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Hembach S, Schmidt S, Orschmann T, Burtscher I, Lickert H, Giesert F, Weisenhorn DV, Wurst W. Engrailed 1 deficiency induces changes in ciliogenesis during human neuronal differentiation. Neurobiol Dis 2024; 194:106474. [PMID: 38518837 DOI: 10.1016/j.nbd.2024.106474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/15/2024] [Accepted: 03/15/2024] [Indexed: 03/24/2024] Open
Abstract
A key pathological feature of Parkinson's Disease (PD) is the progressive degeneration of dopaminergic neurons (DAns) in the substantia nigra pars compacta. Considering the major role of EN1 in the development and maintenance of these DAns and the implications from En1 mouse models, it is highly interesting to study the molecular and protective effect of EN1 also in a human cellular model. Therefore, we generated EN1 knock-out (ko) human induced pluripotent stem cell (hiPSCs) lines and analyzed these during neuronal differentiation. Although the EN1 ko didn't interfere with neuronal differentiation and generation of tyrosine hydroxylase positive (TH+) neurons per se, the neurons exhibited shorter neurites. Furthermore, mitochondrial respiration, as well as mitochondrial complex I abundance was significantly reduced in fully differentiated neurons. To understand the implications of an EN1 ko during differentiation, we performed a transcriptome analysis of human neuronal precursor cells (hNPCs) which unveiled alterations in cilia-associated pathways. Further analysis of ciliary morphology revealed an elongation of primary cilia in EN1-deficient hNPCs. Besides, also Wnt signaling pathways were severely affected. Upon stimulating hNPCs with Wnt which drastically increased EN1 expression in WT lines, the phenotypes concerning mitochondrial function and cilia were exacerbated in EN1 ko hNPCs. They failed to enhance the expression of the complex I subunits NDUFS1 and 3, and now displayed a reduced mitochondrial respiration. Furthermore, Wnt stimulation decreased ciliogenesis in EN1 ko hNPCs but increased ciliary length even further. This further highlights the relevance of primary cilia next to mitochondria for the functionality and correct maintenance of human DAns and provides new possibilities to establish neuroprotective therapies for PD.
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Affiliation(s)
- Sina Hembach
- Institute of Developmental Genetics, Helmholtz Munich, Neuherberg, Germany; Munich School of Life Sciences Weihenstephan, Technical University of Munich, Munich, Germany
| | - Sebastian Schmidt
- Institute of Developmental Genetics, Helmholtz Munich, Neuherberg, Germany; Neurobiological Engineering, Munich Institute of Biomedical Engineering, TUM School of Natural Sciences, Garching, Germany; Deutsche Zentrum für Psychische Gesundheit (DZPG), Site Munich-Augsburg, Munich, Germany
| | - Tanja Orschmann
- Institute of Developmental Genetics, Helmholtz Munich, Neuherberg, Germany
| | - Ingo Burtscher
- Institute of Diabetes and Regeneration Research, Helmholtz Munich, Neuherberg, Germany
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Munich, Neuherberg, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; School of Medicine, Technische Universität München, Munich, Germany
| | - Florian Giesert
- Institute of Developmental Genetics, Helmholtz Munich, Neuherberg, Germany
| | | | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Munich, Neuherberg, Germany; Deutsche Zentrum für Psychische Gesundheit (DZPG), Site Munich-Augsburg, Munich, Germany; Technische Universität München-Weihenstephan, Neuherberg, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.
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2
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Xu J, Hörner M, Nagel M, Korneck M, Noß M, Hauser S, Schöls L, Admard J, Casadei N, Schüle R. Unraveling Axonal Transcriptional Landscapes: Insights from iPSC-Derived Cortical Neurons and Implications for Motor Neuron Degeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586780. [PMID: 38585749 PMCID: PMC10996649 DOI: 10.1101/2024.03.26.586780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Neuronal function and pathology are deeply influenced by the distinct molecular profiles of the axon and soma. Traditional studies have often overlooked these differences due to the technical challenges of compartment specific analysis. In this study, we employ a robust RNA-sequencing (RNA-seq) approach, using microfluidic devices, to generate high-quality axonal transcriptomes from iPSC-derived cortical neurons (CNs). We achieve high specificity of axonal fractions, ensuring sample purity without contamination. Comparative analysis revealed a unique and specific transcriptional landscape in axonal compartments, characterized by diverse transcript types, including protein-coding mRNAs, ribosomal proteins (RPs), mitochondrial-encoded RNAs, and long non-coding RNAs (lncRNAs). Previous works have reported the existence of transcription factors (TFs) in the axon. Here, we detect a subset of previously unreported TFs specific to the axon and indicative of their active participation in transcriptional regulation. To investigate transcripts and pathways essential for central motor neuron (MN) degeneration and maintenance we analyzed KIF1C-knockout (KO) CNs, modeling hereditary spastic paraplegia (HSP), a disorder associated with prominent length-dependent degeneration of central MN axons. We found that several key factors crucial for survival and health were absent in KIF1C-KO axons, highlighting a possible role of these also in other neurodegenerative diseases. Taken together, this study underscores the utility of microfluidic devices in studying compartment-specific transcriptomics in human neuronal models and reveals complex molecular dynamics of axonal biology. The impact of KIF1C on the axonal transcriptome not only deepens our understanding of MN diseases but also presents a promising avenue for exploration of compartment specific disease mechanisms.
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3
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Ma X, Zhao LL, Yu YC, Cheng Y. Engrailed: Pathological and physiological effects of a multifunctional developmental gene. Genesis 2024; 62:e23557. [PMID: 37830136 DOI: 10.1002/dvg.23557] [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: 06/23/2023] [Revised: 09/14/2023] [Accepted: 09/14/2023] [Indexed: 10/14/2023]
Abstract
Engrailed-1 (EN1) is a developmental gene that encodes En1, a highly conserved transcription factor involved in regionalization during early embryogenesis and in the later maintenance of normal neurons. After birth, EN1 still plays a role in the development and physiology of the body; for example, it exerts a protective effect on midbrain dopaminergic (mDA) neurons, and loss of EN1 causes mDA neurons in the ventral midbrain to gradually die approximately 6 weeks after birth, resulting in motor and nonmotor symptoms similar to those observed in Parkinson's disease. Notably, EN1 has been identified as a possible susceptibility gene for idiopathic Parkinson's disease in humans. EN1 is involved in the processes of wound-healing scar production and tissue and organ fibrosis. Additionally, EN1 can lead to tumorigenesis and thus provides a target for the treatment of some tumors. In this review, we summarize the effects of EN1 on embryonic organ development, describe the consequences of the deletion or overexpression of the EN1 gene, and discuss the pathways in which EN1 is involved. We hope to clarify the role of EN1 as a developmental gene and present potential therapeutic targets for diseases involving the EN1 gene.
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Affiliation(s)
- Xiang Ma
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Liang-Liang Zhao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Yi-Chun Yu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Yan Cheng
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, P.R. China
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4
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Lebœuf M, Vargas-Abonce SE, Pezé-Hedsieck E, Dupont E, Jimenez-Alonso L, Moya KL, Prochiantz A. ENGRAILED-1 transcription factor has a paracrine neurotrophic activity on adult spinal α-motoneurons. EMBO Rep 2023; 24:e56525. [PMID: 37534581 PMCID: PMC10398658 DOI: 10.15252/embr.202256525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 08/04/2023] Open
Abstract
Several homeoprotein transcription factors transfer between cells and regulate gene expression, protein translation, and chromatin organization in recipient cells. ENGRAILED-1 is one such homeoprotein expressed in spinal V1 interneurons that synapse on α-motoneurons. Neutralizing extracellular ENGRAILED-1 by expressing a secreted single-chain antibody blocks its capture by spinal motoneurons resulting in α-motoneuron loss and limb weakness. A similar but stronger phenotype is observed in the Engrailed-1 heterozygote mouse, confirming that ENGRAILED-1 exerts a paracrine neurotrophic activity on spinal cord α-motoneurons. Intrathecal injection of ENGRAILED-1 leads to its specific internalization by spinal motoneurons and has long-lasting protective effects against neurodegeneration and weakness. Midbrain dopaminergic neurons express Engrailed-1 and, similarly to spinal cord α-motoneurons, degenerate in the heterozygote. We identify genes expressed in spinal cord motoneurons whose expression changes in mouse Engrailed-1 heterozygote midbrain neurons. Among these, p62/SQSTM1 shows increased expression during aging in spinal cord motoneurons in the Engrailed-1 heterozygote and upon extracellular ENGRAILED-1 neutralization. We conclude that ENGRAILED-1 might regulate motoneuron aging and has non-cell-autonomous neurotrophic activity.
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Affiliation(s)
- Mélanie Lebœuf
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- BrainEver SAS, Paris, France
| | - Stephanie E Vargas-Abonce
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- BrainEver SAS, Paris, France
| | - Eugénie Pezé-Hedsieck
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Edmond Dupont
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | | | - Kenneth L Moya
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Alain Prochiantz
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- BrainEver SAS, Paris, France
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5
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Cardon S, Hervis YP, Bolbach G, Lopin-Bon C, Jacquinet JC, Illien F, Walrant A, Ravault D, He B, Molina L, Burlina F, Lequin O, Joliot A, Carlier L, Sagan S. A cationic motif upstream Engrailed2 homeodomain controls cell internalization through selective interaction with heparan sulfates. Nat Commun 2023; 14:1998. [PMID: 37032404 PMCID: PMC10083169 DOI: 10.1038/s41467-023-37757-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/29/2023] [Indexed: 04/11/2023] Open
Abstract
Engrailed2 (En2) is a transcription factor that transfers from cell to cell through unconventional pathways. The poorly understood internalization mechanism of this cationic protein is proposed to require an initial interaction with cell-surface glycosaminoglycans (GAGs). To decipher the role of GAGs in En2 internalization, we have quantified the entry of its homeodomain region in model cells that differ in their content in cell-surface GAGs. The binding specificity to GAGs and the influence of this interaction on the structure and dynamics of En2 was also investigated at the amino acid level. Our results show that a high-affinity GAG-binding sequence (RKPKKKNPNKEDKRPR), upstream of the homeodomain, controls En2 internalization through selective interactions with highly-sulfated heparan sulfate GAGs. Our data underline the functional importance of the intrinsically disordered basic region upstream of En2 internalization domain, and demonstrate the critical role of GAGs as an entry gate, finely tuning homeoprotein capacity to internalize into cells.
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Affiliation(s)
- Sébastien Cardon
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Yadira P Hervis
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Gérard Bolbach
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
- Sorbonne Université, Mass Spectrometry Sciences Sorbonne University, MS3U platform, 75005, Paris, France
| | | | | | - Françoise Illien
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Astrid Walrant
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Delphine Ravault
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Bingwei He
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Laura Molina
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Fabienne Burlina
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Olivier Lequin
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France
| | - Alain Joliot
- INSERM U932, Institut Curie Centre de Recherche, PSL Research University, Paris, France
| | - Ludovic Carlier
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France.
| | - Sandrine Sagan
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 75005, Paris, France.
