Comparison of amino acidergic neurotransmitters in hippocampus and behavior between different aged h-APP transgenic mice with Alzheimer's disease

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.

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Oral Treatment with the d-Enantiomeric Peptide D3 Improves the Pathology and Behavior of Alzheimer’s Disease Transgenic Mice

ACS Chemical Neuroscience ◽

10.1021/cn100057j ◽

2010 ◽

Vol 1 (9) ◽

pp. 639-648 ◽

Cited By ~ 68

Author(s):

Susanne Aileen Funke ◽

Thomas van Groen ◽

Inga Kadish ◽

Dirk Bartnik ◽

Luitgard Nagel-Steger ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Transgenic Mice ◽

Oral Treatment ◽

And Behavior

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Faculty Opinions recommendation of Nicotinamide restores cognition in Alzheimer's disease transgenic mice via a mechanism involving sirtuin inhibition and selective reduction of Thr231-phosphotau.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1146910.604008 ◽

2009 ◽

Author(s):

Mark A Smith ◽

Bo Su

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Transgenic Mice ◽

Selective Reduction

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Synthesis of a Novel Curcumin Derivative as a Potential Imaging Probe in Alzheimer’s Disease Imaging

Current Alzheimer Research ◽

10.2174/1567205016666190816130516 ◽

2019 ◽

Vol 16 (8) ◽

pp. 723-731 ◽

Cited By ~ 1

Author(s):

Alexander Sturzu ◽

Sumbla Sheikh ◽

Hubert Kalbacher ◽

Thomas Nägele ◽

Christopher Weidenmaier ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Flow Cytometry ◽

Transgenic Mice ◽

Ex Vivo ◽

Amyloid Plaques ◽

Laser Scanning Microscopy ◽

Β Amyloid ◽

Curcumin Derivative

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.

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MiR-335-5p Inhibits β-Amyloid (Aβ) Accumulation to Attenuate Cognitive Deficits Through Targeting c-jun-N-terminal Kinase 3 in Alzheimer’s Disease

Current Neurovascular Research ◽

10.2174/1567202617666200128141938 ◽

2020 ◽

Vol 17 (1) ◽

pp. 93-101 ◽

Cited By ~ 3

Author(s):

Dan Wang ◽

Zhifu Fei ◽

Song Luo ◽

Hai Wang

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Transgenic Mice ◽

Western Blot ◽

Mrna Expression ◽

Cognitive Deficits ◽

Protein Levels ◽

Amyloid Aβ ◽

Β Amyloid ◽

The Relationship

Objectives: Alzheimer's disease (AD), also known as senile dementia, is a common neurodegenerative disease characterized by progressive cognitive impairment and personality changes. Numerous evidences have suggested that microRNAs (miRNAs) are involved in the pathogenesis and development of AD. However, the exact role of miR-335-5p in the progression of AD is still not clearly clarified. Methods: The protein and mRNA levels were measured by western blot and RNA extraction and quantitative real-time PCR (qRT-PCR), respectively. The relationship between miR-335-5p and c-jun-N-terminal kinase 3 (JNK3) was confirmed by dual-luciferase reporter assay. SH-SY5Y cells were transfected with APP mutant gene to establish the in vitro AD cell model. Flow cytometry and western blot were performed to evaluate cell apoptosis. The APP/PS1 transgenic mice were used as an in vivo AD model. Morris water maze test was performed to assess the effect of miR- 335-5p on the cognitive deficits in APP/PS1 transgenic mice. Results: The JNK3 mRNA expression and protein levels of JNK3 and β-Amyloid (Aβ) were significantly up-regulated, and the mRNA expression of miR-335-5p was down-regulated in the brain tissues of AD patients. The expression levels of miR-335-5p and JNK3 were significantly inversely correlated. Further, the dual Luciferase assay verified the relationship between miR-335- 5p and JNK3. Overexpression of miR-335-5p significantly decreased the protein levels of JNK3 and Aβ and inhibited apoptosis in SH-SY5Y/APPswe cells, whereas the inhibition of miR-335-5p obtained the opposite results. Moreover, the overexpression of miR-335-5p remarkably improved the cognitive abilities of APP/PS1 mice. Conclusion: The results revealed that the increased JNK3 expression, negatively regulated by miR-335-5p, may be a potential mechanism that contributes to Aβ accumulation and AD progression, indicating a novel approach for AD treatment.

