| 1. |
- Alm, Henrik, et al.
(författare)
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Exposure to brominated flame retardant PBDE-99 affects cytoskeletal protein expression in the neonatal mouse cerebral cortex
- 2008
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Ingår i: Neurotoxicology. - : Elsevier BV. - 0161-813X .- 1872-9711. ; 29:4, s. 628-637
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Tidskriftsartikel (refereegranskat)abstract
- Polybrominated diphenyl ethers (PBDEs) are environmental contaminants found in human and animal tissues worldwide. Neonatal exposure to the flame retardant 2,2', 4,4',5-pentabromodiphenyl ether (PBDE-99) disrupts normal brain development in mice, and results in disturbed spontaneous behavior in the adult. The mechanisms underlying the late effects of early exposure are not clear. To gain insight into the initial neurodevelopmental damage inflicted by PBDE-99, we investigated the short-term effects of PBDE-99 on protein expression in the developing cerebral cortex of neonatal mice, and the cytotoxic and apoptotic effects of PBDE-99 in primary cultures of fetal rat cortical cells. We used two-dimensional difference gel electrophoresis (2D-DIGE) to analyze protein samples isolated from the cortex of NMRI mice 24h after exposure to a single oral dose of 12 mg/kg PBDE-99 on post-natal day 10. Protein resolution was enhanced by sample pre-fractionation. In the cell model, we determined cell viability using the trypan blue exclusion assay, and apoptosis using immunocytochemical detection of cleaved caspase-3. We determined the identity of 111 differentially expressed proteins, 32 (29%) of which are known to be cytoskeleton-related. Similar to previous findings in the striatum, we found elevated levels of the neuron growth-associated protein Gap43 in the cortex. In cultured cortical cells, a high concentration of PBDE-99 (30 microM) induced cell death without any apparent increase in caspase-3 activity. These results indicate that the permanent neurological damage induced by PBDE-99 during the brain growth spurt involve detrimental effects on cytoskeletal regulation and neuronal maturation in the developing cerebral cortex.
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| 2. |
- Alm, Henrik, et al.
(författare)
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In Vitro Neurotoxicity of PBDE-99 : Immediate and Concentration-Dependent Effects on Protein Expression in Cerebral Cortex Cells
- 2010
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 9:3, s. 1226-1235
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Tidskriftsartikel (refereegranskat)abstract
- Polybrominated diphenyl ethers (PBDEs) are commonly used flame retardants in various consumer products. Pre- and postnatal exposure to congeners of PBDEs disrupts normal brain development in rodents. Two-dimensional difference gel electrophoresis (2D-DIGE) was used to analyze concentration-dependent differences in protein expression in cultured cortical cells isolated from rat fetuses (GD 21) after 24 h exposure to PBDE-99 (3, 10, or 30 muM). Changes on a post-translational level were studied using a 1 h exposure to 30 muM PBDE-99. The effects of 24 h exposure to 3 and 30 muM PBDE-99 on mRNA levels were measured using oligonucleotide microarrays. A total of 62, 46, and 443 proteins were differentially expressed compared to controls after 24 h of exposure to 3, 10, and 30 muM PDBE-99, respectively. Of these, 48, 43, and 238 proteins were successfully identified, respectively. We propose that the biological effects of low-concentration PBDE-99 exposure are fundamentally different than effects of high-concentration exposure. Low-dose PBDE-99 exposure induced marked effects on cytoskeletal proteins, which was not correlated to cytotoxicity or major morphological effects, suggesting that other more regulatory aspects of cytoskeletal functions may be affected. Interestingly, 0.3 and 3 muM, but not 10 or 30 muM increased the expression of phosphorylated (active) Gap43, perhaps reflecting effects on neurite extension processes.
