Integrating lipidomics and gut microbiota to study the anti-hyperlipidemia effect of Sargentodoxae Caulis extract

Background:Sargentodoxae Caulis(SC)is the vine stem of Sargentodoxa Cuneata(Oliv.)Rehd.&E.H.Wilson in C.S.Sargent,and it in traditional Chinese medicine has been known for promoting blood circulation and removing blood stasis as recorded in the ancient book“Illustrated Classics of Materia Medica”.It has been used effectively to treat blood stasis too in modern clinical practice.However,the anti-hyperlipidemia effect of SC is not fully understood.This paper aims at exploring the use of SC stems to improve the balance of blood lipids in the body,and its new role in treating hyperlipidemia.Methods:The effects of SC extract on hyperlipidemia were explored by combining lipidomics and gut microbiota.Secondly,we explored the potential mechanism of SC in treating hyperlipidemia by pathway analysis.Results:The results showed that the stem extract of SC could restore the physiological and biochemical indices of hyperlipidemia in mice,as well as repair the morphological and structural damage to tissues.Compared to the Model group,the SC extract significantly reduced the liver index,epididymal fat index,and Lee’s index.It also significantly decreased serum levels of total cholesterol,triglycerides,low-density lipoprotein cholesterol,peroxisome proliferator-activated receptor gamma(PPAR-γ),D-lactate,and free fatty acids,while significantly increasing the relative content of peroxisome proliferator-activated receptor alpha(PPAR-α).These changes were statistically significant.Non-targeted lipidomics,based on LC-MS,were utilized to investigate the lipid metabolism characteristics in serum,liver,and epididymal fat of the subjects.It was observed that,compared to the blank group,the Model group exhibited significant changes primarily in glycerol lipids and glycerophospholipids.The treatment group also displayed alterations in these lipids.A total of 38,81,and 27 differential lipids were identified in serum,liver,and epididymal fat samples,respectively.Among these,14 common differential lipids were found in both serum and liver samples,and their KEGG enrichment pathways were largely consistent.Among them,the sphingolipid signaling pathway and the glycerophospholipid metabolic pathway were identified as key metabolic pathways that were regulated.Our gut microbiota analysis revealed that SC diminishes the abundance of Actinobacteria by altering the cecal flora in mice.Conclusion:This alteration leads to the downregulation of genes involved in triglyceride metabolism,which in turn changes lipid processing and reduces triglyceride levels.Consequently,SC effectively combats hyperlipidemia.Notably,SC impacts key metabolic pathways,including the sphingolipid signaling and glycerophospholipid metabolism.These findings underscore SC’s therapeutic potential,positioning it as a promising alternative for reducing the health risks associated with hyperlipidemia.

Eight Zhes Decoction ameliorates the lipid dysfunction of nonalcoholic fatty liver disease using integrated lipidomics, network pharmacology and pharmacokinetics

Nonalcoholic fatty liver disease(NAFLD)has developed into the most common chronic liver disease and can lead to liver cancer.Our laboratory previously developed a novel prescription for NAFLD,“Eight Zhes Decoction”(EZD),which has shown good curative effects in clinical practice.However,the pharmacodynamic material basis and mechanism have not yet been revealed.A strategy integrating lipidomics,network pharmacology and pharmacokinetics was used to reveal the active components and mechanisms of EZD against NAFLD.The histopathological results showed that EZD attenuated the degrees of collagen deposition and steatosis in the livers of nonalcoholic steatofibrosis model mice.Furthermore,glycerophospholipid metabolism,arachidonic acid metabolism,glycerolipid metabolism and linoleic acid metabolism with phospholipase A2 group IVA(PLA2G4A)and cytochrome P450 as the core targets and 12,13-cis-epoxyoctadecenoic acid,12(S)-hydroxyeicosatetraenoic acid,leukotriene B4,prostaglandin E2,phosphatidylcholines(PCs)and triacylglycerols(TGs)as the main lipids were found to be involved in the treatment of NAFLD by EZD.Importantly,naringenin,artemetin,canadine,and bicuculline were identified as the active ingredients of EZD against NAFLD;in particular,naringenin reduces PC consumption by inhibiting the expression of PLA2G4A and thus promotes sufficient synthesis of very-low-density lipoprotein to transport excess TGs in the liver.This research provides valuable data and theoretical support for the application of EZD against NAFLD.

