| 1. |
- Berg, Ina, et al.
(författare)
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Modeling Familial Amyloidotic Polyneuropathy (Transthyretin V30M) in Drosophila melanogaster
- 2009
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Ingår i: NEURODEGENERATIVE DISEASES. - : S. Karger AG. - 1660-2854 .- 1660-2862. ; 6:3, s. 127-138
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Transthyretin (TTR) is a prevalent plasma and cerebrospinal fluid protein associated with sporadic and heritable amyloidosis. TTR amyloidosis is linked to a vast number of mutations with varying phenotype, tissue distribution and age of onset. The most prevalent mutation associated with familial amyloidotic polyneuropathy (FAP) is the V30M mutation. Studies of transgenic mouse models of TTR V30M FAP have been hampered by variable phenotype, low disease penetrance, and slow onset. Methods/Results: To model TTR-associated amyloid disease in the Drosophila model system, transgenic Drosophila were generated, expressing wild-type (wt) TTR or TTR V30M, associated with sporadic senile systemic amyloidosis (SSA) and inherited FAP, respectively. We found that expression of FAP-associated TTR V30M mutant in the nervous system resulted in reduced lifespan and in reduced climbing ability indicating neurological impairment, whereas expression of TTR wt showed a milder phenotype. Congo red staining of the Drosophila brain shows positive amyloid binding in the aged TTR V30M flies. Extensive brain vacuole formation was evident for the aged TTR V30M flies, whereas a milder phenotype was shown by the TTR wt flies. In addition, expression of TTR V30M in the eye leads to tissue damage, including rough eye, morphological changes and fibrous deposition. Conclusion: Our results suggest that Drosophila is a promising complementary system for studies of TTR-associated amyloid diseases.
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| 2. |
- Biscaro, Barbara, et al.
(författare)
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Inhibition of Microglial Activation Protects Hippocampal Neurogenesis and Improves Cognitive Deficits in a Transgenic Mouse Model for Alzheimer's Disease
- 2012
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Ingår i: Neurodegenerative Diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 9:4, s. 187-198
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Tidskriftsartikel (refereegranskat)abstract
- Background: Activated microglia with macrophage-like functions invade and surround beta-amyloid (A beta) plaques in Alzheimer's disease (AD), possibly contributing to the turnover of A beta, but they can also secrete proinflammatory factors that may be involved in the pathogenesis of AD. Microglia are known to modulate adult hippocampal neurogenesis. Objectives/Methods: To determine the role of microglia on neurogenesis in brains with A beta pathology, we inhibited microglial activation with the tetracycline derivative minocycline in doubly transgenic mice expressing mutant human amyloid precursor protein (APP) and mutant human presenilin-1 (PS1). Results: Minocycline increased the survival of new dentate granule cells in APP/PS1 mice indicated by more BrdU+/NeuN+ cells as compared to vehicle-treated transgenic littermates, accompanied by improved behavioral performance in a hippocampus-dependent learning task. Both brain levels of A beta and A beta-related morphological deficits in the new neurons labeled with GFP-expressing retrovirus were unaffected in minocycline-treated mice. Conclusions: These results suggest a role for microglia in A beta-related functional deficits and in suppressing the survival of new neurons, and show that modulation of microglial function with minocycline can protect hippocampal neurogenesis in the presence of A beta pathology. Copyright (C) 2012 S. Karger AG, Basel
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| 3. |
- Capetillo-Zarate, Estibaliz, et al.
(författare)
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Intraneuronal A beta Accumulation, Amyloid Plaques, and Synapse Pathology in Alzheimer's Disease
- 2012
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Ingår i: Neurodegenerative Diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 10:1-4, s. 56-59
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Tidskriftsartikel (refereegranskat)abstract
- Background: beta-Amyloid (A beta) plaques are a pathological hallmark of Alzheimer's disease (AD) and multiple lines of evidence have linked A beta with AD. However, synapse loss is known as the best pathological correlate of cognitive impairment in AD, and intraneuronal A beta accumulation has been shown to precede plaque pathology. The progression of A beta accumulation to synapse loss and plaque formation remains incomplete. The objective is to investigate the progression of intraneuronal A beta accumulation in the brain. Methods: To visualize and analyze the development of A beta pathology we perform immunohistochemistry and immunofluorescence microscopy using antibodies against different A beta conformations, synaptic proteins and structural neuronal proteins in brain tissue of AD transgenic mouse models. Results: Our results show the intraneuronal onset of A beta 42 accumulation in AD mouse brains with aging. We observe an inverse correlation of A beta and amyloid fibrils with structural proteins within neurites. Images reveal aggregated amyloid within selective pyramidal neurons, neurites and synapses in AD transgenic mice as plaques arise. Conclusion: The data support that A beta 42 accumulation and aggregation begin within AD-vulnerable neurons in the brain. Progressive intraneuronal A beta 42 aggregation disrupts the normal cytoarchitecture of neurites. Copyright (C) 2012 S. Karger AG, Basel
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| 4. |
- Castelo-Branco, G, et al.
