| 1. |
- Brederlau, Anke, 1968, et al.
(författare)
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Bone morphogenetic proteins but not growth differentiation factors induce dopaminergic differentiation in mesencephalic precursors.
- 2002
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Ingår i: Molecular and cellular neurosciences. - 1044-7431. ; 21:3, s. 367-78
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Tidskriftsartikel (refereegranskat)abstract
- Bone morphogenetic proteins (BMPs) and growth differentiation factors (GDFs) are potential therapeutic molecules for the treatment of Parkinson's disease (PO). Here we compare the effects of BMP3, 5, 6, and 7 and GDF5 and 6 in a rat mesencephalic cell culture system that reflects the developmental stage of neurons around birth. High concentrations of BMP5, 6, and 7 and GDF5 and 6 induced astroglial cell fate and a depletion of oligodendrocytes. Only BMP5, 6, and 7, however, significantly increased the number of tyrosine hydroxylase (TH)-positive neurons and induced nuclear translocation of the phosphorylated BMP-restricted Smad in a substantial number of TH- and microtubule-associated protein 2(MAP2ab)-positive cells. None of the proteins protected TH-positive cells against 6-hydroxydopamine-induced oxidative stress. BMP3 was without any effect throughout the studies. We conclude that BMP5, 6, and 7 act directly and independently on precursors of the dopaminergic and astroglial lineage and induce their differentiation. In contrast, GDF5 and 6 primarily affect nonneuronal cells in mesencephalic cultures of this stage.
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| 2. |
- Brederlau, Anke, 1968
(författare)
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Directing stem cells and progenitors towards neuronal differentiation - implications for experimental therapies for Parkinson's disease
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The insight that stem- and progenitor-cells contribute to replacement of nerve cells in the adult central nervous system is the basis of modern therapies for structural brain repair. Their goal is to protect, support and stimulate endogenous stem cells in areas affected by disease and to replace lost cells by transplanting in vitro generated, tailored nerve cells. In the present thesis growth factors and signaling molecules were investigated for their potential to direct stem- and neural progenitor- cells towards neuronal cell fate. Involved signaling pathways were characterized and candidate molecules identified that might be beneficial for cellbased therapies in Parkinson?s disease. Results show that Bone Morphogenetic Proteins (BMPs) and Growth Differentiation Factors increase astroglial differentiation while inhibiting oligodendrocyte maturation in rat embryonic mesencephalic culture. None of the factors protect dopaminergic neurons against oxidative radicals in vitro. BMP5, 6 and 7, however, promote dopaminergic differentiation by directly targeting the neuronal cell population. In cultures of adult rat hippocampus-derived progenitors (AHPs), endogenous BMPs were found to increase undesired astroglial differentiation via the BMP type I receptors ALK6 and ALK2. By viral transduction of dominant negative ALK2 or ALK6, respectively, BMP signaling was blocked in order to inhibit astroglial cell differentiation. Indeed, the expression of glial fibrillary acidic protein (GFAP), a marker for astrocytes, decreased. The number of oligodendrocytes increased and neurons were not affected. However, the strategy proved impractical since it induced cell death. RT-PCR results indicate that only the ALK6, but not the ALK2 receptor, is dynamically regulated in these cultures, suggesting that ALK6 is mainly responsible for glial differentiation and survival of AHPs. Apoptosis signal-regulating kinase-1 is a ubiquitously expressed enzyme involved in apoptosis. Overexpression of its constitutively active form induced neuronal differentiation in AHP culture. At the same time GFAP expression was inhibited. The effect is mediated via p38 mitogen- activated protein kinase and via inhibition of GFAP promoter activity. In order to generate transplantable dopaminergic neurons, human embryonic stem cells (hESCs) were cocultured with the stromal cell line PA6, known to instruct mouse and primate ESCs towards dopaminergic cell fate. About 11% of hESCs developed into tyrosine hydroxylasepositive (TH-pos) neurons with CNS identity. The hESC-derived neurons displayed action potential in vitro. However, they did not induce behavioral recovery after transplantation to the 6-hydroxydopamine -lesioned rat striatum. Extended differentiation time on PA6 in vitro decreased the risk for teratoma formation after transplantation, but did not elevate the low number of THpos neurons in the graft. In conclusion, certain BMPs as well as ASK1 have been identified as molecules that increase neuronal differentiation. Their putative role in experimental CNS cell therapies is discussed. At the moment, however, the gap between experimental systems and biological reality is difficult to overcome. Further investigations that are necessary to reduce safety concerns in cellbased treatment strategies are outlined.
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| 3. |
- Brederlau, Anke, 1968, et al.
(författare)
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The bone morphogenetic protein type Ib receptor is a major mediator of glial differentiation and cell survival in adult hippocampal progenitor cell culture.
