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Chou FS, Chen CY, Lee AC, Wang PS. Impaired Cell Cycle Progression and Self-Renewal of Fetal Neural Stem and Progenitor Cells in a Murine Model of Intrauterine Growth Restriction. Front Cell Dev Biol 2022; 10:821848. [PMID: 35903551 PMCID: PMC9314876 DOI: 10.3389/fcell.2022.821848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 06/20/2022] [Indexed: 11/30/2022] Open
Abstract
Individuals with intrauterine growth restriction (IUGR) are at an increased risk for neurodevelopmental impairment. Fetal cortical neurogenesis is a time-sensitive process in which fetal neural stem cells (NSCs) follow a distinct pattern of layer-specific neuron generation to populate the cerebral cortex. Here, we used a murine maternal hypoxia-induced IUGR model to study the impact of IUGR on fetal NSC development. In this model, timed-pregnant mice were exposed to hypoxia during the active stage of neurogenesis, followed by fetal brain collection and analysis. In the IUGR fetal brains, we found a significant reduction in cerebral cortical thickness accompanied by decreases in layer-specific neurons. Using EdU labeling, we demonstrated that cell cycle progression of fetal NSCs was delayed, primarily observed in the G2/M phase during inward interkinetic nuclear migration. Following relief from maternal hypoxia exposure, the remaining fetal NSCs re-established their neurogenic ability and resumed production of layer-specific neurons. Surprisingly, the newly generated neurons matched their control counterparts in layer-specific marker expression, suggesting preservation of the fetal NSC temporal identity despite IUGR effects. As expected, the absolute number of neurons generated in the IUGR group remained lower compared to that in the control group due to a reduced fetal NSC pool size as a result of cell cycle defect. Transcriptome analysis identified genes related to energy expenditure and G2/M cell cycle progression being affected by maternal hypoxia-induced IUGR. Taken together, maternal hypoxia-induced IUGR is associated with a defect in cell cycle progression of fetal NSCs, and has a long-term impact on offspring cognitive development.
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Affiliation(s)
- Fu-Sheng Chou
- Department of Pediatrics, The University of Kansas Medical Center, Kansas City, KS, United States
- Division of Neonatology, Children’s Mercy-Kansas City, Kansas City, MO, United States
- *Correspondence: Fu-Sheng Chou, ; Pei-Shan Wang,
| | - Chu-Yen Chen
- Department of Pediatrics, The University of Kansas Medical Center, Kansas City, KS, United States
| | - An-Chun Lee
- Department of Pediatrics, The University of Kansas Medical Center, Kansas City, KS, United States
| | - Pei-Shan Wang
- Department of Pediatrics, The University of Kansas Medical Center, Kansas City, KS, United States
- *Correspondence: Fu-Sheng Chou, ; Pei-Shan Wang,
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Decotret LR, Wadsworth BJ, Li LV, Lim CJ, Bennewith KL, Pallen CJ. Receptor-type protein tyrosine phosphatase alpha (PTPα) mediates MMP14 localization and facilitates triple-negative breast cancer cell invasion. Mol Biol Cell 2021; 32:567-578. [PMID: 33566639 PMCID: PMC8101463 DOI: 10.1091/mbc.e20-01-0060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The ability of cancer cells to invade surrounding tissues requires degradation of the extracellular matrix (ECM). Invasive structures, such as invadopodia, form on the plasma membranes of cancer cells and secrete ECM-degrading proteases that play crucial roles in cancer cell invasion. We have previously shown that the protein tyrosine phosphatase alpha (PTPα) regulates focal adhesion formation and migration of normal cells. Here we report a novel role for PTPα in promoting triple-negative breast cancer cell invasion in vitro and in vivo. We show that PTPα knockdown reduces ECM degradation and cellular invasion of MDA-MB-231 cells through Matrigel. PTPα is not a component of TKS5-positive structures resembling invadopodia; rather, PTPα localizes with endosomal structures positive for MMP14, caveolin-1, and early endosome antigen 1. Furthermore, PTPα regulates MMP14 localization to plasma membrane protrusions, suggesting a role for PTPα in intracellular trafficking of MMP14. Importantly, we show that orthotopic MDA-MB-231 tumors depleted in PTPα exhibit reduced invasion into the surrounding mammary fat pad. These findings suggest a novel role for PTPα in regulating the invasion of triple-negative breast cancer cells.
