Progressive Spatial Memory Impairment, Brain Amyloid Deposition and Changes in Serum Amyloid Levels as a Function of Age in APPswe/PS1dE9 Mice

2018 ◽  
Vol 15 (11) ◽  
pp. 1053-1061 ◽  
Author(s):  
Lu Fu ◽  
Yao Sun ◽  
Yongqing Guo ◽  
Bin Yu ◽  
Haihong Zhang ◽  
...  

Background: Mice co-expressing human amyloid precursor protein with the Swedish mutation (APPswe) and exon-9-deleted presenilin (PS1dE9) has become one of the most widely used mouse models for studying Alzheimer’s disease (AD) pathogenesis and preclinical studies of AD therapeutic approaches. Objective: In this study, we systematically investigated cognitive decline, amyloid-β (Aβ) deposition and cerebral or Aβ serum levels as well as the relationships among these measures in APPswe/PS1dE9 transgenic mice. Method: APPswe/PS1dE9 mice were separated into four equal age cohorts (4, 6, 9, and 12 months). We assessed cognitive capacity, deposited plaques, and the levels of Aβ40/Aβ42 in brain tissue and serum of mice at different ages. Results: APPswe/PS1dE9 mice exhibited declined memory beginning at 6 months of age, with cognitive capacity remarkably impaired at 12-months. Coincidently, amyloid deposits began to develop in transgenic mice brain at 6-months and increased with age. In addition, Aβ42 levels in brains of APPswe/ PS1dE9 mice increased with age with no parallel increase in Aβ40. The concentration of serum Aβ42 declined from 4 to 6 months of age, but a similar age-dependent decrease was not observed for Aβ40. Conclusion: APPswe/PS1dE9 transgenic mice began to develop amyloid plaques at 6 months of age and exhibited a corresponding impairment of spatial learning capacity. Serum Aβ42 level decreased remarkably from 4 to 6 months, at which stage Aβ42 began to accumulate in the brain and deposit as plaques.

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Erik C. B. Johnson ◽  
Kaitlyn Ho ◽  
Gui-Qiu Yu ◽  
Melanie Das ◽  
Pascal E. Sanchez ◽  
...  

Abstract Background Alzheimer’s disease (AD) is the most frequent and costly neurodegenerative disorder. Although diverse lines of evidence suggest that the amyloid precursor protein (APP) is involved in its causation, the precise mechanisms remain unknown and no treatments are available to prevent or halt the disease. A favorite hypothesis has been that APP contributes to AD pathogenesis through the cerebral accumulation of the amyloid-β peptide (Aβ), which is derived from APP through sequential proteolytic cleavage by BACE1 and γ-secretase. However, inhibitors of these enzymes have failed in clinical trials despite clear evidence for target engagement. Methods To further elucidate the roles of APP and its metabolites in AD pathogenesis, we analyzed transgenic mice overexpressing wildtype human APP (hAPP) or hAPP carrying mutations that cause autosomal dominant familial AD (FAD), as well as App knock-in mice that do not overexpress hAPP but have two mouse App alleles with FAD mutations and a humanized Aβ sequence. Results Although these lines of mice had marked differences in cortical and hippocampal levels of APP, APP C-terminal fragments, soluble Aβ, Aβ oligomers and age-dependent amyloid deposition, they all developed cognitive deficits as well as non-convulsive epileptiform activity, a type of network dysfunction that also occurs in a substantive proportion of humans with AD. Pharmacological inhibition of BACE1 effectively reduced levels of amyloidogenic APP C-terminal fragments (C99), soluble Aβ, Aβ oligomers, and amyloid deposits in transgenic mice expressing FAD-mutant hAPP, but did not improve their network dysfunction and behavioral abnormalities, even when initiated at early stages before amyloid deposits were detectable. Conclusions hAPP transgenic and App knock-in mice develop similar pathophysiological alterations. APP and its metabolites contribute to AD-related functional alterations through complex combinatorial mechanisms that may be difficult to block with BACE inhibitors and, possibly, also with other anti-Aβ treatments.


