Non-esterified Free Fatty Acids Research Articles

Mitochondria targeted esculetin administration improves insulin resistance and hyperglycemia-induced atherosclerosis in db/db mice.

The development and progression of hyperglycemia (HG) and HG-associated atherosclerosis are exacerbated by mitochondrial dysfunction due to dysregulated mitochondria-derived ROS generation. We recently synthesized a novel mitochondria-targeted esculetin (Mito-Esc) and tested its dose-response therapeutic efficacy in mitigating HG-induced atherosclerosis in db/db mice. In comparison to simvastatin and pioglitazone, Mito-Esc administration resulted in a considerable reduction in body weights and improved glucose homeostasis, possibly by reducing hepatic gluconeogenesis, as indicated by a reduction in glycogen content, non-esterified free fatty acids (NEFA) levels, and fructose 1,6-bisphosphatase (FBPase) activity. Interestingly, Mito-Esc treatment, by regulating phospho-IRS and phospho-AKT levels, greatly improved palmitate-induced insulin resistance, resulting in enhanced glucose uptake in adipocytes and HepG2 cells. Also, and importantly, Mito-Esc administration prevented HG-induced atheromatous plaque formation and lipid accumulation in the descending aorta. In addition, Mito-Esc administration inhibited the HG-mediated increase in VACM, ICAM, and MAC3 levels in the aortic tissue, as well as reduced the serum pro-inflammatory cytokines and markers of senescence. In line with this, Mito-Esc significantly inhibited monocyte adherence to human aortic endothelial cells (HAECs) treated with high glucose and reduced high glucose-induced premature senescence in HAECs by activating the AMPK-SIRT1 pathway. In contrast, Mito-Esc failed to regulate high glucose-induced endothelial cell senescence under AMPK/SIRT1-depleted conditions. Together, the therapeutic efficacy of Mito-Esc in the mitigation of hyperglycemia-induced insulin resistance and the associated atherosclerosis is in part mediated by potentiating the AMPK-SIRT1 axis. KEY MESSAGES: Mito-Esc administration significantly mitigates diabetes-induced atherosclerosis. Mito-Esc improves hyperglycemia (HG)-associated insulin resistance. Mito-Esc inhibits HG-induced vascular senescence and inflammation in the aorta. Mito-Esc-mediated activation of the AMPK-SIRT1 axis regulates HG-induced endothelial cell senescence.

Anti-adipogenesis effect of indole-3-acrylic acid on human preadipocytes and HFD-induced zebrafish.

Obesity, defined as excessive or abnormal body fat accumulation, which could significantly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) diseases and seriously affect people's quality of life. More than 2 billion people are overweight, and the incidence of obesity is increasing rapidly worldwide, it has become a widely concerned public health issue in the world. Diverse evidence show that active metabolites are involved in the pathophysiological processes of obesity. However, whether the downstream catabolite of tryptophan, 3-indole acrylic acid (IA), is involved in obesity remains unclear. We collected the samples of serum from peripheral blood of obesity and health controls, and liquid chromatography-mass spectrometry (LC-MS) was performed to identify the plasma levels of IA. Additionally, we verified the potential benefits of IA on human preadipocytes and HFD- induced zebrafish by cell viability assay, flow cytometry assay, Oil red O staining, total cholesterol (T-CHO), triglyceride (TG) and nonesterified free fatty acids (NEFA) measurements and Nile Red staining. RNA-Seq, functional analysis and western blot revealed the mechanisms underlying the function of IA. We found that the content of IA in peripheral blood serum of overweight people was significantly lower than that of normal people. In addition, supplementation with IA in zebrafish larvae induced by a high fat diet (HFD) dramatically reduced HFD induced lipid accumulation. IA had no effect on proliferation and apoptosis of preadipocytes, but significantly inhibited adipogenesis of preadipocytes by down-regulate CEBPα and PPARγ. RNA-Seq and functional analysis revealed that IA regulated the adipogenesis of preadipocytes through stimulate the phosphorylation of STAT1. Taken together, IA has been identified as a potent metabolite for the prevention or treatment of obesity.

Alterations in nonesterified free fatty acid trafficking rather than hyperandrogenism contribute to metabolic health in obese women with polycystic ovary syndrome

