateral side. Finally, fibronectin, decorin, and perlecan appeared unrelated to axonal pathfinding in this region and were instead restricted to the external limiting membrane. In summary, the present report provides evidence for an intricate expression of different extracellular molecules that may cooperate in guiding posterior commissure axons.
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Affiliation(s)
- Karen Stanic
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Natalia Saldivia
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Benjamín Förstera
- Department of Physiology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Marcela Torrejón
- Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Hernán Montecinos
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Teresa Caprile
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
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20
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Frei JA, Stoeckli ET. SynCAMs - From axon guidance to neurodevelopmental disorders. Mol Cell Neurosci 2016; 81:41-48. [PMID: 27594578 DOI: 10.1016/j.mcn.2016.08.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 08/28/2016] [Accepted: 08/31/2016] [Indexed: 12/22/2022] Open
Abstract
Many cell adhesion molecules are located at synapses but only few of them can be considered synaptic cell adhesion molecules in the strict sense. Besides the Neurexins and Neuroligins, the LRRTMs (leucine rich repeat transmembrane proteins) and the SynCAMs/CADMs can induce synapse formation when expressed in non-neuronal cells and therefore are true synaptic cell adhesion molecules. SynCAMs (synaptic cell adhesion molecules) are a subfamily of the immunoglobulin superfamily of cell adhesion molecules. As suggested by their name, they were first identified as cell adhesion molecules at the synapse which were sufficient to trigger synapse formation. They also contribute to myelination by mediating axon-glia cell contacts. More recently, their role in earlier stages of neural circuit formation was demonstrated, as they also guide axons both in the peripheral and in the central nervous system. Mutations in SynCAM genes were found in patients diagnosed with autism spectrum disorders. The diverse functions of SynCAMs during development suggest that neurodevelopmental disorders are not only due to defects in synaptic plasticity. Rather, early steps of neural circuit formation are likely to contribute.
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Affiliation(s)
- Jeannine A Frei
- Hussman Institute for Autism, 801 W Baltimore Street, Baltimore, MD 20201, United States
| | - Esther T Stoeckli
- Dept of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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21
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Pignata A, Ducuing H, Castellani V. Commissural axon navigation: Control of midline crossing in the vertebrate spinal cord by the semaphorin 3B signaling. Cell Adh Migr 2016; 10:604-617. [PMID: 27532244 PMCID: PMC5160037 DOI: 10.1080/19336918.2016.1212804] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The mechanisms governing the navigation of commissural axons during embryonic development have been extensively investigated in the past years, often using the drosophila ventral nerve cord and the spinal cord as model systems. Similarities but also specificities in the general strategies, the molecular signals as well as in the regulatory pathways controlling the response of commissural axons to the guidance cues have been found between species. Whether the semaphorin signaling contributes to midline crossing in the fly nervous system remains unknown, while in contrast, it does play a prominent contribution in vertebrates. In this review we discuss the functions of the semaphorins during commissural axon guidance in the developing spinal cord, focusing on the family member semaphorin 3B (Sema3B) in the context of midline crossing in the spinal cord.
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Affiliation(s)
- Aurora Pignata
- a University of Lyon, Université Claude Bernard Lyon 1, NeuroMyogene Institute (INMG), UMR CNRS 5310, INSERM U1217 Lyon , France
| | - Hugo Ducuing
- a University of Lyon, Université Claude Bernard Lyon 1, NeuroMyogene Institute (INMG), UMR CNRS 5310, INSERM U1217 Lyon , France
| | - Valérie Castellani
- a University of Lyon, Université Claude Bernard Lyon 1, NeuroMyogene Institute (INMG), UMR CNRS 5310, INSERM U1217 Lyon , France
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22
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Preitner N, Quan J, Li X, Nielsen FC, Flanagan JG. IMP2 axonal localization, RNA interactome, and function in the development of axon trajectories. Development 2016; 143:2753-9. [PMID: 27385015 DOI: 10.1242/dev.128348] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 06/13/2016] [Indexed: 01/28/2023]
Abstract
RNA-based regulatory mechanisms play important roles in the development and plasticity of neural circuits and neurological disease. Developing axons provide a model well suited to the study of RNA-based regulation, and contain specific subsets of mRNAs that are locally translated and have roles in axon pathfinding. However, the RNA-binding proteins involved in axon pathfinding, and their corresponding mRNA targets, are still largely unknown. Here we find that the RNA-binding protein IMP2 (Igf2bp2) is strikingly enriched in developing axon tracts, including in spinal commissural axons. We used the HITS-CLIP approach to perform a genome-wide identification of RNAs that interact directly with IMP2 in the native context of developing mouse brain. This IMP2 interactome was highly enriched for mRNA targets related to axon guidance. Accordingly, IMP2 knockdown in the developing spinal cord led to strong defects in commissural axon trajectories at the midline intermediate target. These results reveal a highly distinctive axonal enrichment of IMP2, show that it interacts with a network of axon guidance-related mRNAs, and reveal that it is required for normal axon pathfinding during vertebrate development.