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Affiliation(s)
- Lisa R Decotret
- Integrative Oncology, BC Cancer, Vancouver, British Columbia, BC V5Z 4E6, Canada.,Michael Cuccione Childhood Cancer Research Program, BC Children's Hospital Research Institute, Vancouver, British Columbia, BC V5Z 4H4, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada
| | - Brennan J Wadsworth
- Integrative Oncology, BC Cancer, Vancouver, British Columbia, BC V5Z 4E6, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada
| | - Ling Vicky Li
- Michael Cuccione Childhood Cancer Research Program, BC Children's Hospital Research Institute, Vancouver, British Columbia, BC V5Z 4H4, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada
| | - Chinten J Lim
- Michael Cuccione Childhood Cancer Research Program, BC Children's Hospital Research Institute, Vancouver, British Columbia, BC V5Z 4H4, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada
| | - Kevin L Bennewith
- Integrative Oncology, BC Cancer, Vancouver, British Columbia, BC V5Z 4E6, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada
| | - Catherine J Pallen
- Michael Cuccione Childhood Cancer Research Program, BC Children's Hospital Research Institute, Vancouver, British Columbia, BC V5Z 4H4, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, BC V6H 3V4, Canada
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3
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Gyetvai G, Hughes T, Wedmore F, Roe C, Heikal L, Ghezzi P, Mengozzi M. Erythropoietin Increases Myelination in Oligodendrocytes: Gene Expression Profiling Reveals Early Induction of Genes Involved in Lipid Transport and Metabolism. Front Immunol 2017; 8:1394. [PMID: 29123527 PMCID: PMC5662872 DOI: 10.3389/fimmu.2017.01394] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/09/2017] [Indexed: 12/14/2022] Open
Abstract
Several studies have shown that erythropoietin (EPO) has neuroprotective or neuroreparative actions on diseases of the nervous system and that improves oligodendrocyte (OL) differentiation and myelination in vivo and in vitro. This study aims at investigating the early molecular mechanisms for the pro-myelinating action of EPO at the gene expression level. For this purpose, we used a differentiating OL precursor cell line, rat central glia-4 cells. Cells were differentiated or not, and then treated with EPO for 1 or 20 h. RNA was extracted and changes in the gene expression profile were assessed using microarray analysis. Experiments were performed in biological replicates of n = 4. Differentiation alone changed the expression of 11% of transcripts (2,663 out of 24,272), representing 2,436 genes, half of which were upregulated and half downregulated. At 20 h of treatment, EPO significantly affected the expression of 99 genes that were already regulated by differentiation and of 150 genes that were not influenced by differentiation alone. Analysis of the transcripts most upregulated by EPO identified several genes involved in lipid transport (e.g., Cd36) and lipid metabolism (Ppargc1a/Pgc1alpha, Lpin1, Pnlip, Lpin2, Ppard, Plin2) along with Igf1 and Igf2, growth factors known for their pro-myelinating action. All these genes were only induced by EPO and not by differentiation alone, except for Pnlip which was highly induced by differentiation and augmented by EPO. Results were validated by quantitative PCR. These findings suggest that EPO might increase remyelination by inducing insulin-like growth factors and increasing lipid metabolism.
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Affiliation(s)
- Georgina Gyetvai
- Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Trisha Hughes
- Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Florence Wedmore
- Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Cieron Roe
- Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Lamia Heikal
- Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Pietro Ghezzi
- Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Manuela Mengozzi
- Department of Clinical and Experimental Medicine, Brighton and Sussex Medical School, Brighton, United Kingdom
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4
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Shih Y, Ly PTT, Wang J, Pallen CJ. Glial and Neuronal Protein Tyrosine Phosphatase Alpha (PTPα) Regulate Oligodendrocyte Differentiation and Myelination. J Mol Neurosci 2017. [PMID: 28647856 DOI: 10.1007/s12031-017-0941-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
CNS myelination defects occur in mice deficient in receptor-like protein tyrosine phosphatase alpha (PTPα). Here, we investigated the role of PTPα in oligodendrocyte differentiation and myelination using cells and tissues from wild-type (WT) and PTPα knockout (KO) mice. PTPα promoted the timely differentiation of neural stem cell-derived oligodendrocyte progenitor cells (OPCs). Compared to WT OPCs, KO OPC cultures had more NG2+ progenitors, fewer myelin basic protein (MBP)+ oligodendrocytes, and reduced morphological complexity. In longer co-cultures with WT neurons, more KO than WT OPCs remained NG2+ and while equivalent MBP+ populations of WT and KO cells formed, the reduced area occupied by the MBP+ KO cells suggested that their morphological maturation was impeded. These defects were associated with reduced myelin formation in KO OPC/WT neuron co-cultures. Myelin formation was also impaired when WT OPCs were co-cultured with KO neurons, revealing a novel role for neuronal PTPα in myelination. Canonical Wnt/β-catenin signaling is an important regulator of OPC differentiation and myelination. Wnt signaling activity was not dysregulated in OPCs lacking PTPα, but suppression of Wnt signaling by the small molecule XAV939 remediated defects in KO oligodendrocyte differentiation and enhanced myelin formation by KO oligodendrocytes. However, the myelin segments that formed were significantly shorter than those produced by WT oligodendrocytes, raising the possibility of a role for glial PTPα in myelin extension distinct from its pro-differentiating actions. Altogether, this study reveals PTPα as a molecular coordinator of oligodendroglial and neuronal signals that controls multiple aspects of oligodendrocyte development and myelination.
