| 1. |
- Barker, Roger A., et al.
(author)
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GDNF and Parkinson's Disease : Where Next? A Summary from a Recent Workshop
- 2020
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In: Journal of Parkinson's Disease. - 1877-7171. ; 10:3, s. 875-891
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Journal article (peer-reviewed)abstract
- The concept of repairing the brain with growth factors has been pursued for many years in a variety of neurodegenerative diseases including primarily Parkinson's disease (PD) using glial cell line-derived neurotrophic factor (GDNF). This neurotrophic factor was discovered in 1993 and shown to have selective effects on promoting survival and regeneration of certain populations of neurons including the dopaminergic nigrostriatal pathway. These observations led to a series of clinical trials in PD patients including using infusions or gene delivery of GDNF or the related growth factor, neurturin (NRTN). Initial studies, some of which were open label, suggested that this approach could be of value in PD when the agent was injected into the putamen rather than the cerebral ventricles. In subsequent double-blind, placebo-controlled trials, the most recent reporting in 2019, treatment with GDNF did not achieve its primary end point. As a result, there has been uncertainty as to whether GDNF (and by extrapolation, related GDNF family neurotrophic factors) has merit in the future treatment of PD. To critically appraise the existing work and its future, a special workshop was held to discuss and debate this issue. This paper is a summary of that meeting with recommendations on whether there is a future for this therapeutic approach and also what any future PD trial involving GDNF and other GDNF family neurotrophic factors should consider in its design.
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| 2. |
- Marmion, David J., et al.
(author)
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Viral-based rodent and nonhuman primate models of multiple system atrophy : Fidelity to the human disease
- 2021
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In: Neurobiology of Disease. - : Elsevier BV. - 0969-9961. ; 148
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Journal article (peer-reviewed)abstract
- Multiple system atrophy (MSA) is a rare and extremely debilitating progressive neurodegenerative disease characterized by variable combinations of parkinsonism, cerebellar ataxia, dysautonomia, and pyramidal dysfunction. MSA is a unique synucleinopathy, in which alpha synuclein-rich aggregates are present in the cytoplasm of oligodendroglia. The precise origin of the alpha synuclein (aSyn) found in the glial cytoplasmic inclusions (GCIs) as well the mechanisms of neurodegeneration in MSA remain unclear. Despite this fact, cell and animal models of MSA rely on oligodendroglial overexpression of aSyn. In the present study, we utilized a novel oligotrophic AAV, Olig001, to overexpress aSyn specifically in striatal oligodendrocytes of rats and nonhuman primates in an effort to further characterize our novel viral vector-mediated MSA animal models. Using two cohorts of animals with 10-fold differences in Olig001 vector titers, we show a dose-dependent formation of MSA-like pathology in rats. High titer of Olig001-aSyn in these animals were required to produce the formation of pS129+ and proteinase K resistant aSyn-rich GCIs, demyelination, and neurodegeneration. Using this knowledge, we injected high titer Olig001 in the putamen of cynomolgus macaques. After six months, histological analysis showed that oligodendroglial overexpression of aSyn resulted in the formation of hallmark GCIs throughout the putamen, demyelination, a 44% reduction of striatal neurons and a 12% loss of nigral neurons. Furthermore, a robust inflammatory response similar to MSA was produced in Olig001-aSyn NHPs, including microglial activation, astrogliosis, and a robust infiltration of T cells into the CNS. Taken together, oligodendroglial-specific viral vector-mediated overexpression of aSyn in rats and nonhuman primates faithfully reproduces many of the pathological disease hallmarks found in MSA. Future studies utilizing these large animal models of MSA would prove extremely valuable as a pre-clinical platform to test novel therapeutics that are so desperately needed for MSA.
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| 3. |
- Björklund, Anders, et al.
(author)
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Cell therapy for Parkinson's disease: what next?
- 2013
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In: Movement Disorders. - : Wiley. - 0885-3185. ; 28:1, s. 110-115
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Journal article (peer-reviewed)abstract
- The idea to use transplants of dopamine-producing cells to substitute for the lost midbrain dopamine neurons in Parkinson's disease (PD) goes back to the 1970s. In this review we give an overview of the history of cell transplantation in animal models of PD, and summarize the experience gained from the open-label and placebo-controlled clinical trials performed so far using intrastriatal transplants of human fetal dopamine neuroblasts. Further development of this therapeutic approach face numerous challenges, for example in the development of protocols that allow generation of fully functional and safe midbrain dopamine neurons from stem cells. Based on recent promising advancements, efforts are now being made to develop standardized and efficient protocols, and adapt these protocols to good laboratory practice (GLP)/good manufacturing practice (GMP) conditions, to move this technology closer to clinical translation. © 2013 Movement Disorder Society.
