| 1. |
- Larsson, Susanna C., et al.
(författare)
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Does Treating Vascular Risk Factors Prevent Dementia and Alzheimer's Disease? A Systematic Review and Meta-Analysis.
- 2018
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Ingår i: Journal of Alzheimer's Disease. - Stockholm : Karolinska Institutet, Institute of Environmental Medicine. - 1387-2877 .- 1875-8908. ; 64:2, s. 657-668
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Epidemiological evidence has associated Alzheimer's disease (AD) with vascular risk factors (VRFs), but whether treatment of VRFs reduces the incidence of dementia and AD is uncertain.OBJECTIVE: To conduct a systematic review and meta-analysis to summarize available data on the impact of treatment of VRFs on dementia and AD incidence.METHODS: Pertinent studies published until 1 January 2018 were identified from PubMed. Both randomized controlled trials (RCT) and prospective studies that investigated the impact of treatment of VRFs on dementia or AD incidence were included.RESULTS: Eight RCTs and 52 prospective studies were identified. Antihypertensive treatment was associated with a non-significant reduced risk of dementia in RCTs (n = 5; relative risk [RR], 0.84; 95% confidence interval [CI], 0.69-1.02) and prospective studies (n = 3; RR, 0.77; 95% CI, 0.58-1.01) and with reduced AD risk in prospective studies (n = 5; RR = 0.78; 95% CI, 0.66-0.91). In prospective studies, treatment of hyperlipidemia with statins, but not nonstatin lipid-lowering agents, was associated with reduced risk of dementia (n = 17; RR, 0.77; 95% CI, 0.63-0.95) and AD (n = 13; RR, 0.86; 95% CI, 0.80-0.92). The single RCT on statins and dementia incidence showed no association. Data from one RCT and six prospective studies did not support a beneficial impact of antidiabetic drugs or insulin therapy on dementia risk.CONCLUSION: Current evidence indicates that antihypertensives and statins might reduce the incidence of dementia and AD. Further trials to determine the effect of VRF on AD are needed.
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| 2. |
- Tan, Edwin C. K., et al.
(författare)
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Anticholinergic Burden and Risk of Stroke and Death in People with Different Types of Dementia
- 2018
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Ingår i: Journal of Alzheimer's Disease. - Stockholm : Karolinska Institutet, Dept of Neurobiology, Care Sciences and Society. - 1387-2877 .- 1875-8908. ; 65:2, s. 589-596
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Tidskriftsartikel (refereegranskat)abstract
- Background: Anticholinergic burden is associated with poorer cognitive and functional outcomes in people with dementia. However, the impact of anticholinergics on significant adverse outcomes such as stroke has not been studied previously.Objective: To investigate the association between total anticholinergic cognitive burden (ACB) and risk of stroke and death in people with different dementia subtypes.Methods: This was a cohort study of 39,107 people with dementia and no prior history of stroke registered in the Swedish Dementia Registry (SveDem) from 2008-2014. Data were extracted from the Swedish Prescribed Drug Register, the Swedish National Patient Register, and the Swedish Total Population Register. Competing risk regression models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between time-varying ACB score and risk of stroke and all-cause mortality.Results: During a mean follow-up period of 2.31 (standard deviation 1.66) years, 11,224 (28.7%) individuals had a stroke or died. Compared with non-users of anticholinergic medications, ACB score of 1 (HR 1.09, 95% CI 1.04-1.14) and ACB score of >= 2 (HR 1.20, 95% CI 1.14-1.26) increased the risk of developing the composite outcome of stroke and death. When stratifying by dementia disorder, the association remained significant in Alzheimer's disease, mixed dementia, and vascular dementia.Conclusions: The use of anticholinergic medicines may be associated with an increased risk of stroke and death in people with dementia. A dose-response relationship was observed. Careful consideration should be made when prescribing medications with anticholinergic properties to people with dementia.
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| 3. |
- Agholme, Lotta, et al.
