Hyperphosphorylation results in tau dysfunction in DNA folding and protection

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Hyperphosphorylation of tau is a hallmark of Alzheimer's disease (AD), forming paired helical filaments in the brain.
• Existing research primarily links tau hyperphosphorylation to microtubule disassembly and axonal transport deficits, leading to cell death.
• The correlation between tau hyperphosphorylation and DNA damage remains under-explored.

Purpose of the Study:

• To investigate the relationship between tau hyperphosphorylation and DNA damage.
• To determine if phosphorylated tau (p-Tau) contributes to DNA impairment.
• To elucidate the functional consequences of tau hyperphosphorylation on DNA integrity.

Main Methods:

• Utilized N2a cells treated with formaldehyde to induce tau hyperphosphorylation and DNA damage.
• Assessed the effects of phosphorylated tau (p-Tau) on DNA thermal denaturation, renaturation, and protection against reactive oxygen species (ROS).

Main Results:

• Tau hyperphosphorylation and DNA damage were observed concurrently in formaldehyde-treated N2a cells.
• Phosphorylated tau (p-Tau) exhibited diminished ability to prevent DNA thermal denaturation.
• p-Tau lost its capacity to accelerate DNA renaturation and showed impaired protection against ROS-induced DNA damage.

Conclusions:

• Tau hyperphosphorylation is associated not only with microtubule system disassembly but also plays a significant role in DNA impairment.
• Dysfunction of tau protein due to hyperphosphorylation compromises its protective role in maintaining DNA structure against ROS attack.
• These findings offer novel insights into the mechanisms underlying tauopathies, particularly the contribution of DNA damage.