Lipid Fingerprints Research Articles

Characteristic lipids and their potential functions generated during the aging process of yak ghee

Yak ghee is an important food source for Tibetan herdsmen; however, the lipid composition, functional lipids changed and best consumption period during the aging process of yak ghee have not been determined. In this study, we identified a total of 386 lipids in Zhongdian yak ghee during aging, including glycerolipids (292 species), glycerophospholipids (47 species), sphingolipids (24 species), and fatty acyls (23 species). The lipids in yak ghee dynamically changed during aging, with the final product containing several polyunsaturated fatty acids (including linolenic acid, docosahexaenoic acid, and eicosapentaenoic acid), indicating its high nutritional value. Lipid fingerprints of yak ghee during aging revealed that triglyceride (16:0/16:0/20:5) and triglyceride (18:1/18:3/21:0) etc. were the characteristic lipids in aged yak ghee. The characteristic lipids in yak ghee were mainly enriched in the biosynthesis of unsaturated fatty acids, glycerolipid metabolism, and ether lipid metabolism pathways. This study provides insight into the lipid changes of yak ghee during aging, which offers a theoretical basis for the development of high-value yak ghee products.

Freeze-drying donor human milk allows compositional stability for 12 months at ambient temperatures

Breastfeeding, which is recognised as the optimum nutrition for infants, offers numerous benefits. However, circumstances can arise when infants are unable to be breastfed from birth. In such cases, the World Health Organisation (WHO) recommends donor human milk (DHM) as the safest alternative. Current practices freeze DHM and transport it under a cold supply chain, which can create logistical challenges. Here, we investigated the efficacy of freeze-drying as a method for determining the compositional stability of DHM. The samples were freeze-dried and stored at −20°C, 4°C and ambient temperature, with sampling at 1, 3, 6, 9, and 12 months. The macronutrient composition was assessed before and after freeze-drying, protein and lipid profiles were studied using MALDI-TOF MS, and the metabolite profile was analysed through LA-REIMS. The findings revealed that freeze-drying did not significantly alter the macronutrient composition and that microbiological safety was preserved. Lipid, protein, and metabolite fingerprints remained consistent across storage conditions over 12 months. This work provides a broad insight into the compositional stability of DHM after freeze-drying. It suggests the applicability of freeze-drying for long-term preservation without a cold supply chain. The use of freeze-dried DHM may broaden its use in emergency situations and resource-limited settings.

Tracing the Lipid Fingerprints of Preeclampsia.

Preeclampsia (PE) is the most common pregnancy-related complication responsible for maternal mortality and morbidity. PE pathogenesis is characterized by placental dysfunction, impaired invasion of trophoblast, and defective spiral artery remodelling. Even after many years of research on PE, the etiology and pathophysiology of PE is still elusive. Our earlier studies have shown deregulated maternal and placental fatty acid and lipid metabolism to be associated with the pathogenesis of PE. Currently available lipidomics data have shown that glycerophospholipids, sphingolipid and cholesterol metabolism are mainly altered in preeclampsia. Including these five metabolites (SM C28:1, SM C30:1, LPC C19:0, LPE C20:0, propane-1,3-diol) with currently used protein biomarkers like sFlt-1/PlGF will improve PE prediction. Similarly, CE17:1 and CER(d20:1/24:1) alongwith sFlt-1/PlGF makes a better prediction of PE than sFlt-1/PlGF alone A comprehensive map of lipid profiles in early pregnancy may provide an improved understanding of disease pathogenesis and will be useful predictive biomarkers. In this article, we aimed to summarize the significance of lipid metabolism in the preeclampsia pathogenesis and altered lipidome signatures in preeclampsia. We also discuss the future scope of lipidomics in aiding early prediction of PE and future cardiovascular risk in both mother and child.

Female-age-dependent changes in the lipid fingerprint of the mammalian oocytes.

