| 1. |
- Brundin, Patrik, et al.
(author)
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Bilateral caudate and putamen grafts of embryonic mesencephalic tissue treated with lazaroids in Parkinson's disease
- 2000
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In: Brain. - 1460-2156. ; 123, s. 1380-1390
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Journal article (peer-reviewed)abstract
- Five parkinsonian patients were transplanted bilaterally into the putamen and caudate nucleus with human embryonic mesencephalic tissue from between seven and nine donors. To increase graft survival, the lipid peroxidation inhibitor tirilazad mesylate was administered to the tissue before implantation and intravenously to the patients for 3 days thereafter. During the second postoperative year, the mean daily L-dopa dose was reduced by 54% and the UPDRS (Unified Parkinson's Disease Rating Scale) motor score in 'off' phase was reduced by a mean of 40%. At 10-23 months after grafting, PET showed a mean 61% increase of 6-L-[(18)F]fluorodopa uptake in the putamen, and 24% increase in the caudate nucleus, compared with preoperative values. No obvious differences in the pattern of motor recovery were observed between these and other previously studied cases with putamen grafts alone. The amount of mesencephalic tissue implanted in each putamen and caudate nucleus was 42 and 50% lower, respectively, compared with previously transplanted patients from our centre. Despite this reduction in grafted tissue, the magnitudes of symptomatic relief and graft survival were very similar. These findings suggest that tirilazad mesylate may improve survival of grafted dopamine neurons in patients, which is in agreement with observations in experimental animals.
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| 2. |
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| 3. |
- Hagell, Peter, et al.
(author)
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Cell survival and clinical outcome following intrastriatal transplantation in Parkinson disease
- 2001
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In: Journal of Neuropathology and Experimental Neurology. - 0022-3069 .- 1554-6578. ; 60:8, s. 741-752
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Journal article (peer-reviewed)abstract
- Intrastriatal transplantation of embryonic dopaminergic neurons is currently explored as a restorative cell therapy for Parkinson disease (PD). Clinical results have varied, probably due to differences in transplantation methodology and patient selection. In this review, we assess clinical trials and autopsy findings in grafted PD patients and suggest that a minimum number of surviving dopaminergic neurons is required for a favorable outcome. Restoration of [18F]-fluorodopa uptake in the putamen to about 50% of the normal mean seems necessary for moderate to marked clinical benefit to occur. Some studies indicate that this may require mesencephalic tissue from 3-5 human embryos implanted into each hemisphere. The volume, density and pattern of fiber outgrowth and reinnervation, as well as functional integration and dopamine release. are postulated as additional important factors for an optimal clinical outcome. For neural transplantation to become a feasible therapeutic alternative in PD, graft survival must be increased and the need for multiple donors of human embryonic tissue substantially decreased or alternate sources of donor tissue developed. Donor cells derived from alternative sources should demonstrate features comparable to those associated with successful implantation of human embryonic tissue before clinical trials are considered.
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| 4. |
- Hansson, Oskar, et al.
(author)
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Additive effects of caspase inhibitor and lazaroid on the survival of transplanted rat and human embryonic dopamine neurons
- 2000
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In: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 164:1, s. 102-111
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Journal article (peer-reviewed)abstract
- Major practical constraints on neural grafting in Parkinson's disease are the shortage of human donor tissue and the great loss of dopamine neurons during the grafting procedure. The vast majority of implanted embryonic dopamine neurons are believed to die within a few days of transplantation surgery, at least in part through apoptosis. We have previously found that survival of nigral grafts in rodents can be significantly augmented by pretreatment with the caspase inhibitor Ac-YVAD-cmk or by lazaroids (lipid peroxidation inhibitors). We now report that pretreatment with the caspase inhibitor Ac-DEVD-cmk, but not z-VAD-fmk, results in a significantly improved survival of transplanted dopamine neurons of similar magnitude to that achieved in this study using Ac-YVAD-cmk (both 220-230% of control). In addition, we found that treatment of the graft tissue with tirilazad mesylate (a lazaroid allowed for clinical use) almost doubled the survival of grafted dopamine neurons. When Ac-YVAD-cmk and tirilazad mesylate treatments were combined, the number of surviving dopamine neurons increased significantly further to 280% of control. Importantly, the same combination of neuroprotectants enhanced the survival of human dopamine neurons xenotransplanted to immunosuppressed rats (to 240% of control). In conclusion, these results suggest that combining treatments that counteract oxidative stress and caspase activation is a valuable strategy to enhance nigral graft survival that should be considered for clinical application.
