501
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Van den Hove DLA, Kenis G, Brass A, Opstelten R, Rutten BPF, Bruschettini M, Blanco CE, Lesch KP, Steinbusch HWM, Prickaerts J. Vulnerability versus resilience to prenatal stress in male and female rats; implications from gene expression profiles in the hippocampus and frontal cortex. Eur Neuropsychopharmacol 2013. [PMID: 23199416 DOI: 10.1016/j.euroneuro.2012.09.011] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Adverse life events during pregnancy may impact upon the developing fetus, predisposing prenatally stressed offspring to the development of psychopathology. In the present study, we examined the effects of prenatal restraint stress (PS) on anxiety- and depression-related behavior in both male and female adult Sprague-Dawley rats. In addition, gene expression profiles within the hippocampus and frontal cortex (FC) were examined in order to gain more insight into the molecular mechanisms that mediate the behavioral effects of PS exposure. PS significantly increased anxiety-related behavior in male, but not female offspring. Likewise, depression-related behavior was increased in male PS rats only. Further, male PS offspring showed increased basal plasma corticosterone levels in adulthood, whereas both PS males and females had lower stress-induced corticosterone levels when compared to controls. Microarray-based profiling of the hippocampus and FC showed distinct sex-dependent changes in gene expression after PS. Biological processes and/or signal transduction cascades affected by PS included glutamatergic and GABAergic neurotransmission, mitogen-activated protein kinase (MAPK) signaling, neurotrophic factor signaling, phosphodiesterase (PDE)/ cyclic nucleotide signaling, glycogen synthase kinase 3 (GSK3) signaling, and insulin signaling. Further, the data indicated that epigenetic regulation is affected differentially in male and female PS offspring. These sex-specific alterations may, at least in part, explain the behavioral differences observed between both sexes, i.e. relative vulnerability versus resilience to PS in male versus female rats, respectively. These data reveal novel potential targets for antidepressant and mood stabilizing drug treatments including PDE inhibitors and histone deacetylase (HDAC) inhibitors.
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Affiliation(s)
- D L A Van den Hove
- Department of Neuroscience, School for Mental Health and Neuroscience (MHeNS), Maastricht University, European Graduate School of Neuroscience (EURON), Universiteitssingel 50, P.O. Box 616, 6200 MD, Maastricht, The Netherlands; Molecular Psychiatry, Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany.
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502
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Phosphorylation of threonine-19 of PSD-95 by GSK-3β is required for PSD-95 mobilization and long-term depression. J Neurosci 2013; 33:12122-35. [PMID: 23864697 DOI: 10.1523/jneurosci.0131-13.2013] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Activity of glycogen synthase kinase-3β (GSK-3β) is required for long-term depression (LTD) via molecular mechanisms that are incompletely understood. Here, we report that PSD-95, a major scaffold protein of the postsynaptic density (PSD) that promotes synaptic strength, is phosphorylated on threonine-19 (T19) by GSK-3β. In cultured rat hippocampal neurons, phosphorylation of T19 increases rapidly with chemical LTD and is attenuated by pharmacologic or genetic suppression of GSK-3β. In organotypic rat hippocampal slices, we find that a nonphosphorylatable PSD-95 mutant (T19A) tagged with photoactivatable green fluorescent protein (PAGFP) shows enhanced stability in dendritic spines versus wild-type PSD-95, whereas the phosphomimetic mutant (PSD-95-T19D) is more readily dispersed. Further, overexpression of PSD-95-T19A, but not WT-PSD-95, impairs AMPA receptor internalization and the induction of LTD. These data indicate that phosphorylation on T19 by GSK-3β destabilizes PSD-95 within the PSD and is a critical step for AMPA receptor mobilization and LTD.
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503
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Chang SLY, Chou RH, Zeng HJ, Lin YH, Chiu TY, Yang DM, Hung SC, Lai CH, Hsieh JT, Shyu WC, Yu YL. Downregulation of DAB2IP promotes mesenchymal-to-neuroepithelial transition and neuronal differentiation of human mesenchymal stem cells. PLoS One 2013; 8:e75884. [PMID: 24073285 PMCID: PMC3779184 DOI: 10.1371/journal.pone.0075884] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 08/16/2013] [Indexed: 12/05/2022] Open
Abstract
The DOC-2/DAB2 interactive protein (DAB2IP) is a new member of the Ras GTPase–activating protein family. Recent studies have shown that, in addition to its tumor suppressive role in various tumors, DAB2IP also plays an important role in regulating neuronal migration and positioning during brain development. In this study, we determined the roles of DAB2IP in the neuronal differentiation of human mesenchymal stem cells (hMSCs). We found that lentiviral short hairpin RNA (shRNA)-mediated knockdown of DAB2IP promoted the mesenchymal-to-neuroepithelial stem cell transition (MtNeST) and neuronal differentiation, which were accompanied by a reduction of cell proliferation but not apoptosis or cellular senescence. This suggests that DAB2IP plays an important role in the neuronal induction of hMSCs. Moreover, our finding that reduction of glycogen synthase kinase 3 beta (GSK3β) activity upon LiCl pretreatment inhibited both the MtNeST and production of MAP2-positive cells upon DAB2IP knockdown suggests that this transition is most likely mediated by regulation of the GSK3β signaling pathway. Our study demonstrates that DAB2IP participates in the first step of neuron induction of hMSCs, which implies a potentially important role for DAB2IP in the MtNeST during neurogenesis.
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Affiliation(s)
- Sunny Li-Yun Chang
- Graduate Institute of Basic Medical Science, and Graduate Institute of Molecular Systems Biomedicine, China Medical University, Taichung, Taiwan
| | - Ruey-Hwang Chou
- Graduate Institute of Cancer Biology, and Center for Molecular Medicine, China Medical University, Taichung, Taiwan
- Department of Biotechnology, Asia University, Taichung, Taiwan
| | - Hong-Jie Zeng
- Graduate Institute of Cancer Biology, and Center for Molecular Medicine, China Medical University, Taichung, Taiwan
| | - Yu-Hsuan Lin
- Graduate Institute of Cancer Biology, and Center for Molecular Medicine, China Medical University, Taichung, Taiwan
| | - Tai-Yu Chiu
- Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Biophotonics, School of Medical Technology and Engineering and Biophotonics and Molecular Imaging Research Center, National Yang-Ming University, Taipei, Taiwan
| | - De-Ming Yang
- Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Biophotonics, School of Medical Technology and Engineering and Biophotonics and Molecular Imaging Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Shih-Chieh Hung
- Stem Cell Laboratory, Department of Medical Research and Education, Orthopaedics and Traumatology, Taipei Veterans General Hospital and Institute of Clinical Medicine, Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Chih-Ho Lai
- Department of Microbiology, School of Medicine, Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Jer-Tsong Hsieh
- University of Texas, Department of Urology, Southwestern Medical Center, Dallas, Texas, United States of America
| | - Woei-Cherng Shyu
- Graduate Institute of Immunology, China Medical University, Taichung, Taiwan
- Translational Medicine Research Center and Center for Neuropsychiatry, China Medical University Hospital, Taichung, Taiwan
- * E-mail: (YLY); (WCS)
| | - Yung-Luen Yu
- Graduate Institute of Cancer Biology, and Center for Molecular Medicine, China Medical University, Taichung, Taiwan
- Department of Biotechnology, Asia University, Taichung, Taiwan
- * E-mail: (YLY); (WCS)
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504
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Lepski G, Jannes CE, Nikkhah G, Bischofberger J. cAMP promotes the differentiation of neural progenitor cells in vitro via modulation of voltage-gated calcium channels. Front Cell Neurosci 2013; 7:155. [PMID: 24065885 PMCID: PMC3777016 DOI: 10.3389/fncel.2013.00155] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 08/28/2013] [Indexed: 12/01/2022] Open
Abstract
The molecular mechanisms underlying the differentiation of neural progenitor cells (NPCs) remain poorly understood. In this study we investigated the role of Ca2+ and cAMP (cyclic adenosine monophosphate) in the differentiation of NPCs extracted from the subventricular zone of E14.5 rat embryos. Patch clamp recordings revealed that increasing cAMP-signaling with Forskolin or IBMX (3-isobutyl-1-methylxantine) significantly facilitated neuronal functional maturation. A continuous application of IBMX to the differentiation medium substantially increased the functional expression of voltage-gated Na+ and K+ channels, as well as neuronal firing frequency. Furthermore, we observed an increase in the frequency of spontaneous synaptic currents and in the amplitude of evoked glutamatergic and GABAergic synaptic currents. The most prominent acute effect of applying IBMX was an increase in L-type Ca2+currents. Conversely, blocking L-type channels strongly inhibited dendritic outgrowth and synapse formation even in the presence of IBMX, indicating that voltage-gated Ca2+ influx plays a major role in neuronal differentiation. Finally, we found that nifedipine completely blocks IBMX-induced CREB phosphorylation (cAMP-response-element-binding protein), indicating that the activity of this important transcription factor equally depends on both enhanced cAMP and voltage-gated Ca2+-signaling. Taken together, these data indicate that the up-regulation of voltage-gated L-type Ca2+-channels and early electrical excitability are critical steps in the cAMP-dependent differentiation of SVZ-derived NPCs into functional neurons. To our knowledge, this is the first demonstration of the acute effects of cAMP on voltage-gated Ca+2channels in NPC-derived developing neurons.