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| 3. |
- Attoff, Kristina, 1985-
(författare)
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Cell models for evaluation of adult and developmental neurotoxicity : Focus on acrylamide
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is aimed at summarizing some of the alternative in vitro methods and models that have been used to study both adult and developmental neurotoxicity (DNT), and also to pinpoint some of the important aspects of using alternative in vitro methods. The aim of the papers included in this thesis was to challenge the hypothesis that neurotoxicity and DNT of chemicals can be studied using robust endpoints for proliferation and neural differentiation, such as neurite outgrowth, mRNA expression and protein expression, in two different cell lines. The aim was also to characterize the two cell lines and identify marker genes important for differentiation and to evaluate if these markers could be used as indicators for DNT. The hypothesis being that any chemical that change the expression of important genes for the developmental process could possibly result in DNT for the cells. The current developmental neurotoxicity testing guidelines, using animal models, are time consuming, expensive, ethically questionable and have relatively low sensitivity. Because of this, there has been a paradigm shift towards developing and using alternative methods capable of testing and screening large number of substances. The next generation of developmental neurotoxicity testing is predicted to consist of both in silico and in vitro testing that have to be used in a combined fashion so that it will generate a more rapid and efficient toxicity testing. The idea is to use a battery of refined endpoint studies that identify the specific toxicity of a compound, discriminate between different neural subpopulations and the different stages of neural differentiation. The use of transcriptomic approaches has been suggested as an example of such an endpoint. In this thesis we have evaluated the human neuroblastoma cell line SH-SY5Y and the murine neural progenitor cell line C17.2 in their ability to detect neurotoxic and developmental neurotoxic compounds. We have evaluated this by using functional endpoints, such as neurite outgrowth, cell membrane potential and phenotype ratios. We have also studied the effect of selected chemicals on the levels of mRNA markers specific for different neural cell populations or for neural differentiation in general. We have performed whole genome gene expression on the two cell lines during differentiation and identified and selected a limited number of genes that have been evaluated for their ability to detect developmental neurotoxicity. Both cell lines showed that they have the capability to identify neurotoxic and developmental neurotoxic compounds and could possibly serve as an addition to the testing battery of neurotoxicity in the future. Some of the focus of this thesis has been directed towards the neurodevelopmental effects of the neurotoxic compound acrylamide. Most people get exposed to acrylamide through food consumption and from environmental pollution. Since acrylamide crosses the placental barrier, it creates a risk for developmental consequences. We found that acrylamide affected both cell proliferation and differentiation in both cell lines. Acrylamide affected both neuronal and the glial phenotypes in the C17.2 cell line. We also revealed that acrylamide attenuated neural differentiation at concentrations that were seven orders of magnitude lower than the estimated plasma concentration of free acrylamide in the fetus. Low concentrations of acrylamide altered the gene expression of several genes involved in the retinoic acid signaling as well as the CREB signaling pathways during retinoic acid driven differentiation in the SH-SY5Y cells. Since sub-micromolar concentrations seem to inhibit the differentiation process in both cell lines, developmental neurotoxicity induced by daily intake of acrylamide is a matter of concern. We found that the C17.2 cell line could function as a good model for detecting acute neurotoxicity by evaluating the cell membrane potential of the cells in combination with gene expression of neural and stress marker genes.
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| 4. |
- Brännvall, Karin, et al.
(författare)
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Environmental cues from CNS, PNS, and ENS cells regulate CNS progenitor differentiation
- 2008
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Ingår i: NeuroReport. - 0959-4965 .- 1473-558X. ; 19:13, s. 1283-9
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Tidskriftsartikel (refereegranskat)abstract
- Cellular origin and environmental cues regulate stem cell fate determination. Neuroepithelial stem cells form the central nervous system (CNS), whereas neural crest stem cells generate the peripheral (PNS) and enteric nervous system (ENS). CNS neural stem/progenitor cell (NSPC) fate determination was investigated in combination with dissociated cultures or conditioned media from CNS, PNS, or ENS. Cells or media from ENS or PNS cultures efficiently promoted NSPC differentiation into neurons, glia, and smooth muscle cells with a similar morphology as the feeder culture. Together with CNS cells or its conditioned medium, NSPC differentiation was partly inhibited and cells remained immature. Here, we demonstrate that secreted factors from the environment can influence CNS progenitor cells to choose a PNS-like cell fate.
