Molecular Characterization of Plasma HDL,LDL, and VLDL Lipids Cargos from Atherosclerotic Patients with Advanced Carotid Lesions: A Preliminary Report

Carotid atherosclerosis represents a relevant healthcare problem, since unstable plaques are responsible for approximately 15% of neurologic events, namely transient ischemic attack and stroke. Although statins treatment has proven effective in reducing LDL-cholesterol and the onset of acute clinical events, a residual risk may persist suggesting the need for the detection of reliable molecular markers useful for the identification of patients at higher risk regardless of optimal medical therapy. In this regard, several lines of evidence show a relationship among specific biologically active plasma lipids, atherosclerosis, and acute clinical events. We performed a Selected Reaction Monitoring-based High Performance Liquid Chromatography-tandem Mass Spectrometry (SRM-based HPLC-MS/MS) analysis on plasma HDL, LDL, and VLDL fractions purified, by isopycnic salt gradient ultracentrifugation, from twenty-eight patients undergoing carotid endarterectomy, having either a “hard” or a “soft” plaque, with the aim of characterizing the specific lipidomic patterns associated with features of carotid plaque instability. One hundred and thirty lipid species encompassing different lipid (sub)classes were monitored. Supervised multivariate analysis showed that lipids belonging to phosphatidylethanolamine (PE), sphingomyelin (SM), and diacylglycerol (DG) classes mostly contribute to discrimination within each lipoprotein fraction according to the plaque typology. Differential analysis evidenced a significant dysregulation of LDL PE (38:6), SM (32:1), and SM (32:2) between the two groups of patients (adj. p-value threshold = 0.05 and log₂FC ≥ |0.58|). Using this approach, some LDL-associated markers of plaque vulnerability have been identified, in line with the current knowledge of the key roles of these phospholipids in lipoprotein metabolism and cardiovascular disease. This proof-of-concept study reports promising results, showing that lipoprotein lipidomics may present a valuable approach for identifying new biomarkers of potential clinical relevance.     

大豆浓缩磷脂脱杂规律及影响其透明度物质的研究

目的：探究大豆浓缩磷脂的脱杂规律,分析、鉴定影响大豆浓缩磷脂透明度的物质。方法：以食品级大豆浓缩磷脂为原料,透光率为主要评价指标,考察陶瓷膜孔径、料液比、溶剂体系（正己烷、正己烷—无水乙醇）及溶剂配比对大豆浓缩磷脂脱杂的影响;同时对收集到的杂质及脱杂前后的大豆浓缩磷脂进行脂质组学分析、鉴定。结果：在正己烷—无水乙醇双溶剂体系下,选用孔径为20 nm的无机陶瓷膜,食品级大豆浓缩磷脂与正己烷—无水乙醇双溶剂的料液比（m_{大豆浓缩磷脂}∶V_双溶剂）为1∶3 （g/mL）且V_正己烷∶V_无水乙醇为3∶1,可有效脱除食品级大豆浓缩磷脂中影响其透明度的颗粒性和脂溶性杂质;同时,通过脂质组学分析鉴定了影响大豆浓缩磷脂透明度的脂溶性物质为糖酯类物质单半乳糖二酰甘油和衍生酯类物质二甲基磷脂酰乙醇胺。结论：选用纳米级陶瓷膜,在正己烷—无水乙醇体系下,可对大豆浓缩磷脂进行有效脱杂,制备的产品透明度优于进口透明大豆磷脂。     

Are Phosphatidylcholine and Lysophosphatidylcholine Body Levels Potentially Reliable Biomarkers in Obesity? A Review of Human Studies

Phosphatidylcholines (PCs) are the major components of biological membranes in animals and are a class of phospholipids that incorporate choline as a headgroup. Lysophosphatidylcholines (LPCs) are a class of lipid biomolecules derived from the cleavage of PCs, and are the main components of oxidized low-density lipoproteins (oxLDLs) that are involved in the pathogenesis of atherosclerosis. Since obesity is associated with a state of chronic low-grade inflammation, one can anticipate that the lipidomic profile changes in this context and both PCs and LPCs are gaining attention as hypothetically reliable biomarkers of obesity. Thus, a literature search is performed on PubMed, Latin American and Caribbean Health Science Literature (LILACS), and Excerpta Medica DataBASE (Embase) to obtain the findings of population studies to clarify this hypothesis. The search strategy resulted in a total of 2403 reports and 21 studies were included according to the eligibility criteria. Controversial data on the associations of PCs and LPCs with body mass index (BMI) and body fat parameters have been identified. There is an inverse relationship between BMI and most species of PCs, and a majority of studies exhibited negative associations between BMI and LPCs. Other findings regarding the differences between PCs and LPCs in obesity are presented, and the associated uncertainties are discussed in detail.     

基于1,2-二氯乙烷体系的金枪鱼副产物中脂质提取与组学分析

为提高金枪鱼副产物的利用率,减少资源浪费,本试验基于1,2-二氯乙烷体系结合丙酮沉淀法,建立从金枪鱼副产物中同时提取脂质和鱼油的新方法.采用气相色谱法和液相色谱-质谱联用法分别对提取脂质中鱼油和磷脂进行脂质组学研究.通过调节溶剂体系得到1,2-二氯乙烷-甲醇的最佳体积比为1:2.进一步优化提取条件,得到磷脂和鱼油的得率...     

