Plasma Phospholipid Research Articles

Exploring the Interactions between Obesity and Diabetes: Implications for Understanding Metabolic Dysregulation in a Saudi Arabian Adult Population.

The rising prevalence of obesity in Saudi Arabia is a major contributor to the nation's high levels of cardiometabolic diseases such as type 2 diabetes. To assess the impact of obesity on the diabetic metabolic phenotype presented in young Saudi Arabian adults, participants (n = 289, aged 18-40 years) were recruited and stratified into four groups: healthy weight (BMI 18.5-24.99 kg/m2) with (n = 57) and without diabetes (n = 58) or overweight/obese (BMI > 24.99 kg/m2) with (n = 102) and without diabetes (n = 72). Distinct plasma metabolic phenotypes associated with high BMI and diabetes were identified using nuclear magnetic resonance spectroscopy and ultraperformance liquid chromatography mass spectrometry. Increased plasma glucose and dysregulated lipoproteins were characteristics of obesity in individuals with and without diabetes, but the obesity-associated lipoprotein phenotype was partially masked in individuals with diabetes. Although there was little difference between diabetics and nondiabetics in the global plasma LDL cholesterol and phospholipid concentration, the distribution of lipoprotein particles was altered in diabetics with a shift toward denser and more atherogenic LDL5 and LDL6 particles, which was amplified in the presence of obesity. Further investigation is warranted in larger Middle Eastern populations to explore the dysregulation of metabolism driven by interactions between obesity and diabetes in young adults.

Newcastle disease virus infection remodels plasma phospholipid metabolism in chickens

Newcastle disease is a global problem that causes huge economic losses and threatens the health and welfare of poultry. Despite the knowledge gained on the metabolic impact of NDV on cells, the extent to which infection modifies the plasma metabolic network in chickens remains unknown. Herein, we performed targeted metabolomic and lipidomic to create a plasma metabolic network map during NDV infection. Meanwhile, we used single-cell RNA sequencing to explore the heterogeneity of lung tissue cells in response to NDV infection invivo. The results showed that NDV remodeled the plasma phospholipid metabolism network. NDV preferentially targets infected blood endothelial cells, antigen-presenting cells, fibroblasts, and neutrophils in lung tissue. Importantly, NDV may directly regulate ribosome protein transcription to facilitate efficient viral protein translation. In conclusion, NDV infection remodels the plasma phospholipid metabolism network in chickens. This work provides valuable insights to further understand the pathogenesis of NDV.

Effect of fatty acid profiles in varying recipes of ready-to-use therapeutic foods on neurodevelopmental and clinical outcomes of children (6-59 months) with severe wasting: a systematic review.

In 2020, 13.6 million children under 5 years suffered from severe acute malnutrition (SAM)/wasting. Standard ready-to-use therapeutic foods (RUTFs) improve polyunsaturated fatty acid (PUFA) status but contain suboptimal amounts of omega-3 (n-3) PUFAs with unbalanced n-6-to-n-3 PUFA ratios. The aim was to compare the effects of RUTFs with different essential fatty acid contents on PUFA status, neurodevelopmental, and clinical outcomes (mortality, comorbidities, and recovery) of children with severe wasting. Twelve databases, trial repositories, and article references with no publication limitations. Ten studies from randomized, quasi, and cluster-randomized controlled trials providing RUTFs as home treatment to children 6-59 months with SAM/wasting were included. Plasma phospholipid eicosapentaenoic acid content was higher in children receiving RUTF with altered essential fatty acid contents compared with standard RUTF (0.20 [0.15-0.25], P < 0.00001). Docosahexaenoic acid (DHA) status only improved in children receiving RUTF with added fish oil (0.33 [0.15-0.50], P = 0.0003). The Malawi Developmental Assessment tool (MDAT) global development and problem-solving assessment scores were higher in global assessment and gross motor domains in children receiving added fish oil compared with standard formulation (0.19 [0.0-0.38] and 0.29 [0.03-0.55], respectively). Children receiving high-oleic-acid RUTF (lowering the n-6:n-3 PUFA ratio of the RUTF) with or without fish oil had significantly higher scores in social domains compared with those receiving the standard formulation (0.16 [0.00-0.31] and 0.24 [0.09-0.40]). Significantly higher mortality risk was found in children receiving a standard formulation compared with RUTF with a lower n-6:n-3 PUFA ratio (0.79 [0.67-0.94], P = 0.008). Although lowering n-6:n-3 PUFA ratios did not increase plasma DHA, it improved specific neurodevelopmental scores and mortality due to lower linoleic acid (high-oleic-acid peanuts), higher alpha-linolenic acid (altered oil), or both. Additional preformed n-3 long-chain PUFAs (fish oil) with RUTF improved the children's DHA status, neurodevelopmental outcomes, and weight-for-height z score. More research is needed regarding cost, availability, stability, acceptability, and the appropriate amount of n-3 long-chain PUFAs required in RUTFs for the best clinical outcomes. PROSPERO registration no. CRD42022303694.

