Choline and Ethanolamine Plasmalogens Prevent Lead-Induced Cytotoxicity and Lipid Oxidation in HepG2 Cells

Plasmalogens Reversed Oxidative Stress and Inflammatory Response Exacerbated by Damage to Cell Membrane Properties in Acute Liver Injury

BACKGROUND

In acute liver injury (ALI), cell membrane damage could induce an inflammatory response and oxidative stress. As a membrane glycerophospholipid, plasmalogens (PLS) are crucial in regulating the cell membrane properties and exhibit beneficial effects in various liver diseases. However, the specific regulatory effects of PLS in the ALI remain unknown.

METHODS

We utilized CCl4 to induce ALI in AML12 hepatocytes and C57BL/6J mice and examined oxidative stress indicators and inflammatory cytokine levels. Our study further validated the effect of PLS on cell membrane integrity by Lactate Dehydrogenase (LDH) release assay and Dil/Calcein assay, and molecular dynamics (MD) simulations were employed to elucidate the molecular mechanisms by which PLS affected cell membranes.

RESULTS

PLS attenuated hepatocyte damage both in vivo and in vitro. Moreover, PLS increased levels of SOD, GSH, and CAT and inhibited the production of malondialdehyde. PLS succeeded in decreasing proinflammatory cytokines (TNF-α, IL-1β, and IL-6) while increasing anti-inflammatory cytokines (IL-10). Furthermore, PLS effectively maintained the cell membrane integrity. The MD simulations well explained the molecular mechanisms: a high level of PLS modulated the cell membrane properties, enabling them to be more flexible, elastic, and less prone to rupture.

CONCLUSIONS

Our study illustrated the effect and molecular mechanisms of PLS against ALI, potentially broadening its application in liver diseases.

Phospholipid analyses of rabbit ocular surface tissues

The tissues of the integument covering the ocular surface comprise a mucus membrane functioning as a protective physical barrier and has the ability to mount a defensive inflammatory response. Since lipid metabolism has a role in both of these functions, we studied normal membrane phospholipids (PL) of the cornea and bulbar conjunctiva to (1) determine baseline PL profiles of these tissues, (2) compare and contrast these individual PL metabolite profiles as well as groups of metabolites, and (3) describe pathway-specific metabolic interrelations among these tissues. Corneal and conjunctival tissue samples were isolated from rabbit eyes (n = 30) and extracted with chloroform-methanol using a modified Folch procedure. 31P nuclear magnetic resonance spectroscopy was used to qualitatively and quantitatively measure tissue PL profiles. The cornea and conjunctiva, respectively, have the following PL composition (mole % of total detected phospholipid): phosphatidylglycerol (PG) -, 0.4; lysophosphatidylethanolamine 1.2, -; phosphatidic acid -, 0.4; diPG (cardiolipin) 2.1, 3.5; unknown PL at the chemical shift of 0.13 δ 1.5, 0.9; ethanolamine plasmalogen 11.2, 13.0; phosphatidylethanolamine 11.5, 12.8; phosphatidylserine 8.9, 10.1; sphingomyelin 10.2, 10.7; lysophosphatidylcholine 0.9, 1.4; phosphatidylinositol 5.3, 5.3; phosphatidylcholine (PC) plasmalogen or alkylacylPC 2.2, 1.9; PC 45.1, 40.0. In addition, 28 PL metabolic indices were calculated from these data, which permitted pathway-specific lipid analyses. This study (1) establishes PL profiles of the two ocular tissues of the integument that cover the surface of the eye, (2) compares and contrasts indices comprised of ratios and combinations of PL, and (3) describes pathway-specific metabolic interrelations among these tissues to serve as baselines for studies involving the distribution of tissue phospholipids.

Lipidomics Analysis Unravels Aberrant Lipid Species and Pathways Induced by Zinc Oxide Nanoparticles in Kidney Cells

Zinc oxide nanoparticles (ZnO NPs) are widely used in versatile applications, from high technology to household products. While numerous studies have examined the toxic gene profile of ZnO NPs across various tissues, the specific lipid species associated with adverse effects and potential biomarkers remain elusive. In this study, we conducted a liquid chromatography-mass spectrometry based lipidomics analysis to uncover potential lipid biomarkers in human kidney cells following treatment with ZnO NPs. Furthermore, we employed lipid pathway enrichment analysis (LIPEA) to elucidate altered lipid-related signaling pathways. Our results demonstrate that ZnO NPs induce cytotoxicity in renal epithelial cells and modulate lipid species; we identified 64 lipids with a fold change (FC) > 2 and p < 0.01 with corrected p < 0.05 in HK2 cells post-treatment with ZnO NPs. Notably, the altered lipids between control HK2 cells and those treated with ZnO NPs were associated with the sphingolipid, autophagy, and glycerophospholipid pathways. This study unveils novel potential lipid biomarkers of ZnO NP nanotoxicity, representing the first lipidomic profiling of ZnO NPs in human renal epithelial cells.

Lipidomics reveals the lipid metabolism disorders in Fructus Psoraleae-induced hepatotoxicity in rats with kidney-yin deficiency syndrome

Fructus Psoraleae (FP), one of the important traditional Chinese medicines, is widely used in clinic and has been reported to be hepatotoxic. However, there is no report on the mechanism of FP-induced hepatotoxicity based on the theory of You Gu Wu Yun. In this study, plasma samples of rats with different kidney deficiency syndromes were investigated using a lipidomics approach based on UPLC/Q-TOF-MS technique. Firstly, multivariate statistical analysis, VIP value test, statistical test and other methods were used to find the lipid metabolites in the two syndrome model groups that were different from the normal group. The screening of differential lipid metabolites revealed that there were 12 biomarkers between the blank group and the kidney-yang deficiency model group as well as 16 differential metabolites between the kidney-yin deficiency model group, and finally a total of 17 relevant endogenous metabolites were identified, which could be used as differential lipid metabolites to distinguish between kidney-yin deficiency and kidney-yang deficiency evidence. Secondly, the relative content changes of metabolites in rats after administration of FP decoction were further compared to find the substances associated with toxicity after administration, and the diagnostic ability of the identified biomarkers was evaluated using a receiver operating characteristic curve (ROC). Results a total of 14 potential differential lipid metabolites, including LysoPC(20:0/0:0) and LysoPC(16:0/0:0), which may be related to hepatotoxicity in rats with kidney-yin deficiency syndrome were further screened, namely, the potential active lipid metabolites related to hepatotoxicity in rats induced by FP. Finally, cluster analysis, MetPA analysis and KEGG database were used to analyze metabolic pathways. It was discovered that the metabolism of glycerophospholipid and sphingolipid may be strongly related to the mechanism of hepatotoxicity brought on by FP. Overall, we described the lipidomics changes in rats treated with FP decoction and screened out 14 lipid metabolites related to hepatotoxicity in rats with kidney-yin deficiency, which served as a foundation for the theory of "syndrome differentiation and treatment" in traditional Chinese medicine and a guide for further investigation into the subsequent mechanism.