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| 4. |
- Björklund, Tomas, et al.
(author)
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Gene therapy for Parkinson's disease.
- 2010
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In: Movement Disorders. - : Wiley. - 0885-3185. ; 25 Suppl 1, s. 161-173
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Journal article (peer-reviewed)abstract
- The once fantastic theoretical concept that patients with Parkinson's disease (PD) would receive gene therapy in an attempt to alleviate their symptoms and potentially modify the course of their disease has become a reality. On the basis of positive preclinical data, four different gene therapy approaches are currently in Phase I or Phase II clinical trials. Some approaches are intended to increase levels of endogenous dopamine or enhance the function of the prodrug levodopa. Others are intended to normalize basal ganglia circuitry by reducing the PD-related overactivity of specific brain structures such as the subthalamic nucleus. Each is intended for symptomatic benefit. Finally, gene delivery of trophic factors that not only augment dopaminergic function but are potentially disease modifying has a strong preclinical database and are also in clinical trials. Each of these approaches is discussed in the present review.
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| 5. |
- Brundin, Patrik, et al.
(author)
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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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In: Progress in Brain Research. - 1875-7855. ; 200, s. 221-241
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Journal article (peer-reviewed)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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| 6. |
- Cederfjäll, Erik, et al.
(author)
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Continuous DOPA synthesis from a single AAV: dosing and efficacy in models of Parkinson's disease.
- 2013
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 3
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Journal article (peer-reviewed)abstract
- We used a single adeno-associated viral (AAV) vector co-expressing tyrosine hydroxylase (TH) and GTP cyclohydrolase 1 (GCH1) to investigate the relationship between vector dose, and the magnitude and rate of recovery in hemi-parkinsonian rats. Intrastriatal injections of >1E10 genomic copies (gc) of TH-GCH1 vector resulted in complete recovery in drug-naïve behavior tests. Lower vector dose gave partial to no functional improvement. Stereological quantification revealed no striatal NeuN+ cell loss in any of the groups, whereas a TH-GCH1 dose of >1E11 gc resulted in cell loss in globus pallidus. Thus, a TH-GCH1 dose of 1E10 gc gave complete recovery without causing neuronal loss. Safety and efficacy was also studied in non-human primates where the control vector resulted in co-expression of the transgenes in caudate-putamen. In the TH-GCH1 group, GCH1 expression was robust but TH was not detectable. Moreover, TH-GCH1 treatment did not result in functional improvement in non-human primates.
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| 7. |
- Dodiya, Hemraj B., et al.
(author)
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Differential Transduction Following Basal Ganglia Administration of Distinct Pseudotyped AAV Capsid Serotypes in Nonhuman Primates
- 2010
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In: Molecular Therapy. - : Elsevier BV. - 1525-0024 .- 1525-0016. ; 18:3, s. 579-587
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Journal article (peer-reviewed)abstract
- We examined the transduction efficiency of different adeno-associated virus (AAV) capsid serotypes encoding for green fluorescent protein (GFP) flanked by AAV2 inverted terminal repeats in the nonhuman primate basal ganglia as a prelude to translational studies, as well as clinical trials in patients with Parkinson's disease (PD). Six intact young adult cynomolgus monkeys received a single 10 mu l injection of AAV2/1-GFP, AAV2/5-GFP, or AAV2/8-GFP pseudotyped vectors into the caudate nucleus and putamen bilaterally in a pattern that resulted in each capsid serotype being injected into at least four striatal sites. GFP immunohistochemistry revealed excellent transduction rates for each AAV pseudotype. Stereological estimates of GFP(+) cells within the striatum revealed that AAV2/5-GFP transduces significantly higher number of cells than AAV2/8-GFP (P < 0.05) and there was no significant difference between AAV2/5-GFP and AAV2/1-GFP (P = 0.348). Consistent with this result, Cavalieri estimates revealed that AAV2/5-GFP resulted in a significantly larger transduction volume than AAV2/8-GFP (P < 0.05). Each pseudotype transduced striatal neurons effectively [>95% GFP(+) cells colocalized neuron-specific nuclear protein (NeuN)]. The current data suggest that AAV2/5 and AAV2/1 are superior to AAV2/8 for gene delivery to the nonhuman primate striatum and therefore better candidates for therapeutic applications targeting this structure.
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