To determine whether alterations in non-esterified free fatty acids (NEFA) dynamics or degree of hyperandrogenism (HA) contribute to the difference in insulin sensitivity between metabolically healthy (MHO-PCOS) and metabolically unhealthy (MUO-PCOS) obese PCOS women. Prospective cross-sectional study. One hundred-and-twenty-five obese PCOS women. Consecutive obese (BMI≥30 kg/m2) oligo-ovulatory PCOS women (n=125) underwent oGTT and a subgroup of 16 participants underwent modified frequently samples intravenous glucose tolerance test (mFSIVGTT), to determine insulin action and NEFA dynamics. Degree of IR in adipose tissue (AT) basally (Adipo-IR) and dynamically (NEFAnadir, TIMEnadir, and %NEFAsupp); lipolysis rate (SNEFA) and NEFA uptake rate (KNEFA); whole-body insulin action (AIRg, Si, Sg, and DI); and HA (hirsutism score, testosterone [total, free], DHEAS). 85 (68%) subjects were MUO-PCOS and 40 (32%) MHO-PCOS by HOMA-IR. MUO-PCOS and MHO-PCOS did not differ in mean age, BMI, WHR, HA and lipoprotein levels. By mFSIVGTT, 8 MUO-PCOS subjects had lesser Si, KNEFA, and %NEFAsupp, and greater TIMEnidar, NEFAnidar and Adipo-IR, than 8 MHO-PCOS, but similar fasting NEFA and SNEFA. MUO-PCOS had higher HOMA-β% and fasting insulin than MHO-PCOS. In bivalent analysis, Si correlated strongly and negatively with NEFAnadir, weakly and negatively with TIMEnadir, and positively with KNEFA and NEFAsupp, in MUO-PCOS only. Independent of age and BMI, MUO-PCOS women have reduced NEFA uptake and altered insulin-mediated NEFA suppression, but no difference in HA, than MHO-PCOS. Altered insulin-mediated NEFA suppression, rather than HA or lipolysis rate, contributes to variations in insulin sensitivity among obese PCOS women.

Effects of quercetin and hydroxytyrosol supplementation in a high-fat diet on growth, lipid metabolism, and mitochondrial function in spotted seabass (Lateolabrax maculatus)

Endoplasmic reticulum (ER) stress and mitochondrial impairment commonly occur during the progression of fatty liver disease. There is a close connection and crosstalk between mitochondria and ER. The potential positive influence of mitigating ER stress (ERS) and mitochondrial damage in the context of preventing and treating fatty liver was explored in spotted seabass (Lateolabrax maculatus) as a susceptible model to fatty liver. A normal-fat diet (11% fat, NFD) and a high-fat diet (17% fat, HFD) were formulated and three additional diets were prepared by supplementation of quercetin (QUE) (0.1%), hydroxytyrosol (HT) (0.02%) or their combination (0.1% QUE + 0.02% HT) to the HFD (HFD + QUE HFD + HT and HFD + QUE + HT diets).Three replicate groups of fish (25 ± 0.02 g) were fed the test diets to visual satiety for 8 weeks. The results revealed the deterioration of growth, feed intake and feed utilization in HFD group compared to the NFD group whereas QUE and HT application improved their values and the optimum results were achieved for the HFD + QUE + HT group. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, and both serum and hepatic triglyceride (TG), total cholesterol (T-CHO) and non-esterified free fatty acids (NEFA) concentrations were enhanced in HFD group, and their values decreased by QUE and HT, particularly their combined supplementation. The results of oil red O staining exhibited a remarkable reduction in number of lipid droplets in the liver of fish from HFD + QUE + HT group compared to the HFD group. Whole-body and muscle fat contents and abdominal fat index decreased by QUE and HT application. Expression of lipid metabolism related genes (srebp-1c, fas, acc) were down-regulated by QUE and HT treatment. Co-supplementation of QUE and HT down-regulated the expression of ERS-related genes (grp78, chop, perk, atf6, ire1), improved ER ultrastructure, and enhanced the coupling between mitochondria and ER. Moreover, expression of genes associated with hepatic mitochondrial biogenesis (pgc1-α, pgc1-β, nrf1) and mitophagy (pink1, atg5, mul1) was up-regulated in HFD + QUE, HFD + HT and HFD + QUE + HT groups. These data suggest that combined supplementation of QUE and HT in HFD for spotted seabass can improve growth and feed utilization, reduce hepatic damage and fat accumulation, and alleviate HFD induced ERS and mitochondrial dysfunction.

Ameliorative effect of Lactobacillus plantarum CCFM8661 on oleic acid-induced acne: Integrated the gut microbiota link to the acne pathogenesis.

Acne vulgaris is an inflammatory disease of the pilosebaceous unit of the skin that has serious adverse effects on the physical and mental health of patients. Probiotics are extensively employed in dermatology and could be an alternative option for acne therapy. Here, we evaluated the effect of oral ingestion of live and inactivated Lactobacillus plantarum CCFM8661 on oleic acid-induced acne using a mouse model. Results found that live L. plantarum CCFM8661 suppressed the skin inflammation and serum hormone (insulin and testosterone) production in acne mice. Parallelly, live L. plantarum CCFM8661 effectively reduced the formation of skin lipids (TG and NEFA), and normalized the expression of skin lipid metabolism-related genes (PPRA-γ, SREBP-1c, ACCα, FASN, PPRA-α, ACOX1, HSL and ATGL). In comparison, inactivated L. plantarum CCFM8661 had no effect on skin inflammation or serum hormone secretion, but decreased the skin TG and normalized the expression of skin lipid metabolism-related genes (PPRA-γ, SREBP-1c, FASN and ATGL) in acne mice. Both live and inactivated L. plantarum CCFM8661 raised the richness of gut microbiota, reduced the ratio of Bacteroidetes: Firmicutes, and decreased the relative abundance of Staphylococcus in the feces of acne mice. Oral ingestion of L. plantarum CCFM8661, particularly live cells, could alleviate acne by suppressing skin inflammation, normalizing the metabolism of hormones and skin lipids, which may be achieved by improving the gut microbial ecosystem. This article is protected by copyright. All rights reserved.

