Long-chain Unsaturated Fatty Acids Research Articles

Analysis of heterologous expression of phaCBA promotes the acetoin stress response mechanism in Bacillus subtilis using transcriptomics and metabolomics approaches.

Acetoin, a versatile platform chemical and popular food additive, poses a challenge to the biosafety strain Bacillus subtilis when produced in high concentrations due to its intrinsic toxicity. Incorporating the PHB synthesis pathway into Bacillus subtilis 168 has been shown to significantly enhance the strain's acetoin tolerance. This study aims to elucidate the molecular mechanisms underlying the response of B. subtilis 168-phaCBA to acetoin stress, employing transcriptomic and metabolomic analyses. Acetoin stress induces fatty acid degradation and disrupts amino acid synthesis. In response, B. subtilis 168-phaCBA down-regulates genes associated with flagellum assembly and bacterial chemotaxis, while up-regulating genes related to the ABC transport system encoding amino acid transport proteins. Notably, genes coding for cysteine and D-methionine transport proteins (tcyB, tcyC and metQ) and the biotin transporter protein bioY, are up-regulated, enhancing cellular tolerance. Our findings highlight that the expression of phaCBA significantly increases the ratio of long-chain unsaturated fatty acids and modulates intracellular concentrations of amino acids, including L-tryptophan, L-tyrosine, L-leucine, L-threonine, L-methionine, L-glutamic acid, L-proline, D-phenylalanine, L-arginine, and membrane fatty acids, thereby imparting acetoin tolerance. Furthermore, the supplementation with specific exogenous amino acids (L-alanine, L-proline, L-cysteine, L-arginine, L-glutamic acid, and L-isoleucine) alleviates acetoin's detrimental effects on the bacterium. Simultaneously, the introduction of phaCBA into the acetoin-producing strain BS03 addressed the issue of insufficient intracellular cofactors in the fermentation strain, resulting in the successful production of 70.14g/L of acetoin through fed-batch fermentation. This study enhances our understanding of Bacillus's cellular response to acetoin-induced stress and provides valuable insights for the development of acetoin-resistant Bacillus strains.

Human lipocalins bind and export fatty acids through the secretory pathway of yeast cells.

The activation of fatty acids to their acyl-CoA derivatives is a crucial step for their integration into more complex lipids or their degradation via beta-oxidation. Yeast cells employ five distinct acyl-CoA synthases to facilitate this ATP-dependent activation of acyl chains. Notably, mutant cells that are deficient in two of these fatty acid-activating (FAA) enzymes, namely, Faa1 and Faa4, do not take up free fatty acids but rather export them out of the cell. This unique fatty acid export pathway depends on small, secreted pathogenesis-related yeast proteins (Pry). In this study, we investigate whether the expression of human fatty acid-binding proteins, including Albumin, fatty acid-binding protein 4 (Fabp4), and three distinct lipocalins (ApoD, Lcn1, and Obp2a), could promote fatty acid secretion in yeast. To optimize the expression and secretion of these proteins, we systematically examined various signal sequences in both low-copy and high-copy number plasmids. Our findings reveal that directing these fatty-acid binding proteins into the secretory pathway effectively promotes fatty acid secretion from a sensitized quadruple mutant model strain (faa1∆ faa4∆ pry1∆ pry3∆). Furthermore, the level of fatty acid secretion exhibited a positive correlation with the efficiency of protein secretion. Importantly, the expression of all human lipid-binding proteins rescued Pry-dependent fatty acid secretion, resulting in the secretion of both long-chain saturated and unsaturated fatty acids. These results not only affirm the in vitro binding capabilities of lipocalins to fatty acids but also present a novel avenue for enhancing the secretion of valuable lipidic compounds. Given the growing interest in utilizing yeast as a cellular factory for producing poorly soluble compounds and the potential of lipocalins as platforms for engineering substrate-binding specificity, our model is considered as a powerful tool for promoting the secretion of high-value lipid-based molecules.

Long-Chain Polyunsaturated Fatty Acids Accelerate the Rate of Insulin Aggregation and Enhance Toxicity of Insulin Aggregates.

