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Hani T, Fujita K, Kudo T, Taya Y, Sato K, Soeno Y. Tissue-Targeted Transcriptomics Reveals SEMA3D Control of Hypoglossal Nerve Projection to Mouse Tongue Primordia. Acta Histochem Cytochem 2024; 57:35-46. [PMID: 38463205 PMCID: PMC10918430 DOI: 10.1267/ahc.23-00073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/16/2024] [Indexed: 03/12/2024] Open
Abstract
The mouse hypoglossal nerve originates in the occipital motor nuclei at embryonic day (E)10.5 and projects a long distance, reaching the vicinity of the tongue primordia, the lateral lingual swellings, at E11.5. However, the details of how the hypoglossal nerve correctly projects to the primordia are poorly understood. To investigate the molecular basis of hypoglossal nerve elongation, we used a novel transcriptomic approach using the ROKU method. The ROKU algorithm identified 3825 genes specific for lateral lingual swellings at E11.5, of which 34 genes were predicted to be involved in axon guidance. Ingenuity Pathway Analysis-assisted enrichment revealed activation of the semaphorin signaling pathway during tongue development, and quantitative PCR showed that the expressions of Sema3d and Nrp1 in this pathway peaked at E11.5. Immunohistochemistry detected NRP1 in the hypoglossal nerve and SEMA3D as tiny granules in the extracellular space beneath the epithelium of the tongue primordia and in lateral and anterior regions of the mandibular arch. Fewer SEMA3D granules were localized around hypoglossal nerve axons and in the space where they elongated. In developing tongue primordia, tissue-specific regulation of SEMA3D might control the route of hypoglossal nerve projection via its repulsive effect on NRP1.
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Affiliation(s)
- Taisuke Hani
- Department of Pathology, The Nippon Dental University, School of Life Dentistry at Tokyo, 1-9-20, Fujimi, Chiyoda-ku, 102-8159 Tokyo, Japan
| | - Kazuya Fujita
- Department of Pathology, The Nippon Dental University, School of Life Dentistry at Tokyo, 1-9-20, Fujimi, Chiyoda-ku, 102-8159 Tokyo, Japan
| | - Tomoo Kudo
- Department of Pathology, The Nippon Dental University, School of Life Dentistry at Tokyo, 1-9-20, Fujimi, Chiyoda-ku, 102-8159 Tokyo, Japan
| | - Yuji Taya
- Department of Pathology, The Nippon Dental University, School of Life Dentistry at Tokyo, 1-9-20, Fujimi, Chiyoda-ku, 102-8159 Tokyo, Japan
| | - Kaori Sato
- Department of Pathology, The Nippon Dental University, School of Life Dentistry at Tokyo, 1-9-20, Fujimi, Chiyoda-ku, 102-8159 Tokyo, Japan
| | - Yuuichi Soeno
- Department of Pathology, The Nippon Dental University, School of Life Dentistry at Tokyo, 1-9-20, Fujimi, Chiyoda-ku, 102-8159 Tokyo, Japan
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2
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Nitzan A, Corredor-Sanchez M, Galron R, Nahary L, Safrin M, Bruzel M, Moure A, Bonet R, Pérez Y, Bujons J, Vallejo-Yague E, Sacks H, Burnet M, Alfonso I, Messeguer A, Benhar I, Barzilai A, Solomon AS. Inhibition of Sema-3A Promotes Cell Migration, Axonal Growth, and Retinal Ganglion Cell Survival. Transl Vis Sci Technol 2021; 10:16. [PMID: 34817617 PMCID: PMC8626852 DOI: 10.1167/tvst.10.10.16] [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] [Indexed: 11/28/2022] Open
Abstract
Purpose Semaphorin 3A (Sema-3A) is a secreted protein that deflects axons from inappropriate regions and induces neuronal cell death. Intravitreal application of polyclonal antibodies against Sema-3A prevents loss of retinal ganglion cells ensuing from axotomy of optic nerves. This suggested a therapeutic approach for neuroprotection via inhibition of the Sema-3A pathway. Methods To develop potent and specific Sema-3A antagonists, we isolated monoclonal anti-Sema-3A antibodies from a human antibody phage display library and optimized low-molecular weight Sema-3A signaling inhibitors. The best inhibitors were identified using in vitro scratch assays and semiquantitative repulsion assays. Results A therapeutic approach for neuroprotection must have a long duration of action. Therefore, antibodies and low-molecular weight inhibitors were formulated in extruded implants to allow controlled and prolonged release. Following release from the implants, Sema-3A inhibitors antagonized Sema-3A effects in scratch and repulsion assays and protected retinal ganglion cells in animal models of optic nerve injury, retinal ischemia, and glaucoma. Conclusions and Translational Relevance Collectively, our findings indicate that the identified Sema-3A inhibitors should be further evaluated as therapeutic candidates for the treatment of Sema-3A-driven central nervous system degenerative processes.
