Human versus Artificial Intelligence: Validation of a Deep Learning Model for Retinal Layer and Fluid Segmentation in Optical Coherence Tomography Images from Patients with Age-Related Macular Degeneration

Artificial intelligence (AI) models have received considerable attention in recent years for their ability to identify optical coherence tomography (OCT) biomarkers with clinical diagnostic potential and predict disease progression. This study aims to externally validate a deep learning (DL) algorithm by comparing its segmentation of retinal layers and fluid with a gold-standard method for manually adjusting the automatic segmentation of the Heidelberg Spectralis HRA + OCT software Version 6.16.8.0. A total of sixty OCT images of healthy subjects and patients with intermediate and exudative age-related macular degeneration (AMD) were included. A quantitative analysis of the retinal thickness and fluid area was performed, and the discrepancy between these methods was investigated. The results showed a moderate-to-strong correlation between the metrics extracted by both software types, in all the groups, and an overall near-perfect area overlap was observed, except for in the inner segment ellipsoid (ISE) layer. The DL system detected a significant difference in the outer retinal thickness across disease stages and accurately identified fluid in exudative cases. In more diseased eyes, there was significantly more disagreement between these methods. This DL system appears to be a reliable method for accessing important OCT biomarkers in AMD. However, further accuracy testing should be conducted to confirm its validity in real-world settings to ultimately aid ophthalmologists in OCT imaging management and guide timely treatment approaches.

Looking into the lipid profile of avocado and byproducts: Using lipidomics to explore value-added compounds

Consumer priorities in healthy diets and lifestyle boosted the demand for nutritious and functional foods as well as plant-based ingredients. Avocado has become a food trend due to its nutritional and functional values, which in turn is increasing its consumption and production worldwide. Avocado edible portion has a high content of lipids, with the pulp and its oil being rich in monounsaturated fatty acids and essential omega - 3 and omega - 6 polyunsaturated fatty acids (PUFA). These fatty acids are mainly esterified in triacylglycerides, the major lipids in pulp, but also in minor components such as polar lipids (phospholipids and glycolipids). Polar lipids of avocado have been overlooked despite being recently highlighted with functional properties as well. The growth in the industry of avocado products is generating an increased amount of their byproducts, such as seed and peels (nonedible portions), still undervalued. The few studies on avocado byproducts pointed out that they also contain interesting lipids, with seeds particularly rich in polar lipids bearing PUFA, and thus can be reused as a source of add-value phytochemical. Mass spectrometry-based lipidomics approaches appear as an essential tool to unveil the complex lipid signature of avocado and its byproducts, contributing to the recognition of value-added lipids and opening new avenues for their use in novel biotechnological applications. The present review provides an up-to-date overview of the lipid signature from avocado pulp, peel, seed, and its oils.

Plasma lipidomics analysis reveals altered profile of triglycerides and phospholipids in children with Medium-Chain Acyl-CoA dehydrogenase deficiency

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most prevalent mitochondrial fatty acid β-oxidation disorder. In this study, we assessed the variability of the lipid profile in MCADD by analysing plasma samples obtained from 25 children with metabolically controlled MCADD (following a normal diet with frequent feeding and under l-carnitine supplementation) and 21 paediatric control subjects (CT). Gas chromatography-mass spectrometry was employed for the analysis of esterified fatty acids, while high-resolution C18-liquid chromatography-mass spectrometry was used to analyse lipid species. We identified a total of 251 lipid species belonging to 15 distinct lipid classes. Principal component analysis revealed a clear distinction between the MCADD and CT groups. Univariate analysis demonstrated that 126 lipid species exhibited significant differences between the two groups. The lipid species that displayed the most pronounced variations included triacylglycerols and phosphatidylcholines containing saturated and monounsaturated fatty acids, specifically C14:0 and C16:0, which were found to be more abundant in MCADD. The observed changes in the plasma lipidome of children with non-decompensated MCADD suggest an underlying alteration in lipid metabolism. Therefore, longitudinal monitoring and further in-depth investigations are warranted to better understand whether such alterations are specific to MCADD children and their potential long-term impacts.

Mapping the lipidome in mitochondria-associated membranes (MAMs) in an in vitro model of Alzheimer's disease

The disruption of mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) plays a relevant role in Alzheimer's disease (AD). MAMs have been implicated in neuronal dysfunction and death since it is associated with impairment of functions regulated in this subcellular domain, including lipid synthesis and trafficking, mitochondria dysfunction, ER stress-induced unfolded protein response (UPR), apoptosis, and inflammation. Since MAMs play an important role in lipid metabolism, in this study we characterized and investigated the lipidome alterations at MAMs in comparison with other subcellular fractions, namely microsomes and mitochondria, using an in vitro model of AD, namely the mouse neuroblastoma cell line (N2A) over-expressing the APP familial Swedish mutation (APPswe) and the respective control (WT) cells. Phospholipids (PLs) and fatty acids (FAs) were isolated from the different subcellular fractions and analyzed by HILIC-LC-MS/MS and GC-MS, respectively. In this in vitro AD model, we observed a down-regulation in relative abundance of some phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and lysophosphatidylethanolamine (LPE) species with PUFA and few PC with saturated and long-chain FA. We also found an up-regulation of CL, and antioxidant alkyl acyl PL. Moreover, multivariate analysis indicated that each organelle has a specific lipid profile adaptation in N2A APPswe cells. In the FAs profile, we found an up-regulation of C16:0 in all subcellular fractions, a decrease of C18:0 levels in total fraction (TF) and microsomes fraction, and a down-regulation of 9-C18:1 was also found in mitochondria fraction in the AD model. Together, these results suggest that the over-expression of the familial APP Swedish mutation affects lipid homeostasis in MAMs and other subcellular fractions and supports the important role of lipids in AD physiopathology.

Polar Lipids of Marine Microalgae Nannochloropsis oceanica and Chlorococcum amblystomatis Mitigate the LPS-Induced Pro-Inflammatory Response in Macrophages

Microalgae are recognized as a relevant source of bioactive compounds. Among these bioactive products, lipids, mainly glycolipids, have been shown to present immunomodulatory properties with the potential to mitigate chronic inflammation. This study aimed to evaluate the anti-inflammatory effect of polar lipids isolated from Nannochloropsis oceanica and Chlorococcum amblystomatis. Three fractions enriched in (1) digalactosyldiacylglycerol (DGDG) and sulfoquinovosyldiacylglycerol (SQDG), (2) monogalactosyldiacylglycerol (MGDG), and (3) diacylglyceryl-trimethylhomoserine (DGTS) and phospholipids (PL) were obtained from the total lipid extracts (TE) of N. oceanica and C. amblystomatis, and their anti-inflammatory effect was assessed by analyzing their capacity to counteract nitric oxide (NO) production and transcription of pro-inflammatory genes Nos2, Ptgs2, Tnfa, and Il1b in lipopolysaccharide (LPS)-activated macrophages. For both microalgae, TE and Fractions 1 and 3 strongly inhibited NO production, although to different extents. A strong reduction in the LPS-induced transcription of Nos2, Ptgs2, Tnfa, and Il1b was observed for N. oceanica and C. amblystomatis lipids. The most active fractions were the DGTS-and-PL-enriched fraction from N. oceanica and the DGDG-and-SQDG-enriched fraction from C. amblystomatis. Our results reveal that microalgae lipids have strong anti-inflammatory capacity and may be explored as functional ingredients or nutraceuticals, offering a natural solution to tackle chronic inflammation-associated diseases.

