ABSTRACT
Dietary lipids play an essential role in regulating the function of the gut microbiota and gastrointestinal tract, and these luminal interactions contribute to mediating host metabolism. Palmitic Acid Hydroxy Stearic Acids (PAHSAs) are a family of lipids with antidiabetic and anti-inflammatory properties, but whether the gut microbiota contributes to their beneficial effects on host metabolism is unknown. Here, we report that treating chow-fed female and male germ-free (GF) mice with PAHSAs improves glucose tolerance, but these effects are lost upon high fat diet (HFD) feeding. However, transfer of feces from PAHSA-treated, but not vehicle-treated, chow-fed conventional mice increases insulin sensitivity in HFD-fed GF mice. Thus, the gut microbiota is necessary for, and can transmit, the insulin-sensitizing effects of PAHSAs in HFD-fed GF male mice. Analyses of the cecal metagenome and lipidome of PAHSA-treated mice identified multiple lipid species that associate with the gut commensal Bacteroides thetaiotaomicron (Bt) and with insulin sensitivity resulting from PAHSA treatment. Supplementing live, and to some degree, heat-killed Bt to HFD-fed female mice prevented weight gain, reduced adiposity, improved glucose tolerance, fortified the colonic mucus barrier and reduced systemic inflammation compared to HFD-fed controls. These effects were not observed in HFD-fed male mice. Furthermore, ovariectomy partially reversed the beneficial Bt effects on host metabolism, indicating a role for sex hormones in mediating the Bt probiotic effects. Altogether, these studies highlight the fact that PAHSAs can modulate the gut microbiota and that the microbiota is necessary for the beneficial metabolic effects of PAHSAs in HFD-fed mice.
Subject(s)
Diet, High-Fat , Gastrointestinal Microbiome , Insulin Resistance , Obesity , Animals , Male , Female , Mice , Gastrointestinal Microbiome/drug effects , Obesity/metabolism , Obesity/microbiology , Obesity/etiology , Diet, High-Fat/adverse effects , Mice, Inbred C57BL , Stearic Acids/metabolism , Palmitic Acid/metabolism , Feces/microbiology , Mice, ObeseABSTRACT
Extensive evidence supports the connection between obesity-induced inflammation and the heightened expression of IL-6 adipose tissues. However, the mechanism underlying the IL-6 exacerbation in the adipose tissue remains unclear. There is general agreement that TNF-α and stearate concentrations are mildly elevated in adipose tissue in the state of obesity. We hypothesize that TNF-α and stearate co-treatment induce the increased expression of IL-6 in mouse adipocytes. We therefore aimed to determine IL-6 gene expression and protein production by TNF-α/stearate treated adipocytes and investigated the mechanism involved. To test our hypothesis, 3T3-L1 mouse preadipocytes were treated with TNF-α, stearate, or TNF-α/stearate. IL-6 gene expression was assessed by quantitative real-time qPCR. IL-6 protein production secreted in the cell culture media was determined by ELISA. Acetylation of histone was analyzed by Western blotting. Il6 region-associated histone H3 lysine 9/18 acetylation (H3K9/18Ac) was determined by ChIP-qPCR. 3T3-L1 mouse preadipocytes were co-challenged with TNF-α and stearate for 24 h, which led to significantly increased IL-6 gene expression (81 ± 2.1 Fold) compared to controls stimulated with either TNF-α (38 ± 0.5 Fold; p = 0.002) or stearate (56 ± 2.0 Fold; p = 0.013). As expected, co-treatment of adipocytes with TNF-α and stearate significantly increased protein production (338 ± 11 pg/mL) compared to controls stimulated with either TNF-α (28 ± 0.60 pg/mL; p = 0.001) or stearate (53 ± 0.20 pg/mL, p = 0.0015). Inhibition of histone acetyltransferases (HATs) with anacardic acid or curcumin significantly reduced the IL-6 gene expression and protein production by adipocytes. Conversely, TSA-induced acetylation substituted the stimulatory effect of TNF-α or stearate in their synergistic interaction for driving IL-6 gene expression and protein production. Mechanistically, TNF-α/stearate co-stimulation increased the promoter-associated histone H3 lysine 9/18 acetylation (H3K9/18Ac), rendering a transcriptionally permissive state that favored IL-6 expression at the transcriptional and translational levels. Our data represent a TNF-α/stearate cooperativity model driving IL-6 expression in 3T3-L1 cells via the H3K9/18Ac-dependent mechanism, with implications for adipose IL-6 exacerbations in obesity.