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Affiliation(s)
- Anat Nitzan
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Miriam Corredor-Sanchez
- Department of Biological Chemistry, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Barcelona, Spain
| | - Ronit Galron
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Limor Nahary
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Mary Safrin
- Goldschleger Eye Research Institute, Sheba Medical Center, Tel Aviv University Tel Aviv, Israel
| | - Marina Bruzel
- Goldschleger Eye Research Institute, Sheba Medical Center, Tel Aviv University Tel Aviv, Israel
| | - Alejandra Moure
- Department of Biological Chemistry, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Barcelona, Spain
| | - Roman Bonet
- Department of Biological Chemistry, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Barcelona, Spain
| | - Yolanda Pérez
- Department of Biological Chemistry, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Barcelona, Spain
| | - Jordi Bujons
- Department of Biological Chemistry, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Barcelona, Spain
| | | | | | | | - Ignacio Alfonso
- Department of Biological Chemistry, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Barcelona, Spain
| | - Angel Messeguer
- Department of Biological Chemistry, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Barcelona, Spain
| | - Itai Benhar
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ari Barzilai
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Arieh S Solomon
- Goldschleger Eye Research Institute, Sheba Medical Center, Tel Aviv University Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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3
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Whitman MC. Axonal Growth Abnormalities Underlying Ocular Cranial Nerve Disorders. Annu Rev Vis Sci 2021; 7:827-850. [PMID: 34081534 DOI: 10.1146/annurev-vision-093019-114307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Abnormalities in cranial motor nerve development cause paralytic strabismus syndromes, collectively referred to as congenital cranial dysinnervation disorders, in which patients cannot fully move their eyes. These disorders can arise through one of two mechanisms: (a) defective motor neuron specification, usually by loss of a transcription factor necessary for brainstem patterning, or (b) axon growth and guidance abnormalities of the oculomotor, trochlear, and abducens nerves. This review focuses on our current understanding of axon guidance mechanisms in the cranial motor nerves and how disease-causing mutations disrupt axon targeting. Abnormalities of axon growth and guidance are often limited to a single nerve or subdivision, even when the causative gene is ubiquitously expressed. Additionally, when one nerve is absent, its normal target muscles attract other motor neurons. Study of these disorders highlights the complexities of axon guidance and how each population of neurons uses a unique but overlapping set of axon guidance pathways. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Mary C Whitman
- Department of Ophthalmology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA;
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4
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Yu H, Pei T, Ren J, Ding Y, Wu A, Zhou Y. Semaphorin 3A enhances osteogenesis of MG63 cells through interaction with Schwann cells in vitro. Mol Med Rep 2018; 17:6084-6092. [PMID: 29484438 DOI: 10.3892/mmr.2018.8628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/26/2018] [Indexed: 11/06/2022] Open
Abstract
Bone remodeling is under the control of various signals and systems in the body, including the nervous system. Semaphorin (Sema) 3A is a chemorepellent protein which regulates bone mass. Schwann cells, having a pivotal role following nerve injury, interact with Sema3A under numerous circumstances. The present study established a co‑culture system of MG63 and Schwann cells to investigate the role of the interaction between Sema3A and Schwann cells in osteogenesis. The results from the alkaline phosphatase assay, calcium nodule staining and the analysis of the osteogenic gene expression revealed that Sema3A inhibits osteogenic differentiation of MG63 cells in single‑cell culture and promotes osteogenic differentiation of MG63 cells in co‑culture with Schwann cells, in a concentration‑dependent manner. These findings suggest that the presence of Schwann cells induces Sema3A‑associated osteogenic differentiation in bone cells, and also reveals the pivotal role of Sema3A as a regulator in the skeletal and nervous systems, thus contributing to a better understanding of the interaction between these systems.