(författare)
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Amyloid-β Secretion, Generation, and Lysosomal Sequestration in Response to Proteasome Inhibition : Involvement of Autophagy
- 2012
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Ingår i: Journal of Alzheimer's Disease. - : I O S Press. - 1387-2877 .- 1875-8908. ; 31:2, s. 343-358
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Tidskriftsartikel (refereegranskat)abstract
- The proteasome is important for degradation of worn out and misfolded proteins. Decreased proteasome activity has been implicated in Alzheimer's disease (AD). Proteasome inhibition induces autophagy, but it is still unknown whether autophagy is beneficial or deleterious to AD neurons, as the autophagosome has been suggested as a site of amyloid-β (Aβ) generation. In this study, we investigated the effect of proteasome inhibition on Aβ accumulation and secretion, as well as the processing of amyloid-β protein precursor (AβPP) in AβPPSwe transfected SH-SY5Y neuroblastoma cells. We show that proteasome inhibition resulted in autophagy-dependent accumulation of Aβ in lysosomes, and increased levels of intracellular and secreted Aβ. The enhanced levels of Aβ could not be explained by increased amounts of AβPP. Instead, reduced degradation of the C-terminal fragment of AβPP (C99) by the proteasome makes C99 available for γ-secretase cleavage, leading to Aβ generation. Inhibition of autophagy after proteasome inhibition led to reduced levels of intracellular, but not secreted Aβ, and tended to further increase the C99 to AβPP ratio, supporting involvement of the autophagosome in Aβ generation. Furthermore, proteasome inhibition caused a reduction in cellular viability, which was reverted by inhibition of autophagy. Dysfunction of the proteasome could cause lysosomal accumulation of Aβ, as well as increased generation and secretion of Aβ, which is partly facilitated by autophagy. As a decrease in cellular viability was also detected, it is possible that upregulation of autophagy is an unsuccessful rescue mechanism, which instead of being protective, contributes to AD pathogenesis.
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| 4. |
- Agholme, Lotta, et al.
(författare)
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An In Vitro Model for Neuroscience: Differentiation of SH-SY5Y Cells into Cells with Morphological and Biochemical Characteristics of Mature Neurons
- 2010
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Ingår i: Journal of Alzheimer's Disease. - : Ios Press. - 1387-2877 .- 1875-8908. ; 20:4, s. 1069-1082
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Tidskriftsartikel (refereegranskat)abstract
- Neuroscience, including research on Alzheimers disease, is hampered by the lack of suitable in vitro models to study the human nervous system. To counteract this, many attempts to differentiate cell lines into more neuron-like cells have been performed, resulting in partial expression of neuronal features. Furthermore, it has been reported that neuroblastoma cell lines lack mature isoforms of tau. Our aim was to develop an improved in vitro model, generating sustainable cells with morphology and biochemistry of human, mature neurons. To obtain cells with neuronal differentiation and function, we investigated the effect of combining three-dimensional culturing of SH-SY5Y cells in extracellular matrix (ECM) gel with several factors reported to have neuro-differentiating effects. This resulted in cells with apparent neuronal morphology with long, extensively branched neurites. Further investigation revealed expression of several neurospecific markers including synapse protein Sv2 and nuclear marker NeuN, as well as the presence of synapses and axonal vesicle transport. In addition, these cells expressed mature tau isoforms, and tau protein expression was significantly increased compared to undifferentiated cells, reaching levels found in adult human brain. In conclusion, we found that pre-treatment with retinoic acid followed by ECM gel culturing in combination with brain derived neurotrophic factor, neuregulin beta(1), nerve growth factor, and vitamin D-3 treatment generated sustainable cells with unambiguous resemblance to adult neurons. These cells also expresses adult splicing forms of tau with neuronal localization, making this cellular in vitro model useful in many areas of neuroscience research, particularly the Alzheimers disease field.
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| 5. |
- Aho, Leena, et al.
(författare)
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Immunohistochemical Visualization of Amyloid-β Protein Precursor and Amyloid-β in Extra- and Intracellular Compartments in the Human Brain
- 2010
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 20:4, s. 1015-1028
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid-beta (Abeta) peptide, a cleavage product of the amyloid-beta protein precursor (AbetaPP), has been reported to be detected in the intracellular compartment. Most studies reporting the presence of intracellular Abeta are based on the use of immunohistochemistry. In this study, the presence of AbetaPP and Abeta was assessed by applying immunohistochemistry in postmortem human brain tissue samples obtained from 10 neurologically intact subjects, the youngest being 2 years of age, one aged with mild cognitive impairment, 14 neurologically diseased, and in one brain biopsy sample obtained from a subject with normal pressure hydrocephalus. Intracellular immunoreactivity was detected in all ages independent of the disease state or existence of extracellular Abeta aggregates with all antibodies directed to AbetaPP, with three Abeta antibodies (4G8, 6E10, and 82E1), clones that are unable to distinguish Abeta from AbetaPP. These results suggest that it is AbetaPP rather than Abeta that is detected intracellularly when using the antibodies listed above. Furthermore, the staining results varied when different pretreatment strategies were applied. Interestingly intracellular Abeta was detected with antibodies directed to the C-terminus of Abeta (neoepitope) in subjects with Alzheimer's disease. The lack of intracellular immunoreactivity in unimpaired subjects, when using antibodies against neoepitopes, may be due to a lack or a low level of the protein that is thus undetectable at light microscopic level by immunohistochemistry method. The staining results and conclusions depended strongly on the chosen antibody and the pretreatment strategy and thus multiple antibodies must be used when assessing the intracellular accumulation of Abeta.