Maternal hyperglycemia induces alterations in hepatic amino acid, glucose and lipid metabolism of neonatal offspring: Multi-omics insights from a diabetic pig model

ObjectiveTo gain mechanistic insights into adverse effects of maternal hyperglycemia on the liver of neonates, we performed a multi-omics analysis of liver tissue from piglets developed in genetically diabetic (mutant INS gene induced diabetes of youth; MIDY) or wild-type (WT) pigs. MethodsProteome, metabolome and lipidome profiles of liver and clinical parameters of serum samples from 3-day-old WT piglets (n = 9) born to MIDY mothers (PHG) were compared with those of WT piglets (n = 10) born to normoglycemic mothers (PNG). Furthermore, protein–protein interaction network analysis was used to reveal highly interacting proteins that participate in the same molecular mechanisms and to relate these mechanisms with human pathology. ResultsHepatocytes of PHG displayed pronounced lipid droplet accumulation, although the abundances of central lipogenic enzymes such as fatty acid-synthase (FASN) were decreased. Additionally, circulating triglyceride (TG) levels were reduced as a trend. Serum levels of non-esterified free fatty acids (NEFA) were elevated in PHG, potentially stimulating hepatic gluconeogenesis. This is supported by elevated hepatic phosphoenolpyruvate carboxykinase (PCK1) and circulating alanine transaminase (ALT) levels. Even though targeted metabolomics showed strongly elevated phosphatidylcholine (PC) levels, the abundances of multiple key enzymes involved in major PC synthesis pathways – most prominently those from the Kennedy pathway – were paradoxically reduced in PHG liver. Conversely, enzymes involved in PC excretion and breakdown such as PC-specific translocase ATP-binding cassette 4 (ABCB4) and phospholipase A2 were increased in abundance. ConclusionsOur study indicates that maternal hyperglycemia without confounding obesity induces profound molecular changes in the liver of neonatal offspring. In particular, we found evidence for stimulated gluconeogenesis and hepatic lipid accumulation independent of de novo lipogenesis. Reduced levels of PC biosynthesis enzymes and increased levels of proteins involved in PC translocation or breakdown may represent counter-regulatory mechanisms to maternally elevated PC levels. Our comprehensive multi-omics dataset provides a valuable resource for future meta-analysis studies focusing on liver metabolism in newborns from diabetic mothers.

Oleic acid abomasal infusion limits lipolysis and improves insulin sensitivity in adipose tissue from periparturient dairy cows

Excessive adipose tissue (AT) lipolysis around parturition in dairy cows is associated with impaired AT insulin sensitivity and increased incidence of metabolic diseases. Supplementing cows with oleic acid (OA) reduces circulating biomarkers of lipolysis and improves energy balance. Nevertheless, it is unclear if OA alters lipid trafficking in AT. In the liver and skeletal muscle, OA improves mitochondrial function and promotes lipid droplet formation by activating perilipin 5 (PLIN5) and peroxisome proliferator-activated receptor α (PPARα). However, it is unknown if this mechanism occurs in AT. The objective of this study was to determine the effect of OA on AT lipolysis, systemic and AT insulin sensitivity, and AT mitochondrial function in periparturient dairy cows. Twelve rumen-cannulated Holstein cows were infused abomasally following parturition with ethanol (CON) or OA (60 g/d) for 14 d. Subcutaneous AT samples were collected at 11 ± 3.6 d before calving (-12 d), and 6 ± 1.0 d (7 d) and 13 ± 1.4 d (14 d) after parturition. An intravenous glucose tolerance test was performed on d 14. Adipocyte morphometry was performed on hematoxylin and eosin-stained AT sections. The antilipolytic effect of insulin (1 μg/L) was evaluated using an ex vivo explant culture following lipolysis stimulation. PLIN5 and PPARα transcription and translation were determined by real-time quantitative PCR and capillary electrophoresis, respectively. RNA sequencing was used to evaluate the transcriptomic profile of mitochondrial gene networks. In CON cows, postpartum lipolysis increased the percentage of smaller (<3,000 µm2) adipocytes at 14 d compared with -12 d. However, OA limited adipocyte size reduction at 14 d. Likewise, OA decreased lipolysis plasma markers nonesterified free fatty acids and β-hydroxybutyrate at 5 and 7 d. Over the 14-d period, compared with CON, OA increased the concentration of plasma insulin and decreased plasma glucose. During the glucose tolerance test, OA decreased circulating glucose concentration (at 10, 20, 30, 40 min) and the glucose clearance rate. Moreover, OA increased insulin at 10 and 20 min and tended to increase it at 30 min. Following lipolysis stimulation, OA improved the antilipolytic effect of insulin in the AT at 14 d. PLIN5 and PPARA gene expression decreased postpartum regardless of treatment. However, OA increased PLIN5 protein expression at 14 d and increased PPARA at 7 and 14 d. Immunohistochemical analysis of AT and RNA sequencing data showed that OA increased the number of mitochondria and improved mitochondrial function. However, OA had no effect on production and digestibility. Our results demonstrate that OA limits AT lipolysis, improves systemic and AT insulin sensitivity, and is associated with markers of mitochondrial function supporting a shift to lipogenesis in AT of periparturient dairy cows.