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Affiliation(s)
- Hongqiang Yu
- Department of Implantology, School of Stomatology, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Tingting Pei
- Department of Implantology, School of Stomatology, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Jingyi Ren
- Department of Implantology, School of Stomatology, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Ye Ding
- Department of Implantology, School of Stomatology, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Anqian Wu
- Department of Implantology, School of Stomatology, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yanmin Zhou
- Department of Implantology, School of Stomatology, Jilin University, Changchun, Jilin 130021, P.R. China
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Nagata K, Takahashi M, Kiryu-Seo S, Kiyama H, Saido TC. Distinct functional consequences of ECEL1/DINE missense mutations in the pathogenesis of congenital contracture disorders. Acta Neuropathol Commun 2017; 5:83. [PMID: 29132416 PMCID: PMC5683451 DOI: 10.1186/s40478-017-0486-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 10/26/2017] [Indexed: 11/10/2022] Open
Abstract
Endothelin-converting enzyme-like 1 (ECEL1, also termed DINE in rodents), a membrane-bound metalloprotease, has been identified as a gene responsible for distal arthrogryposis (DA). ECEL1-mutated DA is generally characterized by ocular phenotypes in addition to the congenital limb contractures that are common to all DA subtypes. Until now, the consequences of the identified pathogenic mutations have remained incompletely understood because of a lack of detailed phenotypic analyses in relevant mouse models. In this study, we generated a new knock-in mouse strain that carries an ECEL1/DINE pathogenic G607S missense mutation, based on a previous study reporting atypical DA hindlimb phenotypes in two siblings with the mutation. We compared the morphological phenotypes of G607S knock-in mice with C760R knock-in mice that we previously established. Both C760R and G607S knock-in mouse embryos showed similar axonal arborization defects with normal trajectory patterns from the spinal cord to the target hindlimb muscles, as well as axon guidance defects of the abducens nerves. Intriguingly, distinct phenotypes in DINE protein localization and mRNA expression were identified in these knock-in mouse lines. For G607S, DINE mRNA and protein expression was decreased or almost absent in motor neurons. In the C760R mutant mice DINE was expressed and localized in the somata of motor neurons but not in axons. Our mutant mouse data suggest that ECEL1/DINE G607S and C760R mutations both lead to motor innervation defects as primary causes in ECEL1-mutated congenital contracture disorders. However, the functional consequences of the two mutations are distinct, with loss of axonal transport of ECEL1/DINE in C760R mutants and mRNA expression deficits in G607S mutants.
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6
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Aquino JB, Sierra R. Schwann cell precursors in health and disease. Glia 2017; 66:465-476. [PMID: 29124786 DOI: 10.1002/glia.23262] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/07/2017] [Accepted: 10/26/2017] [Indexed: 12/25/2022]
Abstract
Schwann cell precursors (SCPs) are frequently regarded as neural crest-derived cells (NCDCs) found in contact with axons during nerve formation. Nevertheless, cells with SCPs properties can be found up to the adulthood. They are well characterized with regard to both gene expression profile and cellular behavior -for instance, proliferation, migratory capabilities and survival requirements-. They differ in origin regarding their anatomic location: even though most of them are derived from migratory NCCs, there is also contribution of the boundary cap neural crest cells (bNCCs) to the skin and other tissues. Many functions are known for SCPs in normal development, including nerve fasciculation and target innervation, arterial branching patterning and differentiation, and other morphogenetic processes. In addition, SCPs are now known to be a source of many neural (glia, endoneural fibroblasts, melanocytes, visceral neurons, and chromaffin cells) and non-neural-like (mesenchymal stromal cells, able e.g., to generate dentine-producing odontoblasts) cell types. Until now no reports of endoderm-like derivatives were reported so far. Interestingly, in the Schwann cell lineage only early SCPs are likely able to differentiate into melanocytes and bone marrow mesenchymal stromal cells. We have also herein discussed the literature regarding their role in repair as well as in disease mechanisms, such as in diverse cancers. Moreover, many caveats in our knowledge of SCPs biology are highlighted all through this article. Future research should expand more into the relevance of SCPs in pathologies and in other regenerative mechanisms which might bring new unexpected clinically-relevant knowledge.