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Affiliation(s)
- Guilherme Lepski
- Department of Functional and Stereotactic Neurosurgery, University Albert-Ludwig Freiburg, Germany ; Department of Neurosurgery, Eberhard Karls University Tübingen, Germany
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505
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Wei W, Wang Y, Wang Y, Dong J, Min H, Song B, Teng W, Xi Q, Chen J. Developmental hypothyroxinaemia induced by maternal mild iodine deficiency delays hippocampal axonal growth in the rat offspring. J Neuroendocrinol 2013; 25:852-62. [PMID: 23763342 DOI: 10.1111/jne.12058] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 05/29/2013] [Accepted: 06/09/2013] [Indexed: 12/27/2022]
Abstract
Iodine is essential for the biosynthesis of thyroid hormones, including triiodothyronine and thyroxine. Thyroid hormones are important for central nervous system development. Mild maternal iodine deficiency (ID)-induced hypothyroxinaemia causes neurological deficits and mental retardation of the foetus. However, the detailed mechanism underlying these deficits is still largely unknown. Given that the growth-associated protein of 43 kDa (GAP-43), semaphorin 3A (Sema3A) and the glycogen synthase kinase 3β (GSK3β)/collapsin response mediator protein 2 (CRMP2) pathway are essential for axonal development, we hypothesise that hippocampal axonal growth-related proteins may be impaired, which may contribute to hippocampal axonal growth delay in rat offspring exposed to maternal hypothyroxinaemia. To test this hypothesis, maternal hypothyroxinaemia models were established in Wistar rats using a mild ID diet. Besides a negative control group, two maternal hypothyroidism models were created with either a severe ID diet or methimazole in the water. Our results showed that maternal hypothyroxinaemia exposure delayed offspring axonal growth on gestational day 19, postnatal day (PN) 7, PN14 and PN21. Consistent with this, the mean intensity of hippocampal CRMP2 and Tau1 immunofluorescence axonal protein was reduced in the mild ID group. Moreover, maternal hypothyroxinaemia disrupted expressions of GAP-43 and Sema3A. Furthermore, the phosphorylation of GSK3β and CRMP2 was also affected in the treated offspring, implying a potential mechanism by which hypothyroxinaemia-exposure affects neurodevelopment. Taken together, our data support the hypothesis that maternal hypothyroxinaemia may impair axonal growth of the offspring.
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Affiliation(s)
- W Wei
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, China
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506
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Panaccione I, Napoletano F, Forte AM, Kotzalidis GD, Del Casale A, Rapinesi C, Brugnoli C, Serata D, Caccia F, Cuomo I, Ambrosi E, Simonetti A, Savoja V, De Chiara L, Danese E, Manfredi G, Janiri D, Motolese M, Nicoletti F, Girardi P, Sani G. Neurodevelopment in schizophrenia: the role of the wnt pathways. Curr Neuropharmacol 2013; 11:535-58. [PMID: 24403877 PMCID: PMC3763761 DOI: 10.2174/1570159x113119990037] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 03/28/2013] [Accepted: 05/12/2013] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVES To review the role of Wnt pathways in the neurodevelopment of schizophrenia. METHODS SYSTEMATIC PUBMED SEARCH, USING AS KEYWORDS ALL THE TERMS RELATED TO THE WNT PATHWAYS AND CROSSING THEM WITH EACH OF THE FOLLOWING AREAS: normal neurodevelopment and physiology, neurodevelopmental theory of schizophrenia, schizophrenia, and antipsychotic drug action. RESULTS Neurodevelopmental, behavioural, genetic, and psychopharmacological data point to the possible involvement of Wnt systems, especially the canonical pathway, in the pathophysiology of schizophrenia and in the mechanism of antipsychotic drug action. The molecules most consistently found to be associated with abnormalities or in antipsychotic drug action are Akt1, glycogen synthase kinase3beta, and beta-catenin. However, the extent to which they contribute to the pathophysiology of schizophrenia or to antipsychotic action remains to be established. CONCLUSIONS The study of the involvement of Wnt pathway abnormalities in schizophrenia may help in understanding this multifaceted clinical entity; the development of Wnt-related pharmacological targets must await the collection of more data.
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Affiliation(s)
- Isabella Panaccione
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Flavia Napoletano
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Alberto Maria Forte
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Giorgio D. Kotzalidis
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Antonio Del Casale
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Chiara Rapinesi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Chiara Brugnoli
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Daniele Serata
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Federica Caccia
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Ilaria Cuomo
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Elisa Ambrosi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Alessio Simonetti
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Valeria Savoja
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Lavinia De Chiara
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Emanuela Danese
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Giovanni Manfredi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | - Delfina Janiri
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
| | | | - Ferdinando Nicoletti
- NEUROMED, Pozzilli, Isernia, Italy
- Department of Neuropharmacology, Sapienza University, School of Medicine and Pharmacy, Rome, Italy
| | - Paolo Girardi
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
| | - Gabriele Sani
- NESMOS Department (Neuroscience, Mental Health, and Sensory Organs), Sapienza University, School of Medicine and Psychology, Sant’Andrea Hospital, Rome, Italy
- Centro Lucio Bini, Rome, Italy
- IRCCS Santa Lucia Foundation, Department of Clinical and Behavioural Neurology, Neuropsychiatry Laboratory, Rome, Italy
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507
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Ko CY, Wang WL, Wang SM, Chu YY, Chang WC, Wang JM. Glycogen synthase kinase-3β-mediated CCAAT/enhancer-binding protein delta phosphorylation in astrocytes promotes migration and activation of microglia/macrophages. Neurobiol Aging 2013; 35:24-34. [PMID: 23993701 DOI: 10.1016/j.neurobiolaging.2013.07.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 07/17/2013] [Accepted: 07/22/2013] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease is neuropathologically characterized by the accumulation of amyloid-β protein into senile plaques that are sites of chronic inflammation involving reactive microglia, astrocytes, and proinflammatory molecules, such as interleukin-1β and tumor necrosis factor-α. The human CCAAT/enhancer-binding protein (CEBP) delta (CEBPD) is known to be induced in many inflammation-related diseases. In Alzheimer's disease, this protein is responsive to amyloid-β and proinflammatory cytokines in astrocytes. However, the functional role of CEBPD in astrocytes remains largely unclear. In this study, we show that CEBPD is upregulated by interleukin-1β through the mitogen-activated protein kinase p38 (MAPKp38) signaling pathway and phosphorylated by glycogen synthase kinase (GSK)-3β at Ser167 in astrocytes. CEBPD in astrocytes is associated with microglia activation and migration in amyloid precursor protein transgenic mice (AppTg) mice. We further identified that the monocyte chemotactic protein-1, a chemoattractive factor, and migration factors matrix metalloproteinase-1 and -3 are responsive to GSK3β-mediated CEBPD Ser167 phosphorylation. Our results revealed the novel regulation of LiCl on astrocytes and that GSK3β-mediated CEBPD phosphorylation in astrocytes plays an important role in the activation of microglia.
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Affiliation(s)
- Chiung-Yuan Ko
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Pharmacology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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508
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Liu Y, Qin X, Wang DK, Guo YM, Gill HS, Morris N, Parker MD, Chen LM, Boron WF. Effects of optional structural elements, including two alternative amino termini and a new splicing cassette IV, on the function of the sodium-bicarbonate cotransporter NBCn1 (SLC4A7). J Physiol 2013; 591:4983-5004. [PMID: 23959679 DOI: 10.1113/jphysiol.2013.258673] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The SLC4A7 gene encodes the electroneutral sodium/HCO3 cotransporter NBCn1, which plays important physiological and pathophysiological roles in many cell types. Previous work identified six NBCn1 variants differing in the sequence of the extreme N terminus--MEAD in rat only, MERF in human only--as well as in the optional inclusion of cassettes I, II, and III. Earlier work also left open the question of whether optional structural elements (OSEs) affect surface abundance or intrinsic (per-molecule) transport activity. Here, we demonstrate for the first time that SLC4A7 from one species can express both MEAD- and MERF-NBCn1. We also identify a novel cassette IV of 20 aa, and extend by 10 the number of full-length NBCn1 variants. The alternative N termini and four cassettes could theoretically produce 32 major variants. Moreover, we identify a group of cDNAs predicted to encode just the cytosolic N-terminal domain (Nt) of NBCn1. A combination of electrophysiology and biotinylation shows that the OSEs can affect surface abundance and intrinsic HCO3(-) transport activity of NBCn1, as expressed in Xenopus oocytes. Specifically, MEAD tends to increase whereas novel cassette IV reduces surface abundance. Cassettes II, III and novel cassette IV all appear to increase the intrinsic activity of NBCn1.
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Affiliation(s)
- Ying Liu
- L.-M. Chen: Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science and Technology, 1037 Luoyu Rd, Wuhan, Hubei, China 430074.
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509
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Dobson-Stone C, Polly P, Korgaonkar MS, Williams LM, Gordon E, Schofield PR, Mather K, Armstrong NJ, Wen W, Sachdev PS, Kwok JBJ. GSK3B and MAPT polymorphisms are associated with grey matter and intracranial volume in healthy individuals. PLoS One 2013; 8:e71750. [PMID: 23951236 PMCID: PMC3741177 DOI: 10.1371/journal.pone.0071750] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 07/02/2013] [Indexed: 12/12/2022] Open
Abstract
The microtubule-associated protein tau gene (MAPT) codes for a protein that plays an integral role in stabilisation of microtubules and axonal transport in neurons. As well as its role in susceptibility to neurodegeneration, previous studies have found an association between the MAPT haplotype and intracranial volume and regional grey matter volumes in healthy adults. The glycogen synthase kinase-3β gene (GSK3B) codes for a serine/threonine kinase that phosphorylates various proteins, including tau, and has also been associated with risk for neurodegenerative disorders and schizophrenia. We examined the effects of MAPT and two functional promoter polymorphisms in GSK3B (rs3755557 and rs334558) on total grey matter and intracranial volume in three independent cohorts totaling 776 neurologically healthy individuals. In vitro analyses revealed a significant effect of rs3755557 on gene expression, and altered binding of at least two transcription factors, Octamer transcription factor 1 (Oct-1) and Pre-B-cell leukemia transcription factor 1 (Pbx-1), to the GSK3B promoter. Meta-analysis across the three cohorts revealed a significant effect of rs3755557 on total grey matter volume (summary B = 0.082, 95% confidence interval = 0.037–0.128) and intracranial volume (summary B = 0.113, 95% confidence interval = 0.082–0.144). No significant effect was observed for MAPT H1/H2 diplotype or GSK3B rs334558 on total grey matter or intracranial volume. Our genetic and biochemical analyses have identified a role for GSK3B in brain development, which could have important aetiological implications for neurodegenerative and neurodevelopmental disorders.
