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Boulanger JJ, Messier C. Doublecortin in Oligodendrocyte Precursor Cells in the Adult Mouse Brain. Front Neurosci 2017; 11:143. [PMID: 28400715 PMCID: PMC5368229 DOI: 10.3389/fnins.2017.00143] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 03/07/2017] [Indexed: 12/21/2022] Open
Abstract
Key PointsOligodendrocyte precursor cells express doublecortin, a microtubule-associated protein. Oligodendrocyte precursor cells express doublecortin, but at a lower level of expression than in neuronal precursor. Doublecortin is not associated with a potential immature neuronal phenotype in Oligodendrocyte precursor cells.
Oligodendrocyte precursor cells (OPC) are glial cells that differentiate into myelinating oligodendrocytes during embryogenesis and early stages of post-natal life. OPCs continue to divide throughout adulthood and some eventually differentiate into oligodendrocytes in response to demyelinating lesions. There is growing evidence that OPCs are also involved in activity-driven de novo myelination of previously unmyelinated axons and myelin remodeling in adulthood. Considering these roles in the adult brain, OPCs are likely mobile cells that can migrate on some distances before they differentiate into myelinating oligodendrocytes. A number of studies have noted that OPCs express doublecortin (DCX), a microtubule-associated protein expressed in neural precursor cells and in migrating immature neurons. Here we describe the distribution of DCX in OPCs. We found that almost all OPCs express DCX, but the level of expression appears to be much lower than what is found in neural precursor. We found that DCX is downregulated when OPCs start expressing mature oligodendrocyte markers and is absent in myelinating oligodendrocytes. DCX does not appear to signal an immature neuronal phenotype in OPCs in the adult mouse brain. Rather, it could be involved either in cell migration, or as a marker of an immature oligodendroglial cell phenotype.
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Affiliation(s)
| | - Claude Messier
- School of Psychology, University of Ottawa Ottawa, ON, Canada
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Keiner S, Niv F, Neumann S, Steinbach T, Schmeer C, Hornung K, Schlenker Y, Förster M, Witte OW, Redecker C. Effect of skilled reaching training and enriched environment on generation of oligodendrocytes in the adult sensorimotor cortex and corpus callosum. BMC Neurosci 2017; 18:31. [PMID: 28279169 PMCID: PMC5345235 DOI: 10.1186/s12868-017-0347-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 02/23/2017] [Indexed: 11/10/2022] Open
Abstract
Background
Increased motor activity or social interactions through enriched environment are strong stimulators of grey and white matter plasticity in the adult rodent brain. In the present study we evaluated whether specific reaching training of the dominant forelimb (RT) and stimulation of unspecific motor activity through enriched environment (EE) influence the generation of distinct oligodendrocyte subpopulations in the sensorimotor cortex and corpus callosum of the adult rat brain. Animals were placed in three different housing conditions: one group was transferred to an EE, a second group received daily RT, whereas a third group remained in the standard cage. Bromodeoxyuridine (BrdU) was applied at days 2–6 after start of experiments and animals were allowed to survive for 10 and 42 days. Results Enriched environment and daily reaching training of the dominant forelimb significantly increased the number of newly differentiated GSTπ+ oligodendrocytes at day 10 and newly differentiated CNPase+ oligodendrocytes in the sensorimotor cortex at day 42. The myelin level as measured by CNPase expression was increased in the frontal cortex at day 42. Distribution of newly differentiated NG2+ subpopulations changed between 10 and 42 days with an increase of GSTπ+ subtypes and a decrease of NG2+ cells in the sensorimotor cortex and corpus callosum. Analysis of neuronal marker doublecortin (DCX) showed that more than half of NG2+ cells express DCX in the cortex. The number of new DCX+NG2+ cells was reduced by EE at day 10. Conclusions Our results indicate for the first time that specific and unspecific motor training conditions differentially alter the process of differentiation from oligodendrocyte subpopulations, in particular NG2+DCX+ cells, in the sensorimotor cortex and corpus callosum. Electronic supplementary material The online version of this article (doi:10.1186/s12868-017-0347-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Silke Keiner
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany.
| | - Fanny Niv
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Susanne Neumann
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Tanja Steinbach
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Christian Schmeer
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Katrin Hornung
- Department of Cardiothoracic Surgery, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Yvonne Schlenker
- Pneumology, Internal Medicine I, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Martin Förster
- Pneumology, Internal Medicine I, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Otto W Witte
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Christoph Redecker
- Hans Berger Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
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Klempin F, Gertz K, Kronenberg G. Redox homeostasis: unlocking the bottleneck in glia-to-neuron conversion. Stem Cell Investig 2017; 4:7. [PMID: 28217709 DOI: 10.21037/sci.2017.01.07] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 12/29/2016] [Indexed: 01/07/2023]
Affiliation(s)
- Friederike Klempin
- Klinik und Poliklinik für Neurologie, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany;; Max Delbruck Center for Molecular Medicine (MDC), 13125 Berlin, Germany
| | - Karen Gertz
- Klinik und Poliklinik für Neurologie, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Golo Kronenberg
- Klinik und Poliklinik für Neurologie, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany;; Klinik und Poliklinik für Psychiatrie und Psychotherapie, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany;; Klinik und Poliklinik für Psychiatrie und Psychotherapie, Universitätsmedizin Rostock, 18147 Rostock, Germany
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54
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Distribution and fate of DCX/PSA-NCAM expressing cells in the adult mammalian cortex: A local reservoir for adult cortical neuroplasticity? ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s11515-016-1403-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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55
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Rahati M, Nozari M, Eslami H, Shabani M, Basiri M. Effects of enriched environment on alterations in the prefrontal cortex GFAP- and S100B-immunopositive astrocytes and behavioral deficits in MK-801-treated rats. Neuroscience 2016; 326:105-116. [PMID: 27063100 DOI: 10.1016/j.neuroscience.2016.03.065] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 03/17/2016] [Accepted: 03/29/2016] [Indexed: 10/22/2022]
Abstract
A plethora of studies have indicated that enriched environment (EE) paradigm provokes plastic and morphological changes in astrocytes with accompanying increments of their density and positively affects the behavior of rodents. We also previously documented that EE could be employed to preclude several behavioral abnormalities, mainly cognitive deficits, attributed to postnatal N-methyl-d-aspartate (NMDA) receptor antagonist (MK-801) treatment, as a rodent model of schizophrenia (SCH) aspects. Given this, the current study quantitatively investigated the number of cells, presumed to be astrocytes, expressing two astroglia-associated proteins (S100B and glial fibrillary acidic protein (GFAP)) by immunohistochemistry in the prefrontal cortex (PFC), along with anxiety and passive avoidance (PA) learning behaviors by utilizing elevated plus maze (EPM) and shuttle-box tests, in MK-801-treated male wistar rats submitted to EE and non-EE rats. Following a treatment regime of sub-chronic MK-801 (1.0mg/kg i.p. daily for five consecutive days from postnatal day (P) 6), S-100B-positive cells and anxiety level were markedly increased, while the GFAP-positive cells and PA learning were notably attenuated. The trend of diminished GFAP-immunopositive cells and elevated S100B-immunostained cells in the PFC was reversed in the SCH-like rats by exposure of animals to EE, commencing from birth up to the time of experiments on P28-85. Additionally, EE exhibited an ameliorating effect on the behavioral abnormalities evoked by MK-801. Overall, present findings support that improper astrocyte functioning and behavioral changes, reminiscent of the many facets of SCH, occur consequential to repetitive administration of MK-801 and that raising rat pups in an EE mitigates these alterations.
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Affiliation(s)
- M Rahati
- Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran; Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - M Nozari
- Department of Physiology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - H Eslami
- Department of Pharmacology, Molecular Medicine Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - M Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran
| | - M Basiri
- Department of Anatomical Sciences, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran; Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran.
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56
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Eugenín-von Bernhardi J, Dimou L. NG2-glia, More Than Progenitor Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 949:27-45. [PMID: 27714683 DOI: 10.1007/978-3-319-40764-7_2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
NG2-glia are a mysterious and ubiquitous glial population with a highly branched morphology. Initial studies suggested that their unique function is the generation and maintenance of oligodendrocytes in the central nervous system (CNS), important for proper myelination and therefore for axonal support and fast conduction velocity. Over the last years this simplistic notion has been dramatically changed: the wide and homogeneous distribution of NG2-glia within all areas of the developing CNS that is maintained during the whole lifespan, their potential to also differentiate into other cell types in a spatiotemporal manner, their active capability of maintaining their population and their dynamic behavior in altered conditions have raised the question: are NG2-glia simple progenitor cells or do they play further major roles in the normal function of the CNS? In this chapter, we will discuss some important features of NG2-glia like their homeostatic distribution in the CNS and their potential to differentiate into diverse cell types. Additionally, we will give some further insights into the properties that these cells have, like the ability to form synapses with neurons and their plastic behavior triggered by neuronal activity, suggesting that they may play a role specifically in myelin and more generally in brain plasticity. Finally, we will briefly review their behavior in disease models suggesting that their function is extended to repair the brain after insult.
