1
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Lowry ER, Patel T, Costa JA, Chang E, Tariq S, Melikyan H, Davis IM, Aziz S, Dermentzaki G, Lotti F, Wichterle H. Embryonic motor neuron programming factors reactivate immature gene expression and suppress ALS pathologies in postnatal motor neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.03.587963. [PMID: 38617322 PMCID: PMC11014605 DOI: 10.1101/2024.04.03.587963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Aging is a major risk factor in amyotrophic lateral sclerosis (ALS) and other adult-onset neurodegenerative disorders. Whereas young neurons are capable of buffering disease-causing stresses, mature neurons lose this ability and degenerate over time. We hypothesized that the resilience of young motor neurons could be restored by re-expression of the embryonic motor neuron selector transcription factors ISL1 and LHX3. We found that viral re-expression of ISL1 and LHX3 reactivates aspects of the youthful gene expression program in mature motor neurons and alleviates key disease-relevant phenotypes in the SOD1G93A mouse model of ALS. Our results suggest that redeployment of lineage-specific neuronal selector transcription factors can be an effective strategy to attenuate age-dependent phenotypes in neurodegenerative disease.
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Affiliation(s)
- Emily R. Lowry
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Tulsi Patel
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Jonathon A. Costa
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Elizabeth Chang
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
- Department of Neurology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Shahroz Tariq
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Hranush Melikyan
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
- Department of Neurology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Ian M. Davis
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Siaresh Aziz
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Georgia Dermentzaki
- Department of Neurology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Francesco Lotti
- Department of Neurology, Columbia University Irving Medical Center; New York, NY, 10032, USA
| | - Hynek Wichterle
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center; New York, NY, 10032, USA
- Department of Neurology, Columbia University Irving Medical Center; New York, NY, 10032, USA
- Department of Neuroscience, Columbia University Irving Medical Center; New York, NY, 10032, USA
- Department of Rehabilitation and Regenerative Medicine, Columbia University Irving Medical Center; New York, NY, 10032, USA
- Center for Motor Neuron Biology and Disease, Columbia University Irving Medical Center; New York, NY, 10032, USA
- Columbia Stem Cell Initiative, Columbia University Irving Medical Center; New York, NY, 10032, USA
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2
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Gavrish M, Kustova A, Celis Suescún JC, Bessa P, Mitina N, Tarabykin V. Molecular mechanisms of corpus callosum development: a four-step journey. Front Neuroanat 2024; 17:1276325. [PMID: 38298831 PMCID: PMC10827913 DOI: 10.3389/fnana.2023.1276325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024] Open
Abstract
The Corpus Callosum (CC) is a bundle of axons connecting the cerebral hemispheres. It is the most recent structure to have appeared during evolution of placental mammals. Its development is controlled by a very complex interplay of many molecules. In humans it contains almost 80% of all commissural axons in the brain. The formation of the CC can be divided into four main stages, each controlled by numerous intracellular and extracellular molecular factors. First, a newborn neuron has to specify an axon, leave proliferative compartments, the Ventricular Zone (VZ) and Subventricular Zone (SVZ), migrate through the Intermediate Zone (IZ), and then settle at the Cortical Plate (CP). During the second stage, callosal axons navigate toward the midline within a compact bundle. Next stage is the midline crossing into contralateral hemisphere. The last step is targeting a defined area and synapse formation. This review provides an insight into these four phases of callosal axons development, as well as a description of the main molecular players involved.
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Affiliation(s)
- Maria Gavrish
- Laboratory of Genetics of Brain Development, Research Institute of Neurosciences, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Angelina Kustova
- Laboratory of Genetics of Brain Development, Research Institute of Neurosciences, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Juan C. Celis Suescún
- Laboratory of Genetics of Brain Development, Research Institute of Neurosciences, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Paraskevi Bessa
- Charité Hospital, Institute of Cell Biology and Neurobiology, Berlin, Germany
| | - Natalia Mitina
- Laboratory of Genetics of Brain Development, Research Institute of Neurosciences, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Victor Tarabykin
- Charité Hospital, Institute of Cell Biology and Neurobiology, Berlin, Germany
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3
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Petrić Howe M, Patani R. Nonsense-mediated mRNA decay in neuronal physiology and neurodegeneration. Trends Neurosci 2023; 46:879-892. [PMID: 37543480 DOI: 10.1016/j.tins.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/19/2023] [Accepted: 07/09/2023] [Indexed: 08/07/2023]
Abstract
The processes of mRNA export from the nucleus and subsequent mRNA translation in the cytoplasm are of particular relevance in eukaryotic cells. In highly polarised cells such as neurons, finely-tuned molecular regulation of these processes serves to safeguard the spatiotemporal fidelity of gene expression. Nonsense-mediated mRNA decay (NMD) is a cytoplasmic translation-dependent quality control process that regulates gene expression in a wide range of scenarios in the nervous system, including neurodevelopment, learning, and memory formation. Moreover, NMD dysregulation has been implicated in a broad range of neurodevelopmental and neurodegenerative disorders. We discuss how NMD and related aspects of mRNA translation regulate key neuronal functions and, in particular, we focus on evidence implicating these processes in the molecular pathogenesis of neurodegeneration. Finally, we discuss the therapeutic potential and challenges of targeting mRNA translation and NMD across the spectrum of largely untreatable neurological diseases.
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Affiliation(s)
- Marija Petrić Howe
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London (UCL), Queen Square, WC1N 3BG London, UK.
| | - Rickie Patani
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London (UCL), Queen Square, WC1N 3BG London, UK.
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4
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Herrera A, Menendez A, Ochoa A, Bardia L, Colombelli J, Pons S. Neurogenesis redirects β-catenin from adherens junctions to the nucleus to promote axonal growth. Development 2023; 150:dev201651. [PMID: 37519286 PMCID: PMC10482005 DOI: 10.1242/dev.201651] [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: 01/27/2023] [Accepted: 07/26/2023] [Indexed: 08/01/2023]
Abstract
Here, we show that, in the developing spinal cord, after the early Wnt-mediated Tcf transcription activation that confers dorsal identity to neural stem cells, neurogenesis redirects β-catenin from the adherens junctions to the nucleus to stimulate Tcf-dependent transcription in a Wnt-independent manner. This new β-catenin activity regulates genes implicated in several aspects of contralateral axon growth, including axon guidance and adhesion. Using live imaging of ex-vivo chick neural tube, we showed that the nuclear accumulation of β-catenin and the rise in Tcf-dependent transcription both initiate before the dismantling of the adherens junctions and remain during the axon elongation process. Notably, we demonstrated that β-catenin activity in post-mitotic cells depends on TCF7L2 and is central to spinal commissural axon growth. Together, our results reveal Wnt-independent Tcf/β-catenin regulation of genes that control the growth and guidance of commissural axons in chick spinal cord.
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Affiliation(s)
- Antonio Herrera
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Anghara Menendez
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Andrea Ochoa
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Lídia Bardia
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Julien Colombelli
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Sebastian Pons
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Científic de Barcelona, Baldiri Reixac 10-12, Barcelona 08028, Spain
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5
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Carranza A, Howard LJ, Brown HE, Ametepe AS, Evans TA. Slit-independent guidance of longitudinal axons by Drosophila Robo3. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539901. [PMID: 37214810 PMCID: PMC10197545 DOI: 10.1101/2023.05.08.539901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Drosophila Robo3 is a member of the evolutionarily conserved Roundabout (Robo) receptor family and one of three Drosophila Robo paralogs. During embryonic ventral nerve cord development, Robo3 does not participate in canonical Slit-dependent midline repulsion, but instead regulates the formation of longitudinal axon pathways at specific positions along the medial-lateral axis. Longitudinal axon guidance by Robo3 is hypothesized to be Slit dependent, but this has not been directly tested. Here we create a series of Robo3 variants in which the N-terminal Ig1 domain is deleted or modified, in order to characterize the functional importance of Ig1 and Slit binding for Robo3's axon guidance activity. We show that Robo3 requires its Ig1 domain for interaction with Slit and for proper axonal localization in embryonic neurons, but deleting Ig1 from Robo3 only partially disrupts longitudinal pathway formation. Robo3 variants with modified Ig1 domains that cannot bind Slit retain proper localization and fully rescue longitudinal axon guidance. Our results indicate that Robo3 guides longitudinal axons independently of Slit, and that sequences both within and outside of Ig1 contribute to this Slit-independent activity.
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Affiliation(s)
- Abigail Carranza
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701
- Current Address: Texas A&M University School of Medicine, Bryan, TX 77807
| | - LaFreda J. Howard
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701
- Current Address: NAVA PBC, Washington, DC 20005
| | - Haley E. Brown
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701
- Current Address: Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | | | - Timothy A. Evans
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701
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6
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Dailey-Krempel B, Martin AL, Jo HN, Junge HJ, Chen Z. A tug of war between DCC and ROBO1 signaling during commissural axon guidance. Cell Rep 2023; 42:112455. [PMID: 37149867 DOI: 10.1016/j.celrep.2023.112455] [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: 11/18/2022] [Revised: 03/07/2023] [Accepted: 04/14/2023] [Indexed: 05/09/2023] Open
Abstract
Dynamic and coordinated axonal responses to changing environments are critical for establishing neural connections. As commissural axons migrate across the CNS midline, they are suggested to switch from being attracted to being repelled in order to approach and to subsequently leave the midline. A molecular mechanism that is hypothesized to underlie this switch in axonal responses is the silencing of Netrin1/Deleted in Colorectal Carcinoma (DCC)-mediated attraction by the repulsive SLIT/ROBO1 signaling. Using in vivo approaches including CRISPR-Cas9-engineered mouse models of distinct Dcc splice isoforms, we show here that commissural axons maintain responsiveness to both Netrin and SLIT during midline crossing, although likely at quantitatively different levels. In addition, full-length DCC in collaboration with ROBO3 can antagonize ROBO1 repulsion in vivo. We propose that commissural axons integrate and balance the opposing DCC and Roundabout (ROBO) signaling to ensure proper guidance decisions during midline entry and exit.