Inhibiting SETD7 methyl-transferase activity impairs differentiation, lipid metabolism and lactogenesis in mammary epithelial cells

SETD7 (SET7/9, KMT7) is a lysine methyltransferase that targets master regulators of cell proliferation and differentiation. Here, the impact of inhibiting SETD7 catalytic activity on mammary epithelial cell differentiation was studied by focusing on genes associated with epithelial differentiation, lactogenesis, and lipid metabolism in HC11 and EpH4 cell lines. Setd7 mRNA and protein levels were induced upon lactogenic differentiation in both cell lines. Inhibition of SETD7 activity by the compound (R)-PFI-2 increased cell proliferation and downregulated E-cadherin, beta-catenin, lactoferrin, insulin-like growth factor binding protein 5, and beta-casein levels. In addition, inhibition of SETD7 activity affected the lipid profile and altered the mRNA expression of the phospholipid biosynthesis-related genes choline phosphotransferase 1, and ethanolamine-phosphate cytidylyltransferase. Altogether, the results suggest that inhibiting SETD7 catalytic activity impairs mammary epithelial and lactogenic differentiation.

Revealing the polar lipidome, pigment profiles, and antioxidant activity of the giant unicellular green alga, Acetabularia acetabulum

Marine algae are one of the most important sources of high-value compounds such as polar lipids, omega-3 fatty acids, photosynthetic pigments, or secondary metabolites with interesting features for different niche markets. Acetabularia acetabulum is a macroscopic green single-celled alga, with a single nucleus hosted in the rhizoid. This alga is one of the most studied dasycladalean species and represents an important model system in cell biology studies. However, its lipidome and pigment profile have been overlooked. Total lipid extracts were analyzed using hydrophilic interaction liquid chromatography-high resolution mass spectrometry (HILIC-HRMS), tandem mass spectrometry (MS/MS), and high-performance liquid chromatography (HPLC). The antioxidant capacity of lipid extracts was tested using DPPH and ABTS assays. Lipidomics identified 16 polar lipid classes, corresponding to glycolipids, betaine lipids, phospholipids, and sphingolipids, with a total of 191 lipid species, some of them recognized by their bioactivities. The most abundant polar lipids were glycolipids. Lipid classes less studied in algae were identified, such as diacylglyceryl-carboxyhydroxymethylcholine (DGCC) or hexosylceramide (HexCer). The pigment profile of A. acetabulum comprised carotenoids (17.19%), namely cis-neoxanthin, violaxanthin, lutein and β,β-carotene, and chlorophylls a and b (82.81%). A. acetabulum lipid extracts showed high antioxidant activity promoting a 50% inhibition (IC50 ) with concentrations of 57.91 ± 1.20 μg · mL-1 (438.18 ± 8.95 μmol Trolox · g-1 lipid) in DPPH and 20.55 ± 0.60 μg · mL-1 in ABTS assays (918.56 ± 27.55 μmol Trolox · g-1 lipid). This study demonstrates the potential of A. acetabulum as a source of natural bioactive molecules and antioxidant compounds.

Lipidome of extracellular vesicles from Giardia lamblia

Extracellular vesicles (EVs) (exossomes, microvesicles and apoptotic bodies) have been well acknowledged as mediators of intercellular communications in prokaryotes and eukaryotes. Lipids are essential molecular components of EVs but at the moment the knowledge about the lipid composition and the function of lipids in EVs is limited and as for now none lipidomic studies in Giardia EVs was described. Therefore, the focus of the current study was to conduct, for the first time, the characterization of the polar lipidome, namely phospholipid and sphingolipid profiles of G. lamblia trophozoites, microvesicles (MVs) and exosomes, using C18-Liquid Chromatography-Mass Spectrometry (C18-LC-MS) and Tandem Mass Spectrometry (MS/MS). A total of 162 lipid species were identified and semi-quantified, in the trophozoites, or in the MVs and exosomes belonging to 8 lipid classes, including the phospholipid classes phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI), cardiolipins (CL), the sphingolipid classes sphingomyelin (SM) and ceramides (Cer), and cholesterol (ST), and 3 lipid subclasses that include lyso PC (LPC), lyso PE (LPE) and lyso PG (LPG), but showing different abundances. This work also identified, for the first time, in G. lamblia trophozoites, the lipid classes CL, Cer and ST and subclasses of LPC, LPE and LPG. Univariate and multivariate analysis showed clear discrimination of lipid profiles between trophozoite, exosomes and MVs. The principal component analysis (PCA) plot of the lipidomics dataset showed clear discrimination between the three groups. Future studies focused on the composition and functional properties of Giardia EVs may prove crucial to understand the role of lipids in host-parasite communication, and to identify new targets that could be exploited to develop novel classes of drugs to treat giardiasis.

Whole Blood and Plasma-Based Lipid Profiling Reveals Distinctive Metabolic Changes in Systemic Lupus Erythematosus and Systemic Sclerosis

Autoimmune diseases (AID), such as systemic lupus erythematosus (SLE) and systemic sclerosis (SS), are complex conditions involving immune system dysregulation. Diagnosis is challenging, requiring biomarkers for improved detection and prediction of relapses. Lipids have emerged as potential biomarkers due to their role in inflammation and immune response. This study uses an untargeted C18 RP-LC-MS lipidomics approach to comprehensively assess changes in lipid profiles in patients with SLE and SS. By analyzing whole blood and plasma, the study aims to simplify the lipidomic analysis, explore cellular-level lipids, and compare lipid signatures of SLE and SS with healthy controls. Our findings showed variations in the lipid profile of SLE and SS. Sphingomyelin and ceramide molecular species showed significant increases in plasma samples from SS patients, suggesting an atherosclerotic profile and potentially serving as lipid biomarkers. Phosphatidylserine species in whole blood from SLE patients exhibited elevated levels supporting previously reported dysregulated processes of cell death and defective clearance of dying cells in this AID. Moreover, decreased phospholipids bearing PUFA were observed, potentially attributed to the degradation of these species through lipid peroxidation processes. Further studies are needed to better understand the role of lipids in the pathological mechanisms underlying SLE and SS.

