1
|
Yang S, Niou ZX, Enriquez A, LaMar J, Huang JY, Ling K, Jafar-Nejad P, Gilley J, Coleman MP, Tennessen JM, Rangaraju V, Lu HC. NMNAT2 supports vesicular glycolysis via NAD homeostasis to fuel fast axonal transport. Mol Neurodegener 2024; 19:13. [PMID: 38282024 PMCID: PMC10823734 DOI: 10.1186/s13024-023-00690-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 11/28/2023] [Indexed: 01/30/2024] Open
Abstract
BACKGROUND Bioenergetic maladaptations and axonopathy are often found in the early stages of neurodegeneration. Nicotinamide adenine dinucleotide (NAD), an essential cofactor for energy metabolism, is mainly synthesized by Nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2) in CNS neurons. NMNAT2 mRNA levels are reduced in the brains of Alzheimer's, Parkinson's, and Huntington's disease. Here we addressed whether NMNAT2 is required for axonal health of cortical glutamatergic neurons, whose long-projecting axons are often vulnerable in neurodegenerative conditions. We also tested if NMNAT2 maintains axonal health by ensuring axonal ATP levels for axonal transport, critical for axonal function. METHODS We generated mouse and cultured neuron models to determine the impact of NMNAT2 loss from cortical glutamatergic neurons on axonal transport, energetic metabolism, and morphological integrity. In addition, we determined if exogenous NAD supplementation or inhibiting a NAD hydrolase, sterile alpha and TIR motif-containing protein 1 (SARM1), prevented axonal deficits caused by NMNAT2 loss. This study used a combination of techniques, including genetics, molecular biology, immunohistochemistry, biochemistry, fluorescent time-lapse imaging, live imaging with optical sensors, and anti-sense oligos. RESULTS We provide in vivo evidence that NMNAT2 in glutamatergic neurons is required for axonal survival. Using in vivo and in vitro studies, we demonstrate that NMNAT2 maintains the NAD-redox potential to provide "on-board" ATP via glycolysis to vesicular cargos in distal axons. Exogenous NAD+ supplementation to NMNAT2 KO neurons restores glycolysis and resumes fast axonal transport. Finally, we demonstrate both in vitro and in vivo that reducing the activity of SARM1, an NAD degradation enzyme, can reduce axonal transport deficits and suppress axon degeneration in NMNAT2 KO neurons. CONCLUSION NMNAT2 ensures axonal health by maintaining NAD redox potential in distal axons to ensure efficient vesicular glycolysis required for fast axonal transport.
Collapse
Affiliation(s)
- Sen Yang
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA
| | - Zhen-Xian Niou
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA
| | - Andrea Enriquez
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA
| | - Jacob LaMar
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA
- Present address: Department of Biomedical Science, Florida Atlantic University, Jupiter, FL, 33458, USA
| | - Jui-Yen Huang
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
| | - Karen Ling
- Neuroscience Drug Discovery, Ionis Pharmaceuticals, Inc., 2855, Gazelle Court, Carlsbad, CA, 92010, USA
| | - Paymaan Jafar-Nejad
- Neuroscience Drug Discovery, Ionis Pharmaceuticals, Inc., 2855, Gazelle Court, Carlsbad, CA, 92010, USA
| | - Jonathan Gilley
- Department of Clinical Neuroscience, Cambridge University, Cambridge, UK
| | - Michael P Coleman
- Department of Clinical Neuroscience, Cambridge University, Cambridge, UK
| | - Jason M Tennessen
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Vidhya Rangaraju
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA
| | - Hui-Chen Lu
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA.
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA.
| |
Collapse
|
2
|
Tollis P, Vitiello E, Migliaccio F, D'Ambra E, Rocchegiani A, Garone MG, Bozzoni I, Rosa A, Carissimo A, Laneve P, Caffarelli E. The long noncoding RNA nHOTAIRM1 is necessary for differentiation and activity of iPSC-derived spinal motor neurons. Cell Death Dis 2023; 14:741. [PMID: 37963881 PMCID: PMC10646148 DOI: 10.1038/s41419-023-06196-y] [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: 04/14/2023] [Revised: 09/19/2023] [Accepted: 09/28/2023] [Indexed: 11/16/2023]
Abstract
The mammalian nervous system is made up of an extraordinary array of diverse cells that form intricate functional connections. The programs underlying cell lineage specification, identity and function of the neuronal subtypes are managed by regulatory proteins and RNAs, which coordinate the succession of steps in a stereotyped temporal order. In the central nervous system (CNS), motor neurons (MNs) are responsible for controlling essential functions such as movement, breathing, and swallowing by integrating signal transmission from the cortex, brainstem, and spinal cord (SC) towards peripheral muscles. A prime role in guiding the progression of progenitor cells towards the MN fate has been largely attributed to protein factors. More recently, the relevance of a class of regulatory RNAs abundantly expressed in the CNS - the long noncoding RNAs (lncRNAs) - has emerged overwhelmingly. LncRNA-driven gene expression control is key to regulating any step of MN differentiation and function, and its derangement profoundly impacts neuronal pathophysiology. Here, we uncover a novel function for the neuronal isoform of HOTAIRM1 (nHOTAIRM1), a lncRNA specifically expressed in the SC. Using a model system that recapitulates spinal MN (spMN) differentiation, we show that nHOTAIRM1 intervenes in the binary cell fate decision between MNs and interneurons, acting as a pro-MN factor. Furthermore, human iPSC-derived spMNs without nHOTAIRM1 display altered neurite outgrowth, with a significant reduction of both branch and junction numbers. Finally, the expression of genes essential for synaptic connectivity and neurotransmission is also profoundly impaired when nHOTAIRM1 is absent in spMNs. Mechanistically, nHOTAIRM1 establishes both direct and indirect interactions with a number of target genes in the cytoplasm, being a novel post-transcriptional regulator of MN biology. Overall, our results indicate that the lncRNA nHOTAIRM1 is essential for the specification of MN identity and the acquisition of proper morphology and synaptic activity of post-mitotic MNs.