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Affiliation(s)
| | - Andrew L Martin
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ha-Neul Jo
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Harald J Junge
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA
| | - Zhe Chen
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
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7
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Hu Y, Rong R, Wang Y, Yan S, Liu S, Wang L. Downregulating EVA1C exerts the potential to promote neuron growth after neonatal hypoxic-ischemic encephalopathy injury associated with alternative splicing. IBRAIN 2022; 8:481-491. [PMID: 37786591 PMCID: PMC10529346 DOI: 10.1002/ibra.12053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 10/04/2023]
Abstract
Neonatal hypoxic-ischemic encephalopathy (NHIE) is one of the major diseases in newborns during the perinatal stage, which globally is the main reason for children's morbidity and mortality. However, the mechanism of NHIE still remains poorly clear. In this study, the 7-day-old rats were subjected to hypoxic-ischemia (HI), then brain damage was detected. Afterward, the expression of eva-1 homolog C (EVA1C) was measured in vitro by establishing the oxygen-glucose deprivation (OGD) model in SHSY5Y cells and human fetal neurons. Subsequently, the potential function and mechanism of EVA1C were explored by silencing EVA1C and alternative splicing prediction. As a result, obvious neurobehavioral impairment and brain infarction were detected through Zea-Longa score and TTC staining; meanwhile, neuron injury was tested by HE and Nissl staining post HI. Moreover, it was found that the expression of EVA1C was notably upregulated in SHSY5Y cells and human fetal neurons after OGD. In addition, cell survival and growth were increased after silencing EVA1C, which might be associated with alternative splicing. In conclusion, EVA1C interference exhibited potential in promoting neuron survival and growth, associated with exon skipping with the alternative splicing site in 34613318:34687258, which may provide the basis for the therapeutic target and mechanism research of NHIE.
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Affiliation(s)
- Yue Hu
- Department of Anesthesia OperationThe First People's Hospital of Shuangliu DistrictChengduSichuanChina
| | - Rong Rong
- Division of Life Sciences and Medicine, The First Affiliated Hospital of USTCUniversity of Science and Technology of ChinaHefeiAnhuiChina
| | - Yi Wang
- Animal Zoology DepartmentKunming Medical UniversityKunmingYunnanChina
| | - Shan‐Shan Yan
- Animal Zoology DepartmentKunming Medical UniversityKunmingYunnanChina
| | - Su Liu
- Center for Epigenetics and Induced Pluripotent Stem Cells, Kennedy Krieger InstituteJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Lei Wang
- Animal Zoology DepartmentKunming Medical UniversityKunmingYunnanChina
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8
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Moreno-Bravo JA, Rappeneau Q, Roig-Puiggros S, Sotelo C, Chédotal A. Uncoupling axon guidance and neuronal migration in Robo3-deficient inferior olivary neurons. J Comp Neurol 2022; 530:2868-2880. [PMID: 35811330 DOI: 10.1002/cne.25381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/25/2022] [Accepted: 06/02/2022] [Indexed: 12/18/2022]
Abstract
Inferior olivary (IO) neurons are born in the dorsal hindbrain and migrate tangentially toward the ventral midline. During their dorsoventral migration, IO neurons extend long leading processes that cross the midline, transform into axons, and project into the contralateral cerebellum. In absence of the axon guidance receptor Robo3, IO axons fail to cross the midline and project to the ipsilateral cerebellum. Remarkably, the IO cell bodies still reach the midline where they form a nucleus of abnormal cytoarchitecture. The mechanisms underlying the migration of Robo3-deficient IO neurons are unknown. Here, we used three-dimensional imaging and transgenic mice to label subsets of IO neurons and study their migratory behavior in Robo3 knockout. We show that IO migration is delayed in absence of Robo3. Strikingly, Robo3-deficient IO neurons progress toward the midline in a direction opposite to their axons. This occurs through a change of polarity and the generation of a second leading process at the rear of the cell. These results suggest that Robo3 receptor controls the establishment of neuronal polarity and the coupling of axonogenesis and cell body migration in IO neurons.
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Affiliation(s)
- Juan Antonio Moreno-Bravo
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France.,Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), San Juan de Alicante, Spain
| | - Quentin Rappeneau
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | | | | | - Alain Chédotal
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
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9
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Wurmser M, Muppavarapu M, Tait CM, Laumonnerie C, González-Castrillón LM, Wilson SI. Robo2 Receptor Gates the Anatomical Divergence of Neurons Derived From a Common Precursor Origin. Front Cell Dev Biol 2021; 9:668175. [PMID: 34249921 PMCID: PMC8263054 DOI: 10.3389/fcell.2021.668175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/03/2021] [Indexed: 12/25/2022] Open
Abstract
Sensory information relayed to the brain is dependent on complex, yet precise spatial organization of neurons. This anatomical complexity is generated during development from a surprisingly small number of neural stem cell domains. This raises the question of how neurons derived from a common precursor domain respond uniquely to their environment to elaborate correct spatial organization and connectivity. We addressed this question by exploiting genetically labeled mouse embryonic dorsal interneuron 1 (dI1) neurons that are derived from a common precursor domain and give rise to spinal projection neurons with distinct organization of cell bodies with axons projecting either commissurally (dI1c) or ipsilaterally (dI1i). In this study, we examined how the guidance receptor, Robo2, which is a canonical Robo receptor, influenced dI1 guidance during embryonic development. Robo2 was enriched in embryonic dI1i neurons, and loss of Robo2 resulted in misguidance of dI1i axons, whereas dI1c axons remained unperturbed within the mantle zone and ventral commissure. Further, Robo2 profoundly influenced dI1 cell body migration, a feature that was partly dependent on Slit2 signaling. These data suggest that dI1 neurons are dependent on Robo2 for their organization. This work integrated with the field support of a model whereby canonical Robo2 vs. non-canonical Robo3 receptor expression facilitates projection neurons derived from a common precursor domain to read out the tissue environment uniquely giving rise to correct anatomical organization.
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Affiliation(s)
- Maud Wurmser
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | | | | | | | | | - Sara Ivy Wilson
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
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10
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Monteiro FA, Miranda RM, Samina MC, Dias AF, Raposo AASF, Oliveira P, Reguenga C, Castro DS, Lima D. Tlx3 Exerts Direct Control in Specifying Excitatory Over Inhibitory Neurons in the Dorsal Spinal Cord. Front Cell Dev Biol 2021; 9:642697. [PMID: 33996801 PMCID: PMC8117147 DOI: 10.3389/fcell.2021.642697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/30/2021] [Indexed: 11/28/2022] Open
Abstract
The spinal cord dorsal horn is a major station for integration and relay of somatosensory information and comprises both excitatory and inhibitory neuronal populations. The homeobox gene Tlx3 acts as a selector gene to control the development of late-born excitatory (dILB) neurons by specifying glutamatergic transmitter fate in dorsal spinal cord. However, since Tlx3 direct transcriptional targets remain largely unknown, it remains to be uncovered how Tlx3 functions to promote excitatory cell fate. Here we combined a genomics approach based on chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq) and expression profiling, with validation experiments in Tlx3 null embryos, to characterize the transcriptional program of Tlx3 in mouse embryonic dorsal spinal cord. We found most dILB neuron specific genes previously identified to be directly activated by Tlx3. Surprisingly, we found Tlx3 also directly represses many genes associated with the alternative inhibitory dILA neuronal fate. In both cases, direct targets include transcription factors and terminal differentiation genes, showing that Tlx3 directly controls cell identity at distinct levels. Our findings provide a molecular frame for the master regulatory role of Tlx3 in developing glutamatergic dILB neurons. In addition, they suggest a novel function for Tlx3 as direct repressor of GABAergic dILA identity, pointing to how generation of the two alternative cell fates being tightly coupled.
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Affiliation(s)
- Filipe A Monteiro
- Unidade de Biologia Experimental, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,Pain Research Group, Instituto de Biologia Molecular e Celular, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Rafael M Miranda
- Unidade de Biologia Experimental, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,Pain Research Group, Instituto de Biologia Molecular e Celular, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Marta C Samina
- Unidade de Biologia Experimental, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,Pain Research Group, Instituto de Biologia Molecular e Celular, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Ana F Dias
- Pain Research Group, Instituto de Biologia Molecular e Celular, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Alexandre A S F Raposo
- Molecular Neurobiology Group, Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Patrícia Oliveira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Diagnostics, Institute of Molecular Pathology and Immunology, University of Porto, Porto, Portugal
| | - Carlos Reguenga
- Unidade de Biologia Experimental, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,Pain Research Group, Instituto de Biologia Molecular e Celular, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Diogo S Castro
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Molecular Neurobiology Group, Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Stem Cells & Neurogenesis Group, Instituto de Biologia Molecular e Celular, Porto, Portugal
| | - Deolinda Lima
- Unidade de Biologia Experimental, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,Pain Research Group, Instituto de Biologia Molecular e Celular, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
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11
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Daiber T, VanderZwan-Butler CJ, Bashaw GJ, Evans TA. Conserved and divergent aspects of Robo receptor signaling and regulation between Drosophila Robo1 and C. elegans SAX-3. Genetics 2021; 217:iyab018. [PMID: 33789352 PMCID: PMC8045725 DOI: 10.1093/genetics/iyab018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/28/2021] [Indexed: 11/24/2022] Open
Abstract
The evolutionarily conserved Roundabout (Robo) family of axon guidance receptors control midline crossing of axons in response to the midline repellant ligand Slit in bilaterian animals including insects, nematodes, and vertebrates. Despite this strong evolutionary conservation, it is unclear whether the signaling mechanism(s) downstream of Robo receptors are similarly conserved. To directly compare midline repulsive signaling in Robo family members from different species, here we use a transgenic approach to express the Robo family receptor SAX-3 from the nematode Caenorhabditis elegans in neurons of the fruit fly, Drosophila melanogaster. We examine SAX-3's ability to repel Drosophila axons from the Slit-expressing midline in gain of function assays, and test SAX-3's ability to substitute for Drosophila Robo1 during fly embryonic development in genetic rescue experiments. We show that C. elegans SAX-3 is properly translated and localized to neuronal axons when expressed in the Drosophila embryonic CNS, and that SAX-3 can signal midline repulsion in Drosophila embryonic neurons, although not as efficiently as Drosophila Robo1. Using a series of Robo1/SAX-3 chimeras, we show that the SAX-3 cytoplasmic domain can signal midline repulsion to the same extent as Robo1 when combined with the Robo1 ectodomain. We show that SAX-3 is not subject to endosomal sorting by the negative regulator Commissureless (Comm) in Drosophila neurons in vivo, and that peri-membrane and ectodomain sequences are both required for Comm sorting of Drosophila Robo1.