Can oocyte functionality be assessed by observing changes in their intracytoplasmic lipid droplets (LDs) profiles? Lipid profile changes can reliably be detected in human oocytes; lipid changes are linked with maternal age and impaired developmental competence in a mouse model. In all cellular components, lipid damage is the earliest manifestation of oxidative stress (OS), which leads to a cascade of negative consequences for organelles and DNA. Lipid damage is marked by the accumulation of LDs. We hypothesized that impaired oocyte functionality resulting from aging and associated OS could be assessed by changes in LDs profile, hereafter called lipid fingerprint (LF). To investigate if it is possible to detect differences in oocyte LF, we subjected human GV-stage oocytes to spectroscopic examinations. For this, a total of 48 oocytes derived from 26 young healthy women (under 33 years of age) with no history of infertility, enrolled in an oocyte donation program, were analyzed. Furthermore, 30 GV human oocytes from 12 women were analyzed by transmission electron microscopy (TEM). To evaluate the effect of oocytes' lipid profile changes on embryo development, a total of 52 C57BL/6 wild-type mice and 125 Gnpat+/- mice were also used. Human oocytes were assessed by label-free cell imaging via coherent anti-Stokes Raman spectroscopy (CARS). Further confirmation of LF changes was conducted using spontaneous Raman followed by Fourier transform infrared (FTIR) spectroscopies and TEM. Additionally, to evaluate whether LF changes are associated with developmental competence, mouse oocytes and blastocysts were evaluated using TEM and the lipid dyes BODIPY and Nile Red. Mouse embryonic exosomes were evaluated using flow cytometry, FTIR and FT-Raman spectroscopies. Here we demonstrated progressive changes in the LF of oocytes associated with the woman's age consisting of increased LDs size, area, and number. LF variations in oocytes were detectable also within individual donors. This finding makes LF assessment a promising tool to grade oocytes of the same patient, based on their quality. We next demonstrated age-associated changes in oocytes reflected by lipid peroxidation and composition changes; the accumulation of carotenoids; and alterations of structural properties of lipid bilayers. Finally, using a mouse model, we showed that LF changes in oocytes are negatively associated with the secretion of embryonic exosomes prior to implantation. Deficient exosome secretion disrupts communication between the embryo and the uterus and thus may explain recurrent implantation failures in advanced-age patients. Due to differences in lipid content between different species' oocytes, the developmental impact of lipid oxidation and consequent LF changes may differ across mammalian oocytes. Our findings open the possibility to develop an innovative tool for oocyte assessment and highlight likely functional connections between oocyte LDs and embryonic exosome secretion. By recognizing the role of oocyte LF in shaping the embryo's ability to implant, our original work points to future directions of research relevant to developmental biology and reproductive medicine. This research was funded by National Science Centre of Poland, Grants: 2021/41/B/NZ3/03507 and 2019/35/B/NZ4/03547 (to G.E.P.); 2022/44/C/NZ4/00076 (to M.F.H.) and 2019/35/N/NZ3/03213 (to Ł.G.). M.F.H. is a National Agency for Academic Exchange (NAWA) fellow (GA ULM/2019/1/00097/U/00001). K.F. is a Diamond Grant fellow (Ministry of Education and Science GA 0175/DIA/2019/28). The open-access publication of this article was funded by the Priority Research Area BioS under the program "Excellence Initiative - Research University" at the Jagiellonian University in Krakow. The authors declare no competing interest. N/A.