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Affiliation(s)
- Jaime Eugenín-von Bernhardi
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany. .,Graduate School of Systemic Neuroscience, Ludwig-Maximilians-University, 82152, Planegg-Martinsried, Germany.
| | - Leda Dimou
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany.
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57
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Bernardes D, Brambilla R, Bracchi-Ricard V, Karmally S, Dellarole A, Carvalho-Tavares J, Bethea JR. Prior regular exercise improves clinical outcome and reduces demyelination and axonal injury in experimental autoimmune encephalomyelitis. J Neurochem 2015; 136 Suppl 1:63-73. [PMID: 26364732 DOI: 10.1111/jnc.13354] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 08/18/2015] [Accepted: 08/21/2015] [Indexed: 12/22/2022]
Abstract
Although previous studies have shown that forced exercise modulates inflammation and is therapeutic acutely for experimental autoimmune encephalomyelitis (EAE), the long-term benefits have not been evaluated. In this study, we investigated the effects of preconditioning exercise on the clinical and pathological progression of EAE. Female C57BL/6 mice were randomly assigned to either an exercised (Ex) or unexercised (UEx) group and all of them were induced for EAE. Mice in the Ex group had an attenuated clinical score relative to UEx mice throughout the study. At 42 dpi, flow cytometry analysis showed a significant reduction in B cells, CD4(+) T cells, and CD8(+) T cells infiltrating into the spinal cord in the Ex group compared to UEx. Ex mice also had a significant reduction in myelin damage with a corresponding increase in proteolipid protein expression. Finally, Ex mice had a significant reduction in axonal damage. Collectively, our study demonstrates for the first time that a prolonged and forced preconditioning protocol of exercise improves clinical outcome and attenuates pathological hallmarks of EAE at chronic disease. In this study, we show that a program of 6 weeks of preconditioning exercise promoted a significant reduction of cells infiltrating into the spinal cord, a significant reduction in myelin damage and a significant reduction in axonal damage in experimental autoimmune encephalomyelitis (EAE) mice at 42 dpi. Collectively, our study demonstrates for the first time that a preconditioning protocol of exercise improves clinical outcome and attenuates pathological hallmarks of EAE at chronic disease.
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Affiliation(s)
- Danielle Bernardes
- Departamento de Fisiologia e Biofísica, Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.,CAPES Foundation, Ministry of Education of Brazil, Brasília, DF, Brazil.,The Miami Project To Cure Paralysis, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Roberta Brambilla
- The Miami Project To Cure Paralysis, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Valerie Bracchi-Ricard
- The Miami Project To Cure Paralysis, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Department of Biology, Drexel University, Philadelphia, Philadelphia, USA
| | - Shaffiat Karmally
- The Miami Project To Cure Paralysis, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Anna Dellarole
- The Miami Project To Cure Paralysis, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Juliana Carvalho-Tavares
- Departamento de Fisiologia e Biofísica, Núcleo de Neurociências, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - John R Bethea
- Department of Biology, Drexel University, Philadelphia, Philadelphia, USA
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58
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Proliferating cells in the adolescent rat amygdala: Characterization and response to stress. Neuroscience 2015; 311:105-17. [PMID: 26476262 DOI: 10.1016/j.neuroscience.2015.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/24/2015] [Accepted: 10/02/2015] [Indexed: 12/27/2022]
Abstract
The amygdala is a heterogeneous group of nuclei that plays a role in emotional and social learning. As such, there has been increased interest in its development in adolescent animals, a period in which emotional/social learning increases dramatically. While many mechanisms of amygdala development have been studied, the role of cell proliferation during adolescence has received less attention. Using bromodeoxyuridine (BrdU) injections in adolescent and adult rats, we previously found an almost fivefold increase in BrdU-positive cells in the amygdala of adolescents compared to adults. Approximately one third of BrdU-labeled cells in the amygdala contained the putative neural marker doublecortin (DCX), suggesting a potential for neurogenesis. To further investigate this possibility in adolescents, we examined the proliferative dynamics of DCX/BrdU-labeled cells. Surprisingly, DCX/BrdU-positive cells were found to comprise a stable subpopulation of BrdU-containing cells across survivals up to 56 days, and there was no evidence of neural maturation by 28 days after BrdU injection. Additionally, we found that approximately 50% of BrdU+ cells within the adolescent amygdala contain neural-glial antigen (NG2) and are therefore presumptive oligodendrocyte precursors (OPCs). We next characterized the response to a short-lived stressor (3-day repeated variable stress, RVS). The total BrdU-labeled cell number decreased by ∼30% by 13 days following RVS (10 days post-BrdU injection) as assessed by stereologic counting methods, but the DCX/BrdU-labeled subpopulation was relatively resistant to RVS effects. In contrast, NG2/BrdU-labeled cells were strongly influenced by RVS. We conclude that typical neurogenesis is not a feature of the adolescent amygdala. These findings point to several possibilities, including the possibility that DCX/BrdU cells are late-developing neural precursors, or a unique subtype of NG2 cell that is relatively resistant to stress. In contrast, many proliferating OPCs are significantly impacted by a short-lived stressor, suggesting consequences for myelination in the developing amygdala.
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59
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Tomlinson L, Leiton CV, Colognato H. Behavioral experiences as drivers of oligodendrocyte lineage dynamics and myelin plasticity. Neuropharmacology 2015; 110:548-562. [PMID: 26415537 DOI: 10.1016/j.neuropharm.2015.09.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 09/10/2015] [Accepted: 09/12/2015] [Indexed: 12/28/2022]
Abstract
Many behavioral experiences are known to promote hippocampal neurogenesis. In contrast, the ability of behavioral experiences to influence the production of oligodendrocytes and myelin sheath formation remains relatively unknown. However, several recent studies indicate that voluntary exercise and environmental enrichment can positively influence both oligodendrogenesis and myelination, and that, in contrast, social isolation can negatively influence myelination. In this review we summarize studies addressing the influence of behavioral experiences on oligodendrocyte lineage cells and myelin, and highlight potential mechanisms including experience-dependent neuronal activity, metabolites, and stress effectors, as well as both local and systemic secreted factors. Although more study is required to better understand the underlying mechanisms by which behavioral experiences regulate oligodendrocyte lineage cells, this exciting and newly emerging field has already revealed that oligodendrocytes and their progenitors are highly responsive to behavioral experiences and suggest the existence of a complex network of reciprocal interactions among oligodendrocyte lineage development, behavioral experiences, and brain function. Achieving a better understanding of these relationships may have profound implications for human health, and in particular, for our understanding of changes in brain function that occur in response to experiences. This article is part of the Special Issue entitled 'Oligodendrocytes in Health and Disease'.
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60
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Abstract
Oligodendrocyte precursor cells (OPCs) originate in the ventricular zones (VZs) of the brain and spinal cord and migrate throughout the developing central nervous system (CNS) before differentiating into myelinating oligodendrocytes (OLs). It is not known whether OPCs or OLs from different parts of the VZ are functionally distinct. OPCs persist in the postnatal CNS, where they continue to divide and generate myelinating OLs at a decreasing rate throughout adult life in rodents. Adult OPCs respond to injury or disease by accelerating their cell cycle and increasing production of OLs to replace lost myelin. They also form synapses with unmyelinated axons and respond to electrical activity in those axons by generating more OLs and myelin locally. This experience-dependent "adaptive" myelination is important in some forms of plasticity and learning, for example, motor learning. We review the control of OL lineage development, including OL population dynamics and adaptive myelination in the adult CNS.
