Lipid Response Research Articles

Metabolic alterations of endothelial cells under transient and persistent hypoxia: study using a 3D microvessels-on-chip model

ABSTRACT Numerous signaling pathways are activated during hypoxia to facilitate angiogenesis, promoting interactions among endothelial cells and initiating downstream signaling cascades. Although the pivotal role of the nitric oxide (NO) response pathway is well-established, the involvement of arginine-specific metabolism and bioactive lipid mechanisms in 3D flow-activated in vitro models remains less understood. In this study, we explored the levels of arginine-specific metabolites and bioactive lipids in human coronary artery endothelial cells (HCAECs) under both transient and persistent hypoxia. We compared targeted metabolite levels between a 2D static culture model and a 3D microvessels-on-chip model. Notably, we observed robust regulation of NO metabolites in both transient and persistent hypoxic conditions. In the 2D model under transient hypoxia, metabolic readouts of bioactive lipids revealed increased oxidative stress markers, a phenomenon not observed in the 3D microvessels. Furthermore, we made a novel discovery that the responses of bioactive lipids were regulated by hypoxia inducible factor-1α (HIF-1α) in the 2D cell culture model and partially by HIF-1α and flow-induced shear stress in the 3D microvessels. Immunostaining confirmed the HIF-1α-induced regulation under both hypoxic conditions. Real-time oxygen measurements in the 3D microvessels using an oxygen probe validated that oxygen levels were maintained in the 3D model. Overall, our findings underscore the critical regulatory roles of HIF-1α and shear stress in NO metabolites and bioactive lipids in both 2D and 3D cell culture models.

Aging-Induced Changes in Cutibacterium acnes and Their Effects on Skin Elasticity and Wrinkle Formation.

Skin aging involves biomechanical changes like decreased elasticity, increased wrinkle formation, and altered barrier function. The skin microbiome significantly impacts this process. Here, we investigated the effects of decreased Cutibacterium acnes abundance and increase in other skin microorganisms on skin biomechanical properties in 60 healthy Koreans from Seoul, divided into younger (20-29 years) and older (60-75 years) groups. Metagenomic sequencing and skin assessments showed that the older group exhibited decreased C. acnes dominance and increased microbial diversity, correlating with reduced skin elasticity and increased wrinkles. In the younger age group, the enriched pathways included zeatin biosynthesis, distinct biotin metabolism pathways, and cofactor and vitamin metabolism in the younger age group, whereas pathways related to lipid metabolism, energy metabolism, and responses to environmental stressors, including UV damage and pollution, were enriched in the older group, according to functional analysis results. Network analysis indicated higher microbial connectivity in the younger group, suggesting a more stable community, whereas the older group's community displayed higher modularity, indicating more independent and specialized clusters. This study enhances our understanding of the impact of skin microbiome changes on skin aging, particularly the anti-aging effects of C. acnes. Future research should focus on the physiological mechanisms of skin microbiota on skin aging and explore therapeutic potentials to enhance skin health.

Time-specific lipid and gene expression responses to chilling stress in panicoid grass.

This article comments on: Kenchanmane Raju SK, Zhang Y, Mahboub S, Ngu DW, Qiu Y, Harmon FG, Schnable JC, Roston RL. 2024. Rhythmic lipid and gene expression responses to chilling in panicoid grasses. Journal of Experimental Botany 75, https://doi.org/10.1093/jxb/erae247

FABP4-mediated lipid metabolism promotes TNBC progression and breast cancer stem cell activity