Comprehensive lipidomics and volatile compounds profiling reveals correlation of lipids and flavors in DHA-enriched egg yolk

DHA-enriched eggs have gained popularity due to their unique nutritional value,but their flavor can be challenging for some consumers to accept.The study analyzed the correlation of lipids and flavors in DHA-enriched egg yolks using comprehensive lipidomics and volatile compound analysis.The results showed that 411 lipids were detected in two egg yolk samples.Among them,148 lipid species,including 48 DHA-containing lipids,were significantly higher in DHA-enriched egg yolks than in Common ones(P<0.05).Furthermore,of the 24 volatile compounds detected,the contents of benzaldehyde,heptanal,hexanal,decanal and 2-nonanone in DHA-enriched egg yolks were significantly higher than in Common egg yolks(P<0.05).The“fishy”smell characteristic of DHAenriched egg yolks was mainly caused by volatile aldehydes,which may be produced through the hydrolysis of lipids in the egg yolk to free fatty acids and further oxidation.Analysis of the correlation network diagram revealed that phospholipids containing docosahexaenoic acid(DHA),linoleic acid,or oleic acid chains were the main contributors to the characteristic flavor of DHA-enriched egg yolks.Overall,this study explored the effect of different lipids on the flavor of DHA-enriched egg yolks and provided a theoretical basis for the production and improvement of DHA-enriched eggs.

Lipidomics reveals carnitine palmitoyltransferase 1C protects cancer cells from lipotoxicity and senescence

Lipotoxicity, caused by intracellular lipid accumulation, accelerates the degenerative process of cellular senescence, which has implications in cancer development and therapy. Previously, carnitine palmitoyltransferase 1C(CPT1C), a mitochondrial enzyme that catalyzes carnitinylation of fatty acids, was found to be a critical regulator of cancer cell senescence. However, whether loss of CPT1C could induce senescence as a result of lipotoxicity remains unknown. An LC/MS-based lipidomic analysis of PANC-1,MDA-MB-231, HCT-116 and A549 cancer cells was conducted after siRNA depletion of CPT1C. Cellular lipotoxicity was further confirmed by lipotoxicity assays. Significant changes were found in the lipidome of CPT1C-depleted cells, including major alterations in fatty acid, diacylglycerol, triacylglycerol, oxidative lipids, cardiolipin, phosphatidylglycerol, phosphatidylcholine/phosphatidylethanolamine ratio and sphingomyelin. This was coincident with changes in expressions of mRNAs involved in lipogenesis.Histological and biochemical analyses revealed higher lipid accumulation and increased malondialdehyde and reactive oxygen species, signatures of lipid peroxidation and oxidative stress. Reduction of ATP synthesis, loss of mitochondrial transmembrane potential and down-regulation of expression of mitochondriogenesis gene m RNAs indicated mitochondrial dysfunction induced by lipotoxicity, which could further result in cellular senescence. Taken together, this study demonstrated CPT1C plays a critical role in the regulation of cancer cell lipotoxicity and cell senescence, suggesting that inhibition of CPT1C may serve as a new therapeutic strategy through induction of tumor lipotoxicity and senescence.

Lipidomics in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD),the most common chronic liver disorder in Western countries,comprises steatosis to nonalcoholic steatohepatitis(NASH),with the latter having the potential to progress to cirrhosis.The transition from isolated steatosis to NASH is still poorly understood,but lipidomics approach revealed that the hepatic lipidome is extensively altered in the setting of steatosis and steatohepatitis and these alterations correlate with disease progression.Recent data suggest that both quantity and quality of the accumulated lipids are involved in pathogenesis of NAFLD.Changes in glycerophospholipid,sphingolipid,and fatty acid composition have been described in both liver biopsies and plasma of patients with NAFLD,implicating that specific lipid species are involved in oxidative stress,inflammation,and cell death.In this article,we summarize the findings of main human lipidomics studies in NAFLD and delineate the currently available information on the pathogenetic role of each lipid class in lipotoxicity and disease progression.