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6
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Joliot A. Role of PI(4,5)P2 and Cholesterol in Unconventional Protein Secretion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1422:381-392. [PMID: 36988889 DOI: 10.1007/978-3-031-21547-6_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Besides its protective role in the maintenance of cell homeostasis, the plasma membrane is the site of exchanges between the cell interior and the extracellular medium. To circumvent the hydrophobic barrier formed by the acyl chains of the lipid bilayer, protein channels and transporters are key players in the exchange of small hydrophilic compounds such as ions or nutrients, but they hardly account for the transport of larger biological molecules. Exchange of proteins usually relies on membrane-fusion events between vesicles and the plasma membrane. In recent years, several alternative unconventional protein secretion (UPS) pathways across the plasma membrane have been characterised for a specific set of secreted substrates, some of them excluding any membrane-fusion events (Dimou and Nickel, Curr Biol 28:R406-R410, 2018). One of thesbe pathways, referred as type I UPS, relies on the direct translocation of the protein across the plasma membrane and not surprisingly, lipids are essential players in this process. In this chapter, we discuss the roles of phosphatidylinositol(4,5)bisphosphate (PI(4,5)P2) and cholesterol in unconventional pathways involving Engrailed-2 homeoprotein and fibroblast growth factor 2.
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Affiliation(s)
- Alain Joliot
- INSERM U932, Institut Curie Centre de Recherche, PSL Research University, Paris, France.
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Carlier L, Samson D, Khemtemourian L, Joliot A, Fuchs PFJ, Lequin O. Anionic lipids induce a fold-unfold transition in the membrane-translocating Engrailed homeodomain. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184030. [PMID: 35988722 DOI: 10.1016/j.bbamem.2022.184030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 07/17/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Homeoprotein transcription factors have the property of interacting with membranes through their DNA-binding homeodomain, which is involved in unconventional internalization and secretion. Both processes depend on membrane-translocating events but their detailed molecular mechanisms are still poorly understood. We have previously characterized the conformational properties of Engrailed 2 homeodomain (EnHD) in aqueous solution and in micelles as membrane-mimetic environments. In the present study, we used small isotropic lipid bicelles as a more relevant membrane-mimetic model to characterize the membrane-bound state of EnHD. We show that lipid bicelles, in contrast to micelles, adequately reproduce the requirement of anionic lipids in the membrane binding and conformational transition of EnHD. The fold-unfold transition of EnHD induced by anionic lipids was characterized by NMR using 1H, 13C, 15N chemical shifts, nuclear Overhauser effects, residual dipolar couplings, intramolecular and intermolecular paramagnetic relaxation enhancements induced by site-directed spin-label or paramagnetic lipid probe, respectively. A global unpacking of EnHD helices is observed leading to a loss of the native fold. However, near-native propensities of EnHD backbone conformation are maintained in membrane environment, including not only the three helices but also the turn connecting helices H2 and H3. NMR and coarse-grained molecular dynamics simulations reveal that the EnHD adopts a shallow insertion in the membrane, with the three helices oriented parallel to the membrane. EnHD explores extended conformations and closed U-shaped conformations, which are stabilized by anionic lipid recruitment.
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Affiliation(s)
- Ludovic Carlier
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 place Jussieu, F-75005 Paris, France.
| | - Damien Samson
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 place Jussieu, F-75005 Paris, France
| | - Lucie Khemtemourian
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 place Jussieu, F-75005 Paris, France
| | - Alain Joliot
- INSERM U932, Institut Curie Centre de Recherche, PSL University, France
| | - Patrick F J Fuchs
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 place Jussieu, F-75005 Paris, France; Université Paris Cité, UFR Sciences du Vivant, F-75013 Paris, France
| | - Olivier Lequin
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 place Jussieu, F-75005 Paris, France.
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Joliot A, Prochiantz A. Unconventional Secretion, Gate to Homeoprotein Intercellular Transfer. Front Cell Dev Biol 2022; 10:926421. [PMID: 35837333 PMCID: PMC9274163 DOI: 10.3389/fcell.2022.926421] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/07/2022] [Indexed: 11/24/2022] Open
Abstract
Unconventional secretion allows for the secretion of fully mature and biologically active proteins mostly present in the cytoplasm or nucleus. Besides extra vesicle-driven secretion, non-extravesicular pathways also exist that specifically rely on the ability of the secreted proteins to translocate directly across the plasma membrane. This is the case for several homeoproteins, a family of over 300 transcription factors characterized by the structure of their DNA-binding homeodomain. The latter highly conserved homeodomain is necessary and sufficient for secretion, a process that requires PI(4,5)P2 binding, as is the case for FGF2 and HIV Tat unconventional secretion. An important feature of homeoproteins is their ability to cross membranes in both directions and thus to transfer between cells. This confers to homeoproteins their paracrine activity, an essential facet of their physiological functions.
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Affiliation(s)
- Alain Joliot
- INSERM U932, Institut Curie Centre de Recherche, PSL Research University, Paris, France
- *Correspondence: Alain Joliot,
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL Research University, Labex MemoLife, Paris, France
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Non-cell-autonomous OTX2 transcription factor regulates anxiety-related behavior in the mouse. Mol Psychiatry 2021; 26:6469-6480. [PMID: 33963285 PMCID: PMC8760049 DOI: 10.1038/s41380-021-01132-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/06/2021] [Accepted: 04/14/2021] [Indexed: 02/03/2023]
Abstract
The OTX2 homeoprotein transcription factor is expressed in the dopaminergic neurons of the ventral tegmental area, which projects to limbic structures controlling complex behaviors. OTX2 is also produced in choroid plexus epithelium, from which it is secreted into cerebrospinal fluid and transferred to limbic structure parvalbumin interneurons. Previously, adult male mice subjected to early-life stress were found susceptible to anxiety-like behaviors, with accompanying OTX2 expression changes in ventral tegmental area or choroid plexus. Here, we investigated the consequences of reduced OTX2 levels in Otx2 heterozygote mice, as well as in Otx2+/AA and scFvOtx2tg/0 mouse models for decreasing OTX2 transfer from choroid plexus to parvalbumin interneurons. Both male and female adult mice show anxiolysis-like phenotypes in all three models. In Otx2 heterozygote mice, we observed no changes in dopaminergic neuron numbers and morphology in ventral tegmental area, nor in their metabolic output and projections to target structures. However, we found reduced expression of parvalbumin in medial prefrontal cortex, which could be rescued in part by adult overexpression of Otx2 specifically in choroid plexus, resulting in increased anxiety-like behavior. Taken together, OTX2 synthesis by the choroid plexus followed by its secretion into the cerebrospinal fluid is an important regulator of anxiety-related phenotypes in the mouse.
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Di Nardo AA, Joliot A, Prochiantz A. Homeoprotein transduction in neurodevelopment and physiopathology. SCIENCE ADVANCES 2020; 6:6/44/eabc6374. [PMID: 33115744 PMCID: PMC7608782 DOI: 10.1126/sciadv.abc6374] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 09/11/2020] [Indexed: 05/28/2023]
Abstract
Homeoproteins were originally identified for embryonic cell-autonomous transcription activity, but they also have non-cell-autonomous activity owing to transfer between cells. This Review discusses transfer mechanisms and focuses on some established functions, such as neurodevelopmental regulation of axon guidance, and postnatal critical periods of brain plasticity that affect sensory processing and cognition. Homeoproteins are present across all eukaryotes, and intercellular transfer occurs in plants and animals. Proposed functions have evolutionary relevance, such as morphogenetic activity and sexual exchange during the mating of unicellular eukaryotes, while others have physiopathological relevance, such as regulation of mood and cognition by influencing brain compartmentalization, connectivity, and plasticity. There are more than 250 known homeoproteins with conserved transfer domains, suggesting that this is a common mode of signal transduction but with many undiscovered functions.
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Affiliation(s)
- Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, 75005 Paris, France.
| | - Alain Joliot
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, 75005 Paris, France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, 75005 Paris, France.
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11
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H 2O 2 and Engrailed 2 paracrine activity synergize to shape the zebrafish optic tectum. Commun Biol 2020; 3:536. [PMID: 32994473 PMCID: PMC7524761 DOI: 10.1038/s42003-020-01268-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/02/2020] [Indexed: 12/23/2022] Open
Abstract
Although a physiological role for redox signaling is now clearly established, the processes sensitive to redox signaling remains to be identified. Ratiometric probes selective for H2O2 have revealed its complex spatiotemporal dynamics during neural development and adult regeneration and perturbations of H2O2 levels disturb cell plasticity and morphogenesis. Here we ask whether endogenous H2O2 could participate in the patterning of the embryo. We find that perturbations of endogenous H2O2 levels impact on the distribution of the Engrailed homeoprotein, a strong determinant of midbrain patterning. Engrailed 2 is secreted from cells with high H2O2 levels and taken up by cells with low H2O2 levels where it leads to increased H2O2 production, steering the directional spread of the Engrailed gradient. These results illustrate the interplay between protein signaling pathways and metabolic processes during morphogenetic events.
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Apulei J, Kim N, Testa D, Ribot J, Morizet D, Bernard C, Jourdren L, Blugeon C, Di Nardo AA, Prochiantz A. Non-cell Autonomous OTX2 Homeoprotein Regulates Visual Cortex Plasticity Through Gadd45b/g. Cereb Cortex 2020; 29:2384-2395. [PMID: 29771284 DOI: 10.1093/cercor/bhy108] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 04/19/2018] [Indexed: 11/14/2022] Open
Abstract
The non-cell autonomous transfer of OTX2 homeoprotein transcription factor into juvenile mouse cerebral cortex regulates parvalbumin interneuron maturation and critical period timing. By analyzing gene expression in primary visual cortex of wild-type and Otx2+/GFP mice at plastic and nonplastic ages, we identified several putative genes implicated in Otx2-dependent visual cortex plasticity for ocular dominance. Cortical OTX2 infusion in juvenile mice induced Gadd45b/g expression through direct regulation of transcription. Intriguingly, a reverse effect was found in the adult, where reducing cortical OTX2 resulted in Gadd45b/g upregulation. Viral expression of Gadd45b in adult visual cortex directly induced ocular dominance plasticity with concomitant changes in MeCP2 foci within parvalbumin interneurons and in methylation states of several plasticity gene promoters, suggesting epigenetic regulation. This interaction provides a molecular mechanism for OTX2 to trigger critical period plasticity yet suppress adult plasticity.