Effects of supplemental octanoate on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammation-related genes expression of large yellow croaker (Larimichthys crocea) fed with high soybean oil diet.

Dietary high soybean oil (SO) levels might cause hepatic lipid deposition, induce oxidative stress and inflammatory response in aquatic animals, while octanoate (OCT) is beneficial to metabolism and health in mammals. However, the effect of OCT has been studied rarely in aquatic animals. In this study, a 10-week feeding trial was conducted to investigate the effect of supplemental OCT on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammatory response of large yellow croaker (Larimichthys crocea) fed with high SO levels diet. The negative control diet contained 7% fish oil (FO), while the positive control diet contained 7% SO. The other four experimental diets were supplemented with 0.7, 2.1, 6.3 and 18.9 g/kg sodium octanoate (OCT) based on the positive control diet. Results showed that OCT supplementation effectively reduced the hepatic crude lipid, triglyceride (TG), total cholesterol (TC) and non-esterified free fatty acids contents, and alleviated lipid accumulation caused by the SO diet. Meanwhile, OCT supplementation decreased the serum TG, TC, alanine transaminase, aspartate transaminase and low-density lipoprotein cholesterol levels, increased the serum high-density lipoprotein cholesterol level, improved the serum lipid profiles and alleviated hepatic injury. Furthermore, with the supplementation of OCT, the mRNA expression of genes related to lipogenesis (acc1, scd1, fas, srebp1, dgat1 and cebpα) and fatty acid (FA) transport (fabp3, fatp and cd36) were down-regulated, while the mRNA expression of genes related to lipolysis (atgl, hsl and lpl) and FA β-oxidation (cpt1 and mcad) were up-regulated. Besides that, dietary OCT increased the total antioxidant capacity, activities of peroxidase, catalase and superoxide dismutase and the content of reduced glutathione, decreased the content of 8-hydroxy-deoxyguanosine and malondialdehyde and relieved hepatic oxidative stress. Supplementation of 0.7 and 2.1 g/kg OCT down-regulated the mRNA expression of genes related to pro-inflammatory cytokines (tnfα, il1β and ifnγ), and suppressed hepatic inflammatory response. In conclusion, supplementation with 0.7-2.1 g/kg OCT could reduce hepatic lipid accumulation, relieve oxidative stress and regulate inflammatory response in large yellow croaker fed the diet with high SO levels, providing a new way to alleviate the hepatic fat deposition in aquatic animals.

Cellular Uptake, Metabolism and Sensing of Long-Chain Fatty Acids.

Fatty acids (FAs) are critical nutrients that regulate an organism's health and development in mammal. Long-chain fatty acids (LCFAs) can be divided into saturated and unsaturated fatty acids, depending on whether the carbon chain contains at least 1 double bond. The fatty acids that are required for humans and animals are obtained primarily from dietary sources, and LCFAs are absorbed from outside of cells in mammals. LCFAs enter cells through several mechanisms, including passive diffusion and protein-mediated translocation across the plasma membrane, the latter in which FA translocase (FAT/CD36), plasma membrane FA-binding protein (FABPpm), FA transport protein (FATP), and caveolin-1 are believed to have important functions. The LCFAs that are taken up by cells bind to FA-binding proteins (FABPs) and are transported to the specific organelles, where they are activated into acyl-CoA to target specific metabolic pathways. LCFA-CoAs can be esterified to phospholipids, triacylglycerol, cholesteryl ester, and other specialized lipids. Non-esterified free fatty acids are preferentially stored as triacylglycerol molecules. The main pathway by which fatty acids are catabolized is β-oxidation, which occurs in mitochondria and peroxisomes. stearoyl-CoA desaturase (SCD)-dependent and Fatty acid desaturases (FADS)-dependent fatty acid desaturation pathways coexist in cells and provide metabolic plasticity. The process of fatty acid elongation occurs by cycling through condensation, reduction, dehydration, and reduction. Extracellular LCFA can be mediated by membrane protein G protein-coupled receptor 40 (GPR40) or G protein-coupled receptor 120 (GPR120) to activate mammalian target of rapamycin complex 1 (mTORC1) signaling, and intracellular LCFA's sensor remains to be determined. The crystal structures of a phosphatidic acid phosphatase and a membrane-bound fatty acid elongase-condensing enzyme and other LCFA-related proteins provide important insights into the mechanism of utilization, increasing our understanding of the cellular uptake, metabolism and sensing of LCFAs.