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Affiliation(s)
- Dwight E Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, WBSB 1001, Baltimore, Maryland 21205
| | - William D Richardson
- Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, United Kingdom
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61
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de Sousa AA, Dos Reis RR, de Lima CM, de Oliveira MA, Fernandes TN, Gomes GF, Diniz DG, Magalhães NM, Diniz CG, Sosthenes MCK, Bento-Torres J, Diniz JAP, Vasconcelos PFDC, Diniz CWP. Three-dimensional morphometric analysis of microglial changes in a mouse model of virus encephalitis: age and environmental influences. Eur J Neurosci 2015; 42:2036-50. [PMID: 25980955 DOI: 10.1111/ejn.12951] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 04/16/2015] [Accepted: 05/13/2015] [Indexed: 02/05/2023]
Abstract
Many RNA virus CNS infections cause neurological disease. Because Piry virus has a limited human pathogenicity and exercise reduces activation of microglia in aged mice, possible influences of environment and aging on microglial morphology and behavior in mice sublethal encephalitis were investigated. Female albino Swiss mice were raised either in standard (S) or in enriched (EE) cages from age 2 to 6 months (young - Y), or from 2 to 16 months (aged - A). After behavioral tests, mice nostrils were instilled with Piry-virus-infected or with normal brain homogenates. Brain sections were immunolabeled for virus antigens or microglia at 8 days post-infection (dpi), when behavioral changes became apparent, and at 20 and 40 dpi, after additional behavioral testing. Young infected mice from standard (SYPy) and enriched (EYPy) groups showed similar transient impairment in burrowing activity and olfactory discrimination, whereas aged infected mice from both environments (EAPy, SAPy) showed permanent reduction in both tasks. The beneficial effects of an enriched environment were smaller in aged than in young mice. Six-hundred and forty microglial cells, 80 from each group were reconstructed. An unbiased, stereological sampling approach and multivariate statistical analysis were used to search for microglial morphological families. This procedure allowed distinguishing between microglial morphology of infected and control subjects. More severe virus-associated microglial changes were observed in young than in aged mice, and EYPy seem to recover microglial homeostatic morphology earlier than SYPy . Because Piry-virus encephalitis outcomes were more severe in aged mice, it is suggested that the reduced inflammatory response in those individuals may aggravate encephalitis outcomes.
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Affiliation(s)
- Aline A de Sousa
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Renata R Dos Reis
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Camila M de Lima
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Marcus A de Oliveira
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | | | - Giovanni F Gomes
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Daniel G Diniz
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Nara M Magalhães
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - Cristovam G Diniz
- Instituto Federal de Educação, Ciência e Tecnologia do Pará, Bragança, Pará, Brazil
| | - Marcia C K Sosthenes
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - João Bento-Torres
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil
| | - José Antonio P Diniz
- Instituto Evandro Chagas (IEC), Departamento de Arbovirologia e Febres Hemorrágicas, Ananindeua, Pará, Brazil
| | - Pedro F da C Vasconcelos
- Instituto Evandro Chagas (IEC), Departamento de Arbovirologia e Febres Hemorrágicas, Ananindeua, Pará, Brazil
| | - Cristovam Wanderley P Diniz
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Belém, Pará, Brazil.,Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK
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62
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Fannon J, Tarmier W, Fulton D. Neuronal activity and AMPA-type glutamate receptor activation regulates the morphological development of oligodendrocyte precursor cells. Glia 2015; 63:1021-35. [PMID: 25739948 DOI: 10.1002/glia.22799] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 01/09/2015] [Indexed: 11/11/2022]
Abstract
Myelination is initiated when oligodendrocyte precursor cells (OPC) contact target axons. Neuronal activity promotes myelination through actions that may involve OPC AMPA and NMDA glutamate receptors (AMPAR, NMDAR). Therefore, activity and AMPAR/NMDAR activation are predicted to promote the morphological development of OPC. AMPAR can regulate OPC development, but this analysis was not performed in situ and the role of action potentials was not examined. Hence, the influence of activity and AMPAR on OPC morphology and development remain untested in the CNS where axon-glial interactions are preserved. Data on NMDAR are mixed with conflicting results from in vitro and in vivo work. To gain a fuller understanding of activity-dependent OPC development in situ, we explored the role of AMPAR and NMDAR in cerebellar slice cultures that permit the study of endogenous OPC development and myelination. The structure of individual OPC was resolved from cells labeled with membrane targeted GFP. Morphological data were then validated against assays of OPC development. Blocking either activity or AMPAR impaired the morphological development of OPC and promoted proliferation and differentiation. Increasing the pool of oligodendrocytes by blocking activity or AMPAR failed to promote myelination. Instead both myelination and the expression of myelin basic protein were reduced by these treatments suggesting that full differentiation to a myelinating phenotype did not occur. Blocking NMDAR left OPC proliferation, differentiation and morphology unchanged. These data indicate an important role for AMPAR but not NMDAR in mediating the activity-dependent signals that regulate OPC morphology, development and myelination.
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Affiliation(s)
- Jessica Fannon
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
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63
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Dixon KJ, Theus MH, Nelersa CM, Mier J, Travieso LG, Yu TS, Kernie SG, Liebl DJ. Endogenous neural stem/progenitor cells stabilize the cortical microenvironment after traumatic brain injury. J Neurotrauma 2015; 32:753-64. [PMID: 25290253 DOI: 10.1089/neu.2014.3390] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Although a myriad of pathological responses contribute to traumatic brain injury (TBI), cerebral dysfunction has been closely linked to cell death mechanisms. A number of therapeutic strategies have been studied in an attempt to minimize or ameliorate tissue damage; however, few studies have evaluated the inherent protective capacity of the brain. Endogenous neural stem/progenitor cells (NSPCs) reside in distinct brain regions and have been shown to respond to tissue damage by migrating to regions of injury. Until now, it remained unknown whether these cells have the capacity to promote endogenous repair. We ablated NSPCs in the subventricular zone to examine their contribution to the injury microenvironment after controlled cortical impact (CCI) injury. Studies were performed in transgenic mice expressing the herpes simplex virus thymidine kinase gene under the control of the nestin(δ) promoter exposed to CCI injury. Two weeks after CCI injury, mice deficient in NSPCs had reduced neuronal survival in the perilesional cortex and fewer Iba-1-positive and glial fibrillary acidic protein-positive glial cells but increased glial hypertrophy at the injury site. These findings suggest that the presence of NSPCs play a supportive role in the cortex to promote neuronal survival and glial cell expansion after TBI injury, which corresponds with improvements in motor function. We conclude that enhancing this endogenous response may have acute protective roles after TBI.
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Affiliation(s)
- Kirsty J Dixon
- 1The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami, Miami, Florida
| | - Michelle H Theus
- 2The Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, Virginia
| | - Claudiu M Nelersa
- 1The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami, Miami, Florida
| | - Jose Mier
- 1The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami, Miami, Florida
| | - Lissette G Travieso
- 1The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami, Miami, Florida
| | - Tzong-Shiue Yu
- 3Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Steven G Kernie
- 3Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Daniel J Liebl
- 1The Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami, Miami, Florida
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64
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Somkuwar SS, Staples MC, Galinato MH, Fannon MJ, Mandyam CD. Role of NG2 expressing cells in addiction: a new approach for an old problem. Front Pharmacol 2014; 5:279. [PMID: 25566075 PMCID: PMC4271769 DOI: 10.3389/fphar.2014.00279] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 11/30/2014] [Indexed: 12/17/2022] Open
Abstract
Neuron-glial antigen 2 (NG2) is a proteoglycan expressed predominantly in oligodendrocyte progenitor cells (OPCs). NG2-expressing OPCs (NG2-OPCs) are self-renewing cells that are widely distributed in the gray and white matter areas of the central nervous system. NG2-OPCs can mature into premyelinating oligodendrocytes and myelinating oligodendroglia which serve as the primary source of myelin in the brain. This review characterizes NG2-OPCs in brain structure and function, conceptualizes the role of NG2-OPCs in brain regions associated with negative reinforcement and relapse to drug seeking and discusses how NG2-OPCs are regulated by neuromodulators linked to motivational withdrawal. We hope to provide the readers with an overview of the role of NG2-OPCs in brain structure and function in the context of negative affect state in substance abuse disorders and to integrate our current understanding of the physiological significance of the NG2-OPCs in the adult brain.
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Affiliation(s)
- Sucharita S Somkuwar
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
| | - Miranda C Staples
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
| | - Melissa H Galinato
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
| | - McKenzie J Fannon
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
| | - Chitra D Mandyam
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute La Jolla, CA, USA
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65
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Boda E, Buffo A. Beyond cell replacement: unresolved roles of NG2-expressing progenitors. Front Neurosci 2014; 8:122. [PMID: 24904264 PMCID: PMC4033196 DOI: 10.3389/fnins.2014.00122] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/06/2014] [Indexed: 12/19/2022] Open
Abstract
NG2-expressing parenchymal precursors (NG2+p) serve as primary source of myelinating oligodendrocytes in both the developing and adult Central Nervous System (CNS). However, their abundance, limited differentiation potential at adult stages along with stereotypic reaction to injury independent of the extent of myelin loss suggest that NG2+p exert functions additional to myelin production. In support of this view, NG2+p express a complex battery of molecules known to exert neuromodulatory and neuroprotective functions. Further, they establish intimate physical associations with the other CNS cell types, receive functional synaptic contacts and possess ion channels apt to constantly sense the electrical activity of surrounding neurons. These latter features could endow NG2+p with the capability to affect neuronal functions with potential homeostatic outcomes. Here we summarize and discuss current evidence favoring the view that NG2+p can participate in circuit formation, modulate neuronal activity and survival in the healthy and injured CNS, and propose perspectives for studies that may complete our understanding of NG2+p roles in physiology and pathology.