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| 5. |
- Hansson, Oskar, et al.
(author)
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Partial resistance to malonate-induced striatal cell death in transgenic mouse models of Huntington's disease is dependent on age and CAG repeat length
- 2001
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In: Journal of Neurochemistry. - Lund Univ, Sect Neuronal Survival, Wallenberg Neurosci Ctr, Dept Physiol Sci, S-22184 Lund, Sweden. State Univ Campinas, Sch Med Sci, Dept Clin Pathol, Campinas, SP, Brazil. Univ Uppsala, Dept Neurosci, Uppsala, Sweden. GKT, Sch Med, London, England. : BLACKWELL SCIENCE LTD. - 0022-3042 .- 1471-4159. ; 78:4, s. 694-703
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Journal article (peer-reviewed)abstract
- Transgenic, Huntington's disease (HD) mice, expressing exon I of the HD gene with an expanded CAG repeat, are totally resistant to striatal, lesion induced by excessive NMDA receptor activation. We now show that striatal lesions induced by the mitochondrial toxin malonate are reduced by 70-80% in transgenic HD mice compared with wild-type littermate controls. This occurred in 6- and 12-week-old HID mice with 150 CAG repeats (line R6/2) and in 18-week-old, but not 6-week-old, HID mice with 115 CAG repeats (line R6/1). Therefore, we show for the first time that the resistance to neurotoxin in transgenic HD mice is dependent on both the CAG repeat length and the age of the mice. Importantly, most HD patients develop symptoms in adulthood and exhibit an inverse relationship between GAG repeat length and age of onset. Transgenic mice expressing a normal CAG repeat (18 CAG) were not resistant to malonate. Although endogenous glutamate release has been implicated in malonate-induced cell death, glutamate release from striatal synaptosomes was not decreased in HID mice. Malonate-induced striatal cell death was reduced by 50-60% in wild-type mice when they were treated with either the NMDA receptor antagonist MK-801 or the caspase inhibitor zVAD-fmk. These two compounds did not reduce lesion size in transgenic R6/1 mice. This might suggest that NMDA receptor- and caspase-mediated cell death pathways are inhibited and that the limited malonate-induced cell death still occurring in HID mice is independent of these pathways. There were no changes in striatal levels of the two anti cell death proteins Bcl-X-L and X-linked Inhibitor of apoptosis protein (XIAP), before or after the lesion in transgenic HD mice. We propose that mutant huntingtin causes a sublethal grade of metabolic stress which is CAG repeat length-dependent and results in up-regulation over time of cellular defense mechanisms against impaired energy metabolism and excitotoxicity.
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| 6. |
- Larsson, L C, et al.