Chronic inflammation, neuroglial dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

After five waves of coronavirus disease 2019 (COVID-19) outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties ("brain fog"), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions. Of great interest, recent evidence revealed a significant reduction of plasmalogen contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms. Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

Plasmalogen Profiling in Porcine Brain Tissues by LC-MS/MS

Plasmalogen, a functional glycerophospholipid, is known for its beneficial nutritional effects, such as anti-oxidation and anti-inflammation. As the porcine brain is a plasmalogen-rich resource, this study aimed to explore its potential for plasmalogen-based health food product development, with special attention on whether and how the industrial production processes influence the plasmalogen content and composition. In the present work, plasmalogens from different porcine brain products were investigated using liquid chromatography-tandem mass spectrometry. The results indicated that all the porcine brain products showed abundant total plasmalogens, of which more than 95% were ethanolamine plasmalogen species. Acetone precipitation, ethanol extraction, and drying did not significantly affect the plasmalogen content, whereas repeated freeze-thaw cycles in the production process led to noticeable loss. The chemometric investigation suggested that raw products and glycerophospholipid products exhibited different profiles; furthermore, the concentration step seemed to impact the plasmalogen composition. The nutritional assessment revealed that porcine brain products showed favorable values of multiple indexes, including PUFA/SFA ratio, n-6/n-3 ratio, thrombogenicity index, and unsaturation index, suggesting a health-beneficial value. The current study not only shows the feasibility of producing porcine brain-derived plasmalogens, but also provides possible strategies for developing and quality-controlling dietary plasmalogen supplements and healthcare products.

Effects of high-sugar, high-cholesterol, and high-fat diet on phospholipid profile of mouse tissues with a focus on the mechanism of plasmalogen synthesis

High-sugar diet (HSD), high-cholesterol diet (HCD), and high-fat diet (HFD) all modulate the levels of lipids. However, there is a lack of comparative data on the effects of different diets on phospholipids (PLs). Given their important role in physiology and disease, there has been an increasing focus on altered PLs in liver and brain disorders. This study aims to determine the effects of HSD, HCD, and HFD for 14-week feeding on the PL profile of the mouse liver and hippocampus. Quantitative analysis of 116 and 113 PL molecular species in liver and hippocampus tissues revealed that the HSD, HCD, and HFD significantly affected the PLs in liver and hippocampus, especially decreased the levels of plasmenylethanolamine (pPE) and phosphatidylethanolamine (PE). Overall, the impact of HFD on liver PLs was more significant, consistent with the morphological changes in the liver. Compared to HSD and HCD, HFD induced a significant decrease in PC (P-16:0/18:1) and an increase in LPE (18:0) and LPE (18:1) in liver. In the liver of mice fed with different diets, the expression of the key enzymes Gnpat, Agps in the pPE biosynthesis pathway and peroxisome-associated membrane proteins pex14p were decreased. In addition, all diets significantly reduced the expression of Gnpat, pex7p, and pex16p in hippocampus tissue. In conclusion, HSD, HCD, and HFD enhanced lipid accumulation in the liver, led to liver injury, significantly affected the liver and hippocampus PLs, and decreased the expression of genes related to plasmalogen synthesis in mouse liver and hippocampus, which caused severe plasmalogen reduction.

Biomolecules incorporated in halide perovskite nanocrystals: synthesis, optical properties, and applications

Halide perovskite nanocrystals (HPNCs) have emerged at the forefront of nanomaterials research over the past two decades. The physicochemical and optoelectronic properties of these inorganic semiconductor nanoparticles can be modulated through the introduction of various ligands. The use of biomolecules as ligands has been demonstrated to improve the stability, luminescence, conductivity and biocompatibility of HPNCs. The rapid advancement of this field relies on a strong understanding of how the structure and properties of biomolecules influences their interactions with HPNCs, as well as their potential to extend applications of HPNCs towards biological applications. This review addresses the role of several classes of biomolecules (amino acids, proteins, carbohydrates, nucleotides, etc.) that have shown promise for improving the performance of HPNCs and their potential applications. Specifically, we have reviewed the recent advances on incorporating biomolecules with HP nanomaterials on the formation, physicochemical properties, and stability of HP compounds. We have also shed light on the potential for using HPs in biological and environmental applications by compiling some recent of proof-of-concept demonstrations. Overall, this review aims to guide the field towards incorporating biomolecules into the next-generation of high-performance HPNCs for biological and environmental applications.

The fate, acute, and subchronic risks of dinotefuran in the water-sediment system: A systematic analysis at the enantiomer level

Environmental risks associated with neonicotinoid insecticides have attracted considerable attention. This study systematically investigated the stereoselective behavior of dinotefuran in a water-sediment system. The results showed that S-dinotefuran accumulated more easily in sediment and zebrafish. Although dinotefuran enantiomers and metabolites present a low risk to aquatic organisms, the risk of dinotefuran enantiomers to sediment organisms should be considered. Additionally, S-dinotefuran induced more remarkable oxidative damage in zebrafish than that of R-dinotefuran. Nevertheless, R-dinotefuran remarkably activated antioxidant and detoxifying enzymes. Multi-omics analyses revealed that S-dinotefuran induced more differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) in zebrafish. In particular, S-dinotefuran inhibited the expression of ribosome- and proteasome-related genes and proteins, affecting the synthesis and degradation of proteins in zebrafish. R-dinotefuran remarkably activated peroxisome-related genes and proteins, thereby enhancing antioxidant and detoxification abilities of zebrafish. The stereoselective interactions between dinotefuran enantiomers and key DEPs were elucidated using AlphaFold2 modeling and molecular docking techniques, which may serve as the main reason for stereoselective subchronic toxicity. The present study is beneficial for the correct use of dinotefuran and provides an effective means for elucidating the mechanism of the stereoselective behavior of chiral compounds.

