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Yonemura Y, Sakai Y, Nakata R, Hagita-Tatsumoto A, Miyasaka T, Misonou H. Active Transport by Cytoplasmic Dynein Maintains the Localization of MAP2 in Developing Neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538370. [PMID: 37163107 PMCID: PMC10168327 DOI: 10.1101/2023.04.26.538370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
MAP2 has been widely used as a marker of neuronal dendrites because of its extensive restriction in the somatodendritic region of neurons. Despite that, how the precise localization of such a soluble protein is established and maintained against thermal forces and diffusion has been elusive and long remained a mystery in neuroscience. In this study, we aimed to uncover the mechanism behind how MAP2 is retained in the somatodendritic region. Using GFP-tagged MAP2 expressed in cultured hippocampal neurons, we discovered a crucial protein region responsible for the localization of MAP2, the serine/proline-rich (S/P) region. Our pulse-chase live-cell imaging revealed the slow but steady migration of MAP2 toward distal dendrites, which was not observed in a MAP2 mutant lacking the S/P region, indicating that S/P-dependent transport is vital for the proper localization of MAP2. Furthermore, our experiments using an inhibitor of cytoplasmic Dynein, ciliobrevin D, as well as Dynein knockdown, showed that cytoplasmic Dynein is involved in the transport of MAP2 in dendrites. We also found that Dynein complex binds to MAP2 through the S/P region in heterologous cells. Using mathematical modeling based on experimental data, we confirmed that an intermittent active transport mechanism is essential. Thus, we propose that the cytoplasmic Dynein recruits and transports free MAP2 toward distal dendrites, thereby maintaining the precise dendritic localization of MAP2 in neurons. Our findings shed light on the previously unknown mechanism behind MAP2 localization and provide a new direction for soluble protein trafficking research in the field of cell biology of neurons.
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Parcerisas A, Ortega-Gascó A, Pujadas L, Soriano E. The Hidden Side of NCAM Family: NCAM2, a Key Cytoskeleton Organization Molecule Regulating Multiple Neural Functions. Int J Mol Sci 2021; 22:10021. [PMID: 34576185 PMCID: PMC8471948 DOI: 10.3390/ijms221810021] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/12/2021] [Accepted: 09/14/2021] [Indexed: 02/07/2023] Open
Abstract
Although it has been over 20 years since Neural Cell Adhesion Molecule 2 (NCAM2) was identified as the second member of the NCAM family with a high expression in the nervous system, the knowledge of NCAM2 is still eclipsed by NCAM1. The first studies with NCAM2 focused on the olfactory bulb, where this protein has a key role in axonal projection and axonal/dendritic compartmentalization. In contrast to NCAM1, NCAM2's functions and partners in the brain during development and adulthood have remained largely unknown until not long ago. Recent studies have revealed the importance of NCAM2 in nervous system development. NCAM2 governs neuronal morphogenesis and axodendritic architecture, and controls important neuron-specific processes such as neuronal differentiation, synaptogenesis and memory formation. In the adult brain, NCAM2 is highly expressed in dendritic spines, and it regulates synaptic plasticity and learning processes. NCAM2's functions are related to its ability to adapt to the external inputs of the cell and to modify the cytoskeleton accordingly. Different studies show that NCAM2 interacts with proteins involved in cytoskeleton stability and proteins that regulate calcium influx, which could also modify the cytoskeleton. In this review, we examine the evidence that points to NCAM2 as a crucial cytoskeleton regulation protein during brain development and adulthood. This key function of NCAM2 may offer promising new therapeutic approaches for the treatment of neurodevelopmental diseases and neurodegenerative disorders.
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Affiliation(s)
- Antoni Parcerisas
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, University of Barcelona, 08028 Barcelona, Spain; (A.O.-G.); (L.P.)
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
- Department of Basic Sciences, Universitat Internacional de Catalunya, 08195 Sant Cugat del Vallès, Spain
| | - Alba Ortega-Gascó
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, University of Barcelona, 08028 Barcelona, Spain; (A.O.-G.); (L.P.)
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
| | - Lluís Pujadas
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, University of Barcelona, 08028 Barcelona, Spain; (A.O.-G.); (L.P.)
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
| | - Eduardo Soriano
- Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, University of Barcelona, 08028 Barcelona, Spain; (A.O.-G.); (L.P.)
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
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Wang WJ, Zhong YB, Zhao JJ, Ren M, Zhang SC, Xu MS, Xu ST, Zhang YJ, Shan CL. Transcranial pulse current stimulation improves the locomotor function in a rat model of stroke. Neural Regen Res 2021; 16:1229-1234. [PMID: 33318399 PMCID: PMC8284281 DOI: 10.4103/1673-5374.301018] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Previous studies have shown that transcranial pulse current stimulation (tPCS) can increase cerebral neural plasticity and improve patients’ locomotor function. However, the precise mechanisms underlying this effect remain unclear. In the present study, rat models of stroke established by occlusion of the right cerebral middle artery were subjected to tPCS, 20 minutes per day for 7 successive days. tPCS significantly reduced the Bederson score, increased the foot print area of the affected limbs, and reduced the standing time of affected limbs of rats with stroke compared with that before intervention. Immunofluorescence staining and western blot assay revealed that tPCS significantly increased the expression of microtubule-associated protein-2 and growth-associated protein-43 around the ischemic penumbra. This finding suggests that tPCS can improve the locomotor function of rats with stroke by regulating the expression of microtubule-associated protein-2 and growth-associated protein-43 around the ischemic penumbra. These findings may provide a new method for the clinical treatment of poststroke motor dysfunction and a theoretical basis for clinical application of tPCS. The study was approved by the Animal Use and Management Committee of Shanghai University of Traditional Chinese Medicine of China (approval No. PZSHUTCM190315003) on February 22, 2019.
