51
|
Chen M, Puschmann TB, Marasek P, Inagaki M, Pekna M, Wilhelmsson U, Pekny M. Increased Neuronal Differentiation of Neural Progenitor Cells Derived from Phosphovimentin-Deficient Mice. Mol Neurobiol 2017; 55:5478-5489. [PMID: 28956310 PMCID: PMC5994207 DOI: 10.1007/s12035-017-0759-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 08/27/2017] [Indexed: 01/06/2023]
Abstract
Vimentin is an intermediate filament (also known as nanofilament) protein expressed in several cell types of the central nervous system, including astrocytes and neural stem/progenitor cells. Mutation of the vimentin serine sites that are phosphorylated during mitosis (VIMSA/SA) leads to cytokinetic failures in fibroblasts and lens epithelial cells, resulting in chromosomal instability and increased expression of cell senescence markers. In this study, we investigated morphology, proliferative capacity, and motility of VIMSA/SA astrocytes, and their effect on the differentiation of neural stem/progenitor cells. VIMSA/SA astrocytes expressed less vimentin and more GFAP but showed a well-developed intermediate filament network, exhibited normal cell morphology, proliferation, and motility in an in vitro wound closing assay. Interestingly, we found a two- to fourfold increased neuronal differentiation of VIMSA/SA neurosphere cells, both in a standard 2D and in Bioactive3D cell culture systems, and determined that this effect was neurosphere cell autonomous and not dependent on cocultured astrocytes. Using BrdU in vivo labeling to assess neural stem/progenitor cell proliferation and differentiation in the hippocampus of adult mice, one of the two major adult neurogenic regions, we found a modest increase (by 8%) in the fraction of newly born and surviving neurons. Thus, mutation of the serine sites phosphorylated in vimentin during mitosis alters intermediate filament protein expression but has no effect on astrocyte morphology or proliferation, and leads to increased neuronal differentiation of neural progenitor cells.
Collapse
Affiliation(s)
- Meng Chen
- Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 440, 40530, Gothenburg, Sweden
| | - Till B Puschmann
- Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 440, 40530, Gothenburg, Sweden
| | - Pavel Marasek
- Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 440, 40530, Gothenburg, Sweden
| | - Masaki Inagaki
- Department of Physiology, Mie University Graduate School of Medicine, Mie, Japan
| | - Marcela Pekna
- Laboratory of Regenerative Neuroimmunology, Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.,Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,University of Newcastle, Newcastle, NSW, Australia
| | - Ulrika Wilhelmsson
- Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 440, 40530, Gothenburg, Sweden
| | - Milos Pekny
- Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 440, 40530, Gothenburg, Sweden. .,Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia. .,University of Newcastle, Newcastle, NSW, Australia.
| |
Collapse
|
52
|
Zhang S, Wu M, Peng C, Zhao G, Gu R. GFAP expression in injured astrocytes in rats. Exp Ther Med 2017; 14:1905-1908. [PMID: 28962102 PMCID: PMC5609138 DOI: 10.3892/etm.2017.4760] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 02/10/2017] [Indexed: 11/06/2022] Open
Abstract
Glial fibrillary acidic protein (GFAP) is one of the best markers for the activation of astrocytes (AS) following injury or stress in the central nervous system (CNS). The purpose of this study was to examine the expression of GFAP and 14-3-3ε in rat AS subjected to hypoxia. We established primary cultures of AS from cerebral cortex of neonatal Sprague-Dawley rats as a model of glucose deficiency and hypoxia/ischemia-reperfusion. We analyzed the activated astrocyte markers GFAP and 14-3-3ε by western blot analysis and found that both increased over time, starting at 4 h and reaching the highest level at 72 h, at the end of the experiment. GFAP and 14-3-3ε protein localization by double-labeling immunofluorescence showed elevated expression and co-localization in the cytoplasm of AS. GFAP and 14-3-3ε expression remained elevated in AS 72 h after stress conditions, which is possibly related to the excessive activation and dysfunction of the CNS in chronic injuries.
Collapse
Affiliation(s)
- Shuquan Zhang
- Department of Orthopedics, Tianjing Nankai Hospital, Tianjin 300100, P.R. China
| | - Minfei Wu
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China
| | - Chuangang Peng
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China
| | - Guanjie Zhao
- Department of Medicine, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China
| | - Rui Gu
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China
| |
Collapse
|
53
|
Keratin gene mutations influence the keratinocyte response to DNA damage and cytokine induced apoptosis. Arch Dermatol Res 2017. [DOI: 10.1007/s00403-017-1757-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
54
|
Gupta A, Cole S, Labus JS, Joshi S, Nguyen TJ, Kilpatrick LA, Tillisch K, Naliboff BD, Chang L, Mayer EA. Gene expression profiles in peripheral blood mononuclear cells correlate with salience network activity in chronic visceral pain: A pilot study. Neurogastroenterol Motil 2017; 29:10.1111/nmo.13027. [PMID: 28191693 PMCID: PMC5503466 DOI: 10.1111/nmo.13027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 12/12/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND Distinct gene expression profiles in peripheral blood mononuclear cells (PBMCs) consistent with increased sympathetic nervous system activity have been described in different populations under chronic stress. Neuroinflammatory brain changes, possibly related to the migration of primed monocytes to the brain, have been implicated in the pathophysiology of chronic pain. Irritable bowel syndrome (IBS) is a stress-sensitive gastrointestinal disorder associated with altered brain-gut interactions and increased sympathetic/vagal tone and anxiety. Reports about immune alterations in IBS are conflicting. This pilot study aimed to test how PBMC gene expression inflammatory profiles are correlated with altered brain signatures in the salience system. METHODS Sixteen IBS and 16 healthy controls (HCs) completed resting state MRI scans. Gene expression profiles in PBMCs were assessed using human transcriptome array-2. Bioinformatic analyses determined differential expression of PBMCs between IBS and HCs. Partial least squares, a multivariate analysis technique, was used to identify disease correlations between PBMC gene expression profiles and functional activity in the brain's salience network. KEY RESULTS Regions of the salience network, including the mid cingulate cortex, and mid and superior temporal gyrus were positively correlated with several pro-inflammatory genes (interleukin 6, APOL2) in IBS, but negatively correlated with several anti-inflammatory genes (KRT8, APOA4) in HCs. CONCLUSIONS & INFERENCES Based on rodent studies, one may speculate that chronically activated stress signaling pathways in IBS maintain a pro-inflammatory state in the periphery. Alternatively, primed monocytes may migrate to the brain during stress, inducing regional neuroinflammatory changes in salience regions involved in the modulation of visceral sensitivity.
Collapse
Affiliation(s)
- Arpana Gupta
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA
| | - Steve Cole
- David Geffen School of Medicine, UCLA,Department of Hematology-Oncology, UCLA
| | - Jennifer S. Labus
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA
| | - Swapna Joshi
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA,Center for Systems Biomedicine, UCLA
| | - Trang J. Nguyen
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA
| | - Lisa A. Kilpatrick
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA
| | - Kirsten Tillisch
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA,Integrative Medicine, GLA, VHA
| | - Bruce D. Naliboff
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA
| | - Lin Chang
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA
| | - Emeran A. Mayer
- Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA,David Geffen School of Medicine, UCLA,Division of Digestive Diseases, UCLA,Ahmanson-Lovelace Brain Mapping Center, UCLA
| |
Collapse
|
55
|
Consequences of Keratin Phosphorylation for Cytoskeletal Organization and Epithelial Functions. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 330:171-225. [DOI: 10.1016/bs.ircmb.2016.09.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
56
|
Abstract
Intermediate filaments (IFs), together with microtubules and actin microfilaments, are the three main cytoskeletal components in metazoan cells. IFs are formed by a distinct protein family, which is made up of 70 members in humans. Most IF proteins are tissue- or organelle-specific, which includes lamins, the IF proteins of the nucleus. The building block of IFs is an elongated dimer, which consists of a central α-helical 'rod' domain flanked by flexible N- and C-terminal domains. The conserved rod domain is the 'signature feature' of the IF family. Bioinformatics analysis reveals that the rod domain of all IF proteins contains three α-helical segments of largely conserved length, interconnected by linkers. Moreover, there is a conserved pattern of hydrophobic repeats within each segment, which includes heptads and hendecads. This defines the presence of both left-handed and almost parallel coiled-coil regions along the rod length. Using X-ray crystallography on multiple overlapping fragments of IF proteins, the atomic structure of the nearly complete rod domain has been determined. Here, we discuss some specific challenges of this procedure, such as crystallization and diffraction data phasing by molecular replacement. Further insights into the structure of the coiled coil and the terminal domains have been obtained using electron paramagnetic resonance measurements on the full-length protein, with spin labels attached at specific positions. This atomic resolution information, as well as further interesting findings, such as the variation of the coiled-coil stability along the rod length, provide clues towards interpreting the data on IF assembly, collected by a range of methods. However, a full description of this process at the molecular level is not yet at hand.