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Affiliation(s)
- Yuda Shih
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- BC Children's Hospital Research Institute, University of British Columbia, 950 West 28th Ave, Vancouver, BC, V5Z 4H4, Canada
| | - Philip T T Ly
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- BC Children's Hospital Research Institute, University of British Columbia, 950 West 28th Ave, Vancouver, BC, V5Z 4H4, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Jing Wang
- BC Children's Hospital Research Institute, University of British Columbia, 950 West 28th Ave, Vancouver, BC, V5Z 4H4, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Catherine J Pallen
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada.
- BC Children's Hospital Research Institute, University of British Columbia, 950 West 28th Ave, Vancouver, BC, V5Z 4H4, Canada.
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
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Wang WW, Han JH, Wang L, Bao TH. Scutellarin may alleviate cognitive deficits in a mouse model of hypoxia by promoting proliferation and neuronal differentiation of neural stem cells. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2017; 20:272-279. [PMID: 28392899 PMCID: PMC5378964 DOI: 10.22038/ijbms.2017.8355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Objective(s): Scutellarin, a flavonoid extracted from the medicinal herb Erigeron breviscapus Hand-Mazz, protects neurons from damage and inhibits glial activation. Here we examined whether scutellarin may also protect neurons from hypoxia-induced damage. Materials and Methods: Mice were exposed to hypoxia for 7 days and then administered scutellarin (50 mg/kg/d) or vehicle for 30 days Cognitive impairment in the two groups was assessed using the Morris water maze test, cell proliferation in the hippocampus was compared using 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry, and hippocampal levels of nestin and neuronal class III β-tubulin (Tuj-1) were measured using Western blotting. These results were validated in vitro by treating cultured neural stem cells (NSCs) with scutellarin (30 μM). Results: Treating mice with scutellarin shortened escape times and increased the number of platform crossings, it increased the number of BrdU-positive proliferating cells in the hippocampus, and it up-regulated expression of nestin and Tuj-1. Treating NSC cultures with scutellarin increased the number of proliferating cells and the proportion of cells differentiating into neurons instead of astrocytes. The increase in NSC proliferation was associated with phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, while neuronal differentiation was associated with altered expression of differentiation-related genes. Conclusion: Scutellarin may alleviate cognitive impairment in a mouse model of hypoxia by promo-ting proliferation and neuronal differentiation of NSCs.
