| 1. |
- 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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| 2. |
- Correia, Sofia, et al.
(författare)
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Fibroblast growth factor-20 increases the yield of midbrain dopaminergic neurons derived from human embryonic stem cells.
- 2007
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Ingår i: Frontiers in Neuroanatomy. - : Frontiers Media SA. - 1662-5129. ; 1:Dec 30
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Tidskriftsartikel (refereegranskat)abstract
- In the central nervous system, fibroblast growth factor (FGF)-20 has been reported to act preferentially on midbrain dopaminergic neurons. It also promotes the dopaminergic differentiation of stem cells. We have analyzed the effects of FGF-20 on human embryonic stem cells (hESCs) differentiation into dopaminergic neurons. We induced neuronal differentiation of hESCs by co-culturing those with PA6 mouse stromal cells for 3 weeks. When we supplemented the culture medium with FGF-20, the number of tyrosine hydroxylase (TH)-expressing neurons increased fivefold, from 3% to 15% of the hESC-derived cells. The cultured cells also expressed other midbrain dopaminergic markers (PITX3, En1, Msx1, and Aldh1), suggesting that some had differentiated into midbrain dopaminergic neurons. We observed no effect of FGF-20 on the size of the soma area or neurite length of the TH-immunopositive neurons. Regardless of whether FGF-20 had been added or not, 17% of the hESC-derived cells expressed the pan-neuronal marker b-III-Tubulin. The proportion of proliferating cells positive for Ki-67 was also not affected by FGF-20 (7% of the hESC-derived cells). By contrast, after 3 weeks in culture FGF-20 significantly reduced the proportion of cells undergoing cell death, as revealed by immunoreactivity for cleaved caspase-8, Bcl-2 associated X protein (BAX) and cleaved caspase-3 (2.5% to 1.2% of cleaved caspase-3-positive cells out of the hESC-derived cells). Taken together, our results indicate that FGF-20 specifically increases the yield of dopaminergic neurons from hESCs grown on PA6 feeder cells and at least part of this effect is due to a reduction in cell death.
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| 3. |
- Deierborg, Tomas, et al.
(författare)
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Absence of striatal newborn neurons with mature phenotype following defined striatal and cortical excitotoxic brain injuries.
- 2009
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 219, s. 363-367
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Tidskriftsartikel (refereegranskat)abstract
- Experimental stroke and excitotoxic brain lesion to the striatum or cortex increase the proliferation of cells residing within the ventricular wall and cause subsequent migration of newborn neuroblasts into the lesioned brain parenchyma. In this study, we clarify the different events of neurogenesis following striatal or cortical excitotoxic brain lesions in adult rats. Newborn cells were labeled by intraperitoneal injection of bromo-deoxy-uridine (BrdU), or by green fluorescent protein (GFP)-expressing lentiviral vectors injected into the subventricular zone (SVZ). We show that only neural progenitors born the first 5 days in the SVZ reside and expand within this neurogenic niche over time, and that these early labeled cells are more prone to migrate towards the striatum as neuroblasts. However, these neuroblasts could not mature into NeuN(+) neurons in the striatum. Furthermore, we found that cortical lesions, close or distant from the SVZ, could not upregulate SVZ cell proliferation nor promote neurogenesis. Our study demonstrates that both the time window for labeling proliferating cells and the site of lesion are crucial when assessing neurogenesis following brain injury.
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| 4. |
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| 5. |
- Deierborg, Tomas, et al.
