1
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Fuentealba LM, Pizarro H, Marzolo MP. OCRL1 Deficiency Affects the Intracellular Traffic of ApoER2 and Impairs Reelin-Induced Responses. Biomolecules 2024; 14:799. [PMID: 39062513 PMCID: PMC11274606 DOI: 10.3390/biom14070799] [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: 05/29/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/28/2024] Open
Abstract
Lowe Syndrome (LS) is a rare X-linked disorder characterized by renal dysfunction, cataracts, and several central nervous system (CNS) anomalies. The mechanisms underlying the neurological dysfunction in LS remain unclear, albeit they share some phenotypic characteristics similar to the deficiency or dysfunction of the Reelin signaling, a relevant pathway with roles in CNS development and neuronal functions. In this study, we investigated the role of OCRL1, an inositol polyphosphate 5-phosphatase encoded by the OCRL gene, mutated in LS, focusing on its impact on endosomal trafficking and receptor recycling in human neuronal cells. Specifically, we tested the effects of OCRL1 deficiency in the trafficking and signaling of ApoER2/LRP8, a receptor for the ligand Reelin. We found that loss of OCRL1 impairs ApoER2 intracellular trafficking, leading to reduced receptor expression and decreased levels at the plasma membrane. Additionally, human neurons deficient in OCRL1 showed impairments in ApoER2/Reelin-induced responses. Our findings highlight the critical role of OCRL1 in regulating ApoER2 endosomal recycling and its impact on the ApoER2/Reelin signaling pathway, providing insights into potential mechanisms underlying the neurological manifestations of LS.
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Affiliation(s)
| | | | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 7810128, Chile; (L.M.F.); (H.P.)
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2
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Caracci MO, Pizarro H, Alarcón-Godoy C, Fuentealba LM, Farfán P, De Pace R, Santibañez N, Cavieres VA, Pástor TP, Bonifacino JS, Mardones GA, Marzolo MP. The Reelin receptor ApoER2 is a cargo for the adaptor protein complex AP-4: Implications for Hereditary Spastic Paraplegia. Prog Neurobiol 2024; 234:102575. [PMID: 38281682 PMCID: PMC10979513 DOI: 10.1016/j.pneurobio.2024.102575] [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: 07/03/2023] [Revised: 01/11/2024] [Accepted: 01/23/2024] [Indexed: 01/30/2024]
Abstract
Adaptor protein complex 4 (AP-4) is a heterotetrameric complex that promotes export of selected cargo proteins from the trans-Golgi network. Mutations in each of the AP-4 subunits cause a complicated form of Hereditary Spastic Paraplegia (HSP). Herein, we report that ApoER2, a receptor in the Reelin signaling pathway, is a cargo of the AP-4 complex. We identify the motif ISSF/Y within the ApoER2 cytosolic domain as necessary for interaction with the canonical signal-binding pocket of the µ4 (AP4M1) subunit of AP-4. AP4E1- knock-out (KO) HeLa cells and hippocampal neurons from Ap4e1-KO mice display increased co-localization of ApoER2 with Golgi markers. Furthermore, hippocampal neurons from Ap4e1-KO mice and AP4M1-KO human iPSC-derived cortical i3Neurons exhibit reduced ApoER2 protein expression. Analyses of biosynthetic transport of ApoER2 reveal differential post-Golgi trafficking of the receptor, with lower axonal distribution in KO compared to wild-type neurons, indicating a role of AP-4 and the ISSF/Y motif in the axonal localization of ApoER2. Finally, analyses of Reelin signaling in mouse hippocampal and human cortical KO neurons show that AP4 deficiency causes no changes in Reelin-dependent activation of the AKT pathway and only mild changes in Reelin-induced dendritic arborization, but reduces Reelin-induced ERK phosphorylation, CREB activation, and Golgi deployment. This work thus establishes ApoER2 as a novel cargo of the AP-4 complex, suggesting that defects in the trafficking of this receptor and in the Reelin signaling pathway could contribute to the pathogenesis of HSP caused by mutations in AP-4 subunits.
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Affiliation(s)
- Mario O Caracci
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Héctor Pizarro
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Carlos Alarcón-Godoy
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Luz M Fuentealba
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Pamela Farfán
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Raffaella De Pace
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Natacha Santibañez
- Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Viviana A Cavieres
- Departamento de Ciencias Biológicas y Químicas, Fac. Med y Ciencia, USS, Santiago, Chile
| | - Tammy P Pástor
- Escuela de Medicina, Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - Juan S Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Gonzalo A Mardones
- Escuela de Medicina, Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - María-Paz Marzolo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile.
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3
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Caracci MO, Pizarro H, Alarcón-Godoy C, Fuentealba LM, Farfán P, Pace RD, Santibañez N, Cavieres VA, Pástor TP, Bonifacino JS, Mardones GA, Marzolo MP. The Reelin Receptor ApoER2 is a Cargo for the Adaptor Protein Complex AP-4: Implications for Hereditary Spastic Paraplegia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.21.572896. [PMID: 38187774 PMCID: PMC10769347 DOI: 10.1101/2023.12.21.572896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Adaptor protein complex 4 (AP-4) is a heterotetrameric complex that promotes protein export from the trans -Golgi network. Mutations in each of the AP-4 subunits cause a complicated form of Hereditary Spastic Paraplegia (HSP). Herein, we report that ApoER2, a receptor in the Reelin signaling pathway, is a cargo of the AP-4 complex. We identify the motif ISSF/Y within the ApoER2 cytosolic domain as necessary for interaction with the canonical signal-binding pocket of the µ4 (AP4M1) subunit of AP-4. AP4E1 -knock-out (KO) HeLa cells and hippocampal neurons from Ap4e1 -KO mice display increased Golgi localization of ApoER2. Furthermore, hippocampal neurons from Ap4e1 -KO mice and AP4M1 -KO human iPSC-derived cortical i3Neurons exhibit reduced ApoER2 protein expression. Analyses of biosynthetic transport of ApoER2 reveal differential post-Golgi trafficking of the receptor, with lower axonal distribution in KO compared to wild-type neurons, indicating a role of AP-4 and the ISSF/Y motif in the axonal localization of ApoER2. Finally, analyses of Reelin signaling in mouse hippocampal and human cortical KO neurons show that AP4 deficiency causes no changes in Reelin-dependent activation of the AKT pathway and only mild changes in Reelin-induced dendritic arborization, but reduces Reelin-induced ERK phosphorylation, CREB activation, and Golgi deployment. Altogether, this work establishes ApoER2 as a novel cargo of the AP-4 complex, suggesting that defects in the trafficking of this receptor and in the Reelin signaling pathway could contribute to the pathogenesis of HSP caused by mutations in AP-4 subunits.
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4
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Hamad MIK, Emerald BS, Kumar KK, Ibrahim MF, Ali BR, Bataineh MF. Extracellular molecular signals shaping dendrite architecture during brain development. Front Cell Dev Biol 2023; 11:1254589. [PMID: 38155836 PMCID: PMC10754048 DOI: 10.3389/fcell.2023.1254589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 11/28/2023] [Indexed: 12/30/2023] Open
Abstract
Proper growth and branching of dendrites are crucial for adequate central nervous system (CNS) functioning. The neuronal dendritic geometry determines the mode and quality of information processing. Any defects in dendrite development will disrupt neuronal circuit formation, affecting brain function. Besides cell-intrinsic programmes, extrinsic factors regulate various aspects of dendritic development. Among these extrinsic factors are extracellular molecular signals which can shape the dendrite architecture during early development. This review will focus on extrinsic factors regulating dendritic growth during early neuronal development, including neurotransmitters, neurotrophins, extracellular matrix proteins, contact-mediated ligands, and secreted and diffusible cues. How these extracellular molecular signals contribute to dendritic growth has been investigated in developing nervous systems using different species, different areas within the CNS, and different neuronal types. The response of the dendritic tree to these extracellular molecular signals can result in growth-promoting or growth-limiting effects, and it depends on the receptor subtype, receptor quantity, receptor efficiency, the animal model used, the developmental time windows, and finally, the targeted signal cascade. This article reviews our current understanding of the role of various extracellular signals in the establishment of the architecture of the dendrites.