Collapse
Affiliation(s)
- Dmytro Guzenko
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Anastasia A Chernyatina
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Sergei V Strelkov
- Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, Katholieke Universiteit Leuven, Leuven, Belgium.
| |
Collapse
|
57
|
Makihara H, Inaba H, Enomoto A, Tanaka H, Tomono Y, Ushida K, Goto M, Kurita K, Nishida Y, Kasahara K, Goto H, Inagaki M. Desmin phosphorylation by Cdk1 is required for efficient separation of desmin intermediate filaments in mitosis and detected in murine embryonic/newborn muscle and human rhabdomyosarcoma tissues. Biochem Biophys Res Commun 2016; 478:1323-9. [PMID: 27565725 DOI: 10.1016/j.bbrc.2016.08.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 08/21/2016] [Indexed: 11/25/2022]
Abstract
Desmin is a type III intermediate filament (IF) component protein expressed specifically in muscular cells. Desmin is phosphorylated by Aurora-B and Rho-kinase specifically at the cleavage furrow from anaphase to telophase. The disturbance of this phosphorylation results in the formation of unusual long bridge-like IF structures (IF-bridge) between two post-mitotic (daughter) cells. Here, we report that desmin also serves as an excellent substrate for the other type of mitotic kinase, Cdk1. Desmin phosphorylation by Cdk1 loses its ability to form IFs in vitro. We have identified Ser6, Ser27, and Ser31 on murine desmin as phosphorylation sites for Cdk1. Using a site- and phosphorylation-state-specific antibody for Ser31 on desmin, we have demonstrated that Cdk1 phosphorylates desmin in entire cytoplasm from prometaphase to metaphase. Desmin mutations at Cdk1 sites exhibit IF-bridge phenotype, the frequency of which is significantly increased by the addition of Aurora-B and Rho-kinase site mutations to Cdk1 site mutations. In addition, Cdk1-induced desmin phosphorylation is detected in mitotic muscular cells of murine embryonic/newborn muscles and human rhabdomyosarcoma specimens. Therefore, Cdk1-induced desmin phosphorylation is required for efficient separation of desmin-IFs and generally detected in muscular mitotic cells in vivo.
Collapse
Affiliation(s)
- Hiroyuki Makihara
- Division of Biochemistry, Aichi Cancer Center Research Institute, Nagoya, 464-8681, Japan; Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi-Gakuin University, Nagoya, 464-8651, Japan
| | - Hironori Inaba
- Division of Biochemistry, Aichi Cancer Center Research Institute, Nagoya, 464-8681, Japan
| | - Atsushi Enomoto
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Hiroki Tanaka
- Division of Biochemistry, Aichi Cancer Center Research Institute, Nagoya, 464-8681, Japan
| | - Yasuko Tomono
- Division of Molecular and Cell Biology, Shigei Medical Research Institute, Okayama, 701-0202, Japan
| | - Kaori Ushida
- Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Mitsuo Goto
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi-Gakuin University, Nagoya, 464-8651, Japan
| | - Kenichi Kurita
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi-Gakuin University, Nagoya, 464-8651, Japan
| | - Yoshihiro Nishida
- Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Kousuke Kasahara
- Division of Biochemistry, Aichi Cancer Center Research Institute, Nagoya, 464-8681, Japan; Department of Physiology, Mie University School of Medicine, Tsu, Mie, 514-8507, Japan
| | - Hidemasa Goto
- Division of Biochemistry, Aichi Cancer Center Research Institute, Nagoya, 464-8681, Japan; Department of Cellular Oncology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Masaki Inagaki
- Division of Biochemistry, Aichi Cancer Center Research Institute, Nagoya, 464-8681, Japan; Department of Physiology, Mie University School of Medicine, Tsu, Mie, 514-8507, Japan.
| |
Collapse
|
58
|
Finkenstaedt-Quinn SA, Qiu TA, Shin K, Haynes CL. Super-resolution imaging for monitoring cytoskeleton dynamics. Analyst 2016; 141:5674-5688. [PMID: 27549146 DOI: 10.1039/c6an00731g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The cytoskeleton is a key cellular structure that is important in the control of cellular movement, structure, and sensing. To successfully image the individual cytoskeleton components, high resolution and super-resolution fluorescence imaging methods are needed. This review covers the three basic cytoskeletal elements and the relative benefits and drawbacks of fixed versus live cell imaging before moving on to recent studies using high resolution and super-resolution techniques. The techniques covered include the near-diffraction limited imaging methods of confocal microscopy and TIRF microscopy and the super-resolution fluorescence imaging methods of STORM, PALM, and STED.
Collapse
|
59
|
Coch RA, Leube RE. Intermediate Filaments and Polarization in the Intestinal Epithelium. Cells 2016; 5:E32. [PMID: 27429003 PMCID: PMC5040974 DOI: 10.3390/cells5030032] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 01/02/2023] Open
Abstract
The cytoplasmic intermediate filament cytoskeleton provides a tissue-specific three-dimensional scaffolding with unique context-dependent organizational features. This is particularly apparent in the intestinal epithelium, in which the intermediate filament network is localized below the apical terminal web region and is anchored to the apical junction complex. This arrangement is conserved from the nematode Caenorhabditis elegans to humans. The review summarizes compositional, morphological and functional features of the polarized intermediate filament cytoskeleton in intestinal cells of nematodes and mammals. We emphasize the cross talk of intermediate filaments with the actin- and tubulin-based cytoskeleton. Possible links of the intermediate filament system to the distribution of apical membrane proteins and the cell polarity complex are highlighted. Finally, we discuss how these properties relate to the establishment and maintenance of polarity in the intestine.
Collapse
Affiliation(s)
- Richard A Coch
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, Aachen 52074, Germany.
| | - Rudolf E Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, Aachen 52074, Germany.
| |
Collapse
|
60
|
Volkov V, Cavaco-Paulo A. In vitro phosphorylation as tool for modification of silk and keratin fibrous materials. Appl Microbiol Biotechnol 2016; 100:4337-45. [PMID: 27075736 DOI: 10.1007/s00253-016-7515-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 03/28/2016] [Accepted: 03/30/2016] [Indexed: 12/20/2022]
Abstract
An overview is given of the recent work on in vitro enzymatic phosphorylation of silk fibroin and human hair keratin. Opposing to many chemical "conventional" approaches, enzymatic phosphorylation is in fact a mild reaction and the treatment falls within "green chemistry" approach. Silk and keratin are not phosphorylated in vivo, but in vitro. This enzyme-driven modification is a major technological breakthrough. Harsh chemical chemicals are avoided, and mild conditions make enzymatic phosphorylation a real "green chemistry" approach. The current communication presents a novel approach stating that enzyme phosphorylation may be used as a tool to modify the surface charge of biocompatible materials such as keratin and silk.
Collapse
Affiliation(s)
- Vadim Volkov
- CEB - Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057, Braga, Portugal
| | - Artur Cavaco-Paulo
- CEB - Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057, Braga, Portugal.
| |
Collapse
|
61
|
Enzymatic phosphorylation of hair keratin enhances fast adsorption of cationic moieties. Int J Biol Macromol 2016; 85:476-86. [DOI: 10.1016/j.ijbiomac.2015.12.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/24/2015] [Accepted: 12/26/2015] [Indexed: 01/12/2023]
|
62
|
Reactive gliosis in the pathogenesis of CNS diseases. Biochim Biophys Acta Mol Basis Dis 2016; 1862:483-91. [DOI: 10.1016/j.bbadis.2015.11.014] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/19/2015] [Accepted: 11/30/2015] [Indexed: 01/11/2023]
|
63
|
Allen EHA, Courtney DG, Atkinson SD, Moore JE, Mairs L, Poulsen ET, Schiroli D, Maurizi E, Cole C, Hickerson RP, James J, Murgatroyd H, Smith FJD, MacEwen C, Enghild JJ, Nesbit MA, Leslie Pedrioli DM, McLean WHI, Moore CBT. Keratin 12 missense mutation induces the unfolded protein response and apoptosis in Meesmann epithelial corneal dystrophy. Hum Mol Genet 2016; 25:1176-91. [PMID: 26758872 PMCID: PMC4764196 DOI: 10.1093/hmg/ddw001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/04/2016] [Indexed: 11/23/2022] Open
Abstract
Meesmann epithelial corneal dystrophy (MECD) is a rare autosomal dominant disorder caused by dominant-negative mutations within the KRT3 or KRT12 genes, which encode the cytoskeletal protein keratins K3 and K12, respectively. To investigate the pathomechanism of this disease, we generated and phenotypically characterized a novel knock-in humanized mouse model carrying the severe, MECD-associated, K12-Leu132Pro mutation. Although no overt changes in corneal opacity were detected by slit-lamp examination, the corneas of homozygous mutant mice exhibited histological and ultrastructural epithelial cell fragility phenotypes. An altered keratin expression profile was observed in the cornea of mutant mice, confirmed by western blot, RNA-seq and quantitative real-time polymerase chain reaction. Mass spectrometry (MS) and immunohistochemistry demonstrated a similarly altered keratin profile in corneal tissue from a K12-Leu132Pro MECD patient. The K12-Leu132Pro mutation results in cytoplasmic keratin aggregates. RNA-seq analysis revealed increased chaperone gene expression, and apoptotic unfolded protein response (UPR) markers, CHOP and Caspase 12, were also increased in the MECD mice. Corneal epithelial cell apoptosis was increased 17-fold in the mutant cornea, compared with the wild-type (P < 0.001). This elevation of UPR marker expression was also observed in the human MECD cornea. This is the first reporting of a mouse model for MECD that recapitulates the human disease and is a valuable resource in understanding the pathomechanism of the disease. Although the most severe phenotype is observed in the homozygous mice, this model will still provide a test-bed for therapies not only for corneal dystrophies but also for other keratinopathies caused by similar mutations.