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Affiliation(s)
- Carol Dobson-Stone
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - Patsie Polly
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - Mayuresh S. Korgaonkar
- The Brain Dynamics Centre, University of Sydney Medical School and Westmead Millennium Institute, Westmead, Australia
| | - Leanne M. Williams
- The Brain Dynamics Centre, University of Sydney Medical School and Westmead Millennium Institute, Westmead, Australia
- Brain Resource International Database, Brain Resource Ltd., Ultimo, Sydney, New South Wales, Australia, and San Francisco, California
| | - Evian Gordon
- Brain Resource International Database, Brain Resource Ltd., Ultimo, Sydney, New South Wales, Australia, and San Francisco, California
| | - Peter R. Schofield
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - Karen Mather
- Euroa Centre, Prince of Wales Hospital, Randwick, Australia
| | - Nicola J. Armstrong
- Cancer Program, Garvan Institute of Medical Research, Sydney, Australia, School of Mathematics and Statistics, and Prince of Wales Clinical School, University of New South Wales, Sydney, Australia
| | - Wei Wen
- Euroa Centre, Prince of Wales Hospital, Randwick, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Perminder S. Sachdev
- Euroa Centre, Prince of Wales Hospital, Randwick, Australia
- School of Psychiatry, University of New South Wales, Sydney, Australia
| | - John B. J. Kwok
- Neuroscience Research Australia, Randwick, New South Wales, Australia
- Department of Pathology and Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Kensington, Australia
- * E-mail:
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510
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Neuronal apoptosis and motor deficits in mice with genetic inhibition of GSK-3 are Fas-dependent. PLoS One 2013; 8:e70952. [PMID: 23940673 PMCID: PMC3734180 DOI: 10.1371/journal.pone.0070952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 06/24/2013] [Indexed: 11/19/2022] Open
Abstract
Glycogen synthase kinase-3 (GSK-3) inhibitors have been postulated as useful therapeutic tools for the treatment of chronic neurodegenerative and neuropsychiatric diseases. Nevertheless the clinical use of these inhibitors has been limited by their common side effects. Lithium, a non-selective GSK-3 inhibitor has been classically administered to treat bipolar patients but its prescription is decreasing due to its frequent side effects such as hand tremor. This toxicity seems to be higher in the elderly and a clinical trial with lithium for Alzheimer’s disease was stopped due to high rate of discontinuation. We have previously described a mechanism for the adverse effects of chronic lithium that involves neuronal apoptosis via Fas signaling. As lithium inhibits many other enzymatic activities such as inositol monophosphatase and histone deacetylase, here we aim to genetically test whether GSK-3 inhibition induces those adverse effects through Fas receptor. For this purpose we took advantage of a transgenic mouse line with decreased GSK-3 activity (Tet/DN-GSK-3 mice) that shows increased rate of neuronal apoptosis as well as motor deficits and brought it to a Fas deficient background (lpr mice). We found that apoptosis induced by GSK-3 inhibition was absent in Fas deficient background. Interestingly, motor deficits were also absent in Fas deficient Tet/DN-GSK-3 mice. These results demonstrate that Fas signaling contributes to the neurological toxicity of GSK-3 inhibition and suggest that a combination of GSK-3 inhibitors with blockers of Fas signaling could help to improve the application of GSK-3 inhibitors to clinics.
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511
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Role of GSK-3β in isoflurane-induced neuroinflammation and cognitive dysfunction in aged rats. ACTA ACUST UNITED AC 2013; 33:530-535. [PMID: 23904373 DOI: 10.1007/s11596-013-1154-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 04/17/2013] [Indexed: 02/06/2023]
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512
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Dock3 attenuates neural cell death due to NMDA neurotoxicity and oxidative stress in a mouse model of normal tension glaucoma. Cell Death Differ 2013; 20:1250-6. [PMID: 23852370 DOI: 10.1038/cdd.2013.91] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 05/29/2013] [Accepted: 06/11/2013] [Indexed: 02/06/2023] Open
Abstract
Dedicator of cytokinesis 3 (Dock3), a new member of the guanine nucleotide exchange factors for the small GTPase Rac1, promotes axon regeneration following optic nerve injury. In the present study, we found that Dock3 directly binds to the intracellular C-terminus domain of NR2B, an N-methyl-D-aspartate (NMDA) receptor subunit. In transgenic mice overexpressing Dock3 (Dock3 Tg), NR2B expression in the retina was significantly decreased and NMDA-induced retinal degeneration was ameliorated. In addition, overexpression of Dock3 protected retinal ganglion cells (RGCs) from oxidative stress. We previously reported that glutamate/aspartate transporter (GLAST) is a major glutamate transporter in the retina, and RGC degeneration due to glutamate neurotoxicity and oxidative stress is observed in GLAST-deficient (KO) mice. In GLAST KO mice, the NR2B phosphorylation rate in the retina was significantly higher compared with Dock3 Tg:GLAST KO mice. Consistently, glaucomatous retinal degeneration was significantly improved in GLAST KO:Dock3 Tg mice compared with GLAST KO mice. These results suggest that Dock3 overexpression prevents glaucomatous retinal degeneration by suppressing both NR2B-mediated glutamate neurotoxicity and oxidative stress, and identifies Dock3 signaling as a potential therapeutic target for both neuroprotection and axonal regeneration.
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513
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Shah SM, Patel CH, Feng AS, Kollmar R. Lithium alters the morphology of neurites regenerating from cultured adult spiral ganglion neurons. Hear Res 2013; 304:137-44. [PMID: 23856237 DOI: 10.1016/j.heares.2013.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 06/23/2013] [Accepted: 07/01/2013] [Indexed: 01/13/2023]
Abstract
The small-molecule drug lithium (as a monovalent ion) promotes neurite regeneration and functional recovery, is easy to administer, and is approved for human use to treat bipolar disorder. Lithium exerts its neuritogenic effect mainly by inhibiting glycogen synthase kinase 3, a constitutively-active serine/threonine kinase that is regulated by neurotrophin and "wingless-related MMTV integration site" (Wnt) signaling. In spiral ganglion neurons of the cochlea, the effects of lithium and the function of glycogen synthase kinase 3 have not been investigated. We, therefore, set out to test whether lithium modulates neuritogenesis from adult spiral ganglion neurons. Primary cultures of dissociated spiral ganglion neurons from adult mice were exposed to lithium at concentrations between 0 and 12.5 mM. The resulting neurite morphology and growth-cone appearance were measured in detail by using immunofluorescence microscopy and image analysis. We found that lithium altered the morphology of regenerating neurites and their growth cones in a differential, concentration-dependent fashion. Low concentrations of 0.5-2.5 mM (around the half-maximal inhibitory concentration for glycogen synthase kinase 3 and the recommended therapeutic serum concentration for bipolar disorder) enhanced neurite sprouting and branching. A high concentration of 12.5 mM, in contrast, slowed elongation. As the lithium concentration rose from low to high, the microtubules became increasingly disarranged and the growth cones more arborized. Our results demonstrate that lithium selectively stimulates phases of neuritogenesis that are driven by microtubule reorganization. In contrast, most other drugs that have previously been tested on spiral ganglion neurons are reported to inhibit neurite outgrowth or affect only elongation. Lithium sensitivity is a necessary, but not sufficient condition for the involvement of glycogen synthase kinase 3. Our results are, therefore, consistent with, but do not prove lithium inhibiting glycogen synthase kinase 3 activity in spiral ganglion neurons. Experiments with additional drugs and molecular-genetic tools will be necessary to test whether glycogen synthase kinase 3 regulates neurite regeneration from spiral ganglion neurons, possibly by integrating neurotrophin and Wnt signals at the growth cone.
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Affiliation(s)
- S M Shah
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Neuroscience Graduate Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Medical Scholars Program, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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514
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Daulatzai MA. Neurotoxic Saboteurs: Straws that Break the Hippo’s (Hippocampus) Back Drive Cognitive Impairment and Alzheimer’s Disease. Neurotox Res 2013; 24:407-59. [DOI: 10.1007/s12640-013-9407-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/06/2013] [Accepted: 06/17/2013] [Indexed: 12/29/2022]
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515
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Frizzo ME. Putative role of glycogen as a peripheral biomarker of GSK3β activity. Med Hypotheses 2013; 81:376-8. [PMID: 23809426 DOI: 10.1016/j.mehy.2013.05.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 05/19/2013] [Indexed: 11/29/2022]
Abstract
Glycogen synthase kinase 3-β (GSK3β) has a pivotal role in several intracellular signaling cascades that are involved in gene transcription, cytoskeletal reorganization, energy metabolism, cell cycle regulation, and apoptosis. This kinase has pleiotropic functions, and the importance of its activity has recently been shown in neurons and platelets. In addition to its regulatory function in several physiological events, changes in GSK3β activity have been associated with many psychiatric and neurodegenerative illnesses, such as Alzheimer's disease, schizophrenia and autism-spectrum disorders. Beside the reports of its involvement in several pathologies, it has become increasingly apparent that GSK3β might be a common therapeutic target for different classes of psychiatric drugs, and also that the GSK3β ratio may be a useful parameter to determine the biochemical changes that might occur during antidepressant treatment. Although GSK3β is commonly described as a key enzyme in a plethora of signaling cascades, originally it was identified as playing an important role in the regulation of glycogen synthesis, given its ability to inactivate glycogen synthase (GS) by phosphorylation. Acting as a constitutively active kinase, GSK3β phosphorylates GS, which results in a decrease of glycogen production. GSK3β phosphorylation increases glycogen synthesis and storage, while its dephosphorylation decreases glycogen synthesis. Inactivation of GSK3β leads to dephosphorylation of GS and increase in glycogen synthesis in the adipose tissue, muscle and liver. Glycogen levels are reduced by antidepressant treatment, and this effect seems to be related to an effect of drugs on GSK3β activity. Peripherally, glycogen is also abundantly found in platelets, where it is considered a major energy source, required for a variety of its functions, including the release reaction. Recently, analysis of platelets from patients with late-life major depression showed that active forms of GSK3β expression were upregulated by continuous treatment with sertraline. Here, we hypothesized that the quantification of glycogen in platelets might be used as a peripheral biomarker of GSK3β activity. Since it has been recently demonstrated that the modulation of GSK3β activity causes changes in glycogen stores, the glycogen levels in platelets could be used to assay the effects of drugs that have this kinase as a target, or diseases where its activity is affected. In conclusion, we hypothesized that the determination of glycogen peripherally may be useful to indicate a change in the activity of this enzyme, providing a faster and non-invasive approach to guide the therapeutic procedures for the patient.
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Affiliation(s)
- Marcos Emilio Frizzo
- Department of Morphological Sciences, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite, 500, CEP 90050-170 Porto Alegre, Brazil.
