Tau phosphatase activity as a therapeutic target for AD

Area of Science:

• Neuroscience
• Biochemistry
• Cell Biology

Background:

• Tau protein is crucial for microtubule assembly and stability in healthy brains.
• In Alzheimer's disease (AD) brains, tau becomes hyperphosphorylated (AD P-tau), losing its function and destabilizing microtubules.
• This dysfunction in AD P-tau impairs axonal transport and neuronal integrity.

Purpose of the Study:

• To investigate the site-specific dephosphorylation of AD P-tau using phosphorylation-dependent antibodies.
• To determine the effect of specific protein phosphatases (PSPs) on AD P-tau.
• To explore the potential of modulating tau phosphatase activity for AD treatment.

Main Methods:

• Utilized phosphorylation-dependent antibodies to target and analyze AD P-tau.
• Performed in vitro dephosphorylation assays using specific PSPs: PP-1, PP-2A, and PP-2B.
• Examined biochemical, biological, and structural changes in neurofibrillary tangles after dephosphorylation by PP-2A and PP-2B.

Main Results:

• The PSPs PP-1, PP-2A, and PP-2B rapidly dephosphorylated AD P-tau in vitro.
• Dephosphorylation of neurofibrillary tangles by PP-2A and PP-2B induced significant alterations.
• These alterations suggest a restoration of tau's functional properties.

Conclusions:

• Specific tau phosphatases can reverse the pathological hyperphosphorylation of tau in AD.
• Modulating the activity of tau phosphatases (PP-2A, PP-2B) offers a potential therapeutic strategy.
• Enhancing tau phosphatase activity may inhibit neurodegeneration in both sporadic and familial forms of AD.