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Affiliation(s)
- Trent Daiber
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | | | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Timothy A Evans
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
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12
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Dorskind JM, Kolodkin AL. Revisiting and refining roles of neural guidance cues in circuit assembly. Curr Opin Neurobiol 2021; 66:10-21. [PMID: 32823181 PMCID: PMC10725571 DOI: 10.1016/j.conb.2020.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/16/2020] [Accepted: 07/27/2020] [Indexed: 12/14/2022]
Abstract
Neural guidance mechanisms ensure the precise targeting and synaptogenesis events essential for normal circuit function. Neuronal growth cones encounter numerous attractive and repulsive cues as they navigate toward their intermediate and final targets; temporal and spatial regulation of these responses are critical for circuit assembly. Recent work highlights the complexity of these events throughout neural development and the multifaceted functions of a wide range of guidance cues. Here, we discuss recent studies that leverage advances in genetics, single cell tracing, transcriptomics and proteomics to further our understanding of the molecular mechanisms underlying neural guidance and overall circuit organization.
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Affiliation(s)
- Joelle M Dorskind
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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13
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Zang Y, Chaudhari K, Bashaw GJ. New insights into the molecular mechanisms of axon guidance receptor regulation and signaling. Curr Top Dev Biol 2021; 142:147-196. [PMID: 33706917 DOI: 10.1016/bs.ctdb.2020.11.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
As the nervous system develops, newly differentiated neurons need to extend their axons toward their synaptic targets to form functional neural circuits. During this highly dynamic process of axon pathfinding, guidance receptors expressed at the tips of motile axons interact with soluble guidance cues or membrane tethered molecules present in the environment to be either attracted toward or repelled away from the source of these cues. As competing cues are often present at the same location and during the same developmental period, guidance receptors need to be both spatially and temporally regulated in order for the navigating axons to make appropriate guidance decisions. This regulation is exerted by a diverse array of molecular mechanisms that have come into focus over the past several decades and these mechanisms ensure that the correct complement of surface receptors is present on the growth cone, a fan-shaped expansion at the tip of the axon. This dynamic, highly motile structure is defined by a lamellipodial network lining the periphery of the growth cone interspersed with finger-like filopodial projections that serve to explore the surrounding environment. Once axon guidance receptors are deployed at the right place and time at the growth cone surface, they respond to their respective ligands by initiating a complex set of signaling events that serve to rearrange the growth cone membrane and the actin and microtubule cytoskeleton to affect axon growth and guidance. In this review, we highlight recent advances that shed light on the rich complexity of mechanisms that regulate axon guidance receptor distribution, activation and downstream signaling.
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Affiliation(s)
- Yixin Zang
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Karina Chaudhari
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
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14
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Alvarez S, Varadarajan SG, Butler SJ. Dorsal commissural axon guidance in the developing spinal cord. Curr Top Dev Biol 2020; 142:197-231. [PMID: 33706918 DOI: 10.1016/bs.ctdb.2020.10.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Commissural axons have been a key model system for identifying axon guidance signals in vertebrates. This review summarizes the current thinking about the molecular and cellular mechanisms that establish a specific commissural neural circuit: the dI1 neurons in the developing spinal cord. We assess the contribution of long- and short-range signaling while sequentially following the developmental timeline from the birth of dI1 neurons, to the extension of commissural axons first circumferentially and then contralaterally into the ventral funiculus.
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Affiliation(s)
- Sandy Alvarez
- Department of Neurobiology, University of California, Los Angeles, CA, United States; Molecular Biology Interdepartmental Doctoral Program, University of California, Los Angeles, CA, United States
| | | | - Samantha J Butler
- Department of Neurobiology, University of California, Los Angeles, CA, United States; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, CA, United States.
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15
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Suter TACS, Blagburn SV, Fisher SE, Anderson-Keightly HM, D'Elia KP, Jaworski A. TAG-1 Multifunctionality Coordinates Neuronal Migration, Axon Guidance, and Fasciculation. Cell Rep 2020; 30:1164-1177.e7. [PMID: 31995756 PMCID: PMC7049094 DOI: 10.1016/j.celrep.2019.12.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 10/25/2019] [Accepted: 12/22/2019] [Indexed: 11/03/2022] Open
Abstract
Neuronal migration, axon fasciculation, and axon guidance need to be closely coordinated for neural circuit assembly. Spinal motor neurons (MNs) face unique challenges during development because their cell bodies reside within the central nervous system (CNS) and their axons project to various targets in the body periphery. The molecular mechanisms that contain MN somata within the spinal cord while allowing their axons to exit the CNS and navigate to their final destinations remain incompletely understood. We find that the MN cell surface protein TAG-1 anchors MN cell bodies in the spinal cord to prevent their emigration, mediates motor axon fasciculation during CNS exit, and guides motor axons past dorsal root ganglia. TAG-1 executes these varied functions in MN development independently of one another. Our results identify TAG-1 as a key multifunctional regulator of MN wiring that coordinates neuronal migration, axon fasciculation, and axon guidance. Suter et al. demonstrate that the motor neuron cell surface molecule TAG-1 confines motor neurons to the central nervous system, promotes motor axon fasciculation, and steers motor axons past inappropriate targets. This study highlights how a single cell adhesion molecule coordinates multiple steps in neuronal wiring through partially divergent mechanisms.
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Affiliation(s)
- Tracey A C S Suter
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
| | - Sara V Blagburn
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
| | - Sophie E Fisher
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
| | | | - Kristen P D'Elia
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Department of Biology, Providence College, Providence, RI 02918, USA
| | - Alexander Jaworski
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA.
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16
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Pak JS, DeLoughery ZJ, Wang J, Acharya N, Park Y, Jaworski A, Özkan E. NELL2-Robo3 complex structure reveals mechanisms of receptor activation for axon guidance. Nat Commun 2020; 11:1489. [PMID: 32198364 PMCID: PMC7083938 DOI: 10.1038/s41467-020-15211-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 02/24/2020] [Indexed: 11/24/2022] Open
Abstract
Axon pathfinding is critical for nervous system development, and it is orchestrated by molecular cues that activate receptors on the axonal growth cone. Robo family receptors bind Slit guidance cues to mediate axon repulsion. In mammals, the divergent family member Robo3 does not bind Slits, but instead signals axon repulsion from its own ligand, NELL2. Conversely, canonical Robos do not mediate NELL2 signaling. Here, we present the structures of NELL-Robo3 complexes, identifying a mode of ligand engagement for Robos that is orthogonal to Slit binding. We elucidate the structural basis for differential binding between NELL and Robo family members and show that NELL2 repulsive activity is a function of its Robo3 affinity and is enhanced by ligand trimerization. Our results reveal a mechanism of oligomerization-induced Robo activation for axon guidance and shed light on Robo family member ligand binding specificity, conformational variability, divergent modes of signaling, and evolution.
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Affiliation(s)
- Joseph S Pak
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
- Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, 60637, USA
| | - Zachary J DeLoughery
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI, 02912, USA
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI, 02912, USA
| | - Jing Wang
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
- Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, 60637, USA
| | - Nischal Acharya
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI, 02912, USA
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI, 02912, USA
| | - Yeonwoo Park
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
| | - Alexander Jaworski
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI, 02912, USA.
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI, 02912, USA.
| | - Engin Özkan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA.
- Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, 60637, USA.
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17
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Abstract
The spinal cord receives, relays and processes sensory information from the periphery and integrates this information with descending inputs from supraspinal centres to elicit precise and appropriate behavioural responses and orchestrate body movements. Understanding how the spinal cord circuits that achieve this integration are wired during development is the focus of much research interest. Several families of proteins have well-established roles in guiding developing spinal cord axons, and recent findings have identified new axon guidance molecules. Nevertheless, an integrated view of spinal cord network development is lacking, and many current models have neglected the cellular and functional diversity of spinal cord circuits. Recent advances challenge the existing spinal cord axon guidance dogmas and have provided a more complex, but more faithful, picture of the ontogenesis of vertebrate spinal cord circuits.
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18
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Aizawa S, Okada T, Keino-Masu K, Doan TH, Koganezawa T, Akiyama M, Tamaoka A, Masu M. Abnormal Pyramidal Decussation and Bilateral Projection of the Corticospinal Tract Axons in Mice Lacking the Heparan Sulfate Endosulfatases, Sulf1 and Sulf2. Front Mol Neurosci 2020; 12:333. [PMID: 32038163 PMCID: PMC6985096 DOI: 10.3389/fnmol.2019.00333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/27/2019] [Indexed: 11/13/2022] Open
Abstract
The corticospinal tract (CST) plays an important role in controlling voluntary movement. Because the CST has a long trajectory throughout the brain toward the spinal cord, many axon guidance molecules are required to navigate the axons correctly during development. Previously, we found that double-knockout (DKO) mouse embryos lacking the heparan sulfate endosulfatases, Sulf1 and Sulf2, showed axon guidance defects of the CST owing to the abnormal accumulation of Slit2 protein on the brain surface. However, postnatal development of the CST, especially the pyramidal decussation and spinal cord projection, could not be assessed because DKO mice on a C57BL/6 background died soon after birth. We recently found that Sulf1/2 DKO mice on a mixed C57BL/6 and CD-1/ICR background can survive into adulthood and therefore investigated the anatomy and function of the CST in the adult DKO mice. In Sulf1/2 DKO mice, abnormal dorsal deviation of the CST fibers on the midbrain surface persisted after maturation of the CST. At the pyramidal decussation, some CST fibers located near the midline crossed the midline, whereas others located more laterally extended ipsilaterally. In the spinal cord, the crossed CST fibers descended in the dorsal funiculus on the contralateral side and entered the contralateral gray matter normally, whereas the uncrossed fibers descended in the lateral funiculus on the ipsilateral side and entered the ipsilateral gray matter. As a result, the CST fibers that originated from 1 side of the brain projected bilaterally in the DKO spinal cord. Consistently, microstimulation of 1 side of the motor cortex evoked electromyogram responses only in the contralateral forelimb muscles of the wild-type mice, whereas the same stimulation evoked bilateral responses in the DKO mice. The functional consequences of the CST defects in the Sulf1/2 DKO mice were examined using the grid-walking, staircase, and single pellet-reaching tests, which have been used to evaluate motor function in mice. Compared with the wild-type mice, the Sulf1/2 DKO mice showed impaired performance in these tests, indicating deficits in motor function. These findings suggest that disruption of Sulf1/2 genes leads to both anatomical and functional defects of the CST.
