| 1. |
- Andersson, Henrik, et al.
(författare)
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Orexin A Phosphorylates the gamma-Aminobutyric Acid Type A Receptor beta(2) Subunit on a Serine Residue and Changes the Surface Expression of the Receptor in SH-SY5Y Cells Exposed to Propofol
- 2015
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Ingår i: Journal of Neuroscience Research. - : WILEY-BLACKWELL. - 0360-4012 .- 1097-4547. ; 93:11, s. 1748-1755
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Tidskriftsartikel (refereegranskat)abstract
- Propofol activates the gamma-aminobutyric acid type A receptor (GABA(A)R) and causes a reversible neurite retraction, leaving a thin, thread-like structure behind; it also reverses the transport of vesicles in rat cortical neurons. The awakening peptide orexin A (OA) inhibits this retraction via phospholipase D (PLD) and protein kinase CE (PKCE). The human SH-SY5Y cells express both GABA(A)Rs and orexin 1 and 2 receptors. These cells are used to examine the interaction between OA and the GABAAR. The effects of OA are studied with flow cytometry and immunoblotting. This study shows that OA stimulates phosphorylation on the serine residues of the GABA(A)R beta(2) subunit and that the phosphorylation is caused by the activation of PLD and PKCE. OA administration followed by propofol reduces the cell surface expression of the GABA(A)R, whereas propofol stimulation before OA increases the surface expression. The GABA(A)R beta(2) subunit is important for receptor recirculation, and the effect of OA on propofol-stimulated cells may be due to a disturbed recirculation of the GABA(A)R. (C) 2015 Wiley Periodicals, Inc.
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| 2. |
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| 3. |
- Corell, Mikael, et al.
(författare)
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GABA and its B-receptor are present at the node of Ranvier in a small population of sensory fibers, implicating a role in myelination
- 2015
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 93:2, s. 285-295
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Tidskriftsartikel (refereegranskat)abstract
- The γ-aminobutyric acid (GABA) type B receptor has been implicated in glial cell development in the peripheral nervous system (PNS), although the exact function of GABA signaling is not known. To investigate GABA and its B receptor in PNS development and degeneration, we studied the expression of the GABAB receptor, GABA, and glutamic acid decarboxylase GAD65/67 in both development and injury in fetal dissociated dorsal root ganglia (DRG) cell cultures and in the rat sciatic nerve. We found that GABA, GAD65/67, and the GABAB receptor were expressed in premyelinating and nonmyelinating Schwann cells throughout development and after injury. A small population of myelinated sensory fibers displayed all of these molecules at the node of Ranvier, indicating a role in axon-glia communication. Functional studies using GABAB receptor agonists and antagonists were performed in fetal DRG primary cultures to study the function of this receptor during development. The results show that GABA, via its B receptor, is involved in the myelination process but not in Schwann cell proliferation. The data from adult nerves suggest additional roles in axon-glia communication after injury.
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| 6. |
- Israelsson, Charlotte, et al.
(författare)
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Anti-inflammatory treatment of traumatic brain injury with Rabeximod reduces cerebral antigen presentation in mice
- 2015
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 93:10, s. 1519-1525
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Tidskriftsartikel (refereegranskat)abstract
- A major component of the damaging effect after traumatic brain injury (TBI) is activation of the inflammatory system. In particular, chemokines and chemokine-regulated factors become activated in resident brain cells and signal to different invading immune cells. For evaluation of the effect on invading cells 3 days after injury, mice were treated with a single initial dose of the anti-inflammatory agent Rabeximod in an experimental TBI model. For comparison, mice subjected to TBI were similarly injected with cyclophosphamide. TBI resulted in reduced body weight, an effect further enhanced by administration of Rabeximod, without obvious influence on motor performance. As revealed by quantitative RT-PCR, microglial upregulation of chemokine Ccl3 in response to TBI was unaffected by Rabeximod. Also, injury-induced expression of Cxcl10 in plasmacytoid dendritic cells (DCs) and endothelial expression of platelet selectin (Selp) were uninfluenced by Rabeximod. In contrast, Rabeximod robustly reduced the H2-Aa transcript characteristic for classical DCs defined by CD11c/Itgax in the injured brain. In addition, the expression of lysozyme 2 in large phagocytic cells was impaired by Rabeximod. These results show that Rabeximod exerts a selective and potent inhibition of cells serving cortical antigen presentation after brain trauma.
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| 7. |
- Moyano, A. L., et al.
