scholarly journals Epitope map of two polyclonal antibodies that recognize amyloid lesions in patients with Alzheimer's disease

1992 ◽  
Vol 282 (2) ◽  
pp. 517-522 ◽  
Author(s):  
J Ghiso ◽  
T Wisniewski ◽  
R Vidal ◽  
A Rostagno ◽  
B Frangione
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amino Acids ◽  
Synthetic Peptides ◽  
Polyclonal Antibodies ◽  
Sf9 Cells ◽  
Beta Turn ◽  
App Processing ◽  
Conformational Epitopes ◽  
N Terminus

Two synthetic peptides with sequences identical with those of fragments of the extracellular domain of the Alzheimer's-disease amyloid precursor protein (APP) were used to raise antibodies. SP28 comprises positions 597-624 of the APP695 isoform, whereas SP41 extends towards the N-terminus (amino acids 584-624) and contains the entire SP28 peptide. Using e.l.i.s.a. and inhibition experiments we identified the two beta-turn-containing segments 602-607 and 617-624 as the epitopes recognized by anti-SP41 and anti-SP28 respectively. Both antibodies immunolabelled amyloid lesions in brains from Alzheimer's-disease patients and patients with related disorders, whereas they were unreactive in control brains. However, when probed on immunoblots, anti-SP28 failed to detect full-length APP from baculovirus-infected Sf9 cells, and anti-SP41 reacted weakly compared with other anti-APP antisera. The data suggest that these antibodies are directed to conformational epitopes not existent in the native molecules but present after alternative APP processing.

The involvement of the GGA protein family in BACE transport and APP processing in Alzheimer's disease

2008 ◽  
Vol 35 (S 01) ◽  
Author(s):  
C Steinmetz ◽  
B von Einem ◽  
D Schwanzar ◽  
F Dolp ◽  
A.C Ludolph ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Family ◽  
App Processing

scholarly journals Shotgun lipidomics of liver and brain tissue of Alzheimer’s disease model mice treated with acitretin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna A. Lauer ◽  
Daniel Janitschke ◽  
Malena dos Santos Guilherme ◽  
Vu Thu Thuy Nguyen ◽  
Cornel M. Bachmann ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Amyloid Β ◽  
Lipid Homeostasis ◽  
Medical Surveillance ◽  
Shotgun Lipidomics ◽  
App Processing ◽  
Cognitive Improvement ◽  
The Impact

AbstractAlzheimer’s disease (AD) is a very frequent neurodegenerative disorder characterized by an accumulation of amyloid-β (Aβ). Acitretin, a retinoid-derivative and approved treatment for Psoriasis vulgaris, increases non-amyloidogenic Amyloid-Precursor-Protein-(APP)-processing, prevents Aβ-production and elicits cognitive improvement in AD mouse models. As an unintended side effect, acitretin could result in hyperlipidemia. Here, we analyzed the impact of acitretin on the lipidome in brain and liver tissue in the 5xFAD mouse-model. In line with literature, triglycerides were increased in liver accompanied by increased PCaa, plasmalogens and acyl-carnitines, whereas SM-species were decreased. In brain, these effects were partially enhanced or similar but also inverted. While for SM and plasmalogens similar effects were found, PCaa, TAG and acyl-carnitines showed an inverse effect in both tissues. Our findings emphasize, that potential pharmaceuticals to treat AD should be carefully monitored with respect to lipid-homeostasis because APP-processing itself modulates lipid-metabolism and medication might result in further and unexpected changes. Moreover, deducing effects of brain lipid-homeostasis from results obtained for other tissues should be considered cautiously. With respect to acitretin, the increase in brain plasmalogens might display a further positive probability in AD-treatment, while other results, such as decreased SM, indicate the need of medical surveillance for treated patients.

The Link between Exercise and Homocysteine in the Alzheimer’s disease: A Bioinformatic Network Model

2021 ◽  
Vol 20 ◽  
Author(s):  
Luana Leão ◽  
Laís Felício ◽  
Knut Engedal ◽  
Gro Tangen ◽  
Kari Kristiansen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amino Acids ◽  
Coronary Heart Disease ◽  
Network Models ◽  
Cell Loss ◽  
Neurological Complications ◽  
Memory Deficit ◽  
Tau Pathology ◽  
Increased Risk

: Elevated peripheral expression of homocysteine (Hcy) is associated with an increased risk of coronary heart disease and stroke, diabetes, and cancer. It is also associated with cognitive impairment as it has been reported that high levels of Hcy cause cognitive dysfunction and memory deficit. Among several etiological factors that contribute to the pathogenesis of neurodegenerative diseases, including Alzheimer’s disease (AD), Hcy seems to directly contribute to the generation of neurotoxicity factors. This study aims to hypothesize the molecular mechanism by which exercise can reduce the risk of neurological complications promoted by hyperhomocysteinemia (HHcy), and discuss how exercise could reduce the risk of developing AD by using bioinformatics network models. According to the genes network, there are connections between proteins and amino acids associated with Hcy, exercise, and AD. Studies have evidenced that exercise may be one of several processes by which nitric acid availability can be maximized in the human body, which is particularly important in reducing cell loss and tau pathology , thereby reducing in the risk of complications associated with HHcy and AD.

scholarly journals Ceramide and Related-Sphingolipid Levels Are Not Altered in Disease-Associated Brain Regions of APPSLand APPSL/PS1M146LMouse Models of Alzheimer's Disease: Relationship with the Lack of Neurodegeneration?

