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| 2. |
- Francardo, Veronica, et al.
(författare)
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Impact of the lesion procedure on the profiles of motor impairment and molecular responsiveness to L-DOPA in the 6-hydroxydopamine mouse model of Parkinson's disease.
- 2011
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Ingår i: Neurobiology of disease. - : Elsevier BV. - 1095-953X .- 0969-9961. ; 42:3, s. 327-40
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Tidskriftsartikel (refereegranskat)abstract
- 6-Hydroxydopamine (6-OHDA) lesions are being used in the mouse for basic research on Parkinson's disease and L-DOPA-induced dyskinesia. We set out to compare unilateral lesion models produced by intrastriatal or intramesencephalic injections of a fixed 6-OHDA concentration (3.2 μg/μl) in C57BL/6 mice. In the first experiment, toxin injections were performed either at two striatal coordinates (1 or 2 μl per site, termed "striatum(2 × 1 μl)" and "striatum(2 × 2 μl)" models), in the medial forebrain bundle (MFB), or in the substantia nigra pars compacta (SN) (1 μl per site). All the four lesion models produced significant forelimb use asymmetry, but spontaneous turning asymmetry only occurred in the MFB and striatum(2 × 2 μl) models. After the behavioral studies, the induction of phosphorylated extracellular signal-regulated kinases 1 and 2 (pERK1/2) by acute L-DOPA (30 mg/kg) was used as a marker of post-synaptic supersensitivity. Striatal pERK1/2 expression was sparse in the SN and striatum(2 × 1 μl) groups, but pronounced in the striatum(2 × 2 μl) and MFB-lesioned mice. In further experiments, mice with MFB and striatal(2 × 2 μl) lesions were used to compare behavioral and molecular responses to chronic L-DOPA treatment (12 days at 3 and 6 mg/kg/day). Maximally severe abnormal involuntary movements (AIMs) occurred in all MFB-lesioned mice, whereas only 35% of the mice with striatal lesions developed dyskinesia. Striatal tissue levels of dopamine were significantly lower in the dyskinetic animals (both MFB and striatum(2 × 2 μl) groups) in comparison with the non-dyskinetic ones. Noradrenaline levels were significantly reduced only in MFB lesioned animals and did not differ among the dyskinetic and non-dyskinetic cases with striatal lesions. In all groups, the L-DOPA-induced AIM scores correlated closely with the number of cells immunoreactive for tyrosine hydroxylase or FosB/∆FosB in the striatum. In conclusion, among the four lesion procedures examined here, only the MFB and striatum(2 × 2 μl) models yielded a degree of dopamine denervation sufficient to produce spontaneous postural asymmetry and molecular supersensitivity to L-DOPA. Both lesion models are suitable to reproduce L-DOPA-induced dyskinesia, although only MFB lesions yield a pronounced and widespread expression of post-synaptic supersensitivity markers in the striatum.
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| 3. |
- Francardo, Veronica, et al.
(författare)
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Pharmacological stimulation of sigma-1 receptors has neurorestorative effects in experimental parkinsonism
- 2014
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 137, s. 1998-2014
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Tidskriftsartikel (refereegranskat)abstract
- Sigma-1 receptor ligands may have neuroprotective and neurorestorative properties. In a mouse model of parkinsonism, Francardo et al. show that chronic treatment with the sigma-1 receptor agonist PRE-084 increases the density of striatal dopaminergic fibres and improves forelimb use. Boosting sigma-1 receptor activity may have disease-modifying effects in ParkinsonA ' s disease.The sigma-1 receptor, an endoplasmic reticulum-associated molecular chaperone, is attracting great interest as a potential target for neuroprotective treatments. We provide the first evidence that pharmacological modulation of this protein produces functional neurorestoration in experimental parkinsonism. Mice with intrastriatal 6-hydroxydopamine lesions were treated daily with the selective sigma-1 receptor agonist, PRE-084, for 5 weeks. At the dose of 0.3 mg/kg/day, PRE-084 produced a gradual and significant improvement of spontaneous forelimb use. The behavioural recovery was paralleled by an increased density of dopaminergic fibres in the most denervated striatal regions, by a modest recovery of dopamine levels, and by an upregulation of neurotrophic factors (BDNF and GDNF) and their downstream effector pathways (extracellular signal regulated kinases 1/2 and Akt). No treatment-induced behavioural-histological restoration occurred in sigma-1 receptor knockout mice subjected to 6-hydroxydopamine lesions and treated with PRE-084. Immunoreactivity for the sigma-1 receptor protein was evident in both astrocytes and neurons in the substantia nigra and the striatum, and its intracellular distribution was modulated by PRE-084 (the treatment resulted in a wider intracellular distribution of the protein). Our results suggest that sigma-1 receptor regulates endogenous defence and plasticity mechanisms in experimental parkinsonism. Boosting the activity of this protein may have disease-modifying effects in Parkinson's disease.
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| 4. |
- Lindgren, Hanna, et al.