Advances in paediatric nonalcoholic fatty liver disease:Role of lipidomics

Due its close relationship with obesity,nonalcoholic fatty liver disease(NAFLD)has become a major worldwide health issue even in childhood.The most accepted pathophysiological hypothesis is represented by the“multiple hits”theory,in which both hepatic intracellular lipid accumulation and insulin resistance mainly contribute to liver injury through several factors.Among these,lipotoxicity has gained particular attention.In this view,the pathogenic role of different lipid classes in NAFLD(e.g.,sphingolipids,fatty acids,ceramides,etc.)has been highlighted in recent lipidomics studies.Although there is some contrast between plasma and liver findings,lipidomic profile in the NAFLD context provides novel insights by expanding knowledge in the intricate field of NAFLD pathophysiology as well as by suggesting innovative therapeutic approaches in order to improve both NAFLD prevention and treatment strategies.Selective changes of distinct lipid species might be an attractive therapeutic target for treating NAFLD.Herein the most recent evidence in this attractive field has been summarized to provide a comprehensive overview of the lipidomic scenario in paediatric NAFLD.

Effects of different processing methods on the lipid composition of hazelnut oil:a lipidomics analysis

Although hazelnut oil is rich in nutrients,its quality is greatly affected by how it is processed.However,no studies to date have comprehensively analyzed the lipid composition of hazelnut oil using different processing methods.Here,we conducted a lipidomics analysis using UPLC-QTOF-MS to characterize the lipid composition of cold-pressed hazelnut oil(CPO),ultrasonic-assisted hexane hazelnut oil(UHO)and enzyme-assisted aqueous hazelnut oil(EAO).A total of 10 subclasses of 98 lipids were identified,including35 glycerolipids(GLs),56 glycerophospholipids(GPs)and 7 sphingolipids(SPs).The total lipid and GL content were the highest in CPO,GP content was the highest in UHO and the ceramide content in SPs was most abundant in EAO.Multivariate statistical analysis showed that the lipid profiles of hazelnut oil prepared with different processing methods varied.Twelve significantly different lipids(TAG 54:3,TAG 52:2,TAG54:4,TAG 54:2,TAG 52:3,TAG 54:5,DAG 36:2,DAG 36:4,DAG 36:3,PC 36:2,PA 36:2 and PE 36:3)were identified,and these lipids could potentially be used as biomarkers to distinguish between hazelnut oil subjected to different processing methods.Our results provide useful information for hazelnut oil applications and new insight into the effects of edible oil processing.

Functional lipidomics in patients on home parenteral nutrition: Effect of lipid emulsions

