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Klotz L, Antel J, Kuhlmann T. Inflammation in multiple sclerosis: consequences for remyelination and disease progression. Nat Rev Neurol 2023; 19:305-320. [PMID: 37059811 DOI: 10.1038/s41582-023-00801-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2023] [Indexed: 04/16/2023]
Abstract
Despite the large number of immunomodulatory or immunosuppressive treatments available to treat relapsing-remitting multiple sclerosis (MS), treatment of the progressive phase of the disease has not yet been achieved. This lack of successful treatment approaches is caused by our poor understanding of the mechanisms driving disease progression. Emerging concepts suggest that a combination of persisting focal and diffuse inflammation within the CNS and a gradual failure of compensatory mechanisms, including remyelination, result in disease progression. Therefore, promotion of remyelination presents a promising intervention approach. However, despite our increasing knowledge regarding the cellular and molecular mechanisms regulating remyelination in animal models, therapeutic increases in remyelination remain an unmet need in MS, which suggests that mechanisms of remyelination and remyelination failure differ fundamentally between humans and demyelinating animal models. New and emerging technologies now allow us to investigate the cellular and molecular mechanisms underlying remyelination failure in human tissue samples in an unprecedented way. The aim of this Review is to summarize our current knowledge regarding mechanisms of remyelination and remyelination failure in MS and in animal models of the disease, identify open questions, challenge existing concepts, and discuss strategies to overcome the translational roadblock in the field of remyelination-promoting therapies.
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Affiliation(s)
- Luisa Klotz
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Jack Antel
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Tanja Kuhlmann
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Québec, Canada.
- Institute of Neuropathology, University Hospital Münster, Münster, Germany.
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2
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Osorio MJ, Mariani JN, Zou L, Schanz SJ, Heffernan K, Cornwell A, Goldman SA. Glial progenitor cells of the adult human white and grey matter are contextually distinct. Glia 2023; 71:524-540. [PMID: 36334067 PMCID: PMC10100527 DOI: 10.1002/glia.24291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 09/19/2022] [Accepted: 10/18/2022] [Indexed: 11/07/2022]
Abstract
Genomic analyses have revealed heterogeneity among glial progenitor cells (GPCs), but the compartment selectivity of human GPCs (hGPCs) is unclear. Here, we asked if GPCs of human grey and white brain matter are distinct in their architecture and associated gene expression. RNA profiling of NG2-defined hGPCs derived from adult human neocortex and white matter differed in their expression of genes involved in Wnt, NOTCH, BMP and TGFβ signaling, suggesting compartment-selective biases in fate and self-renewal. White matter hGPCs over-expressed the BMP antagonists BAMBI and CHRDL1, suggesting their tonic suppression of astrocytic fate relative to cortical hGPCs, whose relative enrichment of cytoskeletal genes presaged their greater morphological complexity. In human glial chimeric mice, cortical hGPCs assumed larger and more complex morphologies than white matter hGPCs, and both were more complex than their mouse counterparts. These findings suggest that human grey and white matter GPCs comprise context-specific pools with distinct functional biases.
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Affiliation(s)
- Maria Joana Osorio
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA.,Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - John N Mariani
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Lisa Zou
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Steven J Schanz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Kate Heffernan
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Adam Cornwell
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Steven A Goldman
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA.,Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
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3
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Clinical correlations of cerebrospinal fluid biomarkers including neuron-glia 2 and neurofilament light chain in patients with multiple system atrophy. Parkinsonism Relat Disord 2022; 102:30-35. [DOI: 10.1016/j.parkreldis.2022.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/14/2022] [Accepted: 07/14/2022] [Indexed: 11/19/2022]
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4
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Acute brain injuries trigger microglia as an additional source of the proteoglycan NG2. Acta Neuropathol Commun 2020; 8:146. [PMID: 32843103 PMCID: PMC7449013 DOI: 10.1186/s40478-020-01016-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/10/2020] [Indexed: 01/07/2023] Open
Abstract
NG2 is a type I transmembrane glycoprotein known as chondroitin sulfate proteoglycan 4 (CSPG4). In the healthy central nervous system, NG2 is exclusively expressed by oligodendrocyte progenitor cells and by vasculature pericytes. A large body of immunohistochemical studies showed that under pathological conditions such as acute brain injuries and experimental autoimmune encephalomyelitis (EAE), a number of activated microglia were NG2 immuno-positive, suggesting NG2 expression in these cells. Alternative explanations for the microglial NG2 labeling consider the biochemical properties of NG2 or the phagocytic activity of activated microglia. Reportedly, the transmembrane NG2 proteoglycan can be cleaved by a variety of proteases to deposit the NG2 ectodomain into the extracellular matrix. The ectodomain, however, could also stick to the microglial surface. Since microglia are phagocytic cells engulfing debris of dying cells, it is difficult to identify a genuine expression of NG2. Recent studies showing (1) pericytes giving rise to microglial after stroke, and (2) immune cells of NG2-EYFP knock-in mice lacking NG2 expression in an EAE model generated doubts for the de novo expression of NG2 in microglia after acute brain injuries. In the current study, we took advantage of three knock-in mouse lines (NG2-CreERT2, CX3CR1-EGFP and NG2-EYFP) to study NG2 expression indicated by transgenic fluorescent proteins in microglia after tMCAO (transient middle cerebral artery occlusion) or cortical stab wound injury (SWI). We provide strong evidence that NG2-expressing cells, including OPCs and pericytes, did not differentiate into microglia after acute brain injuries, whereas activated microglia did express NG2 in a disease-dependent manner. A subset of microglia continuously activated the NG2 gene at least within the first week after tMCAO, whereas within 3 days after SWI a limited number of microglia at the lesion site transiently expressed NG2. Immunohistochemical studies demonstrated that these microglia with NG2 gene activity also synthesized the NG2 protein, suggesting activated microglia as an additional source of the NG2 proteoglycan after acute brain injuries.