(författare)
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Function of Wnts in dopaminergic neuron development
- 2006
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Ingår i: Neuro-degenerative diseases. - : S. Karger AG. - 1660-2854 .- 1660-2862. ; 3:1-2, s. 5-11
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Tidskriftsartikel (refereegranskat)abstract
- Dopaminergic (DA) neurons in the ventral midbrain (VM) are one of the major cell types lost in Parkinson’s disease (PD). Proof of principle exists for cell replacement therapies for PD, but wider application is halted by the unavailability of abundant sources of DA neurons. Stem cells might constitute one of these sources. However, efficient protocols promoting their specific differentiation into a DA neuronal phenotype are required. In this review, we summarize the latest findings concerning the contribution of the Wnt family of glycolipoproteins in the development of VM DA neurons. Regulators of Wnt signaling are involved in several neurodevelopmental processes. Recent results indicate that Wnts are key regulators of proliferation and differentiation of DA precursors during VM neurogenesis and different Wnts have specific and unique activity profiles. Interestingly, chemical inhibitors of glycogen synthase kinase-3β stabilize β-catenin and increase DA differentiation in VM precursor cultures. We hereby propose that Wnts are likely to contribute in the future to improve stem/precursor cell replacement therapy approaches to PD.
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| 5. |
- Cedres, N, et al.
(författare)
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Brain Atrophy Subtypes and the ATN Classification Scheme in Alzheimer's Disease
- 2021
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Ingår i: Neuro-degenerative diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 20:4, s. 153-164
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Introduction:</i></b> We investigated the association between atrophy subtypes of Alzheimer’s disease (AD), the ATN classification scheme, and key demographic and clinical factors in 2 cohorts with different source characteristics (a highly selective research-oriented cohort, the Alzheimer’s Disease Neuroimaging Initiative [ADNI]; and a naturalistic heterogeneous clinically oriented cohort, Karolinska Imaging Dementia Study [KIDS]). <b><i>Methods:</i></b> A total of 382 AD patients were included. Factorial analysis of mixed data was used to investigate associations between AD subtypes based on brain atrophy patterns, ATN profiles based on cerebrospinal fluid biomarkers, and age, sex, Mini Mental State Examination (MMSE), cerebrovascular disease (burden of white matter signal abnormalities, WMSAs), and <i>APOE</i> genotype. <b><i>Results:</i></b> Older patients with high WMSA burden, belonging to the typical AD subtype and showing A+T+N+ or A+T+N− profiles clustered together and were mainly from ADNI. Younger patients with low WMSA burden, limbic-predominant or minimal atrophy AD subtypes, and A+T−N− or A+T−N+ profiles clustered together and were mainly from KIDS. <i>APOE</i> ε4 carriers more frequently showed the A+T−N− and A+T+N− profiles. <b><i>Conclusions:</i></b> Our findings align with the recent framework for biological subtypes of AD: the combination of risk factors, protective factors, and brain pathologies determines belonging of AD patients to distinct subtypes.
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| 6. |
- Chwiszczuk, L, et al.
(författare)
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Higher Frequency and Complexity of Sleep Disturbances in Dementia with Lewy Bodies as Compared to Alzheimer's Disease
- 2016
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Ingår i: Neuro-degenerative diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 16:3-4, s. 152-160
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background:</i></b> Sleep disturbances (SDs) are common in patients with all forms of dementia. However, most studies focus on Alzheimer's disease (AD) and less is known about the prevalence and characteristics of SD in dementia with Lewy bodies (DLB). <b><i>Objective:</i></b> The aims of this cross-sectional study were: (1) to examine the frequency of SD in DLB versus AD; (2) to compare patients with and without SD with regard to relevant clinical variables, and (3) to investigate the associations between SD and medication use. <b><i>Methods:</i></b> Patients with a first-time diagnosis of probable or possible DLB or AD were selected from the Dementia Study of Western Norway and recruited from clinics for old age psychiatry from 2010 until the end of 2013. <b><i>Results:</i></b> In all, 123 (55.7%) subjects with dementia suffered from at least one SD. Insomnia was present in 77 (34.8%), and 34 (20.7%) patients had probable REM-sleep behaviour disorder (RBD). All SDs were also significantly more frequent in patients with DLB than in AD, and DLB patients also more often had several co-occurring SDs. The presence of any SD was associated with more neuropsychiatric symptoms, higher morbidity, more parkinsonian symptoms and excessive daytime sleepiness. Antiparkinsonian medication was used more often in RBD, restless leg syndrome (RLS) and periodic limb movements, and benzodiazepines were also common in RLS. <b><i>Conclusions:</i></b> Sleep problems are more common in DLB patients compared to AD, and are associated with more clinical impairment. DLB patients frequently have several sleep problems occurring simultaneously, which suggests a need for screening and accurate assessment of sleep in DLB.
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| 7. |
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| 8. |
- Czell, D., et al.