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| 6. |
- Alafuzoff, Irina
(författare)
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Alzheimer's disease-related lesions
- 2013
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 33:Suppl 1, s. S173-S179
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Forskningsöversikt (refereegranskat)abstract
- The invitation to contribute to "Alzheimer's Disease: Advances for a New Century" gave me an opportunity to briefly summarize my personal opinions about how the field of neuropathology has evolved. The goal is to briefly exemplify the changes that have influenced the way we conduct our diagnostic work as well as the way we interpret our results. From an era of histological stains, we have moved to visualization of altered proteins in predicted brain regions; we have also realized that in many aged subjects, not one but a plethora of co-pathologies are seen, and finally, we have become aware that the degenerative process is initiated much earlier than we ever suspected.
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| 7. |
- Alafuzoff, Irina, et al.
(författare)
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Mixed Brain Pathology Is the Most Common Cause of Cognitive Impairment in the Elderly
- 2020
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Ingår i: Journal of Alzheimer's Disease. - : IOS PRESS. - 1387-2877 .- 1875-8908. ; 78:1, s. 453-465
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Tidskriftsartikel (refereegranskat)abstract
- Background: Systemic diseases, diabetes mellitus (DM), and cardiovascular disease (CaVD) have been suggested being risk factors for cognitive impairment (CI) and/or influence Alzheimer's disease neuropathologic change (ADNC).Objective: The purpose was to assess the type and the extent of neuropathological alterations in the brain and to assess whether brain pathology was associated with CaVD or DM related alterations in peripheral organs, i.e., vessels, heart, and kidney.Methods: 119 subjects, 15% with DM and 24% with CI, age range 80 to 89 years, were chosen and neuropathological alterations were assessed applying immunohistochemistry.Results: Hyperphosphorylated tau (HP tau) was seen in 99%, amyloid-beta (A beta) in 71%, transactive DNA binding protein 43 (TDP43) in 62%, and alpha-synuclein (alpha S) in 21% of the subjects. Primary age related tauopathy was diagnosed in 29% (more common in females), limbic predominant age-related TDP encephalopathy in 4% (14% of subjects with CI), and dementia with Lewy bodies in 3% (14% of subjects with CI) of the subjects. High/intermediate level of ADNC was seen in 47% and the extent of HPt increased with age. The extent of ADNC was not associated with the extent of pathology observed in peripheral organs, i.e., DM or CaVD. Contrary, brain alterations such as pTDP43 and cerebrovascular lesions (CeVL) were influenced by DM, and CeVL correlated significantly with the extent of vessel pathology.Conclusion: In most (66%) subjects with CI, the cause of impairment was "mixed pathology", i.e., ADNC combined with TDP43, alpha S, or vascular brain lesions. Furthermore, our results suggest that systemic diseases, DMand CaVD, are risk factors for CI but not related to ADNC.
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| 8. |
- Alikhani, Nyosha, et al.
