Chain Unsaturated Fatty Acids Research Articles

PPARγ Modulates Long Chain Fatty Acid Processing in the Intestinal Epithelium.

Nuclear receptor PPARγ affects lipid metabolism in several tissues, but its role in intestinal lipid metabolism has not been explored. As alterations have been observed in the plasma lipid profile of ad libitum fed intestinal epithelium-specific PPARγ knockout mice (iePPARγKO), we submitted these mice to lipid gavage challenges. Within hours after gavage with long chain unsaturated fatty acid (FA)-rich canola oil, the iePPARγKO mice had higher plasma free FA levels and lower gastric inhibitory polypeptide levels than their wild-type (WT) littermates, and altered expression of incretin genes and lipid metabolism-associated genes in the intestinal epithelium. Gavage with the medium chain saturated FA-rich coconut oil did not result in differences between the two genotypes. Furthermore, the iePPARγKO mice did not exhibit defective lipid uptake and stomach emptying; however, their intestinal transit was more rapid than in WT mice. When fed a canola oil-rich diet for 4.5 months, iePPARγKO mice had higher body lean mass than the WT mice. We conclude that intestinal epithelium PPARγ is activated preferentially by long chain unsaturated FAs compared to medium chain saturated FAs. Furthermore, we hypothesize that the iePPARγKO phenotype originates from altered lipid metabolism and release in epithelial cells, as well as changes in intestinal motility.

The MXL-3/SBP-1 Axis Is Responsible for Glucose-Dependent Fat Accumulation in C. elegans.

Chronic exposure to elevated glucose levels leads to fatty acid accumulation, which promotes the development of metabolic diseases such as obesity and type 2 diabetes. MXL-3 is a conserved transcriptional factor that modulates the inhibition of lipolysis in Caenorhabditis elegans. However, the role of MXL-3 in lipid metabolism during nutrient excess remains unknown. We hypothesized that inhibition of MXL-3 prevents glucose-dependent fat accumulation. Nematodes from wild-type N2, MXL-3::GFP and sbp-1 or mxl-3 null strains were grown on standard, high glucose or high glucose plus metformin plates for 24 h. Using laser-scanning confocal microscopy, we monitored the glucose-induced activation of MXL-3 labeled with GFP (MXL-3::GFP). Lipid levels were determined by Oil Red O (ORO) staining and gas chromatography/mass spectrometry, and gene expression was assessed by qRT-PCR. We found that high glucose activated MXL-3 by increasing its rate of nuclear entry, which in turn increased lipid levels via sterol regulatory element-binding protein (SBP-1). This activated critical genes that synthesize long chain unsaturated fatty acids (MUFAs and PUFAs) and repress lipolytic genes. Interestingly, the anti-diabetic drug metformin inhibited MXL-3 activation and subsequently prevented glucose-dependent fat accumulation. These findings highlight the importance of the MXL-3/SBP-1 axis in the regulation of lipid metabolism during nutritional excess and provide new insight into the mechanism by which metformin prevents lipid accumulation. This study also suggests that inhibition of MXL-3 may serve as a potential target for the treatment of chronic metabolic diseases, including obesity, type 2 diabetes, and cardiovascular disease.

The impact of sugar and fatty acid on the bioactivity of N-fatty acyl-L-tyrosine aglycone

