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Biojone C, Cannarozzo C, Seiffert N, Diniz CRAF, Brunello CA, Castrén E, Casarotto P. Mutation in the TRKB Cholesterol Recognition Site that blocks Antidepressant Binding does not Influence the Basal or BDNF-Stimulated Activation of TRKB. Cell Mol Neurobiol 2023; 44:4. [PMID: 38104054 PMCID: PMC10725331 DOI: 10.1007/s10571-023-01438-1] [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: 11/01/2023] [Accepted: 11/04/2023] [Indexed: 12/19/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) acting upon its receptor Neurotrophic tyrosine kinase receptor 2 (NTRK2, TRKB) plays a central role in the development and maintenance of synaptic function and activity- or drug-induced plasticity. TRKB possesses an inverted cholesterol recognition and alignment consensus sequence (CARC), suggesting this receptor can act as a cholesterol sensor. We have recently shown that antidepressant drugs directly bind to the CARC domain of TRKB dimers, and that this binding as well as biochemical and behavioral responses to antidepressants are lost with a mutation in the TRKB CARC motif (Tyr433Phe). However, it is not clear if this mutation can also compromise the receptor function and lead to behavioral alterations. Here, we observed that Tyr433Phe mutation does not alter BDNF binding to TRKB, or BDNF-induced dimerization of TRKB. In this line, primary cultures from embryos of heterozygous Tyr433Phe mutant mice (hTRKB.Tyr433Phe) are responsive to BDNF-induced activation of TRKB, and samples from adult mice do not show any difference on TRKB activation compared to wild-type littermates (TRKB.wt). The behavioral phenotype of hTRKB.Tyr433Phe mice is indistinguishable from the wild-type mice in cued fear conditioning, contextual discrimination task, or the elevated plus maze, whereas mice heterozygous to BDNF null allele show a phenotype in context discrimination task. Taken together, our results indicate that Tyr433Phe mutation in the TRKB CARC motif does not show signs of loss-of-function of BDNF responses, while antidepressant binding to TRKB and responses to antidepressants are lost in Tyr433Phe mutants, making them an interesting mouse model for antidepressant research.
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Affiliation(s)
- Caroline Biojone
- Neuroscience Center - HiLife, University of Helsinki, P. O. Box 63, 00014, Helsinki, Finland
- Department of Biomedicine, Faculty of Health, Aarhus University, Aarhus, Denmark
- Translational Neuropsychiatry Unit (TNU), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Cecilia Cannarozzo
- Neuroscience Center - HiLife, University of Helsinki, P. O. Box 63, 00014, Helsinki, Finland
| | - Nina Seiffert
- Neuroscience Center - HiLife, University of Helsinki, P. O. Box 63, 00014, Helsinki, Finland
| | - Cassiano R A F Diniz
- Neuroscience Center - HiLife, University of Helsinki, P. O. Box 63, 00014, Helsinki, Finland
- Center for Neuroscience, University of California, Davis, CA, USA
| | - Cecilia A Brunello
- Neuroscience Center - HiLife, University of Helsinki, P. O. Box 63, 00014, Helsinki, Finland
| | - Eero Castrén
- Neuroscience Center - HiLife, University of Helsinki, P. O. Box 63, 00014, Helsinki, Finland
| | - Plinio Casarotto
- Neuroscience Center - HiLife, University of Helsinki, P. O. Box 63, 00014, Helsinki, Finland.
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2
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Dong X, Shu L, Zhang J, Yang X, Cheng X, Zhao X, Qu W, Zhu Q, Shou Y, Peng G, Sun B, Yi W, Shu Q, Li X. Ogt-mediated O-GlcNAcylation inhibits astrocytes activation through modulating NF-κB signaling pathway. J Neuroinflammation 2023; 20:146. [PMID: 37349834 DOI: 10.1186/s12974-023-02824-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 06/05/2023] [Indexed: 06/24/2023] Open
Abstract
Previous studies have shown that Ogt-mediated O-GlcNAcylation is essential for neuronal development and function. However, the function of O-GlcNAc transferase (Ogt) and O-GlcNAcylation in astrocytes remains largely unknown. Here we show that Ogt deficiency induces inflammatory activation of astrocytes in vivo and in vitro, and impairs cognitive function of mice. The restoration of O-GlcNAcylation via GlcNAc supplementation inhibits the activation of astrocytes, inflammation and improves the impaired cognitive function of Ogt deficient mice. Mechanistically, Ogt interacts with NF-κB p65 and catalyzes the O-GlcNAcylation of NF-κB p65 in astrocytes. Ogt deficiency induces the activation of NF-κB signaling pathway by promoting Gsk3β binding. Moreover, Ogt depletion induces the activation of astrocytes derived from human induced pluripotent stem cells. The restoration of O-GlcNAcylation inhibits the activation of astrocytes, inflammation and reduces Aβ plaque of AD mice in vitro and in vivo. Collectively, our study reveals a critical function of Ogt-mediated O-GlcNAcylation in astrocytes through regulating NF-κB signaling pathway.
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Affiliation(s)
- Xiaoxue Dong
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China
| | - Liqi Shu
- Department of Neurology, The Warren Alpert Medical School of Brown University, Providence, RI, 02908, USA
| | - Jinyu Zhang
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China
| | - Xu Yang
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China
| | - Xuejun Cheng
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China
| | - Xingsen Zhao
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China
| | - Wenzheng Qu
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China
| | - Qiang Zhu
- MOE Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yikai Shou
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China
| | - Guoping Peng
- The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Binggui Sun
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, Zhejiang, China.
| | - Wen Yi
- MOE Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
| | - Qiang Shu
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China.
| | - Xuekun Li
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou, 310052, China.
- The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou, 310029, China.
- Zhejiang University Cancer Center, Zhejiang University, Hangzhou, 310029, China.
- Binjiang Institute of Zhejiang University, Hangzhou, 310053, China.
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3
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Bhattacharjee S, Iyer EPR, Iyer SC, Nanda S, Rubaharan M, Ascoli GA, Cox DN. The Zinc-BED Transcription Factor Bedwarfed Promotes Proportional Dendritic Growth and Branching through Transcriptional and Translational Regulation in Drosophila. Int J Mol Sci 2023; 24:6344. [PMID: 37047316 PMCID: PMC10094446 DOI: 10.3390/ijms24076344] [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: 02/21/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023] Open
Abstract
Dendrites are the primary points of sensory or synaptic input to a neuron and play an essential role in synaptic integration and neural function. Despite the functional importance of dendrites, relatively less is known about the underlying mechanisms regulating cell type-specific dendritic patterning. Herein, we have dissected the functional roles of a previously uncharacterized gene, CG3995, in cell type-specific dendritic development in Drosophila melanogaster. CG3995, which we have named bedwarfed (bdwf), encodes a zinc-finger BED-type protein that is required for proportional growth and branching of dendritic arbors. It also exhibits nucleocytoplasmic expression and functions in both transcriptional and translational cellular pathways. At the transcriptional level, we demonstrate a reciprocal regulatory relationship between Bdwf and the homeodomain transcription factor (TF) Cut. We show that Cut positively regulates Bdwf expression and that Bdwf acts as a downstream effector of Cut-mediated dendritic development, whereas overexpression of Bdwf negatively regulates Cut expression in multidendritic sensory neurons. Proteomic analyses revealed that Bdwf interacts with ribosomal proteins and disruption of these proteins resulted in phenotypically similar dendritic hypotrophy defects as observed in bdwf mutant neurons. We further demonstrate that Bdwf and its ribosomal protein interactors are required for normal microtubule and F-actin cytoskeletal architecture. Finally, our findings reveal that Bdwf is required to promote protein translation and ribosome trafficking along the dendritic arbor. These findings shed light on the complex, combinatorial, and multi-functional roles of transcription factors (TFs) in directing the diversification of cell type-specific dendritic development.
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Affiliation(s)
| | | | | | - Sumit Nanda
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA
| | - Myurajan Rubaharan
- Neuroscience Institute, Georgia State University, Atlanta, GA 30302, USA
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA
| | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA 30302, USA
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4
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Vainchtein ID, Alsema AM, Dubbelaar ML, Grit C, Vinet J, van Weering HRJ, Al‐Izki S, Biagini G, Brouwer N, Amor S, Baker D, Eggen BJL, Boddeke EWGM, Kooistra SM. Characterizing microglial gene expression in a model of secondary progressive multiple sclerosis. Glia 2023; 71:588-601. [PMID: 36377669 PMCID: PMC10100411 DOI: 10.1002/glia.24297] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 09/30/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022]
Abstract
Multiple sclerosis (MS) is the most common inflammatory, demyelinating and neurodegenerative disease of the central nervous system in young adults. Chronic-relapsing experimental autoimmune encephalomyelitis (crEAE) in Biozzi ABH mice is an experimental model of MS. This crEAE model is characterized by an acute phase with severe neurological disability, followed by remission of disease, relapse of neurological disease and remission that eventually results in a chronic progressive phase that mimics the secondary progressive phase (SPEAE) of MS. In both MS and SPEAE, the role of microglia is poorly defined. We used a crEAE model to characterize microglia in the different phases of crEAE phases using morphometric and RNA sequencing analyses. At the initial, acute inflammation phase, microglia acquired a pro-inflammatory phenotype. At the remission phase, expression of standard immune activation genes was decreased while expression of genes associated with lipid metabolism and tissue remodeling were increased. Chronic phase microglia partially regain inflammatory gene sets and increase expression of genes associated with proliferation. Together, the data presented here indicate that microglia obtain different features at different stages of crEAE and a particularly mixed phenotype in the chronic stage. Understanding the properties of microglia that are present at the chronic phase of EAE will help to understand the role of microglia in secondary progressive MS, to better aid the development of therapies for this phase of the disease.
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Affiliation(s)
- Ilia D. Vainchtein
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Astrid M. Alsema
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Marissa L. Dubbelaar
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Corien Grit
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Jonathan Vinet
- Department of Biomedical, Metabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModenaItaly
| | - Hilmar R. J. van Weering
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Sarah Al‐Izki
- Department of NeuroimmunologyBlizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of LondonLondonUK
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModenaItaly
| | - Nieske Brouwer
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Sandra Amor
- Department of NeuroimmunologyBlizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of LondonLondonUK
- Department of PathologyVUMCAmsterdamThe Netherlands
| | - David Baker
- Department of NeuroimmunologyBlizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of LondonLondonUK
| | - Bart J. L. Eggen
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Erik W. G. M. Boddeke
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
- Department of Cellular and Molecular MedicineCenter for Healthy Ageing, University of CopenhagenCopenhagenDenmark
| | - Susanne M. Kooistra
- Department of Biomedical Sciences of Cells & Systems, Section Molecular NeurobiologyUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
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5
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Biojone C, C Casarotto P, Cannarozzo C, Fred SM, Herrera-Rodríguez R, Lesnikova A, Voipio M, Castrén E. nNOS-induced tyrosine nitration of TRKB impairs BDNF signaling and restrains neuronal plasticity. Prog Neurobiol 2023; 222:102413. [PMID: 36682419 DOI: 10.1016/j.pneurobio.2023.102413] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 12/01/2022] [Accepted: 01/17/2023] [Indexed: 01/21/2023]
Abstract
Nitric oxide (NO) has been long recognized as an important modulator of neural plasticity, but characterization of the molecular mechanisms involved - specially the guanylyl cyclase-independent ones - has been challenging. There is evidence that NO could modify BDNF-TRKB signaling, a key mediator of neuronal plasticity. However, the mechanism underlying the interplay of NO and TRKB remains unclear. Here we show that NO induces nitration of the tyrosine 816 in the TRKB receptor in vivo and in vitro, and that post-translational modification inhibits TRKB phosphorylation and binding of phospholipase Cγ1 (PLCγ1) to this same tyrosine residue. Additionally, nitration triggers clathrin-dependent endocytosis of TRKB through the adaptor protein AP-2 and ubiquitination, thereby increasing translocation of TRKB away from the neuronal surface and directing it towards lysosomal degradation. Accordingly, inhibition of nitric oxide increases TRKB phosphorylation and TRKB-dependent neurite branching in neuronal cultures. In vivo, chronic inhibition of neuronal nitric oxide synthase (nNOS) dramatically reduced TRKB nitration and facilitated TRKB signaling in the visual cortex, and promoted a shift in ocular dominance upon monocular deprivation - an indicator of increased plasticity. Altogether, our data describe and characterize a new molecular brake on plasticity, namely nitration of TRKB receptors.