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Affiliation(s)
- Nicolas Preitner
- Department of Cell Biology and Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Jie Quan
- Department of Cell Biology and Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Xinmin Li
- Department of Cell Biology and Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Finn C Nielsen
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, Copenhagen Ø DK-2100, Denmark
| | - John G Flanagan
- Department of Cell Biology and Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
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Noraz N, Jaaoini I, Charoy C, Watrin C, Chounlamountri N, Benon A, Malleval C, Boudin H, Honnorat J, Castellani V, Pellier-Monnin V. Syk kinases are required for spinal commissural axon repulsion at the midline via the ephrin/Eph pathway. Development 2016; 143:2183-93. [PMID: 27122172 DOI: 10.1242/dev.128629] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 04/15/2016] [Indexed: 12/26/2022]
Abstract
In the hematopoietic system, Syk family tyrosine kinases are essential components of immunoreceptor ITAM-based signaling. While there is increasing data indicating the involvement of immunoreceptors in neural functions, the contribution of Syk kinases remains obscure. Previously, we identified phosphorylated forms of Syk kinases in specialized populations of migrating neurons or projecting axons. Moreover, we identified ephrin/Eph as guidance molecules utilizing the ITAM-bearing CD3zeta (Cd247) and associated Syk kinases for the growth cone collapse response induced in vitro Here, we show that in the developing spinal cord, Syk is phosphorylated in navigating commissural axons. By analyzing axon trajectories in open-book preparations of Syk(-/-); Zap70(-/-) mouse embryos, we show that Syk kinases are dispensable for attraction towards the midline but confer growth cone responsiveness to repulsive signals that expel commissural axons from the midline. Known to serve a repulsive function at the midline, ephrin B3/EphB2 are obvious candidates for driving the Syk-dependent repulsive response. Indeed, Syk kinases were found to be required for ephrin B3-induced growth cone collapse in cultured commissural neurons. In fragments of commissural neuron-enriched tissues, Syk is in a constitutively phosphorylated state and ephrin B3 decreased its level of phosphorylation. Direct pharmacological inhibition of Syk kinase activity was sufficient to induce growth cone collapse. In conclusion, Syk kinases act as a molecular switch of growth cone adhesive and repulsive responses.
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Affiliation(s)
- Nelly Noraz
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Iness Jaaoini
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Camille Charoy
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Chantal Watrin
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Naura Chounlamountri
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Aurélien Benon
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Céline Malleval
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Hélène Boudin
- INSERM U1064, Institut de Transplantation Urologie-Néphrologie, Nantes F-44035, France
| | - Jérôme Honnorat
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France Hospices Civils de Lyon, Lyon F-69000, France
| | - Valérie Castellani
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Véronique Pellier-Monnin
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
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Masu M. Proteoglycans and axon guidance: a new relationship between old partners. J Neurochem 2016; 139 Suppl 2:58-75. [PMID: 26709493 DOI: 10.1111/jnc.13508] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 12/08/2015] [Accepted: 12/11/2015] [Indexed: 01/12/2023]
Abstract
Neural circuits are formed with great precision during development. Accumulated evidence over the past three decades has demonstrated that growing axons are navigated toward their targets by the combined actions of attractants and repellents together with their receptors. It has long been known that proteoglycans, glycosylated proteins possessing covalently attached glycosaminoglycans, play a critical role in axon guidance; however, the molecular mechanisms by which proteoglycans regulate axon behaviors remain largely unknown. Glycosaminoglycans such as heparan sulfate and chondroitin sulfate are large linear polysaccharides composed of repeating disaccharide units that are highly modified by specific sulfation and epimerization. Recent biochemical and molecular biological studies have identified the enzymes that are involved in the biosynthesis of glycosaminoglycans. Interestingly, many mutants lacking glycosaminoglycan-synthesizing enzymes or proteoglycans in several model organisms show defects in specific nerve tract formation. In parallel, detailed biochemical studies have identified the molecular interactions between axon guidance molecules and glycosaminoglycans that have specific modification in their sugar chains. This review summarizes the structure and function of axon guidance molecules and glycosaminoglycans, and then tries to combine the knowledge from these studies to understand the role of proteoglycans from a new vantage point. Deciphering the sugar code is important for understanding the complicated nature of proteoglycans in axon guidance. Neural circuits are formed by the combined actions of axon guidance molecules. Proteoglycans play critical roles in regulating axon guidance through the interaction between signaling molecules and glycosaminoglycan chains attached to the core protein. This paper summarizes the structure and functions of axon guidance molecules and glycosaminoglycans and reviews the molecular mechanisms by which proteoglycans regulate axon guidance from a new vantage point. This article is part of the 60th Anniversary special issue.
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Affiliation(s)
- Masayuki Masu
- Department of Molecular Neurobiology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan.