Subject(s)
3T3-L1 Cells , Adipocytes , Histones , Interleukin-6 , Tumor Necrosis Factor-alpha , Animals , Mice , Acetylation , Adipocytes/metabolism , Adipocytes/drug effects , Gene Expression Regulation/drug effects , Histones/metabolism , Interleukin-6/metabolism , Interleukin-6/genetics , Stearic Acids/pharmacology , Stearic Acids/metabolism , Tumor Necrosis Factor-alpha/metabolism , Tumor Necrosis Factor-alpha/pharmacologyABSTRACT
The effects of common migration substances in milk packaging on digestive protease were studied. We choose the common migrants found in eight types of multi-layer composite milk packaging. Enzyme activity experiments revealed that pepsin activity decreased by approximately 18 % at 500 µg/mL of stearic acid and stearamide treatment, while trypsin activity decreased by approximately 18 % only by stearic acid treatment (500 µg/mL). Subsequently, fluorescence spectroscopy, circular dichroism spectroscopy, and molecular docking technology were employed to investigate the inhibition mechanism of protease activity by migrating substances in three systems: stearic acid-trypsin, stearic acid-pepsin, and stearamide-pepsin. Results showed that the inhibitory effect of stearic acid on trypsin is a reversible mixed inhibition, whereas the inhibitory effects of stearic acid and stearamide on pepsin are non-competitive. In all three systems, ΔH < 0, ΔS < 0, and ΔG < 0, indicating the binding process between the migrant and the protease is a spontaneous exothermic process primarily driven by hydrogen bonding and van der Waals forces. In addition, their binding constants are all around 104 L/moL, indicating that there are moderate binding affinities exist between migrants and proteases. The binding process results in the quenching of the protease's endogenous fluorescence and induces alterations in the enzyme's secondary structure. Synchronized fluorescence spectroscopy showed that stearic acid enhanced the hydrophobicity near the Tyr residue of trypsin. The molecular docking results indicated that the binding affinity of stearic acid-trypsin, stearic acid-pepsin, and stearamide-pepsin was -22.51 kJ/mol, -12.35 kJ/mol, -19.28 kJ/mol respectively, which consistent with the trend in the enzyme activity results. This study can provide references for the selection of milk packaging materials and the use of processing additives, ensuring food health and safety.
Subject(s)
Food Packaging , Milk , Molecular Docking Simulation , Spectrometry, Fluorescence , Trypsin , Animals , Milk/chemistry , Trypsin/metabolism , Trypsin/chemistry , Stearic Acids/chemistry , Stearic Acids/metabolism , Pepsin A/metabolism , Pepsin A/chemistry , Circular Dichroism , Peptide Hydrolases/metabolism , Peptide Hydrolases/chemistry , ThermodynamicsABSTRACT
AIM: Fatty acid esters of hydroxy fatty acids (FAHFA) are a class of bioactive lipids with anti-inflammatory, antidiabetic and cardioprotective properties. FAHFA hydrolysis into its fatty acid (FA) and hydroxy fatty acid (HFA) constituents can affect the bioavailability of FAHFA and its subsequent biological effects. We aimed to investigate FAHFA levels and FAHFA hydrolysis activity in children with or without obesity, and in adults with or without coronary artery disease (CAD). MATERIALS AND METHODS: Our study cohort included 20 children without obesity, 40 children with obesity, 10 adults without CAD and 28 adults with CAD. We quantitated plasma levels of four families of FAHFA [palmitic acid hydroxy stearic acid (PAHSA), palmitoleic acid hydroxy stearic acid (POHSA), oleic acid hydroxy stearic acid (OAHSA), stearic acid hydroxy stearic acid] and their corresponding FA and HFA constituents using liquid chromatography-tandem mass spectrometry analysis. Surrogate FAHFA hydrolysis activity was estimated as the FA/FAHFA or HFA/FAHFA ratio. RESULTS: Children with obesity had lower plasma PAHSA (p = .001), OAHSA (p = .006) and total FAHFA (p = .011) levels, and higher surrogate FAHFA hydrolysis activity represented by PA/PAHSA (p = .040) and HSA/OAHSA (p = .025) compared with children without obesity. Adults with CAD and a history of myocardial infarction (MI) had lower POHSA levels (p = .026) and higher PA/PAHSA (p = .041), POA/POHSA (p = .003) and HSA/POHSA (p = .038) compared with those without MI. CONCLUSION: Altered FAHFA metabolism is associated with obesity and MI, and inhibition of FAHFA hydrolysis should be studied further as a possible therapeutic strategy in obesity and MI.
