Ether Lipids Research Articles

Ether lipid biosynthesis promotes lifespan extension and enables diverse pro-longevity paradigms in Caenorhabditis elegans.

Biguanides, including the world's most prescribed drug for type 2 diabetes, metformin, not only lower blood sugar, but also promote longevity in preclinical models. Epidemiologic studies in humans parallel these findings, indicating favorable effects of metformin on longevity and on reducing the incidence and morbidity associated with aging-related diseases. Despite this promise, the full spectrum of molecular effectors responsible for these health benefits remains elusive. Through unbiased screening in Caenorhabditis elegans, we uncovered a role for genes necessary for ether lipid biosynthesis in the favorable effects of biguanides. We demonstrate that biguanides prompt lifespan extension by stimulating ether lipid biogenesis. Loss of the ether lipid biosynthetic machinery also mitigates lifespan extension attributable to dietary restriction, target of rapamycin (TOR) inhibition, and mitochondrial electron transport chain inhibition. A possible mechanistic explanation for this finding is that ether lipids are required for activation of longevity-promoting, metabolic stress defenses downstream of the conserved transcription factor skn-1/Nrf. In alignment with these findings, overexpression of a single, key, ether lipid biosynthetic enzyme, fard-1/FAR1, is sufficient to promote lifespan extension. These findings illuminate the ether lipid biosynthetic machinery as a novel therapeutic target to promote healthy aging.

Alveolar type II epithelial cell FASN maintains lipid homeostasis in experimental COPD.

Alveolar epithelial type II (AEC2) cells strictly regulate lipid metabolism to maintain surfactant synthesis. Loss of AEC2 cell function and surfactant production are implicated in the pathogenesis of the smoking-related lung disease chronic obstructive pulmonary disease (COPD). Whether smoking alters lipid synthesis in AEC2 cells and whether altering lipid metabolism in AEC2 cells contributes to COPD development are unclear. In this study, high-throughput lipidomic analysis revealed increased lipid biosynthesis in AEC2 cells isolated from mice chronically exposed to cigarette smoke (CS). Mice with a targeted deletion of the de novo lipogenesis enzyme, fatty acid synthase (FASN), in AEC2 cells (FasniΔAEC2) exposed to CS exhibited higher bronchoalveolar lavage fluid (BALF) neutrophils, higher BALF protein, and more severe airspace enlargement. FasniΔAEC2 mice exposed to CS had lower levels of key surfactant phospholipids but higher levels of BALF ether phospholipids, sphingomyelins, and polyunsaturated fatty acid-containing phospholipids, as well as increased BALF surface tension. FasniΔAEC2 mice exposed to CS also had higher levels of protective ferroptosis markers in the lung. These data suggest that AEC2 cell FASN modulates the response of the lung to smoke by regulating the composition of the surfactant phospholipidome.

The transcription factor ChREBP links mitochondrial lipidomes to mitochondrial morphology and progression of diabetic kidney disease

A substantial body of evidence has established the contributions of both mitochondrial dynamics and lipid metabolism to the pathogenesis of diabetic kidney disease (DKD). However, the precise interplay between these two key metabolic regulators of DKD is not fully understood. Here, we uncover a link between mitochondrial dynamics and lipid metabolism by investigating the role of carbohydrate-response element-binding protein (ChREBP), a glucose-responsive transcription factor and a master regulator of lipogenesis, in kidney podocytes. We find that inducible podocyte-specific knockdown of ChREBP in diabetic db/db mice improves key biochemical and histological features of DKD in addition to significantly reducing mitochondrial fragmentation. Because of the critical role of ChREBP in lipid metabolism, we interrogated whether and how mitochondrial lipidomes play a role in ChREBP-mediated mitochondrial fission. Our findings suggest a key role for a family of ether phospholipids in ChREBP-induced mitochondrial remodeling. We find that overexpression of glyceronephosphate O-acyltransferase, a critical enzyme in the biosynthesis of plasmalogens, reverses the protective phenotype of ChREBP deficiency on mitochondrial fragmentation. Finally, our data also points to Gnpat as a direct transcriptional target of ChREBP. Taken together, our results uncover a distinct mitochondrial lipid signature as the link between ChREBP-induced mitochondrial dynamics and progression of DKD.