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516
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Sampath S, Narasimhan A, Chinta R, Nair KJ, Khurana A, Nayak D, Kumar A, Karundevi B. Effect of homeopathic preparations of Syzygium jambolanum and Cephalandra indica on gastrocnemius muscle of high fat and high fructose-induced type-2 diabetic rats. HOMEOPATHY 2013; 102:160-71. [DOI: 10.1016/j.homp.2013.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 04/30/2013] [Accepted: 05/07/2013] [Indexed: 01/05/2023]
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517
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Fetal DNA Methylation Associates with Early Spontaneous Preterm Birth and Gestational Age. PLoS One 2013; 8:e67489. [PMID: 23826308 PMCID: PMC3694903 DOI: 10.1371/journal.pone.0067489] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 05/19/2013] [Indexed: 12/24/2022] Open
Abstract
Spontaneous preterm birth (PTB, <37 weeks gestation) is a major public health concern, and children born preterm have a higher risk of morbidity and mortality throughout their lives. Recent studies suggest that fetal DNA methylation of several genes varies across a range of gestational ages (GA), but it is not yet clear if fetal epigenetic changes associate with PTB. The objective of this study is to interrogate methylation patterns across the genome in fetal leukocyte DNA from African Americans with early PTB (241/7–340/7 weeks; N = 22) or term births (390/7–406/7weeks; N = 28) and to evaluate the association of each CpG site with PTB and GA. DNA methylation was assessed across the genome with the HumanMethylation450 BeadChip. For each individual sample and CpG site, the proportion of DNA methylation was estimated. The associations between methylation and PTB or GA were evaluated by fitting a separate linear model for each CpG site, adjusting for relevant covariates. Overall, 29 CpG sites associated with PTB (FDR<.05; 5.7×10−10<p<2.9×10−6) independent of GA. Also, 9637 sites associated with GA (FDR<.05; 9.5×10−16<p<1.0×10−3), with 61.8% decreasing in methylation with shorter GA. GA-associated CpG sites were depleted in the CpG islands of their respective genes (p<2.2×10−16). Gene set enrichment analysis (GSEA) supported enrichment of GA-associated CpG sites in genes that play a role in embryonic development as well as the extracellular matrix. Additionally, this study replicated the association of several CpG sites associated with gestational age in other studies (CRHBP, PIK3CD and AVP). Dramatic differences in fetal DNA methylation are evident in fetuses born preterm versus at term, and the patterns established at birth may provide insight into the long-term consequences associated with PTB.
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518
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Chana G, Bousman CA, Money TT, Gibbons A, Gillett P, Dean B, Everall IP. Biomarker investigations related to pathophysiological pathways in schizophrenia and psychosis. Front Cell Neurosci 2013; 7:95. [PMID: 23805071 PMCID: PMC3693064 DOI: 10.3389/fncel.2013.00095] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 06/03/2013] [Indexed: 12/28/2022] Open
Abstract
Post-mortem brain investigations of schizophrenia have generated swathes of data in the last few decades implicating candidate genes and protein. However, the relation of these findings to peripheral biomarker indicators and symptomatology remain to be elucidated. While biomarkers for disease do not have to be involved with underlying pathophysiology and may be largely indicative of diagnosis or prognosis, the ideal may be a biomarker that is involved in underlying disease processes and which is therefore more likely to change with progression of the illness as well as potentially being more responsive to treatment. One of the main difficulties in conducting biomarker investigations for major psychiatric disorders is the relative inconsistency in clinical diagnoses between disorders such as bipolar and schizophrenia. This has led some researchers to investigate biomarkers associated with core symptoms of these disorders, such as psychosis. The aim of this review is to evaluate the contribution of post-mortem brain investigations to elucidating the pathophysiology pathways involved in schizophrenia and psychosis, with an emphasis on major neurotransmitter systems that have been implicated. This data will then be compared to functional neuroimaging findings as well as findings from blood based gene expression investigations in schizophrenia in order to highlight the relative overlap in pathological processes between these different modalities used to elucidate pathogenesis of schizophrenia. In addition we will cover some recent and exciting findings demonstrating microRNA (miRNA) dysregulation in both the blood and the brain in patients with schizophrenia. These changes are pertinent to the topic due to their known role in post-transcriptional modification of gene expression with the potential to contribute or underlie gene expression changes observed in schizophrenia. Finally, we will discuss how post-mortem studies may aid future biomarker investigations.
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Affiliation(s)
- Gursharan Chana
- Department of Psychiatry, Melbourne Brain Centre, The University of Melbourne Parkville, VIC, Australia
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519
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Xia C, Nguyen M, Garrison AK, Zhao Z, Wang Z, Sutherland C, Ma L. CNP/cGMP signaling regulates axon branching and growth by modulating microtubule polymerization. Dev Neurobiol 2013; 73:673-87. [PMID: 23420620 DOI: 10.1002/dneu.22078] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 02/13/2013] [Accepted: 02/13/2013] [Indexed: 11/06/2022]
Abstract
The peptide hormone CNP has recently been found to positively regulate axon branching and growth via activation of cGMP signaling in embryonic dorsal root ganglion (DRG) neurons, but the cellular mechanisms mediating the regulation of these developmental processes have not been established. In this study, we provide evidence linking CNP/cGMP signaling to microtubule dynamics via the microtubule regulator CRMP2. First, phosphorylation of CRMP2 can be suppressed by cGMP activation in embryonic DRG neurons, and non-phosphorylated CRMP2 promotes axon branching and growth. In addition, real time analysis of growing microtubule ends indicates a similar correlation of CRMP2 phosphorylation and its activity in promoting microtubule polymerization rates and durations in both COS cells and DRG neuron growth cones. Moreover, direct activation of cGMP signaling leads to increased assembly of dynamic microtubules in DRG growth cones. Finally, low doses of a microtubule depolymerization drug nocodazole block CNP/cGMP-dependent axon branching and growth. Taken together, our results support a critical role of microtubule dynamics in mediating CNP/cGMP regulation of axonal development.
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Affiliation(s)
- Caihong Xia
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, USA
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520
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Holowacz T, Alexson TO, Coles BL, Doble BW, Kelly KF, Woodgett JR, Van Der Kooy D. The responses of neural stem cells to the level of GSK-3 depend on the tissue of origin. Biol Open 2013; 2:812-21. [PMID: 23951407 PMCID: PMC3744073 DOI: 10.1242/bio.20131941] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 05/29/2013] [Indexed: 12/31/2022] Open
Abstract
Neural stem cells (NSCs) can be obtained from a variety of sources, but not all NSCs exhibit the same characteristics. We have examined how the level of glycogen synthase kinase-3 activity regulates NSCs obtained from different sources: the mouse embryonic striatum, embryonic hippocampus, and mouse ES cells. Growth of striatal NSCs is enhanced by mild inhibition of GSK-3 but not by strong inhibition that is accompanied by Wnt/TCF transcriptional activation. In contrast, the growth of hippocampal NSCs is enhanced by both mild inhibition of GSK-3 as well as stronger inhibition. Active Wnt/TCF signaling, which occurs normally in the embryonic hippocampus, is required for growth of neural stem and progenitor cells. In the embryonic striatal germinal zone, however, TCF signaling is normally absent and its activation inhibits growth of NSCs from this region. Using a genetic model for progressive loss of GSK-3, we find that primitive ES cell-derived NSCs resemble striatal NSCs. That is, partial loss of GSK-3 alleles leads to an increase in NSCs while complete ablation of GSK-3, and activation of TCF-signaling, leads to their decline. Furthermore, expression of dominant negative TCF-4 in the GSK-3-null background was effective in blocking expression of Wnt-response genes and was also able to rescue neuronal gene expression. These results reveal that GSK-3 regulates NSCs by divergent pathways depending on the tissue of origin. The responses of these neural precursor cells may be contingent on baseline Wnt/TCF signaling occurring in a particular tissue.
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Affiliation(s)
- Tamara Holowacz
- Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto , Toronto, ON M5S 3E1 , Canada
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521
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SAD kinases sculpt axonal arbors of sensory neurons through long- and short-term responses to neurotrophin signals. Neuron 2013; 79:39-53. [PMID: 23790753 DOI: 10.1016/j.neuron.2013.05.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2013] [Indexed: 11/20/2022]
Abstract
Extrinsic cues activate intrinsic signaling mechanisms to pattern neuronal shape and connectivity. We showed previously that three cytoplasmic Ser/Thr kinases, LKB1, SAD-A, and SAD-B, control early axon-dendrite polarization in forebrain neurons. Here, we assess their role in other neuronal types. We found that all three kinases are dispensable for axon formation outside of the cortex but that SAD kinases are required for formation of central axonal arbors by subsets of sensory neurons. The requirement for SAD kinases is most prominent in NT-3 dependent neurons. SAD kinases transduce NT-3 signals in two ways through distinct pathways. First, sustained NT-3/TrkC signaling increases SAD protein levels. Second, short-duration NT-3/TrkC signals transiently activate SADs by inducing dephosphorylation of C-terminal domains, thereby allowing activating phosphorylation of the kinase domain. We propose that SAD kinases integrate long- and short-duration signals from extrinsic cues to sculpt axon arbors within the CNS.
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522
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Abstract
MicroRNAs (miRNAs) regulate dendritogenesis and plasticity. However, the biological function of miRNAs in axons has not been extensively investigated. Here, using rat primary cortical neurons cultured in a microfluidic chamber, we found that the distal axons of the neurons expressed the miR-17-92 cluster, and proteins that regulate production and activity of mature miRNAs, Dicer and Argonaute 2, respectively, were present in the distal axons. Overexpression of the miR-17-92 cluster in cortical neurons substantially increased axonal outgrowth, whereas distal axonal attenuation of endogenous miR-19a, a key miRNA of the miR-17-92 cluster, with the miRNA hairpin inhibitor suppressed axonal outgrowth. Moreover, overexpression of the miR-17-92 cluster reduced phosphatase and tensin homolog (PTEN) proteins and elevated phosphorylated mammalian target of rapamycin (mTOR) in the distal axons. In contrast, distal axonal attenuation of miR-19a increased PTEN proteins and inactivated mTOR in the axons, but did not affect these protein levels in the cell bodies. Overexpression of PTEN and attenuation of endogenous PTEN prevailed over the enhancement and inhibitory effects of the miR-19a on axonal outgrowth, respectively. Axonal application of LY294002, a phosphoinositide3-kinase inhibitor, or rapamycin, an mTOR inhibitor, abolished axonal outgrowth enhanced by overexpression of the miR-17-92 cluster. Collectively, these findings demonstrate that axonal alteration of miR-17-92 cluster expression regulates axonal outgrowth and that local modulation of PTEN protein levels by miR-19a likely contributes to the axonal outgrowth.