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| 5. |
- 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. |
- Corell, Mikael
(författare)
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Neuron-glial Interaction in the Developing Peripheral Nervous System
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The nervous system, including the brain, is the most sophisticated organ in the mammalian body. In such a complex network, neuron-glial interaction is essential and controls most developmental processes, such as stem cell fate determination, migration, differentiation, synapse formation, ensheathment and myelination. Many of these events are critical for the developmental process and small errors can lead to growth retardation, malformation or disease. The understanding of the normal progress of nervous system development is fundamental and will help the discovery of new treatments for disease. This thesis discusses three types of neuron-glia interactions at different developmental stages; neural stem/progenitor cell (NSPC) differentiation, building and maintaining the structure of the sciatic nerve, and myelin formation. In Paper I we show that NSPCs, based upon their morphology and expression of specific protein markers, have the capacity to differentiate into cells of either the peripheral nervous system (PNS) or enteric nervous system (ENS) when grown with PNS or ENS primary cell cultures, or fed with conditioned medium from these. This indicates that soluble factors secreted from the PNS or ENS cultures are important for stem cell differentiation and fate determination. The adhesion protein neuronal cadherin (N-cadherin) is implicated in migration, differentiation and nerve outgrowth in the developing PNS. In Paper II N-cadherin was exclusively found in ensheathing glia (nonmyelinating Schwann cells, satellite cells and enteric glia) in contact with each other or with axons. Functional blocking of N-cadherin in dissociated fetal dorsal root ganglia (DRG) cultures led to a decrease in attachment between Schwann cells. N-cadherin-mediated adhesion of nonmyelinating Schwann cells may be important in encapsulating thin calibre axons and provide support to myelinating Schwann cells. In Paper III the inhibitory gamma aminobutyric acid (GABA) and GABAB receptors were studied in the Schwann cell of the adult sciatic nerve and DRG cultures. GABAB receptors were primarily expressed in nonmyelinating Schwann cells and protein levels decreased during development and myelination. Blocking the GABAB receptor in long-term DRG cultures led to decreased levels of mRNA markers for myelin. These results indicate that the GABA and GABAB receptors may be involved in Schwann cell myelination.
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| 7. |
- Corell, Mikael, et al.
(författare)
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Spatiotemporal Distribution and Function of N-Cadherin in Postnatal Schwann Cells : A Matter of Adhesion?
- 2010
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 88:11, s. 2338-2349
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Tidskriftsartikel (refereegranskat)abstract
- During embryonic development of the peripheral nervous system (PNS), the adhesion molecule neuronal cadherin (N-cadherin) is expressed by Schwann cell precursors and associated with axonal growth cones. N-cadherin expression levels decrease as precursors differentiate into Schwann cells. In this study, we investigated the distribution of N-cadherin in the developing postnatal and adult rat peripheral nervous system. N-cadherin was found primarily in ensheathing glia throughout development, concentrated at neuron glial or glial glial contacts of the sciatic nerve, dorsal root ganglia (DRG), and myenteric plexi. In the sciatic nerve, N-cadherin decreases with age and progress of myelination. In adult animals, N-cadherin was found exclusively in nonmyelinating Schwann cells. The distribution of N-cadherin in developing E17 DRG primary cultures is similar to what was observed in vivo. Functional studies of N-cadherin in these cultures, using the antagonist peptide INPISGQ, show a disruption of the attachment between Schwann cells, but no interference in the initial or long-term contact between Schwann cells and axons. We suggest that N-cadherin acts primarily in the adhesion between glial cells during postnatal development. It may form adherents/junctions between nonmyelinating glia, which contribute to the stable tubular structure encapsulating thin caliber axons and thus stabilize the nerve structure as a whole.
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| 8. |
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| 9. |
- Emanuelsson, Ida, et al.
(författare)
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Expression and regulation of CYP17A1 and 3β-hydroxysteroid dehydrogenase in cells of the nervous system : potential effects of vitamin D on brain steroidogenesis
- 2018
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Ingår i: Neurochemistry International. - : Elsevier BV. - 0197-0186 .- 1872-9754. ; 113, s. 46-55
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Tidskriftsartikel (refereegranskat)abstract
- Steroids are reported to have diverse functions in the nervous system. Enzymatic production of steroid hormones has been reported in different cell types, including astrocytes and neurons. However, the information on some of the steroidogenic enzymes involved is insufficient in many respects. Contradictory results have been reported concerning the relative importance of different cell types in the nervous system for expression of CYP17A1 and 3b-hydroxysteroid dehydrogenase (3b-HSD). 3b-HSD is important in all basic steroidogenic pathways and CYP17A1 is required to form sex hormones. In the current investigation we studied the expression of these enzymes in cultured primary rat astrocytes, in neuron-enriched cells from rat cerebral cortex and in human neuroblastoma SH-SY5Y cells, a cell line often used as an in vitro model of neuronal function and differentiation. As part of this study we also examined potential effects on CYP17A1 and 3b-HSD by vitamin D, a compound previously shown to have regulatory effects in steroid hormone-producing cells outside the brain. The results of our study indicate that astrocytes are a major site for expression of 3b-HSD whereas expression of CYP17A1 is found in both astrocytes and neurons. The current data suggest that neurons, contrary to some previous reports, are not involved in 3b-HSD reactions. Previous studies have shown that vitamin D can influence gene expression and hormone production by steroidogenic enzymes in some cells. We found that vitamin D suppressed CYP17A1-mediated activity by 20% in SH-SY5Ycells and astrocytes. Suppression of CYP17A1 mRNA levels was considerably stronger, about 50% in SH-SY5Y cells and 75% in astrocytes. In astrocytes 3b-HSD was also suppressed by vitamin D, about 20% at the enzyme activity level and 60% at the mRNA level. These data suggest that vitamin D-mediated regulation of CYP17A1 and 3b-HSD, particularly on the transcriptional level, may play a role in the nervous system.