Lipid fingerprinting and geographical origin identification of large yellow croaker (Larimichthys crocea) using UHPLC-QTOF-MS

The Large Yellow Croaker (LYC) with rich lipids offers numerous health benefits, yet its lipid profile remains underexplored. Therefore, the lipids of LYC were comprehensively profiled and compared based lipidomics. Higher nutritional value of LYC was identified based on lipid and fatty acid assessment, particularly ovary and brain. A total of 963 lipid species belonging to 47 lipid subclasses were identified, exhibiting higher levels of glycerophospholipids (GPs) and sphingolipids (SPs) in the brain, as well as high levels of glycolipids (GLs) in the muscle. Furthermore, unique lipid subclasses were detected in the brain (Acylcarnitine (CAR), Alpha-hydroxy-N-stearoyl phytosphingosine (Cer-AP)) and ovary (N-arachidonoyl glycine (NAGly)). Notably, 8 lipid subclasses were selected as potential contributors for four tissues differentiation. Additionally, identification of LYC from various origins was achieved through lipidomics for the first time. LYC from Zhejiang and Fujian provinces could be distinguished by 100 lipid biomarkers. Most different lipids significantly negatively correlated with seawater pH and dissolved oxygen, but positively correlated with netting density, depth, environmental temperature and salinity. This comprehensive analysis provided valuable insights into LYC’s nutritional values and origin identified.

Exploring molecular mechanisms underlying changes in lipid fingerprinting of salmon (Salmo salar) during air frying integrating machine learning-guided REIMS and lipidomics analysis

Lipid oxidation in air-fried seafood poses a risk to human health. However, the effect of a prooxidant environment on lipid oxidation in seafood at different air frying (AF) temperatures remains unknown. An integrated machine learning (ML) - guided REIMS and lipidomics method was applied to explore lipid profiles, lipid oxidation, and lipid metabolic pathways of salmons under different AF temperatures (140, 160, 180, and 200 °C). A significant difference in the lipidomic fingerprinting of air-dried salmon at different temperatures was shown by the main ML methods (neural networks, support vector machines, ensemble learning, and naïve bayes). In total, 773 differential expression metabolites (DEMs) were identified, including glycerophospholipids (GPs), glycerides (GLs), and sphingolipids. A total of 34 DEMs with p values <0.05 and variable importance of projection values >1.0 were analyzed, belonging to linoleic acid metabolism, GL metabolism, and GP metabolism pathways. Correlation network analysis revealed that some characteristic DEMs (phosphatidylcholine, lyso-phosphatidylcholine, triglycerides, fatty acids, and phosphatidylethanolamine) were highly correlated with lipid oxidation. In addition, variations of volatile compounds, color values, texture characteristics, and thiobarbituric acid-reactive substance values were analyzed to corroborate the oxidation characteristics.

4-Cholesten-3-one Modified the Lipidome of MDA-MB-231 Cells and Potentiated the Effect of Docetaxel.

Lipids are essential for energy production, signaling, and membrane formation, hence increased lipid metabolism may lead to cancer growth. 4-cholesten-3-one (4Cone), a sterol metabolite, has various biological activities, including the inhibition of cancer growth. This study examined whether 4Cone could change the lipid profile of triple-negative breast cancer cells (MDA-MB-231) and whether in combination with the anti-cancer chemotherapy docetaxel (TXT) could further reduce cancer aggressiveness. The effect of 4Cone, TXT, or their combination (4Cone/TXT) on migration and proliferation was examined utilizing the wound healing and MTT assays. The expression of the lipogenesis-related enzymes was assessed using RT-qPCR and lipid profile was examined using mass spectrometry. 4Cone and TXT individually reduced cell viability and migration of MDA-MB-231 cancer cells; however, their combination (4Cone/TXT) had a greater impact on both attributes. All treated cells showed markedly decreased levels of the multidrug resistance enzyme PGP as well as the lipogenic enzymes FASN, ACC1, SCD1, HMGCR, and DGAT. Furthermore, lipid fingerprints were markedly different in treated cells compared with the untreated group. 4Cone increased the percentage of sphingomyelin (SM) while it decreased the percentage of ceramide (Cer); 4Cone in conjunction with TXT had the reverse effect. Triglyceride levels were reduced in 4Cone- and 4Cone/TXT-treated cells, but interestingly, they increased in TXT-treated cells. Additionally, treated cancer cells exhibited changes in glycerophospholipid subclasses. 4Cone alone or in combination with TXT alters the lipid profile by reducing a key lipogenic enzyme, resulting in the inhibition of cell proliferation and migration.

