| 1. |
- Aniszewska, Agata, et al.
(författare)
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Modeling Parkinson's disease-related symptoms in alpha-synuclein overexpressing mice
- 2022
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Ingår i: Brain and Behavior. - : John Wiley & Sons. - 2162-3279 .- 2162-3279. ; 12:7
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Forskningsöversikt (refereegranskat)abstract
- Background: Intracellular deposition of alpha-synuclein (alpha-syn) as Lewy bodies and Lewy neurites is a central event in the pathogenesis of Parkinson's disease (PD) and other alpha-synucleinopathies. Transgenic mouse models overexpressing human alpha-syn, are useful research tools in preclinical studies of pathogenetic mechanisms. Such mice develop alpha-syn inclusions as well as neurodegeneration with a topographical distribution that varies depending on the choice of promoter and which form of alpha-syn that is overexpressed. Moreover, they display motor symptoms and cognitive disturbances that to some extent resemble the human conditions.Purpose: One of the main motives for assessing behavior in these mouse models is to evaluate the potential of new treatment strategies, including their impact on motor and cognitive symptoms. However, due to a high within-group variability with respect to such features, the behavioral studies need to be applied with caution. In this review, we discuss how to make appropriate choices in the experimental design and which tests that are most suitable for the evaluation of PD-related symptoms in such studies.Methods: We have evaluated published results on two selected transgenic mouse models overexpressing wild type (L61) and mutated (A30P) alpha-syn in the context of their validity and utility for different types of behavioral studies.Conclusions: By applying appropriate behavioral tests, alpha-syn transgenic mouse models provide an appropriate experimental platform for studies of symptoms related to PD and other alpha-synucleinopathies.
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| 2. |
- Borenäs, Marcus, et al.
(författare)
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ALK signaling primes the DNA damage response sensitizing ALK-driven neuroblastoma to therapeutic ATR inhibition
- 2024
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 1091-6490. ; 121:1
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Tidskriftsartikel (refereegranskat)abstract
- High-risk neuroblastoma (NB) is a significant clinical challenge. MYCN and Anaplastic Lymphoma Kinase (ALK), which are often involved in high-risk NB, lead to increased replication stress in cancer cells, suggesting therapeutic strategies. We previously identified an ATR (ataxia telangiectasia and Rad3-related)/ALK inhibitor (ATRi/ALKi) combination as such a strategy in two independent genetically modified mouse NB models. Here, we identify an underlying molecular mechanism, in which ALK signaling leads to phosphorylation of ATR and CHK1, supporting an effective DNA damage response. The importance of ALK inhibition is supported by mouse data, in which ATRi monotreatment resulted in a robust initial response, but subsequent relapse, in contrast to a 14-d ALKi/ATRi combination treatment that resulted in a robust and sustained response. Finally, we show that the remarkable response to the 14-d combined ATR/ALK inhibition protocol reflects a robust differentiation response, reprogramming tumor cells to a neuronal/Schwann cell lineage identity. Our results identify an ability of ATR inhibition to promote NB differentiation and underscore the importance of further exploring combined ALK/ATR inhibition in NB, particularly in high-risk patient groups with oncogene-induced replication stress.
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| 3. |
- Ekmark-Lewén, Sara, et al.
(författare)
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Reduction of brain stem pathology and transient amelioration of early cognitive symptoms in transgenic mice treated with a monoclonal antibody against α-synuclein oligomers/protofibrils
- 2023
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Ingår i: AGING BRAIN. - : Elsevier. - 2589-9589. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Immunotherapy against alpha-synuclein (alpha-syn) is a promising novel treatment strategy for Parkinson's disease (PD) and related alpha-synucleinopathies. We have previously shown that systemic treatment with the monoclonal oligomer/protofibril-selective antibody mAb47 targeting cytotoxic alpha-syn leads to reduced central nervous system levels of such species as well as an indication of reduced late-stage symptoms in aged (Thy-1)-h[A30P] alpha-syn transgenic mice. Here, we performed an early-onset long-term treatment study with this antibody to evaluate effects on brain pathology and behavioral outcomes in the same mouse model. Compared to the placebo group, the treatment strongly reduced phosphorylated alpha-syn (pS129 alpha-syn) pathology in the upper brain stem. Moreover, a preserved recognition memory and risk assessment behavior could be seen in antibody-treated mice at six months of age, even although these effects were no longer significant at eleven months of age. Importantly, no evidence of inflammatory responses or other potential toxic effects was seen with the treatment. Taken together, this study supports the strategy to target alpha-syn oligomers/protofibrils with monoclonal antibodies to counteract early symptoms and slow down the progression of PD and other alpha-synucleinopathies.
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| 4. |
- Roshanbin, Sahar, 1984-, et al.
(författare)
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Age-related increase of alpha-synuclein oligomers is associated with motor disturbances in L61 transgenic mice
- 2021
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 101, s. 207-220
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Tidskriftsartikel (refereegranskat)abstract
- The pathogenesis of Parkinson's disease involves fibrillization and deposition of alpha-synuclein (alpha-syn) into Lewy bodies. Accumulating evidence suggests that alpha-syn oligomers are particularly neurotoxic. Transgenic (tg) mice overexpressing wild-type human alpha-syn under the Thy-1 promoter (L61) reproduce many Parkinson's disease features, but the pathogenetic relevance of alpha-syn oligomers in this mouse model has not been studied in detail. Here, we report an age progressive increase of alpha-syn oligomers in the brain of L61 tg mice. Interestingly, more profound motor symptoms were observed in animals with higher levels of membrane-bound oligomers. As this tg model is X-linked, we also performed subset analyses, indicating that both sexes display a similar age-related increase in alpha-syn oligomers. However, compared with females, males featured increased brain levels of oligomers from an earlier age, in addition to a more severe behavioral phenotype with hyperactivity and thigmotaxis in the open field test. Taken together, our data indicate that alpha-syn oligomers are central to the development of brain pathology and behavioral deficits in the L61 tg alpha-syn mouse model.
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| 5. |
- Tepper, Beata, et al.
(författare)
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Aged Opossums Show Alterations in Spatial Learning Behavior and Reduced Neurogenesis in the Dentate Gyrus
- 2019
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media S.A.. - 1662-4548 .- 1662-453X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- In many mammalian species including opossums, adult neurogenesis, the function of which is not completely understood, declines with aging. Aging also causes impairment of cognition. To understand whether new neurons contribute to learning and memory, we performed experiments on young and aged laboratory opossums, Monodelphis domestica, and examined the association between spatial memory using the Morris water maze test and the rate of adult neurogenesis in the dentate gyrus (DG). Modification of this test allowed us to assess how both young and aged opossums learn and remember the location of the platform in the water maze. We found that both young and aged opossums were motivated to perform this task. However, aged opossums needed more time to achieve the test than young opossums. Classical parameters measuring spatial learning in a water maze during a probe test showed that young opossums spent more time in the platform zone crossing it more often than aged opossums. Additionally, hippocampal neurogenesis was lower in the aged opossums than in the young animals but new neurons were still generated in the DG of aged opossums. Our data revealed individual differences in the levels of doublecortin in relation to memory performance across aged opossums. These differences were correlated with distinct behaviors, particularly, aged opossums with high levels of DCX achieved high performance levels in the water maze task. We, therefore suggest that new neurons in the DG of Monodelphis opossums contribute to learning and memory.
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