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Affiliation(s)
- Satoshi Aizawa
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Department of Molecular Neurobiology, Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.,Department of Neurology, Division of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Takuya Okada
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Department of Molecular Neurobiology, Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Kazuko Keino-Masu
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Department of Molecular Neurobiology, Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Tri Huu Doan
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Department of Physiology, Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Tadachika Koganezawa
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Department of Physiology, Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.,Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Masahiro Akiyama
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Akira Tamaoka
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Department of Neurology, Division of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Masayuki Masu
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.,Department of Molecular Neurobiology, Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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19
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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: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [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
N6-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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20
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Roig-Puiggros S, Vigouroux RJ, Beckman D, Bocai NI, Chiou B, Davimes J, Gomez G, Grassi S, Hoque A, Karikari TK, Kiffer F, Lopez M, Lunghi G, Mazengenya P, Meier S, Olguín-Albuerne M, Oliveira MM, Paraíso-Luna J, Pradhan J, Radiske A, Ramos-Hryb AB, Ribeiro MC, Schellino R, Selles MC, Singh S, Theotokis P, Chédotal A. Construction and reconstruction of brain circuits: normal and pathological axon guidance. J Neurochem 2019; 153:10-32. [PMID: 31630412 DOI: 10.1111/jnc.14900] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 02/06/2023]
Abstract
Perception of our environment entirely depends on the close interaction between the central and peripheral nervous system. In order to communicate each other, both systems must develop in parallel and in coordination. During development, axonal projections from the CNS as well as the PNS must extend over large distances to reach their appropriate target cells. To do so, they read and follow a series of axon guidance molecules. Interestingly, while these molecules play critical roles in guiding developing axons, they have also been shown to be critical in other major neurodevelopmental processes, such as the migration of cortical progenitors. Currently, a major hurdle for brain repair after injury or neurodegeneration is the absence of axonal regeneration in the mammalian CNS. By contrasts, PNS axons can regenerate. Many hypotheses have been put forward to explain this paradox but recent studies suggest that hacking neurodevelopmental mechanisms may be the key to promote CNS regeneration. Here we provide a seminar report written by trainees attending the second Flagship school held in Alpbach, Austria in September 2018 organized by the International Society for Neurochemistry (ISN) together with the Journal of Neurochemistry (JCN). This advanced school has brought together leaders in the fields of neurodevelopment and regeneration in order to discuss major keystones and future challenges in these respective fields.
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Affiliation(s)
| | - Robin J Vigouroux
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Danielle Beckman
- California National Primate Research Center, UC Davis, Davis, California, USA
| | - Nadia I Bocai
- Laboratory of Amyloidosis and Neurodegeneration, Fundación Instituto Leloir, Buenos Aires, Argentina.,Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Brian Chiou
- Department of Pediatrics, University of California - San Francisco, San Francisco, California, USA
| | - Joshua Davimes
- Faculty of Health Sciences School of Anatomical Sciences, University of the Witwatersrand, Parktown Johannesburg, South Africa
| | - Gimena Gomez
- Laboratorio de Parkinson Experimental, Instituto de Investigaciones Farmacológicas (ININFA-CONICET-UBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Sara Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Ashfaqul Hoque
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Thomas K Karikari
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.,School of Life Sciences, University of Warwick, Coventry, UK.,Midlands Integrative Biosciences Training Partnership, University of Warwick, Coventry, UK
| | - Frederico Kiffer
- Division of Radiation Health, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.,Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Mary Lopez
- Institute for Stroke and Dementia Research, LMU Munich, Munich, Germany
| | - Giulia Lunghi
- Department of Medical Biotechnology and Translational Medicin, University of Milano, Segrate, Italy
| | - Pedzisai Mazengenya
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sonja Meier
- Queensland Brain Institute, The University of Queensland, St Lucia, Queensland, Australia
| | - Mauricio Olguín-Albuerne
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Mauricio M Oliveira
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juan Paraíso-Luna
- Ramón y Cajal Institute of Health Research (IRYCIS), Department of Biochemistry and Molecular Biology and University Research Institute in Neurochemistry (IUIN), Complutense University, Madrid, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jonu Pradhan
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Andressa Radiske
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Ana Belén Ramos-Hryb
- Instituto de Biología y Medicina Experimental (IBYME)-CONICET, Buenos Aires, Argentina.,Grupo de Neurociencia de Sistemas, Instituto de Fisiología y Biofísica (IFIBIO) Bernardo Houssay, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Mayara C Ribeiro
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, New York, USA
| | - Roberta Schellino
- Neuroscience Department "Rita Levi-Montalcini" and Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Torino, Italy
| | - Maria Clara Selles
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Shripriya Singh
- System Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Paschalis Theotokis
- Department of Neurology, Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Thessaloniki, Macedonia, Greece
| | - Alain Chédotal
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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21
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Pignata A, Ducuing H, Boubakar L, Gardette T, Kindbeiter K, Bozon M, Tauszig-Delamasure S, Falk J, Thoumine O, Castellani V. A Spatiotemporal Sequence of Sensitization to Slits and Semaphorins Orchestrates Commissural Axon Navigation. Cell Rep 2019; 29:347-362.e5. [PMID: 31597096 DOI: 10.1016/j.celrep.2019.08.098] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/05/2019] [Accepted: 08/28/2019] [Indexed: 01/24/2023] Open
Abstract
Accurate perception of guidance cues is crucial for cell and axon migration. During initial navigation in the spinal cord, commissural axons are kept insensitive to midline repellents. Upon midline crossing in the floor plate, they switch on responsiveness to Slit and Semaphorin repulsive signals and are thus propelled away and prevented from crossing back. Whether and how the different midline repellents control specific aspects of this navigation remain to be elucidated. We set up a paradigm for live-imaging and super-resolution analysis of PlexinA1, Neuropilin-2, and Robo1/2 receptor dynamics during commissural growth cone navigation in chick and mouse embryos. We uncovered a remarkable program of sensitization to midline cues achieved by unique spatiotemporal sequences of receptor allocation at the growth-cone surface that orchestrates receptor-specific growth-cone behavior changes. This reveals post-translational mechanisms whereby coincident guidance signals are temporally resolved to allow the generation of specific guidance responses.
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Affiliation(s)
- Aurora Pignata
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Hugo Ducuing
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Leila Boubakar
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Thibault Gardette
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Karine Kindbeiter
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Muriel Bozon
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Servane Tauszig-Delamasure
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Julien Falk
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France
| | - Olivier Thoumine
- Interdisciplinary Institute for Neuroscience, UMR CNRS 5297, University of Bordeaux 146 rue Léo Saignat, 33000 Bordeaux, France
| | - Valérie Castellani
- University of Lyon, University of Lyon 1 Claude Bernard Lyon1, NeuroMyoGene Institute, CNRS UMR5310, INSERM U1217, 8 Avenue Rockefeller, 69008 Lyon, France.
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22
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Comer JD, Alvarez S, Butler SJ, Kaltschmidt JA. Commissural axon guidance in the developing spinal cord: from Cajal to the present day. Neural Dev 2019; 14:9. [PMID: 31514748 PMCID: PMC6739980 DOI: 10.1186/s13064-019-0133-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 08/23/2019] [Indexed: 12/11/2022] Open
Abstract
During neuronal development, the formation of neural circuits requires developing axons to traverse a diverse cellular and molecular environment to establish synaptic contacts with the appropriate postsynaptic partners. Essential to this process is the ability of developing axons to navigate guidance molecules presented by specialized populations of cells. These cells partition the distance traveled by growing axons into shorter intervals by serving as intermediate targets, orchestrating the arrival and departure of axons by providing attractive and repulsive guidance cues. The floor plate in the central nervous system (CNS) is a critical intermediate target during neuronal development, required for the extension of commissural axons across the ventral midline. In this review, we begin by giving a historical overview of the ventral commissure and the evolutionary purpose of decussation. We then review the axon guidance studies that have revealed a diverse assortment of midline guidance cues, as well as genetic and molecular regulatory mechanisms required for coordinating the commissural axon response to these cues. Finally, we examine the contribution of dysfunctional axon guidance to neurological diseases.
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Affiliation(s)
- J D Comer
- Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA.,Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA.,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, USA
| | - S Alvarez
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.,Molecular Biology Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - S J Butler
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - J A Kaltschmidt
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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23
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Nonsense-mediated RNA decay in the brain: emerging modulator of neural development and disease. Nat Rev Neurosci 2019; 19:715-728. [PMID: 30410025 DOI: 10.1038/s41583-018-0079-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Steady-state RNA levels are controlled by the balance between RNA synthesis and RNA turnover. A selective RNA turnover mechanism that has received recent attention in neurons is nonsense-mediated RNA decay (NMD). NMD has been shown to influence neural development, neural stem cell differentiation decisions, axon guidance and synaptic plasticity. In humans, NMD factor gene mutations cause some forms of intellectual disability and are associated with neurodevelopmental disorders, including schizophrenia and autism spectrum disorder. Impairments in NMD are linked to neurodegenerative disorders, including amyotrophic lateral sclerosis. We discuss these findings, their clinical implications and challenges for the future.
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24
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Johnson V, Junge HJ, Chen Z. Temporal regulation of axonal repulsion by alternative splicing of a conserved microexon in mammalian Robo1 and Robo2. eLife 2019; 8:e46042. [PMID: 31392959 PMCID: PMC6687390 DOI: 10.7554/elife.46042] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 07/25/2019] [Indexed: 11/13/2022] Open
Abstract
Proper connectivity of the nervous system requires temporal and spatial control of axon guidance signaling. As commissural axons navigate across the CNS midline, ROBO-mediated repulsion has traditionally been thought to be repressed before crossing, and then to become upregulated after crossing. The regulation of the ROBO receptors involves multiple mechanisms that control protein expression, trafficking, and activity. Here, we report that mammalian ROBO1 and ROBO2 are not uniformly inhibited precrossing and are instead subject to additional temporal control via alternative splicing at a conserved microexon. The NOVA splicing factors regulate the developmental expression of ROBO1 and ROBO2 variants with small sequence differences and distinct guidance activities. As a result, ROBO-mediated axonal repulsion is activated early in development to prevent premature crossing and becomes inhibited later to allow crossing. Postcrossing, the ROBO1 and ROBO2 isoforms are disinhibited to prevent midline reentry and to guide postcrossing commissural axons to distinct mediolateral positions.
