Age-related increase of monoamine oxidase B in amyloid-negative cognitively unimpaired elderly subjects

Area of Science:

• Neuroimaging
• Neuroscience
• Gerontology

Background:

• Monoamine oxidase B (MAO-B) is prevalent in reactive astrocytes and elevated during neuroinflammation.
• Age-related changes in MAO-B within amyloid-negative, cognitively unimpaired elderly individuals require further PET evaluation.
• ¹⁸F-THK5351 PET shows high affinity for MAO-B, potentially serving as a neuroinflammation biomarker.

Purpose of the Study:

• To investigate age-related topographic changes of ¹⁸F-THK5351 PET retention in amyloid-negative, cognitively unimpaired elderly subjects.
• To assess the utility of ¹⁸F-THK5351 as a PET imaging biomarker for age-related neuroinflammation.

Main Methods:

• Utilized positron emission tomography (PET) with the radiotracer ¹⁸F-THK5351.
• Evaluated age-related changes in tracer retention through visual, voxel-based, and region of interest (ROI)-based analyses.
• Employed Statistical Parametric Mapping and PETSurfer tools on data from 31 amyloid-negative, cognitively unimpaired elderly participants.

Main Results:

• Visual inspection revealed ¹⁸F-THK5351 accumulation spreading from medial to inferolateral temporal and basal frontal lobes, and cingulate gyrus in elderly groups.
• Voxel- and ROI-based analyses confirmed a correlation between ¹⁸F-THK5351 accumulation and participant age, particularly in the inferior temporal lobes.

Conclusions:

• Demonstrated an age-dependent increase in ¹⁸F-THK5351 retention in amyloid-negative, cognitively unimpaired subjects.
• Suggests an aging-associated increase in MAO-B-positive reactive astrocytes.
• Highlights the potential of ¹⁸F-THK5351 PET for imaging age-related neuroinflammation.