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Affiliation(s)
- Jorge B Aquino
- Developmental Biology & Regenerative Medicine Laboratory, Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Derqui-Pilar, Buenos Aires, Argentina
| | - Romina Sierra
- Developmental Biology & Regenerative Medicine Laboratory, Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Derqui-Pilar, Buenos Aires, Argentina
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7
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Chilton JK, Guthrie S. Axons get ahead: Insights into axon guidance and congenital cranial dysinnervation disorders. Dev Neurobiol 2017; 77:861-875. [DOI: 10.1002/dneu.22477] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 12/07/2016] [Accepted: 12/07/2016] [Indexed: 11/12/2022]
Affiliation(s)
- John K. Chilton
- Wellcome Wolfson Centre for Medical Research; University of Exeter Medical School, Wellcome-Wolfson Centre for Medical Research; Exeter EX2 5DW United Kingdom
| | - Sarah Guthrie
- School of Life Sciences; University of Sussex; Falmer Brighton, BN1 9QG
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8
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Masuda T, Taniguchi M. Contribution of semaphorins to the formation of the peripheral nervous system in higher vertebrates. Cell Adh Migr 2016; 10:593-603. [PMID: 27715392 PMCID: PMC5160040 DOI: 10.1080/19336918.2016.1243644] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Semaphorins are a large family of proteins characterized by sema domains and play a key role not only in the formation of neural circuits, but in the immune system, angiogenesis, tumor progression, and bone metabolism. To date, 15 semaphorins have been reported to be involved in the formation of the peripheral nervous system (PNS) in higher vertebrates. A number of experiments have revealed their functions in the PNS, where they act mainly as axonal guidance cues (as repellents or attractants). Semaphorins also play an important role in the migration of neurons and formation of sensory-motor connections in the PNS. This review summarizes recent knowledge regarding the functions of higher vertebrate semaphorins in the formation of the PNS.
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Affiliation(s)
- Tomoyuki Masuda
- a Department of Neurobiology , Faculty of Medicine, University of Tsukuba , Ibaraki , Japan.,b Doctoral and Master's Programs in Kansei , Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba , Ibaraki , Japan
| | - Masahiko Taniguchi
- c Department of Cell Science , Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine , Hokkaido , Japan
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9
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Huettl RE, Eckstein S, Stahl T, Petricca S, Ninkovic J, Götz M, Huber AB. Functional dissection of the Pax6 paired domain: Roles in neural tube patterning and peripheral nervous system development. Dev Biol 2015; 413:86-103. [PMID: 26187199 DOI: 10.1016/j.ydbio.2015.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 06/21/2015] [Accepted: 07/11/2015] [Indexed: 10/23/2022]
Abstract
During development of the CNS, stem and progenitor cell proliferation, cell fate designation, and patterning decisions are tightly regulated by interdependent networks of key transcriptional regulators. In a genetic approach we analyzed divergent functionality of the PAI and RED sub-domains of the Pax6 Paired domain (PD) during progenitor zone formation, motor and interneuron development, and peripheral connectivity at distinct levels within the neural tube: within the hindbrain, mutation of the PAI sub-domain severely affected patterning of the p3 and pMN domains and establishment of the corresponding motor neurons. Exit point designation of hypoglossal axons was disturbed in embryos harboring either mutations in the PD sub-domains or containing a functional Pax6 Null allele. At brachial spinal levels, we propose a selective involvement of the PAI sub-domain during patterning of ventral p2 and pMN domains, critically disturbing generation of specific motor neuron subtypes and increasing V2 interneuron numbers. Our findings present a novel aspect of how Pax6 not only utilizes its modular structure to perform distinct functions via its paired and homeodomain. Individual sub-domains can exert distinct functions, generating a new level of complexity for transcriptional regulation by one single transcription factor not only in dorso-ventral, but also rostro-caudal neural tube patterning.
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Affiliation(s)
- Rosa-Eva Huettl
- Institute of Developmental Genetics, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Simone Eckstein
- Institute of Developmental Genetics, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Tessa Stahl
- Institute of Stem Cell Research, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Stefania Petricca
- Institute of Stem Cell Research, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Jovica Ninkovic
- Institute of Stem Cell Research, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Magdalena Götz
- Institute of Stem Cell Research, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Andrea B Huber
- Institute of Developmental Genetics, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
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10
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Yoshikawa M, Hirabayashi M, Ito R, Ozaki S, Aizawa S, Masuda T, Senzaki K, Shiga T. Contribution of the Runx1 transcription factor to axonal pathfinding and muscle innervation by hypoglossal motoneurons. Dev Neurobiol 2015; 75:1295-314. [PMID: 25762373 DOI: 10.1002/dneu.22285] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 02/18/2015] [Accepted: 03/01/2015] [Indexed: 11/12/2022]
Abstract
The runt-related transcription factor Runx1 contributes to cell type specification and axonal targeting projections of the nociceptive dorsal root ganglion neurons. Runx1 is also expressed in the central nervous system, but little is known of its functions in brain development. At mouse embryonic day (E) 17.5, Runx1-positive neurons were detected in the ventrocaudal subdivision of the hypoglossal nucleus. Runx1-positive neurons lacked calcitonin gene-related peptide (CGRP) expression, whereas Runx1-negative neurons expressed CGRP. Expression of CGRP was not changed in Runx1-deficient mice at E17.5, suggesting that Runx1 alone does not suppress CGRP expression. Hypoglossal axon projections to the intrinsic vertical (V) and transverse (T) tongue muscles were sparser in Runx1-deficient mice at E17.5 compared to age-matched wild-type littermates. Concomitantly, vesicular acetylcholine transporter-positive axon terminals and acetylcholine receptor clusters were less dense in the V and T tongue muscles of Runx1-deficient mice. These abnormalities in axonal projection were not caused by a reduction in the total number hypoglossal neurons, failed synaptogenesis, or tongue muscles deficits. Our results implicate Runx1 in the targeting of ventrocaudal hypoglossal axons to specific tongue muscles. However, Runx1 deficiency did not alter neuronal survival or the expression of multiple motoneuron markers as in other neuronal populations. Thus, Runx1 appears to have distinct developmental functions in different brain regions.