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Dehydroepiandrosterone (DHEA) and its Sulphate (DHEAS) in Alzheimer’s Disease

Current Alzheimer Research ◽

10.2174/1567205017666200317092310 ◽

2020 ◽

Vol 17 (2) ◽

pp. 141-157 ◽

Cited By ~ 2

Author(s):

Dubravka S. Strac ◽

Marcela Konjevod ◽

Matea N. Perkovic ◽

Lucija Tudor ◽

Gordana N. Erjavec ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Large Scale ◽

Therapeutic Potential ◽

Relevant Literature ◽

Comprehensive Overview ◽

Brain Functions ◽

Specific Effects ◽

And Behavior

Background: Neurosteroids Dehydroepiandrosterone (DHEA) and Dehydroepiandrosterone Sulphate (DHEAS) are involved in many important brain functions, including neuronal plasticity and survival, cognition and behavior, demonstrating preventive and therapeutic potential in different neuropsychiatric and neurodegenerative disorders, including Alzheimer’s disease. Objective: The aim of the article was to provide a comprehensive overview of the literature on the involvement of DHEA and DHEAS in Alzheimer’s disease. Method: PubMed and MEDLINE databases were searched for relevant literature. The articles were selected considering their titles and abstracts. In the selected full texts, lists of references were searched manually for additional articles. Results: We performed a systematic review of the studies investigating the role of DHEA and DHEAS in various in vitro and animal models, as well as in patients with Alzheimer’s disease, and provided a comprehensive discussion on their potential preventive and therapeutic applications. Conclusion: Despite mixed results, the findings of various preclinical studies are generally supportive of the involvement of DHEA and DHEAS in the pathophysiology of Alzheimer’s disease, showing some promise for potential benefits of these neurosteroids in the prevention and treatment. However, so far small clinical trials brought little evidence to support their therapy in AD. Therefore, large-scale human studies are needed to elucidate the specific effects of DHEA and DHEAS and their mechanisms of action, prior to their applications in clinical practice.

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Alterations in the Gut-Microbial-Inflammasome-Brain Axis in a Mouse Model of Alzheimer’s Disease

Cells ◽

10.3390/cells10040779 ◽

2021 ◽

Vol 10 (4) ◽

pp. 779

Author(s):

Pradeep K. Shukla ◽

David F. Delotterie ◽

Jianfeng Xiao ◽

Joseph F. Pierre ◽

RadhaKrishna Rao ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Mouse Model ◽

Gut Microbiota ◽

Transgenic Mice ◽

Nlrp3 Inflammasome ◽

Inflammasome Activation ◽

Gut Barrier Function ◽

Elevated Expression ◽

5Xfad Mice

Alzheimer’s disease (AD), a progressive neurodegenerative disorder characterized by memory loss and cognitive decline, is a major cause of death and disability among the older population. Despite decades of scientific research, the underlying etiological triggers are unknown. Recent studies suggested that gut microbiota can influence AD progression; however, potential mechanisms linking the gut microbiota with AD pathogenesis remain obscure. In the present study, we provided a potential mechanistic link between dysbiotic gut microbiota and neuroinflammation associated with AD progression. Using a mouse model of AD, we discovered that unfavorable gut microbiota are correlated with abnormally elevated expression of gut NLRP3 and lead to peripheral inflammasome activation, which in turn exacerbates AD-associated neuroinflammation. To this end, we observe significantly altered gut microbiota compositions in young and old 5xFAD mice compared to age-matched non-transgenic mice. Moreover, 5xFAD mice demonstrated compromised gut barrier function as evident from the loss of tight junction and adherens junction proteins compared to non-transgenic mice. Concurrently, we observed increased expression of NLRP3 inflammasome and IL-1β production in the 5xFAD gut. Consistent with our hypothesis, increased gut–microbial–inflammasome activation is positively correlated with enhanced astrogliosis and microglial activation, along with higher expression of NLRP3 inflammasome and IL-1β production in the brains of 5xFAD mice. These data indicate that the elevated expression of gut–microbial–inflammasome components may be an important trigger for subsequent downstream activation of inflammatory and potentially cytotoxic mediators, and gastrointestinal NLRP3 may promote NLRP3 inflammasome-mediated neuroinflammation. Thus, modulation of the gut microbiota may be a potential strategy for the treatment of AD-related neurological disorders in genetically susceptible hosts.

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