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| 10. |
- Fex Svenningsen, Åsa, et al.
(författare)
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Macrophage migration inhibitory factor (MIF) modulates trophic signaling through interaction with serine protease HTRA1
- 2017
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Ingår i: Cellular and Molecular Life Sciences (CMLS). - : Springer Science and Business Media LLC. - 1420-682X .- 1420-9071. ; 24, s. 4561-4572
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Tidskriftsartikel (refereegranskat)abstract
- Macrophage migration inhibitory factor (MIF), a small conserved protein, is abundant in the immune- and central nervous system (CNS). MIF has several receptors and binding partners that can modulate its action on a cellular level. It is upregulated in neurodegenerative diseases and cancer although its function is far from clear. Here, we report the finding of a new binding partner to MIF, the serine protease HTRA1. This enzyme cleaves several growth factors, extracellular matrix molecules and is implicated in some of the same diseases as MIF. We show that the function of the binding between MIF and HTRA1 is to inhibit the proteolytic activity of HTRA1, modulating the availability of molecules that can change cell growth and differentiation. MIF is therefore the first endogenous inhibitor ever found for HTRA1. It was found that both molecules were present in astrocytes and that the functional binding has the ability to modulate astrocytic activities important in development and disease of the CNS.
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| 11. |
- Fex Svenningsen, Åsa
(författare)
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Regulation of Injury Induced Schwann Cell Proliferation Schwann Cell Proliferation
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this study was to investigate injury induced proliferation of Schwann cells with emphasis of the effects of the insulin-like growth factors (IGF-I and IGF-II) and the sex hormones progesterone and estrogen. Proliferation, measured as [3H] thymidine incorporation, was studied in cultured segments of the rat sciatic nerve or through the use of the thymidine analogue bromo- deoxy-uridine (BrdU) in combination with immunocytochemistry. The latter technique was also used for identification of the proliferating cells in the nerve segments. Exposure of the nerve segments to the truncated or long R3 IGF-1, IGF-II or insulin during 48 h resulted in an increased incorporation of [3H] thymidine. BrdU-labelling revealed that the overwhelming majority of the proliferating cells in the nerve segments were Schwann cells, suggesting that this cell type posses receptors for both the IGF’s and insulin. Estrogen enhanced [3H] thymidine incorporation into male and newborn rats while progesterone stimulated incorporation into segments from females and newborn rats. The results imply that Schwann cells have receptors for estrogen and progesterone and that these receptors like the ones for insulin and the IGF’s may be involved in the control of Schwann cell proliferation. In additional experiments we found that injury induced proliferation of adult Schwann cell proliferation was dependent on Ca2+, calmodulin and protein kinase, while agents, which enhance the formation of cAMP, were inhibitory. These findings are in contrast to the results obtained in cultures of neonatal Schwann cells where agents, which favour c-AMP formation, are mitogenic. Thus, when Schwann cells are maintained in the integrated environment of the nerve, their responses to mitogens are different from those observed in cultures of purified cells. A new model describing how Schwann cells proliferation could be regulated is presented.
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| 12. |
- Hjæresen, Simone, et al.
(författare)
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High temperature requirement A1 and macrophage migration inhibitory factor in the cerebrospinal fluid; a potential marker of conversion from relapsing-remitting to secondary progressive multiple sclerosis
- 2024
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Ingår i: Journal of the Neurological Sciences. - 0022-510X .- 1878-5883. ; 457
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Tidskriftsartikel (refereegranskat)abstract
- Background: Predictive and prognostic biomarkers for multiple sclerosis (MS) remain a significant gap in MS diagnosis and treatment monitoring. Currently, there are no timely markers to diagnose the transition to secondary progressive MS (SPMS). Objective: This study aims to evaluate the discriminatory potential of the High temperature requirement serine protease (HTRA1)/Macrophage migration inhibitory factor (MIF) cerebrospinal fluid (CSF) ratio in distinguishing relapsing-remitting (RRMS) patients from SPMS patients. Methods: The MIF and HTRA1 CSF levels were determined using ELISA in healthy controls (n = 23), RRMS patients before (n = 22) and after 1 year of dimethyl fumarate treatment (n = 11), as well as in SPMS patients before (n = 11) and after 2 years of mitoxantrone treatment (n = 7). The ability of the HTRA1/MIF ratio to discriminate the different groups was determined using receiver operating curve (ROC) analyses. Results: The ratio was significantly increased in treatment naïve RRMS patients while decreased again in SPMS patients at baseline. Systemic administrated disease modifying treatment (DMT) only significantly affected the ratio in RRMS patients. ROC analysis demonstrated that the ratio could discriminate treatment naïve RRMS patients from SPMS patients with 91% sensitivity and 100% specificity. Conclusion: The HTRA1/MIF ratio is a strong candidate as a MS biomarker for SPMS conversion.