Plasma phospholipids profiling changes were associated with the therapeutic response to Roxadustat in peritoneal dialysis patients.

Background: Elevated Phospholipids (PLs) and sphingolipid (SM) metabolism relates to with poor clinical status and adverse outcome of end-stage kidney disease patients undergoing peritoneal dialysis (PD). Studies have suggested that the use of hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) (Roxadustat) is associated with altered lipid metabolism. Observing on how PLs and SMs changes after the HIF-PHI treatment in PD patients may help understand the possible effect of HIF-PHI on PD patients besides correcting of anemia. Materials and methods: Stable peritoneal dialysis (PD) patients treated with Roxadustat for over 3months were included. Phospholipid and sphingolipid metabolism were measured before and after treatment. Results: 25 PD patients were included. Overall, phospholipid and sphingolipid metabolism showed a decreasing trend after HIF-PHI treatment. Levels of LysoPC (20:0), 1,2-dilinoleoyl-sn-glycero-3-phosphocholine [CisPC (DLPC) (18:2)], lysophosphatidylethanolamine (LysoPE) (14:0), and sphingomyelin (d18:1/17:0) (17:0) were significantly decreased (all p < 0.05). Further regression analyses confirmed the significant relationship between the increased of hemoglobin levels and the decrease in egg lyso PC: phosphatidylethanolamines (PE) (16:0-18:1), PE (16:0-18:2), PE (16:0-22:6), PE (18:0-20:4), PE (18:0-18:2), LysoPE (18:0), LysoPE (18:1), and phosphatidylcholine (PC) (18:1-18:0). Conclusion: This study demonstrated that phospholipid and sphingolipid metabolism decreased after administration of HIF-PHI and was associated with improvement of anemia.

Sıçanlarda sirkadiyen ritim bozuklukları ile ilgili çeşitli koşulların plazma ve eritrosit lipidleri üzerindeki etkileri: peroksizomal bir bakış açısı

Purpose: Lipidomics studies of sleep restriction, which is known to be associated with circadian perturbations, revealed alterations in some plasma phospholipid levels including plasmalogens which are partly synthesized in liver peroxisomes. To this end it was aimed to investigate effects of various conditions known to cause circadian rhythm disturbances on various peroxisomal parameters and to compare those effects with that of fenofibrate, a peroxisome proliferator-activated receptor alpha agonist.&#x0D; Materials and Methods: Plasmalogens and some fatty acids in erythrocyte lysates were analyzed by GC. Peroxisomal metabolites including very long chain fatty acids as well as phytanic and pristanic acids in plasma were measured by GC-MS. Immunohistological analyses by catalase antibodies were conducted on liver sections. &#x0D; Results: All the conditions tested exhibited increased catalase immunoreactivity in liver sections compared to that of controls. Both calorie restriction, time-restricted feeding, as well as fenofibrate treatment exhibited lower C18:0 plasmalogen contents of erythrocyte lysates. As plasmalogens are known to be synthesized by peroxisomes, the present results suggest that the peroxisomal lipid content in membranes might be affected by conditions co-occuring with circadian perturbations.&#x0D; Conclusion: Shared effects of conditions associated with circadian rhythm disturbances and peroxisomal induction by fenofibrate on erythrocyte membrane lipids might indicate a link between them.