In the present study, a series of fatty acids-based (short, medium and long unsaturated chains) glycosylated N-fatty acyl-L-tyrosines and N-lipoyl-L-tyrosine methyl esters were synthesized and evaluated for their cytotoxic and antimicrobial activities. The aglycone moiety was synthesized using different chemical reagents. The glycosylation of aglycone moiety with different carbohydrates was performed using the Lewis acid, $$\hbox {BF}_{3.}\hbox {Et}_{2}\hbox {O}$$ . All the synthesized compounds were tested against a panel of four cancer cell lines. The glycosylated N-fatty acyl-L-tyrosines showed moderate activity against all the cell lines and the $$\hbox {IC}_{50}$$ values were in the range of $$15.6{-}45.6\;{\upmu }\hbox {M}$$ . However, the oleic acid analogues (10a, 10d) exhibited $$\hbox {IC}_{50}$$ values of 15.6, $$17.6\;{\upmu }\hbox {M}$$ , respectively, against MDA-MB-231 cell line. Glycosylated N-lipoyl-L-tyrosine methyl esters (6b–6d) showed promising activity against all the tested cell lines and the $$\hbox {IC}_{50}$$ values ranged between $$9.4{-}13.8\;{\upmu }\hbox {M}$$ . The compound 6d exhibited significant cytotoxicity and $$\hbox {IC}_{50}$$ values were 10.5, 9.4, 10.9 and $$12.1\;{\upmu }\hbox {M}$$ against A549, PC3, MDA-MB-231 and HepG2 cell lines, respectively. Moreover, the non-glycosylated N-fatty acyl-L-tyrosine and methyl N-fatty acyl-L-tyrosinate derivatives showed excellent and moderate antimicrobial activity against some of the tested bacterial strains. The glycosylated N-fatty acyl-L-tyrosines with short, medium and long chain unsaturated fatty acids and glycosylated N-lipoyl-L-tyrosine methyl esters were synthesized and further evaluated for their biological activities to examine the impact of sugar and fatty acid on the bioactivity of N-fatty acyl-L-tyrosine derivatives.

Lipid distribution, composition and uptake in bovine articular cartilage studied using Raman micro-spectrometry and confocal microscopy.

The distribution and composition of endogenous lipids in articular cartilage and transport of exogenous fatty acids have been investigated on a microscopic scale in fresh bovine articular cartilage. To investigate the distribution and composition of the endogenous lipids, hyperspectral Raman maps were taken of chondrocytes and their surrounding matrix in both the deep and superficial zones. These revealed differences in both lipid distribution and composition between the two zones. Extracellular lipid was observed surrounding the cells in the superficial zone but not in the deep zone. Additionally, intracellular lipid droplets were observed that were larger and more numerous in the deep zone (P = 0.01). The extracellular lipid was primarily free saturated fatty acid, whereas the cellular lipid droplets contained triglycerides with unsaturated fatty acid chains. Fatty acid uptake and transport were investigated by incubating cartilage samples in Dulbecco's modified Eagle's medium containing fluorescently labelled palmitate for a range of times and temperatures. After incubation, the palmitate distribution was imaged using confocal microscopy. Palmitate accumulated preferentially in the territorial matrix only in the superficial zone where the concentration was up to 100‐fold greater than that in the bulk matrix (P = 0.001). Palmitate uptake by the chondrocytes in both zones showed differential temperature sensitivity (P = 0.05), which would support the idea that cells take up palmitate by both active and passive mechanisms. The study reveals large differences between chondrocytes in the superficial and deep zones in their lipid content, in their extracellular lipid environment and in their access to exogenous fatty acids.

Cytochrome P450 1A2 N‐terminal Site Directed Mutagenesis: Effects on Lipid Microdomain Localization