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Affiliation(s)
- Caroline Biojone
- Neuroscience Center, HiLife, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland; Aarhus University, Department of Biomedicine, Faculty of Health, and Translational Neuropsychiatry Unit, Department of Clinical Medicine.
| | - Plinio C Casarotto
- Neuroscience Center, HiLife, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Cecilia Cannarozzo
- Neuroscience Center, HiLife, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Senem Merve Fred
- Neuroscience Center, HiLife, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | | | - Angelina Lesnikova
- Neuroscience Center, HiLife, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Mikko Voipio
- Neuroscience Center, HiLife, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Eero Castrén
- Neuroscience Center, HiLife, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland.
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6
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Bhattacharjee S, Iyer EPR, Iyer SC, Nanda S, Rubaharan M, Ascoli GA, Cox DN. The Zinc-BED transcription factor Bedwarfed promotes proportional dendritic growth and branching through transcriptional and translational regulation in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.15.528686. [PMID: 36824896 PMCID: PMC9948997 DOI: 10.1101/2023.02.15.528686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Dendrites are the primary points of sensory or synaptic inputs to a neuron and play an essential role in synaptic integration and neural function. Despite the functional importance of dendrites, relatively less is known about the underlying mechanisms regulating cell-type specific dendritic patterning. Herein, we have dissected functional roles of a previously uncharacterized gene, CG3995 , in cell-type specific dendritic development in Drosophila melanogaster . CG3995 , which we have named bedwarfed ( bdwf ), encodes a zinc-finger BED-type protein which is required for proportional growth and branching of dendritic arbors, exhibits nucleocytoplasmic expression, and functions in both transcriptional and translational cellular pathways. At the transcriptional level, we demonstrate a reciprocal regulatory relationship between Bdwf and the homeodomain transcription factor (TF) Cut. We show that Cut positively regulates Bdwf expression and that Bdwf acts as a downstream effector of Cut-mediated dendritic development, whereas overexpression of Bdwf negatively regulates Cut expression in multidendritic sensory neurons. Proteomic analyses revealed that Bdwf interacts with ribosomal proteins and disruption of these proteins produced phenotypically similar dendritic hypotrophy defects as observed in bdwf mutant neurons. We further demonstrate that Bdwf and its ribosomal protein interactors are required for normal microtubule and F-actin cytoskeletal architecture. Finally, our findings reveal that Bdwf is required to promote protein translation and ribosome trafficking along the dendritic arbor. Taken together, these results provide new insights into the complex, combinatorial and multi-functional roles of transcription factors (TFs) in directing diversification of cell-type specific dendritic development.
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Affiliation(s)
| | | | | | - Sumit Nanda
- Center for Neural Informatics, Structures, & Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, 22030, USA
| | | | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, & Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, 22030, USA
| | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
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7
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Nunnelly LF, Campbell M, Lee DI, Dummer P, Gu G, Menon V, Au E. St18 specifies globus pallidus projection neuron identity in MGE lineage. Nat Commun 2022; 13:7735. [PMID: 36517477 PMCID: PMC9751150 DOI: 10.1038/s41467-022-35518-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
The medial ganglionic eminence (MGE) produces both locally-projecting interneurons, which migrate long distances to structures such as the cortex as well as projection neurons that occupy subcortical nuclei. Little is known about what regulates the migratory behavior and axonal projections of these two broad classes of neurons. We find that St18 regulates the migration and morphology of MGE neurons in vitro. Further, genetic loss-of-function of St18 in mice reveals a reduction in projection neurons of the globus pallidus pars externa. St18 functions by influencing cell fate in MGE lineages as we observe a large expansion of nascent cortical interneurons at the expense of putative GPe neurons in St18 null embryos. Downstream of St18, we identified Cbx7, a component of Polycomb repressor complex 1, and find that it is essential for projection neuron-like migration but not morphology. Thus, we identify St18 as a key regulator of projection neuron vs. interneuron identity.
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Affiliation(s)
- Luke F Nunnelly
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Melissa Campbell
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Dylan I Lee
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Patrick Dummer
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Guoqiang Gu
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Vilas Menon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Edmund Au
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY, 10032, USA.
- Department of Rehabilitation and Regenerative Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA.
- Columbia Translational Neuroscience Initiative Scholar, Columbia University Irving Medical Center, New York, NY, 10032, USA.
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8
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Bhattacharjee S, Lottes EN, Nanda S, Golshir A, Patel AA, Ascoli GA, Cox DN. PP2A phosphatase regulates cell-type specific cytoskeletal organization to drive dendrite diversity. Front Mol Neurosci 2022; 15:926567. [PMID: 36452406 PMCID: PMC9702092 DOI: 10.3389/fnmol.2022.926567] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 10/27/2022] [Indexed: 11/15/2022] Open
Abstract
Uncovering molecular mechanisms regulating dendritic diversification is essential to understanding the formation and modulation of functional neural circuitry. Transcription factors play critical roles in promoting dendritic diversity and here, we identify PP2A phosphatase function as a downstream effector of Cut-mediated transcriptional regulation of dendrite development. Mutant analyses of the PP2A catalytic subunit (mts) or the scaffolding subunit (PP2A-29B) reveal cell-type specific regulatory effects with the PP2A complex required to promote dendritic growth and branching in Drosophila Class IV (CIV) multidendritic (md) neurons, whereas in Class I (CI) md neurons, PP2A functions in restricting dendritic arborization. Cytoskeletal analyses reveal requirements for Mts in regulating microtubule stability/polarity and F-actin organization/dynamics. In CIV neurons, mts knockdown leads to reductions in dendritic localization of organelles including mitochondria and satellite Golgi outposts, while CI neurons show increased Golgi outpost trafficking along the dendritic arbor. Further, mts mutant neurons exhibit defects in neuronal polarity/compartmentalization. Finally, genetic interaction analyses suggest β-tubulin subunit 85D is a common PP2A target in CI and CIV neurons, while FoxO is a putative target in CI neurons.
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Affiliation(s)
| | - Erin N. Lottes
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Sumit Nanda
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States
| | - Andre Golshir
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Atit A. Patel
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, and Plasticity, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States
| | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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9
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Antagonistic Activities of Fmn2 and ADF Regulate Axonal F-Actin Patch Dynamics and the Initiation of Collateral Branching. J Neurosci 2022; 42:7355-7369. [PMID: 36481742 PMCID: PMC9525169 DOI: 10.1523/jneurosci.3107-20.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 08/17/2022] [Accepted: 08/22/2022] [Indexed: 12/15/2022] Open
Abstract
Interstitial collateral branching of axons is a critical component in the development of functional neural circuits. Axon collateral branches are established through a series of cellular processes initiated by the development of a specialized, focal F-actin network in axons. The formation, maintenance and remodeling of this F-actin patch is critical for the initiation of axonal protrusions that are subsequently consolidated to form a collateral branch. However, the mechanisms regulating F-actin patch dynamics are poorly understood. Fmn2 is a formin family member implicated in multiple neurodevelopmental disorders. We find that Fmn2 regulates the initiation of axon collateral protrusions in chick spinal neurons and in zebrafish motor neurons. Fmn2 localizes to the protrusion-initiating axonal F-actin patches and regulates the lifetime and size of these F-actin networks. The F-actin nucleation activity of Fmn2 is necessary for F-actin patch stability but not for initiating patch formation. We show that Fmn2 insulates the F-actin patches from disassembly by the actin-depolymerizing factor, ADF, and promotes long-lived, larger patches that are competent to initiate axonal protrusions. The regulation of axonal branching can contribute to the neurodevelopmental pathologies associated with Fmn2 and the dynamic antagonism between Fmn2 and ADF may represent a general mechanism of formin-dependent protection of Arp2/3-initiated F-actin networks from disassembly.SIGNIFICANCE STATEMENT Axonal branching is a key process in the development of functional circuits and neural plasticity. Axon collateral branching is initiated by the elaboration of F-actin filaments from discrete axonal F-actin networks. We show that the neurodevelopmental disorder-associated formin, Fmn2, is a critical regulator of axon collateral branching. Fmn2 localizes to the collateral branch-inducing F-actin patches in axons and regulates the stability of these actin networks. The F-actin nucleation activity of Fmn2 protects the patches from ADF-mediated disassembly. Opposing activities of Fmn2 and ADF exert a dynamic regulatory control on axon collateral branch initiation and may underly the neurodevelopmental defects associated with Fmn2.
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10
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Hao L, Zhang H, Peng X, Yang Y, Yang M, Guo Y, Wang X, Jing W. Decreased Spire2 Expression is Involved in Epilepsy. Neuroscience 2022; 504:1-9. [PMID: 36122882 DOI: 10.1016/j.neuroscience.2022.09.008] [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: 08/14/2021] [Revised: 09/05/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022]
Abstract
Epilepsy is a neurological disorder caused by abnormally elevated neuronal firing and excitability. Spire2, also known as the nucleating factor of F-actin, plays an important role in long-range vesicle transport. This study showed that Spire2 was highly expressed in neurons in the cortex and hippocampus. Its knockdown significantly reduced the initiation current of the evoked action potential and the frequency of action potential, suggesting that Spire2 knockdown inhibits the threshold current of the neuron. In the cortex of patients with refractory temporal lobe epilepsy (TLE), Spire2 expression was significantly reduced. Decreased expression levels of Spire2 were also observed in kainic acid (KA) and pentylenetetrazole (PTZ) animal models. In the KA and PTZ models, Spire2-knockdown mice showed significantly increased seizures and shortened intervals between seizures, with a tendency to increase seizure duration. In contrast, Spire2-overexpressing mice showed reduced numbers of spontaneous seizures. In conclusion, this study revealed a significantly decreased expression of Spire2 in the brain tissues of epileptic individuals and an inhibitory role for this protein in the development of epilepsy. In addition, knockdown of Spire2 aggravated abnormal firing in epileptic mice, while its overexpression had the opposite effect. These findings provide new insights into the mechanism of epileptogenesis.