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Kaji S, Maki T, Ueda J, Ishimoto T, Inoue Y, Yasuda K, Sawamura M, Hikawa R, Ayaki T, Yamakado H, Takahashi R. BCAS1-positive immature oligodendrocytes are affected by the α-synuclein-induced pathology of multiple system atrophy. Acta Neuropathol Commun 2020; 8:120. [PMID: 32727582 PMCID: PMC7391509 DOI: 10.1186/s40478-020-00997-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023] Open
Abstract
Multiple system atrophy (MSA) is pathologically characterized by the presence of fibrillar α-synuclein-immunoreactive inclusions in oligodendrocytes. Although the myelinating process of oligodendrocytes can be observed in adult human brains, little is known regarding the presence of α-synuclein pathology in immature oligodendrocytes and how their maturation and myelination are affected in MSA brains. Recently, breast carcinoma amplified sequence 1 (BCAS1) has been found to be specifically expressed in immature oligodendrocytes undergoing maturation and myelination. Here, we analyzed the altered dynamics of oligodendroglial maturation in both MSA brains and primary oligodendroglial cell cultures which were incubated with α-synuclein pre-formed fibrils. The numbers of BCAS1-expressing oligodendrocytes that displayed a matured morphology negatively correlated with the density of pathological inclusions in MSA brains but not with that in Parkinson’s disease and diffuse Lewy body disease. In addition, a portion of the BCAS1-expressing oligodendrocyte population showed cytoplasmic inclusions, which were labeled with antibodies against phosphorylated α-synuclein and cleaved caspase-9. Further in vitro examination indicated that the α-synuclein pre-formed fibrils induced cytoplasmic inclusions in the majority of BCAS1-expressing oligodendrocytes. In contrast, the majority of BCAS1-non-expressing mature oligodendrocytes did not develop inclusions on day 4 after maturation induction. Furthermore, exposure of α-synuclein pre-formed fibrils in the BCAS1-positive phase caused a reduction in oligodendroglial cell viability. Our results indicated that oligodendroglial maturation and myelination are impaired in the BCAS1-positive phase of MSA brains, which may lead to the insufficient replacement of defective oligodendrocytes. In vitro, the high susceptibility of BCAS1-expressing primary oligodendrocytes to the extracellular α-synuclein pre-formed fibrils suggests the involvement of insufficient oligodendroglial maturation in MSA disease progression and support the hypothesis that the BCAS1-positive oligodendrocyte lineage cells are prone to take up aggregated α-synuclein in vivo.
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6
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Insights into the pathogenesis of multiple system atrophy: focus on glial cytoplasmic inclusions. Transl Neurodegener 2020; 9:7. [PMID: 32095235 PMCID: PMC7025408 DOI: 10.1186/s40035-020-0185-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 01/31/2020] [Indexed: 12/15/2022] Open
Abstract
Multiple system atrophy (MSA) is a debilitating and fatal neurodegenerative disorder. The disease severity warrants urgent development of disease-modifying therapy, but the disease pathogenesis is still enigmatic. Neurodegeneration in MSA brains is preceded by the emergence of glial cytoplasmic inclusions (GCIs), which are insoluble α-synuclein accumulations within oligodendrocytes (OLGs). Thus, preventive strategies against GCI formation may suppress disease progression. However, although numerous studies have tried to elucidate the molecular pathogenesis of GCI formation, difficulty remains in understanding the pathological interaction between the two pivotal aspects of GCIs; α-synuclein and OLGs. The difficulty originates from several enigmas: 1) what triggers the initial generation and possible propagation of pathogenic α-synuclein species? 2) what contributes to OLG-specific accumulation of α-synuclein, which is abundantly expressed in neurons but not in OLGs? and 3) how are OLGs and other glial cells affected and contribute to neurodegeneration? The primary pathogenesis of GCIs may involve myelin dysfunction and dyshomeostasis of the oligodendroglial cellular environment such as autophagy and iron metabolism. We have previously reported that oligodendrocyte precursor cells are more prone to develop intracellular inclusions in the presence of extracellular fibrillary α-synuclein. This finding implies a possibility that the propagation of GCI pathology in MSA brains is mediated through the internalization of pathological α-synuclein into oligodendrocyte precursor cells. In this review, in order to discuss the pathogenesis of GCIs, we will focus on the composition of neuronal and oligodendroglial inclusions in synucleinopathies. Furthermore, we will introduce some hypotheses on how α-synuclein pathology spreads among OLGs in MSA brains, in the light of our data from the experiments with primary oligodendrocyte lineage cell culture. While various reports have focused on the mysterious source of α-synuclein in GCIs, insights into the mechanism which regulates the uptake of pathological α-synuclein into oligodendroglial cells may yield the development of the disease-modifying therapy for MSA. The interaction between glial cells and α-synuclein is also highlighted with previous studies of post-mortem human brains, cultured cells, and animal models, which provide comprehensive insight into GCIs and the MSA pathomechanisms.
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Gilsoul M, Grisar T, Delgado-Escueta AV, de Nijs L, Lakaye B. Subtle Brain Developmental Abnormalities in the Pathogenesis of Juvenile Myoclonic Epilepsy. Front Cell Neurosci 2019; 13:433. [PMID: 31611775 PMCID: PMC6776584 DOI: 10.3389/fncel.2019.00433] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/09/2019] [Indexed: 12/17/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME), a lifelong disorder that starts during adolescence, is the most common of genetic generalized epilepsy syndromes. JME is characterized by awakening myoclonic jerks and myoclonic-tonic-clonic (m-t-c) grand mal convulsions. Unfortunately, one third of JME patients have drug refractory m-t-c convulsions and these recur in 70-80% who attempt to stop antiepileptic drugs (AEDs). Behavioral studies documented impulsivity, but also impairment of executive functions relying on organization and feedback, which points to prefrontal lobe dysfunction. Quantitative voxel-based morphometry (VBM) revealed abnormalities of gray matter (GM) volumes in cortical (frontal and parietal) and subcortical structures (thalamus, putamen, and hippocampus). Proton magnetic resonance spectroscopy (MRS) found evidence of dysfunction of thalamic neurons. White matter (WM) integrity was disrupted in corpus callosum and frontal WM tracts. Magnetic resonance imaging (MRI) further unveiled anomalies in both GM and WM structures that were already present at the time of seizure onset. Aberrant growth trajectories of brain development occurred during the first 2 years of JME diagnosis. Because of genetic origin, disease causing variants were sought, first by positional cloning, and most recently, by next generation sequencing. To date, only six genes harboring pathogenic variants (GABRA1, GABRD, EFHC1, BRD2, CASR, and ICK) with Mendelian and complex inheritance and covering a limited proportion of the world population, are considered as major susceptibility alleles for JME. Evidence on the cellular role, developmental and cell-type expression profiles of these six diverse JME genes, point to their pathogenic variants driving the first steps of brain development when cell division, expansion, axial, and tangential migration of progenitor cells (including interneuron cortical progenitors) sculpture subtle alterations in brain networks and microcircuits during development. These alterations may explain "microdysgenesis" neuropathology, impulsivity, executive dysfunctions, EEG polyspike waves, and awakening m-t-c convulsions observed in JME patients.