Transcriptome and metabolome analyses reveal gender-specific expression genes in sea cucumber (Holothuria leucospilota)

The sea cucumber Holothuria leucospilota, a nutritive and commercial marine species, has a high protein and low lipid content. To date, the mechanisms underlying gender determination and differentiation in sea cucumbers remain unclear. Identifying gender-specific molecular markers is an effective method of revealing the genetic basis of gender determination and differentiation. The inability to distinguish between male and female individuals causes reproductive efficiency to decline in aquaculture. In this study, we used the gonads of the sea cucumber H. leucospilota as samples to conduct the experiment. The differentially abundant metabolites (DAMs) detected by liquid chromatography-mass spectrometry were enriched in pathways associated with prolactin metabolism, insulin metabolism, hypoxia-inducible factor-1 signaling, and calcium signaling. At the transcriptome level, Illumina sequencing was performed on H. leucospilota, demonstrating that gender-specific expression genes were enriched in the retinoic acid-inducible gene I-like receptor signaling pathway, C-type lectin receptor signaling pathway, alpha-linolenic acid metabolism, and ether lipid metabolism by the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. By analyzing the common pathways between DAMs and differentially expressed genes, we found that gender-related genes of H. leucospilota were mostly enriched in the necroptosis pathway and the cysteine and methionine metabolism pathways. According to the common pathways, uch-sc1 and uch-sc2 are male-specific expression genes, and uch-sc3 and bhmt are female-specific expression genes at the mRNA level. These results provide information on gender differences in H. leucospilota.

Low colostrum intake results in potential accumulation of peroxisome lipid substrates in vaginal tissue of 3-week-old gilts.

Low colostrum intake relates to poorer health and infertility in swine. We previously connected vaginal lipid profiles at weaning to fertility of sows. We hypothesized vaginal lipidome varied with colostrum intake. Our objective was to determine whether indicators of colostrum intake, immunocrit (IM) and weight gain 24 h postnatal (PN), related to vaginal lipids at d21 PN. Gilts (n=60) were weighed and blood sampled to measure IM. On d21 PN vaginal swabs were taken and lipids measured using multiple reaction monitoring. Abundance of multiple lipids differed (P<0.05) between gilts categorized as high versus low IM and high versus low 24 h gain. The abundance of multiple lipids correlated with IM and 24 h gain. Phosphatidylcholine PC(36:3), PC(36:2), and arachidonic acid (C20:4) positively (P<0.05) correlated with IM. The ether lipid PCo(38:6) and multiple cholesteryl esters negatively (P<0.05) correlated with IM. ROC analysis indicated arachidonic acid and docosanoic acid (C22:0) may serve as excellent biomarkers that distinguish between high and low IM. Similar to gilts found to be infertile, lipid profiles of low colostrum intake animals had greater abundance of very long chain fatty acids, lipids with high levels of unsaturation, and cholesteryl esters, which are metabolized in peroxisomes indicating their potential dysfunction.

Lipid-correlated alterations in the transcriptome are enriched in several specific pathways in the postmortem prefrontal cortex of Japanese patients with schizophrenia.