Analysis of Phosphatidylinositol Modifications by Reactive Nitrogen Species Using LC-MS: Coming to Grips with Their Nitroxidative Susceptibility

Phosphatidylinositols (PIs) are complex lipids that play a key role in cell signaling. Like other phospholipids, they are esterified with unsaturated fatty acyl residues (FAs), making them susceptible to modification by reactive oxygen and nitrogen species (RNS). Recent studies using mass spectrometry (MS)-based lipidomics approaches have revealed that lipid nitration results in a plethora of structurally and chemically modified lipids (epilipids), including nitrated and nitroxidized derivatives of phosphatidylcholines, phosphatidylethanolamines, phosphatidylserines, and cardiolipins. However, there is a notable lack of knowledge regarding the characterization of RNS-modified PI derivatives. In this study, we used C18 high-resolution liquid chromatography-tandem MS approaches to describe the fragmentation signature of nitrated and nitroxidized PIs, bearing different fatty acyl chains. Using this approach and accurate mass measurements, we were able to identify nitro- PI derivatives, dinitro- and nitrohydroxy- derivatives for a few PI species. The data showed the typical neutral loss of nitrous acid (HNO₂) as well as the fragmentation patterns corresponding to modified fatty acyl chains (such as NO_x-RCOO^-, [M - NO_x-RCOOH - H]^- and [M - NO_x-RCOOH - C₆H₁₀O₅ - H]^-), making it possible to identify these epilipids. The susceptibility of PIs to nitration was also investigated, revealing that it depends exclusively on the chains of unsaturated FAs esterified in PI, showing a higher conversion rate for those with C18:1. Overall, the knowledge gathered in this study will contribute to the precise characterization of these epilipids in complex biological samples, offering new opportunities to unveil the pathophysiological roles of nitrated and nitroxidized PI derivatives at the cellular and tissue levels.

Differences and Similarities in Lipid Composition, Nutritional Value, and Bioactive Potential of Four Edible Chlorella vulgaris Strains

The microalga Chlorella vulgaris is a popular food ingredient widely used in the industry, with an increasing market size and value. Currently, several edible strains of C. vulgaris with different organoleptic characteristics are commercialized to meet consumer needs. This study aimed to compare the fatty acid (FA) and lipid profile of four commercialized strains of C. vulgaris (C-Auto, C-Hetero, C-Honey, and C-White) using gas- and liquid-chromatography coupled to mass-spectrometry approaches, and to evaluate their antioxidant and anti-inflammatory properties. Results showed that C-Auto had a higher lipid content compared to the other strains and higher levels of omega-3 polyunsaturated FAs (PUFAs). However, the C-Hetero, C-Honey, and C-White strains had higher levels of omega-6 PUFAs. The lipidome signature was also different between strains, as C-Auto had a higher content of polar lipids esterified to omega-3 PUFAs, while C-White had a higher content of phospholipids with omega-6 PUFAs. C-Hetero and C-Honey showed a higher content of triacylglycerols. All extracts showed antioxidant and anti-inflammatory activity, highlighting C-Auto with greater potential. Overall, the four strains of C. vulgaris can be selectively chosen as a source of added-value lipids to be used as ingredients in food and nutraceutical applications for different market needs and nutritional requirements.

Evaluation of Lipid Extracts from the Marine Fungi Emericellopsis cladophorae and Zalerion maritima as a Source of Anti-Inflammatory, Antioxidant and Antibacterial Compounds

Marine environments occupy more than 70% of the earth's surface, integrating very diverse habitats with specific characteristics. This heterogeneity of environments is reflected in the biochemical composition of the organisms that inhabit them. Marine organisms are a source of bioactive compounds, being increasingly studied due to their health-beneficial properties, such as antioxidant, anti-inflammatory, antibacterial, antiviral, or anticancer. In the last decades, marine fungi have stood out for their potential to produce compounds with therapeutic properties. The objective of this study was to determine the fatty acid profile of isolates from the fungi Emericellopsis cladophorae and Zalerion maritima and assess the anti-inflammatory, antioxidant, and antibacterial potential of their lipid extracts. The analysis of the fatty acid profile, using GC-MS, showed that E. cladophorae and Z. maritima possess high contents of polyunsaturated fatty acids, 50% and 34%, respectively, including the omega-3 fatty acid 18:3 n-3. Emericellopsis cladophorae and Z. maritima lipid extracts showed anti-inflammatory activity expressed by the capacity of their COX-2 inhibition which was 92% and 88% of inhibition at 200 µg lipid mL^-1, respectively. Emericellopsis cladophorae lipid extracts showed a high percentage of inhibition of COX -2 activity even at low concentrations of lipids (54% of inhibition using 20 µg lipid mL^-1), while a dose-dependent behaviour was observed in Z. maritima. The antioxidant activity assays of total lipid extracts demonstrated that the lipid extract from E. cladophorae did not show antioxidant activity, while Z. maritima gave an IC₂₀ value of 116.6 ± 6.2 µg mL^-1 equivalent to 92.1 ± 4.8 µmol Trolox g^-1 of lipid extract in the DPPH• assay, and 101.3 ± 14.4 µg mL^-1 equivalent to 106.6 ± 14.8 µmol Trolox g^-1 of lipid extract in the ABTS•⁺ assay. The lipid extract of both fungal species did not show antibacterial properties at the concentrations tested. This study is the first step in the biochemical characterization of these marine organisms and demonstrates the bioactive potential of lipid extracts from marine fungi for biotechnological applications.

The plasma phospholipidome of the bottlenose dolphin (Tursiops truncatus) is modulated by both sex and developmental stage

Lipidomics represent a valid complementary tool to the biochemical analysis of plasma in humans. However, in cetaceans, these tools have been unexplored. Here, we evaluated how the plasma lipid composition of Tursiops truncatus is modulated by developmental stage and sex, aiming at a potential use of lipidomics in integrated strategies to monitor cetacean health. We characterized the fatty acid profile and detected a total of 26 fatty acids in T. truncatus plasma. The most abundant fatty acids were palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1n-9). Interestingly, there are consistent differences between the fatty acid profile of mature female and mature male specimens. Phospholipidome analysis identified 320 different lipid species belonging to phosphatidylcholine (PC, 105 lipid species), lysophosphatidylcholine (42), phosphatidylethanolamine (PE, 67), lysophosphatidylethanolamine (18), phosphatidylglycerol (14), lysophosphatidylglycerol (8), phosphatidylinositol (14), lysophosphatidylinositol (2), phosphatidylserine (3), sphingomyelin (45) and ceramides (2) classes. The statistical analysis of the phospholipidome showed that its composition allows discriminating mature animals between sexes and mature males from immature males. Notably, discrimination between sexes is mainly determined by the contents of PE plasmalogens and lysophospholipids (LPC and LPE), while the differences between mature and immature male animals were mainly determined by the levels of PC lipids. This is the first time that a correlation between developmental stage and sex and the lipid composition of the plasma has been established in cetaceans. Being able to discern between age and sex-related changes is an encouraging step towards using these tools to also detect differences related to disease/dysfunction processes.

