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Nutrients Dec 2022Medium-chain fatty acids contain 6-12 carbon atoms and are absorbed directly into the blood vessels, proceeding to the portal vein and, finally, to the liver, where...
Medium-chain fatty acids contain 6-12 carbon atoms and are absorbed directly into the blood vessels, proceeding to the portal vein and, finally, to the liver, where they are immediately utilized for energy. We aimed to determine the medium-chain fatty acid levels in women with and without breast cancer. A total of 200 women (100 breast cancer subjects and 100 control subjects) were recruited for the study as per the inclusion and exclusion criteria. Blood samples were collected for biochemical estimations. Fatty acid methyl esters were isolated, and medium-chain fatty acid levels in plasma were analyzed using gas chromatography (GC-FID). Statistical analysis was performed using SPSS 20.0 software; ≤ 0.05 was considered statistically significant. The fatty acid analysis revealed a significant decrease in the levels of caprylic acid (C:8) and lauric acid (C:12) and a significant increase in the level of capric acid (C:10) in the breast cancer subjects when compared to the control group. The level of caproic acid (C:6) was not significantly increased in the breast cancer subjects. In particular, the HER2- and ER-positive breast cancer subjects showed a decrease in their caprylic acid and lauric acid levels compared to other receptors. The results of the current study imply that lower levels of caprylic and lauric acid may be associated with a higher risk of breast cancer. The relevance of medium-chain fatty acids for preventive and therapeutic interventions will be amplified by further research on the possibility that alteration in a patient's medium-chain fatty acid composition may mechanistically contribute to disease progression or breast cancer risk.
Topics: Humans; Female; Caprylates; Breast Neoplasms; Fatty Acids; Lauric Acids
PubMed: 36558514
DOI: 10.3390/nu14245351 -
Molecular Metabolism Apr 2020Nutrient sensing by hypothalamic neurons is critical for the regulation of food intake and energy expenditure. We aimed to identify long- and medium-chain fatty acid...
OBJECTIVES
Nutrient sensing by hypothalamic neurons is critical for the regulation of food intake and energy expenditure. We aimed to identify long- and medium-chain fatty acid species transported into the brain, their effects on energy balance, and the mechanisms by which they regulate activity of hypothalamic neurons.
METHODS
Simultaneous blood and cerebrospinal fluid (CSF) sampling was undertaken in rats and metabolic analyses using radiolabeled fatty acid tracers were performed on mice. Electrophysiological recording techniques were used to investigate signaling mechanisms underlying fatty acid-induced changes in activity of pro-opiomelanocortin (POMC) neurons.
RESULTS
Medium-chain fatty acid (MCFA) octanoic acid (C8:0), unlike long-chain fatty acids, was rapidly transported into the hypothalamus of mice and almost exclusively oxidized, causing rapid, transient reductions in food intake and increased energy expenditure. Octanoic acid differentially regulates the excitability of POMC neurons, activating these neurons directly via GPR40 and inducing inhibition via an indirect non-synaptic, purine, and adenosine receptor-dependent mechanism.
CONCLUSIONS
MCFA octanoic acid is a central signaling nutrient that targets POMC neurons via distinct direct and indirect signal transduction pathways to instigate changes in energy status. These results could explain the beneficial health effects that accompany MCFA consumption.
Topics: Animals; Caprylates; Energy Metabolism; Male; Neurons; Rats; Rats, Wistar
PubMed: 32180560
DOI: 10.1016/j.molmet.2020.01.002 -
Metabolic Engineering May 2023Cells build fatty acids in tightly regulated assembly lines, or fatty acid synthases (FASs), in which β-ketoacyl-acyl carrier protein (ACP) synthases (KSs) catalyze...
Cells build fatty acids in tightly regulated assembly lines, or fatty acid synthases (FASs), in which β-ketoacyl-acyl carrier protein (ACP) synthases (KSs) catalyze sequential carbon-carbon bond forming reactions that generate acyl-ACPs of varying lengths-precursors for a diverse set of lipids and oleochemicals. To date, most efforts to control fatty acid synthesis in engineered microbes have focused on modifying termination enzymes such as acyl-ACP thioesterases, which release free fatty acids from acyl-ACPs. Changes to the substrate specificity of KSs provide an alternative-and, perhaps, more generalizable-approach that focuses on controlling the acyl-ACPs available for downstream products. This study combines mutants of FabF and FabB, the two elongating KSs of the E. coli FAS, with in vitro and in vivo analyses to explore the use of KS mutants to control fatty acid synthesis. In vitro, single amino acid substitutions in the gating loop and acyl binding pocket of FabF shifted the product profiles of reconstituted FASs toward short chains and showed that KS mutants, alone, can cause large shifts in average length (i.e., 6.5-13.5). FabB, which is essential for unsaturated fatty acid synthesis, blunted this effect in vivo, but exogenously added cis-vaccenic acid (C18:1) enabled sufficient transcriptional repression of FabB to restore it. Strikingly, a single mutant of FabB afforded titers of octanoic acid as high as those generated by an engineered thioesterase. Findings indicate that fatty acid synthesis must be decoupled from microbial growth to resolve the influence of KS mutants on fatty acid profiles but show that these mutants offer a versatile approach for tuning FAS outputs.