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Affiliation(s)
- Wen-Jing Wang
- Center of Rehabilitation, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine; School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yan-Biao Zhong
- Center of Rehabilitation, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jing-Jun Zhao
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai; Department of Rehabilitation Medicine, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Meng Ren
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Si-Cong Zhang
- Center of Rehabilitation, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine; School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ming-Shu Xu
- Laboratory of Neurobiology, Shanghai Research Institute of Acupuncture and Meridian, Shanghai, China
| | - Shu-Tian Xu
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ying-Jie Zhang
- Laboratory of Neurobiology, Shanghai Research Institute of Acupuncture and Meridian, Shanghai, China
| | - Chun-Lei Shan
- Center of Rehabilitation, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine; School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Sabogal-Guáqueta AM, Arias-Londoño JD, Gutierrez-Vargas J, Sepulveda-Falla D, Glatzel M, Villegas-Lanau A, Cardona-Gómez GP. Common disbalance in the brain parenchyma of dementias: Phospholipid profile analysis between CADASIL and sporadic Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165797. [PMID: 32302650 DOI: 10.1016/j.bbadis.2020.165797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 10/25/2022]
Abstract
Sporadic Alzheimer's disease (SAD) is the most common form of dementia, and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most frequent hereditary ischemic small vessel disease of the brain. Relevant biomarkers or specific metabolic signatures could provide powerful tools to manage these diseases. Therefore, the main goal of this study was to compare the postmortem frontal cortex gray matter, white matter and cerebrospinal fluid (CSF) between a cognitively healthy group and CADASIL and SAD groups. We evaluated 352 individual lipids, belonging to 13 lipid classes/subclasses, using mass spectrometry, and the lipid profiles were subjected to multivariate analysis to discriminate between the dementia groups (CADASIL and SAD) and healthy controls. The main lipid molecular species showing greater discrimination by partial least squares-discriminant analysis (PLS-DA) and a higher significance multivariate correlation (sMC) index were as follows: phosphatidylserine (PS) PS(44:7) and lysophosphatidylethanolamine (LPE) LPE(18:2) in gray matter (GM); phosphatidylethanolamine (PE) PE(32:2) and phosphatidylcholine PC PC(44:6) in white matter (WM), and ether PE (ePE) ePE(38:2) and ether PC (ePC) ePC(34:3) in CSF. Common phospholipid molecular species were obtained in both dementias, such as PS(44:7) and lyso PC (LPC) LPC(22:5) in GM, PE(32:2) in WM and phosphatidic acid (PA) PA(38:5) and PC(42:7) in CFS. Our exploratory study suggests that phospholipids (PLs) involved in neurotransmission alteration, connectivity impairment and inflammation response in GM, WM and CSF are a transversal phenomenon affecting dementias such as CADASIL and SAD independent of the etiopathogenesis, thus providing a possible common prodromal phospholipidic biomarker of dementia.
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Affiliation(s)
- Angélica María Sabogal-Guáqueta
- Cellular and Molecular Neurobiology Area, Group of Neuroscience, SIU, Faculty of Medicine, University of Antioquia UdeA, Calle 70 No. 52 - 21, Medellín, Colombia
| | - Julián David Arias-Londoño
- Department of Systems Engineering, University of Antioquia UdeA, Calle 70 No. 52 - 21, Medellín, Colombia
| | | | - D Sepulveda-Falla
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg D-20246, Germany; Brain Biobank, Group of Neuroscience, SIU, Faculty of Medicine, University of Antioquia, Calle 70 No. 52 - 21, Medellín, Colombia
| | - M Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg D-20246, Germany
| | - Andrés Villegas-Lanau
- Brain Biobank, Group of Neuroscience, SIU, Faculty of Medicine, University of Antioquia, Calle 70 No. 52 - 21, Medellín, Colombia
| | - Gloria Patricia Cardona-Gómez
- Cellular and Molecular Neurobiology Area, Group of Neuroscience, SIU, Faculty of Medicine, University of Antioquia UdeA, Calle 70 No. 52 - 21, Medellín, Colombia.