Types of fish consumption differ across socioeconomic strata and impact differently on plasma fish-based omega-3 fatty acids: a cross-sectional study

PurposeWe investigated the associations of socioeconomic position (SEP) with total and type of fish intake in a large general population and validated whether types of fish intake were differently associated with plasma EPA and DHA in a subset of the population.MethodsFrom the Lifelines Cohort Study, 94,246 participants aged 44 ± 13 years old were included to test the association of two SEP indicators, i.e., education level and household income level, with dietary intakes of total, oily, lean, fried, and other types of fish. In a subset of 575 participants (mean age: 50 ± 13 years), EPA and DHA levels were measured in plasma phospholipids and triglycerides. Dietary fish intake was assessed using Food Frequency Questionnaire. Linear regressions were applied and adjusted for relevant covariates.ResultsCompared to the high education level, lower education levels were negatively associated with total, oily, lean, and other fish intake (p < 0.001 for all), and positively associated with fried fish intake (β (SE): 0.04 (0.04), p < 0.001 for middle education; 0.07 (0.04), p < 0.001 for low education), independently of relevant covariates. Similar results were observed for income levels. In the subset population, total and oily fish intakes were positively associated with plasma EPA and DHA (p < 0.02 for all). Lean and other fish intakes were positively associated with only DHA (p < 0.008 for all), but not EPA, while fried fish was not associated with either EPA or DHA in plasma (p > 0.1 for all).ConclusionLower SEP was associated with a lower total intake of fish, and of oily and lean fish, but with higher intake of fried fish. Fried fish was not associated with the fish-based EPA and DHA in plasma. Hence, SEP-related differences in fish consumption are both quantitative and qualitative.

Plasma essential fatty acid on hospital admission is a marker of COVID-19 disease severity

It is important for allocation of resources to predict those COVID patients at high risk of dying or organ failure. Early signals to initiate cellular events of host immunity can be derived from essential fatty acid metabolites preceding the cascade of proinflammatory signals. Much research has focused on understanding later proinflammatory responses. We assessed if remodelling of plasma phospholipid content of essential fatty acids by the COVID-19 virus provides early markers for potential death and disease severity. Here we show that, at hospital admission, COVID-19 infected subjects who survive exhibit higher proportions of C20:4n-6 in plasma phospholipids concurrent with marked proinflammatory cytokine elevation in plasma compared to healthy subjects. In contrast, more than half of subjects who die of this virus exhibit very low C18:2n-6 and C20:4n-6 content in plasma phospholipids on hospital admission compared with healthy control subjects. Moreover, in these subjects who die, the low level of primary inflammatory signals indicates limited or aberrant stimulation of host immunity. We conclude that COVID-19 infection results in early fundamental remodelling of essential fatty acid metabolism. In subjects with high mortality, it appears that plasma n-6 fatty acid content is too low to stimulate cellular events of host immunity.