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Affiliation(s)
- Wei-Wei Wang
- Department of Cardiology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, PR China; Key Laboratory of Stem Cells and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, Yunnan, PR China; Department of Anatomy and Development Biology, Monash University, Clayton, vic 3800, Australia
| | - Jian-Hong Han
- The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, PR China
| | - Lin Wang
- The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, PR China
| | - Tian-Hao Bao
- The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, PR China; Mental Health Center of Kunming Medical University, Kunming City, Yunnan Province, PR China
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6
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Dubreuil V, Sap J, Harroch S. Protein tyrosine phosphatase regulation of stem and progenitor cell biology. Semin Cell Dev Biol 2015; 37:82-9. [DOI: 10.1016/j.semcdb.2014.09.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/11/2014] [Accepted: 09/15/2014] [Indexed: 12/18/2022]
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7
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Aschner Y, Khalifah AP, Briones N, Yamashita C, Dolgonos L, Young SK, Campbell MN, Riches DWH, Redente EF, Janssen WJ, Henson PM, Sap J, Vacaresse N, Kapus A, McCulloch CAG, Zemans RL, Downey GP. Protein tyrosine phosphatase α mediates profibrotic signaling in lung fibroblasts through TGF-β responsiveness. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:1489-502. [PMID: 24650563 DOI: 10.1016/j.ajpath.2014.01.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/23/2013] [Accepted: 01/14/2014] [Indexed: 02/07/2023]
Abstract
Fibrotic lung diseases represent a diverse group of progressive and often fatal disorders with limited treatment options. Although the pathogenesis of these conditions remains incompletely understood, receptor type protein tyrosine phosphatase α (PTP-α encoded by PTPRA) has emerged as a key regulator of fibroblast signaling. We previously reported that PTP-α regulates cellular responses to cytokines and growth factors through integrin-mediated signaling and that PTP-α promotes fibroblast expression of matrix metalloproteinase 3, a matrix-degrading proteinase linked to pulmonary fibrosis. Here, we sought to determine more directly the role of PTP-α in pulmonary fibrosis. Mice genetically deficient in PTP-α (Ptpra(-/-)) were protected from pulmonary fibrosis induced by intratracheal bleomycin, with minimal alterations in the early inflammatory response or production of TGF-β. Ptpra(-/-) mice were also protected from pulmonary fibrosis induced by adenoviral-mediated expression of active TGF-β1. In reciprocal bone marrow chimera experiments, the protective phenotype tracked with lung parenchymal cells but not bone marrow-derived cells. Because fibroblasts are key contributors to tissue fibrosis, we compared profibrotic responses in wild-type and Ptpra(-/-) mouse embryonic and lung fibroblasts. Ptpra(-/-) fibroblasts exhibited hyporesponsiveness to TGF-β, manifested by diminished expression of αSMA, EDA-fibronectin, collagen 1A, and CTGF. Ptpra(-/-) fibroblasts exhibited markedly attenuated TGF-β-induced Smad2/3 transcriptional activity. We conclude that PTP-α promotes profibrotic signaling pathways in fibroblasts through control of cellular responsiveness to TGF-β.
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Affiliation(s)
- Yael Aschner
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Anthony P Khalifah
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Natalie Briones
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
| | - Cory Yamashita
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Respirology, Department of Medicine, University of Western Ontario, London, Ontario, Canada
| | - Lior Dolgonos
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Scott K Young
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
| | - Megan N Campbell
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
| | - David W H Riches
- Department of Pediatrics, National Jewish Health, Denver, Colorado
| | | | - William J Janssen
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Peter M Henson
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado; Department of Pediatrics, National Jewish Health, Denver, Colorado; Department of Immunology, University of Colorado, Aurora, Colorado
| | - Jan Sap
- Unit of Epigenetics and Cell Fate, UMR7216, University of Paris-Diderot, Paris, France
| | - Nathalie Vacaresse
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Andras Kapus
- Keenan Research Center, Li Ka Shing Knowledge Institute-St. Michael's Hospital, University of Toronto, Ontario, Canada; Department of Surgery, University of Toronto, Ontario, Canada
| | | | - Rachel L Zemans
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado
| | - Gregory P Downey
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado; Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado, Aurora, Colorado; Department of Pediatrics, National Jewish Health, Denver, Colorado; Department of Immunology, University of Colorado, Aurora, Colorado.
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8
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New insights into the roles of the contactin cell adhesion molecules in neural development. ADVANCES IN NEUROBIOLOGY 2014; 8:165-94. [PMID: 25300137 DOI: 10.1007/978-1-4614-8090-7_8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In vertebrates, the contactin (CNTN) family of neural cell recognition molecules includes six related cell adhesion molecules that play non-overlapping roles in the formation and maintenance of the nervous system. CNTN1 and CNTN2 are the prototypical members of the family and have been involved, through cis- and trans-interactions with distinct cell adhesion molecules, in neural cell migration, axon guidance, and the organization of myelin subdomains. In contrast, the roles of CNTN3-6 are less well characterized although the generation of null mice and the recent identification of a common extracellular binding partner have considerably advanced our grasp of their physiological roles in particular as they relate to the wiring of sensory tissues. In this review, we aim to present a summary of our current understanding of CNTN functions and give an overview of the challenges that lie ahead in understanding the roles these proteins play in nervous system development and maintenance.