(författare)
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Brain injury activates microglia that induce neural stem cell proliferation ex vivo and promote differentiation of neurosphere-derived cells into neurons and oligodendrocytes
- 2010
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Ingår i: Neuroscience. - : Elsevier BV. - 1873-7544 .- 0306-4522. ; 171:4, s. 1386-1396
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Tidskriftsartikel (refereegranskat)abstract
- Brain damage, such as ischemic stroke, enhances proliferation of neural stem/progenitor cells (NSPCs) in the subventricular zone (SVZ) To date, no reliable in vitro systems, which can be used to unravel the potential mechanisms underlying this lesion induced effect, have been established Here we developed an ex vivo method to investigate how the proliferation of NSPCs changes over time after experimental stroke or excitotoxic striatal lesion in the adult rat brain by studying the effects of microglial cells derived from an in jured brain on NSPCs We isolated NSPCs from the SVZ of brains with lesions and analyzed their growth and differentiation when cultured as neurospheres We found that NSPCs isolated from the brains 1-2 weeks following injury consistently generated more and larger neurospheres than those harvested from naive brains We attributed these effects to the presence of microglial cells in NSPC cultures that originated from injured brains We suggest that the effects are due to released factors because we observed increased proliferation of NSPCs isolated from non-injured brains when they were exposed to conditioned medium from cultures containing microglial cells derived from injured brains Furthermore, we found that NSPCs derived from injured brains were more likely to differentiate into neurons and oligodendrocytes than astrocytes Our ex vivo system reliably mimics what is ob served in vivo following brain injury It constitutes a powerful tool that could be used to identify factors that promote NSPC proliferation and differentiation in response to injury induced activation of microglial cells, by using tools such as proteomics and gene array technology (C) 2010 IBRO Published by Elsevier Ltd All rights reserved
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| 6. |
- Deierborg, Tomas, et al.
(författare)
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Emerging restorative treatments for Parkinson's disease.
- 2008
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Ingår i: Progress in Neurobiology. - : Elsevier BV. - 1873-5118 .- 0301-0082. ; 85, s. 407-432
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Tidskriftsartikel (refereegranskat)abstract
- Several exciting approaches for restorative therapy in Parkinson's disease have emerged over the past two decades. This review initially describes experimental and clinical data regarding growth factor administration. We focus on glial cell line-derived neurotrophic factor (GDNF), particularly its role in neuroprotection and in regeneration in Parkinson's disease. Thereafter, we discuss the challenges currently facing cell transplantation in Parkinson's disease and briefly consider the possibility to continue testing intrastriatal transplantation of fetal dopaminergic progenitors clinically. We also give a more detailed overview of the developmental biology of dopaminergic neurons and the potential of certain stem cells, i.e. neural and embryonic stem cells, to differentiate into dopaminergic neurons. Finally, we discuss adult neurogenesis as a potential tool for restoring lost dopamine neurons in patients suffering from Parkinson's disease.
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| 7. |
- Fedele, Valentina, et al.
(författare)
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Neurogenesis In The R6/2 Mouse Model Of Huntington'S Disease Is Impaired At The Level Of Neurod1
- 2011
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Ingår i: Neuroscience. - : Elsevier BV. - 1873-7544 .- 0306-4522. ; 173, s. 76-81
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Tidskriftsartikel (refereegranskat)abstract
- Adult neurogenesis is impaired in the hippocampus of transgenic R6 mouse models of Huntington's disease (HD). The phenotypes of R6 transgenic mice mimic several symptoms and signs of the disease (Li et al., 2005). They exhibit neurological and endocrine changes resembling some symptoms seen in humans. The reduction in neurogenesis is only apparent in the dentate gyrus as the number of newborn neurons in the subventricular zone, and olfactory bulb, is normal in R6 mice. The mechanism(s) underlying the reduction in hippocampal neurogenesis is still not fully understood. Here we show that the number of neuroblasts, but not granule neuron progenitors, is greatly reduced in 11-week old transgenic mice compared with wild-type (WT) controls. We demonstrate that NeuroD1 expression is reduced in the hippocampus. This is coupled to a decreased expression of downstream markers doublecortin and calretinin in maturing neurons. Taken together, our results suggest that mutant huntingtin (Htt) causes alterations of proteins expression in hippocampal progenitors, which might contribute to cognitive deficits in Huntington's disease. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
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| 8. |
- Paul-Visse, Gesine, et al.
