scholarly journals Impaired astrocytic Ca2+ signalling in awake Alzheimer's disease transgenic mice

2021 ◽  
Author(s):  
Knut Sindre Åbjørsbråten ◽  
Gry H. E. Syverstad Skaaraas ◽  
Céline Cunen ◽  
Daniel M. Bjørnstad ◽  
Kristin M. Gullestad Binder ◽  
...  

Increased astrocytic Ca2+ signaling related to amyloid plaques has been shown in Alzheimer's disease mouse models, but to date no reports have characterized behaviorally induced astrocytic Ca2+ signalling in such mice without the confounding effects of anesthesia. Here, we employ an event-based algorithm to assess astrocytic Ca2+ signals in the neocortex of awake-behaving tg-ArcSwe mice and non-transgenic wildtype littermates while monitoring pupil responses and behavior. We demonstrate an attenuated astrocytic Ca2+ response to locomotion and an uncoupling of pupil responses and astrocytic Ca2+ signalling in 15-months old plaque-bearing mice. This points to a potential decoupling of neuromodulatory activation and astrocytic Ca2+ activity, which may account for some of the cognitive dysfunctions observed in Alzheimer’s disease.

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Celeste A. Roney ◽  
Veera Arora ◽  
Padmakar V. Kulkarni ◽  
Peter P. Antich ◽  
Frederick J. Bonte

Detecting aggregated amyloid peptides (Aβplaques) presents targets for developing biomarkers of Alzheimer's disease (AD). Polymeric n-butyl-2-cyanoacrylate (PBCA) nanoparticles (NPs) were encapsulated with radiolabelled amyloid affinityI125-clioquinol (CQ, 5-chloro-7-iodo-8-hydroxyquinoline) as in vivo probes.I125-CQ-PBCA NPs crossed the BBB (2.3±0.9 ID/g) (P<.05) in the WT mouse (N= 210), compared toI125-CQ (1.0±0.4 ID/g).I125-CQ-PBCA NP brain uptake increased in AD transgenic mice (APP/PS1) versus WT (N= 38;2.54×105±5.31×104 DLU/mm2; versus1.98×105±2.22×104 DLU/mm2) and in APP/PS1/Tau. Brain increases were in mice intracranially injected with aggregated Aβ42peptide (N= 17;7.19×105±1.25×105 DLU/mm2), versus WT (6.07×105±7.47×104 DLU/mm2). Storage phosphor imaging and histopathological staining of the plaques,Fe2+andCu2+, validated results.I125-CQ-PBCA NPs have specificity for Aβin vitro and in vivo and are promising as in vivo SPECT (I123), or PET (I124) amyloid imaging agents.


2019 ◽  
Vol 16 (8) ◽  
pp. 723-731 ◽  
Author(s):  
Alexander Sturzu ◽  
Sumbla Sheikh ◽  
Hubert Kalbacher ◽  
Thomas Nägele ◽  
Christopher Weidenmaier ◽  
...  

Background: Curcumin has been of interest in the field of Alzheimer’s disease. Early studies on transgenic mice showed promising results in the reduction of amyloid plaques.However, curcumin is very poorly soluble in aqueous solutions and not easily accessible to coupling as it contains only phenolic groups as potential coupling sites. For these reasons only few imaging studies using curcumin bound as an ester were performed and curcumin is mainly used as nutritional supplement. Methods: In the present study we produced an aminoethyl ether derivative of curcumin using a nucleophilic substitution reaction. This is a small modification and should not impact the properties of curcumin while introducing an easily accessible reactive amino group. This novel compound could be used to couple curcumin to other molecules using the standard methods of peptide synthesis. We studied the aminoethyl-curcumin compound and a tripeptide carrying this aminoethyl-curcumin and the fluorescent dye fluorescein (FITC-curcumin) in vitro on cell culture using confocal laser scanning microscopy and flow cytometry. Then these two substances were tested ex vivo on brain sections prepared from transgenic mice depicting Alzheimer-like β-amyloid plaques. Results: In the in vitro CLSM microscopy and flow cytometry experiments we found dot-like unspecific uptake and only slight cytotoxicity correlating with this uptake. As these measurements were optimized for the use of fluorescein as dye we found that the curcumin at 488nm fluorescence excitation was not strong enough to use it as a fluorescence marker in these applications. In the ex vivo sections CLSM experiments both the aminoethyl-curcumin and the FITC-curcumin peptide bound specifically to β- amyloid plaques. Conclusion: In conclusion we successfully produced a novel curcumin derivative which could easily be coupled to other imaging or therapeutic molecules as a sensor for amyloid plaques.