Subject(s)
Coronary Artery Disease , Fatty Acids , Humans , Male , Female , Child , Coronary Artery Disease/blood , Adult , Hydrolysis , Fatty Acids/blood , Fatty Acids/metabolism , Middle Aged , Adolescent , Stearic Acids/blood , Stearic Acids/metabolism , Pediatric Obesity/blood , Pediatric Obesity/complications , Pediatric Obesity/metabolism , Esters/blood , Fatty Acids, Monounsaturated/blood , Obesity/blood , Obesity/complications , Obesity/metabolism , Cohort StudiesABSTRACT
Constipation is a major gastrointestinal (GI) symptom worldwide, with diverse causes of formation, and requires effective and safe therapeutic measures. In the present study, we used loperamide hydrochloride to establish a constipation model and assessed the effect of Bifidobacterium on constipation and its possible mechanism of relief. The results showed that B. longum S3 exerted a constipation-relieving effect primarily by improving the gut microbiota, enriching genera including Lactobacillus, Alistipes, and Ruminococcaceae UCG-007, and decreasing the bacteria Lachnospiraceae NK4B4 group. These changes may thereby increase acetic acid and stearic acid (C18:0) levels, which significantly increase the expression levels of ZO-1 and MUC-2, repair intestinal barrier damage and reduce inflammation (IL-6). Furthermore, it also inhibited oxidative stress levels (SOD and CAT), decreased the expression of water channel proteins (AQP4 and AQP8), significantly elevated the Gas, 5-HT, PGE2, and Ach levels, and reduced nNOS and VIP levels to improve the intestinal luminal transit time and fecal water content. Collectively, these changes resulted in the alleviation of constipation.
Subject(s)
Acetic Acid , Bifidobacterium longum , Constipation , Gastrointestinal Microbiome , Loperamide , Probiotics , Stearic Acids , Loperamide/adverse effects , Constipation/chemically induced , Constipation/drug therapy , Constipation/metabolism , Animals , Mice , Probiotics/pharmacology , Stearic Acids/metabolism , Male , Gastrointestinal Microbiome/drug effects , Disease Models, Animal , Intestines/microbiologyABSTRACT
Nanoenabled strategies have recently attracted attention as a sustainable platform for agricultural applications. Here, we present a mechanistic understanding of nanobiointeraction through an orthogonal investigation. Pristine (nS) and stearic acid surface-modified (cS) sulfur nanoparticles (NPs) as a multifunctional nanofertilizer were applied to tomato (Solanum lycopersicumL.) through soil. Both nS and cS increased root mass by 73% and 81% and increased shoot weight by 35% and 50%, respectively, compared to the untreated controls. Bulk sulfur (bS) and ionic sulfate (iS) had no such stimulatory effect. Notably, surface modification of S NPs had a positive impact, as cS yielded 38% and 51% greater shoot weight compared to nS at 100 and 200 mg/L, respectively. Moreover, nS and cS significantly improved leaf photosynthesis by promoting the linear electron flow, quantum yield of photosystem II, and relative chlorophyll content. The time-dependent gene expression related to two S bioassimilation and signaling pathways showed a specific role of NP surface physicochemical properties. Additionally, a time-dependent Global Test and machine learning strategy applied to understand the NP surface modification domain metabolomic profiling showed that cS increased the contents of IA, tryptophan, tomatidine, and scopoletin in plant leaves compared to the other treatments. These findings provide critical mechanistic insights into the use of nanoscale sulfur as a multifunctional soil amendment to enhance plant performance as part of nanoenabled agriculture.
Subject(s)
Nanoparticles , Solanum lycopersicum , Sulfur , Solanum lycopersicum/metabolism , Solanum lycopersicum/drug effects , Sulfur/metabolism , Sulfur/chemistry , Nanoparticles/chemistry , Nanoparticles/metabolism , Photosynthesis , Surface Properties , Time Factors , Fertilizers , Stearic Acids/metabolism , Stearic Acids/chemistry , Plant Leaves/metabolismABSTRACT
Oil palm, a tropical woody oil crop, is widely used in food, cosmetics, and pharmaceuticals due to its high production efficiency and economic value. Palm oil is rich in free fatty acids, polyphenols, vitamin E, and other nutrients, which are beneficial for human health when consumed appropriately. Therefore, investigating the dynamic changes in free fatty acid content at different stages of development and hypothesizing the influence of regulatory genes on free fatty acid metabolism is crucial for improving palm oil quality and accelerating industry growth. LC-MS/MS is used to analyze the composition and content of free fatty acids in the flesh after 95 days (MS1 and MT1), 125 days (MS2 and MT2), and 185 days (MS3 and MT3) of Seedless (MS) and Tenera (MT) oil palm species fruit pollination. RNA-Seq was used to analyze the expression of genes regulating free fatty acid synthesis and accumulation, with differences in genes and metabolites mapped to the KEGG pathway map using the KEGG (Kyoto encyclopedia of genes and genomes) enrichment analysis method. A metabolomics study identified 17 types of saturated and 13 types of unsaturated free fatty acids during the development of MS and MT. Transcriptomic research revealed that 10,804 significantly different expression genes were acquired in the set differential gene threshold between MS and MT. The results showed that FabB was positively correlated with the contents of three main free fatty acids (stearic acid, myristate acid, and palmitic acid) and negatively correlated with the contents of free palmitic acid in the flesh of MS and MT. ACSL and FATB were positively correlated with the contents of three main free fatty acids and negatively correlated with free myristate acid. The study reveals that the expression of key enzyme genes, FabB and FabF, may improve the synthesis of free myristate in oil palm flesh, while FabF, ACSL, and FATB genes may facilitate the production of free palmitoleic acid. These genes may also promote the synthesis of free stearic acid and palmitoleic acid in oil palm flesh. However, the FabB gene may inhibit stearic acid synthesis, while ACSL and FATB genes may hinder myristate acid production. This study provides a theoretical basis for improving palm oil quality.