Collapse
Affiliation(s)
- Edwin H A Allen
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK, Centre for Dermatology and Genetic Medicine, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Scotland DD1 5EH, UK
| | - David G Courtney
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | - Sarah D Atkinson
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | - Johnny E Moore
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK, Cathedral Eye Clinic, Academy Street, Belfast BT15 1ED, UK
| | - Laura Mairs
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | | | - Davide Schiroli
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | - Eleonora Maurizi
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | - Christian Cole
- Centre for Dermatology and Genetic Medicine, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Scotland DD1 5EH, UK
| | - Robyn P Hickerson
- Centre for Dermatology and Genetic Medicine, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Scotland DD1 5EH, UK
| | - John James
- Microscopy Facility, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Helen Murgatroyd
- Department of Ophthalmology, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Frances J D Smith
- Centre for Dermatology and Genetic Medicine, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Scotland DD1 5EH, UK
| | - Carrie MacEwen
- Department of Ophthalmology, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Interdisciplinary Nanoscience Center (iNANO) and Center for Insoluble Protein Structures (inSPIN), Science Park, Aarhus University, Aarhus, Denmark and
| | - M Andrew Nesbit
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | - Deena M Leslie Pedrioli
- Centre for Dermatology and Genetic Medicine, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Scotland DD1 5EH, UK
| | - W H Irwin McLean
- Centre for Dermatology and Genetic Medicine, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Scotland DD1 5EH, UK,
| | - C B Tara Moore
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK,
| |
Collapse
|
64
|
Liu Z, Chopp M. Astrocytes, therapeutic targets for neuroprotection and neurorestoration in ischemic stroke. Prog Neurobiol 2015; 144:103-20. [PMID: 26455456 DOI: 10.1016/j.pneurobio.2015.09.008] [Citation(s) in RCA: 401] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 08/06/2015] [Accepted: 09/05/2015] [Indexed: 01/04/2023]
Abstract
Astrocytes are the most abundant cell type within the central nervous system. They play essential roles in maintaining normal brain function, as they are a critical structural and functional part of the tripartite synapses and the neurovascular unit, and communicate with neurons, oligodendrocytes and endothelial cells. After an ischemic stroke, astrocytes perform multiple functions both detrimental and beneficial, for neuronal survival during the acute phase. Aspects of the astrocytic inflammatory response to stroke may aggravate the ischemic lesion, but astrocytes also provide benefit for neuroprotection, by limiting lesion extension via anti-excitotoxicity effects and releasing neurotrophins. Similarly, during the late recovery phase after stroke, the glial scar may obstruct axonal regeneration and subsequently reduce the functional outcome; however, astrocytes also contribute to angiogenesis, neurogenesis, synaptogenesis, and axonal remodeling, and thereby promote neurological recovery. Thus, the pivotal involvement of astrocytes in normal brain function and responses to an ischemic lesion designates them as excellent therapeutic targets to improve functional outcome following stroke. In this review, we will focus on functions of astrocytes and astrocyte-mediated events during stroke and recovery. We will provide an overview of approaches on how to reduce the detrimental effects and amplify the beneficial effects of astrocytes on neuroprotection and on neurorestoration post stroke, which may lead to novel and clinically relevant therapies for stroke.
Collapse
Affiliation(s)
- Zhongwu Liu
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA.
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, MI, USA; Department of Physics, Oakland University, Rochester, MI, USA
| |
Collapse
|
65
|
Tu WL, Cheng CY, Wang SH, Tang PC, Chen CF, Chen HH, Lee YP, Chen SE, Huang SY. Profiling of differential gene expression in the hypothalamus of broiler-type Taiwan country chickens in response to acute heat stress. Theriogenology 2015; 85:483-494.e8. [PMID: 26462659 DOI: 10.1016/j.theriogenology.2015.09.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 08/21/2015] [Accepted: 09/12/2015] [Indexed: 12/18/2022]
Abstract
Acute heat stress severely impacts poultry production. The hypothalamus acts as a crucial center to regulate body temperature, detect temperature changes, and modulate the autonomic nervous system and endocrine loop for heat retention and dissipation. The purpose of this study was to investigate global gene expression in the hypothalamus of broiler-type B strain Taiwan country chickens after acute heat stress. Twelve 30-week-old hens were allocated to four groups. Three heat-stressed groups were subjected to acute heat stress at 38 °C for 2 hours without recovery (H2R0), with 2 hours of recovery (H2R2), and with 6 hours of recovery (H2R6). The control hens were maintained at 25 °C. At the end, hypothalamus samples were collected for gene expression analysis. The results showed that 24, 11, and 25 genes were upregulated and 41, 15, and 42 genes were downregulated in H2R0, H2R2, and H2R6 treatments, respectively. The expressions of gonadotropin-releasing hormone 1 (GNRH1), heat shock 27-kDa protein 1 (HSPB1), neuropeptide Y (NPY), and heat shock protein 25 (HSP25) were upregulated at all recovery times after heat exposure. Conversely, the expression of TPH2 was downregulated at all recovery times. A gene ontology analysis showed that most of the differentially expressed genes were involved in biological processes including cellular processes, metabolic processes, localization, multicellular organismal processes, developmental processes, and biological regulation. A functional annotation analysis showed that the differentially expressed genes were related to the gene networks of responses to stress and reproductive functions. These differentially expressed genes might be essential and unique key factors in the heat stress response of the hypothalamus in chickens.
Collapse
Affiliation(s)
- Wei-Lin Tu
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Chuen-Yu Cheng
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Shih-Han Wang
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Pin-Chi Tang
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan; Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan; Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan
| | - Chih-Feng Chen
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan; Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan; Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan
| | - Hsin-Hsin Chen
- Department of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yen-Pai Lee
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
| | - Shuen-Ei Chen
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan; Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan; Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan.
| | - San-Yuan Huang
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan; Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan; Center for the Integrative and Evolutionary Galliformes Genomics, iEGG Center, National Chung Hsing University, Taichung, Taiwan; Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung, Taiwan.
| |
Collapse
|
66
|
Lebkuechner I, Wilhelmsson U, Möllerström E, Pekna M, Pekny M. Heterogeneity of Notch signaling in astrocytes and the effects of GFAP and vimentin deficiency. J Neurochem 2015; 135:234-48. [DOI: 10.1111/jnc.13213] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 06/09/2015] [Accepted: 06/11/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Isabell Lebkuechner
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy at the University of Gothenburg; Gothenburg Sweden
| | - Ulrika Wilhelmsson
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy at the University of Gothenburg; Gothenburg Sweden
| | - Elin Möllerström
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy at the University of Gothenburg; Gothenburg Sweden
| | - Marcela Pekna
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy at the University of Gothenburg; Gothenburg Sweden
- Florey Institute of Neuroscience and Mental Health; Parkville Victoria Australia
- University of Newcastle; New South Wales Australia
| | - Milos Pekny
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy at the University of Gothenburg; Gothenburg Sweden
- Florey Institute of Neuroscience and Mental Health; Parkville Victoria Australia
- University of Newcastle; New South Wales Australia
| |
Collapse
|
67
|
Wunderlich KA, Tanimoto N, Grosche A, Zrenner E, Pekny M, Reichenbach A, Seeliger MW, Pannicke T, Perez MT. Retinal functional alterations in mice lacking intermediate filament proteins glial fibrillary acidic protein and vimentin. FASEB J 2015; 29:4815-28. [PMID: 26251181 DOI: 10.1096/fj.15-272963] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/27/2015] [Indexed: 01/02/2023]
Abstract
Vimentin (Vim) and glial fibrillary acidic protein (GFAP) are important components of the intermediate filament (IF) (or nanofilament) system of astroglial cells. We conducted full-field electroretinogram (ERG) recordings and found that whereas photoreceptor responses (a-wave) were normal in uninjured GFAP(-/-)Vim(-/-) mice, b-wave amplitudes were increased. Moreover, we found that Kir (inward rectifier K(+)) channel protein expression was reduced in the retinas of GFAP(-/-)Vim(-/-) mice and that Kir-mediated current amplitudes were lower in Müller glial cells isolated from these mice. Studies have shown that the IF system, in addition, is involved in the retinal response to injury and that attenuated Müller cell reactivity and reduced photoreceptor cell loss are observed in IF-deficient mice after experimental retinal detachment. We investigated whether the lack of IF proteins would affect cell survival in a retinal ischemia-reperfusion model. We found that although cell loss was induced in both genotypes, the number of surviving cells in the inner retina was lower in IF-deficient mice. Our findings thus show that the inability to produce GFAP and Vim affects normal retinal physiology and that the effect of IF deficiency on retinal cell survival differs, depending on the underlying pathologic condition.