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Affiliation(s)
- Enrica Boda
- Department of Neuroscience Rita Levi-Montalcini, Neuroscience Institute Cavalieri Ottolenghi, University of Turin Turin, Italy
| | - Annalisa Buffo
- Department of Neuroscience Rita Levi-Montalcini, Neuroscience Institute Cavalieri Ottolenghi, University of Turin Turin, Italy
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66
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Boulanger JJ, Messier C. From precursors to myelinating oligodendrocytes: contribution of intrinsic and extrinsic factors to white matter plasticity in the adult brain. Neuroscience 2014; 269:343-66. [PMID: 24721734 DOI: 10.1016/j.neuroscience.2014.03.063] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 03/28/2014] [Accepted: 03/28/2014] [Indexed: 12/21/2022]
Abstract
Oligodendrocyte precursor cells (OPC) are glial cells that metamorphose into myelinating oligodendrocytes during embryogenesis and early stages of post-natal life. OPCs continue to divide throughout adulthood and some eventually differentiate into oligodendrocytes in response to demyelinating lesions. There is growing evidence that OPCs are also involved in activity-driven de novo myelination of previously unmyelinated axons and myelin remodeling in adulthood. In this review, we summarize the interwoven factors and cascades that promote the activation, recruitment and differentiation of OPCs into myelinating oligodendrocytes in the adult brain based mostly on results found in the study of demyelinating diseases. The goal of the review was to draw a complete picture of the transformation of OPCs into mature oligodendrocytes to facilitate the study of this transformation in both the normal and diseased adult brain.
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Affiliation(s)
| | - C Messier
- School of Psychology, University of Ottawa, Canada.
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67
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Environmental enrichment induces neuroplastic changes in middle age female BalbC mice and increases the hippocampal levels of BDNF, p-Akt and p-MAPK1/2. Neuroscience 2014; 260:158-70. [DOI: 10.1016/j.neuroscience.2013.12.026] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 12/09/2013] [Accepted: 12/11/2013] [Indexed: 12/21/2022]
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68
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L'Episcopo F, Tirolo C, Caniglia S, Testa N, Morale MC, Serapide MF, Pluchino S, Marchetti B. Targeting Wnt signaling at the neuroimmune interface for dopaminergic neuroprotection/repair in Parkinson's disease. J Mol Cell Biol 2014; 6:13-26. [PMID: 24431301 DOI: 10.1093/jmcb/mjt053] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
During the past three decades, the Wingless-type MMTV integration site (Wnt) signaling cascade has emerged as an essential system regulating multiple processes in developing and adult brain. Accumulating evidence points to a dysregulation of Wnt signaling in major neurodegenerative pathologies including Parkinson's disease (PD), a common neurodegenerative disorder characterized by the progressive loss of midbrain dopaminergic (mDA) neurons and deregulated activation of astrocytes and microglia. This review highlights the emerging link between Wnt signaling and key inflammatory pathways during mDA neuron damage/repair in PD progression. In particular, we summarize recent evidence documenting that aging and neurotoxicant exposure strongly antagonize Wnt/β-catenin signaling in mDA neurons and subventricular zone (SVZ) neuroprogenitors via astrocyte-microglial interactions. Dysregulation of the crosstalk between Wnt/β-catenin signaling and anti-oxidant/anti-inflammatory pathways delineate novel mechanisms driving the decline of SVZ plasticity with age and the limited nigrostriatal dopaminergic self-repair in PD. These findings hold a promise in developing therapies that target Wnt/β-catenin signaling to enhance endogenous restoration and neuronal outcome in age-dependent diseases, such as PD.
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Affiliation(s)
- Francesca L'Episcopo
- OASI Institute for Research and Care on Mental Retardation and Brain Aging (IRCCS), Neuropharmacology Section, Via Conte Ruggero 73, 94018 Troina, Italy
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69
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Microglial response to Alzheimer's disease is differentially modulated by voluntary wheel running and enriched environments. Brain Struct Funct 2013; 220:941-53. [PMID: 24374506 DOI: 10.1007/s00429-013-0693-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 12/17/2013] [Indexed: 10/25/2022]
Abstract
Alzheimer's disease (AD) is an untreatable neurodegenerative disease that deteriorates memory. Increased physical/cognitive activity reduces dementia risk by promoting neuronal and glial response. Although few studies have investigated microglial response in wild-type rodents following exposure to physical/cognitive stimulation, environmental-induced changes of microglia response to AD have been neglected. We investigated effects of running (RUN) and enriched (ENR) environments on numerical density (N v, #/mm(3)) and morphology of microglia in a triple transgenic (3×Tg-AD) mouse model of AD that closely mimics AD pathology in humans. We used immunohistochemical approach to characterise microglial domain by measuring their overall cell surface, volume and somata volume. 3×Tg-AD mice housed in standard control (STD) environment showed significant increase in microglial N v (11.7 %) in CA1 stratum lacunosum moleculare (S.Mol) of the hippocampus at 12 months compared to non-transgenic (non-Tg) animals. Exposure to combined RUN and ENR environments prevented an increase in microglial N v in 3×Tg-AD and reduced microglial numbers to non-Tg control levels. Interestingly, 3×Tg-AD mice housed solely in ENR environment displayed significant decrease in microglial N v in CA1 subfield (9.3 % decrease), stratum oriens (11.5 % decrease) and S.Mol (7.6 % decrease) of the hippocampus compared to 3×Tg-AD mice housed in STD environment. Morphological analysis revealed microglial hypertrophy due to pronounced increase in microglia surface, volume and somata volume (61, 78 and 41 %) in 3×Tg-AD mice housed in RUN (but not in ENR) compared to STD environment. These results indicate that exposure to RUN and ENR environments have differential effects on microglial density and activation-associated changes in microglial morphology.
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70
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Wang S, Young KM. White matter plasticity in adulthood. Neuroscience 2013; 276:148-60. [PMID: 24161723 DOI: 10.1016/j.neuroscience.2013.10.018] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 01/24/2023]
Abstract
CNS white matter is subject to a novel form of neural plasticity which has been termed "myelin plasticity". It is well established that oligodendrocyte generation and the addition of new myelin internodes continue throughout normal adulthood. These new myelin internodes maybe required for the de novo myelination of previously unmyelinated axons, myelin sheath replacement, or even myelin remodeling. Each process could alter axonal conduction velocity, but to what end? We review the changes that occur within the white matter over the lifetime, the known regulators and mediators of white matter plasticity in the mature CNS, and the physiological role this plasticity may play in CNS function.
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Affiliation(s)
- S Wang
- Menzies Research Institute Tasmania, University of Tasmania, Hobart 7000, Australia
| | - K M Young
- Menzies Research Institute Tasmania, University of Tasmania, Hobart 7000, Australia.
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71
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Effects of an alpha7 nicotinic receptor agonist and stress on spatial memory in an animal model of Alzheimer's disease. BIOMED RESEARCH INTERNATIONAL 2013; 2013:952719. [PMID: 24058919 PMCID: PMC3766554 DOI: 10.1155/2013/952719] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 01/23/2023]
Abstract
The aim of the present study was to test the effects of PNU-282987 on spatial learning and memory and hippocampal neurogenesis in both intact and chronically stressed transgenic mice. Transgenic mice with susceptibility to Alzheimer's disease (AD) under immobilization stress and not-stressed animals receiving 0 and 1 mg/kg of PNU-282987 (PNU) were evaluated in a water maze task. The effects of PNU and stress on proliferation of new cells in the hippocampus of these animals were also assessed. The latency to escape the platform was significantly higher in transgenic stressed mice compared to those in the wild stressed group, as well as in transgenic animals without PNU compared to control wild group. On retention of the task, differences emerged on stressed wild animals, PNU wild group, and stressed wild mice receiving PNU. However, no significant differences were detected on new cell proliferation. The results of the present study did not show any impact of stress in acquisition of a spatial task both in wild and transgenic mice. No clear effects of PNU on acquisition of a spatial task in transgenic mice with susceptibility to AD were detected. Although PNU and stress effects were detected on retention of the task in wild animals, no changes were noted in transgenic mice.