Subject(s)
Arecaceae , Fatty Acids, Nonesterified , Humans , Fatty Acids, Nonesterified/metabolism , Fatty Acids/metabolism , Palm Oil , Chromatography, Liquid , Myristates/metabolism , Arecaceae/genetics , Arecaceae/metabolism , Tandem Mass Spectrometry , Fatty Acids, Unsaturated/metabolism , Palmitic Acid/metabolism , Gene Expression Profiling , Stearic Acids/metabolism , Plant Oils/metabolismABSTRACT
KEY MESSAGE: Modifications of multiple copies of the BnaSAD2 gene family with genomic editing technology result in higher stearic acid content in the seed of polyploidy rapeseed. Solid fats from vegetable oils are widely used in food processing industry. Accumulating data showed that stearic acid is more favorite as the major composite among the saturate fatty acids in solid fats in considerations of its effects on human health. Rapeseed is the third largest oil crop worldwide, and has potential to be manipulated to produce higher saturated fatty acids as raw materials of solid fats. Toward that end, we identified four SAD2 gene family members in B. napus genome and established spatiotemporal expression pattern of the BnaSAD2 members. Genomic editing technology was applied to mutate all the copies of BnaSAD2 in this allopolyploid species and mutants at multiple alleles were generated and characterized to understand the effect of each BnaSAD2 member on blocking desaturation of stearic acid. Mutations occurred at BnaSAD2.A3 resulted in more dramatic changes of fatty acid profile than ones on BnaSAD2.C3, BnaSAD2.A5 and BnaSAD2.C4. The content of stearic acid in mutant seeds with single locus increased dramatically with a range of 3.1-8.2%. Furthermore, combination of different mutated alleles of BnaSAD2 resulted in more dramatic changes in fatty acid profiles and the double mutant at BnaSAD2.A3 and BnaSAD2.C3 showed the most dramatic phenotypic changes compared with its single mutants and other double mutants, leading to 11.1% of stearic acid in the seeds. Our results demonstrated that the members of BnaSAD2 have differentiated in their efficacy as a Δ9-Stearoyl-ACP-Desaturase and provided valuable rapeseed germplasm for breeding high stearic rapeseed oil.
Subject(s)
Brassica napus , Brassica rapa , Humans , Brassica napus/genetics , Brassica napus/metabolism , Gene Editing , Plant Breeding , Fatty Acids/metabolism , Stearic Acids/metabolism , Plant Oils , Brassica rapa/genetics , Seeds/genetics , Seeds/metabolismABSTRACT
S-acylation is a reversible posttranslational protein modification consisting of attachment of a fatty acid to a cysteine via a thioester bond. Research over the last few years has shown that a variety of different fatty acids, such as palmitic acid (C16:0), stearate (C18:0), or oleate (C18:1), are used in cells to S-acylate proteins. We recently showed that GNAI proteins can be acylated on a single residue, Cys3, with either C16:0 or C18:1, and that the relative proportion of acylation with these fatty acids depends on the level of the respective fatty acid in the cell's environment. This has functional consequences for GNAI proteins, with the identity of the acylating fatty acid affecting the subcellular localization of GNAIs. Unclear is whether this competitive acylation is specific to GNAI proteins or a more general phenomenon in the proteome. We perform here a proteome screen to identify proteins acylated with different fatty acids. We identify 218 proteins acylated with C16:0 and 308 proteins acylated with C18-lipids, thereby uncovering novel targets of acylation. We find that most proteins that can be acylated by C16:0 can also be acylated with C18-fatty acids. For proteins with more than one acylation site, we find that this competitive acylation occurs on each individual cysteine residue. This raises the possibility that the function of many different proteins can be regulated by the lipid environment via differential S-acylation.