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Affiliation(s)
- Maxime Gilsoul
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Thierry Grisar
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Antonio V. Delgado-Escueta
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Epilepsy Genetics/Genomics Lab, Neurology and Research Services, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Laurence de Nijs
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- School for Mental Health and Neuroscience, Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, Netherlands
| | - Bernard Lakaye
- GIGA-Stem Cells, University of Liège, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Liège, Belgium
- GENESS International Consortium, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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Kirby L, Jin J, Cardona JG, Smith MD, Martin KA, Wang J, Strasburger H, Herbst L, Alexis M, Karnell J, Davidson T, Dutta R, Goverman J, Bergles D, Calabresi PA. Oligodendrocyte precursor cells present antigen and are cytotoxic targets in inflammatory demyelination. Nat Commun 2019; 10:3887. [PMID: 31467299 PMCID: PMC6715717 DOI: 10.1038/s41467-019-11638-3] [Citation(s) in RCA: 211] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 07/24/2019] [Indexed: 01/09/2023] Open
Abstract
Oligodendrocyte precursor cells (OPCs) are abundant in the adult central nervous system, and have the capacity to regenerate oligodendrocytes and myelin. However, in inflammatory diseases such as multiple sclerosis (MS) remyelination is often incomplete. To investigate how neuroinflammation influences OPCs, we perform in vivo fate-tracing in an inflammatory demyelinating mouse model. Here we report that OPC differentiation is inhibited by both effector T cells and IFNγ overexpression by astrocytes. IFNγ also reduces the absolute number of OPCs and alters remaining OPCs by inducing the immunoproteasome and MHC class I. In vitro, OPCs exposed to IFNγ cross-present antigen to cytotoxic CD8 T cells, resulting in OPC death. In human demyelinated MS brain lesions, but not normal appearing white matter, oligodendroglia exhibit enhanced expression of the immunoproteasome subunit PSMB8. Therefore, OPCs may be co-opted by the immune system in MS to perpetuate the autoimmune response, suggesting that inhibiting immune activation of OPCs may facilitate remyelination.
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Affiliation(s)
- Leslie Kirby
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jing Jin
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | - Matthew D Smith
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Kyle A Martin
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | - Hayley Strasburger
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Leyla Herbst
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Maya Alexis
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | | | | | - Ranjan Dutta
- Department of Neuroscience, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Joan Goverman
- Department of Immunology, University of Washington, Seattle, WA, USA
| | - Dwight Bergles
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Peter A Calabresi
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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Abstract
The study of brain plasticity has tended to focus on the synapse, where well-described activity-dependent mechanisms are known to play a key role in learning and memory. However, it is becoming increasingly clear that plasticity occurs beyond the synapse. This review focuses on the emerging concept of white matter plasticity. For example, there is growing evidence, both from animal studies and from human neuroimaging, that activity-dependent regulation of myelin may play a role in learning. This previously overlooked phenomenon may provide a complementary but powerful route through which experience shapes the brain.
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Peterson BS, Zargarian A, Peterson JB, Goh S, Sawardekar S, Williams SCR, Lythgoe DJ, Zelaya FO, Bansal R. Hyperperfusion of Frontal White and Subcortical Gray Matter in Autism Spectrum Disorder. Biol Psychiatry 2019; 85:584-595. [PMID: 30711191 PMCID: PMC6420395 DOI: 10.1016/j.biopsych.2018.11.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/21/2018] [Accepted: 11/27/2018] [Indexed: 01/09/2023]
Abstract
BACKGROUND Our aim was to assess resting cerebral blood flow (rCBF) in children and adults with autism spectrum disorder (ASD). METHODS We acquired pulsed arterial spin labeling magnetic resonance imaging data in 44 generally high-functioning participants with ASD simplex and 66 typically developing control subjects with comparable mean full-scale IQs. We compared rCBF values voxelwise across diagnostic groups and assessed correlations with symptom scores. We also assessed the moderating influences of participant age, sex, and IQ on our findings and the correlations of rCBF with N-acetylaspartate metabolite levels. RESULTS We detected significantly higher rCBF values throughout frontal white matter and subcortical gray matter in participants with ASD. rCBF correlated positively with socialization deficits in participants with ASD in regions where hyperperfusion was greatest. rCBF declined with increasing IQ in the typically developing group, a correlation that was absent in participants with ASD, whose rCBF values were elevated across all IQ levels. rCBF in the ASD group correlated inversely with N-acetylaspartate metabolite levels throughout the frontal white matter, with greater rCBF accompanying lower and increasingly abnormal N-acetylaspartate levels relative to those of typically developing control subjects. CONCLUSIONS These findings taken together suggest the presence of altered metabolism, likely of mitochondrial origin, and dysfunctional maintenance processes that support axonal functioning in ASD. These disturbances in turn likely reduce neural efficiency for cognitive and social functioning and trigger compensatory responses from supporting glial cells, which subsequently increase rCBF to affected white matter. These findings, if confirmed, suggest cellular and molecular targets for novel therapeutics that address axonal pathology and bolster glial compensatory responses in ASD.
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Affiliation(s)
- Bradley S Peterson
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, California; Keck School of Medicine, University of Southern California, Los Angeles, California.
| | - Ariana Zargarian
- Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Jarod B Peterson
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, California
| | | | - Siddhant Sawardekar
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, California
| | - Steven C R Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - David J Lythgoe
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Fernando O Zelaya
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Ravi Bansal
- Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, California; Keck School of Medicine, University of Southern California, Los Angeles, California
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12
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Sultan N, Amin LE, Zaher AR, Scheven BA, Grawish ME. Dental pulp stem cells: Novel cell-based and cell-free therapy for peripheral nerve repair. World J Stomatol 2019; 7:1-19. [DOI: 10.5321/wjs.v7.i1.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/15/2018] [Accepted: 01/08/2019] [Indexed: 02/06/2023] Open
Abstract
The regeneration of peripheral nerves comprises complicated steps involving a set of cellular and molecular events in distal nerve stumps with axonal sprouting and remyelination. Stem cell isolation and expansion for peripheral nerve repair (PNR) can be achieved using a wide diversity of prenatal and adult tissues, such as bone marrow or brain tissues. The ability to obtain stem cells for cell-based therapy (CBT) is limited due to donor site morbidity and the invasive nature of the harvesting process. Dental pulp stem cells (DPSCs) can be relatively and simply isolated from the dental pulps of permanent teeth, extracted for surgical or orthodontic reasons. DPSCs are of neural crest origin with an outstanding ability to differentiate into multiple cell lineages. They have better potential to differentiate into neural and glial cells than other stem cell sources through the expression and secretion of certain markers and a range of neurotropic factors; thus, they should be considered a good choice for PNR using CBT. In addition, these cells have paracrine effects through the secretion of neurotrophic growth factors and extracellular vesicles, which can enhance axonal growth and remyelination by decreasing the number of dying cells and activating local inhabitant stem cell populations, thereby revitalizing dormant or blocked cells, modulating the immune system and regulating inflammatory responses. The use of DPSC-derived secretomes holds great promise for controllable and manageable therapy for peripheral nerve injury. In this review, up-to-date information about the neurotrophic and neurogenic properties of DPSCs and their secretomes is provided.