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Affiliation(s)
- Verity Johnson
- Department of Molecular, Cellular and Developmental BiologyUniversity of ColoradoBoulderUnited States
| | - Harald J Junge
- Department of Molecular, Cellular and Developmental BiologyUniversity of ColoradoBoulderUnited States
| | - Zhe Chen
- Department of Molecular, Cellular and Developmental BiologyUniversity of ColoradoBoulderUnited States
- Linda Crnic Institute for Down SyndromeUniversity of Colorado school of MedicineAuroraUnited States
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25
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Ye X, Qiu Y, Gao Y, Wan D, Zhu H. A Subtle Network Mediating Axon Guidance: Intrinsic Dynamic Structure of Growth Cone, Attractive and Repulsive Molecular Cues, and the Intermediate Role of Signaling Pathways. Neural Plast 2019; 2019:1719829. [PMID: 31097955 PMCID: PMC6487106 DOI: 10.1155/2019/1719829] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/25/2019] [Accepted: 03/06/2019] [Indexed: 01/01/2023] Open
Abstract
A fundamental feature of both early nervous system development and axon regeneration is the guidance of axonal projections to their targets in order to assemble neural circuits that control behavior. In the navigation process where the nerves grow toward their targets, the growth cones, which locate at the tips of axons, sense the environment surrounding them, including varies of attractive or repulsive molecular cues, then make directional decisions to adjust their navigation journey. The turning ability of a growth cone largely depends on its highly dynamic skeleton, where actin filaments and microtubules play a very important role in its motility. In this review, we summarize some possible mechanisms underlying growth cone motility, relevant molecular cues, and signaling pathways in axon guidance of previous studies and discuss some questions regarding directions for further studies.
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Affiliation(s)
- Xiyue Ye
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
| | - Yan Qiu
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
| | - Yuqing Gao
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
| | - Dong Wan
- Department of Emergency, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Huifeng Zhu
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
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26
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Gruner HN, Kim M, Mastick GS. Robo1 and 2 Repellent Receptors Cooperate to Guide Facial Neuron Cell Migration and Axon Projections in the Embryonic Mouse Hindbrain. Neuroscience 2019; 402:116-129. [PMID: 30685539 PMCID: PMC6435285 DOI: 10.1016/j.neuroscience.2019.01.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 01/12/2019] [Accepted: 01/14/2019] [Indexed: 11/19/2022]
Abstract
The facial nerve is necessary for our ability to eat, speak, and make facial expressions. Both the axons and cell bodies of the facial nerve undergo a complex embryonic developmental pattern involving migration of the cell bodies caudally and tangentially through rhombomeres, and simultaneously the axons projecting to exit the hindbrain to form the facial nerve. Our goal in this study was to test the functions of the chemorepulsive receptors Robo1 and Robo2 in facial neuron migration and axon projection by analyzing genetically marked motor neurons in double-mutant mouse embryos through the migration time course, E10.0-E13.5. In Robo1/2 double mutants, axon projection and cell body migration errors were more severe than in single mutants. Most axons did not make it to their motor exit point, and instead projected into and longitudinally within the floor plate. Surprisingly, some facial neurons had multiple axons exiting and projecting into the floor plate. At the same time, a subset of mutant facial cell bodies failed to migrate caudally, and instead either streamed dorsally toward the exit point or shifted into the floor plate. We conclude that Robo1 and Robo2 have redundant functions to guide multiple aspects of the complex cell migration of the facial nucleus, as well as regulating axon trajectories and suppressing formation of ectopic axons.
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Affiliation(s)
- Hannah N. Gruner
- Department of Biology, University of Nevada, 1664 N Virginia St, Reno, NV 89557, USA.
| | - Minkyung Kim
- Department of Biology, University of Nevada, 1664 N Virginia St, Reno, NV 89557, USA.
| | - Grant S. Mastick
- Department of Biology, University of Nevada, 1664 N Virginia St, Reno, NV 89557, USA.
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27
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Taroc EZM, Lin JM, Tulloch AJ, Jaworski A, Forni PE. GnRH-1 Neural Migration From the Nose to the Brain Is Independent From Slit2, Robo3 and NELL2 Signaling. Front Cell Neurosci 2019; 13:70. [PMID: 30881290 PMCID: PMC6406018 DOI: 10.3389/fncel.2019.00070] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/12/2019] [Indexed: 11/28/2022] Open
Abstract
Gonadotropin releasing hormone-1 (GnRH-1) neurons play a pivotal role in controlling pubertal onset and fertility once they reach their hypothalamic location. During embryonic development, GnRH-1 neurons migrate from the nasal area to the hypothalamus where they modulate gonadotropin release from the pituitary gland. Defective migration of the GnRH-1 neurons to the brain, lack of GnRH-1 secretion or signaling cause hypogonadotropic hypogonadism (HH), a pathology characterized by delayed or absence of puberty. Binding of the guidance cue Slit2 to the receptor roundabout 3 (Robo3) has been proposed to modulate GnRH-1 cell motility and basal forebrain (bFB) access during migration. However, evidence suggests that Neural EGFL Like 2 (NELL2), not Slit2, binds to Robo3. To resolve this discrepancy, we analyzed GnRH-1 neuronal migration in NELL2, Robo3, and Slit2 knock-out mouse lines. Our data do not confirm a negative effect for monogenic Robo3 and Slit2 mutations on GnRH-1 neuronal migration from the nasal area to the brain. Moreover, we found no changes in GnRH-1 neuronal migration in the brain after NELL2 loss-of-function. However, we found that Slit2 loss-of-function alters the patterning of GnRH-1 cells in the brain, suggesting that Slit2 loss-of-function affects GnRH-1 cell positioning in the brain in a Robo3 independent fashion. Our results challenge previous theories on GnRH-1 neuronal migration mechanisms and provide a new impetus to identify and understand the complex genetic mechanisms causing disorders like Kallmann syndrome (KS) and HH.
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Affiliation(s)
- Ed Zandro M Taroc
- Department of Biological Sciences, University at Albany, Albany, NY, United States
| | - Jennifer M Lin
- Department of Biological Sciences, University at Albany, Albany, NY, United States
| | - Alastair J Tulloch
- Department of Neuroscience, Brown University, Providence, RI, United States
| | - Alexander Jaworski
- Department of Neuroscience, Brown University, Providence, RI, United States
| | - Paolo E Forni
- Department of Biological Sciences, University at Albany, Albany, NY, United States
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28
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Lindenmaier LB, Parmentier N, Guo C, Tissir F, Wright KM. Dystroglycan is a scaffold for extracellular axon guidance decisions. eLife 2019; 8:42143. [PMID: 30758284 PMCID: PMC6395066 DOI: 10.7554/elife.42143] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 02/13/2019] [Indexed: 12/13/2022] Open
Abstract
Axon guidance requires interactions between extracellular signaling molecules and transmembrane receptors, but how appropriate context-dependent decisions are coordinated outside the cell remains unclear. Here we show that the transmembrane glycoprotein Dystroglycan interacts with a changing set of environmental cues that regulate the trajectories of extending axons throughout the mammalian brain and spinal cord. Dystroglycan operates primarily as an extracellular scaffold during axon guidance, as it functions non-cell autonomously and does not require signaling through its intracellular domain. We identify the transmembrane receptor Celsr3/Adgrc3 as a binding partner for Dystroglycan, and show that this interaction is critical for specific axon guidance events in vivo. These findings establish Dystroglycan as a multifunctional scaffold that coordinates extracellular matrix proteins, secreted cues, and transmembrane receptors to regulate axon guidance.
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Affiliation(s)
| | - Nicolas Parmentier
- Institiute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Caiying Guo
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Fadel Tissir
- Institiute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science University, Portland, United States
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29
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Kinoshita-Kawada M, Hasegawa H, Hongu T, Yanagi S, Kanaho Y, Masai I, Mishima T, Chen X, Tsuboi Y, Rao Y, Yuasa-Kawada J, Wu JY. A crucial role for Arf6 in the response of commissural axons to Slit. Development 2019; 146:dev172106. [PMID: 30674481 PMCID: PMC6382006 DOI: 10.1242/dev.172106] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 01/14/2019] [Indexed: 12/23/2022]
Abstract
A switch in the response of commissural axons to the repellent Slit is crucial for ensuring that they cross the ventral midline only once. However, the underlying mechanisms remain to be elucidated. We have found that both endocytosis and recycling of Robo1 receptor are crucial for modulating Slit sensitivity in vertebrate commissural axons. Robo1 endocytosis and its recycling back to the cell surface maintained the stability of axonal Robo1 during Slit stimulation. We identified Arf6 guanosine triphosphatase and its activators, cytohesins, as previously unknown components in Slit-Robo1 signalling in vertebrate commissural neurons. Slit-Robo1 signalling activated Arf6. The Arf6-deficient mice exhibited marked defects in commissural axon midline crossing. Our data showed that a Robo1 endocytosis-triggered and Arf6-mediated positive-feedback strengthens the Slit response in commissural axons upon their midline crossing. Furthermore, the cytohesin-Arf6 pathways modulated this self-enhancement of the Slit response before and after midline crossing, resulting in a switch that reinforced robust regulation of axon midline crossing. Our study provides insights into endocytic trafficking-mediated mechanisms for spatiotemporally controlled axonal responses and uncovers new players in the midline switch in Slit responsiveness of commissural axons.
