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Published on: October 10, 2017
Methotrexate decreases PP2A methylation and increases tau phosphorylation in neuron
Seung Yong Yoon1, Hyo In Choi, Jung Eun Choi
1Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, 388-1 PoongNap-Dong, SongPa-Gu, Seoul 138-736, Republic of Korea.
Folate deficiency exacerbates Alzheimer's disease (AD) pathology, increasing tau phosphorylation and amyloid precursor protein (APP) levels. This may occur by inactivating protein phosphatase-2A (PP2A), a key enzyme in neurodegeneration.
Area of Science:
- Neuroscience
- Biochemistry
- Pathology
Background:
- Folate deficiency is linked to Alzheimer's disease (AD) pathogenesis.
- Key AD pathologies include hyperphosphorylated tau and beta-amyloid (Aβ) deposition from amyloid precursor protein (APP).
Purpose of the Study:
- To investigate the molecular mechanisms linking folate deficiency to AD pathogenesis.
- To determine the effect of folate antagonism on neuronal cultures and AD-related markers.
Main Methods:
- Primary rat neuron cultures were treated with methotrexate (MTX), a folate antagonist.
- Western blot, immunocytochemistry, and MTS assay were used to analyze tau phosphorylation, APP levels, beta-secretase, neuronal viability, and methylated protein phosphatase-2A (PP2A).
Main Results:
- MTX treatment increased levels of phosphorylated tau, APP, and beta-secretase.
- Neuronal viability was reduced following MTX treatment.
- Methylated protein phosphatase-2A (PP2A), the active form of the tau phosphatase, was reduced, suggesting PP2A inactivation.
Conclusions:
- Folate deficiency enhances characteristic AD pathologies, including tau phosphorylation.
- PP2A inactivation is a potential mechanism by which folate deficiency contributes to AD pathology.
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