- 2004
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Ingår i: Molecular biology of the cell. - 1059-1524. ; 15:8, s. 3863-75
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Tidskriftsartikel (refereegranskat)abstract
- Bone morphogenetic proteins (BMPs) act as growth regulators and inducers of differentiation. They transduce their signal via three different type I receptors, termed activin receptor-like kinase 2 (Alk2), Alk3, or bone morphogenetic protein receptor Ia (BMPRIa) and Alk6 or BMPRIb. Little is known about functional differences between the three type I receptors. Here, we have investigated consequences of constitutively active (ca) and dominant negative (dn) type I receptor overexpression in adult-derived hippocampal progenitor cells (AHPs). The dn receptors have a nonfunctional intracellular but functional extracellular domain. They thus trap BMPs that are endogenously produced by AHPs. We found that effects obtained by overexpression of dnAlk2 and dnAlk6 were similar, suggesting similar ligand binding patterns for these receptors. Thus, cell survival was decreased, glial fibrillary acidic protein (GFAP) expression was reduced, whereas the number of oligodendrocytes increased. No effect on neuronal differentiation was seen. Whereas the expression of Alk2 and Alk3 mRNA remained unchanged, the Alk6 mRNA was induced after impaired BMP signaling. After dnAlk3 overexpression, cell survival and astroglial differentiation increased in parallel to augmented Alk6 receptor signaling. We conclude that endogenous BMPs mediate cell survival, astroglial differentiation and the suppression of oligodendrocytic cell fate mainly via the Alk6 receptor in AHP culture.
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| 4. |
- Brederlau, Anke, 1968, et al.
(författare)
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Transplantation of human embryonic stem cell-derived cells to a rat model of Parkinson's disease: effect of in vitro differentiation on graft survival and teratoma formation.
- 2006
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Ingår i: Stem cells (Dayton, Ohio). - : Oxford University Press (OUP). - 1066-5099 .- 1549-4918. ; 24:6, s. 1433-40
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Tidskriftsartikel (refereegranskat)abstract
- Human embryonic stem cells (hESCs) have been proposed as a source of dopamine (DA) neurons for transplantation in Parkinson's disease (PD). We have investigated the effect of in vitro predifferentiation on in vivo survival and differentiation of hESCs implanted into the 6-OHDA (6-hydroxydopamine)-lesion rat model of PD. The hESCs were cocultured with PA6 cells for 16, 20, or 23 days, leading to the in vitro differentiation into DA neurons. Grafted hESC-derived cells survived well and expressed neuronal markers. However, very few exhibited a DA neuron phenotype. Reversal of lesion-induced motor deficits was not observed. Rats grafted with hESCs predifferentiated in vitro for 16 days developed severe teratomas, whereas most rats grafted with hESCs predifferentiated for 20 and 23 days remained healthy until the end of the experiment. This indicates that prolonged in vitro differentiation of hESCs is essential for preventing formation of teratomas.
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| 5. |
- Faigle, Roland, 1977, et al.
(författare)
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ASK1 inhibits astroglial development via p38 mitogen-activated protein kinase and promotes neuronal differentiation in adult hippocampus-derived progenitor cells.
- 2004
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Ingår i: Molecular and cellular biology. - 0270-7306. ; 24:1, s. 280-93
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms controlling differentiation and lineage specification of neural stem cells are still poorly understood, and many of the molecules involved in this process and their specific functions are yet unknown. We investigated the effect of apoptosis signal-regulating kinase 1 (ASK1) on neural stem cells by infecting adult hippocampus-derived rat progenitors with an adenovirus encoding the constitutively active form of ASK1. Following ASK1 overexpression, a significantly larger number of cells differentiated into neurons and a substantial increase in Mash1 transcription was observed. Moreover, a marked depletion of glial cells was observed, persisting even after additional treatment of ASK1-infected cultures with potent glia inducers such as leukemia inhibitory factor and bone morphogenetic protein. Analysis of the promoter for glial fibrillary acidic protein revealed that ASK1 acts as a potent inhibitor of glial-specific gene transcription. However, the signal transducers and activators of transcription 3 (STAT3)-binding site in the promoter was dispensable, while the activation of p38 mitogen-activated protein kinase was crucial for this effect, suggesting the presence of a novel mechanism for the inhibition of glial differentiation.
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| 6. |
- Kondziella, Daniel, 1976, et al.
(författare)
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Choreathetosis due to abuse of levothyroxine.