The protein components of the cytochrome P450 monooxygenase system consist of cytochromes P450 (CYPs), NADPH‐dependent cytochrome P450 reductase (CPR), and cytochrome b5. They form functional complexes that catalyze the oxidation of exogenous and endogenous molecules, rendering them more water soluble. In eukaryotes, these membrane bound proteins are found in many tissues and are located primarily in the endoplasmic reticulum. The lipid milieu into which the P450 system proteins reside is heterogenous, consisting of ordered and disordered domains. Ordered domains have a higher content of saturated fatty acids, cholesterol, and sphingomyelin than disordered domains, whereas disordered domains have a higher content of phospholipids with more unsaturated fatty acid chains. When a bilayer membrane is treated with non‐ionic detergent such as Brij 98, the disordered domains readily solubilize whereas ordered regions remain intact. Our lab has shown that various P450 system proteins reside in different lipid microdomains. For example, despite their high level of amino acid sequence similarity, CYP1A2 and CYP1A1 reside in ordered and disordered regions, respectively. Furthermore, our lab has shown that the N‐terminal amino acid sequences of CYP1A2 and CYP1A1 contribute to their specific localization in the ER membrane. The goal of this study is to use site directed mutagenesis to identify which N‐terminal amino acids may be responsible in the lipid raft localization of CYP1A2 and how this effects CYP1A2 enzymatic activity. CYP1A2 N‐terminal amino acids were mutated to their CYP1A1 counterparts and expressed in HEK293‐T cells, and their microdomain localization determined. Although substitution of the NH2‐terminal amino acids of CYP1A2 with that of CYP1A1 leads to changes in their microdomain localization, the results show that Serine4Aspartic Acid and Proline5Phenylalanine mutations alone do not alter microdomain localization of the CYP1A proteins.Support or Funding InformationThis work was supported, in whole or in part, by National Institutes of Health, NIEHS, United StatesPublic Health Service Grants ES004344, and ES013648.

From Fish Waste to Omega-3 Concentrates in a Biorefinery Concept

The present work reports a case study for the industrialization of a biorefinery aimed at valorizing fish processing residues in order to obtain ω-3 concentrates for the nutraceutical sector. The biorefinery includes a series of processes: oil extraction from fish waste, fish oil transesterification with ethanol, ω-3 concentration based on supercritical CO2 fractionation. The biorefinery is at first designed and then modeled by Aspen Plus™: this allows for a comprehensive picture (mass and energy flows, processing costs and costs for investment) of the overall process. In accordance with the zero-waste concept, all the biorefinery by-products are valorized: fish proteins as fishmeal, and glycerol, saturated fatty acids and short chain unsaturated fatty acids as liquid biofuel. In addition, fish oil transesterification with ethanol is also experimentally tested in different operational conditions in order to maximize fish oil conversion to fatty acid ethyl esters. A trout processing company located in Trentino Province, Italy, represents the case study. The company produces 870 t/year of fish waste. Mass balances allow estimating a production of 26.6 t/year of ω-3 rich oil (income: 1.3 M€), 160 t/year of fish proteins (income: 0.27 M€), and 160 t/year of liquid biofuel. The biofuel, fed to a 100 kWel CHP unit, allows to produce 720 MWhe/year and 870 MWhth/year, covering the total electricity consumption of the plant and providing more than 45% of the thermal energy needs. This translates into a reduction in utility costs of about 0.12 M€ and avoids the emission of 416 t/year of CO2. Finally, the total investment costs for the whole biorefinery amount to about 3.34 M€. In conclusion, this study demonstrates that the production of ω-3 rich fish oils in a bio-refinery concept could become a good opportunity for valorizing fish by-products and increasing the competitiveness of the fish processing industry.

Quantitative Analysis of Degummed Calophyllum Inophyllum Oil

The chemical properties of biodiesel fuel are much depends upon the fatty ester composition. The Calophyllum inophyllum seed oil without purification in crude stage and purified Calophyllum inophyllum oil in degummed stage were studied. The Crude Calophyllum Inophyllum Oil (CCIO) and Degummed Calophyllum Inophyllum Oil (DCIO) was the test samples considered for fatty acid quantitative analysis. The composition of fatty acids was identified by using Gas Chromatography (GC) to quantitative the test samples. In the results, the higher percentage presence of straight chain saturated fatty acid (palmitic) and unsaturated fatty acid (linoleic and oleic) has identified in the CCIO sample. By Degumming process, the percentage level of saturated fatty acid Palmitic diminished and unsaturated fatty acid Linoleic increased respectively; also the lesser amount formation of saturated fatty acid Capric, but unsaturated fatty acid Oleic and saturated fatty acid Myristic was completely removed.