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523
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Ethanol neurotoxicity in the developing cerebellum: underlying mechanisms and implications. Brain Sci 2013; 3:941-63. [PMID: 24961432 PMCID: PMC4061865 DOI: 10.3390/brainsci3020941] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/08/2013] [Accepted: 06/04/2013] [Indexed: 01/18/2023] Open
Abstract
Ethanol is the main constituent of alcoholic beverages that exerts toxicity to neuronal development. Ethanol affects synaptogenesis and prevents proper brain development. In humans, synaptogenesis takes place during the third trimester of pregnancy, and in rodents this period corresponds to the initial few weeks of postnatal development. In this period neuronal maturation and differentiation begin and neuronal cells start migrating to their ultimate destinations. Although the neuronal development of all areas of the brain is affected, the cerebellum and cerebellar neurons are more susceptible to the damaging effects of ethanol. Ethanol’s harmful effects include neuronal cell death, impaired differentiation, reduction of neuronal numbers, and weakening of neuronal plasticity. Neuronal development requires many hormones and growth factors such as retinoic acid, nerve growth factors, and cytokines. These factors regulate development and differentiation of neurons by acting through various receptors and their signaling pathways. Ethanol exposure during development impairs neuronal signaling mechanisms mediated by the N-methyl-d-aspartate (NMDA) receptors, the retinoic acid receptors, and by growth factors such as brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-I), and basic fibroblast growth factor (bFGF). In combination, these ethanol effects disrupt cellular homeostasis, reduce the survival and migration of neurons, and lead to various developmental defects in the brain. Here we review the signaling mechanisms that are required for proper neuronal development, and how these processes are impaired by ethanol resulting in harmful consequences to brain development.
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524
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Atkins RJ, Stylli SS, Luwor RB, Kaye AH, Hovens CM. Glycogen synthase kinase-3β (GSK-3β) and its dysregulation in glioblastoma multiforme. J Clin Neurosci 2013; 20:1185-92. [PMID: 23768967 DOI: 10.1016/j.jocn.2013.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 02/09/2013] [Indexed: 01/10/2023]
Abstract
Glioblastoma multiforme (GBM) is the most frequently occurring and devastating human brain malignancy, retaining almost universal mortality and a median survival of only 14 months, even with recent advances in multimodal treatments. Gliomas are characterised as being both highly resistant to chemo- and radiotherapy and highly invasive, rendering conventional interventions palliative. The continual dismal prognosis for GBM patients identifies an urgent need for the evolutionary development of new treatment modalities. This includes molecular targeted therapies as many signaling molecules and associated pathways have been implicated in the development and survival of malignant gliomas including the protein kinase, glycogen synthase kinase 3 beta (GSK-3β). Here we review the activity and function of GSK-3β in a number of signaling pathways and its role in gliomagenesis.
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Affiliation(s)
- R J Atkins
- Department of Surgery, The University of Melbourne, The Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3050, Australia.
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525
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Liu J, Baek C, Han X, Shoureshi P, Soriano S. Role of glycogen synthase kinase-3β in ketamine-induced developmental neuroapoptosis in rats. Br J Anaesth 2013; 110 Suppl 1:i3-9. [DOI: 10.1093/bja/aet057] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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526
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Wang D, Tan QR, Zhang ZJ. Neuroprotective effects of paeoniflorin, but not the isomer albiflorin, are associated with the suppression of intracellular calcium and calcium/calmodulin protein kinase II in PC12 cells. J Mol Neurosci 2013; 51:581-90. [PMID: 23695964 DOI: 10.1007/s12031-013-0031-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 05/08/2013] [Indexed: 12/26/2022]
Abstract
The root of Paeonia lactiflora Pall (family Ranunculaceae) or peony root, a herbal medicine, possesses therapeutic potential for neurodegenerative diseases. The isomers paeoniflorin (PF) and albiflorin (AF) are major constituents contained in peony root. Our previous study has shown notable neuroprotective effects of PF. In the present study, we further compared the effects of AF and PF against glutamate (Glu)-induced cell damage and the underlying mechanisms in differentiated PC12 cells. Both AF and PF significantly ameliorated Glu-induced reduction of cell viability, nuclear and mitochondrial apoptotic alteration, reactive oxygen species accumulation, and B-cell lymphoma 2 (Bcl-2)/Bax ratio. The two isomers also enhanced phosphorylation of AKT and its downstream element glycogen synthase kinase-3β, and this effect was abrogated by the AKT inhibitor LY294002. PF, but not AF, however, suppressed intracellular Ca(2+) overload and the expression of calcium/calmodulin protein kinase II (CaMKII). The improvement of cell damage by the CaMKII inhibitor KN93 further confirms the role of CaMKII in PF-mediated neuroprotection. These results suggest that both AF and PF possess robust effects in protecting neuronal cells against Glu toxicity. PF further displayed remarkable effects in preventing intracellular Ca(2+) overload and suppressing overexpression of CaMKII. Differential mechanisms may be involved in neuroprotective action of the two isomers.
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Affiliation(s)
- Di Wang
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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527
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Kao CY, Hsu YC, Liu JW, Lee DC, Chung YF, Chiu IM. The mood stabilizer valproate activates human FGF1
gene promoter through inhibiting HDAC and GSK-3 activities. J Neurochem 2013; 126:4-18. [DOI: 10.1111/jnc.12292] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 04/22/2013] [Indexed: 01/23/2023]
Affiliation(s)
- Chien-Yu Kao
- Division of Regenerative Medicine; Institute of Cellular and System Medicine; National Health Research Institutes; Miaoli Taiwan
- Graduate Program of Biotechnology in Medicine; Institute of Molecular Medicine; National Tsing Hua University; Hsinchu Taiwan
| | - Yi-Chao Hsu
- Division of Regenerative Medicine; Institute of Cellular and System Medicine; National Health Research Institutes; Miaoli Taiwan
| | - Jen-Wei Liu
- Division of Regenerative Medicine; Institute of Cellular and System Medicine; National Health Research Institutes; Miaoli Taiwan
- Department of Life Sciences; National Chung Hsing University; Taichung Taiwan
| | - Don-Ching Lee
- Division of Regenerative Medicine; Institute of Cellular and System Medicine; National Health Research Institutes; Miaoli Taiwan
| | - Yu-Fen Chung
- Division of Regenerative Medicine; Institute of Cellular and System Medicine; National Health Research Institutes; Miaoli Taiwan
| | - Ing-Ming Chiu
- Division of Regenerative Medicine; Institute of Cellular and System Medicine; National Health Research Institutes; Miaoli Taiwan
- Graduate Program of Biotechnology in Medicine; Institute of Molecular Medicine; National Tsing Hua University; Hsinchu Taiwan
- Department of Life Sciences; National Chung Hsing University; Taichung Taiwan
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528
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Mouri A, Nagai T, Ibi D, Yamada K. Animal models of schizophrenia for molecular and pharmacological intervention and potential candidate molecules. Neurobiol Dis 2013; 53:61-74. [DOI: 10.1016/j.nbd.2012.10.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 10/23/2012] [Accepted: 10/28/2012] [Indexed: 12/22/2022] Open
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529
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Zhang S, Guo T, Chan H, Sze SK, Koh CG. Integrative transcriptome and proteome study to identify the signaling network regulated by POPX2 phosphatase. J Proteome Res 2013; 12:2525-36. [PMID: 23621870 DOI: 10.1021/pr301113c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
POPX2 is a serine/threonine phosphatase belonging to the protein phosphatase 2C (PP2C) family that has been found to be elevated in invasive breast cancer cells. Silencing of POPX2 results in lower cell motility and invasiveness. The molecular mechanism of POPX2-regulated cell motility is not well understood. To identify the relevant signaling pathways, we investigated the transcriptome and proteome of POPX2-knockdown MDA-MB-231 breast cancer cells. Our data suggest that POPX2 might be involved in the regulation of focal adhesions and cytoskeleton dynamics through the regulation of MAP kinase (MAPK1/3) and glycogen synthase kinase 3 (GSK3α/β) activities. Silencing POPX2 alters phosphorylation levels of MAPK1/3 and GSK3α/β and results in reduced activity of these kinases. Both MAPK and GSK3 are known to regulate the activities of transcription factors. MAPK1/3 are also implicated in the phosphorylation of stathmin. The level of phospho-stathmin was found to be lower in POPX2 knockdown cells. As phosphorylation of stathmin inhibits its microtubule severing activity, we observed less stable microtubules in POPX2 knockdown cells. Taken together, our data suggest that POPX2 might regulate cell motility through its regulation of the MAPK1/3, leading to changes in the cytoskeleton and cell motility.
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Affiliation(s)
- Songjing Zhang
- School of Biological Sciences, Nanyang Technological University, Singapore 6387551
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530
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Squassina A, Costa M, Congiu D, Manchia M, Angius A, Deiana V, Ardau R, Chillotti C, Severino G, Calza S, Del Zompo M. Insulin-like growth factor 1 (IGF-1) expression is up-regulated in lymphoblastoid cell lines of lithium responsive bipolar disorder patients. Pharmacol Res 2013; 73:1-7. [PMID: 23619527 DOI: 10.1016/j.phrs.2013.04.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 04/11/2013] [Accepted: 04/11/2013] [Indexed: 01/30/2023]
Abstract
Bipolar disorder (BD) is a debilitating psychiatric disease characterized by alternating episodes of mania and depression. Among mood stabilizers, lithium is the mainstay for the treatment of BD, with approximately one-third of patients showing remission from episode recurrence. While there is evidence suggesting genetic load for lithium response in BD, its molecular underpinnings are still not completely understood. To identify genes potentially involved in (or correlated with) lithium response, we carried out a genome-wide expression analysis on lymphoblastoid cell lines (LCLs) from 10 BD patients responders (R) and 10 non-responders (NR) to lithium. We compared expression levels of the two groups and tested whether in vitro lithium treatment had different effects in LCLs of R compared to NR. At basal, 2060 genes were differentially expressed between R and NR while no genes were differentially regulated by lithium in the two groups. After pathway analysis based on the 2060 genes, 9 genes were selected for validation with qRT-PCR. Eight genes were validated in the same sample of LCLs while only insulin-like growth factor 1 (IGF-1) was significantly over-expressed in R compared to NR in the same sample as well as in an independent sample comprised of 6 R and 6 NR (sample 1, fold change=1.94; p=0.005; sample 2, fold change=2.21; p=0.005). IGF-1 was also significantly over-expressed in R but not in NR when compared to a sample of non-psychiatric controls. Our findings suggest that IGF-1 may be involved in lithium response, supporting further investigation on its potential as a biomarker.