Distinctive serum lipidomic profile of IVIG-resistant Kawasaki disease children before and after treatment

Kawasaki Disease (KD) is an acute inflammatory disorder associated with systemic vasculitis. Intravenous immunoglobulin (IVIG) is an effective therapy for KD, yet, about 20% of cases show IVIG resistance with persistent inflammation. The lipid profile in IVIG-resistant KD patients and the relationship between lipid characteristics and IVIG resistance remain unknown. In this study, serum samples from twenty KD patients with different IVIG responses (sensitive, intermediate, or resistant) were collected both before and after treatment, and lipidomic analysis was performed using high-performance liquid chromatography-mass spectrometry. As a result, before treatment, six lipid species were found as the most variant features, in which all the top decreased lipids in the IVIG-resistant group were lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE), suggesting the potential to be IVIG-resistant markers in pretreatment diagnosis. During treatment, lipidomic changes showed a weaker response in the IVIG-resistant group. After treatment, LPC and LPE species exhibited lower in the IVIG-resistant group and negative correlation with the inflammatory markers, indicating that the unique metabolism may occur among IVIG-responsiveness. These results might contribute to diagnosing IVIG-resistant patients more accurately for alternative therapy and to a better understanding of how lipid metabolism is associated with IVIG sensitiveness/resistance in KD.

Alismatis Rhizoma methanolic extract—Effects on metabolic syndrome and mechanisms of triterpenoids using a metabolomic and lipidomic approach

Alismatis rhizoma is a traditional Chinese medicine. Studies have demonstrated that Alismatis rhizoma also has therapeutic effects on metabolic syndrome. However, the pharmacodynamic material basis and mechanism are still unclear. First, UHPLC/Q-Orbitrap MS was used to detect the chemical components of the Alismatis rhizoma extract, and 31 triterpenoids and 2 sesquiterpenes were preliminarily identified. Then, to investigate the mechanism of the Alismatis rhizoma extract on metabolic syndrome, a mouse model of metabolic syndrome induced by high-fructose drinks was established. The results of serum biochemical analysis showed that the levels of TG, TC, LDL-C, and UA after the Alismatis rhizoma extract treatment were markedly decreased. ¹H-NMR was used to conduct non-targeted metabolomics studies. A total of 20 differential metabolites were associated with high-fructose–induced metabolic syndrome, which were mainly correlated with 11 metabolic pathways. Moreover, UHPLC/Q-Orbitrap MS lipidomics analysis found that a total of 53 differential lipids were screened out. The results showed that Alismatis rhizoma extract mainly reduces the synthesis of glycerophospholipid and ceramide and improves the secretion of bile acid. This study shows that the Alismatis rhizoma extract can treat metabolic syndrome mainly by inhibiting energy metabolism, amino acid metabolism, and regulating bile acid to reduce phospholipid content.

LC/MS analysis of storage-induced plasmalogen loss in ready-to-eat fish

Plasmalogens are functional and oxidation-sensitive phospholipids abundant in fish. Chilling and freezing are common storage methods for maintaining the quality of fish, but their effect on plasmalogen preservation has not been studied. Therefore, plasmalogen loss in ready-to-eat tuna meat during storage under different conditions was investigated. LC/MS was used to analyze the time- and temperature-dependent changes of plasmalogens, which was the most evident for the species with an ethanolamine headgroup and polyunsaturated fatty acyl chains. Moreover, a series of oxidized plasmalogen molecules were identified, and their storage-induced accumulation was observed. Plasmalogen loss was strongly correlated with total lipid oxidation and phospholipid degradation. Repeated freeze-thaw cycles were found to accelerate the loss of plasmalogens, whereas the different thawing methods did not. The present study provides a deeper understanding of changes in lipid nutrients from fish meat during storage and demonstrates the importance of using advanced strategies to maintain food quality.

A Pex7 Deficient Mouse Series Correlates Biochemical and Neurobehavioral Markers to Genotype Severity—Implications for the Disease Spectrum of Rhizomelic Chondrodysplasia Punctata Type 1

Rhizomelic chondrodysplasia punctata type 1 (RCDP1) is a peroxisome biogenesis disorder caused by defects in PEX7 leading to impairment in plasmalogen (Pls) biosynthesis and phytanic acid (PA) oxidation. Pls deficiency is the main pathogenic factor that determines the severity of RCDP. Severe (classic) RCDP patients have negligible Pls levels, congenital cataracts, skeletal dysplasia, growth and neurodevelopmental deficits, and cerebral hypomyelination and cerebellar atrophy on brain MRI. Individuals with milder or nonclassic RCDP have higher Pls levels, better growth and cognitive outcomes. To better understand the pathophysiology of RCDP disorders, we generated an allelic series of Pex7 mice either homozygous for the hypomorphic allele, compound heterozygous for the hypomorphic and null alleles or homozygous for the null allele. Pex7 transcript and protein were almost undetectable in the hypomorphic model, and negligible in the compound heterozygous and null mice. Pex7 deficient mice showed a graded reduction in Pls and increases in C26:0-LPC and PA in plasma and brain according to genotype. Neuropathological evaluation showed significant loss of cerebellar Purkinje cells over time and a decrease in brain myelin basic protein (MBP) content in Pex7 deficient models, with more severe effects correlating with Pex7 genotype. All Pex7 deficient mice exhibited a hyperactive behavior in the open field environment. Brain neurotransmitters analysis of Pex7 deficient mice showed a significant reduction in levels of dopamine, norepinephrine, serotonin and GABA. Also, a significant correlation was found between brain neurotransmitter levels, the hyperactivity phenotype, Pls level and the severity of Pex7 genotype. In conclusion, our study showed evidence of a genotype-phenotype correlation between the severity of Pex7 deficiency and several clinical and neurobiochemical phenotypes in RCDP1 mouse models. We propose that PA accumulation may underlie the cerebellar atrophy seen in older RCDP1 patients, as even relatively low tissue levels were strongly associated with Purkinje cells loss over time in the murine models. Also, our data demonstrate the interrelation between Pls, brain neurotransmitter deficiencies and the neurobehavioral phenotype, which could be further used as a valuable clinical endpoint for therapeutic interventions. Finally, these models show that incremental increases in Pex7 levels result in dramatic improvements in phenotype.