Subject(s)
Cysteine , Palmitic Acid , Proteome , Stearic Acids , Acylation , Cysteine/metabolism , Palmitic Acid/metabolism , Proteome/metabolism , HEK293 Cells , HeLa Cells , Humans , Stearic Acids/metabolismABSTRACT
The intracellular membrane domain (IMD) is a laterally discrete region of the mycobacterial plasma membrane, enriched in the subpolar region of the rod-shaped cell. Here, we report genome-wide transposon sequencing to discover the controllers of membrane compartmentalization in Mycobacterium smegmatis. The putative gene cfa showed the most significant effect on recovery from membrane compartment disruption by dibucaine. Enzymatic analysis of Cfa and lipidomic analysis of a cfa deletion mutant (Δcfa) demonstrated that Cfa is an essential methyltransferase for the synthesis of major membrane phospholipids containing a C19:0 monomethyl-branched stearic acid, also known as tuberculostearic acid (TBSA). TBSA has been intensively studied due to its abundant and genus-specific production in mycobacteria, but its biosynthetic enzymes had remained elusive. Cfa catalyzed the S-adenosyl-l-methionine-dependent methyltransferase reaction using oleic acid-containing lipid as a substrate, and Δcfa accumulated C18:1 oleic acid, suggesting that Cfa commits oleic acid to TBSA biosynthesis, likely contributing directly to lateral membrane partitioning. Consistent with this model, Δcfa displayed delayed restoration of subpolar IMD and delayed outgrowth after bacteriostatic dibucaine treatment. These results reveal the physiological significance of TBSA in controlling lateral membrane partitioning in mycobacteria. IMPORTANCE As its common name implies, tuberculostearic acid is an abundant and genus-specific branched-chain fatty acid in mycobacterial membranes. This fatty acid, 10-methyl octadecanoic acid, has been an intense focus of research, particularly as a diagnostic marker for tuberculosis. It was discovered in 1934, and yet the enzymes that mediate the biosynthesis of this fatty acid and the functions of this unusual fatty acid in cells have remained elusive. Through a genome-wide transposon sequencing screen, enzyme assay, and global lipidomic analysis, we show that Cfa is the long-sought enzyme that is specifically involved in the first step of generating tuberculostearic acid. By characterizing a cfa deletion mutant, we further demonstrate that tuberculostearic acid actively regulates lateral membrane heterogeneity in mycobacteria. These findings indicate the role of branched fatty acids in controlling the functions of the plasma membrane, a critical barrier for the pathogen to survive in its human host.
Subject(s)
Dibucaine , Mycobacterium , Humans , Mycobacterium/metabolism , Stearic Acids/metabolism , Fatty Acids , Oleic Acid , Methyltransferases/metabolismABSTRACT
During fern spore germination, lipid hydrolysis primarily provides the energy to activate their metabolism. In this research, fatty acids (linoleic, oleic, palmitic and stearic) were quantified in the spores exposed or not to priming (hydration-dehydration treatments). Five fern species were investigated, two from xerophilous shrubland and three from a cloud forest. We hypothesised that during the priming hydration phase, the fatty acids profile would change in concentration, depending on the spore type (non-chlorophyllous and crypto-chlorophyllous). The fatty acid concentration was determined by gas chromatograph-mass spectrometer. Chlorophyll in spores was vizualised by epifluorescence microscopy and quantified by high-resolution liquid chromatography with a DAD-UV/Vis detector. Considering all five species and all the treatments, the oleic acid was the most catabolised. After priming, we identified two patterns in the fatty acid metabolism: (1) in non-chlorophyllous species, oleic, palmitic, and linoleic acids were catabolised during imbibition and (2) in crypto-chlorophyllous species, these fatty acids increased in concentration. These patterns suggest that crypto-chlorophyllous spores with homoiochlorophylly (chlorophyll retained after drying) might not require the assembly of new photosynthetic apparatus during dark imbibition. Thus, these spores might require less energy from pre-existing lipids and less fatty acids as 'building blocks' for cell membranes than non-chlorophyllous spores, which require de novo synthesis and structuring of the photosynthetic apparatus.
Subject(s)
Fatty Acids , Ferns , Fatty Acids/metabolism , Ferns/metabolism , Spores/physiology , Lipid Metabolism , Oleic Acid/metabolism , Stearic Acids/metabolism , Palmitic Acid/metabolismABSTRACT
BACKGRUOUND: Chronic exposure to elevated levels of saturated fatty acids results in pancreatic ß-cell senescence. However, targets and effective agents for preventing stearic acid-induced ß-cell senescence are still lacking. Although melatonin administration can protect ß-cells against lipotoxicity through anti-senescence processes, the precise underlying mechanisms still need to be explored. Therefore, we investigated the anti-senescence effect of melatonin on stearic acid-treated mouse ß-cells and elucidated the possible role of microRNAs in this process. METHODS: ß-Cell senescence was identified by measuring the expression of senescence-related genes and senescence-associated ß-galactosidase staining. Gain- and loss-of-function approaches were used to investigate the involvement of microRNAs in stearic acid-evoked ß-cell senescence and dysfunction. Bioinformatics analyses and luciferase reporter activity assays were applied to predict the direct targets of microRNAs. RESULTS: Long-term exposure to a high concentration of stearic acid-induced senescence and upregulated miR-146a-5p and miR- 8114 expression in both mouse islets and ß-TC6 cell lines. Melatonin effectively suppressed this process and reduced the levels of these two miRNAs. A remarkable reversibility of stearic acid-induced ß-cell senescence and dysfunction was observed after silencing miR-146a-5p and miR-8114. Moreover, V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (Mafa) was verified as a direct target of miR-146a-5p and miR-8114. Melatonin also significantly ameliorated senescence and dysfunction in miR-146a-5pand miR-8114-transfected ß-cells. CONCLUSION: These data demonstrate that melatonin protects against stearic acid-induced ß-cell senescence by inhibiting miR-146a- 5p and miR-8114 and upregulating Mafa expression. This not only provides novel targets for preventing stearic acid-induced ß-cell dysfunction, but also points to melatonin as a promising drug to combat type 2 diabetes progression.
