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- Aldskogius, Håkan, et al.
(författare)
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Microglia and Neuropathic Pain
- 2013
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Ingår i: CNS & Neurological Disorders. - : Wiley. - 1871-5273 .- 1996-3181. ; 12:6, s. 768-772
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Tidskriftsartikel (refereegranskat)abstract
- Neuropathic pain is a serious consequence of injury or disease in the nervous system itself. Current treatment options for this condition are often unsatisfactory. From being originally viewed as a diseased caused by neuronal dysfunction, a growing body of evidence implicate activated microglia as a key player in the development of this pain condition. In this review, some of the evidence for this proposal is briefly discussed and placed in a translational context, pointing out the difficulties in translating commonly used animal models of neuropathic pain to the clinical condition, as well as emphasizing the broader role of activated microglia in the injured or diseased nervous system.
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| 3. |
- Correa, Fernando, et al.
(författare)
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The Nrf2-inducible antioxidant defense in astrocytes can be both up- and down-regulated by activated microglia:Involvement of p38 MAPK.
- 2011
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Ingår i: Glia. - : Wiley. - 1098-1136 .- 0894-1491. ; 59:5, s. 785-99
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Tidskriftsartikel (refereegranskat)abstract
- The effects of microglia-conditioned medium (MCM) on the inducible Nrf2 system in astrocyte-rich cultures were investigated by determination of glutathione (GSH) levels, γglutamylcysteine ligase (γGCL) activity, the protein levels of Nrf2, Keap1, the modulatory subunit of γGCL (γGCL-M) and activated MAP kinases (ERK1/2, JNK and p38). Microglia were either cultured for 24 h in serum-free culture medium to achieve microglia-conditioned medium from non-activated cells (MCM(0) ), used as control condition, or activated with different concentrations (0.1-1,000 ng mL(-1) ) of lipopolysaccharide (LPS) to produce MCM(0.1-1,000) . Acute exposure (24 h) to MCM(100) increased GSH, γGCL activity, the protein levels of γGCL-M, Nrf2, and activated JNK and ERK1/2 in astrocyte-rich cultures. In contrast, treatment with MCM(10) for 24 h decreased components of the Nrf2 system in parallel with activation of p38 MAPK. Stimulation of the Nrf2 system by tBHQ was partly intact after 24 h but blocked after 72 h treatment with MCM(10) and MCM(100) . This down-regulation after 72 h correlated with activation of p38 MAPK and lack of ERK1/2 and JNK activation. The negative effects were partly reversed by an inhibitor of p38 which restored tBHQ mediated protection against oxidative stress. In conclusion, the study showed a negative effect of MCM(10) on the inducible anti-oxidant defense in astrocyte-rich cultures at both 24 and 72 h that correlated with activation of p38 and was partly reversed by a p38 inhibitor. A transient protective effect of MCM(100) on astrocyte-rich cultures against H(2)O(2) toxicity was observed at 24 h which coincided with activation of JNK and ERK1/2.
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| 9. |
- Pfenninger, Cosima, et al.
(författare)
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Prospectively isolated CD133/CD24-positive ependymal cells from the adult spinal cord and lateral ventricle wall differ in their long-term in vitro self-renewal and in vivo gene expression.
- 2011
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Ingår i: GLIA. - : Wiley. - 1098-1136 .- 0894-1491. ; 59:1, s. 68-81
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Tidskriftsartikel (refereegranskat)abstract
- In contrast to ependymal cells located above the subventricular zone (SVZ) of the adult lateral ventricle wall (LVW), adult spinal cord (SC) ependymal cells possess certain neural stem cell characteristics. The molecular basis of this difference is unknown. In this study, antibodies against multiple cell surface markers were applied to isolate pure populations of SC and LVW ependymal cells, which allowed a direct comparison of their in vitro behavior and in vivo gene expression profile. Isolated CD133(+)/CD24(+)/CD45(-)/CD34(-) ependymal cells from the SC displayed in vitro self-renewal and differentiation capacity, whereas those from the LVW did not. SC ependymal cells showed a higher expression of several genes involved in cell division, cell cycle regulation, and chromosome stability, which is consistent with a long-term self-renewal capacity, and shared certain transcripts with neural stem cells of the embryonic forebrain. They also expressed several retinoic acid (RA)-regulated genes and responded to RA exposure. LVW ependymal cells showed higher transcript levels of many genes regulated by transforming growth factor-β family members. Among them were Dlx2, Id2, Hey1, which together with Foxg1 could explain their potential to turn into neuroblasts under certain environmental conditions. © 2010 Wiley-Liss, Inc.
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| 10. |
- Potokar, Maja, et al.
(författare)
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Intermediate filaments attenuate stimulation-dependent mobility of endosomes/lysosomes in astrocytes.