To investigate the fatty acid-based functional lipidomics of patients on long-term home parenteral nutrition receiving different intravenous lipid emulsions. METHODSA cross-sectional comparative study was carried out on 3 groups of adults on home parenteral nutrition (HPN), receiving an HPN admixture containing an olive-soybean oil-based intravenous lipid emulsion (IVLE) (OO-IVLE; n = 15), a soybean- medium-chain triacylglycerol-olive-fish oil-based IVLE (SMOF-IVLE; n = 8) or HPN without IVLE (No-IVLE; n = 8) and 42 healthy controls (HCs). The inclusion criteria were: duration of HPN ≥ 3 mo, current HPN admixtures ≥ 2 mo and HPN infusions ≥ 2/wk. Blood samples were drawn 4-6 h after the discontinuation of the overnight HPN infusion. The functional lipidomics panel included: the red blood cell (RBC) fatty acid (FA) profile, molecular biomarkers [membrane fluidity: saturated/monounsaturated FA ratio = saturated fatty acid (SFA)/monounsaturated fatty acid (MUFA) index; inflammatory risk: n-6/n-3 polyunsaturated fatty acid (PUFA) ratio = n-6/n-3 index; cardiovascular risk: sum of n-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) = n-3 index; free radical stress: sum of FA trans isomers = %trans index] and FA pathway enzyme activity estimate (delta-9-desaturase = D9D; delta-6-desaturase = D6D; delta-5-desaturase = D5D; elongase = ELO). Statistics were carried out using nonparametric tests. The amount of each FA was calculated as a percentage of the total FA content (relative%). RESULTSIn the OO-IVLE group, the percentage of oleic acid in the RBCs was positively correlated with the weekly load of OO-IVLE (r = 0.540, P = 0.043). In the SMOF-IVLE cohort, the RBC membrane EPA and DHA were positively correlated with the daily amount of SMOF-IVLE (r = 0.751, P = 0.044) and the number of HPN infusions per week (r = 0.753; P = 0.046), respectively. The SMOF-IVLE group showed the highest EPA and DHA and the lowest arachidonic acid percentages (P < 0.001). The RBC membrane linoleic acid content was lower, and oleic and vaccenic acids were higher in all the HPN groups in comparison to the HCs. Vaccenic acid was positively correlated with the weekly HPN load of glucose in both the OO-IVLE (r = 0.716; P = 0.007) and the SMOF-IVLE (r = 0.732; P = 0.053) groups. The estimated activity of D9D was higher in all the HPN groups than in the HCs (P < 0.001). The estimated activity of D5D was lower in the SMOF-IVLE group than in the HCs (P = 0.013). The SFA/MUFA ratio was lower in all the HPN groups than in the HCs (P < 0.001). The n-6/n-3 index was lower and the n-3 index was higher in the SMOF-IVLE group in comparison to the HCs and to the other HPN groups (P < 0.001). The %trans index did not differ among the four groups. CONCLUSIONThe FA profile of IVLEs significantly influenced the cell membrane functional lipidomics. The amount of glucose in the HPN may play a relevant role, mediated by the insulin regulation of the FA pathway enzyme activities.

Modifier-concept of colorectal carcinogenesis: Lipidomics as a technical tool in pathway analysis

In the modifier concept of intestinal carcinogenesis, lipids have been established as important variables and one focus is given to long-chain fatty acids. Increased consumption of long-chain fatty acids is in discussion to modify the development of colorectal carcinoma in humans. Saturated long-chain fatty acids, in particular, are assumed to promote carcinogenesis, whereas poly-unsaturated forms are likely to act in the opposite way. At present, the molecular mechanisms behind these effects are not well understood. Recently, it has been demonstrated by lipidomics and associated molecular techniques, that activation and metabolic channeling of long-chain fatty acids are important mechanisms to modify colorectal carcinogenesis. In this Editorial, an overview about the present concept of long-chain fatty acids and its derivatives in colorectal carcinogenesis as well as technical algorithms in lipid analysis is given.

Advances in pediatric non-alcoholic fatty liver disease: From genetics to lipidomics

As a result of the obesity epidemic,non-alcoholic fatty liver disease(NAFLD)represents a global medical concern in childhood with a closely related increased cardiometabolic risk.Knowledge on NAFLD pathophysiology has been largely expanded over the last decades.Besides the well-known key NAFLD genes(including the I148M variant of the PNPLA3 gene,the E167K allele of the TM6SF2,the GCKR gene,the MBOAT7-TMC4 rs641738 variant,and the rs72613567:TA variant in the HSD17B13 gene),an intriguing pathogenic role has also been demonstrated for the gut microbiota.More interestingly,evidence has added new factors involved in the“multiple hits”theory.In particular,omics determinants have been highlighted as potential innovative markers for NAFLD diagnosis and treatment.In fact,different branches of omics including metabolomics,lipidomics(in particular sphingolipids and ceramides),transcriptomics(including micro RNAs),epigenomics(such as DNA methylation),proteomics,and glycomics represent the most attractive pathogenic elements in NAFLD development,by providing insightful perspectives in this field.In this perspective,we aimed to provide a comprehensive overview of NAFLD pathophysiology in children,from the oldest pathogenic elements(including genetics)to the newest intriguing perspectives(such as omics branches).

