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Hausrat TJ, Vogl C, Neef J, Schweizer M, Yee BK, Strenzke N, Kneussel M. Monoallelic loss of the F-actin-binding protein radixin facilitates startle reactivity and pre-pulse inhibition in mice. Front Cell Dev Biol 2022; 10:987691. [DOI: 10.3389/fcell.2022.987691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/11/2022] [Indexed: 11/29/2022] Open
Abstract
Hearing impairment is one of the most common disorders with a global burden and increasing prevalence in an ever-aging population. Previous research has largely focused on peripheral sensory perception, while the brain circuits of auditory processing and integration remain poorly understood. Mutations in the rdx gene, encoding the F-actin binding protein radixin (Rdx), can induce hearing loss in human patients and homozygous depletion of Rdx causes deafness in mice. However, the precise physiological function of Rdx in hearing and auditory information processing is still ill-defined. Here, we investigated consequences of rdx monoallelic loss in the mouse. Unlike the homozygous (−/−) rdx knockout, which is characterized by the degeneration of actin-based stereocilia and subsequent hearing loss, our analysis of heterozygous (+/−) mutants has revealed a different phenotype. Specifically, monoallelic loss of rdx potentiated the startle reflex in response to acoustic stimulation of increasing intensities, suggesting a gain of function relative to wildtype littermates. The monoallelic loss of the rdx gene also facilitated pre-pulse inhibition of the acoustic startle reflex induced by weak auditory pre-pulse stimuli, indicating a modification to the circuit underlying sensorimotor gating of auditory input. However, the auditory brainstem response (ABR)-based hearing thresholds revealed a mild impairment in peripheral sound perception in rdx (+/-) mice, suggesting minor aberration of stereocilia structural integrity. Taken together, our data suggest a critical role of Rdx in the top-down processing and/or integration of auditory signals, and therefore a novel perspective to uncover further Rdx-mediated mechanisms in central auditory information processing.
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Giannos P, Prokopidis K, Forbes SC, Celoch K, Candow DG, Tartar JL. Gene Expression Changes of Murine Cortex Homeostasis in Response to Sleep Deprivation Hint Dysregulated Aging-like Transcriptional Responses. Brain Sci 2022; 12:825. [PMID: 35884632 PMCID: PMC9313387 DOI: 10.3390/brainsci12070825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 12/04/2022] Open
Abstract
Sleep deprivation leads to the deterioration in the physiological functioning of the brain, cognitive decline, and many neurodegenerative diseases, all of which progress with advancing age. Sleep insufficiency and impairments in cognitive function are characterized by progressive neuronal losses in the cerebral cortex. In this study, we analyze gene expression profiles following sleep-deprived murine models and circadian matched controls to identify genes that might underlie cortical homeostasis in response to sleep deprivation. Screening of the literature resulted in three murine (Mus musculus) gene expression datasets (GSE6514, GSE78215, and GSE33491) that included cortical tissue biopsies from mice that are sleep deprived for 6 h (n = 15) and from circadian controls that are left undisturbed (n = 15). Cortical differentially expressed genes are used to construct a network of encoded proteins that are ranked based on their interactome according to 11 topological algorithms. The analysis revealed three genes-NFKBIA, EZR, and SGK1-which exhibited the highest multi-algorithmic topological significance. These genes are strong markers of increased brain inflammation, cytoskeletal aberrations, and glucocorticoid resistance, changes that imply aging-like transcriptional responses during sleep deprivation in the murine cortex. Their potential role as candidate markers of local homeostatic response to sleep loss in the murine cortex warrants further experimental validation.
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Affiliation(s)
- Panagiotis Giannos
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, South Kensington, London SW7 2AZ, UK
- Society of Meta-Research and Biomedical Innovation, London W12 0BZ, UK;
| | - Konstantinos Prokopidis
- Society of Meta-Research and Biomedical Innovation, London W12 0BZ, UK;
- Department of Musculoskeletal Biology, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Scott C. Forbes
- Department of Physical Education Studies, Faculty of Education, Brandon University, Brandon, MB R7A 6A9, Canada;
| | - Kamil Celoch
- Department of Psychology and Neuroscience, Nova Southeastern University, Fort Lauderdale, FL 33314, USA; (K.C.); (J.L.T.)
| | - Darren G. Candow
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK S4S 0A2, Canada;
| | - Jaime L. Tartar
- Department of Psychology and Neuroscience, Nova Southeastern University, Fort Lauderdale, FL 33314, USA; (K.C.); (J.L.T.)