2019 ◽  
Vol 19 (5) ◽  
pp. 342-348 ◽  
Author(s):  
Zhi-You Cai ◽  
Chuan-Ling Wang ◽  
Tao-Tao Lu ◽  
Wen-Ming Yang

Background:Liver kinase B1 (LKB1)/5’-adenosine monophosphate-activated protein kinase (AMPK) signaling, a metabolic checkpoint, plays a neuro-protective role in the pathogenesis of Alzheimer’s disease (AD). Amyloid-β (Aβ) acts as a classical biomarker of AD. The aim of the present study was to explore whether berberine (BBR) activates LKB1/AMPK signaling and ameliorates Aβ pathology.Methods:The Aβ levels were detected using enzyme-linked immunosorbent assay and immunohistochemistry. The following biomarkers were measured by Western blotting: phosphorylated (p-) LKB1 (Ser334 and Thr189), p-AMPK (AMPKα and AMPKβ1), synaptophysin, post-synaptic density protein 95 and p-cAMP-response element binding protein (p-CREB). The glial fibrillary acidic protein (GFAP) was determined using Western blotting and immunohistochemistry.Results:BBR inhibited Aβ expression in the brain of APP/PS1 mice. There was a strong up-regulation of both p-LKB1 (Ser334 and Thr189) and p-AMPK (AMPKα and AMPKβ1) in the brains of APP/PS1 transgenic mice after BBR-treatment (P<0.01). BBR promoted the expression of synaptophysin, post-synaptic density protein 95 and p-CREB(Ser133) in the AD brain, compared with the model mice.Conclusion:BBR alleviates Aβ pathogenesis and rescues synapse damage via activating LKB1/AMPK signaling in the brain of APP/PS1 transgenic mice.


2009 ◽  
Vol 1294 ◽  
pp. 202-210 ◽  
Author(s):  
Hiroshi Kitaguchi ◽  
Hidekazu Tomimoto ◽  
Masafumi Ihara ◽  
Masunari Shibata ◽  
Kengo Uemura ◽  
...  

2007 ◽  
Vol 171 (6) ◽  
pp. 2012-2020 ◽  
Author(s):  
Tristan Bolmont ◽  
Florence Clavaguera ◽  
Melanie Meyer-Luehmann ◽  
Martin C. Herzig ◽  
Rebecca Radde ◽  
...  

2010 ◽  
Vol 48 (1) ◽  
pp. 136-144 ◽  
Author(s):  
D. Allan Butterfield ◽  
Veronica Galvan ◽  
Miranda Bader Lange ◽  
Huidong Tang ◽  
Renã A. Sowell ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhanglong Peng ◽  
Supinder Bedi ◽  
Vivek Mann ◽  
Alamelu Sundaresan ◽  
Kohei Homma ◽  
...  

To mimic Alzheimer’s disease, transgenic mice overexpressing the amyloid precursor protein (APP) were used in this study. We hypothesize that the neuroprotective effects of ETAS®50, a standardized extract of Asparagus officinalis stem produced by Amino Up Co., Ltd. (Sapporo, Japan), are linked to the inhibition of the apoptosis cascade through an enhancement of the stress-response proteins: heat shock proteins (HSPs). APP-overexpressing mice (double-transgenic APP and PS1 mouse strains with a 129s6 background), ages 6-8 weeks old, and weighing 20-24 grams were successfully bred in our laboratory. The animals were divided into 5 groups. APP-overexpressing mice and wild-type (WT) mice were pretreated with ETAS®50 powder (50% elemental ETAS and 50% destrin) at 200 mg/kg and 1000 mg/kg body weight. Saline, the vehicle for ETAS®50, was administered in APP-overexpressing mice and WT mice. ETAS®50 and saline were administered by gavage daily for 1 month. Cognitive assessments, using the Morris Water Maze, demonstrated that memory was recovered following ETAS®50 treatment as compared to nontreated APP mice. At euthanization, the brain was removed and HSPs, amyloid β, tau proteins, and caspase-3 were evaluated through immunofluorescence staining with the appropriate antibodies. Our data indicate that APP mice have cognitive impairment along with elevated amyloid β, tau proteins, and caspase-3. ETAS®50 restored cognitive function in these transgenic mice, increased both HSP70 and HSP27, and attenuated pathogenic level of amyloid β, tau proteins, and caspsase-3 leading to neuroprotection. Our results were confirmed with a significant increase in HSP70 gene expression in the hippocampus.


2008 ◽  
Vol 4 ◽  
pp. T157-T157
Author(s):  
Anna Lord ◽  
Hillevi Englund ◽  
Fredrik Clausen ◽  
Lars Hillered ◽  
Frida Ekholm Pettersson ◽  
...  

2013 ◽  
Vol 34 (3) ◽  
pp. 609-620 ◽  
Author(s):  
Thomas van Groen ◽  
Inga Kadish ◽  
Susanne Aileen Funke ◽  
Dirk Bartnik ◽  
Dieter Willbold

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