Advances on Current Techniques and Methodologies in Milk Lipidomics

Milk is a complex biological fluid containing lipids,proteins,carbohydrates and minerals,which are essential for infant growth.While the lipid portion constitutes only 3%-5%of the total milk composition,it accounts for over 50%of the infant’s daily energy intake.The dominant portion(approximately 98%)is in the form of triacylglycerols and polar lipids,such as glycerophospholipids and sphingolipids,forming minor components.Recently,with the development of lipidomics,important progresses have been made in milk lipidomics,and the identification and quantification of several milk lipids at the group and molecular species level has become a reality,thereby providing useful information for the infant formula industry.In this review,an overview of the separation of the main components of milk lipids was presented,including glycerolipids,phospholipids and sphingolipids.The analytical methods and strategies for milk lipidomics,including gas chromatography-mass spectrometry(MS),capillary electrophoresis MS,nuclear magnetic resonance,matrix-assisted laser desorption ionization-MS,electrospray ionization-MS,shotgun lipidomics and liquid chromatography-MS,were reviewed.Additionally,the bioinformatics of lipidomics for milk lipid determination,including lipid classification,lipid databases and lipid analysis software,were investigated.This review would aid future investigations of the nutrition of milk lipids and refined researches on formula milk powder.

Glycerophospholipids pathways and chromosomal instability in gastric cancer: Global lipidomics analysis

BACKGROUND Based on the breakthrough of genomics analysis, The Cancer Genome Atlas Research Group recently proposed an integrative genomic analysis, dividing gastric cancer(GC) into four subtypes, characterized by the chromosomal instability(CIN) status. However, the CIN status of GC is still vaguely characterized and lacking the valuable easy-to-use CIN markers to diagnosis in molecular and histological detection.AIM To explore the associations of CIN with downstream lipidomics profiles.METHODS We collected cancerous and noncancerous tissue samples from 18 patients with GC; the samples were divided into CIN and non-CIN types based on the system of The Cancer Genome Atlas Research Group and 409 sequenced oncogenes and tumor suppressor genes. We identified the lipidomics profiles of the GC samples and samples of their adjacent noncancerous tissues by using liquid chromatography–mass spectrometry. Furthermore, we selected leading metabolites based on variable importance in projection scores of > 1.0 and P <0.05.RESULTS Twelve men and six women participated in this study; the participants had a median age of 67.5 years(range, 52–87 years) and were divided into CIN(n = 9)and non-CIN(n = 9) groups. The GC samples exhibited distinct profiles of lysophosphocholine, phosphocholine, phosphatidylethanolamine,phosphatidylinositol, phosphoserine, sphingomyelin, ceramide, and triglycerides compared with their adjacent noncancerous tissues. The glycerophospholipid levels(phosphocholine, phosphatidylethanolamine, and phosphatidylinositol)were 1.4-to 2.3-times higher in the CIN group compared with the non-CIN group(P < 0.05). Alterations in the glycerolipid and glycerophospholipid pathways indicated progression of GC toward CIN.CONCLUSION The lipidomics profiles of GC samples were distinct from those of their adjacent noncancerous tissues. CIN status of GC is primarily associated with downstream lipidomics in the glycerophospholipid pathway.

Analysis of the metabolic mechanism in Cantharidin-induced hepatotoxicity in LO2 cells using lipidomics analysis

Background:Cantharidin is a major active compound from Banmao(Mylabris).Cantharidin has obvious anticancer activity.However,its clinical application is limited due to serious hepatotoxicity.Methods:To evaluate the toxicity of human liver LO2 cells exposed to cantharidin by lipidomics.After exposing LO2 cells to different doses of cantharidin,the metabolites in LO2 cells were analyzed by nontargeted lipidomics based on liquid chromatography-mass spectrometry.Partial least-squares discriminant analysis and orthogonal partial least-squares discriminant analysis were used to screen differentially expressed metabolites,and then the main metabolic pathways were analyzed.Results:Pattern recognition analysis showed that the lipid metabolite profiles were changed significantly after cantharidin treatment,and 39 differential lipid metabolites were found.Additional analysis showed that these metabolites could mainly involve the metabolic pathways of triglyceride and acylcarnitine for cantharidin toxicity to LO2 cells.Conclusion:Cantharidin has obvious toxic effects on LO2 cells from the perspective of lipid metabolism.Moreover,the LO2 cytotoxicity induced by cantharidin is mainly related to the disorder of triglyceride and acylcarnitine metabolism.It can provide a scientific basis for cantharidin-induced hepatotoxicity.