Collapse
Affiliation(s)
- Paolo Tollis
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Rome, Italy
- Center for Life Nano-& Neuro-Science, Fondazione Istituto Italiano di Tecnologia, Rome, Italy
| | - Erika Vitiello
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Rome, Italy
- Center for Human Technology, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy
| | - Francesco Migliaccio
- Department of Electrical Engineering and Information Technology, University Federico II, Naples, Italy
- Institute for Applied Mathematics "Mauro Picone", CNR, Naples, Italy
| | - Eleonora D'Ambra
- Center for Life Nano-& Neuro-Science, Fondazione Istituto Italiano di Tecnologia, Rome, Italy
| | - Anna Rocchegiani
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Rome, Italy
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Maria Giovanna Garone
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Rome, Italy
- The Novo Nordisk Foundation Center for Stem Cell Medicine, reNEW Melbourne, Murdoch Children's Research Institute, Parkville, VIC, 3052, Australia
- Stem Cell Biology Department, Murdoch Children's Research Institute, Parkville, VIC, 3052, Australia
| | - Irene Bozzoni
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Rome, Italy
- Center for Life Nano-& Neuro-Science, Fondazione Istituto Italiano di Tecnologia, Rome, Italy
| | - Alessandro Rosa
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Rome, Italy
- Center for Life Nano-& Neuro-Science, Fondazione Istituto Italiano di Tecnologia, Rome, Italy
| | | | - Pietro Laneve
- Institute of Molecular Biology and Pathology, Rome, CNR, Italy.
| | | |
Collapse
|
3
|
Teixeira-Castro A, Sousa JC, Vieira C, Pereira-Sousa J, Vilasboas-Campos D, Marques F, Pinto-do-Ó P, Maciel P. Learning the Biochemical Basis of Axonal Guidance: Using Caenorhabditis elegans as a Model. Biomedicines 2023; 11:1731. [PMID: 37371826 DOI: 10.3390/biomedicines11061731] [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: 06/01/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
AIM Experimental models are a powerful aid in visualizing molecular phenomena. This work reports how the worm Caenorhabditis elegans (C. elegans) can be effectively explored for students to learn how molecular cues dramatically condition axonal guidance and define nervous system structure and behavior at the organism level. Summary of work: A loosely oriented observational activity preceded detailed discussions on molecules implied in axonal migration. C. elegans mutants were used to introduce second-year medical students to the deleterious effects of gene malfunctioning in neuron response to extracellular biochemical cues and to establish links between molecular function, nervous system structure, and animal behavior. Students observed C. elegans cultures and associated animal behavior alterations with the lack of function of specific axon guidance molecules (the soluble cue netrin/UNC-6 or two receptors, DCC/UNC-40 and UNC-5H). Microscopical observations of these strains, in combination with pan-neuronal GFP expression, allowed optimal visualization of severely affected neurons. Once the list of mutated genes in each strain was displayed, students could also relate abnormal patterns in axon migration/ventral and dorsal nerve cord neuron formation in C. elegans with mutated molecular components homologous to those in humans. SUMMARY OF RESULTS Students rated the importance and effectiveness of the activity very highly. Ninety-three percent found it helpful to grasp human axonal migration, and all students were surprised with the power of the model in helping to visualize the phenomenon.
Collapse
Affiliation(s)
- Andreia Teixeira-Castro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Cármen Vieira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Joana Pereira-Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Daniela Vilasboas-Campos
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Perpétua Pinto-do-Ó
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| |
Collapse
|
4
|
Breau MA, Trembleau A. Chemical and mechanical control of axon fasciculation and defasciculation. Semin Cell Dev Biol 2023; 140:72-81. [PMID: 35810068 DOI: 10.1016/j.semcdb.2022.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/14/2022] [Accepted: 06/21/2022] [Indexed: 01/28/2023]
Abstract
Neural networks are constructed through the development of robust axonal projections from individual neurons, which ultimately establish connections with their targets. In most animals, developing axons assemble in bundles to navigate collectively across various areas within the central nervous system or the periphery, before they separate from these bundles in order to find their specific targets. These processes, called fasciculation and defasciculation respectively, were thought for many years to be controlled chemically: while guidance cues may attract or repulse axonal growth cones, adhesion molecules expressed at the surface of axons mediate their fasciculation. Recently, an additional non-chemical parameter, the mechanical longitudinal tension of axons, turned out to play a role in axon fasciculation and defasciculation, through zippering and unzippering of axon shafts. In this review, we present an integrated view of the currently known chemical and mechanical control of axon:axon dynamic interactions. We highlight the facts that the decision to cross or not to cross another axon depends on a combination of chemical, mechanical and geometrical parameters, and that the decision to fasciculate/defasciculate through zippering/unzippering relies on the balance between axon:axon adhesion and their mechanical tension. Finally, we speculate about possible functional implications of zippering-dependent axon shaft fasciculation, in the collective migration of axons, and in the sorting of subpopulations of axons.