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Affiliation(s)
- Lixia Hao
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China; Department of Rehabilitation Medicine, the Affiliated Hospital of Inner Mongolia Medical University, China
| | - Hui Zhang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Xiaoyan Peng
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Yi Yang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Min Yang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Yi Guo
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Xuefeng Wang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China.
| | - Wei Jing
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China; Department of Neurology, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, Shanxi, China; Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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11
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Simiate and the focal adhesion kinase FAK1 cooperate in the regulation of dendritogenesis. Sci Rep 2022; 12:11274. [PMID: 35787638 PMCID: PMC9253104 DOI: 10.1038/s41598-022-14460-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/07/2022] [Indexed: 11/09/2022] Open
Abstract
Despite the crucial importance of dendritogenesis for the correct functioning of neurons, the molecular mechanisms underlying neuronal arborisation are still not well understood. Current models suggest that distinct parts and phases of dendritic development are regulated by the expression of distinct transcription factors, that are able to target the cytoskeleton. Two proteins recently implicated in dendritogenesis are the Focal Adhesion Kinase FAK1 and the Actin-binding protein Simiate. Using heterologous expression systems as well as mouse brain extracts in combination with coprecipitation assays, we show that Simiate is able to associate with FAK1. Differential centrifugation experiments further revealed the interaction to be present in cytosolic as well as nuclear fractions. Inside the nucleus though, Simiate preferentially binds to a FAK1 isoform of 80 kDa, which has previously been shown to regulate transcription factor activity. Investigating the function of both proteins in primary hippocampal cultures, we further found that FAK1 and Simiate have distinct roles in dendritogenesis: While FAK1 increases dendrite length and number, Simiate preferentially enhances growth and branching. However, if being confined to the nucleus, Simiate selectively triggers primary dendrite formation, enhancing transcription activity at the same time. Since the effect on primary dendrites is specifically re-normalized by a co-expression of FAK1 and Simiate in the nucleus, the data implies that the two proteins interact to counterbalance each other in order to control dendrite formation. Looking at the role of the cytosolic interaction of FAK1 and Simiate, we found that neurotrophin induced dendritogenesis causes a striking colocalisation of FAK1 and Simiate in dendritic growth cones, which is not present otherwise, thus suggesting that the cytosolic interaction stimulates growth cone mediated dendritogenesis in response to certain external signals. Taken together, the data show that FAK1 and Simiate exert several and distinct actions during the different phases of dendritogenesis and that these actions are related to their subcellular localisation and their interaction.
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12
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Hale C, Moulton JK, Otis Y, Ganter G. ARMADILLO REGULATES NOCICEPTIVE SENSITIVITY IN THE ABSENCE OF INJURY. Mol Pain 2022; 18:17448069221111155. [PMID: 35712882 PMCID: PMC9500252 DOI: 10.1177/17448069221111155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Abnormal pain has recently been estimated to affect ∼50 million adults each year within the United States. With many treatment options for abnormal pain, such as opioid analgesics, carrying numerous deleterious side effects, research into safer and more effective treatment options is crucial. To help elucidate the mechanisms controlling nociceptive sensitivity, the Drosophila melanogaster larval nociception model has been used to characterize well-conserved pathways through the use of genetic modification and/or injury to alter the sensitivity of experimental animals. Mammalian models have provided evidence of β-catenin signaling involvement in neuropathic pain development. By capitalizing on the conserved nature of β-catenin functions in the fruit fly, here we describe a role for Armadillo, the fly homolog to mammalian β-catenin, in regulating baseline sensitivity in the primary nociceptor of the fly, in the absence of injury, using under- and over-expression of Armadillo in a cell-specific manner. Underexpression of Armadillo resulted in hyposensitivity, while overexpression of wild-type Armadillo or expression of a degradation-resistant Armadillo resulted in hypersensitivity. Neither underexpression nor overexpression of Armadillo resulted in observed dendritic morphological changes that could contribute to behavioral phenotypes observed. These results showed that focused manipulation of Armadillo expression within the nociceptors is sufficient to modulate baseline response in the nociceptors to a noxious stimulus and that these changes are not shown to be associated with a morphogenetic effect.
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Affiliation(s)
- Christine Hale
- Graduate School of Biomedical Science and Engineering6251University of Maine System
| | | | - Yvonne Otis
- School of Biological Sciences172741University of New England College of Arts and Sciences
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13
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The branching code: A model of actin-driven dendrite arborization. Cell Rep 2022; 39:110746. [PMID: 35476974 DOI: 10.1016/j.celrep.2022.110746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 12/24/2021] [Accepted: 04/06/2022] [Indexed: 11/21/2022] Open
Abstract
The cytoskeleton is crucial for defining neuronal-type-specific dendrite morphologies. To explore how the complex interplay of actin-modulatory proteins (AMPs) can define neuronal types in vivo, we focused on the class III dendritic arborization (c3da) neuron of Drosophila larvae. Using computational modeling, we reveal that the main branches (MBs) of c3da neurons follow general models based on optimal wiring principles, while the actin-enriched short terminal branches (STBs) require an additional growth program. To clarify the cellular mechanisms that define this second step, we thus concentrated on STBs for an in-depth quantitative description of dendrite morphology and dynamics. Applying these methods systematically to mutants of six known and novel AMPs, we revealed the complementary roles of these individual AMPs in defining STB properties. Our data suggest that diverse dendrite arbors result from a combination of optimal-wiring-related growth and individualized growth programs that are neuron-type specific.
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14
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Kilo L, Stürner T, Tavosanis G, Ziegler AB. Drosophila Dendritic Arborisation Neurons: Fantastic Actin Dynamics and Where to Find Them. Cells 2021; 10:2777. [PMID: 34685757 PMCID: PMC8534399 DOI: 10.3390/cells10102777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 01/27/2023] Open
Abstract
Neuronal dendrites receive, integrate, and process numerous inputs and therefore serve as the neuron's "antennae". Dendrites display extreme morphological diversity across different neuronal classes to match the neuron's specific functional requirements. Understanding how this structural diversity is specified is therefore important for shedding light on information processing in the healthy and diseased nervous system. Popular models for in vivo studies of dendrite differentiation are the four classes of dendritic arborization (c1da-c4da) neurons of Drosophila larvae with their class-specific dendritic morphologies. Using da neurons, a combination of live-cell imaging and computational approaches have delivered information on the distinct phases and the time course of dendrite development from embryonic stages to the fully developed dendritic tree. With these data, we can start approaching the basic logic behind differential dendrite development. A major role in the definition of neuron-type specific morphologies is played by dynamic actin-rich processes and the regulation of their properties. This review presents the differences in the growth programs leading to morphologically different dendritic trees, with a focus on the key role of actin modulatory proteins. In addition, we summarize requirements and technological progress towards the visualization and manipulation of such actin regulators in vivo.
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Affiliation(s)
- Lukas Kilo
- Dendrite Differentiation, German Center for Neurodegenerative Diseases, 53115 Bonn, Germany; (L.K.); (G.T.)
| | - Tomke Stürner
- Department of Zoology, University of Cambridge, Cambridge CB2 1TN, UK;
| | - Gaia Tavosanis
- Dendrite Differentiation, German Center for Neurodegenerative Diseases, 53115 Bonn, Germany; (L.K.); (G.T.)
- LIMES-Institute, University of Bonn, 53115 Bonn, Germany
| | - Anna B. Ziegler
- Institute of Neuro- and Behavioral Biology, University of Münster, 48149 Münster, Germany
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15
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van Olst L, Rodriguez-Mogeda C, Picon C, Kiljan S, James RE, Kamermans A, van der Pol SMA, Knoop L, Michailidou I, Drost E, Franssen M, Schenk GJ, Geurts JJG, Amor S, Mazarakis ND, van Horssen J, de Vries HE, Reynolds R, Witte ME. Meningeal inflammation in multiple sclerosis induces phenotypic changes in cortical microglia that differentially associate with neurodegeneration. Acta Neuropathol 2021; 141:881-899. [PMID: 33779783 PMCID: PMC8113309 DOI: 10.1007/s00401-021-02293-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/15/2021] [Accepted: 03/03/2021] [Indexed: 12/21/2022]
Abstract
Meningeal inflammation strongly associates with demyelination and neuronal loss in the underlying cortex of progressive MS patients, thereby contributing significantly to clinical disability. However, the pathological mechanisms of meningeal inflammation-induced cortical pathology are still largely elusive. By extensive analysis of cortical microglia in post-mortem progressive MS tissue, we identified cortical areas with two MS-specific microglial populations, termed MS1 and MS2 cortex. The microglial population in MS1 cortex was characterized by a higher density and increased expression of the activation markers HLA class II and CD68, whereas microglia in MS2 cortex showed increased morphological complexity and loss of P2Y12 and TMEM119 expression. Interestingly, both populations associated with inflammation of the overlying meninges and were time-dependently replicated in an in vivo rat model for progressive MS-like chronic meningeal inflammation. In this recently developed animal model, cortical microglia at 1-month post-induction of experimental meningeal inflammation resembled microglia in MS1 cortex, and microglia at 2 months post-induction acquired a MS2-like phenotype. Furthermore, we observed that MS1 microglia in both MS cortex and the animal model were found closely apposing neuronal cell bodies and to mediate pre-synaptic displacement and phagocytosis, which coincided with a relative sparing of neurons. In contrast, microglia in MS2 cortex were not involved in these synaptic alterations, but instead associated with substantial neuronal loss. Taken together, our results show that in response to meningeal inflammation, microglia acquire two distinct phenotypes that differentially associate with neurodegeneration in the progressive MS cortex. Furthermore, our in vivo data suggests that microglia initially protect neurons from meningeal inflammation-induced cell death by removing pre-synapses from the neuronal soma, but eventually lose these protective properties contributing to neuronal loss.
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Affiliation(s)
- Lynn van Olst
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Carla Rodriguez-Mogeda
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Carmen Picon
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Svenja Kiljan
- Department of Anatomy and Neurosciences, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Rachel E James
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Alwin Kamermans
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Susanne M A van der Pol
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Lydian Knoop
- Department of Pathology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Iliana Michailidou
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Evelien Drost
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Marc Franssen
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Geert J Schenk
- Department of Anatomy and Neurosciences, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Jeroen J G Geurts
- Department of Anatomy and Neurosciences, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Nicholas D Mazarakis
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Jack van Horssen
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Richard Reynolds
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
- Centre for Molecular Neuropathology, LKC School of Medicine, Nanyang Technological University, Singapore, Singapore.
| | - Maarten E Witte
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands.
- Department of Pathology, Amsterdam UMC, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam, Netherlands.
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16
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Fernández A, Quintana E, Velasco P, Moreno-Jimenez B, de Andrés B, Gaspar ML, Liste I, Vilar M, Mira H, Cano E. Senescent accelerated prone 8 (SAMP8) mice as a model of age dependent neuroinflammation. J Neuroinflammation 2021; 18:75. [PMID: 33736657 PMCID: PMC7977588 DOI: 10.1186/s12974-021-02104-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/03/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aging and age-related diseases are strong risk factors for the development of neurodegenerative diseases. Neuroinflammation (NIF), as the brain's immune response, plays an important role in aged associated degeneration of central nervous system (CNS). There is a need for well characterized animal models that will allow the scientific community to understand and modulate this process. METHODS We have analyzed aging-phenotypical and inflammatory changes of brain myeloid cells (bMyC) in a senescent accelerated prone aged (SAMP8) mouse model, and compared with their senescence resistant control mice (SAMR1). We have performed morphometric methods to evaluate the architecture of cellular prolongations and determined the appearance of Iba1+ clustered cells with aging. To analyze specific constant brain areas, we have performed stereology measurements of Iba1+ cells in the hippocampal formation. We have isolated bMyC from brain parenchyma (BP) and choroid plexus plus meningeal membranes (m/Ch), and analyzed their response to systemic lipopolysaccharide (LPS)-driven inflammation. RESULTS Aged 10 months old SAMP8 mice present many of the hallmarks of aging-dependent neuroinflammation when compared with their SAMR1 control, i.e., increase of protein aggregates, presence of Iba1+ clusters, but not an increase in the number of Iba1+ cells. We have further observed an increase of main inflammatory mediator IL-1β, and an augment of border MHCII+Iba1+ cells. Isolated CD45+ bMyC from brain parenchyma (BP) and choroid plexus plus meningeal membranes (m/Ch) have been analyzed, showing that there is not a significant increase of CD45+ cells from the periphery. Our data support that aged-driven pro-inflammatory cytokine interleukin 1 beta (IL-1β) transcription is enhanced in CD45+BP cells. Furthermore, LPS-driven systemic inflammation produces inflammatory cytokines mainly in border bMyC, sensed to a lesser extent by the BP bMyC, showing that IL-1β expression is further augmented in aged SAMP8 compared to control SAMR1. CONCLUSION Our data validate the SAMP8 model to study age-associated neuroinflammatory events, but careful controls for age and strain are required. These animals show morphological changes in their bMyC cell repertoires associated to age, corresponding to an increase in the production of pro-inflammatory cytokines such as IL-1β, which predispose the brain to an enhanced inflammatory response after LPS-systemic challenge.