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Affiliation(s)
- Alessio Squassina
- Section of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Monserrato, Cagliari 09042, Italy.
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531
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Functional implications of hippocampal adult neurogenesis in intellectual disabilities. Amino Acids 2013; 45:113-31. [DOI: 10.1007/s00726-013-1489-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 03/15/2013] [Indexed: 12/19/2022]
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532
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Yang YM, Gupta SK, Kim KJ, Powers BE, Cerqueira A, Wainger BJ, Ngo HD, Rosowski KA, Schein PA, Ackeifi CA, Arvanites AC, Davidow LS, Woolf CJ, Rubin LL. A small molecule screen in stem-cell-derived motor neurons identifies a kinase inhibitor as a candidate therapeutic for ALS. Cell Stem Cell 2013; 12:713-26. [PMID: 23602540 DOI: 10.1016/j.stem.2013.04.003] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 03/08/2013] [Accepted: 04/01/2013] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease, characterized by motor neuron (MN) death, for which there are no truly effective treatments. Here, we describe a new small molecule survival screen carried out using MNs from both wild-type and mutant SOD1 mouse embryonic stem cells. Among the hits we found, kenpaullone had a particularly impressive ability to prolong the healthy survival of both types of MNs that can be attributed to its dual inhibition of GSK-3 and HGK kinases. Furthermore, kenpaullone also strongly improved the survival of human MNs derived from ALS-patient-induced pluripotent stem cells and was more active than either of two compounds, olesoxime and dexpramipexole, that recently failed in ALS clinical trials. Our studies demonstrate the value of a stem cell approach to drug discovery and point to a new paradigm for identification and preclinical testing of future ALS therapeutics.
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Affiliation(s)
- Yin M Yang
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
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533
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Gamble KL, Young ME. Metabolism as an integral cog in the mammalian circadian clockwork. Crit Rev Biochem Mol Biol 2013; 48:317-31. [PMID: 23594144 DOI: 10.3109/10409238.2013.786672] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Circadian rhythms are an integral part of life. These rhythms are apparent in virtually all biological processes studies to date, ranging from the individual cell (e.g. DNA synthesis) to the whole organism (e.g. behaviors such as physical activity). Oscillations in metabolism have been characterized extensively in various organisms, including mammals. These metabolic rhythms often parallel behaviors such as sleep/wake and fasting/feeding cycles that occur on a daily basis. What has become increasingly clear over the past several decades is that many metabolic oscillations are driven by cell-autonomous circadian clocks, which orchestrate metabolic processes in a temporally appropriate manner. During the process of identifying the mechanisms by which clocks influence metabolism, molecular-based studies have revealed that metabolism should be considered an integral circadian clock component. The implications of such an interrelationship include the establishment of a vicious cycle during cardiometabolic disease states, wherein metabolism-induced perturbations in the circadian clock exacerbate metabolic dysfunction. The purpose of this review is therefore to highlight recent insights gained regarding links between cell-autonomous circadian clocks and metabolism and the implications of clock dysfunction in the pathogenesis of cardiometabolic diseases.
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Affiliation(s)
- Karen L Gamble
- Division of Behavioral Neurobiology, Department of Psychiatry, University of Alabama at Birmingham, Birmingham, Alabama, USA
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534
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Glycogen synthase kinase-3β positively regulates protein synthesis and cell proliferation through the regulation of translation initiation factor 4E-binding protein 1. Oncogene 2013; 33:1690-9. [DOI: 10.1038/onc.2013.113] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 12/31/2012] [Accepted: 02/15/2013] [Indexed: 12/17/2022]
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535
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Pérezleón JA, Osorio-Paz I, Francois L, Salceda R. Immunohistochemical localization of glycogen synthase and GSK3β: control of glycogen content in retina. Neurochem Res 2013; 38:1063-9. [PMID: 23512644 DOI: 10.1007/s11064-013-1017-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/04/2013] [Accepted: 03/12/2013] [Indexed: 11/30/2022]
Abstract
Glycogen has an important role in energy handling in several brain regions. In the brain, glycogen is localized in astrocytes and its role in several normal and pathological processes has been described, whereas in the retina, glycogen metabolism has been scarcely investigated. The enzyme glycogen phosphorylase has been located in retinal Müller cells; however the cellular location of glycogen synthase (GS) and its regulatory partner, glycogen synthase kinase 3β (GSK3β), has not been investigated. Our aim was to localize these enzymes in the rat retina by immunofluorescence techniques. We found both GS and GSK3β in Müller cells in the synaptic layers, and within the inner segments of photoreceptor cells. The presence of these enzymes in Müller cells suggests that glycogen could be regulated within the retina as in other tissues. Indeed, we showed that glycogen content in the whole retina in vitro was increased by high glucose concentrations, glutamate, and insulin. In contrast, retina glycogen levels were not modified by norepinephrine nor by depolarization with high KCl concentrations. Insulin also induced an increase in glycogen content in cultured Müller cells. The effect of insulin in both, whole retina and cultured Müller cells was blocked by inhibitors of phosphatidyl-inositol 3-kinase, strongly suggesting that glycogen content in retina is modulated by the insulin signaling pathway. The expression of GS and GSK3β in the synaptic layers and photoreceptor cells suggests an important role of GSK3β regulating glycogen synthase in neurons, which opens multiple feasible roles of insulin within the retina.
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Affiliation(s)
- Jorge Alberto Pérezleón
- Departamento de Ciencias Químico Biológicas, Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo PRONAF y Estocolmo s/n, Colonia PRONAF, 31330 Ciudad Juárez, Chihuahua, Mexico.
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536
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Li XH, Chen C, Tu Y, Sun HT, Zhao ML, Cheng SX, Qu Y, Zhang S. Sirt1 Promotes Axonogenesis by Deacetylation of Akt and Inactivation of GSK3. Mol Neurobiol 2013; 48:490-9. [DOI: 10.1007/s12035-013-8437-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 02/27/2013] [Indexed: 10/27/2022]
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537
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Kim HJ, Woo HM, Ryu J, Bok J, Kim JW, Choi SB, Park MH, Park HY, Koo SK. Conditional deletion of pten leads to defects in nerve innervation and neuronal survival in inner ear development. PLoS One 2013; 8:e55609. [PMID: 23393595 PMCID: PMC3564925 DOI: 10.1371/journal.pone.0055609] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 01/02/2013] [Indexed: 12/25/2022] Open
Abstract
All cellular phenomena and developmental events, including inner ear development, are modulated through harmonized signaling networks. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a tumor suppressor, is a major signaling component involved in cross talk with key regulators of development; i.e., Wnt, Notch, and bone morphogenetic proteins. Although Pten function has been studied in various systems, its role in inner ear development is poorly understood. Here, we used inner ear-specific Pten conditional knockout mice and examined the characteristics of the inner ear. In a detailed analysis of the phenotype, reduced cochlear turning and widened epithelia were observed. Phalloidin staining of sensory epithelium revealed that hair cell patterns were disturbed; i.e., additional rows of hair cells were discovered. The neural abnormality revealed a reduction in and disorganization of nerve fibers, including apoptosis at the neural precursor stage. Pten deficiency induced increased phosphorylation of Akt at Ser473. The elevation of inhibitory glycogen synthase kinase 3β Ser9 phosphorylation (pGSK3β) was sustained until the neuronal differentiation stage at embryonic day 14.5, instead of pGSK3β downregulation. This is the first report on the influence of Pten/Akt/GSK3β signaling on the development of spiral ganglia. These results suggest that Pten is required for the maintenance of neuroblast number, neural precursors, and differentiation in the inner ear.