Lipid profile variability in children at different ages measured in dried blood spots

Dried blood spot (DBS) is a minimally invasive sampling technique that has several advantages over conventional venipuncture/arterial blood sampling. More recently, DBS has also been applied for lipidomics analysis, but this is an area that requires further research. The few works found in the literature on lipidomics of DBS samples performed the analysis in adult samples, leaving pediatric ages unmapped. The objective of this study was to assess the variability of the lipid profile (identified by high-resolution C18 RP-LC-MS/MS) of DBS at pediatric age (0-10 days, 2-18 months, and 3-13 years) and to identify age-related variations. The results revealed that the lipidomic signature of the three age groups is significantly different, especially for a few species of neutral lipids and phosphatidylcholines. The main contributors to the differentiation of the groups correspond to 3 carnitine (Car), 2 cholesteryl ester (CE), 2 diacylglycerol (DG), 2 triacylglycerol (TG), 3 phosphatidylcholine (PC), 1 ether-linked PC, 1 phosphatidylethanolamine (PE), 1 ether-linked PE and 1 phosphatidylinositol (PI) species, all with statistically significant differences. Additionally, lipid species containing linoleic acid (C18:2) were shown to have significantly lower levels in the 0-10 days group with a gradual increase in the 2-18 month, reaching the highest concentrations in the 3-13 year group. The results of this study highlighted the adaptations of the lipid profile at different pediatric ages. These results may help improve understanding of the evolution of lipid metabolism throughout childhood and should be investigated further.

Retinal layer and fluid segmentation in optical coherence tomography images using a hierarchical framework

Purpose

The development of accurate methods for retinal layer and fluid segmentation in optical coherence tomography images can help the ophthalmologists in the diagnosis and follow-up of retinal diseases. Recent works based on joint segmentation presented good results for the segmentation of most retinal layers, but the fluid segmentation results are still not satisfactory. We report a hierarchical framework that starts by distinguishing the retinal zone from the background, then separates the fluid-filled regions from the rest, and finally, discriminates the several retinal layers.

Approach

Three fully convolutional networks were trained sequentially. The weighting scheme used for computing the loss function during training is derived from the outputs of the networks trained previously. To reinforce the relative position between retinal layers, the mutex Dice loss (included for optimizing the last network) was further modified so that errors between more "distant" layers are more penalized. The method's performance was evaluated using a public dataset.

Results

The proposed hierarchical approach outperforms previous works in the segmentation of the inner segment ellipsoid layer and fluid (Dice coefficient = 0.95 and 0.82, respectively). The results achieved for the remaining layers are at a state-of-the-art level.

Conclusions

The proposed framework led to significant improvements in fluid segmentation, without compromising the results in the retinal layers. Thus, its output can be used by ophthalmologists as a second opinion or as input for automatic extraction of relevant quantitative biomarkers.

Mitochondrial Fatty Acid β-Oxidation Disorders: From Disease to Lipidomic Studies-A Critical Review

Fatty acid oxidation disorders (FAODs) are inborn errors of metabolism (IEMs) caused by defects in the fatty acid (FA) mitochondrial β-oxidation. The most common FAODs are characterized by the accumulation of medium-chain FAs and long-chain (3-hydroxy) FAs (and their carnitine derivatives), respectively. These deregulations are associated with lipotoxicity which affects several organs and potentially leads to life-threatening complications and comorbidities. Changes in the lipidome have been associated with several diseases, including some IEMs. In FAODs, the alteration of acylcarnitines (CARs) and FA profiles have been reported in patients and animal models, but changes in polar and neutral lipid profile are still scarcely studied. In this review, we present the main findings on FA and CAR profile changes associated with FAOD pathogenesis, their correlation with oxidative damage, and the consequent disturbance of mitochondrial homeostasis. Moreover, alterations in polar and neutral lipid classes and lipid species identified so far and their possible role in FAODs are discussed. We highlight the need of mass-spectrometry-based lipidomic studies to understand (epi)lipidome remodelling in FAODs, thus allowing to elucidate the pathophysiology and the identification of possible biomarkers for disease prognosis and an evaluation of therapeutic efficacy.

Molecular programming modulates hepatic lipid metabolism and adult metabolic risk in the offspring of obese mothers in a sex-specific manner

Male and female offspring of obese mothers are known to differ extensively in their metabolic adaptation and later development of complications. We investigate the sex-dependent responses in obese offspring mice with maternal obesity, focusing on changes in liver glucose and lipid metabolism. Here we show that maternal obesity prior to and during gestation leads to hepatic steatosis and inflammation in male offspring, while female offspring are protected. Females from obese mothers display important changes in hepatic transcriptional activity and triglycerides profile which may prevent the damaging effects of maternal obesity compared to males. These differences are sustained later in life, resulting in a better metabolic balance in female offspring. In conclusion, sex and maternal obesity drive differently transcriptional and posttranscriptional regulation of major metabolic processes in offspring liver, explaining the sexual dimorphism in obesity-associated metabolic risk.

Sex and maternal obesity drive differently transcriptional and posttranscriptional regulation of major metabolic processes in the livers of female and male offspring, contributing to the sexual dimorphism in obesity-associated metabolic risk.

Tracking Prostate Carcinogenesis over Time through Urine Proteome Profiling in an Animal Model: An Exploratory Approach

Prostate cancer (PCa) is one of the most lethal diseases in men, which justifies the search for new diagnostic tools. The aim of the present study was to gain new insights into the progression of prostate carcinogenesis by analyzing the urine proteome. To this end, urine from healthy animals and animals with prostate adenocarcinoma was analyzed at two time points: 27 and 54 weeks. After 54 weeks, the incidence of pre-neoplastic and neoplastic lesions in the PCa animals was 100%. GeLC-MS/MS and subsequent bioinformatics analyses revealed several proteins involved in prostate carcinogenesis. Increased levels of retinol-binding protein 4 and decreased levels of cadherin-2 appear to be characteristic of early stages of the disease, whereas increased levels of enolase-1 and T-kininogen 2 and decreased levels of isocitrate dehydrogenase 2 describe more advanced stages. With increasing age, urinary levels of clusterin and corticosteroid-binding globulin increased and neprilysin levels decreased, all of which appear to play a role in prostate hyperplasia or carcinogenesis. The present exploratory analysis can be considered as a starting point for studies targeting specific human urine proteins for early detection of age-related maladaptive changes in the prostate that may lead to cancer.

Grieving Experiences of Parents with Children in End-of-Life Care—A Qualitative Review Protocol

Parents that accompany their children in end-of-life care until death go through a devastating, complex and vulnerable situation, which is experienced in a unique way and with individual needs, given the specificity of the palliative care setting in which it occurs. This qualitative review aims to identify and synthesize the best evidence available on the grieving experiences of parents with children in end-of-life care in a palliative care setting. This qualitative review protocol is according to the review method proposed by the Joanna Briggs Institute. The results will enable us to identify how parents of children in end-of-life care in a palliative care setting experience their grieving process. This review will broaden the horizon of understanding of the specificities of the grieving experience of parents who have accompanied their children in end-of-life care until their death in a palliative care setting and promote research in this context. The results of the review will also allow the construction of an “end-of-life grieving script”, with the aim of identifying one’s individuality in the grieving process. This protocol is registered at Open Science Framework.