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Affiliation(s)
- Andrés Fernández
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Elena Quintana
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Patricia Velasco
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Belén Moreno-Jimenez
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Belén de Andrés
- Unidad de Inmunobiología, Instituto de Salud Carlos II, Madrid, Spain
| | | | - Isabel Liste
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Marçal Vilar
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Helena Mira
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Eva Cano
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain.
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17
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Tejos-Bravo M, Oakley RH, Whirledge SD, Corrales WA, Silva JP, García-Rojo G, Toledo J, Sanchez W, Román-Albasini L, Aliaga E, Aguayo F, Olave F, Maracaja-Coutinho V, Cidlowski JA, Fiedler JL. Deletion of hippocampal Glucocorticoid receptors unveils sex-biased microRNA expression and neuronal morphology alterations in mice. Neurobiol Stress 2021; 14:100306. [PMID: 33665240 PMCID: PMC7906897 DOI: 10.1016/j.ynstr.2021.100306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 01/18/2021] [Accepted: 02/02/2021] [Indexed: 12/14/2022] Open
Abstract
Sex differences in the brain have prompted many researchers to investigate the underlying molecular actors, such as the glucocorticoid receptor (GR). This nuclear receptor controls gene expression, including microRNAs (miRNAs), in non-neuronal cells. Here, we investigated sex-biased effects of GR on hippocampal miRNA expression and neuronal morphology by generating a neuron-specific GR knockout mouse (Emx1-Nr3c1−/−). The levels of 578 mature miRNAs were assessed using NanoString technology and, in contrast to males, female Emx1-Nr3c1−/− mice showed a substantially higher number of differentially expressed miRNAs, confirming a sex-biased effect of GR ablation. Based on bioinformatic analyses we identified several transcription factors potentially involved in miRNA regulation. Functional enrichment analyses of the miRNA-mRNA interactions revealed pathways related to neuronal arborization and both spine morphology and density in both sexes. Two recognized regulators of dendritic morphology, CAMKII-α and GSK-3β, increased their protein levels by GR ablation in female mice hippocampus, without changes in males. Additionally, sex-specific effects of GR deletion were observed on CA1 neuronal arborization and dendritic spine features. For instance, a reduced density of mushroom spines in apical dendrites was evidenced only in females, while a decreased length in basal dendrites was noted only in males. However, length and arborization of apical dendrites were reduced by GR ablation irrespective of the sex. Overall, our study provides new insights into the sex-biased GR actions, especially in terms of miRNAs expression and neuronal morphology in the hippocampus.
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Affiliation(s)
- Macarena Tejos-Bravo
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile
| | - Robert H Oakley
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Shannon D Whirledge
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Wladimir A Corrales
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile
| | - Juan P Silva
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile
| | - Gonzalo García-Rojo
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile.,Carrera de Odontología. Facultad de Ciencias, Universidad de La Serena, La Serena, Chile
| | - Jorge Toledo
- Laboratory of Scientific Image Analysis (SCIAN-Lab), Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8380453, Chile
| | - Wendy Sanchez
- Laboratory of Scientific Image Analysis (SCIAN-Lab), Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8380453, Chile
| | - Luciano Román-Albasini
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile
| | - Esteban Aliaga
- Department of Kinesiology and the Neuropsychology and Cognitive Neurosciences Research Center (CINPSI-Neurocog), Faculty of Health Sciences, Universidad Católica del Maule, Talca, Chile
| | - Felipe Aguayo
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile
| | - Felipe Olave
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile
| | - Vinicius Maracaja-Coutinho
- Advanced Center for Chronic Diseases -ACCDiS. Faculty of Chemical and Pharmaceutical Sciences. Department of Biochemistry and Molecular Biology. Universidad de Chile, Independencia, 8380492, Santiago, Chile
| | - John A Cidlowski
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Jenny L Fiedler
- Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Independencia, 8380492, Santiago, Chile
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Alizzi RA, Xu D, Tenenbaum CM, Wang W, Gavis ER. The ELAV/Hu protein Found in neurons regulates cytoskeletal and ECM adhesion inputs for space-filling dendrite growth. PLoS Genet 2020; 16:e1009235. [PMID: 33370772 PMCID: PMC7793258 DOI: 10.1371/journal.pgen.1009235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 01/08/2021] [Accepted: 10/29/2020] [Indexed: 12/17/2022] Open
Abstract
Dendritic arbor morphology influences how neurons receive and integrate extracellular signals. We show that the ELAV/Hu family RNA-binding protein Found in neurons (Fne) is required for space-filling dendrite growth to generate highly branched arbors of Drosophila larval class IV dendritic arborization neurons. Dendrites of fne mutant neurons are shorter and more dynamic than in wild-type, leading to decreased arbor coverage. These defects result from both a decrease in stable microtubules and loss of dendrite-substrate interactions within the arbor. Identification of transcripts encoding cytoskeletal regulators and cell-cell and cell-ECM interacting proteins as Fne targets using TRIBE further supports these results. Analysis of one target, encoding the cell adhesion protein Basigin, indicates that the cytoskeletal defects contributing to branch instability in fne mutant neurons are due in part to decreased Basigin expression. The ability of Fne to coordinately regulate the cytoskeleton and dendrite-substrate interactions in neurons may shed light on the behavior of cancer cells ectopically expressing ELAV/Hu proteins. Different types of neurons have different sizes and shapes that are tailored to their particular functions. In the fruit fly larva, a set of sensory neurons called class IV da neurons have highly branched trees of dendrites that cover the epidermis to sense potentially harmful stimuli. Neurons whose dendrites completely fill the territory they sample are also found in zebrafish, worms, mice and humans. We show that an RNA-binding protein called Fne plays an important role in coordinating different contributions to dendrite branching in class IV da neurons by impacting the organization of the cytoskeleton within the neuron and the ability of the dendrite to contact the substratum outside of it. The identification of mRNAs that code for cytoskeleton regulators and adhesive proteins as targets of Fne using a genome-wide approach further supports these results. While the ability of Fne to exert control over such proteins is crucial to generating the space-filling growth of neurons, it can be deleterious if not properly employed, such as when the homologs of Fne are expressed in cancer cells.
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Affiliation(s)
- Rebecca A. Alizzi
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Derek Xu
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Conrad M. Tenenbaum
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Wei Wang
- Lewis-Sigler Institute, Princeton University, Princeton, New Jersey, United States of America
| | - Elizabeth R. Gavis
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- * E-mail:
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19
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Nanda S, Bhattacharjee S, Cox DN, Ascoli GA. Distinct Relations of Microtubules and Actin Filaments with Dendritic Architecture. iScience 2020; 23:101865. [PMID: 33319182 PMCID: PMC7725934 DOI: 10.1016/j.isci.2020.101865] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/09/2020] [Accepted: 11/20/2020] [Indexed: 12/15/2022] Open
Abstract
Microtubules (MTs) and F-actin (F-act) have long been recognized as key regulators of dendritic morphology. Nevertheless, precisely ascertaining their distinct influences on dendritic trees have been hampered until now by the lack of direct, arbor-wide cytoskeletal quantification. We pair live confocal imaging of fluorescently labeled dendritic arborization (da) neurons in Drosophila larvae with complete multi-signal neural tracing to separately measure MTs and F-act. We demonstrate that dendritic arbor length is highly interrelated with local MT quantity, whereas local F-act enrichment is associated with dendritic branching. Computational simulation of arbor structure solely constrained by experimentally observed subcellular distributions of these cytoskeletal components generated synthetic morphological and molecular patterns statistically equivalent to those of real da neurons, corroborating the efficacy of local MT and F-act in describing dendritic architecture. The analysis and modeling outcomes hold true for the simplest (class I), most complex (class IV), and genetically altered (Formin3 overexpression) da neuron types.
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Affiliation(s)
- Sumit Nanda
- Center for Neural Informatics, Structures, & Plasticity and Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA
| | | | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, & Plasticity and Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, VA 22032, USA
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20
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Luo F, Luo S, Qian W, Zhang L, Chen C, Xu M, Wang G, Wang Z, Wang J, Wang W. Developmental deficits and early signs of neurodegeneration revealed by PD patient derived dopamine neurons. Stem Cell Res 2020; 49:102027. [PMID: 33059129 DOI: 10.1016/j.scr.2020.102027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 08/07/2020] [Accepted: 09/29/2020] [Indexed: 12/13/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease affecting millions of elder people due to the degeneration of dopamine neurons in the striatum and substantia nigra. The clinical manifestations of PD include tremor, rigidity, bradykinesia and postural instability. Studying PD is challenging due to two obstacles: 1) disease models such as primary neurons or animal models usually couldn't recapitulate the disease phenotype, and 2) accessibility of human autopsied brain samples is very limited if not impossible. Induced pluripotent stem cells (iPSCs)-derived neuronal cells from patients emerge as an ideal in vitro model for disease modeling and drug development. Here we describe a cell density-dependent method for preparing functional hiPSC-derived dopamine neurons (iDAs) with ~90% purity (TH-positive cells). iDAs derived from PD patient exhibit the disease-related phenotypes, for example, slowed morphogenesis, reduced dopamine release, impaired mitochondrial function, and α-synuclein accumulation as early as 35 days after induction. Furthermore, we found that the effects of cell density are different between iDA development stages, whereas high cell density increases stress for early neural progenitor cells (NPCs), but are neural-protective for mature iDAs, high density also favors morphogenesis. Hence, using stage and density-dependent strategies we can obtain high quality iDAs, which are critical for disease modeling, drug development and cell replacement therapy.
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Affiliation(s)
- Fang Luo
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Sushan Luo
- Department of Neurology & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Wenjing Qian
- Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Lin Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Chen Chen
- Department of Neurology & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Meimei Xu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Guangling Wang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Zhongfeng Wang
- Department of Neurology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
| | - Jian Wang
- Department of Neurology & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China.
| | - Wenyuan Wang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China; Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China.
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21
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Wang YH, Ding ZY, Cheng YJ, Chien CT, Huang ML. An Efficient Screen for Cell-Intrinsic Factors Identifies the Chaperonin CCT and Multiple Conserved Mechanisms as Mediating Dendrite Morphogenesis. Front Cell Neurosci 2020; 14:577315. [PMID: 33100975 PMCID: PMC7546278 DOI: 10.3389/fncel.2020.577315] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/02/2020] [Indexed: 12/25/2022] Open
Abstract
Dendritic morphology is inextricably linked to neuronal function. Systematic large-scale screens combined with genetic mapping have uncovered several mechanisms underlying dendrite morphogenesis. However, a comprehensive overview of participating molecular mechanisms is still lacking. Here, we conducted an efficient clonal screen using a collection of mapped P-element insertions that were previously shown to cause lethality and eye defects in Drosophila melanogaster. Of 280 mutants, 52 exhibited dendritic defects. Further database analyses, complementation tests, and RNA interference validations verified 40 P-element insertion genes as being responsible for the dendritic defects. Twenty-eight mutants presented severe arbor reduction, and the remainder displayed other abnormalities. The intrinsic regulators encoded by the identified genes participate in multiple conserved mechanisms and pathways, including the protein folding machinery and the chaperonin-containing TCP-1 (CCT) complex that facilitates tubulin folding. Mutant neurons in which expression of CCT4 or CCT5 was depleted exhibited severely retarded dendrite growth. We show that CCT localizes in dendrites and is required for dendritic microtubule organization and tubulin stability, suggesting that CCT-mediated tubulin folding occurs locally within dendrites. Our study also reveals novel mechanisms underlying dendrite morphogenesis. For example, we show that Drosophila Nogo signaling is required for dendrite development and that Mummy and Wech also regulate dendrite morphogenesis, potentially via Dpp- and integrin-independent pathways. Our methodology represents an efficient strategy for identifying intrinsic dendrite regulators, and provides insights into the plethora of molecular mechanisms underlying dendrite morphogenesis.