Alterations of Plasma Metabolomics Profile in Thalassemia Patients with Low Bone Mineral Density

Background: Osteoporosis is commonly found in thalassemia patients; however, its pathogenesis is not thoroughly understood. Metabolomics is the study of metabolites in biofluids, which help to elucidate the underlying mechanism of several metabolic diseases. Nevertheless, plasma metabolomics profiling has not been carefully investigated in thalassemia patients with low bone mineral density (BMD). Objective: To investigate the alterations of plasma targeted metabolomics in adult thalassemia patients with low BMD. Methods: We conducted a cross-sectional study from February 2022 to January 2023 at Outpatient Hematology Clinic, Chiang Mai University. Thalassemia patients, confirmed by HPLC hemoglobin typing, who aged 19-50 years (male) or more than 19 years (premenopausal female) were eligible. Exclusion criteria were (1) current use or history of any bone modifying agent use within 1 year, (2) severe hepatic or renal impairment, (3) active malignancy or infection. Age- and sex-matched with normal body mass index were also recruited as controls. Two-point BMD, plasma targeted metabolomics by using liquid chromatography coupled with mass spectrometry (LC/MS), and serum bone turnover markers, including bone resorption using CTX, and bone formation using P1NP, were assessed. Interested metabolomes included 19 amino acids, 7 free fatty acids, 20 acylcarnitine intermediates of branched-chain amino acids and fatty acids, 37 phospholipid derivatives, and 4 Krebs' cycle metabolomes. Low BMD was defined as a Z-score of less than -2.0 at any site. Outcomes were the alterations of plasma levels of metabolomes among control, thalassemia with normal BMD, and thalassemia with low BMD. Results: There were a total of 80 thalassemia patients and 40 controls recruited. The mean age of patients was 34.8 years (SD 8.7). Twenty-six patients (32.5%) were male. Forty-seven patients (58.8%) were transfusion-dependent thalassemia. Low BMD was detected in 37 patients (47.5%). We found several plasma metabolomes that were significantly changed between controls and thalassemia and further altered when compared between thalassemia with normal BMD and low BMD (Figure 1). Considering plasma amino acids, glutamate level was significantly increased while glutamine level was decreased. Regarding fatty acid-related metabolomes, arachidonic acid level was increased in thalassemia with low BMD. In addition, several fatty acid-derived medium- and long-chain acylcarnitine levels were higher in plasma of thalassemia with low BMD, particularly C14:0 carnitine. Among plasma phospholipid derivatives, phosphatidylinositol (PI) and lysoPI levels were significantly increased in thalassemia with low BMD. Four plasma Krebs' cycle metabolites were not different among groups. Surprisingly, two serum bone turnover markers (CTX and P1NP) were not sensitive for detecting low bone mineral density in thalassemia (Control vs Thalassemia with normal BMD vs Thalassemia with low BMD: CTX 0.27±0.17 vs 0.36±0.20 vs 0.34±0.19 ng/mL, p=0.079 and P1NP 57.2±25.0 vs 57.2±34.0 vs 53.7±26.4 ng/mL, p=0.824). Conclusion: There were several changes in plasma metabolome levels among thalassemia with low BMD, including altered glutamate-glutamine metabolism, impaired fatty acid oxidation, and increased plasma phosphatidylinositol. Interestingly, these changes were found in patients with normal BMD and further increased in patients with low BMD. Our findings suggest the role of plasma metabolomics as non-invasive biomarkers for osteoporotic condition in thalassemia patients.

Lipoprotein(a)-60 Years Later-What Do We Know?

Lipoprotein(a) (Lp(a)) molecule includes two protein components: apolipoprotein(a) and apoB100. The molecule is the main transporter of oxidized phospholipids (OxPL) in plasma. The concentration of this strongly atherogenic lipoprotein is predominantly regulated by the LPA gene expression. Lp(a) is regarded as a risk factor for several cardiovascular diseases. Numerous epidemiological, clinical and in vitro studies showed a strong association between increased Lp(a) and atherosclerotic cardiovascular disease (ASCVD), calcific aortic valve disease/aortic stenosis (CAVD/AS), stroke, heart failure or peripheral arterial disease (PAD). Although there are acknowledged contributions of Lp(a) to the mentioned diseases, clinicians struggle with many inconveniences such as a lack of well-established treatment lowering Lp(a), and common guidelines for diagnosing or assessing cardiovascular risk among both adult and pediatric patients. Lp(a) levels are different with regard to a particular race or ethnicity and might fluctuate during childhood. Furthermore, the lack of standardization of assays is an additional impediment. The review presents the recent knowledge on Lp(a) based on clinical and scientific research, but also highlights relevant aspects of future study directions that would approach more suitable and effective managing risk associated with increased Lp(a), as well as control the Lp(a) levels.