Strategies to enhance shotgun lipidomics for comprehensive analysis of cellular lipids

The discipline of lipidomics, as coined in 2003, has made profound advances and been rapidly expanded. Direct infusion-based shotgun lipidomics contributes a major part of the research in this discipline. However, despite of its numerous advantages over other lipidomics platforms, the classical shotgun lipidomics approach suffers ion suppression and has the difficulties to assess low abundance lipid classes, particularly those less ionizable or that do not yield sensitive and specific fragments. To overcome this obstacle and broaden coverage, strategies have been developed based on unique chemistry and/or physics of lipid classes of interest to enhance shotgun lipidomics. This article overviews the recent enhancements of shotgun lipidomics, including prefractionation, acid/base hydrolysis, derivatization, charge feature utilization. We believe that, by this versatile platform, comprehensive coverage of cellular lipidomes would be achieved in more accurate and effective manner. Therefore, application of the enhanced shotgun lipidomics would greatly accelerate lipidomics research to substantiate the aberrant lipid metabolism, signaling, trafficking, and homeostasis under pathological conditions and their underpinning biochemical mechanisms. It would also facilitate precision medicine studies.

Importance of quality control in lipidomics profiling based on mass spectrometry

As a current analytical instrument for lipidomics profiling with high sensitivity, selectivity, and throughput, mass spectrometry (MS) has been widely used in the field of clinical medicine, nutrition, bromatology, botany and etc. During the routine use of shotgun- MS and high performance liquid chromatography-MS (HPLC-MS) in lipid analysis, an important problem to be solved is the defective repeatability and stability resulting from signal attenuation or drifts in LC-peak shape and retention time of MS platform. To remove or minimize the influence, extensively accepted and applied QC (quality control) samples must be performed. In this review, we emphasize the importance of the application of QC samples, which could 1) provide the ability to equilibrate the analytical platform at the beginning; 2) act as a quality assurance (QA) procedure during the analytical process; 3) perform signal correction in the data handling with the purpose of reducing analytical variation and improving the precision of quantitative analysis; 4) the data between different laboratories can be compared through the incorporation of particular QC samples-Standard Reference Material (SRM) 1950. In addition, we display 4 types and requirements of QC samples during quality control in lipidomics profiling. Lipidomics profiling based on MS strongly requires commonly accepted guidelines for quality control to perform routine, large-scale researches, so as to integrate data from different scientists for more information.

Comprehensive evaluation of the metabolic effects of insect meal from Tenebrio molitor L.in growing pigs by transcriptomics, metabolomics and lipidomics

Background:The hypothesis was tested that insect meal(IM)as protein source influences intermediary metabolism of growing pigs.To test this,30 male,5-week-old crossbred pigs were randomly assigned to 3 groups of 10 pigs each with similar body weights(BW)and fed isonitrogenous diets either without(CON)or with 5%IM(IM5)or 10%IM(IM10)from Tenebrio molitor L.for 4 weeks and key metabolic tissues(liver,muscle,plasma)were analyzed using omics-techniques.Results:Most performance parameters did not differ across the groups,whereas ileal digestibilities of most amino acids were 6.7 to 15.6%-units lower in IM10 than in CON(P<0.05).Transcriptomics of liver and skeletal muscle revealed a total of 166 and 198,respectively,transcripts differentially expressed between IM10 and CON(P<0.05).Plasma metabolomics revealed higher concentrations of alanine,citrulline,glutamate,proline,serine,tyrosine and valine and a lower concentration of asparagine in IM10 than in CON(P<0.05).Only one out of fourteen quantifiable amino acid metabolites,namely methionine sulfoxide(MetS),in plasma was elevated by 45%and 71%in IM5 and IM10,respectively,compared to CON(P<0.05).Plasma concentrations of both,major carnitine/acylcarnitine species and bile acids were not different across groups.Lipidomics of liver and plasma demonstrated no differences in the concentrations of triacylglycerols,cholesterol and the main phospholipids,lysophospholipids and sphingolipids between groups.The percentages of all individual phosphatidylcholine(PC)and phosphatidylethanolamine(PE)species in the liver showed no differences between groups,except those with 6 double bonds(PC 38:6,PC 40:6,PE 38:6,PE 40:6),which were markedly lower in IM10 than in CON(P<0.05).In line with this,the percentage of C22:6n-3 in hepatic total lipids was lower in IM10 than in the other groups(P<0.05).Conclusions:Comprehensive analyzes of the transcriptome,lipidome and metabolome of key metabolic tissues indicate that partial or complete replacement of a conventional protein source by IM in the diet has only a weak impact on the intermediary metabolism of growing pigs.Thus,it is concluded that IM from Tenebrio molitor L.can be used as a dietary source of protein in pigs without causing adverse effects on metabolism.