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Affiliation(s)
- Mariko Kinoshita-Kawada
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
- Department of Neurology, Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Neurology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Hiroshi Hasegawa
- Department of Physiological Chemistry, Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Tsunaki Hongu
- Department of Physiological Chemistry, Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Shigeru Yanagi
- Laboratory of Molecular Biochemistry, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Yasunori Kanaho
- Department of Physiological Chemistry, Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Ichiro Masai
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Takayasu Mishima
- Department of Neurology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Xiaoping Chen
- Department of Neurology, Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Yoshio Tsuboi
- Department of Neurology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Yi Rao
- State Key Laboratory of Biomembrane and Membrane Biology, Peking-Tsinghua Center for Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University School of Life Sciences, Beijing 100871, China
| | - Junichi Yuasa-Kawada
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
- Department of Neurology, Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Neurology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
- Center for Advanced Medical Innovation, Kyushu University, Fukuoka 812-8582, Japan
- Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Jane Y Wu
- Department of Neurology, Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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30
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Melrose J. Keratan sulfate (KS)-proteoglycans and neuronal regulation in health and disease: the importance of KS-glycodynamics and interactive capability with neuroregulatory ligands. J Neurochem 2019; 149:170-194. [PMID: 30578672 DOI: 10.1111/jnc.14652] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 11/26/2018] [Accepted: 12/13/2018] [Indexed: 12/18/2022]
Abstract
Compared to the other classes of glycosaminoglycans (GAGs), that is, chondroitin/dermatan sulfate, heparin/heparan sulfate and hyaluronan, keratan sulfate (KS), have the least known of its interactive properties. In the human body, the cornea and the brain are the two most abundant tissue sources of KS. Embryonic KS is synthesized as a linear poly-N-acetyllactosamine chain of d-galactose-GlcNAc repeat disaccharides which become progressively sulfated with development, sulfation of GlcNAc is more predominant than galactose. KS contains multi-sulfated high-charge density, monosulfated and non-sulfated poly-N-acetyllactosamine regions and thus is a heterogeneous molecule in terms of chain length and charge distribution. A recent proteomics study on corneal KS demonstrated its interactivity with members of the Slit-Robbo and Ephrin-Ephrin receptor families and proteins which regulate Rho GTPase signaling and actin polymerization/depolymerization in neural development and differentiation. KS decorates a number of peripheral nervous system/CNS proteoglycan (PG) core proteins. The astrocyte KS-PG abakan defines functional margins of the brain and is up-regulated following trauma. The chondroitin sulfate/KS PG aggrecan forms perineuronal nets which are dynamic neuroprotective structures with anti-oxidant properties and roles in neural differentiation, development and synaptic plasticity. Brain phosphacan a chondroitin sulfate, KS, HNK-1 PG have roles in neural development and repair. The intracellular microtubule and synaptic vesicle KS-PGs MAP1B and SV2 have roles in metabolite transport, storage, and export of neurotransmitters and cytoskeletal assembly. MAP1B has binding sites for tubulin and actin through which it promotes cytoskeletal development in growth cones and is highly expressed during neurite extension. The interactive capability of KS with neuroregulatory ligands indicate varied roles for KS-PGs in development and regenerative neural processes.
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Affiliation(s)
- James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, St. Leonards, New South Wales, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia.,Sydney Medical School, Northern Campus, Royal North Shore Hospital, The University of Sydney, New South Wales, Australia.,Faculty of Medicine and Health, Royal North Shore Hospital, The University of Sydney, St. Leonards, New South Wales, Australia
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31
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Yang T, Huang H, Shao Q, Yee S, Majumder T, Liu G. miR-92 Suppresses Robo1 Translation to Modulate Slit Sensitivity in Commissural Axon Guidance. Cell Rep 2018; 24:2694-2708.e6. [PMID: 30184503 DOI: 10.1016/j.celrep.2018.08.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 07/17/2018] [Accepted: 08/07/2018] [Indexed: 01/09/2023] Open
Abstract
Temporospatial regulation of guidance signaling is essential for axon outgrowth and pathfinding in the developing nervous system. Regulation of Robo1 levels in commissural neurons modulates Slit sensitivity facilitating proper axon guidance. The mechanisms underlying this regulation in the vertebrate nervous system are not well understood. Here, we report that miR-92, a highly conserved microRNA (miRNA), regulates chicken Robo1 expression in commissural neurons by binding to the 3' untranslated region (3' UTR) of Robo1 mRNA. miR-92 and Robo1 are differentially expressed in the developing spinal cord. miR-92 interacts with the Robo1 3'UTR to cause translational repression, but not mRNA degradation. Disruption of the miR-92/Robo1 3' UTR interaction induces premature responsiveness to Slit2 repulsion of precrossing commissural axons (CAs) in vitro and causes CA projection defects in vivo. These results indicate that miR-92 represses Robo1 expression thereby regulating Slit sensitivity to control CA projection and midline crossing.
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Affiliation(s)
- Tao Yang
- Department of Biological Sciences, University of Toledo, M.S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Huai Huang
- Department of Biological Sciences, University of Toledo, M.S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Qiangqiang Shao
- Department of Biological Sciences, University of Toledo, M.S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Shirley Yee
- Department of Biological Sciences, University of Toledo, M.S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Tanushree Majumder
- Department of Biological Sciences, University of Toledo, M.S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Guofa Liu
- Department of Biological Sciences, University of Toledo, M.S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA.
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32
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Vahedi-Hunter TA, Estep JA, Rosette KA, Rutlin ML, Wright KM, Riccomagno MM. Cas Adaptor Proteins Coordinate Sensory Axon Fasciculation. Sci Rep 2018; 8:5996. [PMID: 29662228 PMCID: PMC5902548 DOI: 10.1038/s41598-018-24261-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 03/29/2018] [Indexed: 11/09/2022] Open
Abstract
Development of complex neural circuits like the peripheral somatosensory system requires intricate mechanisms to ensure axons make proper connections. While much is known about ligand-receptor pairs required for dorsal root ganglion (DRG) axon guidance, very little is known about the cytoplasmic effectors that mediate cellular responses triggered by these guidance cues. Here we show that members of the Cas family of cytoplasmic signaling adaptors are highly phosphorylated in central projections of the DRG as they enter the spinal cord. Furthermore, we provide genetic evidence that Cas proteins regulate fasciculation of DRG sensory projections. These data establish an evolutionarily conserved requirement for Cas adaptor proteins during peripheral nervous system axon pathfinding. They also provide insight into the interplay between axonal fasciculation and adhesion to the substrate.
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Affiliation(s)
- Tyler A Vahedi-Hunter
- Neuroscience Program, Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Jason A Estep
- Cell, Molecular and Developmental Biology Program, Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Kylee A Rosette
- Vollum Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Michael L Rutlin
- Department of Biochemistry and Molecular Biophysics, Columbia College of Physicians and Surgeons, Columbia University, New York, New York, 10032, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Martin M Riccomagno
- Neuroscience Program, Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA. .,Cell, Molecular and Developmental Biology Program, Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA.
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33
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Dominici C, Rappeneau Q, Zelina P, Fouquet S, Chédotal A. Non-cell autonomous control of precerebellar neuron migration by Slit and Robo proteins. Development 2018; 145:dev150375. [PMID: 29343636 DOI: 10.1242/dev.150375] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 12/11/2017] [Indexed: 02/05/2023]
Abstract
During development, precerebellar neurons migrate tangentially from the dorsal hindbrain to the floor plate. Their axons cross it but their cell bodies stop their ventral migration upon reaching the midline. It has previously been shown that Slit chemorepellents and their receptors, Robo1 and Robo2, might control the migration of precerebellar neurons in a repulsive manner. Here, we have used a conditional knockout strategy in mice to test this hypothesis. We show that the targeted inactivation of the expression of Robo1 and Robo2 receptors in precerebellar neurons does not perturb their migration and that they still stop at the midline. The selective ablation of the expression of all three Slit proteins in floor-plate cells has no effect on pontine neurons and only induces the migration of a small subset of inferior olivary neurons across the floor plate. Likewise, we show that the expression of Slit proteins in the facial nucleus is dispensable for pontine neuron migration. Together, these results show that Robo1 and Robo2 receptors act non-cell autonomously in migrating precerebellar neurons and that floor-plate signals, other than Slit proteins, must exist to prevent midline crossing.
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Affiliation(s)
- Chloé Dominici
- Sorbonne Universités, UPMC Paris 06, INSERM, CNRS, Institut de la Vision 75012, Paris, France
| | - Quentin Rappeneau
- Sorbonne Universités, UPMC Paris 06, INSERM, CNRS, Institut de la Vision 75012, Paris, France
| | - Pavol Zelina
- Sorbonne Universités, UPMC Paris 06, INSERM, CNRS, Institut de la Vision 75012, Paris, France
| | - Stéphane Fouquet
- Sorbonne Universités, UPMC Paris 06, INSERM, CNRS, Institut de la Vision 75012, Paris, France
| | - Alain Chédotal
- Sorbonne Universités, UPMC Paris 06, INSERM, CNRS, Institut de la Vision 75012, Paris, France
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34
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Howard LJ, Brown HE, Wadsworth BC, Evans TA. Midline axon guidance in the Drosophila embryonic central nervous system. Semin Cell Dev Biol 2017; 85:13-25. [PMID: 29174915 DOI: 10.1016/j.semcdb.2017.11.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/13/2017] [Accepted: 11/21/2017] [Indexed: 02/02/2023]
Abstract
Studies in the fruit fly Drosophila melanogaster have provided many fundamental insights into the genetic regulation of neural development, including the identification and characterization of evolutionarily conserved axon guidance pathways and their roles in important guidance decisions. Due to its highly organized and fast-developing embryonic nervous system, relatively small number of neurons, and molecular and genetic tools for identifying, labeling, and manipulating individual neurons or small neuronal subsets, studies of axon guidance in the Drosophila embryonic CNS have allowed researchers to dissect these genetic mechanisms with a high degree of precision. In this review, we discuss the major axon guidance pathways that regulate midline crossing of axons and the formation and guidance of longitudinal axon tracts, two processes that contribute to the development of the precise three-dimensional structure of the insect nerve cord. We focus particularly on recent insights into the roles and regulation of canonical midline axon guidance pathways, and on additional factors and pathways that have recently been shown to contribute to axon guidance decisions at and near the midline.
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Affiliation(s)
- LaFreda J Howard
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA
| | - Haley E Brown
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA
| | - Benjamin C Wadsworth
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA
| | - Timothy A Evans
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA.
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35
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Abstract
The Drosophila motor system starts to assemble during embryonic development. It is composed of 30 muscles per abdominal hemisegment and 36 motor neurons assembling into nerve branches to exit the CNS, navigate within the muscle field and finally establish specific connections with their target muscles. Several families of guidance molecules that play a role controlling this process as well as transcriptional regulators that program the behavior of specific motor neuron have been identified. In this review we summarize the role of both groups of molecules in the motor system as well as their relationship where known. It is apparent that partially redundant guidance protein families and membrane molecules with different functional output direct guidance decisions cooperatively. Some distinct transcriptional regulators seem to control guidance of specific nerve branches globally directing the expression of groups of pathfinding molecules in all motor neurons within the same motor branch.