Lipids and Fatty Acid Composition Reveal Differences between Durum Wheat Landraces and Modern Cultivars.

Durum wheat (Triticum turgidum L. ssp. durum) landraces, traditional local varieties representing an intermediate stage in domestication, are gaining attention due to their high genetic variability and performance in challenging environments. While major kernel metabolites have been examined, limited research has been conducted on minor bioactive components like lipids, despite their nutritional benefits. To address this, we analyzed twenty-two tetraploid accessions, comprising modern elite cultivars and landraces, to (i) verify if the selection process for yield-related traits carried out during the Green Revolution has influenced lipid amount and composition; (ii) uncover the extent of lipid compositional variability, giving evidence that lipid fingerprinting effectively identifies evolutionary signatures; and (iii) identify genotypes interesting for breeding programs to improve yield and nutrition. Interestingly, total fat did not correlate with kernel weight, indicating lipid composition as a promising trait for selection. Tri- and di-acylglycerol were the major lipid components along with free fatty acids, and their relative content varied significantly among genotypes. In particular, landraces belonging to T. turanicum and carthlicum ecotypes differed significantly in total lipid and fatty acid profiles. Our findings provide evidence that landraces can be a genetically relevant source of lipid variability, with potential to be exploited for improving wheat nutritional quality.

Allergic inflammation triggers dyslipidemia via IgG signalling.

Allergic diseases begin early in life and are often chronic, thus creating an inflammatory environment that may precede or exacerbate other pathologies. In this regard, allergy has been associated to metabolic disorders and with a higher risk of cardiovascular disease, but the underlying mechanisms remain incompletely understood. We used a murine model of allergy and atherosclerosis, different diets and sensitization methods, and cell-depleting strategies to ascertain the contribution of acute and late phase inflammation to dyslipidemia. Untargeted lipidomic analyses were applied to define the lipid fingerprint of allergic inflammation at different phases of allergic pathology. Expression of genes related to lipid metabolism was assessed in liver and adipose tissue at different times post-allergen challenge. Also, changes in serum triglycerides (TGs) were evaluated in a group of 59 patients ≥14 days after the onset of an allergic reaction. We found that allergic inflammation induces a unique lipid signature that is characterized by increased serum TGs and changes in the expression of genes related to lipid metabolism in liver and adipose tissue. Alterations in blood TGs following an allergic reaction are independent of T-cell-driven late phase inflammation. On the contrary, the IgG-mediated alternative pathway of anaphylaxis is sufficient to induce a TG increase and a unique lipid profile. Lastly, we demonstrated an increase in serum TGs in 59 patients after undergoing an allergic reaction. Overall, this study reveals that IgG-mediated allergic inflammation regulates lipid metabolism.

Lipidomic approach to identify Escherichia coli and Shigella spp. by matrix-assisted laser desorption/ionization mass spectrometry

PurposeEscherichia coli (E. coli) and Shigella species, being highly similar, present a challenge for differentiation using classical methods such as phenotyping, 16S rRNA sequencing, or protein profiling using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). The paper proposes a method for identifying E. coli, S. flexneri, S. sonnei, and S. boydii by augmenting the Bruker Biotyper database with reference spectra of lipid profiles obtained using MALDI MS in the positive mode. Materials/methodsLipid extracts were made from cultured E. coli, S. flexneri, S. sonnei and S. boydii using the Bligh & Dyer protocol. MALDI MS spectra in positive ion mode were performed for the extracts. Reference spectra were created from 30 spectra for each bacterium and added to the Bruker Biotyper database. ResultsIdentification of bacteria based on lipid profiles in the Biotyper database gave correct results with scores above 2.49. Statistical analysis of the results by Partial Least Squares-Discriminant Analysis (PLS-DA) showed that it is possible to correctly differentiate the microorganisms studied using the lipidomic approach. A panel of six m/z values was proposed for which the value of the area under the ROC curve is 1, thus enabling the identification of E. coli and S. flexneri with 100 ​% accuracy. ConclusionsIdentification of bacteria from lipid fingerprints obtained by the MALDI MS technique is possible and may become a useful tool in the future, especially for microorganisms that are difficult to distinguish by other methods.