Schizophrenia is a chronic relapsing psychiatric disorder that is characterized by many symptoms and has a high heritability. There were studies showing that the phospholipid abnormalities in subjects with schizophrenia (Front Biosci, S3, 2011, 153; Schizophr Bull, 48, 2022, 1125; Sci Rep, 7, 2017, 6; Anal Bioanal Chem, 400, 2011, 1933). Disturbances in prefrontal cortex phospholipid and fatty acid composition have been reported in subjects with schizophrenia (Sci Rep, 7, 2017, 6; Anal Bioanal Chem, 400, 2011, 1933; Schizophr Res, 215, 2020, 493; J Psychiatr Res, 47, 2013, 636; Int J Mol Sci, 22, 2021). For exploring the signaling pathways contributing to the lipid changes in previous study (Sci Rep, 7, 2017, 6), we performed two types of transcriptome analyses in subjects with schizophrenia: an unbiased transcriptome analysis solely based on RNA-seq data and a correlation analysis between levels of gene expression and lipids. RNA-Seq analysis was performed in the postmortem prefrontal cortex from 10 subjects with schizophrenia and 5 controls. Correlation analysis between the transcriptome and lipidome from 9 subjects, which are the same samples in the previous lipidomics study (Sci Rep, 7, 2017, 6). Extraction of differentially expressed genes (DEGs) and further sequence and functional group analysis revealed changes in gene expression levels in phosphoinositide 3-kinase (PI3K)-Akt signaling and the complement system. In addition, a correlation analysis clarified alterations in ether lipid metabolism pathway, which is not found as DEGs in transcriptome analysis alone. This study provided results of the integrated analysis of the schizophrenia-associated transcriptome and lipidome within the PFC and revealed that lipid-correlated alterations in the transcriptome are enriched in specific pathways including ether lipid metabolism pathway.

Synthesis of ethyl glyceryl ethers from catalyzed glycerol acid and ethanol to develop bio-additives to improve fuel characteristics

Synthesis of ethyl glyceryl ethers from catalyzed glycerol acid and ethanol to develop bio-additives to improve fuel characteristics

[Similarities and differences of myocardial metabolic characteristics between HFpEF and HFrEF mice based on LC-MS/MS metabolomics].

Objective: To reveal the similarities and differences in myocardial metabolic characteristics between heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) mice using metabolomics. Methods: The experimental mice were divided into 4 groups, including control, HFpEF, sham and HFrEF groups (10 mice in each group). High fat diet and Nω-nitroarginine methyl ester hydrochloride (L-NAME) were applied to construct a"two-hit"HFpEF mouse model. Transverse aortic constriction (TAC) surgery was used to construct the HFrEF mouse model. The differential expression of metabolites in the myocardium of HFpEF and HFrEF mice was detected by untargeted metabolomics (UHPLC-QE-MS). Variable importance in projection>1 and P<0.05 were used as criteria to screen and classify the differentially expressed metabolites between the mice models. KEGG functional enrichment and pathway impact analysis demonstrated significantly altered metabolic pathways in both HFpEF and HFrEF mice. Results: One hundred and nine differentially expressed metabolites were detected in HFpEF mice, and 270 differentially expressed metabolites were detected in HFrEF mice. Compared with the control group, the most significantly changed metabolite in HFpEF mice was glycerophospholipids, while HFrEF mice presented with the largest proportion of carboxylic acids and their derivatives. KEGG enrichment and pathway impact analysis showed that the differentially expressed metabolites in HFpEF mice were mainly enriched in pathways such as biosynthesis of unsaturated fatty acids, ether lipid metabolism, amino sugar and nucleotide sugar metabolism, glycerophospholipid metabolism, arachidonic acid metabolism and arginine and proline metabolism. The differentially expressed metabolites in HFrEF mice were mainly enriched in arginine and proline metabolism, glycine, serine and threonine metabolism, pantothenate and CoA biosynthesis, glycerophospholipid metabolism, nicotinate and nicotinamide metabolism and arachidonic acid metabolism, etc. Conclusions: HFpEF mice have a significantly different myocardial metabolite expression profile compared with HFrEF mice. In addition, biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, glycerophospholipid metabolism and arginine and proline metabolism are significantly altered in both HFpEF and HFrEF mice, suggesting that these metabolic pathways may play an important role in disease progression in both types of heart failure.