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Alther TA, Domanitskaya E, Stoeckli ET. Calsyntenin1-mediated trafficking of axon guidance receptors regulates the switch in axonal responsiveness at a choice point. Development 2016; 143:994-1004. [DOI: 10.1242/dev.127449] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 01/26/2016] [Indexed: 02/04/2023]
Abstract
Axon guidance at choice points depends on the precise regulation of guidance receptors on the growth cone surface. Upon arrival at the intermediate target or choice point, a switch from attraction to repulsion is required for the axon to move on. Dorsal commissural (dI1) axons crossing the ventral midline of the spinal cord in the floor plate represent a convenient model for the analysis of the molecular mechanism underlying the switch in axonal behavior.
We identified a role of Calsyntenin1 in the regulation of vesicular trafficking of guidance receptors in dI1 axons at choice points. In cooperation with RabGDI, Calsyntenin1 shuttles Rab11-positive vesicles containing Robo1 to the growth cone surface in a precisely regulated manner. In contrast, Calsyntenin1-mediated trafficking of Frizzled3, a guidance receptor in the Wnt pathway, is independent of RabGDI. Thus, tightly regulated insertion of guidance receptors, which is required for midline crossing and the subsequent turn into the longitudinal axis, is achieved by specific trafficking.
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Affiliation(s)
- Tobias A. Alther
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Elena Domanitskaya
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Esther T. Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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Schiweck J, Beauchamp M, Humo M, Lelievre V. Old friends, new story: The role of Slit2C signaling through PlexinA1. Cell Adh Migr 2015; 9:417-21. [PMID: 26632339 DOI: 10.1080/19336918.2015.1106670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Growth cone guidance is driven by attractive and repulsive signaling cues. Until recently, repulsive signaling by semaphorins was thought to be mediated through Plexin receptors, whereas Slits-induced repulsion was solely mediated through Robo receptors. In a recent report published in Nature Neuroscience, Celine Delloye-Bourgeois and colleagues (2015) combined phenotypic analyses of transgenic mouse lines and in vitro biochemical experiments to identify PlexinA1 as a novel receptor for Slits. Strikingly, they uncovered for the very first time that the Slit2C-terminal fragment possesses some unique biological activity as binding partner for PlexinA1. Even more excitingly, the signaling cascade triggered by SlitC binding to PlexinA1 mediates growth cone collapse of commissural axons both in vivo and ex vivo and nicely complements Robo-Slit signaling in the developing spinal cord midline to prevent midline recrossing.
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Affiliation(s)
- Juliane Schiweck
- a Joint Master in Neuroscience; University of Strasbourg-France ; Strasbourg , France
| | - Marta Beauchamp
- a Joint Master in Neuroscience; University of Strasbourg-France ; Strasbourg , France
| | - Muris Humo
- a Joint Master in Neuroscience; University of Strasbourg-France ; Strasbourg , France
| | - Vincent Lelievre
- a Joint Master in Neuroscience; University of Strasbourg-France ; Strasbourg , France
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Hara S, Kaneyama T, Inamata Y, Onodera R, Shirasaki R. Interstitial branch formation within the red nucleus by deep cerebellar nuclei-derived commissural axons during target recognition. J Comp Neurol 2015; 524:999-1014. [DOI: 10.1002/cne.23888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/29/2015] [Accepted: 08/21/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Satoshi Hara
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences; Osaka University; Suita Osaka 565-0871 Japan
| | - Takeshi Kaneyama
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences; Osaka University; Suita Osaka 565-0871 Japan
| | - Yasuyuki Inamata
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences; Osaka University; Suita Osaka 565-0871 Japan
| | - Ryota Onodera
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences; Osaka University; Suita Osaka 565-0871 Japan
| | - Ryuichi Shirasaki
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences; Osaka University; Suita Osaka 565-0871 Japan
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Avilés EC, Stoeckli ET. Canonical wnt signaling is required for commissural axon guidance. Dev Neurobiol 2015; 76:190-208. [PMID: 26014644 PMCID: PMC4755210 DOI: 10.1002/dneu.22307] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 05/20/2015] [Accepted: 05/20/2015] [Indexed: 12/20/2022]
Abstract
Morphogens have been identified as guidance cues for postcrossing commissural axons in the spinal cord. Shh has a dual effect on postcrossing commissural axons: a direct repellent effect mediated by Hhip as a receptor, and an indirect effect by shaping a Wnt activity gradient. Wnts were shown to be attractants for postcrossing commissural axons in both chicken and mouse embryos. In mouse, the effects of Wnts on axon guidance were concluded to depend on the planar cell polarity (PCP) pathway. Canonical Wnt signaling was excluded based on the absence of axon guidance defects in mice lacking Lrp6 which is an obligatory coreceptor for Fzd in canonical Wnt signaling. In the loss-of-function studies reported here, we confirmed a role for the PCP pathway in postcrossing commissural axon guidance also in the chicken embryo. However, taking advantage of the precise temporal control of gene silencing provided by in ovo RNAi, we demonstrate that canonical Wnt signaling is also required for proper guidance of postcrossing commissural axons in the developing spinal cord. Thus, axon guidance does not seem to depend on any one of the classical Wnt signaling pathways but rather involve a network of Wnt receptors and downstream components.