Metabolic remodeling is a pivotal feature of cancer, with cancer stem cells frequently showcasing distinctive metabolic behaviors. Nonetheless, understanding the metabolic intricacies of triple-negative breast cancer (TNBC) and breast cancer stem cells (BCSCs) has remained elusive. In this study, we meticulously characterized the metabolic profiles of TNBC and BCSCs and delved into their potential implications for TNBC treatment. Our findings illuminated the robust lipid metabolism activity within TNBC tumors, especially in BCSCs. Furthermore, we discovered that Fabp4, through its mediation of fatty acid uptake, plays a crucial role in regulating TNBC lipid metabolism. Knocking down Fabp4 or inhibiting its activity significantly suppressed TNBC tumor progression in both the MMTV-Wnt1 spontaneous TNBC model and the TNBC patient-derived xenograft model. Mechanistically, Fabp4's influence on TNBC tumor progression was linked to its regulation of mitochondrial stability, the CPT1-mediated fatty acid oxidation process, and ROS production. Notably, in a high-fat diet model, Fabp4 deficiency proved to be a substantial inhibitor of obesity-accelerated TNBC progression. Collectively, these findings shed light on the unique metabolic patterns of TNBC and BCSCs, underscore the biological significance of Fabp4-mediated fatty acid metabolism in governing TNBC progression, and offer a solid theoretical foundation for considering metabolic interventions in breast cancer treatment. SignificanceTriple-negative breast cancer progression and breast cancer stem cell activity can be restricted by targeting a critical regulator of lipid responses, FABP4.

Value of measuring markers of lipid metabolism in horses during an oral glucose test.

Characterizing the lipid response to an oral glucose test (OGT) might improve our understanding of Equine Metabolic Syndrome. To describe the effects of an OGT on lipid metabolism and determine the value of measuring triglyceride and nonesterified fatty acid (NEFA) concentrations in hyperinsulinemic (HI) and insulin-resistant (IR) horses. Twenty horses including 7 HI-IR horses, 4 HI-non-IR horses, and 9 non-HI-non-IR horses (control). Cross-sectional design. Horses underwent an OGT, with blood samples collected at 0, 60, 90, and 120 minutes. Insulin, glucose, triglyceride, and NEFA concentrations were measured and compared over time and between groups, with P < .05 considered significant. In all horses, the OGT had a significant effect on triglyceride concentrations (median [interquartile range]: .35 [.30-.50] mmol/L at 0 minute vs .25 [.21-.37] mmol/L at 120 minutes, P = .005) and on NEFA concentrations (.1 [.1-.2] mEq/L at 0 minute vs .05 [.05-.1] mEq/L at 120 minutes, P = .0009). However, horses with HI and IR had higher triglyceride areas under the curve (AUC, 79.46 ± 46.59 vs 33.32 ± 6.75 mmol/L*min, P = .01) as well as NEFA AUC (9.1 ± 2.9 vs 6.0 ± 6.8 mEq/L*min, P = .03) than control horses. No significant difference was detected between control and HI non-IR horses. Determining triglyceride and NEFA concentrations might help assess tissue insulin resistance during an OGT.

The Role of Food Matrices Supplemented with Milk Fat Globule Membrane in the Bioaccessibility of Lipid Components and Adaptation of Cellular Lipid Metabolism of Caco-2 Cells.

This study aimed to evaluate the digestive efficiency of food matrices supplemented with milk fat globule membrane isolated from buttermilk (BM-MFGM), using the INFOGEST in vitro digestion protocol hyphenated with the assessment of the digested material on the lipid profile of the Caco-2 cell culture model. First, we examined lipid profiles in food matrices supplemented with BM-MFGM and their subsequent digestion. The results showed distinct lipid profiles in different food matrices and micellar fractions. The presence of BM-MFGM lipids changed the cellular lipid profiles in Caco-2 cell cultures, with diverging contents in cholesteryl esters, triacylglycerides, and neutral lipids depending on the micellar food matrix factor. Hierarchical clustering analysis revealed patterns in cellular lipid responses to micellar stimuli, while volcano plots highlighted significant changes in cellular lipid profiles post-treatment. Thus, this study underscores the importance of in vitro digestion protocols in guiding food matrix selection for bioactive ingredient supplementation, elucidating intestinal epithelium responses to digested food stimuli.

Effects of Single Low-Carbohydrate, High-Fat Meal Consumption on Postprandial Lipemia and Markers of Endothelial Dysfunction: A Systematic Review of Current Evidence.