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5
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Li D, Musante V, Zhou W, Picciotto MR, Nairn AC. Striatin-1 is a B subunit of protein phosphatase PP2A that regulates dendritic arborization and spine development in striatal neurons. J Biol Chem 2018; 293:11179-11194. [PMID: 29802198 DOI: 10.1074/jbc.ra117.001519] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/06/2018] [Indexed: 01/09/2023] Open
Abstract
Striatin-1, a subunit of the serine/threonine phosphatase PP2A, is preferentially expressed in neurons in the striatum. As a member of the striatin family of B subunits, striatin-1 is a core component together with PP2A of a multiprotein complex called STRIPAK, the striatin-interacting phosphatase and kinase complex. Little is known about the function of striatin-1 or the STRIPAK complex in the mammalian striatum. Here, we identify a selective role for striatin-1 in striatal neuron maturation. Using a small hairpin RNA (shRNA) knockdown approach in primary striatal neuronal cultures, we determined that reduced expression of striatin-1 results in increased dendritic complexity and an increased density of dendritic spines, classified as stubby spines. The dendritic phenotype was rescued by co-expression of a striatin-1 mutant construct insensitive to the knockdown shRNA but was not rescued by co-expression of PP2A- or Mob3-binding deficient striatin-1 constructs. Reduction of striatin-1 did not result in deficits in neuronal connectivity in this knockdown model, as we observed no abnormalities in synapse formation or in spontaneous excitatory postsynaptic currents. Thus, this study suggests that striatin-1 is a regulator of neuronal development in striatal neurons.
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Affiliation(s)
- Daniel Li
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Veronica Musante
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Wenliang Zhou
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Marina R Picciotto
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
| | - Angus C Nairn
- From the Department of Psychiatry, Yale University, New Haven, Connecticut 06520
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Dendritic space-filling requires a neuronal type-specific extracellular permissive signal in Drosophila. Proc Natl Acad Sci U S A 2017; 114:E8062-E8071. [PMID: 28874572 DOI: 10.1073/pnas.1707467114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neurons sometimes completely fill available space in their receptive fields with evenly spaced dendrites to uniformly sample sensory or synaptic information. The mechanisms that enable neurons to sense and innervate all space in their target tissues are poorly understood. Using Drosophila somatosensory neurons as a model, we show that heparan sulfate proteoglycans (HSPGs) Dally and Syndecan on the surface of epidermal cells act as local permissive signals for the dendritic growth and maintenance of space-filling nociceptive C4da neurons, allowing them to innervate the entire skin. Using long-term time-lapse imaging with intact Drosophila larvae, we found that dendrites grow into HSPG-deficient areas but fail to stay there. HSPGs are necessary to stabilize microtubules in newly formed high-order dendrites. In contrast to C4da neurons, non-space-filling sensory neurons that develop in the same microenvironment do not rely on HSPGs for their dendritic growth. Furthermore, HSPGs do not act by transporting extracellular diffusible ligands or require leukocyte antigen-related (Lar), a receptor protein tyrosine phosphatase (RPTP) and the only known Drosophila HSPG receptor, for promoting dendritic growth of space-filling neurons. Interestingly, another RPTP, Ptp69D, promotes dendritic growth of C4da neurons in parallel to HSPGs. Together, our data reveal an HSPG-dependent pathway that specifically allows dendrites of space-filling neurons to innervate all target tissues in Drosophila.
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Liu Y, Xu YF, Zhang L, Huang L, Yu P, Zhu H, Deng W, Qin C. Effective expression of Drebrin in hippocampus improves cognitive function and alleviates lesions of Alzheimer's disease in APP (swe)/PS1 (ΔE9) mice. CNS Neurosci Ther 2017; 23:590-604. [PMID: 28597477 DOI: 10.1111/cns.12706] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 04/18/2017] [Accepted: 04/18/2017] [Indexed: 02/06/2023] Open
Abstract
AIMS Alzheimer's disease (AD), a progressive development dementia, is increasingly impacting patients' living conditions worldwide. Despite medical care and funding support, there are still no highly individualized drugs and practical strategies for clinical prevention and treatment. Developmentally regulated brain protein (abbreviated as Drebrin or Dbn, also known as Dbn1 in mouse) exists in neurons, especially in dendrites, and is an actin-binding protein that modulates synaptic morphology and long-term memory. However, the majority of previous studies have focused on its upstream proteins and neglected the impact Drebrin has on behavior and AD in vivo. METHODS Here, we tracked the behavioral performances of 4-, 8-, 12-, and 16-month-old AD mice and investigated the expression level of Drebrin in their hippocampi. A Pearson correlation analysis between Drebrin levels and behavioral data was performed. Subsequently, 2-month-old AD mice were injected with rAAV-zsGreen-Dbn1 vector, composing the APP/PS1-Dbn1 group, and sex- and age-matched AD mice were injected with rAAV-tdTomato vector to serve as the control group. All mice were conducted behavioral tests and molecular detection 6 months later. RESULTS (i) The expression of Drebrin is decreased in the hippocampus of aged AD mice compared with that of age-matched WT and young adult AD mice; (ii) cognitive ability of APP/PS1 mice decreases with age; (iii) Drebrin protein expression in the hippocampus correlates with behavioral performance in different aged AD mice; (iv) cognitive ability improved significantly in APP/PS1-Dbn1 mice; (v) the expression level of Drebrin in APP/PS1-Dbn1 mouse hippocampus was significantly increased; (vi) the pathological lesion of AD was alleviated in APP/PS1-Dbn1 mice; (vii) the filamentous actin (F-actin) and microtubule-associated protein 2(MAP-2) in APP/PS1-Dbn1 mice were notably more than control mice. CONCLUSION In this study, an effective expression of Drebrin improves cognitive abilities and alleviates lesions in an AD mouse model. These results may provide some valid resources for therapy and research of AD.