2009 ◽  
Vol 5 (4S_Part_4) ◽  
pp. P107-P107
Author(s):  
Samir Kumar-Singh ◽  
Daniel Pirici ◽  
Christine Van Broeckhoven

2019 ◽  
Author(s):  
Yao Sun ◽  
Yongqing Guo ◽  
Xuejian Feng ◽  
Meng Jia ◽  
Ning Ai ◽  
...  

Abstract Tau hyper-phosphorylation has been considered a major contributor to neurodegeneration in Alzheimer’s disease (AD) and related tauopathies, and has gained prominence in therapeutic development for AD. To elucidate the pathogenic mechanisms underlying AD and evaluate therapeutic approaches targeting tau, numerous transgenic mouse models that recapitulate critical AD-like pathology have been developed. Tau P301S transgenic mice is one of the most widely used mouse models in AD research. Extensive studies have demonstrated that sex significantly influences AD pathology, behavioral status and therapeutic outcomes, suggesting that studies using mouse models of AD must consider sex- and age-related differences in neuropathology, behavior, and plasma content. Method: We systematically investigated differences in tau P301S transgenic mice (PS19 line) and wildtype littermates of different sex behavioral performance, tau neuropathology and biomarkers in plasma and brain. Results: Male P301S transgenic mice exhibited significant changes in weight loss, survival rate, clasping, kyphosis, composite phenotype assessment, nest building performance, tau phosphorylation at Ser202/Thr205 and astrocyte activation compared to that of wild type littermates. In contrast, female P301S transgenic mice were only sensitive in the Morris Water Maze and open field test. In addition, we characterized the upregulation of interferon (IFN)-γ, interleukin (IL)-5, and IL-6 and the absense of macrophage-inflammatory protein (MIP)-3α. Male P301S transgenic mice expressed more plasma biomarkers than those of female P301S mice. Conclusion: Our findings highlight sexual dimorphism in the behavior, neuropathology, and biomarkers in tau P301S transgenic AD mice, indicating that the use of male P301S transgenic mice may be more suitable for assessing anti-phosphorylated tau therapeutic strategies for AD and related tauopathies.


2001 ◽  
Vol 67 ◽  
pp. 195-202 ◽  
Author(s):  
Karen Duff

A range of transgenic mice have been created to model Alzheimer's disease. These include mice expressing human forms of the amyloid precursor protein, the presenilins and, more recently, tau. Several of the models develop features of the disease including amyloid pathology, cholinergic deficits, neurodegeneration and cognitive impairment. Progress in the characterization and use of these model animals is discussed.


NeuroImage ◽  
2011 ◽  
Vol 55 (4) ◽  
pp. 1600-1609 ◽  
Author(s):  
Jing Yang ◽  
Youssef Zaim Wadghiri ◽  
Dung Minh Hoang ◽  
Wai Tsui ◽  
Yanjie Sun ◽  
...  

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Clémence Dudeffant ◽  
Matthias Vandesquille ◽  
Kelly Herbert ◽  
Clément M. Garin ◽  
Sandro Alves ◽  
...  

2011 ◽  
Vol 7 ◽  
pp. S311-S311
Author(s):  
Zhizhen Zeng ◽  
Tsing-Bau Chen ◽  
Brett Connolly ◽  
Patricia Miller ◽  
Stacey O'Malley ◽  
...  

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