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Affiliation(s)
- Jessica Apulei
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Namsuk Kim
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Damien Testa
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Jérôme Ribot
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - David Morizet
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Clémence Bernard
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Laurent Jourdren
- Genomic Core Facility, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL University, Paris, France
| | - Corinne Blugeon
- Genomic Core Facility, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL University, Paris, France
| | - Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, Paris, France
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13
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OTX2 Non-Cell Autonomous Activity Regulates Inner Retinal Function. eNeuro 2020; 7:ENEURO.0012-19.2020. [PMID: 32737182 PMCID: PMC7477954 DOI: 10.1523/eneuro.0012-19.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/19/2020] [Accepted: 05/05/2020] [Indexed: 12/11/2022] Open
Abstract
OTX2 is a homeoprotein transcription factor expressed in photoreceptors and bipolar cells in the retina. OTX2, like many other homeoproteins, transfers between cells and exerts non-cell autonomous effects such as promoting the survival of retinal ganglion cells that do not express the protein. Here we used a genetic approach to target extracellular OTX2 in the retina by conditional expression of a secreted single-chain anti-OTX2 antibody. Compared with control mice, the expression of this antibody by parvalbumin-expressing neurons in the retina is followed by a reduction in visual acuity in 1-month-old mice with no alteration of the retinal structure or cell type number or aspect. The a-waves and b-waves measured by electroretinogram were also indistinguishable from those of control mice, suggesting no functional deficit of photoreceptors and bipolar cells. Mice expressing the OTX2-neutralizing antibody did show a significant doubling in the flicker amplitude and a reduction in oscillatory potential, consistent with a change in inner retinal function. Our results show that interfering in vivo with OTX2 non-cell autonomous activity in the postnatal retina leads to an alteration in inner retinal cell functions and causes a deficit in visual acuity.
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14
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Amblard I, Dupont E, Alves I, Miralvès J, Queguiner I, Joliot A. Bidirectional transfer of homeoprotein EN2 across the plasma membrane requires PIP 2. J Cell Sci 2020; 133:jcs244327. [PMID: 32434869 DOI: 10.1242/jcs.244327] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/05/2020] [Indexed: 01/21/2023] Open
Abstract
Homeoproteins are a class of transcription factors sharing the unexpected property of intercellular trafficking that confers to homeoproteins a paracrine mode of action. Homeoprotein paracrine action participates in the control of patterning processes, including axonal guidance, brain plasticity and boundary formation. Internalization and secretion, the two steps of intercellular transfer, rely on unconventional mechanisms, but the cellular mechanisms at stake still need to be fully characterized. Thanks to the design of new quantitative and sensitive assays dedicated to the study of homeoprotein transfer within HeLa cells in culture, we demonstrate a core role of phosphatidylinositol (4,5)-bisphosphate (PIP2) together with cholesterol in the translocation of the homeobox protein engrailed-2 (EN2) across the plasma membrane. By using drug and enzyme treatments, we show that both secretion and internalization are regulated according to PIP2 levels. The requirement for PIP2 and cholesterol in EN2 trafficking correlates with their selective affinity for this protein in artificial bilayers, which is drastically decreased in a paracrine-deficient mutant of EN2. We propose that the bidirectional plasma membrane translocation events that occur during homeoprotein secretion and internalization are parts of a common process.
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Affiliation(s)
- Irène Amblard
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France
- Sorbonne University, Paris, France
| | - Edmond Dupont
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Isabel Alves
- CBMN, UMR 5248 CNRS, University of Bordeaux, 33600 Pessac, France
| | - Julie Miralvès
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Isabelle Queguiner
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Alain Joliot
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France
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15
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Nijssen J, Aguila J, Hoogstraaten R, Kee N, Hedlund E. Axon-Seq Decodes the Motor Axon Transcriptome and Its Modulation in Response to ALS. Stem Cell Reports 2019; 11:1565-1578. [PMID: 30540963 PMCID: PMC6294264 DOI: 10.1016/j.stemcr.2018.11.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 11/06/2018] [Accepted: 11/06/2018] [Indexed: 12/11/2022] Open
Abstract
Spinal motor axons traverse large distances to innervate target muscles, thus requiring local control of cellular events for proper functioning. To interrogate axon-specific processes we developed Axon-seq, a refined method incorporating microfluidics, RNA sequencing (RNA-seq), and bioinformatic quality control. We show that the axonal transcriptome is distinct from that of somas and contains fewer genes. We identified 3,500-5,000 transcripts in mouse and human stem cell-derived spinal motor axons, most of which are required for oxidative energy production and ribogenesis. Axons contained transcription factor mRNAs, e.g., Ybx1, with implications for local functions. As motor axons degenerate in amyotrophic lateral sclerosis (ALS), we investigated their response to the SOD1G93A mutation, identifying 121 ALS-dysregulated transcripts. Several of these are implicated in axonal function, including Nrp1, Dbn1, and Nek1, a known ALS-causing gene. In conclusion, Axon-seq provides an improved method for RNA-seq of axons, increasing our understanding of peripheral axon biology and identifying therapeutic targets in motor neuron disease.
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Affiliation(s)
- Jik Nijssen
- Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden
| | - Julio Aguila
- Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden
| | - Rein Hoogstraaten
- Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden; Department of Translational Neuroscience, Brain Center Rudolf Magnus, UMC Utrecht, Utrecht 3984 CG, Netherlands
| | - Nigel Kee
- Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden
| | - Eva Hedlund
- Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden.
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16
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Global Analysis of Intercellular Homeodomain Protein Transfer. Cell Rep 2019; 28:712-722.e3. [PMID: 31315049 PMCID: PMC9472292 DOI: 10.1016/j.celrep.2019.06.056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 05/06/2019] [Accepted: 06/14/2019] [Indexed: 11/20/2022] Open
Abstract
The homeodomain is found in hundreds of transcription factors that play roles in fate determination via cell-autonomous regulation of gene expression. However, some homeodomain-containing proteins (HPs) are thought to be secreted and penetrate neighboring cells to affect the recipient cell fate. To determine whether this is a general characteristic of HPs, we carried out a large-scale validation for intercellular transfer of HPs. Our screening reveals that intercellular transfer is a general feature of HPs, but it occurs in a cell-context-sensitive manner. We also found the secretion is not solely a function of the homeodomain, but it is supported by external motifs containing hydrophobic residues. Thus, mutations of hydrophobic residues of HPs abrogate secretion and consequently interfere with HP function in recipient cells. Collectively, our study proposes that HP transfer is an intercellular communication method that couples the functions of interacting cells. Lee et al. evaluate capabilities of homeodomain proteins (HPs) for transfer between cells. They find that intercellular transfer is a general but cell-context-sensitive property of HP. Intercellular HP transfer can be an unconventional way for the cells to communicate with neighboring cells that associate structurally and functionally.
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17
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Kaddour H, Coppola E, Di Nardo AA, Le Poupon C, Mailly P, Wizenmann A, Volovitch M, Prochiantz A, Pierani A. Extracellular Pax6 Regulates Tangential Cajal–Retzius Cell Migration in the Developing Mouse Neocortex. Cereb Cortex 2019; 30:465-475. [DOI: 10.1093/cercor/bhz098] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 04/09/2019] [Accepted: 04/16/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- H Kaddour
- Center for Interdisciplinary Research in Biology, Centre National de la Recherche Scientifique Unité mixte de recherche 7241/Institut national de la santé et de la recherche médicale U1050, Paris Science Lettre University, Labex MemoLife, Collège de France, 11 place Marcelin Berthelot, Paris, France
- Institut Jacques Monod, Centre National de la Recherche Scientifique Unité mixte de recherche 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion, Paris, France
- Imagine Institute for Genetic Diseases, Université Paris Descartes, 24 Boulevard du Montparnasse, Paris, France
- Institute of Psychiatry and Neuroscience of Paris, Université Paris Descartes, 102–108 Rue de la Santé, Paris, France
| | - E Coppola
- Institut Jacques Monod, Centre National de la Recherche Scientifique Unité mixte de recherche 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion, Paris, France
- Imagine Institute for Genetic Diseases, Université Paris Descartes, 24 Boulevard du Montparnasse, Paris, France
- Institute of Psychiatry and Neuroscience of Paris, Université Paris Descartes, 102–108 Rue de la Santé, Paris, France
| | - A A Di Nardo
- Center for Interdisciplinary Research in Biology, Centre National de la Recherche Scientifique Unité mixte de recherche 7241/Institut national de la santé et de la recherche médicale U1050, Paris Science Lettre University, Labex MemoLife, Collège de France, 11 place Marcelin Berthelot, Paris, France
| | - C Le Poupon
- Center for Interdisciplinary Research in Biology, Centre National de la Recherche Scientifique Unité mixte de recherche 7241/Institut national de la santé et de la recherche médicale U1050, Paris Science Lettre University, Labex MemoLife, Collège de France, 11 place Marcelin Berthelot, Paris, France
| | - P Mailly
- Center for Interdisciplinary Research in Biology, Centre National de la Recherche Scientifique, Core Facility Orion, 11 Place Marcelin Berthelot, Paris, France
| | - A Wizenmann
- Department of Anatomy, Institute of Clinical Anatomy and Cell, University of Tübingen, Osterbergstrasse 3, Tübingen, Germany
| | - M Volovitch
- Center for Interdisciplinary Research in Biology, Centre National de la Recherche Scientifique Unité mixte de recherche 7241/Institut national de la santé et de la recherche médicale U1050, Paris Science Lettre University, Labex MemoLife, Collège de France, 11 place Marcelin Berthelot, Paris, France
| | - A Prochiantz
- Center for Interdisciplinary Research in Biology, Centre National de la Recherche Scientifique Unité mixte de recherche 7241/Institut national de la santé et de la recherche médicale U1050, Paris Science Lettre University, Labex MemoLife, Collège de France, 11 place Marcelin Berthelot, Paris, France
| | - A Pierani
- Institut Jacques Monod, Centre National de la Recherche Scientifique Unité mixte de recherche 7592, Université Paris Diderot, Sorbonne Paris Cité, 15 Rue Hélène Brion, Paris, France
- Imagine Institute for Genetic Diseases, Université Paris Descartes, 24 Boulevard du Montparnasse, Paris, France
- Institute of Psychiatry and Neuroscience of Paris, Université Paris Descartes, 102–108 Rue de la Santé, Paris, France
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18
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Zhang X, Piano I, Messina A, D'Antongiovanni V, Crò F, Provenzano G, Bozzi Y, Gargini C, Casarosa S. Retinal defects in mice lacking the autism-associated gene Engrailed-2. Neuroscience 2019; 408:177-190. [DOI: 10.1016/j.neuroscience.2019.03.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/26/2019] [Accepted: 03/31/2019] [Indexed: 10/27/2022]
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19
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Fritzsch B, Elliott KL, Pavlinkova G. Primary sensory map formations reflect unique needs and molecular cues specific to each sensory system. F1000Res 2019; 8:F1000 Faculty Rev-345. [PMID: 30984379 PMCID: PMC6439788 DOI: 10.12688/f1000research.17717.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/21/2019] [Indexed: 12/21/2022] Open
Abstract
Interaction with the world around us requires extracting meaningful signals to guide behavior. Each of the six mammalian senses (olfaction, vision, somatosensation, hearing, balance, and taste) has a unique primary map that extracts sense-specific information. Sensory systems in the periphery and their target neurons in the central nervous system develop independently and must develop specific connections for proper sensory processing. In addition, the regulation of sensory map formation is independent of and prior to central target neuronal development in several maps. This review provides an overview of the current level of understanding of primary map formation of the six mammalian senses. Cell cycle exit, combined with incompletely understood molecules and their regulation, provides chemoaffinity-mediated primary maps that are further refined by activity. The interplay between cell cycle exit, molecular guidance, and activity-mediated refinement is the basis of dominance stripes after redundant organ transplantations in the visual and balance system. A more advanced level of understanding of primary map formation could benefit ongoing restoration attempts of impaired senses by guiding proper functional connection formations of restored sensory organs with their central nervous system targets.