Collapse
Affiliation(s)
- Marie Anne Breau
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS UMR 7622), Institut de Biologie Paris Seine (IBPS), Developmental Biology Laboratory, Paris, France
| | - Alain Trembleau
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS UMR8246), Inserm U1130, Institut de Biologie Paris Seine (IBPS), Neuroscience Paris Seine (NPS), Paris, France.
| |
Collapse
|
5
|
Li X, Shim S, Hardin KR, Vanaja KG, Song H, Levchenko A, Ming GL, Zheng JQ. Signal amplification in growth cone gradient sensing by a double negative feedback loop among PTEN, PI(3,4,5)P 3 and actomyosin. Mol Cell Neurosci 2022; 123:103772. [PMID: 36055521 PMCID: PMC9856701 DOI: 10.1016/j.mcn.2022.103772] [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: 06/01/2022] [Revised: 08/23/2022] [Accepted: 08/26/2022] [Indexed: 01/24/2023] Open
Abstract
Axon guidance during neural wiring involves a series of precisely controlled chemotactic events by the motile axonal tip, the growth cone. A fundamental question is how neuronal growth cones make directional decisions in response to extremely shallow gradients of guidance cues with exquisite sensitivity. Here we report that nerve growth cones possess a signal amplification mechanism during gradient sensing process. In neuronal growth cones of Xenopus spinal neurons, phosphatidylinositol-3,4,5-trisphosphate (PIP3), an important signaling molecule in chemotaxis, was actively recruited to the up-gradient side in response to an external gradient of brain-derived neurotrophic factor (BDNF), resulting in an intracellular gradient with approximate 30-fold amplification of the input. Furthermore, a reverse gradient of phosphatase and tensin homolog (PTEN) was induced by BDNF within the growth cone and the increased PTEN activity at the down-gradient side is required for the amplification of PIP3 signals. Mechanistically, the establishment of both positive PIP3 and reverse PTEN gradients depends on the filamentous actin network. Together with computational modeling, our results revealed a double negative feedback loop among PTEN, PIP3 and actomyosin for signal amplification, which is essential for gradient sensing of neuronal growth cones in response to diffusible cues.
Collapse
Affiliation(s)
- Xiong Li
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA
| | - Sangwoo Shim
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA; Department of Cell Biology, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA
| | - Katherine R Hardin
- Department of Cell Biology, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA
| | - Kiran G Vanaja
- Department of Biomedical Engineering and Yale Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Hongjun Song
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Andre Levchenko
- Department of Biomedical Engineering and Yale Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Guo-Li Ming
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, 733 N. Broadway, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - James Q Zheng
- Department of Cell Biology, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA.
| |
Collapse
|
6
|
Guidance landscapes unveiled by quantitative proteomics to control reinnervation in adult visual system. Nat Commun 2022; 13:6040. [PMID: 36229455 PMCID: PMC9561644 DOI: 10.1038/s41467-022-33799-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 09/30/2022] [Indexed: 12/24/2022] Open
Abstract
In the injured adult central nervous system (CNS), activation of pro-growth molecular pathways in neurons leads to long-distance regeneration. However, most regenerative fibers display guidance defects, which prevent reinnervation and functional recovery. Therefore, the molecular characterization of the proper target regions of regenerative axons is essential to uncover the modalities of adult reinnervation. In this study, we use mass spectrometry (MS)-based quantitative proteomics to address the proteomes of major nuclei of the adult visual system. These analyses reveal that guidance-associated molecules are expressed in adult visual targets. Moreover, we show that bilateral optic nerve injury modulates the expression of specific proteins. In contrast, the expression of guidance molecules remains steady. Finally, we show that regenerative axons are able to respond to guidance cues ex vivo, suggesting that these molecules possibly interfere with brain target reinnervation in adult. Using a long-distance regeneration model, we further demonstrate that the silencing of specific guidance signaling leads to rerouting of regenerative axons in vivo. Altogether, our results suggest ways to modulate axon guidance of regenerative neurons to achieve circuit repair in adult.
Collapse
|
7
|
Neuronal subtype-specific growth cone and soma purification from mammalian CNS via fractionation and fluorescent sorting for subcellular analyses and spatial mapping of local transcriptomes and proteomes. Nat Protoc 2022; 17:222-251. [PMID: 35022617 PMCID: PMC9751848 DOI: 10.1038/s41596-021-00638-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 09/24/2021] [Indexed: 11/09/2022]
Abstract
During neuronal development, growth cones (GCs) of projection neurons navigate complex extracellular environments to reach distant targets, thereby generating extraordinarily complex circuitry. These dynamic structures located at the tips of axonal projections respond to substrate-bound as well as diffusible guidance cues in a neuronal subtype- and stage-specific manner to construct highly specific and functional circuitry. In vitro studies of the past decade indicate that subcellular localization of specific molecular machinery in GCs underlies the precise navigational control that occurs during circuit 'wiring'. Our laboratory has recently developed integrated experimental and analytical approaches enabling high-depth, quantitative proteomic and transcriptomic investigation of subtype- and stage-specific GC molecular machinery directly from the rodent central nervous system (CNS) in vivo. By using these approaches, a pure population of GCs and paired somata can be isolated from any neuronal subtype of the CNS that can be fluorescently labeled. GCs are dissociated from parent axons using fluid shear forces, and a bulk GC fraction is isolated by buoyancy ultracentrifugation. Subtype-specific GCs and somata are purified by recently developed fluorescent small particle sorting and established FACS of neurons and are suitable for downstream analyses of proteins and RNAs, including small RNAs. The isolation of subtype-specific GCs and parent somata takes ~3 h, plus sorting time, and ~1-2 h for subsequent extraction of molecular contents. RNA library preparation and sequencing can take several days to weeks, depending on the turnaround time of the core facility involved.