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Affiliation(s)
- Yan Liu
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Yan-Feng Xu
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Ling Zhang
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Lan Huang
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Pin Yu
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Hua Zhu
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Wei Deng
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Chuan Qin
- Comparative Medicine Centre, Peking Union Medical College (PUMC) and Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS), Beijing, China
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Hoffman A, Taleski G, Sontag E. The protein serine/threonine phosphatases PP2A, PP1 and calcineurin: A triple threat in the regulation of the neuronal cytoskeleton. Mol Cell Neurosci 2017; 84:119-131. [PMID: 28126489 DOI: 10.1016/j.mcn.2017.01.005] [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: 09/02/2016] [Revised: 01/16/2017] [Accepted: 01/21/2017] [Indexed: 01/08/2023] Open
Abstract
The microtubule, F-actin and neurofilament networks play a critical role in neuronal cell morphogenesis, polarity and synaptic plasticity. Significantly, the assembly/disassembly and stability of these cytoskeletal networks is crucially modulated by protein phosphorylation and dephosphorylation events. Herein, we aim to more closely examine the role played by three major neuronal Ser/Thr protein phosphatases, PP2A, PP1 and calcineurin, in the homeostasis of the neuronal cytoskeleton. There is strong evidence that these enzymes interact with and dephosphorylate a variety of cytoskeletal proteins, resulting in major regulation of neuronal cytoskeletal dynamics. Conversely, we also discuss how multi-protein cytoskeletal scaffolds can also influence the regulation of these phosphatases, with important implications for neuronal signalling and homeostasis. Not surprisingly, deregulation of these cytoskeletal scaffolds and phosphatase dysfunction are associated with many neurological diseases.
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Affiliation(s)
- Alexander Hoffman
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, and Hunter Medical Research Institute, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Goce Taleski
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, and Hunter Medical Research Institute, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Estelle Sontag
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, and Hunter Medical Research Institute, University of Newcastle, Callaghan, NSW 2308, Australia.
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Shelton MA, Newman JT, Gu H, Sampson AR, Fish KN, MacDonald ML, Moyer CE, DiBitetto JV, Dorph-Petersen KA, Penzes P, Lewis DA, Sweet RA. Loss of Microtubule-Associated Protein 2 Immunoreactivity Linked to Dendritic Spine Loss in Schizophrenia. Biol Psychiatry 2015; 78:374-85. [PMID: 25818630 PMCID: PMC4520801 DOI: 10.1016/j.biopsych.2014.12.029] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 11/25/2014] [Accepted: 12/19/2014] [Indexed: 02/05/2023]
Abstract
BACKGROUND Microtubule-associated protein 2 (MAP2) is a neuronal protein that plays a role in maintaining dendritic structure through its interaction with microtubules. In schizophrenia (Sz), numerous studies have revealed that the typically robust immunoreactivity (IR) of MAP2 is significantly reduced across several cortical regions. The relationship between MAP2-IR reduction and lower dendritic spine density, which is frequently reported in Sz, has not been explored in previous studies, and MAP2-IR loss has not been investigated in the primary auditory cortex (Brodmann area 41), a site of conserved pathology in Sz. METHODS Using quantitative spinning disk confocal microscopy in two cohorts of subjects with Sz and matched control subjects (Sz subjects, n = 20; control subjects, n = 20), we measured MAP2-IR and dendritic spine density and spine number in deep layer 3 of BA41. RESULTS Subjects with Sz exhibited a significant reduction in MAP2-IR. The reductions in MAP2-IR were not associated with neuron loss, loss of MAP2 protein, clinical confounders, or technical factors. Dendritic spine density and number also were reduced in Sz and correlated with MAP2-IR. In 12 (60%) subjects with Sz, MAP2-IR values were lower than the lowest values in control subjects; only in this group were spine density and number significantly reduced. CONCLUSIONS These findings demonstrate that MAP2-IR loss is closely linked to dendritic spine pathology in Sz. Because MAP2 shares substantial sequence, regulatory, and functional homology with MAP tau, the wealth of knowledge regarding tau biology and the rapidly expanding field of tau therapeutics provide resources for identifying how MAP2 is altered in Sz and possible leads to novel therapeutics.
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Affiliation(s)
- Micah A Shelton
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jason T Newman
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Hong Gu
- Department of Statistics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Allan R Sampson
- Department of Statistics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Kenneth N Fish
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Matthew L MacDonald
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Caitlin E Moyer
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - James V DiBitetto
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Karl-Anton Dorph-Petersen
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University, Aarhus, Denmark
| | - Peter Penzes
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - David A Lewis
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Robert A Sweet
- Translational Neuroscience Program, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania.
