| 1. |
- Angot, Elodie, et al.
(författare)
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Alpha-Synuclein Cell-to-Cell Transfer and Seeding in Grafted Dopaminergic Neurons In Vivo.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:6
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Tidskriftsartikel (refereegranskat)abstract
- Several people with Parkinson's disease have been treated with intrastriatal grafts of fetal dopaminergic neurons. Following autopsy, 10-22 years after surgery, some of the grafted neurons contained Lewy bodies similar to those observed in the host brain. Numerous studies have attempted to explain these findings in cell and animal models. In cell culture, α-synuclein has been found to transfer from one cell to another, via mechanisms that include exosomal transport and endocytosis, and in certain cases seed aggregation in the recipient cell. In animal models, transfer of α-synuclein from host brain cells to grafted neurons has been shown, but the reported frequency of the event has been relatively low and little is known about the underlying mechanisms as well as the fate of the transferred α-synuclein. We now demonstrate frequent transfer of α-synuclein from a rat brain engineered to overexpress human α-synuclein to grafted dopaminergic neurons. Further, we show that this model can be used to explore mechanisms underlying cell-to-cell transfer of α-synuclein. Thus, we present evidence both for the involvement of endocytosis in α-synuclein uptake in vivo, and for seeding of aggregation of endogenous α-synuclein in the recipient neuron by the transferred α-synuclein. Finally, we show that, at least in a subset of the studied cells, the transmitted α-synuclein is sensitive to proteinase K. Our new model system could be used to test compounds that inhibit cell-to-cell transfer of α-synuclein and therefore might retard progression of Parkinson neuropathology.
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| 2. |
- Angot, Elodie, et al.
(författare)
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Are synucleinopathies prion-like disorders?
- 2010
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Ingår i: Lancet Neurology. - 1474-4465. ; Okt, s. 1128-1138
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Tidskriftsartikel (refereegranskat)abstract
- A shared neuropathological feature of idiopathic Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy is the development of intracellular aggregates of α-synuclein that gradually engage increasing parts of the nervous system. The pathogenetic mechanisms underlying these neurodegenerative disorders, however, are unknown. Several studies have highlighted similarities between classic prion diseases and these neurological proteinopathies. Specifically, identification of Lewy bodies in fetal mesencephalic neurons transplanted in patients with Parkinson's disease raised the hypothesis that α-synuclein, the main component of Lewy bodies, could be transmitted from the host brain to a graft of healthy neurons. These results and others have led to the hypothesis that a prion-like mechanism might underlie progression of synucleinopathy within the nervous system. We review experimental findings showing that misfolded α-synuclein can transfer between cells and, once transferred into a new cell, can act as a seed that recruits endogenous α-synuclein, leading to formation of larger aggregates. This model suggests that strategies aimed at prevention of cell-to-cell transfer of α-synuclein could retard progression of symptoms in Parkinson's disease and other synucleinopathies.
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| 3. |
- Anisimov, Sergey, et al.
(författare)
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Identification of molecules derived from human fibroblast feeder cells that support the proliferation of human embryonic stem cells.
- 2011
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Ingår i: Cellular & Molecular Biology Letters. - : Walter de Gruyter GmbH. - 1689-1392. ; 16:1, s. 79-88
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Tidskriftsartikel (refereegranskat)abstract
- The majority of human embryonic stem cell lines depend on a feeder cell layer for continuous growth in vitro, so that they can remain in an undifferentiated state. Limited knowledge is available concerning the molecular mechanisms that underlie the capacity of feeder cells to support both the proliferation and pluripotency of these cells. Importantly, feeder cells generally lose their capacity to support human embryonic stem cell proliferation in vitro following long-term culture. In this study, we performed large-scale gene expression profiles of human foreskin fibroblasts during early, intermediate and late passages using a custom DNA microarray platform (NeuroStem 2.0 Chip). The microarray data was validated using RT-PCR and virtual SAGE analysis. Our comparative gene expression study identified a limited number of molecular targets potentially involved in the ability of human neonatal foreskin fibroblasts to serve as feeder cells for human embryonic stem cell cultures. Among these, the C-KIT, leptin and pigment epithelium-derived factor (PEDF) genes were the most interesting candidates.
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| 4. |
- Barker, Roger A., et al.
(författare)
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A new approach to disease-modifying drug trials in Parkinson's disease
- 2013
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 123:6, s. 2364-2365
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Translating new findings in the laboratory into therapies for patients is a slow and expensive process. The development of therapies for neurodegenerative diseases is further complicated by the difficulty in determining whether the drug truly retards the slow degenerative process or provides only symptomatic benefit. In this issue, Aviles-Olmos et al. describe a first in Parkinson's disease (PD) patient study using a drug previously approved for diabetes treatment. In addition to suggesting that the drug may indeed be disease modifying in PD, their innovative approach suggests there may be more rapid and inexpensive avenues for testing novel therapies in PD.