Unraveling enhanced membrane lipid biosynthesis in Chlamydomonas reinhardtii starchless mutant sta6 by using an electrospray ionization mass spectrometry-based lipidomics method

The unicellular green alga Chlamydomonas reinhardtii,a well-established model organism,has been widely used in dissecting glycerolipid metabolism in oxygenating photosynthetic organisms.In previous studies,it has been found that shunting carbon precursors from the starch synthesis pathway can lead to a 10-fold increase in TAG content as compared to the wild type,but it is unknown whether inactivation of AGPase may affect membrane lipids biosynthesis.The study aims to investigate global changes in lipid metabolism and homeostasis in the starchless mutant C.reinhardtii sta6.By utilizing an electrospray ionization/mass spectrometry(ESI/MS)-based lipidomics approach,a total of 105 membrane lipid molecules of C.reinhardtii were resolved,including 16 monogalactosyldiacylglycerol(MGDG),16 digalactosyldiacylglycerol(DGDG),11 phosphatidylglycerol(PG),6 sulfoquinovosyldiacylglycerol(SQDG),49 diacylglyceryl-N,N,N-trimethylhomoserine(DGTS),2 phosphatidylethanolamine(PE),and 5 phosphatidylinositol(PI)molecules.The quantitative results indicated that the membrane lipid profiles were similar between the two C.reinhardtii strains grown under both low-and high-light conditions,but the cellular contents of a great number of lipids were altered in sta6 due to the defect in starch biosynthesis.Under low-light conditions,sta6 accumulated more PI,MGDG,DGDG but less amounts of DGTS as compared to WT.Under high light,sta6 cells contained higher content membrane lipids than cc-124,except for PG,which is more or less similar in both strains.Our results demonstrate that the cellular membrane lipid homeostasis underwent profound changes in the starchless mutant,and thereby its physiological impact remains to be explored.

Plasma lipidomics reveal systemic changes persistent throughout early life following a childhood burn injury

Background:Non-severe paediatric burns can result in poor long-term health outcomes.This occurs even in cases with good acute burn-related outcomes,including minimal scarring.The mechanisms that underpin the transition from non-severe burn to sustained negative long-term health impacts are currently unknown.However,sustained metabolic and immune changes have been observed in paediatric burn studies,suggesting these changes may be important.The plasma lipidome consists of a rich pool of bioactive metabolites that play critical roles in systemic processes including molecular signalling and inflammation.We hypothesised that changes in the plasma lipidome may reflect underlying changes in health status and be linked to long-term health after burn trauma.Methods:This study analysed the lipidome in children who had previously experienced a non-severe burn,compared to non-injured controls.Thirty-three participants were recruited between the ages of 5 and 8 years who had experienced a non-severe burn between the ages of 1 and 3 years.Plasma samples were also collected from a non-injured,healthy,age and gender matched control group(n=21).Plasma lipids were measured using reversed-phase liquid chromatographymass spectrometery(LC-MS).Results:In total 838 reproducible lipid species from 19 sub-classes passed quality control procedures and progressed to statistical analysis.Analysis of individual lipid metabolites showed significantly higher concentrations of lysophosphatidylethanolamines and phosphatidylethanolamines,and significantly lower concentrations in myristic,palmitic and palmitoleic acids in the plasma of those who had experienced burn injury compared to controls.Conclusion:Long-term changes in the lipid profile may give insight into the mechanisms underlying poor long-term health subsequent to non-severe burn injury.Further work to investigate the relationship between long-term pathology and lipidomic changes may lead to a better understanding of the causes of secondary morbidity post-burn and to clinical intervention to reduce the long-term health burden of burn trauma.