(author)
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Intrastriatal ventral mesencephalic xenografts of porcine tissue in rats : immune responses and functional effects
- 2000
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In: Cell Transplantation. - 0963-6897. ; 9:2, s. 72-261
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Journal article (peer-reviewed)abstract
- Transplantation of neural tissue from other species has the potential to improve function in patients with neurodegenerative disorders. We investigated the functional effects of embryonic porcine dopaminergic neurons transplanted in a rat model of Parkinson's disease and the immune responses to the grafts in immunosuppressed and nonimmunosuppressed hosts. Twenty-three rats with unilateral 6-hydroxydopamine lesions received dissociated, 27-day-old embryonic porcine ventral mesencephalic tissue in the right striatum. Eighteen rats received cyclosporine (10 mg/kg, IP, daily) during the whole period of 14 weeks, in combination with prednisolone (20 mg/kg, IP, daily) the first 4 days. Five rats served as nonimmunosuppressed controls. All rats were tested for amphetamine-induced rotational behavior at 3-week intervals. Two immunosuppressed rats were excluded due to severe side effects of the treatment. Functional recovery was seen in 9 of 16 immunosuppressed rats at 12 weeks. Six animals remained functionally recovered at 14 weeks and contained an average of 5750+/-1450 (SEM) dopaminergic neurons. Between 9 and 14 weeks, three immunosuppressed rats rejected their grafts, based on rotation scores and immunohistochemical demonstration of cell infiltrates. One additional immunosuppressed rat showed evidence of ongoing rejection at 14 weeks. The striata in animals with ongoing or recent rejection contained large numbers of CD4- and CD8-positive lymphocytes, NK cells, macrophages, and microglia cells, whereas scar tissue was found in rats with grafts rejected at earlier time points (n = 11). Embryonic porcine ventral mesencephalic tissue matures in the adult rat striatum, reinnervates the host brain, and restores behavioral defects. Immunosuppressive treatment was necessary for long-term graft survival and functional recovery, but did not sufficiently protect from rejection mechanisms. Porcine neural tissue is an interesting alternative to embryonic human tissue for intracerebral transplantation in neurodegenerative diseases. However, to achieve stable graft survival in discordant xenogeneic combinations, an appropriate immunosuppressive treatment or donor tissue modifications are needed.
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| 7. |
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| 8. |
- Petersén, Åsa, et al.
(author)
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Evidence for Dysfunction of the Nigrostriatal Pathway in the R6/1 Line of Transgenic Huntington's Disease Mice.
- 2002
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In: Neurobiology of Disease. - : Elsevier BV. - 0969-9961. ; 11:1, s. 134-146
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Journal article (peer-reviewed)abstract
- The present multidisciplinary study examined nigrostriatal dopamine and striatal amino acid transmission in the R6/1 line of transgenic Huntington's disease (HD) mice expressing exon 1 of the HD gene with 115 CAG repeats. Although the number of tyrosine hydroxylase-positive neurons was not reduced and nigrostriatal connectivity remained intact in 16-week-old R6/1 mice, the size of tyrosine hydroxylase-positive neurons in the substantia nigra was reduced by 15%, and approximately 30% of these cells exhibited aggregated huntingtin. In addition, using in vivo microdialysis, we found that basal extracellular striatal dopamine levels were reduced by 70% in R6/1 mice compared to their wild-type littermates. Intrastriatal perfusion with malonate in R6/1 mice resulted in a short-lasting, attenuated increase in local dopamine release compared to wild-type mice. Furthermore, the size of the malonate-induced striatal lesion was 80% smaller in these animals. Taken together, these findings suggest that a functional deficit in nigrostriatal dopamine transmission may contribute to the behavioral phenotype and the resistance to malonate-induced neurotoxicity characteristic of R6/1 HD mice.
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| 9. |
- Piccini, P, et al.
(author)
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Delayed recovery of movement-related cortical function in Parkinson's disease after striatal dopaminergic grafts
- 2000
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In: Annals of Neurology. - 1531-8249. ; 48:5, s. 689-695
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Journal article (peer-reviewed)abstract
- Intrastriatal transplantation of dopaminergic neurones aims to repair the selective loss of nigrostriatal projections and the consequent dysfunction of striatocortical circuitries in Parkinson's disease (PD). Here, we have studied the effects of bilateral human embryonic dopaminergic grafts on the movement-related activation of frontal cortical areas in 4 PD patients using H2 15O positron emission tomography and a joystick movement task. At 6.5 months after transplantation, mean striatal dopamine storage capacity as measured by 18F-dopa positron emission tomography was already significantly elevated in these patients. This was associated with a modest clinical improvement on the Unified Parkinson's Disease Rating Scale, whereas the impaired cortical activation was unchanged. At 18 months after surgery, there was further significant clinical improvement in the absence of any additional increase in striatal 18F-dopa uptake. Rostral supplementary motor and dorsal prefrontal cortical activation during performance of joystick movements had significantly improved, however. Our data suggest that the function of the graft goes beyond that of a simple dopamine delivery system and that functional integration of the grafted neurones within the host brain is necessary to produce substantial clinical recovery in PD.
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