Dietary Eicosapentaenoic Acid Containing Phosphoethanolamine Plasmalogens Remodels the Lipidome of White Adipose Tissue and Suppresses High-Fat Diet Induced Obesity in Mice.

Dietary supplementation of docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) can alter the lipidome profiles of adipocytes, thereby counteract obesity. DHA/EPA in the form of phospholipids demonstrates higher bioavailability than triglyceride or ethyl ester (EE), but their effects on the lipidome and metabolic changes during obesity are still unknown. High-fat diet-induced obese mice are treated with different molecular forms of EPA, and EPA supplemented as phosphoethanolamine plasmalogens (PlsEtn) has a superior effect on reducing fat mass accumulation than phosphatidylcholine (PC) or EE. The lipidomics analysis indicates that EPA in form of PlsEtn but not PC or EE significantly decreases total PC and sphingomyelin content in white adipose tissue (WAT). Some specific polyunsaturated fatty acid -containing PCs and ether phospholipids are increased in EPA-PlsEtn-fed mice, which may attribute to the upregulation of unsaturated fatty acid biosynthesis and fatty acid elongation reactions in WAT. In addition, the expression of genes related to fatty acid catabolism is also promoted by EPA-PlsEtn supplementation, which may cause the decreased content of saturated and monounsaturated fatty acid-containing PCs. EPA-PlsEtn supplementation is demonstrated to remodel lipidome and regulate the fatty acid metabolic process in WAT, indicating it may serve as a new strategy for obesity treatment in the future.

Supercritical transesterification of vegetable oil and ethanol: temperature and residence time effects on phase formation and water content

Supercritical transesterification has emerged as a readily available alternative for biodiesel production since no catalyst is required, thereby generating fewer waste products. In this research, the supercritical transesterification of refined vegetable oil and aqueous ethanol was carried out at temperatures 400 to 480 °C and a 12:1 ethanol to oil molar ratio, to assess the effect of temperature and residence time in the formation of a homogeneous phase, effluent appearance and increased water content derived from glycerol etherification. The results showed that water was produced at temperatures higher than 400 °C, as expected from the occurrence of glycerol etherification, and that prolonged times resulted in gas and soot formation, indicating esters decomposition. Through water mass balances, it was possible to identify the set of operation conditions in which the water formed from glycerol etherification matched with the maximum expected according to the proposed reaction scheme.

37-OR: SGLT2 Inhibitors Exert Anti-inflammatory and Antioxidant Effects in Epicardial Adipose Tissue of Severe Heart Failure Subjects