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Affiliation(s)
- Mohammad I. K. Hamad
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Kukkala K. Kumar
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Marwa F. Ibrahim
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bassam R. Ali
- Department of Genetics and Genomics, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mo’ath F. Bataineh
- Department of Nutrition and Health, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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5
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Chen M, Xu L, Wu Y, Soba P, Hu C. The organization and function of the Golgi apparatus in dendrite development and neurological disorders. Genes Dis 2023; 10:2425-2442. [PMID: 37554209 PMCID: PMC10404969 DOI: 10.1016/j.gendis.2022.11.009] [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: 07/04/2022] [Revised: 09/13/2022] [Accepted: 11/05/2022] [Indexed: 12/24/2022] Open
Abstract
Dendrites are specialized neuronal compartments that sense, integrate and transfer information in the neural network. Their development is tightly controlled and abnormal dendrite morphogenesis is strongly linked to neurological disorders. While dendritic morphology ranges from relatively simple to extremely complex for a specified neuron, either requires a functional secretory pathway to continually replenish proteins and lipids to meet dendritic growth demands. The Golgi apparatus occupies the center of the secretory pathway and is regulating posttranslational modifications, sorting, transport, and signal transduction, as well as acting as a non-centrosomal microtubule organization center. The neuronal Golgi apparatus shares common features with Golgi in other eukaryotic cell types but also forms distinct structures known as Golgi outposts that specifically localize in dendrites. However, the organization and function of Golgi in dendrite development and its impact on neurological disorders is just emerging and so far lacks a systematic summary. We describe the organization of the Golgi apparatus in neurons, review the current understanding of Golgi function in dendritic morphogenesis, and discuss the current challenges and future directions.
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Affiliation(s)
- Meilan Chen
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education Institute for Brain, Science and Rehabilitation, South China Normal University, Guangzhou, Guangdong 510631, China
- Department of Ophthalmology, Guangdong Second Provincial General Hospital, Guangzhou, Guangdong 510320, China
| | - Lu Xu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education Institute for Brain, Science and Rehabilitation, South China Normal University, Guangzhou, Guangdong 510631, China
| | - Yi Wu
- Department of Ophthalmology, Guangdong Second Provincial General Hospital, Guangzhou, Guangdong 510320, China
| | - Peter Soba
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Bonn 53115, Germany
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
| | - Chun Hu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education Institute for Brain, Science and Rehabilitation, South China Normal University, Guangzhou, Guangdong 510631, China
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6
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Nakagawa N, Iwasato T. Golgi polarity shift instructs dendritic refinement in the neonatal cortex by mediating NMDA receptor signaling. Cell Rep 2023; 42:112843. [PMID: 37516101 DOI: 10.1016/j.celrep.2023.112843] [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: 03/07/2023] [Revised: 05/15/2023] [Accepted: 07/05/2023] [Indexed: 07/31/2023] Open
Abstract
Dendritic refinement is a critical component of activity-dependent neuronal circuit maturation, through which individual neurons establish specific connectivity with their target axons. Here, we demonstrate that the developmental shift of Golgi polarity is a key process in dendritic refinement. During neonatal development, the Golgi apparatus in layer 4 spiny stellate (SS) neurons in the mouse barrel cortex lose their original apical positioning and acquire laterally polarized distributions. This lateral Golgi polarity, which is oriented toward the barrel center, peaks on postnatal days 5-7 (P5-P7) and disappears by P15, which aligns with the developmental time course of SS neuron dendritic refinement. Genetic ablation of N-methyl-D-aspartate (NMDA) receptors, key players in dendritic refinement, disturbs the lateral Golgi polarity. Golgi polarity manipulation disrupts the asymmetric dendritic projection pattern and the primary-whisker-specific response of SS neurons. Our results elucidate activity-dependent Golgi dynamics and their critical role in developmental neuronal circuit refinement.
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Affiliation(s)
- Naoki Nakagawa
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics (NIG), Mishima, Shizuoka 411-8540, Japan; Graduate Institute for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan.
| | - Takuji Iwasato
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics (NIG), Mishima, Shizuoka 411-8540, Japan; Graduate Institute for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan.
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7
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Kounoupa Z, Tivodar S, Theodorakis K, Kyriakis D, Denaxa M, Karagogeos D. Rac1 and Rac3 GTPases and TPC2 are required for axonal outgrowth and migration of cortical interneurons. J Cell Sci 2023; 136:286920. [PMID: 36744839 DOI: 10.1242/jcs.260373] [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: 06/24/2022] [Accepted: 01/31/2023] [Indexed: 02/07/2023] Open
Abstract
Rho GTPases, among them Rac1 and Rac3, are major transducers of extracellular signals and are involved in multiple cellular processes. In cortical interneurons, the neurons that control the balance between excitation and inhibition of cortical circuits, Rac1 and Rac3 are essential for their development. Ablation of both leads to a severe reduction in the numbers of mature interneurons found in the murine cortex, which is partially due to abnormal cell cycle progression of interneuron precursors and defective formation of growth cones in young neurons. Here, we present new evidence that upon Rac1 and Rac3 ablation, centrosome, Golgi complex and lysosome positioning is significantly perturbed, thus affecting both interneuron migration and axon growth. Moreover, for the first time, we provide evidence of altered expression and localization of the two-pore channel 2 (TPC2) voltage-gated ion channel that mediates Ca2+ release. Pharmacological inhibition of TPC2 negatively affected axonal growth and migration of interneurons. Our data, taken together, suggest that TPC2 contributes to the severe phenotype in axon growth initiation, extension and interneuron migration in the absence of Rac1 and Rac3.
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Affiliation(s)
- Zouzana Kounoupa
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Simona Tivodar
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Kostas Theodorakis
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Dimitrios Kyriakis
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg
| | - Myrto Denaxa
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre 'Al. Fleming', Vari, 16672, Greece
| | - Domna Karagogeos
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
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8
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Bae T, Fasching L, Wang Y, Shin JH, Suvakov M, Jang Y, Norton S, Dias C, Mariani J, Jourdon A, Wu F, Panda A, Pattni R, Chahine Y, Yeh R, Roberts RC, Huttner A, Kleinman JE, Hyde TM, Straub RE, Walsh CA, Urban AE, Leckman JF, Weinberger DR, Vaccarino FM, Abyzov A. Analysis of somatic mutations in 131 human brains reveals aging-associated hypermutability. Science 2022; 377:511-517. [PMID: 35901164 PMCID: PMC9420557 DOI: 10.1126/science.abm6222] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We analyzed 131 human brains (44 neurotypical, 19 with Tourette syndrome, 9 with schizophrenia, and 59 with autism) for somatic mutations after whole genome sequencing to a depth of more than 200×. Typically, brains had 20 to 60 detectable single-nucleotide mutations, but ~6% of brains harbored hundreds of somatic mutations. Hypermutability was associated with age and damaging mutations in genes implicated in cancers and, in some brains, reflected in vivo clonal expansions. Somatic duplications, likely arising during development, were found in ~5% of normal and diseased brains, reflecting background mutagenesis. Brains with autism were associated with mutations creating putative transcription factor binding motifs in enhancer-like regions in the developing brain. The top-ranked affected motifs corresponded to MEIS (myeloid ectopic viral integration site) transcription factors, suggesting a potential link between their involvement in gene regulation and autism.
