Rapid identification of glycerophospholipids from RAW264.7 cells by UPLC/ESI -QTOF-MS

Maternal and fetal metabolomic alterations in maternal lipopolysaccharide exposure-induced male offspring glucose metabolism disorders

Maternal lipopolysaccharide (LPS) exposure during pregnancy induces metabolic abnormalities in male offspring, but the underlying mechanisms remain unclear. The purpose of this study was to investigate the effects of maternal LPS exposure during pregnancy on metabolic profiling of maternal serum and male fetal liver using Liquid Chromatograph Mass Spectrometer techniques. From day 15 to day 17 of gestation, pregnant mice were administered intraperitoneal LPS (experimental group) (50 μg/kg/d) or saline (control group). On day 18 of gestation, maternal serum and male fetal liver were collected. After LPS exposure, levels of 38 and 75 metabolites, mainly glycerophospholipid and fatty acid metabolites, were altered in maternal serum and male fetal liver, respectively. It was found that in maternal serum and male fetal livers, the glycerophospholipids containing saturated fatty acids (SFAs) and the SFAs were upregulated, while the glycerophospholipids containing polyunsaturated fatty acids (PUFAs) and the PUFAs were downregulated. This concordance between maternal and fetal alterations in glycerophospholipid and fatty acid metabolites may be a metabolomic signature of the early intrauterine period and may provide insight into the mechanisms by which maternal LPS exposure induces disorders of glucose metabolism in male offspring.

Determination and comparison of phospholipid profiles in eggs from seven different species using UHPLC-ESI-Triple TOF-MS

Egg yolk phospholipids from seven different species were purified (purity > 96%) using SPE columns, and subsequently the phospholipid profiles were identified and quantified by ultra-high-performance liquid chromatography-electrospray ionization-triple time-of flight mass spectrometry (UHPLC-ESI-Triple TOF-MS). Eight phospholipid classes and 87 molecular species were characterized. Principal component analysis showed that the molecular species and concentration of phospholipids in pigeon and hen egg yolks had a significant difference with other eggs. Hierarchical cluster analysis indicated that the phospholipid profiles of pigeon egg yolks were closest to hen egg yolks, followed by quail, duck, ostrich, emu and goose egg yolks. Different relative quantities of certain molecular species were different among egg yolk types; for instance, phosphatidylcholine (16:0/16:1) in goose egg yolks and phosphatidylethanolamine (16:0/18:3) in ostrich egg yolks. This study provides a basis for a better understanding of the phospholipid profiles of egg yolks, and better evaluation of the nutritional value of eggs.

Exploring the Lipidome: Current Lipid Extraction Techniques for Mass Spectrometry Analysis

In recent years, high-throughput lipid profiling has contributed to understand the biological, physiological and pathological roles of lipids in living organisms. Across all kingdoms of life, important cell and systemic processes are mediated by lipids including compartmentalization, signaling and energy homeostasis. Despite important advances in liquid chromatography and mass spectrometry, sample extraction procedures remain a bottleneck in lipidomic studies, since the wide structural diversity of lipids imposes a constrain in the type and amount of lipids extracted. Differences in extraction yield across lipid classes can induce a bias on down-stream analysis and outcomes. This review aims to summarize current lipid extraction techniques used for untargeted and targeted studies based on mass spectrometry. Considerations, applications, and limitations of these techniques are discussed when used to extract lipids in complex biological matrices, such as tissues, biofluids, foods, and microorganisms.

Modulation of Lipid Metabolism by Celastrol

Hyperlipidemia, characterized by high serum lipids, is a risk factor for cardiovascular disease. Recent studies have identified an important role for celastrol, a proteasome inhibitor isolated from Tripterygium wilfordii Hook. F., in obesity-related metabolic disorders. However, the exact influences of celastrol on lipid metabolism remain largely unknown. Celastrol inhibited the terminal differentiation of 3T3-L1 adipocytes and decreased the levels of triglycerides in wild-type mice. Lipidomics analysis revealed that celastrol increased the metabolism of lysophosphatidylcholines (LPCs), phosphatidylcholines (PCs), sphingomyelins (SMs), and phosphatidylethanolamines (PEs). Further, celastrol reversed the tyloxapol-induced hyperlipidemia induced associated with increased plasma LPCs, PCs, SMs, and ceramides (CMs). Among these lipids, LPC(16:0), LPC(18:1), PC(22:2/15:0), and SM(d18:1/22:0) were also decreased by celastrol in cultured 3T3-L1 adipocytes, mice, and tyloxapol-treated mice. The mRNAs encoded by hepatic genes associated with lipid synthesis and catabolism, including Lpcat1, Pld1, Smpd3, and Sptc2, were altered in tyloxapol-induced hyperlipidemia, and significantly recovered by celastrol treatment. The effect of celastrol on lipid metabolism was significantly reduced in Fxr-null mice, resulting in decreased Cers6 and Acer2 mRNAs compared to wild-type mice. These results establish that FXR was responsible in part for the effects of celastrol in controlling lipid metabolism and contributing to the recovery of aberrant lipid metabolism in obesity-related metabolic disorders.

Rapid identification of erythrocyte phospholipids in Sprague-Dawley rats by ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

A rapid, sensitive, and reliable approach for analyzing five kinds of erythrocyte phospholipids in Sprague-Dawley rats was provided by ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry with MassLynx(TM) MassFragment. Improving conventional high performance liquid chromatography techniques, ultra high performance liquid chromatography integrated with quadrupole time-of-flight tandem mass spectrometry offers high sensitivity and increased analytical speed by using columns packed with sub-2 μm particles (1.7 μm), which allows a faster separation to be achieved. Through this method, 83 phospholipids were tentatively characterized based on their mass spectra and tandem mass spectra, as well as by matching the in-house formula database within a mass error of 5 ppm, including 40 phosphatidylcholines, 24 phosphatidyl ethanolamines, three phosphatidylinositols, six phosphatidylserines, and ten sphingomyelins. Our present results proved that the established method could be used to qualitatively analyze complex erythrocyte phospholipids in Sprague-Dawley rats and provide a useful data base for pharmacology and phospholipidomics to seek potential biomarkers of disease prediction.