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| 13. |
- Kindlundh-Högberg, Anna M. S., et al.
(författare)
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MDMA (Ecstasy) decreases the number of neurons and stem cells in embryonic cortical cultures
- 2010
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Ingår i: Cellular and molecular neurobiology. - : Springer Science and Business Media LLC. - 0272-4340 .- 1573-6830. ; 30:1, s. 13-21
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Tidskriftsartikel (refereegranskat)abstract
- Ecstasy, 3,4-methylenedioxymetamphetamine (MDMA), is a recreational drug used among adolescents, including young pregnant women. MDMA passes the placental barrier and may therefore influence fetal development. The aim was to investigate the direct effect of MDMA on cortical cells using dissociated CNS cortex of rat embryos, E17. The primary culture was exposed to a single dose of MDMA and collected 5 days later. MDMA caused a dramatic, dose-dependent (100 and 400 microM) decrease in nestin-positive stem cell density, as well as a significant reduction (400 microM) in NeuN-positive cells. By qPCR, MDMA (200 microM) caused a significant decrease in mRNA expression of the 5HT3 receptor, dopamine D(1) receptor, and glutamate transporter EAAT2-1, as well as an increase in mRNA levels of the NMDA NR1 receptor subunit and the 5HT(1A) receptor. In conclusion, MDMA caused a marked reduction in stem cells and neurons in embryonic cortical primary cell cultures, which was accompanied by changes in mRNA expression of specific receptors and transporters for glutamatergic and monoaminergic neurotransmitters.
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| 14. |
- Kononenko, Olga, et al.
(författare)
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Opioid precursor protein isoform is targeted to the cell nuclei in the human brain
- 2017
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Ingår i: Biochimica et Biophysica Acta. - : Elsevier BV. - 0006-3002 .- 1878-2434 .- 0304-4165 .- 1872-8006. ; 1861:2, s. 246-255
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neuropeptide precursors are traditionally viewed as proteins giving rise to small neuropeptide molecules. Prodynorphin (PDYN) is the precursor protein to dynorphins, endogenous ligands for the κ-opioid receptor. Alternative mRNA splicing of neuropeptide genes may regulate cell- and tissue-specific neuropeptide expression and produce novel protein isoforms. We here searched for novel PDYN mRNA and their protein product in the human brain.METHODS: Novel PDYN transcripts were identified using nested PCR amplification of oligo(dT) selected full-length capped mRNA. Gene expression was analyzed by qRT-PCR, PDYN protein by western blotting and confocal imaging, dynorphin peptides by radioimmunoassay. Neuronal nuclei were isolated using fluorescence-activated nuclei sorting (FANS) from postmortem human striatal tissue. Immunofluorescence staining and confocal microscopy was performed for human caudate nucleus.RESULTS: Two novel human PDYN mRNA splicing variants were identified. Expression of one of them was confined to the striatum where its levels constituted up to 30% of total PDYN mRNA. This transcript may be translated into ∆SP-PDYN protein lacking 13 N-terminal amino acids, a fragment of signal peptide (SP). ∆SP-PDYN was not processed to mature dynorphins and surprisingly, was targeted to the cell nuclei in a model cellular system. The endogenous PDYN protein was identified in the cell nuclei in human striatum by western blotting of isolated neuronal nuclei, and by confocal imaging.CONCLUSIONS AND GENERAL SIGNIFICANCE: High levels of alternatively spliced ∆SP-PDYN mRNA and nuclear localization of PDYN protein suggests a nuclear function for this isoform of the opioid peptide precursor in human striatum.