Reclassification of Clostridium difficile as Clostridioides difficile (Hall and O’Toole 1935) Prévot 1938

The recent proposal by Lawson and Rainey (2015) to restrict the genus Clostridium to Clostridium butyricum and related species has ramifications for the members of the genera that fall outside this clade that should not be considered as Clostridium sensu stricto. One such organism of profound medical importance is C. difficile that is a major cause of hospital-acquired diarrhea and mortality in individuals. Based on 16S rRNA gene sequence analysis, the closest relative of Clostridium difficile is Clostridium mangenotii with a 94.7% similarity value and both are located within the family Peptostreptococcaceae that is phylogenetically far removed from C. butyricum and other members of Clostridium sensu stricto. Clostridium difficile and Clostridium mangenotii each produce abundant H2 gas when grown in PYG broth and also produce a range of straight and branched chain saturated and unsaturated fatty acids with C16:0 as a major product. The cell wall peptidoglycan contains meso-DAP as the diagnostic diamino acid. Based on phenotypic, chemotaxonomic and phylogenetic analyses, novel genus Clostridioides gen. nov. is proposed for Clostridium difficile as Clostridioides difficile gen. nov. comb. nov. and that Clostridium mangenotii be transferred to this genus as Clostridioides mangenotii comb. nov. The type species of Clostridioides is Clostridioides difficile.

Analysis of diacylglycerols by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry: Double bond location and isomers separation

Diacylglycerols (DAGs) are important lipid intermediates and have been implicated in human diseases. Isomerism complicates their mass spectrometric analysis; in particular, it is difficult to identify fatty acid substituents and locate the double bond positions in unsaturated DAGs. We have developed an analytical strategy using ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) in conjunction with dimethyl disulfide (DMDS) derivatization and collision cross-section (CCS) measurement to characterize DAGs in biological samples. The method employs non-aqueous reversed-phase chromatographic separation and profile collision energy (CE) mode for MSE and MS/MS analyses. Three types of fragment ions were produced simultaneously. Hydrocarbon ions (m/z 50–200) obtained at high CE helped to distinguish unsaturated and saturated DAGs rapidly. Neutral loss ions and acylium ions (m/z 300–400) produced at low CE were used to identify fatty acid substituents. Informative methyl thioalkane fragment ions were used to locate the double bonds of unsaturated DAGs. Mono-methylthio derivatives were formed mainly by the reaction of DAGs with DMDS, where methyl thiol underwent addition to the first double bond farthest from the ester terminus of unsaturated fatty acid chains. The addition of CCS values maximized the separation of isomeric DAG species and improved the confidence of DAG identification. Fourteen DAGs were identified in mouse myotube cells based on accurate masses, characteristic fragment ions, DMDS derivatization, and CCS values.

Cat's choose 30% of their calories as protein which is associated with both body composition and circulating metabolites