Looking in Depth at Oxidized Cholesteryl Esters by LC-MS/MS: Reporting Specific Fragmentation Fingerprints and Isomer Discrimination

Cholesteryl esters (CE) are prone to oxidation under increased oxidative stress conditions, but little is known about oxidized CE species (oxCE). To date, only a few oxCE have been identified, however, mainly based on the detection of molecular ions by mass spectrometry (MS) or target approaches for specific oxCE. The study of oxCE occurring from radical oxidation is still scarcely addressed. In this work, we made a comprehensive assessment of oxCE derivatives and their specific fragmentation patterns to identify detailed structural features and isomer differentiation using high-resolution C18 HPLC-MS- and MS/MS-based lipidomic approaches. The LC-MS/MS analysis allowed us to pinpoint oxCE structural isomers of long-chain and short-chain species, eluting at different retention times (t_R). Data analysis revealed that oxCE can be modified either in the fatty acyl moiety or in the cholesterol ring. The location of the hydroxy/hydroperoxy group originates characteristic fragment ions, namely the unmodified cholestenyl cation (m/z 369) for the isomer with oxidation in the fatty acyl chain or ions at m/z 367 and m/z 385 (369 + 16) when oxygenation occurs in the cholesterol ring. Additionally, we identified CE 18:2 and 20:4 aldehydic and carboxylic short-chain products that showed a clear fragmentation pattern that confirmed the modification in the fatty acyl chain. Specific fragmentation fingerprinting allowed discrimination of the isobaric short-chain species, namely carboxylic short-chain products, from hydroxy aldehyde short-chain products, with a hydroxycholesterol moiety. This new information is important to identify different oxCE in biological samples and will contribute to unraveling their role in biological conditions and diseases such as cardiovascular disease.

Bioprospecting Bioactive Polar Lipids from Olive (Olea europaea cv. Galega vulgar) Fruit Seeds: LC-HR-MS/MS Fingerprinting and Sub-Geographic Comparison

Olive seeds have been considered as a new nutritionally healthy food supplement. They are rich in monounsaturated n-9 and essential polyunsaturated n-6 lipids. However, little is known about their polar lipids, potentially bioactive and chemical identity markers for olive pulp and oil. This work aimed to identify the polar lipidome of olive seeds to find possible bioactive compounds and markers of geographic origin, by studying samples from six Portuguese sub-regions. Polar lipids were obtained by solid/liquid extraction, NH₂-solid-phase extraction, and identified by hydrophilic interaction liquid chromatography (HILIC)-HR-ESI-MS and MS/MS. Ninety-four compounds were identified, including phospholipids, glycolipids, sphingolipids, and acyl sterol glycosides, several of which bear polyunsaturated fatty acids. Multivariate statistical analysis found unique profiles within each sub-region and markers of geographic identity, primarily phosphatidylcholines, phosphatidylethanolamines, and lysophosphatidylethanolamines. Therefore, polar lipid signatures should be further investigated, to assess their bioactivity, nutritional value, and chemical identity for valuing olive seeds and their oil.

Novel Exosome Biomarker Candidates for Alzheimer's Disease Unravelled Through Mass Spectrometry Analysis

Exosomes are small extracellular vesicles (EVs) present in human biofluids that can transport specific disease-associated molecules. Consequently blood-derived exosomes have emerged as important peripheral biomarker sources for a wide range of diseases, among them Alzheimer’s disease (AD). Although there is no effective cure for AD, an accurate diagnosis, relying on easily accessible peripheral biofluids, is still necessary to discriminate this disease from other dementias, test potential therapies and even monitor rate of disease progression. The ultimate goal is to produce a cost-effective and widely available alternative, which can also be employed as a first clinical screen. In this study, EVs with exosome-like characteristics were isolated from serum of Controls and AD cases through precipitation- and column-based methods, followed by mass spectrometry analysis. The resulting proteomes were characterized by Gene Ontology (GO) and multivariate analyses. Although GO terms were similar for exosomes’ proteomes of Controls and ADs, using both methodologies, a clear segregation of disease cases was obtained when using the precipitation-based method. Nine significantly different abundant proteins were identified between Controls and AD cases, representing putative biomarker candidate targets. Among them are AACT and C4BPα, two Aβ-binding proteins, whose exosome levels were further validated in individuals from independent cohorts using antibody-based approaches. The findings discussed represent an important contribution to the identification of novel exosomal biomarker candidates useful as potential blood-based tools for AD diagnosis.

Applications of lipidomics in marine organisms: Progresses, challenges and future perspectives

Marine ecosystems comprise a high diversity of life forms, such as algae, invertebrates, and vertebrates. These organisms have adapted their physiology according to the conditions of the environments in which...

Food grade extraction of Chlorella vulgaris polar lipids: A comparative lipidomic study

Glycolipids and phospholipids are the main reservoirs of omega polyunsaturated fatty acids in microalgae. Their extraction for the food industry requires food grade solvents, however, the use of these solvents is generally associated with low extraction yields. In this study, we evaluated the lipid extraction efficiency of food-grade ethanol, ultrasound-assisted ethanol (UAE) and dichloromethane/methanol (DCM) from Chlorella vulgaris cultivated under autotrophic and heterotrophic conditions. Yields of lipids, fatty acids (FA), and complex lipid profiles were determined by gravimetry, GC-MS, and LC-MS/MS, respectively. UAE and DCM showed the highest lipid yields with similar purity. The FA profiles were identical for all extracts. The polar lipidome of the DCM and UAE extracts was comparable, while the EtOH extracts were significantly different. These results demonstrated the effectiveness of UAE extraction to obtain high yields of polar lipids and omega-3 and -6-rich extracts from C. vulgaris that can be used for food applications.

Comprehensive Metabolomics and Lipidomics Profiling of Prostate Cancer Tissue Reveals Metabolic Dysregulations Associated with Disease Development

Prostate cancer (PCa) is a global health problem that affects millions of men every year. In the past decade, metabolomics and related subareas, such as lipidomics, have demonstrated an enormous potential to identify novel mechanisms underlying PCa development and progression, providing a good basis for the development of new and more effective therapies and diagnostics. In this study, a multiplatform metabolomics and lipidomics approach, combining untargeted mass spectrometry (MS) and nuclear magnetic resonance (NMR)-based techniques, was applied to PCa tissues to investigate dysregulations associated with PCa development, in a cohort of 40 patients submitted to radical prostatectomy for PCa. Results revealed significant alterations in the levels of 26 metabolites and 21 phospholipid species in PCa tissue compared with adjacent nonmalignant tissue, suggesting dysregulation in 13 metabolic pathways associated with PCa development. The most affected metabolic pathways were amino acid metabolism, nicotinate and nicotinamide metabolism, purine metabolism, and glycerophospholipid metabolism. A clear interconnection between metabolites and phospholipid species participating in these pathways was observed through correlation analysis. Overall, these dysregulations may reflect the reprogramming of metabolic responses to produce high levels of cellular building blocks required for rapid PCa cell proliferation.