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Affiliation(s)
- Taejeong Bae
- Department of Quantitative Health Sciences, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
| | - Liana Fasching
- Child Study Center, Yale University, New Haven, CT 06520
| | - Yifan Wang
- Department of Quantitative Health Sciences, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
| | - Joo Heon Shin
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD
| | - Milovan Suvakov
- Department of Quantitative Health Sciences, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
| | - Yeongjun Jang
- Department of Quantitative Health Sciences, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
| | - Scott Norton
- Child Study Center, Yale University, New Haven, CT 06520
| | - Caroline Dias
- Division of Genetics and Genomics and Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA, USA
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | | | | | - Feinan Wu
- Child Study Center, Yale University, New Haven, CT 06520
| | - Arijit Panda
- Department of Quantitative Health Sciences, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
| | - Reenal Pattni
- Department of Psychiatry and Behavioral Sciences, Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Yasmine Chahine
- Division of Genetics and Genomics and Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA, USA
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | - Rebecca Yeh
- Division of Genetics and Genomics and Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA, USA
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | - Rosalinda C. Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham Al, 35294
| | - Anita Huttner
- Department of Pathology, Yale University, New Haven, CT 06520
| | - Joel E. Kleinman
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD
| | - Thomas M. Hyde
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD
| | - Richard E. Straub
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Christopher A. Walsh
- Division of Genetics and Genomics and Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA, USA
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | | | - Alexander E. Urban
- Department of Psychiatry and Behavioral Sciences, Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | | | - Daniel R. Weinberger
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD
- Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD
| | - Flora M. Vaccarino
- Child Study Center, Yale University, New Haven, CT 06520
- Department of Neuroscience, Yale University, New Haven, CT 06520
| | - Alexej Abyzov
- Department of Quantitative Health Sciences, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905
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9
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Maternal Ethanol Exposure Acutely Elevates Src Family Kinase Activity in the Fetal Cortex. Mol Neurobiol 2021; 58:5210-5223. [PMID: 34272687 PMCID: PMC8497457 DOI: 10.1007/s12035-021-02467-x] [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: 04/09/2021] [Accepted: 06/20/2021] [Indexed: 11/24/2022]
Abstract
Fetal alcohol syndrome (FAS) is characterized by disrupted fetal brain development and postnatal cognitive impairment. The targets of alcohol are diverse, and it is not clear whether there are common underlying molecular mechanisms producing these disruptions. Prior work established that acute ethanol exposure causes a transient increase in tyrosine phosphorylation of multiple proteins in cultured embryonic cortical cells. In this study, we show that a similar tyrosine phosphorylation transient occurs in the fetal brain after maternal dosing with ethanol. Using phospho-specific antibodies and immunohistochemistry, we mapped regions of highest tyrosine phosphorylation in the fetal cerebral cortex and found that areas of dendritic and axonal growth showed elevated tyrosine phosphorylation 10 min after maternal ethanol exposure. These were also areas of Src expression and Src family kinase (SFK) activation loop phosphorylation (pY416) expression. Importantly, maternal pretreatment with the SFK inhibitor dasatinib completely prevents both the pY416 increase and the tyrosine phosphorylation response. The phosphorylation response was observed in the perisomatic region and neurites of immature migrating and differentiating primary neurons. Importantly, the initial phosphotyrosine transient (~ 30 min) targets both Src and Dab1, two critical elements in Reelin signaling, a pathway required for normal cortical development. This initial phosphorylation response is followed by sustained reduction in Ser3 phosphorylation of n-cofilin, a critical actin severing protein and an identified downstream effector of Reelin signaling. This biochemical disruption is associated with sustained reduction of F-actin content and disrupted Golgi apparatus morphology in developing cortical neurons. The finding outlines a model in which the initial activation of SFKs by ethanol has the potential to disrupt multiple developmentally important signaling systems for several hours after maternal exposure.
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10
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Alexander CJ, Barzik M, Fujiwara I, Remmert K, Wang YX, Petralia RS, Friedman TB, Hammer JA. Myosin 18Aα targets the guanine nucleotide exchange factor β-Pix to the dendritic spines of cerebellar Purkinje neurons and promotes spine maturation. FASEB J 2021; 35:e21092. [PMID: 33378124 PMCID: PMC8357457 DOI: 10.1096/fj.202001449r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/24/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022]
Abstract
Myosin 18Aα is a myosin 2-like protein containing unique N- and C-terminal protein interaction domains that co-assembles with myosin 2. One protein known to bind to myosin 18Aα is β-Pix, a guanine nucleotide exchange factor (GEF) for Rac1 and Cdc42 that has been shown to promote dendritic spine maturation by activating the assembly of actin and myosin filaments in spines. Here, we show that myosin 18A⍺ concentrates in the spines of cerebellar Purkinje neurons via co-assembly with myosin 2 and through an actin binding site in its N-terminal extension. miRNA-mediated knockdown of myosin 18A⍺ results in a significant defect in spine maturation that is rescued by an RNAi-immune version of myosin 18A⍺. Importantly, β-Pix co-localizes with myosin 18A⍺ in spines, and its spine localization is lost upon myosin 18A⍺ knockdown or when its myosin 18A⍺ binding site is deleted. Finally, we show that the spines of myosin 18A⍺ knockdown Purkinje neurons contain significantly less F-actin and myosin 2. Together, these data argue that mixed filaments of myosin 2 and myosin 18A⍺ form a complex with β-Pix in Purkinje neuron spines that promotes spine maturation by enhancing the assembly of actin and myosin filaments downstream of β-Pix's GEF activity.
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Affiliation(s)
- Christopher J Alexander
- Molecular Cell Biology Laboratory, Cell and Developmental Biology Center, NHLBI, NIH, Bethesda, MD, USA
| | - Melanie Barzik
- Laboratory of Molecular Genetics, NIDCD, NIH, Bethesda, MD, USA
| | - Ikuko Fujiwara
- Graduate School of Science, Osaka City University, Osaka, Japan
| | | | - Ya-Xian Wang
- Advanced Imaging Core, NIDCD, NIH, Betheda, MD, USA
| | | | | | - John A Hammer
- Molecular Cell Biology Laboratory, Cell and Developmental Biology Center, NHLBI, NIH, Bethesda, MD, USA
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11
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Jausoro I, Marzolo MP. Reelin activates the small GTPase TC10 and VAMP7 to promote neurite outgrowth and regeneration of dorsal root ganglia (DRG) neurons. J Neurosci Res 2021; 99:392-406. [PMID: 32652719 DOI: 10.1002/jnr.24688] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 05/27/2020] [Accepted: 06/11/2020] [Indexed: 01/16/2023]
Abstract
Axonal outgrowth is a fundamental process during the development of central (CNS) and peripheral (PNS) nervous system as well as in nerve regeneration and requires accurate axonal navigation and extension to the correct target. These events need proper coordination between membrane trafficking and cytoskeletal rearrangements and are under the control of the small GTPases of the Rho family, among other molecules. Reelin, a relevant protein for CNS development and synaptic function in the adult, is also present in the PNS. Upon sciatic nerve damage, Reelin expression increases and, on the other hand, mice deficient in Reelin exhibit an impaired nerve regeneration. However, the mechanism(s) involved the Reelin-dependent axonal growth is still poorly understood. In this work, we present evidence showing that Reelin stimulates dorsal root ganglia (DRG) regeneration after axotomy. Moreover, dissociated DRG neurons express the Reelin receptor Apolipoprotein E-receptor 2 and also require the presence of TC10 to develop their axons. TC10 is a Rho GTPase that promotes neurite outgrowth through the exocytic fusion of vesicles at the growth cone. Here, we demonstrate for the first time that Reelin controls TC10 activation in DRG neurons. Besides, we confirmed that the known CNS Reelin target Cdc42 is also activated in DRG and controls TC10 activity. Finally, in the process of membrane addition, we found that Reelin stimulates the fusion of membrane carriers containing the v-SNARE protein VAMP7 in vesicles that contain TC10. Altogether, our work shows a new role of Reelin in PNS, opening the option of therapeutic interventions to improve the regeneration process.
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Affiliation(s)
- Ignacio Jausoro
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Maria-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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12
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Kim JY, Hwang HG, Lee JY, Kim M, Kim JY. Cortactin deacetylation by HDAC6 and SIRT2 regulates neuronal migration and dendrite morphogenesis during cerebral cortex development. Mol Brain 2020; 13:105. [PMID: 32711564 PMCID: PMC7382832 DOI: 10.1186/s13041-020-00644-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 07/15/2020] [Indexed: 01/11/2023] Open
Abstract
Proper dendrite morphogenesis and neuronal migration are crucial for cerebral cortex development and neural circuit formation. In this study, we sought to determine if the histone deacetylase HDAC6 plays a role in dendrite development and neuronal migration of pyramidal neurons during cerebral cortex development. It was observed that knockdown of HDAC6 leads to defective dendrite morphogenesis and abnormal Golgi polarization in vitro, and the expression of wild type cortactin or deacetyl-mimetic cortactin 9KR rescued the defective phenotypes of the HDAC6 knockdown neurons. This suggests that HDAC6 promotes dendritic growth and Golgi polarization through cortactin deacetylation in vitro. We also demonstrated that ectopic expression of SIRT2, a cytoplasmic NAD+ − dependent deacetylase, suppresses the defects of HDAC6 knockdown neurons. These results indicate that HDAC6 and SIRT2 may be functionally redundant during dendrite development. Neurons transfected with both HDAC6 and SIRT2 shRNA or acetyl-mimetic cortactin 9KQ showed slow radial migration compared to the control cells during cerebral cortex development. Furthermore, a large portion of cortactin 9KQ-expressing pyramidal neurons at layer II/III in the cerebral cortex failed to form an apical dendrite toward the pial surface and had an increased number of primary dendrites, and the percentage of neurons with dendritic Golgi decreased in cortactin 9KQ-expressing cells, compared to control neurons. Taken together, this study suggests that HDAC6 and SIRT2 regulate neuronal migration and dendrite development through cortactin deacetylation in vivo.