(författare)
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L-DOPA-induced dopamine efflux in the striatum and the substantia nigra in a rat model of Parkinson's disease: temporal and quantitative relationship to the expression of dyskinesia.
- 2010
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Ingår i: Journal of neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 112:6, s. 1465-76
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Tidskriftsartikel (refereegranskat)abstract
- Abstract L-DOPA-induced dyskinesia in Parkinson's Disease (PD) is associated with large increases in brain dopamine (DA) levels following drug dosing, but the precise significance of this phenomenon is not understood. Here we compare DA efflux and metabolism in the striatum and the substantia nigra (SN) in dyskinetic and non-dyskinetic animals following a standard dose of L-DOPA. Rats with 6-OHDA lesions were treated chronically with L-DOPA, monitored on the abnormal involuntary movements (AIMs) scale, and then subjected to intracerebral microdialysis under freely-moving conditions. Following s.c. L-DOPA injection, peak extracellular DA levels in both striatum and SN were twice as large in dyskinetic animals compared to non-dyskinetic rats. This effect was not attributable to differences in DOPA levels or DA metabolism. The larger DA efflux in dyskinetic animals was blunted by 5-HT1A/5-HT1B receptor agonists and TTX infusion, reflecting release from serotonin neurons. Striatal levels of serotonin and its main metabolite, 5-hydroxyindolacetic acid were indeed elevated in dyskinetic animals compared to non-dyskinetic rats, indicating a larger serotonergic innervation density in the former group. High DA release was, however, not sufficient to explain dyskinesia. The AIMs output per unit concentration of striatal extracellular DA was indeed much larger in dyskinetic animals compared to non-dyskinetic cases at most time points examined. The present results indicate that both a high DA release post L-DOPA administration and an increased responsiveness to DA must coexist for a full expression of dyskinesia.
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| 5. |
- Ran, C., et al.
(författare)
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Strong association between glucocerebrosidase mutations and Parkinson's disease in Sweden
- 2016
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 45
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Tidskriftsartikel (refereegranskat)abstract
- Several genetic studies have demonstrated an association between mutations in glucocerebrosidase (GBA), originally implicated in Gaucher's disease, and an increased risk of Parkinson's disease (PD). We have investigated the possible involvement of genetic GBA variations in PD in the Swedish population. Three GBA variants, E326K, N370S, and L444P were screened in the largest Swedish Parkinson cohort reported to date; 1625 cases and 2025 control individuals. We found a significant association with high effect size of the rare variant L444P with PD (odds ratio 8.17; 95% confidence interval: 2.51-26.23; p-value = 0.0020) and a significant association of the common variant E326K (odds ratio 1.60; 95% confidence interval: 1.16-2.22; p-value = 0.026). The rare variant N370S showed a trend for association. Most L444P carriers (68%) were found to reside in northern Sweden, which is consistent with a higher prevalence of Gaucher's disease in this part of the country. Our findings support the role of GBA mutations as risk factors for PD and point to lysosomal dysfunction as a mechanism contributing to PD etiology. (C) 2016 The Author(s). Published by Elsevier Inc.
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| 6. |
- von Otter, Malin, 1978, et al.
(författare)
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Kinesin Light Chain 1 Gene Haplotypes in Three Conformational Diseases
- 2010
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Ingår i: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 12:3, s. 229-236
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Tidskriftsartikel (refereegranskat)abstract
- A functional intracellular transport system is essential to maintain cell shape and function especially in elongated cells, e.g. neurons and lens fibre cells. Impaired intracellular transport has been suggested as a common pathological mechanism for age-related diseases characterised by protein aggregation. Here, we hypothesise that common genetic variation in the transport protein kinesin may influence the risk of Parkinson's disease (PD), Alzheimer's disease (AD) and age-related cataract. This case-control study involves a PD material (165 cases and 190 controls), an AD material (653 cases and 845 controls) and a cataract material (495 cases and 183 controls). Genetic variation in the kinesin light chain 1-encoding gene (KLC1) was tagged by six tag single nucleotide polymorphisms (SNPs). Single SNPs and haplotypes were analysed for associations with disease risk, age parameters, mini-mental state examination scores and cerebrospinal fluid biomarkers for AD using logistic or linear regression. Genetic variation in KLC1 did not influence risk of PD. Weak associations with risk of AD were seen for rs8007903 and rs3212079 (P (c) = 0.04 and P (c) = 0.02, respectively). Two SNPs (rs8007903 and rs8702) influenced risk of cataract (P (c) = 0.0007 and P (c) = 0.04, respectively). However, the allele of rs8007903 that caused increased risk of AD caused reduced risk of cataract, speaking against a common functional effect of this particular SNP in the two diseases. Haplotype analyses did not add significantly to the associations found in the single SNP analyses. Altogether, these results do not convincingly support KLC1 as a major susceptibility gene in any of the studied diseases, although there is a small effect of KLC1 in relation to cataract.
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