Diamond Quantum Sensing Revealing the Relation between Free Radicals and Huntington's Disease

Area of Science:

• Biochemistry
• Cell Biology
• Neuroscience

Background:

• Huntington's disease (HD) is a rare neurodegenerative disorder caused by polyglutamine (PolyQ) expansion.
• PolyQ aggregation leads to cellular damage, partly through increased free radical production.
• The precise location and generation mechanism of these free radicals remain unclear.

Purpose of the Study:

• To investigate the subcellular localization of free radical generation in Huntington's disease.
• To explore the relationship between PolyQ aggregation and free radical production.
• To utilize nanoscale MRI for high-resolution detection of free radicals.

Main Methods:

• Employing relaxometry with fluorescent nanodiamonds (FNDs) for nanoscale MRI measurements.
• Using tetracycline-inducible human embryonic kidney cells expressing mutant Huntington protein (HEK PQ) to model PolyQ aggregation.
• Correlating FND signal changes with PolyQ aggregate formation and localization.

Main Results:

• Fluorescent nanodiamonds (FNDs) were found to be highly colocalized with PolyQ aggregates within autolysosomes.
• Increased PolyQ aggregation directly correlated with elevated free radical production.
• Autolysosome dysfunction is implicated in the free radical generation observed in HD models.

Conclusions:

• Free radical generation in Huntington's disease models occurs in close proximity to PolyQ aggregates, specifically within autolysosomes.
• This study establishes a direct link between PolyQ aggregation, autolysosome dysfunction, and oxidative stress in HD.
• Nanoscale MRI with FNDs offers a powerful tool for studying subcellular radical dynamics in disease.