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Affiliation(s)
- Nessma Sultan
- Department of Oral Biology, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt
| | - Laila E Amin
- Department of Oral Biology, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt
| | - Ahmed R Zaher
- Department of Oral Biology, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt
| | - Ben A Scheven
- School of Dentistry, Oral Biology, College of Medical and Dental Sciences, University of Birmingham, Birmingham B5 7EG, United Kingdom
| | - Mohammed E Grawish
- Department of Oral Biology, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt
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13
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Srivastava RK, Bulte JWM, Walczak P, Janowski M. Migratory potential of transplanted glial progenitors as critical factor for successful translation of glia replacement therapy: The gap between mice and men. Glia 2017; 66:907-919. [PMID: 29266673 DOI: 10.1002/glia.23275] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 11/13/2017] [Accepted: 11/16/2017] [Indexed: 01/09/2023]
Abstract
Neurological disorders are a major threat to public health. Stem cell-based regenerative medicine is now a promising experimental paradigm for its treatment, as shown in pre-clinical animal studies. Initial attempts have been on the replacement of neuronal cells only, but glial progenitors (GPs) are now becoming strong alternative cellular therapeutic candidates to replace oligodendrocytes and astrocytes as knowledge accumulates about their important emerging role in various disease processes. There are many examples of successful therapeutic outcomes for transplanted GPs in small animal models, but clinical translation has proved to be challenging due to the 1,000-fold larger volume of the human brain compared to mice. Human GPs transplanted into the mouse brain migrate extensively and can induce global cell replacement, but a similar extent of migration in the human brain would only allow for local rather than global cell replacement. We review here the mechanisms that govern cell migration, which could potentially be exploited to enhance the migratory properties of GPs through cell engineering pre-transplantation. We furthermore discuss the (dis)advantages of the various cell delivery routes that are available, with particular emphasis on intra-arterial injection as the most suitable route for achieving global cell distribution in the larger brain. Now that therapeutic success has proven to be feasible in small animal models, future efforts will need to be directed to enhance global cell delivery and migration to make bench-to-bedside translation a reality.
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Affiliation(s)
- Rohit K Srivastava
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jeff W M Bulte
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Chemical & Biomolecular Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland.,Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Piotr Walczak
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Neurology and Neurosurgery, Faculty of Medical Sciences, University of Warmia and Mazury, Olsztyn, Poland
| | - Miroslaw Janowski
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of NeuroRepair, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
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14
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Li P, Li HX, Jiang HY, Zhu L, Wu HY, Li JT, Lai JH. Expression of NG2 and platelet-derived growth factor receptor alpha in the developing neonatal rat brain. Neural Regen Res 2017; 12:1843-1852. [PMID: 29239330 PMCID: PMC5745838 DOI: 10.4103/1673-5374.219045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Platelet-derived growth factor receptor alpha (PDGFRα) is a marker of oligodendrocyte precursor cells in the central nervous system. NG2 is also considered a marker of oligodendrocyte precursor cells. However, whether there are differences in the distribution and morphology of oligodendrocyte precursor cells labeled by NG2 or PDGFRα in the developing neonatal rat brain remains unclear. In this study, by immunohistochemical staining, NG2 positive (NG2+) cells were ubiquitous in the molecular layer, external pyramidal layer, internal pyramidal layer, and polymorphic layer of the cerebral cortex, and corpus callosum, external capsule, piriform cortex, and medial septal nucleus. NG2+ cells were stellate or fusiform in shape with long processes that were progressively decreased and shortened over the course of brain development. The distribution and morphology of PDGFRα positive (PDGFRα+) cells were coincident with NG2+ cells. The colocalization of NG2 and PDGFRα in the cell bodies and processes of some cells was confirmed by double immunofluorescence labeling. Moreover, cells double-labeled for NG2 and PDGFRα were predominantly in the early postnatal stage of development. The numbers of NG2+/PDGFRα+ cells and PDGFRα+ cells decreased, but the number of NG2+ cells increased from postnatal days 3 to 14 in the developing brain. In addition, amoeboid microglial cells of the corpus callosum, newborn brain macrophages in the normal developing brain, did not express NG2 or PDGFRα, but NG2 expression was detected in amoeboid microglia after hypoxia. The present results suggest that NG2 and PDGFRα are specific markers of oligodendrocyte precursor cells at different stages during early development. Additionally, the NG2 protein is involved in inflammatory and pathological processes of amoeboid microglial cells.
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Affiliation(s)
- Ping Li
- College of Forensic Science, Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi Province; Department of Anatomy and Histology & Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, Kunming, Yunnan Province, China
| | - Heng-Xi Li
- Department of Anatomy and Histology & Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, Kunming, Yunnan Province, China
| | - Hong-Yan Jiang
- Department of Anatomy and Histology & Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, Kunming, Yunnan Province, China
| | - Lie Zhu
- Department of Plastic Surgery, Changzheng Hospital, Shanghai, China
| | - Hai-Ying Wu
- Department of Emergency and Intensive Care Unit, First Affiliated Hospital, Kunming Medical University, Kunming, Yunnan Province, China
| | - Jin-Tao Li
- Neuroscience Institute, Faculty of Basic Medical Sciences, Kunming Medical University, Kunming, Yunnan Province, China
| | - Jiang-Hua Lai
- College of Forensic Science, Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
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Transgenic rat model of Huntington's disease: a histopathological study and correlations with neurodegenerative process in the brain of HD patients. BIOMED RESEARCH INTERNATIONAL 2014; 2014:291531. [PMID: 25162006 PMCID: PMC4137602 DOI: 10.1155/2014/291531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 06/26/2014] [Accepted: 06/26/2014] [Indexed: 01/09/2023]
Abstract
Rats transgenic for Huntington's disease (tgHD51 CAG rats), surviving up to two years, represent an animal model of HD similar to the late-onset form of human disease. This enables us to follow histopathological changes in course of neurodegenerative process (NDP) within the striatum and compare them with postmortem samples of human HD brains. A basic difference between HD pathology in human and tgHD51 rats is in the rate of NDP progression that originates primarily from slow neuronal degeneration consequently resulting in lesser extent of concomitant reactive gliosis in the brain of tgHD51 rats. Although larger amount of striatal neurons displays only gradual decrease in their size, their number is significantly reduced in the oldest tgHD51 rats. Our quantitative analysis proved that the end of the first year represents the turn in the development of morphological changes related to the progression of NDP in tgHD51 rats. Our data also support the view that all types of CNS glial cells play an important, irreplaceable role in NDP. To the best of our knowledge, our findings are the first to document that tgHD51 CAG rats can be used as a valid animal model for detailed histopathological studies related to HD in human.