Lipid metabolism is dysregulated in a mouse model of diabetes

Much evidence for diabetes mellitus being associated with dysregulated lipid metabolism has been accrued from studies using blood plasma. However, the systemic dysregulation these results point to is not understood. This study used Lipid Traffic Analysis on data from a mouse model of diabetes to test the hypothesis that the systemic control of lipid metabolism differed in a model of diabetes. This provided eidence for changes in the systemic control of both triglyceride and phospholipid metabolism that were not attributable to dietary intake. This supports the conclusion that diabetes is a systemic condition associated with dysregulated lipid metabolism through several pathways.

Associations Between Serum Fatty Acids and Immunological Markers in Children Developing Islet Autoimmunity-The TRIGR Nested Case-Control Study

Aims

Altered immune functions as well as fatty acid intake and status have been associated with the development of type 1 diabetes. We aimed to study the relationship between fatty acids and immunological markers in young children with increased genetic risk for type 1 diabetes in order to define putative mechanisms related to development of islet autoimmunity.

Methods

Serum samples for fatty acid and immunological marker measurements were obtained in the Trial to Reduce IDDM in the Genetically at Risk (TRIGR) ancillary study (Divia) from children born between 2002 and 2007 in 15 countries. Case children (n = 95) were defined as having repeated positivity for at least two out of four diabetes-associated autoantibodies. For each case child, control children were selected matched for country and date of birth (n = 173). Serum fatty acids and immunological markers were measured from cord serum and at the age of 6 and 12 months. Spearman correlation coefficients were calculated between fatty acids and immunological markers.

Results

Correlations between circulating fatty acids and immunological markers were different in case children who developed islet autoimmunity than in control children already at birth continuing across the first year of life. In case children, saturated fatty acids (SFAs) showed stronger correlations with immunological markers, while in controls, polyunsaturated fatty acids (PUFAs) showed stronger correlations.

Conclusions

In cases, SFAs were associated with several immunological markers (CXCL10, IL-6, IL-9, IL-17, and CM-CSF) previously linked to the type 1 diabetes disease process. Findings indicate that fatty acids could have immunomodulatory potential in the early phase of the disease development, although causality between fatty acids and the immunological pathways remains to be explored.

Trial registry number

NCT00179777.

Plasmalogenic Lipid Analogs as Platelet-Activating Factor Antagonists: A Potential Novel Class of Anti-inflammatory Compounds

Plasmalogens and Platelet-Activating Factor (PAF) are both bioactive ether phospholipids. Whereas plasmalogens are recognized for their important antioxidant function and modulatory role in cell membrane structure and dynamics, PAF is a potent pro-inflammatory lipid mediator known to have messenger functions in cell signaling and inflammatory response. The relationship between these two types of lipids has been rarely studied in terms of their metabolic interconversion and reciprocal modulation of the pro-inflammation/anti-inflammation balance. The vinyl-ether bonded plasmalogen lipid can be the lipid sources for the precursor of the biosynthesis of ether-bonded PAF. In this opinion paper, we suggest a potential role of plasmalogenic analogs of PAF as modulators and PAF antagonists (anti-PAF). We discuss that the metabolic interconversion of these two lipid kinds may be explored towards the development of efficient preventive and relief strategies against PAF-mediated pro-inflammation. We propose that plasmalogen analogs, acting as anti-PAF, may be considered as a new class of bioactive anti-inflammatory drugs. Despite of the scarcity of available experimental data, the competition between PAF and its natural plasmalogenic analogs for binding to the PAF receptor (PAF-R) can be proposed as a mechanistic model and potential therapeutic perspective against multiple inflammatory diseases (e.g., cardiovascular and neurodegenerative disorders, diabetes, cancers, and various manifestations in coronavirus infections such as COVID-19).

Lymphatic Absorption of Microbial Plasmalogens in Rats

Plasmalogens, functional glycerophospholipids with biological roles in the human body, are associated with various diseases. Although a variety of saturated and/or unsaturated fatty acids in plasmalogens are presumed to have different functions in the human body, there are limited reports validating such functions of plasmalogens. In this study, we focused on the bacterial plasmalogen derived from Selenomonas ruminantium subsp. lactilytica (NBRC No. 103574) with different main species of hydrocarbon chains at the sn-1 position and shorter fatty acids at the sn-2 position than animal plasmalogens. Optimum culture conditions of S. ruminantium for high-yield production of plasmalogens, such as pH and the concentration of caproic acid, were investigated under anaerobic conditions using a 2-L scale jar fermenter. The obtained plasmalogen mainly consisted of the ethanolamine plasmalogen (PlsEtn). The molar ratios of PlsEtn species obtained from S. ruminantium, at sn-1/sn-2 positions, were p16:1/14:0 (68.4%), p16:1/16:1 (29.2%), p16:1/16:0 (0.7%), p16:1/15:0 (0.3%), and p17:1/14:0 (0.3%). Subsequently, duodenal infusion of the emulsion carrying the lipid extracted from S. ruminantium was carried out in lymph duct-cannulated rats. In the lymphatic plasmalogen of rats, the level of PlsEtns with molar ratios p16:1/14:0 and p16:1/16:1, the main species of plasmalogens from S. ruminantium, increased gradually until 3–4 h after lipid injection and then gradually decreased. In addition, the level of PlsEtns with p16:1/20:4 and p16:1/22:6 rapidly increased, peaking at 1–1.5 h and 1.5–2 h after lipid injection, respectively. The increase in the number of PlsEtns with p16:1/20:4 and p16:1/22:6 suggested that 20:4 and 22:6, the main fatty acids at the sn-2 position in the rat lymphatic plasmalogen, were preferentially re-esterified at the sn-2 position, regardless of the types of hydrocarbon chains at the sn-1 position. Thus, we showed that bacterial PlsEtns with “unnatural” structures against rats could be absorbed into the lymph. Our findings provide insights into the association between the chemical structure of plasmalogens and their biological functions in humans.