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72
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van Wijngaarden P, Franklin RJM. Ageing stem and progenitor cells: implications for rejuvenation of the central nervous system. Development 2013; 140:2562-75. [PMID: 23715549 DOI: 10.1242/dev.092262] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The growing burden of the rapidly ageing global population has reinvigorated interest in the science of ageing and rejuvenation. Among organ systems, rejuvenation of the central nervous system (CNS) is arguably the most complex and challenging of tasks owing, among other things, to its startling structural and functional complexity and its restricted capacity for repair. Thus, the prospect of meaningful rejuvenation of the CNS has seemed an impossible goal; however, advances in stem cell science are beginning to challenge this assumption. This Review outlines these advances with a focus on ageing and rejuvenation of key endogenous stem and progenitor cell compartments in the CNS. Insights gleaned from studies of model organisms, chiefly rodents, will be considered in parallel with human studies.
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Affiliation(s)
- Peter van Wijngaarden
- Wellcome Trust-MRC Cambridge Stem Cell Institute and Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.
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73
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Saul ML, Helmreich DL, Callahan LM, Fudge JL. Differences in amygdala cell proliferation between adolescent and young adult rats. Dev Psychobiol 2013; 56:517-28. [PMID: 23775606 DOI: 10.1002/dev.21115] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 03/12/2013] [Indexed: 01/10/2023]
Abstract
Adolescence is characterized by changes in both behavior and neural organization. During this period, the amygdala, a structure that mediates social and emotional behaviors, is changing in terms of neural and glia density. We examined cell proliferation within the amygdala of adolescent (post natal day (PND) 31) and adult (PND 70) male Sprague-Dawley rats using BrdU (bromodeoxyuridine) to label dividing cells. BrdU-labeled cells were distributed throughout the amygdala, often found in fibers surrounding major nuclei. Using two independent cell counting strategies under light and confocal microcopy, respectively, we found significantly more labeled cells in the amygdala in adolescent compared to adult animals (239.3 ± 87.18 vs. 44.75 ± 13.68; n=4/group; p<.05). BrdU/doublecortin (DCX) positive cells constitute approximately 30% of all dividing cells in the amygdala in both adolescents and adults. These data suggest that compared to young adulthood, adolescence is a relatively active period of cell proliferation in the amygdala. Moreover, the normal decline in dividing cells with age does not preferentially affect cells co-containing DCX-immunoreactivity.
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Affiliation(s)
- Michele L Saul
- Department of Neurobiology and Anatomy, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY, 14642
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74
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Apoptosis of glutamatergic neurons fails to trigger a neurogenic response in the adult neocortex. J Neurosci 2013; 33:6278-84. [PMID: 23575827 DOI: 10.1523/jneurosci.5885-12.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Adult neurogenesis is actively studied in part because of the potential to manipulate endogenous neural stem and progenitor cells for tissue repair. Although constitutive generation of neurons in the adult rodent olfactory bulb and hippocampal dentate gyrus is widely accepted and stroke-induced generation of striatal inhibitory neurons consistently observed, evidence supporting the generation of neurons in the neocortex after neuronal loss remains slim. Nevertheless, a few studies suggested that targeted apoptosis of neocortical glutamatergic neurons could trigger the generation of new ones in the adult brain. In light of such studies, we tested whether apoptosis of glutamatergic cortical neurons using two novel transgenic approaches in mice, an inducible Caspase-8 protein and an inducible diphtheria toxin gene, results in new neurons. After a thorough analysis, no new neurons were detected in the neocortex. Interestingly, an increase in the expression of the neuroblast marker DCX was observed in both models, in some cases in cells with morphologies previously associated with poststroke neuroblasts, but DCX(+) cells coexpressed the oligodendrocyte precursor marker Olig2, suggesting caution when using DCX as a marker for neuroblasts after injury. Given that the adult neocortex lacks an innate potential to regenerate lost glutamatergic neurons, future strategies should concentrate on manipulating the differentiation potential of endogenous or exogenous precursor cells.
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75
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Viana L, Lima C, Oliveira M, Borges R, Cardoso T, Almeida I, Diniz D, Bento-Torres J, Pereira A, Batista-de-Oliveira M, Lopes A, Silva R, Abadie-Guedes R, Amâncio dos Santos A, Lima D, Vasconcelos P, Cunningham C, Guedes R, Picanço-Diniz C. Litter size, age-related memory impairments, and microglial changes in rat dentate gyrus: Stereological analysis and three dimensional morphometry. Neuroscience 2013; 238:280-96. [DOI: 10.1016/j.neuroscience.2013.02.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/12/2013] [Accepted: 02/12/2013] [Indexed: 10/27/2022]
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76
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Kim YG, Jeon S, Sin GY, Shim JK, Kim BK, Shin HJ, Lee JH, Huh YM, Lee SJ, Kim EH, Park EK, Kim SH, Chang JH, Kim DS, Kim SH, Hong YK, Kang SG, Lang FF. Existence of glioma stroma mesenchymal stemlike cells in Korean glioma specimens. Childs Nerv Syst 2013; 29:549-63. [PMID: 23274635 DOI: 10.1007/s00381-012-1988-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 11/23/2012] [Indexed: 12/15/2022]
Abstract
PURPOSE It was presented that mesenchymal stem cells (MSCs) can be isolated from western glioma specimens. However, whether MSCs exist in glioma specimens of different ethnicities is unknown. To verify the existence of MSCs in an independent cohort, we undertook studies to isolate MSCs from a group of Korean patients. We hypothesized that cells resembling MSCs that were deemed mesenchymal stemlike cells (MSLCs) exist in an independent cohort of Korean gliomas. METHODS We cultured fresh glioma specimens using the protocols used for culturing MSCs. The cultured cells were analyzed with fluorescence-activated cell sorting (FACS) for surface markers associated with MSCs. Cultured cells were exposed to mesenchymal differentiation conditions. To presume possible locations of MSLCs in the glioma, sections of glioma were analyzed by immunofluorescent labeling for CD105, CD31, and NG2. RESULTS From nine of 31 glioma specimens, we isolated cells resembling MSCs, which were deemed Korean glioma stroma MSLCs (KGS-MSLCs). KGS-MSLCs were spindle shaped and adherent to plastic. KGS-MSLCs had similar surface markers to MSCs (CD105(+), CD90(+), CD73(+), and CD45(-)). KGS-MSLCs were capable of mesenchymal differentiation and might be located around endothelial cells, pericytes, and in a disorganized perivascular area inside glioma stroma. CONCLUSIONS We found that cells resembling MSCs indeed exist in an independent cohort of glioma patients, as presented in western populations. We could presume that the possible location of KGS-MSLCs was in perivascular area or in glioma stroma that was a disorganized vascular niche. It might be possible that KGS-MSLCs could be one of constituent of stroma of glioma microenvironment.
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Affiliation(s)
- Young Goo Kim
- Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
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Llorens-Martín M, Fuster-Matanzo A, Teixeira CM, Jurado-Arjona J, Ulloa F, Defelipe J, Rábano A, Hernández F, Soriano E, Avila J. GSK-3β overexpression causes reversible alterations on postsynaptic densities and dendritic morphology of hippocampal granule neurons in vivo. Mol Psychiatry 2013; 18:451-60. [PMID: 23399915 DOI: 10.1038/mp.2013.4] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Adult hippocampal neurogenesis (AHN) is crucial for the maintenance of hippocampal function. Several neurodegenerative diseases such as Alzheimer's disease (AD) are accompanied by memory deficits that could be related to alterations in AHN. Here, we took advantage of a conditional mouse model to study the involvement of glycogen synthase kinase-3β (GSK-3β) overexpression (OE) in AHN. By injecting GFP- and PSD95-GFP-expressing retroviruses, we have determined that hippocampal GSK-3β-OE causes dramatic alterations in both dendritic tree morphology and post-synaptic densities in newborn neurons. Alterations in previously damaged neurons were reverted by switching off the transgenic system and also by using a physiological approach (environmental enrichment) to increase hippocampal plasticity. Furthermore, comparative morphometric analysis of granule neurons from patients with AD and from GSK-3β overexpressing mice revealed shared morphological alterations. Taken together, these data indicate that GSK-3β is crucial for hippocampal function, thereby supporting this kinase as a relevant target for the treatment of AD.