- 2010
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Ingår i: Glia. - : Wiley. - 1098-1136 .- 0894-1491. ; 58:10, s. 1208-19
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Tidskriftsartikel (refereegranskat)abstract
- Intermediate filament (IF) proteins upregulation is a hallmark of astrocyte activation and reactive gliosis, but its pathophysiological implications remain incompletely understood. A recently reported association between IFs and directional mobility of peptidergic vesicles allows us to hypothesize that IFs affect vesicle dynamics and exocytosis-mediated astrocyte communication with neighboring cells. Here, we ask whether the trafficking of recycling vesicles (i.e., those fused to and then retrieved from the plasma membrane) and endosomes/lysosomes depends on IFs. Recycling vesicles were labeled by antibodies against vesicle glutamate transporter 1 (VGLUT1) and atrial natriuretic peptide (ANP), respectively, and by lysotracker, which labels endosomes/lysosomes. Quantitative fluorescence microscopy was used to monitor the mobility of labeled vesicles in astrocytes, derived from either wild-type (WT) mice or mice deficient in glial fibrillary acidic protein and vimentin (GFAP(-/-)Vim(-/-)), the latter lacking astrocyte IFs. Stimulation with ionomycin or ATP enhanced the mobility of VGLUT1-positive vesicles and reduced the mobility of ANP-positive vesicles in WT astrocytes. In GFAP(-/-)Vim(-/-) astrocytes, both vesicle types responded to stimulation, but the relative increase in mobility of VGLUT1-positive vesicles was more prominent compared with nonstimulated cells, whereas the stimulation-dependent attenuation of ANP-positive vesicles mobility was reduced compared with nonstimulated cells. The mobility of endosomes/lysosomes decreased following stimulation in WT astrocytes. However, in GFAP(-/-)Vim(-/-) astrocytes, a small increase in the mobility of endosomes/lysosomes was observed. These findings show that astrocyte IFs differentially affect the stimulation-dependent mobility of vesicles. We propose that upregulation of IFs in pathologic states may alter the function of astrocytes by deregulating vesicle trafficking.
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| 11. |
- Puschmann, Till B., et al.
(författare)
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Bioactive 3D cell culture system minimizes cellular stress and maintains the in vivo-like morphological complexity of astroglial cells
- 2013
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Ingår i: Glia. - : Wiley. - 0894-1491 .- 1098-1136. ; 61:3, s. 432-440
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Tidskriftsartikel (refereegranskat)abstract
- We tested the hypothesis that astrocytes grown in a suitable three-dimensional (3D) cell culture system exhibit morphological and biochemical features of in vivo astrocytes that are otherwise lost upon transfer from the in vivo to a two-dimensional (2D) culture environment. First, we report development of a novel bioactively coated nanofiber-based 3D culture system (Bioactive3D) that supports cultures of primary mouse astrocytes. Second, we show that Bioactive3D culture system maintains the in vivo-like morphological complexity of cultured cells, allows movement of astrocyte filopodia in a way that resembles the in vivo situation, and also minimizes the cellular stress, an inherent feature of standard 2D cell culture systems. Third, we demonstrate that the expression of gap junctions is reduced in astrocytes cultured in a 3D system that supports well-organized cell-cell communication, in contrast to the enforced planar tiling of cells in a standard 2D system. Finally, we show that astrocytes cultured in the Bioactive3D system do not show the undesired baseline activation but are fully responsive to activation-inducing stimuli. Thus, astrocytes cultured in the Bioactive3D appear to more closely resemble astrocytes in vivo and represent a superior in vitro system for assessing (patho)physiological and pharmacological responses of these cells and potentially also in co-cultures of astrocytes and other cell types.
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| 12. |
- Reyes, Juan F, et al.
(författare)
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Alpha-synuclein transfers from neurons to oligodendrocytes.