The exact mechanisms behind cardioprotective effects of SGLT-2 inhibitors (SGLT-2i) are still not fully elucidated. Using complex transcriptomic, metabolomic and immunochemical methods we analysed epicardial (EAT) and subcutaneous (SAT) adipose tissue of patients with severe heart failure treated with SGLT-2i in order to identify possible cardioprotective pathways. Twenty six subjects with severe heart failure with reduced ejection fraction (NYHA III-IV) treated with SGLT-2i (18 with type 2 diabetes mellitus - T2DM) and 26 age-, BMI- and left ventricular ejection fraction-matched control subjects (8 with T2DM) scheduled for heart transplantation or mechanical support implantation were included into the study. The complex analysis of EAT and SAT included liquid chromatography in combination with mass spectrometry for metabolomics, RT-qPCR for transcriptomics and flow cytometry and immunochemistry for detection of immune cells and mitochondria. Compared with controls, EAT of SGLT-2i subjects showed marked reduction in allover immune cell infiltration along with a decrease in Th1 and Th2 cells and mRNA levels of macrophage marker ADGRE1. This was not the case for SAT, where only reduced mRNA levels of inflammatory markers including IL6 and MCP1 were detected. Moreover, mitochondrial staining revealed improvement of mitochondrial morphology in EAT of SGLT-2i group accompanied by decreased oxidative stress. Finally, enhanced enrichment of ether lipids with oleic acid noted on metabolomic analysis suggests reduced disposition to ferroptosis (iron-dependent lipid peroxidation-regulated cell death) further contributing to decreased oxidative stress in EAT of SGLT-2i subjects. In conclusion, SGLT-2i treatment is associated with reduced inflammation and oxidative stress in EAT, which could at least partially explain their cardioprotective effects. Disclosure M.Mraz: None. I.Pleyerova: None. K.Rosolová: None. P.Novodvorsky: Advisory Panel; Sanofi, Boehringer-Ingelheim, Consultant; Novo Nordisk, Merck &amp; Co., Inc., Novartis, Speaker's Bureau; Novo Nordisk, Sanofi, Eli Lilly and Company, KRKA, Mundipharma, Abbott. P.Ivak: Consultant; Abbott, Other Relationship; Abbott. V.Melenovsky: None. I.Netuka: Board Member; LeviticusCardio Ltd., Consultant; Abbott, CARMAT SA, Other Relationship; Abbott, CARMAT SA, Stock/Shareholder; LeviticusCardio Ltd. M.Haluzik: Advisory Panel; Novo Nordisk, Lilly Diabetes, Boehringer-Ingelheim, Research Support; Sanofi, Speaker's Bureau; Abbott, AstraZeneca. B.Kasperova: None. S.Stemberkova: None. P.Svoboda: None. D.Hlavácek: None. J.Mahrík: None. O.Kuda: None. T.Cajka: None. L.Tomanová: None. Funding NV19-02-00118; National Institute for Research of Metabolic and Cardiovascular Diseases (EXCELES, LX22NPO5104) Funded by the European Union - Next Generation EU; Ministry of Health, Czech Republic Conceptual Development of Research Organization Institute

Polystyrene nanospheres-induced hepatotoxicity in swamp eel (Monopterus albus): From biochemical, pathological and transcriptomic perspectives

As ubiquitous emerging pollutants, microplastics (MPs) in aquatic environments have aroused critical global concerns. Despite the occurrence and characteristics of MPs in freshwater agroecosystems well-described by our previous study, their ecotoxicological implications in Monopterus albus remains unfathomed. Herein, we dissected toxic effects and mechanisms of PS-NPs exposure against M. albus hepatic tissues at concentrations of 0.5 (L), 5 (M), 10 (H) mg/L for 28 days using physiochemical measurements, histopathological analysis and transcriptomic sequencing. Results showed that upon PS-NPs treatments, levels of ROS, MDA, 8-OHdG and MFO activity were significantly enhanced relative to the control (C) group, while SP content and T-AOC activity were dramatically suppressed, suggesting ROS burst, lipid peroxidation and DNA damage may occur in liver tissues. This oxidative damage further triggered impaired hepatic function and histopathology, disordered lipid metabolism and hepatocyte apoptosis, as reflected by significantly diminished activities of GPT, GOT, ACP, AKP and LDH, paralleled with augmented levels of TG, TC and HSI as well as Cytc and Caspase-3,8,9 activities. Noticeably, concentration-dependent rises of apoptotic rate, vacuolar degeneration and lipid deposition were manifest in TUNEL, H&E and ORO staining. In addition, a total of 375/475/981 up-regulated as well as 260/611/1422 down-regulated DEGs in C vs L, C vs M and C vs H categories were identified based on RNA-seq, respectively. These DEGs were significantly annotated and enriched into GO terms (membrane, cytoplasm, response to stimuli, oxidation-reduction process) as well as KEGG pathways (ether lipid metabolism, apoptosis, chemical carcinogenesis-reactive oxygen species, non-alcoholic fatty liver disease). Moreover, signaling cascades Keap1-Nrf2, p53 and PPAR were either substantially initiated or dysregulated to orchestrate PS-NPs hepatotoxicity featuring oxidative damage, hepatocyte apoptosis and lipid steatosis. Collectively, this study not only expounded on toxicological mechanisms whereby PS-MPs exerted deleterious effects on M. albus, but also pointed to ecological risks of PS-MPs-induced hepatoxicity and lipid steatosis in this commercially-important species.

