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Cell-Extrinsic Differentiation Block Mediated by EphA3 in Pre-Leukaemic Thymus Contributes to Disease Progression. Cancers (Basel) 2021; 13:cancers13153858. [PMID: 34359759 PMCID: PMC8345401 DOI: 10.3390/cancers13153858] [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: 05/31/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 11/19/2022] Open
Abstract
Simple Summary The NUP98-HOXD13 (NHD13) mouse is a model of T-cell leukaemia (T-ALL) featuring a pre-leukemic phase, in which T-cell progenitors from the thymus of an NHD13 mouse can engraft into the thymus of a recipient mouse—an ability that normal T-cell progenitors do not possess. However, loss of this engraftment ability (by deletion of the Lyl1 gene) did not result in any loss of leukemogenesis activity, indicating the activity of redundant oncogenic pathways in this model. Having observed an overexpression of the EphA3 protein in the NHD13 thymocytes, we hypothesized that this gene might be involved in a redundant leukaemogenic pathway. Deletion of EphA3 did not affect the engraftment ability of the thymocytes, but did reduce the incidence of T-ALL. We thus uncovered a distinct mechanism of leukaemogenesis, which we believe operates in parallel to that mediated by Lyl1. Abstract We recently characterised the NUP98-HOXD13 (NHD13) mouse as a model of T-cell pre-leukaemia, featuring thymocytes that can engraft in recipient animals and progress to T-cell acute lymphoblastic leukaemia (T-ALL). However, loss of this engraftment ability by deletion of Lyl1 did not result in any loss of leukemogenesis activity. In the present study, we observe that NHD13 thymocytes overexpress EPHA3, and we characterise thymocyte behaviour in NHD13 mice with deletion of EphA3, which show a markedly reduced incidence of T-ALL. Deletion of EphA3 from the NHD13 mice does not prevent the abnormal accumulation or transplantation ability of these thymocytes. However, upon transplantation, these cells are unable to block the normal progression of recipient wild type (WT) progenitor cells through the normal developmental pathway. This is in contrast to the EphA3+/+ NHD13 thymocytes, which block the progression of incoming WT progenitors past the DN1 stage. Therefore, EphA3 is not critical for classical self-renewal, but is essential for mediating an interaction between the abnormally self-renewing cells and healthy progenitors—an interaction that results in a failure of the healthy cells to differentiate normally. We speculate that this may orchestrate a loss of healthy cell competition, which in itself has been demonstrated to be oncogenic, and that this may explain the decrease in T-ALL incidence in the absence of EphA3. We suggest that pre-leukaemic self-renewal in this model is a complex interplay of cell-intrinsic and -extrinsic factors, and that multiple redundant pathways to leukaemogenesis are active.
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Javier-Torrent M, Marco S, Rocandio D, Pons-Vizcarra M, Janes PW, Lackmann M, Egea J, Saura CA. Presenilin/γ-secretase-dependent EphA3 processing mediates axon elongation through non-muscle myosin IIA. eLife 2019; 8:43646. [PMID: 31577226 PMCID: PMC6774734 DOI: 10.7554/elife.43646] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 09/18/2019] [Indexed: 01/08/2023] Open
Abstract
EphA/ephrin signaling regulates axon growth and guidance of neurons, but whether this process occurs also independently of ephrins is unclear. We show that presenilin-1 (PS1)/γ-secretase is required for axon growth in the developing mouse brain. PS1/γ-secretase mediates axon growth by inhibiting RhoA signaling and cleaving EphA3 independently of ligand to generate an intracellular domain (ICD) fragment that reverses axon defects in PS1/γ-secretase- and EphA3-deficient hippocampal neurons. Proteomic analysis revealed that EphA3 ICD binds to non-muscle myosin IIA (NMIIA) and increases its phosphorylation (Ser1943), which promotes NMIIA filament disassembly and cytoskeleton rearrangement. PS1/γ-secretase-deficient neurons show decreased phosphorylated NMIIA and NMIIA/actin colocalization. Moreover, pharmacological NMII inhibition reverses axon retraction in PS-deficient neurons suggesting that NMIIA mediates PS/EphA3-dependent axon elongation. In conclusion, PS/γ-secretase-dependent EphA3 cleavage mediates axon growth by regulating filament assembly through RhoA signaling and NMIIA, suggesting opposite roles of EphA3 on inhibiting (ligand-dependent) and promoting (receptor processing) axon growth in developing neurons.