Collapse
|
8
|
Rayêe D, Iack PM, Christoff RR, Lourenço MR, Bonifácio C, Boltz J, Lent R, Garcez PP. The Dynamics of Axon Bifurcation Development in the Cerebral Cortex of Typical and Acallosal Mice. Neuroscience 2021; 477:14-24. [PMID: 34601063 DOI: 10.1016/j.neuroscience.2021.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 09/22/2021] [Accepted: 09/26/2021] [Indexed: 11/30/2022]
Abstract
The corpus callosum (CC) is a major interhemispheric commissure of placental mammals. Early steps of CC formation rely on guidance strategies, such as axonal branching and collateralization. Here we analyze the time-course dynamics of axonal bifurcation during typical cortical development or in a CC dysgenesis mouse model. We use Swiss mice as a typical CC mouse model and find that axonal bifurcation rates rise in the cerebral cortex from embryonic day (E)17 and are reduced by postnatal day (P)9. Since callosal neurons populate deep and superficial cortical layers, we compare the axon bifurcation ratio between those neurons by electroporating ex vivo brains at E13 and E15, using eGFP reporter to label the newborn neurons on organotypic slices. Our results suggest that deep layer neurons bifurcate 32% more than superficial ones. To investigate axonal bifurcation in CC dysgenesis, we use BALB/c mice as a spontaneous CC dysgenesis model. BALB/c mice present a typical layer distribution of SATB2 callosal cells, despite the occurrence of callosal anomalies. However, using anterograde DiI tracing, we find that BALB/c mice display increased rates of axonal bifurcations during early and late cortical development in the medial frontal cortex. Midline guidepost cells adjacent to the medial frontal cortex are significant reduced in the CC dysgenesis mouse model. Altogether these data suggest that callosal collateral axonal exuberance is maintained in the absence of midline guidepost signaling and might facilitate aberrant connections in the CC dysgenesis mouse model.
Collapse
Affiliation(s)
- Danielle Rayêe
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Institute of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Pamela Meneses Iack
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | - Raissa R Christoff
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | - Michele R Lourenço
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro - IFRJ, Brazil
| | | | - Jürgen Boltz
- Institute of General Zoology and Animal Physiology, University of Jena, 07743 Jena, Germany
| | - Roberto Lent
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Institute D'Or for Research and Education, Rio de Janeiro, Brazil
| | - Patricia P Garcez
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil.
| |
Collapse
|
9
|
Razar RBBA, Qu Y, Gunaseelan S, Chua JJE. The importance of fasciculation and elongation protein zeta-1 in neural circuit establishment and neurological disorders. Neural Regen Res 2021; 17:1165-1171. [PMID: 34782550 PMCID: PMC8643053 DOI: 10.4103/1673-5374.327327] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The human brain contains an estimated 100 billion neurons that must be systematically organized into functional neural circuits for it to function properly. These circuits range from short-range local signaling networks between neighboring neurons to long-range networks formed between various brain regions. Compelling converging evidence indicates that alterations in neural circuits arising from abnormalities during early neuronal development or neurodegeneration contribute significantly to the etiology of neurological disorders. Supporting this notion, efforts to identify genetic causes of these disorders have uncovered an over-representation of genes encoding proteins involved in the processes of neuronal differentiation, maturation, synaptogenesis and synaptic function. Fasciculation and elongation protein zeta-1, a Kinesin-1 adapter, has emerged as a key central player involved in many of these processes. Fasciculation and elongation protein zeta-1-dependent transport of synaptic cargoes and mitochondria is essential for neuronal development and synapse establishment. Furthermore, it acts downstream of guidance cue pathways to regulate axo-dendritic development. Significantly, perturbing its function causes abnormalities in neuronal development and synapse formation both in the brain as well as the peripheral nervous system. Mutations and deletions of the fasciculation and elongation protein zeta-1 gene are linked to neurodevelopmental disorders. Moreover, altered phosphorylation of the protein contributes to neurodegenerative disorders. Together, these findings strongly implicate the importance of fasciculation and elongation protein zeta-1 in the establishment of neuronal circuits and its maintenance.
Collapse
Affiliation(s)
- Rafhanah Banu Bte Abdul Razar
- Department of Physiology, Yong Loo Lin School of Medicine; LSI Neurobiology Programme; Institute for Health Innovation and Technology, National University of Singapore, Singapore, Singapore
| | - Yinghua Qu
- Department of Physiology, Yong Loo Lin School of Medicine; LSI Neurobiology Programme, National University of Singapore, Singapore, Singapore
| | - Saravanan Gunaseelan
- Department of Physiology, Yong Loo Lin School of Medicine; LSI Neurobiology Programme, National University of Singapore, Singapore, Singapore
| | - John Jia En Chua
- Department of Physiology, Yong Loo Lin School of Medicine; LSI Neurobiology Programme; Institute for Health Innovation and Technology; Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore; Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| |
Collapse
|
10
|
Vasilev F, Ezhova Y, Chun JT. Signaling Enzymes and Ion Channels Being Modulated by the Actin Cytoskeleton at the Plasma Membrane. Int J Mol Sci 2021; 22:ijms221910366. [PMID: 34638705 PMCID: PMC8508623 DOI: 10.3390/ijms221910366] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 02/06/2023] Open
Abstract
A cell should deal with the changing external environment or the neighboring cells. Inevitably, the cell surface receives and transduces a number of signals to produce apt responses. Typically, cell surface receptors are activated, and during this process, the subplasmalemmal actin cytoskeleton is often rearranged. An intriguing point is that some signaling enzymes and ion channels are physically associated with the actin cytoskeleton, raising the possibility that the subtle changes of the local actin cytoskeleton can, in turn, modulate the activities of these proteins. In this study, we reviewed the early and new experimental evidence supporting the notion of actin-regulated enzyme and ion channel activities in various cell types including the cells of immune response, neurons, oocytes, hepatocytes, and epithelial cells, with a special emphasis on the Ca2+ signaling pathway that depends on the synthesis of inositol 1,4,5-trisphosphate. Some of the features that are commonly found in diverse cells from a wide spectrum of the animal species suggest that fine-tuning of the activities of the enzymes and ion channels by the actin cytoskeleton may be an important strategy to inhibit or enhance the function of these signaling proteins.