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| 15. |
- Lundqvist, Jessica, 1973-
(författare)
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Neuroblastoma SH-SY5Y and neural progenitor C17.2 cell lines as models for neurotoxicological studies
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- We are surrounded by chemicals, thus understanding how exposure to these chemicals affect us during our life is of great social importance. In order to predict human acute toxicity of chemicals, cosmetics or drugs, development of novel in vitro test strategies is required. The overall aim of this thesis was to evaluate whether two different cell line models could be used to predict acute neurotoxicity or developmental neurotoxicity. In paper one, we identified changes in cell membrane potential (CMP) as the most sensitive indicator of toxicity in neuroblastoma SH-SY5Y cells.In the following studies, we evaluated the capacity of the murine neural progenitor cell line C17.2 to differentiate into mixed cell cultures. Upon differentiation of the C17.2 cells we could identify two morphologically distinguishable cell types; astrocytes and neurons (Paper II). We then investigated how differentiated C17.2 cells responded to non-cytotoxic concentrations of three known neurotoxic and three non-neurotoxic substances. The neurotoxicants induced depolarisation of CMP and alteration in the mRNA expression of at least one of the three biomarkers studied, i.e. βIII-tubulin, glial fibrillary acidic protein or heat shock protein-32. In contrast, no significant effects were observed when exposed to non-neurotoxic compounds (Paper IV).To further characterise the C17.2 cell model during differentiation, an mRNA microarray analysis of the whole genome was performed. The 30 most significantly altered biomarkers with association to neuronal development were identified. The mRNA expression of the 30 biomarkers were used as a panel to alert for developmental neurotoxicity by exposing C17.2 cells during differentiation to toxicants known to induce impaired nervous system development. All but two of the selected genes were significantly altered by at least one of the chemicals, but none of the 30 genes were affected when treated with the negative control (Paper III). In conclusion, the differentiated C17.2 neural progenitor cell line seems to be an attractive model for studying and predicting acute and developmental neurotoxicity.
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| 16. |
- Nordberg Karlsson, Eva, et al.
(författare)
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The modular xylanase Xyn10A from Rhodothermus marinus is cell-attached, and its C-terminal domain has several putative homologues among cell-attached proteins within the phylum Bacteroidetes
- 2004
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Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 1574-6968 .- 0378-1097. ; 241:2, s. 233-242
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Tidskriftsartikel (refereegranskat)abstract
- Until recently, the function of the fifth domain of the thermostable modular xylanase Xyn10A from Rhodothermus marinus was unresolved. A putative homologue to this domain was however identified in a mannanase (Man26A) from the same microorganism which raised questions regarding a common function. An extensive search of all accessible data-bases as well as the partially sequenced genomes of R. marinus and Cytophaga hutchinsonii showed that homologues of this domain were encoded by multiple genes in microorganisms in the phylum Bacteroidetes. Moreover, the domain occurred invariably at the C-termini of proteins that were predominantly extra-cellular/cell attached. A primary structure motif of three conserved regions including structurally important glycines and a proline was also identified suggesting a conserved 3D fold. This bioinformatic evidence suggested a possible role of this domain in mediating cell attachment. To confirm this theory, R. marinus was grown, and activity assays showed that the major part of the xylanase activity was connected to whole cells. Moreover, immunocytochemical detection using a Xyn10A-specific antibody proved presence of Xyn10A on the R. marinus cell surface. In the light of this, a revision of experimental data present on both Xyn10A and Man26A was performed, and the results all indicate a cell-anchoring role of the domain, suggesting that this domain represents a novel type of module that mediates cell attachment in proteins originating from members of the phylum Bacteroidetes.
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| 17. |
- Pickering, Chris, et al.
(författare)
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A low ethanol dose affects all types of cells in mixed long-term embryonic cultures of the cerebellum
- 2010
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Ingår i: Basic & Clinical Pharmacology & Toxicology. - : Wiley. - 1742-7835 .- 1742-7843. ; 106:6, s. 472-478
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Tidskriftsartikel (refereegranskat)abstract
- The beneficial effect of the '1-drink-a-day' lifestyle is suggested by studies of cardiovascular health, and this recommendation is increasingly followed in many countries. The main objective of this study was to determine whether this pattern of ethanol use would be detrimental to a pregnant woman. We exposed a primary culture of rat cerebellum from embryonic day 17 (corresponding to second trimester in humans) to ethanol at a concentration of 17.6 mM which is roughly equivalent to one glass of wine. Acutely, there was no change in cell viability after 5 or 8 days of exposure relative to control. By 11 days, a reduction in the number of viable cells was observed without an accompanying change in caspase-3 activity (marker of apoptotic cell death), suggesting changes in cell proliferation. As the proportion of nestin-positive cells was higher in the ethanol-treated cultures after 5 days, we hypothesized that an increase in differentiation to neurons would compensate for the ongoing neuronal death. However, there were limits to this compensatory ability as the relative proportion of nestin-positive cells was decreased after 11 days. To further illustrate the negative long-term effects of this ethanol dose, cultures were exposed for 30 days. After this period, virtually no neurons or myelinating oligodendrocytes were present in the ethanol-treated cultures. In conclusion, chronic exposure to ethanol, even at small doses, dramatically and persistently affects normal development.