Microwave-Assisted Extraction/UHPLC-Q-Orbitrap-MS-Based Lipidomic Workflow for Comprehensive Study of Lipids in Soft Cheese.

In this work, Microwave-Assisted Extraction (MAE) was proposed as an alternative and environmentally friendly technique in lipidomics to study the lipid fingerprint of soft cheeses, such as mozzarella. For method development, a first step concerning an evaluation of extraction solvents was carried out via testing three different mixtures, including methanol/ethyl acetate, isopropanol/ethyl acetate, and ethanol/ethyl acetate, at a 1:2 v/v ratio. The latter was chosen as a solvent mixture for subsequent method optimization. MAE conditions, in terms of solvent volume, time, and temperature, were explored to define their effects on extraction capability through a full factorial experimental design. The best compromise to extract more lipids at the same time was obtained with 24 mL g-1 for solvent-to-solid ratio, 65 °C for temperature, and 18 min for time. Lipid analyses were conducted by UHPLC-Q-Orbitrap-MS associated with multivariate statistics. The developed lipidomic workflow allowed for the extraction of over 400 lipids grouped into 18 different subclasses. The results confirmed that MAE is a suitable technique for lipid extraction in the omics approach with high efficiency, even using low-cost and less toxic solvents. Moreover, a comprehensive structure characterization of extracted lipids, in terms of fatty acid composition and regiochemistry, was carried out.

Abstract 4436: Phenotypic heterogeneity in pancreatic ductal adenocarcinoma revealed by single-cell lipidomics

Abstract Introduction: The high chemoresistance of pancreatic ductal adenocarcinoma (PDAC) is partly attributed to the phenotypic plasticity and high adaptability of PDAC cells to the challenges of the harsh microenviroment. Phenotypic presentation of the PDAC cell is also determined by the lipid composition of the plasma membrane and lipid species that organize the rigid or more flexible lipid bilayer and determine the cellular mobility and plasticity. Lipids are also important energy and signaling molecules that contribute to the aggressiveness of the cell. Here we focus on differences in lipid profile of PDAC cells in epithelial and mesenchymal cell state using single-cell lipidomics approach (SpaceM). Methods: Lipid profile of 2D cultures of eight conventional and ten primary patient derived cell lines of different source (patient derived xenograft, ascites, primary tumor, organoid derived) was investigated. Epithelial (E) or mesenchymal (M) cell state was evaluated by gene and protein expression of EMT markers. Matrix-Assisted Laser Desorption/Ionization (MALDI)-imaging MS was used for data acquisition on positive ion mode at 25 µm step size and m/z range of 600-1000. For annotating lipids in MALDI-imaging data, we used the METASPACE cloud software. For constructing single-cell lipidomic profiles we used the SpaceM method. In total, around 150.000 cells were analyzed and 1400 lipid ions detected. Results: Gene expression analysis suggested prominent metabolism of structural lipids in the conventional epithelial cells. In UMAP analysis of single cell lipidomics data, each cell line, conventional and primary, presented a unique lipid fingerprint with however prominent clustering into the two phenotypes, epithelial and mesenchymal. We detected enrichment of alkyl-acyl phosphatidylcholines, alkyl-acyl phospatidylethanolamines, ceramides and sphingolipids in the epithelial phenotype. Mesenchymal phenotype was enriched for lipids involved in lateral diffusion and low bilayer thickness supporting the increased fluidity of the mesenchymal cell membrane. Furthermore, mesenchymal phenotype was enriched for lipid droplets and energy storing triacylglycerols, also confirmed by histological lipid droplet staining. Conclusions: Using the single cell lipid information, a successful grouping to epithelial or mesenchymal subtype could be performed regardless of sample source, suggesting a conserved lipid profile typical for the two states. Further detailed investigation of single cell lipidomics data aims to unveil the prominent epithelial-mesenchymal state lipid markers and open a niche for functional investigations of cell-state specific markers and potential cell-state targeting. Citation Format: Marija Trajkovic-Arsic, Jeany Delafiori, Mohammed Shahraz, Corinna Münch, Smiths S. Lueong, Sven T. Liffers, Doris Hellerschmied, Theodore Alexandrov, Jens T. Siveke. Phenotypic heterogeneity in pancreatic ductal adenocarcinoma revealed by single-cell lipidomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4436.