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Affiliation(s)
- Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, USA
| | | | - Gabriela Pavlinkova
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic
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20
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Thompson AJ, Pillai EK, Dimov IB, Foster SK, Holt CE, Franze K. Rapid changes in tissue mechanics regulate cell behaviour in the developing embryonic brain. eLife 2019; 8:e39356. [PMID: 30642430 PMCID: PMC6333438 DOI: 10.7554/elife.39356] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 12/10/2018] [Indexed: 12/17/2022] Open
Abstract
Tissue mechanics is important for development; however, the spatio-temporal dynamics of in vivo tissue stiffness is still poorly understood. We here developed tiv-AFM, combining time-lapse in vivo atomic force microscopy with upright fluorescence imaging of embryonic tissue, to show that during development local tissue stiffness changes significantly within tens of minutes. Within this time frame, a stiffness gradient arose in the developing Xenopus brain, and retinal ganglion cell axons turned to follow this gradient. Changes in local tissue stiffness were largely governed by cell proliferation, as perturbation of mitosis diminished both the stiffness gradient and the caudal turn of axons found in control brains. Hence, we identified a close relationship between the dynamics of tissue mechanics and developmental processes, underpinning the importance of time-resolved stiffness measurements.
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Affiliation(s)
- Amelia J Thompson
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Eva K Pillai
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Ivan B Dimov
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Sarah K Foster
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Christine E Holt
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Kristian Franze
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
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21
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Di Nardo AA, Fuchs J, Joshi RL, Moya KL, Prochiantz A. The Physiology of Homeoprotein Transduction. Physiol Rev 2019; 98:1943-1982. [PMID: 30067157 DOI: 10.1152/physrev.00018.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The homeoprotein family comprises ~300 transcription factors and was long seen as primarily involved in developmental programs through cell autonomous regulation. However, recent evidence reveals that many of these factors are also expressed in the adult where they exert physiological functions not yet fully deciphered. Furthermore, the DNA-binding domain of most homeoproteins contains two signal sequences allowing their secretion and internalization, thus intercellular transfer. This review focuses on this new-found signaling in cell migration, axon guidance, and cerebral cortex physiological homeostasis and speculates on how it may play important roles in early arealization of the neuroepithelium. It also describes the use of homeoproteins as therapeutic proteins in mouse models of diseases affecting the central nervous system, in particular Parkinson disease and glaucoma.
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Affiliation(s)
- Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Julia Fuchs
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Rajiv L Joshi
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Kenneth L Moya
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University , Paris , France
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22
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Prochiantz A. How to navigate counter dogmatic research findings. EMBO J 2018; 37:embj.201898945. [PMID: 29343544 DOI: 10.15252/embj.201898945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Paris, France
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23
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Soltani A, Lebrun S, Carpentier G, Zunino G, Chantepie S, Maïza A, Bozzi Y, Desnos C, Darchen F, Stettler O. Increased signaling by the autism-related Engrailed-2 protein enhances dendritic branching and spine density, alters synaptic structural matching, and exaggerates protein synthesis. PLoS One 2017; 12:e0181350. [PMID: 28809922 PMCID: PMC5557355 DOI: 10.1371/journal.pone.0181350] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 06/29/2017] [Indexed: 12/13/2022] Open
Abstract
Engrailed 1 (En1) and 2 (En2) code for closely related homeoproteins acting as transcription factors and as signaling molecules that contribute to midbrain and hindbrain patterning, to development and maintenance of monoaminergic pathways, and to retinotectal wiring. En2 has been suggested to be an autism susceptibility gene and individuals with autism display an overexpression of this homeogene but the mechanisms remain unclear. We addressed in the present study the effect of exogenously added En2 on the morphology of hippocampal cells that normally express only low levels of Engrailed proteins. By means of RT-qPCR, we confirmed that En1 and En2 were expressed at low levels in hippocampus and hippocampal neurons, and observed a pronounced decrease in En2 expression at birth and during the first postnatal week, a period characterized by intense synaptogenesis. To address a putative effect of Engrailed in dendritogenesis or synaptogenesis, we added recombinant En1 or En2 proteins to hippocampal cell cultures. Both En1 and En2 treatment increased the complexity of the dendritic tree of glutamatergic neurons, but only En2 increased that of GABAergic cells. En1 increased the density of dendritic spines both in vitro and in vivo. En2 had similar but less pronounced effect on spine density. The number of mature synapses remained unchanged upon En1 treatment but was reduced by En2 treatment, as well as the area of post-synaptic densities. Finally, both En1 and En2 elevated mTORC1 activity and protein synthesis in hippocampal cells, suggesting that some effects of Engrailed proteins may require mRNA translation. Our results indicate that Engrailed proteins can play, even at low concentrations, an active role in the morphogenesis of hippocampal cells. Further, they emphasize the over-regulation of GABA cell morphology and the vulnerability of excitatory synapses in a pathological context of En2 overexpression.
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Affiliation(s)
- Asma Soltani
- UMR 8250, Centre National de la Recherche Scientifique, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Solène Lebrun
- UMR 8250, Centre National de la Recherche Scientifique, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Gilles Carpentier
- Laboratoire Croissance, Réparation et Régénération Tissulaires (CRRET), EA 4397 / ERL 9215, Centre National de la Recherche Scientifique, Université Paris Est Créteil, Créteil, France
| | - Giulia Zunino
- Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Sandrine Chantepie
- Laboratoire Croissance, Réparation et Régénération Tissulaires (CRRET), EA 4397 / ERL 9215, Centre National de la Recherche Scientifique, Université Paris Est Créteil, Créteil, France
| | - Auriane Maïza
- Laboratoire Croissance, Réparation et Régénération Tissulaires (CRRET), EA 4397 / ERL 9215, Centre National de la Recherche Scientifique, Université Paris Est Créteil, Créteil, France
| | - Yuri Bozzi
- Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Claire Desnos
- UMR 8250, Centre National de la Recherche Scientifique, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - François Darchen
- UMR 8250, Centre National de la Recherche Scientifique, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Olivier Stettler
- UMR 8250, Centre National de la Recherche Scientifique, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Laboratoire Croissance, Réparation et Régénération Tissulaires (CRRET), EA 4397 / ERL 9215, Centre National de la Recherche Scientifique, Université Paris Est Créteil, Créteil, France
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24
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Ahmed MU, Maurya AK, Cheng L, Jorge EC, Schubert FR, Maire P, Basson MA, Ingham PW, Dietrich S. Engrailed controls epaxial-hypaxial muscle innervation and the establishment of vertebrate three-dimensional mobility. Dev Biol 2017; 430:90-104. [PMID: 28807781 DOI: 10.1016/j.ydbio.2017.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/07/2017] [Accepted: 08/08/2017] [Indexed: 11/16/2022]
Abstract
Chordates are characterised by contractile muscle on either side of the body that promotes movement by side-to-side undulation. In the lineage leading to modern jawed vertebrates (crown group gnathostomes), this system was refined: body muscle became segregated into distinct dorsal (epaxial) and ventral (hypaxial) components that are separately innervated by the medial and hypaxial motors column, respectively, via the dorsal and ventral ramus of the spinal nerves. This allows full three-dimensional mobility, which in turn was a key factor in their evolutionary success. How the new gnathostome system is established during embryogenesis and how it may have evolved in the ancestors of modern vertebrates is not known. Vertebrate Engrailed genes have a peculiar expression pattern as they temporarily demarcate a central domain of the developing musculature at the epaxial-hypaxial boundary. Moreover, they are the only genes known with this particular expression pattern. The aim of this study was to investigate whether Engrailed genes control epaxial-hypaxial muscle development and innervation. Investigating chick, mouse and zebrafish as major gnathostome model organisms, we found that the Engrailed expression domain was associated with the establishment of the epaxial-hypaxial boundary of muscle in all three species. Moreover, the outgrowing epaxial and hypaxial nerves orientated themselves with respect to this Engrailed domain. In the chicken, loss and gain of Engrailed function changed epaxial-hypaxial somite patterning. Importantly, in all animals studied, loss and gain of Engrailed function severely disrupted the pathfinding of the spinal motor axons, suggesting that Engrailed plays an evolutionarily conserved role in the separate innervation of vertebrate epaxial-hypaxial muscle.
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Affiliation(s)
- Mohi U Ahmed
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK
| | - Ashish K Maurya
- Institute of Molecular&Cell Biology, Proteos, 61 Biopolis Drive, Singapore 138673, Republic of Singapore
| | - Louise Cheng
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK; Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia
| | - Erika C Jorge
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK; Universidade Federal de Minas Gerais - Departamento de Morfologia, Av Antônio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil
| | - Frank R Schubert
- Institute of Biomedical and Biomolecular Science, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
| | - Pascal Maire
- Institut Cochin, INSERM U567, CNRS UMR 8104, Univ. Paris Descartes, Département Génétique et Développement, Equipegénétique et développement du systèmeneuromusculaire, 24 Rue du Fg St Jacques, 75014 Paris, France
| | - M Albert Basson
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK
| | - Philip W Ingham
- Institute of Molecular&Cell Biology, Proteos, 61 Biopolis Drive, Singapore 138673, Republic of Singapore; Dept. of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Republic of Singapore
| | - Susanne Dietrich
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK; Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK.