Collapse
Affiliation(s)
- Kirsten A Wunderlich
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Naoyuki Tanimoto
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Antje Grosche
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Eberhart Zrenner
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Milos Pekny
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Andreas Reichenbach
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Mathias W Seeliger
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Pannicke
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Maria-Thereza Perez
- *Department of Clinical Sciences, Division of Ophthalmology, and NanoLund, Nanometer Structure Consortium, Lund University, Lund, Sweden; Graduate School of Cellular and Molecular Neuroscience, Center for Integrative Neuroscience (CIN), and Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Institute of Human Genetics, University of Regensburg, Regensburg, Germany; Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; **Hunter Medical Research Institute, University of Newcastle, Newcastle, New South Wales, Australia; and Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| |
Collapse
|
68
|
Cells transplanted onto the surface of the glial scar reveal hidden potential for functional neural regeneration. Proc Natl Acad Sci U S A 2015; 112:E3431-40. [PMID: 26080415 DOI: 10.1073/pnas.1501835112] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cell transplantation therapy has long been investigated as a therapeutic intervention for neurodegenerative disorders, including spinal cord injury, Parkinson's disease, and amyotrophic lateral sclerosis. Indeed, patients have high hopes for a cell-based therapy. However, there are numerous practical challenges for clinical translation. One major problem is that only very low numbers of donor cells survive and achieve functional integration into the host. Glial scar tissue in chronic neurodegenerative disorders strongly inhibits regeneration, and this inhibition must be overcome to accomplish successful cell transplantation. Intraneural cell transplantation is considered to be the best way to deliver cells to the host. We questioned this view with experiments in vivo on a rat glial scar model of the auditory system. Our results show that intraneural transplantation to the auditory nerve, preceded by chondroitinase ABC (ChABC)-treatment, is ineffective. There is no functional recovery, and almost all transplanted cells die within a few weeks. However, when donor cells are placed on the surface of a ChABC-treated gliotic auditory nerve, they autonomously migrate into it and recapitulate glia- and neuron-guided cell migration modes to repair the auditory pathway and recover auditory function. Surface transplantation may thus pave the way for improved functional integration of donor cells into host tissue, providing a less invasive approach to rescue clinically important neural tracts.
Collapse
|
69
|
Ho FC, Zhang W, Li YY, Chan BP. Mechanoresponsive, omni-directional and local matrix-degrading actin protrusions in human mesenchymal stem cells microencapsulated in a 3D collagen matrix. Biomaterials 2015; 53:392-405. [DOI: 10.1016/j.biomaterials.2015.02.102] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/22/2015] [Accepted: 02/24/2015] [Indexed: 10/25/2022]
|
70
|
The amount of keratins matters for stress protection of the colonic epithelium. PLoS One 2015; 10:e0127436. [PMID: 26000979 PMCID: PMC4441500 DOI: 10.1371/journal.pone.0127436] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/15/2015] [Indexed: 11/19/2022] Open
Abstract
Keratins (K) are important for epithelial stress protection as evidenced by keratin mutations predisposing to human liver diseases and possibly inflammatory bowel diseases. A role for K8 in the colon is supported by the ulcerative colitis-phenotype with epithelial hyperproliferation and abnormal ion transport in K8-knockout (K8-/-) mice. The heterozygote knockout (K8+/-) colon appears normal but displays a partial ion transport-defect. Characterizing the colonic phenotype we show that K8+/- colon expresses ~50% less keratins compared to K8 wild type (K8+/+) but de novo K7 expression is observed in the top-most cells of the K8+/- and K8-/- crypts. The K8+/- colonic crypts are significantly longer due to increased epithelial hyperproliferation, but display no defects in apoptosis or inflammation in contrast to K8-/-. When exposed to colitis using the dextran sulphate sodium-model, K8+/- mice showed higher disease sensitivity and delayed recovery compared to K8+/+ littermates. Therefore, the K8+/- mild colonic phenotype correlates with decreased keratin levels and increased sensitivity to experimental colitis, suggesting that a sufficient amount of keratin is needed for efficient stress protection in the colonic epithelia.
Collapse
|
71
|
Shinjyo N, de Pablo Y, Pekny M, Pekna M. Complement Peptide C3a Promotes Astrocyte Survival in Response to Ischemic Stress. Mol Neurobiol 2015; 53:3076-3087. [DOI: 10.1007/s12035-015-9204-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/29/2015] [Indexed: 01/04/2023]
|
72
|
Burda JE, Bernstein AM, Sofroniew MV. Astrocyte roles in traumatic brain injury. Exp Neurol 2015; 275 Pt 3:305-315. [PMID: 25828533 DOI: 10.1016/j.expneurol.2015.03.020] [Citation(s) in RCA: 506] [Impact Index Per Article: 56.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 02/28/2015] [Accepted: 03/08/2015] [Indexed: 01/15/2023]
Abstract
Astrocytes sense changes in neural activity and extracellular space composition. In response, they exert homeostatic mechanisms critical for maintaining neural circuit function, such as buffering neurotransmitters, modulating extracellular osmolarity and calibrating neurovascular coupling. In addition to upholding normal brain activities, astrocytes respond to diverse forms of brain injury with heterogeneous and progressive changes of gene expression, morphology, proliferative capacity and function that are collectively referred to as reactive astrogliosis. Traumatic brain injury (TBI) sets in motion complex events in which noxious mechanical forces cause tissue damage and disrupt central nervous system (CNS) homeostasis, which in turn trigger diverse multi-cellular responses that evolve over time and can lead either to neural repair or secondary cellular injury. In response to TBI, astrocytes in different cellular microenvironments tune their reactivity to varying degrees of axonal injury, vascular disruption, ischemia and inflammation. Here we review different forms of TBI-induced astrocyte reactivity and the functional consequences of these responses for TBI pathobiology. Evidence regarding astrocyte contribution to post-traumatic tissue repair and synaptic remodeling is examined, and the potential for targeting specific aspects of astrogliosis to ameliorate TBI sequelae is considered.
Collapse
Affiliation(s)
- Joshua E Burda
- Department of Neurobiology and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095-1763, USA
| | - Alexander M Bernstein
- Department of Neurobiology and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095-1763, USA
| | - Michael V Sofroniew
- Department of Neurobiology and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095-1763, USA.
| |
Collapse
|
73
|
Glial fibrillary acidic protein (GFAP) and the astrocyte intermediate filament system in diseases of the central nervous system. Curr Opin Cell Biol 2015; 32:121-30. [PMID: 25726916 DOI: 10.1016/j.ceb.2015.02.004] [Citation(s) in RCA: 539] [Impact Index Per Article: 59.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 02/04/2015] [Accepted: 02/09/2015] [Indexed: 01/14/2023]
Abstract
Glial fibrillary acidic protein (GFAP) is the hallmark intermediate filament (IF; also known as nanofilament) protein in astrocytes, a main type of glial cells in the central nervous system (CNS). Astrocytes have a range of control and homeostatic functions in health and disease. Astrocytes assume a reactive phenotype in acute CNS trauma, ischemia, and in neurodegenerative diseases. This coincides with an upregulation and rearrangement of the IFs, which form a highly complex system composed of GFAP (10 isoforms), vimentin, synemin, and nestin. We begin to unravel the function of the IF system of astrocytes and in this review we discuss its role as an important crisis-command center coordinating cell responses in situations connected to cellular stress, which is a central component of many neurological diseases.