Cardiac phospholipidome is altered during ischemia and reperfusion in an ex vivo rat model

Acute myocardial infarction (AMI) is the leading cause of death, morbidity, and health costs worldwide. In AMI, a sudden blockage of blood flow causes myocardial ischemia and cell death. Reperfusion after ischemia has paradoxical effects and may exacerbate the myocardial injury, a process known as ischemic reperfusion injury. In this work we evaluated the lipidome of isolated rat hearts, maintained in controlled perfusion (CT), undergoing global ischemia (ISC) or ischemia followed by reperfusion (IR). 153 polar lipid levels were significantly different between conditions. 48 features had q < 0.001 and included 8 phosphatidylcholines and 4 lysophospholipids, which were lower in ISC compared to CT, and even lower in the IR group, suggesting that IR induces more profound changes than ISC. We observed that the levels of 16 alkyl acyl phospholipids were significantly altered during ISC and IR. Overall, these data indicate that myocardial lipid remodelling and possibly damage occurs to a greater extent during reperfusion. The adaptation of cardiac lipidome during ISC and IR described is consistent with the presence of oxidative damage and may reflect the impact of AMI on the lipidome at the cellular level and provide new insights into the role of lipids in the pathophysiology of acute myocardial ischemia/reperfusion injury.

Polar Lipids Composition, Antioxidant and Anti-Inflammatory Activities of the Atlantic Red Seaweed Grateloupia turuturu

Grateloupia turuturu Yamada, 1941, is a red seaweed widely used for food in Japan and Korea which was recorded on the Atlantic Coast of Europe about twenty years ago. This seaweed presents eicosapentaenoic acid (EPA) and other polyunsaturated fatty acids (PUFAs) in its lipid fraction, a feature that sparked the interest on its potential applications. In seaweeds, PUFAs are mostly esterified to polar lipids, emerging as healthy phytochemicals. However, to date, these biomolecules are still unknown for G. turuturu. The present work aimed to identify the polar lipid profile of G. turuturu, using modern lipidomics approaches based on high performance liquid chromatography coupled to high resolution mass spectrometry (LC-MS) and gas chromatography coupled to mass spectrometry (GC-MS). The health benefits of polar lipids were identified by health lipid indices and the assessment of antioxidant and anti-inflammatory activities. The polar lipids profile identified from G. turuturu included 205 lipid species distributed over glycolipids, phospholipids, betaine lipids and phosphosphingolipids, which featured a high number of lipid species with EPA and PUFAs. The nutritional value of G. turuturu has been shown by its protein content, fatty acyl composition and health lipid indices, thus confirming G. turuturu as an alternative source of protein and lipids. Some of the lipid species assigned were associated to biological activity, as polar lipid extracts showed antioxidant activity evidenced by free radical scavenging potential for the 2,2'-azino-bis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS^●+) radical (IC₅₀ ca. 130.4 μg mL^-1) and for the 2,2-diphenyl-1-picrylhydrazyl (DPPH^●) radical (IC₂₅ ca. 129.1 μg mL^-1) and anti-inflammatory activity by inhibition of the COX-2 enzyme (IC₅₀ ca. 33 µg mL^-1). Both antioxidant and anti-inflammatory activities were detected using a low concentration of extracts. This integrative approach contributes to increase the knowledge of G. turuturu as a species capable of providing nutrients and bioactive molecules with potential applications in the nutraceutical, pharmaceutical and cosmeceutical industries.

Protein Aggregation Patterns Inform about Breast Cancer Response to Antiestrogens and Reveal the RNA Ligase RTCB as Mediator of Acquired Tamoxifen Resistance

Simple Summary

Acquired resistance to antiestrogenic therapy remains the major obstacle to curing luminal subtype breast cancer. While current treatment in acquired endocrine-resistant settings includes combined therapy with receptor tyrosine kinase or cyclin-dependent kinase inhibitors, progression to incurable disease remains possible. In recent years, the antioxidant system and the protein quality control network have been associated with the enhanced resistance of breast cancer cells to hormonal therapy. In this work, we raise the hypothesis that antiestrogen treatment induces the accumulation of protein aggregates in sensitive cells, which in turn could hinder the activation of survival pathways. We present evidence concerning a novel way to identify antiestrogen response and disclose a novel protein, RTBC, that controls acquired antiestrogen resistance. This work opens a new avenue for research towards finding breast cancer prognostic markers and therapeutic targets, where the identification of proteins prone to aggregate could help to identify antiestrogen response and understand mechanisms of disease.

Abstract

The protein quality control network, including autophagy, the proteasome and the unfolded protein response (UPR), is triggered by stress and is overactive in acquired antiestrogen therapy resistance. We show for the first time that the aggresome load correlates with apoptosis and is increased in antiestrogen-sensitive cells compared to endocrine-resistant variants. LC-MS/MS analysis of the aggregated proteins obtained after 4OH-tamoxifen and Fulvestrant treatment identified proteins with essential function in protein quality control in antiestrogen-sensitive cells, but not in resistant variants. These include the UPR modulators RTCB and PDIA6, as well as many proteasome proteins such as PSMC2 and PSMD11. RTCB is a tRNA and XBP1 ligase and its aggregation induced by antiestrogens correlated with impaired XBP1s expression in sensitive cells. Knock down of RTCB was sufficient to restore sensitivity to tamoxifen in endocrine-resistant cells and increased the formation of aggresomes, leading to apoptotic cell death. Analysis of primary human breast cancer samples and their metastases appearing after endocrine treatment showed that RTCB is only localized to aggresomes in the primary tumors, while total aggresomes, including aggregated RTCB, were significantly reduced in the metastases. Therefore, different protein aggregation patterns may indicate loss of function of essential proteins resulting in enhanced protein aggregation that can be used to identify antiestrogen-resistant breast cancer cells and improve the response to antiestrogenic therapy.