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Cicvaric A, Sachernegg HM, Stojanovic T, Symmank D, Smani T, Moeslinger T, Uhrin P, Monje FJ. Podoplanin Gene Disruption in Mice Promotes in vivo Neural Progenitor Cells Proliferation, Selectively Impairs Dentate Gyrus Synaptic Depression and Induces Anxiety-Like Behaviors. Front Cell Neurosci 2020; 13:561. [PMID: 32009902 PMCID: PMC6974453 DOI: 10.3389/fncel.2019.00561] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/05/2019] [Indexed: 12/20/2022] Open
Abstract
Podoplanin (Pdpn), a brain-tumor-related glycoprotein identified in humans and animals, is endogenously expressed in several organs critical for life support such as kidney, lung, heart and brain. In the brain, Pdpn has been identified in proliferative nestin-positive adult neural progenitor cells and in neurons of the neurogenic hippocampal dentate gyrus (DG), a structure associated to anxiety, critical for learning and memory functions and severely damaged in people with Alzheimer's Disease (AD). The in vivo role of Pdpn in adult neurogenesis and anxiety-like behavior remained however unexplored. Using mice with disrupted Pdpn gene as a model organism and applying combined behavioral, molecular biological and electrophysiological assays, we here show that the absence of Pdpn selectively impairs long-term synaptic depression in the neurogenic DG without affecting the CA3-Schaffer's collateral-CA1 synapses. Pdpn deletion also enhanced the proliferative capacity of DG neural progenitor cells and diminished survival of differentiated neuronal cells in vitro. In addition, mice with podoplanin gene disruption showed increased anxiety-like behaviors in experimentally validated behavioral tests as compared to wild type littermate controls. Together, these findings broaden our knowledge on the molecular mechanisms influencing hippocampal synaptic plasticity and neurogenesis in vivo and reveal Pdpn as a novel molecular target for future studies addressing general anxiety disorder and synaptic depression-related memory dysfunctions.
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Affiliation(s)
- Ana Cicvaric
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannah M. Sachernegg
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Tamara Stojanovic
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Dörte Symmank
- Center for Physiology and Pharmacology, Institute for Physiology, Medical University of Vienna, Vienna, Austria
| | - Tarik Smani
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville (IBiS)/University of Seville/CIBERCV, Seville, Spain
| | - Thomas Moeslinger
- Center for Physiology and Pharmacology, Institute for Physiology, Medical University of Vienna, Vienna, Austria
| | - Pavel Uhrin
- Center for Physiology and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Francisco J. Monje
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
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Derouiche A, Geiger KD. Perspectives for Ezrin and Radixin in Astrocytes: Kinases, Functions and Pathology. Int J Mol Sci 2019; 20:ijms20153776. [PMID: 31382374 PMCID: PMC6695708 DOI: 10.3390/ijms20153776] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 02/06/2023] Open
Abstract
Astrocytes are increasingly perceived as active partners in physiological brain function and behaviour. The structural correlations of the glia–synaptic interaction are the peripheral astrocyte processes (PAPs), where ezrin and radixin, the two astrocytic members of the ezrin-radixin-moesin (ERM) family of proteins are preferentially localised. While the molecular mechanisms of ERM (in)activation appear universal, at least in mammalian cells, and have been studied in great detail, the actual ezrin and radixin kinases, phosphatases and binding partners appear cell type specific and may be multiplexed within a cell. In astrocytes, ezrin is involved in process motility, which can be stimulated by the neurotransmitter glutamate, through activation of the glial metabotropic glutamate receptors (mGluRs) 3 or 5. However, it has remained open how this mGluR stimulus is transduced to ezrin activation. Knowing upstream signals of ezrin activation, ezrin kinase(s), and membrane-bound binding partners of ezrin in astrocytes might open new approaches to the glial role in brain function. Ezrin has also been implicated in invasive behaviour of astrocytomas, and glial activation. Here, we review data pertaining to potential molecular interaction partners of ezrin in astrocytes, with a focus on PKC and GRK2, and in gliomas and other diseases, to stimulate further research on their potential roles in glia-synaptic physiology and pathology.
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Affiliation(s)
- Amin Derouiche
- Institute of Anatomy II, Goethe-University Frankfurt, D-60590 Frankfurt am Main, Germany.
| | - Kathrin D Geiger
- Neuropathology, Institute for Pathology, Carl Gustav Carus University Hospital, TU Dresden, D-01307 Dresden, Germany
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Moon Y, Kim JY, Kim WR, Kim HJ, Jang MJ, Nam Y, Kim K, Kim H, Sun W. Function of ezrin-radixin-moesin proteins in migration of subventricular zone-derived neuroblasts following traumatic brain injury. Stem Cells 2014; 31:1696-705. [PMID: 23649635 DOI: 10.1002/stem.1420] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 04/16/2013] [Indexed: 12/15/2022]
Abstract
Throughout life, newly generated neuroblasts from the subventricular zone migrate toward the olfactory bulb through the rostral migratory stream. Upon brain injury, these migrating neuroblasts change their route and begin to migrate toward injured regions, which is one of the regenerative responses after brain damage. This injury-induced migration is triggered by stromal cell-derived factor 1 (SDF1) released from microglia near the damaged site; however, it is still unclear how these cells transduce SDF1 signals and change their direction. In this study, we found that SDF1 promotes the phosphorylation of ezrin-radixin-moesin (ERM) proteins, which are key molecules in organizing cell membrane and linking signals from the extracellular environment to the intracellular actin cytoskeleton. Blockade of ERM activation by overexpressing dominant-negative ERM (DN-ERM) efficiently perturbed the migration of neuroblasts. Considering that DN-ERM-expressing neuroblasts failed to maintain proper migratory cell morphology, it appears that ERM-dependent regulation of cell shape is required for the efficient migration of neuroblasts. These results suggest that ERM activation is an important step in the directional migration of neuroblasts in response to SDF1-CXCR4 signaling following brain injury.