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Affiliation(s)
- Hyung Jin Kim
- Center for Biomedical Sciences, National Institute of Health, Osong Health Technology Administration Complex 643, Yeonje-ri, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, South Korea
| | - Hae-Mi Woo
- Center for Biomedical Sciences, National Institute of Health, Osong Health Technology Administration Complex 643, Yeonje-ri, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, South Korea
| | - Jihee Ryu
- Center for Biomedical Sciences, National Institute of Health, Osong Health Technology Administration Complex 643, Yeonje-ri, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, South Korea
| | - Jinwoong Bok
- Department of Anatomy, BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Jin Woo Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, South Korea
| | - Sang Back Choi
- Center for Biomedical Sciences, National Institute of Health, Osong Health Technology Administration Complex 643, Yeonje-ri, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, South Korea
| | - Mi-Hyun Park
- Center for Biomedical Sciences, National Institute of Health, Osong Health Technology Administration Complex 643, Yeonje-ri, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, South Korea
| | - Hyun-Young Park
- Center for Biomedical Sciences, National Institute of Health, Osong Health Technology Administration Complex 643, Yeonje-ri, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, South Korea
| | - Soo Kyung Koo
- Center for Biomedical Sciences, National Institute of Health, Osong Health Technology Administration Complex 643, Yeonje-ri, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, South Korea
- * E-mail:
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538
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Monroe JD, Heathcote RD. Protein phosphatases regulate the growth of developing neurites. Int J Dev Neurosci 2013; 31:250-7. [DOI: 10.1016/j.ijdevneu.2013.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/04/2013] [Accepted: 01/21/2013] [Indexed: 01/01/2023] Open
Affiliation(s)
- Jerry D. Monroe
- Department of Biological SciencesUniversity of Wisconsin–Milwaukee Box 413MilwaukeeWI53201USA
| | - R. David Heathcote
- Department of Biological SciencesUniversity of Wisconsin–Milwaukee Box 413MilwaukeeWI53201USA
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539
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Eom T, Zhang C, Wang H, Lay K, Fak J, Noebels JL, Darnell RB. NOVA-dependent regulation of cryptic NMD exons controls synaptic protein levels after seizure. eLife 2013; 2:e00178. [PMID: 23359859 PMCID: PMC3552424 DOI: 10.7554/elife.00178] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 11/29/2012] [Indexed: 12/13/2022] Open
Abstract
The neuronal RNA binding protein NOVA regulates splicing, shuttles to the cytoplasm, and co-localizes with target transcripts in dendrites, suggesting links between splicing and local translation. Here we identified >200 transcripts showing NOVA-dependent changes in abundance, but, surprisingly, HITS-CLIP revealed NOVA binds these RNAs in introns rather than 3′ UTRs. This led us to discover NOVA-regulated splicing of cryptic exons within these introns. These exons triggered nonsense mediated decay (NMD), as UPF1 and protein synthesis were required for NOVA's effect on RNA levels. Their regulation was dynamic and physiologically relevant. The NMD exons were regulated by seizures, which also induced changes in Nova subcellular localization and mediated large changes in synaptic proteins, including proteins implicated in familial epilepsy. Moreover, Nova haploinsufficient mice had spontaneous epilepsy. The data reveal a hidden means of dynamic RNA regulation linking electrical activity to splicing and protein output, and of mediating homeostatic excitation/inhibition balance in neurons. DOI:http://dx.doi.org/10.7554/eLife.00178.001 After the DNA in a gene has been transcribed into messenger RNA, portions of the mRNA called introns are removed, and the remaining stretches of mRNA, which are known as exons, are spliced together. Within eukaryotic cells, a process known as alternative splicing allows a single gene to encode for multiple protein variants by ensuring that some exons are included in the final, modified mRNA, while other exons are excluded. This modified mRNA is then translated into proteins. Eukaryotic cells also contain proteins that bind to RNA to regulate alternative splicing. These RNA-binding proteins are often found in both the cytoplasm and nucleus of cells, and their involvement in splicing may be linked to other processes in the cell such as mRNA localization and translation. It has also become clear over the past two decades that certain types of RNA-binding proteins, including NOVA proteins, are only found in neurons, and that these proteins have been best characterized as alternative splicing regulators. Recent work has also suggested that they also have important roles in regulating neuronal activity and development, and that their actions in neuronal nuclei and cytoplasm might be coordinated. Now Eom et al. use the predictive power of a high throughput sequencing and crosslinking method termed HITS-CLIP to show that NOVA proteins can indirectly regulate cytoplasmic mRNA levels by regulating the process of alternative splicing in the nucleus to produce ‘cryptic’ exons in the brains of mice. The presence of these exons in the mRNA leads to the production of premature termination codons in the cytoplasm. These codons trigger a process called nonsense-mediated decay that involves identifying mRNA transcripts that contain nonsense mutations, and then degrading them. These cryptic exons were seen in mice missing the NOVA proteins, where they are expressed in abnormally high levels; in normal mice, these exons have not been seen before, hence they were termed ‘cryptic’. Eom et al. also show that these cryptic exons are physiologically relevant by inducing epileptic seizures in mice. Following the seizures, they find that the NOVA proteins up-regulate and down-regulate the levels of different cryptic exons, leading to changes in the levels of the proteins encoded by these mRNAs, including proteins that inhibit further seizures. Overall the results indicate that, by controlling the production of various proteins in neurons, these previously unknown cryptic exons have important roles in the workings of the brain. DOI:http://dx.doi.org/10.7554/eLife.00178.002
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Affiliation(s)
- Taesun Eom
- Laboratory of Molecular Neuro-Oncology , Rockefeller University , New York , United States
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540
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Feijs KL, Kleine H, Braczynski A, Forst AH, Herzog N, Verheugd P, Linzen U, Kremmer E, Lüscher B. ARTD10 substrate identification on protein microarrays: regulation of GSK3β by mono-ADP-ribosylation. Cell Commun Signal 2013; 11:5. [PMID: 23332125 PMCID: PMC3627616 DOI: 10.1186/1478-811x-11-5] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/20/2012] [Indexed: 12/24/2022] Open
Abstract
Background Although ADP-ribosylation has been described five decades ago, only recently a distinction has been made between eukaryotic intracellular poly- and mono-ADP-ribosylating enzymes. Poly-ADP-ribosylation by ARTD1 (formerly PARP1) is best known for its role in DNA damage repair. Other polymer forming enzymes are ARTD2 (formerly PARP2), ARTD3 (formerly PARP3) and ARTD5/6 (formerly Tankyrase 1/2), the latter being involved in Wnt signaling and regulation of 3BP2. Thus several different functions of poly-ADP-ribosylation have been well described whereas intracellular mono-ADP-ribosylation is currently largely undefined. It is for example not known which proteins function as substrate for the different mono-ARTDs. This is partially due to lack of suitable reagents to study mono-ADP-ribosylation, which limits the current understanding of this post-translational modification. Results We have optimized a novel screening method employing protein microarrays, ProtoArrays®, applied here for the identification of substrates of ARTD10 (formerly PARP10) and ARTD8 (formerly PARP14). The results of this substrate screen were validated using in vitro ADP-ribosylation assays with recombinant proteins. Further analysis of the novel ARTD10 substrate GSK3β revealed mono-ADP-ribosylation as a regulatory mechanism of kinase activity by non-competitive inhibition in vitro. Additionally, manipulation of the ARTD10 levels in cells accordingly influenced GSK3β activity. Together these data provide the first evidence for a role of endogenous mono-ADP-ribosylation in intracellular signaling. Conclusions Our findings indicate that substrates of ADP-ribosyltransferases can be identified using protein microarrays. The discovered substrates of ARTD10 and ARTD8 provide the first sets of proteins that are modified by mono-ADP-ribosyltransferases in vitro. By studying one of the ARTD10 substrates more closely, the kinase GSK3β, we identified mono-ADP-ribosylation as a negative regulator of kinase activity.
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Affiliation(s)
- Karla Lh Feijs
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany.
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TNiK is required for postsynaptic and nuclear signaling pathways and cognitive function. J Neurosci 2013; 32:13987-99. [PMID: 23035106 DOI: 10.1523/jneurosci.2433-12.2012] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Traf2 and NcK interacting kinase (TNiK) contains serine-threonine kinase and scaffold domains and has been implicated in cell proliferation and glutamate receptor regulation in vitro. Here we report its role in vivo using mice carrying a knock-out mutation. TNiK binds protein complexes in the synapse linking it to the NMDA receptor (NMDAR) via AKAP9. NMDAR and metabotropic receptors bidirectionally regulate TNiK phosphorylation and TNiK is required for AMPA expression and synaptic function. TNiK also organizes nuclear complexes and in the absence of TNiK, there was a marked elevation in GSK3β and phosphorylation levels of its cognate phosphorylation sites on NeuroD1 with alterations in Wnt pathway signaling. We observed impairments in dentate gyrus neurogenesis in TNiK knock-out mice and cognitive testing using the touchscreen apparatus revealed impairments in pattern separation on a test of spatial discrimination. Object-location paired associate learning, which is dependent on glutamatergic signaling, was also impaired. Additionally, TNiK knock-out mice displayed hyperlocomotor behavior that could be rapidly reversed by GSK3β inhibitors, indicating the potential for pharmacological rescue of a behavioral phenotype. These data establish TNiK as a critical regulator of cognitive functions and suggest it may play a regulatory role in diseases impacting on its interacting proteins and complexes.
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542
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Zhou X, Wang H, Burg MB, Ferraris JD. Inhibitory phosphorylation of GSK-3β by AKT, PKA, and PI3K contributes to high NaCl-induced activation of the transcription factor NFAT5 (TonEBP/OREBP). Am J Physiol Renal Physiol 2013; 304:F908-17. [PMID: 23324178 DOI: 10.1152/ajprenal.00591.2012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
High NaCl activates the transcription factor nuclear factor of activated T cells 5 (NFAT5), leading to increased transcription of osmoprotective target genes. Kinases PKA, PI3K, AKT1, and p38α were known to contribute to the high NaCl-induced increase of NFAT5 activity. We now identify another kinase, GSK-3β. siRNA-mediated knock-down of GSK-3β increases NFAT5 transcriptional and transactivating activities without affecting high NaCl-induced nuclear localization of NFAT5 or NFAT5 protein expression. High NaCl increases phosphorylation of GSK-3β-S9, which inhibits GSK-3β. In GSK-3β-null mouse embryonic fibroblasts transfection of GSK-3β, in which serine 9 is mutated to alanine, so that it cannot be inhibited by phosphorylation at that site, inhibits high NaCl-induced NFAT5 transcriptional activity more than transfection of wild-type GSK-3β. High NaCl-induced phosphorylation of GSK-3β-S9 depends on PKA, PI3K, and AKT, but not p38α. Overexpression of PKA catalytic subunit α or of catalytically active AKT1 reduces inhibition of NFAT5 by GSK-3β, but overexpression of p38α together with its catalytically active upstream kinase, MKK6, does not. Thus, GSK-3β normally inhibits NFAT5 by suppressing its transactivating activity. When activated by high NaCl, PKA, PI3K, and AKT1, but not p38α, increase phosphorylation of GSK-3β-S9, which reduces the inhibitory effect of GSK-3β on NFAT5, and thus contributes to activation of NFAT5.
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Affiliation(s)
- Xiaoming Zhou
- Department of Medicine, Uniformed Services University, 4301 Jones Bridge Rd., Bethesda, MD 20814, USA.