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Affiliation(s)
- M Llorens-Martín
- Department of Molecular Neurobiology, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
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78
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L'Episcopo F, Tirolo C, Testa N, Caniglia S, Morale MC, Impagnatiello F, Pluchino S, Marchetti B. Aging-induced Nrf2-ARE pathway disruption in the subventricular zone drives neurogenic impairment in parkinsonian mice via PI3K-Wnt/β-catenin dysregulation. J Neurosci 2013; 33:1462-85. [PMID: 23345222 PMCID: PMC3564519 DOI: 10.1523/jneurosci.3206-12.2013] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 11/13/2012] [Accepted: 11/19/2012] [Indexed: 12/21/2022] Open
Abstract
Aging and exposure to environmental toxins including MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) are strong risk factors for developing Parkinson's disease (PD), a common neurologic disorder characterized by selective degeneration of midbrain dopaminergic (DAergic) neurons and astrogliosis. Aging and PD impair the subventricular zone (SVZ), one of the most important brain regions for adult neurogenesis. Because inflammation and oxidative stress are the hallmarks of aging and PD, we investigated the nature, timing, and signaling mechanisms contributing to aging-induced SVZ stem/neuroprogenitor cell (NPC) inhibition in aging male mice and attempted to determine to what extent manipulation of these pathways produces a functional response in the outcome of MPTP-induced DAergic toxicity. We herein reveal an imbalance of Nrf2-driven antioxidant/anti-inflammatory genes, such as Heme oxygenase1 in the SVZ niche, starting by middle age, amplified upon neurotoxin treatment and associated with an exacerbated proinflammatory SVZ microenvironment converging to dysregulate the Wingless-type MMTV integration site (Wnt)/β-catenin signaling, a key regulatory pathway for adult NPCs. In vitro experiments using coculture paradigms uncovered aged microglial proinflammatory mediators as critical inhibitors of NPC proliferative potential. We also found that interruption of PI3K (phosphatidylinositol3-kinase)/Akt and the Wnt/Fzd/β-catenin signaling cascades, which switch glycogen synthase kinase 3β (GSK-3β) activation on and off, were causally related to the impairment of SVZ-NPCs. Moreover, a synergy between dysfunctional microglia of aging mice and MPTP exposure further inhibited astrocyte proneurogenic properties, including the expression of key Wnts components. Last, pharmacological activation/antagonism studies in vivo and in vitro suggest the potential that aged SVZ manipulation is associated with DAergic functional recovery.
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Affiliation(s)
- Francesca L'Episcopo
- Oasi Maria Institute for Research and Care on Mental Retardation and Brain Aging, Neuropharmacology Section, 94018 Troina, Italy
- Department of Clinical and Molecular Biomedicine, Pharmacology Section, School of Medicine, University of Catania, 95125 Catania, Italy
| | - Cataldo Tirolo
- Oasi Maria Institute for Research and Care on Mental Retardation and Brain Aging, Neuropharmacology Section, 94018 Troina, Italy
| | - Nunzio Testa
- Oasi Maria Institute for Research and Care on Mental Retardation and Brain Aging, Neuropharmacology Section, 94018 Troina, Italy
| | - Salvatore Caniglia
- Oasi Maria Institute for Research and Care on Mental Retardation and Brain Aging, Neuropharmacology Section, 94018 Troina, Italy
| | - Maria C. Morale
- Oasi Maria Institute for Research and Care on Mental Retardation and Brain Aging, Neuropharmacology Section, 94018 Troina, Italy
| | | | - Stefano Pluchino
- John van Geest Centre for Brain Repair, Wellcome Trust-Medical Research Council Stem Cell Institute and NIHR Biomedical Research Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0PY, United Kingdom
| | - Bianca Marchetti
- Oasi Maria Institute for Research and Care on Mental Retardation and Brain Aging, Neuropharmacology Section, 94018 Troina, Italy
- Department of Clinical and Molecular Biomedicine, Pharmacology Section, School of Medicine, University of Catania, 95125 Catania, Italy
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Marchetti B, Pluchino S. Wnt your brain be inflamed? Yes, it Wnt! Trends Mol Med 2013; 19:144-56. [PMID: 23312954 DOI: 10.1016/j.molmed.2012.12.001] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 12/06/2012] [Accepted: 12/06/2012] [Indexed: 12/15/2022]
Abstract
The roles of Wnts in neural development, synaptogenesis, and cancer are generally well characterized. Nonetheless, evidence exists that interactions between the immune and nervous systems control major brain regenerative processes ranging from physiological or pathological (reparative) regeneration to neurogenesis and synaptic plasticity. Recent studies describe deregulated Wnt-Fzd signaling in degenerative and inflammatory central nervous system (CNS) disorders, and the expression of Wnt signaling components in the immune system, and in immune-like cells of the mammalian CNS. This would suggest a likely involvement of Wnts in inflammation-driven brain damage and inflammation-directed brain repair. Here, we review how Wnts modulate neuroimmune interactions and offer a perspective on the most challenging therapeutic opportunities for those CNS diseases where injury-reactive Wnt-flavored inflammation precedes secondary neurodegeneration.
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Affiliation(s)
- Bianca Marchetti
- Department of Clinical and Molecular Biomedicine, Pharmacology Section, Medical School, University of Catania, 95125 Catania, Italy.
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80
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Eyre HA, Papps E, Baune BT. Treating depression and depression-like behavior with physical activity: an immune perspective. Front Psychiatry 2013; 4:3. [PMID: 23382717 PMCID: PMC3562851 DOI: 10.3389/fpsyt.2013.00003] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 01/07/2013] [Indexed: 12/18/2022] Open
Abstract
The increasing burden of major depressive disorder makes the search for an extended understanding of etiology, and for the development of additional treatments highly significant. Biological factors may be useful biomarkers for treatment with physical activity (PA), and neurobiological effects of PA may herald new therapeutic development in the future. This paper provides a thorough and up-to-date review of studies examining the neuroimmunomodulatory effects of PA on the brain in depression and depression-like behaviors. From a neuroimmune perspective, evidence suggests PA does enhance the beneficial and reduce the detrimental effects of the neuroimmune system. PA appears to increase the following factors: interleukin (IL)-10, IL-6 (acutely), macrophage migration inhibitory factor, central nervous system-specific autoreactive CD4+ T cells, M2 microglia, quiescent astrocytes, CX3CL1, and insulin-like growth factor-1. On the other hand, PA appears to reduce detrimental neuroimmune factors such as: Th1/Th2 balance, pro-inflammatory cytokines, C-reactive protein, M1 microglia, and reactive astrocytes. The effect of other mechanisms is unknown, such as: CD4+CD25+ T regulatory cells (T regs), CD200, chemokines, miRNA, M2-type blood-derived macrophages, and tumor necrosis factor (TNF)-α [via receptor 2 (R2)]. The beneficial effects of PA are likely to occur centrally and peripherally (e.g., in visceral fat reduction). The investigation of the neuroimmune effects of PA on depression and depression-like behavior is a rapidly developing and important field.
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Affiliation(s)
- Harris A Eyre
- Discipline of Psychiatry, School of Medicine, University of Adelaide Adelaide, SA, Australia ; School of Medicine and Dentistry, James Cook University Townsville, QLD, Australia
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81
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Klaissle P, Lesemann A, Huehnchen P, Hermann A, Storch A, Steiner B. Physical activity and environmental enrichment regulate the generation of neural precursors in the adult mouse substantia nigra in a dopamine-dependent manner. BMC Neurosci 2012; 13:132. [PMID: 23110504 PMCID: PMC3504527 DOI: 10.1186/1471-2202-13-132] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 10/14/2012] [Indexed: 12/14/2022] Open
Abstract
Background Parkinson’s disease is characterized by a continuous loss of neurons within the substantia nigra (SN) leading to a depletion of dopamine. Within the adult SN as a non-neurogenic region, cells with mainly oligodendrocytic precursor characteristics, expressing the neuro-glial antigen-2 (NG2) are continuously generated. Proliferation of these cells is altered in animal models of Parkinson’s disease (PD). Exercise and environmental enrichment re-increase proliferation of NG2+ cells in PD models, however, a possible mechanistic role of dopamine for this increase is not completely understood. NG2+ cells can differentiate into oligodendrocytes but also into microglia and neurons as observed in vitro suggesting a possible hint for endogenous regenerative capacity of the SN. We investigated the role of dopamine in NG2-generation and differentiation in the adult SN stimulated by physical activity and environmental enrichment. Results We used the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-model for dopamine depletion and analysed newborn cells in the SN at different maturation stages and time points depending on voluntary physical activity, enriched environment and levodopa-treatment. We describe an activity- induced increase of new NG2-positive cells and also mature oligodendrocytes in the SN of healthy mice. Running and enriched environment refused to stimulate NG2-generation and oligodendrogenesis in MPTP-mice, an effect which could be reversed by pharmacological levodopa-induced rescue. Conclusion We suggest dopamine being a key regulator for activity-induced generation of NG2-cells and oliogodendrocytes in the SN as a potentially relevant mechanism in endogenous nigral cellular plasticity.