- 2009
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Ingår i: Journal of neurology. - : Springer Science and Business Media LLC. - 1432-1459 .- 0340-5354. ; 256:12, s. 2106-8
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Tidskriftsartikel (refereegranskat)abstract
- Choreathetosis due to thyrotoxicosis is a rare movement disorder of acute onset. Here we present the first report of choreathetosis secondary to abuse of levothyroxine. A 35-year-old woman with autoimmune thyroiditis tripled her daily levothyroxine intake and lost 20 kg of weight during the following 6 months. She soon developed incapacitating choreathetosis. When levothyroxine was reduced to her usual dosage, all symptoms vanished in 7 days. The prompt effect of dose correction points towards a direct influence of levothyroxine on the basal ganglia; alternatively, the effects of levothyroxine might have been indirect and, possibly, autoimmune-mediated. Abuse of levothyroxine and related thyroid-tropic substances should be included into the differential diagnosis of acute choreathetosis.
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| 7. |
- Larsson, Alice, et al.
(författare)
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Do patients with large vessel occlusion ischemic stroke harboring prestroke disability benefit from thrombectomy?
- 2020
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Ingår i: Journal of Neurology. - : Springer Science and Business Media LLC. - 0340-5354 .- 1432-1459. ; 267, s. 2667-2674
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Evidence of endovascular treatment (EVT) for acute large vessel occlusion (LVO) ischemic stroke in patients harboring substantial prestroke disability is lacking due to their exclusion from randomized trials. Here, we used routine care observational data to compare outcomes in patients with and without prestroke disability receiving EVT for LVO ischemic stroke. Methods: Consecutive patients undergoing EVT for acute LVO ischemic stroke at the Sahlgrenska University Hospital from January 1st, 2015 to March 31st, 2018 were registered in the Sahlgrenska Stroke Recanalization Registry. Pre- and poststroke functional levels were assessed by the modified Rankin Scale (mRS). Outcomes were recanalization rate (mTICI = 2b/3), symptomatic intracranial hemorrhage [sICH], complications during hospital stay, and return to prestroke functional level and mortality at 3 months. Results: Among 591 patients, 90 had prestroke disability (mRS ≥ 3). The latter group were older, more often female, had more comorbidities and higher NIHSS scores before intervention compared to patients without prestroke disability. Recanalization rates (80.0% vs 85.0%, p = 0.211), sICH (2.2% vs 6.3% p = 0.086) and the proportion of patients returning to prestroke functional level (22.7% vs 14.8% p = 0.062) did not significantly differ between those with and without prestroke disability. Patients with prestroke disability had higher complication rates during hospital stay (55.2% vs 40.1% p < 0.01) and mortality at 3 months (48.9% vs 24.3% p < 0.001). Conclusion: One of five with prestroke disability treated with thrombectomy for a LVO ischemic stroke returned to their prestroke functional level. However, compared to patients without prestroke disability, mortality at 3 months was higher. © 2020, The Author(s).
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| 8. |
- Lindberg, Olle R, et al.
(författare)
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Characterization of Epidermal Growth Factor-Induced Dysplasia in the Adult Rat Subventricular Zone.
- 2012
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Ingår i: Stem cells and development. - : Mary Ann Liebert Inc. - 1557-8534 .- 1547-3287. ; 21:8, s. 1356-1366
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Tidskriftsartikel (refereegranskat)abstract
- Epidermal growth factor (EGF) is a mitogen widely used when culturing adult neural stem cells in vitro. Although proliferative effects can also be observed in vivo, intracerebroventricular infusion of EGF has been found to counteract neuronal determination and promote glial differentiation instead. However, EGF receptor activation has different effects on the subventricular zone (SVZ) in mice and rats, possibly because of species differences in SVZ cell composition. Specifically in the rat, EGF stimulation of the SVZ induces the formation of hyperplastic polyps. The present study aims at molecular and morphological characterization of these subventricular polyps. Using immunohistochemistry, electron microscopy, and gene expression analysis, we demonstrate in hyperplastic EGF-induced polyps an upregulation in protein expression of Sox2, Olig2, GFAP, nestin, and vimentin. We found polyp-specific dysplastic changes in the form of coexpression of Sox2 and Olig2. This highly proliferative, Sox2/Olig2 coexpressing dysplastic cell type is >10-fold enriched in the hyperplastic polyps compared with control SVZ and most likely causes the polyp formation. Unique ultrastructural features of the polyps include a lack of ependymal cell lining as well as a large number of cells with large, light, ovoid nuclei and a cytoplasm with abundant ribosomes, whereas other polyp cells contain invaginated nuclei but fewer ribosomes. EGF also induced changes in the expression of Id genes Id1, Id2, and Id4 in the SVZ. Taken together, we here demonstrate dysplastic, structural, and phenotypical changes in the rat SVZ following EGF stimulation, which are specific to hyperplastic polyps.