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| 5. |
- Boza-Serrano, Antonio, et al.
(författare)
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The role of Galectin-3 in α-synuclein-induced microglial activation
- 2014
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Ingår i: Acta Neuropathologica Communications. - : Springer Science and Business Media LLC. - 2051-5960. ; 2
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Forskningsöversikt (refereegranskat)abstract
- Background: Parkinson's disease (PD) is the most prevalent neurodegenerative motor disorder. The neuropathology is characterized by intraneuronal protein aggregates of α-synuclein and progressive degeneration of dopaminergic neurons within the substantia nigra. Previous studies have shown that extracellular α-synuclein aggregates can activate microglial cells, induce inflammation and contribute to the neurodegenerative process in PD. However, the signaling pathways involved in α-synuclein-mediated microglia activation are poorly understood. Galectin-3 is a member of a carbohydrate-binding protein family involved in cell activation and inflammation. Therefore, we investigated whether galectin-3 is involved in the microglia activation triggered by α-synuclein. Results: We cultured microglial (BV2) cells and induced cell activation by addition of exogenous α-synuclein monomers or aggregates to the cell culture medium. This treatment induced a significant increase in the levels of proinflammatory mediators including the inducible Nitric Oxide Synthase (iNOS), interleukin 1 Beta (IL-1β) and Interleukin-12 (IL-12). We then reduced the levels of galectin-3 expression using siRNA or pharmacologically targeting galectin-3 activity using bis-(3-deoxy-3-(3-fluorophenyl-1H-1,2,3-triazol-1-yl)-β-D-galactopyranosyl)-sulfane. Both approaches led to a significant reduction in the observed inflammatory response induced by α-synuclein. We confirmed these findings using primary microglial cells obtained from wild-type and galectin-3 null mutant mice. Finally, we performed injections of α-synuclein in the olfactory bulb of wild type mice and observed that some of the α-synuclein was taken up by activated microglia that were immunopositive for galectin-3. Conclusions: We show that α-synuclein aggregates induce microglial activation and demonstrate for the first time that galectin-3 plays a significant role in microglia activation induced by α-synuclein. These results suggest that genetic down-regulation or pharmacological inhibition of galectin-3 might constitute a novel therapeutic target in PD and other synucleinopathies.
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| 8. |
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| 9. |
- Brundin, Patrik, et al.
(författare)
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Neural grafting in Parkinson's disease: problems and possibilities
- 2010
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Ingår i: Progress in Brain Research. - 1875-7855. ; 184, s. 265-294
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Forskningsöversikt (refereegranskat)abstract
- Neural transplantation has emerged as a possible therapy for Parkinson's disease (PD). Clinical studies performed during the 1990s, where dopaminergic neurons derived from the human embryonic brain were transplanted into striatum of patients with PD, provided proof-of-principle that long-lasting therapeutic benefits can be achieved. Subsequent studies, in particular two that followed a double-blind, sham surgery, placebo-control design, showed variable and mostly negative results. They also revealed that some patients develop involuntary movements, so called graft-induced dyskinesias, as side effects. Thus, while nigral transplants clearly work well in select PD cases, the technique needs refinement before it can successfully be performed in a large series of patients. In this review, we describe the clinical neural transplantation trials in PD and the likely importance of factors such as patient selection, trial design, preparation of the donor tissue, and surgical techniques for successful outcome and avoiding unwanted side effects. We also highlight that it was recently found that neuropathological signs typical for PD can appear inside some of the grafted neurons over a decade after surgery. Finally, we discuss future possibilities offered by stem cells as potential sources of dopamine neurons that can be used for transplantation in PD.
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| 10. |
- Brundin, Patrik, et al.
(författare)
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Neuropathology in transplants in Parkinson's disease: Implications for disease pathogenesis and the future of cell therapy.
- 2012
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Ingår i: Progress in Brain Research. - 1875-7855. ; 200, s. 221-241
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Tidskriftsartikel (refereegranskat)abstract
- Neural transplantation is over a century old, but the modern era encompasses only the last 30-40 years. For most of this time period, research has focused on reversing disability engendered by neurologic disease and brain damage. Only recently was it recognized that the underlying neurological disease itself might negatively impact the grafted neurons. We have found that a subset of neurons within embryonic neural grafts that survive more than 10 years in Parkinson patients display Lewy bodies, a classical feature of Parkinson's disease neuropathology. Additionally, the grafted cells placed in the Parkinson's disease brain eventually downregulate the expression of dopamine transporter and tyrosine hydroxylase in a manner similar to what is seen in the substantia nigra dopamine neurons that are degenerating due to the disease. We discuss these findings in terms of how they might improve our understanding of Parkinson's disease pathogenesis and the effects they may have on the future of neural cell replacement strategies.
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