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543
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Wnt5a cooperates with canonical Wnts to generate midbrain dopaminergic neurons in vivo and in stem cells. Proc Natl Acad Sci U S A 2013; 110:E602-10. [PMID: 23324743 DOI: 10.1073/pnas.1208524110] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Wnts are a family of secreted proteins that regulate multiple steps of neural development and stem cell differentiation. Two of them, Wnt1 and Wnt5a, activate distinct branches of Wnt signaling and individually regulate different aspects of midbrain dopaminergic (DA) neuron development. However, several of their functions and interactions remain to be elucidated. Here, we report that loss of Wnt1 results in loss of Lmx1a and Ngn2 expression, as well as agenesis of DA neurons in the midbrain floor plate. Remarkably, a few ectopic DA neurons still emerge in the basal plate of Wnt1(-/-) mice, where Lmx1a is ectopically expressed. These results indicate that Wnt1 orchestrates DA specification and neurogenesis in vivo. Analysis of Wnt1(-/-);Wnt5a(-/-) mice revealed a greater loss of Nurr1(+) cells and DA neurons than in single mutants, indicating that Wnt1 and Wnt5a interact genetically and cooperate to promote midbrain DA neuron development in vivo. Our results unravel a functional interaction between Wnt1 and Wnt5a resulting in enhanced DA neurogenesis. Taking advantage of these findings, we have developed an application of Wnts to improve the generation of midbrain DA neurons from neural and embryonic stem cells. We thus show that coordinated Wnt actions promote DA neuron development in vivo and in stem cells and suggest that coordinated Wnt administration can be used to improve DA differentiation of stem cells and the development of stem cell-based therapies for Parkinson's disease.
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544
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Peng X, Gao H, Wang Y, Yang B, Liu T, Sun Y, Jin H, Jiang L, Li L, Wu M, Qian Q. Conversion of rat embryonic stem cells into neural precursors in chemical-defined medium. Biochem Biophys Res Commun 2013; 431:783-7. [PMID: 23321306 DOI: 10.1016/j.bbrc.2013.01.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 01/07/2013] [Indexed: 11/17/2022]
Abstract
Rat embryonic stem (ES) cells hold great interest for the research of neurodevelopment and neurodegenerative diseases. However, neural conversion of rat ES cells in vitro has proven to be a challenge owing to the proliferation arrest and apoptosis. Here we report that rat ES cells can commit efficiently to a neural fate in the presence of CHIR99021 and Y-27632 (CY medium). In addition, CHIR99021 is crucial for maintaining the metabolic activity of differentiated rat ES cells, while Y-27632 facilitates the neural differentiation of rat ES cells by inhibiting bone morphogenetic protein expression. The chemical-defined CY medium also provides a platform for exploring the mechanism of neural commitment and optimizing the production efficiency of neural precursor from rat ES cells.
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Affiliation(s)
- Xinrong Peng
- Laboratory of Viral and Gene Therapy, Eastern Hepatobiliary Surgical Hospital, The Second Military Medical University, Shanghai, PR China
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545
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Marchetti B, Pluchino S. Wnt your brain be inflamed? Yes, it Wnt! Trends Mol Med 2013; 19:144-56. [PMID: 23312954 DOI: 10.1016/j.molmed.2012.12.001] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 12/06/2012] [Accepted: 12/06/2012] [Indexed: 12/15/2022]
Abstract
The roles of Wnts in neural development, synaptogenesis, and cancer are generally well characterized. Nonetheless, evidence exists that interactions between the immune and nervous systems control major brain regenerative processes ranging from physiological or pathological (reparative) regeneration to neurogenesis and synaptic plasticity. Recent studies describe deregulated Wnt-Fzd signaling in degenerative and inflammatory central nervous system (CNS) disorders, and the expression of Wnt signaling components in the immune system, and in immune-like cells of the mammalian CNS. This would suggest a likely involvement of Wnts in inflammation-driven brain damage and inflammation-directed brain repair. Here, we review how Wnts modulate neuroimmune interactions and offer a perspective on the most challenging therapeutic opportunities for those CNS diseases where injury-reactive Wnt-flavored inflammation precedes secondary neurodegeneration.
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Affiliation(s)
- Bianca Marchetti
- Department of Clinical and Molecular Biomedicine, Pharmacology Section, Medical School, University of Catania, 95125 Catania, Italy.
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546
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Suo WZ. Accelerating Alzheimer’s pathogenesis by GRK5 deficiency via cholinergic dysfunction. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/aad.2013.24020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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547
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Negative Symptoms of Psychosis Correlate with Gene Expression of the Wnt/β-Catenin Signaling Pathway in Peripheral Blood. PSYCHIATRY JOURNAL 2013; 2013:852930. [PMID: 24236287 PMCID: PMC3820119 DOI: 10.1155/2013/852930] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 12/19/2012] [Indexed: 11/18/2022]
Abstract
Genes in the Wnt (wingless)/β-catenin signaling pathway have been implicated in schizophrenia pathogenesis. No study has examined this pathway in the broader context of psychosis symptom severity. We investigated the association between symptom severity scores and expression of 25 Wnt pathway genes in blood from 19 psychotic patients. Significant correlations between negative symptom scores and deshivelled 2 (DVL2) (radj = −0.70; P = 0.0008) and glycogen synthase kinase 3 beta (GSK3B) (radj = 0.48; P = 0.039) were observed. No gene expression levels were associated with positive symptoms. Our findings suggest that the Wnt signaling pathway may harbor biomarkers for severity of negative but not positive symptoms.
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548
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Byun J, Kim BT, Kim YT, Jiao Z, Hur EM, Zhou FQ. Slit2 inactivates GSK3β to signal neurite outgrowth inhibition. PLoS One 2012; 7:e51895. [PMID: 23284807 PMCID: PMC3526488 DOI: 10.1371/journal.pone.0051895] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 11/09/2012] [Indexed: 01/29/2023] Open
Abstract
Slit molecules comprise one of the four canonical families of axon guidance cues that steer the growth cone in the developing nervous system. Apart from their role in axon pathfinding, emerging lines of evidence suggest that a wide range of cellular processes are regulated by Slit, ranging from branch formation and fasciculation during neurite outgrowth to tumor progression and to angiogenesis. However, the molecular and cellular mechanisms downstream of Slit remain largely unknown, in part, because of a lack of a readily manipulatable system that produces easily identifiable traits in response to Slit. The present study demonstrates the feasibility of using the cell line CAD as an assay system to dissect the signaling pathways triggered by Slit. Here, we show that CAD cells express receptors for Slit (Robo1 and Robo2) and that CAD cells respond to nanomolar concentrations of Slit2 by markedly decelerating the rate of process extension. Using this system, we reveal that Slit2 inactivates GSK3β and that inhibition of GSK3β is required for Slit2 to inhibit process outgrowth. Furthermore, we show that Slit2 induces GSK3β phosphorylation and inhibits neurite outgrowth in adult dorsal root ganglion neurons, validating Slit2 signaling in primary neurons. Given that CAD cells can be conveniently manipulated using standard molecular biological methods and that the process extension phenotype regulated by Slit2 can be readily traced and quantified, the use of a cell line CAD will facilitate the identification of downstream effectors and elucidation of signaling cascade triggered by Slit.
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Affiliation(s)
- Justin Byun
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Bo Taek Kim
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Yun Tai Kim
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Korea Food Research Institute, Seongnam, Republic of Korea
| | - Zhongxian Jiao
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Eun-Mi Hur
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea
- * E-mail: (F-QZ); (E-MH)
| | - Feng-Quan Zhou
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (F-QZ); (E-MH)
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549
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Yang SH, Kalkan T, Morrisroe C, Smith A, Sharrocks AD. A genome-wide RNAi screen reveals MAP kinase phosphatases as key ERK pathway regulators during embryonic stem cell differentiation. PLoS Genet 2012; 8:e1003112. [PMID: 23271975 PMCID: PMC3521700 DOI: 10.1371/journal.pgen.1003112] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 10/08/2012] [Indexed: 01/13/2023] Open
Abstract
Embryonic stem cells and induced pluripotent stem cells represent potentially important therapeutic agents in regenerative medicine. Complex interlinked transcriptional and signaling networks control the fate of these cells towards maintenance of pluripotency or differentiation. In this study we have focused on how mouse embryonic stem cells begin to differentiate and lose pluripotency and, in particular, the role that the ERK MAP kinase and GSK3 signaling pathways play in this process. Through a genome-wide siRNA screen we have identified more than 400 genes involved in loss of pluripotency and promoting the onset of differentiation. These genes were functionally associated with the ERK and/or GSK3 pathways, providing an important resource for studying the roles of these pathways in controlling escape from the pluripotent ground state. More detailed analysis identified MAP kinase phosphatases as a focal point of regulation and demonstrated an important role for these enzymes in controlling ERK activation kinetics and subsequently determining early embryonic stem cell fate decisions.
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Affiliation(s)
- Shen-Hsi Yang
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Tuzer Kalkan
- Wellcome Trust–Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Claire Morrisroe
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Austin Smith
- Wellcome Trust–Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Andrew D. Sharrocks
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
- * E-mail:
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550
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Alhusban A, Kozak A, Ergul A, Fagan SC. AT1 receptor antagonism is proangiogenic in the brain: BDNF a novel mediator. J Pharmacol Exp Ther 2012; 344:348-59. [PMID: 23211364 DOI: 10.1124/jpet.112.197483] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Candesartan is an angiotensin II type 1 receptor blocker (ARB) that has been to shown to limit ischemic stroke and improve stroke outcome. In experimental stroke, candesartan induces a proangiogenic effect that is partly attributable to vascular endothelial growth factor. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family that has been reported to have angiogenic effects and play an important role in recovery after stroke. The purpose of this investigation was to determine the role of BDNF in the proangiogenic effect of candesartan in the brain under hypertensive conditions. Accordingly, spontaneously hypertensive rats were treated with candesartan, and brain tissue samples were collected for quantification of BDNF expression. In addition, human cerebromicrovascular endothelial cells were treated with either low-dose (1 ƒM) or high-dose (1 µM) angiotensin II alone or in combination with candesartan (0.16 µM) to assess the effect of candesartan treatment and BDNF involvement in the behavior of endothelial cells. Candesartan significantly increased the expression of BDNF in the SHR (P < 0.05). In addition, candesartan reversed the antiangiogenic effect of the 1-µM dose of AngII (P = 0.0001). The observed effects of candesartan were ablated by neutralizing the effects of BDNF. Treatment with the AT2 antagonist PD-123319 significantly reduced tube-like formation in endothelial cells. AT2 stimulation induced the BDNF expression and migration (P < 0.05). In conclusion, candesartan exerts a proangiogenic effect on brain microvascular endothelial cells treated with angiotensin II. This response is attributable to increased BDNF expression and is mediated through stimulation of the AT2 receptor.
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Affiliation(s)
- Ahmed Alhusban
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA, USA
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