Klf4-Sirt3/Pparα-Lcad pathway contributes to high phosphate-induced lipid degradation

BackgroundPhosphorus commonly reduces lipid deposition in the vertebrates. However, the underlying mechanisms involved in the process remain unclear.MethodsYellow catfish were given three experimental diets with dietary phosphate levels of 3.22, 6.47 and 7.99 g Pi kg− 1, respectively, for 8 weeks. The contents of triglyceride, non-esterified free fatty acids, adenosine triphosphate, nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide, enzymatic activities, mRNA and protein expression were determined in the intestinal tissues. Hematoxylin and eosin, Oil Red O staining, and transmission electron microscope were performed for intestinal tissues. Primary intestinal epithelial cells were isolated from yellow catfish intestine. Western blot analysis, Immunoprecipitation assays, Immunofluorescence staining, and RNA extraction and quantitative real-time PCR were decided. Luciferase reporter assays and electrophoretic mobility shift assay were used to evaluate the function of Sirt3, PPARα and Lcad promoters.ResultsHigh dietary phosphate intake activated intestinal phosphate absorption and excretion, and reduced lipid deposition through increasing lipolysis in the intestine. Moreover, phosphate incubation increased the mRNA and protein expression of krüppel like factor 4 (klf4), silent mating-type information regulation 2 homolog 3 (sirt3), peroxisome proliferator activated receptor alpha (pparα) and long chain acyl-CoA dehydrogenase (lcad) in the intestinal epithelial cells (IECs), and klf4 knockdown attenuated the phosphate-induced increase of protein levels of Sirt3, Pparα and Lcad. Further investigation found that Klf4 overexpression increased the activity of sirt3 and pparα promoters, which in turn reduced the acetylation and protein level of Lcad.ConclusionDietary Pi excess induced lipid degradation by the activation of the Klf4-Sirt3/Pparα-Lcad pathway in the intestine and primary IECs.Graphical 2J2H-vAY8k8xL15UHAsvLYVideo

A Novel in Duck Myoblasts: The Transcription Factor Retinoid X Receptor Alpha (RXRA) Inhibits Lipid Accumulation by Promoting CD36 Expression.

Retinoid X receptor alpha (RXRA) is a well-characterized factor that regulates lipid metabolism; however, the regulatory mechanism in muscle cells of poultry is still unknown. The overexpression and the knockdown of RXRA in myoblasts (CS2 cells), RT-PCR, and western blotting were used to detect the expression levels of genes and proteins related to PPAR-signaling pathways. Intracellular triglycerides (TGs), cholesterol (CHOL), and nonesterified free fatty acids (NEFAs) were detected by the Elisa kit. Fat droplets were stained with Oil Red O. The double-fluorescein reporter gene and chromatin immunoprecipitation (CHIP) were used to verify the relationship between RXRA and candidate target genes. The RXRA gene was highly expressed in duck breast muscle, and its mRNA and its protein were reduced during the differentiation of CS2 cells. The CS2 cells, with the overexpression of RXRA, showed reduced content in TGs, CHOL, NEFAs, and lipid droplets and upregulated the mRNA expression of CD36, ACSL1, and PPARG genes and the protein expression of CD36 and PPARG. The knockdown of RXRA expression in CS2 cells enhanced the content of TGs, CHOL, NEFAs, and lipid droplets and downregulated the mRNA and protein expression of CD36, ACLS1, ELOVL6, and PPARG. The overexpression of the RXRA gene, the activity of the double-luciferase reporter gene of the wild-type CD36 promoter was higher than that of the mutant type. RXRA bound to -860/-852 nt, -688/-680 nt, and -165/-157 nt at the promoter region of CD36. Moreover, the overexpression of CD36 in CS2 cells could suppress the content of TGs, CHOL, NEFAs, and lipid droplets, while the knockdown expression of CD36 increased the content of TGs, CHOL, NEFAs, and lipid droplets. In this study, the transcription factor, RXRA, inhibited the accumulation of TGs, CHOL, NEFAs, and fat droplets in CS2 cells by promoting CD36 expression.