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25
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Kukreja S, Gautam P, Saxena R, Saxena M, Udaykumar N, Kumar A, Bhatt R, Kumar V, Sen J. Identification of novel candidate regulators of retinotectal map formation through transcriptional profiling of the chick optic tectum. J Comp Neurol 2017; 525:459-477. [PMID: 27410778 DOI: 10.1002/cne.24073] [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: 11/02/2015] [Revised: 07/06/2016] [Accepted: 07/08/2016] [Indexed: 11/06/2022]
Abstract
Information from the retina is carried along the visual pathway with accuracy and spatial conservation as a result of topographically mapped axonal connections. The optic tectum in the midbrain is the primary region to which retinal ganglion cells project their axons in the chick. The two primary axes of the retina project independently onto the tectum using different sets of guidance cues to give rise to the retinotectal map. Specificity of the map is determined by attractive or repulsive interactions between molecular tags that are distributed in gradients in the retina and the tectum. Despite several studies, knowledge of the retinotectal guidance molecules is far from being complete. We screened for all molecules that are expressed differentially along the anterior-posterior and medial-lateral axes of the chick tectum using microarray based transcriptional profiling and identified several novel candidate retinotectal guidance molecules. Two such genes, encoding Wnt5a and Raldh2, the synthesizing enzymes for retinoic acid, were further analyzed for their function as putative regulators of retinotectal map formation. Wnt5a and retinoic acid were found to exhibit differential effects on the growth of axons from retinal explants derived from different quadrants of the retina. This screen also yielded a large number of genes expressed in a lamina-specific manner in the tectum, which may have other roles in tectal development. J. Comp. Neurol. 525:459-477, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Shweta Kukreja
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.,Shweta Kukreja is now at the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
| | - Pratibha Gautam
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.,Pratibha Gautam is now at the Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Richa Saxena
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.,Richa Saxena is now at the Central Drug Research Institute, Jankipuram, Lucknow, Uttar Pradesh, 226031, India
| | - Monika Saxena
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Niveda Udaykumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Aditi Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Ritesh Bhatt
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Vidur Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Jonaki Sen
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
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26
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A1 Adenosine Receptor Activation Modulates Central Nervous System Development and Repair. Mol Neurobiol 2016; 54:8128-8139. [DOI: 10.1007/s12035-016-0292-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 11/08/2016] [Indexed: 01/22/2023]
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27
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Morales D, Kania A. Cooperation and crosstalk in axon guidance cue integration: Additivity, synergy, and fine-tuning in combinatorial signaling. Dev Neurobiol 2016; 77:891-904. [PMID: 27739221 DOI: 10.1002/dneu.22463] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/17/2016] [Accepted: 10/10/2016] [Indexed: 12/31/2022]
Abstract
Neural circuit development involves the coordinated growth and guidance of axons to their targets. Following the identification of many guidance cue molecules, recent experiments have focused on the interactions of their signaling cascades, which can be generally classified as additive or non-additive depending on the signal convergence point. While additive (parallel) signaling suggests limited molecular interaction between the pathways, non-additive signaling involves crosstalk between pathways and includes more complex synergistic, hierarchical, and permissive guidance cue relationships. Here the authors have attempted to classify recent studies that describe axon guidance signal integration according to these divisions. They also discuss the mechanistic implications of such interactions, as well as general ideas relating signal integration to the generation of diversity of axon guidance responses. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 891-904, 2017.
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Affiliation(s)
- Daniel Morales
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, H2W 1R7, Canada.,Integrated Program in Neuroscience, McGill University, Montréal, Quebec, H3A 2B4, Canada
| | - Artur Kania
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, H2W 1R7, Canada.,Integrated Program in Neuroscience, McGill University, Montréal, Quebec, H3A 2B4, Canada.,Department of Anatomy and Cell Biology, Division of Experimental Medicine, McGill University, Montréal, Quebec, H3A 2B2, Canada.,Department of Biology, Division of Experimental Medicine, McGill University, Montréal, Quebec, H3A 2B2, Canada.,Faculté de Médecine, Université de Montréal, Montréal, Quebec, H3C 3J7, Canada
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28
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Mechanosensing is critical for axon growth in the developing brain. Nat Neurosci 2016; 19:1592-1598. [PMID: 27643431 PMCID: PMC5531257 DOI: 10.1038/nn.4394] [Citation(s) in RCA: 367] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/25/2016] [Indexed: 02/07/2023]
Abstract
During nervous system development, neurons extend axons along well-defined pathways. The current understanding of axon pathfinding is based mainly on chemical signaling. However, growing neurons interact not only chemically but also mechanically with their environment. Here we identify mechanical signals as important regulators of axon pathfinding. In vitro, substrate stiffness determined growth patterns of Xenopus retinal ganglion cell axons. In vivo atomic force microscopy revealed a noticeable pattern of stiffness gradients in the embryonic brain. Retinal ganglion cell axons grew toward softer tissue, which was reproduced in vitro in the absence of chemical gradients. To test the importance of mechanical signals for axon growth in vivo, we altered brain stiffness, blocked mechanotransduction pharmacologically and knocked down the mechanosensitive ion channel piezo1. All treatments resulted in aberrant axonal growth and pathfinding errors, suggesting that local tissue stiffness, read out by mechanosensitive ion channels, is critically involved in instructing neuronal growth in vivo.
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29
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Bernard C, Vincent C, Testa D, Bertini E, Ribot J, Di Nardo AA, Volovitch M, Prochiantz A. A Mouse Model for Conditional Secretion of Specific Single-Chain Antibodies Provides Genetic Evidence for Regulation of Cortical Plasticity by a Non-cell Autonomous Homeoprotein Transcription Factor. PLoS Genet 2016; 12:e1006035. [PMID: 27171438 PMCID: PMC4865174 DOI: 10.1371/journal.pgen.1006035] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 04/18/2016] [Indexed: 11/19/2022] Open
Abstract
During postnatal life the cerebral cortex passes through critical periods of plasticity allowing its physiological adaptation to the environment. In the visual cortex, critical period onset and closure are influenced by the non-cell autonomous activity of the Otx2 homeoprotein transcription factor, which regulates the maturation of parvalbumin-expressing inhibitory interneurons (PV cells). In adult mice, the maintenance of a non-plastic adult state requires continuous Otx2 import by PV cells. An important source of extra-cortical Otx2 is the choroid plexus, which secretes Otx2 into the cerebrospinal fluid. Otx2 secretion and internalization requires two small peptidic domains that are part of the DNA-binding domain. Thus, mutating these “transfer” sequences also modifies cell autonomous transcription, precluding this approach to obtain a cell autonomous-only mouse. Here, we develop a mouse model with inducible secretion of an anti-Otx2 single-chain antibody to trap Otx2 in the extracellular milieu. Postnatal secretion of this single-chain antibody by PV cells delays PV maturation and reduces plasticity gene expression. Induced adult expression of this single-chain antibody in cerebrospinal fluid decreases Otx2 internalization by PV cells, strongly induces plasticity gene expression and reopens physiological plasticity. We provide the first mammalian genetic evidence for a signaling mechanism involving intercellular transfer of a homeoprotein transcription factor. Our single-chain antibody mouse model is a valid strategy for extracellular neutralization that could be applied to other homeoproteins and signaling molecules within and beyond the nervous system. Classically, cell signaling is based on the secretion of molecules that bind cell surface receptors. Lipophilic agents can do without cell-surface receptors due to their ability to diffuse through the plasma membrane, but this is normally not the case for proteins, which cannot pass the membrane barrier. However, homeoprotein transcription factors represent an exception as they are secreted and internalized by live cells owing to two peptidic domains. An important illustration of this novel signaling mechanism is provided by Otx2, a homeoprotein that travels from the choroid plexus to specific inhibitory neurons in the cerebral cortex, where it regulates physiological plasticity throughout life. Because the two transfer peptides are in the DNA-binding domain of Otx2, it is impossible to mutate them without altering both cell signaling and cell-autonomous functions. We have therefore developed a mouse in which a secreted anti-Otx2 single-chain antibody can be induced to trap extracellular Otx2 while leaving its cell autonomous function untouched. We show that neutralizing extracellular Otx2 modifies the expression of plasticity genes in the visual cortex, thus providing the first genetic demonstration for homeoprotein signaling in a mammal.
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Affiliation(s)
- Clémence Bernard
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
| | - Clémentine Vincent
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
| | - Damien Testa
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
| | - Eva Bertini
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
| | - Jérôme Ribot
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
| | - Ariel A. Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
| | - Michel Volovitch
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241/INSERM U1050, PSL Research University, Paris, France
- * E-mail:
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Abstract
During the three decades of cell-penetrating peptides era the superfamily of CPPs has rapidly expanded, and the quest for new sequences continues. CPPs have been well recognized by scientific community and they have been used for transduction of a wide variety of molecules and particles into cultured cells and in vivo. In parallel with application of CPPs for delivering of active payloads, the mechanisms that such peptides take advantage of for gaining access to cells' insides have been in the focus of intense studies. Although the common denominator "cell penetration" unites all CPPs, the interaction partners on the cell surface, evoked cellular responses and even the uptake mechanisms might greatly vary between different peptide types. Here we present some possibilities for classification of CPPs based on their type of origin, physical-chemical properties, and the extent of modifications and design efforts. We also briefly analyze the internalization mechanisms with regard to their classification into groups based on physical-chemical characteristics.
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31
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Neuroprotective Transcription Factors in Animal Models of Parkinson Disease. Neural Plast 2015; 2016:6097107. [PMID: 26881122 PMCID: PMC4736191 DOI: 10.1155/2016/6097107] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/10/2015] [Accepted: 07/14/2015] [Indexed: 11/28/2022] Open
Abstract
A number of transcription factors, including En1/2, Foxa1/2, Lmx1a/b, Nurr1, Otx2, and Pitx3, with key roles in midbrain dopaminergic (mDA) neuron development, also regulate adult mDA neuron survival and physiology. Mouse models with targeted disruption of some of these genes display several features reminiscent of Parkinson disease (PD), in particular the selective and progressive loss of mDA neurons in the substantia nigra pars compacta (SNpc). The characterization of these animal models has provided valuable insights into various mechanisms of PD pathogenesis. Therefore, the dissection of the mechanisms and survival signalling pathways engaged by these transcription factors to protect mDA neuron from degeneration can suggest novel therapeutic strategies. The work on En1/2-mediated neuroprotection also highlights the potential of protein transduction technology for neuroprotective approaches in PD.
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Dissecting the role of Engrailed in adult dopaminergic neurons--Insights into Parkinson disease pathogenesis. FEBS Lett 2015; 589:3786-94. [PMID: 26459030 DOI: 10.1016/j.febslet.2015.10.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/18/2015] [Accepted: 10/06/2015] [Indexed: 11/23/2022]
Abstract
The homeoprotein Engrailed (Engrailed-1/Engrailed-2, collectively En1/2) is not only a survival factor for mesencephalic dopaminergic (mDA) neurons during development, but continues to exert neuroprotective and physiological functions in adult mDA neurons. Loss of one En1 allele in the mouse leads to progressive demise of mDA neurons in the ventral midbrain starting from 6 weeks of age. These mice also develop Parkinson disease-like motor and non-motor symptoms. The characterization of En1 heterozygous mice have revealed striking parallels to central mechanisms of Parkinson disease pathogenesis, mainly related to mitochondrial dysfunction and retrograde degeneration. Thanks to the ability of homeoproteins to transduce cells, En1/2 proteins have also been used to protect mDA neurons in various experimental models of Parkinson disease. This neuroprotection is partly linked to the ability of En1/2 to regulate the translation of certain nuclear-encoded mitochondrial mRNAs for complex I subunits. Other transcription factors that govern mDA neuron development (e.g. Foxa1/2, Lmx1a/b, Nurr1, Otx2, Pitx3) also continue to function for the survival and maintenance of mDA neurons in the adult and act through partially overlapping but also diverse mechanisms.
