Evaluating a targeted multiple reaction monitoring approach to global untargeted lipidomic analyses of human plasma

Abstract

The Lipidyzer platform was recently updated on a SCIEX QTRAP 6500+ mass spectrometer and offers a targeted lipidomics assay including 1150 different lipids. We evaluated this targeted approach using human plasma samples and compared the results against a global untargeted lipidomics method using a highresolution Q Exactive HF Orbitrap mass spectrometer. Methods: Lipids from human plasma samples (N = 5) were extracted using a modified Bligh-Dyer approach. A global untargeted analysis was performed using a Thermo Orbitrap Q Exactive HF mass spectrometer, followed by data analysis using Progenesis QI software. Multiple reaction monitoring (MRM)-based targeted analysis was performed using a QTRAP 6500+ mass spectrometer, followed by data analysis using SCIEX OS software. The samples were injected on three separate days to assess reproducibility for both approaches. Results: Overall, 465 lipids were identified from 11 lipid classes in both approaches, of which 159 were similar between the methods, 168 lipids were unique to the MRM approach, and 138 lipids were unique to the untargeted approach. Phosphatidylcholine and phosphatidylethanolamine species were the most commonly identified using the untargeted approach, while triacylglycerol species were the most commonly identified using the targeted MRM approach. The targeted MRM approach had more consistent relative abundances across the three days than the untargeted approach. Overall, the coefficient of variation for inter-day comparisons across all lipid classes was 23% for the untargeted approach and 9% for the targeted MRM approach. Conclusions: The targeted MRM approach identified similar numbers of lipids to a conventional untargeted approach, but had better representation of 11 lipid classes commonly identified by both approaches. Based on the separation methods employed, the conventional untargeted approach could better detect phosphatidylcholine and sphingomyelin lipid classes. The targeted MRM approach had lower inter-day variability than the untargeted approach when tested using a small group of plasma samples. These studies highlight the advantages in using targeted MRM approaches for human plasma lipidomics analysis.

Grape Lipidomics: An Extensive Profiling thorough UHPLC-MS/MS Method

“…The graphs show how the compound classes are distributed along the separation time according to their m/z for the three types of columns. The XBridge Amide column, which was recently used by Khan et al [51] for the lipidomic analyses of human plasma, did not guarantee, in our application, a suitable separation of TG, DG and MGDG, which represent around 60% of the compounds identified in our matrix (Figure 1). and MGDG, which represent around 60 % of the compounds identified in our matrix (Figure 1).…”

“…The first tested method was set up with an XBridge Amide HPLC column (4.6 × 150 mm, 3.5 µm) (Waters, Milford, MA, USA) [51].…”

Adipose-Specific PPARα Knockout Mice Have Increased Lipogenesis by PASK–SREBP1 Signaling and a Polarity Shift to Inflammatory Macrophages in White Adipose Tissue

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