Haemotobiochemical changes and management of post-partum fatty liver syndrome in Malabari goats

The fatty liver syndrome was confirmed by haemotobiochemical and hepatic ultrasonographic investigations in 12 Malabari goats within six weeks after kidding. Animals were divided into two groups with six does each which received two different treatments. Ketonex bolus, which contains nicotinic acid, disodium hydrogen phosphate, and live yeast was given to the goats in Group I. The animals in Group II received syrup Bexoliv, which contains tricholine citrate, methionine, inositol, vitamin E, biotin, selenium, silymarin, iron, copper, and B12. In addition to this, animals of both groups received glycerin orally. On the fifteenth day of treatment, the animals were reevaluated. Six apparently healthy adult female goats within six weeks of kidding were selected as control. Before treatment, the neutrophil count showed a significant increase and lymphocyte and monocyte counts showed a decrease in the study groups. Blood beta-hydroxybutyrate (βHB), serum non-esterified free fatty acids (NEFA) and serum urea nitrogen (SUN) levels showed a significant increase before treatment and reduced after treatment among both groups. Hepatic ultrasonography showed hyperechogenicity of parenchyma before treatment when compared to after treatment. The animals showed improvement with both treatments.

Abstract 14621: The Endothelial Lipase Loss of Function Mutation R450G Causes Hyperalphalipoproteinemia That Does Not Protect Against ASCVD

Background: High-density lipoprotein cholesterol (HDL-C) levels and cardiovascular risk are inversely related in epidemiological studies. However, some rare monogenetic mutations that raise HDL do not appear to confer atheroprotection. Methods: The LIPG gene, encoding Endothelial Lipase (EL), was sequenced in 337 patients with hyperalphalipoproteinemia (HDL-C&gt;80mg/dL) for whom a causative variant in other genes affecting plasma HDL levels ( CETP, APOA1, ABCA1, LCAT, LPL, GALNT2 ) had been excluded. HDL particle size distribution was determined using a Lipoprint HDL subtraction test and further assessed by non-denaturing gradient gel electrophoresis followed by densitometric scanning. EL variants were cloned by site directed mutagenesis, expressed in HEK293 cells and compared to wild-type EL. Their expression in cell extracts and secretion in culture medium were measured by western-blot and ELISA. EL phospholipase enzymatic activity was assessed by measuring the production of non-esterified free fatty acids (FFA) using native and reconstituted HDL (rHDL) as substrates. Results: We identified the novel EL R450G missense mutation in three individuals (2 heterozygotes and one homozygote). Their HDL particles were larger than those of normolipemic controls (66±14% vs. 36±6% of large HDL1 particles; P=0.02). Six week treatment with Probucol 1g/day reduced the amount of HDL1 in those patients. Despite elevated circulating HDL levels, these patients presented with atherosclerotic cardiovascular disease. In vitro, the R450G variant was expressed and secreted normally from cells but displayed markedly reduced enzymatic activity compared with wild-type EL (Vmax = 6±4, vs. 32±5 nmol/Hr and Km = 0.01±0.07 vs. 0.30±0.15 mM, respectively; P&lt;0.01, all). Conclusion: EL-R450G is a loss-of-function variant associated with hyperalphalipoproteinemia. Carriers of this mutation do not appear to be protected against atherosclerosis.

PMON244 Alterations in Nonesterified Free Fatty Acids (NEFA) Trafficking Rather Than Hyperandrogenism Contribute to Variations in Insulin Sensitivity Among Obese Women with Polycystic Ovary Syndrome

Abstract Objectives To compare the metabolic and hormonal features of metabolically unhealthy obese PCOS women (MU-PCOS) vs. metabolically healthy obese PCOS women (MH-PCOS) and determine whether alterations in non-esterified free fatty acids (NEFA) response to hyperinsulinemia contribute to variations in insulin sensitivity between MU-PCOS and MH-PCOS. Design Prospective cross-sectional study. Setting Tertiary-care academic center. Methods Insulin resistance (IR) in the basal state was assessed by HOMA-IR in 125 consecutive obese oligo-ovulatory PCOS women (BMI≥ 30 kg/m2; NIH 1990 or Rotterdam 2003 Phenotype A/B) undergoing an oral glucose tolerance test (oGTT); and IR in the dynamic state assessed by the modified frequently sampled intravenous glucose tolerance test (mFSIVGTT) in a subgroup of 16 non-diabetic obese PCOS women. Main Outcome Measures: Primary outcome measures were: 1) IR in AT was assessed in the basal state by the Adipose Insulin Resistance Index [Adipo-IR]) and dynamically by the mFSIVGTT-derived indices of insulin-mediated NEFA suppression [NEFAnadir, TIMEnadir, and %NEFAsupp]); 2) peak lipolysis rate [SNEFA]; and 3) peak NEFA uptake rate [KNEFA]. Secondary outcome measures were levels of insulin and glucose during oGTT, HOMA-β%, and degree of hyperandrogenism (i.e. mF-G score, free testosterone [T], total T, DHEAS). Results Eighty-five obese PCOS participants undergoing oGTT had a HOMA-IR index of ≥2.5 (MU-PCOS) and 40 had a HOMA-IR of &amp;lt;2.5 (MH-PCOS). MU-PCOS had higher mean HOMA-β%, levels of fasting, 1-hr and 2-hr. glucose and insulin, and peak insulin during the oGTT, and higher prevalence of prediabetes and elevated 1-hr. glucose and a trend towards higher prevalence of type 2 diabetes mellitus (T2DM), than MH-PCOS. Alternatively, measures of HA were similar between the groups. Assessing IR dynamically, subjects were subdivided into MU-PCOS by an insulin sensitivity index [Si] ≤1.7 [mU/L]−1·min−1 (n=8) or MH-PCOS by an Si ≥5.6 [mU/L]−1·min−1 (n=8), matched for age and BMI. MU-PCOS had lower Si and KNEFA, smaller %NEFAsupp, longer TIMEnidar, and higher NEFAnidar and Adipo-IR than MH-PCOS, although fasting plasma NEFA levels and SNEFA were similar. In bivalent analysis, Si correlated strongly and negatively with NEFAnadir, weakly and negatively with TIMEnadir, and positively and strongly with KNEFA and NEFAsupp, in MUO-PCOS only. Conclusion Independent of age and BMI, metabolically unhealthy obese PCOS women, compared with metabolically healthy obese PCOS women, had lower rates of NEFA uptake and altered insulin-mediated plasma NEFA suppression in response to mFSIVGTT-determined endogenous insulin secretion, rather than disparities in HA and rate of lipolysis, mechanism that may contribute to variations in insulin sensitivity among obese PCOS women. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Antifatigue effect of naringin on improving antioxidant capacity and mitochondrial function and preventing muscle damage.