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Friocourt F, Chédotal A. The Robo3 receptor, a key player in the development, evolution, and function of commissural systems. Dev Neurobiol 2017; 77:876-890. [DOI: 10.1002/dneu.22478] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 12/04/2016] [Accepted: 12/06/2016] [Indexed: 12/15/2022]
Affiliation(s)
- François Friocourt
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision; 17 Rue Moreau Paris 75012 France
| | - Alain Chédotal
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision; 17 Rue Moreau Paris 75012 France
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37
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Wang B, Li H, Mutlu SA, Bowser DA, Moore MJ, Wang MC, Zheng H. The Amyloid Precursor Protein Is a Conserved Receptor for Slit to Mediate Axon Guidance. eNeuro 2017; 4:ENEURO.0185-17.2017. [PMID: 28785723 PMCID: PMC5534435 DOI: 10.1523/eneuro.0185-17.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 05/29/2017] [Indexed: 02/03/2023] Open
Abstract
The amyloid precursor protein (APP) is a receptor-like membrane protein. Although APP processing and β-amyloid production play a central role in Alzheimer's disease (AD) pathogenesis, the physiological function of APP remains elusive. Here, we identify APP as a novel receptor for Slit that mediates axon guidance and neural circuit formation. APP deficiency abolishes the Slit repulsive effect in a 3D olfactory explant culture, consistent with its callosal projection deficit in vivo and reminiscent of Slit loss. Inactivation of APP ortholog APL-1 in Caenorhabditis elegans results in pioneer axon mistargeting and genetic analysis places APL-1 in the SLT-1 (Slit)/SAX-3 (Robo) repulsive pathway. Slit binds to APP through the E1 domain, which triggers APP ectodomain shedding and recruitment of the intracellular FE65 and Pak1 complex and associated Rac1 GTPase activation. Our study establishes APP as a novel receptor for Slit ligand mediating axon guidance and neural circuit formation.
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Affiliation(s)
- Baiping Wang
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - Hongmei Li
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - Sena A. Mutlu
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030
| | - Devon A. Bowser
- Interdisciplinary Bioinnovation PhD Program, Tulane University, New Orleans, LA 70118
| | - Michael J. Moore
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118
| | - Meng C. Wang
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - Hui Zheng
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
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38
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Lin J, Fu S, Yang C, Redies C. Pax3 overexpression induces cell aggregation and perturbs commissural axon projection during embryonic spinal cord development. J Comp Neurol 2017; 525:1618-1632. [PMID: 27864937 DOI: 10.1002/cne.24146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/06/2016] [Accepted: 10/23/2016] [Indexed: 12/12/2022]
Abstract
Pax3 is a transcription factor that belongs to the paired box family. In the developing spinal cord it is expressed in the dorsal commissural neurons, which project ascending axons contralaterally to form proper spinal cord-brain circuitry. While it has been shown that Pax3 induces cell aggregation in vitro, little is known about the role of Pax3 in cell aggregation and spinal circuit formation in vivo. We have reported that Pax3 is involved in neuron differentiation and that its overexpression induces ectopic cadherin-7 expression. In this study we report that Pax3 overexpression also induces cell aggregation in vivo. Tissue sections and open book preparations revealed that Pax3 overexpression prevents commissural axons from projecting to the contralateral side of the spinal cord. Cells overexpressing Pax3 aggregated in cell clusters that contained shortened neurites with perturbed axon growth and elongation. Pax3-specific shRNA partially rescued the morphological change induced by Pax3 overexpression in vivo. Our results indicate that the normal expression of Pax3 is necessary for proper axonal pathway finding and commissural axon projection. In conclusion, Pax3 regulates neural circuit formation during embryonic development. J. Comp. Neurol. 525:1618-1632, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Juntang Lin
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany.,Henan Key Lab of Medical Tissue Regeneration, College of Life Science and Technology, College of Biomedical Engineering, Xinxiang Medical University, Xinxiang, China
| | - Sulei Fu
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany
| | - Ciqing Yang
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany.,Henan Key Lab of Medical Tissue Regeneration, College of Life Science and Technology, College of Biomedical Engineering, Xinxiang Medical University, Xinxiang, China
| | - Christoph Redies
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany
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39
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Ke C, Gao F, Tian X, Li C, Shi D, He W, Tian Y. Slit2/Robo1 Mediation of Synaptic Plasticity Contributes to Bone Cancer Pain. Mol Neurobiol 2017; 54:295-307. [PMID: 26738857 DOI: 10.1007/s12035-015-9564-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/29/2015] [Indexed: 12/11/2022]
Abstract
Synaptic plasticity is fundamental to spinal sensitivity of bone cancer pain. Here, we have shown that excitatory synaptogenesis contributes to bone cancer pain. New synapse formation requires neurite outgrowth and an interaction between axons and dendrites, accompanied by the appositional organization of presynaptic and postsynaptic specializations. We have shown that Slit2, Robo1, and RhoA act as such cues that promote neurite outgrowth and guide the axon for synapse formation. Sarcoma inoculation induces excitatory synaptogenesis and bone cancer pain which are reversed by Slit2 knockdown but aggravated by Robo1 knockdown. Synaptogenesis of cultured neurons are inhibited by Slit2 knockdown but enhanced by Robo1 knockdown. Sarcoma implantation induces an increase in Slit2 and decreases Robo1 and RhoA, while Slit2 knockdown results in an increase of Robo1 and RhoA. These results have demonstrated a molecular mechanism of synaptogenesis in bone cancer pain.
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Affiliation(s)
- Changbin Ke
- Institute of Anesthesiology and Pain (IAP) and Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan City, 442000, Hubei Province, China
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Feng Gao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xuebi Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Caijuan Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Dai Shi
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wensheng He
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yuke Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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40
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de Ramon Francàs G, Zuñiga NR, Stoeckli ET. The spinal cord shows the way - How axons navigate intermediate targets. Dev Biol 2016; 432:43-52. [PMID: 27965053 DOI: 10.1016/j.ydbio.2016.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/26/2016] [Accepted: 12/01/2016] [Indexed: 12/13/2022]
Abstract
Functional neural circuits depend on the establishment of specific connections between neurons and their target cells. To this end, many axons have to travel long distances to reach their target cells during development. Studies addressing the molecular mechanisms of axon guidance have to overcome the complexity of subpopulation-specific requirements with respect to pathways, guidance cues, and target recognition. Compared to the brain, the relatively simple structure of the spinal cord provides an advantage for experimental studies of axon guidance mechanisms. Therefore, the so far best understood model for axon guidance is the dI1 population of dorsal interneurons of the spinal cord. They extend their axons ventrally towards the floor plate. After midline crossing, they turn rostrally along the contralateral floor-plate border. Despite the fact that the trajectory of dI1 axons seems to be rather simple, the number of axon guidance molecules involved in the decisions taken by these axons is bewildering. Because guidance molecules and mechanisms are conserved throughout the developing nervous system, we can generalize what we have learned about the navigation of the floor plate as an intermediate target for commissural axons to the brain.
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Affiliation(s)
- Gemma de Ramon Francàs
- University of Zurich, Department of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Nikole R Zuñiga
- University of Zurich, Department of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Esther T Stoeckli
- University of Zurich, Department of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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41
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Abstract
Slits are secreted proteins that bind to Roundabout (Robo) receptors. Slit-Robo signaling is best known for mediating axon repulsion in the developing nervous system. However, in recent years the functional repertoire of Slits and Robo has expanded tremendously and Slit-Robo signaling has been linked to roles in neurogenesis, angiogenesis and cancer progression among other processes. Likewise, our mechanistic understanding of Slit-Robo signaling has progressed enormously. Here, we summarize new insights into Slit-Robo evolutionary and system-dependent diversity, receptor-ligand interactions, signaling crosstalk and receptor activation.
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Affiliation(s)
- Heike Blockus
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, Paris 75012, France Ecole des Neurosciences de Paris, Paris F-75005, France
| | - Alain Chédotal
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, Paris 75012, France
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42
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Reichert MC, Brown HE, Evans TA. In vivo functional analysis of Drosophila Robo1 immunoglobulin-like domains. Neural Dev 2016; 11:15. [PMID: 27539083 PMCID: PMC4991095 DOI: 10.1186/s13064-016-0071-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 08/15/2016] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND In animals with bilateral symmetry, midline crossing of axons in the developing central nervous system is regulated by Slit ligands and their neuronal Roundabout (Robo) receptors. Multiple structural domains are present in an evolutionarily conserved arrangement in Robo family proteins, but our understanding of the functional importance of individual domains for midline repulsive signaling is limited. METHODS We have examined the functional importance of each of the five conserved immunoglobulin-like (Ig) domains within the Drosophila Robo1 receptor. We generated a series of Robo1 variants, each lacking one of the five Ig domains (Ig1-5), and tested each for their ability to bind Slit when expressed in cultured Drosophila cells. We used a transgenic approach to express each variant in robo1's normal expression pattern in wild-type and robo1 mutant embryos, and examined the effects of deleting each domain on receptor expression, axonal localization, regulation, and midline repulsive signaling in vivo. RESULTS We show that individual deletion of Ig domains 2-5 does not interfere with Robo1's ability to bind Slit, while deletion of Ig1 strongly disrupts Slit binding. None of the five Ig domains (Ig1-5) are individually required for proper expression of Robo1 in embryonic neurons, for exclusion from commissural axon segments in wild-type embryos, or for downregulation by Commissureless (Comm), a negative regulator of Slit-Robo repulsion in Drosophila. Each of the Robo1 Ig deletion variants (with the exception of Robo1∆Ig1) were able to restore midline crossing in robo1 mutant embryos to nearly the same extent as full-length Robo1, indicating that Ig domains 2-5 are individually dispensable for midline repulsive signaling in vivo. CONCLUSIONS Our findings indicate that four of the five Ig domains within Drosophila Robo1 are dispensable for its role in midline repulsion, despite their strong evolutionary conservation, and highlight a unique requirement for the Slit-binding Ig1 domain in the regulation of midline crossing.
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Affiliation(s)
- Marie C Reichert
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, 72701, USA
- Present address: Intramural Research Training Program, National Human Genome Research Institute, Bethesda, MD, 20892, USA
| | - Haley E Brown
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Timothy A Evans
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, 72701, USA.