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10
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Motor recovery and cortical plasticity after functional electrical stimulation in a rat model of focal stroke. Am J Phys Med Rehabil 2015; 93:791-800. [PMID: 24800715 DOI: 10.1097/phm.0000000000000104] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE The aim of this study was to investigate the functional responses and plastic cortical changes in a sample of animals with sequelae of cerebral ischemia that were subjected to a model of functional electrical stimulation (FES). DESIGN Rats received an ischemic cortical lesion (Rose Bengal method) and were randomized and submitted to an FES stimulation (1-2 mA, 30 Hz, 20-40 mins for 14 days) or sham stimulation. The Foot Fault Test was performed before inducing the cortical lesion and also before and after FES. Brain immunochemistry labeling with microtubule-associated protein-2 and neurofilament-200 markers was performed after FES. RESULTS The authors found a decreased percentage of errors in the Foot Fault Test (P < 0.001) in the stimulated group compared with the sham group after FES. FES has not altered the lesion size. Spontaneous motor parameters returned to basal values in both groups. The qualitative analysis showed an increased amount of radial microtubule-associated protein-2 immunoreactive fibers in the preserved cortex adjacent to stroke site in the stimulated animals. Regarding the measurements of neurofilament-200 immunostaining, there were no differences between the hemispheres or groups in area or intensity. CONCLUSIONS Acute and short period of FES led to motor recovery of ankle joint neurodisability. The extent to which compensatory plasticity occurs after stroke or after FES and the extent to which it contributes to functional recovery are yet unclear. The changes induced by the stimulation may improve the ability of the nervous system to undergo spontaneous recovery, which is of substantial interest for neurorehabilitation strategies.
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Chow AM, Tang DWF, Hanif A, Brown IR. Localization of heat shock proteins in cerebral cortical cultures following induction by celastrol. Cell Stress Chaperones 2014; 19:845-51. [PMID: 24700193 PMCID: PMC4389844 DOI: 10.1007/s12192-014-0508-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 03/17/2014] [Accepted: 03/19/2014] [Indexed: 12/28/2022] Open
Abstract
Hsp70, Hsp32, and Hsp27 were induced by celastrol in rat cerebral cortical cultures at dosages that did not affect cell viability. Pronounced differences were observed in the cellular localization of these heat shock proteins in cell types of cerebral cortical cultures. Celastrol-induced Hsp70 localized to the cell body and cellular processes of neurons that were identified by neuron-specific βIII-tubulin. Hsp70 was not detected in adjacent GFAP-positive glial cells that demonstrated a strong signal for Hsp27 and Hsp32 in both glial cell bodies and cellular processes. Cells in the cerebral cortex region of the brain are selectively impacted during the progression of Alzheimer's disease which is a "protein misfolding disorder." Heat shock proteins provide a line of defense against misfolded, aggregation-prone proteins. Celastrol is a potential agent to counter this neurodegenerative disorder as recent evidence indicates that in vivo administration of celastrol in a transgenic model of Alzheimer's reduces an important neuropathological hallmark of this disease, namely, amyloid beta pathology that involves protein aggregation.
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Affiliation(s)
- Ari M. Chow
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4 Canada
| | - Derek W. F. Tang
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4 Canada
| | - Asad Hanif
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4 Canada
| | - Ian R. Brown
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4 Canada
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Komulainen E, Zdrojewska J, Freemantle E, Mohammad H, Kulesskaya N, Deshpande P, Marchisella F, Mysore R, Hollos P, Michelsen KA, Mågard M, Rauvala H, James P, Coffey ET. JNK1 controls dendritic field size in L2/3 and L5 of the motor cortex, constrains soma size, and influences fine motor coordination. Front Cell Neurosci 2014; 8:272. [PMID: 25309320 PMCID: PMC4162472 DOI: 10.3389/fncel.2014.00272] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 08/20/2014] [Indexed: 11/23/2022] Open
Abstract
Genetic anomalies on the JNK pathway confer susceptibility to autism spectrum disorders, schizophrenia, and intellectual disability. The mechanism whereby a gain or loss of function in JNK signaling predisposes to these prevalent dendrite disorders, with associated motor dysfunction, remains unclear. Here we find that JNK1 regulates the dendritic field of L2/3 and L5 pyramidal neurons of the mouse motor cortex (M1), the main excitatory pathway controlling voluntary movement. In Jnk1-/- mice, basal dendrite branching of L5 pyramidal neurons is increased in M1, as is cell soma size, whereas in L2/3, dendritic arborization is decreased. We show that JNK1 phosphorylates rat HMW-MAP2 on T1619, T1622, and T1625 (Uniprot P15146) corresponding to mouse T1617, T1620, T1623, to create a binding motif, that is critical for MAP2 interaction with and stabilization of microtubules, and dendrite growth control. Targeted expression in M1 of GFP-HMW-MAP2 that is pseudo-phosphorylated on T1619, T1622, and T1625 increases dendrite complexity in L2/3 indicating that JNK1 phosphorylation of HMW-MAP2 regulates the dendritic field. Consistent with the morphological changes observed in L2/3 and L5, Jnk1-/- mice exhibit deficits in limb placement and motor coordination, while stride length is reduced in older animals. In summary, JNK1 phosphorylates HMW-MAP2 to increase its stabilization of microtubules while at the same time controlling dendritic fields in the main excitatory pathway of M1. Moreover, JNK1 contributes to normal functioning of fine motor coordination. We report for the first time, a quantitative Sholl analysis of dendrite architecture, and of motor behavior in Jnk1-/- mice. Our results illustrate the molecular and behavioral consequences of interrupted JNK1 signaling and provide new ground for mechanistic understanding of those prevalent neuropyschiatric disorders where genetic disruption of the JNK pathway is central.