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Affiliation(s)
- Younghye Moon
- Department of Anatomy and Division of Brain Korea 21 Biomedical Science, Korea University College of Medicine, Seoul, Korea; Brain and Neuroendocrine Laboratory, School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Korea
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Cho HM, Kim JY, Kim H, Sun W. Phosphatase and actin regulator 4 is associated with intermediate filaments in adult neural stem cells and their progenitor astrocytes. Histochem Cell Biol 2014; 142:411-9. [PMID: 24748504 DOI: 10.1007/s00418-014-1220-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2014] [Indexed: 11/25/2022]
Abstract
Phosphatase and actin regulator 4 (Phactr4) is a newly discovered protein that inhibits protein phosphatase 1 and shows actin-binding activity. We previously found that Phactr4 is expressed in the neurogenic niche in adult mice, although its precise subcellular localization and possible function in neural stem cells (NSCs) is not yet understood. Here, we show that Phactr4 formed punctiform clusters in the cytosol of subventricular zone-derived adult NSCs and their progeny in vitro. These Phactr4 signals were not associated with F-actin fibers but were closely associated with intermediate filaments such as nestin and glial fibrillary acidic protein (GFAP) fibers. Direct binding of Phactr4 with nestin and GFAP filaments was demonstrated using Duolink protein interaction analyses and immunoprecipitation assays. Interestingly, when nestin fibers were de-polymerized during the mitosis or by the phosphatase inhibitor, Phactr4 appeared to be dissociated from nestin, suggesting that their protein interaction is regulated by the protein phosphorylation. These results suggest that Phactr4 forms functional associations with intermediate filament networks in adult NSCs.
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Affiliation(s)
- Hyo Min Cho
- Department of Anatomy, Brain Korea 21, Korea University College of Medicine, Anam-Dong, Sungbuk-Gu, Seoul, 136-705, Korea
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The Histochem Cell Biol conspectus: the year 2013 in review. Histochem Cell Biol 2014; 141:337-63. [PMID: 24610091 PMCID: PMC7087837 DOI: 10.1007/s00418-014-1207-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2014] [Indexed: 11/29/2022]
Abstract
Herein, we provide a brief synopsis of all manuscripts published in Histochem Cell Biol in the year 2013. For ease of reference, we have divided the manuscripts into the following categories: Advances in Methodologies; Molecules in Health and Disease; Organelles, Subcellular Structures and Compartments; Golgi Apparatus; Intermediate Filaments and Cytoskeleton; Connective Tissue and Extracellular Matrix; Autophagy; Stem Cells; Musculoskeletal System; Respiratory and Cardiovascular Systems; Gastrointestinal Tract; Central Nervous System; Peripheral Nervous System; Excretory Glands; Kidney and Urinary Bladder; and Male and Female Reproductive Systems. We hope that the readership will find this annual journal synopsis of value and serve as a quick, categorized reference guide for “state-of-the-art” manuscripts in the areas of histochemistry, immunohistochemistry, and cell biology.
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Choi KM, Kim JY, Kim Y. Distribution of the Immunoreactivity for Glycoprotein M6B in the Neurogenic Niche and Reactive Glia in the Injury Penumbra Following Traumatic Brain Injury in Mice. Exp Neurobiol 2013; 22:277-82. [PMID: 24465143 PMCID: PMC3897689 DOI: 10.5607/en.2013.22.4.277] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 11/07/2013] [Accepted: 11/07/2013] [Indexed: 11/19/2022] Open
Abstract
The location and morphology of astrocytes are known to contribute to their diversity, and this diversity is often associated with their selective functions. However, molecular markers for astrocyte subtypes are largely unknown. In this study, we found that the immunoreactivity for glycoprotein GPM6B (M6B-IR) is preferentially expressed in the astrocytes associated with ventricles or neurogenic regions of the adult mouse brain. In particular, M6B-IR in the neurogenic niche was confined to glial fibrillary acidic protein- or nestin-expressing neural stem cells. Furthermore, in the injury penumbra, reactive astrocytes expressing nestin also exhibited strong M6B-IR. These results reveal that GPM6B is a potential molecular marker for a subset of astrocytes, as well as for the injury-dependent activation of astrocytes.
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Affiliation(s)
- Kyung Mee Choi
- Department of Anatomy, Korea University College of Medicine, Seoul 136-705, Korea
| | - Joo Yeon Kim
- Department of Anatomy, Korea University College of Medicine, Seoul 136-705, Korea
| | - Younghwa Kim
- Department of Emergency Medical Technology, College of Nursing and Public Health, Kyungil University, Gyeongsan 721-701, Korea
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