Postprandial lipemia (PPL) is associated with increased risk of endothelial dysfunction (ED), a precursor of atherosclerotic cardiovascular disease (ASCVD). The effects of low-carbohydrate, high-fat (LCHF) diets on ASCVD risk are uncertain; therefore, gaining a greater understanding of LCHF meals on PPL may provide valuable insights. The current systematic review investigated the effects of single LCHF meal consumption on PPL and markers of ED. CINAHL Plus, PubMed, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for key terms related to endothelial function, cardiovascular disease, glycemia, lipemia, and the postprandial state with no restriction on date. Full-text articles were independently screened by 2 reviewers, of which 16 studies were eligible to be included in the current review. All trials reported a minimum analysis of postprandial triglycerides (PPTG) following consumption of an LCHF meal (<26% of energy as carbohydrate). Results were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Single-meal macronutrient composition was found to play a key role in determining postprandial lipid and lipoprotein responses up to 8 hours post-meal. Consumption of LCHF meals increased PPTG and may contribute to ED via reduced flow-mediated dilation and increased oxidative stress; however, energy and macronutrient composition varied considerably between studies. Consumption of an LCHF meal had a negative impact on PPL based on some, but not all, single-meal studies; therefore, the contribution of LCHF meals to cardiometabolic health outcomes remains unclear. Further research is needed on specific categories of LCHF diets to establish a causal relationship between postprandial modulation of lipids/lipoproteins and impaired vascular endothelial function. PROSPERO registration no. CRD 42023398774.

Alterations to sphingolipid metabolism from antipsychotic administration in healthy volunteers are restored following the use of cannabidiol

Randomized clinical trials substantiate cannabidiol (CBD) as a next-generation antipsychotic, effective in alleviating positive and negative symptoms associated with psychosis, while minimising the adverse effects seen with established treatments. Although the mechanisms remain debated, CBD is known to induce drug-responsive changes in lipid-based retrograde neurotransmitters. Lipid aberrations are also frequently observed with antipsychotics, which may contribute to their efficacy or increase the risk of undesirables, including metabolic dysfunction, obesity and dyslipidaemia. Our study investigated CBD's impact following lipid responses triggered by interaction with second-generation antipsychotics (SGA) in a randomized phase I safety study. Untargeted mass spectrometry assessed the lipidomic profiles of human sera, collected from 38 healthy volunteers. Serum samples were obtained prior to commencement of any medication (t = 0), 3 days after consecutive administration of one of the five, placebo-controlled, treatment arms designed to achieve steady-state concentrations of each SGA (amisulpride, 150 mg/day; quetiapine, 300 mg/day; olanzapine 10 mg/day; risperidone, 3 mg/day), and after six successive days of SGA treatment combined with CBD (800 mg/day). Receiver operating characteristics (ROC) refined 3712 features to a putative list of 15 lipids significantly altered (AUC > 0.7), classified into sphingolipids (53 %), glycerolipids (27 %) and glycerophospholipids (20 %). Targeted mass spectrometry confirmed reduced sphingomyelin and ceramide levels with antipsychotics, which mapped along their catabolic pathway and were restored by CBD. These sphingolipids inversely correlated with body weight after olanzapine, quetiapine, and risperidone treatment, where CBD appears to have arrested or attenuated these effects. Herein, we propose CBD may alleviate aberrant sphingolipid metabolism and that further investigation into sphingolipids as markers for monitoring side effects of SGAs and efficacy of CBD is warranted.