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Affiliation(s)
- Emilia Komulainen
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | - Justyna Zdrojewska
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | - Erika Freemantle
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | - Hasan Mohammad
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | | | - Prasannakumar Deshpande
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | - Francesca Marchisella
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | - Raghavendra Mysore
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | - Patrik Hollos
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
| | | | - Mats Mågard
- Institute for Immune Technology, Medicon Village, University of Lund Lund, Sweden
| | - Heikki Rauvala
- Neuroscience Center, University of Helsinki Helsinki, Finland
| | - Peter James
- Institute for Immune Technology, Medicon Village, University of Lund Lund, Sweden
| | - Eleanor T Coffey
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
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Kida E, Rabe A, Walus M, Albertini G, Golabek AA. Long-term running alleviates some behavioral and molecular abnormalities in Down syndrome mouse model Ts65Dn. Exp Neurol 2013. [DOI: 10.1016/j.expneurol.2012.11.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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14
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Sontag JM, Nunbhakdi-Craig V, White CL, Halpain S, Sontag E. The protein phosphatase PP2A/Bα binds to the microtubule-associated proteins Tau and MAP2 at a motif also recognized by the kinase Fyn: implications for tauopathies. J Biol Chem 2012; 287:14984-93. [PMID: 22403409 DOI: 10.1074/jbc.m111.338681] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The predominant brain microtubule-associated proteins MAP2 and tau play a critical role in microtubule cytoskeletal organization and function. We have previously reported that PP2A/Bα, a major protein phosphatase 2A (PP2A) holoenzyme, binds to and dephosphorylates tau, and regulates microtubule stability. Here, we provide evidence that MAP2 co-purifies with and is dephosphorylated by endogenous PP2A/Bα in bovine gray matter. It co-localizes with PP2A/Bα in immature and mature human neuronal cell bodies. PP2A co-immunoprecipitates with and directly interacts with MAP2. Using in vitro binding assays, we show that PP2A/Bα binds to MAP2c isoforms through a region encompassing the microtubule-binding domain and upstream proline-rich region. Tau and MAP2 compete for binding to and dephosphorylation by PP2A/Bα. Remarkably, the protein-tyrosine kinase Fyn, which binds to the proline-rich RTPPKSP motif conserved in both MAP2 and tau, inhibits the interaction of PP2A/Bα with either tau or MAP2c. The corresponding synthetic RTPPKSP peptide, but not the phosphorylated RpTPPKSP version, competes with Tau and MAP2c for binding to PP2A/Bα. Significantly, down-regulation of PP2A/Bα and deregulation of Fyn-Tau protein interactions have been linked to enhanced tau phosphorylation in Alzheimer disease. Together, our results suggest that PP2A/Bα is part of segregated MAP2 and tau signaling scaffolds that can coordinate the action of key kinases and phosphatases involved in modulating neuronal plasticity. Deregulation of these compartmentalized multifunctional protein complexes is likely to contribute to tau deregulation, microtubule disruption, and altered signaling in tauopathies.
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Affiliation(s)
- Jean-Marie Sontag
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales 2308, Australia
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15
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Microtubule-Associated Proteins as Indicators of Differentiation and the Functional State of Nerve Cells. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11055-012-9556-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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16
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Theunissen PT, Robinson JF, Pennings JLA, de Jong E, Claessen SMH, Kleinjans JCS, Piersma AH. Transcriptomic concentration-response evaluation of valproic acid, cyproconazole, and hexaconazole in the neural embryonic stem cell test (ESTn). Toxicol Sci 2011; 125:430-8. [PMID: 22045034 DOI: 10.1093/toxsci/kfr293] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Alternative developmental toxicity assays are urgently needed to reduce animal use in regulatory developmental toxicology. We previously designed an in vitro murine neural embryonic stem cell test (ESTn) as a model for neurodevelopmental toxicity testing (Theunissen et al., 2010). Toxicogenomic approaches have been suggested for incorporation into the ESTn to further increase predictivity and to provide mechanistic insights. Therefore, in this study, using a transcriptomic approach, we investigated the concentration-dependent effects of three known (neuro) developmental toxicants, two triazoles, cyproconazole (CYP) and hexaconazole (HEX), and the anticonvulsant valproic acid (VPA). Compound effects on gene expression during neural differentiation and corresponding regulated gene ontology (GO) terms were identified after 24 h of exposure in relation to morphological changes on day 11 of culture. Concentration-dependent responses on individual gene expression and on biological processes were determined for each compound, providing information on mechanism and concentration-response characteristics. All compounds caused enrichment of the embryonic development process. CYP and VPA but not HEX significantly enriched the neuron development process. Furthermore, specific responses for triazole compounds and VPA were observed within the GO-term sterol metabolic process. The incorporation of transcriptomics in the ESTn was shown to enable detection of effects, which precede morphological changes and provide a more sensitive measure of concentration-dependent effects as compared with classical morphological assessments. Furthermore, mechanistic insight can be instrumental in the extrapolation of effects in the ESTn to human hazard assessment.