Circulating Omega-3 and Omega-6 Fatty Acids, Cognitive Decline, and Dementia in Older Adults.

Comprising nearly 35% of brain lipids, polyunsaturated fatty acids (PUFA) are essential for optimal brain function. However, the role of PUFA on cognitive health outcomes later in life is largely unknown. We investigated prospective associations of plasma phospholipid omega-3 (ALA [18 : 3], EPA [20 : 5], DPA [22 : 5], DHA [22 : 6]) and omega-6 (LA [18 : 2], AA [20 : 4]) PUFA with cognitive decline, risk of cognitive impairment and dementia among adults aged≥65 years in the Cardiovascular Health Study. Circulating fatty acid concentrations were measured serially at baseline (1992/1993), 6 years, and 13 years later. Cognitive decline and impairment were assessed using the 100-point Modified Mini-Mental State Examination (3MSE) up to 7 times. Clinical dementia was identified using adjudicated neuropsychological tests, and ICD-9 codes. Among 3,564 older adults free of stroke and dementia at baseline, cognitive function declined annually by approximately -0.5 3MSE points; 507 participants developed cognitive impairment and 499 dementia over up to 23 years of follow-up. In multivariable models, higher circulating arachidonic acid (AA) concentrations were associated with slower cognitive decline and lower dementia risk, with associations growing stronger with greater length of follow-up (hazard ratio [HR,95% CI] of dementia per interquintile range, 0.74 [0.56-0.97] at 5 years, and 0.53 [0.37-0.77] at 15 years). Circulating docosapentaenoic (DPA) concentrations were associated with slower cognitive decline and lower risk of cognitive impairment (extreme-quintile HR, 0.72 [95% CI: 0.55, 0.95]). Findings were generally null or inconsistent for other omega-3 or omega-6 PUFA. Circulating AA and DPA, but not other PUFA, are associated with slower rate of cognitive decline and lower risk of dementia or cognitive impairment later in life.

Associations between Fatty Acid Intakes and Plasma Phospholipid Fatty Acid Concentrations in the European Prospective Investigation into Cancer and Nutrition.

The aim of this study is to determine the correlations between dietary fatty acid (FA) intakes and plasma phospholipid (PL) FA levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The dietary intake of 60 individual FAs was estimated using centre-specific validated dietary questionnaires. Plasma PL FA concentrations of these FAs were measured in non-fasting venous plasma samples in nested case-control studies within the EPIC cohort (n = 4923, using only non-cases). Spearman rank correlations were calculated to determine associations between FA intakes and plasma PL FA levels. Correlations between FA intakes and circulating levels were low to moderately high (-0.233 and 0.554). Moderate positive correlations were found for total long-chain n-3 poly-unsaturated FA (PUFA) (r = 0.354) with the highest (r = 0.406) for n-3 PUFA docosahexaenoic acid (DHA). Moderate positive correlations were also found for the non-endogenously synthesized trans-FA (r = 0.461 for total trans-FA C16-18; r = 0.479 for industrial trans-FA (elaidic acid)). Our findings indicate that dietary FA intakes might influence the plasma PL FA status to a certain extent for several specific FAs. The stronger positive correlations for health-enhancing long-chain PUFAs and the health-deteriorating trans-FA that are not endogenously produced are valuable for future cancer prevention public health interventions.

