Degradation Of Free Fatty Acids Research Articles

Gut Microbiota Regulate Saturated Free Fatty Acid Metabolism in Heart Failure

Aims: Heart failure (HF) is associated with profound changes in cardiac metabolism. At present, there is still a lack of relevant research to explore the key microbiome and their metabolites affecting the progression of HF. Herein, the interaction of gut microbiota and circulating free fatty acid (FFA) in HF patients and mice is investigated. Methods and Results: In HF patients, by applying metagenomics analysis and targeted FFA metabolomics, enriched abundance of Clostridium sporogenes (C.sp) in early and late stage of HF patients, which negatively correlated to saturated free fatty acid (SFA) levels, is identified. KEGG analysis further indicates microbiota gene enrichment in FFA degradation in early HF, and decreased gene expression in FFA synthesis in late HF. In HF mice (C57BL/6J) induced by isoproterenol (ISO), impaired intestinal permeability is observed, and decreased fecal C.sp and increased SFA are further validated. At last, by supplementing C.sp to ISO‐induced HF mice, the cardiac function, fibrosis, and myocardial size are partially rescued, together with decreased circulating SFA levels. Conclusions: Clostridium abundance is increased in HF, compensating cardiac function deterioration via downregulation of circulating SFA levels. The results demonstrate that the gut microbiota–SFA axis plays an important role in HF protection, which may provide a strategic advantage for the probiotic therapy development in HF.

The Role of Annexin A6 in Triple‐negative breast cancer metabolism and disease progression

The ability of cancer cells to alter their metabolism is one of the major mechanisms underlying therapeutic resistance in solid tumors, including the hard‐to‐treat triple‐negative breast cancer (TNBC) subtype. Here, we report the synergism between Annexin A6 (AnxA6) and Lapatinib‐resistance (Lap‐R) in the context of metabolic reprogramming. Metabolic profiling of TNBC cell lines show extensive diversity amongst the proliferative basal‐like (BSL) vs the highly motile mesenchymal‐like (MSL) molecular subtypes. In this study, we demonstrate that down regulation of AnxA6 in AnxA6‐, expressing and Lap‐R cell lines attenuated mitochondrial respiration, glycolytic flux, and cellular ATP production capacity, diminishing the overall energy phenotype of the cell. Additionally, AnxA6‐depletion altered lipid metabolism by decreasing lipid droplet accumulation, but enhancing the mitochondrial uptake and degradation of free fatty acids for ATP production via fatty acid oxidation (FAO). Our NMR‐based metabolomics revealed that AnxA6 depleted and Lap‐R TNBC cells rely on active amino acid metabolites and gluconeogenic precursors including alanine, glycine, and lactic acid to sustain their high proliferative rate. Collectively, these results demonstrate that the expression of AnxA6 underlies TNBC metabolic dependency and hence provide novel insights into the failure of EGFR‐targeted therapies as therapeutic options for TNBC patients.

Optimization of superheated steam treatment conditions for wheat aleurone layer flour

Although, wheat aleurone layer flour (WALF) is a good source of nutrients, it has certain disadvantages due relatively high levels of lipids and various of microorganisms and enzymes. Therefore, in the current study, the effect of superheated steam (SS) treatment on stabilization of WALF was investigated. This study aims to explore the effects of SS treatment on the degradation of free fatty acids of WALF under different conditions. The optimal process was obtained by an orthogonal optimization experiment, including optimized SS temperature, material moisture and treatment time. Results showed that the free fatty acids content of WALF significantly were decreased with SS treatment as the increase of treatment temperature, material moisture content and treatment times (p<0.05). Therefore, the optimum treatment conditions were selected during SS treatment. Compared with raw WALF, the activity of enzymes, total number of microbial colonies and phytate content in WALF were notably reduced after the SS of optimal condition. Nevertheless, its total dietary fiber content, insoluble dietary fiber content, pentosan content, total phenol content and total antioxidant capacity presented a remarkable increase (p<0.05).