Regio-specific lipid fingerprinting of edible sea cucumbers using LC/MS

Sea cucumbers are a rich source of bioactive compounds and are gaining popularity as nutrient-rich seafood. They are consumed as a whole organism in Pacific regions. However, limited data are available on the comparison of their lipid composition and nutritional value. In this study, untargeted liquid chromatography/mass spectrometry was applied to comprehensively profile lipids in the skin, meat, and intestinal contents of three color-distinct edible sea cucumbers. Multivariate principal component analysis revealed that the lipid composition of the intestinal contents of red, black, and blue sea cucumbers differs from that of skin, and meats. Polyunsaturated fatty acids (PUFAs) are abundant in the intestinal contents, followed by meats of sea cucumber. Lipid nutritional quality assessments based on fatty acid composition revealed a high P:S ratio, low index of atherogenicity, and high health promotion indices for the intestinal contents of red sea cucumber, suggesting its potential health benefits. In addition, hierarchical cluster analysis revealed that the intestinal contents of sea cucumbers were relatively high in PUFA-enriched phospholipids and lysophospholipids. Ceramides are abundant in black skin, blue meat, and red intestinal content samples. Overall, this study provides the first insights into a comprehensive regio-specific profile of the lipid content of sea cucumbers and their potential use as a source of lipid nutrients in food and nutraceuticals.

Lipidomics Reveals Myocardial Lipid Composition in a Murine Model of Insulin Resistance Induced by a High-Fat Diet.

Ectopic fat accumulation in non-adipose tissues is closely related to diabetes-related myocardial dysfunction. Nevertheless, the complete picture of the lipid metabolites involved in the metabolic-related myocardial alterations is not fully characterized. The aim of this study was to characterize the specific lipid profile in hearts in an animal model of obesity/insulin resistance induced by a high-fat diet (HFD). The cardiac lipidome profiles were assessed via liquid chromatography-mass spectrometry (LC-MS)/MS-MS and laser desorption/ionization-mass spectrometry (LDI-MS) tissue imaging in hearts from C57BL/6J mice fed with an HFD or standard-diet (STD) for 12 weeks. Targeted lipidome analysis identified a total of 63 lipids (i.e., 48 triacylglycerols (TG), 5 diacylglycerols (DG), 1 sphingomyelin (SM), 3 phosphatidylcholines (PC), 1 DihydroPC, and 5 carnitines) modified in hearts from HFD-fed mice compared to animals fed with STD. Whereas most of the TG were up-regulated in hearts from animals fed with an HFD, most of the carnitines were down-regulated, thereby suggesting a reduction in the mitochondrial β-oxidation. Roughly 30% of the identified metabolites were oxidated, pointing to an increase in lipid peroxidation. Cardiac lipidome was associated with a specific biochemical profile and a specific liver TG pattern. Overall, our study reveals a specific cardiac lipid fingerprint associated with metabolic alterations induced by HFD.

Fatty Acid Profiling as a Tool for Fostering the Traceability of the Halophyte Plant Salicornia ramosissima and Contributing to Its Nutritional Valorization.