Collapse
Affiliation(s)
- Filip Vasilev
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), 900 Rue St Denis, Montreal, QC H2X 0A9, Canada
- Correspondence: (F.V.); (J.T.C.); Tel.: +1-514-249-5862 (F.V.); +39-081-583-3407 (J.T.C.)
| | - Yulia Ezhova
- Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Montreal, QC H1T 2M4, Canada;
| | - Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy
- Correspondence: (F.V.); (J.T.C.); Tel.: +1-514-249-5862 (F.V.); +39-081-583-3407 (J.T.C.)
| |
Collapse
|
11
|
SenGupta S, Parent CA, Bear JE. The principles of directed cell migration. Nat Rev Mol Cell Biol 2021; 22:529-547. [PMID: 33990789 PMCID: PMC8663916 DOI: 10.1038/s41580-021-00366-6] [Citation(s) in RCA: 206] [Impact Index Per Article: 68.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2021] [Indexed: 02/03/2023]
Abstract
Cells have the ability to respond to various types of environmental cues, and in many cases these cues induce directed cell migration towards or away from these signals. How cells sense these cues and how they transmit that information to the cytoskeletal machinery governing cell translocation is one of the oldest and most challenging problems in biology. Chemotaxis, or migration towards diffusible chemical cues, has been studied for more than a century, but information is just now beginning to emerge about how cells respond to other cues, such as substrate-associated cues during haptotaxis (chemical cues on the surface), durotaxis (mechanical substrate compliance) and topotaxis (geometric features of substrate). Here we propose four common principles, or pillars, that underlie all forms of directed migration. First, a signal must be generated, a process that in physiological environments is much more nuanced than early studies suggested. Second, the signal must be sensed, sometimes by cell surface receptors, but also in ways that are not entirely clear, such as in the case of mechanical cues. Third, the signal has to be transmitted from the sensing modules to the machinery that executes the actual movement, a step that often requires amplification. Fourth, the signal has to be converted into the application of asymmetric force relative to the substrate, which involves mostly the cytoskeleton, but perhaps other players as well. Use of these four pillars has allowed us to compare some of the similarities between different types of directed migration, but also to highlight the remarkable diversity in the mechanisms that cells use to respond to different cues provided by their environment.
Collapse
Affiliation(s)
- Shuvasree SenGupta
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Carole A Parent
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - James E Bear
- UNC Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
| |
Collapse
|
12
|
Mutalik SP, Gupton SL. Glycosylation in Axonal Guidance. Int J Mol Sci 2021; 22:ijms22105143. [PMID: 34068002 PMCID: PMC8152249 DOI: 10.3390/ijms22105143] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/01/2021] [Accepted: 05/08/2021] [Indexed: 12/15/2022] Open
Abstract
How millions of axons navigate accurately toward synaptic targets during development is a long-standing question. Over decades, multiple studies have enriched our understanding of axonal pathfinding with discoveries of guidance molecules and morphogens, their receptors, and downstream signalling mechanisms. Interestingly, classification of attractive and repulsive cues can be fluid, as single guidance cues can act as both. Similarly, guidance cues can be secreted, chemotactic cues or anchored, adhesive cues. How a limited set of guidance cues generate the diversity of axonal guidance responses is not completely understood. Differential expression and surface localization of receptors, as well as crosstalk and spatiotemporal patterning of guidance cues, are extensively studied mechanisms that diversify axon guidance pathways. Posttranslational modification is a common, yet understudied mechanism of diversifying protein functions. Many proteins in axonal guidance pathways are glycoproteins and how glycosylation modulates their function to regulate axonal motility and guidance is an emerging field. In this review, we discuss major classes of glycosylation and their functions in axonal pathfinding. The glycosylation of guidance cues and guidance receptors and their functional implications in axonal outgrowth and pathfinding are discussed. New insights into current challenges and future perspectives of glycosylation pathways in neuronal development are discussed.
Collapse
|
13
|
Fingleton E, Li Y, Roche KW. Advances in Proteomics Allow Insights Into Neuronal Proteomes. Front Mol Neurosci 2021; 14:647451. [PMID: 33935646 PMCID: PMC8084103 DOI: 10.3389/fnmol.2021.647451] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/25/2021] [Indexed: 11/29/2022] Open
Abstract
Protein–protein interaction networks and signaling complexes are essential for normal brain function and are often dysregulated in neurological disorders. Nevertheless, unraveling neuron- and synapse-specific proteins interaction networks has remained a technical challenge. New techniques, however, have allowed for high-resolution and high-throughput analyses, enabling quantification and characterization of various neuronal protein populations. Over the last decade, mass spectrometry (MS) has surfaced as the primary method for analyzing multiple protein samples in tandem, allowing for the precise quantification of proteomic data. Moreover, the development of sophisticated protein-labeling techniques has given MS a high temporal and spatial resolution, facilitating the analysis of various neuronal substructures, cell types, and subcellular compartments. Recent studies have leveraged these novel techniques to reveal the proteomic underpinnings of well-characterized neuronal processes, such as axon guidance, long-term potentiation, and homeostatic plasticity. Translational MS studies have facilitated a better understanding of complex neurological disorders, such as Alzheimer’s disease (AD), Schizophrenia (SCZ), and Autism Spectrum Disorder (ASD). Proteomic investigation of these diseases has not only given researchers new insight into disease mechanisms but has also been used to validate disease models and identify new targets for research.