Lipidomics Indicates the Hepatotoxicity Effects of EtOAc Extract of Rhizoma Paridis

Rhizoma Paridis is a traditional Chinese medicine commonly used in the clinical treatment of gynecological diseases. Previous studies have shown that aqueous extracts of Rhizoma Paridis exhibit some hepatotoxicity to hepatocytes. Here, using lipidomics analysis, we investigated the potential hepatotoxicity of Rhizoma Paridis and its possible mechanism. The hepatic damaging of different solvent extracts of Rhizoma Paridis on zebrafish larvae were determined by a combination of mortality dose, biochemical, morphological, and functional tests. We found that ethyl acetate extracts (AcOEtE) were the most toxic fraction. Notably, lipidomic responsible for the pharmacological effects of AcOEtE were investigated by Q-Exactive HF-X mass spectrometer (Thermo Scientific high-resolution) coupled in tandem with a UHPLC system. Approximately 1958 unique spectral features were detected, of which 325 were identified as unique lipid species. Among these lipid species, phosphatidylethanolamine cardiolipin Ceramide (Cer), lysophosphatidylinositol sphingosine (Sph), etc., were significantly upregulated in the treated group. Pathway analysis indicates that Rhizoma Paridis may cause liver damage via interfering with the glycerophospholipid metabolism. Collectively, this study has revealed previously uncharacterized lipid metabolic disorder involving lipid synthesis, metabolism, and transport that functionally determines hepatic fibrosis procession.

Effects of chronic HBV infection on lipid metabolism in non-alcoholic fatty liver disease: A lipidomic analysis

INTRODUCTION AND OBJECTIVES

Chronic hepatitis B virus (HBV) infection exerts an impact on lipid metabolism, but its interaction with dysmetabolism-based non-alcoholic fatty liver disease (NAFLD) remains uncertain. The purpose of the study was to investigate the effects of HBV infection on lipid metabolism, hepatic steatosis and related impairments of NAFLD patients.

METHODS

Biopsy-proven Chinese NAFLD patients with (NAFLD-HBV group, n = 21) or without chronic HBV infection (NAFLD group, n = 41) were enrolled in the case-control study. Their serum lipidomics was subjected to individual investigation by ultra-performance liquid chromatography-tandem mass spectrometry. Steatosis, activity, and fibrosis (SAF) scoring revealed the NAFLD-specific pathological characteristics.

RESULTS

Chronic HBV infection was associated with global alteration of serum lipidomics in NAFLD patients. Upregulation of phosphatidylcholine (PCs), choline plasmalogen (PC-Os) and downregulation of free fatty acids (FFAs), lysophosphatidylcholine (LPCs) dominated the HBV-related lipidomic characteristics. Compared to those of NAFLD group, the levels of serum hepatoxic lipids (FFA16:0, FFA16: 1, FFA18:1, FFA18:2) were significantly lowered in the NAFLD-HBV group. These low-level FFAs demonstrated correlation to statistical improvements in aspartate aminotransferase activity (FFA16:0, r = 0.33; FFA16:1, r = 0.37; FFA18:1, r = 0.32; FFA18:2, r = 0.42), hepatocyte steatosis (FFA16: 1, r = 0.39; FFA18:1, r = 0.39; FFA18:2, r = 0.32), and ballooning (FFA16:0, r = 0.30; FFA16:1, r = 0.45; FFA18:1, r = 0.36; FFA18:2, r = 0.30) (all P < 0.05).

CONCLUSION

Chronic HBV infection may impact on the serum lipidomics and steatosis-related pathological characteristics of NAFLD.

Aged Pericarpium Citri Reticulatae 'Chachi' Attenuates Oxidative Damage Induced by tert-Butyl Hydroperoxide (t-BHP) in HepG2 Cells

This study investigated the protective effects of aged Pericarpium Citri Reticulatae 'Chachi' (PCR-C) on tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in HepG2 cells. According to HPLC analysis, PCR-C aged 10 years (PCR-C10) had the highest flavonoids content, especially polymethoxyflavones (PMFs), compared with the fresh peel of Citrus reticulata cv. 'Chachiensis' and PCR-C aged 1, 3, and 5 years. Then, flavonoids-rich PCR-C samples and non-flavonoids-rich PCR-C samples (NF) were prepared by extracting and purifying PCR-C of different aging periods, for further cell experiments. Pretreatment with flavonoids-rich PCR-C samples (particularly PCR-C10) considerably reversed t-BHP-induced oxidative damage in HepG2 cells by improving cell viability, increasing SOD activity and GSH levels and reducing the overproduction of ROS and MDA. Correlation analysis further indicated that the accumulation of PMFs, mainly 5,6,7,4'-tetramethoxyflavone and nobiletin, was the main reason that PCR-C10 maintained the redox balance in HepG2 cells. These findings provided direct evidence for the cellular antioxidant activity of aged PCR-C and a guide for PCR-C's classification, authentication and rational use.

Acute hepatotoxicity and nephrotoxicity risk assessment of the Tibetan medicine 25 flavors of the turquoise pill based on 1H-NMR metabonomics

ETHNOPHARMACOLOGICAL RELEVANCE

25 flavors of the turquoise pill, a traditional Tibetan medicine for the treatment of various types of hepatitis, has not been investigated on its safety, especially the component mineral turquoise, which is believed to be essential but worried for its potential toxicity.

AIM OF THE STUDY

To explore the potential acute toxicity and function of 25 flavors of the turquoise pill and turquoise, the possible mechanism of the effects of turquoise and 25 flavors of the turquoise pill were systematically studied based on 1H NMR metabolomics.

MATERIALS AND METHODS

The rats were administered with turquoise and 25 flavors of the turquoise pill by gavage for 7 days, and samples of serum, liver, and kidney were collected. The potential toxicity and function of turquoise and 25 flavors of the turquoise pill on the liver and kidney of SD rats were evaluated by 1H NMR metabonomics, histopathology, and biochemical indexes.

RESULTS

The results demonstrated that 25 flavors of the turquoise pill could scavenge free oxygen radicals, strengthen aerobic respiration and inhibit glycolysis in the liver. It did not cause oxidative stress in the kidney with no obvious damage. By modulation of branched-chain amino acids (BCAAs), 25 flavors of the turquoise pill can improve the utilization of glucose and promote aerobic respiration of the kidney.

CONCLUSION

Considering the high dosage and short duration used in this study relative to their typical clinical usage, administration of 25 flavors of the turquoise pill and its component mineral turquoise are safe to livers and kidneys.