Development of a new online SPE-HPLC-MS/MS method for the profiling and quantification of sphingolipids and phospholipids in red blood cells – Application to the study of Gaucher's disease

Red blood cells (RBCs) are the subject of clinical attention due to their biological importance. Recently, it has been shown that certain erythrocyte pathologies could be linked to an abnormal lipid composition. In this work, we have developed a simple and fast method using online sample preparation with liquid chromatography coupled to mass spectrometry (SPE-HPLC-MS/MS), to identify a large number of sphingolipids (SL) and phospholipids (PL). The use of online sample preparation considerably reduces analysis times (15 min including extraction and separation of lipids + 2 min for system re-equilibration) and facilitates experimentation while ensuring very good extraction yields. This method was then successfully applied to the quantification of 30 sphingolipids and phospholipids in plasma and erythrocyte extracts from a cohort of individuals with Gaucher disease, treated or not by enzymotherapy. Our results for the study of this disease, led us to establish the lipid profile of the healthy red blood cells, still not very well-known to date. For this, we adopted a semi-targeted approach, based on the use of a triple-quadrupole analyzer and identified more than two hundred different lipid species. These promising results will hopefully enable us to enrich our knowledge of the normal red blood cells lipidome.

Early Pregnancy Maternal Plasma Phospholipid Saturated Fatty Acids and Fetal Growth: Findings from a Multi-Racial/Ethnic Birth Cohort in US.

Saturated fatty acids (SFAs) during pregnancy are associated with disrupted metabolic programming among offspring at birth and later growth. We examined plasma phospholipid SFAs in early pregnancy and fetal growth throughout pregnancy. We enrolled 321 pregnant women from the NICHD Fetal Growth Studies-Singleton Cohort at gestational weeks 8-13. Ultrasonogram schedules were randomly assigned to capture weekly fetal growth. We measured plasma phospholipid SFAs at early pregnancy using blood samples and modeled fetal growth trajectories across tertiles of SFAs with cubic splines using linear mixed models after full adjustment. We then compared pairwise weekly fetal growth biometrics referencing the lowest tertile in each SFA using the Wald test. We found that even-chain and very long even-chain SFAs were inversely associated, whereas odd-chain SFAs were positively associated with fetal weight and size. Compared with the lowest tertile, the highest tertile of pentadecanoic acid (15:0) had a greater fetal weight and size, starting from week 13 until late pregnancy (at week 39: 3429.89 vs. 3269.08 g for estimated fetal weight; 328.14 vs. 323.00 mm for head circumference). Our findings could inspire future interventions using an alternative high-fat diet rich in odd-chain SFAs for optimal fetal growth.

Investigating Associations of Omega-3 Fatty Acids, Lung Function Decline, and Airway Obstruction.

Rationale: Inflammation contributes to lung function decline and the development of chronic obstructive pulmonary disease. Omega-3 fatty acids have antiinflammatory properties and may benefit lung health. Objectives: To investigate associations of omega-3 fatty acids with lung function decline and incident airway obstruction in a diverse sample of adults from general-population cohorts. Methods: Complementary study designs: 1) longitudinal study of plasma phospholipid omega-3 fatty acids and repeated FEV1 and FVC measures in the NHLBI Pooled Cohorts Study and 2) two-sample Mendelian randomization (MR) study of genetically predicted omega-3 fatty acids and lung function parameters. Measurements and Main Results: The longitudinal study found that higher omega-3 fatty acid levels were associated with attenuated lung function decline in 15,063 participants, with the largest effect sizes for the most metabolically downstream omega-3 fatty acid, docosahexaenoic acid (DHA). An increase in DHA of 1% of total fatty acids was associated with attenuations of 1.4 ml/yr for FEV1 (95% confidence interval [CI], 1.1-1.8) and 2.0 ml/yr for FVC (95% CI, 1.6-2.4) and a 7% lower incidence of spirometry-defined airway obstruction (95% CI, 0.89-0.97). DHA associations persisted across sexes and smoking histories and in Black, White, and Hispanic participants, with associations of the largest magnitude in former smokers and Hispanic participants. The MR study showed similar trends toward positive associations of genetically predicted downstream omega-3 fatty acids with FEV1 and FVC. Conclusions: The longitudinal and MR studies provide evidence supporting beneficial effects of higher levels of downstream omega-3 fatty acids, especially DHA, on lung health.