Time-course atherogenic blood lipid response to statin discontinuation in dyslipidemic adults

Background and aimsHalf of dyslipidemic patients sometimes discontinue statin medication. It is unclear if blood atherogenic risk increases right after statin discontinuation or if there is a lingering protective effect. We sought to determine if a legacy effect prevented blood lipid increases during the first stages of statin cessation. Methods and resultsAtherogenic blood lipid profile was measured in 10 overweight (BMI 31 ± 3 kg m−2) middle-aged males (62 ± 7 years old), statin users, while fasted and postprandially. Trials were conducted before (i.e., Day 0) and after 4, 7, 15, and 30 days of statin withdrawal and 20 days after statins reloading (Day 50).Four days after statin discontinuation, blood fasting LDL-c, total cholesterol (CHOL), and triglyceride (TG) concentrations increased by 30%, 18%, and 17%, respectively (P < 0.05). The increases in LDL-c, CHOL, and TG peaked after 7–15 days at 79%, 48%, and 34% of basal levels (P < 0.001), respectively. There were no significant correlations between the increases in blood lipids and the dose or years under statin treatment (P = 0.156–0.575). Twenty days after resuming statins, blood LDL-c (2.79 ± 1.06 vs 2.20 ± 0.50 mmol L−1; P = 0.568), CHOL (4.85 ± 1.41 vs 4.25 ± 0.83 mmol L−1; P = 0.747), and TG (1.47 ± 0.60 vs 1.50 ± 0.68 mmol L−1; P = 0.782), returned to basal levels. ConclusionsOur data does not support a statin lingering/legacy effect in blood lipids since they dangerously increased after only 4 days of statin withdrawal in every patient, regardless of dose and years under treatment. Reloading statins restored blood lipids, evidencing a reproducible biological effect at the whole-body level.

Rhythmic lipid and gene expression responses to chilling in panicoid grasses.

Chilling stress threatens plant growth and development, particularly affecting membrane fluidity and cellular integrity. Understanding plant membrane responses to chilling stress is important for unraveling the molecular mechanisms of stress tolerance. Whereas core transcriptional responses to chilling stress and stress tolerance are conserved across species, the associated changes in membrane lipids appear to be less conserved, as which lipids are affected by chilling stress varies by species. Here, we investigated changes in gene expression and membrane lipids in response to chilling stress during one 24h cycle in chilling-tolerant foxtail millet (Setaria italica), and chilling-sensitive sorghum (Sorghum bicolor) and Urochloa (browntop signal grass, Urochloa fusca, lipids only), leveraging their evolutionary relatedness and differing levels of chilling stress tolerance. We show that most chilling-induced lipid changes are conserved across the three species, while we observed distinct, time-specific responses in chilling-tolerant foxtail millet, indicating the presence of a finely orchestrated adaptive mechanism. We detected rhythmicity in lipid responses to chilling stress in the three grasses, which were also present in Arabidopsis thaliana, suggesting the conservation of rhythmic patterns across species and highlighting the importance of accounting for time of day. When integrating lipid datasets with gene expression profiles, we identified potential candidate genes that showed corresponding transcriptional changes in response to chilling stress, providing insights into the differences in regulatory mechanisms between chilling-sensitive sorghum and chilling-tolerant foxtail millet.

Photoinduced bidirectional mesophase transition in vesicles containing azobenzene amphiphiles.

The functionality and efficiency of proteins within a biological membrane are highly dependent on both the membrane lipid composition and the physiochemical properties of the solution. Lipid mesophases are directly influenced by changes in temperature, pH, water content or due to individual properties of single lipids such as photoswitchability. In this work, we were able to induce light- and temperature-driven mesophase transitions in a model membrane system containing a mixture of 1,2-dipalmitoyl-phosphatidylcholine phospholipids and azobenzene amphiphiles. We observed reversible and reproducible transitions between the lamellar and Pn3m cubic phase after illuminating the sample for 5 min with light of 365 and 455 nm wavelengths, respectively, to switch between the cis and trans states of the azobenzene N=N double bond. These light-controlled mesophase transitions were found for mixed complexes with up to 20% content of the photosensitive molecule and at temperatures below the gel-to-liquid crystalline phase transition temperature of 33°C. Our results demonstrate the potential to design bespoke model systems to study the response of membrane lipids and proteins upon changes in mesophase without altering the environment and thus provide a possible basis for drug delivery systems.

Metabolic Responses to an Acute Glucose Challenge: The Differential Effects of Eight Weeks of Almond vs. Cracker Consumption in Young Adults.