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Harlow DE, Macklin WB. Inhibitors of myelination: ECM changes, CSPGs and PTPs. Exp Neurol 2013; 251:39-46. [PMID: 24200549 DOI: 10.1016/j.expneurol.2013.10.017] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 10/22/2013] [Accepted: 10/26/2013] [Indexed: 01/06/2023]
Abstract
After inflammation-induced demyelination, such as in the disease multiple sclerosis, endogenous remyelination often fails. However, in animal models of demyelination induced with toxins, remyelination can be quite robust. A significant difference between inflammation-induced and toxin-induced demyelination is the response of local cells within the lesion, including astrocytes, oligodendrocytes, microglia/macrophages, and NG2+ cells, which respond to inflammatory stimuli with increased extracellular matrix (ECM) protein and chondroitin sulfate proteoglycan (CSPG) production and deposition. Here, we summarize current knowledge of ECM changes in demyelinating lesions, as well as oligodendrocyte responses to aberrant ECM proteins and CSPGs after various types of demyelinating insults. The discovery that CSPGs act through the receptor protein tyrosine phosphatase sigma (PTPσ) and the Rho-ROCK pathway to inhibit oligodendrocyte process extension and myelination, but not oligodendrocyte differentiation (Pendleton et al., Experimental Neurology (2013) vol. 247, pp. 113-121), highlights the need to better understand the ECM changes that accompany demyelination and their influence on oligodendrocytes and effective remyelination.
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Affiliation(s)
- Danielle E Harlow
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, 12801 East 17th Avenue, Research Complex 1 South, Mail Stop 8108, Aurora, CO 80045, USA; Center for NeuroScience, University of Colorado School of Medicine, 12801 East 17th Avenue, Research Complex 1 South, Mail Stop 8108, Aurora, CO 80045, USA.
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, 12801 East 17th Avenue, Research Complex 1 South, Mail Stop 8108, Aurora, CO 80045, USA; Center for NeuroScience, University of Colorado School of Medicine, 12801 East 17th Avenue, Research Complex 1 South, Mail Stop 8108, Aurora, CO 80045, USA.
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10
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Pendleton JC, Shamblott MJ, Gary DS, Belegu V, Hurtado A, Malone ML, McDonald JW. Chondroitin sulfate proteoglycans inhibit oligodendrocyte myelination through PTPσ. Exp Neurol 2013; 247:113-21. [PMID: 23588220 DOI: 10.1016/j.expneurol.2013.04.003] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 03/19/2013] [Accepted: 04/05/2013] [Indexed: 11/30/2022]
Abstract
CNS damage often results in demyelination of spared axons due to oligodendroglial cell death and dysfunction near the injury site. Although new oligodendroglia are generated following CNS injury and disease, the process of remyelination is typically incomplete resulting in long-term functional deficits. Chondroitin sulfate proteoglycans (CSPGs) are upregulated in CNS grey and white matter following injury and disease and are a major component of the inhibitory scar that suppresses axon regeneration. CSPG inhibition of axonal regeneration is mediated, at least in part, by the protein tyrosine phosphatase sigma (PTPσ) receptor. Recent evidence demonstrates that CSPGs inhibit OL process outgrowth, however, the means by which their effects are mediated remains unclear. Here we investigate the role of PTPσ in CSPG inhibition of OL function. We found that the CSPGs, aggrecan, neurocan and NG2 all imposed an inhibitory effect on OL process outgrowth and myelination. These inhibitory effects were reversed by degradation of CSPGs with Chondroitinase ABC prior to OL exposure. RNAi-mediated down-regulation of PTPσ reversed the inhibitory effect of CSPGs on OL process outgrowth and myelination. Likewise, CSPG inhibition of process outgrowth and myelination was significantly reduced in cultures containing PTPσ(-/-) OLs. Finally, inhibition of Rho-associated kinase (ROCK) increased OL process outgrowth and myelination during exposure to CSPGs. These results suggest that in addition to their inhibitory effects on axon regeneration, CSPGs have multiple inhibitory actions on OLs that result in incomplete remyelination following CNS injury. The identification of PTPσ as a receptor for CSPGs, and the participation of ROCK downstream of CSPG exposure, reveal potential therapeutic targets to enhance white matter repair in the damaged CNS.
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Affiliation(s)
- James C Pendleton
- International Center for Spinal Cord Injury, Hugo W. Moser Research Institute at Kennedy Krieger, USA
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