Valorizing Constituents of Cashew Nut Shell Liquid toward the Sustainable Development of New Drugs against Chagas Disease.

Six new ether phospholipid analogues encompassing constituents from cashew nut shell liquid as the lipid portion were synthesized in an effort to valorize byproducts of the cashew industry toward the generation of potent compounds against Chagas disease. Anacardic acids, cardanols, and cardols were used as the lipid portions and choline as the polar headgroup. The compounds were evaluated for their in vitro antiparasitic activity against different developmental stages of Trypanosoma cruzi. Compounds 16 and 17 were found to be the most potent against T. cruzi epimastigotes, trypomastigotes, and intracellular amastigotes exhibiting selectivity indices against the latter 32-fold and 7-fold higher than current drug benznidazole, respectively. Hence, four out of six analogues can be considered as hit-compounds toward the sustainable development of new treatments for Chagas disease, based on inexpensive agro-waste material.

Circulating ether lipids in prostate cancer.

e17009 Background: Decreased circulating levels of ether lipids (glycerophospholipids with an ether-linked fatty alcohol, e.g. plasmalogens) have been observed in obesity, diabetes and cardiovascular disease. In vitro and in vivo studies suggest that ether lipids are anti-inflammatory and protective against obesity. A recent landmark study revealed that ether lipids can kill cancer cells through ferroptosis. However, the role of ether lipids in prostate cancer has not been thoroughly investigated despite the known association of dysregulated lipid metabolism with poorer clinical outcomes. The aim of this study was to assess the relationship between the circulating profiles of ether lipids and clinical outcomes in localised and metastatic prostate cancer. Methods: The profiles of ~150 ether lipids (8 lipid classes) in plasma lipidomic data from localised prostate cancer (389 men in Australia) and metastatic castration-resistant prostate cancer (mCRPC)(2 cohorts –147 men in USA, 128 men in Australia) were analysed for associations with disease progression or overall survival (OS). Open-access genomic data of mCRPC tumours (108 men, CbioPortal) were analysed for aberrations in genes associated with ether lipid metabolism in relation to clinical outcome. Results: Previously in these study cohorts, we had identified men with poorer prognosis based on their plasma lipidome and our validated sphingolipid signature. These men with poorer prognosis have lower plasma levels of ether lipids than those with better prognosis (t-test p &lt; 0.05, localised disease – 110 ether lipids, mCRPC – 54 ether lipids). Decreased plasma levels of up to 46 ether lipid species were associated with higher rates of clinical relapse in localised disease (hazard ratio (HR) range 0.37-0.73, p-value range 0.006-0.049), shorter radiological progression-free survival in mCRPC (HR range 0.35-0.73, p-value range 0.00009-0.049), and shorter OS in mCRPC (HR range 0.33-0.79, p-value range 0.000004-0.0497). Chromosomal loss of tumour GNPAT, an essential gene in ether lipid synthesis, was associated with shorter OS in mCRPC (HR = 1.36, 95% CI 1.02-1.81, p = 0.03). Conclusions: Lower circulating levels of ether lipids were associated with worse prognosis in localised and metastatic prostate cancer, suggesting that these lipids are protective against disease progression. Further research is required to understand the role of ether lipids in disease progression, and to determine if modulation of ether lipid levels through supplementation is beneficial.