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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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44
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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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45
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Hernandez-Enriquez B, Wu Z, Martinez E, Olsen O, Kaprielian Z, Maness PF, Yoshida Y, Tessier-Lavigne M, Tran TS. Floor plate-derived neuropilin-2 functions as a secreted semaphorin sink to facilitate commissural axon midline crossing. Genes Dev 2016; 29:2617-32. [PMID: 26680304 PMCID: PMC4699389 DOI: 10.1101/gad.268086.115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Commissural axon guidance depends on a myriad of cues expressed by intermediate targets. Secreted semaphorins signal through neuropilin-2/plexin-A1 receptor complexes on post-crossing commissural axons to mediate floor plate repulsion in the mouse spinal cord. Here, we show that neuropilin-2/plexin-A1 are also coexpressed on commissural axons prior to midline crossing and can mediate precrossing semaphorin-induced repulsion in vitro. How premature semaphorin-induced repulsion of precrossing axons is suppressed in vivo is not known. We discovered that a novel source of floor plate-derived, but not axon-derived, neuropilin-2 is required for precrossing axon pathfinding. Floor plate-specific deletion of neuropilin-2 significantly reduces the presence of precrossing axons in the ventral spinal cord, which can be rescued by inhibiting plexin-A1 signaling in vivo. Our results show that floor plate-derived neuropilin-2 is developmentally regulated, functioning as a molecular sink to sequester semaphorins, preventing premature repulsion of precrossing axons prior to subsequent down-regulation, and allowing for semaphorin-mediated repulsion of post-crossing axons.
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Affiliation(s)
| | - Zhuhao Wu
- Laboratory of Brain Development and Repair, The Rockefeller University, New York, New York 10065, USA
| | - Edward Martinez
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA
| | - Olav Olsen
- Laboratory of Brain Development and Repair, The Rockefeller University, New York, New York 10065, USA
| | | | - Patricia F Maness
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA
| | - Yutaka Yoshida
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA
| | - Marc Tessier-Lavigne
- Laboratory of Brain Development and Repair, The Rockefeller University, New York, New York 10065, USA
| | - Tracy S Tran
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA
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46
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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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47
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Jaworski A, Tom I, Tong RK, Gildea HK, Koch AW, Gonzalez LC, Tessier-Lavigne M. Operational redundancy in axon guidance through the multifunctional receptor Robo3 and its ligand NELL2. Science 2015; 350:961-5. [PMID: 26586761 DOI: 10.1126/science.aad2615] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Axon pathfinding is orchestrated by numerous guidance cues, including Slits and their Robo receptors, but it remains unclear how information from multiple cues is integrated or filtered. Robo3, a Robo family member, allows commissural axons to reach and cross the spinal cord midline by antagonizing Robo1/2-mediated repulsion from midline-expressed Slits and potentiating deleted in colorectal cancer (DCC)-mediated midline attraction to Netrin-1, but without binding either Slits or Netrins. We identified a secreted Robo3 ligand, neural epidermal growth factor-like-like 2 (NELL2), which repels mouse commissural axons through Robo3 and helps steer them to the midline. These findings identify NELL2 as an axon guidance cue and establish Robo3 as a multifunctional regulator of pathfinding that simultaneously mediates NELL2 repulsion, inhibits Slit repulsion, and facilitates Netrin attraction to achieve a common guidance purpose.
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Affiliation(s)
- Alexander Jaworski
- Division of Research, Genentech, South San Francisco, CA 94080, USA. Laboratory of Brain Development and Repair, The Rockefeller University, New York, NY 10065, USA. Department of Neuroscience, Brown University, Providence, RI 02912, USA.
| | - Irene Tom
- Department of Protein Chemistry, Genentech, South San Francisco, CA 94080, USA
| | - Raymond K Tong
- Department of Protein Chemistry, Genentech, South San Francisco, CA 94080, USA
| | - Holly K Gildea
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Alexander W Koch
- Department of Protein Chemistry, Genentech, South San Francisco, CA 94080, USA
| | - Lino C Gonzalez
- Department of Protein Chemistry, Genentech, South San Francisco, CA 94080, USA
| | - Marc Tessier-Lavigne
- Division of Research, Genentech, South San Francisco, CA 94080, USA. Laboratory of Brain Development and Repair, The Rockefeller University, New York, NY 10065, USA.
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48
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Neuhaus-Follini A, Bashaw GJ. The Intracellular Domain of the Frazzled/DCC Receptor Is a Transcription Factor Required for Commissural Axon Guidance. Neuron 2015; 87:751-63. [PMID: 26291159 DOI: 10.1016/j.neuron.2015.08.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 07/24/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022]
Abstract
In commissural neurons of Drosophila, the conserved Frazzled (Fra)/Deleted in Colorectal Cancer (DCC) receptor promotes midline axon crossing by signaling locally in response to Netrin and by inducing transcription of commissureless (comm), an antagonist of Slit-Roundabout midline repulsion, through an unknown mechanism. Here, we show that Fra is cleaved to release its intracellular domain (ICD), which shuttles between the cytoplasm and the nucleus, where it functions as a transcriptional activator. Rescue and gain-of-function experiments demonstrate that the Fra ICD is sufficient to regulate comm expression and that both γ-secretase proteolysis of Fra and Fra's function as a transcriptional activator are required for its ability to regulate comm in vivo. Our data uncover an unexpected role for the Fra ICD as a transcription factor whose activity regulates the responsiveness of commissural axons at the midline and raise the possibility that nuclear signaling may be a common output of axon guidance receptors.
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Affiliation(s)
- Alexandra Neuhaus-Follini
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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49
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Abstract
UNLABELLED Commissural axons grow along precise trajectories that are guided by several cues secreted from the ventral midline. After initial attraction to the floor plate using Netrin1 activation of its main attractive receptor, DCC (deleted in colorectal cancer), axons cross the ventral midline, and many turn to grow longitudinally on the contralateral side. After crossing the midline, axons are thought to lose their responsiveness to Netrin1 and become sensitive to midline Slit-Robo repulsion. We aimed to address the in vivo significance of Netrin1 in guiding post-crossing axon trajectories in mouse embryos. Surprisingly, in contrast to the spinal cord, Netrin1 and DCC mutants had abundant commissural axons crossing in the hindbrain. In Netrin1 and DCC mutants, many post-crossing axons made normal turns to grow longitudinally, but projected abnormally at angles away from the midline. In addition, exposure of cultured hindbrain explants to ectopic Netrin1 caused attractive deflection of post-crossing axons. Thus, Netrin1-DCC signaling is not required to attract pre-crossing axons toward the hindbrain floor plate, but is active in post-crossing guidance. Also in contrast with spinal cord, analysis of hindbrain post-crossing axons in Robo1/2 mutant embryos showed that Slit-Robo repulsive signaling was not required for post-crossing trajectories. Our findings show that Netrin1-DCC attractive signaling, but not Slit-Robo repulsive signaling, remains active in hindbrain post-crossing commissural axons to guide longitudinal trajectories, suggesting surprising regional diversity in commissural axon guidance mechanisms. SIGNIFICANCE STATEMENT The left and right sides of the brainstem and spinal cord are connected primarily by axon fibers that grow across the ventral midline, and then away on the other side to their targets. Based on spinal cord, axons are initially attracted by diffusible attractive protein signals to approach and cross the midline, and then are thought to switch to repulsive cues to grow away on the opposite side. Our results in the hindbrain show that the major midline attractant, Netrin1, is not required for midline crossing. However, the post-crossing axons depend on Netrin1 attraction to set their proper trajectories on the other side. Overall, these findings suggest that commissural axons use distinct mechanisms to navigate in different CNS regions.
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Graser S, Mentrup B, Schneider D, Klein-Hitpass L, Jakob F, Hofmann C. Overexpression of tissue-nonspecific alkaline phosphatase increases the expression of neurogenic differentiation markers in the human SH-SY5Y neuroblastoma cell line. Bone 2015; 79:150-61. [PMID: 26032516 DOI: 10.1016/j.bone.2015.05.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 04/24/2015] [Accepted: 05/23/2015] [Indexed: 12/16/2022]
Abstract
Patients suffering from the rare hereditary disease hypophosphatasia (HPP), which is based on mutations in the ALPL gene, tend to develop central nervous system (CNS) related issues like epileptic seizures and neuropsychiatric illnesses such as anxiety and depression, in addition to well-known problems with the mineralization of bones and teeth. Analyses of the molecular role of tissue-nonspecific alkaline phosphatase (TNAP) in transgenic SH-SY5Y(TNAPhigh) neuroblastoma cells compared to SH-SY5Y(TNAPlow) cells indicate that the enzyme influences the expression levels of neuronal marker genes like RNA-binding protein, fox-1 homolog 3 (NEUN) and enolase 2, gamma neuronal (NSE) as well as microtubule-binding proteins like microtubule-associated protein 2 (MAP2) and microtubule-associated protein tau (TAU) during neurogenic differentiation. Fluorescence staining of SH-SY5Y(TNAPhigh) cells reveals TNAP localization throughout the whole length of the developed projection network and even synapsin Ι co-localization with strong TNAP signals at some spots at least at the early time points of differentiation. Additional immunocytochemical staining shows higher MAP2 expression in SH-SY5Y(TNAPhigh) cells and further a distinct up-regulation of tau and MAP2 in the course of neurogenic differentiation. Interestingly, transgenic SH-SY5Y(TNAPhigh) cells are able to develop longer cellular processes compared to control cells after stimulation with all-trans retinoic acid (RA). Current therapies for HPP prioritize improvement of the bone phenotype. Unraveling the molecular role of TNAP in extraosseous tissues, like in the CNS, will help to improve treatment strategies for HPP patients. Taking this rare disease as a model may also help to dissect TNAP's role in neurodegenerative diseases and even improve future treatment of common pathologies.
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Affiliation(s)
- Stephanie Graser
- Orthopedic Department, Orthopedic Center for Musculoskeletal Research, University of Wuerzburg, Germany
| | - Birgit Mentrup
- Orthopedic Department, Orthopedic Center for Musculoskeletal Research, University of Wuerzburg, Germany
| | - Doris Schneider
- Orthopedic Department, Orthopedic Center for Musculoskeletal Research, University of Wuerzburg, Germany
| | - Ludger Klein-Hitpass
- Institute of Cell Biology, Faculty of Medicine, University of Duisburg-Essen, Germany
| | - Franz Jakob
- Orthopedic Department, Orthopedic Center for Musculoskeletal Research, University of Wuerzburg, Germany
| | - Christine Hofmann
- Children's Hospital, Section of Pediatric Rheumatology and Osteology, University of Wuerzburg, Germany.
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