Subject(s)
Diabetes Mellitus, Type 2 , Insulin-Secreting Cells , Melatonin , MicroRNAs , Mice , Animals , Melatonin/pharmacology , Melatonin/metabolism , Diabetes Mellitus, Type 2/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , MicroRNAs/pharmacology , Cellular Senescence , Stearic Acids/pharmacology , Stearic Acids/metabolism , Maf Transcription Factors, Large/metabolism , Maf Transcription Factors, Large/pharmacologyABSTRACT
Increased levels of 17-ß estradiol (E2) due to pregnancy in young women or to hormonal replacement therapy in postmenopausal women have long been associated with an increased risk of yeast infections. Nevertheless, the effect underlying the role of E2 in Candida albicans infections is not well understood. To address this issue, functional, transcriptomic, and metabolomic analyses were performed on C. albicans cells subjected to temperature and serum induction in the presence or absence of E2. Increased filament formation was observed in E2 treated cells. Surprisingly, cells treated with a combination of E2 and serum showed decreased filament formation. Furthermore, the transcriptomic analysis revealed that serum and E2 treatment is associated with downregulated expression of genes involved in filamentation, including HWP1, ECE1, IHD1, MEP1, SOD5, and ALS3, in comparison with cells treated with serum or estrogen alone. Moreover, glucose transporter genes HGT20 and GCV2 were downregulated in cells receiving both serum and E2. Functional pathway enrichment analysis of the differentially expressed genes (DEGs) suggested major involvement of E2 signaling in several metabolic pathways and the biosynthesis of secondary metabolites. The metabolomic analysis determined differential secretion of 36 metabolites based on the different treatments' conditions, including structural carbohydrates and fatty acids important for hyphal cell wall formation such as arabinonic acid, organicsugar acids, oleic acid, octadecanoic acid, 2-keto-D-gluconic acid, palmitic acid, and steriacstearic acid with an intriguing negative correlation between D-turanose and ergosterol under E2 treatment. In conclusion, these findings suggest that E2 signaling impacts the expression of several genes and the secretion of several metabolites that help regulate C. albicans morphogenesis and virulence.
Subject(s)
Candida albicans , Hyphae , Female , Humans , Cell Wall/metabolism , Ergosterol/metabolism , Fatty Acids/metabolism , Estrogens/pharmacology , Polysaccharides/metabolism , Estradiol/pharmacology , Estradiol/metabolism , Stearic Acids/metabolism , Stearic Acids/pharmacology , Glucose Transport Proteins, Facilitative/genetics , Glucose Transport Proteins, Facilitative/metabolism , Glucose Transport Proteins, Facilitative/pharmacology , Carbohydrates , Palmitic Acids/metabolism , Palmitic Acids/pharmacology , Oleic Acids/metabolism , Oleic Acids/pharmacology , Gene Expression Regulation, FungalABSTRACT
The transition from late pregnancy to early lactation is characterized by marked changes in energy balance of dairy ruminants. The mobilization of adipose tissue led to an increase in plasma non-esterified fatty acids (NEFA) and ß-hydroxybutyrate (BHB). The aim of this study was to analyze the total plasma fatty acids of healthy and hyperketonemic dairy ewes in early lactation through gas chromatography (GC) to evaluate metabolic alterations. An observational study was used with a cross-sectional experimental design. Forty-six Sarda dairy ewes were enrolled in the immediate post-partum (7 ± 3 days in milk) and divided into two groups according to serum BHB concentration: non-hyperketonemic group (n = 28; BHB < 0.86 mmol/L) and hyperketonemic group (n = 18; BHB ≥ 0.86 mmol/L). A two-way ANOVA included the effect of group and parity was used to evaluate differences in fatty acids (FA) concentrations. A total of 34 plasma FA was assessed using GC. 12 out of 34 FA showed a significant different between groups and 3 out of 34 were tended to significance. Only NEFA concentration and stearic acid were influenced by parity. The results may suggest possible links with lipid metabolism, inflammatory and immune responses in hyperketonemic group. In conclusion, GC represents a useful tool in the study of hyperketonemia and primiparous dairy ewes might show a greater risk to develop this condition.