Topics: Escherichia coli; Fatty Acids; Escherichia coli Proteins; Fatty Acids, Volatile
PubMed: 36963462
DOI: 10.1016/j.ymben.2023.03.008 -
Current Biology : CB Mar 2022The Vespidae is a diverse family of wasps and hornets that are formidable predators of insects, including social bees, and includes a number of invasive species....
The Vespidae is a diverse family of wasps and hornets that are formidable predators of insects, including social bees, and includes a number of invasive species. Recently, the world's largest hornet, Vespa mandarinia Smith (Hymenoptera: Vespidae), which occurs naturally in the Indomalayan region, has been found in Canada and the United States. Some simulations indicate that it could rapidly spread throughout Washington and Oregon in the western US, as well as some eastern parts of the country, threaten native bees and honeybees, and harm bee-pollinated crop production worth over $100 million annually. There is consequently an urgent need to learn more about V. mandarinia's reproductive biology and to develop trapping methods to locate its nests and to control its reproduction. We identified V. mandarinia queen-produced sex pheromone from the 5 and 6 intersegmental sternal glands of virgin queens. The major active compounds were hexanoic acid, octanoic acid, and decanoic acid. When placed in field traps, the synthetic compounds and a queen-equivalent mixture rapidly attracted hundreds of males but no females or other species.
Topics: Animals; Bees; Introduced Species; Male; Reproduction; Sex Attractants; Wasps
PubMed: 35290766
DOI: 10.1016/j.cub.2022.01.065 -
Frontiers in Physiology 2022Acyl-ghrelin (AG) is an orexigenic hormone that has a unique octanoyl modification on its third serine residue. It is often referred to as the "hunger hormone" due to... (Review)
Review
Acyl-ghrelin (AG) is an orexigenic hormone that has a unique octanoyl modification on its third serine residue. It is often referred to as the "hunger hormone" due to its involvement in stimulating food intake and regulating energy homeostasis. The discovery of the enzyme ghrelin-O-acyltransferase (GOAT), which catalyses ghrelin acylation, provided further insights into the relevance of this lipidation process for the activation of the growth hormone secretagogue receptor (GHS-R) by acyl-ghrelin. Although acyl-ghrelin is predominantly linked with octanoic acid, a range of saturated fatty acids can also bind to ghrelin possibly leading to specific functions. Sources of ghrelin acylation include beta-oxidation of longer chain fatty acids, with contributions from fatty acid synthesis, the diet, and the microbiome. In addition, both acyl-ghrelin and unacyl-ghrelin (UAG) have feedback effects on lipid metabolism which in turn modulate their levels. Recently we showed that whilst acyl-ghrelin promotes adult hippocampal neurogenesis and enhances memory function, UAG inhibits these processes. As a result, we postulated that the circulating acyl-ghrelin:unacyl-ghrelin (AG:UAG) ratio might be an important regulator of neurogenesis and cognition. In this review, we discuss emerging evidence behind the relevance of ghrelin acylation in the context of brain physiology and pathology, as well as the current challenges of identifying the provenance of the acyl moiety.
PubMed: 35845996
DOI: 10.3389/fphys.2022.831641 -
Applied and Environmental Microbiology Aug 2022The marine bacterium Alcanivorax borkumensis produces a surface-active glycine-glucolipid during growth with long-chain alkanes. A high-performance liquid chromatography...