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Affiliation(s)
- Evelyn C Avilés
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Esther T Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
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29
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Welniarz Q, Dusart I, Gallea C, Roze E. One hand clapping: lateralization of motor control. Front Neuroanat 2015; 9:75. [PMID: 26082690 PMCID: PMC4451425 DOI: 10.3389/fnana.2015.00075] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/17/2015] [Indexed: 12/20/2022] Open
Abstract
Lateralization of motor control refers to the ability to produce pure unilateral or asymmetric movements. It is required for a variety of coordinated activities, including skilled bimanual tasks and locomotion. Here we discuss the neuroanatomical substrates and pathophysiological underpinnings of lateralized motor outputs. Significant breakthroughs have been made in the past few years by studying the two known conditions characterized by the inability to properly produce unilateral or asymmetric movements, namely human patients with congenital “mirror movements” and model rodents with a “hopping gait”. Whereas mirror movements are associated with altered interhemispheric connectivity and abnormal corticospinal projections, abnormal spinal cord interneurons trajectory is responsible for the “hopping gait”. Proper commissural axon guidance is a critical requirement for these mechanisms. Interestingly, the analysis of these two conditions reveals that the production of asymmetric movements involves similar anatomical and functional requirements but in two different structures: (i) lateralized activation of the brain or spinal cord through contralateral silencing by cross-midline inhibition; and (ii) unilateral transmission of this activation, resulting in lateralized motor output.
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Affiliation(s)
- Quentin Welniarz
- Neuroscience Paris Seine, CNRS UMR8246, Inserm U1130, Sorbonne Universités, UPMC UM119 Paris, France ; Inserm U1127, CNRS UMR 7225, Sorbonne Universités, UPMC UMR S1127, Institut du Cerveau et de la Moelle épinière, ICM Paris, France
| | - Isabelle Dusart
- Neuroscience Paris Seine, CNRS UMR8246, Inserm U1130, Sorbonne Universités, UPMC UM119 Paris, France
| | - Cécile Gallea
- Inserm U1127, CNRS UMR 7225, Sorbonne Universités, UPMC UMR S1127, Institut du Cerveau et de la Moelle épinière, ICM Paris, France
| | - Emmanuel Roze
- Inserm U1127, CNRS UMR 7225, Sorbonne Universités, UPMC UMR S1127, Institut du Cerveau et de la Moelle épinière, ICM Paris, France ; Département des Maladies du Système Nerveux, AP-HP, Hôpital Pitié Salpêtrière Paris, France
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30
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Abstract
Many neurological disorders are characterised by structural changes in neuronal connections, ranging from presymptomatic synaptic changes to the loss or rewiring of entire axon bundles. The molecular mechanisms that underlie this perturbed connectivity are poorly understood, but recent studies suggest a role for axon guidance proteins. Axon guidance proteins guide growing axons during development and control structural plasticity of synaptic connections in adults. Changes in expression or function of these proteins might induce pathological changes in neural circuits that predispose to, or cause, neurological diseases. For some neurological disorders, such as midline crossing disorders, investigators have identified causative mutations in genes for axon guidance. However, for most other disorders, evidence is correlative and further studies are needed to confirm the pathological role of defects in proteins for axon guidance. Importantly, further insight into how dysregulation of axon guidance proteins causes disease will help the development of therapeutic strategies for neurological disorders.
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Affiliation(s)
- Eljo Y Van Battum
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands
| | - Sara Brignani
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands.