As in other mammals, domestic cats have specific taste preferences that can be influenced by macronutrient composition and physical characteristics of food as well as the presence or absence of specific taste imparting compounds (palatability enhancers). This study investigated the relationship of body composition and food choice and that choice on subsequent metabolomic shifts. Experimental foods were prepared with similar palatability for a population (as evaluated by the ratio of the test food to the total daily food consumed [grams test/(grams test+grams control)] through manipulations of factors independent of macronutrients. These foods with similar palatability preference for the population as a whole were then investigated for intake choice with 27 cats with varying adiposity (mean 24.4% fat, min 7.2%, max 32.2%). Four completely balanced foods were available to the cats at all times. The four foods were: a) a food with 42% of calories from protein, b) 43% calories from fat, c) 52% calories from carbohydrate and, d) intermediate levels of calories from protein, fat and carbohydrate. Cats chose 30.3% of calories from protein (Std Dev 4%, min 24% max 38%). Body composition was associated with the choice of percent calories as protein (p=0.008); lean body mass had a linear negative association (p=0.02), as did fat mass (p=0.04) while there was a positive association for the interaction (p=0.02). Overall cats with high body lean and high body fat showed the highest preference for dietary protein. There was a positive association between the percent of calories as protein and urea cycle metabolites (arginine, n‐acetyl arginine, n‐delta ornithine) while increasing calories from protein were negatively associated with specific metabolites in the TCA cycle (isocitrate, alpha ketoglutarate). There was a negative correlation between percent of calories consumed as protein and that consumed as carbohydrate (r=0.84; p<0.001) with only a slight relationships between either protein or carbohydrate calories and percent of calories consumed as fat (p≥ 0.1). However, there was a positive relationship between protein intake and a number of long chain unsaturated fatty acids (oleate, arachidate and docosapentaenoate). In summary, when given the opportunity to choose between foods which had similar palatability cats chose to consume 30.3% of their calories as protein and had specific preferences related to body composition. These intake preferences were associated with metabolic changes reflecting metabolic shifts.Support or Funding InformationHill's Pet Nutrition, Inc.

The Effect of monoglycerides on the crystallisation of triglyceride

Abstract There has been increased interest recently in how different lipids interact with each other in solid phases and in the properties and consequences of the inter-lipid associations. The crystallisation behaviour of the triglycerides is noticeably influenced by the presence of monoglycerides. The main aim of this work was to extend studies of the influences of saturated and unsaturated monoglycerides on the crystallization of triglycerides. We aim to gain more insight into the effect of monoglycerides on miglyol oil, palm oil and olive oil crystallization. Optical microscopy, differential scanning calorimetry (DSC), small X-ray scattering (SAXS) and wide X-ray scattering (WAXS) were used in this study. Our results suggest that the presence of saturated monoglyceride affects the oil crystallization behaviour. Conversely, triglycerides with unsaturated fatty acid chains show little impact. The results provide evidence that saturated and unsaturated monglycerides are incorporated into the α- phase of palm oil.

Metabolic phenotyping of human blood plasma: a powerful tool to discriminate between cancer types?

Accumulating evidence has shown that cancer cell metabolism differs from that of normal cells. However, up to now it is not clear whether different cancer types are characterized by a specific metabolite profile. Therefore, this study aims to evaluate whether the plasma metabolic phenotype allows to discriminate between lung and breast cancer. The proton nuclear magnetic resonance spectrum of plasma is divided into 110 integration regions, representing the metabolic phenotype. These integration regions reflect the relative metabolite concentrations and were used to train a classification model in discriminating between 80 female breast cancer patients and 54 female lung cancer patients, all with an adenocarcinoma. The validity of the model was examined by permutation testing and by classifying an independent validation cohort of 60 female breast cancer patients and 81 male lung cancer patients, all with an adenocarcinoma. The model allows to classify 99% of the breast cancer patients and 93% of the lung cancer patients correctly with an area under the curve (AUC) of 0.96 and can be validated in the independent cohort with a sensitivity of 89%, a specificity of 82% and an AUC of 0.94. Decreased levels of sphingomyelin and phosphatidylcholine (phospholipids with choline head group) and phospholipids with short, unsaturated fatty acid chains next to increased levels of phospholipids with long, saturated fatty acid chains seem to indicate that cell membranes of lung tumors are more rigid and less sensitive to lipid peroxidation. The other discriminating metabolites are pointing to a more pronounced response of the body to the Warburg effect for lung cancer. Metabolic phenotyping of plasma allows to discriminate between lung and breast cancer, indicating that the metabolite profile reflects more than a general cancer marker. NCT02362776.

Oxidative stability of fatty acid alkyl esters: a review.