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Affiliation(s)
- Peter T Theunissen
- Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), 3720 BA Bilthoven, The Netherlands.
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17
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Pennucci R, Tavano S, Tonoli D, Gualdoni S, de Curtis I. Rac1 and Rac3 GTPases regulate the development of hilar mossy cells by affecting the migration of their precursors to the hilus. PLoS One 2011; 6:e24819. [PMID: 21949760 PMCID: PMC3176786 DOI: 10.1371/journal.pone.0024819] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 08/18/2011] [Indexed: 11/21/2022] Open
Abstract
We have previously shown that double deletion of the genes for Rac1 and Rac3 GTPases during neuronal development affects late developmental events that perturb the circuitry of the hippocampus, with ensuing epileptic phenotype. These effects include a defect in mossy cells, the major class of excitatory neurons of the hilus. Here, we have addressed the mechanisms that affect the loss of hilar mossy cells in the dorsal hippocampus of mice depleted of the two Rac GTPases. Quantification showed that the loss of mossy cells was evident already at postnatal day 8, soon after these cells become identifiable by a specific marker in the dorsal hilus. Comparative analysis of the hilar region from control and double mutant mice revealed that synaptogenesis was affected in the double mutants, with strongly reduced presynaptic input from dentate granule cells. We found that apoptosis was equally low in the hippocampus of both control and double knockout mice. Labelling with bromodeoxyuridine at embryonic day 12.5 showed no evident difference in the proliferation of neuronal precursors in the hippocampal primordium, while differences in the number of bromodeoxyuridine-labelled cells in the developing hilus revealed a defect in the migration of immature, developing mossy cells in the brain of double knockout mice. Overall, our data show that Rac1 and Rac3 GTPases participate in the normal development of hilar mossy cells, and indicate that they are involved in the regulation of the migration of the mossy cell precursor by preventing their arrival to the dorsal hilus.
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Affiliation(s)
- Roberta Pennucci
- Cell Adhesion Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milano, Italy
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18
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Felfly H, Xue J, Zambon AC, Muotri A, Zhou D, Haddad GG. Identification of a neuronal gene expression signature: role of cell cycle arrest in murine neuronal differentiation in vitro. Am J Physiol Regul Integr Comp Physiol 2011; 301:R727-45. [PMID: 21677276 PMCID: PMC3174756 DOI: 10.1152/ajpregu.00217.2011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 06/08/2011] [Indexed: 12/11/2022]
Abstract
Stem cells are a potential key strategy for treating neurodegenerative diseases in which the generation of new neurons is critical. A better understanding of the characteristics and molecular properties of neural stem cells (NSCs) and differentiated neurons can help with assessing neuronal maturity and, possibly, in devising better therapeutic strategies. We have performed an in-depth gene expression profiling study of murine NSCs and primary neurons derived from embryonic mouse brains. Microarray analysis revealed a neuron-specific gene expression signature that distinguishes primary neurons from NSCs, with elevated levels of transcripts involved in neuronal functions, such as neurite development and axon guidance in primary neurons and decreased levels of multiple cytokine transcripts. Among the differentially expressed genes, we found a statistically significant enrichment of genes in the ephrin, neurotrophin, CDK5, and actin pathways, which control multiple neuronal-specific functions. We then artificially blocked the cell cycle of NSCs with mitomycin C (MMC) and examined cellular morphology and gene expression signatures. Although these MMC-treated NSCs displayed a neuronal morphology and expressed some neuronal differentiation marker genes, their gene expression patterns were very different from primary neurons. We conclude that 1) fully differentiated mouse primary neurons display a specific neuronal gene expression signature; 2) cell cycle block at the S phase in NSCs with MMC does not induce the formation of fully differentiated neurons; 3) cytokines change their expression pattern during differentiation of NSCs into neurons; and 4) signaling pathways of ephrin, neurotrophin, CDK5, and actin, related to major neuronal features, are dynamically enriched in genes showing changes in expression level.