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Distribution and phenotype of TrkB oligodendrocyte lineage cells in the adult rat spinal cord. Brain Res 2014; 1582:21-33. [PMID: 25072185 DOI: 10.1016/j.brainres.2014.07.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 07/18/2014] [Accepted: 07/21/2014] [Indexed: 12/12/2022]
Abstract
The distribution and phenotype of a previously undescribed population of nonneuronal cells in the intact spinal cord that expresses TrkB, the cognate receptor for brain derived neurotrophic factor (BDNF) and neurotrophin 4 (NT-4), were characterized by examining the extent of co-localization of TrkB with NG2, which identifies oligodendrocyte progenitors (OPCs) or CC1, a marker for mature oligodendrocytes (OLs). All TrkB nonneuronal cells expressed Olig2, confirming their role in the OL lineage. Similar to OPCs and OLs, TrkB cells resided in gray and white matter of the spinal cord in similar abundance. Less than 2% of TrkB cells expressed NG2, while over 80% of TrkB cells in the adult spinal cord co-expressed CC1. Most OPCs did not express detectable levels of TrkB, however a small OPC pool (~5%) showed TrkB immunoreactivity. The majority of mature OLs (~65%) expressed TrkB, but a population of mature OLs (~36%) did not express TrkB at detectable levels, and 17% of TrkB nonneuronal cells did not express NG2 or CC1. Approximately 20% of the TrkB nonneuronal population in the ventral horn resided in close proximity to motor neurons and were categorized as perineuronal. We conclude that TrkB is expressed by several pools of OL lineage cells in the adult spinal cord. These findings are important in understanding the neurotrophin regulation of OL lineage cells in the adult spinal cord.
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Oligodendrocyte loss during the disease course in a canine model of the lysosomal storage disease fucosidosis. J Neuropathol Exp Neurol 2014; 73:536-47. [PMID: 24806306 DOI: 10.1097/nen.0000000000000075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hypomyelination is a poorly understood feature of many neurodegenerative lysosomal storage diseases, including fucosidosis in children and animals. To gain insight into hypomyelination in fucosidosis, we investigated lysosomal storage, oligodendrocyte death, and axonal and neuron loss in CNS tissues of fucosidosis-affected dogs aged 3 weeks to 42 months using immunohistochemistry, electron microscopy, and gene expression assays. Vacuole accumulation in fucosidosis oligodendrocytes commenced by 5 weeks of age; all oligodendrocytes were affected by 16 weeks. Despite progressive vacuolation, mature oligodendrocyte loss by apoptosis (caspase-6 positive) in the corpus callosum and cerebellar white matter stabilized by 16 weeks, with no further subsequent loss. Axonal neurofilament loss progressed only in late disease, suggesting that disturbed axon-oligodendrocyte interactions are unlikely to be the primary cause of hypomyelination. A 67% decline in the number of Purkinje cell layer oligodendrocytes coincided with a 67% increase in the number of caspase-6-positive Purkinje cells at 16 weeks, suggesting that early oligodendrocyte loss contributes to Purkinje cell apoptosis. Fucosidosis hypomyelination appeared to follow normal spatiotemporal patterns of myelination, with greater loss of oligodendrocytes and larger downregulation of CNP, MAL, and PLP1 genes at 16 weeks in the cerebellum versus the frontal cortex. These studies suggest that survival of oligodendrocytes in fucosidosis is limited during active myelination, although the mechanisms remain unknown.
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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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Medina-Rodríguez EM, Arenzana FJ, Bribián A, de Castro F. Protocol to isolate a large amount of functional oligodendrocyte precursor cells from the cerebral cortex of adult mice and humans. PLoS One 2013; 8:e81620. [PMID: 24303061 PMCID: PMC3841116 DOI: 10.1371/journal.pone.0081620] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 10/24/2013] [Indexed: 01/09/2023] Open
Abstract
During development, oligodendrocytes are generated from oligodendrocyte precursor cells (OPCs), a cell type that is a significant proportion of the total cells (3-8%) in the adult central nervous system (CNS) of both rodents and humans. Adult OPCs are responsible for the spontaneous remyelination that occurs in demyelinating diseases like Multiple Sclerosis (MS) and they constitute an interesting source of cells for regenerative therapy in such conditions. However, there is little data regarding the neurobiology of adult OPCs isolated from mice since an efficient method to isolate them has yet to be established. We have designed a protocol to obtain viable adult OPCs from the cerebral cortex of different mouse strains and we have compared its efficiency with other well-known methods. In addition, we show that this protocol is also useful to isolate functional OPCs from human brain biopsies. Using this method we can isolate primary cortical OPCs in sufficient quantities so as to be able to study their survival, maturation and function, and to facilitate an evaluation of their utility in myelin repair.
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Affiliation(s)
| | | | - Ana Bribián
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Toledo, Spain
| | - Fernando de Castro
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Toledo, Spain
- * E-mail:
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20
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Abstract
Oligodendrocytes are the myelin-forming cells of the CNS. They differentiate from oligodendrocyte precursor cells (OPCs) that are produced from progenitors throughout life but more actively during the neonatal period and in response to demyelinating insults. An accurate regulation of oligodendrogenesis is required to generate oligodendrocytes during these developmental or repair processes. We hypothesized that this regulation implicates transcription factors, which are expressed by OPCs and/or their progenitors. Ascl1/Mash1 is a proneural transcription factor previously implicated in embryonic oligodendrogenesis and operating in genetic interaction with Olig2, an essential transcriptional regulator in oligodendrocyte development. Herein, we have investigated the contribution of Ascl1 to oligodendrocyte development and remyelination in the postnatal cortex. During the neonatal period, Ascl1 expression was detected in progenitors of the cortical subventricular zone and in cortical OPCs. Different genetic approaches to delete Ascl1 in cortical progenitors or OPCs reduced neonatal oligodendrogenesis, showing that Ascl1 positively regulated both OPC specification from subventricular zone progenitors as well as the balance between OPC differentiation and proliferation. Examination of remyelination processes, both in the mouse model for focal demyelination of the corpus callosum and in multiple sclerosis lesions in humans, indicated that Ascl1 activity was upregulated along with increased oligodendrogenesis observed in remyelinating lesions. Additional genetic evidence indicated that remyelinating oligodendrocytes derived from Ascl1(+) progenitors/OPCs and that Ascl1 was required for proper remyelination. Together, our results show that Ascl1 function modulates multiple steps of OPC development in the postnatal brain and in response to demyelinating insults.