Oxidative Stress Linked Organ Lipid Hydroperoxidation and Dysregulation in Mouse Model of Nonalcoholic Steatohepatitis: Revealed by Lipidomic Profiling of Liver and Kidney

Nonalcoholic steatohepatitis (NASH) is a prevalent disease related to lipid metabolism disorder and oxidative stress. Lipid hydroperoxidation is known to be a critical driving force of various disorders and diseases. However, the combination of both intact and hydroperoxidized lipids in NASH has not yet been studied. In this work, the liver and kidney samples from NASH-model mice were comprehensively investigated by using the LC/MS-based lipidomic analysis. As a result, triglycerides showed the amount accumulation and the profile alteration for the intact lipids in the NASH group, while phosphatidylethanolamines, lysophosphatidylethanolamines, plasmalogens, and cardiolipins largely depleted, suggesting biomembrane damage and mitochondria dysfunction. Notably, the lipid hydroperoxide species of triglyceride and phosphatidylcholine exhibited a significant elevation in both the liver and the kidney of the NASH group and showed considerable diagnostic ability. Furthermore, the relationship was revealed between the lipid metabolism disturbance and the lipid hydroperoxide accumulation, which played a key role in the vicious circle of NASH. The present study suggested that the omics approach to the lipid hydroperoxide profile might be the potential diagnostic marker of NASH and other oxidative stress-related diseases, as well as the evaluative treatment index of antioxidants.

Lipids: biomarkers of healthy aging

Life expectancy, and longevity have been increasing in recent years. However, this is, in most cases, accompanied by age-related diseases. Thus, it became essential to better understand the mechanisms inherent to aging, and to establish biomarkers that characterize this physiological process. Among all biomolecules, lipids appear to be a good target for the study of these biomarkers. In fact, some lipids have already been associated with age-related diseases. With the development of analytical techniques such as Mass Spectrometry, and Nuclear Magnetic Resonance, Lipidomics has been increasingly used to study pathological, and physiological states of an organism. Thus, the study of serum, and plasma lipidome in centenarians, and elderly individuals without age-related diseases can be a useful tool for the identification of aging biomarkers, and to understand physiological aging, and longevity. This review focus on the importance of lipids as biomarkers of aging, and summarize the changes in the lipidome that have been associated with aging, and longevity.

Metabolomic Markers of Southern Dietary Patterns in the Jackson Heart Study

SCOPE

New biomarkers are needed that are representative of dietary intake.

METHODS AND RESULTS

We assess metabolites associated with Southern dietary patterns in 1401 Jackson Heart Study participants. Three dietary patterns are empirically derived using principal component analysis: meat and fast food, fish and vegetables, and starchy foods. We randomly select two subsets of the study population: two-third sample for discovery (n = 934) and one-third sample for replication (n = 467). Among the 327 metabolites analyzed, 14 are significantly associated with the meat and fast food dietary pattern, four are significantly associated with the fish and vegetables dietary pattern, and none are associated with the starchy foods dietary pattern in the discovery sample. In the replication sample, nine remain associated with the meat and fast food dietary pattern [indole-3-propanoic acid, C24:0 lysophosphatidylcholine (LPC), N-methyl proline, proline betaine, C34:2 phosphatidylethanolamine (PE) plasmalogen, C36:5 PE plasmalogen, C38:5 PE plasmalogen, cotinine, hydroxyproline] and three remain associated with the fish and vegetables dietary pattern [1,7-dimethyluric acid, C22:6 lysophosphatidylethanolamine, docosahexaenoic acid (DHA)].

CONCLUSION

Twelve metabolites are discovered and replicated in association with dietary patterns detected in a Southern U.S. African-American population, which could be useful as biomarkers of Southern dietary patterns.

Absorption Kinetics of Ethanolamine Plasmalogen and Its Hydrolysate in Mice

Ethanolamine plasmalogen (PlsEtn), a subclass of ethanolamine glycerophospholipid (EtnGpl), has been reported to have many biological and dietary functions. In terms of PlsEtn absorption, some studies have reported that PlsEtn is re-esterized at the sn-2 position using lymph cannulation and the everted jejunal sac model. In this study, we aimed to better understand the uptake kinetics of PlsEtn and increase its absorption. We thus compared the uptake kinetics of PlsEtn with that of the lyso-form, in which the fatty acid at the sn-2 position was hydrolyzed enzymatically. Upon administration of EtnGpl (extracted from oysters or ascidians, 75.4 mol% and 88.4 mol% of PlsEtn ratio, respectively), the plasma PlsEtn species in mice showed the highest levels at 4 or 8 hours after administration. In the contrast, administration of the EtnGpl hydrolysate, which contained lysoEtnGpl and free fatty acids, markedly increased the plasma levels of PlsEtn species at 2 h after administration. The area under the plasma concentration-time curve (AUC), especially the AUC0-4 h of PlsEtn species, was higher with hydrolysate administration than that with EtnGpl administration. These results indicate that EtnGpl hydrolysis accelerated the absorption and metabolism of PlsEtn. Consequently, using a different experimental approach from that used in previous studies, we reconfirmed that PlsEtn species were absorbed via hydrolysis at the sn-2 position, suggesting that hydrolysis in advance could increase PlsEtn uptake.

Quantitative and Comparative Investigation of Plasmalogen Species in Daily Foodstuffs

Plasmalogens are an animal-derived functional phospholipid increasingly known as a safe and effective nutritional ingredient, however, the quantitation and comparison of plasmalogen species in foods is limited. In the present work, determination methods for dietary plasmalogens using liquid chromatography-tandem mass spectroscopy under positive and negative ionization modes were compared. The negative-mode method, which showed better selectivity, sensitivity, and accuracy, was then applied in 14 kinds of livestock, poultry, and seafood samples. Livestock and poultry showed abundant total plasmalogen (530.83-944.94 nmol/g), higher than fish (46.08-399.75 nmol/g) and mollusk (10.00-384.76 nmol/g). While fish and mollusk samples expressed healthier fatty acyl composition, with higher eicosapentaenoyl and more beneficial n-6/n-3 ratio than the land animal meats, especially for squid and octopus, with eicosapentaenoyl of 98.4% and 94.5%, respectively. The correlations among plasmalogen species varied in different foodstuffs with distinguishing patterns, suggesting the customizable strategies for achieving targeted plasmalogen species. These findings not only provided fundamental comparison of plasmalogen among daily foodstuffs, but also contributed to extend the dietary plasmalogen sources for health food development.