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Affiliation(s)
- Masaaki Yoshikawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, 30-1 Oyaguchi-Kamicho, Itabashi, Tokyo, 173-8610, Japan.,Doctoral Program in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Mizuki Hirabayashi
- Doctoral Program in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Ryota Ito
- Doctoral Program in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Shigeru Ozaki
- Doctoral Program in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Shin Aizawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, 30-1 Oyaguchi-Kamicho, Itabashi, Tokyo, 173-8610, Japan
| | - Tomoyuki Masuda
- Doctoral Program in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Kouji Senzaki
- Doctoral Program in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Takashi Shiga
- Doctoral Program in Kansei, Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
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11
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Generation of a Nkx2.2Cre knock-in mouse line: Analysis of cell lineages in the central nervous system. Differentiation 2015; 89:70-6. [DOI: 10.1016/j.diff.2015.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 02/10/2015] [Accepted: 03/11/2015] [Indexed: 11/21/2022]
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12
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Helmbrecht MS, Soellner H, Truckenbrodt AML, Sundermeier J, Cohrs C, Hans W, de Angelis MH, Feuchtinger A, Aichler M, Fouad K, Huber AB. Loss of Npn1 from motor neurons causes postnatal deficits independent from Sema3A signaling. Dev Biol 2014; 399:2-14. [PMID: 25512301 DOI: 10.1016/j.ydbio.2014.11.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 11/24/2014] [Accepted: 11/25/2014] [Indexed: 12/20/2022]
Abstract
The correct wiring of neuronal circuits is of crucial importance for the function of the vertebrate nervous system. Guidance cues like the neuropilin receptors (Npn) and their ligands, the semaphorins (Sema) provide a tight spatiotemporal control of sensory and motor axon growth and guidance. Among this family of guidance partners the Sema3A-Npn1 interaction has been shown to be of great importance, since defective signaling leads to wiring deficits and defasciculation. For the embryonic stage these defects have been well described, however, also after birth the organism can adapt to new challenges by compensational mechanisms. Therefore, we used the mouse lines Olig2-Cre;Npn1(cond) and Npn1(Sema-) to investigate how postnatal organisms cope with the loss of Npn1 selectively from motor neurons or a systemic dysfunctional Sema3A-Npn1 signaling in the entire organism, respectively. While in Olig2-Cre(+);Npn1(cond-/-) mice clear anatomical deficits in paw posturing, bone structure, as well as muscle and nerve composition became evident, Npn1(Sema-) mutants appeared anatomically normal. Furthermore, Olig2-Cre(+);Npn1(cond) mutants revealed a dysfunctional extensor muscle innervation after single-train stimulation of the N.radial. Interestingly, these mice did not show obvious deficits in voluntary locomotion, however, skilled motor function was affected. In contrast, Npn1(Sema-) mutants were less affected in all behavioral tests and able to improve their performance over time. Our data suggest that loss of Sema3A-Npn1 signaling is not the only cause for the observed deficits in Olig2-Cre(+);Npn1(cond-/-) mice and that additional, yet unknown binding partners for Npn1 may be involved that allow Npn1(Sema-) mutants to compensate for their developmental deficits.
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Affiliation(s)
- Michaela S Helmbrecht
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany.
| | - Heidi Soellner
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Anna M L Truckenbrodt
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Julia Sundermeier
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Christian Cohrs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany; DFG-Research Center for Regenerative Therapies Dresden, Technische Universität and Paul Langerhans Institute Dresden, German Center for Diabetes Research (DZD), Germany
| | - Wolfgang Hans
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany; Chair of Experimental Genetics, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising-Weihenstephan, Germany; German Center for Diabetes Research (DZD), Ingostädter Landstr. 1, 85764 Neuherberg, Germany
| | - Annette Feuchtinger
- Research Unit Analytical Pathology, Insititute of Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Michaela Aichler
- Research Unit Analytical Pathology, Insititute of Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany
| | - Karim Fouad
- Faculty of Rehabilitation Medicine and Centre for Neuroscience, University of Alberta, Canada
| | - Andrea B Huber
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany.
