Aβ peptide immunization reduces behavioural impairment and plaques in a model of Alzheimer's disease

Janus, Christopher; Pearson, Jacqueline; McLaurin, JoAnne; Mathews, Paul M.; Jiang, Ying; Schmidt, Stephen D.; Chishti, M. Azhar; Horne, Patrick; Heslin, Donna; French, John B.; Mount, Howard T.J.; Nixon, Ralph A.; Mercken, Marc; Bergeron, Catherine; Fraser, Paul E.; George-Hyslop, Peter St; Westaway, David

doi:10.1038/35050110

Cited by 1,389 publications

(959 citation statements)

References 27 publications

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Section: Resultsmentioning

confidence: 99%

“…These mice develop early synaptic deficits 12 and several neuropathological features at older age, including amyloid plaques and dystrophic neurites 13 . Although Tg2576 mice lack neurofibrillary tangles and significant neuronal loss 14 , there is strong evidence that accumulation of the amyloid-β (Aβ) peptide, derived via APP proteolysis, is responsible for age-related memory decline in this model [15][16][17] .By means of several experimental approaches, we demonstrate an increase of caspase-3 activity in Tg2576 hippocampal synapses at 3 months of age, much earlier than amyloid plaque deposition is detectable 11 . We report that this enhanced local caspase-3 activity leads to a permanent activation of calcineurin which causes, in turn, AMPA receptor (AMPAR) GluR1 subunit dephosphorylation and its removal from the post-synaptic sites.…”

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confidence: 83%

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Caspase-3 triggers early synaptic dysfunction in a mouse model of Alzheimer's disease

et al. 2010

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SummarySynaptic loss is the best pathological correlate of the cognitive decline in Alzheimer's Disease; yet, the molecular mechanisms underlying synaptic failure are unknown. Here we report a non-apoptotic baseline caspase-3 activity in hippocampal dendritic spines, and an enhancement of this activity at the onset of memory decline in the Tg2576-APPswe mouse model of Alzheimer's Disease. We show that, in spines, caspase-3 activates calcineurin which, in turn, triggers dephosphorylation and removal of the GluR1 subunit of AMPA-type receptor from post-synaptic sites. These molecular modifications lead to alterations of glutamatergic synaptic transmission and plasticity, and correlate with spine degeneration and a deficit in hippocampal-dependent memory. Importantly, pharmacological inhibition of caspase-3 activity in Tg2576 mice rescues the observed Alzheimerlike phenotypes. Therefore, we identify a novel caspase-3-dependent mechanism driving synaptic failure and contributing to cognitive dysfunction in Alzheimer's Disease. These findings point to caspase-3 as possible avenues for pharmacological therapy during early disease stages.Episodic hippocampal-dependent memory loss, the earliest clinical sign of Alzheimer's disease, is thought to be due to changes in synaptic function rather than neuronal loss 1,2 . Specifically, functional brain imaging studies revealed hippocampal mild abnormalities prior to clinical diagnosis and in the absence of structural brain atrophy, suggesting an altered functional connectivity of hippocampus at early stages of disease [3][4][5] .Dendritic spines are likely to be the first affected synaptic elements during early cognitive decline 6 . This is supported by several lines of evidence, such as: i) hippocampal spine-mediated plasticity underlies learning and memory 7 ; ii) post-mortem hippocampus from Alzheimer patients shows a significant decrease in dendritic spine density compared to age-matched controls 8 and iii) transgenic 3 mice expressing mutated forms of the amyloid precursor protein (APP), associated with familial Alzheimer's Disease, show age-dependent reductions in spine density, prior to plaque deposition 9 .Nevertheless, the molecular link between APP mutations triggering Alzheimer's Disease, and the occurrence of early spine loss remains elusive. Interestingly, a localized caspase-3 activity, causing synaptic failure, has been observed in vitro 10 , but the molecular mechanism linking caspase-3 activity to synaptic loss is far from being elucidated.Here, we analyzed caspase-3 activity in hippocampal synapses of the Tg2576 transgenic mouse model, harboring the human APPswe mutant allele linked to familial Alzheimer's Disease 11 . These mice develop early synaptic deficits 12 and several neuropathological features at older age, including amyloid plaques and dystrophic neurites 13 . Although Tg2576 mice lack neurofibrillary tangles and significant neuronal loss 14 , there is strong evidence that accumulation of the amyloid-β (Aβ) peptide, derived via APP proteolysis, is r...