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Affiliation(s)
- Ying-Hsuan Wang
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Zhao-Ying Ding
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi, Taiwan
| | - Ying-Ju Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | - Min-Lang Huang
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi, Taiwan
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22
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Hu C, Kanellopoulos AK, Richter M, Petersen M, Konietzny A, Tenedini FM, Hoyer N, Cheng L, Poon CLC, Harvey KF, Windhorst S, Parrish JZ, Mikhaylova M, Bagni C, Calderon de Anda F, Soba P. Conserved Tao Kinase Activity Regulates Dendritic Arborization, Cytoskeletal Dynamics, and Sensory Function in Drosophila. J Neurosci 2020; 40:1819-1833. [PMID: 31964717 PMCID: PMC7046460 DOI: 10.1523/jneurosci.1846-19.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 12/11/2022] Open
Abstract
Dendritic arborization is highly regulated and requires tight control of dendritic growth, branching, cytoskeletal dynamics, and ion channel expression to ensure proper function. Abnormal dendritic development can result in altered network connectivity, which has been linked to neurodevelopmental disorders, including autism spectrum disorders (ASDs). How neuronal growth control programs tune dendritic arborization to ensure function is still not fully understood. Using Drosophila dendritic arborization (da) neurons as a model, we identified the conserved Ste20-like kinase Tao as a negative regulator of dendritic arborization. We show that Tao kinase activity regulates cytoskeletal dynamics and sensory channel localization required for proper sensory function in both male and female flies. We further provide evidence for functional conservation of Tao kinase, showing that its ASD-linked human ortholog, Tao kinase 2 (Taok2), could replace Drosophila Tao and rescue dendritic branching, dynamic microtubule alterations, and behavioral defects. However, several ASD-linked Taok2 variants displayed impaired rescue activity, suggesting that Tao/Taok2 mutations can disrupt sensory neuron development and function. Consistently, we show that Tao kinase activity is required in developing and as well as adult stages for maintaining normal dendritic arborization and sensory function to regulate escape and social behavior. Our data suggest an important role for Tao kinase signaling in cytoskeletal organization to maintain proper dendritic arborization and sensory function, providing a strong link between developmental sensory aberrations and behavioral abnormalities relevant for Taok2-dependent ASDs.SIGNIFICANCE STATEMENT Autism spectrum disorders (ASDs) are linked to abnormal dendritic arbors. However, the mechanisms of how dendritic arbors develop to promote functional and proper behavior are unclear. We identified Drosophila Tao kinase, the ortholog of the ASD risk gene Taok2, as a regulator of dendritic arborization in sensory neurons. We show that Tao kinase regulates cytoskeletal dynamics, controls sensory ion channel localization, and is required to maintain somatosensory function in vivo Interestingly, ASD-linked human Taok2 mutations rendered it nonfunctional, whereas its WT form could restore neuronal morphology and function in Drosophila lacking endogenous Tao. Our findings provide evidence for a conserved role of Tao kinase in dendritic development and function of sensory neurons, suggesting that aberrant sensory function might be a common feature of ASDs.
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Affiliation(s)
- Chun Hu
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | | | - Melanie Richter
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Meike Petersen
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Anja Konietzny
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Federico M Tenedini
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nina Hoyer
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lin Cheng
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Carole L C Poon
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
| | - Kieran F Harvey
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
- Department of Anatomy and Developmental Biology, and Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Sabine Windhorst
- Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, 98195 Washington, and
| | - Marina Mikhaylova
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Froylan Calderon de Anda
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Peter Soba
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany,
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23
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Hinkle JJ, Olschowka JA, Love TM, Williams JP, O'Banion MK. Cranial irradiation mediated spine loss is sex-specific and complement receptor-3 dependent in male mice. Sci Rep 2019; 9:18899. [PMID: 31827187 PMCID: PMC6906384 DOI: 10.1038/s41598-019-55366-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 11/27/2019] [Indexed: 12/14/2022] Open
Abstract
Cranial irradiation is the main therapeutic treatment for primary and metastatic malignancies in the brain. However, cranial radiation therapy produces long-term impairment in memory, information processing, and attention that contribute to a decline in quality of life. The hippocampal neural network is fundamental for proper storage and retrieval of episodic and spatial memories, suggesting that hippocampal signaling dysfunction could be responsible for the progressive memory deficits observed following irradiation. Previous rodent studies demonstrated that irradiation induces significant loss in dendritic spine number, alters spine morphology, and is associated with behavioral task deficits. Additionally, the literature suggests a common mechanism in which synaptic elimination via microglial-mediated phagocytosis is complement dependent and associated with cognitive impairment in aging as well as disease. We demonstrate sexual dimorphisms in irradiation-mediated alterations of microglia activation markers and dendritic spine density. Further, we find that the significant dendritic spine loss observed in male mice following irradiation is microglia complement receptor 3 (CR3)-dependent. By identifying sex-dependent cellular and molecular factors underlying irradiation-mediated spine loss, therapies can be developed to counteract irradiation-induced cognitive decline and improve patient quality of life.
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Affiliation(s)
- Joshua J Hinkle
- Department of Neuroscience and Del Monte Neuroscience Institute, University of Rochester School of Medicine & Dentistry, Rochester, New York, 14642, USA
| | - John A Olschowka
- Department of Neuroscience and Del Monte Neuroscience Institute, University of Rochester School of Medicine & Dentistry, Rochester, New York, 14642, USA
| | - Tanzy M Love
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine & Dentistry, Rochester, New York, 14642, USA
| | - Jacqueline P Williams
- Department of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York, 14642, USA
| | - M Kerry O'Banion
- Department of Neuroscience and Del Monte Neuroscience Institute, University of Rochester School of Medicine & Dentistry, Rochester, New York, 14642, USA. .,Department of Neurology, University of Rochester School of Medicine & Dentistry, Rochester, New York, 14642, USA.
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24
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Predicting Reactive Astrogliosis Propagation by Bayesian Computational Modeling: the Repeater Stations Model. Mol Neurobiol 2019; 57:879-895. [PMID: 31522382 DOI: 10.1007/s12035-019-01749-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/26/2019] [Indexed: 10/26/2022]
Abstract
Reactive astrogliosis occurs upon focal brain injury and in neurodegenerative diseases. The mechanisms that propagate reactive astrogliosis to distal parts of the brain, in a rapid wave that activates astrocytes and other cell types along the way, are not completely understood. It is proposed that damage-associated molecular patterns (DAMP) released by necrotic cells from the injury core have a major role in the reactive astrogliosis initiation but whether they also participate in reactive astrogliosis propagation remains to be determined. We here developed a Bayesian computational model to define the most probable model for reactive astrogliosis propagation. Starting with experimental data from GFAP-immunostained reactive astrocytes, we defined five types of astrocytes based on morphometrical cues and registered the position of each reactive astrocyte cell type in the hemisphere ipsilateral to the injured site after 3 and 7 days post-ischemia. We developed equations for the changes in DAMP concentration (due to diffusion, binding to receptors or degradation), soluble mediators secretion, and for the evolution reactive astrogliosis. We tested four predefined models based on abovementioned previous hypothesis and modifications to it. Our results showed that DAMP diffusion alone has not justified the reactive astrogliosis propagation as previously assumed. Only two models succeeded in accurately reproducing the experimentally measured data and they highlighted the role of microglia and the glial secretion of soluble mediators to sustain the reactive signal and activating neighboring astrocytes. Thus, our in silico analysis proposes that glial cells behave as repeater stations of the injury signal in order to propagate reactive astrogliosis.
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25
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Shah BS, Shimell JJ, Bamji SX. Regulation of dendrite morphology and excitatory synapse formation by zDHHC15. J Cell Sci 2019; 132:jcs.230052. [PMID: 31189538 PMCID: PMC6633394 DOI: 10.1242/jcs.230052] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/28/2019] [Indexed: 12/11/2022] Open
Abstract
Protein palmitoylation is the most common post-translational lipid modification in the brain and is mediated by a family of 24 zDHHC enzymes. There has been growing interest in zDHHCs due to mounting evidence that these enzymes play key roles in the development and function of neuronal connections, and the fact that a number of zDHHCs have been associated with neurodevelopmental and neurodegenerative diseases. Loss-of-function variants in several zDHHCs, including zDHHC15, have been identified in patients with intellectual disabilities; however, the function of zDHHC15 in the brain has not been well studied. Here, we demonstrate that knocking down zDHHC15 in primary rat hippocampal cultures reduces dendritic outgrowth and arborization, as well as spine maturation. Moreover, knockdown of zDHHC15 reduces palmitoylation of PSD-95 and its trafficking into dendrites, resulting in an overall decrease in the density of excitatory synapses being formed onto mutant cells. Summary: Disruption of zDHHC15 function in primary hippocampal cultures reduces dendritic outgrowth, spine maturation, excitatory synapse density and trafficking of PSD-95 into dendrites.
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Affiliation(s)
- Bhavin S Shah
- Department of Cellular & Physiological Sciences & the Brain Research Centre, University of British Columbia, 2350 Health Sciences Mall, Vancouver, B.C., V6T-1Z3, Canada
| | - Jordan J Shimell
- Department of Cellular & Physiological Sciences & the Brain Research Centre, University of British Columbia, 2350 Health Sciences Mall, Vancouver, B.C., V6T-1Z3, Canada
| | - Shernaz X Bamji
- Department of Cellular & Physiological Sciences & the Brain Research Centre, University of British Columbia, 2350 Health Sciences Mall, Vancouver, B.C., V6T-1Z3, Canada
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26
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Cuartero MI, de la Parra J, Pérez-Ruiz A, Bravo-Ferrer I, Durán-Laforet V, García-Culebras A, García-Segura JM, Dhaliwal J, Frankland PW, Lizasoain I, Moro MÁ. Abolition of aberrant neurogenesis ameliorates cognitive impairment after stroke in mice. J Clin Invest 2019; 129:1536-1550. [PMID: 30676325 DOI: 10.1172/jci120412] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 01/17/2019] [Indexed: 12/23/2022] Open
Abstract
Poststroke cognitive impairment is considered one of the main complications during the chronic phase of ischemic stroke. In the adult brain, the hippocampus regulates both encoding and retrieval of new information through adult neurogenesis. Nevertheless, the lack of predictive models and studies based on the forgetting processes hinders the understanding of memory alterations after stroke. Our aim was to explore whether poststroke neurogenesis participates in the development of long-term memory impairment. Here, we show a hippocampal neurogenesis burst that persisted 1 month after stroke and that correlated with an impaired contextual and spatial memory performance. Furthermore, we demonstrate that the enhancement of hippocampal neurogenesis after stroke by physical activity or memantine treatment weakened existing memories. More importantly, stroke-induced newborn neurons promoted an aberrant hippocampal circuitry remodeling with differential features at ipsi- and contralesional levels. Strikingly, inhibition of stroke-induced hippocampal neurogenesis by temozolomide treatment or using a genetic approach (Nestin-CreERT2/NSE-DTA mice) impeded the forgetting of old memories. These results suggest that hippocampal neurogenesis modulation could be considered as a potential approach for treatment of poststroke cognitive impairment.