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31
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Martinez E, Tran TS. Vertebrate spinal commissural neurons: a model system for studying axon guidance beyond the midline. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:283-97. [PMID: 25619385 DOI: 10.1002/wdev.173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/27/2014] [Accepted: 12/04/2014] [Indexed: 12/21/2022]
Abstract
For bilaterally symmetric organisms, the transfer of information between the left and right side of the nervous system is mediated by commissures formed by neurons that project their axons across the body midline to the contralateral side of the central nervous system (CNS). After crossing the midline, many of these axons must travel long distances to reach their targets, including those that extend from spinal commissural neurons. Owing to the highly stereotyped trajectories of spinal commissural neurons that can be divided into several segments as these axons project to their targets, it is an ideal system for investigators to ask fundamental questions related to mechanisms of short- and long-range axon guidance, fasciculation, and choice point decisions at the midline intermediate target. In addition, studies of patterning genes of the nervous system have revealed complex transcription factor codes that function in a combinatorial fashion to specify individual classes of spinal neurons including commissural neurons. Despite these advances and the functional importance of spinal commissural neurons in mediating the transfer of external sensory information from the peripheral nervous system (PNS) to the CNS, only a handful of studies have begun to elucidate the mechanistic logic underlying their long-range pathfinding and the characterization of their synaptic targets. Using in vitro assays, in vivo labeling methodologies, in combination with both loss- and gain-of-function experiments, several studies have revealed that the molecular mechanisms of long-range spinal commissural axon pathfinding involve an interplay between classical axon guidance cues, morphogens and cell adhesion molecules. For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Edward Martinez
- Department of Biological Sciences, Rutgers University, Newark, NJ, USA
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Delloye-Bourgeois C, Jacquier A, Charoy C, Reynaud F, Nawabi H, Thoinet K, Kindbeiter K, Yoshida Y, Zagar Y, Kong Y, Jones YE, Falk J, Chédotal A, Castellani V. PlexinA1 is a new Slit receptor and mediates axon guidance function of Slit C-terminal fragments. Nat Neurosci 2015; 18:36-45. [PMID: 25485759 DOI: 10.1038/nn.3893] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 11/12/2014] [Indexed: 02/07/2023]
Abstract
Robo-Slit and Plexin-Semaphorin signaling participate in various developmental and pathogenic processes. During commissural axon guidance in the spinal cord, chemorepulsion by Semaphorin3B and Slits controls midline crossing. Slit processing generates an N-terminal fragment (SlitN) that binds to Robo1 and Robo2 receptors and mediates Slit repulsive activity, as well as a C-terminal fragment (SlitC) with an unknown receptor and bioactivity. We identified PlexinA1 as a Slit receptor and found that it binds the C-terminal Slit fragment specifically and transduces a SlitC signal independently of the Robos and the Neuropilins. PlexinA1-SlitC complexes are detected in spinal cord extracts, and ex vivo, SlitC binding to PlexinA1 elicits a repulsive commissural response. Analysis of various ligand and receptor knockout mice shows that PlexinA1-Slit and Robo-Slit signaling have complementary roles during commissural axon guidance. Thus, PlexinA1 mediates both Semaphorin and Slit signaling, and Slit processing generates two active fragments, each exerting distinct effects through specific receptors.
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Affiliation(s)
| | - Arnaud Jacquier
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
| | - Camille Charoy
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
| | - Florie Reynaud
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
| | - Homaira Nawabi
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
| | - Karine Thoinet
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
| | - Karine Kindbeiter
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
| | - Yutaka Yoshida
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Yvrick Zagar
- 1] INSERM, UMRS_U968, Institut de la Vision, Paris, France. [2] Sorbonne Universités, Université Pierre et Marie Curie (UPMC) University of Paris 06, Institut de la Vision, Paris, France. [3] CNRS, UMR_7210, Paris, France
| | - Youxin Kong
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Yvonne E Jones
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Julien Falk
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
| | - Alain Chédotal
- 1] INSERM, UMRS_U968, Institut de la Vision, Paris, France. [2] Sorbonne Universités, Université Pierre et Marie Curie (UPMC) University of Paris 06, Institut de la Vision, Paris, France. [3] CNRS, UMR_7210, Paris, France
| | - Valérie Castellani
- University of Lyon, University Claude Bernard Lyon 1, CGphiMC UMR CNRS 5534, Lyon, France
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Andermatt I, Wilson NH, Bergmann T, Mauti O, Gesemann M, Sockanathan S, Stoeckli ET. Semaphorin 6B acts as a receptor in post-crossing commissural axon guidance. Development 2014; 141:3709-20. [PMID: 25209245 DOI: 10.1242/dev.112185] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Semaphorins are a large family of axon guidance molecules that are known primarily as ligands for plexins and neuropilins. Although class-6 semaphorins are transmembrane proteins, they have been implicated as ligands in different aspects of neural development, including neural crest cell migration, axon guidance and cerebellar development. However, the specific spatial and temporal expression of semaphorin 6B (Sema6B) in chick commissural neurons suggested a receptor role in axon guidance at the spinal cord midline. Indeed, in the absence of Sema6B, post-crossing commissural axons lacked an instructive signal directing them rostrally along the contralateral floorplate border, resulting in stalling at the exit site or even caudal turns. Truncated Sema6B lacking the intracellular domain was unable to rescue the loss-of-function phenotype, confirming a receptor function of Sema6B. In support of this, we demonstrate that Sema6B binds to floorplate-derived plexin A2 (PlxnA2) for navigation at the midline, whereas a cis-interaction between PlxnA2 and Sema6B on pre-crossing commissural axons may regulate the responsiveness of axons to floorplate-derived cues.