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13
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Gutekunst CA, Gross RE. Plexin a4 expression in adult rat cranial nerves. J Chem Neuroanat 2014; 61-62:13-9. [PMID: 24970554 PMCID: PMC4267999 DOI: 10.1016/j.jchemneu.2014.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/21/2014] [Accepted: 06/16/2014] [Indexed: 12/16/2022]
Abstract
PlexinsA1-A4 participate in class 3 semaphorin signaling as co-receptors to neuropilin 1 and 2. PlexinA4 is the latest member of the PlexinA subfamily to be identified. In previous studies, we described the expression of PlexinA4 in the brain and spinal cord of the adult rat. Here, antibodies to PlexinA4 were used to reveal immunolabeling in most of the cranial nerve surveyed. Labeling was found in the olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, and hypoglossal nerves. This is the first detailed description of the cellular and subcellular distribution of PlexinA4 in the adult cranial nerves. The findings will set the basis for future studies on the potential role of PlexinA4 in regeneration and repair of the adult central and peripheral nervous system.
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Affiliation(s)
| | - Robert E Gross
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA; Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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14
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Liang D, Wang X, Mittal A, Dhiman S, Hou SY, Degenhardt K, Astrof S. Mesodermal expression of integrin α5β1 regulates neural crest development and cardiovascular morphogenesis. Dev Biol 2014; 395:232-44. [PMID: 25242040 DOI: 10.1016/j.ydbio.2014.09.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/10/2014] [Accepted: 09/11/2014] [Indexed: 01/09/2023]
Abstract
Integrin α5-null embryos die in mid-gestation from severe defects in cardiovascular morphogenesis, which stem from defective development of the neural crest, heart and vasculature. To investigate the role of integrin α5β1 in cardiovascular development, we used the Mesp1(Cre) knock-in strain of mice to ablate integrin α5 in the anterior mesoderm, which gives rise to all of the cardiac and many of the vascular and muscle lineages in the anterior portion of the embryo. Surprisingly, we found that mutant embryos displayed numerous defects related to the abnormal development of the neural crest such as cleft palate, ventricular septal defect, abnormal development of hypoglossal nerves, and defective remodeling of the aortic arch arteries. We found that defects in arch artery remodeling stem from the role of mesodermal integrin α5β1 in neural crest proliferation and differentiation into vascular smooth muscle cells, while proliferation of pharyngeal mesoderm and differentiation of mesodermal derivatives into vascular smooth muscle cells was not defective. Taken together our studies demonstrate a requisite role for mesodermal integrin α5β1 in signaling between the mesoderm and the neural crest, thereby regulating neural crest-dependent morphogenesis of essential embryonic structures.
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Affiliation(s)
- Dong Liang
- Thomas Jefferson University, Department of Medicine, Center for Translational Medicine, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Xia Wang
- Thomas Jefferson University, Department of Medicine, Center for Translational Medicine, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Ashok Mittal
- Thomas Jefferson University, Department of Medicine, Center for Translational Medicine, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Sonam Dhiman
- Thomas Jefferson University, Department of Medicine, Center for Translational Medicine, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Shuan-Yu Hou
- Thomas Jefferson University, Department of Medicine, Center for Translational Medicine, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Karl Degenhardt
- Childrens Hospital of Pennsylvania, University of Pennsylvania, Philadelphia, PA 19107, USA
| | - Sophie Astrof
- Thomas Jefferson University, Department of Medicine, Center for Translational Medicine, 1020 Locust Street, Philadelphia, PA 19107, USA.
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15
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García-Peña CM, Kim M, Frade-Pérez D, Avila-González D, Téllez E, Mastick GS, Tamariz E, Varela-Echavarría A. Ascending midbrain dopaminergic axons require descending GAD65 axon fascicles for normal pathfinding. Front Neuroanat 2014; 8:43. [PMID: 24926237 PMCID: PMC4046268 DOI: 10.3389/fnana.2014.00043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/19/2014] [Indexed: 12/22/2022] Open
Abstract
The Nigrostriatal pathway (NSP) is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold.