The marine bacterium Alcanivorax borkumensis produces a surface-active glycine-glucolipid during growth with long-chain alkanes. A high-performance liquid chromatography (HPLC) method was developed for absolute quantification. This method is based on the conversion of the glycine-glucolipid to phenacyl esters with subsequent measurement by HPLC with diode array detection (HPLC-DAD). Different molecular species were separated by HPLC and identified as glucosyl-tetra(3-hydroxy-acyl)-glycine with varying numbers of 3-hydroxy-decanoic acid or 3-hydroxy-octanoic acid groups via mass spectrometry. The growth rate of cells with pyruvate as the sole carbon source was elevated compared to hexadecane as recorded by the increase in cell density as well as oxygen/carbon dioxide transfer rates. The amount of the glycine-glucolipid produced per cell during growth on hexadecane was higher compared with growth on pyruvate. The glycine-glucolipid from pyruvate-grown cells contained considerable amounts of 3-hydroxy-octanoic acid, in contrast to hexadecane-grown cells, which almost exclusively incorporated 3-hydroxy-decanoic acid into the glycine-glucolipid. The predominant proportion of the glycine-glucolipid was found in the cell pellet, while only minute amounts were present in the cell-free supernatant. The glycine-glucolipid isolated from the bacterial cell broth, cell pellet, or cell-free supernatant showed the same structure containing a glycine residue, in contrast to previous reports, which suggested that a glycine-free form of the glucolipid exists which is secreted into the supernatant. In conclusion, the glycine-glucolipid of is resident to the cell wall and enables the bacterium to bind and solubilize alkanes at the lipid-water interface. Alcanivorax borkumensis is one of the most abundant marine bacteria found in areas of oil spills, where it degrades alkanes. The production of a glycine-glucolipid is considered an essential element for alkane degradation. We developed a quantitative method and determined the structure of the glycine-glucolipid in different fractions of the cultures after growth in various media. Our results show that the amount of the glycine-glucolipid in the cells by far exceeds the amount measured in the supernatant, confirming the proposed cell wall localization. These results support the scenario that the surface hydrophobicity of cells increases by producing the glycine-glucolipid, allowing the cells to attach to the alkane-water interface and form a biofilm. We found no evidence for a glycine-free form of the glucolipid.
Topics: Alcanivoraceae; Alkanes; Bacteria; Biodegradation, Environmental; Cell Wall; Glycine; Pyruvic Acid; Water
PubMed: 35938787
DOI: 10.1128/aem.01126-22 -
Foods (Basel, Switzerland) May 2022and screened from Guizhou specialty food were used to prepare fermented pork loin ham. The sensory qualities and flavor profiles of fermented pork loin hams from 0 to...
and screened from Guizhou specialty food were used to prepare fermented pork loin ham. The sensory qualities and flavor profiles of fermented pork loin hams from 0 to 42 days were investigated in order to reveal the dynamics of fermented pork loin ham. The results show that total free amino acids (TFAA) content reached the highest value on the 35th day, and the umami amino acids, including aspartic acid (ASP), glutamic acid (GLU), glycine (GLY), and alanine (ALA), were the main amino acids in all periods. Notably, the RV coefficient (0.875) indicates that free amino acids (FAA) are highly correlated with the sensory score of the E-tongue. In terms of the volatile compounds identified, the esters content gradually increased between 7 and 42 days, and ethyl octanoate was the most abundant compound during all periods. These esters imparted a characteristic aroma component to the fermented pork loin ham. The most important finding was that the increase in the content of esters represented by octanoic acid-ethyl ester might be related to the increase in the content of FAA with the increase in fermentation time. Both the E-nose and E-tongue showed good discrimination ability for fermented tenderloin ham with different fermentation times, which was crucial in cases with large clusters. In addition, the multiple factor analysis (MFA) indicated that the E-nose aroma value might be the key factor in distinguishing fermented pork loin ham with different fermentation times.
PubMed: 35627071
DOI: 10.3390/foods11101501 -
Environmental Health Perspectives Feb 2023Perfluoroalkyl acids (PFAA) have been measured in ovarian follicular fluid from women using fertilization (IVF), although associations between follicular fluid PFAA and...
BACKGROUND
Perfluoroalkyl acids (PFAA) have been measured in ovarian follicular fluid from women using fertilization (IVF), although associations between follicular fluid PFAA and IVF outcomes have been inconsistent.
OBJECTIVES
We investigated the association between follicular fluid PFAA and embryo quality in women undergoing IVF.
METHODS
We prospectively enrolled 729 women undergoing IVF treatment in Guangxi province, China, from July 2018 to December 2018. We measured 32 PFAA, including branched isomers, in follicular fluid using ultra-performance liquid chromatography coupled to tandem mass spectrometry. We applied restricted cubic splines, linear regression, and log-binominal regression models to investigate associations between follicular fluid PFAA and embryo quality, adjusting for confounding variables and investigated oocyte maturity as an intervening variable using causal mediation analysis. We further estimated the overall effect of the PFAA mixture on outcomes using Bayesian kernel machine regression (BKMR).