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Affiliation(s)
- Míriam Javier-Torrent
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sergi Marco
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Daniel Rocandio
- Institut de Recerca Biomédica de Lleida, Universitat de Lleida, Lleida, Spain
| | - Maria Pons-Vizcarra
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Peter W Janes
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | - Martin Lackmann
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | - Joaquim Egea
- Institut de Recerca Biomédica de Lleida, Universitat de Lleida, Lleida, Spain
| | - Carlos A Saura
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
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Cadwell CR, Bhaduri A, Mostajo-Radji MA, Keefe MG, Nowakowski TJ. Development and Arealization of the Cerebral Cortex. Neuron 2019; 103:980-1004. [PMID: 31557462 PMCID: PMC9245854 DOI: 10.1016/j.neuron.2019.07.009] [Citation(s) in RCA: 145] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 05/15/2019] [Accepted: 07/03/2019] [Indexed: 12/16/2022]
Abstract
Adult cortical areas consist of specialized cell types and circuits that support unique higher-order cognitive functions. How this regional diversity develops from an initially uniform neuroepithelium has been the subject of decades of seminal research, and emerging technologies, including single-cell transcriptomics, provide a new perspective on area-specific molecular diversity. Here, we review the early developmental processes that underlie cortical arealization, including both cortex intrinsic and extrinsic mechanisms as embodied by the protomap and protocortex hypotheses, respectively. We propose an integrated model of serial homology whereby intrinsic genetic programs and local factors establish early transcriptomic differences between excitatory neurons destined to give rise to broad "proto-regions," and activity-dependent mechanisms lead to progressive refinement and formation of sharp boundaries between functional areas. Finally, we explore the potential of these basic developmental processes to inform our understanding of the emergence of functional neural networks and circuit abnormalities in neurodevelopmental disorders.
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Affiliation(s)
- Cathryn R Cadwell
- Department of Anatomic Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Aparna Bhaduri
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94122, USA; The Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research at the University of California, San Francisco, San Francisco, CA 94143, USA
| | - Mohammed A Mostajo-Radji
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94122, USA; The Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research at the University of California, San Francisco, San Francisco, CA 94143, USA
| | - Matthew G Keefe
- Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Tomasz J Nowakowski
- The Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research at the University of California, San Francisco, San Francisco, CA 94143, USA; Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA.
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Andretta E, Cartón-García F, Martínez-Barriocanal Á, de Marcondes PG, Jimenez-Flores LM, Macaya I, Bazzocco S, Bilic J, Rodrigues P, Nieto R, Landolfi S, Ramon y Cajal S, Schwartz S, Brown A, Dopeso H, Arango D. Investigation of the role of tyrosine kinase receptor EPHA3 in colorectal cancer. Sci Rep 2017; 7:41576. [PMID: 28169277 PMCID: PMC5294649 DOI: 10.1038/srep41576] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 12/22/2016] [Indexed: 12/23/2022] Open
Abstract
EPH signaling deregulation has been shown to be important for colorectal carcinogenesis and genome-wide sequencing efforts have identified EPHA3 as one of the most frequently mutated genes in these tumors. However, the role of EPHA3 in colorectal cancer has not been thoroughly investigated. We show here that ectopic expression of wild type EPHA3 in colon cancer cells did not affect their growth, motility/invasion or metastatic potential in vivo. Moreover, overexpression of mutant EPHA3 or deletion of the endogenous mutant EPHA3 in colon cancer cells did not affect their growth or motility. EPHA3 inactivation in mice did not initiate the tumorigenic process in their intestine, and had no effects on tumor size/multiplicity after tumor initiation either genetically or pharmacologically. In addition, immunohistochemical analysis of EPHA3 tumor levels did not reveal associations with survival or clinicopathological features of colorectal cancer patients. In conclusion, we show that EPHA3 does not play a major role in colorectal tumorigenesis. These results significantly contribute to our understanding of the role of EPH signaling during colorectal carcinogenesis, and highlighting the need for detailed functional studies to confirm the relevance of putative cancer driver genes identified in sequencing efforts of the cancer genome.