Microalgae as Sustainable Bio-Factories of Healthy Lipids: Evaluating Fatty Acid Content and Antioxidant Activity

The demand for sustainable and environmentally friendly food sources and food ingredients is increasing, and microalgae are promoted as a sustainable source of essential and bioactive lipids, with high levels of omega-3 fatty acids (ω-3 FA), comparable to those of fish. However, most FA screening studies on algae are scattered or use different methodologies, preventing a true comparison of its content between microalgae. In this work, we used gas-chromatography mass-spectrometry (GC-MS) to characterize the FA profile of seven different commercial microalgae with biotechnological applications (Chlorella vulgaris, Chlorococcum amblystomatis, Scenedesmus obliquus, Tetraselmis chui, Phaeodactylum tricornutum, Spirulina sp., and Nannochloropsis oceanica). Screening for antioxidant activity was also performed to understand the relationship between FA profile and bioactivity. Microalgae exhibited specific FA profiles with a different composition, namely in the ω-3 FA profile, but with species of the same phylum showing similar tendencies. The different lipid extracts showed similar antioxidant activities, but with a low activity of the extracts of Nannochloropsis oceanica. Overall, this study provides a direct comparison of FA profiles between microalgae species, supporting the role of these species as alternative, sustainable, and healthy sources of essential lipids.

The plasma phospholipidome of Tursiops truncatus: From physiological insight to the design of prospective tools for managed cetacean monitorization

Plasma biochemical analysis remains one of the established ways of monitoring captive marine mammal health. More recently, complementary plasma lipidomic analysis has proven to be a valid tool in disease diagnosis and prevention, with the potential to validate and complement common biochemical analysis, providing a more integrative approach. In this study, we thoroughly characterized the plasma polar lipid content of Tursiops truncatus, the most common cetacean species held under human care. Our results showed that phosphatidylcholine, lysophosphatidylcholine, and sphingomyelins (CerPCho) are the most represented phospholipid classes in T. truncatus plasma. Palmitic, oleic, and stearic acids are the major fatty acid (FA) present esterified to the plasma polar lipids of this species, although some n-3 species are also remarkably present, namely eicosapentaenoic and docosahexaenoic acids. The polar lipidome identified by HILIC LC-MS allowed identifying 304 different lipid species. These species belong to the phosphatidylcholine (103 lipid species), lysophosphatidylcholine (35), phosphatidylethanolamine (71), lysophosphatidylethanolamine (20), phosphatidylglycerol (13), lysophosphatidylglycerol (5), phosphatidylinositol (15), lysophosphatidylinositol (3), phosphatidylserine (6) lysophosphatidylserine (1), and sphimgomyelin (32) classes. This was the first time that the dolphin plasma phospholipid profile was characterized, providing a knowledge that will be important to further understand lipid metabolism and physiological regulation in small cetaceans. Furthermore, this study proved the practicability of the use of plasma lipid profiling for health assessment in marine mammals under human care.

Polar Lipids of Commercial Ulva spp. of Different Origins: Profiling and Relevance for Seaweed Valorization

Macroalgae of the genus Ulva have long been used as human food. Local environmental conditions, among other factors, can have an impact on their nutrient and phytochemical composition, as well as on the value of the seaweed for food and non-food applications. This study is the first to initiate a comparison between commercial Ulva spp. from different European origins, France (FR, wild-harvested Ulva spp.), and Portugal (PT, farm-raised Ulva rigida), in terms of proximate composition, esterified fatty acids (FA), and polar lipids. The ash content was higher in PT samples, while FR samples had higher levels of proteins, lipids, and carbohydrates and other compounds. The profile of esterified FA, as well as FA-containing polar lipids at the class and species levels were also significantly different. The FR samples showed about three-fold higher amount of n-3 polyunsaturated FA, while PT samples showed two-fold higher content of monounsaturated FA. Quantification of glycolipids and phospholipids revealed, respectively, two-fold and three-fold higher levels in PT samples. Despite the differences found, the polar lipids identified in both batches included some lipid species with recognized bioactivity, valuing Ulva biomass with functional properties, increasing their added value, and promoting new applications, namely in nutraceutical and food markets.

Plasma Phospholipidomic Profile Differs between Children with Phenylketonuria and Healthy Children

Phenylketonuria (PKU) is a disease of the catabolism of phenylalanine (Phe), caused by an impaired function of the enzyme phenylalanine hydroxylase. Therapeutics is based on the restriction of Phe intake, which mostly requires a modification of the diet. Dietary restrictions can lead to imbalances in specific nutrients, including lipids. In the present study, the plasma phospholipidome of PKU and healthy children (CT) was analyzed by hydrophilic interaction liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Using this approach, 187 lipid species belonging to nine different phospholipid classes and three ceramides were identified. Principal component analysis of the lipid species data set showed a distinction between PKU and CT groups. Univariate analysis revealed that 146 species of phospholipids were significantly different between both groups. Lipid species showing significant variation included phosphatidylcholines, containing polyunsaturated fatty acids (PUFA), which were more abundant in PKU. The high level of PUFA-containing lipid species in children with PKU may be related to a diet supplemented with PUFA. This study was the first report comparing the plasma polar lipidome of PKU and healthy children, highlighting that the phospholipidome of PKU children is significantly altered compared to CT. However, further studies with larger cohorts are needed to clarify whether these changes are specific to phenylketonuric children.

Characterization of Non-volatile Oxidation Products Formed from Triolein in a Model Study at Frying Temperature

Frying allows cooking food while promoting their organoleptic properties, imparting crunchiness and flavor. The drawback is the oxidation of triacylglycerides (TAGs), leading to the formation of primary oxidized TAGs. Although they have been associated with chronic and degenerative diseases, they are precursors of pleasant flavors in fried foods. Nevertheless, there is a lack of knowledge about the oxidation species present in foods and their involvement in positive/negative health effects. In this work, high-resolution (HR) C₃₀ reversed-phase (RP)-liquid chromatography (LC)-tandem HR mass spectrometry (MS/MS) was used to identify primary oxidation TAGs resulting from heating triolein (160 °C, 5 min). This allows simulating the initial heating process of frying oils usually used to prepare fried foods, such as chips, crisps, and snacks. Beyond hydroxy, dihydroxy, hydroperoxy, and hydroxy-hydroperoxy derivatives, already reported in phospholipids oxidized by Fenton reaction, new compounds were identified, such as dihydroxy-hydroperoxy-triolein derivatives and positional isomers (9/10- and 9/12-dihydroxy-triolein derivatives). These compounds should be considered when proposing flavor formation pathways and/or mitigating lipid-derived reactive oxygen species occurring during food frying.

Polar lipidomic profile shows Chlorococcum amblystomatis as a promising source of value-added lipids

There is a growing trend to explore microalgae as an alternative resource for the food, feed, pharmaceutical, cosmetic and fuel industry. Moreover, the polar lipidome of microalgae is interesting because of the reports of bioactive polar lipids which could foster new applications for microalgae. In this work, we identified for the first time the Chlorococcum amblystomatis lipidome using hydrophilic interaction liquid chromatography-high resolution electrospray ionization- tandem mass spectrometry (HILIC-HR-ESI-MS/MS). The Chlorococcum amblystomatis strain had a lipid content of 20.77% and the fatty acid profile, determined by gas chromatography-mass spectrometry, has shown that this microalga contains high amounts of omega-3 polyunsaturated fatty acids (PUFAs). The lipidome identified included 245 molecular ions and 350 lipid species comprising 15 different classes of glycolipids (6), phospholipids (7) and betaine lipids (2). Of these, 157 lipid species and the main lipid species of each class were esterified with omega-3 PUFAs. The lipid extract has shown antioxidant activity and anti-inflammatory potential. Lipid extracts also had low values of atherogenic (0.54) and thrombogenic index (0.27). In conclusion, the lipid extracts of Chlorococcum amblystomatis have been found to be a source of lipids rich in omega-3 PUFAs for of great value for the food, feed, cosmetic, nutraceutical and pharmaceutical industries.