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Affiliation(s)
- Irwin Andermatt
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Nicole H Wilson
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Timothy Bergmann
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Olivier Mauti
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Matthias Gesemann
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Shanthini Sockanathan
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Esther T Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
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Stanic K, Vera A, González M, Recabal A, Astuya A, Torrejón M, Montecinos H, Caprile T. Complementary expression of EphA7 and SCO-spondin during posterior commissure development. Front Neuroanat 2014; 8:49. [PMID: 25009468 PMCID: PMC4068196 DOI: 10.3389/fnana.2014.00049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 06/02/2014] [Indexed: 12/05/2022] Open
Abstract
Bilaterally symmetric organisms need to exchange information between the two sides of their bodies in order to integrate sensory inputs and coordinate motor control. This exchange occurs through commissures formed by neurons that project axons across the midline to the contralateral side of the central nervous system. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. It is located in the dorsal portion of the prosomere 1, at the caudal diencephalon. The axons of the posterior commissure principally come from neurons of ventrolateral and dorsolateral pretectal nuclei (parvocellular and magnocellular nucleus of the posterior commissure, respectively) that extend their axons toward the dorsal region. The trajectory of these axons can be divided into the following three stages: (1) dorsal axon extension towards the lateral roof plate; (2) fasciculation in the lateral roof plate; and (3) midline decision of turning to the ipsilateral side or continuing to the opposite side. The mechanisms and molecules that guide the axons during these steps are unknown. In the present work, immunohistochemical and in situ hybridization analyses were performed, with results suggesting the participation of EphA7 in guiding axons from the ventral to the dorsal region of the prosomere 1 through the generation of an axonal corridor limited by repulsive EphA7 walls. At the lateral roof plate, the axons became fasciculated in presence of SCO-spondin until reaching the midline. Finally, EphA7 expression was observed in the diencephalic midline roof plate, specifically in the region where some axons turn to the ipsilateral side, suggesting its participation in this decision. In summary, the present work proposes a mechanism of posterior commissure formation orchestrated by the complementary expression of the axon guidance cues SCO-spondin and EphA7.
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Affiliation(s)
- Karen Stanic
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - América Vera
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Melissa González
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Antonia Recabal
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Allison Astuya
- Laboratory of Cell Culture and Marine Genomics, Marine Biotechnology Unit, Faculty of Natural and Oceanographic Sciences and Program COPAS Sur-Austral, University of Concepción, Concepción , Chile
| | - Marcela Torrejón
- Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Hernán Montecinos
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Teresa Caprile
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
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Frei JA, Stoeckli ET. SynCAMs extend their functions beyond the synapse. Eur J Neurosci 2014; 39:1752-60. [DOI: 10.1111/ejn.12544] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/17/2014] [Accepted: 02/03/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Jeannine A. Frei
- Institute of Molecular Life Sciences and Neuroscience Center Zurich; University of Zurich; Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Esther T. Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich; University of Zurich; Winterthurerstrasse 190 8057 Zurich Switzerland
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Inamata Y, Shirasaki R. Dbx1 triggers crucial molecular programs required for midline crossing by midbrain commissural axons. Development 2014; 141:1260-71. [PMID: 24553291 DOI: 10.1242/dev.102327] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Axon guidance by commissural neurons has been well documented, providing us with a molecular logic of how midline crossing is achieved during development. Despite these advances, knowledge of the intrinsic genetic programs is still limited and it remains obscure whether the expression of a single transcription factor is sufficient to activate transcriptional programs that ultimately enable midline crossing. Here, we show in the mouse that the homeodomain transcription factor Dbx1 is expressed by a subset of progenitor cells that give rise to commissural neurons in the dorsal midbrain. Gain- and loss-of-function analyses indicate that the expression of Dbx1 alone is sufficient and necessary to trigger midline crossing in vivo. We also show that Robo3 controls midline crossing as a crucial downstream effector of the Dbx1-activated molecular programs. Furthermore, Dbx1 suppresses the expression of the transcriptional program for ipsilateral neuron differentiation in parallel. These results suggest that a single transcription factor, Dbx1, has an essential function in assigning midline-crossing identity, thereby contributing crucially to the establishment of the wiring laterality in the developing nervous system.
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Affiliation(s)
- Yasuyuki Inamata
- Cellular and Molecular Neurobiology Laboratory, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
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Charoy C, Arbeille E, Thoinet K, Castellani V. Culture of isolated floor plate tissue and production of conditioned medium to assess functional properties of floor plate-released signals. J Vis Exp 2014:e50884. [PMID: 24561889 DOI: 10.3791/50884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
During development, progenitors and post-mitotic neurons receive signals from adjacent territories that regulate their fate. The floor-plate is a group of glial cells lining the ependymal canal at ventral position. The floor-plate expresses key morphogens contributing to the patterning of cell lineages in the spinal cord. At later developmental stages, the floor-plate regulates the navigation of axons in the spinal cord, acting as a barrier to prevent the crossing of ipsilateral axons and controlling midline crossing by commissural axons(1). These functions are achieved through the secretion of various guidance cues. Some of these cues act as attractants and repellents for the growing axons while others regulate guidance receptors and downstream signaling to modulate the sensitivity of the axons to the local guidance cues(2,3). Here we describe a method that allows investigating the properties of floor-plate derived signals in a variety of developmental contexts, based on the production of Floor-Plate conditioned medium (FP(cm))(4-6). We then exemplify the use of this FP(cm) in the context of axon guidance. First, the spinal cord is isolated from mouse embryo at E12.5 and the floor-plate is dissected out and cultivated in a plasma-thrombin matrix (Figure 1). Second two days later, commissural tissue are dissected out from E12.5 embryos, triturated and exposed to the FP(cm). Third, the tissue are processed for Western blot analysis of commissural markers.