The purpose of this study was to investigate and to process the current literary knowledge of the physico-chemical properties of vegetable oil raw used for biodiesel production in terms of its qualitative stability. An object of investigation was oxidative stability of biodiesel. In the study, we focused on the qualitative physico-chemical properties of vegetable oils used for biodiesel production, oxidative degradation and its mechanisms, oxidation of lipids, mechanisms of autooxidation, effectivennes of different synthetic antioxidants in relation to oxidative stability of biodiesel and methods of oxidative stability determination. Knowledge of the physical and chemical properties of vegetable oil as raw material and the factors affecting these properties is critical for the production of quality biodiesel and its sustainability. According to the source of oilseed, variations in the chemical composition of the vegetable oil are expressed by variations in the molar ratio among different fatty acids in the structure. The relative ratio of fatty acids present in the raw material is kept relatively constant after the transesterification reaction. The quality of biodiesel physico-chemical properties is influenced by the chain length and the level of unsaturation of the produced fatty acid alkyl esters. A biodiesel is thermodynamically stable. Its instability primarily occurs from contact of oxygen present in the ambient air that is referred to as oxidative instability. For biodiesel is oxidation stability a general term. It is necessary to distinguish ‘storage stability' and ‘thermal stability', in relation to oxidative degradation, which may occur during extended periods of storage, transportation and end use. Fuel instability problems can be of two related types, short-term oxidative instability and long-term storage instability. Storage instability is defined in terms of solid formation, which can plug nozzles, filters, and degrade engine performance. Biodiesels are more susceptible to degradation compared to fossil diesel because of the presence of unsaturated fatty acid chain in it. The mechanisms of oxidative degradation are autoxidation in presence of atmospheric oxygen; thermal or thermal-oxidative degradation from excess heat; hydrolysis in presence of moisture or water during storage and in fuel lines; and microbial contamination from contact with dust particles or water droplets containing fungi or bacteria into the fuel. The oxidation of lipids is a complex process in which unsaturated fatty acids are reacted with molecular oxygen by means of free radicals. The radicals react with lipids, and cause oxidative destruction of unsaturated, polyunsaturated fatty acids, therefore, known as lipid peroxidation. The factors such as heat, oxygen, light, and some metal ions, especially iron and copper, also play a significant role in creating oxidation. Oxidative products formed in biodiesel affect fuel storage life, contribute to deposit formation in tanks, and they may cause clogging of fuel filters and injection systems. The volatile organic acids formed as secondary by products of the oxidative degradation, may stimulate corrosion in the fuel system. Poor stability can lead to increasing acid numbers, increasing fuel viscosity, and the formation of gums and sediments. In general, antioxidants can prevent oxidation. Biodiesel, because it contains large numbers of molecules with double bonds, is much less oxidatively stable than petroleum-based diesel fuel. Oxidation stability is the important parameter to determine the storage of biodiesel for longer period of time. Biodiesel samples were evaluated according to methods on the base of kept in contact with pure oxygen at elevated temperatures and pressures. The results show that the performance antioxidants variation is observed for biodiesel. The most commonly used primary synthetic antioxidants

Review of the stability of biodiesel produced from less common vegetable oils of African origin

The stability of biodiesel is dependent on storage conditions such as contact with ambient air and metals, exposure to sunlight and high temperature conditions which accelerate oxidation reactions. In addition, biodiesels are more susceptible to degradation when compared to fossil diesel because of the presence of unsaturated fatty acid chains which are prone to oxidation. The stability of biodiesel is categorised according to oxidation stability, storage stability and thermal stability. Oxidation instability can led to the formation of oxidation products such as aldehydes, alcohols, shorter chain carboxylic acids, insolubles, gums and sediments in the biodiesel. Thermal instability is concerned with the increased rate of oxidation at higher temperature, which in turn increases the weight of oil and fat due to the formation of insolubles. Storage stability is the ability of liquid fuel to resist change to its physical and chemical characteristics brought about by its interaction with its storage environment, such as contamination with metals. These fuel instabilities give rise to the formation of undesirable substances in biodiesel beyond acceptable limits as per global biodiesel standards such as those of the American Society for Testing and Materials (ASTM D6751) and European Standards (EN 14214). When such fuel is used in the engine, it impairs engine performance through fuel filter plugging, injector fouling, and deposit formation in the engine combustion chamber and various components of the fuel system. We review the stability of biodiesel made from less common vegetable oils of African origin and synthetic antioxidants used in improving the stability of produced biodiesels.