This study investigated the dynamic responses to an acute glucose challenge following chronic almond versus cracker consumption for 8 weeks (clinicaltrials.gov ID: NCT03084003). Seventy-three young adults (age: 18-19 years, BMI: 18-41 kg/m2) participated in an 8-week randomized, controlled, parallel-arm intervention and were randomly assigned to consume either almonds (2 oz/d, n=38) or an isocaloric control snack of graham crackers (325 kcal/d, n=35) daily for 8 weeks. Twenty participants from each group underwent a 2-hour oral glucose tolerance test (oGTT) at the end of the 8-week intervention. Metabolite abundances in the oGTT serum samples were quantified using untargeted metabolomics, and targeted analyses for free PUFAs, total fatty acids, oxylipins, and endocannabinoids. Multivariate, univariate, and chemical enrichment analyses were conducted to identify significant metabolic shifts. Findings exhibit a biphasic lipid response distinguished by higher levels of unsaturated triglycerides in the earlier periods of the oGTT followed by lower levels in the latter period in the almond versus cracker group (p-value<0.05, chemical enrichment analyses). Almond (vs. cracker) consumption was also associated with higher AUC120 min of aminomalonate, and oxylipins (p-value<0.05), but lower AUC120 min of L-cystine, N-acetylmannosamine, and isoheptadecanoic acid (p-value<0.05). Additionally, the Matsuda Index in the almond group correlated with AUC120 min of CE 22:6 (r=-0.46; p-value<0.05) and 12,13 DiHOME (r=0.45; p-value<0.05). Almond consumption for 8 weeks leads to dynamic, differential shifts in response to an acute glucose challenge, marked by alterations in lipid and amino acid mediators involved in metabolic and physiological pathways.

Impact of urban pollution on freshwater biofilms: Oxidative stress, photosynthesis and lipid responses

Urban ecosystems are subjected to multiple anthropogenic stresses, which impact aquatic communities. Artificial light at night (ALAN) for instance can significantly alter the composition of algal communities as well as the photosynthetic cycles of autotrophic organisms, possibly leading to cellular oxidative stress. The combined effects of ALAN and chemical contamination could increase oxidative impacts in aquatic primary producers, although such combined effects remain insufficiently explored. To address this knowledge gap, a one-month experimental approach was implemented under controlled conditions to elucidate effects of ALAN and dodecylbenzyldimethylammonium chloride (DDBAC) on aquatic biofilms. DDBAC is a biocide commonly used in virucidal products, and is found in urban aquatic ecosystems. The bioaccumulation of DDBAC in biofilms exposed or not to ALAN was analyzed. The responses of taxonomic composition, photosynthetic activity, and fatty acid composition of biofilms were examined. The results indicate that ALAN negatively affects photosynthetic yield and chlorophyll production of biofilms. Additionally, exposure to DDBAC at environmental concentrations induces lipid peroxidation, with an increase of oxylipins. This experimental study provides first insights on the consequences of ALAN and DDBAC for aquatic ecosystems. It also opens avenues for the identification of new biomarkers that could be used to monitor urban pollution impacts in natural environments.

Lipid responses to perfluorooctane sulfonate exposure for multiple rat organs

Perfluorooctane sulfonate (PFOS) is a persistent chemical that has long been a threat to human health. However, the molecular effects of PFOS on various organs are not well studied. In this study, male Sprague–Dawley rats were treated with various doses of PFOS through gavage for 21 days. Subsequently, the liver, lung, heart, kidney, pancreas, testis, and serum of the rats were harvested for lipid analysis. We applied a focusing lipidomic analytical strategy to identify key lipid responses of phosphorylcholine-containing lipids, including phosphatidylcholines and sphingomyelins. Partial least squares discriminant analysis revealed that the organs most influenced by PFOS exposure were the liver, kidney, and testis. Changes in the lipid profiles of the rats indicated that after exposure, levels of diacyl-phosphatidylcholines and 22:6-containing phosphatidylcholines in the liver, kidney, and testis of the rats decreased, whereas the level of 20:3-containing phosphatidylcholines increased. Furthermore, levels of polyunsaturated fatty acids-containing plasmenylcholines decreased. Changes in sphingomyelin levels indicated organ-dependent responses. Decreased levels of sphingomyelins in the liver, nonmonotonic dose responses in the kidney, and irregular responses in the testis after PFOS exposure are observed. These lipid responses may be associated with alterations pertaining to phosphatidylcholine synthesis, fatty acid metabolism, membrane properties, and oxidative stress in the liver, kidney, and testis. Lipid responses in the liver could have contributed to the observed increase in liver to body weight ratios. The findings suggest potential toxicity and possible mechanisms associated with PFOS in multiple organs.