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Affiliation(s)
- Ji-Ye Kim
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, South Korea
| | - Hee-Gon Hwang
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, South Korea
| | - Joo-Yong Lee
- Graduate School of Analytical Science and Technology (GRAST), Chungnam National University, Daejeon, South Korea
| | - Minkyu Kim
- Divison of Animal and Dairy Science, Chungnam National University, Daejeon, South Korea
| | - Jeong-Yoon Kim
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, South Korea.
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13
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Jossin Y. Reelin Functions, Mechanisms of Action and Signaling Pathways During Brain Development and Maturation. Biomolecules 2020; 10:biom10060964. [PMID: 32604886 PMCID: PMC7355739 DOI: 10.3390/biom10060964] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/24/2020] [Accepted: 06/24/2020] [Indexed: 12/14/2022] Open
Abstract
During embryonic development and adulthood, Reelin exerts several important functions in the brain including the regulation of neuronal migration, dendritic growth and branching, dendritic spine formation, synaptogenesis and synaptic plasticity. As a consequence, the Reelin signaling pathway has been associated with several human brain disorders such as lissencephaly, autism, schizophrenia, bipolar disorder, depression, mental retardation, Alzheimer’s disease and epilepsy. Several elements of the signaling pathway are known. Core components, such as the Reelin receptors very low-density lipoprotein receptor (VLDLR) and Apolipoprotein E receptor 2 (ApoER2), Src family kinases Src and Fyn, and the intracellular adaptor Disabled-1 (Dab1), are common to most but not all Reelin functions. Other downstream effectors are, on the other hand, more specific to defined tasks. Reelin is a large extracellular protein, and some aspects of the signal are regulated by its processing into smaller fragments. Rather than being inhibitory, the processing at two major sites seems to be fulfilling important physiological functions. In this review, I describe the various cellular events regulated by Reelin and attempt to explain the current knowledge on the mechanisms of action. After discussing the shared and distinct elements of the Reelin signaling pathway involved in neuronal migration, dendritic growth, spine development and synaptic plasticity, I briefly outline the data revealing the importance of Reelin in human brain disorders.
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Affiliation(s)
- Yves Jossin
- Laboratory of Mammalian Development & Cell Biology, Institute of Neuroscience, Université Catholique de Louvain, 1200 Brussels, Belgium
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14
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Xu Z, Chen Y, Chen Y. Spatiotemporal Regulation of Rho GTPases in Neuronal Migration. Cells 2019; 8:cells8060568. [PMID: 31185627 PMCID: PMC6627650 DOI: 10.3390/cells8060568] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 06/01/2019] [Accepted: 06/04/2019] [Indexed: 12/17/2022] Open
Abstract
Neuronal migration is essential for the orchestration of brain development and involves several contiguous steps: interkinetic nuclear movement (INM), multipolar–bipolar transition, locomotion, and translocation. Growing evidence suggests that Rho GTPases, including RhoA, Rac, Cdc42, and the atypical Rnd members, play critical roles in neuronal migration by regulating both actin and microtubule cytoskeletal components. This review focuses on the spatiotemporal-specific regulation of Rho GTPases as well as their regulators and effectors in distinct steps during the neuronal migration process. Their roles in bridging extracellular signals and cytoskeletal dynamics to provide optimal structural support to the migrating neurons will also be discussed.
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Affiliation(s)
- Zhenyan Xu
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518055, Guangdong, China.
| | - Yuewen Chen
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518055, Guangdong, China.
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen 518057, Guangdong, China.
| | - Yu Chen
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518055, Guangdong, China.
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen 518057, Guangdong, China.
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15
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Caracci MO, Fuentealba LM, Marzolo MP. Golgi Complex Dynamics and Its Implication in Prevalent Neurological Disorders. Front Cell Dev Biol 2019; 7:75. [PMID: 31134199 PMCID: PMC6514153 DOI: 10.3389/fcell.2019.00075] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 04/18/2019] [Indexed: 12/13/2022] Open
Abstract
Coupling of protein synthesis with protein delivery to distinct subcellular domains is essential for maintaining cellular homeostasis, and defects thereof have consistently been shown to be associated with several diseases. This function is particularly challenging for neurons given their polarized nature and differential protein requirements in synaptic boutons, dendrites, axons, and soma. Long-range trafficking is greatly enhanced in neurons by discrete mini-organelles resembling the Golgi complex (GC) referred to as Golgi outposts (GOPs) which play an essential role in the development of dendritic arborization. In this context, the morphology of the GC is highly plastic, and the polarized distribution of this organelle is necessary for neuronal migration and polarized growth. Furthermore, synaptic components are readily trafficked and modified at GOP suggesting a function for this organelle in synaptic plasticity. However, little is known about GOPs properties and biogenesis and the role of GOP dysregulation in pathology. In this review, we discuss current literature supporting a role for GC dynamics in prevalent neurological disorders such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and epilepsy, and examine the association of these disorders with the wide-ranging effects of GC function on common cellular pathways regulating neuronal excitability, polarity, migration, and organellar stress. First, we discuss the role of Golgins and Golgi-associated proteins in the regulation of GC morphology and dynamics. Then, we consider abnormal GC arrangements observed in neurological disorders and associations with common neuronal defects therein. Finally, we consider the cell signaling pathways involved in the modulation of GC dynamics and argue for a master regulatory role for Reelin signaling, a well-known regulator of neuronal polarity and migration. Determining the cellular pathways involved in shaping the Golgi network will have a direct and profound impact on our current understanding of neurodevelopment and neuropathology and aid the development of novel therapeutic strategies for improved patient care and prognosis.
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Affiliation(s)
- Mario O Caracci
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luz M Fuentealba
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María-Paz Marzolo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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16
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Liu J, He J, Huang Y, Xiao H, Jiang Z, Hu Z. The Golgi apparatus in neurorestoration. JOURNAL OF NEURORESTORATOLOGY 2019. [DOI: 10.26599/jnr.2019.9040017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The central role of the Golgi apparatus in critical cellular processes such as the transport, processing, and sorting of proteins and lipids has placed it at the forefront of cell science. Golgi apparatus dysfunction caused by primary defects within the Golgi or pharmacological and oxidative stress has been implicated in a wide range of neurodegenerative diseases. In addition to participating in disease progression, the Golgi apparatus plays pivotal roles in angiogenesis, neurogenesis, and synaptogenesis, thereby promoting neurological recovery. In this review, we focus on the functions of the Golgi apparatus and its mediated events during neurorestoration.
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17
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Pathogenic predictions of non-synonymous variants and their impacts: A computational assessment of ARHGEF6 gene. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2018. [DOI: 10.1016/j.ejmhg.2018.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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BIG2-ARF1-RhoA-mDia1 Signaling Regulates Dendritic Golgi Polarization in Hippocampal Neurons. Mol Neurobiol 2018; 55:7701-7716. [PMID: 29455446 DOI: 10.1007/s12035-018-0954-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 02/05/2018] [Indexed: 01/08/2023]
Abstract
Proper dendrite development is essential for establishing neural circuitry, and Rho GTPases play key regulatory roles in this process. From mouse brain lysates, we identified Brefeldin A-inhibited guanine exchange factor 2 (BIG2) as a novel Rho GTPase regulatory protein involved in dendrite growth and maintenance. BIG2 was highly expressed during early development, and knockdown of the ARFGEF2 gene encoding BIG2 significantly reduced total dendrite length and the number of branches. Expression of the constitutively active ADP-ribosylation factor 1 ARF1 Q71L rescued the defective dendrite morphogenesis of ARFGEF2-null neurons, indicating that BIG2 controls dendrite growth and maintenance by activating ARF1. Moreover, BIG2 co-localizes with the Golgi apparatus and is required for Golgi deployment into major dendrites in cultured hippocampal neurons. Simultaneous overexpression of BIG2 and ARF1 activated RhoA, and treatment with the RhoA activator lysophosphatidic acid in neurons lacking BIG2 or ARF1 increased the number of cells with dendritic Golgi, suggesting that BIG2 and ARF1 activate RhoA to promote dendritic Golgi polarization. mDia1 was identified as a downstream effector of BIG2-ARF1-RhoA axis, mediating Golgi polarization and dendritic morphogenesis. Furthermore, in utero electroporation of ARFGEF2 shRNA into the embryonic mouse brain confirmed an in vivo role of BIG2 for Golgi deployment into the apical dendrite. Taken together, our results suggest that BIG2-ARF1-RhoA-mDia1 signaling regulates dendritic Golgi polarization and dendrite growth and maintenance in hippocampal neurons.