Collapse
Affiliation(s)
- Erin Fingleton
- National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, United States
| | - Yan Li
- National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, United States
| | - Katherine W Roche
- National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, United States
| |
Collapse
|
14
|
Clark-Cotton MR, Henderson NT, Pablo M, Ghose D, Elston TC, Lew DJ. Exploratory polarization facilitates mating partner selection in Saccharomyces cerevisiae. Mol Biol Cell 2021; 32:1048-1063. [PMID: 33689470 PMCID: PMC8101489 DOI: 10.1091/mbc.e21-02-0068] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Yeast decode pheromone gradients to locate mating partners, providing a model for chemotropism. How yeast polarize toward a single partner in crowded environments is unclear. Initially, cells often polarize in unproductive directions, but then they relocate the polarity site until two partners’ polarity sites align, whereupon the cells “commit” to each other by stabilizing polarity to promote fusion. Here we address the role of the early mobile polarity sites. We found that commitment by either partner failed if just one partner was defective in generating, orienting, or stabilizing its mobile polarity sites. Mobile polarity sites were enriched for pheromone receptors and G proteins, and we suggest that such sites engage in an exploratory search of the local pheromone landscape, stabilizing only when they detect elevated pheromone levels. Mobile polarity sites were also enriched for pheromone secretion factors, and simulations suggest that only focal secretion at polarity sites would produce high pheromone concentrations at the partner’s polarity site, triggering commitment.
Collapse
Affiliation(s)
| | - Nicholas T Henderson
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27708
| | - Michael Pablo
- Department of Chemistry, Chapel Hill, NC 27599.,Program in Molecular and Cellular Biophysics, Chapel Hill, NC 27599
| | - Debraj Ghose
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27708
| | - Timothy C Elston
- Department of Pharmacology and Computational Medicine Program, UNC Chapel Hill, Chapel Hill, NC 27599
| | - Daniel J Lew
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27708
| |
Collapse
|
15
|
García-Guillén IM, Alonso A, Puelles L, Marín F, Aroca P. Multiple Regionalized Genes and Their Putative Networks in the Interpeduncular Nucleus Suggest Complex Mechanisms of Neuron Development and Axon Guidance. Front Neuroanat 2021; 15:643320. [PMID: 33664652 PMCID: PMC7921722 DOI: 10.3389/fnana.2021.643320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 01/26/2021] [Indexed: 12/27/2022] Open
Abstract
The interpeduncular nucleus (IPN) is a highly conserved limbic structure in the vertebrate brain, located in the isthmus and rhombomere 1. It is formed by various populations that migrate from different sites to the distinct domains within the IPN: the prodromal, rostral interpeduncular, and caudal interpeduncular nuclei. The aim here was to identify genes that are differentially expressed across these domains, characterizing their putative functional roles and interactions. To this end, we screened the 2,038 genes in the Allen Developing Mouse Brain Atlas database expressed at E18.5 and we identified 135 genes expressed within the IPN. The functional analysis of these genes highlighted an overrepresentation of gene families related to neuron development, cell morphogenesis and axon guidance. The interactome analysis within each IPN domain yielded specific networks that mainly involve members of the ephrin/Eph and Cadherin families, transcription factors and molecules related to synaptic neurotransmission. These results bring to light specific mechanisms that might participate in the formation, molecular regionalization, axon guidance and connectivity of the different IPN domains. This genoarchitectonic model of the IPN enables data on gene expression and interactions to be integrated and interpreted, providing a basis for the further study of the connectivity and function of this poorly understood nuclear complex under both normal and pathological conditions.
Collapse
Affiliation(s)
- Isabel M García-Guillén
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia and IMIB-Arrixaca, Murcia, Spain
| | - Antonia Alonso
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia and IMIB-Arrixaca, Murcia, Spain
| | - Luis Puelles
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia and IMIB-Arrixaca, Murcia, Spain
| | - Faustino Marín
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia and IMIB-Arrixaca, Murcia, Spain
| | - Pilar Aroca
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia and IMIB-Arrixaca, Murcia, Spain
| |
Collapse
|
16
|
Clements J, Buhler K, Winant M, Vulsteke V, Callaerts P. Glial and Neuronal Neuroglian, Semaphorin-1a and Plexin A Regulate Morphological and Functional Differentiation of Drosophila Insulin-Producing Cells. Front Endocrinol (Lausanne) 2021; 12:600251. [PMID: 34276554 PMCID: PMC8281472 DOI: 10.3389/fendo.2021.600251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 06/11/2021] [Indexed: 11/21/2022] Open
Abstract
The insulin-producing cells (IPCs), a group of 14 neurons in the Drosophila brain, regulate numerous processes, including energy homeostasis, lifespan, stress response, fecundity, and various behaviors, such as foraging and sleep. Despite their importance, little is known about the development and the factors that regulate morphological and functional differentiation of IPCs. In this study, we describe the use of a new transgenic reporter to characterize the role of the Drosophila L1-CAM homolog Neuroglian (Nrg), and the transmembrane Semaphorin-1a (Sema-1a) and its receptor Plexin A (PlexA) in the differentiation of the insulin-producing neurons. Loss of Nrg results in defasciculation and abnormal neurite branching, including ectopic neurites in the IPC neurons. Cell-type specific RNAi knockdown experiments reveal that Nrg, Sema-1a and PlexA are required in IPCs and glia to control normal morphological differentiation of IPCs albeit with a stronger contribution of Nrg and Sema-1a in glia and of PlexA in the IPCs. These observations provide new insights into the development of the IPC neurons and identify a novel role for Sema-1a in glia. In addition, we show that Nrg, Sema-1a and PlexA in glia and IPCs not only regulate morphological but also functional differentiation of the IPCs and that the functional deficits are likely independent of the morphological phenotypes. The requirements of nrg, Sema-1a, and PlexA in IPC development and the expression of their vertebrate counterparts in the hypothalamic-pituitary axis, suggest that these functions may be evolutionarily conserved in the establishment of vertebrate endocrine systems.