(författare)
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The adult human brain harbors multipotent perivascular mesenchymal stem cells.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Blood vessels and adjacent cells form perivascular stem cell niches in adult tissues. In this perivascular niche, a stem cell with mesenchymal characteristics was recently identified in some adult somatic tissues. These cells are pericytes that line the microvasculature, express mesenchymal markers and differentiate into mesodermal lineages but might even have the capacity to generate tissue-specific cell types. Here, we isolated, purified and characterized a previously unrecognized progenitor population from two different regions in the adult human brain, the ventricular wall and the neocortex. We show that these cells co-express markers for mesenchymal stem cells and pericytes in vivo and in vitro, but do not express glial, neuronal progenitor, hematopoietic, endothelial or microglial markers in their native state. Furthermore, we demonstrate at a clonal level that these progenitors have true multilineage potential towards both, the mesodermal and neuroectodermal phenotype. They can be epigenetically induced in vitro into adipocytes, chondroblasts and osteoblasts but also into glial cells and immature neurons. This progenitor population exhibits long-term proliferation, karyotype stability and retention of phenotype and multipotency following extensive propagation. Thus, we provide evidence that the vascular niche in the adult human brain harbors a novel progenitor with multilineage capacity that appears to represent mesenchymal stem cells and is different from any previously described human neural stem cell. Future studies will elucidate whether these cells may play a role for disease or may represent a reservoir that can be exploited in efforts to repair the diseased human brain.
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| 9. |
- Roybon, Laurent, et al.
(författare)
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Effects on differentiation of embryonic ventral midbrain progenitors by Lmx1a, MSX1, Ngn2, and Pitx3.
- 2008
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Ingår i: The Journal of Neuroscience : the official journal of the Society for Neuroscience. - 1529-2401. ; 28:14, s. 3644-3656
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Tidskriftsartikel (refereegranskat)abstract
- Neurons derived from neural stem cells could potentially be used for cell therapy in neurodegenerative disorders, such as Parkinson's disease. To achieve controlled differentiation of neural stem cells, we expressed transcription factors involved in the development of midbrain dopaminergic neurons in rat and human neural progenitors. Using retroviral-mediated transgene delivery, we overexpressed Lmx1a (LIM homeobox transcription factor 1, alpha), Msx1 (msh homeobox homolog 1), Ngn2 (neurogenin 2), or Pitx3 (paired-like homeodomain transcription factor 3) in neurospheres derived from embryonic day 14.5 rat ventral mesencephalic progenitors. We also expressed either Lmx1a or Msx1 in the human embryonic midbrain-derived progenitor cell line NGC-407. Rat cells transduced with Ngn2 exited the cell cycle and expressed the neuronal marker microtubule-associated protein 2 and catecholamine-neuron protein vesicular monoamine transporter 2. Interestingly, Pitx3 downregulated the expression of SOX2 (SRY-box containing gene 2) and Nestin, altered cell morphology, but never induced neuronal or glial differentiation. Ngn2 exhibited a strong neuron-inducing effect. In contrast, few Lmx1a-transduced cells matured into neurons, and Msx1 overexpression promoted oligodendrogenesis rather than neuronal differentiation. Importantly, none of these four genes, alone or in combination, enhanced differentiation of rat neural stem cells into dopaminergic neurons. Notably, the overexpression of Lmx1a, but not Msx1, in human neural progenitors increased the yield of tyrosine hydroxylase-immunoreactive cells by threefold. Together, we demonstrate that induced overexpression of transcription factor genes has profound and specific effects on the differentiation of rat and human midbrain progenitors, although few dopamine neurons are generated.
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| 10. |
- Roybon, Laurent, et al.
(författare)
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Failure of transdifferentiation of adult hematopoietic stem cells into neurons.
- 2006
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 24:6, s. 1594-1604
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies of bone marrow-derived stem cell transdifferentiation into neurons have not involved purified cell populations and determined their exact phenotype prior to differentiation. The present study investigates whether highly purified mouse adult hematopoietic stem cells (HSCs), characterized by lineage marker depletion and expression of the cell surface markers Sca1 and c-Kit (Lin(-)Sca1(+) c-Kit(+) [LSK]), can be stimulated to adopt a neuronal fate. When the HSCLSK cells were cultured in vitro in neuronal differentiation medium supplemented with retinoic acid, 50% of the cells expressed the neural progenitor marker nestin and no cells had become postmitotic. Electrophysiological recordings on neuron-like cells showed that these cells were incapable of generating action potentials. When the HSCLSK cells either were grown in vitro together with neural precursor cells or were transplanted into the striatum or cerebellum of wild-type mouse, they either differentiated into Iba1-immunopositive macrophage/microglia or died. In conclusion, we demonstrate that adult HSCLSK cells do not have the capacity to leave the hematopoietic lineage and differentiate into neurons.
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