(författare)
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Phenotypes in Swiss Patients with Familial ALS Carrying TARDBP Mutations
- 2013
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Ingår i: Neurodegenerative Diseases. - : S. Karger AG. - 1660-2854 .- 1660-2862. ; 12:3, s. 150-155
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recently, mutations in the TARDBP gene encoding the TAR DNA-binding protein 43 (TDP-43) have been identified in some familial annyotrophic lateral sclerosis (ALS) and sporadic ALS patients. The phenotype and frequency of TARDBP mutation carriers reportedly varies greatly among European populations. Objective: To define the phenotypic spectrum of TARDBP mutations and their frequency in a Swiss population. Methods: A total of 225 patients diagnosed with ALS (182 sporadic cases, 43 familial cases) were screened for TARDBP mutations. All patients were carefully examined and interviewed for a familial predisposition. Except for 1 patient who was followed at the University of Geneva, all patients were followed at the Kantonsspital St. Gallen. Results: 43 patients (19.5%) had a definite family history for ALS. A TARDBP mutation was identified in 4 of these (9.3%). Two female ALS patients carried the p.Asn352Ser mutation. Both had limb onset and a slowly progressive course of the disease. A novel mutation (p.Gly376Asp) was identified in a 44-year-old female patient. Survival amongst affected family members varied between 6 and 18 months. The patient and also the other siblings affected with ALS had an accessory nipple. A fourth male patient carried the p.Ala-90Val mutation. None of the patients had overt cognitive impairment. TARDBP mutations were not found among patients with sporadic forms of ALS. Conclusion: In this Swiss population, the frequency of familial ALS is higher than reported earlier in other populations. The novel p.Gly376Asp TARDBP mutation is associated with rapid disease progression and may be associated with an accessory nipple while the p.Asn352Ser mutation is associated with slow disease progression.
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| 9. |
- Englund, Hillevi, 1980-, et al.
(författare)
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Oligomerization partially explains the lowering of Aβ42 in Alzheimer's disease cerebrospinal fluid
- 2009
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Ingår i: Neuro-degenerative diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 6:4, s. 139-147
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Tidskriftsartikel (refereegranskat)abstract
- Background/aim: The lowering of natively analyzed Aβ42 in cerebrospinal fluid (CSF) is used as a diagnostic tool in Alzheimer’s disease (AD). Presence of Aβ oligomers can interfere with such analyses causing underestimation of Aβ levels due to epitope masking. The aim was to investigate if the lowering of CSF Aβ42 seen is caused by oligomerization. Methods: Aβ42 was analyzed under both denaturing and non-denaturing conditions. An Aβ42 oligomer ratio was calculated from these quantifications. Presence of oligomers leads to Aβ42 epitope masking during non-denaturing assays, resulting in a higher ratio. Results: The Aβ42 oligomer ratio was used for assessment of oligomerized Aβ in human CSF, after being evaluated in transgenic mouse brain homogenates. AD and mild cognitive impairment (MCI) samples displayed the expected decrease in natively measured Aβ42 compared to healthy controls and frontotemporal dementia, but not when analyzing under denaturing conditions. Accordingly, AD and MCI CSF had a higher Aβ42 oligomer ratio in CSF. Conclusion: Combining denaturing and non-denaturing quantifications of Aβ42 into an oligomer ratio enables assessment of Aβ oligomers in biological samples. The increased Aβ42 oligomer ratio for AD and MCI indicates presence of oligomers in CSF and that the lowering of natively measured Aβ42 is caused by oligomerization.
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| 10. |
- Gallo, Valentina, et al.
(författare)
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Parkinson's Disease Case Ascertainment in the EPIC Cohort : The NeuroEPIC4PD Study
- 2015
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Ingår i: Neurodegenerative Diseases. - : S. Karger. - 1660-2854 .- 1660-2862. ; 15:6, s. 331-338
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Large epidemiological prospective studies represent an important opportunity for investigating risk factors for rare diseases such as Parkinson's disease (PD). Here we describe the procedures we used for ascertaining PD cases in the EPIC (European Prospective Investigation into Cancer and Nutrition) study. Methods: The following three-phase procedure was used: (1) elaboration of a NeuroEPIC4PD template for clinical data collection, (2) identification of all potential PD cases via record linkage and (3) validation of the diagnosis through clinical record revision, in a population of 220,494 subjects recruited in 7 European countries. All cases were labelled with the NeuroEPIC4PD diagnoses of 'definite', 'very likely', 'probable', or 'possible' PD. Results: A total of 881 PD cases were identified, with over 2,741,780 person-years of follow-up (199 definite, 275 very likely, 146 probable, and 261 possible). Of these, 734 were incident cases. The mean age at diagnosis was 67.9 years (SD 9.2) and 458 patients (52.0%) were men. Bradykinesia was the most frequent presenting motor sign (76.5%). Tremor-dominant and akinetic rigid forms of PD were the most common types of PD. A total of 289 patients (32.8%) were dead at the time of the last follow-up. Conclusions: This exercise proved that it is feasible to ascertain PD in large population-based cohort studies and offers a potential framework to be replicated in similar studies.
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