Dietary n-3 alpha-linolenic and n-6 linoleic acids modestly lower serum lipoprotein(a) concentration but differentially influence other atherogenic lipoprotein traits: A randomized trial

Background and aimsLipoprotein(a) [Lp(a)] is a causal, genetically determined cardiovascular risk factor. Limited evidence suggests that dietary unsaturated fat may increase serum Lp(a) concentration by 10–15 %. Linoleic acid may increase Lp(a) concentration through its endogenous conversion to arachidonic acid, a process regulated by the fatty acid desaturase (FADS) gene cluster. We aimed to compare the Lp(a) and other lipoprotein trait-modulating effects of dietary alpha-linolenic (ALA) and linoleic acids (LA). Additionally, we examined whether FADS1 rs174550 genotype modifies Lp(a) responses. MethodsA genotype-based randomized trial was performed in 118 men homozygous for FADS1 rs174550 SNP (TT or CC). After a 4-week run-in period, the participants were randomized to 8-week intervention diets enriched with either Camelina sativa oil (ALA diet) or sunflower oil (LA diet) 30–50 mL/day based on their BMI. Serum lipid profile was measured at baseline and at the end of the intervention. ResultsALA diet lowered serum Lp(a) concentration by 7.3 % (p = 0.003) and LA diet by 9.5 % (p < 0.001) (p = 0.089 for between-diet difference). Both diets led to greater absolute decreases in individuals with higher baseline Lp(a) concentration (p < 0.001). Concentrations of LDL cholesterol (LDL-C), non-HDL-C, remnant-C, and apolipoprotein B were lowered more by the ALA diet (p < 0.01). Lipid or lipoprotein responses were not modified by the FADS1 rs174550 genotype. ConclusionsA considerable increase in either dietary ALA or LA from vegetable oils has a similar Lp(a)-lowering effect, whereas ALA may lower other major atherogenic lipids and lipoproteins to a greater extent than LA. Genetic differences in endogenous PUFA conversion may not influence serum Lp(a) concentration.

Does medication use affect blood pressure and lipid-lowering in tree nut and peanut interventions? A meta-analysis of randomised control trials

