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- Caddick, Jenny, et al.
(författare)
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Phenotypic and functional characteristics of mesenchymal stem cells differentiated along a Schwann cell lineage.
- 2006
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Ingår i: Glia. - : Wiley. - 0894-1491 .- 1098-1136. ; 54:8, s. 840-849
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the phenotypic and bioassay characteristics of bone marrow mesenchymal stromal cells (MSCs) differentiated along a Schwann cell lineage using glial growth factor. Expression of the Schwann cell markers S100, P75, and GFAP was determined by immunocytochemical staining and Western blotting. The levels of the stem cell markers Stro-1 and alkaline phosphatase and the neural progenitor marker nestin were also examined throughout the differentiation process. The phenotypic properties of cells differentiated at different passages were also compared. In addition to a phenotypic characterization, the functional ability of differentiated MSCs has been investigated employing a co-culture bioassay with dissociated primary sensory neurons. Following differentiation, MSCs underwent morphological changes similar to those of cultured Schwann cells and stained positively for all three Schwann cell markers. Quantitative Western blot analysis showed that the levels of S100 and P75 protein were significantly elevated upon differentiation. Differentiated MSCs were also found to enhance neurite outgrowth in co-culture with sensory neurons to a level equivalent or superior to that produced by Schwann cells. These findings support the assertion that MSCs can be differentiated into cells that are Schwann cell-like in terms of both phenotype and function.
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| 5. |
- Danilov, Alexandre, et al.
(författare)
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Ultrastructural and antigenic properties of neural stem cells and their progeny in adult rat subventricular zone.
- 2009
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Ingår i: GLIA. - : Wiley. - 1098-1136 .- 0894-1491. ; Aug 15, s. 136-152
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Tidskriftsartikel (refereegranskat)abstract
- Neural stem cells (NSCs) in the subventricular zone (SVZ) continuously generate olfactory bulb interneurons in the adult rodent brain. Based on their ultrastructural and antigenic properties, NSCs, transient amplifying precursor cells, and neuroblasts (B, C, and A cells, respectively) have been distinguished in mouse SVZ. Here, we aimed to identify these cell types in rat SVZ ultrastructurally and at the light microscopy level, and to determine the antigenic properties of each cell type using gold and fluorescence immunolabeling. We found astrocytes with single cilia (NSCs, correspond to B cells) and neuroblasts (A cells). We also observed mitotic cells, ependymal cells, displaced ependymal cells, and mature astrocytes. In contrast, transient amplifying precursor cells (C cells) were not detected. The NSCs and neuroblasts had epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor alpha (PDGFRalpha) expressed on the ciliary apparatus and were the only cell types incorporating the proliferation marker BrdU. Throughout mitosis, EGFR and PDGFRalpha were associated with the microtubule of the mitotic spindle. Ependymal and displaced ependymal cells also expressed EGFR and PDGFRalpha on their cilia but did not incorporate BrdU. Our findings indicate that the NSCs in adult rat SVZ give rise directly to neuroblasts. During mitosis, the NSCs disassemble the primary cilium and symmetrically distribute EGFR and PDGFRalpha among their progeny. (c) 2008 Wiley-Liss, Inc.
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- Gunnarson, Eli, et al.
(författare)
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Identification of a molecular target for glutamate regulation of astrocyte water permeability
- 2008
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Ingår i: Glia. - : Wiley. - 0894-1491 .- 1098-1136. ; 56:6, s. 587-596
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Tidskriftsartikel (refereegranskat)abstract
- Astrocytes play a key role for maintenance of brain water homeostasis, but little is known about mechanisms of short-term regulation of astrocyte water permeability. Here, we report that glutamate increases astrocyte water permeability and that the molecular target for this effect is the aquaporin-4 (AQP4) serine 111 residue, which is in a strategic position for control of the water channel gating. The glutamate effect involves activation of group I metabotropic glutamate receptors (mGluR), intracellular calcium release, and activation of calcium/calmodulin-dependent protein kinase II (CaMKII) and nitric oxide synthase (NOS). The physiological impact of our results is underlined by the finding that mGluR activation increases the rate of hypoosmotic tissue swelling in acute rat hippocampal slices. Cerebral ischemia is associated with an excessive release of glutamate, and in postischemic cerebral edema ablation of AQP4 attenuates the degree of damage. Thus, we have identified AQP4 as the molecular target for drugs that may attenuate the development of brain edema.
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| 9. |
- Hebsgaard, Josephine, et al.
(författare)
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Dopamine neuron precursors within the developing human mesencephalon show radial glial characteristics.