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Zarin AA, Asadzadeh J, Labrador JP. Transcriptional regulation of guidance at the midline and in motor circuits. Cell Mol Life Sci 2014; 71:419-32. [PMID: 23917723 PMCID: PMC11113760 DOI: 10.1007/s00018-013-1434-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 07/01/2013] [Accepted: 07/22/2013] [Indexed: 12/16/2022]
Abstract
Axon navigation through the developing body of an embryo is a challenging and exquisitely precise process. Axonal processes within the nervous system harbor extremely complicated internal regulatory mechanisms that enable each of them to respond to environmental cues in a unique way, so that every single neuron has an exact stereotypical localization and axonal projection pattern. Receptors and adhesion molecules expressed on axonal membranes will determine their guidance properties. Axon guidance is thought to be controlled to a large extent through transcription factor codes. These codes would be responsible for the deployment of specific guidance receptors and adhesion molecules on axonal membranes to allow them to reach their targets. Although families of transcriptional regulators as well as families of guidance molecules have been conserved across evolution, their relationships seem to have developed independently. This review focuses on the midline and the neuromuscular system in both vertebrates and Drosophila in which such relationships have been particularly well studied.
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Affiliation(s)
- Aref Arzan Zarin
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
- Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Jamshid Asadzadeh
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
- Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Juan-Pablo Labrador
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
- Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
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Delloye-Bourgeois C, Jacquier A, Falk J, Castellani V. Use of pHluorin to assess the dynamics of axon guidance receptors in cell culture and in the chick embryo. J Vis Exp 2014:e50883. [PMID: 24458135 DOI: 10.3791/50883] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
During development, axon guidance receptors play a crucial role in regulating axons sensitivity to both attractive and repulsive cues. Indeed, activation of the guidance receptors is the first step of the signaling mechanisms allowing axon tips, the growth cones, to respond to the ligands. As such, the modulation of their availability at the cell surface is one of the mechanisms that participate in setting the growth cone sensitivity. We describe here a method to precisely visualize the spatio-temporal cell surface dynamics of an axon guidance receptor both in vitro and in vivo in the developing chick spinal cord. We took advantage of the pH-dependent fluorescence property of a green fluorescent protein (GFP) variant to specifically detect the fraction of the axon guidance receptor that is addressed to the plasma membrane. We first describe the in vitro validation of such pH-dependent constructs and we further detail their use in vivo, in the chick spinal chord, to assess the spatio-temporal dynamics of the axon guidance receptor of interest.
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Abstract
In this issue of Neuron, Oh and Gu (2013) present a model in which intimately related embryonic nerves and blood vessels are patterned independently in response to different guidance cues from a central organizer: the whisker.
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Haddick PCG, Tom I, Luis E, Quiñones G, Wranik BJ, Ramani SR, Stephan JP, Tessier-Lavigne M, Gonzalez LC. Defining the ligand specificity of the deleted in colorectal cancer (DCC) receptor. PLoS One 2014; 9:e84823. [PMID: 24400119 PMCID: PMC3882260 DOI: 10.1371/journal.pone.0084823] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/20/2013] [Indexed: 11/23/2022] Open
Abstract
The growth and guidance of many axons in the developing nervous system require Netrin-mediated activation of Deleted in Colorectal Cancer (DCC) and other still unknown signaling cues. Commissural axon guidance defects are more severe in DCC mutant mice than Netrin-1 mutant mice, suggesting additional DCC activating signals besides Netrin-1 are involved in proper axon growth. Here we report that interaction screens on extracellular protein microarrays representing over 1,000 proteins uniquely identified Cerebellin 4 (CBLN4), a member of the C1q-tumor necrosis factor (TNF) family, and Netrin-1 as extracellular DCC-binding partners. Immunofluorescence and radio-ligand binding studies demonstrate that Netrin-1 competes with CBLN4 binding at an overlapping site within the membrane-proximal fibronectin domains (FN) 4–6 of DCC and binds with ∼5-fold higher affinity. CBLN4 also binds to the DCC homolog, Neogenin-1 (NEO1), but with a lower affinity compared to DCC. CBLN4-null mice did not show a defect in commissural axons of the developing spinal cord but did display a transient increase in the number of wandering axons in the brachial plexus, consistent with a role in axon guidance. Overall, the data solidifies CBLN4 as a bona fide DCC ligand and strengthens its implication in axon guidance.