Unsaturated compounds induce up-regulation of CD86 on dendritic cells in the in vitro sensitization assay LCSA.

Unsaturated compounds are known to cause false-positive reactions in the local lymph node assay (LLNA) but not in the guinea pig maximization test. We have tested a panel of substances (succinic acid, undecylenic acid, 1-octyn-3-ol, fumaric acid, maleic acid, linoleic acid, oleic acid, alpha-linolenic acid, squalene, and arachidonic acid) in the loose-fit coculture-based sensitization assay (LCSA) to evaluate whether unspecific activation of dendritic cells is a confounder for sensitization testing in vitro. Eight out of 10 tested substances caused significant up-regulation of CD86 on dendritic cells cocultured with keratinocytes and would have been classified as sensitizers; only succinic acid was tested negative, and squalene had to be excluded from data analysis due to poor solubility in cell culture medium. Based on human data, only undecylenic acid can be considered a true sensitizer. The true sensitizing potential of 1-octyn-3-ol is uncertain. Fumaric acid and its isomer maleic acid are not known as sensitizers, but their esters are contact allergens. A group of 18- to 20-carbon chain unsaturated fatty acids (linoleic acid, oleic acid, alpha-linolenic acid, and arachidonic acid) elicited the strongest reaction in vitro. This is possibly due to the formation of pro-inflammatory lipid mediators in the cell culture causing nonspecific activation of dendritic cells. In conclusion, both the LLNA and the LCSA seem to provide false-positive results for unsaturated fatty acids. The inclusion of T cells in dendritic cell-based in vitro sensitization assays may help to eliminate false-positive results due to nonspecific dendritic cell activation. This would lead to more accurate prediction of sensitizers, which is paramount for consumer health protection and occupational safety.

Rapid Mitogenic Regulation of the mTORC1 Inhibitor, DEPTOR, by Phosphatidic Acid

The mammalian target of rapamycin complex 1 (mTORC1) is regulated, in part, by the endogenous inhibitor DEPTOR. However, the mechanism of DEPTOR regulation with regard to rapid mTORC1 activation remains unknown. We report that DEPTOR is rapidly and temporarily dissociated from mTORC1 upon mitogenic stimulation, suggesting a mechanism underlying acute mTORC1 activation. This mitogen-stimulated DEPTOR dissociation is blocked by inhibition or depletion of the mTORC1 regulator, phospholipase D (PLD), and recapitulated with the addition of the PLD product phosphatidic acid (PA). Our mass spectrometry analysis has independently identified DEPTOR as an mTOR binding partner dissociated by PA. Interestingly, only PA species with unsaturated fatty acid chains, such as those produced by PLD, are capable of displacing DEPTOR and activating mTORC1, with high affinity for the FRB domain of mTOR. Our findings reveal a mechanism of mTOR regulation and provide a molecular explanation for the exquisite specificity of PA function.