Collapse
|
17
|
Peregrina C, Del Toro D. FLRTing Neurons in Cortical Migration During Cerebral Cortex Development. Front Cell Dev Biol 2020; 8:578506. [PMID: 33043013 PMCID: PMC7527468 DOI: 10.3389/fcell.2020.578506] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/17/2020] [Indexed: 01/26/2023] Open
Abstract
During development, two coordinated events shape the morphology of the mammalian cerebral cortex, leading to the cortex's columnar and layered structure: the proliferation of neuronal progenitors and cortical migration. Pyramidal neurons originating from germinal zones migrate along radial glial fibers to their final position in the cortical plate by both radial migration and tangential dispersion. These processes rely on the delicate balance of intercellular adhesive and repulsive signaling that takes place between neurons interacting with different substrates and guidance cues. Here, we focus on the function of the cell adhesion molecules fibronectin leucine-rich repeat transmembrane proteins (FLRTs) in regulating both the radial migration of neurons, as well as their tangential spread, and the impact these processes have on cortex morphogenesis. In combining structural and functional analysis, recent studies have begun to reveal how FLRT-mediated responses are precisely tuned - from forming different protein complexes to modulate either cell adhesion or repulsion in neurons. These approaches provide a deeper understanding of the context-dependent interactions of FLRTs with multiple receptors involved in axon guidance and synapse formation that contribute to finely regulated neuronal migration.
Collapse
Affiliation(s)
- Claudia Peregrina
- Department of Biological Sciences, Faculty of Medicine, Institute of Neurosciences, University of Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Daniel Del Toro
- Department of Biological Sciences, Faculty of Medicine, Institute of Neurosciences, University of Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| |
Collapse
|
18
|
Trans-Axonal Signaling in Neural Circuit Wiring. Int J Mol Sci 2020; 21:ijms21145170. [PMID: 32708320 PMCID: PMC7404203 DOI: 10.3390/ijms21145170] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/24/2022] Open
Abstract
The development of neural circuits is a complex process that relies on the proper navigation of axons through their environment to their appropriate targets. While axon–environment and axon–target interactions have long been known as essential for circuit formation, communication between axons themselves has only more recently emerged as another crucial mechanism. Trans-axonal signaling governs many axonal behaviors, including fasciculation for proper guidance to targets, defasciculation for pathfinding at important choice points, repulsion along and within tracts for pre-target sorting and target selection, repulsion at the target for precise synaptic connectivity, and potentially selective degeneration for circuit refinement. This review outlines the recent advances in identifying the molecular mechanisms of trans-axonal signaling and discusses the role of axon–axon interactions during the different steps of neural circuit formation.
Collapse
|
19
|
Pfister BJ, Grasman JM, Loverde JR. Exploiting biomechanics to direct the formation of nervous tissue. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2020. [DOI: 10.1016/j.cobme.2020.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
20
|
Expression of Genes Involved in Axon Guidance: How Much Have We Learned? Int J Mol Sci 2020; 21:ijms21103566. [PMID: 32443632 PMCID: PMC7278939 DOI: 10.3390/ijms21103566] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/15/2020] [Accepted: 05/16/2020] [Indexed: 12/20/2022] Open
Abstract
Neuronal axons are guided to their target during the development of the brain. Axon guidance allows the formation of intricate neural circuits that control the function of the brain, and thus the behavior. As the axons travel in the brain to find their target, they encounter various axon guidance cues, which interact with the receptors on the tip of the growth cone to permit growth along different signaling pathways. Although many scientists have performed numerous studies on axon guidance signaling pathways, we still have an incomplete understanding of the axon guidance system. Lately, studies on axon guidance have shifted from studying the signal transduction pathways to studying other molecular features of axon guidance, such as the gene expression. These new studies present evidence for different molecular features that broaden our understanding of axon guidance. Hence, in this review we will introduce recent studies that illustrate different molecular features of axon guidance. In particular, we will review literature that demonstrates how axon guidance cues and receptors regulate local translation of axonal genes and how the expression of guidance cues and receptors are regulated both transcriptionally and post-transcriptionally. Moreover, we will highlight the pathological relevance of axon guidance molecules to specific diseases.