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Affiliation(s)
- Patrick C. G. Haddick
- Department of Neuroscience, Genentech, South San Francisco, California, United States of America
| | - Irene Tom
- Department of Protein Chemistry, Genentech, South San Francisco, California, United States of America
| | - Elizabeth Luis
- Department of Protein Chemistry, Genentech, South San Francisco, California, United States of America
| | - Gabriel Quiñones
- Department of Protein Chemistry, Genentech, South San Francisco, California, United States of America
| | - Bernd J. Wranik
- Department of Protein Chemistry, Genentech, South San Francisco, California, United States of America
| | - Sree R. Ramani
- Department of Protein Chemistry, Genentech, South San Francisco, California, United States of America
| | - Jean-Philippe Stephan
- Department of Protein Chemistry, Genentech, South San Francisco, California, United States of America
| | - Marc Tessier-Lavigne
- Department of Neuroscience, Genentech, South San Francisco, California, United States of America
| | - Lino C. Gonzalez
- Department of Protein Chemistry, Genentech, South San Francisco, California, United States of America
- * E-mail:
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Demilly A, Steinmetz P, Gazave E, Marchand L, Vervoort M. Involvement of the Wnt/β-catenin pathway in neurectoderm architecture in Platynereis dumerilii. Nat Commun 2013; 4:1915. [DOI: 10.1038/ncomms2915] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 04/19/2013] [Indexed: 12/14/2022] Open
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Abstract
Commissural circuits are brain and spinal cord connections which interconnect the two sides of the central nervous system (CNS). They play essential roles in brain and spinal cord processing, ensuring left-right coordination and synchronization of information and commands. During the formation of neuronal circuits, all commissural neurons of the central nervous system must accomplish a common task, which is to project their axon onto the other side of the nervous system, across the midline that delineates the two halves of the CNS. How this task is accomplished has been the topic of extensive studies over the last past 20 years and remains one of the best models to investigate axon guidance mechanisms. In the first part of this review, I will introduce the commissural circuits, their general role in the physiology of the nervous system, and their recognized or suspected pathogenic properties in human diseases. In the second part of the review, I will concentrate on two commissural circuits, the spinal commissures and the corpus callosum, to detail the cellular and molecular mechanisms governing their formation, mostly during their navigation at the midline.
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Carmeliet P, Ruiz de Almodovar C, Carmen RDA. VEGF ligands and receptors: implications in neurodevelopment and neurodegeneration. Cell Mol Life Sci 2013; 70:1763-78. [PMID: 23475071 PMCID: PMC11113464 DOI: 10.1007/s00018-013-1283-7] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 01/28/2013] [Accepted: 01/28/2013] [Indexed: 12/15/2022]
Abstract
Intensive research in the last decade shows that the prototypic angiogenic factor vascular endothelial growth factor (VEGF) can have direct effects in neurons and modulate processes such as neuronal migration, axon outgrowth, axon guidance and neuronal survival. Depending on the neuronal cell type and the process, VEGF seems to exert these effects by signaling via different receptors. It is also becoming clear that other VEGF ligands such as VEGF-B, -C and -D can act in various neuronal cell types as well. Moreover, apart from playing a role in physiological conditions, VEGF and VEGF-B have been related to different neurological disorders. We give an update on how VEGF controls different processes during neurodevelopment as well as on its role in several neurodegenerative disorders. We also discuss recent findings demonstrating that other VEGF ligands influence processes such as neurogenesis and dendrite arborization and participate in neurodegeneration.
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Affiliation(s)
- Peter Carmeliet
- Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, K.U.Leuven, 3000, Leuven, Belgium.
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Charoy C, Nawabi H, Reynaud F, Derrington E, Bozon M, Wright K, Falk J, Helmbacher F, Kindbeiter K, Castellani V. gdnf activates midline repulsion by Semaphorin3B via NCAM during commissural axon guidance. Neuron 2012; 75:1051-66. [PMID: 22998873 DOI: 10.1016/j.neuron.2012.08.021] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2012] [Indexed: 02/06/2023]
Abstract
The Neurotrophic factor gdnf plays diverse developmental roles, supporting survival and also acting as a chemoattractant for axon and cell migration. We report that in the developing spinal cord, a focal source of gdnf is present in the floor plate (FP) where commissural axons cross the midline. Gdnf has no direct guidance properties but switches on the responsiveness of crossing commissural growth cones to the midline repellent Semaphorin3B by suppressing calpain-mediated processing of the Sema3B signaling coreceptor Plexin-A1. Analysis of single and double mutant mouse models indicates that although gdnf is the principal trigger of Sema3B midline repulsion, it acts with another FP cue, NrCAM. Finally, genetic and in vitro experiments provide evidence that this gdnf effect is RET independent and mediated by NCAM/GFRα1 signaling. This study identifies a regulator of midline crossing and reveals interplays between Semaphorin and gdnf signaling during axon guidance.
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Affiliation(s)
- Camille Charoy
- University of Lyon, University Claude Bernard Lyon1, CGphiMC UMR CNRS 5534, 69622 Villeurbanne, France
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