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Affiliation(s)
- Philipp Klaissle
- Department of Neurology, Charité University Medicine Berlin; CCM, Charitéplatz 1, Berlin, 10117, Germany
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82
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Feliciano DM, Bordey A. Newborn cortical neurons: only for neonates? Trends Neurosci 2012; 36:51-61. [PMID: 23062965 DOI: 10.1016/j.tins.2012.09.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 08/08/2012] [Accepted: 09/18/2012] [Indexed: 01/19/2023]
Abstract
Despite a century of debate over the existence of adult cortical neurogenesis, a consensus has not yet been reached. Here, we review evidence of the existence, origin, migration, and integration of neurons into the adult and neonatal cerebral cortex. We find that the lack of consensus likely stems from the low rate of postnatal cortical neurogenesis that has been observed, the fact that neurogenesis may be limited to subtypes of interneurons, and variability in other conditions, both physiological and environmental. We emphasize that neurogenesis occurs in the neonatal cortex and that neural stem cells are present into adulthood; it is possible that these progenitors are dormant, but they may be reactivated, for example, following injury.
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Affiliation(s)
- David M Feliciano
- Department of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA
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83
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Properties and fate of oligodendrocyte progenitor cells in the corpus callosum, motor cortex, and piriform cortex of the mouse. J Neurosci 2012; 32:8173-85. [PMID: 22699898 DOI: 10.1523/jneurosci.0928-12.2012] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Oligodendrocyte progenitor cells (OPCs) in the postnatal mouse corpus callosum (CC) and motor cortex (Ctx) reportedly generate only oligodendrocytes (OLs), whereas those in the piriform cortex may also generate neurons. OPCs have also been subdivided based on their expression of voltage-gated ion channels, ability to respond to neuronal activity, and proliferative state. To determine whether OPCs in the piriform cortex have inherently different physiological properties from those in the CC and Ctx, we studied acute brain slices from postnatal transgenic mice in which GFP expression identifies OL lineage cells. We whole-cell patch clamped GFP-expressing (GFP(+)) cells within the CC, Ctx, and anterior piriform cortex (aPC) and used prelabeling with 5-ethynyl-2'-deoxyuridine (EdU) to assess cell proliferation. After recording, slices were immunolabeled and OPCs were defined by strong expression of NG2. NG2(+) OPCs in the white and gray matter proliferated and coexpressed PDGFRα and voltage-gated Na(+) channels (I(Na)). Approximately 70% of OPCs were capable of generating regenerative depolarizations. In addition to OLIG2(+) NG2(+) I(Na)(+) OPCs and OLIG2(+) NG2(neg) I(Na)(neg) OLs, we identified cells with low levels of NG2 limited to the soma or the base of some processes. These cells had a significantly reduced I(Na) and a reduced ability to incorporate EdU when compared with OPCs and probably correspond to early differentiating OLs. By combining EdU labeling and lineage tracing using Pdgfrα-CreER(T2) : R26R-YFP transgenic mice, we double labeled OPCs and traced their fate in the postnatal brain. These OPCs generated OLs but did not generate neurons in the aPC or elsewhere at any time that we examined.
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84
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Gerber YN, Sabourin JC, Hugnot JP, Perrin FE. Unlike physical exercise, modified environment increases the lifespan of SOD1G93A mice however both conditions induce cellular changes. PLoS One 2012; 7:e45503. [PMID: 23029057 PMCID: PMC3447796 DOI: 10.1371/journal.pone.0045503] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 08/21/2012] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is characterized by a gradual muscular paralysis resulting from progressive motoneurons death. ALS etiology remains unknown although it has been demonstrated to be a multifactorial disease involving several cellular partners. There is currently no effective treatment. Even if the effect of exercise is under investigation for many years, whether physical exercise is beneficial or harmful is still under debate. METHODS AND FINDINGS We investigated the effect of three different intensities of running exercises on the survival of SOD1(G93A) mice. At the early-symptomatic stage (P60), males were isolated and randomly assigned to 5 conditions: 2 sedentary groups ("sedentary" and "sedentary treadmill" placed on the inert treadmill), and 3 different training intensity groups (5 cm/s, 10 cm/s and 21 cm/s; 15 min/day, 5days/week). We first demonstrated that an appropriate "control" of the environment is of the utmost importance since comparison of the two sedentary groups evidenced an 11.6% increase in survival in the "sedentary treadmill" group. Moreover, we showed by immunohistochemistry that this increased lifespan is accompanied with motoneurons survival and increased glial reactivity in the spinal cord. In a second step, we showed that when compared with the proper control, all three running-based training did not modify lifespan of the animals, but result in motoneurons preservation and changes in glial cells activation. CONCLUSIONS/SIGNIFICANCE We demonstrate that increase in survival induced by a slight daily modification of the environment is associated with motoneurons preservation and strong glial modifications in the lumbar spinal cord of SOD1(G93A). Using the appropriate control, we then demonstrate that all running intensities have no effect on the survival of ALS mice but induce cellular modifications. Our results highlight the critical importance of the control of the environment in ALS studies and may explain discrepancy in the literature regarding the effect of exercise in ALS.
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Affiliation(s)
- Yannick N. Gerber
- INSERM U1051, Institute for Neurosciences of Montpellier, Pathologies Sensorielles, Neuroplasticité et Thérapies, Saint-Eloi Hospital, Montpellier, France
- IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Jean-Charles Sabourin
- Integrative Biology of Neurodegeneration, Neuroscience Department, University of the Basque Country UPV/EHU, Bilbao, Spain
| | - Jean-Philippe Hugnot
- INSERM U1051, Institute for Neurosciences of Montpellier, Pathologies Sensorielles, Neuroplasticité et Thérapies, Saint-Eloi Hospital, Montpellier, France
| | - Florence E. Perrin
- INSERM U1051, Institute for Neurosciences of Montpellier, Pathologies Sensorielles, Neuroplasticité et Thérapies, Saint-Eloi Hospital, Montpellier, France
- IKERBASQUE Basque Foundation for Science, Bilbao, Spain
- Integrative Biology of Neurodegeneration, Neuroscience Department, University of the Basque Country UPV/EHU, Bilbao, Spain
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Kohman RA, DeYoung EK, Bhattacharya TK, Peterson LN, Rhodes JS. Wheel running attenuates microglia proliferation and increases expression of a proneurogenic phenotype in the hippocampus of aged mice. Brain Behav Immun 2012; 26:803-10. [PMID: 22056294 PMCID: PMC3275652 DOI: 10.1016/j.bbi.2011.10.006] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 11/23/2022] Open
Abstract
Aging is associated with low-grade neuroinflammation including primed microglia that may contribute to deficits in neural plasticity and cognitive function. The current study evaluated whether exercise modulates division and/or activation state of microglia in the dentate gyrus of the hippocampus, as activated microglia can express a classic inflammatory or an alternative neuroprotective phenotype. We also assessed hippocampal neurogenesis to determine whether changes in microglia were associated with new neuron survival. Adult (3.5 months) and aged (18 months) male BALB/c mice were individually housed with or without running wheels for 8 weeks. Mice received bromodeoxyuridine injections during the first or last 10 days of the experiment to label dividing cells. Immunofluorescence was conducted to measure microglia division, co-expression of the neuroprotective indicator insulin-like growth factor (IGF-1), and new neuron survival. The proportion of new microglia was increased in aged mice, and decreased from wheel running. Running increased the proportion of microglia expressing IGF-1 suggesting exercise shifts microglia phenotype towards neuroprotection. Additionally, running enhanced survival of new neurons in both age groups. Findings suggest that wheel running may attenuate microglia division and promote a proneurogenic phenotype in aged mice.
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Affiliation(s)
- Rachel A Kohman
- Department of Psychology, University of Illinois, Beckman Institute, Urbana, IL 61801-3873, USA.
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Abstract
Over the years it has become evident that the immune system can affect the function of the central nervous system (CNS), including altering cognitive processes. The impact of immune activation on the CNS is particularly important for aged individuals, as the brain's resident immune cells, microglia, acquire a pro-inflammatory profile. The low-grade chronic neuroinflammation that develops with normal aging likely contributes to the susceptibility to cognitive deficits and a host of age-related pathologies. Understanding why microglia show increased inflammatory activity (i.e., neuroinflammation) and identifying effective treatments to reduce microglia activation is expected to have beneficial effects on cognitive performance and measures of neural plasticity. However, microglia also promote regeneration after injury. Therefore, effective treatments must dampen inflammatory activity while preserving microglia's neuroprotective function. Discovering factors that induce neuroinflammation and investigating potential preventative therapies is expected to uncover the ways of maintaining normal microglia activity in the aged brain.
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Affiliation(s)
- Rachel A Kohman
- Department of Psychology, University of Illinois at Urbana-Champaign, Beckman Institute, Urbana, IL, USA.