- 2009
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Ingår i: GLIA. - : Wiley. - 1098-1136 .- 0894-1491. ; 57, s. 1648-1659
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Tidskriftsartikel (refereegranskat)abstract
- Specification and differentiation of neural precursors into dopaminergic neurons within the ventral mesencephalon has been subject to much attention due to the implication of dopaminergic neurons in Parkinson's disease and the perspective of generating sources of therapeutically active cells to be used for cell replacement therapy for the disease. However, despite intensive research efforts, little is known about the characteristics of the dopamine neuron progenitors in human. We show that the dopamine neuron determinant LMX1a is expressed in the diencephalic and mesencephalic dopaminergic neuron domains during human development. Within the mesencephalon, LMX1a is expressed in the dopaminergic neurons and their progenitors located in the ventricular zone of the floor plate region. Furthermore, the neural progenitors in the developing human ventral mesencephalon have a radial morphology and express the radial glial markers Vimentin and BLBP. These radial glia are mitotic and act as precursors for the dopaminergic neurons. Finally, we show that progenitors isolated from the human ventral mesencephalon maintain their radial glial characteristics and neurogenic capacity after expansion in vitro, making them a promising future source of cells to be used in cell replacement therapy for Parkinson's disease. (c) 2009 Wiley-Liss, Inc.
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| 10. |
- Hede, Sanna-Maria, et al.
(författare)
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GFAP promoter driven transgenic expression of PDGFB in the mouse brain leads to glioblastoma in a Trp53 null background
- 2009
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Ingår i: Glia. - : Wiley. - 0894-1491 .- 1098-1136. ; 57:11, s. 1143-1153
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastomas are the most common and malignant astrocytic brain tumors in human adults. The tumor suppressor gene TP53 is commonly mutated and/or lost in astrocytic brain tumors and the TP53 alterations are often found in combination with excessive growth factor signaling via PDGF/PDGFRalpha. Here, we have generated transgenic mice over-expressing human PDGFB in brain, under control of the human GFAP promoter. These mice showed no phenotype, but on a Trp53 null background a majority of them developed brain tumors. This occurred at 2-6 months of age and tumors displayed human glioblastoma-like features with integrated development of Pdgfralpha+ tumor cells and Pdgfrbeta+/Nestin+ vasculature. The transgene was expressed in subependymal astrocytic cells, in glia limitans, and in astrocytes throughout the brain substance, and subsequently, microscopic tumor lesions were initiated equally in all these areas. With tumor size, there was an increase in Nestin positivity and variability in lineage markers. These results indicate an unexpected plasticity of all astrocytic cells in the adult brain, not only of SVZ cells. The results also indicate a contribution of widely distributed Pdgfralpha+ precursor cells in the tumorigenic process.
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- Nielsen, Henrietta, et al.
(författare)
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Binding and Uptake of A beta 1-42 by Primary Human Astrocytes In Vitro
- 2009
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Ingår i: GLIA. - : Wiley. - 1098-1136 .- 0894-1491. ; 57:9, s. 978-988
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Tidskriftsartikel (refereegranskat)abstract
- Clearance of the amyloid-P peptide (A beta) as a remedy for Alzheimer's disease (AD) is a major target in on-going clinical trials. In vitro studies confirmed that A beta is taken up by rodent astrocytes, but knowledge on human astrocyte-mediated A beta clearance is sparse. Therefore, by means of flow cytometry and confocal laser scanning microscopy (CLSM), we evaluated the binding and internalization of A beta 1-42 by primary human fetal astrocytes and adult astrocytes, isolated from nondemented subjects (n = 8) and AD subjects (n = 6). Furthermore, we analyzed whether alpha 1-antichymotrypsin (ACT), which is found in amyloid plaques and can influence A beta fibrillogenesis, affects the A beta uptake by human astrocytes. Upon over night exposure of astrocytes to FAM-labeled A beta 1-42 (10 mu M) preparations, (80.7 +/- 17.7)% fetal and (52.9 +/- 20.9)% adult A beta-positive astrocytes (P = 0.018) were observed. No significant difference was found in A beta 1-42 uptake between AD and non-AD astrocytes, and no influence of ApoE genotype on A beta 1-42 uptake was observed in any group. There was no difference in the percentage of A beta-positive cells upon exposure to A beta 1-42 (10 mu M) combined with ACT (1,000:1, 100:1, and 10:1 molar ratio), versus A beta 1-42 alone. CLSM revealed binding of A beta 1-42 to the cellular surfaces and cellular internalization of smaller A beta 1-42 fragments. Under these conditions, there was no increase in cellular release of the proinflammatory chemokine monocyte-chemoattractant protein 1, as compared with nontreated control astrocytes. Thus, primary human astrocytes derived from different sources can bind and internalize A beta 1-42, and fetal astrocytes were more efficient in A beta 1-42 uptake than adult astrocytes. (C) 2008 Wiley-Liss, Inc.
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| 16. |
- Pekny, Milos, 1965, et al.
(författare)
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Astrocyte activation and reactive gliosis.