Lipidomics Analysis Indicates Disturbed Hepatocellular Lipid Metabolism in Reynoutria multiflora-Induced Idiosyncratic Liver Injury

The root of Reynoutria multiflora (Thunb.) Moldenke (syn.: Polygonum multiflorum Thunb., HSW) is a distinguished herb that has been popularly used in traditional Chinese medicine (TCM). Evidence of its potential side effect on liver injury has accumulated and received much attention. The objective of this study was to profile the metabolic characteristics of lipids in injured liver of rats induced by HSW and to find out potential lipid biomarkers of toxic consequence. A lipopolysaccharide (LPS)-induced rat model of idiosyncratic drug-induced liver injury (IDILI) was constructed and evident liver injury caused by HSW was confirmed based on the combination of biochemical, morphological, and functional tests. A lipidomics method was developed for the first time to investigate the alteration of lipid metabolism in HSW-induced IDILI rat liver by using ultra-high-performance liquid chromatography/Q-exactive Orbitrap mass spectrometry coupled with multivariate analysis. A total of 202 characterized lipids, including phosphatidylcholine (PC), lysophosphatidylcholine (LPC), phosphatidylethanolamine (PE), lysophosphatidylethanolamine (LPE), sphingomyelin (SM), phosphatidylinositol (PI), lysophosphatidylinositol (LPI), phosphatidylserine (PS), phosphoglycerols (PG), and ceramide (Cer), were compared among groups of LPS and LPS + HSW. A total of 14 out 26 LPC, 22 out of 47 PC, 19 out of 29 LPE, 16 out of 36 PE, and 10 out of 15 PI species were increased in HSW-treated rat liver, which indicated that HSW may cause liver damage via interfering the phospholipid metabolism. The present work may assist lipid biomarker development of HSW-induced DILI and it also provide new insights into the relationships between phospholipid perturbation and herbal-induced idiosyncratic DILI.

Monodisperse microsphere-based immobilized metal affinity chromatography approach for preparing Antarctic krill phospholipids followed by HILIC-MS analysis

Phospholipids enriched krill is a functional food beneficial in cardiovascular diseases. Herein, monodisperse microsphere-based immobilized metal affinity chromatographic material (MM-IMAC) was synthesized with Ti⁴⁺ incorporated to enrich phospholipids from krill by coordination with phosphate group. The extract was profiled by hydrophilic interaction chromatography-mass spectrometry (HILIC-MS) with 154 phospholipid molecular species detected. The parameters were loading solvent n-hexane/isopropanol (2:8, v/v), flow rate 0.8 mL·min^-1, and eluting volume 1 mL. Besides, eicosapentaenoic and docosahexaenoic acids structured phospholipids were located, such as phosphatidylcholine (PC) 20:5/22:6, phosphatidylinositol (PI) 18:0/20:5, etc. Finally, this method was validated in linearity (R² ≥ 0.9953), sensitivity (LOD ≤ 0.53 μg·mL^-1 and LOQ ≤ 1.66 μg·mL^-1), precision (RSD_intraday ≤ 4.86% and RSD_interday ≤ 6.25%), and recovery (58-83%). It indicated that the MM-Ti⁴⁺-IMAC-HILIC-MS was reliable and efficient in specific study of phospholipids in food matrix.

Comprehensive lipidomic profiling in serum and multiple tissues from a mouse model of diabetes

INTRODUCTION

Diabetes mellitus is a serious metabolic disorder causing multiple organ damage in human. However, the lipidomic profiles in different organs and their associations are rarely studied in either diabetic patients or animals.

OBJECTIVES

To evaluate and compare the characteristics of lipid species in serum and multiple tissues in a diabetic mouse model.

METHODS

Semi-quantitative profiling analyses of intact and oxidized lipids were performed in serum and multiple tissues from a diabetic mouse model fed a high fat diet and treated with streptozotocin by using LC/HRMS and MS/MS. The total content of each lipid class, and the tissue-specific lipid species in all tissue samples were determined and compared by multivariate analyses.

RESULTS

The diabetic mouse model displayed characteristic differences in serum and multiple organs: the brain and heart showed the largest reduction in cardiolipin, while the kidney had more alterations in triacylglycerol. Interestingly, the lipidomic differences also existed between different regions of the same organ: cardiolipin species with highly polyunsaturated fatty acyls decreased only in atrium but not in ventricle, while renal cortex showed longer fatty acyl chains for both increased and decreased triacylglycerol species than renal medulla. Importantly, diabetes caused an accumulation of lipid hydroperoxides, suggesting that oxidative stress was induced in all organs except for the brain during the development of diabetes.

CONCLUSIONS

These findings provided novel insight into the organ-specific relationship between diabetes and lipid metabolism, which might be useful for evaluating not only diabetic tissue injury but also the effectiveness of diabetic treatments.

Lead exposure and its interactions with oxidative stress polymorphisms on lung function impairment: Results from a longitudinal population-based study

Exposure to lead (Pb) and cadmium (Cd) were related to lung function impairment, and this association may be modified by genetic variants in oxidative stress response. Here we enrolled 1243 coke-oven workers in a prospective cohort who were followed up from 2010 to 2014, assessed the associations of Pb and Cd exposure with 4-year lung function impairment, and further explored the interaction effects of Pb with 2664 single nucleotide polymorphisms (SNPs) in 345 oxidative stress related genes. Urinary levels of Pb, Cd, and two oxidative stress biomarkers [8-iso-prostaglandin F2α (8-iso-PGF2α) for lipid peroxidation and 8-hydroxy-2'-deoxyguanosine (8-OHdG) for oxidative DNA damage] were measured at baseline only and their lung function levels were measured both at baseline and at the end of follow-up. Each 10-fold increase in urinary Pb was associated with -159 (95%CI: -254, -64.2) mL and -3.63% (95%CI: -6.48%, -0.78%) changes in FEV₁ and percent predicted FEV₁ (ppFEV₁), respectively. But none significant associations were observed for Cd. NQO1 rs2917670 showed significant interaction with Pb on elevated FEV₁ decline after multiple comparison (P_int=1.54 × 10^-5). In addition, urinary Pb increased with 8-iso-PGF2α and the rs2917670-C could significantly decrease NQO1 expression in normal lung tissues. These findings suggested the gene-environmental interaction of NQO1 rs2917670 and Pb exposure on the reduction of FEV₁. The effect of Pb exposure on elevated oxidative stress and the decreased expression of antioxidant enzyme NQO1 caused by rs2917670-C allele may partly explain the underlying biological mechanism.