Cyanidin-3-glucoside protects the photooxidative damage of retinal pigment epithelium cells by regulating sphingolipid signaling and inhibiting MAPK pathway

Cyanidin-3-glucoside(C3G)is the most common anthocyanin in dark grains and berries and is a food functional factor to improve visual health.However,the mechanisms of C3G on blue light-induced retinal pigment epithelial(RPE)cell photooxidative damage needs further exploration.We investigated the effects of C3G on blue light-irradiated A2E-containing RPE cells and explored whether sphingolipid,mitogen-activated protein kinase(MAPK),and mitochondria-mediated pathways are involved in this mechanism.Blue light irradiation led to mitochondria and lysosome damage in RPE cells,whereas C3G preserved mitochondrial morphology and function and maintained the lysosomal integrity.C3G suppressed the phosphorylation of JNK and p38 MAPK and mitochondria-mediated pathways to inhibit RPE cell apoptosis.Lipidomics data showed that C3G protected RPE cells against blue light-induced lipid peroxidation and apoptosis by maintaining sphingolipids balance.C3G significantly inhibited ceramide(Cer d18:0/15:0,Cer d18:0/16:0 and Cer d18:0/18:0)accumulation and elevated galactosylceramide(GalCer d18:1/15:0 and GalCer d18:1/16:0)levels in the irradiated A2E-containing RPE cells.Furthermore,C3G attenuated cell membrane damage by increasing phosphatidylcholine and phosphatidylserine levels.C3G inhibited apoptosis and preserved the structure of mitochondria and lysosome by regulating sphingolipid signaling and suppression of MAPK activation in RPE cells.Thus,dietary supplementation of C3G prevents retinal photooxidative damage.

Repeated inoculation with rumen fluid accelerates the rumen bacterial transition with no benefit on production performance in postpartum Holstein dairy cows

Background The dairy cow’s postpartum period is characterized by dramatic physiological changes,therefore imposing severe challenges on the animal for maintaining health and milk output.The dynamics of the ruminal microbiota are also tremendous and may play a crucial role in lactation launch.We aim to investigate the potential benefits of early microbial intervention by fresh rumen microbiota transplantation(RMT)and sterile RMT in postpartum dairy cows.Twelve fistulated peak-lactation dairy cows were selected to be the donors for rumen fluid collection.Thirty postpartum cows were divided into 3 groups as the transplantation receptors respectively receiving 10 L fresh rumen fluid(FR),10 L sterile rumen fluid(SR),or 10 L saline(CON)during 3 d after calving.Results Production performance,plasma indices,plasma lipidome,ruminal microbiome,and liver transcriptome were recorded.After fresh and sterile RMT,we found that the molar proportion of propionic acid was increased on d 7 in the FR and SR groups and the bacterial composition was also significantly changed when compared with the CON group.A similarity analysis showed that the similarities between the CON group and FR or SR group on d 7 were 48.40%or 47.85%,whereas the similarities between microbiota on d 7 and 21 in the FR and SR groups were 68.34%or 66.85%.Dry matter intake and feed efficiency were not affected by treatments.Plasmaβ-hydroxybutyrate concentration in the FR group was decreased and significantly different lipids mainly included phosphatidylcholine and lysophosphatidylcholine containing polyunsaturated fatty acids.Hepatic transcriptomics analysis indicated acutephase response pathways were upregulated in the SR group.Conclusions Our study suggests that RMT can shorten the transition process of the ruminal microbiota of postpartum dairy cows with no benefit on dry matter intake or feed efficiency.Inoculation with rumen fluid may not be a useful approach to promote the recovery of postpartum dairy cows.