基于脂质组学揭示饲喂裂殖藻粉对山羊乳脂质的影响

基于气相色谱法和超高效液相色谱-四极杆-飞行时间串联质谱法探究饲喂裂殖藻粉（Schizochytrium spp.）对山羊乳脂肪酸组成及全脂质组成的影响，并与市售纯牛乳和二十二碳六烯酸（docosahexaenoic acid,DHA）牛乳进行差异性分析。结果表明，山羊乳脂肪含量显著高于牛乳，肉豆蔻酸、棕榈酸和油酸是乳中主要的脂肪酸组成。饲喂裂殖藻粉能显著增加山羊乳中DHA含量。甘油三酯是2种乳中主要的脂质成分，山羊乳中磷脂含量显著高于牛乳。DHA在乳品脂质中主要以甘油酯型DHA形式存在，山羊乳较牛乳含更丰富的磷脂型DHA。裂殖藻粉添加量50 g/d为山羊乳中DHA富集的最佳添加量。通过在日粮中添加DHA原料，能够进一步提高山羊乳的营养价值，解决目前膳食DHA来源单一的问题。本研究为婴幼儿配方奶粉及富DHA功能性乳脂产品的开发和营养调控提供有力的理论依据和参考，并为乳制品类型的鉴定提供方法与数据基础。     

Untargeted metabolomics and lipidomics to assess plasma metabolite changes in dairy goats with subclinical hyperketonemia

Subclinical hyperketonemia (SCHK) is the major metabolic disease observed during the transition period in dairy goats, and is characterized by high plasma levels of nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). However, no prior study has comprehensively assessed metabolomic profiles of dairy goats with SCHK. Plasma samples were collected within 1 h after kidding from SCHK goats (BHB concentration >0.8 mM, n = 7) and clinically healthy goats (BHB concentration <0.8 mM, n = 7) with similar body condition score (2.75 ± 0.15, mean ± standard error of the mean) and parity (primiparous). A combination of targeted and untargeted mass spectrometric approaches was employed for analyzing the various changes in the plasma lipidome and metabolome. Statistical analyses were performed using the GraphPad Prism 8.0, SIMCA-P software (version 14.1), and R packages (version 4.1.3). Plasma aminotransferase, nonesterified fatty acids, and BHB concentrations were greater in the SCHK group, but plasma glucose concentrations were lower. A total of 156 metabolites and 466 lipids were identified. The analysis of untargeted metabolomics data by principal component analysis and orthogonal partial least squares discriminant analysis revealed a separation between SCHK and clinically healthy goats. According to the screening criteria (unpaired t-test, P < 0.05), 30 differentially altered metabolites and 115 differentially altered lipids were detected. Pathway enrichment analysis identified citrate cycle, alanine, aspartate and glutamate metabolism, glyoxylate and dicarboxylate metabolism, and phenylalanine metabolism as significantly altered pathways. A greater concentration of plasma isocitric acid and cis-aconitic acid levels was observed in SCHK goats. In addition, AA such as lysine and isoleucine were greater, whereas alanine and phenylacetylglycine were lower in SCHK dairy goats. Dairy goats with SCHK also exhibited greater oleic acid, acylcarnitine, and phosphatidylcholine and lower choline and sphingomyelins. Acylcarnitines, oleic acid, and tridecanoic acid displayed positive correlations with several lipid species. Alanine, hippuric acid, and histidinyl-phenylalanine were negatively correlated with several lipids. Overall, altered metabolites in SCHK dairy goats indicated a more severe degree of negative energy balance. Data also indicated an imbalance in the tricarboxylic acid (TCA) cycle, lipid metabolism, and AA metabolism. The findings provide a more comprehensive understanding of the pathogenesis of SCHK in dairy goats.     

Chemical derivatization strategy for mass spectrometry-based lipidomics

Lipids, serving as the structural components of cellular membranes, energy storage, and signaling molecules, play the essential and multiple roles in biological functions of mammals. Mass spectrometry (MS) is widely accepted as the first choice for lipid analysis, offering good performance in sensitivity, accuracy, and structural characterization. However, the untargeted qualitative profiling and absolute quantitation of lipids are still challenged by great structural diversity and high structural similarity. In recent decade, chemical derivatization mainly targeting carboxyl group and carbon-carbon double bond of lipids have been developed for lipidomic analysis with diverse advantages: (i) offering more characteristic structural information; (ii) improving the analytical performance, including chromatographic separation and MS sensitivity; (iii) providing one-to-one chemical isotope labeling internal standards based on the isotope derivatization regent in quantitative analysis. Moreover, the chemical derivatization strategy has shown great potential in combination with ion mobility mass spectrometry and ambient mass spectrometry. Herein, we summarized the current states and advances in chemical derivatization-assisted MS techniques for lipidomic analysis, and their strengths and challenges are also given. In summary, the chemical derivatization-based lipidomic approach has become a promising and reliable technique for the analysis of lipidome in complex biological samples.