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Nin MS, Martinez LA, Pibiri F, Nelson M, Pinna G. Neurosteroids reduce social isolation-induced behavioral deficits: a proposed link with neurosteroid-mediated upregulation of BDNF expression. Front Endocrinol (Lausanne) 2011; 2:73. [PMID: 22649384 PMCID: PMC3355888 DOI: 10.3389/fendo.2011.00073] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 10/26/2011] [Indexed: 11/13/2022] Open
Abstract
The pharmacological action of selective serotonin reuptake inhibitor antidepressants may include a normalization of the decreased brain levels of the brain-derived neurotrophic factor (BDNF) and of neurosteroids such as the progesterone metabolite allopregnanolone, which are decreased in patients with depression and posttraumatic stress disorders (PTSD). The allopregnanolone and BDNF level decrease in PTSD and depressed patients is associated with behavioral symptom severity. Antidepressant treatment upregulates both allopregnanolone levels and the expression of BDNF in a manner that significantly correlates with improved symptomatology, which suggests that neurosteroid biosynthesis and BDNF expression may be interrelated. Preclinical studies using the socially isolated mouse as an animal model of behavioral deficits, which resemble some of the symptoms observed in PTSD patients, have shown that fluoxetine and derivatives improve anxiety-like behavior, fear responses and aggressive behavior by elevating the corticolimbic levels of allopregnanolone and BDNF mRNA expression. These actions appeared to be independent and more selective than the action of these drugs on serotonin reuptake inhibition. Hence, this review addresses the hypothesis that in PTSD or depressed patients, brain allopregnanolone levels, and BDNF expression upregulation may be mechanisms at least partially involved in the beneficial actions of antidepressants or other selective brain steroidogenic stimulant molecules.
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Affiliation(s)
- Mauricio Schüler Nin
- Department of Psychiatry, College of Medicine, Psychiatric Institute, University of Illinois at ChicagoChicago, IL, USA
- Coordenadoria de Aperfeicoamento de Pessoal de Nivel Superior Foundation, Ministry of Education of BrazilBrasilia, Brazil
| | - Luis A. Martinez
- Department of Psychiatry, College of Medicine, Psychiatric Institute, University of Illinois at ChicagoChicago, IL, USA
| | - Fabio Pibiri
- Department of Psychiatry, College of Medicine, Psychiatric Institute, University of Illinois at ChicagoChicago, IL, USA
| | - Marianela Nelson
- Department of Psychiatry, College of Medicine, Psychiatric Institute, University of Illinois at ChicagoChicago, IL, USA
| | - Graziano Pinna
- Department of Psychiatry, College of Medicine, Psychiatric Institute, University of Illinois at ChicagoChicago, IL, USA
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Morrens J, Van Den Broeck W, Kempermann G. Glial cells in adult neurogenesis. Glia 2011; 60:159-74. [PMID: 22076934 DOI: 10.1002/glia.21247] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 08/30/2011] [Indexed: 01/17/2023]
Abstract
Adult neurogenesis is an exceptional feature of the adult brain and in an intriguing way bridges between neuronal and glial neurobiology. Essentially, all classes of glial cells are directly or indirectly linked to this process. Cells with astrocytic features, for example, serve as radial glia-like stem cells in the two neurogenic regions of the adult brain, the hippocampal dentate gyrus and the subventricular zone of the lateral ventricles, producing new neurons, create a microenvironment permissive for neurogenesis, and are themselves generated alongside the new neurons in an associated but independently regulated process. Oligodendrocytes are generated from precursor cells intermingled with those generating neurons in an independent lineage. NG2 cells have certain precursor cell properties and are found throughout the brain parenchyma. They respond to extrinsic stimuli and injury but do not generate neurons even though they can express some preneuronal markers. Microglia have positive and negative regulatory effects as constituents of the "neurogenic niche". Ependymal cells play incompletely understood roles in adult neurogenesis, but under certain conditions might exert (back-up) precursor cell functions. Glial contributions to adult neurogenesis can be direct or indirect and are mediated by mechanisms ranging from gap-junctional to paracrine and endocrine. As the two neurogenic regions differ between each other and both from the non-neurogenic rest of the brain, the question arises in how far regionalization of both the glia-like precursor cells as well as of the glial cells determines site-specific "neurogenic permissiveness." In any case, however, "neurogenesis" appears to be an essentially glial achievement.
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Affiliation(s)
- Joachim Morrens
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Klempin F, Kronenberg G, Cheung G, Kettenmann H, Kempermann G. Properties of doublecortin-(DCX)-expressing cells in the piriform cortex compared to the neurogenic dentate gyrus of adult mice. PLoS One 2011; 6:e25760. [PMID: 22022443 PMCID: PMC3192736 DOI: 10.1371/journal.pone.0025760] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 09/11/2011] [Indexed: 12/12/2022] Open
Abstract
The piriform cortex receives input from the olfactory bulb and (via the entorhinal cortex) sends efferents to the hippocampus, thereby connecting the two canonical neurogenic regions of the adult rodent brain. Doublecortin (DCX) is a cytoskeleton-associated protein that is expressed transiently in the course of adult neurogenesis. Interestingly, the adult piriform cortex, which is usually considered non-neurogenic (even though some reports exist that state otherwise), also contains an abundant population of DCX-positive cells. We asked how similar these cells would be to DCX-positive cells in the course of adult hippocampal neurogenesis. Using BAC-generated transgenic mice that express GFP under the DCX promoter, we studied DCX-expression and electrophysiological properties of DCX-positive cells in the mouse piriform cortex in comparison with the dentate gyrus. While one class of cells in the piriform cortex indeed showed features similar to newly generated immature granule neurons, the majority of DCX cells in the piriform cortex was mature and revealed large Na+ currents and multiple action potentials. Furthermore, when proliferative activity was assessed, we found that all DCX-expressing cells in the piriform cortex were strictly postmitotic, suggesting that no DCX-positive “neuroblasts” exist here as they do in the dentate gyrus. We conclude that DCX in the piriform cortex marks a unique population of postmitotic neurons with a subpopulation that retains immature characteristics associated with synaptic plasticity. DCX is thus, per se, no marker of neurogenesis but might be associated more broadly with plasticity.
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Affiliation(s)
- Friederike Klempin
- ISCRM, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Golo Kronenberg
- Department of Neurology and Center for Stroke Research Berlin, Charité University Medicine Berlin, Berlin, Germany
| | - Giselle Cheung
- Max-Delbrück-Center for Molecular Medicine (MDC) Berlin-Buch, Berlin-Buch, Germany
- Center for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Helmut Kettenmann
- Max-Delbrück-Center for Molecular Medicine (MDC) Berlin-Buch, Berlin-Buch, Germany
| | - Gerd Kempermann
- CRTD –Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
- * E-mail:
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Hiramoto T, Kang G, Suzuki G, Satoh Y, Kucherlapati R, Watanabe Y, Hiroi N. Tbx1: identification of a 22q11.2 gene as a risk factor for autism spectrum disorder in a mouse model. Hum Mol Genet 2011; 20:4775-85. [PMID: 21908517 DOI: 10.1093/hmg/ddr404] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Although twin studies indicate clear genetic bases of autism spectrum disorder (ASD), the precise mechanisms through which genetic variations causally result in ASD are poorly understood. Individuals with 3 Mb and nested 1.5 Mb hemizygosity of the chromosome 22q11.2 represent genetically identifiable cases of ASD. However, because more than 30 genes are deleted even in the minimal deletion cases of 22q11.2 deficiency, the individual 22q11.2 gene(s) responsible for ASD remain elusive. Here, we examined the impact of constitutive heterozygosity of Tbx1, a 22q11.2 gene, on the behavioral phenotypes of ASD and characterized the regional and cellular expression of its mRNA and protein in mice. Congenic Tbx1 heterozygous (HT) mice were impaired in social interaction, ultrasonic vocalization, memory-based behavioral alternation, working memory and thigmotaxis, compared with wild-type (WT) mice. These phenotypes were not due to non-specific alterations in olfactory function, exploratory behavior, motor movement or anxiety-related behavior. Tbx1 mRNA and protein were ubiquitously expressed throughout the brains of C57BL/6J mice, but protein expression was enriched in regions that postnatally retain the capacity of neurogenesis, and in fact, postnatally proliferating cells expressed Tbx1. In postnatally derived hippocampal culture cells of C57BL/6J mice, Tbx1 levels were higher during proliferation than during differentiation, and expressed in neural progenitor cells, immature and matured neurons and glial cells. Taken together, our data suggest that Tbx1 is a gene responsible for the phenotypes of 22q11.2 hemizygosity-associated ASD possibly through its role in diverse cell types, including postnatally and prenatally generated neurons.
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Affiliation(s)
- Takeshi Hiramoto
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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