Including nuts in the diet has been associated with improvements in cardiovascular disease (CVD) risk factors including high blood pressure (BP) and hyperlipidaemia (1–2). However, few studies have investigated if the same benefits exist for medicated and unmedicated populations. This systematic review and meta-analysis investigated the effects of nut intake on BP and lipids, with a sub-analysis evaluating response differences according to BP and lipid-lowering medication usage. MEDLINE, EMBASE, Scopus and Web of Sciences databases were searched for randomised controlled trials (RCTs) of longer than 3 weeks duration that assessed the effects of whole tree nuts or peanuts on BP and lipid responses. The American Diabetes Association Quality Criteria checklist was used to assess the risk of bias, and studies with a negative rating were removed from the meta-analysis. A random-effects meta-analysis was conducted, with subgroup analyses performed based on medication use (medicated, unmedicated, unreported, and mixed-use). Inter-study heterogeneity was estimated using the I2 test statistic. Data from 107 articles describing 98 studies (61 parallel, and 37 cross-over designs) were included in the meta-analysis. Overall, significant benefits of nut consumption were observed for triglycerides (TG) (mean difference [MD]: −0.11 mmol/L, 95% confidence intervals [CI]: −0.16, −0.06, p &lt; 0.01, I2: 32.95%), total cholesterol (TC) (MD: −0.15 mmol/L, 95% CI: −0.22, −0.08, p &lt; 0.01, I2: 61.84%), and low-density lipoprotein cholesterol (LDL-C) (MD: −0.12 mmol/L, 95% CI: −0.19, −0.06, p &lt; 0.01, I2: 52.7%), but not high-density lipoprotein cholesterol, systolic BP, or diastolic BP. Among unmedicated populations, nut intake resulted in a significant decrease in TG (MD: −0.16 mmol/L, 95% CI: −0.30, −0.03, I2: 75.93%), and TC (MD: −0.21 mmol/L, 95% CI: −0.39, −0.03, I2: 86.59%), while in those with unreported medication use, there were significant decreases in TG (MD: −0.08 mmol/L, 95% CI: −0.15, −0.01, I2: 0%), TC (MD: −0.15 mmol/L, 95% CI: −0.22, −0.07, I2: 0%) and LDL-C (MD: −0.12 mmol/L, 95% CI: −0.19, −0.06, I2: 0.44%). No significant effects were observed for BP and lipids in the mixed medication group. While there were significant improvements in lipid profiles overall with tree nuts and peanuts consumption, we observed no benefits for BP. Furthermore, significant beneficial effects on lipids were only observed in those with unreported and no medication use. Few studies investigated effects in medicated participants only (n = 1 study for lipids), and the precise proportion of medication use within the mixed medicated group remains unclear. Consequently, it remains uncertain whether the lipid-lowering properties of consuming nuts remain when hyperlipidaemia is managed with medications. Further studies are needed to explore the influence of medication in combination with dietary approaches on responses to additional CVD risk factors.

Different responses of lipids and lignin phenols to nitrogen addition in meadow grassland soil

PurposeNitrogen (N) enrichment can affect the composition and stability of soil organic carbon (SOC) pools by altering vegetation and soil properties. However, the response of plant-derived carbon components in soil to different N addition levels is unclear. We investigated the changes and potential driving processes of plant-derived carbon components (especially lignins and lipids) in meadow grassland soils under long-term N addition in eastern Inner Mongolia, China.Materials and methodsBiomarker technology was utilised to analyse changes in plant-derived carbon components (C>20 free lipids, bound lipids, and lignin phenols) in soil under different N addition levels, including changes in soil chemical properties, enzyme activity, plant biomass, and diversity under N addition, as well as the specific pathways involved.Results and discussionWe found that high levels of N addition significantly reduced the concentration of soil lignin phenols whereas increased the accumulation of lipids (free and bound lipids). Compared with changes in plant biomass and diversity, soil chemical properties and enzyme activity play a more significant role in regulating the accumulation and degradation of plant-derived carbon. Structural equation modelling (SEM) showed that decreases in lignin phenol concentration were related to specific biochemical decomposition processes (increased polyphenol oxidase activity and decreased C/N). The increase in lipids associated with the protective effects of minerals mediated by pH.ConclusionsIn general, plant-derived carbon components showed inconsistent responses to N addition, lignin phenol concentration decreased and lipid concentration increased, which was mainly related to the change of soil biochemical properties. Plant-derived carbon components only showed significant changes under high N addition levels. Furthermore, our research indicates that SOC sequestration and functioning are highly dependent on soil biochemical properties, which weakens the influence of changes in plant carbon input on soil carbon storage.

Evaluation of Virus-Free Chrysanthemum 'Hangju' Productivity and Response to Virus Reinfection in the Field: Molecular Insights into Virus-Host Interactions.