Salicornia ramosissima, commonly known as glasswort or sea asparagus, is a halophyte plant cultivated for human consumption that is often referred to as a sea vegetable rich in health-promoting n-3 fatty acids (FAs). Yet, the effect of abiotic conditions, such as salinity and temperature, on the FA profile of S. ramosissima remains largely unknown. These factors can potentially shape its nutritional composition and yield unique fatty acid signatures that can reveal its geographical origin. In this context, samples of S. ramosissima were collected from four different locations along the coastline of mainland Portugal and their FAs were profiled through gas chromatography-mass spectrometry. The lipid extracts displayed a high content of essential FAs, such as 18:2n-6 and 18:3n-3. In addition to an epoxide fatty acid exclusively identified in samples from the Mondego estuary, the relative abundance of FAs varied between origin sites, revealing that FA profiles can be used as site-specific lipid fingerprints. This study highlights the role of abiotic conditions on the nutritional profile of S. ramosissima and establishes FA profiling as a potential avenue to trace the geographic origin of this halophyte plant. Overall, the present approach can make origin certification possible, safeguard quality, and enhance consumers' trust in novel foods.

Combining imaging mass spectrometry and immunohistochemistry to analyse the lipidome of spinal cord inflammation

Inflammation is a complex process that accompanies many pathologies. Actually, dysregulation of the inflammatory process is behind many autoimmune diseases. Thus, treatment of such pathologies may benefit from in-depth knowledge of the metabolic changes associated with inflammation. Here, we developed a strategy to characterize the lipid fingerprint of inflammation in a mouse model of spinal cord injury. Using lipid imaging mass spectrometry (LIMS), we scanned spinal cord sections from nine animals injected with lysophosphatidylcholine, a chemical model of demyelination. The lesions were demonstrated to be highly heterogeneous, and therefore, comparison with immunofluorescence experiments carried out in the same section scanned by LIMS was required to accurately identify the morphology of the lesion. Following this protocol, three main areas were defined: the lesion core, the peri-lesion, which is the front of the lesion and is rich in infiltrating cells, and the uninvolved tissue. Segmentation of the LIMS experiments allowed us to isolate the lipid fingerprint of each area in a precise way, as demonstrated by the analysis using classification models. A clear difference in lipid signature was observed between the lesion front and the epicentre, where the damage was maximized. This study is a first step to unravel the changes in the lipidome associated with inflammation in the context of diverse pathologies, such as multiple sclerosis.Graphical abstract

Lipid fingerprint-based histology accurately classifies nevus, primary melanoma, and metastatic melanoma samples.

Probably, the most important factor for the survival of a melanoma patient is early detection and precise diagnosis. Although in most cases these tasks are readily carried out by pathologists and dermatologists, there are still difficult cases in which no consensus among experts is achieved. To deal with such cases, new methodologies are required. Following this motivation, we explore here the use of lipid imaging mass spectrometry as a complementary tool for the aid in the diagnosis. Thus, 53 samples (15 nevus, 24 primary melanomas, and 14 metastasis) were explored with the aid of a mass spectrometer, using negative polarity. The rich lipid fingerprint obtained from the samples allowed us to set up an artificial intelligence-based classification model that achieved 100% of specificity and precision both in training and validation data sets. A deeper analysis of the image data shows that the technique reports important information on the tumor microenvironment that may give invaluable insights in the prognosis of the lesion, with the correct interpretation.

