Global Monitoring of the Mammalian Lipidome by Quantitative Shotgun Lipidomics

Abstract

The emerging field of lipidomics presents the systems biology approach to identify and quantify the full lipid repertoire of cells, tissues, and organisms. The importance of the lipidome is demonstrated by a number of biological studies on dysregulation of lipid metabolism in human diseases such as cancer, diabetes, and neurodegenerative diseases. Exploring changes and regulations in the huge networks of lipids and their metabolic pathways requires a lipidomics methodology: Advanced mass spectrometry that resolves the complexity of the lipidome. Here, we report a comprehensive protocol of quantitative shotgun lipidomics that enables identification and quantification of hundreds of molecular lipid species, covering a wide range of lipid classes, extracted from cultured mammalian cells.

Investigation of the phosphatidylserine binding properties of the lipid biosensor, Lactadherin C2 (LactC2), in different membrane environments

“…This work is important for outlining the possibility of stark lipidomic differences from organism to organism within the same family. Similar lipidomic analysis has been done for drosophila (Niehoff et al 2014; Parisi et al 2011) and mammalian cell lines (Dennis et al 2010; Nielsen et al 2017; Sampaio et al 2011). This work begs caution and attention when selecting lipid biomarkers for work within organisms whose nuanced lipid profiles are not enumerated.…”

Lysosomal Changes in Mitosis

“…Mass spectrometry-based quantitative shotgun lipidomics was performed according to a protocol from Nielsen and colleagues [ 40 ] with minor applied changes. In brief, lipid internal standards were added to each sample prior to lipid extraction to allow lipids to be quantitated.…”

Accurate quantification of lipid species affected by isobaric overlap in Fourier-transform mass spectrometry

“…A major issue of lipidomic analysis is the substantial isotopic overlap of lipid species differing only by the number of double bonds (DB). Particularly, the natural abundance of 13 C-atoms (about 1.1%) contributes significantly to the second isotopic peak resulting in intensities of >10% related to the monoisotopic peak of a typical glycerophospholipid. The overlap of the monoisotopic peak (M DB=i +0) with the second isotopic peak of a species of the same lipid class and number of C-atoms but with one additional DB (M DB=i+1 +2) is termed Type-II isotopic effect (6).…”

“…In low resolution mass spectrometry (LRMS) this effect is frequently corrected by algorithms based on calculated isotope patterns in both shotgun (6,7) and LC-based lipidomic methods (8). In contrast, the application of high-resolution MS (HRMS) allows the resolution of a Type-II overlap caused by incorporation of two 13 C-atoms with a mass difference of 8.94 mDa of M i+1 +2 and M i +0 (9). Additionally, accurate quantification of lipid species in both, LRMS and HRMS, requires consideration of decreasing abundance of the monoisotopic peak with increasing C-atom numbers (Type-I isotopic effect) (6).…”