P02-030-23 Plasma Phospholipid Polyunsaturated Fatty Acids in Early Pregnancy and Thyroid Function Throughout Pregnancy: A Longitudinal Study

P02-030-23 Plasma Phospholipid Polyunsaturated Fatty Acids in Early Pregnancy and Thyroid Function Throughout Pregnancy: A Longitudinal Study

Interaction between plasma phospholipid odd-chain fatty acids and GAD65 autoantibodies on the incidence of adult-onset diabetes: the EPIC-InterAct case–cohort study

Aims/hypothesisIslet autoimmunity may progress to adult-onset diabetes. We investigated whether circulating odd-chain fatty acids (OCFA) 15:0 and 17:0, which are inversely associated with type 2 diabetes, interact with autoantibodies against GAD65 (GAD65Ab) on the incidence of adult-onset diabetes.MethodsWe used the European EPIC-InterAct case–cohort study including 11,124 incident adult-onset diabetes cases and a subcohort of 14,866 randomly selected individuals. Adjusted Prentice-weighted Cox regression estimated HRs and 95% CIs of diabetes in relation to 1 SD lower plasma phospholipid 15:0 and/or 17:0 concentrations or their main contributor, dairy intake, among GAD65Ab-negative and -positive individuals. Interactions between tertiles of OCFA and GAD65Ab status were estimated by proportion attributable to interaction (AP).ResultsLow concentrations of OCFA, particularly 17:0, were associated with a higher incidence of adult-onset diabetes in both GAD65Ab-negative (HR 1.55 [95% CI 1.48, 1.64]) and GAD65Ab-positive (HR 1.69 [95% CI 1.34, 2.13]) individuals. The combination of low 17:0 and high GAD65Ab positivity vs high 17:0 and GAD65Ab negativity conferred an HR of 7.51 (95% CI 4.83, 11.69), with evidence of additive interaction (AP 0.25 [95% CI 0.05, 0.45]). Low dairy intake was not associated with diabetes incidence in either GAD65Ab-negative (HR 0.98 [95% CI 0.94, 1.02]) or GAD65Ab-positive individuals (HR 0.97 [95% CI 0.79, 1.18]).Conclusions/interpretationLow plasma phospholipid 17:0 concentrations may promote the progression from GAD65Ab positivity to adult-onset diabetes.Graphical

Ligand dependent interaction between PC-TP and PPARδ mitigates diet-induced hepatic steatosis in male mice

Phosphatidylcholine transfer protein (PC-TP; synonym StarD2) is a soluble lipid-binding protein that transports phosphatidylcholine (PC) between cellular membranes. To better understand the protective metabolic effects associated with hepatic PC-TP, we generated a hepatocyte-specific PC-TP knockdown (L-Pctp−/−) in male mice, which gains less weight and accumulates less liver fat compared to wild-type mice when challenged with a high-fat diet. Hepatic deletion of PC-TP also reduced adipose tissue mass and decreases levels of triglycerides and phospholipids in skeletal muscle, liver and plasma. Gene expression analysis suggest that the observed metabolic changes are related to transcriptional activity of peroxisome proliferative activating receptor (PPAR) family members. An in-cell protein complementation screen between lipid transfer proteins and PPARs uncovered a direct interaction between PC-TP and PPARδ that was not observed for other PPARs. We confirmed the PC-TP– PPARδ interaction in Huh7 hepatocytes, where it was found to repress PPARδ-mediated transactivation. Mutations of PC-TP residues implicated in PC binding and transfer reduce the PC-TP-PPARδ interaction and relieve PC-TP-mediated PPARδ repression. Reduction of exogenously supplied methionine and choline reduces the interaction while serum starvation enhances the interaction in cultured hepatocytes. Together our data points to a ligand sensitive PC-TP– PPARδ interaction that suppresses PPAR activity.

