Comprehensive analyses of oxidized phospholipids using a measured MS/MS spectra library

Area of Science:

• Analytical Chemistry
• Lipidomics
• Biochemistry

Background:

• Oxidized phospholipids (OxPLs) are implicated in various diseases, including arteriosclerosis, diabetes, and cancer.
• Understanding the structure-specific behavior and physiological relevance of OxPLs is critical for disease research.

Purpose of the Study:

• To develop a comprehensive analytical method for characterizing the structure-specific behavior of OxPLs.
• To establish a measured MS/MS spectra library of OxPLs for accurate identification.
• To enable the detection and monitoring of OxPLs in biological samples.

Main Methods:

• Preparation of biogenic OxPLs by incorporating oxidized fatty acids into cultured cells.
• Untargeted lipidomics using LC-quadrupole/TOF-MS to collect MS/MS spectra for approximately 400 OxPL molecular species.
• Development of a broad-targeted lipidomics system using triple quadrupole MS with optimized multiple reaction monitoring for isomer separation.
• Detection sensitivity achieved as low as 10 fmol.

Main Results:

• A comprehensive MS/MS spectra library of biogenic OxPLs was established.
• A sensitive broad-targeted lipidomics system capable of detecting OxPLs at 10 fmol levels was developed.
• The system successfully monitored endogenous OxPLs in mouse peritoneal macrophages, revealing a 12/15-lipoxygenase-dependent production pathway.

Conclusions:

• The developed analytical method provides high precision in separating OxPL structural isomers.
• This advanced technique facilitates the elucidation of OxPL structure-specific behavior and their physiological relevance in vivo.
• The findings pave the way for deeper investigation into the role of OxPLs in various disease pathologies.