- 2005
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Ingår i: Glia. - : Wiley. - 0894-1491 .- 1098-1136. ; 50:4, s. 427-34
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Tidskriftsartikel (refereegranskat)abstract
- Astrocytes become activated (reactive) in response to many CNS pathologies, such as stroke, trauma, growth of a tumor, or neurodegenerative disease. The process of astrocyte activation remains rather enigmatic and results in so-called "reactive gliosis," a reaction with specific structural and functional characteristics. In stroke or in CNS trauma, the lesion itself, the ischemic environment, disrupted blood-brain barrier, the inflammatory response, as well as in metabolic, excitotoxic, and in some cases oxidative crises--all affect the extent and quality of reactive gliosis. The fact that astrocytes function as a syncytium of interconnected cells both in health and in disease, rather than as individual cells, adds yet another dimension to this picture. This review focuses on several aspects of astrocyte activation and reactive gliosis and discusses its possible roles in the CNS trauma and ischemia. Particular emphasis is placed on the lessons learnt from mouse genetic models in which the absence of intermediate filament proteins in astrocytes leads to attenuation of reactive gliosis with distinct pathophysiological and clinical consequences.
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| 18. |
- Persson, Mikael, 1979, et al.
(författare)
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Microglial GLT-1 is upregulated in response to herpes simplex virus infection to provide an antiviral defence via glutathione.
- 2007
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Ingår i: Glia. - : Wiley. - 0894-1491 .- 1098-1136. ; 55:14, s. 1449-58
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus (HSV) can enter the central nervous system and cause encephalitis (HSV-1) or meningitis (HSV-2). Microglia, the immunocompetent cells of the central nervous system, are potentially able to detect viral infections. Microglia have been shown to express the glutamate transporter GLT-1 during pathological events, leading to increased microglial glutamate uptake and glutathione synthesis. This study aims to address the role of GLT-1 and glutathione, a major antioxidant with antiviral properties, during HSV infections. Using neuron-enriched mixed primary cultures from rat, it was found that microglia have higher resistance to HSV infections than neurons or astrocytes after 24 h incubation with HSV. Purified microglia in culture were used to further address this. It was found that microglia were able to detect HSV and responded by releasing tumor necrosis factor-alpha (TNF-alpha) and upregulating GLT-1 after 24 h incubation with 1 PFU/cell HSV-1 or HSV-2. Furthermore, the microglial glutathione levels were not significantly diminished after 24 h. Inhibition of the microglial glutathione synthesis with 200 microM buthionine sulfoximide (BSO) led to significantly more infected cells after 24 h incubation with 1 PFU/cell HSV-1 or HSV-2. These data indicate that the higher resistance in microglia against HSV infections may be due to the expression of GLT-1, which can maintain the glutathione levels and provide a mechanism for microglial self-defense against HSV.
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- Thored, Pär, et al.
(författare)
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Long-term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke
- 2009
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Ingår i: Glia. - Chichester, West Sussex : John Wiley & Sons. - 0894-1491 .- 1098-1136. ; 57:8, s. 835-849
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Tidskriftsartikel (refereegranskat)abstract
- Neural stem cells (NSCs) in the adult rat subventricular zone (SVZ) generate new striatal neurons during several months after ischemic stroke. Whether the microglial response associated with ischemic injury extends into SVZ and influences neuroblast production is unknown. Here, we demonstrate increased numbers of activated microglia in ipsilateral SVZ concomitant with neuroblast migration into the striatum at 2, 6, and 16 weeks, with maximum at 6 weeks, following 2 h middle cerebral artery occlusion in rats. In the peri-infarct striatum, numbers of activated microglia peaked already at 2 weeks and declined thereafter. Microglia in SVZ were resident or originated from bone marrow, with maximum proliferation during the first 2 weeks postinsult. In SVZ, microglia exhibited ramified or intermediate morphology, signifying a downregulated inflammatory profile, whereas amoeboid or round phagocytic microglia were frequent in the peri-infarct striatum. Numbers of microglia expressing markers of antigen-presenting cells (MHC-II, CD86) increased in SVZ but very few lymphocytes were detected. Using quantitative PCR, strong short- and long-term increase (at 1 and 6 weeks postinfarct) of insulin-like growth factor-1 (IGF-1) gene expression was detected in SVZ tissue. Elevated numbers of IGF-1-expressing microglia were found in SVZ at 2, 6, and 16 weeks after stroke. At 16 weeks, 5% of microglia but no other cells in SVZ expressed the IGF-1 protein, which mitigates apoptosis and promotes proliferation and differentiation of NSCs. The long-term accumulation of microglia with proneurogenic phenotype in the SVZ implies a supportive role of these cells for the continuous neurogenesis after stroke.
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| 24. |
- Levine, C
(författare)
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HISTORY OF THE SCHWANN CELL
- 2009
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Ingår i: GLIA. - 0894-1491. ; 57:13, s. S3-S3
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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