Physiological Benefits of Dietary Lysophospholipid Supplementation in a Marine Fish Model: Deep Analyses of Modes of Action.

Given the hydrophilic structure of lysophospholipids (LPLs), their dietary inclusion translates into a better emulsifying capacity of the dietary components. The present study aimed to understand the mechanisms underlying the growth-promoting effect of LPL supplementation by undertaking deep analyses of the proximal intestine and liver interactomes. The Atlantic salmon (Salmo salar) was selected as the main aquaculture species model. The animals were divided into two groups: one was fed a control diet (C-diet) and the other a feed (LPL-diet) supplemented with an LPL-based digestive enhancer (0.1% AQUALYSO®, Adisseo). The LPL-diet had a positive effect on the fish by increasing the final weight by 5% and reducing total serum lipids, mainly due to a decrease in the plasma phospholipid (p < 0.05). In the intestine, the upregulated interactome suggests a more robust digestive capacity, improving vesicle-trafficking-related proteins, complex sugar hydrolysis, and lipid metabolism. In the liver, the LPL-diet promotes better nutrients, increasing several metabolic pathways. The downregulation of the responses to stress and stimuli could be related to a reduced proinflammatory state. This study on the benefits and modes of action of dietary LPLs opens a new window into fish nutrition and could be extended to other productive species.

Fatty Acid Composition of Plasma and Liver Lipid Components as Influenced by Diet in the Growing Chick

The influence of dietary protein and cholesterol on plasma and liver lipids and on their component fatty acid composition was studied in growing chicks. Increased dietary protein decreased plasma and α-lipoprotein lipid levels and increased liver cholesterol. Cholesterol supplementation elevated plasma and liver lipids but decreased α-lipoprotein lipids. In general, feeding a low-protein or a cholesterol-supplemented diet resulted in similar fatty acid changes. Both treatments resulted in significantly increased oleic and decreased arachidonic acid levels in the plasma cholesterol esters, glycerides and phospholipids. The oleic acid level of the liver lipids was also higher in chicks fed the low-protein or cholesterol-supplemented diets. The dietary treatments tended to decrease linoleic acid levels particularly in the cholesterol ester fraction. The cholesterol ester fraction showed the most consistent changes.

Patients with Anorexia Nervosa Demonstrate Deficiencies of Selected Essential Fatty Acids, Compensatory Changes in Nonessential Fatty Acids and Decreased Fluidity of Plasma Lipids

The objective of this study was to assess the essential fatty acid status of patients with anorexia nervosa. Blood was collected from eight fasting female anorexia nervosa patients with a mean of 81% ideal body weight. Fatty acid composition of phospholipids, nonesterified fatty acids, triglycerides and cholesteryl esters of plasma were determined by capillary gas chromatography to indicate polyunsaturated fatty acids status compared with 19 healthy female adults <25 y old. Subjects with anorexia nervosa showed polyunsaturated fatty acid deficiencies in plasma phospholipids different from simple nutritional essential fatty acid deficiency or chronic malnutrition. The phospholipid profile showed significantly lower (n-6) and (n-3) elongation and desaturation products, and elevated short-chain saturated, short-chain monounsaturated, branched-chain and odd-chain fatty acids. These elevations indicate enhancement of biosynthesis of alternative fatty acids that only partially compensated for the loss of polyunsaturated fatty acids in providing membrane “fluidity.” Calculated mean melting point of the fatty acids of phospholipids in patients with anorexia nervosa was elevated 7.7°C above normal values. These results demonstrate that patients with anorexia nervosa have deficiencies of selected essential fatty acids, compensatory changes in nonessential fatty acids and decreased fluidity of plasma lipids.