Collapse
|
74
|
Kobayashi F, Yamamoto M, Kitamura K, Asuka K, Kinoshita H, Matsunaga S, Abe SI. Desmin and Vimentin Expression during Embryonic Development of Tensor Veli Palatini Muscle in Mice. J HARD TISSUE BIOL 2015. [DOI: 10.2485/jhtb.24.134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | | | | | - Kishi Asuka
- Division of Oral Anatomy, Department of Morphological Biology, Ohu University School of Dentistry
| | | | | | | |
Collapse
|
75
|
Pekny M, Pekna M. Astrocyte reactivity and reactive astrogliosis: costs and benefits. Physiol Rev 2014; 94:1077-98. [PMID: 25287860 DOI: 10.1152/physrev.00041.2013] [Citation(s) in RCA: 606] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Astrocytes are the most abundant cells in the central nervous system (CNS) that provide nutrients, recycle neurotransmitters, as well as fulfill a wide range of other homeostasis maintaining functions. During the past two decades, astrocytes emerged also as increasingly important regulators of neuronal functions including the generation of new nerve cells and structural as well as functional synapse remodeling. Reactive gliosis or reactive astrogliosis is a term coined for the morphological and functional changes seen in astroglial cells/astrocytes responding to CNS injury and other neurological diseases. Whereas this defensive reaction of astrocytes is conceivably aimed at handling the acute stress, limiting tissue damage, and restoring homeostasis, it may also inhibit adaptive neural plasticity mechanisms underlying recovery of function. Understanding the multifaceted roles of astrocytes in the healthy and diseased CNS will undoubtedly contribute to the development of treatment strategies that will, in a context-dependent manner and at appropriate time points, modulate reactive astrogliosis to promote brain repair and reduce the neurological impairment.
Collapse
Affiliation(s)
- Milos Pekny
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Marcela Pekna
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| |
Collapse
|
76
|
|
77
|
PEKNY T, ANDERSSON D, WILHELMSSON U, PEKNA M, PEKNY M. Short general anaesthesia induces prolonged changes in gene expression in the mouse hippocampus. Acta Anaesthesiol Scand 2014; 58:1127-33. [PMID: 25039928 DOI: 10.1111/aas.12369] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND The long-term molecular changes in the central nervous system constitute an important aspect of general anaesthesia, but little is known about to what extent these molecular changes are affected by anaesthesia duration. The aim of the present study was to evaluate the effects of short duration (20 min) general anaesthesia with isoflurane or avertin on the expression of 20 selected genes in the mouse hippocampus at 1 and 4 days after anaesthesia. METHODS Nine to eleven-weeks-old male mice received one of the following treatments: 20 min of avertin-induced anaesthesia (n=11), 20 min of isoflurane-induced anaesthesia (n=10) and no anaesthesia (n=5). One and four days after anaesthesia, gene expression in the hippocampus was determined with reverse transcription quantitative real-time polymerase chain reaction. RESULTS We found that anaesthesia led to the upregulation of six genes: Hspd1 (heat shock protein 1), Plat (tissue plasminogen activator) and Npr3 (natriuretic peptide receptor 3) were upregulated only 1 day after anaesthesia, whereas Thbs4 (thrombospondin 4) was upregulated only 4 days after anaesthesia. Syp (synaptophysin) and Mgst1 (microsomal glutathione S-transferase 1) were upregulated at both time points. Hspd1, Mgst1 and Syp expression was increased regardless of the anaesthetic used, Npr3 and Plat were increased only in mice exposed to avertin, and Thbs4 was upregulated only after isoflurane-induced anaesthesia. CONCLUSIONS This study shows that some of the effects of short general anaesthesia on gene expression in the mouse hippocampus persist for at least 4 days.
Collapse
Affiliation(s)
- T. PEKNY
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
| | - D. ANDERSSON
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
| | - U. WILHELMSSON
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
| | - M. PEKNA
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
- Florey Institute of Neuroscience and Mental Health; Parkville Victoria Australia
| | - M. PEKNY
- Center for Brain Repair and Rehabilitation; Department of Clinical Neuroscience and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
- Florey Institute of Neuroscience and Mental Health; Parkville Victoria Australia
| |
Collapse
|
78
|
Abstract
Exclusively neuron-centric approaches to neuropathological mechanisms have not resulted in major new breakthroughs in the prevention and therapy of neurodegenerative diseases. In the present paper, we review the role of glia in neurodegeneration in an attempt to identify novel targets that could be used to develop much-needed strategies for the containment and cure of neurodegenerative disorders. We discuss this in the context of glial roles in the homoeostasis and defence of the brain. We consider the mounting evidence supporting a change away from the perception of reactive glial responses merely as secondary detrimental processes that exacerbate the course of neurological disorders, in favour of an emerging contemporary view of glial pathological responses as complex and multistaged defensive processes that also have the potential for dysfunction.
Collapse
|
79
|
Liu Z, Li Y, Cui Y, Roberts C, Lu M, Wilhelmsson U, Pekny M, Chopp M. Beneficial effects of gfap/vimentin reactive astrocytes for axonal remodeling and motor behavioral recovery in mice after stroke. Glia 2014; 62:2022-33. [PMID: 25043249 DOI: 10.1002/glia.22723] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/25/2014] [Accepted: 07/03/2014] [Indexed: 12/12/2022]
Abstract
The functional role of reactive astrocytes after stroke is controversial. To elucidate whether reactive astrocytes contribute to neurological recovery, we compared behavioral outcome, axonal remodeling of the corticospinal tract (CST), and the spatio-temporal change of chondroitin sulfate proteoglycan (CSPG) expression between wild-type (WT) and glial fibrillary acidic protein/vimentin double knockout (GFAP(-/-) Vim(-/-) ) mice subjected to Rose Bengal induced cerebral cortical photothrombotic stroke in the right forelimb motor area. A foot-fault test and a single pellet reaching test were performed prior to and on day 3 after stroke, and weekly thereafter to monitor functional deficit and recovery. Biotinylated dextran amine (BDA) was injected into the left motor cortex to anterogradely label the CST axons. Compared with WT mice, the motor functional recovery and BDA-positive CST axonal length in the denervated side of the cervical gray matter were significantly reduced in GFAP(-/-) Vim(-/-) mice (n = 10/group, P < 0.01). Immunohistological data showed that in GFAP(-/-) Vim(-/-) mice, in which astrocytic reactivity is attenuated, CSPG expression was significantly increased in the lesion remote areas in both hemispheres, but decreased in the ischemic lesion boundary zone, compared with WT mice (n = 12/group, P < 0.001). Our data suggest that attenuated astrocytic reactivity impairs or delays neurological recovery by reducing CST axonal remodeling in the denervated spinal cord. Thus, manipulation of astrocytic reactivity post stroke may represent a therapeutic target for neurorestorative strategies.
Collapse
Affiliation(s)
- Zhongwu Liu
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan
| | | | | | | | | | | | | | | |
Collapse
|
80
|
Martone T, Giordano P, Dagna F, Carulli D, Albera R, Rossi F. Nestin expression and reactive phenomena in the mouse cochlea after kanamycin ototoxicity. Eur J Neurosci 2014; 39:1729-41. [PMID: 24689961 DOI: 10.1111/ejn.12576] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/28/2014] [Indexed: 11/28/2022]
Abstract
Following injury to the adult mammalian cochlea, hair cells cannot be spontaneously replaced. Nonetheless, the postnatal cochlea contains progenitor cells, distinguished by the expression of nestin, which are able to proliferate and form neurospheres in vitro. Such resident progenitors might be endowed with reparative potential. However, to date little is known about their behaviour in situ following hair cell injury. Using adult mice and ex vivo cochlear cultures, we sought to determine whether: (i) resident cochlear progenitors respond to kanamycin ototoxicity and compensate for it; and (ii) the reparative potential of cochlear progenitors can be stimulated by the addition of growth factors. Morphological changes of cochlear tissue, expression of nestin mRNA and protein and cell proliferation were investigated in these models. Our observations show that ototoxic injury has modest effects on nestin expression and cell proliferation. On the other hand, the addition of growth factors to the injured cochlear explants induced the appearance of nestin-positive cells in the supporting cell area of the organ of Corti. The vast majority of nestin-expressing cells, however, were not proliferating. Growth factors also had a robust stimulatory effect on axonal sprouting and the proliferative response, which was more pronounced in injured cochleae. On the whole, our findings indicate that nestin expression after kanamycin ototoxicity is related to tissue reactivity rather than activation of resident progenitors attempting to replace the lost receptors. In addition, administration of growth factors significantly enhances tissue remodelling, suggesting that cochlear repair may be promoted by the exogenous application of regeneration-promoting substances.