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| 18. |
- Sundblom, Jimmy, 1981-
(författare)
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Autosomal Dominant Leukodystrophy with Autonomic Symptoms and Rippling Muscle Disease : Translational Studies of Two Neurogenetic Diseases
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is a large variety of diseases caused by single-gene mutations. Although most of these conditions are rare, together they impose a significant burden to the population. This thesis describes clinical and genetic studies of two single-gene diseases: 1) Adult-onset autosomal dominant leukodystrophy with autonomic symptoms (ADLD) caused by LMNB1 gene duplications, and characterized by autonomic, pyramidal and cerebellar symptoms. Spinal cords of patients with ADLD were studied by MRI and found to be thin, with high signal intensity in white matter. Histopathology showed loss of myelinated fibres with some reactive gliosis. DNA samples from four different families with ADLD were obtained, and the LMNB1 gene was screened for duplications. Single nucleotide polymorphism array revealed LMNB1 duplications in all ADLD families. LMNB1 mRNA and protein levels were assessed in white blood cells using quantitative polymerase chain reaction and Western blot, and increased levels of LMNB1 mRNA and lamin B1 protein could be demonstrated. We concluded that spinal cord atrophy in patients with ADLD is a valuable differential diagnostic sign, and that increased levels of LMNB1 can be detected in peripheral blood. 2) Rippling muscle disease (RMD) is caused by CAV3 gene mutations. Clinical features are percussion-induced muscle mounding, –rapid contractions and undulating muscle contractions (rippling). The CAV3 gene was sequenced in 38 members of a family with RMD. Twenty-two individuals had clinical features of RMD. No muscle weakness was seen. All patients with signs of RMD carried the p.A46T CAV3 mutation, showing that the p.A46T mutation was benign and that the diagnosis can be made clinically. In vitro contracture test results from 10 of the subjects were collected, but no association between pathological test results and RMD was found.
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| 19. |
- Svenningsen, Åsa Fex, et al.
(författare)
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Effects on DHEA levels by estrogen in rat astrocytes and CNS co-cultures via the regulation of CYP7B1-mediated metabolism
- 2011
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Ingår i: Neurochemistry International. - : Elsevier BV. - 0197-0186 .- 1872-9754. ; 58:6, s. 620-624
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Tidskriftsartikel (refereegranskat)abstract
- The neurosteroid dehydroepiandrosterone (DHEA) is formed locally in the CNS and has been implicated in several processes essential for CNS function, including control of neuronal survival. An important metabolic pathway for DHEA in the CNS involves the steroid hydroxylase CYP7B1. In previous studies, CYP7B1 was identified as a target for estrogen regulation in cells of kidney and liver. In the current study, we examined effects of estrogens on CYP7B1-mediated metabolism of DHEA in primary cultures of rat astrocytes and co-cultures of rat CNS cells. Astrocytes, which interact with neurons in several ways, are important for brain neurosteroidogenesis. We found that estradiol significantly suppressed CYP7B1-mediated DHEA hydroxylation in primary mixed CNS cultures from fetal and newborn rats. Also, CYP7B1-mediated DHEA hydroxylation and CYP7B1 mRNA were markedly suppressed by estrogen in primary cultures of rat astrocytes. Interestingly, diarylpropionitrile, a well-known agonist of estrogen receptor β, also suppressed CYP7B1-mediated hydroxylation of DHEA. Several previous studies have reported neuroprotective effects of estrogens. The current data indicate that one of the mechanisms whereby estrogen can exert protective effects in the CNS may involve increase of the levels of DHEA by suppression of its metabolism.
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| 20. |
- Wicher, Grzegorz, et al.