The aim of this study was to explore effects of naringin (Nar) on antifatigue ability; the weight-loaded and non-loading swimming tests were performed. Compared with the control group, dietary supplementation of Nar significantly prolonged the weight-loaded swimming time to exhaustion of mice (P < 0.01). Nar significantly reduced the serum lactic acid (LD) level (P < 0.05) and lactate dehydrogenase (LDH) activity (P < 0.001), while increased the serum non-esterified free fatty acids (NEFA) level (P < 0.001). In addition, Nar significantly increased the liver glycogen and muscle glycogen contents (P < 0.05) and the phosphoenolpyruvate carboxykinase (PEPCK) (P < 0.01) and glucokinase (GCK) mRNA levels (P < 0.001) in liver and gastrocnemius (GAS) muscle. Furthermore, Nar significantly improved the antioxidant capacity, mitochondrial function, and muscle mitochondrial fatty acid β-oxidation (P < 0.05), and decreased inflammation and muscle damage-related gene expression (P < 0.05). These findings suggested that Nar can improve antifatigue effect by enhancing antioxidant capacity and mitochondrial function and preventing muscle damage.

Nutritional programming of large yellow croaker (Larimichthys crocea) larvae by dietary vegetable oil: effects on growth performance, lipid metabolism and antioxidant capacity.

The nutritional status experienced in the early development of life plays a vital role in the long-term metabolic state of the individual, which is known as nutritional programming. The present study investigated the long-term effects of vegetable oil (VO) nutritional programming during the early life of large yellow croaker. First, larvae were fed either a fish oil (FO) diet or a VO diet for 30 d. Subsequently, under the same conditions, all fish were fed a commercial diet for 90 d and thereafter challenged with an FO or VO diet for 30 d. The results showed that growth performance was significantly lower in larvae fed the VO diet than in those in fed the FO diet in the stimulus phase. Notably, VO nutritional history fish showed lower levels of liver lipids liver total triglycerides and serum nonesterified free fatty acids than the FO nutritional history fish when juveniles were challenged with the VO diet, which was consistent with the expression of lipogenesis-related genes and proteins. Moreover, the VO nutritional history fish showed lower liver damage and higher antioxidant capacity than FO nutritional history fish when challenged with the VO diet. In summary, this study showed that a short VO stimulus during the early life stage of large yellow croaker, had a long-term effect on lipid metabolism and the antioxidant system. Specifically, VO nutritional programming had a positive effect on alleviating abnormal lipid deposition on the liver, liver damage, and the reduction of hepatic antioxidant capacity caused by a VO diet.

Role of fatty acid transport protein 4 in metabolic tissues: insights into obesity and fatty liver disease.

Fatty acid (FA) metabolism is a series of processes that provide structural substances, signalling molecules and energy. Ample evidence has shown that FA uptake is mediated by plasma membrane transporters including FA transport proteins (FATPs), caveolin-1, fatty-acid translocase (FAT)/CD36, and fatty-acid binding proteins. Unlike other FA transporters, the functions of FATPs have been controversial because they contain both motifs of FA transport and fatty acyl-CoA synthetase (ACS). The widely distributed FATP4 is not a direct FA transporter but plays a predominant function as an ACS. FATP4 deficiency causes ichthyosis premature syndrome in mice and humans associated with suppression of polar lipids but an increase in neutral lipids including triglycerides (TGs). Such a shift has been extensively characterized in enterocyte-, hepatocyte-, and adipocyte-specific Fatp4-deficient mice. The mutants under obese and non-obese fatty livers induced by different diets persistently show an increase in blood non-esterified free fatty acids and glycerol indicating the lipolysis of TGs. This review also focuses on FATP4 role on regulatory networks and factors that modulate FATP4 expression in metabolic tissues including intestine, liver, muscle, and adipose tissues. Metabolic disorders especially regarding blood lipids by FATP4 deficiency in different cell types are herein discussed. Our results may be applicable to not only patients with FATP4 mutations but also represent a model of dysregulated lipid homeostasis, thus providing mechanistic insights into obesity and development of fatty liver disease.