Subject(s)
Fatty Acids, Nonesterified , Fatty Acids , 3-Hydroxybutyric Acid , Animals , Cross-Sectional Studies , Fatty Acids/metabolism , Fatty Acids, Nonesterified/metabolism , Female , Lactation/physiology , Milk/chemistry , Pregnancy , Sheep , Stearic Acids/metabolismABSTRACT
BACKGROUND: Zygosaccharomyces rouxii plays an irreplaceable role in the manufacture of traditional fermented foods, which are produced in a high-salt environment. However, there is little research on strategies for improving salt tolerance of Z. rouxii. RESULTS: In this study, metabolomics was used to reveal the changes in intracellular metabolites under salt stress, and the results show that most of the carbohydrate contents decreased, the contents of xanthohumol and glycerol increased (fold change 4.07 and 5.35, respectively), while the contents of galactinol, xylitol and d-threitol decreased (fold change -9.43, -5.83 and -3.59, respectively). In addition, the content of four amino acids and six organic acids decreased, while that of the ten nucleotides increased. Notably, except for stearic acid (C18:0), all fatty acid contents increased. Guided by the metabolomics results, the effect of addition of seven exogenous fatty acids (C12:0, C14:0, C16:0, C18:0, C16:1, C18:1, and C18:2) on the salt tolerance of Z. rouxii was analyzed, and the results suggested that four exogenous fatty acids (C12:0, C16:0, C16:1, and C18:1) can increase the biomass yield and maximum growth rate. Physiological analyses demonstrated that exogenous fatty acids could regulate the distribution of fatty acids in the cell membrane, increase the degree of unsaturation, improve membrane fluidity, and maintain cell integrity, morphology and surface roughness. CONCLUSION: These results are applicable to revealing the metabolic mechanisms of Z. rouxii under salt stress and screening potential protective agents to improve stress resistance by adding exogenous fatty acids. © 2022 Society of Chemical Industry.
Subject(s)
Zygosaccharomyces , Amino Acids/metabolism , Fatty Acids/metabolism , Glycerol/metabolism , Nucleotides/metabolism , Saccharomycetales , Salt Tolerance , Stearic Acids/metabolism , Xylitol/metabolism , Xylitol/pharmacology , Zygosaccharomyces/metabolismABSTRACT
The intake of food with high levels of saturated fatty acids (SatFAs) is associated with the development of obesity and insulin resistance. SatFAs, such as palmitic (PA) and stearic (SA) acids, have been shown to accumulate in the hypothalamus, causing several pathological consequences. Autophagy is a lysosomal-degrading pathway that can be divided into macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA). Previous studies showed that PA impairs macroautophagy function and insulin response in hypothalamic proopiomelanocortin (POMC) neurons. Here, we show in vitro that the exposure of POMC neurons to PA or SA also inhibits CMA, possibly by decreasing the total and lysosomal LAMP2A protein levels. Proteomics of lysosomes from PA- and SA-treated cells showed that the inhibition of CMA could impact vesicle formation and trafficking, mitochondrial components, and insulin response, among others. Finally, we show that CMA activity is important for regulating the insulin response in POMC hypothalamic neurons. These in vitro results demonstrate that CMA is inhibited by PA and SA in POMC-like neurons, giving an overview of the CMA-dependent cellular pathways that could be affected by such inhibition and opening a door for in vivo studies of CMA in the context of the hypothalamus and obesity.
Subject(s)
Chaperone-Mediated Autophagy , Humans , Insulin/metabolism , Neurons/metabolism , Obesity/metabolism , Pro-Opiomelanocortin/metabolism , Stearic Acids/metabolism , Stearic Acids/pharmacologyABSTRACT
The prevalence of invasive aspergillosis with azole resistance is increasing, but the mechanisms underlying the development of resistance and treatment strategies are still limited. The present work is focused on finding a relationship between long-chain unsaturated fatty acids (LCUFAs), Aspergillus fumigatus development, and antifungal resistance. The effects of LCUFAs on antifungal agents in vitro were determined, and the stearic acid desaturase gene (sdeA) of A. fumigatus was characterized. In in vitro antifungal tests, LCUFAs antagonized the antifungal activity of itraconazole by extracting it from media, thereby preventing it from entering cells. The OA auxotrophic phenotype caused by an sdeA deletion confirmed that SdeA was required for OA biosynthesis in A. fumigatus. Furthermore, several low-level sdeA-overexpressing mutants with impaired vegetative growth phenotypes were successfully constructed. Additionally, an sdeA-overexpressing mutant, OEsdeA-5, showed lowered sensitivity levels to itraconazole. Moreover, RNA sequencing of OEsdeA-5 revealed that the altered gene-expression pattern. Through targeted metabolomics, decreased palmitic acid and stearic acid contents, accompanied by higher palmitoleic acid, margaroleic acid, and OA production levels, were found in OEsdeA-5. This study provides a novel insight of understanding of azole resistance and a potential target for drug development.