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21
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Nielsen HM, Ek D, Avdic U, Orbjörn C, Hansson O, Veerhuis R, Rozemuller AJM, Brun A, Minthon L, Wennström M. NG2 cells, a new trail for Alzheimer's disease mechanisms? Acta Neuropathol Commun 2013; 1:7. [PMID: 24252600 PMCID: PMC4046664 DOI: 10.1186/2051-5960-1-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 02/28/2013] [Indexed: 02/07/2023] Open
Abstract
Background Neuron Glial 2 (NG2) cells are glial cells known to serve as oligodendrocyte progenitors as well as modulators of the neuronal network. Altered NG2 cell morphology and up-regulation as well as increased shedding of the proteoglycan NG2 expressed on the cell surface have been described in rodent models of brain injury. Here we describe alterations in the human NG2 cell population in response to pathological changes characteristic of Alzheimer’s disease (AD). Results Immunohistological stainings of postmortem brain specimens from clinically diagnosed and postmortem verified AD patients and non-demented controls revealed reduced NG2 immunoreactivity as well as large numbers of NG2 positive astrocytes in individuals with high amyloid beta plaque load. Since fibrillar amyloid beta (Aβ)1-42 is the major component of AD-related senile plaques, we exposed human NG2 cells to oligomer- and fibril enriched preparations of Aβ1-42. We found that both oligomeric and fibrillar Aβ1-42 induced changes in NG2 cell morphology. Further, in vitro exposure to fibrillar Aβ1-42 decreased the NG2 concentrations in both cell lysates and supernatants. Interestingly, we also found significantly decreased levels of soluble NG2 in the cerebrospinal fluid (CSF) from clinically diagnosed AD patients compared to non-demented individuals. Additionally, the CSF NG2 levels were found to significantly correlate with the core AD biomarkers Aß1-42, T-tau and P-tau. Conclusion Our results demonstrate major alterations in the NG2 cell population in relation to AD pathology which highlights the NG2 cell population as a new attractive research target in the search for cellular mechanisms associated with AD pathogenesis. Electronic supplementary material The online version of this article (doi:10.1186/2051-5960-1-7) contains supplementary material, which is available to authorized users.
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22
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Myelin repair and functional recovery mediated by neural cell transplantation in a mouse model of multiple sclerosis. Neurosci Bull 2013; 29:239-50. [PMID: 23471865 DOI: 10.1007/s12264-013-1312-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 01/25/2013] [Indexed: 01/09/2023] Open
Abstract
Cellular therapies are becoming a major focus for the treatment of demyelinating diseases such as multiple sclerosis (MS), therefore it is important to identify the most effective cell types that promote myelin repair. Several components contribute to the relative benefits of specific cell types including the overall efficacy of the cell therapy, the reproducibility of treatment, the mechanisms of action of distinct cell types and the ease of isolation and generation of therapeutic populations. A range of distinct cell populations promote functional recovery in animal models of MS including neural stem cells and mesenchymal stem cells derived from different tissues. Each of these cell populations has advantages and disadvantages and likely works through distinct mechanisms. The relevance of such mechanisms to myelin repair in the adult central nervous system is unclear since the therapeutic cells are generally derived from developing animals. Here we describe the isolation and characterization of a population of neural cells from the adult spinal cord that are characterized by the expression of the cell surface glycoprotein NG2. In functional studies, injection of adult NG2(+) cells into mice with ongoing MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) enhanced remyelination in the CNS while the number of CD3(+) T cells in areas of spinal cord demyelination was reduced approximately three-fold. In vivo studies indicated that in EAE, NG2(+) cells stimulated endogenous repair while in vitro they responded to signals in areas of induced inflammation by differentiating into oligodendrocytes. These results suggested that adult NG2(+) cells represent a useful cell population for promoting neural repair in a variety of different conditions including demyelinating diseases such as MS.
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23
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Ahmed Z, Asi YT, Lees AJ, Revesz T, Holton JL. Identification and quantification of oligodendrocyte precursor cells in multiple system atrophy, progressive supranuclear palsy and Parkinson's disease. Brain Pathol 2012; 23:263-73. [PMID: 22994884 DOI: 10.1111/j.1750-3639.2012.00637.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 09/07/2012] [Indexed: 12/20/2022] Open
Abstract
Multiple system atrophy is a neurodegenerative disorder characterized pathologically by abnormal accumulations of α-synuclein in the cytoplasm of oligodendrocytes, which are termed glial cytoplasmic inclusions (GCIs). Oligodendrocytes are responsible for myelinating axons and providing neurotrophic support, but in MSA, myelin loss, axonal loss and gliosis are consistent features suggesting that GCIs play a central role in disease pathogenesis. Oligodendroglial, myelin and axonal degeneration are also features of multiple sclerosis (MS) in which recent studies have highlighted the robust remyelination capacity of the central nervous system (CNS). The cells responsible for remyelination are called oligodendroglial precursor cells (OPCs). In this study, we investigated the role of OPCs in the pathogenesis of MSA and progressive supranuclear palsy (PSP), a neurodegenerative disease in which neuropathological changes include oligodendroglial inclusions composed of microtubule-associated protein tau. Despite the lability of OPC-specific antigens, we successfully identified OPCs and demonstrated that tau and α-synuclein do not accumulate in OPCs. We also showed that the density of OPCs was increased in a white matter region of the MSA brain, which is also severely affected by GCIs and myelin degeneration. These findings raise the possibility that OPCs could be available to repair disease-associated damage in MSA, consistent with their biological function.