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Affiliation(s)
- Elena Andretta
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Fernando Cartón-García
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Águeda Martínez-Barriocanal
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Priscila Guimarães de Marcondes
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Lizbeth M. Jimenez-Flores
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Irati Macaya
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Sarah Bazzocco
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Josipa Bilic
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Paulo Rodrigues
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Rocio Nieto
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | | | | | - Simo Schwartz
- Group of Drug Delivery and Targeting, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain
| | - Arthur Brown
- Robarts Research Institute, London, Ontario, Canada
| | - Higinio Dopeso
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
| | - Diego Arango
- Group of Biomedical Research in Digestive Tract Tumors, CIBBIM-Nanomedicine, Vall d’Hebron University Hospital, Research Institute (VHIR), Universitat Autònoma de Barcelona, Passeig Vall d’Hebron, 119-129, 08035 Barcelona, Spain
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Lahtela J, Pradhan B, Närhi K, Hemmes A, Särkioja M, Kovanen PE, Brown A, Verschuren EW. The putative tumor suppressor gene EphA3 fails to demonstrate a crucial role in murine lung tumorigenesis or morphogenesis. Dis Model Mech 2015; 8:393-401. [PMID: 25713296 PMCID: PMC4381338 DOI: 10.1242/dmm.019257] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 02/12/2015] [Indexed: 01/04/2023] Open
Abstract
Treatment of non-small cell lung cancer (NSCLC) is based on histological analysis and molecular profiling of targetable driver oncogenes. Therapeutic responses are further defined by the landscape of passenger mutations, or loss of tumor suppressor genes. We report here a thorough study to address the physiological role of the putative lung cancer tumor suppressor EPH receptor A3 (EPHA3), a gene that is frequently mutated in human lung adenocarcinomas. Our data shows that homozygous or heterozygous loss of EphA3 does not alter the progression of murine adenocarcinomas that result from Kras mutation or loss of Trp53, and we detected negligible postnatal expression of EphA3 in adult wild-type lungs. Yet, EphA3 was expressed in the distal mesenchyme of developing mouse lungs, neighboring the epithelial expression of its Efna1 ligand; this is consistent with the known roles of EPH receptors in embryonic development. However, the partial loss of EphA3 leads only to subtle changes in epithelial Nkx2-1, endothelial Cd31 and mesenchymal Fgf10 RNA expression levels, and no macroscopic phenotypic effects on lung epithelial branching, mesenchymal cell proliferation, or abundance and localization of CD31-positive endothelia. The lack of a discernible lung phenotype in EphA3-null mice might indicate lack of an overt role for EPHA3 in the murine lung, or imply functional redundancy between EPHA receptors. Our study shows how biological complexity can challenge in vivo functional validation of mutations identified in sequencing efforts, and provides an incentive for the design of knock-in or conditional models to assign the role of EPHA3 mutation during lung tumorigenesis.
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Affiliation(s)
- Jenni Lahtela
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FI-00014, Finland
| | - Barun Pradhan
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FI-00014, Finland
| | - Katja Närhi
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FI-00014, Finland
| | - Annabrita Hemmes
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FI-00014, Finland
| | - Merja Särkioja
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FI-00014, Finland
| | - Panu E Kovanen
- Department of Pathology, HUSLAB and Haartman Institute, Helsinki University Central Hospital and University of Helsinki FI-00014, Finland
| | - Arthur Brown
- Spinal Cord Injury Team, Robarts Research Institute, University of Western Ontario, London, ON N6A 5K8, Canada
| | - Emmy W Verschuren
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki FI-00014, Finland.
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Agrawal P, Wang M, Kim S, Lewis AE, Bush JO. Embryonic expression of EphA receptor genes in mice supports their candidacy for involvement in cleft lip and palate. Dev Dyn 2014; 243:1470-6. [PMID: 25073978 DOI: 10.1002/dvdy.24170] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Eph receptors, comprising the A- and B-subfamilies, are the largest family of receptor tyrosine kinases in the mammalian genome, and their function is critical for morphogenesis in a variety of contexts. Whereas signaling through B-type Ephs has been demonstrated to play a role in cleft lip and palate (CL/P), the involvement of A-type Ephs has not been examined in this context notwithstanding a recent genome-wide association study that identified the EPHA3 locus as a candidate for non-syndromic CL/P. RESULTS Here, we present a systematic analysis of the gene expression patterns for the nine EphA receptors at progressive stages of mouse development and find that EphA3, EphA4, and EphA7 exhibit restricted overlapping patterns of expression during palate development. We find that homozygous mutation of EphA3 or compound homozygous mutation of EphA3 and EphA4 in mice does not result in defective midfacial development, supporting the possibility of redundant function with EphA7. We also document previously undescribed expression patterns in other tissues of the craniofacial complex including the lacrimal duct and salivary glands. CONCLUSIONS Together, these results are consistent with the hypothesis that mutations in EPHA family genes may cause CL/P and also suggest that functional redundancy between family members may be at play.