Subject(s)
Aspergillus fumigatus/genetics , Drug Resistance, Fungal/genetics , Fatty Acids/metabolism , Itraconazole/pharmacology , Microbial Viability/genetics , Antifungal Agents/pharmacology , Aspergillus fumigatus/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression Regulation, Fungal , Metabolomics/methods , Mutation , Palmitic Acid/metabolism , RNA-Seq/methods , Reverse Transcriptase Polymerase Chain Reaction , Stearic Acids/metabolism , Stearoyl-CoA Desaturase/genetics , Stearoyl-CoA Desaturase/metabolismABSTRACT
Long-chain acyl-CoA synthetases (ACSLs) are a family of enzymes that convert long-chain free fatty acids into their active form, acyl-CoAs. Recent knock-out mouse studies revealed that among ACSL isoenzymes, ACSL6 plays an important role in the maintenance of docosahexaenoic acid (DHA)-containing glycerophospholipids. Several transcript variants of the human ACSL6 gene have been found; the two major ACSL6 variants, ACSL6V1 and V2, encode slightly different short motifs that both contain a conserved structural domain, the fatty acid Gate domain. In the present study, we expressed recombinant human ACSL6V1 and V2 in Spodoptera frugiperda 9 (Sf9) cells using the baculovirus expression system, and then, using our novel ACSL assay system with liquid chromatography-tandem mass spectrometry (LC-MS/MS), we examined the substrate specificities of the recombinant human ACSL6V1 and V2 proteins. The results showed that both ACSL6V1 and V2 could convert various kinds of long-chain fatty acids into their acyl-CoAs. Oleic acid was a good common substrate and eicosapolyenoic acids were poor common substrates for both variants. However, ACSL6V1 and V2 differed considerably in their preferences for octadecapolyenoic acids, such as linoleic acid, and docosapolyenoic acids, such as DHA and docosapentaenoic acid (DPA): ACSL6V1 preferred octadecapolyenoic acids, whereas V2 strongly preferred docosapolyenoic acids. Moreover, our kinetic studies revealed that ACSL6V2 had a much higher affinity for DHA than ACSL6V1. Our results suggested that ACSL6V1 and V2 might exert different physiological functions and indicated that ACSL6V2 might be critical for the maintenance of membrane phospholipids bearing docosapolyenoic acids such as DHA.
Subject(s)
Coenzyme A Ligases/metabolism , Phospholipids/metabolism , Animals , Coenzyme A Ligases/genetics , Docosahexaenoic Acids/chemistry , Docosahexaenoic Acids/metabolism , Enzyme Assays , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , Kinetics , Linoleic Acid/metabolism , Phospholipids/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sf9 Cells , Spodoptera , Stearic Acids/metabolism , Substrate Specificity/genetics , Tandem Mass SpectrometryABSTRACT
Covalent attachment of C16:0 to proteins (palmitoylation) regulates protein function. Proteins are also S-acylated by other fatty acids including C18:0. Whether protein acylation with different fatty acids has different functional outcomes is not well studied. We show here that C18:0 (stearate) and C18:1 (oleate) compete with C16:0 to S-acylate Cys3 of GNAI proteins. C18:0 becomes desaturated so that C18:0 and C18:1 both cause S-oleoylation of GNAI. Exposure of cells to C16:0 or C18:0 shifts GNAI acylation towards palmitoylation or oleoylation, respectively. Oleoylation causes GNAI proteins to shift out of cell membrane detergent-resistant fractions where they potentiate EGFR signaling. Consequently, exposure of cells to C18:0 reduces recruitment of Gab1 to EGFR and reduces AKT activation. This provides a molecular mechanism for the anti-tumor effects of C18:0, uncovers a mechanistic link how metabolites affect cell signaling, and provides evidence that the identity of the fatty acid acylating a protein can have functional consequences.
Subject(s)
GTP-Binding Protein alpha Subunits, Gi-Go/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Signal Transduction/physiology , Stearic Acids/metabolism , Acylation , Cell Membrane/metabolism , Cell Proliferation , Fatty Acids/metabolism , GTP-Binding Protein alpha Subunits, Gi-Go/genetics , Humans , Lipoylation , MCF-7 Cells , Oleic Acids/metabolismABSTRACT
Microbes use signaling factors for intraspecies and interspecies communications. While many intraspecies signaling factors have been found and characterized, discovery of factors for interspecies communication is lagging behind. To facilitate the discovery of such factors, we explored the potential of a mixed microbial culture (MMC) derived from wheatgrass, in which heterogeneity of this microbial community might elicit signaling factors for interspecies communication. The stability of Wheatgrass MMC in terms of community structure and metabolic output was first characterized by 16S ribosomal RNA amplicon sequencing and liquid chromatography/mass spectrometry (LC/MS), respectively. In addition, detailed MS analyses led to the identification of 12-hydroxystearic acid (12-HSA) as one of the major metabolites produced by Wheatgrass MMC. Stereochemical analysis revealed that Wheatgrass MMC produces mostly the (R)-isomer, although a small amount of the (S)-isomer was also observed. Furthermore, 12-HSA was found to modulate planktonic growth and biofilm formation of various marine bacterial strains. The current study suggests that naturally derived MMCs could serve as a simple and reproducible platform to discover potential signaling factors for interspecies communication. In addition, the study indicates that hydroxylated long-chain fatty acids, such as 12-HSA, may constitute a new class of interspecies signaling factors.