Collapse
Affiliation(s)
- Tiziana Martone
- Department of Neuroscience, Neuroscience Institute of Turin (NIT), Turin, Italy; Neuroscience Institute Cavalieri-Ottolenghi (NICO), University of Turin, Orbassano, Turin, Italy
| | | | | | | | | | | |
Collapse
|
81
|
Goto H, Inagaki M. New insights into roles of intermediate filament phosphorylation and progeria pathogenesis. IUBMB Life 2014; 66:195-200. [PMID: 24659572 DOI: 10.1002/iub.1260] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 03/06/2014] [Indexed: 01/20/2023]
Abstract
Intermediate filaments (IFs) form one of the major cytoskeletal systems in the cytoplasm or beneath the nuclear membrane. Because of their insoluble nature, cellular IFs had been considered to be stable for a long time. The discovery that a purified protein kinase phosphorylated a purified IF protein and in turn induced the disassembly of IF structure in vitro led to the novel concept of dynamic IF regulation. Since then, a variety of protein kinases have been identified to phosphorylate IF proteins such as vimentin in a spatiotemporal regulated manner. A series of studies using cultured cells have demonstrated that preventing IF phosphorylation during mitosis inhibits cytokinesis by the retention of an IF bridge-like structure (IF-bridge) connecting the two daughter cells. Knock-in mice expressing phosphodeficient vimentin variants developed binucleation/aneuploidy in lens epithelial cells, which promoted microophthalmia and lens cataract. Therefore, mitotic phosphorylation of vimentin is of great importance in the completion of cytokinesis, the impairment of which promotes chromosomal instability and premature aging. © 2014 IUBMB Life, 66(3):195-200, 2014.
Collapse
Affiliation(s)
- Hidemasa Goto
- Division of Biochemistry, Aichi Cancer Center Research Institute, Kanokoden, Chikusa-Ku, Nagoya, Japan.,Department of Cellular Oncology, Graduate School of Medicine, Nagoya University, Showa-Ku, Nagoya, Japan
| | - Masaki Inagaki
- Division of Biochemistry, Aichi Cancer Center Research Institute, Kanokoden, Chikusa-Ku, Nagoya, Japan.,Department of Cellular Oncology, Graduate School of Medicine, Nagoya University, Showa-Ku, Nagoya, Japan
| |
Collapse
|
82
|
Burcham PC, Raso A, Henry PJ. Airborne acrolein induces keratin-8 (Ser-73) hyperphosphorylation and intermediate filament ubiquitination in bronchiolar lung cell monolayers. Toxicology 2014; 319:44-52. [PMID: 24594012 DOI: 10.1016/j.tox.2014.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/24/2013] [Accepted: 02/13/2014] [Indexed: 01/12/2023]
Abstract
The combustion product acrolein is a key mediator of pulmonary edema in victims of smoke inhalation injury. Since studying acrolein toxicity in conventional in vitro systems is complicated by reactivity with nucleophilic culture media constituents, we explored an exposure system which delivers airborne acrolein directly to lung cell monolayers at the air-liquid interface. Calu-3 lung adenocarcinoma cells were maintained on membrane inserts such that the basal surface was bathed in nucleophile-free media while the upper surface remained in contact with acrolein-containing air. Cells were exposed to airborne acrolein for 30 min before they were allowed to recover in fresh media, with cell sampling at defined time points to allow evaluation of toxicity and protein damage. After prior exposure to acrolein, cell ATP levels remained close to controls for 4h but decreased in an exposure-dependent manner by 24h. A loss of transepithelial electrical resistance and increased permeability to fluorescein isothiocyanate-labeled dextran preceded ATP loss. Use of antibody arrays to monitor protein expression in exposed monolayers identified strong upregulation of phospho-keratin-8 (Ser(73)) as an early consequence of acrolein exposure. These changes were accompanied by chemical damage to keratin-8 and other intermediate filament family members, while acrolein exposure also resulted in controlled ubiquitination of high mass proteins within the intermediate filament extracts. These findings confirm the usefulness of systems allowing delivery of airborne smoke constituents to lung cell monolayers during studies of the molecular basis for acute smoke intoxication injury.
Collapse
Affiliation(s)
- Philip C Burcham
- Pharmacology and Anaesthesiology Unit, School of Medicine & Pharmacology, The University of Western Australia, Nedlands, WA 6009, Australia.
| | - Albert Raso
- Pharmacology and Anaesthesiology Unit, School of Medicine & Pharmacology, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Peter J Henry
- Pharmacology and Anaesthesiology Unit, School of Medicine & Pharmacology, The University of Western Australia, Nedlands, WA 6009, Australia
| |
Collapse
|
83
|
Butovich IA, Lu H, McMahon A, Ketelson H, Senchyna M, Meadows D, Campbell E, Molai M, Linsenbardt E. Biophysical and morphological evaluation of human normal and dry eye meibum using hot stage polarized light microscopy. Invest Ophthalmol Vis Sci 2014; 55:87-101. [PMID: 24282231 DOI: 10.1167/iovs.13-13355] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE To study melting characteristics and the morphology of human and mouse meibum. METHODS Hot stage cross-polarized light microscopy (HSPM) and immunohistochemical approaches were used. RESULTS Isolated human meibum, and meibum of mice (either isolated or within the meibomian ducts of mice), were found to be in liquid-crystal state at physiological temperatures. Melting of both types of meibum started at approximately 10°C and was completed at approximately 40°C. Melting curves of isolated meibum and meibum inside the meibomian ducts were multiphasic with at least two or three clearly defined phase transition temperatures, typically at approximately 12 ± 2°C (minor transition), 21 ± 3°C, and 32 ± 3°C, regardless the source of meibum. Melting was highly cooperative in nature. Samples of abnormal human meibum collected from dry eye patients with meibomian gland dysfunction often showed an increased presence of nonlipid, nonmelting, nonbirefringent, chloroform-insoluble inclusions of a protein nature. The inclusions were positively stained for cytokeratins. The presence of these inclusions was semiquantitatively characterized using a newly proposed 0 to 4 scale. In the presence of large amounts of these inclusions, melting characteristics of meibum and its structural integrity were altered. CONCLUSIONS HSPM is an effective tool that is suitable for biophysical and morphological evaluation of meibum. Morphological properties and melting characteristics of human meibum were found to be similar to those of mice. Abnormal meibum of many dry eye patients contained large quantities of nonlipid, protein-like inclusions, which were routinely absent in meibum of normal controls.
Collapse
Affiliation(s)
- Igor A Butovich
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
| | | | | | | | | | | | | | | | | |
Collapse
|
84
|
Pekny M, Wilhelmsson U, Pekna M. The dual role of astrocyte activation and reactive gliosis. Neurosci Lett 2014; 565:30-8. [PMID: 24406153 DOI: 10.1016/j.neulet.2013.12.071] [Citation(s) in RCA: 477] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 12/21/2013] [Accepted: 12/29/2013] [Indexed: 11/16/2022]
Abstract
Astrocyte activation and reactive gliosis accompany most of the pathologies in the brain, spinal cord, and retina. Reactive gliosis has been described as constitutive, graded, multi-stage, and evolutionary conserved defensive astroglial reaction [Verkhratsky and Butt (2013) In: Glial Physiology and Pathophysiology]. A well- known feature of astrocyte activation and reactive gliosis are the increased production of intermediate filament proteins (also known as nanofilament proteins) and remodeling of the intermediate filament system of astrocytes. Activation of astrocytes is associated with changes in the expression of many genes and characteristic morphological hallmarks, and has important functional consequences in situations such as stroke, trauma, epilepsy, Alzheimer's disease (AD), and other neurodegenerative diseases. The impact of astrocyte activation and reactive gliosis on the pathogenesis of different neurological disorders is not yet fully understood but the available experimental evidence points to many beneficial aspects of astrocyte activation and reactive gliosis that range from isolation and sequestration of the affected region of the central nervous system (CNS) from the neighboring tissue that limits the lesion size to active neuroprotection and regulation of the CNS homeostasis in times of acute ischemic, osmotic, or other kinds of stress. The available experimental data from selected CNS pathologies suggest that if not resolved in time, reactive gliosis can exert inhibitory effects on several aspects of neuroplasticity and CNS regeneration and thus might become a target for future therapeutic interventions.
Collapse
Affiliation(s)
- Milos Pekny
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg SE-405 30, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.
| | - Ulrika Wilhelmsson
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg SE-405 30, Sweden
| | - Marcela Pekna
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg SE-405 30, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| |
Collapse
|
85
|
Kikuchi R, Yamamoto M, Kitamura K, Shiozaki K, Kishi A, Usami A, Abe S. Medial Pterygoid initiated the Growth of the Mandible through Premature Muscle Contraction. J HARD TISSUE BIOL 2014. [DOI: 10.2485/jhtb.23.225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
86
|
Abstract
The dynamics of oral mucosa is known by its inherent defensive nature. Certain areas demand tough shield when subjected to mechanical insults. This is met by structural scaffolding material referred as cytoskeleton comprised of intracellular protein filaments called cytokeratins in the surface squames of oral epithelia. They also equally contribute towards the architecture of odontogenic apparatus and salivary gland. Differentiation of epithelial cells within stratified epithelia regulates the expression of specific keratin gene. Any mutation in, or autoantibodies to keratins, desmosomal and cornified envelope proteins is translated into genetic and acquired human disorders. Sound knowledge of structural proteins, their expression, distribution and function plays a vital role in acquainting with these disorders and their application as differentiation markers. Thus, they form an integral aid in diagnostic pathology and may be instrumental in the future interventions by gene therapy. This review focuses on basics to current updates on oral cytokeratins with an emphasis on the genetic and acquired disorders of cytokeratins with oral implications.