Asymmetric Synthesis of Methoxylated Ether Lipids: Total Synthesis of a Triene C18 : 3 Omega‐8 MEL Derivative

AbstractThe asymmetric synthesis of a triene C18 : 3 n‐8 methoxylated ether lipid (MEL) of the 1‐O‐alkyl‐sn‐glycerol type is described by two different routes. The C18 : 3 hydrocarbon chain is attached by an ether linkage to the pro‐S hydroxymethyl group of the glycerol backbone, and constitutes an all‐cis methylene skipped triene framework, along with a methoxyl group in the 2’‐position and R‐configuration at the resulting chiral centre. The initial synthesis was based on the polyacetylene approach involving a semi‐hydrogenation of the resulting triyne. A modified approach based on a combined polyacetylene‐Wittig strategy was also successfully executed and an attempt made to compare and evaluate these strategies. Both syntheses were started from our previously described enantio‐ and diastereomerically pure isopropylidene‐protected glyceryl glycidyl ether, a double‐C3 building block designed as a head group synthon for synthesis of various types of MELs which was shown to suit the Wittig‐based approach very well.

Plasma Lipidomics Profiles Highlight the Associations of the Dual Antioxidant/Pro-oxidant Molecules Sphingomyelin and Phosphatidylcholine with Subclinical Atherosclerosis in Patients with Type 1 Diabetes.

Here, we report on our study of plasma lipidomics profiles of patients with type 1 diabetes (T1DM) and explore potential associations. One hundred and seven patients with T1DM were consecutively recruited. Ultrasound imaging of peripheral arteries was performed using a high image resolution B-mode ultrasound system. Untargeted lipidomics analysis was performed using UHPLC coupled to qTOF/MS. The associations were evaluated using machine learning algorithms. SM(32:2) and ether lipid species (PC(O-30:1)/PC(P-30:0)) were significantly and positively associated with subclinical atherosclerosis (SA). This association was further confirmed in patients with overweight/obesity (specifically with SM(40:2)). A negative association between SA and lysophosphatidylcholine species was found among lean subjects. Phosphatidylcholines (PC(40:6) and PC(36:6)) and cholesterol esters (ChoE(20:5)) were associated positively with intima-media thickness both in subjects with and without overweight/obesity. In summary, the plasma antioxidant molecules SM and PC differed according to the presence of SA and/or overweight status in patients with T1DM. This is the first study showing the associations in T1DM, and the findings may be useful in the targeting of a personalized approach aimed at preventing cardiovascular disease in these patients.

Comprehensive Lipid Profile of Eight Echinoderm Species by RPLC-Triple TOF-MS/MS.

Echinoderms are of broad interest for abundant bioactive lipids. The comprehensive lipid profiles in eight echinoderm species were obtained by UPLC-Triple TOF-MS/MS with characterization and semi-quantitative analysis of 961 lipid molecular species in 14 subclasses of 4 classes. Phospholipids (38.78-76.83%) and glycerolipids (6.85-42.82%) were the main classes in all investigated echinoderm species, with abundant ether phospholipids, whereas the proportion of sphingolipids was higher in sea cucumbers. Two sulfated lipid subclasses were detected in echinoderms for the first time; sterol sulfate was rich in sea cucumbers, whereas sulfoquinovosyldiacylglycerol existed in the sea star and sea urchins. Furthermore, PC(18:1/24:2), PE(16:0/14:0), and TAG(50:1e) could be used as lipid markers to distinguish eight echinoderm species. In this study, the differentiation of eight echinoderms was achieved by lipidomics and revealed the uniqueness of the natural biochemical fingerprints of echinoderms. The findings will help evaluate the nutritional value in the future.

Tailoring basic and acidic properties of MgAl hydrotalcite by fluoride anions: Effect on glycerol oligomerisation