The shoot apical meristem culture has been used widely to produce virus-free plantlets which have the advantages of strong disease resistance, high yield, and prosperous growth potential. However, this virus-free plant will be naturally reinfected in the field. The physiological and metabolic responses in the reinfected plant are still unknown. The flower of chrysanthemum 'Hangju' is a traditional medicine which is unique to China. In this study, we found that the virus-free 'Hangju' (VFH) was reinfected with chrysanthemum virus B/R in the field. However, the reinfected VFH (RVFH) exhibited an increased yield and medicinal components compared with virus-infected 'Hangju' (VIH). Comparative analysis of transcriptomes was performed to explore the molecular response mechanisms of the RVFH to CVB infection. A total of 6223 differentially expressed genes (DEGs) were identified in the RVFH vs. the VIH. KEGG enrichment and physiological analyses indicated that treatment with the virus-free technology significantly mitigated the plants' lipid and galactose metabolic stress responses in the RVFH. Furthermore, GO enrichment showed that plant viral diseases affected salicylic acid (SA)-related processes in the RVFH. Specifically, we found that phenylalanine ammonia-lyase (PAL) genes played a major role in defense-related SA biosynthesis in 'Hangju'. These findings provided new insights into the molecular mechanisms underlying plant virus-host interactions and have implications for developing strategies to improve plant resistance against viruses.

Phosphorus drives adaptive shifts in membrane lipid pools and synthesis between soils

Phospholipids are key constituents of microbial membranes and account for a substantial fraction of microbial P, while P-free betaine lipids provide a pathway for membrane synthesis independent of P. The aim of this study was to test if modulation of relative amounts of phospholipids vs P-free betaine lipids is a response to P availability. To examine responses of membrane lipids to P availability, we added P or P + C to an extremely P-poor sandstone-derived soil (total P = 41 μg g−1) and a higher P shale-derived soil (total P = 201 μg g−1). By using D2O labelling and LC-MS we were able to disentangle membrane lipid synthesis dependent on P (i.e. 2H incorporation into phospholipids) from membrane lipid synthesis independent of P (i.e. 2H incorporation into P-free betaine lipids). In unamended soils, P-free betaine lipids were almost 60% of the membrane lipid pool of the P-poor sandstone-derived soil, but only 10% of the higher-P shale-derived soil. Hence, to produce a unit of membrane lipid, the microbial population of sandstone soil required only 54% as much P as the microbial population of shale soil. Four days after adding P to the sandstone soil, phospholipids accounted for a larger proportion of the pool and synthesis of membrane lipids while pool and synthesis of P-free betaine lipids decreased. The increased allocation to phospholipids in sandstone soil amended with P likely reflected amelioration of P limitation given that P addition did not affect pools or synthesis of phospholipids versus betaine lipids in the higher-P shale soil. Collectively these data support the idea that having membranes with a high proportion of P-free betaine lipids is a key adaptive trait of microbial populations of P-poor soil, while the plasticity afforded by membrane lipid remodelling enables short-term fine-tuning of membrane lipid composition to P availability.

SIRT3 rs11246020 Polymorphism Associated Postprandial Triglyceride Dysmetabolism.

Energy metabolism is regulated by SIRT3, no research has been done on the connection between lipid metabolism in the oral fat test and SIRT3 polymorphism. Thus, we conducted a case-control study to investigate the connection between postprandial lipid and SIRT3 polymorphism. 402 non-obese Chinese subjects were enrolled and their postprandial lipid response to oral fat tolerance test (OFTT) was observed to understand the relationship between rs11246020 gene and postprandial triglyceride metabolism. In a binary logic regression model, a protective effect of the T allele of the rs11246020 SIRT3 for postprandial hypertriglyceridemia was shown (OR=0.417, 95% CI = 0.219-0.794, p=0.008). Compared to the CC genotype, individuals with the TT+CT variant of the rs11246020 SIRT3 gene demonstrated significantly lower levels of homeostasis model assessment of insulin resistance (HOMA-IR) (p=0.04), postprandial plasma glucose (PPG) (p=0.037), fasting plasma glucose (FPG) (p=0.02), and 4-hour triglyceridemia (Tg) (p=0.032). The C allele of rs11246020 SIRT3 gene may be a risk factor to increased possibility of postprandial triglyceridemia after an oral fat test, which involved in the mechanism of glucose and insulin metabolism.