Collapse
Affiliation(s)
- Roopa S Rao
- Professor and Head, Department of Oral Pathology and Microbiology, Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences MSRIT Post, MSR Nagar, Bangalore, Karnataka, India
| | - Shankargouda Patil
- Associate Professor, Department of Oral Pathology and Microbiology, Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences MSRIT Post, MSR Nagar, Bangalore, Karnataka, India
| | - B S Ganavi
- Postgraduate Student, Department of Oral Pathology and Microbiology, Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences MSRIT Post, MSR Nagar, Bangalore, Karnataka, India
| |
Collapse
|
87
|
Song J, Li Z, He Y, Liu C, Sun B, Zhang C, Zeng J, Du P, Zhang H, Yu Y, Chen D. Decabrominated diphenyl ether (BDE‐209) and/or BDE‐47 exposure alters protein expression in purified neural stem/progenitor cells determined by proteomics analysis. Int J Dev Neurosci 2013; 33:8-14. [PMID: 24239914 DOI: 10.1016/j.ijdevneu.2013.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 10/28/2013] [Accepted: 10/31/2013] [Indexed: 02/08/2023] Open
Affiliation(s)
- Jie Song
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Zhi‐hua Li
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Yu‐Tian He
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Chuan‐Xin Liu
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Bin Sun
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Chun‐Fang Zhang
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Jie Zeng
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Pei‐Li Du
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Hui‐li Zhang
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| | - Yan‐hong Yu
- Department of Obstetrics and GynecologySouthern Medical UniversityGuangzhouPR China
| | - Dun‐Jin Chen
- Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical UniversityKey Laboratory for Major Obstetric Diseases of Guangdong ProvinceGuangzhouPR China
| |
Collapse
|
88
|
Alam CM, Silvander JSG, Daniel EN, Tao GZ, Kvarnström SM, Alam P, Omary MB, Hänninen A, Toivola DM. Keratin 8 modulates β-cell stress responses and normoglycaemia. J Cell Sci 2013; 126:5635-44. [PMID: 24144696 DOI: 10.1242/jcs.132795] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Keratin intermediate filament (IF) proteins are epithelial cell cytoskeletal components that provide structural stability and protection from cell stress, among other cellular and tissue-specific functions. Numerous human diseases are associated with IF gene mutations, but the function of keratins in the endocrine pancreas and their potential significance for glycaemic control are unknown. The impact of keratins on β-cell organisation and systemic glucose control was assessed using keratin 8 (K8) wild-type (K8(+/+)) and K8 knockout (K8(-/-)) mice. Islet β-cell keratins were characterised under basal conditions, in streptozotocin (STZ)-induced diabetes and in non-obese diabetic (NOD) mice. STZ-induced diabetes incidence and islet damage was assessed in K8(+/+) and K8(-/-) mice. K8 and K18 were the predominant keratins in islet β-cells and K8(-/-) mice expressed only remnant K18 and K7. K8 deletion resulted in lower fasting glucose levels, increased glucose tolerance and insulin sensitivity, reduced glucose-stimulated insulin secretion and decreased pancreatic insulin content. GLUT2 localisation and insulin vesicle morphology were disrupted in K8(-/-) β-cells. The increased levels of cytoplasmic GLUT2 correlated with resistance to high-dose STZ-induced injury in K8(-/-) mice. However, K8 deletion conferred no long-term protection from STZ-induced diabetes and prolonged STZ-induced stress caused increased exocrine damage in K8(-/-) mice. β-cell keratin upregulation occurred 2 weeks after treatments with low-dose STZ in K8(+/+) mice and in diabetic NOD mice, suggesting a role for keratins, particularly in non-acute islet stress responses. These results demonstrate previously unrecognised functions for keratins in β-cell intracellular organisation, as well as for systemic blood glucose control under basal conditions and in diabetes-induced stress.
Collapse
Affiliation(s)
- Catharina M Alam
- Department of Biosciences, Cell Biology, Åbo Akademi University, Tykistökatu 6A, FIN-20520 Turku, Finland
| | | | | | | | | | | | | | | | | |
Collapse
|
89
|
Matsuyama M, Tanaka H, Inoko A, Goto H, Yonemura S, Kobori K, Hayashi Y, Kondo E, Itohara S, Izawa I, Inagaki M. Defect of mitotic vimentin phosphorylation causes microophthalmia and cataract via aneuploidy and senescence in lens epithelial cells. J Biol Chem 2013; 288:35626-35. [PMID: 24142690 PMCID: PMC3861614 DOI: 10.1074/jbc.m113.514737] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vimentin, a type III intermediate filament (IF) protein, is phosphorylated predominantly in mitosis. The expression of a phosphorylation-compromised vimentin mutant in T24 cultured cells leads to cytokinetic failure, resulting in binucleation (multinucleation). The physiological significance of intermediate filament phosphorylation during mitosis for organogenesis and tissue homeostasis was uncertain. Here, we generated knock-in mice expressing vimentin that have had the serine sites phosphorylated during mitosis substituted by alanine residues. Homozygotic mice (VIM(SA/SA)) presented with microophthalmia and cataracts in the lens, whereas heterozygotic mice (VIM(WT/SA)) were indistinguishable from WT (VIM(WT/WT)) mice. In VIM(SA/SA) mice, lens epithelial cell number was not only reduced but the cells also exhibited chromosomal instability, including binucleation and aneuploidy. Electron microscopy revealed fiber membranes that were disorganized in the lenses of VIM(SA/SA), reminiscent of similar characteristic changes seen in age-related cataracts. Because the mRNA level of the senescence (aging)-related gene was significantly elevated in samples from VIM(SA/SA), the lens phenotype suggests a possible causal relationship between chromosomal instability and premature aging.
Collapse
|
90
|
Skalli O, Wilhelmsson U, Örndahl C, Fekete B, Malmgren K, Rydenhag B, Pekny M. Astrocytoma grade IV (glioblastoma multiforme) displays 3 subtypes with unique expression profiles of intermediate filament proteins. Hum Pathol 2013; 44:2081-8. [DOI: 10.1016/j.humpath.2013.03.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/25/2013] [Accepted: 03/27/2013] [Indexed: 11/15/2022]
|
91
|
Luiz Andrade Scherholz P, Cristina de Souza P, Spadacci-Morena D, Godosevicius Katz S. Vimentin is synthesized by mouse vascular trophoblast giant cells from embryonic day 7.5 onwards and is a characteristic factor of these cells. Placenta 2013; 34:518-25. [DOI: 10.1016/j.placenta.2013.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 03/28/2013] [Accepted: 04/05/2013] [Indexed: 12/31/2022]
|
92
|
Intermediate filaments are important for astrocyte response to oxidative stress induced by oxygen–glucose deprivation and reperfusion. Histochem Cell Biol 2013; 140:81-91. [DOI: 10.1007/s00418-013-1110-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2013] [Indexed: 01/01/2023]
|
93
|
Pekny T, Faiz M, Wilhelmsson U, Curtis MA, Matej R, Skalli O, Pekny M. Synemin is expressed in reactive astrocytes and Rosenthal fibers in Alexander disease. APMIS 2013; 122:76-80. [DOI: 10.1111/apm.12088] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 01/09/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Tulen Pekny
- Department of Clinical Neuroscience and Rehabilitation; Center for Brain Repair and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Göteborg Sweden
| | - Maryam Faiz
- Department of Clinical Neuroscience and Rehabilitation; Center for Brain Repair and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Göteborg Sweden
| | - Ulrika Wilhelmsson
- Department of Clinical Neuroscience and Rehabilitation; Center for Brain Repair and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Göteborg Sweden
| | - Maurice A. Curtis
- Department of Clinical Neuroscience and Rehabilitation; Center for Brain Repair and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Göteborg Sweden
| | - Radoslav Matej
- Department of Pathology and Molecular Medicine; Thomayer's Hospital; Prague Czech Republic
| | - Omar Skalli
- Department of Biological Sciences; University of Memphis; Memphis TN USA
| | - Milos Pekny
- Department of Clinical Neuroscience and Rehabilitation; Center for Brain Repair and Rehabilitation; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Göteborg Sweden
| |
Collapse
|
94
|
Abstract
All cells are influenced by mechanical forces. In the brain, force-generating and load-bearing proteins twist, turn, ratchet, flex, compress, expand and bend to mediate neuronal signalling and plasticity. Although the functions of mechanosensitive proteins have been thoroughly described in classical sensory systems, the effects of endogenous mechanical energy on cellular function in the brain have received less attention, and many working models in neuroscience do not currently integrate principles of cellular mechanics. An understanding of cellular-mechanical concepts is essential to allow the integration of mechanobiology into ongoing studies of brain structure and function.