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19
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Saxena M, Agnihotri N, Sen J. Perturbation of canonical and non-canonical BMP signaling affects migration, polarity and dendritogenesis of mouse cortical neurons. Development 2018; 145:dev.147157. [PMID: 29180570 DOI: 10.1242/dev.147157] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 11/16/2017] [Indexed: 01/07/2023]
Abstract
Bone morphogenetic protein (BMP) signaling has been implicated in the regulation of patterning of the forebrain and as a regulator of neurogenesis and gliogenesis in the mammalian cortex. However, its role in other aspects of cortical development in vivo remains unexplored. We hypothesized that BMP signaling might regulate additional processes during the development of cortical neurons after observing active BMP signaling in a spatiotemporally dynamic pattern in the mouse cortex. Our investigation revealed that BMP signaling specifically regulates the migration, polarity and the dendritic morphology of upper layer cortical neurons born at E15.5. On further dissection of the role of canonical and non-canonical BMP signaling in each of these processes, we found that migration of these neurons is regulated by both pathways. Their polarity, however, appears to be affected more strongly by canonical BMP signaling, whereas dendritic branch formation appears to be somewhat more strongly affected by LIMK-mediated non-canonical BMP signaling.
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Affiliation(s)
- Monika Saxena
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India
| | - Nitin Agnihotri
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India
| | - Jonaki Sen
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India
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20
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The functions of Reelin in membrane trafficking and cytoskeletal dynamics: implications for neuronal migration, polarization and differentiation. Biochem J 2017; 474:3137-3165. [PMID: 28887403 DOI: 10.1042/bcj20160628] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/27/2017] [Accepted: 08/01/2017] [Indexed: 02/06/2023]
Abstract
Reelin is a large extracellular matrix protein with relevant roles in mammalian central nervous system including neurogenesis, neuronal polarization and migration during development; and synaptic plasticity with its implications in learning and memory, in the adult. Dysfunctions in reelin signaling are associated with brain lamination defects such as lissencephaly, but also with neuropsychiatric diseases like autism, schizophrenia and depression as well with neurodegeneration. Reelin signaling involves a core pathway that activates upon reelin binding to its receptors, particularly ApoER2 (apolipoprotein E receptor 2)/LRP8 (low-density lipoprotein receptor-related protein 8) and very low-density lipoprotein receptor, followed by Src/Fyn-mediated phosphorylation of the adaptor protein Dab1 (Disabled-1). Phosphorylated Dab1 (pDab1) is a hub in the signaling cascade, from which several other downstream pathways diverge reflecting the different roles of reelin. Many of these pathways affect the dynamics of the actin and microtubular cytoskeleton, as well as membrane trafficking through the regulation of the activity of small GTPases, including the Rho and Rap families and molecules involved in cell polarity. The complexity of reelin functions is reflected by the fact that, even now, the precise mode of action of this signaling cascade in vivo at the cellular and molecular levels remains unclear. This review addresses and discusses in detail the participation of reelin in the processes underlying neurogenesis, neuronal migration in the cerebral cortex and the hippocampus; and the polarization, differentiation and maturation processes that neurons experiment in order to be functional in the adult brain. In vivo and in vitro evidence is presented in order to facilitate a better understanding of this fascinating system.
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21
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Konietzny A, Bär J, Mikhaylova M. Dendritic Actin Cytoskeleton: Structure, Functions, and Regulations. Front Cell Neurosci 2017; 11:147. [PMID: 28572759 PMCID: PMC5435805 DOI: 10.3389/fncel.2017.00147] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/05/2017] [Indexed: 12/28/2022] Open
Abstract
Actin is a versatile and ubiquitous cytoskeletal protein that plays a major role in both the establishment and the maintenance of neuronal polarity. For a long time, the most prominent roles that were attributed to actin in neurons were the movement of growth cones, polarized cargo sorting at the axon initial segment, and the dynamic plasticity of dendritic spines, since those compartments contain large accumulations of actin filaments (F-actin) that can be readily visualized using electron- and fluorescence microscopy. With the development of super-resolution microscopy in the past few years, previously unknown structures of the actin cytoskeleton have been uncovered: a periodic lattice consisting of actin and spectrin seems to pervade not only the whole axon, but also dendrites and even the necks of dendritic spines. Apart from that striking feature, patches of F-actin and deep actin filament bundles have been described along the lengths of neurites. So far, research has been focused on the specific roles of actin in the axon, while it is becoming more and more apparent that in the dendrite, actin is not only confined to dendritic spines, but serves many additional and important functions. In this review, we focus on recent developments regarding the role of actin in dendrite morphology, the regulation of actin dynamics by internal and external factors, and the role of F-actin in dendritic protein trafficking.
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Affiliation(s)
- Anja Konietzny
- DFG Emmy Noether Group 'Neuronal Protein Transport,' Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-EppendorfHamburg, Germany
| | - Julia Bär
- DFG Emmy Noether Group 'Neuronal Protein Transport,' Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-EppendorfHamburg, Germany
| | - Marina Mikhaylova
- DFG Emmy Noether Group 'Neuronal Protein Transport,' Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-EppendorfHamburg, Germany
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22
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Ampuero E, Jury N, Härtel S, Marzolo MP, van Zundert B. Interfering of the Reelin/ApoER2/PSD95 Signaling Axis Reactivates Dendritogenesis of Mature Hippocampal Neurons. J Cell Physiol 2016; 232:1187-1199. [PMID: 27653801 DOI: 10.1002/jcp.25605] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 09/12/2016] [Indexed: 12/21/2022]
Abstract
Reelin, an extracellular glycoprotein secreted in embryonic and adult brain, participates in neuronal migration and neuronal plasticity. Extensive evidence shows that reelin via activation of the ApoER2 and VLDLR receptors promotes dendrite and spine formation during early development. Further evidence suggests that reelin signaling is needed to maintain a stable architecture in mature neurons, but, direct evidence is lacking. During activity-dependent maturation of the neuronal circuitry, the synaptic protein PSD95 is inserted into the postsynaptic membrane to induce structural refinement and stability of spines and dendrites. Given that ApoER2 interacts with PSD95, we tested if reelin signaling interference in adult neurons reactivates the dendritic architecture. Unlike findings in developing cultures, the presently obtained in vitro and in vivo data show, for the first time, that reelin signaling interference robustly increase dendritogenesis and reduce spine density in mature hippocampal neurons. In particular, the expression of a mutant ApoER2 form (ApoER2-tailless), which is unable to interact with PSD95 and hence cannot transduce reelin signaling, resulted in robust dendritogenesis in mature hippocampal neurons in vitro. These results indicate that reelin/ApoER2/PSD95 signaling is important for neuronal structure maintenance in mature neurons. Mechanistically, obtained immunofluorescent data indicate that reelin signaling impairment reduced synaptic PSD95 levels, consequently leading to synaptic re-insertion of NR2B-NMDARs. Our findings underscore the importance of reelin in maintaining adult network stability and reveal a new mode for reactivating dendritogenesis in neurological disorders where dendritic arbor complexity is limited, such as in depression, Alzheimer's disease, and stroke. J. Cell. Physiol. 232: 1187-1199, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Estibaliz Ampuero
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
| | - Nur Jury
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
| | - Steffen Härtel
- SCIAN-Lab, CIMT, Bomedical Neuroscience Institute (BNI), ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica, Santiago, Chile
| | - Brigitte van Zundert
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
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23
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Bock HH, May P. Canonical and Non-canonical Reelin Signaling. Front Cell Neurosci 2016; 10:166. [PMID: 27445693 PMCID: PMC4928174 DOI: 10.3389/fncel.2016.00166] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/08/2016] [Indexed: 12/11/2022] Open
Abstract
Reelin is a large secreted glycoprotein that is essential for correct neuronal positioning during neurodevelopment and is important for synaptic plasticity in the mature brain. Moreover, Reelin is expressed in many extraneuronal tissues; yet the roles of peripheral Reelin are largely unknown. In the brain, many of Reelin's functions are mediated by a molecular signaling cascade that involves two lipoprotein receptors, apolipoprotein E receptor-2 (Apoer2) and very low density-lipoprotein receptor (Vldlr), the neuronal phosphoprotein Disabled-1 (Dab1), and members of the Src family of protein tyrosine kinases as crucial elements. This core signaling pathway in turn modulates the activity of adaptor proteins and downstream protein kinase cascades, many of which target the neuronal cytoskeleton. However, additional Reelin-binding receptors have been postulated or described, either as coreceptors that are essential for the activation of the "canonical" Reelin signaling cascade involving Apoer2/Vldlr and Dab1, or as receptors that activate alternative or additional signaling pathways. Here we will give an overview of canonical and alternative Reelin signaling pathways, molecular mechanisms involved, and their potential physiological roles in the context of different biological settings.