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Affiliation(s)
- Claudia M García-Peña
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, México
| | - Minkyung Kim
- Department of Biology, University of Nevada Reno, NV, USA
| | - Daniela Frade-Pérez
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, México
| | - Daniela Avila-González
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, México
| | - Elisa Téllez
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, México
| | | | - Elisa Tamariz
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, México
| | - Alfredo Varela-Echavarría
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, México
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16
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Kipanyula MJ, Kimaro WH, Yepnjio FN, Aldebasi YH, Farahna M, Nwabo Kamdje AH, Abdel-Magied EM, Seke Etet PF. Signaling pathways bridging fate determination of neural crest cells to glial lineages in the developing peripheral nervous system. Cell Signal 2013; 26:673-82. [PMID: 24378534 DOI: 10.1016/j.cellsig.2013.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 12/13/2013] [Accepted: 12/22/2013] [Indexed: 11/29/2022]
Abstract
Fate determination of neural crest cells is an essential step for the development of different crest cell derivatives. Peripheral glia development is marked by the choice of the neural crest cells to differentiate along glial lineages. The molecular mechanism underlying fate acquisition is poorly understood. However, recent advances have identified different transcription factors and genes required for the complex instructive signaling process that comprise both local environmental and cell intrinsic cues. Among others, at least the roles of Sox10, Notch, and neuregulin 1 have been documented in both in vivo and in vitro models. Cooperative interactions of such factors appear to be necessary for the switch from multipotent neural crest cells to glial lineage precursors in the peripheral nervous system. This review summarizes recent advances in the understanding of fate determination of neural crest cells into different glia subtypes, together with the potential implications in regenerative medicine.
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Affiliation(s)
- Maulilio John Kipanyula
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3016, Chuo Kikuu, Morogoro, Tanzania.
| | - Wahabu Hamisi Kimaro
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3016, Chuo Kikuu, Morogoro, Tanzania
| | - Faustin N Yepnjio
- Neurology Department, Yaoundé Central Hospital, Department of Internal Medicine and Specialties, University of Yaoundé I, P.O. Box 1937, Yaoundé, Cameroon
| | - Yousef H Aldebasi
- Department of Optometry, College of Applied Medical Sciences, Qassim University, 51452 Buraydah, Saudi Arabia
| | - Mohammed Farahna
- Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, 51452 Buraydah, Saudi Arabia
| | | | - Eltuhami M Abdel-Magied
- Department of Anatomy and Histology, College of Medicine, Qassim University, 51452 Buraydah, Saudi Arabia
| | - Paul Faustin Seke Etet
- Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, 51452 Buraydah, Saudi Arabia.
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17
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Hua ZL, Smallwood PM, Nathans J. Frizzled3 controls axonal development in distinct populations of cranial and spinal motor neurons. eLife 2013; 2:e01482. [PMID: 24347548 PMCID: PMC3865743 DOI: 10.7554/elife.01482] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Disruption of the Frizzled3 (Fz3) gene leads to defects in axonal growth in the VIIth and XIIth cranial motor nerves, the phrenic nerve, and the dorsal motor nerve in fore- and hindlimbs. In Fz3−/− limbs, dorsal axons stall at a precise location in the nerve plexus, and, in contrast to the phenotypes of several other axon path-finding mutants, Fz3−/− dorsal axons do not reroute to other trajectories. Affected motor neurons undergo cell death 2 days prior to the normal wave of developmental cell death that coincides with innervation of muscle targets, providing in vivo evidence for the idea that developing neurons with long-range axons are programmed to die unless their axons arrive at intermediate targets on schedule. These experiments implicate planar cell polarity (PCP) signaling in motor axon growth and they highlight the question of how PCP proteins, which form cell–cell complexes in epithelia, function in the dynamic context of axonal growth. DOI:http://dx.doi.org/10.7554/eLife.01482.001 For the nervous system to become wired up correctly, neurons within the developing embryo must project over long distances to form connections with remote targets. They do this by lengthening their axons—the ‘cables’ along which electrical signals flow—and some axons in adult humans can grow to be more than 1 metre long. This type of long-range pathfinding activity is particularly common for neurons that control movement, as many of these neurons must establish connections with muscles that are some distance away from the brain. For example, motor neurons in the brainstem form connections with muscles in the face to control facial expressions, while motor neurons in parts of the spinal cord project to muscles in the limbs. Multiple signaling pathways tell the developing axons which direction to grow en route to their final targets. Now, Hua et al. have shown that an evolutionarily conserved protein called Frizzled3 is also involved in this process. In mouse embryos that lacked Frizzled3, the motor nerves that control breathing and limb movements were thinner than those in normal mice. In the mutant animals, many motor axons failed to form connections with their targets. Instead, these axons came to an abrupt halt midway along their intended paths and the neurons from which they originated died soon afterwards. These experiments support the idea that developing neurons are programmed to die unless their axons progress on the appropriate schedule. As well as increasing our knowledge of the networks of connections that form within the developing mammalian nervous system, the work of Hua et al. provides new insights into some of the molecular mechanisms by which these connections are established. DOI:http://dx.doi.org/10.7554/eLife.01482.002