RESULTS
We detected 8 of 32 measured PFAA in of follicular fluid samples. Higher PFAA concentrations were associated with fewer high-quality embryos from IVF. The high-quality embryo rates at the 50th percentile of linear perfluoro-1-octanesulfonate acid (n-PFOS), all branched PFOS isomers (Br-PFOS) and linear perfluoro--octanoic acid (n-PFOA) were [95% confidence interval (CI): , ], (95% CI: , ) and (95% CI: , ) lower, respectively, than the high quality embryo rates at the reference 10th percentile of PFAA. Oocyte maturity mediated 11.76% (95% CI: 3.18, 31.80%) and 14.28% (95% CI: 2.95, 31.27%) of the n-PFOS and n-PFOA associations, respectively. The results of the BKMR models showed a negative association between the PFAA mixture and the probability of high-quality embryos, with branched PFOS isomers having posterior inclusion probabilities of 1 and accounting for the majority of the association.
DISCUSSION
Exposure to higher PFAA concentrations in follicular fluid was associated with poorer embryo quality during IVF. Branched PFOS isomers may have a stronger effect than linear PFOS isomers. More studies are needed to confirm these findings and to directly estimate the effects on pregnancy and live-birth outcomes. https://doi.org/10.1289/EHP10857.
Topics: Pregnancy; Female; Humans; Follicular Fluid; Alkanesulfonic Acids; Prospective Studies; Fluorocarbons; Bayes Theorem; China; Fertilization in Vitro
PubMed: 36723383
DOI: 10.1289/EHP10857 -
Molecules (Basel, Switzerland) Aug 2022The use of plant-based products has been shown to efficiently inhibit fungi-mediated diseases in agricultural crops. Here, we extracted and evaluated the composition of...
The use of plant-based products has been shown to efficiently inhibit fungi-mediated diseases in agricultural crops. Here, we extracted and evaluated the composition of noni, L., essential oil and assessed its activities against in L. Using in silico molecular approaches, potential interactions between the essential oil major components and tyrosine-tRNA ligase were predicted. Finally, we also measured the potential interference of plant physiology (the stomatal conductance and net photosynthesis) mediated by the application of the essential oil. Chromatographic analysis revealed that octanoic acid (75.8%), hexanoic acid (12.8%), and isobutyl pent-4-enyl carbonate (3.1%) were the major essential oil compounds. Octanoic acid and noni essential oil, when used as preventive measures, reduce fungal mycelial growth at a concentration of 5 mg/mL without causing significant damage to the treated leaves, which reinforces their efficacies as preventive tools against . Molecular docking analyses predicted very stable interactions between the major essential oil constituents and tyrosine-tRNA ligase, suggesting the interference of these plant-based molecules upon enzyme activation. Octanoic acid and essential oil at concentrations of 20 mg/mL decreased the stomatal conductance and net photosynthesis rate of melon plants, resulting in robust phytotoxicity. Collectively, our findings indicated that despite the phytotoxicity risks at higher concentrations, essential oil and octanoic acid, have potential as alternative tools for the integrative management of .
Topics: Ascomycota; Caprylates; Molecular Docking Simulation; Morinda; Oils, Volatile; Plant Extracts; Tyrosine-tRNA Ligase
PubMed: 36014413
DOI: 10.3390/molecules27165173 -
Chemistry (Weinheim An Der Bergstrasse,... Jan 2021The chemical background of olfactory perception has been subject of intensive research, but no available model can fully explain the sense of smell. There are also...
The chemical background of olfactory perception has been subject of intensive research, but no available model can fully explain the sense of smell. There are also inconsistent results on the role of the isotopology of molecules. In experiments with human subjects it was found that the isotope effect is weak with acetone and D -acetone. In contrast, clear differences were observed in the perception of octanoic acid and D -octanoic acid. Furthermore, a trained sniffer dog was initially able to distinguish between these isotopologues of octanoic acid. In chromatographic measurements, the respective deuterated molecule showed weaker interaction with a non-polar liquid phase. Quantum chemical calculations give evidence that deuterated octanoic acid binds more strongly to a model receptor than non-deuterated. In contrast, the binding of the non-deuterated molecule is stronger with acetone. The isotope effect is calculated in the framework of statistical mechanics. It results from a complicated interplay between various thermostatistical contributions to the non-covalent free binding energies and it turns out to be very molecule-specific. The vibrational terms including non-classical zero-point energies play about the same role as rotational/translational contributions and are larger than bond length effects for the differential isotope perception of odor for which general rules cannot be derived.
Topics: Acetone; Animals; Caprylates; Deuterium; Dogs; Odorants; Olfactory Perception; Organic Chemicals; Smell; Working Dogs
PubMed: 33058253
DOI: 10.1002/chem.202003754