In this work, two families of catalysts based on mixed metal oxides derived from MgAl hydrotalcites were synthesized with a Mg/Al molar ratio of 3. On the one hand, in the first family, the fluoride anion was incorporated in the interlayer space by using ammonium fluoride, exploiting the “memory effect” characteristic of hydrotalcites. In the second family, fluoride anions substituted oxides anions in the layer, incorporating directly them during the precipitation of hydroxides, by using cryolite as a precursor for both fluorine and aluminium. The hydrotalcites were transformed into mixed metal oxides by thermal treatment and tested in the glycerol etherification reaction at 230 ºC, in a batch reactor at atmospheric pressure. The hydrotalcites and the corresponding mixed metal oxides were characterized by different experimental techniques, such as X-ray diffraction (XRD), elemental analysis (CHF), N2 sorption at − 196 ºC, thermogravimetric analysis (ATD-TG), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of CO2 and NH3 (CO2-TPD and NH3-DTP) and solid state nuclear magnetic resonace (ssNMR) of 19F. It was found that the mixed metal oxides prepared from hydrotalcites, where fluorine was incorporated in the synthesis step using cryolite, achieved the maximum conversion values and complete selectivity towards diglycerol. Diglycerols were the unique detected products and, in some cases, the formation of triglycerols was also detected.

Ether lipids and a peroxisomal riddle in sperm.

Sperm are terminally differentiated cells that lack most of the membranous organelles, resulting in a high abundance of ether glycerolipids found across different species. Ether lipids include plasmalogens, platelet activating factor, GPI-anchors and seminolipid. These lipids play important roles in sperm function and performance, and thus are of special interest as potential fertility markers and therapeutic targets. In the present article, we first review the existing knowledge on the relevance of the different types of ether lipids for sperm production, maturation and function. To further understand ether-lipid metabolism in sperm, we then query available proteomic data from highly purified sperm, and produce a map of metabolic steps retained in these cells. Our analysis pinpoints the presence of a truncated ether lipid biosynthetic pathway that would be competent for the production of precursors through the initial peroxisomal core steps, but devoid of subsequent microsomal enzymes responsible for the final synthesis of all complex ether-lipids. Despite the widely accepted notion that sperm lack peroxisomes, the thorough analysis of published data conducted herein identifies nearly 70% of all known peroxisomal resident proteins as part of the sperm proteome. In view of this, we highlight open questions related to lipid metabolism and possible peroxisomal functions in sperm. We propose a repurposed role for the truncated peroxisomal ether-lipid pathway in detoxification of products from oxidative stress, which is known to critically influence sperm function. The likely presence of a peroxisomal-derived remnant compartment that could act as a sink for toxic fatty alcohols and fatty aldehydes generated by mitochondrial activity is discussed. With this perspective, our review provides a comprehensive metabolic map associated with ether-lipids and peroxisomal-related functions in sperm and offers new insights into potentially relevant antioxidant mechanisms that warrant further research.

Phase behavior and structure of a biocompatible microemulsion based on Tween 20, 2-ethylhexylglycerine and isopropyl palmitate in water

Microemulsions are thermodynamically stable mixtures of water and oil. For many applications, such as in cosmetics, it is important that the components are biocompatible. For the formulation of a new biocompatible microemulsion based on Tween 20 (Tw20) surfactant, the glycerol ether 2-ethylhexylglycerin (EHG) is employed as an alternative to commonly used short- to medium chain alcohols as cosurfactant. Tw20 itself is not capable of any significant solubilization but the addition of EHG allows to enhance the solubilization capacity for the polar oil isopropyl palmitate (IPP) largely. At a Tw20 to EHG molar ratio of 1:12, i.e., very large excess of cosurfactant, the solubilization capacity is increased by nearly three orders of magnitude compared to a pure Tw20 solution. The resulting oil-in-water (O/W) microemulsion is studied using static and dynamic light scattering (SLS/DLS) and small-angle neutron scattering (SANS). The SANS spectra are analyzed with a core–shell ellipsoid model, which indicates formation of oblate droplets at higher EHG content. Dynamic light scattering experiments confirm the presence of microemulsion droplets with hydrodynamic radii increasing from 3.8 to 19.8 nm upon addition of cosurfactant. In summary, this study shows that EHG is a cosurfactant that enhances the solubilization properties of a biocompatible surfactant largely and thereby renders it very useful for formulations.