Label-free Electrochemical Sensor for Ex-vivo Monitoring of Alzheimer's Disease Biomarker

2016 ◽  
Vol 29 (3) ◽  
pp. 748-755 ◽  
Author(s):  
Waleed A. El-Said ◽  
Kawthar Abd El-Hameed ◽  
Nagwa Abo El-Maali ◽  
Hayam G. Sayyed
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Electrochemical Sensor ◽  
Ex Vivo ◽  
Label Free ◽  
Disease Biomarker

Induced conformational change on ferrocenyl-terminated alkyls and their application as transducers for label-free immunosensing of Alzheimer's disease biomarker

RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 2414-2421 ◽  
Author(s):  
Abdelmoneim Mars ◽  
Wicem Argoubi ◽  
Sami Ben Aoun ◽  
Noureddine Raouafi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Electron Transfer ◽  
Conformational Change ◽  
Conformational Changes ◽  
Rate Constants ◽  
Label Free ◽  
Alkyl Chains ◽  
Disease Biomarker

ApoE Alzheimer's disease biomarker can be sensitively detected by a label-free platform using flexible ferrocene-terminated alkyl chains. The immunorecognition triggers conformational changes, which improve the rate constants of electron-transfer.

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

2019 ◽  
Vol 16 (8) ◽  
pp. 723-731 ◽  
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.

scholarly journals Pharmacological ablation of astrocytes reduces Aβ degradation and synaptic connectivity in an ex vivo model of Alzheimer’s disease

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Nicola Davis ◽  
Bibiana C. Mota ◽  
Larissa Stead ◽  
Emily O. C. Palmer ◽  
Laura Lombardero ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Culture Media ◽  
Ex Vivo ◽  
Wild Type ◽  
Insulin Degrading Enzyme ◽  
Ex Vivo Model ◽  
Model Of Alzheimer’S Disease ◽  
Aβ Clearance ◽  
5Xfad Mice

Abstract Background Astrocytes provide a vital support to neurons in normal and pathological conditions. In Alzheimer’s disease (AD) brains, reactive astrocytes have been found surrounding amyloid plaques, forming an astrocytic scar. However, their role and potential mechanisms whereby they affect neuroinflammation, amyloid pathology, and synaptic density in AD remain unclear. Methods To explore the role of astrocytes on Aβ pathology and neuroinflammatory markers, we pharmacologically ablated them in organotypic brain culture slices (OBCSs) from 5XFAD mouse model of AD and wild-type (WT) littermates with the selective astrocytic toxin L-alpha-aminoadipate (L-AAA). To examine the effects on synaptic circuitry, we measured dendritic spine number and size in OBCSs from Thy-1-GFP transgenic mice incubated with synthetic Aβ42 or double transgenics Thy-1-GFP/5XFAD mice treated with LAAA or vehicle for 24 h. Results Treatment of OBCSs with L-AAA resulted in an increased expression of pro-inflammatory cytokine IL-6 in conditioned media of WTs and 5XFAD slices, associated with changes in microglia morphology but not in density. The profile of inflammatory markers following astrocytic loss was different in WT and transgenic cultures, showing reductions in inflammatory mediators produced in astrocytes only in WT sections. In addition, pharmacological ablation of astrocytes led to an increase in Aβ levels in homogenates of OBCS from 5XFAD mice compared with vehicle controls, with reduced enzymatic degradation of Aβ due to lower neprilysin and insulin-degrading enzyme (IDE) expression. Furthermore, OBSCs from wild-type mice treated with L-AAA and synthetic amyloid presented 56% higher levels of Aβ in culture media compared to sections treated with Aβ alone, concomitant with reduced expression of IDE in culture medium, suggesting that astrocytes contribute to Aβ clearance and degradation. Quantification of hippocampal dendritic spines revealed a reduction in their density following L-AAA treatment in all groups analyzed. In addition, pharmacological ablation of astrocytes resulted in a decrease in spine size in 5XFAD OBCSs but not in OBCSs from WT treated with synthetic Aβ compared to vehicle control. Conclusions Astrocytes play a protective role in AD by aiding Aβ clearance and supporting synaptic plasticity.

scholarly journals Effects of Risperidone and Galantamine Treatment on Alzheimer’s Disease Biomarker Levels in Cerebrospinal Fluid

2017 ◽  
Vol 57 (2) ◽  
pp. 387-393 ◽  
Author(s):  
Victor Bloniecki ◽  
Dag Aarsland ◽  
Kaj Blennow ◽  
Jeffrey Cummings ◽  
Farshad Falahati ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Disease Biomarker

P1-010: Quantification of the synaptic protein neurogranin in cerebrospinal fluid across different neurodegenerative diseases: A selective Alzheimer's disease biomarker?

2015 ◽  
Vol 11 (7S_Part_7) ◽  
pp. P340-P340
Author(s):  
Henrietta Wellington ◽  
Ulrika Törnqvist ◽  
Erik Portelius ◽  
Ross W. Paterson ◽  
Nadia K. Magdalinou ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Neurodegenerative Diseases ◽  
Synaptic Protein ◽  
Disease Biomarker

IC-P-136: Mathematical and statistical methods to model the trajectory and estimate the age at onset of Alzheimer's disease biomarker changes

2012 ◽  
Vol 8 (4S_Part_2) ◽  
pp. P72-P72
Author(s):  
Kewei Chen ◽  
Adam Fleisher ◽  
Napatkamon Ayutyanont ◽  
Yakeel Quiroz ◽  
Sergio Alvarez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Statistical Methods ◽  
Age At Onset ◽  
Disease Biomarker

scholarly journals Alzheimer’s disease biomarker roadmap 2020: Fluid biomarkers

2020 ◽  
Vol 16 (S5) ◽  
Author(s):  
Nicholas J Ashton ◽  
Antoine Leuzy ◽  
Thomas K Karikari ◽  
Alessandra Dodich ◽  
Marina Boccardi ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Disease Biomarker
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