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Affiliation(s)
- Zeshan Ahmed
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
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24
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Chang A, Staugaitis SM, Dutta R, Batt CE, Easley KE, Chomyk AM, Yong VW, Fox RJ, Kidd GJ, Trapp BD. Cortical remyelination: a new target for repair therapies in multiple sclerosis. Ann Neurol 2012; 72:918-26. [PMID: 23076662 DOI: 10.1002/ana.23693] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 06/15/2012] [Accepted: 06/26/2012] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Generation and differentiation of new oligodendrocytes in demyelinated white matter is the best described repair process in the adult human brain. However, remyelinating capacity falters with age in patients with multiple sclerosis (MS). Because demyelination of cerebral cortex is extensive in brains from MS patients, we investigated the capacity of cortical lesions to remyelinate and directly compared the extent of remyelination in lesions that involve cerebral cortex and adjacent subcortical white matter. METHODS Postmortem brain tissue from 22 patients with MS (age 27-77 years) and 6 subjects without brain disease were analyzed. Regions of cerebral cortex with reduced myelin were examined for remyelination, oligodendrocyte progenitor cells, reactive astrocytes, and molecules that inhibit remyelination. RESULTS New oligodendrocytes that were actively forming myelin sheaths were identified in 30 of 42 remyelinated subpial cortical lesions, including lesions from 3 patients in their 70s. Oligodendrocyte progenitor cells were not decreased in demyelinated or remyelinated cortices when compared to adjacent normal-appearing cortex or controls. In demyelinated lesions involving cortex and adjacent white matter, the cortex showed greater remyelination, more actively remyelinating oligodendrocytes, and fewer reactive astrocytes. Astrocytes in the white matter, but not in cortical portions of these lesions, significantly upregulate CD44, hyaluronan, and versican, molecules that form complexes that inhibit oligodendrocyte maturation and remyelination. INTERPRETATION Endogenous remyelination of the cerebral cortex occurs in individuals with MS regardless of disease duration or chronological age of the patient. Cortical remyelination should be considered as a primary outcome measure in future clinical trials testing remyelination therapies.
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Affiliation(s)
- Ansi Chang
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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25
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Xu JP, Zhao J, Li S. Roles of NG2 glial cells in diseases of the central nervous system. Neurosci Bull 2012; 27:413-21. [PMID: 22108818 DOI: 10.1007/s12264-011-1838-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
NG2 cells are a novel distinct class of central nervous system (CNS) glial cells, characterized by the expression of the chondroitin sulfate proteoglycan NG2. They have been detected in a variety of human CNS diseases. As morphological, physiological and biomolecular studies of NG2 cells have been conducted, their roles have been gradually revealed. Research on cellular and molecular mechanisms in the pathophysiological state was built on the preliminary findings of their physiological functions; and in turn, this helps to clarify their physiological roles and leads to the identification of novel therapeutic targets. This review summarizes recent findings regarding the potential roles of NG2 cells in traumatic brain injury, multiple sclerosis, glioma, epilepsy, Alzheimer's disease and electroconvulsive therapy for depression.
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Affiliation(s)
- Jian-Ping Xu
- Department of Physiology, Dalian Medical University, Dalian 116044, China
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26
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Choudhury ME, Sugimoto K, Kubo M, Nagai M, Nomoto M, Takahashi H, Yano H, Tanaka J. A cytokine mixture of GM-CSF and IL-3 that induces a neuroprotective phenotype of microglia leading to amelioration of (6-OHDA)-induced Parkinsonism of rats. Brain Behav 2011; 1:26-43. [PMID: 22398979 PMCID: PMC3217672 DOI: 10.1002/brb3.11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 06/02/2011] [Accepted: 06/16/2011] [Indexed: 01/09/2023] Open
Abstract
Dopamine (DA) agonists are widely used as primary treatments for Parkinson's disease. However, they do not prevent progressive degeneration of dopaminergic neurons, the central pathology of the disease. In this study, we found that subcutaneous injection of a cytokine mixture containing granulocyte macrophage colony-stimulating factor and interleukin-3 (IL-3) markedly suppressed dopaminergic neurodegeneration in 6-hydroxydopamine-lesioned rats, an animal model of Parkinson's disease. The cytokine mixture suppressed the decrease of DA content in the striatum, and ameliorated motor function in the lesioned rats. In response to the cytokine injection, dopaminergic neurons in the substantia nigra pars compacta increased expression of the antiapoptotic protein Bcl-xL. Microglial activation in the pars compacta was evident in both the saline- and cytokine-injected rats. However, the cytokine mixture suppressed expression of the proinflammatory cytokines IL-1β and tumor necrosis factors α, and upregulated the neuroprotective factors insulin-like growth factor-1 and hepatocyte growth factor. Similar responses were observed in cultured microglia. Detailed morphometric analyses revealed that NG2 proteoglycan-expressing glial cells increased in the cytokine-injected rats, while astrocytic activation with increased expression of antioxidative factors was evident only in the saline-injected rats. Thus, the present findings show that the cytokine mixture was markedly effective in suppressing neurodegeneration. Its neuroprotective effects may be mediated by increased expression of Bcl-xL in dopaminergic neurons, and the activation of beneficial actions of microglia that promote neuronal survival. Furthermore, this cytokine mixture may have indirect actions on NG2 proteoglycan-expressing glia, whose role may be implicated in neuronal survival.
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Affiliation(s)
| | - Kana Sugimoto
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
- Department of Basic and Clinical Neuroscience, Ehime Proteo‐Medicine Research Center, Ehime University, Toon, Ehime, Japan
| | - Madoka Kubo
- Department of Therapeutic Medicine, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Masahiro Nagai
- Department of Therapeutic Medicine, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Masahiro Nomoto
- Department of Therapeutic Medicine, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
| | - Hisaaki Takahashi
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
- Department of Basic and Clinical Neuroscience, Ehime Proteo‐Medicine Research Center, Ehime University, Toon, Ehime, Japan
| | - Hajime Yano
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
- Department of Basic and Clinical Neuroscience, Ehime Proteo‐Medicine Research Center, Ehime University, Toon, Ehime, Japan
| | - Junya Tanaka
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan
- Department of Basic and Clinical Neuroscience, Ehime Proteo‐Medicine Research Center, Ehime University, Toon, Ehime, Japan
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27
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Platelet-derived growth factor receptor (PDGFR) expression in primary spinal cord gliomas. J Neurooncol 2011; 106:235-42. [PMID: 21789698 DOI: 10.1007/s11060-011-0666-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 07/06/2011] [Indexed: 02/06/2023]
Abstract
Abnormal signaling through the platelet-derived growth factor receptor (PDGFR) has been proposed as a possible mechanism of spinal cord glioma initiation and progression. However, the extent of PDGFR expression in human spinal cord gliomas remains unknown. In this study we perform immunohistochemical analysis of PDGFRα expression in a series of 33 primary intramedullary spinal cord gliomas of different types and grades. PDGFRα was seen to be expressed in a significant subset of these tumors across all major glioma types including ependymoma, oligodendroglioma, pilocytic astrocytoma, astrocytoma, and glioblastoma. These results support the hypothesis that growth factor signaling through the PDGFR may be important for the development of at least a subset of human spinal cord gliomas. Further studies investigating the prognostic significance of PDGFR expression as well as the role of PDGF signaling on the development of intramedullary spinal cord gliomas are warranted.