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| 9. |
- Lindberg, Olle R, et al.
(författare)
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EGF-Induced Expansion of Migratory Cells in the Rostral Migratory Stream
- 2012
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- The presence of neural stem cells in the adult brain is currently widely accepted and efforts are made to harness the regenerative potential of these cells. The dentate gyrus of the hippocampal formation, and the subventricular zone (SVZ) of the anterior lateral ventricles, are considered the main loci of adult neurogenesis. The rostral migratory stream (RMS) is the structure funneling SVZ progenitor cells through the forebrain to their final destination in the olfactory bulb. Moreover, extensive proliferation occurs in the RMS. Some evidence suggest the presence of stem cells in the RMS, but these cells are few and possibly of limited differentiation potential. We have recently demonstrated the specific expression of the cytoskeleton linker protein radixin in neuroblasts in the RMS and in oligodendrocyte progenitors throughout the brain. These cell populations are greatly altered after intracerebroventricular infusion of epidermal growth factor (EGF). In the current study we investigate the effect of EGF infusion on the rat RMS. We describe a specific increase of radixin(+)/Olig2(+) cells in the RMS. Negative for NG2 and CNPase, these radixin+/Olig2(+) cells are distinct from typical oligodendrocyte progenitors. The expanded Olig2(+) population responds rapidly to EGF and proliferates after only 24 hours along the entire RMS, suggesting local activation by EGF throughout the RMS rather than migration from the SVZ. In addition, the radixin+/Olig2(+) progenitors assemble in chains in vivo and migrate in chains in explant cultures, suggesting that they possess migratory properties within the RMS. In summary, these results provide insight into the adaptive capacity of the RMS and point to an additional stem cell source for future brain repair strategies.
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| 10. |
- Lindberg, Olle R, et al.
(författare)
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Epidermal growth factor treatment of the adult brain subventricular zone leads to focal microglia/macrophage accumulation and angiogenesis.
- 2014
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Ingår i: Stem cell reports. - : Elsevier BV. - 2213-6711. ; 2:4, s. 440-8
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Tidskriftsartikel (refereegranskat)abstract
- One of the major components of the subventricular zone (SVZ) neurogenic niche is the specialized vasculature. The SVZ vasculature isthought to be important in regulating progenitor cell proliferation and migration. Epidermal growth factor (EGF) is a mitogen witha wide range of effects. When stem and progenitor cells in the rat SVZ are treated with EGF, using intracerebroventricular infusion,dysplastic polyps are formed. Upon extended infusion, blood vessels are recruited into the polyps. In the current study we demonstrate how polyps develop through distinct stages leading up to angiogenesis. As polyps progress, microglia/macrophages accumulate in the polyp core concurrent with increasing cell death. Both microglia/macrophage accumulation and cell death peak during angiogenesis and subsequently decline following polyp vascularization. This model of inducible angiogenesis in the SVZ neurogenic niche suggests involvement of microglia/macrophages in acquired angiogenesis and can be used in detail to study angiogenesis inthe adult brain.
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| 11. |
- Nyberg, Jenny, 1976, et al.
(författare)
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Glucose-dependent insulinotropic polypeptide is expressed in adult hippocampus and induces progenitor cell proliferation.
- 2005
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Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - : Society for Neuroscience. - 1529-2401. ; 25:7, s. 1816-25
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Tidskriftsartikel (refereegranskat)abstract
- The hippocampal dentate gyrus (DG) is an area of active proliferation and neurogenesis within the adult brain. The molecular events controlling adult cell genesis in the hippocampus essentially remain unknown. It has been reported previously that adult male and female rats from the strains Sprague Dawley (SD) and spontaneously hypertensive (SHR) have a marked difference in proliferation rates of cells in the hippocampal DG. To exploit this natural variability and identify potential regulators of cell genesis in the hippocampus, hippocampal gene expression from male SHR as well as male and female SD rats was analyzed using a cDNA array strategy. Hippocampal expression of the gene-encoding glucose-dependent insulinotropic polypeptide (GIP) varied strongly in parallel with cell-proliferation rates in the adult rat DG. Moreover, robust GIP immunoreactivity could be detected in the DG. The GIP receptor is expressed by cultured adult hippocampal progenitors and throughout the granule cell layer of the DG, including progenitor cells. Thus, these cells have the ability to respond to GIP. Indeed, exogenously delivered GIP induced proliferation of adult-derived hippocampal progenitors in vivo as well as in vitro, and adult GIP receptor knock-out mice exhibit a significantly lower number of newborn cells in the hippocampal DG compared with wild-type mice. This investigation demonstrates the presence of GIP in the brain for the first time and provides evidence for a regulatory function for GIP in progenitor cell proliferation.
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| 12. |
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