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Affiliation(s)
- Zhong L Hua
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
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18
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Corson SL, Kim M, Mistretta CM, Bradley RM. Gustatory solitary tract development: a role for neuropilins. Neuroscience 2013; 252:35-44. [PMID: 23933306 DOI: 10.1016/j.neuroscience.2013.07.068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 07/27/2013] [Accepted: 07/29/2013] [Indexed: 01/13/2023]
Abstract
The rostral nucleus of the solitary tract (rNST) receives orosensory information from taste bud cells in the tongue and palate via cranial nerves VII and IX. These nerves enter the brainstem, form the solitary tract (ST) and synapse with neurons in the rNST, which then relay incoming sensory information to other brain areas to process external gustatory stimuli. Factors that direct or regulate the trajectory of the developing ST are largely unknown. We used 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) to identify ST projections originating from cells in the geniculate ganglia of embryonic rats from embryonic day 14 through 18 (E14-E18). After identifying the ST fibers, immunolabeling for and protein expression analysis of the axon guidance molecules neuropilin-1 (Npn-1) and neuropilin-2 (Npn-2) and their binding partners, semaphorin-3A (Sema-3A) and semaphorin-3F (Sema-3F) were performed. The results detail the formation of ST projections into the gustatory brainstem and their relationship to developing rNST neurons. DiI-labeled ST fibers were present in the brainstem as early as E14. Npn-1 was expressed in the ST and in the trigeminal tract at E14, but levels of the protein declined through E18. The expression levels of the binding partner of Npn-1, Sema-3A, increased from E14 to E18. Npn-2 was expressed in the ST and, additionally, in radially oriented, tuft-like structures within the brainstem at E14. Expression levels of Npn-2 also declined through E18, in contrast to the expression levels of its binding partner, Sema-3F, which increased during this time period. For the first time, the time course and particular molecular components involved in development of the ST have been identified. These results indicate that the neuropilin and semaphorin families of axon guidance molecules are potential molecular participants in ST formation.
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Affiliation(s)
- Sara L Corson
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, 1011 N. University Avenue, Ann Arbor, MI 48109, USA.
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19
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Huettl RE, Haehl T, Huber AB. Fasciculation and guidance of spinal motor axons in the absence of FGFR2 signaling. PLoS One 2012; 7:e41095. [PMID: 22815929 PMCID: PMC3398880 DOI: 10.1371/journal.pone.0041095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 06/18/2012] [Indexed: 11/18/2022] Open
Abstract
During development, fibroblast growth factors (FGF) are essential for early patterning events along the anterior-posterior axis, conferring positional identity to spinal motor neurons by activation of different Hox codes. In the periphery, signaling through one of four fibroblast growth factor receptors supports the development of the skeleton, as well as induction and maintenance of extremities. In previous studies, FGF receptor 2 (FGFR2) was found to interact with axon bound molecules involved in axon fasciculation and extension, thus rendering this receptor an interesting candidate for the promotion of proper peripheral innervation. However, while the involvement of FGFR2 in limb bud induction has been extensively studied, its role during axon elongation and formation of distinct nervous projections has not been addressed so far. We show here that motor neurons in the spinal cord express FGFR2 and other family members during the establishment of motor connections to the forelimb and axial musculature. Employing a conditional genetic approach to selectively ablate FGFR2 from motor neurons we found that the patterning of motor columns and the expression patterns of other FGF receptors and Sema3A in the motor columns of mutant embryos are not altered. In the absence of FGFR2 signaling, pathfinding of motor axons is intact, and also fasciculation, distal advancement of motor nerves and gross morphology and positioning of axonal projections are not altered. Our findings therefore show that FGFR2 is not required cell-autonomously in motor neurons during the formation of initial motor projections towards limb and axial musculature.
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Affiliation(s)
- Rosa-Eva Huettl
- Institute of Developmental Genetics, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
| | - Teresa Haehl
- Institute of Developmental Genetics, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
| | - Andrea B. Huber
- Institute of Developmental Genetics, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
- * E-mail:
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