Dramatic increase of alpha-hydroxyaldehydes derived from plasmalogens in the aged human brain

Area of Science:

• Biochemistry
• Neuroscience
• Lipidomics

Background:

• Plasmalogens are crucial for brain tissue function.
• Degradation occurs through hydrolysis (producing aldehydes) and oxidation (generating epoxides).
• Understanding these degradation pathways is key to studying age-related brain changes.

Purpose of the Study:

• To develop and validate a method for quantifying plasmalogens, free aldehydes, and plasmalogen epoxides in human brain samples.
• To investigate the relationship between these lipid species and aging.
• To identify the role of lipid peroxidation in age-related plasmalogen damage.

Main Methods:

• Derivatization of aldehydes (free and plasmalogen-derived) and plasmalogen epoxides using pentafluorobenzylhydroxylamine hydrochloride (PFBHA HCl).
• Quantification using Gas Chromatography with Flame Ionization Detection (GC/FID) and Gas Chromatography/Mass Spectrometry (GC/MSD).
• Acid hydrolysis to release plasmalogen-derived aldehydes.

Main Results:

• A method was established for quantifying plasmalogens, free aldehydes, and plasmalogen epoxides in human brain tissue.
• The ratio of plasmalogens to derived aldehydes remained constant with age.
• The ratio of plasmalogen epoxides to plasmalogens increased significantly in individuals around 70 years and older.

Conclusions:

• Lipid peroxidation plays a role in the degradation of plasmalogens in the aging human brain.
• The increase in plasmalogen epoxides indicates oxidative stress contributes to brain aging.
• This method provides a tool to study age-related changes in brain lipids and their implications for neurological health.