Obese mother offspring have hepatic lipidic modulation that contributes to sex-dependent metabolic adaptation later in life

With the increasing prevalence of obesity in women of reproductive age, there is an urgent need to understand the metabolic impact on the fetus. Sex-related susceptibility to liver diseases has been demonstrated but the underlying mechanism remains unclear. Here we report that maternal obesity impacts lipid metabolism differently in female and male offspring. Males, but not females, gained more weight and had impaired insulin sensitivity when born from obese mothers compared to control. Although lipid mass was similar in the livers of female and male offspring, sex-specific modifications in the composition of fatty acids, triglycerides and phospholipids was observed. These overall changes could be linked to sex-specific regulation of genes controlling metabolic pathways. Our findings revised the current assumption that sex-dependent susceptibility to metabolic disorders is caused by sex-specific postnatal regulation and instead we provide molecular evidence supporting in utero metabolic adaptations in the offspring of obese mothers.

Insights in the Role of Lipids, Oxidative Stress and Inflammation in Rheumatoid Arthritis Unveiled by New Trends in Lipidomic Investigations

Rheumatoid arthritis (RA) is a highly debilitating chronic inflammatory autoimmune disease most prevalent in women. The true etiology of this disease is complex, multifactorial, and is yet to be completely elucidated. However, oxidative stress and lipid peroxidation are associated with the development and pathogenesis of RA. In this case, oxidative damage biomarkers have been found to be significantly higher in RA patients, associated with the oxidation of biomolecules and the stimulation of inflammatory responses. Lipid peroxidation is one of the major consequences of oxidative stress, with the formation of deleterious lipid hydroperoxides and electrophilic reactive lipid species. Additionally, changes in the lipoprotein profile seem to be common in RA, contributing to cardiovascular diseases and a chronic inflammatory environment. Nevertheless, changes in the lipid profile at a molecular level in RA are still poorly understood. Therefore, the goal of this review was to gather all the information regarding lipid alterations in RA analyzed by mass spectrometry. Studies on the variation of lipid profile in RA using lipidomics showed that fatty acid and phospholipid metabolisms, especially in phosphatidylcholine and phosphatidylethanolamine, are affected in this disease. These promising results could lead to the discovery of new diagnostic lipid biomarkers for early diagnosis of RA and targets for personalized medicine.

Serum phospholipidomics reveals altered lipid profile and promising biomarkers in multiple sclerosis

Multiple sclerosis is a neurodegenerative disease causing disability in young adults. Alterations in metabolism and lipid profile have been associated with this disease. Several studies have reported changes in the metabolism of arachidonic acid and the profile of fatty acids, ceramides, phospholipids and lipid peroxidation products. Nevertheless, the understanding of the modulation of circulating lipids at the molecular level in multiple sclerosis remains unclear. In the present study, we sought to assess the existence of a distinctive lipid signature of multiple sclerosis using an untargeted lipidomics approach. It also aimed to assess the differences in lipid profile between disease status (relapse and remission). For this, we used hydrophilic interaction liquid chromatography coupled with mass spectrometry for phospholipidomic profiling of serum samples from patients with multiple sclerosis. Our results demonstrated that multiple sclerosis has a phospholipidomic signature different from that of healthy controls, especially the PE, PC, LPE, ether-linked PE and ether-linked PC species. Plasmalogen PC and PE species, which are natural endogenous antioxidants, as well as PC and PE polyunsaturated fatty acid esterified species showed significantly lower levels in patients with multiple sclerosis and patients in both remission and relapse of multiple sclerosis. Our results show for the first time that the serum phospholipidome of multiple sclerosis is significantly different from that of healthy controls and that few phospholipids, with the lowest p-value, such as PC(34:3), PC(36:6), PE(40:10) and PC(38:1) may be suitable as biomarkers for clinical applications in multiple sclerosis.

Microaneurysm detection in color eye fundus images for diabetic retinopathy screening

Diabetic retinopathy (DR) is a diabetes complication, which in extreme situations may lead to blindness. Since the first stages are often asymptomatic, regular eye examinations are required for an early diagnosis. As microaneurysms (MAs) are one of the first signs of DR, several automated methods have been proposed for their detection in order to reduce the ophthalmologists' workload. Although local convergence filters (LCFs) have already been applied for feature extraction, their potential as MA enhancement operators was not explored yet. In this work, we propose a sliding band filter for MA enhancement aiming at obtaining a set of initial MA candidates. Then, a combination of the filter responses with color, contrast and shape information is used by an ensemble of classifiers for final candidate classification. Finally, for each eye fundus image, a score is computed from the confidence values assigned to the MAs detected in the image. The performance of the proposed methodology was evaluated in four datasets. At the lesion level, sensitivities of 64% and 81% were achieved for an average of 8 false positives per image (FPIs) in e-ophtha MA and SCREEN-DR, respectively. In the last dataset, an AUC of 0.83 was also obtained for DR detection.

Valuing Bioactive Lipids from Green, Red and Brown Macroalgae from Aquaculture, to Foster Functionality and Biotechnological Applications

Marine edible macroalgae have functional proprieties that might improve human health and wellbeing. Lipids represent a minor fraction of macroalgae, yet with major interest as main carriers of omega 3 polyunsaturated fatty acids and intrinsic bioactive properties. In this study, we used lipid extracts from the green macroalgae Ulva rigida and Codium tomentosum; the red Gracilaria gracilis,Palmaria palmata and Porphyra dioica; and the brown Fucus vesiculosus, produced in a land-based integrated multitrophic aquaculture (IMTA) system. We determined the lipid quality indices based on their fatty acid profiles and their bioactivities as putative antioxidant, anti-inflammatory and antiproliferative agents. The results reveal to be species-specific, namely U. rigida displayed the lowest atherogenicity and thrombogenicity indices. Palmaria palmata and F. vesiculosus lipid extracts displayed the lowest inhibitory concentration in the free radical scavenging antioxidant assays. Ulva rigida, C. tomentosum, P. palmata and P. dioica inhibited COX-2 activity by up to 80%, while P. dioica and P. palmata extracts showed the highest cytotoxic potential in the MDA-MB-231 breast cancer cells. This work enhances the valorization of macroalgae as functional foods and promising ingredients for sustainable and healthy diets and fosters new applications of high-valued algal biomass, in a species-specific context.