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Affiliation(s)
- Puja Agrawal
- Department of Cell and Tissue Biology, Program in Craniofacial and Mesenchymal Biology and Institute for Human Genetics, University of California, San Francisco, California; Department of Molecular and Cell Biology, University of California, Berkeley, California
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Keane N, Freeman C, Swords R, Giles FJ. EPHA3 as a novel therapeutic target in the hematological malignancies. Expert Rev Hematol 2014; 5:325-40. [DOI: 10.1586/ehm.12.19] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Lahtela J, Corson LB, Hemmes A, Brauer MJ, Koopal S, Lee J, Hunsaker TL, Jackson PK, Verschuren EW. A high-content cellular senescence screen identifies candidate tumor suppressors, including EPHA3. Cell Cycle 2013; 12:625-34. [PMID: 23324396 PMCID: PMC3594263 DOI: 10.4161/cc.23515] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Activation of a cellular senescence program is a common response to prolonged oncogene activation or tumor suppressor loss, providing a physiological mechanism for tumor suppression in premalignant cells. The link between senescence and tumor suppression supports the hypothesis that a loss-of-function screen measuring bona fide senescence marker activation should identify candidate tumor suppressors. Using a high-content siRNA screening assay for cell morphology and proliferation measures, we identify 12 senescence-regulating kinases and determine their senescence marker signatures, including elevation of senescence-associated β-galactosidase, DNA damage and p53 or p16INK4a expression. Consistent with our hypothesis, SNP array CGH data supports loss of gene copy number of five senescence-suppressing genes across multiple tumor samples. One such candidate is the EPHA3 receptor tyrosine kinase, a gene commonly mutated in human cancer. We demonstrate that selected intracellular EPHA3 tumor-associated point mutations decrease receptor expression level and/or receptor tyrosine kinase (RTK) activity. Our study therefore describes a new strategy to mine for novel candidate tumor suppressors and provides compelling evidence that EPHA3 mutations may promote tumorigenesis only when key senescence-inducing pathways have been inactivated.
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Affiliation(s)
- Jenni Lahtela
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
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Brennaman LH, Zhang X, Guan H, Triplett JW, Brown A, Demyanenko GP, Manis PB, Landmesser L, Maness PF. Polysialylated NCAM and ephrinA/EphA regulate synaptic development of GABAergic interneurons in prefrontal cortex. ACTA ACUST UNITED AC 2012; 23:162-77. [PMID: 22275477 DOI: 10.1093/cercor/bhr392] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A novel function for the neural cell adhesion molecule (NCAM) was identified in ephrinA/EphA-mediated repulsion as an important regulatory mechanism for development of GABAergic inhibitory synaptic connections in mouse prefrontal cortex. Deletion of NCAM, EphA3, or ephrinA2/3/5 in null mutant mice increased the numbers and size of perisomatic synapses between GABAergic basket interneurons and pyramidal cells in the developing cingulate cortex (layers II/III). A functional consequence of NCAM loss was increased amplitudes and faster kinetics of miniature inhibitory postsynaptic currents in NCAM null cingulate cortex. NCAM and EphA3 formed a molecular complex and colocalized with the inhibitory presynaptic marker vesicular GABA transporter (VGAT) in perisomatic puncta and neuropil in the cingulate cortex. EphrinA5 treatment promoted axon remodeling of enhanced green fluorescent protein-labeled basket interneurons in cortical slice cultures and induced growth cone collapse in wild-type but not NCAM null mutant neurons. NCAM modified with polysialic acid (PSA) was required to promote ephrinA5-induced axon remodeling of basket interneurons in cortical slices, likely by providing a permissive environment for ephrinA5/EphA3 signaling. These results reveal a new mechanism in which NCAM and ephrinAs/EphA3 coordinate to constrain GABAergic interneuronal arborization and perisomatic innervation, potentially contributing to excitatory/inhibitory balance in prefrontal cortical circuitry.