Collapse
|
21
|
Sending messages in moving cells: mRNA localization and the regulation of cell migration. Essays Biochem 2020; 63:595-606. [PMID: 31324705 DOI: 10.1042/ebc20190009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 07/05/2019] [Accepted: 07/09/2019] [Indexed: 12/13/2022]
Abstract
Cell migration is a fundamental biological process involved in tissue formation and homeostasis. The correct polarization of motile cells is critical to ensure directed movement, and is orchestrated by many intrinsic and extrinsic factors. Of these, the subcellular distribution of mRNAs and the consequent spatial control of translation are key modulators of cell polarity. mRNA transport is dependent on cis-regulatory elements within transcripts, which are recognized by trans-acting proteins that ensure the efficient delivery of certain messages to the leading edge of migrating cells. At their destination, translation of localized mRNAs then participates in regional cellular responses underlying cell motility. In this review, we summarize the key findings that established mRNA targetting as a critical driver of cell migration and how the characterization of polarized mRNAs in motile cells has been expanded from just a few species to hundreds of transcripts. We also describe the molecular control of mRNA trafficking, subsequent mechanisms of local protein synthesis and how these ultimately regulate cell polarity during migration.
Collapse
|
22
|
Isabella AJ, Barsh GR, Stonick JA, Dubrulle J, Moens CB. Retinoic Acid Organizes the Zebrafish Vagus Motor Topographic Map via Spatiotemporal Coordination of Hgf/Met Signaling. Dev Cell 2020; 53:344-357.e5. [PMID: 32302545 PMCID: PMC7237105 DOI: 10.1016/j.devcel.2020.03.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 02/14/2020] [Accepted: 03/19/2020] [Indexed: 02/08/2023]
Abstract
Information flow through neural circuits often requires their organization into topographic maps in which the positions of cell bodies and synaptic targets correspond. To understand how topographic map development is controlled, we examine the mechanism underlying targeting of vagus motor axons to the pharyngeal arches in zebrafish. We reveal that retinoic acid organizes topography by specifying anterior-posterior identity in vagus motor neurons. We then show that chemoattractant signaling between Hgf and Met is required for vagus innervation of the pharyngeal arches. Finally, we find that retinoic acid controls the spatiotemporal dynamics of Hgf/Met signaling to coordinate axon targeting with the developmental progression of the pharyngeal arches and show that experimentally altering the timing of Hgf/Met signaling is sufficient to redirect axon targeting and disrupt the topographic map. These findings establish a mechanism of topographic map development in which the regulation of chemoattractant signaling in space and time guides axon targeting.
Collapse
Affiliation(s)
- Adam J Isabella
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Gabrielle R Barsh
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Molecular and Cellular Biology Graduate Program and Medical Scientist Training Program, University of Washington, Seattle, WA 98195, USA
| | - Jason A Stonick
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Julien Dubrulle
- Shared Resources, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Cecilia B Moens
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Molecular and Cellular Biology Graduate Program and Medical Scientist Training Program, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
23
|
Lhx2/9 and Etv1 Transcription Factors have Complementary roles in Regulating the Expression of Guidance Genes slit1 and sema3a. Neuroscience 2020; 434:66-82. [PMID: 32200077 DOI: 10.1016/j.neuroscience.2020.03.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 01/02/2023]
Abstract
During neural network development, growing axons read a map of guidance cues expressed in the surrounding tissue that lead the axons toward their targets. In particular, Xenopus retinal ganglion axons use the cues Slit1 and Semaphorin 3a (Sema3a) at a key guidance decision point in the mid-diencephalon in order to continue on to their midbrain target, the optic tectum. The mechanisms that control the expression of these cues, however, are poorly understood. Extrinsic Fibroblast Growth Factor (Fgf) signals are known to help coordinate the development of the brain by regulating gene expression. Here, we propose Lhx2/9 and Etv1 as potential downstream effectors of Fgf signalling to regulate slit1 and sema3a expression in the Xenopus forebrain. We find that lhx2/9 and etv1 mRNAs are expressed complementary to and within slit1/sema3a expression domains, respectively. Our data indicate that Lhx2 functions as an indirect repressor in that lhx2 overexpression within the forebrain downregulates the mRNA expression of both guidance genes, and in vitro lhx2/9 overexpression decreases the activity of slit1 and sema3a promoters. The Lhx2-VP16 constitutive activator fusion reduces sema3a promoter function, and the Lhx2-En constitutive repressor fusion increases slit1 induction. In contrast, etv1 gain of function transactivates both guidance genes in vitro and in the forebrain. Based on these data, together with our previous work, we hypothesize that Fgf signalling promotes both slit1 and sema3a expression in the forebrain through Etv1, while using Lhx2/9 to limit the extent of expression, thereby establishing the proper boundaries of guidance cue expression.
Collapse
|
24
|
Lee WS, Lee WH, Bae YC, Suk K. Axon Guidance Molecules Guiding Neuroinflammation. Exp Neurobiol 2019; 28:311-319. [PMID: 31308791 PMCID: PMC6614065 DOI: 10.5607/en.2019.28.3.311] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 12/19/2022] Open
Abstract
Axon guidance molecules (AGMs), such as Netrins, Semaphorins, and Ephrins, have long been known to regulate axonal growth in the developing nervous system. Interestingly, the chemotactic properties of AGMs are also important in the postnatal period, such as in the regulation of immune and inflammatory responses. In particular, AGMs play pivotal roles in inflammation of the nervous system, by either stimulating or inhibiting inflammatory responses, depending on specific ligand-receptor combinations. Understanding such regulatory functions of AGMs in neuroinflammation may allow finding new molecular targets to treat neurodegenerative diseases, in which neuroinflammation underlies aetiology and progression.
Collapse
Affiliation(s)
- Won Suk Lee
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 41944, Korea.,Brain Science and Engineering Institute, Kyungpook National University, Daegu 41944, Korea
| | - Won-Ha Lee
- BK21 Plus KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
| | - Kyoungho Suk
- Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 41944, Korea.,Brain Science and Engineering Institute, Kyungpook National University, Daegu 41944, Korea
| |
Collapse
|