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Affiliation(s)
- María Isabel Cuartero
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
| | - Juan de la Parra
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
| | - Alberto Pérez-Ruiz
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
| | - Isabel Bravo-Ferrer
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
| | - Violeta Durán-Laforet
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
| | - Alicia García-Culebras
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
| | - Juan Manuel García-Segura
- Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain.,Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, UCM, Madrid, Spain
| | - Jagroop Dhaliwal
- Program in Neuroscience & Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Paul W Frankland
- Program in Neuroscience & Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ignacio Lizasoain
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
| | - María Ángeles Moro
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid (UCM), and Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Instituto Universitario de Investigación en Neuroquímica (IUIN), UCM, Madrid, Spain
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27
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Jonckheere J, Deloulme JC, Dall’Igna G, Chauliac N, Pelluet A, Nguon AS, Lentini C, Brocard J, Denarier E, Brugière S, Couté Y, Heinrich C, Porcher C, Holtzmann J, Andrieux A, Suaud-Chagny MF, Gory-Fauré S. Short- and long-term efficacy of electroconvulsive stimulation in animal models of depression: The essential role of neuronal survival. Brain Stimul 2018; 11:1336-1347. [DOI: 10.1016/j.brs.2018.08.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/12/2018] [Accepted: 08/03/2018] [Indexed: 12/28/2022] Open
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28
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Nithianandam V, Chien CT. Actin blobs prefigure dendrite branching sites. J Cell Biol 2018; 217:3731-3746. [PMID: 30042190 PMCID: PMC6168249 DOI: 10.1083/jcb.201711136] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/28/2018] [Accepted: 07/09/2018] [Indexed: 02/08/2023] Open
Abstract
Nithianandam and Chien show via in vivo imaging that a dynamic population of F-actin termed actin blobs propagates bidirectionally in dendrites and stalls at future branching sites. The F-actin–severing protein Tsr/cofilin is a regulator of actin blob dynamics and dendrite branching. The actin cytoskeleton provides structural stability and adaptability to the cell. Neuronal dendrites frequently undergo morphological changes by emanating, elongating, and withdrawing branches. However, the knowledge about actin dynamics in dendrites during these processes is limited. By performing in vivo imaging of F-actin markers, we found that F-actin was highly dynamic and heterogeneously distributed in dendritic shafts with enrichment at terminal dendrites. A dynamic F-actin population that we named actin blobs propagated bidirectionally at an average velocity of 1 µm/min. Interestingly, these actin blobs stalled at sites where new dendrites would branch out in minutes. Overstabilization of F-actin by the G15S mutant abolished actin blobs and dendrite branching. We identified the F-actin–severing protein Tsr/cofilin as a regulator of dynamic actin blobs and branching activity. Hence, actin blob localization at future branching sites represents a dendrite-branching mechanism to account for highly diversified dendritic morphology.
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Affiliation(s)
- Vanitha Nithianandam
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Ting Chien
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan .,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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29
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Tenenbaum CM, Misra M, Alizzi RA, Gavis ER. Enclosure of Dendrites by Epidermal Cells Restricts Branching and Permits Coordinated Development of Spatially Overlapping Sensory Neurons. Cell Rep 2018; 20:3043-3056. [PMID: 28954223 DOI: 10.1016/j.celrep.2017.09.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 08/24/2017] [Accepted: 08/31/2017] [Indexed: 12/25/2022] Open
Abstract
Spatial arrangement of different neuron types within a territory is essential to neuronal development and function. How development of different neuron types is coordinated for spatial coexistence is poorly understood. In Drosophila, dendrites of four classes of dendritic arborization (C1-C4da) neurons innervate overlapping receptive fields within the larval epidermis. These dendrites are intermittently enclosed by epidermal cells, with different classes exhibiting varying degrees of enclosure. The role of enclosure in neuronal development and its underlying mechanism remain unknown. We show that the membrane-associated protein Coracle acts in C4da neurons and epidermal cells to locally restrict dendrite branching and outgrowth by promoting enclosure. Loss of C4da neuron enclosure results in excessive branching and growth of C4da neuron dendrites and retraction of C1da neuron dendrites due to local inhibitory interactions between neurons. We propose that enclosure of dendrites by epidermal cells is a developmental mechanism for coordinated innervation of shared receptive fields.
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Affiliation(s)
- Conrad M Tenenbaum
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Mala Misra
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Rebecca A Alizzi
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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30
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DeVault L, Li T, Izabel S, Thompson-Peer KL, Jan LY, Jan YN. Dendrite regeneration of adult Drosophila sensory neurons diminishes with aging and is inhibited by epidermal-derived matrix metalloproteinase 2. Genes Dev 2018; 32:402-414. [PMID: 29563183 PMCID: PMC5900713 DOI: 10.1101/gad.308270.117] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 02/26/2018] [Indexed: 11/30/2022]
Abstract
DeVault et al. show that the capacity for regeneration was present in adult neurons but diminished as the animal aged. The regenerated dendrites showed preferential alignment with the extracellular matrix, and inhibition of matrix metalloproteinase 2 led to increased dendrite regeneration. Dendrites possess distinct structural and functional properties that enable neurons to receive information from the environment as well as other neurons. Despite their key role in neuronal function, current understanding of the ability of neurons to regenerate dendrites is lacking. This study characterizes the structural and functional capacity for dendrite regeneration in vivo in adult animals and examines the effect of neuronal maturation on dendrite regeneration. We focused on the class IV dendritic arborization (c4da) neuron of the Drosophila sensory system, which has a dendritic arbor that undergoes dramatic remodeling during the first 3 d of adult life and then maintains a relatively stable morphology thereafter. Using a laser severing paradigm, we monitored regeneration after acute and spatially restricted injury. We found that the capacity for regeneration was present in adult neurons but diminished as the animal aged. Regenerated dendrites recovered receptive function. Furthermore, we found that the regenerated dendrites show preferential alignment with the extracellular matrix (ECM). Finally, inhibition of ECM degradation by inhibition of matrix metalloproteinase 2 (Mmp2) to preserve the extracellular environment characteristics of young adults led to increased dendrite regeneration. These results demonstrate that dendrites retain regenerative potential throughout adulthood and that regenerative capacity decreases with aging.
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Affiliation(s)
- Laura DeVault
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Tun Li
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Sarah Izabel
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Katherine L Thompson-Peer
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Lily Yeh Jan
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Yuh Nung Jan
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
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31
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Dendritic Cytoskeletal Architecture Is Modulated by Combinatorial Transcriptional Regulation in Drosophila melanogaster. Genetics 2017; 207:1401-1421. [PMID: 29025914 PMCID: PMC5714456 DOI: 10.1534/genetics.117.300393] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 10/04/2017] [Indexed: 01/08/2023] Open
Abstract
Transcription factors (TFs) have emerged as essential cell autonomous mediators of subtype specific dendritogenesis; however, the downstream effectors of these TFs remain largely unknown, as are the cellular events that TFs control to direct morphological change. As dendritic morphology is largely dictated by the organization of the actin and microtubule (MT) cytoskeletons, elucidating TF-mediated cytoskeletal regulatory programs is key to understanding molecular control of diverse dendritic morphologies. Previous studies in Drosophila melanogaster have demonstrated that the conserved TFs Cut and Knot exert combinatorial control over aspects of dendritic cytoskeleton development, promoting actin and MT-based arbor morphology, respectively. To investigate transcriptional targets of Cut and/or Knot regulation, we conducted systematic neurogenomic studies, coupled with in vivo genetic screens utilizing multi-fluor cytoskeletal and membrane marker reporters. These analyses identified a host of putative Cut and/or Knot effector molecules, and a subset of these putative TF targets converge on modulating dendritic cytoskeletal architecture, which are grouped into three major phenotypic categories, based upon neuromorphometric analyses: complexity enhancer, complexity shifter, and complexity suppressor. Complexity enhancer genes normally function to promote higher order dendritic growth and branching with variable effects on MT stabilization and F-actin organization, whereas complexity shifter and complexity suppressor genes normally function in regulating proximal-distal branching distribution or in restricting higher order branching complexity, respectively, with spatially restricted impacts on the dendritic cytoskeleton. Collectively, we implicate novel genes and cellular programs by which TFs distinctly and combinatorially govern dendritogenesis via cytoskeletal modulation.
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Jenkins BV, Saunders HAJ, Record HL, Johnson-Schlitz DM, Wildonger J. Effects of mutating α-tubulin lysine 40 on sensory dendrite development. J Cell Sci 2017; 130:4120-4131. [PMID: 29122984 PMCID: PMC5769580 DOI: 10.1242/jcs.210203] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/06/2017] [Indexed: 12/28/2022] Open
Abstract
Microtubules are essential for neuronal structure and function. Axonal and dendritic microtubules are enriched in post-translational modifications that impact microtubule dynamics, transport and microtubule-associated proteins. Acetylation of α-tubulin lysine 40 (K40) is a prominent and conserved modification of neuronal microtubules. However, the cellular role of microtubule acetylation remains controversial. To resolve how microtubule acetylation might affect neuronal morphogenesis, we mutated endogenous α-tubulin in vivo using a new Drosophila strain that facilitates the rapid knock-in of designer αTub84B alleles (the predominant α-tubulin-encoding gene in flies). Leveraging our new strain, we found that microtubule acetylation, as well as polyglutamylation and (de)tyrosination, is not essential for survival. However, we found that dendrite branch refinement in sensory neurons relies on α-tubulin K40. Mutagenesis of K40 reveals moderate yet significant changes in dendritic lysosome transport, microtubule polymerization and Futsch protein distribution in dendrites but not in axons. Our studies point to an unappreciated role for α-tubulin K40 and acetylation in dendrite morphogenesis. While our results are consistent with the idea that acetylation tunes microtubule function within neurons, they also suggest there may be an acetylation-independent requirement for α-tubulin K40. This article has an associated First Person interview with the first author of the paper. Highlighted Article: Neurons are enriched in post-translationally modified microtubules. Targeted mutagenesis of endogenous α-tubulin in flies reveals that dendrite branch refinement is altered by acetylation-blocking mutations.