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33
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Genestine M, Lin L, Durens M, Yan Y, Jiang Y, Prem S, Bailoor K, Kelly B, Sonsalla PK, Matteson PG, Silverman J, Crawley JN, Millonig JH, DiCicco-Bloom E. Engrailed-2 (En2) deletion produces multiple neurodevelopmental defects in monoamine systems, forebrain structures and neurogenesis and behavior. Hum Mol Genet 2015. [PMID: 26220976 DOI: 10.1093/hmg/ddv301] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Many genes involved in brain development have been associated with human neurodevelopmental disorders, but underlying pathophysiological mechanisms remain undefined. Human genetic and mouse behavioral analyses suggest that ENGRAILED-2 (EN2) contributes to neurodevelopmental disorders, especially autism spectrum disorder. In mouse, En2 exhibits dynamic spatiotemporal expression in embryonic mid-hindbrain regions where monoamine neurons emerge. Considering their importance in neuropsychiatric disorders, we characterized monoamine systems in relation to forebrain neurogenesis in En2-knockout (En2-KO) mice. Transmitter levels of serotonin, dopamine and norepinephrine (NE) were dysregulated from Postnatal day 7 (P7) to P21 in En2-KO, though NE exhibited the greatest abnormalities. While NE levels were reduced ∼35% in forebrain, they were increased 40 -: 75% in hindbrain and cerebellum, and these patterns paralleled changes in locus coeruleus (LC) fiber innervation, respectively. Although En2 promoter was active in Embryonic day 14.5 -: 15.5 LC neurons, expression diminished thereafter and gene deletion did not alter brainstem NE neuron numbers. Significantly, in parallel with reduced NE levels, En2-KO forebrain regions exhibited reduced growth, particularly hippocampus, where P21 dentate gyrus granule neurons were decreased 16%, suggesting abnormal neurogenesis. Indeed, hippocampal neurogenic regions showed increased cell death (+77%) and unexpectedly, increased proliferation. Excess proliferation was restricted to early Sox2/Tbr2 progenitors whereas increased apoptosis occurred in differentiating (Dcx) neuroblasts, accompanied by reduced newborn neuron survival. Abnormal neurogenesis may reflect NE deficits because intra-hippocampal injections of β-adrenergic agonists reversed cell death. These studies suggest that disruption of hindbrain patterning genes can alter monoamine system development and thereby produce forebrain defects that are relevant to human neurodevelopmental disorders.
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Affiliation(s)
- Matthieu Genestine
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers
| | - Lulu Lin
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, Graduate School of Biological Sciences, Rutgers
| | - Madel Durens
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, Graduate School of Biological Sciences, Rutgers
| | - Yan Yan
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, Graduate School of Biological Sciences, Rutgers
| | - Yiqin Jiang
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers
| | - Smrithi Prem
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers
| | - Kunal Bailoor
- Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Brian Kelly
- Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Patricia K Sonsalla
- Department of Neurology, Rutgers Robert Wood Johnson Medical School, Rutgers
| | - Paul G Matteson
- Center for Advanced Biotechnology and Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Jill Silverman
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Jacqueline N Crawley
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA, USA
| | - James H Millonig
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, Center for Advanced Biotechnology and Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Emanuel DiCicco-Bloom
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, Graduate School of Biological Sciences, Rutgers, Department of Pediatrics, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA and
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34
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Abstract
Signaling classically involves the secretion of diverse molecules that bind specific cell-surface receptors and engage intracellular transduction cascades. Some exceptions-namely, lipophilic agents-can cross plasma membranes to bind intracellular receptors and be carried to the nucleus to regulate transcription. Homeoprotein transcription factors are among the few proteins with such a capacity. Here, we review the signaling activities of homeoproteins in the developing and adult nervous system, with particular emphasis on axon/cell migration and postnatal critical periods of cerebral cortex plasticity. We also describe homeoprotein non-cell-autonomous mechanisms and explore how this "novel" signaling pathway impacts emerging research in brain development and physiology. In this context, we explore hypotheses on the evolution of signaling, the role of homeoproteins as early morphogens, and their therapeutic potential for neurological and psychiatric diseases.
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35
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Quiñinao C, Prochiantz A, Touboul J. Local homeoprotein diffusion can stabilize boundaries generated by graded positional cues. Development 2015; 142:1860-8. [PMID: 25968317 PMCID: PMC5207310 DOI: 10.1242/dev.113688] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Boundary formation in the developing neuroepithelium decides on the position and size of compartments in the adult nervous system. In this study, we start from the French Flag model proposed by Lewis Wolpert, in which boundaries are formed through the combination of morphogen diffusion and of thresholds in cell responses. In contemporary terms, a response is characterized by the expression of cell-autonomous transcription factors, very often of the homeoprotein family. Theoretical studies suggest that this sole mechanism results in the formation of boundaries of imprecise shapes and positions. Alan Turing, on the other hand, proposed a model whereby two morphogens that exhibit self-activation and reciprocal inhibition, and are uniformly distributed and diffuse at different rates lead to the formation of territories of unpredictable shapes and positions but with sharp boundaries (the 'leopard spots'). Here, we have combined the two models and compared the stability of boundaries when the hypothesis of local homeoprotein intercellular diffusion is, or is not, introduced in the equations. We find that the addition of homeoprotein local diffusion leads to a dramatic stabilization of the positioning of the boundary, even when other parameters are significantly modified. This novel Turing/Wolpert combined model has thus important theoretical consequences for our understanding of the role of the intercellular diffusion of homeoproteins in the developmental robustness of and the changes that take place in the course of evolution.
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Affiliation(s)
- Cristóbal Quiñinao
- Collège de France, Centre for Interdisciplinary Research in Biology, UMR CNRS 7241/INSERM 1050, Labex MemoLife, 11 place Marcelin Berthelot, Paris 75231, France Laboratoire Jacques-Louis Lions, CNRS UMR 7598, Université Pierre et Marie Curie (UPMC) - Paris VI, 4 place Jussieu, Paris 75005, France
| | - Alain Prochiantz
- Collège de France, Centre for Interdisciplinary Research in Biology, UMR CNRS 7241/INSERM 1050, Labex MemoLife, 11 place Marcelin Berthelot, Paris 75231, France
| | - Jonathan Touboul
- Collège de France, Centre for Interdisciplinary Research in Biology, UMR CNRS 7241/INSERM 1050, Labex MemoLife, 11 place Marcelin Berthelot, Paris 75231, France INRIA Paris Rocquencourt, MYCENAE Team, Domaine de Voluceau, Le Chesnay 78153, France
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36
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Prochiantz A, Fuchs J, Di Nardo AA. Postnatal signalling with homeoprotein transcription factors. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0518. [PMID: 25135979 DOI: 10.1098/rstb.2013.0518] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Homeoprotein (HP) transcription factors were originally identified for their embryonic cell-autonomous developmental functions. In this review, we discuss their postnatal and adult physiological functions based on the study of Otx2, Engrailed-1 and Engrailed-2 (collectively Engrailed). For Engrailed, we discuss its function in the cell-autonomous regulation of ventral midbrain dopaminergic neuron survival and physiology and in the non-cell-autonomous maintenance of axons. For Otx2, we describe how the protein is expressed in the choroid plexus and transported into cortical parvalbumin cells where it regulates plasticity in the visual cortex. These two examples illustrate how the understanding of HP postnatal and adult functions, including signalling functions, may lead to the identification of disease-associated genetic pathways and to the development of original therapeutic strategies.
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Affiliation(s)
- Alain Prochiantz
- CIRB, CNRS UMR 7241/INSERM U1050, College de France, 11 place Marcelin Berthelot, Paris Cedex 05 75231, France
| | - Julia Fuchs
- CIRB, CNRS UMR 7241/INSERM U1050, College de France, 11 place Marcelin Berthelot, Paris Cedex 05 75231, France
| | - Ariel A Di Nardo
- CIRB, CNRS UMR 7241/INSERM U1050, College de France, 11 place Marcelin Berthelot, Paris Cedex 05 75231, France
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37
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Rampon C, Gauron C, Lin T, Meda F, Dupont E, Cosson A, Ipendey E, Frerot A, Aujard I, Le Saux T, Bensimon D, Jullien L, Volovitch M, Vriz S, Joliot A. Control of brain patterning by Engrailed paracrine transfer: a new function of the Pbx interaction domain. Development 2015; 142:1840-9. [PMID: 25926358 PMCID: PMC4440920 DOI: 10.1242/dev.114181] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 03/02/2015] [Indexed: 12/28/2022]
Abstract
Homeoproteins of the Engrailed family are involved in the patterning of mesencephalic boundaries through a mechanism classically ascribed to their transcriptional functions. In light of recent reports on the paracrine activity of homeoproteins, including Engrailed, we asked whether Engrailed intercellular transfer was also involved in brain patterning and boundary formation. Using time-controlled activation of Engrailed combined with tools that block its transfer, we show that the positioning of the diencephalic-mesencephalic boundary (DMB) requires Engrailed paracrine activity. Both zebrafish Eng2a and Eng2b are competent for intercellular transfer in vivo, but only extracellular endogenous Eng2b, and not Eng2a, participates in DMB positioning. In addition, disruption of the Pbx-interacting motif in Engrailed, known to strongly reduce the gain-of-function phenotype, also downregulates Engrailed transfer, thus revealing an unsuspected participation of the Pbx interaction domain in this pathway.