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28
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Cerebral cortex demyelination and oligodendrocyte precursor response to experimental autoimmune encephalomyelitis. Neurobiol Dis 2011; 43:678-89. [PMID: 21679768 DOI: 10.1016/j.nbd.2011.05.021] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 05/06/2011] [Accepted: 05/28/2011] [Indexed: 11/20/2022] Open
Abstract
Experimentally induced autoimmune encephalomyelitis (EAE) in mice provides an animal model that shares many features with human demyelinating diseases such as multiple sclerosis (MS). To what extent the cerebral cortex is affected by the process of demyelination and how the corollary response of the oligodendrocyte lineage is explicated are still not completely known aspects of EAE. By performing a detailed in situ analysis of expression of myelin and oligodendrocyte markers we have identified areas of subpial demyelination in the cerebral cortex of animals with conventionally induced EAE conditions. On EAE-affected cerebral cortices, the distribution and relative abundance of cells of the oligodendrocyte lineage were assessed and compared with control mouse brains. The analysis demonstrated that A2B5(+) glial restricted progenitors (GRPs) and NG2(+)/PDGFR-α(+) oligodendrocyte precursor cells (OPCs) were increased in number during "early" disease, 20 days post MOG immunization, whereas in the "late" disease, 39 days post-immunization, they were strongly diminished, and there was an accompanying reduction in NG2(+)/O4(+) pre-oligodendrocytes and GST-π mature oligodendrocytes. These results, together with the observed steady-state amount of NG2(-)/O4(+) pre-myelinating oligodendrocytes, suggested that oligodendroglial precursors attempted to compensate for the progressive loss of myelin, although these cells appeared to fail to complete the last step of their differentiation program. Our findings confirm that this chronic model of EAE reproduces the features of neocortex pathology in progressive MS and suggest that, despite the proliferative response of the oligodendroglial precursors, the failure to accomplish final differentiation may be a key contributing factor to the impaired remyelination that characterizes these demyelinating conditions.
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29
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Del Bigio MR. Cell proliferation in human ganglionic eminence and suppression after prematurity-associated haemorrhage. Brain 2011; 134:1344-61. [PMID: 21478186 DOI: 10.1093/brain/awr052] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In premature infants, germinal matrix haemorrhage in the brain is a common occurrence. However, cell proliferation and fate determination in the normal human germinal matrix is poorly understood. Human ganglionic eminence samples were collected prospectively from autopsies of premature and term infants with no evidence of pathological process (n=78; dying at post-menstrual age 14-88 weeks). The ganglionic eminence was thickest at 20-26 weeks and involuted by 34-36 weeks. Proliferating cells, detected by Ki67 immunoreactivity, were abundant throughout the ganglionic eminence prior to 18 weeks, after which a sharp boundary between the dorsal and ventral ganglionic eminence appeared with reduced cell proliferation in the dorsal region. Ki67 immunoreactivity persisted in the majority of ventral cells until ∼28 weeks, after which time the proportion of proliferating cells dropped quickly. The expression of cell lineage markers (such as Olig2, SOX2, platelet-derived growth factor receptor alpha) showed partitioning at the microscopic level. The hypothesis that germinal matrix haemorrhage suppresses cell proliferation was then addressed. In comparison to controls, germinal matrix haemorrhage (n=47; born at post-menstrual age 18-34 weeks followed by survival of 0 h to 98 days) was associated with significantly decreased cell proliferation if survival was >12 h. The cell cycle arrest transcription factor p53 was transiently increased and the oligodendroglial lineage markers Olig2 and platelet-derived growth factor receptor alpha were decreased. Cell death was negligible. A low level of microglial activation was detected. Haemorrhage-associated suppression of cell proliferation in premature human infants could partially explain the reduced brain size and clinical effects in children who suffer germinal matrix haemorrhage after premature birth.
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Affiliation(s)
- Marc R Del Bigio
- Department of Pathology, University of Manitoba, 401 Brodie Centre, 727 McDermot Avenue, Winnipeg MB, R3E 3P5, Canada.
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Abstract
The myelin sheath is an essential component of the vertebrate nervous system, and its disruption causes numerous diseases, including multiple sclerosis (MS), and neurodegeneration. Although we understand a great deal about the early development of the glial cells that make myelin (Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system), we know much less about the cellular and molecular mechanisms that regulate the later stages of differentiation that orchestrate myelin formation. Over the past decade, the zebrafish has been employed as a model with which to dissect the development of myelinated axons. Forward genetic screens have revealed new genes essential for myelination, as well as new roles for genes previously implicated in myelinated axon formation in other systems. High-resolution in vivo imaging in zebrafish has also begun to illuminate novel cell behaviors during myelinating glial cell development. Here we review the contribution of zebrafish research to our understanding of myelinated axon formation to date. We also describe and discuss many of the methodologies used in these studies and preview future endeavors that will ensure that the zebrafish remains at the cutting edge of this important area of research.
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Affiliation(s)
- Tim Czopka
- Centre for Neuroregeneration, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, UK
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Those enigmatic NG2 cells . . . . NEURON GLIA BIOLOGY 2010; 5:1. [PMID: 20422752 DOI: 10.1017/s1740925x09990445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Chordin-induced lineage plasticity of adult SVZ neuroblasts after demyelination. Nat Neurosci 2010; 13:541-550. [PMID: 20418875 DOI: 10.1038/nn.2536] [Citation(s) in RCA: 169] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 03/25/2010] [Indexed: 12/14/2022]
Abstract
The mechanisms that regulate the developmental potential of adult neural progenitor populations under physiological and pathological conditions remain poorly defined. Glutamic acid decarboxylase 65 (GAD65)- and Doublecortin (Dcx)-expressing cells constitute major progenitor populations in the adult mouse subventricular zone (SVZ). Under normal physiological conditions, SVZ-derived GAD65-positive and Dcx-positive cells expressed the transcription factor Pax6 and migrated along the rostral migratory stream to the olfactory bulb to generate interneurons. After lysolecithin-induced demyelination of corpus callosum, however, these cells altered their molecular and cellular properties and migratory path. Demyelination upregulated chordin in the SVZ, which redirected GAD65-positive and Dcx-positive progenitors from neuronal to glial fates, generating new oligodendrocytes in the corpus callosum. Our findings suggest that the lineage plasticity of SVZ progenitor cells could be a potential therapeutic strategy for diseased or injured brain.
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