Collapse
|
95
|
Shetty S. Keratinization and its disorders. Oman Med J 2012; 27:348-57. [PMID: 23074543 DOI: 10.5001/omj.2012.90] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/08/2012] [Indexed: 02/05/2023] Open
Abstract
Keratins are a diverse group of structural proteins that form the intermediate filament network responsible for maintaining the structural integrity of keratinocytes. In humans, there are around 30 keratin families divided into two groups, namely, acidic and basic keratins, which are arranged in pairs. They are expressed in a highly specific pattern related to the epithelial type and stage of cellular differentiation. A total of 54 functional genes exist which codes for these keratin families. The expression of specific keratin genes is regulated by the differentiation of epithelial cells within the stratifying squamous epithelium. Mutations in most of these genes are now associated with specific tissue fragility disorders which may manifest both in skin and mucosa depending on the expression pattern. The keratins and keratin-associated proteins are useful as differentiation markers because their expression is both region specific and differentiation specific. Antibodies to keratin are considered as important tissue differentiation markers and therefore are an integral aid in diagnostic pathology. The present review discusses the structure of keratin, the various types of keratin and their distribution and the disorders associated with keratinization with special emphasis on the disorders of the oral cavity. A brief note on the clinical significance of keratin is also mentioned.
Collapse
Affiliation(s)
- Shibani Shetty
- Senior Lecturer, Dept. of Oral Pathology and Microbiology, M. R Ambedkar Dental College and hospital, Bangalore- 560005Karnataka, India
| | | |
Collapse
|
96
|
Kraft AW, Hu X, Yoon H, Yan P, Xiao Q, Wang Y, Gil SC, Brown J, Wilhelmsson U, Restivo JL, Cirrito JR, Holtzman DM, Kim J, Pekny M, Lee JM. Attenuating astrocyte activation accelerates plaque pathogenesis in APP/PS1 mice. FASEB J 2012; 27:187-98. [PMID: 23038755 DOI: 10.1096/fj.12-208660] [Citation(s) in RCA: 226] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The accumulation of aggregated amyloid-β (Aβ) in amyloid plaques is a neuropathological hallmark of Alzheimer's disease (AD). Reactive astrocytes are intimately associated with amyloid plaques; however, their role in AD pathogenesis is unclear. We deleted the genes encoding two intermediate filament proteins required for astrocyte activation-glial fibrillary acid protein (Gfap) and vimentin (Vim)-in transgenic mice expressing mutant human amyloid precursor protein and presenilin-1 (APP/PS1). The gene deletions increased amyloid plaque load: APP/PS1 Gfap(-/-)Vim(-/-) mice had twice the plaque load of APP/PS1 Gfap(+/+)Vim(+/+) mice at 8 and 12 mo of age. APP expression and soluble and interstitial fluid Aβ levels were unchanged, suggesting that the deletions had no effect on APP processing or Aβ generation. Astrocyte morphology was markedly altered by the deletions: wild-type astrocytes had hypertrophied processes that surrounded and infiltrated plaques, whereas Gfap(-/-)Vim(-/-) astrocytes had little process hypertrophy and lacked contact with adjacent plaques. Moreover, Gfap and Vim gene deletion resulted in a marked increase in dystrophic neurites (2- to 3-fold higher than APP/PS1 Gfap(+/+)Vim(+/+) mice), even after normalization for amyloid load. These results suggest that astrocyte activation limits plaque growth and attenuates plaque-related dystrophic neurites. These activities may require intimate contact between astrocyte and plaque.
Collapse
Affiliation(s)
- Andrew W Kraft
- The Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63124, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
97
|
Keratin 8/18 regulation of cell stiffness-extracellular matrix interplay through modulation of Rho-mediated actin cytoskeleton dynamics. PLoS One 2012; 7:e38780. [PMID: 22685604 PMCID: PMC3369864 DOI: 10.1371/journal.pone.0038780] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 05/10/2012] [Indexed: 01/16/2023] Open
Abstract
Cell mechanical activity generated from the interplay between the extracellular matrix (ECM) and the actin cytoskeleton is essential for the regulation of cell adhesion, spreading and migration during normal and cancer development. Keratins are the intermediate filament (IF) proteins of epithelial cells, expressed as pairs in a lineage/differentiation manner. Hepatic epithelial cell IFs are made solely of keratins 8/18 (K8/K18), hallmarks of all simple epithelia. Notably, our recent work on these epithelial cells has revealed a key regulatory function for K8/K18 IFs in adhesion/migration, through modulation of integrin interactions with ECM, actin adaptors and signaling molecules at focal adhesions. Here, using K8-knockdown rat H4 hepatoma cells and their K8/K18-containing counterparts seeded on fibronectin-coated substrata of different rigidities, we show that the K8/K18 IF-lacking cells lose their ability to spread and exhibit an altered actin fiber organization, upon seeding on a low-rigidity substratum. We also demonstrate a concomitant reduction in local cell stiffness at focal adhesions generated by fibronectin-coated microbeads attached to the dorsal cell surface. In addition, we find that this K8/K18 IF modulation of cell stiffness and actin fiber organization occurs through RhoA-ROCK signaling. Together, the results uncover a K8/K18 IF contribution to the cell stiffness-ECM rigidity interplay through a modulation of Rho-dependent actin organization and dynamics in simple epithelial cells.
Collapse
|
98
|
Gene and protein expressions of vimentin and desmin during embryonic development of the mylohyoid muscle. Anat Sci Int 2012; 87:126-31. [DOI: 10.1007/s12565-012-0132-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Accepted: 03/13/2012] [Indexed: 10/28/2022]
|
99
|
Parpura V, Heneka MT, Montana V, Oliet SHR, Schousboe A, Haydon PG, Stout RF, Spray DC, Reichenbach A, Pannicke T, Pekny M, Pekna M, Zorec R, Verkhratsky A. Glial cells in (patho)physiology. J Neurochem 2012; 121:4-27. [PMID: 22251135 DOI: 10.1111/j.1471-4159.2012.07664.x] [Citation(s) in RCA: 402] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neuroglial cells define brain homeostasis and mount defense against pathological insults. Astroglia regulate neurogenesis and development of brain circuits. In the adult brain, astrocytes enter into intimate dynamic relationship with neurons, especially at synaptic sites where they functionally form the tripartite synapse. At these sites, astrocytes regulate ion and neurotransmitter homeostasis, metabolically support neurons and monitor synaptic activity; one of the readouts of the latter manifests in astrocytic intracellular Ca(2+) signals. This form of astrocytic excitability can lead to release of chemical transmitters via Ca(2+) -dependent exocytosis. Once in the extracellular space, gliotransmitters can modulate synaptic plasticity and cause changes in behavior. Besides these physiological tasks, astrocytes are fundamental for progression and outcome of neurological diseases. In Alzheimer's disease, for example, astrocytes may contribute to the etiology of this disorder. Highly lethal glial-derived tumors use signaling trickery to coerce normal brain cells to assist tumor invasiveness. This review not only sheds new light on the brain operation in health and disease, but also points to many unknowns.
Collapse
Affiliation(s)
- Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Civitan International Research Center, Atomic Force Microscopy & Nanotechnology Laboratories, and Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, Alabama, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
100
|
Windoffer R, Beil M, Magin TM, Leube RE. Cytoskeleton in motion: the dynamics of keratin intermediate filaments in epithelia. ACTA ACUST UNITED AC 2012; 194:669-78. [PMID: 21893596 PMCID: PMC3171125 DOI: 10.1083/jcb.201008095] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Epithelia are exposed to multiple forms of stress. Keratin intermediate filaments are abundant in epithelia and form cytoskeletal networks that contribute to cell type–specific functions, such as adhesion, migration, and metabolism. A perpetual keratin filament turnover cycle supports these functions. This multistep process keeps the cytoskeleton in motion, facilitating rapid and protein biosynthesis–independent network remodeling while maintaining an intact network. The current challenge is to unravel the molecular mechanisms underlying the regulation of the keratin cycle in relation to actin and microtubule networks and in the context of epithelial tissue function.
Collapse
Affiliation(s)
- Reinhard Windoffer
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, 52057 Aachen, Germany
| | | | | | | |
Collapse
|