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Updated: Aug 31, 2025
09:33
Quantitative 3D In Silico Modeling q3DISM of Cerebral Amyloid-beta Phagocytosis in Rodent Models of Alzheimer's Disease
Published on: December 26, 2016
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Aqp4 stop codon readthrough facilitates amyloid-β clearance from the brain
Darshan Sapkota1,2,3, Colin Florian1,2, Brookelyn M Doherty4
1Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA.
Brain : a Journal of Neurology
|August 24, 2022
Summary
Alzheimer's disease clearance of amyloid-beta is enhanced by a specific Aquaporin 4 variant (AQP4X). Small molecules boosting AQP4X production show potential for treating neurodegenerative diseases.
Area of Science:
- Neuroscience
- Molecular Biology
- Pharmacology
Background:
- Alzheimer's disease involves toxic amyloid-beta aggregation, with limited success from current immunotherapies.
- Aquaporin 4 (AQP4) in astrocytes aids brain amyloid-beta clearance, but its perivascular fraction decreases in Alzheimer's disease.
- A C-terminally elongated AQP4 variant (AQP4X) is generated by stop codon readthrough and localizes perivascularly.
Purpose of the Study:
- To investigate if the AQP4X variant specifically mediates amyloid-beta clearance.
- To identify small molecules that enhance AQP4 readthrough and AQP4X production.
- To evaluate the therapeutic potential of AQP4X-enhancing compounds for Alzheimer's disease.
Main Methods:
- Utilized Aquaporin 4 readthrough-specific knockout mice to isolate AQP4X function.
- Employed high-throughput screening and counterscreening to identify small molecule enhancers of AQP4 readthrough.
- Validated identified compounds on endogenous astrocyte AQP4 and tested their efficacy in vivo.
Main Results:
- Confirmed that the AQP4X isoform is crucial for mediating amyloid-beta clearance.
- Discovered small molecule compounds that effectively enhance AQP4 sequence readthrough.
- Demonstrated that these compounds improve brain amyloid-beta clearance in vivo, dependent on AQP4X.
Conclusions:
- The AQP4X variant plays a specific role in clearing amyloid-beta from the brain.
- Small molecules enhancing AQP4X production represent a promising pharmaceutical strategy for Alzheimer's disease.
- This approach may also be applicable to other protein-aggregation disorders in neurodegenerative diseases.
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