(författare)
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Extracellular clusterin promotes neuronal network complexity in vitro
- 2008
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Ingår i: NeuroReport. - 0959-4965 .- 1473-558X. ; 19:15, s. 1487-1491
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Tidskriftsartikel (refereegranskat)abstract
- Clusterin (apolipoprotein J), a highly conserved amphiphatic glycoprotein and chaperone, has been implicated in a wide range of physiological and pathological processes. As a secreted protein, clusterin has been shown to act extracellularly where it is involved in lipid transportation and clearance of cellular debris. Intracellularly, clusterin may regulate signal transduction and is upregulated after cell stress. After neural injury, clusterin may be involved in nerve cell survival and postinjury neuroplasticity. In this study, we investigated the role of extracelullar clusterin on neuronal network complexity in vitro. Quantitative analysis of clustrin-treated neuronal cultures showed significantly higher network complexity. These findings suggest that in addition to previously demonstrated neuroprotective roles, clusterin may also be involved in neuronal process formation, elongation, and plasticity.
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| 21. |
- Wicher, Grzegorz, et al.
(författare)
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Low density lipoprotein-related protein-2/megalin is expressed in oligodendrocytes in the mouse spinal cord white matter
- 2006
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 0360-4012 .- 1097-4547. ; 83:5, s. 864-873
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Tidskriftsartikel (refereegranskat)abstract
- Lipoprotein receptor-related protein-2 (LRP2)/megalin is a member of the low density lipoprotein receptor (LDLR) family, and is essential in absorptive epithelia for endocytosis of lipoproteins, low molecular weight proteins, cholesterol and vitamins, as well as in cellular signaling. Previous studies have shown megalin expression in ependymal cells and choroid plexus. We have investigated megalin expression in the spinal cord of postnatal mice with immunohistochemistry and immunoblot. Antibodies recognizing either the cytoplasmic tail (MM6) or the extracellular domain (E11) of megalin labeled oligodendrocytes in the spinal cord white matter, in parallel with myelination. MM6 antibodies, predominantly labeled the nuclei, whereas E11 antibodies labeled the cytoplasm of these cells. MM6 antibodies labeled also nuclei of oligodendrocytes cultured from embryonic mouse spinal cord. Immunoblots of spinal cord showed intact megalin, as well as its carboxyterminal fragment, the part remaining after shedding of the extracellular domain of megalin. Megalin-immunoreactive oligodendrocytes also expressed presenilin 1, an enzyme responsible for gamma-secretase mediated endodomain cleavage. These findings show that spinal cord oligodendrocytes are phenotypically different from those in the brain, and indicate that megalin translocates signals from the cell membrane to the nucleus of oligodendrocytes during the formation and maintenance of myelin of long spinal cord pathways.
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| 22. |
- Wu, Zhigang, et al.
(författare)
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Microfluidic high viability neural cell separation using viscoelastically tuned hydrodynamic spreading
- 2008
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Ingår i: Biomedical microdevices (Print). - : Springer Science and Business Media LLC. - 1387-2176 .- 1572-8781. ; 10:5, s. 631-638
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Tidskriftsartikel (refereegranskat)abstract
- A high viability microfluidic cell separation technique of high throughput was demonstrated based on size difference continuous mode hydrodynamic spreading with viscoelastic tuning. Using water with fluorescent dye as sample fluid and in parallel introducing as elution a viscoelastic biocompatible polymer solution of alginic sodium, the spreading behavior was investigated at different polymer concentrations and flow rates. Particle separation was studied in the same detail for 9.9 mu m and 1.9 mu m latex beads. Using buffered aqueous solutions and further surface treatments to protect from cell adhesion, separation between neuron cells and glial cells from rat's spine cord was demonstrated and compared to the separation of latex particles of 20 and 4.6 mu m sizes. High relative viability (above 90%) of neural cells was demonstrated compared the reference cells of the same batch.
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| 23. |
- Wu, Zhigang, et al.
(författare)
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Microfluidic high viability separation of neural cells
- 2009
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Ingår i: 2009 4TH IEEE INTERNATIONAL CONFERENCE ON NANO/MICRO ENGINEERED AND MOLECULAR SYSTEMS, VOLS 1 AND 2, Shenzhen, CHINA, JAN 05-08, 2009. - : IEEE. - 9781424446292 ; , s. 1079-1083
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Konferensbidrag (refereegranskat)abstract
- A novel microfluidic platform is presented for sorting by size dissociated neurons, glia and stem cells from biopsies of the central nerve system. A highly biocompatible aqueous polymer solution was used in hydrodynamic spreading controlled cell separation. Before cell separation, particles were used for demonstration. To verify the results the fractions were studied using flow cytometry. Further, they were cultured and differentiated. The study indicated that the technique is ready for biological study and that it has a high potential for applications in neural cell regeneration therapy.
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| 24. |
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| 25. |
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