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Affiliation(s)
- Hans H Bock
- Clinic of Gastroenterology and Hepatology, Heinrich-Heine-University Düsseldorf Düsseldorf, Germany
| | - Petra May
- Clinic of Gastroenterology and Hepatology, Heinrich-Heine-University Düsseldorf Düsseldorf, Germany
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24
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Lee GH, D'Arcangelo G. New Insights into Reelin-Mediated Signaling Pathways. Front Cell Neurosci 2016; 10:122. [PMID: 27242434 PMCID: PMC4860420 DOI: 10.3389/fncel.2016.00122] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 04/27/2016] [Indexed: 11/21/2022] Open
Abstract
Reelin, a multifunctional extracellular protein that is important for mammalian brain development and function, is secreted by different cell types in the prenatal or postnatal brain. The spatiotemporal regulation of Reelin expression and distribution during development relates to its multifaceted function in the brain. Prenatally Reelin controls neuronal radial migration and proper positioning in cortical layers, whereas postnatally Reelin promotes neuronal maturation, synaptic formation and plasticity. The molecular mechanisms underlying the distinct biological functions of Reelin during and after brain development involve unique and overlapping signaling pathways that are activated following Reelin binding to its cell surface receptors. Distinct Reelin ligand isoforms, such as the full-length protein or fragments generated by proteolytic cleavage differentially affect the activity of downstream signaling pathways. In this review, we discuss recent advances in our understanding of the signaling transduction pathways activated by Reelin that regulate different aspects of brain development and function. A core signaling machinery, including ApoER2/VLDLR receptors, Src/Fyn kinases, and the adaptor protein Dab1, participates in all known aspects of Reelin biology. However, distinct downstream mechanisms, such as the Crk/Rap1 pathway and cell adhesion molecules, play crucial roles in the control of neuronal migration, whereas the PI3K/Akt/mTOR pathway appears to be more important for dendrite and spine development. Finally, the NMDA receptor (NMDAR) and an unidentified receptor contribute to the activation of the MEK/Erk1/2 pathway leading to the upregulation of genes involved in synaptic plasticity and learning. This knowledge may provide new insight into neurodevelopmental or neurodegenerative disorders that are associated with Reelin dysfunction.
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Affiliation(s)
- Gum Hwa Lee
- College of Pharmacy, Chosun University Gwangju, South Korea
| | - Gabriella D'Arcangelo
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey Piscataway, NJ, USA
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25
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Chang C, Niu Z, Gu N, Zhao W, Wang G, Jia Y, Li D, Xu C. Analysis of the ways and methods of signaling pathways in regulating cell cycle of NIH3T3 at transcriptional level. BMC Cell Biol 2015; 16:25. [PMID: 26511608 PMCID: PMC4625951 DOI: 10.1186/s12860-015-0071-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 10/19/2015] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND To analyze the ways and methods of signaling pathways in regulating cell cycle progression of NIH3T3 at transcriptional level, we modeled cell cycle of NIH3T3 and found that G1 phase of NIH3T3 cell cycle was at 5-15 h after synchronization, S phase at 15-21 h, G2 phase at 21-22 h, M phase at 22-25 h. RESULTS Mouse Genome 430 2.0 microarray was used to detect the gene expression profiles of the model, and results showed remarkable changes in the expressions of 64 cell cycle genes and 960 genes associated with other physiological activity during the cell cycle of NIH3T3. For the next step, IPA software was used to analyze the physiological activities, cell cycle genes-associated signal transduction activities and their regulatory roles of these genes in cell cycle progression, and our results indicated that the reported genes were involved in 17 signaling pathways in the regulation of cell cycle progression. Newfound genes such as PKC, RAS, PP2A, NGR and PI3K etc. belong to the functional category of molecular mechanism of cancer, cyclins and cell cycle regulation HER-2 signaling in breast cancer signaling pathways. These newfound genes could promote DNA damage repairment and DNA replication progress, regulate the metabolism of protein, and maintain the cell cycle progression of NIH3T3 modulating the reported genes CCND1 and C-FOS. CONCLUSION All of the aforementioned signaling pathways interacted with the cell cycle network, indicating that NIH3T3 cell cycle was regulated by a number of signaling pathways.
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Affiliation(s)
- Cuifang Chang
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Zhipeng Niu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Ningning Gu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Weiming Zhao
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Gaiping Wang
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Yifeng Jia
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Deming Li
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Cunshuan Xu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
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Valenzuela JI, Perez F. Diversifying the secretory routes in neurons. Front Neurosci 2015; 9:358. [PMID: 26500481 PMCID: PMC4595659 DOI: 10.3389/fnins.2015.00358] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/18/2015] [Indexed: 12/23/2022] Open
Abstract
Nervous system homeostasis and synaptic function need dedicated mechanisms to locally regulate the molecular composition of the neuronal plasma membrane and allow the development, maintenance and plastic modification of the neuronal morphology. The cytoskeleton and intracellular trafficking lies at the core of all these processes. In most mammalian cells, the Golgi apparatus (GA) is at the center of the biosynthetic pathway, located in the proximity of the microtubule-organizing center. In addition to this central localization, the somatic GA in neurons is complemented by satellite Golgi outposts (GOPs) in dendrites, which are essential for dendritic morphogenesis and are emerging like local stations of membranes trafficking to synapses. Largely, GOPs participation in post-ER trafficking has been determined by imaging the transport of the exogenous protein VSVG. Here we review the diversity of neuronal cargoes that traffic through GOPs and the assortment of different biosynthetic routes to synapses. We also analyze the recent advances in understanding the role of cytoskeleton and Golgi matrix proteins in the biogenesis of GOPs and how the diversity of secretory routes can be generated.