Production of hydrocarbons from fatty acids and animal fat in the presence of water and sodium carbonate: Reactor performance and fuel properties

The thermal degradation of free fatty acids and animal fat in a moving bed of sodium carbonate and 5wt% of water were carried out at 430±20°C at a pilot scale plant. During start-up the loading rates for a 60:40 mixture of oleic and stearic acids were 10kg/h resulting in a 69±5% of bio-crude. The acidity index was remarkably low within a range of 0.64–0.80mg KOH/g during 3weeks of operation. The loading rates for animal fat were increased from 10 to 40kg/h corresponding to a weight hourly space velocity of 0.03–0.1h−1 over a period of 6months. Heat transfer into the reactor was the limiting criterion. The main product with a yield of 65±5% was bio-crude showing an acidity index of 0.5–1.8mg KOH/g. The mean value for kinematic viscosity at 40°C was 1.78mm2/s. The net calorific value of bio-crude was 41.6MJ/kg. Coke deposits on sodium carbonate were determined to be 5±1%. The gaseous products ranged from 25wt% to 30wt%. The presence of CO2, H2, CH4, C2H6, C2H4 and C3 to C5 hydrocarbons as major components was established by gas chromatography. The gases were directly fed into an on-site gas line and used for heating purposes. The distillation curve of bio-crude from animal fat showed hydrocarbon based bio-fuels in the boiling ranges of gasoline and diesel. Upon rectification 66% of bio-diesel and 21% of bio-gasoline were obtained. This corresponds to a total yield of 43% bio-diesel and 14% bio-gasoline from animal fat. The bio-diesel had favorable low-temperature properties (cold filter plugging point=−18°C) with oxidation stability between that of mineral oil based diesel and fatty acid methyl ester fuels. The gasoline fraction lacked low-boiling hydrocarbons as indicated by a vapor pressure of 26kPa instead of 60-90kPa (DIN EN 228). Thus, water-cooled condensers need to be improved for a full-scale plant. The results are discussed in terms of German specifications for standard fuels.

Monitoring of Ketogenic Diet for Carnitine Metabolites by Subcutaneous Microdialysis

The ketogenic diet (KD) provides ketones from the degradation of free fatty acids for energy metabolism. It is a therapeutic option for pharmacoresistant epilepsies. Carnitine is the carrier molecule that transports fatty acids across the mitochondrial membrane for degradation into ketones. The integrity of this transport system is a prerequisite for an adequate ketogenic response. For monitoring of tissue metabolism with KD, we used the sampling method of s.c. microdialysis (MD), which permits minimally invasive, frequent, and extensive metabolic monitoring independent of blood tests. By using this new method, we monitored changes in carnitine metabolism induced by KD, particularly in free carnitine (C0), acetylcarnitine (C2), and hydroxybutyrylcarnitine (C4OH). Correlation of microdialysate and tissue concentrations for carnitines in vitro was about 85%. Carnitine metabolism was monitored in seven children started on a KD for pharmacoresistant epilepsy after a conventional initial fasting period. Detected metabolic changes consisted of a slight decrease in s.c. C0 and a marked increase in C2/CO and C4OH/CO levels. The levels of s.c. C4OH strongly correlate with beta-hydroxybutyrate (beta-OHB) levels in plasma providing an additional parameter for the carnitine reserve of the body and reflect an optimal ketogenic energy supply. Subcutaneous MD allows close and extensive monitoring of metabolism with a KD.

Degradation of triglycerides by a pseudomonad isolated from milk: the roles of lipase and esterase studied using recombinant strains over-producing, or specifically deficient in these enzymes.

The roles of lipase and esterase in causing hydrolytic spoilage of milk by a highly lipolytic psychrotrophic strain of Pseudomonas fluorescens, LS107d2, has been studied. Strains of LS107d2 have been constructed that over-produce, or are specifically deficient in, a lipase (encoded by lipA) and an esterase (encoded by estA). Southern blot analysis reveals that LS107d2 contains only one esterase and one lipase (encoded by estA and lipA) and this was confirmed by the phenotypes of mutants on triolein and tributyrin-containing agar. Analysis of broth cultures showed that the lipase is secreted into the culture medium; in contrast, the esterase is not secreted. Free fatty acid (FFA) levels in whole milk cultures of wild-type, over-producing and the mutant strains of LS107d2 have been examined. From these studies it is concluded that esterase is not involved in the accumulation of FFA by hydrolysing short chain fatty acid esters; that the highly lipolytic phenotype of LS107d2 is due solely to a single secreted lipase; and that the main FFA accumulated in milk cultures of LS107d2 are C4, C16, C18 and C18: 1. Evidence is also presented demonstrating that FFA degradation, as well as production, determines the level of FFA in milk contaminated with lipolytic organisms.