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Affiliation(s)
- Christine Rampon
- Université Paris Diderot, Sorbonne Paris Cité, Paris 75205, Cedex 13, France Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
| | - Carole Gauron
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
| | - Thibault Lin
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
| | - Francesca Meda
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France École Normale Supérieure, Institute of Biology at the Ecole Normale Supérieure (IBENS), CNRS UMR8197, INSERM U1024, PSL Research University, Paris F-75005, France
| | - Edmond Dupont
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
| | - Adrien Cosson
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
| | - Eliane Ipendey
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France École Normale Supérieure, Institute of Biology at the Ecole Normale Supérieure (IBENS), CNRS UMR8197, INSERM U1024, PSL Research University, Paris F-75005, France
| | - Alice Frerot
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
| | - Isabelle Aujard
- Ecole Normale Supérieure-PSL Research University, Département de Chimie, UMR 8640 CNRS-ENS-UPMC PASTEUR, 24, rue Lhomond, Paris 75005, France
| | - Thomas Le Saux
- Ecole Normale Supérieure-PSL Research University, Département de Chimie, UMR 8640 CNRS-ENS-UPMC PASTEUR, 24, rue Lhomond, Paris 75005, France
| | - David Bensimon
- École Normale Supérieure, Institute of Biology at the Ecole Normale Supérieure (IBENS), CNRS UMR8197, INSERM U1024, PSL Research University, Paris F-75005, France Laboratoire de Physique Statistique, UMR CNRS-ENS 8550, Paris F-75005, France Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095-1569, USA
| | - Ludovic Jullien
- Ecole Normale Supérieure-PSL Research University, Département de Chimie, UMR 8640 CNRS-ENS-UPMC PASTEUR, 24, rue Lhomond, Paris 75005, France
| | - Michel Volovitch
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France École Normale Supérieure, Institute of Biology at the Ecole Normale Supérieure (IBENS), CNRS UMR8197, INSERM U1024, PSL Research University, Paris F-75005, France
| | - Sophie Vriz
- Université Paris Diderot, Sorbonne Paris Cité, Paris 75205, Cedex 13, France Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
| | - Alain Joliot
- Center for Interdisciplinary Research in Biology (CIRB) - CNRS UMR 7241, INSERM U1050, Labex MemoLife, PSL Research University, Collège de France, Paris F-75005, France
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38
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Omi M, Nakamura H. Engrailed and tectum development. Dev Growth Differ 2015; 57:135-45. [DOI: 10.1111/dgd.12197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 12/11/2014] [Accepted: 12/18/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Minoru Omi
- Division of Cell Biology and Neuroscience; Department of Morphological and Physiological Sciences; Faculty of Medical Sciences; University of Fukui; Fukui 910-1193 Japan
| | - Harukazu Nakamura
- Frontier Research Institute for Interdisciplinary Science (FRIS); Tohoku University; 6-3, Aramaki aza Aoba, Aoba-ku Sendai 980-8578 Japan
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Engrailed 1 mediates correct formation of limb innervation through two distinct mechanisms. PLoS One 2015; 10:e0118505. [PMID: 25710467 PMCID: PMC4340014 DOI: 10.1371/journal.pone.0118505] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 01/19/2015] [Indexed: 12/24/2022] Open
Abstract
Engrailed-1 (En1) is expressed in the ventral ectoderm of the developing limb where it plays an instructive role in the dorsal-ventral patterning of the forelimb. Besides its well-described role as a transcription factor in regulating gene expression through its DNA-binding domain, En1 may also be secreted to form an extracellular gradient, and directly impact on the formation of the retinotectal map. We show here that absence of En1 causes mispatterning of the forelimb and thus defects in the dorsal-ventral pathfinding choice of motor axons in vivo. In addition, En1 but not En2 also has a direct and specific repulsive effect on motor axons of the lateral aspect of the lateral motor column (LMC) but not on medial LMC projections. Moreover, an ectopic dorsal source of En1 pushes lateral LMC axons to the ventral limb in vivo. Thus, En1 controls the establishment of limb innervation through two distinct molecular mechanisms.
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40
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REES TOBIAS. Developmental diseases-an introduction to the neurological human (in motion). AMERICAN ETHNOLOGIST 2015. [DOI: 10.1111/amet.12123] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- TOBIAS REES
- Social Studies of Medicine; McGill University; 3647 Peel Street, Montreal, Quebec H3A 1×1 Canada
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41
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Vertical signalling involves transmission of Hox information from gastrula mesoderm to neurectoderm. PLoS One 2014; 9:e115208. [PMID: 25514127 PMCID: PMC4267835 DOI: 10.1371/journal.pone.0115208] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 11/19/2014] [Indexed: 11/23/2022] Open
Abstract
Development and patterning of neural tissue in the vertebrate embryo involves a set of molecules and processes whose relationships are not fully understood. Classical embryology revealed a remarkable phenomenon known as vertical signalling, a gastrulation stage mechanism that copies anterior-posterior positional information from mesoderm to prospective neural tissue. Vertical signalling mediates unambiguous copying of complex information from one tissue layer to another. In this study, we report an investigation of this process in recombinates of mesoderm and ectoderm from gastrulae of Xenopus laevis. Our results show that copying of positional information involves non cell autonomous autoregulation of particular Hox genes whose expression is copied from mesoderm to neurectoderm in the gastrula. Furthermore, this information sharing mechanism involves unconventional translocation of the homeoproteins themselves. This conserved primitive mechanism has been known for three decades but has only recently been put into any developmental context. It provides a simple, robust way to pattern the neurectoderm using the Hox pattern already present in the mesoderm during gastrulation. We suggest that this mechanism was selected during evolution to enable unambiguous copying of rather complex information from cell to cell and that it is a key part of the original ancestral mechanism mediating axial patterning by the highly conserved Hox genes.
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Abstract
The visual system is beautifully crafted to transmit information of the external world to visual processing and cognitive centers in the brain. For visual information to be relayed to the brain, a series of axon pathfinding events must take place to ensure that the axons of retinal ganglion cells, the only neuronal cell type in the retina that sends axons out of the retina, find their way out of the eye to connect with targets in the brain. In the past few decades, the power of molecular and genetic tools, including the generation of genetically manipulated mouse lines, have multiplied our knowledge about the molecular mechanisms involved in the sculpting of the visual system. Here, we review major advances in our understanding of the mechanisms controlling the differentiation of RGCs, guidance of their axons from the retina to the primary visual centers, and the refinement processes essential for the establishment of topographic maps and eye-specific axon segregation. Human disorders, such as albinism and achiasmia, that impair RGC axon growth and guidance and, thus, the establishment of a fully functioning visual system will also be discussed.
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Affiliation(s)
- Lynda Erskine
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Scotland, UK
| | - Eloisa Herrera
- Instituto de Neurosciencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain
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43
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Engrailed homeoproteins in visual system development. Cell Mol Life Sci 2014; 72:1433-45. [PMID: 25432704 PMCID: PMC4366559 DOI: 10.1007/s00018-014-1776-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/31/2014] [Accepted: 11/06/2014] [Indexed: 12/28/2022]
Abstract
Engrailed is a homeoprotein transcription factor. This family of transcription factors is characterized by their DNA-binding homeodomain and some members, including Engrailed, can transfer between cells and regulate protein translation in addition to gene transcription. Engrailed is intimately involved in the development of the vertebrate visual system. Early expression of Engrailed in dorsal mesencephalon contributes to the development and organization of a visual structure, the optic tectum/superior colliculus. This structure is an important target for retinal ganglion cell axons that carry visual information from the retina. Engrailed regulates the expression of Ephrin axon guidance cues in the tectum/superior colliculus. More recently it has been reported that Engrailed itself acts as an axon guidance cue in synergy with the Ephrin system and is proposed to enhance retinal topographic precision.
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44
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Hjorth JJJ, Sterratt DC, Cutts CS, Willshaw DJ, Eglen SJ. Quantitative assessment of computational models for retinotopic map formation. Dev Neurobiol 2014; 75:641-66. [PMID: 25367067 PMCID: PMC4497816 DOI: 10.1002/dneu.22241] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 10/27/2014] [Accepted: 10/28/2014] [Indexed: 11/10/2022]
Abstract
Molecular and activity-based cues acting together are thought to guide retinal axons to their terminal sites in vertebrate optic tectum or superior colliculus (SC) to form an ordered map of connections. The details of mechanisms involved, and the degree to which they might interact, are still not well understood. We have developed a framework within which existing computational models can be assessed in an unbiased and quantitative manner against a set of experimental data curated from the mouse retinocollicular system. Our framework facilitates comparison between models, testing new models against known phenotypes and simulating new phenotypes in existing models. We have used this framework to assess four representative models that combine Eph/ephrin gradients and/or activity-based mechanisms and competition. Two of the models were updated from their original form to fit into our framework. The models were tested against five different phenotypes: wild type, Isl2-EphA3(ki/ki), Isl2-EphA3(ki/+), ephrin-A2,A3,A5 triple knock-out (TKO), and Math5(-/-) (Atoh7). Two models successfully reproduced the extent of the Math5(-/-) anteromedial projection, but only one of those could account for the collapse point in Isl2-EphA3(ki/+). The models needed a weak anteroposterior gradient in the SC to reproduce the residual order in the ephrin-A2,A3,A5 TKO phenotype, suggesting either an incomplete knock-out or the presence of another guidance molecule. Our article demonstrates the importance of testing retinotopic models against as full a range of phenotypes as possible, and we have made available MATLAB software, we wrote to facilitate this process.
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Affiliation(s)
- J J Johannes Hjorth
- Cambridge Computational Biology Institute, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA, United Kingdom
| | - David C Sterratt
- Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, United Kingdom
| | - Catherine S Cutts
- Cambridge Computational Biology Institute, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA, United Kingdom
| | - David J Willshaw
- Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, United Kingdom
| | - Stephen J Eglen
- Cambridge Computational Biology Institute, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA, United Kingdom
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45
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Suetterlin P, Drescher U. Target-independent ephrina/EphA-mediated axon-axon repulsion as a novel element in retinocollicular mapping. Neuron 2014; 84:740-52. [PMID: 25451192 PMCID: PMC4250266 DOI: 10.1016/j.neuron.2014.09.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2014] [Indexed: 11/29/2022]
Abstract
EphrinAs and EphAs play critical roles during topographic map formation in the retinocollicular projection; however, their complex expression patterns in both the retina and superior colliculus (SC) have made it difficult to uncover their precise mechanisms of action. We demonstrate here that growth cones of temporal axons collapse when contacting nasal axons in vitro, and removing ephrinAs from axonal membranes by PI-PLC treatment abolishes this response. In conditional knockout mice, temporal axons display no major targeting defects when ephrinA5 is removed only from the SC, but substantial mapping defects were observed when ephrinA5 expression was removed from both the SC and from the retina, with temporal axons invading the target areas of nasal axons. Together, these data indicate that ephrinA5 drives repellent interactions between temporal and nasal axons within the SC, and demonstrates for the first time that target-independent mechanisms play an essential role in retinocollicular map formation in vivo. EphrinA expression on nasal axons mediates growth cone collapse of temporal axons Analysis of retinocollicular projection in a conditional knockout of ephrinA5 Disruption of repellent axon-axon interactions leads to mapping defects In vivo evidence for target-independent mapping mechanisms in visual system
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Affiliation(s)
- Philipp Suetterlin
- MRC Centre for Developmental Neurobiology, New Hunt's House, Guy's Campus, Kings College London, London SE1 1UL, UK
| | - Uwe Drescher
- MRC Centre for Developmental Neurobiology, New Hunt's House, Guy's Campus, Kings College London, London SE1 1UL, UK.