Effect of Olein Fractions of Milk Fat on Oxidative Stability of Ice Cream

The effect of low melting fractions of milk fat on oxidative stability of ice cream was investigated. Cream was fractionated at three different temperatures (25, 15, and 10°C), designated as LF-25, LF-15, and LF-10. All the low melting fractions were individually incorporated into ice cream and compared with a control, unmodified milk fat. The other ingredients were the same as in the control. Ice creams were stored at –18°C for six months and sampled every 30 days. Fractionation induced major changes in the fatty acid composition of all fractions. Concentration of short-chain and long chain unsaturated fatty acids increased in the low melting fractions. Peroxide value and anisidine value of LF-10 increased from 0.23 to 3.95 (meq/kg O2) and 3.87 to 8.04. Conjugated dienes of control and LF-10 after six months were 1.39 and 4.72 at the same storage period. The flavor score of LF-10 was more than the control and remained indifferent from the control until two months of storage. After six months, the flavor score of LF-10 dropped by 3.6 points as compared to the control, 1.2 points. Low melting fractions of milk fat can be added in the formulation of ice cream to improve its nutritional value with acceptable sensory attributes. However, storage of ice cream formulated from low melting fractions is not recommended for over 60 days at –18°C.

Asolectin from soybeans as a natural compatibilizer for cellulose‐reinforced biocomposites from tung oil

ABSTRACTThe free radical copolymerization of tung oil, divinylbenzene, and n‐butyl methacrylate results in bio‐based thermosetting polymers with tunable properties. Biocomposites have been obtained by the reinforcement of such bio‐based resins with α‐cellulose. Asolectin from soybeans consists of a mixture of natural, polyunsaturated phospholipids. Because of its long, unsaturated fatty acid chains, and the presence of phosphate and ammonium groups, asolectin from soybeans is a good candidate for acting as a natural compatibilizer between the hydrophobic matrix and the hydrophilic reinforcement. In the current work, we investigate the changes in properties resulting from the addition of asolectin to a tung oil‐based polymer reinforced with α‐cellulose. An evaluation of the cure‐kinetics of the tung oil‐based resin has been conducted by dielectric analysis (DEA), and the final biocomposites have been thoroughly characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), Soxhlet extraction, and scanning electron microscopy (SEM). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41833.

Dose-response estrogen promotes osteogenic differentiation via GPR40 (FFAR1) in murine BMMSCs.

Estrogen plays an essential role in bone formation, and estrogen modulation dysfunction is tightly associated with postmenopausal osteoporosis (PMOP). The underlying mechanisms of estrogen-mediated osteogenic differentiation have not been well defined. In this study, murine bone marrow mesenchymal stem cells were induced to undergo osteogenic differentiation, and gene expression analysis or GPR40 expression manipulation was performed. Bilateral ovariectomized or sham-operated C57BL/6 mice were administered GPR40 agonist (GW9508) for bone mineral density analysis. We identified GPR40, a long chain unsaturated fatty acid receptor, to be regulated by estrogen and involved in osteogenic differentiation both invivo and invitro. Mechanistically, the Wnt/β-catenin signaling pathway is essential for GPR40 to promote osteogenic differentiation. Furthermore, invivo GW9508 administration rescued estrogen-deficient bone loss, indicating the essential role of the GPR40 receptor. To our knowledge, this is the first study that provides evidence for GPR40 as a positive regulator of osteogenesis and Wnt/β-catenin signaling. These results indicate that GPR40 may function as an endogenous promoter of estrogen-induced osteogenic differentiation through Wnt/β-catenin signaling activation. Therefore, as the global population of ages and the prevalence of metabolic-related disorders, especially PMOP, increases, our findings suggest that GPR40 is a key in understanding the link between bone and fat. It may also be a useful target for the treatment of bone complications in the future.

Directed Interesterification of Coconut Oil to Produce Structured Lipid

Structured lipid is triglycerides composed of medium chain saturated fatty acids and unsaturated fatty acids. Coconut oil contains adequate amounts of medium chain and unsaturated fatty acids. The objective of this research is to evaluate a new method of producing structured lipid directly from coconut oil through directed interesterification in a solvent at three successively decreasing temperatures. The tested solvents are cellosolve and acetone. The results of the research showed that the new method is indeed effective and acetone is the better solvent. Three stages directed interesterification of coconut oil in acetone solvent could deliver around 24% of structured lipid.