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Affiliation(s)
- José I Valenzuela
- Cell Biology Department, Institut Curie, PSL Research University, UMR144 Paris, France ; Dynamics of Intracellular Organisation, Centre National de la Recherche Scientifique -UMR144 Paris, France
| | - Franck Perez
- Cell Biology Department, Institut Curie, PSL Research University, UMR144 Paris, France ; Dynamics of Intracellular Organisation, Centre National de la Recherche Scientifique -UMR144 Paris, France
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Pasten C, Cerda J, Jausoro I, Court FA, Cáceres A, Marzolo MP. ApoER2 and Reelin are expressed in regenerating peripheral nerve and regulate Schwann cell migration by activating the Rac1 GEF protein, Tiam1. Mol Cell Neurosci 2015; 69:1-11. [PMID: 26386179 DOI: 10.1016/j.mcn.2015.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/07/2015] [Indexed: 11/17/2022] Open
Abstract
ApoER2 and its ligand Reelin participate in neuronal migration during development. Upon receptor binding, Reelin induces the proteolytic processing of ApoER2 as well as the activation of signaling pathway, including small Rho GTPases. Besides its presence in the central nervous system (CNS), Reelin is also secreted by Schwann cells (SCs), the glial cells of the peripheral nervous system (PNS). Reelin deficient mice (reeler) show decreased axonal regeneration in the PNS; however neither the presence of ApoER2 nor the role of the Reelin signaling pathway in the PNS have been evaluated. Interestingly SC migration occurs during PNS development and during injury-induced regeneration and involves activation of small Rho GTPases. Thus, Reelin-ApoER2 might regulate SC migration during axon regeneration in the PNS. Here we demonstrate the presence of ApoER2 in PNS. After sciatic nerve injury Reelin was induced and its receptor ApoER2 was proteolytically processed. In vitro, SCs express both Reelin and ApoER2 and Reelin induces SC migration. To elucidate the molecular mechanism underlying Reelin-dependent SC migration, we examined the involvement of Rac1, a conspicuous small GTPase family member. FRET experiments revealed that Reelin activates Rac1 at the leading edge of SCs. In addition, Tiam1, a major Rac1-specific GEF was required for Reelin-induced SC migration. Moreover, Reelin-induced SC migration was decreased after suppression of the polarity protein PAR3, consistent with its association to Tiam1. Even more interesting, we demonstrated that PAR3 binds preferentially to the full-length cytoplasmic tail of ApoER2 corresponding to the splice-variant containing the exon 19 that encodes a proline-rich insert and that ApoER2 was required for SC migration. Our study reveals a novel function for Reelin/ApoER2 in PNS, inducing cell migration of SCs, a process relevant for PNS development and regeneration.
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Affiliation(s)
- Consuelo Pasten
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Nucleus for Regenerative Biology, Santiago, Chile
| | - Joaquín Cerda
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Nucleus for Regenerative Biology, Santiago, Chile
| | - Ignacio Jausoro
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Nucleus for Regenerative Biology, Santiago, Chile
| | - Felipe A Court
- Millennium Nucleus for Regenerative Biology, Santiago, Chile; Departmento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alfredo Cáceres
- Laboratory of Neurobiology, Instituto Mercedes y Martin Ferreyra (INIMEC) CONICET, Córdoba, Argentina
| | - Maria-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Nucleus for Regenerative Biology, Santiago, Chile.
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Barkovich AJ, Dobyns WB, Guerrini R. Malformations of cortical development and epilepsy. Cold Spring Harb Perspect Med 2015; 5:a022392. [PMID: 25934463 DOI: 10.1101/cshperspect.a022392] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Malformations of cortical development (MCDs) are an important cause of epilepsy and an extremely interesting group of disorders from the perspective of brain development and its perturbations. Many new MCDs have been described in recent years as a result of improvements in imaging, genetic testing, and understanding of the effects of mutations on the ability of their protein products to correctly function within the molecular pathways by which the brain functions. In this review, most of the major MCDs are reviewed from a clinical, embryological, and genetic perspective. The most recent literature regarding clinical diagnosis, mechanisms of development, and future paths of research are discussed.
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Affiliation(s)
- A James Barkovich
- Department of Radiology and Biomedical Imaging, Neurology, Pediatrics, and Neurosurgery, University of California, San Francisco, San Francisco, California 94143-0628
| | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington 98101
| | - Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer, University of Florence, Florence 50139, Italy
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29
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Regulating Rac in the nervous system: molecular function and disease implication of Rac GEFs and GAPs. BIOMED RESEARCH INTERNATIONAL 2015; 2015:632450. [PMID: 25879033 PMCID: PMC4388020 DOI: 10.1155/2015/632450] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/06/2015] [Indexed: 12/11/2022]
Abstract
Rho family GTPases, including RhoA, Rac1, and Cdc42 as the most studied members, are master regulators of actin cytoskeletal organization. Rho GTPases control various aspects of the nervous system and are associated with a number of neuropsychiatric and neurodegenerative diseases. The activity of Rho GTPases is controlled by two families of regulators, guanine nucleotide exchange factors (GEFs) as the activators and GTPase-activating proteins (GAPs) as the inhibitors. Through coordinated regulation by GEFs and GAPs, Rho GTPases act as converging signaling molecules that convey different upstream signals in the nervous system. So far, more than 70 members of either GEFs or GAPs of Rho GTPases have been identified in mammals, but only a small subset of them have well-known functions. Thus, characterization of important GEFs and GAPs in the nervous system is crucial for the understanding of spatiotemporal dynamics of Rho GTPase activity in different neuronal functions. In this review, we summarize the current understanding of GEFs and GAPs for Rac1, with emphasis on the molecular function and disease implication of these regulators in the nervous system.
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Quassollo G, Wojnacki J, Salas DA, Gastaldi L, Marzolo MP, Conde C, Bisbal M, Couve A, Cáceres A. A RhoA Signaling Pathway Regulates Dendritic Golgi Outpost Formation. Curr Biol 2015; 25:971-82. [PMID: 25802147 DOI: 10.1016/j.cub.2015.01.075] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 12/02/2014] [Accepted: 01/30/2015] [Indexed: 12/30/2022]
Abstract
The neuronal Golgi apparatus (GA) localizes to the perinuclear region and dendrites as tubulo-vesicular structures designated Golgi outposts (GOPs). Current evidence suggests that GOPs shape dendrite morphology and serve as platforms for the local delivery of synaptic receptors. However, the mechanisms underlying GOP formation remain a mystery. Using live-cell imaging and confocal microscopy in cultured hippocampal neurons, we now show that GOPs destined to major "apical" dendrites are generated from the somatic GA by a sequence of events involving: (1) generation of a GA-derived tubule; (2) tubule elongation and deployment into the dendrite; (3) tubule fission; and (4) transport and condensation of the fissioned tubule. A RhoA-Rock signaling pathway involving LIMK1, PKD1, slingshot, cofilin, and dynamin regulates polarized GOP formation by controlling the tubule fission. Our observations identify a mechanism underlying polarized GOP biogenesis and provide new insights regarding involvement of RhoA in dendritic development and polarization.
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Affiliation(s)
- Gonzalo Quassollo
- Laboratorio Neurobiología, INIMEC-CONICET, Av. Friuli 2434, 5016 Córdoba, Argentina; Universidad Nacional de Córdoba, Av. Haya de la Torre s/n, 5000 Córdoba, Argentina
| | - Jose Wojnacki
- Laboratorio Neurobiología, INIMEC-CONICET, Av. Friuli 2434, 5016 Córdoba, Argentina; Universidad Nacional de Córdoba, Av. Haya de la Torre s/n, 5000 Córdoba, Argentina
| | - Daniela A Salas
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Biomedical Neuroscience Institute, Facultad de Medicina, Universidad de Chile, Independencia 1027, 8380453 Santiago, Chile
| | - Laura Gastaldi
- Laboratorio Neurobiología, INIMEC-CONICET, Av. Friuli 2434, 5016 Córdoba, Argentina; Universidad Nacional de Córdoba, Av. Haya de la Torre s/n, 5000 Córdoba, Argentina
| | - María Paz Marzolo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo OHiggins 340, 8331010 Santiago, Chile
| | - Cecilia Conde
- Laboratorio Neurobiología, INIMEC-CONICET, Av. Friuli 2434, 5016 Córdoba, Argentina; Universidad Nacional de Córdoba, Av. Haya de la Torre s/n, 5000 Córdoba, Argentina; Instituto Universitario Ciencias Biomédicas Córdoba, Av. Friuli 2786, 5016 Córdoba, Argentina
| | - Mariano Bisbal
- Laboratorio Neurobiología, INIMEC-CONICET, Av. Friuli 2434, 5016 Córdoba, Argentina; Universidad Nacional de Córdoba, Av. Haya de la Torre s/n, 5000 Córdoba, Argentina; Instituto Universitario Ciencias Biomédicas Córdoba, Av. Friuli 2786, 5016 Córdoba, Argentina
| | - Andrés Couve
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Biomedical Neuroscience Institute, Facultad de Medicina, Universidad de Chile, Independencia 1027, 8380453 Santiago, Chile
| | - Alfredo Cáceres
- Laboratorio Neurobiología, INIMEC-CONICET, Av. Friuli 2434, 5016 Córdoba, Argentina; Universidad Nacional de Córdoba, Av. Haya de la Torre s/n, 5000 Córdoba, Argentina; Instituto Universitario Ciencias Biomédicas Córdoba, Av. Friuli 2786, 5016 Córdoba, Argentina.