(författare)
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Sulfatides in Extracellular Vesicles Isolated From Plasma of Multiple Sclerosis Patients
- 2016
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 94:12, s. 1579-1587
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs) are membrane nanovesicles of diverse sizes secreted by different cell types and are involved in intercellular communication. EVs shuttle proteins, nucleic acids, and lipids that reflect their cellular origin and could mediate their biological function in recipient cells. EVs circulate in biological fluids and are considered as potential biomarkers that could be used to analyze and characterize disease development, course and response to treatment. EVs exhibit specific distribution of glycolipids and membrane organization, but little is known about the biological significance of this distribution or how it could contribute to pathological conditions such as multiple sclerosis (MS). We provide the first description of sulfatide composition in plasma-derived EVs by ultra-high-performance liquid chromatography tandem mass spectrometry. We found that EVs of different sizes showed C16:0 sulfatide but no detectable levels of C18:0, C24:0, or C24:1 sulfatide species. Small EVs isolated at 100,000 x g-enriched in exosomes-from plasma of patients with MS showed a significant increase of C16: 0 sulfatide compared with healthy controls. Nanoparticle tracking analysis showed that the particle size distribution in MS plasma was significantly different compared with healthy controls. Characterization of small EVs isolated from MS plasma showed similar protein content and similar levels of exosomal markers (Alix, Rab-5B) and vesicular marker MHC class I (major histocompatibility complex class I) compared with healthy controls. Our findings indicate that C16: 0 sulfatide associated with small EVs is a candidate biomarker for MS that could potentially reflect pathological changes associated with this disease and/or the effects of its treatment.
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| 9. |
- Sedzik, Jan, et al.
(författare)
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Glycans of Myelin Proteins
- 2015
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 93:1, s. 1-18
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Forskningsöversikt (refereegranskat)abstract
- Human P0 is the main myelin glycoprotein of the peripheral nervous system. It can bind six different glycans, all linked to Asn(93), the unique glycosylation site. Other myelin glycoproteins, also with a single glycosylation site (PMP22 at Asn(36), MOG at Asn(31)), bind only one glycan. The MAG has 10 glycosylation sites; the glycoprotein OMgp has 11 glycosylation sites. Aside from P0, no comprehensive data are available on other myelin glycoproteins. Here we review and analyze all published data on the physicochemical structure of the glycans linked to P0, PMP22, MOG, and MAG. Most data concern bovine P0, whose glycan moieties have an MW ranging from 1,294.56 Da (GP3) to 2,279.94 Da (GP5). The pI of glycosylated P0 protein varies from pH 9.32 to 9.46. The most charged glycan is MS2 containing three sulfate groups and one glucuronic acid; whereas the least charged one is the BA2 residue. All glycans contain one fucose and one galactose. The most mannose rich are the glycans MS2 and GP4, each of them has four mannoses; OPPE1 contains five N-acetylglucosamines and one sulfated glucuronic acid; GP4 contains one sialic acid. Furthermore, human P0 variants causing both gain and loss of glycosylation have been described and cause peripheral neuropathies with variable clinical severity. In particular, the substitution (TM)-M-95 is a very common in Europe and is associated with a late-onset axonal neuropathy. Although peripheral myelin is made up largely of glycoproteins, mutations altering glycosylation have been described only in P0. This attractive avenue of research requires further study.
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| 10. |
- Soares, Ana Francisca, et al.
(författare)
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Glycogen metabolism is impaired in the brain of male type 2 diabetic Goto-Kakizaki rats
- 2019
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 1097-4547 .- 0360-4012. ; 97:8, s. 1004-1017
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Tidskriftsartikel (refereegranskat)abstract
- Diabetes impacts the central nervous system predisposing to cognitive decline. While glucose is the main source of energy fueling the adult brain, brain glycogen is necessary for adequate neuronal function, synaptic plasticity and memory. In this study, we tested the hypothesis that brain glycogen metabolism is impaired in type 2 diabetes (T2D). 13 C magnetic resonance spectroscopy (MRS) during [1-13 C]glucose i.v. infusion was employed to detect 13 C incorporation into whole-brain glycogen in male Goto-Kakizaki (GK) rats, a lean model of T2D, and control Wistar rats. Labeling from [1-13 C]glucose into brain glycogen occurred at a rate of 0.25 ± 0.12 and 0.48 ± 0.22 µmol/g/h in GK and Wistar rats, respectively (p = 0.028), despite similar brain glycogen concentrations. In addition, the appearance of [1-13 C]glucose in the brain was used to evaluate glucose transport and consumption. T2D caused a 31% reduction (p = 0.031) of the apparent maximum transport rate (Tmax ) and a tendency for reduced cerebral metabolic rate of glucose (CMRglc ; -29%, p = 0.062), indicating impaired glucose utilization in T2D. After MRS in vivo, gas chromatography-mass spectrometry was employed to measure regional 13 C fractional enrichment of glucose and glycogen in the cortex, hippocampus, striatum, and hypothalamus. The diabetes-induced reduction in glycogen labeling was most prominent in the hippocampus and hypothalamus, which are crucial for memory and energy homeostasis, respectively. These findings were further supported by changes in the phosphorylation rate of glycogen synthase, as analyzed by Western blotting. Altogether, the present results indicate that T2D is associated with impaired brain glycogen metabolism.
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