FT-IR data discrimination using principal component analysis toward the green extraction of avocado oil: A study comprehending electrostatic misfits of polar solvents

Avocado oil is renowned for its nutritional and health benefits. This study examines the avocado oil extraction process using ethanol and acetone as green solvents to evaluate yield, kinetics, mass transfer, thermodynamics, and oil quality, compared to hexane nonrenewable solvent. Fourier transform infrared spectroscopy combined with principal component analysis (PCA) is used to evaluate the oil composition. UNIFAC and COSMO-SAC models are used to understand the solubility of avocado oil in ethanol and acetone at infinite dilution. In addition, density functional theory is applied to explain the extraction mechanisms. PCA identified key wavelengths in the lipid fingerprint region, while the dry avocado pulp exhibited critical features at around 2924, 2367, 3755, and 2754 cm-1, avocado oil demonstrated crucial signals at 1746, 3746, 3690, and 3801 cm-1. This study found that the oil extracted with acetone and hexane had comparable compositions. The UNIFAC and COSMO-SAC models estimated ΔH∞ values between -8.156 to -47.889 kJ.mol-1 and ΔS∞ between -0.201 to 0.008 kJ.mol-1.K-1. The chemical hardness was calculated to be about 40% higher for ethanol than acetone, while molecular entropy was 10% lower. The results indicate that acetone has the potential to be a greener solvent for avocado oil extraction.

Characterization of the cellular lipid composition during SARS-CoV-2 infection.

Emerging and re-emerging zoonotic viral diseases continue to significantly impact public health. Of particular interest are enveloped viruses (e.g., SARS-CoV-2, the causative pathogen of COVID-19), which include emerging pathogens of highest concern. Enveloped viruses contain a viral envelope that encapsulates the genetic material and nucleocapsid, providing structural protection and functional bioactivity. The viral envelope is composed of a coordinated network of glycoproteins and lipids. The lipid composition of the envelope consists of lipids preferentially appropriated from host cell membranes. Subsequently, changes to the host cell lipid metabolism and an accounting of what lipids are changed during viral infection provide an opportunity to fingerprint the host cell's response to the infecting virus. To address this issue, we comprehensively characterized the lipid composition of VeroE6-TMPRSS2 cells infected with SARS-CoV-2. Our approach involved using an innovative solid-phase extraction technique to efficiently extract cellular lipids combined with liquid chromatography coupled to high-resolution tandem mass spectrometry. We identified lipid changes in cells exposed to SARS-CoV-2, of which the ceramide to sphingomyelin ratio was most prominent. The identification of a lipid profile (i.e., lipid fingerprint) that is characteristic of cellular SARS-CoV-2 infection lays the foundation for targeting lipid metabolism pathways to further understand how enveloped viruses infect cells, identifying opportunities to aid antiviral and vaccine development.

Untargeted Lipidomics and Chemometric Tools for the Characterization and Discrimination of Irradiated Camembert Cheese Analyzed by UHPLC-Q-Orbitrap-MS.

In this work, an investigation using UHPLC-Q-Orbitrap-MS and multivariate statistics was conducted to obtain the lipid fingerprint of Camembert cheese and to explore its correlated variation with respect to X-ray irradiation treatment. A total of 479 lipids, categorized into 16 different lipid subclasses, were measured. Furthermore, the identification of oxidized lipids was carried out to better understand the possible phenomena of lipid oxidation related to this technological process. The results confirm that the lipidomic approach adopted is effective in implementing the knowledge of the effects of X-ray irradiation on food and evaluating its safety aspects. Furthermore, Partial Least Squares-Discriminant Analysis (PLS-DA) and Linear Discriminant Analysis (LDA) were applied showing high discriminating ability with excellent values of accuracy, specificity and sensitivity. Through the PLS-DA and LDA models, it was possible to select 40 and 24 lipids, respectively, including 3 ceramides (Cer), 1 hexosyl ceramide (HexCer), 1 lysophosphatidylcholine (LPC), 1 lysophosphatidylethanolamine (LPE), 3 phosphatidic acids (PA), 4 phosphatidylcholines (PC), 10 phosphatidylethanolamines (PE), 5 phosphatidylinositols (PI), 2 phosphatidylserines (PS), 3 diacylglycerols (DG) and 9 oxidized triacylglycerols (OxTG) as potential markers of treatment useful in food safety control plans.