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Affiliation(s)
- Hady Felfly
- Department of Pediatrics, School of Medicine, University of California San Diego, CA, USA
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19
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Gardiner J, Overall R, Marc J. The microtubule cytoskeleton acts as a key downstream effector of neurotransmitter signaling. Synapse 2011; 65:249-56. [PMID: 20687109 DOI: 10.1002/syn.20841] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microtubules are well known to play a key role in the trafficking of neurotransmitters to the synapse. However, less attention has been paid to their role as downstream effectors of neurotransmitter signaling in the target neuron. Here, we show that neurotransmitter-based signaling to the microtubule cytoskeleton regulates downstream microtubule function through several mechanisms. These include tubulin posttranslational modification, binding of microtubule-associated proteins, release of microtubule-interacting second messenger molecules, and regulation of tubulin expression levels. We review the evidence for neurotransmitter regulation of the microtubule cytoskeleton, focusing on the neurotransmitters serotonin, melatonin, dopamine, glutamate, glycine, and acetylcholine. Some evidence suggests that microtubules may even play a more direct role in propagating action potentials through conductance of electric current. In turn, there is evidence for the regulation of neurotransmission by the microtubule cytoskeleton.
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Affiliation(s)
- John Gardiner
- The School of Biological Sciences, The University of Sydney 2006, New South Wales, Australia.
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20
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Huang J, Furuya A, Hayashi K, Furuichi T. Interaction between very-KIND Ras guanine exchange factor and microtubule-associated protein 2, and its role in dendrite growth--structure and function of the second kinase noncatalytic C-lobe domain. FEBS J 2011; 278:1651-61. [PMID: 21385318 DOI: 10.1111/j.1742-4658.2011.08085.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The kinase noncatalytic C-lobe domain (KIND) is a putative protein-protein interaction module. Four KIND-containing proteins, Spir-2 (actin-nuclear factor), PTPN13 (protein tyrosine phosphatase), FRMPD2 (scaffold protein) and very-KIND (v-KIND) (brain-specific Ras guanine nucleotide exchange factor), have been identified to date. Uniquely, v-KIND has two KINDs (i.e. KIND1 and KIND2), whereas the other three proteins have only one. The functional role of KIND, however, remains unclear. We previously demonstrated that v-KIND interacts with the high-molecular weight microtubule-associated protein 2 (MAP2), a dendritic microtubule-associated protein, leading to negative regulation of neuronal dendrite growth. In the present study, we analyzed the structure-function relationships of the v-KIND-MAP2 interaction by generating a series of mutant constructs. The interaction with endogenous MAP2 in mouse cerebellar granule cells was specific to v-KIND KIND2, but not KIND1, and was not observed for the KINDs from other KIND-containing proteins. The binding core modules critical for the v-KIND-MAP2 interaction were defined within 32 residues of the mouse v-KIND KIND2 and 43 residues of the mouse MAP2 central domain. Three Leu residues at amino acid positions 461, 474 and 477 in the MAP2-binding core module of KIND2 contributed to the interaction. The MAP2-binding core module itself promoted dendrite branching as a dominant-negative regulator of v-KIND in hippocampal neurons. The results reported in the present study demonstrate the structural and functional determinant underlying the v-KIND-MAP2 interaction that controls dendrite arborization patterns.
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Affiliation(s)
- Jinhong Huang
- Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Saitama, Japan
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21
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Hamodeh S, Eicke D, Napper R, Harvey R, Sultan F. Population based quantification of dendrites: evidence for the lack of microtubule-associate protein 2a,b in Purkinje cell spiny dendrites. Neuroscience 2010; 170:1004-14. [DOI: 10.1016/j.neuroscience.2010.08.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 08/04/2010] [Accepted: 08/11/2010] [Indexed: 01/14/2023]
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22
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An abbreviated protocol for multilineage neural differentiation of murine embryonic stem cells and its perturbation by methyl mercury. Reprod Toxicol 2010; 29:383-92. [PMID: 20412851 DOI: 10.1016/j.reprotox.2010.04.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 04/08/2010] [Accepted: 04/09/2010] [Indexed: 12/19/2022]
Abstract
Alternative assays are highly desirable to reduce the extensive experimental animal use in developmental toxicity testing. In the present study, we developed an improved test system for assessing neurodevelopmental toxicity using differentiating embryonic stem cells. We advanced previously established methods by merging, modifying and abbreviating the original 20-day protocol into a more efficient 13-day neural differentiation protocol. Using morphological observation, immunocytochemistry, gene expression and flow cytometry, it was shown predominantly multiple lineages of neuroectodermal cells were formed in our protocol and to a lower extent, endodermal and mesodermal differentiated cell types. This abbreviated protocol should lead to an advanced screening method using morphology in combination with selected differentiation markers aimed at predicting neurodevelopmental toxicity. Finally, the assay was shown to express differential sensitivity to a model developmental neurotoxicant, methyl mercury.
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23
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Microtubule assembly, organization and dynamics in axons and dendrites. Nat Rev Neurosci 2009; 10:319-32. [PMID: 19377501 DOI: 10.1038/nrn2631] [Citation(s) in RCA: 769] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
During the past decade enormous advances have been made in our understanding of the basic molecular machinery that is involved in the development of neuronal polarity. Far from being mere structural elements, microtubules are emerging as key determinants of neuronal polarity. Here we review the current understanding of the regulation of microtubule assembly, organization and dynamics in axons and dendrites. These studies provide new insight into microtubules' function in neuronal development and their potential contribution to plasticity.
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