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Section: Resultsmentioning

confidence: 99%

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confidence: 83%

Caspase-3 triggers early synaptic dysfunction in a mouse model of Alzheimer's disease

et al. 2010

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“…[58][59][60][61] Not surprisingly, active and passive immunotherapy targeting Ab have been actively pursued as a possible treatment for AD patients. 31,[62][63][64] More than a decade ago we proposed an AD vaccine strategy 37 based on the concept of an EV composed of several copies of an immunodominant self B cell epitope of Ab combined with universal foreign Th epitopes to provide T cell support for robust antibody production.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Efficacy of Preventive and Therapeutic Vaccines Targeting the N Terminus of β-Amyloid in an Animal Model of Alzheimer’s Disease

et al. 2017

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Previously, we reported that Alzheimer's disease (AD) epitope vaccines (EVs) composed of N-terminal b-amyloid (Ab 42 ) B cell epitope fused with universal foreign T helper (Th) epitope(s) were immunogenic, potent, and safe in different amyloid precursor protein (APP) transgenic mice with early AD-like pathology. However, developing an effective therapeutic vaccine is much more challenging, especially when a self-antigen such as Ab 42 is a target. Here, we directly compare the efficacy of anti-Ab 42 antibodies in Tg2576 mice with low or high levels of AD-like pathology at the start of immunizations: 6-6.5 months for preventive vaccinations and 16-19 months for therapeutic vaccinations. EV in a preventive setting induced high levels of anti-Ab antibodies, significantly reducing pathologic forms of Ab in the brains of Tg2576 mice. When used therapeutically for immunesenescent Tg2576 mice, EV induced low levels of antibodies not sufficient for clearing of AD-like pathology. Separately, we demonstrated that EV was also not effective in 11-11.5-month-old Tg2576 mice with moderate AD-like pathology. However, we augmented the titers of anti-Ab antibodies in transgenic (Tg) mice of the same age possessing the pre-existing memory Th cells and detected a significant decrease in diffuse and core plaques in cortical regions compared to control animals along with improved novel object recognition performance. INTRODUCTIONA critical goal of developing therapeutic interventions for Alzheimer's disease (AD) has been the identification of suitable targets. During the last two decades, the predominant theory of the etiology of AD was that Ab has a central role in the onset and progression of AD, as delineated in the amyloid cascade hypothesis. 1,2 According to this hypothesis, the accumulation of Ab peptide, either by overproduction or aberrant clearance, results in deposition of Ab in plaques, which leads to the formation of neurofibrillary tau tangles and cell death, resulting in dementia. Later on, the amyloid cascade hypothesis evolved to focus on oligomers and protofibrils of Ab as instigators in the destruction of synaptic function. [3][4][5] Support for the amyloid cascade hypothesis was spurred by the identification of mutations in amyloid precursor protein (APP) that are associated with familial AD 6-8 or protection against amyloid pathology and age-related Alzheimer's disease. [9][10][11] In addition, it was discovered that overexpression of APP due to trisomy 21 in Downs disease was associated with a high incidence of AD in these individuals. [12][13][14] Today it is clear that the pathological tau also plays a vital role in the development of AD pathology and progression of this disease, 15 correlating better with the degree of dementia than Ab plaques. Importantly, substantial data suggest that Ab pathology emerges many years prior to tau pathology and accelerates formation of toxic tau aggregates, [16][17][18] supporting the preventive rather than therapeutic potential of anti-amyloid therapies.Immunotherapies target...

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“…Antibodies show promise in this regard. Both passive and active immunization against Aβ in mouse models of AD prevented memory loss and behavioral impairment, and reduced Aβ neuropathology [92][93][94][95][96]. These studies led to the development of several active and passive vaccination strategies in clinical trials.…”

Section: Extracellular Clearance Degradation and Prevention Of Uptamentioning

confidence: 99%

Prion-Like Propagation of Protein Aggregation and Related Therapeutic Strategies

Kaufman

Diamond

2013

Neurotherapeutics

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Aβ peptide immunization reduces behavioural impairment and plaques in a model of Alzheimer's disease

Cited by 1,389 publications

References 27 publications

Caspase-3 triggers early synaptic dysfunction in a mouse model of Alzheimer's disease

Caspase-3 triggers early synaptic dysfunction in a mouse model of Alzheimer's disease

Comparison of Efficacy of Preventive and Therapeutic Vaccines Targeting the N Terminus of β-Amyloid in an Animal Model of Alzheimer’s Disease

Prion-Like Propagation of Protein Aggregation and Related Therapeutic Strategies

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