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Affiliation(s)
- Leann H Brennaman
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
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10
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Anatomical coupling of sensory and motor nerve trajectory via axon tracking. Neuron 2011; 71:263-77. [PMID: 21791286 DOI: 10.1016/j.neuron.2011.06.021] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2011] [Indexed: 11/20/2022]
Abstract
It is a long-standing question how developing motor and sensory neuron projections cooperatively form a common principal grid of peripheral nerve pathways relaying behavioral outputs and somatosensory inputs. Here, we explored this issue through targeted cell lineage and gene manipulation in mouse, combined with in vitro live axon imaging. In the absence of motor projections, dorsal (epaxial) and ventral (hypaxial) sensory projections form in a randomized manner, while removal of EphA3/4 receptor tyrosine kinases expressed by epaxial motor axons triggers selective failure to form epaxial sensory projections. EphA3/4 act non-cell-autonomously by inducing sensory axons to track along preformed epaxial motor projections. This involves cognate ephrin-A proteins on sensory axons but is independent from EphA3/4 signaling in motor axons proper. Assembly of peripheral nerve pathways thus involves motor axon subtype-specific signals that couple sensory projections to discrete motor pathways.
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Gallarda BW, Bonanomi D, Müller D, Brown A, Alaynick WA, Andrews SE, Lemke G, Pfaff SL, Marquardt T. Segregation of axial motor and sensory pathways via heterotypic trans-axonal signaling. Science 2008; 320:233-6. [PMID: 18403711 DOI: 10.1126/science.1153758] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Execution of motor behaviors relies on circuitries effectively integrating immediate sensory feedback to efferent pathways controlling muscle activity. It remains unclear how, during neuromuscular circuit assembly, sensory and motor projections become incorporated into tightly coordinated, yet functionally separate pathways. We report that, within axial nerves, establishment of discrete afferent and efferent pathways depends on coordinate signaling between coextending sensory and motor projections. These heterotypic axon-axon interactions require motor axonal EphA3/EphA4 receptor tyrosine kinases activated by cognate sensory axonal ephrin-A ligands. Genetic elimination of trans-axonal ephrin-A --> EphA signaling in mice triggers drastic motor-sensory miswiring, culminating in functional efferents within proximal afferent pathways. Effective assembly of a key circuit underlying motor behaviors thus critically depends on trans-axonal signaling interactions resolving motor and sensory projections into discrete pathways.
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Affiliation(s)
- Benjamin W Gallarda
- Gene Expression Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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Learning and memory impairment in Eph receptor A6 knockout mice. Neurosci Lett 2008; 438:205-9. [PMID: 18450376 DOI: 10.1016/j.neulet.2008.04.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 04/01/2008] [Accepted: 04/07/2008] [Indexed: 11/20/2022]
Abstract
Genetic inhibition of the ephrin receptor (EphA6) in mice produced behavioral deficits specifically in tests of learning and memory. Using a fear conditioning training paradigm, mice deficient in EphA6 did not acquire the task as strongly as did wild type (WT) mice. When tested in the same context 24h later, knockout (KO) mice did not freeze as much as WT mice indicating reduced memory of the consequences of the training context. The KO mice also displayed less freezing when presented with the conditioning stimulus (CS) in a separate context. In the hidden platform phase of the Morris water maze (MWM) task, KO mice did not reach the same level of proficiency as did WT mice. KO mice also exhibited less preference for the target quadrant during a probe trial and were significantly impaired on an initial reversal of the platform. These findings suggest that EphA6, in line with a number of other Eph receptors and their ephrin ligands, is involved in neural circuits underlying aspects of learning and memory.
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Reber M, Hindges R, Lemke G. Eph receptors and ephrin ligands in axon guidance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 621:32-49. [PMID: 18269209 DOI: 10.1007/978-0-387-76715-4_3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Michael Reber
- INSERM U.575, Centre de Neurochimie, 5, rue Blaise Pascal, 67084 Strasbourg, France.