Metabolic signatures associated with Western and Prudent dietary patterns in women

BACKGROUND

The Western dietary pattern (WD) is positively associated with risk of coronary artery disease (CAD) and cancer, whereas the Prudent dietary pattern (PD) may be protective. Foods may influence metabolite concentrations as well as oxidative stress and lipid dysregulation, biological mechanisms associated with CAD and cancer.

OBJECTIVE

The aim was to assess the association of 2 derived dietary pattern scores with serum metabolites and identify metabolic pathways associated with the metabolites.

METHODS

We evaluated the cross-sectional association between each dietary pattern (WD, PD) and metabolites in 2199 Women's Health Initiative (WHI) participants. With FFQ and factor analysis, we determined 2 dietary patterns consistent with WD and PD. Metabolites were measured with LC-tandem MS. Metabolite discovery among 904 WHI Observational Study (WHI-OS) participants was replicated among 1295 WHI Hormone Therapy Trial (WHI-HT) participants. We analyzed each of 495 metabolites with each dietary score (WD, PD) in linear regression models.

RESULTS

The PD included higher vegetables and fruit intake compared with the WD with higher saturated fat and meat intake. Independent of energy intake, BMI, physical activity, and other confounding variables, 45 overlapping metabolites were identified (WHI-OS) and replicated (WHI-HT) with an opposite direction of associations for the WD compared with the PD [false discovery rate (FDR) P < 0.05]. In metabolite set enrichment analyses, phosphatidylethanolamine (PE) plasmalogens were positively enriched for association with WD [normalized enrichment score (NES) = 2.01, P = 0.001, FDR P = 0.005], and cholesteryl esters (NES = -1.77, P = 0.005, FDR P = 0.02), and phosphatidylcholines (NES = -1.72, P = 0.01, P = 0.03) were negatively enriched for WD. PE plasmalogens were positively correlated with saturated fat and red meat. Phosphatidylcholines and cholesteryl esters were positively correlated with fatty fish.

CONCLUSIONS

Distinct metabolite signatures associated with Western and Prudent dietary patterns highlight the positive association of mitochondrial oxidative stress and lipid dysregulation with a WD and the inverse association with a PD.

Quantitative and comparative study of plasmalogen molecular species in six edible shellfishes by hydrophilic interaction chromatography mass spectrometry

Shellfishes contain plasmalogens correlating to the functions of brain, heart, etc. Herein, a mild acid hydrolysis and hydrophilic interaction chromatography (HILIC) tandem mass spectrometry method was developed for analyzing plasmalogens in six shellfish species. A total of 19 plasmalogen molecular species were successfully identified, including nine phosphatidylcholine plasmalogen (plasPC), seven phosphatidylethanolamine plasmalogen (plasPE), and three phosphatidylserine plasmalogen (plasPS). The quantitative results indicated that mussel (32 μg·mg^-1) possessed the highest content of plasmalogens, followed by oyster (21 μg·mg^-1) and razor clam (15 μg·mg^-1). The statistic models showed that the plasPE P-18:0/20:5 (m/z 748), plasPE P-16:0/22:2 & P-18:0/20:2 (m/z 754) and plasPS were the most contributing difference between shellfishes. The results indicated that this method was sensitive and precise to determine plasmalogens in shellfish, and mussel was demonstrated to be a good choice for the large-scale preparation of plasmalogens.

Tumor Resection Induces Alterations on Serum Phospholipidome of Liver Cancer Patients

Hepatocellular carcinoma and cholangiocarcinoma are the most common primary malignant liver tumors. Since the liver plays a key role in lipid metabolism, the study of serum phospholipid (PL) profiles may provide a better understanding of alterations in hepatic lipid metabolism. In this study, we used a high-resolution HILIC-LC-MS lipidomic approach to establish the serum phospholipidome profile of patients with liver cancer before (T0) and after tumor resection (T1) and a control group (CT) of healthy individuals. After the analysis of PL profiles, we observed that the phospholipidome of patients with liver cancer was significantly modified after the tumor resection procedure. We observed an upregulation of some phosphatidylcholine (PtdCho) species, namely, PtdCho(36:6), PtdCho(42:6), PtdCho(38:5), PtdCho(36:5), PtdCho(38:6) and choline plasmalogens (PlsCho), and/or 1-O-alkyl-2-acyl-glycerophosphocholine (PakCho) in patients with liver cancer at T0 compared to the CT group, and a downregulation after tumor resection (T1) when compared to T0. These results show that LC-MS can detect different serum PL profiles in patients with liver cancer, before and after tumor resection, by defining a specific PL fingerprint that was used to determine the effect of tumor and tumor resection on lipid metabolism.

Lipidomic profiling of dairy cattle oocytes by high performance liquid chromatography-high resolution tandem mass spectrometry for developmental competence markers

A comparative lipidomic profiling analysis of dairy cattle oocytes with different developmental competences was performed using a combination of high performance liquid chromatography-high resolution tandem mass spectrometry and multivariate statistical analysis. Significant lipidomic changes were identified in degenerating oocytes. Total triacylglycerol in the degenerating oocytes was 1.8-fold higher than that in the normal oocytes; however, total cardiolipin was 53.5% lesser than that in the normal oocytes, which indicated attenuation of energy metabolism. Compared to those in the normal oocytes, triacylglycerols in the degenerating oocytes were composed of longer and more unsaturated acyl chains. In contrast, the acyl chains in free fatty acids present in the degenerating oocytes were shorter and with lesser degree of unsaturation compared to those in the normal oocytes. Moreover, a significant decrease in degenerating oocytes were found in total phosphatidylinositol (14.8 ± 7.6 pmol vs. 24.8 ± 5.5 pmol), total phosphatidylcholine (20.8 ± 8.7 pmol vs. 33.5 ± 7.2 pmol), and total plasmalogen ethanolamine (9.0 ± 4.7 pmol vs. 16.8 ± 5.2 pmol), which indicated dysfunction of lipid-metabolizing enzymes in oocytes during degeneration. Thus, increase of triacylglycerols together with the decrease of certain phospholipid species could be potential markers of oocyte developmental competence. In addition to providing a new approach to investigate the lipidomic changes in oocyte development, the lipidomic profiling in the present study has revealed insights that hold potential to unravel the role of lipid metabolism in oocyte developmental competence in cattle.