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Laurence Barrier ◽  
Bernard Fauconneau ◽  
Anastasia Noël ◽  
Sabrina Ingrand
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Animal Models ◽  
Neuronal Death ◽  
Time Course ◽  
Neuronal Loss ◽  
Brain Regions ◽  
App Processing ◽  
Ceramide Accumulation ◽  
The Brain

There is evidence linking sphingolipid abnormalities, APP processing, and neuronal death in Alzheimer's disease (AD). We previously reported a strong elevation of ceramide levels in the brain of the APPSL/PS1Ki mouse model of AD, preceding the neuronal death. To extend these findings, we analyzed ceramide and related-sphingolipid contents in brain from two other mouse models (i.e., APPSLand APPSL/PS1M146L) in which the time-course of pathology is closer to that seen in most currently available models. Conversely to our previous work, ceramides did not accumulate in disease-associated brain regions (cortex and hippocampus) from both models. However, the APPSL/PS1Ki model is unique for its drastic neuronal loss coinciding with strong accumulation of neurotoxic Aβisoforms, not observed in other animal models of AD. Since there are neither neuronal loss nor toxic Aβspecies accumulation in APPSLmice, we hypothesized that it might explain the lack of ceramide accumulation, at least in this model.

The amyloid precursor protein (APP) processing as a biological link between Alzheimer’s disease and cancer

2019 ◽  
Vol 49 ◽  
pp. 83-91 ◽  
Author(s):  
Fernando Galvão ◽  
Kamila Castro Grokoski ◽  
Bruno Batista da Silva ◽  
Marcelo Lazzaron Lamers ◽  
Ionara Rodrigues Siqueira
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Precursor Protein ◽  
Precursor Protein ◽  
App Processing

scholarly journals Modeling the β secretase cleavage site and humanizing Amyloid-Beta Precursor Protein in rat and mouse to study Alzheimer Disease.

2020 ◽  
Author(s):  
Lutgarde Serneels ◽  
Dries T'Syen ◽  
Laura Perez-Benito ◽  
Tom Theys ◽  
Bart De Strooper
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amino Acid ◽  
Alzheimer Disease ◽  
Early Onset ◽  
Computational Modelling ◽  
Original Strain ◽  
Rodent Models ◽  
App Processing

Abstract Background Three amino acid differences between rodent and human APP affect medically important features including β-secretase cleavage of APP and aggregation of the Aβ peptide(1–3). Most rodent models for Alzheimer’s disease (AD) are therefore based on the human APP sequence expressed from artificial mini-genes randomly inserted in the rodent genome. While these models mimic rather well biochemical aspects of the disease such as Aβ-aggregation, they are also prone to overexpression artifacts and to complex phenotypical alterations due to genes affected in or close to the insertion sites of the mini-genes(4,5). Knock-in strategies introducing clinical mutants in a humanized endogenous rodent APP sequence(6) represent useful improvements, but need to be compared with appropriate humanized wild type (WT) mice.Methods Computational modelling of the human β-CTF bound to BACE1 was used to study the differential processing of rodent and human APP. We humanized the three pivotal residues G676R, F681Y and R684H (labeled according to the human APP770 isoform) in the mouse as well as in the rat by a CRISPR-Cas9 approach. These new models, termed mouse and rat App hu/hu , express APP from the endogenous promotor. We also introduced the early-onset familial Alzheimer’s disease (FAD) mutation M139T into the endogenous Rat Psen 1 gene.Results We show that the three amino acid substitutions in the rodent sequence lower the affinity of APP substrate for BACE1 cleavage. The effect on β-secretase processing was confirmed as both humanized rodent models produce three times more (human) Aβ compared to their WT rodent original strain. These models represent suitable controls or starting points for studying the effect of transgenes or knock-in mutations on APP processing(6). We introduced the early-onset familial Alzheimer disease (FAD) mutation M139T into the endogenous Rat Psen 1 gene and provide an initial characterization of Aβ processing in this novel rat AD model.Conclusion The different humanized APP models (rat and mouse) expressing human Aβ and PSEN1 M139T are valuable controls to study APP processing in vivo and allow to implement the use of human Aβ Elisa which is more sensitive than their rodent counterpart. These animals will be made available to the research community.

scholarly journals Neuronal aging potentiates beta-amyloid generation via amyloid precursor protein endocytosis

2019 ◽  
Author(s):  
Tatiana Burrinha ◽  
Ricardo Gomes ◽  
Ana Paula Terrasso ◽  
Cláudia Guimas Almeida
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Precursor Protein ◽  
Precursor Protein ◽  
App Processing ◽  
Early Endosomes ◽  
Primary Mouse ◽  
Β Amyloid ◽  
Aβ Production

AbstractAging increases the risk of Alzheimer’s disease (AD). During normal aging synapses decline and β-Amyloid (Aβ) accumulates. An Aβ defective clearance with aging is postulated as responsible for Aβ accumulation, although a role for increased Aβ production with aging can also lead to Aβ accumulation. To test this hypothesis, we established a long-term culture of primary mouse neurons that mimics neuronal aging (lysosomal lipofuscin accumulation and synapse decline). Intracellular endogenous Aβ42 accumulated in aged neurites due to increased amyloid-precursor protein (APP) processing. We show that APP processing is up-regulated by a specific age-dependent increase in APP endocytosis. Endocytosed APP accumulated in early endosomes that, in turn were found augmented in aged neurites. APP processing and early endosomes up-regulation was recapitulated in vivo. Finally, we found that inhibition of Aβ production reduced the decline in synapses in aged neurons. We propose that potentiation of APP endocytosis by neuronal aging increases Aβ production, which contributes to aging-dependent decline in synapses.SummaryHow aging increases the risk of Alzheimer’s disease is not clear. We show that normal neuronal aging increases the intracellular production of β-amyloid, due to an upregulation of the amyloid precursor protein endocytosis. Importantly, increased Aβ production contributes to the aging-dependent synapse loss.

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