- 2014
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Ingår i: GLIA. - : Wiley. - 1098-1136 .- 0894-1491. ; 62:3, s. 387-398
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Tidskriftsartikel (refereegranskat)abstract
- The origin of α-synuclein (α-syn)-positive glial cytoplasmic inclusions found in oligodendrocytes in multiple system atrophy (MSA) is enigmatic, given the fact that oligodendrocytes do not express α-syn mRNA. Recently, neuron-to-neuron transfer of α-syn was suggested to contribute to the pathogenesis of Parkinson's disease. In this study, we explored whether a similar transfer of α-syn might occur from neurons to oligodendrocytes, which conceivably could explain how glial cytoplasmic inclusions are formed. We studied oligodendrocytes in vitro and in vivo and examined their ability to take up different α-syn assemblies. First, we treated oligodendrocytes with monomeric, oligomeric, and fibrillar forms of α-syn proteins and investigated whether α-syn uptake is dynamin-dependent. Second, we injected the same α-syn species into the mouse cortex to assess their uptake in vivo. Finally, we monitored the presence of human α-syn within rat oligodendroglial cells grafted in the striatum of hosts displaying Adeno-Associated Virus-mediated overexpression of human α-syn in the nigro-striatal pathway. Here, we show that oligodendrocytes take up recombinant α-syn monomers, oligomers and, to a lesser extent, fibrils in vitro in a concentration and time-dependent manner, and that this process is inhibited by dynasore. Further, we demonstrate in our injection model that oligodendrocytes also internalize α-syn in vivo. Finally, we provide the first direct evidence that α-syn can transfer to grafted oligodendroglial cells from host rat brain neurons overexpressing human α-syn. Our findings support the hypothesis of a neuron-to-oligodendrocyte transfer of α-syn, a mechanism that may play a crucial role in the progression and pathogenesis of MSA. GLIA 2014;62:387-398.
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| 20. |
- Liu, Z. W., et al.
(författare)
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Beneficial Effects of GFAP/Vimentin Reactive Astrocytes for Axonal Remodeling and Motor Behavioral Recovery in Mice after Stroke
- 2014
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Ingår i: Glia. - : Wiley. - 0894-1491. ; 62:12, s. 2022-2033
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Tidskriftsartikel (refereegranskat)abstract
- The functional role of reactive astrocytes after stroke is controversial. To elucidate whether reactive astrocytes contribute to neurological recovery, we compared behavioral outcome, axonal remodeling of the corticospinal tract (CST), and the spatio-temporal change of chondroitin sulfate proteoglycan (CSPG) expression between wild-type (WT) and glial fibrillary acidic protein/vimentin double knockout (GFAP(-/-)Vim(-/-)) mice subjected to Rose Bengal induced cerebral cortical photothrombotic stroke in the right forelimb motor area. A foot-fault test and a single pellet reaching test were performed prior to and on day 3 after stroke, and weekly thereafter to monitor functional deficit and recovery. Biotinylated dextran amine (BDA) was injected into the left motor cortex to anterogradely label the CST axons. Compared with WT mice, the motor functional recovery and BDA-positive CST axonal length in the denervated side of the cervical gray matter were significantly reduced in GFAP(-/-)Vim(-/-) mice (n=10/group, P<0.01). Immunohistological data showed that in GFAP(-/-)Vim(-/-) mice, in which astrocytic reactivity is attenuated, CSPG expression was significantly increased in the lesion remote areas in both hemispheres, but decreased in the ischemic lesion boundary zone, compared with WT mice (n=12/group, P<0.001). Our data suggest that attenuated astrocytic reactivity impairs or delays neurological recovery by reducing CST axonal remodeling in the denervated spinal cord. Thus, manipulation of astrocytic reactivity post stroke may represent a therapeutic target for neurorestorative strategies. GLIA 2014;62:2022-2033 Post stroke, GFAP/Vimentin knockout mice with attenuated gliosis have reduced or slower neurological recovery and corticospinal remodeling, and increased chondroitin sulfate proteoglycan expression, suggesting that reactive astrocytes promote recovery.
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| 23. |
- Persson, Åsa, 1980, et al.
(författare)
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Radixin expression in microglia after cortical stroke lesion
- 2013
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Ingår i: Glia. - : Wiley. - 0894-1491. ; 61:5, s. 790-799
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Tidskriftsartikel (refereegranskat)abstract
- Stroke induces extensive tissue remodeling, resulting in the activation of several cell types in the brain as well as recruitment of blood-borne leucocytes. Radixin is part of a cytoskeleton linker protein family with the ability to connect transmembrane proteins to the actin cytoskeleton, promoting cell functions involving a dynamic cytoskeleton such as morphological changes, cell division and migration which are common events of different cell types after stroke. In the healthy adult brain radixin is expressed in Olig2+ cells throughout the brain and in neural progenitor cells in the subventricular zone. In the current study, we detected a 2.5 fold increase in the number of radixin positive cells in the peri-infarct cortex two weeks after the induction of cortical stroke by photothrombosis. Similarly, the number of Olig2+ cells increased in the peri-infarct area after stroke; however, the number of radixin+/Olig2+ cells was unchanged. Neural progenitor cells maintained radixin expression on their route to the infarct. More surprising however, was the expression of radixin in activated microglia in the peri-infarct cortex. Seventy percent of Iba1+ cells expressed radixin after stroke, a population which was not present in the control brain. Furthermore, activation of radixin was predominantly detected in the peri-infarct region of oligodendrocyte progenitors and microglia. The specific location of radixin+ cells in the peri-infarct region and in microglia suggests a role for radixin in microglial activation after stroke.
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