Changes in blood metabolite concentrations in response to repeated capture, anaesthesia and blood sampling in the golden perch, Macquaria ambigua

1. 1. The major metabolic changes associated with repeated capture, aquarium transfer, anaesthesia and blood sampling were investigated in an Australian freshwater fish, the golden perch ( Macquaria ambigua), 2. 2. A compounded stress response was seen after repetition of the procedure, in which the plasma glucose rose within 3 hr and amino acid concentrations rose and the serum free fatty acids concentration fell after 24 hr. 3. 3. Alanine was identified as an important circulating energy store in the stress response of golden perch. 4. 4. No change was noted in the serum protein, plasma lactate or β-hydroxybutyrate concentrations, indicating that tissue damage and hypoxia were absent, and that degradation of free fatty acids did not produce metabolites excess to the requirements of gluconeogenesis and the tricarboxylic acid cycle.

Behavior of certain parameters of lipid and energy metabolism. IV. Regulation of lipid and energy metabolism in livers and race and mini pigs

To characterize the lipid and the energy metabolism in the livers of genetically different types of pigs (land race pig and mini pig), the authors determined the activities of enzymes typical of and limiting these metabolic pathways. Furthermore, they measured the concentrations of typical metabolites and ascertained parameters that are of importance in energy metabolism. The concentrations of acetyl CoA and free fatty acids in the livers of mini pigs were significantly greater than those in the livers of land race pigs, whereas the cholesterol, glycerol, triglyceride and acetoacetate concentrations were reduced. The activities of glucose-6-phosphate dehydrogenase (E.C.1.1.1.49.), citrate synthase (E.C.4.1.3.7.) and ATP citrate lyase (E.C.4.1.3.8.) were lower in the livers of mini pigs than in the livers of land race pigs, whereas the activity of fatty acid synthase was higher. The concentrations of cyclic 3',5'-adenosine monophosphate (AMP) and adenosine diphosphate (ADP) were lower in the livers of mini pigs than in those of land race pigs. In land race pigs, the metabolic process seems, therefore, to be determined in favour of the degradation of free fatty acids and of the generation of energy. In mini pigs, lipogenesis in the liver appears to be the decisive metabolic pathway. The possibility of a higher coordinating control mechanism of the lipid and the energy metabolism is discussed.

Changes in wheat lipids during mixing and resting of flour‐water doughs

AbstractLipids extracted with water‐saturated n‐butanol from flour and flour‐water doughs were examined to determine the extent of oxidations and other changes which occurred in mixing and resting dough. Extracted lipids were converted to fatty acid methyl esters (FAME) and quantified by gas‐liquid chromatography (g.l.c.) using heptadecanoic acid (17 : 0) as internal standard. The original flour or dough and the corresponding solvent‐extracted residues were acid hydrolysed, and the hydrolysate lipids converted to FAME for g.l.c. determination of the total lipid and residual unextracted lipid contents. The total flour or dough lipids equalled the extracted lipids + unextracted lipids, except where there were unavoidable autoxidative losses of linoleate (18 : 2) and linolenate (18 : 3).The unextracted flour lipids (13% of total lipids) were not oxidised during dough mixing. There were no changes in any of the extracted lipid classes other than free fatty acids (FFA) and monoglycerides (MG) which showed losses of 18 : 2 and 18 : 3 after aerobic dough mixing. Losses of FFA and MG are attributed to lipoxygenase activity during dough mixing and the period immediately after. The small amount of 18 : 2 in the “free” petroleum ether‐extracted FFA appeared to be unaffected by lipoxygenase.Recoveries of FFA other than 18 : 2 or 18 : 3 were constant, indicating no lipolysis of glycerolipids and no general oxidation or degradation of FFA. Experiments with [U‐14C]palmitic acid confirmed that there was no oxidation, degradation or re‐esterification of FFA.Much of the non‐polar lipids (steryl ester, triglyceride, diglyceride, FFA, MG) and almost all of the polar lipids were bound on dough mixing. Binding was non‐selective with regard to fatty acid composition. Triglyceride was the only lipid class bound to a greater extent in anaerobic dough than in aerobic dough. Some selectivity of binding between lipid classes was indicated.