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31
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Wu YK, Fujishima K, Kengaku M. Differentiation of apical and basal dendrites in pyramidal cells and granule cells in dissociated hippocampal cultures. PLoS One 2015; 10:e0118482. [PMID: 25705877 PMCID: PMC4338060 DOI: 10.1371/journal.pone.0118482] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/18/2015] [Indexed: 11/21/2022] Open
Abstract
Hippocampal pyramidal cells and dentate granule cells develop morphologically distinct dendritic arbors, yet also share some common features. Both cell types form a long apical dendrite which extends from the apex of the cell soma, while short basal dendrites are developed only in pyramidal cells. Using quantitative morphometric analyses of mouse hippocampal cultures, we evaluated the differences in dendritic arborization patterns between pyramidal and granule cells. Furthermore, we observed and described the final apical dendrite determination during dendritic polarization by time-lapse imaging. Pyramidal and granule cells in culture exhibited similar dendritic patterns with a single principal dendrite and several minor dendrites so that the cell types were not readily distinguished by appearance. While basal dendrites in granule cells are normally degraded by adulthood in vivo, cultured granule cells retained their minor dendrites. Asymmetric growth of a single principal dendrite harboring the Golgi was observed in both cell types soon after the onset of dendritic growth. Time-lapse imaging revealed that up until the second week in culture, final principal dendrite designation was not stabilized, but was frequently replaced by other minor dendrites. Before dendritic polarity was stabilized, the Golgi moved dynamically within the soma and was repeatedly repositioned at newly emerging principal dendrites. Our results suggest that polarized growth of the apical dendrite is regulated by cell intrinsic programs, while regression of basal dendrites requires cue(s) from the extracellular environment in the dentate gyrus. The apical dendrite designation is determined from among multiple growing dendrites of young developing neurons.
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Affiliation(s)
- You Kure Wu
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kazuto Fujishima
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto, Japan
| | - Mineko Kengaku
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto, Japan
- * E-mail:
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32
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Seong MW, Park JH, Yoo HM, Yang SW, Oh KH, Ka SH, Park DE, Lee ST, Chung CH. c-Cbl regulates αPix-mediated cell migration and invasion. Biochem Biophys Res Commun 2014; 455:153-8. [PMID: 25450678 DOI: 10.1016/j.bbrc.2014.10.129] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 10/27/2014] [Indexed: 12/23/2022]
Abstract
c-Cbl, a RING-type ubiquitin E3 ligase, down-regulates receptor tyrosine kinases, including EGF receptor, and inhibits cell proliferation. Moreover, c-Cbl mutations are frequently found in patients with myeloid neoplasm. Therefore, c-Cbl is known as a tumor suppressor. αPix is expressed only in highly proliferative and mobile cells, including immune cells, and up-regulated in certain invasive tumors, such as glioblastoma multiforme. Here, we showed that c-Cbl serves as an ubiquitin E3 ligase for proteasome-mediated degradation of αPix, but not βPix. Remarkably, the rat C6 and human A172 glioma cells were unable to express c-Cbl, which leads to a dramatic accumulation of αPix. Depletion of αPix by shRNA markedly reduced the ability of the glioma cells to migrate and invade, whereas complementation of shRNA-insensitive αPix promoted it. These results indicate that c-Cbl negatively regulates αPix-mediated cell migration and invasion and the lack of c-Cbl in the C6 and A172 glioma cells is responsible for their malignant behavior.
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Affiliation(s)
- Min Woo Seong
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea
| | - Ji Ho Park
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea
| | - Hee Min Yoo
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea
| | - Seung Wook Yang
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea
| | - Kyu Hee Oh
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea
| | - Seung Hyeun Ka
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea
| | - Dong Eun Park
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea
| | - Soon-Tae Lee
- Department of Neurology, Seoul National University Hospital, Seoul 110-744, Republic of Korea
| | - Chin Ha Chung
- School of Biological Sciences and Institute for Protein Metabolism, Seoul National University, Seoul 151-742, Republic of Korea.
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Abstract
Among the largest cells in the body, neurons possess an immense surface area and intricate geometry that poses many unique cell biological challenges. This morphological complexity is critical for neural circuit formation and enables neurons to compartmentalize cell-cell communication and local intracellular signalling to a degree that surpasses other cell types. The adaptive plastic properties of neurons, synapses and circuits have been classically studied by measurement of electrophysiological properties, ionic conductances and excitability. Over the last 15 years, the field of synaptic and neural electrophysiology has collided with neuronal cell biology to produce a more integrated understanding of how these remarkable highly differentiated cells utilize common eukaryotic cellular machinery to decode, integrate and propagate signals in the nervous system. The present article gives a very brief and personal overview of the organelles and trafficking machinery of neuronal dendrites and their role in dendritic and synaptic plasticity.
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34
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Radial Glia, the Keystone of the Development of the Hippocampal Dentate Gyrus. Mol Neurobiol 2014; 51:131-41. [DOI: 10.1007/s12035-014-8692-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 03/24/2014] [Indexed: 01/20/2023]
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35
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Förster E. Reelin, neuronal polarity and process orientation of cortical neurons. Neuroscience 2014; 269:102-11. [PMID: 24657457 DOI: 10.1016/j.neuroscience.2014.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/01/2014] [Accepted: 03/04/2014] [Indexed: 12/22/2022]
Abstract
Deficient reelin signaling leads to characteristic layering malformations in the cerebral cortex and causes polarity defects of cortical neurons. Since the discovery of reelin much has been learned about the molecular mechanisms that underlie the characteristic defects of layering defects in the reeler mutant. More recent studies provided insights in the crosstalk between reelin signaling and molecular pathways that control polarity development of radially migrating neurons. The present review summarizes and discusses recent findings on the role of reelin in modulating polarization and process orientation of neurons in the neocortex and hippocampus.
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Affiliation(s)
- E Förster
- Institute of Neuroanatomy, University Medical Center Hamburg Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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36
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Reelin in the Years: Controlling Neuronal Migration and Maturation in the Mammalian Brain. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/597395] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The extracellular protein Reelin was initially identified as an essential factor in the control of neuronal migration and layer formation in the developing mammalian brain. In the years following its discovery, however, it became clear that Reelin is a multifunctional protein that controls not only the positioning of neurons in the developing brain, but also their growth, maturation, and synaptic activity in the adult brain. In this review, we will highlight the major discoveries of the biological activities of Reelin and the underlying molecular mechanisms that affect the development and function of the mammalian brain, from embryonic ages to adulthood.
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Notter T, Knuesel I. Reelin immunoreactivity in neuritic varicosities in the human hippocampal formation of non-demented subjects and Alzheimer's disease patients. Acta Neuropathol Commun 2013; 1:27. [PMID: 24252415 PMCID: PMC3893416 DOI: 10.1186/2051-5960-1-27] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/10/2013] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Reelin and its downstream signaling members are important modulators of actin and microtubule cytoskeleton dynamics, a fundamental prerequisite for proper neurodevelopment and adult neuronal functions. Reductions in Reelin levels have been suggested to contribute to Alzheimer's disease (AD) pathophysiology. We have previously reported an age-related reduction in Reelin levels and its accumulation in neuritic varicosities along the olfactory-limbic tracts, which correlated with cognitive impairments in aged mice. Here, we aimed to investigate whether a similar Reelin-associated neuropathology is observed in the aged human hippocampus and whether it correlated with dementia status. RESULTS Our immunohistochemical stainings revealed the presence of N- and C-terminus-containing Reelin fragments in corpora amylacea (CAm), aging-associated spherical deposits. The density of these deposits was increased in the molecular layer of the subiculum of AD compared to non-demented individuals. Despite the limitation of a small sample size, our evaluation of several neuronal and glial markers indicates that the presence of Reelin in CAm might be related to aging-associated impairments in neuronal transport leading to accumulation of organelles and protein metabolites in neuritic varicosities, as previously suggested by the findings and discussions in rodents and primates. CONCLUSIONS Our results indicate that aging- and disease-associated changes in Reelin levels and proteolytic processing might play a role in the formation of CAm by altering cytoskeletal dynamics. However, its presence may also be an indicator of a degenerative state of neuritic compartments.
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