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46
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Nordströma U, Beauvais G, Ghosh A, Pulikkaparambil Sasidharan BC, Lundblad M, Fuchs J, Joshi RL, Lipton JW, Roholt A, Medicetty S, Feinstein TN, Steiner JA, Escobar Galvis ML, Prochiantz A, Brundin P. Progressive nigrostriatal terminal dysfunction and degeneration in the engrailed1 heterozygous mouse model of Parkinson's disease. Neurobiol Dis 2014; 73:70-82. [PMID: 25281317 DOI: 10.1016/j.nbd.2014.09.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 08/28/2014] [Accepted: 09/21/2014] [Indexed: 01/17/2023] Open
Abstract
Current research on Parkinson's disease (PD) pathogenesis requires relevant animal models that mimic the gradual and progressive development of neuronal dysfunction and degeneration that characterizes the disease. Polymorphisms in engrailed 1 (En1), a homeobox transcription factor that is crucial for both the development and survival of mesencephalic dopaminergic neurons, are associated with sporadic PD. This suggests that En1 mutant mice might be a promising candidate PD model. Indeed, a mouse that lacks one En1 allele exhibits decreased mitochondrial complex I activity and progressive midbrain dopamine neuron degeneration in adulthood, both features associated with PD. We aimed to further characterize the disease-like phenotype of these En1(+/-) mice with a focus on early neurodegenerative changes that can be utilized to score efficacy of future disease modifying studies. We observed early terminal defects in the dopaminergic nigrostriatal pathway in En1(+/-) mice. Several weeks before a significant loss of dopaminergic neurons in the substantia nigra could be detected, we found that striatal terminals expressing high levels of dopaminergic neuron markers TH, VMAT2, and DAT were dystrophic and swollen. Using transmission electron microscopy, we identified electron dense bodies consistent with abnormal autophagic vacuoles in these terminal swellings. In line with these findings, we detected an up-regulation of the mTOR pathway, concurrent with a downregulation of the autophagic marker LC3B, in ventral midbrain and nigral dopaminergic neurons of the En1(+/-) mice. This supports the notion that autophagic protein degradation is reduced in the absence of one En1 allele. We imaged the nigrostriatal pathway using the CLARITY technique and observed many fragmented axons in the medial forebrain bundle of the En1(+/-) mice, consistent with axonal maintenance failure. Using in vivo electrochemistry, we found that nigrostriatal terminals in the dorsal striatum were severely deficient in dopamine release and reuptake. Our findings support a progressive retrograde degeneration of En1(+/-) nigrostriatal neurons, akin to what is suggested to occur in PD. We suggest that using the En1(+/-) mice as a model will provide further key insights into PD pathogenesis, and propose that axon terminal integrity and function can be utilized to estimate dopaminergic neuron health and efficacy of experimental PD therapies.
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Affiliation(s)
- Ulrika Nordströma
- Neuronal Survival Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC B11, 221 84 Lund, Sweden
| | - Geneviève Beauvais
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Anamitra Ghosh
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Baby Chakrapani Pulikkaparambil Sasidharan
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Martin Lundblad
- Developmental and Regenerative Neurobiology, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC A11, 221 84, Lund University, Sweden
| | - Julia Fuchs
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, Paris, France
| | - Rajiv L Joshi
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, Paris, France
| | - Jack W Lipton
- Department of Translational Science and Molecular Medicine and The Udall Center of Excellence in Parkinson's Disease Research, Michigan State University, Grand Rapids, MI, USA
| | - Andrew Roholt
- Renovo Neural, Inc. 10000 Cedar Avenue, Cleveland, OH 44106, USA
| | - Satish Medicetty
- Renovo Neural, Inc. 10000 Cedar Avenue, Cleveland, OH 44106, USA
| | - Timothy N Feinstein
- Confocal Microscopy and Quantitative Imaging Core Facility,Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Jennifer A Steiner
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Martha L Escobar Galvis
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Alain Prochiantz
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, Paris, France
| | - Patrik Brundin
- Neuronal Survival Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC B11, 221 84 Lund, Sweden
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
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47
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Reingruber J, Holcman D. Computational and mathematical methods for morphogenetic gradient analysis, boundary formation and axonal targeting. Semin Cell Dev Biol 2014; 35:189-202. [PMID: 25194659 DOI: 10.1016/j.semcdb.2014.08.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 08/21/2014] [Accepted: 08/26/2014] [Indexed: 10/24/2022]
Abstract
Morphogenesis and axonal targeting are key processes during development that depend on complex interactions at molecular, cellular and tissue level. Mathematical modeling is essential to bridge this multi-scale gap in order to understand how the emergence of large structures is controlled at molecular level by interactions between various signaling pathways. We summarize mathematical modeling and computational methods for time evolution and precision of morphogenetic gradient formation. We discuss tissue patterning and the formation of borders between regions labeled by different morphogens. Finally, we review models and algorithms that reveal the interplay between morphogenetic gradients and patterned activity for axonal pathfinding and the generation of the retinotopic map in the visual system.
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Affiliation(s)
- Jürgen Reingruber
- Group of Computational Biology and Applied Mathematics, Institute of Biology (IBENS), CNRS INSERM 1024, Ecole Normale Supérieure, 46 rue d'Ulm, 75005 Paris, France.
| | - David Holcman
- Group of Computational Biology and Applied Mathematics, Institute of Biology (IBENS), CNRS INSERM 1024, Ecole Normale Supérieure, 46 rue d'Ulm, 75005 Paris, France.
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48
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Cissé M, Checler F. Eph receptors: new players in Alzheimer's disease pathogenesis. Neurobiol Dis 2014; 73:137-49. [PMID: 25193466 DOI: 10.1016/j.nbd.2014.08.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/01/2014] [Accepted: 08/22/2014] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) is devastating and leads to permanent losses of memory and other cognitive functions. Although recent genetic evidences strongly argue for a causative role of Aβ in AD onset and progression (Jonsson et al., 2012), its role in AD etiology remains a matter of debate. However, even if not the sole culprit or pathological trigger, genetic and anatomical evidences in conjunction with numerous pharmacological studies, suggest that Aβ peptides, at least contribute to the disease. How Aβ contributes to memory loss remains largely unknown. Soluble Aβ species referred to as Aβ oligomers have been shown to be neurotoxic and induce network failure and cognitive deficits in animal models of the disease. In recent years, several proteins were described as potential Aβ oligomers receptors, amongst which are the receptor tyrosine kinases of Eph family. These receptors together with their natural ligands referred to as ephrins have been involved in a plethora of physiological and pathological processes, including embryonic neurogenesis, learning and memory, diabetes, cancers and anxiety. Here we review recent discoveries on Eph receptors-mediated protection against Aβ oligomers neurotoxicity as well as their potential as therapeutic targets in AD pathogenesis.
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Affiliation(s)
- Moustapha Cissé
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNS, "Labex Distalz", 660 route des Lucioles, 06560, Sophia-Antipolis, Valbonne, France..
| | - Frédéric Checler
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNS, "Labex Distalz", 660 route des Lucioles, 06560, Sophia-Antipolis, Valbonne, France..
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49
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Kim N, Acampora D, Dingli F, Loew D, Simeone A, Prochiantz A, Di Nardo AA. Immunoprecipitation and mass spectrometry identify non-cell autonomous Otx2 homeoprotein in the granular and supragranular layers of mouse visual cortex. F1000Res 2014; 3:178. [PMID: 25165539 PMCID: PMC4133762 DOI: 10.12688/f1000research.4869.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/29/2014] [Indexed: 11/20/2022] Open
Abstract
Plasticity in the visual cerebral cortex is regulated by the internalization of Otx2 homeoprotein into parvalbumin neurons in cortical layers II/III and IV. However the Otx2 locus is not active in these neurons and the protein is imported from external sources, including the choroid plexus. Because Otx1 and Otx2 may have redundant functions, we wanted to verify if part of the staining in parvalbumin neurons corresponds to Otx1 transported from cortical layer V neurons. It is demonstrated here that Otx staining in layer IV cells is maintained in Otx1-null mice. The immunoprecipitation of extracts from finely dissected granular and supragranular cortex (layers I-IV) gave immunoblots with a band corresponding to Otx2 and not Otx1. Moreover, high-resolution mass spectrometry analysis after immunoprecipitation identifies two peptides within the Otx2 homeodomain. One of these peptides is specific for Otx2 and is not found in Otx1. These results unambiguously establish that the staining in parvalbumin neurons revealed with the anti-Otx2 antibodies used in our previous studies identifies non-cell autonomous Otx2.
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Affiliation(s)
- Namsuk Kim
- CIRB, CNRS UMR 7241 / INSERM U1050, College de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Dario Acampora
- Institute of Genetics and Biophysics, Via Pietro Castellino 111, 80131 Napoli, Italy ; IRCCS Neuromed, 86077 Pozzilli (IS), Italy
| | - Florent Dingli
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 75248 Paris Cedex 05, France
| | - Damarys Loew
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 75248 Paris Cedex 05, France
| | - Antonio Simeone
- Institute of Genetics and Biophysics, Via Pietro Castellino 111, 80131 Napoli, Italy ; IRCCS Neuromed, 86077 Pozzilli (IS), Italy
| | - Alain Prochiantz
- CIRB, CNRS UMR 7241 / INSERM U1050, College de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Ariel A Di Nardo
- CIRB, CNRS UMR 7241 / INSERM U1050, College de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
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50
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Stettler O, Moya KL. Distinct roles of homeoproteins in brain topographic mapping and in neural circuit formation. Semin Cell Dev Biol 2014; 35:165-72. [PMID: 25042849 DOI: 10.1016/j.semcdb.2014.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 07/07/2014] [Indexed: 01/02/2023]
Abstract
The construction of the brain is a highly regulated process, requiring coordination of various cellular and molecular mechanisms that together ensure the stability of the cerebrum architecture and functions. The mature brain is an organ that performs complex computational operations using specific sensory information from the outside world and this requires precise organization within sensory networks and a separation of sensory modalities during development. We review here the role of homeoproteins in the arealization of the brain according to sensorimotor functions, the micropartition of its cytoarchitecture, and the maturation of its sensory circuitry. One of the most interesting observation about homeoproteins in recent years concerns their ability to act both in a cell-autonomous and non-cell-autonomous manner. The highlights in the present review collectively show how these two modes of action of homeoproteins confer various functions in shaping cortical maps.
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Affiliation(s)
- Olivier Stettler
- Laboratoire CRRET EAC 7149, Université Paris-Est Créteil, 61, Av. du Général de Gaulle, 94010 Créteil Cedex, France.
| | - Kenneth L Moya
- Collège de France, Center for Interdisciplinary Research in Biology, UMR CNRS 7241/INSERM U1050, 11 place Marcelin Berthelot, 75005 Paris, France; Labex Memolife, PSL Research University, France
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