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Stephen LJ, Fawkes AL, Verhoeve A, Lemke G, Brown A. A critical role for the EphA3 receptor tyrosine kinase in heart development. Dev Biol 2007; 302:66-79. [PMID: 17046737 DOI: 10.1016/j.ydbio.2006.08.058] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Revised: 08/23/2006] [Accepted: 08/24/2006] [Indexed: 10/24/2022]
Abstract
Eph proteins are receptor tyrosine kinases that control changes in cell shape and migration during development. We now describe a critical role for EphA3 receptor signaling in heart development as revealed by the phenotype of EphA3 null mice. During heart development mesenchymal outgrowths, the atrioventricular endocardial cushions, form in the atrioventricular canal. This morphogenetic event requires endocardial cushion cells to undergo an epithelial to mesenchymal transformation (EMT), and results in the formation of the atrioventricular valves and membranous portions of the atrial and ventricular septa. We show that EphA3 knockouts have significant defects in the development of their atrial septa and atrioventricular endocardial cushions, and that these cardiac abnormalities lead to the death of approximately 75% of homozygous EphA3(-/-) mutants. We demonstrate that EphA3 and its ligand, ephrin-A1, are expressed in adjacent cells in the developing endocardial cushions. We further demonstrate that EphA3(-/-) atrioventricular endocardial cushions are hypoplastic compared to wildtype and that EphA3(-/-) endocardial cushion explants give rise to fewer migrating mesenchymal cells than wildtype explants. Thus our results indicate that EphA3 plays a crucial role in the development and morphogenesis of the cells that give rise to the atrioventricular valves and septa.
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Affiliation(s)
- Lesley J Stephen
- BioTherapeutics Research Group, The John P Robarts Research Institute, and The University of Western Ontario, London, Ontario, Canada
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15
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Irizarry-Ramírez M, Willson CA, Cruz-Orengo L, Figueroa J, Velázquez I, Jones H, Foster RD, Whittemore SR, Miranda JD. Upregulation of EphA3 Receptor after Spinal Cord Injury. J Neurotrauma 2005; 22:929-35. [PMID: 16083359 DOI: 10.1089/neu.2005.22.929] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Spinal cord injury (SCI) releases a cascade of events that leads to the onset of an inhibitory milieu for axonal regeneration. Some of these changes result from the presence of repulsive factors that may restrict axonal outgrowth after trauma. The Eph receptor tyrosine kinase (RTK) family has emerged as a key repellent cue known to be involved in neurite outgrowth, synapse formation, and axonal pathfinding during development. Given the nonpermissive environment for axonal regeneration after SCI, we questioned whether re-expression of one of these molecules occurs during regenerative failure. We examined the expression profile of EphA3 at the mRNA and protein levels after SCI, using the NYU contusion model. There is a differential distribution of this molecule in the adult spinal cord and EphA3 showed an increase in expression after several injury models like optic nerve and brain injury. Standardized semi-quantitative RT-PCR analysis demonstrated a time-dependent change in EphA3 mRNA levels, without alterations in beta-actin levels. The basal level of EphA3 mRNA in the adult spinal cord is low and its expression was induced 2 days after trauma (the earliest time point analyzed) and this upregulation persisted for 28 days post-injury (the latest time point examined). These results were corroborated at the protein level by immunohistochemical analysis and the cell phenotype identified by double labeling studies. In control animals, EphA3 immunoreactivity was observed in motor neurons of the ventral horn but not in lesioned animals. In addition, GFAP-positive cells were visualized in the ventral region of injured white matter. These results suggest that upregulation of EphA3 in reactive astrocytes may contribute to the repulsive environment for neurite outgrowth and may be involved in the pathophysiology generated after SCI.
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Affiliation(s)
- Margarita Irizarry-Ramírez
- Department of Clinical Laboratory Science, University of Puerto Rico Medical Science Campus, San Juan, Puerto Rico
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Cobb J, Duboule D. Comparative analysis of genes downstream of the Hoxd cluster in developing digits and external genitalia. Development 2005; 132:3055-67. [PMID: 15944189 DOI: 10.1242/dev.01885] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mammalian Hox genes encode transcription factors that are crucial for proper morphogenesis along the various body axes. Despite their extensive structural and functional characterization, the nature of their target genes remains elusive. We have addressed this question by using DNA microarrays to screen for genes whose expression in developing distal forelimbs and genital eminences was significantly modified in the absence of the full Hoxd gene complement. This comparative approach not only identified specific candidate genes, but also allowed the examination of whether a similar Hox expression pattern in distinct tissues leads to the modulation of the same or different downstream genes. We report here a set of potential target genes, most of which were not previously known to play a role in the early stages of either limb or genital bud development. Interestingly, we find that the majority of these candidate genes are differentially expressed in both structures,although often at different times. This supports the idea that both appendices involve similar genetic controls, both upstream and downstream of the Hox gene family. These results highlight the surprising mechanistic relationship between these rather different body parts and suggest a common developmental strategy to build up the most distal appendicular structures of the body, i.e. the digits and the penis/clitoris.
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Affiliation(s)
- John Cobb
- National Research Center (NCCR Zoology and Animal Biology, University of Geneva, Sciences III, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland
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