(författare)
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Decreased proteolytic activity of the mitochondrial amyloid-β degrading enzyme, PreP peptidasome, in Alzheimer's disease brain mitochondria
- 2011
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 27:1, s. 75-87
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Tidskriftsartikel (refereegranskat)abstract
- Accumulation of amyloid-β peptide (Aβ), the neurotoxic peptide implicated in the pathogenesis of Alzheimer's disease (AD), has been shown in brain mitochondria of AD patients and of AD transgenic mouse models. The presence of Aβ in mitochondria leads to free radical generation and neuronal stress. Recently, we identified the presequence protease, PreP, localized in the mitochondrial matrix in mammalian mitochondria as the novel mitochondrial Aβ-degrading enzyme. In the present study, we examined PreP activity in the mitochondrial matrix of the human brain's temporal lobe, an area of the brain highly susceptible to Aβ accumulation and reactive oxygen species (ROS) production. We found significantly lower hPreP activity in AD brains compared with non-AD age-matched controls. By contrast, in the cerebellum, a brain region typically spared from Aβ accumulation, there was no significant difference in hPreP activity when comparing AD samples to non-AD controls. We also found significantly reduced PreP activity in the mitochondrial matrix of AD transgenic mouse brains (Tg mAβPP and Tg mAβPP/ABAD) when compared to non-transgenic aged-matched mice. Furthermore, mitochondrial fractions isolated from AD brains and Tg mAβPP mice had higher levels of 4-hydroxynonenal, an oxidative product, as compared with those from non-AD and nonTg mice. Accordingly, activity of cytochrome c oxidase was significantly reduced in the AD mitochondria. These findings suggest that decreased PreP proteolytic activity, possibly due to enhanced ROS production, contributes to Aβ accumulation in mitochondria leading to the mitochondrial toxicity and neuronal death that is exacerbated in AD. Clearance of mitochondrial Aβ by PreP may thus be of importance in the pathology of AD.
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| 9. |
- Almkvist, Ove, et al.
(författare)
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Odor Identification Across Time in Mutation Carriers and Non-Carriers in Autosomal-Dominant Alzheimer’s Disease
- 2024
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 97:2, s. 587-598
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Tidskriftsartikel (refereegranskat)abstract
- Background: Impaired odor identification is a characteristic of sporadic Alzheimer’sdisease(AD), but its presence in autosomal-dominantAD (adAD) remains uncertain. Objective: To investigate odor identification ability in mutation carriers (MC) and non-carriers (NC) of adAD in relation to years to estimated clinical onset clinical onset (YECO) of disease. Methods: Participants from six families with autosomal-dominant mutations (APP Swedish, APPArctic, and PSEN1 mutations) included 20 MC and 20 NC. The groups were comparable in age, gender, education, number of APOE ɛ4 alleles, and YECO, but differed in global cognition (Mini-Mental State Examination). The MC group included individuals in asymptomatic, symptomatic cognitively unimpaired, mild cognitive impairment, and dementia stages of disease, spanning approximately 40 years of the AD continuum. All NC were asymptomatic. Olfactory function was assessed by means of free and cued identification of common odors summarized as total identification. Results: MC performed poorer than NC in free and total identification. Four MC and none of the NC were anosmic. Olfactory functions in MC and NC were significantly and inversely related to time course (YECO) for both free and total identification. The decline in free identification began approximately 10 years prior to the estimated clinical onset of AD in MC. Odor identification proficiency was associated with episodic memory and executive function in MC and NC. Conclusions: Impaired odor identification is present well before the clinical diagnosis of AD in MC and is associated with disease progression. Odor identification ability may be a useful early biomarker for adAD.
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| 10. |
- Almkvist, Ove, et al.
(författare)
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Subcortical and Cortical Regions of Amyloid-β Pathology Measured by C-11-PiB PET Are Differentially Associated with Cognitive Functions and Stages of Disease in Memory Clinic Patients
- 2021
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 81:4, s. 1613-1624
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Tidskriftsartikel (refereegranskat)abstract
- Background: The effect of regional brain amyloid-beta (A beta) pathology on specific cognitive functions is incompletely known.Objective: The relationship between A beta and cognitive functions was investigated in this cross-sectional multicenter study of memory clinic patients.Methods: The participants were patients diagnosed with Alzheimer's disease (AD, n = 83), mild cognitive impairment (MCI, n = 60), and healthy controls (HC, n = 32), who had been scanned by C-11-PiB PET in 13 brain regions of both hemispheres and who had been assessed by cognitive tests covering seven domains.Results: Hierarchic multiple regression analyses were performed on each cognitive test as dependent variable, controlling for demographic characteristics and APOE status (block 1) and PiB measures in 13 brain regions (block 2) as independent variables. The model was highly significant for each cognitive test and most strongly for tests of episodic memory (learning and retention) versus PiB in putamen, visuospatially demanding tests (processing and retention) versus the occipital lobe, semantic fluency versus the parietal lobe, attention versus posterior gyrus cinguli, and executive function versus nucleus accumbens. In addition, education had a positively and APOE status a negatively significant effect on cognitive tests.Conclusion: Five subcortical and cortical regions with A beta pathology are differentially associated with cognitive functions and stages of disease in memory clinic patients.
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