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Affiliation(s)
- Brian V Jenkins
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Harriet A J Saunders
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA.,Integrated Program in Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Helena L Record
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | - Jill Wildonger
- Biochemistry Department, University of Wisconsin-Madison, Madison, WI 53706, USA
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33
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The Proteome of BLOC-1 Genetic Defects Identifies the Arp2/3 Actin Polymerization Complex to Function Downstream of the Schizophrenia Susceptibility Factor Dysbindin at the Synapse. J Neurosci 2017; 36:12393-12411. [PMID: 27927957 DOI: 10.1523/jneurosci.1321-16.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/01/2016] [Accepted: 10/20/2016] [Indexed: 12/16/2022] Open
Abstract
Proteome modifications downstream of monogenic or polygenic disorders have the potential to uncover novel molecular mechanisms participating in pathogenesis and/or extragenic modification of phenotypic expression. We tested this idea by determining the proteome sensitive to genetic defects in a locus encoding dysbindin, a protein required for synapse biology and implicated in schizophrenia risk. We applied quantitative mass spectrometry to identify proteins expressed in neuronal cells the abundance of which was altered after downregulation of the schizophrenia susceptibility factor dysbindin (Bloc1s8) or two other dysbindin-interacting polypeptides, which assemble into the octameric biogenesis of lysosome-related organelles complex 1 (BLOC-1). We found 491 proteins sensitive to dysbindin and BLOC-1 loss of function. Gene ontology of these 491 proteins singled out the actin cytoskeleton and the actin polymerization factor, the Arp2/3 complex, as top statistical molecular pathways contained within the BLOC-1-sensitive proteome. Subunits of the Arp2/3 complex were downregulated by BLOC-1 loss of function, thus affecting actin dynamics in early endosomes of BLOC-1-deficient cells. Furthermore, we demonstrated that Arp2/3, dysbindin, and subunits of the BLOC-1 complex biochemically and genetically interact, modulating Drosophila melanogaster synapse morphology and homeostatic synaptic plasticity. Our results indicate that ontologically prioritized proteomics identifies novel pathways that modify synaptic phenotypes associated with neurodevelopmental disorder gene defects. SIGNIFICANCE STATEMENT The mechanisms associated with schizophrenia are mostly unknown despite the increasing number of genetic loci identified that increase disease risk. We present an experimental strategy that impartially and comprehensively interrogates the proteome of neurons to identify effects of genetic mutations in a schizophrenia risk factor, dysbindin. We find that the expression of the actin polymerization complex Arp2/3 is reduced in dysbindin-deficient cells, thus affecting actin-dependent phenotypes in two cellular compartments where dysbindin resides, endosomes and presynapses. Our studies indicate that a central cellular structure affected by schizophrenia susceptibility loci is the actin cytoskeleton, an organelle necessary for synaptic function in the presynaptic and postsynaptic compartment.
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Vormberg A, Effenberger F, Muellerleile J, Cuntz H. Universal features of dendrites through centripetal branch ordering. PLoS Comput Biol 2017; 13:e1005615. [PMID: 28671947 PMCID: PMC5515450 DOI: 10.1371/journal.pcbi.1005615] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 07/18/2017] [Accepted: 06/05/2017] [Indexed: 11/19/2022] Open
Abstract
Dendrites form predominantly binary trees that are exquisitely embedded in the networks of the brain. While neuronal computation is known to depend on the morphology of dendrites, their underlying topological blueprint remains unknown. Here, we used a centripetal branch ordering scheme originally developed to describe river networks—the Horton-Strahler order (SO)–to examine hierarchical relationships of branching statistics in reconstructed and model dendritic trees. We report on a number of universal topological relationships with SO that are true for all binary trees and distinguish those from SO-sorted metric measures that appear to be cell type-specific. The latter are therefore potential new candidates for categorising dendritic tree structures. Interestingly, we find a faithful correlation of branch diameters with centripetal branch orders, indicating a possible functional importance of SO for dendritic morphology and growth. Also, simulated local voltage responses to synaptic inputs are strongly correlated with SO. In summary, our study identifies important SO-dependent measures in dendritic morphology that are relevant for neural function while at the same time it describes other relationships that are universal for all dendrites. Similarly to river beds, dendritic trees of nerve cells form elaborate networks that branch out to cover extensive areas. In the 1940s, ecologist Robert E. Horton developed an ordering system for branches in river networks that was refined in the 1950s by geoscientist Arthur N. Strahler, the Horton-Strahler order (SO). Branches at the tips start with order 1 and increase their order in a systematic way when encountering new branches on the way to the root. SO relationships have recently become popular for quantifying dendritic morphologies. Various branching statistics can be studied as a function of SO. Here we describe that topological measures such as the number of branches, the branch bifurcation ratio and the size of subtrees exhibit stereotypical relations with SO in dendritic trees independently of cell type, mirroring universal features of binary trees. Other functionally more relevant features such as mean branch lengths, local diameters and simulated voltage responses to synaptic inputs directly correlate with SO in a cell type-specific manner, indicating the importance of SO for understanding dendrite growth as well as neural computation.
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Affiliation(s)
- Alexandra Vormberg
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt/Main, Germany
- Frankfurt Institute for Advanced Studies (FIAS), Frankfurt/Main, Germany
- * E-mail: (A.V.); (H.C.)
| | - Felix Effenberger
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt/Main, Germany
- Frankfurt Institute for Advanced Studies (FIAS), Frankfurt/Main, Germany
| | - Julia Muellerleile
- Institute of Clinical Neuroanatomy, Goethe University Frankfurt/Main, Germany
| | - Hermann Cuntz
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt/Main, Germany
- Frankfurt Institute for Advanced Studies (FIAS), Frankfurt/Main, Germany
- * E-mail: (A.V.); (H.C.)
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35
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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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36
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Corty MM, Tam J, Grueber WB. Dendritic diversification through transcription factor-mediated suppression of alternative morphologies. Development 2016; 143:1351-62. [PMID: 27095495 DOI: 10.1242/dev.130906] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/25/2016] [Indexed: 01/23/2023]
Abstract
Neurons display a striking degree of functional and morphological diversity, and the developmental mechanisms that underlie diversification are of significant interest for understanding neural circuit assembly and function. We find that the morphology of Drosophila sensory neurons is diversified through a series of suppressive transcriptional interactions involving the POU domain transcription factors Pdm1 (Nubbin) and Pdm2, the homeodomain transcription factor Cut, and the transcriptional regulators Scalloped and Vestigial. Pdm1 and Pdm2 are expressed in a subset of proprioceptive sensory neurons and function to inhibit dendrite growth and branching. A subset of touch receptors show a capacity to express Pdm1/2, but Cut represses this expression and promotes more complex dendritic arbors. Levels of Cut expression are diversified in distinct sensory neurons by selective expression of Scalloped and Vestigial. Different levels of Cut impact dendritic complexity and, consistent with this, we show that Scalloped and Vestigial suppress terminal dendritic branching. This transcriptional hierarchy therefore acts to suppress alternative morphologies to diversify three distinct types of somatosensory neurons.
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Affiliation(s)
- Megan M Corty
- Department of Neuroscience, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA Department of Physiology and Cellular Biophysics, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA
| | - Justina Tam
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA
| | - Wesley B Grueber
- Department of Neuroscience, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA Department of Physiology and Cellular Biophysics, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, New York, NY 10032, USA
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37
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Chaharbakhshi E, Jemc JC. Broad-complex, tramtrack, and bric-à-brac (BTB) proteins: Critical regulators of development. Genesis 2016; 54:505-518. [DOI: 10.1002/dvg.22964] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/08/2016] [Accepted: 08/11/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Edwin Chaharbakhshi
- Department of Biology; Loyola University Chicago; Chicago IL
- Stritch School of Medicine; Loyola University Chicago; Maywood IL
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38
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Sears JC, Broihier HT. FoxO regulates microtubule dynamics and polarity to promote dendrite branching in Drosophila sensory neurons. Dev Biol 2016; 418:40-54. [PMID: 27546375 DOI: 10.1016/j.ydbio.2016.08.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 08/12/2016] [Accepted: 08/16/2016] [Indexed: 01/15/2023]
Abstract
The size and shape of dendrite arbors are defining features of neurons and critical determinants of neuronal function. The molecular mechanisms establishing arborization patterns during development are not well understood, though properly regulated microtubule (MT) dynamics and polarity are essential. We previously found that FoxO regulates axonal MTs, raising the question of whether it also regulates dendritic MTs and morphology. Here we demonstrate that FoxO promotes dendrite branching in all classes of Drosophila dendritic arborization (da) neurons. FoxO is required both for initiating growth of new branches and for maintaining existing branches. To elucidate FoxO function, we characterized MT organization in both foxO null and overexpressing neurons. We find that FoxO directs MT organization and dynamics in dendrites. Moreover, it is both necessary and sufficient for anterograde MT polymerization, which is known to promote dendrite branching. Lastly, FoxO promotes proper larval nociception, indicating a functional consequence of impaired da neuron morphology in foxO mutants. Together, our results indicate that FoxO regulates dendrite structure and function and suggest that FoxO-mediated pathways control MT dynamics and polarity.
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Affiliation(s)
- James C Sears
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Heather T Broihier
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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39
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Lei W, Omotade OF, Myers KR, Zheng JQ. Actin cytoskeleton in dendritic spine development and plasticity. Curr Opin Neurobiol 2016; 39:86-92. [PMID: 27138585 DOI: 10.1016/j.conb.2016.04.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/15/2016] [Accepted: 04/15/2016] [Indexed: 01/20/2023]
Abstract
Synapses are the basic unit of neuronal communication and their disruption is associated with many neurological disorders. Significant progress has been made towards understanding the molecular and genetic regulation of synapse formation, modulation, and dysfunction, but the underlying cellular mechanisms remain incomplete. The actin cytoskeleton not only provides the structural foundation for synapses, but also regulates a diverse array of cellular activities underlying synaptic function. Here we will discuss the regulation of the actin cytoskeleton in dendritic spines, the postsynaptic compartment of excitatory synapses. We will focus on a select number of actin regulatory processes, highlighting recent advances, the complexity of crosstalk between different pathways, and the challenges of understanding their precise impact on the structure and function of synapses.
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Affiliation(s)
- Wenliang Lei
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Omotola F Omotade
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Kenneth R Myers
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - James Q Zheng
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States; Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, GA 30322, United States.
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40
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Abstract
Dendrite branching is an essential process for building complex nervous systems. It determines the number, distribution and integration of inputs into a neuron, and is regulated to create the diverse dendrite arbor branching patterns characteristic of different neuron types. The microtubule cytoskeleton is critical to provide structure and exert force during dendrite branching. It also supports the functional requirements of dendrites, reflected by differential microtubule architectural organization between neuron types, illustrated here for sensory neurons. Both anterograde and retrograde microtubule polymerization occur within growing dendrites, and recent studies indicate that branching is enhanced by anterograde microtubule polymerization events in nascent branches. The polarities of microtubule polymerization events are regulated by the position and orientation of microtubule nucleation events in the dendrite arbor. Golgi outposts are a primary microtubule nucleation center in dendrites and share common nucleation machinery with the centrosome. In addition, pre-existing dendrite microtubules may act as nucleation sites. We discuss how balancing the activities of distinct nucleation machineries within the growing dendrite can alter microtubule polymerization polarity and dendrite branching, and how regulating this balance can generate neuron type-specific morphologies.
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Affiliation(s)
- Caroline Delandre
- a Laboratory for Genetic Control of Neuronal Architecture, RIKEN Brain Science Institute , Wako , Saitama , Japan
| | - Reiko Amikura
- a Laboratory for Genetic Control of Neuronal Architecture, RIKEN Brain Science Institute , Wako , Saitama , Japan
| | - Adrian W Moore
- a Laboratory for Genetic Control of Neuronal Architecture, RIKEN Brain Science Institute , Wako , Saitama , Japan
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41
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Williams PA, Tribble JR, Pepper KW, Cross SD, Morgan BP, Morgan JE, John SWM, Howell GR. Inhibition of the classical pathway of the complement cascade prevents early dendritic and synaptic degeneration in glaucoma. Mol Neurodegener 2016; 11:26. [PMID: 27048300 PMCID: PMC4822272 DOI: 10.1186/s13024-016-0091-6] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 12/13/2022] Open
Abstract
Background Glaucoma is a complex, multifactorial disease characterised by the loss of retinal ganglion cells and their axons leading to a decrease in visual function. The earliest events that damage retinal ganglion cells in glaucoma are currently unknown. Retinal ganglion cell death appears to be compartmentalised, with soma, dendrite and axon changes potentially occurring through different mechanisms. There is mounting evidence from other neurodegenerative diseases suggesting that neuronal dendrites undergo a prolonged period of atrophy, including the pruning of synapses, prior to cell loss. In addition, recent evidence has shown the role of the complement cascade in synaptic pruning in glaucoma and other diseases. Results Using a genetic (DBA/2J mouse) and an inducible (rat microbead) model of glaucoma we first demonstrate that there is loss of retinal ganglion cell synapses and dendrites at time points that precede axon or soma loss. We next determine the role of complement component 1 (C1) in early synaptic loss and dendritic atrophy during glaucoma. Using a genetic knockout of C1qa (D2.C1qa-/- mouse) or pharmacological inhibition of C1 (in the rat bead model) we show that inhibition of C1 is sufficient to preserve dendritic and synaptic architecture. Conclusions This study further supports assessing the potential for complement-modulating therapeutics for the prevention of retinal ganglion cell degeneration in glaucoma.