Raman spectroscopy combined with comprehensive gas chromatography for label-free characterization of plasma-derived extracellular vesicle subpopulations

Raman spectroscopy together with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GCxGC–TOFMS) was employed to characterize exomere- (<50 nm) and exosome-sized (50–80 nm) EVs isolated from human plasma by the novel on-line immunoaffinity chromatography – asymmetric flow field-flow fractionation method. CD9+, CD63+, and CD81+ EVs were selected to represent general EV subpopulations secreted into plasma, while CD61+ EVs represented the specific EV subset derived from platelets. Raman spectroscopy could distinguish EVs from non-EV particles, including apolipoprotein B-100-containing lipoproteins, signifying its potential in EV purity assessment. Moreover, platelet-derived (CD61+) EVs of both exomere and exosome sizes were discriminated from other EV subpopulations due to different biochemical compositions. Further investigations demonstrated composition differences between exomere- and exosome-sized EVs, confirming the applicability of Raman spectroscopy in distinguishing EVs, not only from different origins but also sizes. In addition, fatty acids that act as building blocks for lipids and membranes in EVs were studied by GCxGC—TOF-MS. The results achieved highlighted differences in EV fatty acid compositions in both esterified (membrane lipids) and non-esterified (free fatty acids) fractions, indicating possible differences in membrane structures, biological functions, and roles in cell-to-cell communications of EV subpopulations.

Slow-release urea partially replacing soybean in the diet of Holstein dairy cows: intake, blood parameters, nutrients digestibility, energy utilization, and milk production

Abstract The present experiment aimed to evaluate the partial replacement of soybean with slow-release urea (Optigen 1200™) in the diet of lactating cows for 84 d. Three-hundred multiparous lactating Holstein (635 ± 25 kg of body weight, BW) cows were stratified by live body weight; parity and previous milk production were randomly assigned into two experimental groups with 150 cows per each treatment. In the control treatment, 25 g soybean meal was replaced by 5.7 g slow-release urea for 84 d. Optigen treatment did not affect feed intake, daily milk production, milk composition, or milk (feed) efficiency; however, it increased (P&lt;0.01) total BW gain and daily BW gain. Optigen treatment increased (P&lt;0.01) the digestibility of crude protein and neutral detergent fiber. Optigen treatment increased (P&lt;0.01) estimated N balance, milk urea-N, and net energy (NE) for gain. Without affecting blood total protein, creatinine, urea-N, triglycerides, glucose, β-hydroxybutyrate, or non-esterified free fatty acids, Optigen treatment increased the concentrations of blood albumin and cholesterol compared to the control (P&lt;0.05). In conclusion, slow-release urea could replace soybean meal in ruminant diets with no adverse effects on feed intake, nitrogen utilization, or digestibility; however, it improved the total tract digestibility of fiber and crude protein in cows.

Que Zui tea ameliorates hepatic lipid accumulation and oxidative stress in high fat diet induced nonalcoholic fatty liver disease

In this study, the protective effects of hot water (QW) and aqueous-ethanol extracts (QA) from Que Zui tea on non-alcoholic fatty liver disease (NAFLD) were investigated. Quantitative and qualitative analysis revealed that QW and QA were rich in polyphenols, especially 6′-O-caffeoylarbutin. Both QW and QA significantly reduced body weight and liver index, increased serum levels of high density lipoprotein cholesterol (HDL-C), and decreased the levels of total cholesterol (TC), triglyceride (TG), nonesterified free fatty acids (NEFA) and low density lipoprotein cholesterol (LDL-C) in NAFLD rats induced high fat diet. Furthermore, the contents of TC, TG, NEFA, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the liver tissues were inhibited after QW and QA administration. Histopathological examination showed that QW and QA significantly reduced liver lipid accumulation of NAFLD rats. In addition, QW and QA could enhance increase the activity of antioxidant (glutathione, superoxide dismutase and catalase) in the liver by regulation Nrf2 signaling pathway, thereby alleviating liver damage caused by lipid peroxidation. QW and QA activated AMPK/PPAR-α signaling pathway by increasing the expression of adiponectin and its receptor AdipoR2, thereby reducing fat production and enhancing fatty acid β oxidation. These data suggested that QW and QA had the potential to in the prevention and treatment of NAFLD.