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Affiliation(s)
| | - James R Tribble
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | | | - Stephen D Cross
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - B Paul Morgan
- Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Simon W M John
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Department of Ophthalmology, Tufts University of Medicine, Boston, MA, 02111, USA. .,The Howard Hughes Medical Institute, Bar Harbor, ME, 04609, USA.
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA, USA.
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42
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Hensel N, Schön A, Konen T, Lübben V, Förthmann B, Baron O, Grothe C, Leifheit-Nestler M, Claus P, Haffner D. Fibroblast growth factor 23 signaling in hippocampal cells: impact on neuronal morphology and synaptic density. J Neurochem 2016; 137:756-69. [PMID: 26896818 DOI: 10.1111/jnc.13585] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/18/2016] [Accepted: 02/09/2016] [Indexed: 12/16/2022]
Abstract
Endocrine fibroblast growth factor 23 (FGF23) is predominantly secreted by osteocytes and facilitates renal phosphate excretion. However, FGF23 is also present in cerebrospinal fluid. In chronic kidney disease, FGF23 serum levels are excessively elevated and associated with learning and memory deficits. Structural plasticity of the hippocampus such as formation of new synapses or an altered dendritic arborization comprises a cellular and morphological correlate of memory formation. Therefore, we hypothesize that FGF23 alters hippocampal neuron morphology and synapses. To address this, we prepared primary murine hippocampal cultures and incubated them with recombinant FGF23 alone or together with a soluble isoform of its co-receptor α-Klotho. Neuronal expression of a fluorescent reporter allowed for a detailed evaluation of the neuronal morphology by Sholl analysis. Additionally, we evaluated synaptic density, identified by stainings, for synaptic markers. We show an enhanced number of primary neurites combined with a reduced arborization, resulting in a less complex morphology of neurons treated with FGF23. Moreover, FGF23 enhances the synaptic density in a FGF-receptor (FGF-R) dependent manner. Finally, we addressed the corresponding signaling events downstream of FGF-R employing a combination of western blots and quantitative immunofluorescence. Interestingly, FGF23 induces phospholipase Cγ activity in primary hippocampal neurons. Co-application of soluble α-Klotho leads to activation of the Akt-pathway and modifies FGF23-impact on neuronal morphology and synaptic density. Compared with other FGFs, this alternative signaling pattern is a possible reason for differential effects of FGF23 on hippocampal neurons and may thereby contribute to learning and memory deficits in chronic kidney disease patients. In this study, we show that fibroblast growth factor 23 inhibits neuronal ramification and enhances the synaptic density in primary hippocampal cultures accompanied by phospholipase Cγ-activation. Co-application of the co-receptor α-Klotho leads to an Akt-activation and further modifies neuronal morphology and number of synapses. Those effects provide a mechanistic basis for memory deficits in patients suffering from chronic kidney disease (CKD) characterized by excessively elevated FGF23 levels as well as memory deficits.
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Affiliation(s)
- Niko Hensel
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
| | - Anne Schön
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Timo Konen
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
| | - Verena Lübben
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany.,Center of Systems Neuroscience (ZSN) Hannover, Hannover, Germany
| | | | - Olga Baron
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
| | - Claudia Grothe
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany.,Center of Systems Neuroscience (ZSN) Hannover, Hannover, Germany
| | - Maren Leifheit-Nestler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Peter Claus
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany.,Center of Systems Neuroscience (ZSN) Hannover, Hannover, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
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43
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Zwarts L, Vanden Broeck L, Cappuyns E, Ayroles JF, Magwire MM, Vulsteke V, Clements J, Mackay TFC, Callaerts P. The genetic basis of natural variation in mushroom body size in Drosophila melanogaster. Nat Commun 2015; 6:10115. [PMID: 26656654 PMCID: PMC4682101 DOI: 10.1038/ncomms10115] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/04/2015] [Indexed: 11/30/2022] Open
Abstract
Genetic variation in brain size may provide the basis for the evolution of the brain and complex behaviours. The genetic substrate and the selective pressures acting on brain size are poorly understood. Here we use the Drosophila Genetic Reference Panel to map polymorphic variants affecting natural variation in mushroom body morphology. We identify 139 genes and 39 transcription factors and confirm effects on development and adult plasticity. We show correlations between morphology and aggression, sleep and lifespan. We propose that natural variation in adult brain size is controlled by interaction of the environment with gene networks controlling development and plasticity.
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Affiliation(s)
- Liesbeth Zwarts
- KU Leuven—University of Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, B-3000 Leuven, Belgium
- VIB Center for the Biology of Disease, B-3000 Leuven, Belgium
| | - Lies Vanden Broeck
- KU Leuven—University of Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, B-3000 Leuven, Belgium
- VIB Center for the Biology of Disease, B-3000 Leuven, Belgium
| | - Elisa Cappuyns
- KU Leuven—University of Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, B-3000 Leuven, Belgium
- VIB Center for the Biology of Disease, B-3000 Leuven, Belgium
| | - Julien F. Ayroles
- Department of Biological Sciences, Program in Genetics and W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina, 27695-7614, USA
| | - Michael M. Magwire
- Department of Biological Sciences, Program in Genetics and W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina, 27695-7614, USA
| | - Veerle Vulsteke
- KU Leuven—University of Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, B-3000 Leuven, Belgium
- VIB Center for the Biology of Disease, B-3000 Leuven, Belgium
| | - Jason Clements
- KU Leuven—University of Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, B-3000 Leuven, Belgium
- VIB Center for the Biology of Disease, B-3000 Leuven, Belgium
| | - Trudy F. C. Mackay
- Department of Biological Sciences, Program in Genetics and W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, North Carolina, 27695-7614, USA
| | - Patrick Callaerts
- KU Leuven—University of Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, B-3000 Leuven, Belgium
- VIB Center for the Biology of Disease, B-3000 Leuven, Belgium
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Santiago C, Bashaw GJ. Transcription factors and effectors that regulate neuronal morphology. Development 2015; 141:4667-80. [PMID: 25468936 DOI: 10.1242/dev.110817] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Transcription factors establish the tremendous diversity of cell types in the nervous system by regulating the expression of genes that give a cell its morphological and functional properties. Although many studies have identified requirements for specific transcription factors during the different steps of neural circuit assembly, few have identified the downstream effectors by which they control neuronal morphology. In this Review, we highlight recent work that has elucidated the functional relationships between transcription factors and the downstream effectors through which they regulate neural connectivity in multiple model systems, with a focus on axon guidance and dendrite morphogenesis.
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Affiliation(s)
- Celine Santiago
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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45
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Lee J, Peng Y, Lin WY, Parrish JZ. Coordinate control of terminal dendrite patterning and dynamics by the membrane protein Raw. Development 2014; 142:162-73. [PMID: 25480915 DOI: 10.1242/dev.113423] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The directional flow of information in neurons depends on compartmentalization: dendrites receive inputs whereas axons transmit them. Axons and dendrites likewise contain structurally and functionally distinct subcompartments. Axon/dendrite compartmentalization can be attributed to neuronal polarization, but the developmental origin of subcompartments in axons and dendrites is less well understood. To identify the developmental bases for compartment-specific patterning in dendrites, we screened for mutations that affect discrete dendritic domains in Drosophila sensory neurons. From this screen, we identified mutations that affected distinct aspects of terminal dendrite development with little or no effect on major dendrite patterning. Mutation of one gene, raw, affected multiple aspects of terminal dendrite patterning, suggesting that Raw might coordinate multiple signaling pathways to shape terminal dendrite growth. Consistent with this notion, Raw localizes to branch-points and promotes dendrite stabilization together with the Tricornered (Trc) kinase via effects on cell adhesion. Raw independently influences terminal dendrite elongation through a mechanism that involves modulation of the cytoskeleton, and this pathway is likely to involve the RNA-binding protein Argonaute 1 (AGO1), as raw and AGO1 genetically interact to promote terminal dendrite growth but not adhesion. Thus, Raw defines a potential point of convergence in distinct pathways shaping terminal dendrite patterning.
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Affiliation(s)
- Jiae Lee
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Yun Peng
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Wen-Yang Lin
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, WA 98195, USA
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46
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Rasson AS, Bois JS, Pham DSL, Yoo H, Quinlan ME. Filament assembly by Spire: key residues and concerted actin binding. J Mol Biol 2014; 427:824-839. [PMID: 25234086 DOI: 10.1016/j.jmb.2014.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 07/28/2014] [Accepted: 09/04/2014] [Indexed: 01/09/2023]
Abstract
The most recently identified class of actin nucleators, WASp homology domain 2 (WH2) nucleators, use tandem repeats of monomeric actin-binding WH2 domains to facilitate actin nucleation. WH2 domains are involved in a wide variety of actin regulatory activities. Structurally, they are expected to clash with interprotomer contacts within the actin filament. Thus, the discovery of their role in nucleation was surprising. Here we use Drosophila Spire (Spir) as a model system to investigate both how tandem WH2 domains can nucleate actin and what differentiates nucleating WH2-containing proteins from their non-nucleating counterparts. We found that the third WH2 domain in Spir (Spir-C or SC) plays a unique role. In the context of a short nucleation construct (containing only two WH2 domains), placement of SC in the N-terminal position was required for the most potent nucleation. We found that the native organization of the WH2 domains with respect to each other is necessary for binding to actin with positive cooperativity. We identified two residues within SC that are critical for its activity. Using this information, we were able to convert a weak synthetic nucleator into one with activity equal to a native Spir construct. Lastly, we found evidence that SC binds actin filaments, in addition to monomers.
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Affiliation(s)
- Amy S Rasson
- Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles E. Young Drive, Los Angeles, CA 90095, USA
| | - Justin S Bois
- Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles E. Young Drive, Los Angeles, CA 90095, USA
| | - Duy Stephen L Pham
- Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles E. Young Drive, Los Angeles, CA 90095, USA
| | - Haneul Yoo
- Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles E. Young Drive, Los Angeles, CA 90095, USA
| | - Margot E Quinlan
- Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles E. Young Drive, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Paul D. Boyer Hall, 611 Charles E. Young Drive East, Box 951570, Los Angeles, CA 90095-1570, USA.
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47
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Boehme M, Guenther M, Stahr A, Liebmann M, Jaenisch N, Witte OW, Frahm C. Impact of indomethacin on neuroinflammation and hippocampal neurogenesis in aged mice. Neurosci Lett 2014; 572:7-12. [DOI: 10.1016/j.neulet.2014.04.043] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/24/2014] [Accepted: 04/26/2014] [Indexed: 11/24/2022]
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48
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Ferreira T, Ou Y, Li S, Giniger E, van Meyel DJ. Dendrite architecture organized by transcriptional control of the F-actin nucleator Spire. J Cell Sci 2014. [DOI: 10.1242/jcs.149369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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