Long-chain polyunsaturated fatty acids (LCPUFAs) are essential components of a human diet. These molecules are critically important for cognitive attention and memory, mood states, coronary circulation, and cirrhosis. However, recently reported findings demonstrated that docosahexaenoic (DHA) and arachidonic acids (ARA), ω-3 and ω-6 LCPUFAs, accelerated the aggregation rates of insulin and α-synuclein, proteins that are directly linked to diabetes type 2 and Parkinson's disease, respectively. Furthermore, both DHA and ARA uniquely altered the structure and toxicity of the corresponding protein aggregates. Our objective is to ascertain whether other LCPUFAs, alongside long-chain unsaturated fatty acid (LCUFA) proteins, exhibit similar effects on amyloidogenic proteins. To explore this matter, we investigated the effect of 10 different LCPUFAs and LCUFAs on the rate of insulin aggregation. We found that all of the analyzed fatty acids strongly accelerated insulin aggregation. Moreover, we found that protein aggregates that were formed in the presence of these fatty acids exerted significantly higher cell toxicity compared with insulin fibrils grown in the lipid-free environment. These findings show that interactions between amyloid-associated proteins and LCPUFAs can be the underlying molecular cause of neurodegenerative diseases.

Cistanche deserticola improves ovariectomized-induced osteoporosis mainly by regulating lipid metabolism: Insights from serum metabolomics using UPLC/Q-TOF-MS

Ethnopharmacological relevanceCistanche deserticola (C. deserticola) is an edible and traditional medicine widely used in China, which has been confirmed to be effective in the treatment of postmenopausal osteoporosis (PMOP). Despite its proven efficacy, the exact role of C. deserticola in bone metabolism and its underlying mechanism has remained unclear. Aim of the studyIn this research, we employed an in vivo model utilizing ovariectomized (OVX) rats to characterize the anti-osteoporotic activity and metabolic mechanism of the ethanol extract of C. deserticola (CHE). Materials and methodsFifty female Sprague-Dawley (SD) rats were randomly divided into five groups including sham operation group, model group, 0.1 g/kg estradiol valerate (EV) group as the positive control, low (0.6 g/kg) and high (1.2 g/kg) dosage CHE groups. Biochemical parameter analyses and histopathological experiments were conducted to assess the pharmacodynamic effects. Metabolomic analysis was conducted on serum samples to examine the metabolic profiles, identify potential biomarkers, and elucidate the metabolic pathways associated with CHE in OVX rats. ResultsCHE treatment demonstrated significant anti-osteoporosis activity by regulating serum biochemical markers of bone turnover, improving cancellous bone structure, and reversing the decrease in bone mineral density. Furthermore, the clinical equivalent dose group (CHL) achieved superior overall outcomes. The main interventions of CHE on OVX rats involved the modulation of several key pathways, including steroid hormone biosynthesis, arachidonic acid metabolism, tyrosine and tryptophan metabolism, biotin metabolism, regulation of TRP channels by inflammatory mediators, primary bile acid biosynthesis, regulation of lipolysis in adipocytes, and bile secretion. 23 potential efficacy-related biomarkers within the metabolic network were identified. Among them, long-chain unsaturated fatty acids (eg. DHA and docosapentaenoic acid), steroid hormones, amino acids and carbohydrates were strongly correlated with bone resorption and formation markers. Additionally, it was observed four pathways (nucleotide, carbon, amino acid, and lipid metabolism) were implicated in the effects of CHE. ConclusionThis study demonstrates that CHE improves bone loss in PMOP mainly through regulating lipid metabolism pathways, which provides an evidence base for CHE treatment of PMOP.

NMR and Docking Calculations Reveal Novel Atomistic Selectivity of a Synthetic High-Affinity Free Fatty Acid vs. Free Fatty Acids in Sudlow's Drug Binding Sites in Human Serum Albumin.

Saturation transfer difference (STD), inter-ligand NOEs (INPHARMA NMR), and docking calculations are reported for investigating specific binding sites of the high-affinity synthetic 7-nitrobenz-2-oxa-1,3-diazoyl-4-C12 fatty acid (NBD-C12 FA) with non-labeled human serum albumin (HSA) and in competition with the drugs warfarin and ibuprofen. A limited number of negative interligand NOEs between NBD-C12 FA and warfarin were interpreted in terms of a short-range allosteric competitive binding in the wide Sudlow's binding site II (FA7) of NBD-C12 FA with Ser-202, Lys-199, and Trp-214 and warfarin with Arg-218 and Arg-222. In contrast, the significant number of interligand NOEs between NBD-C12 FA and ibuprofen were interpreted in terms of a competitive binding mode in Sudlow's binding site I (FA3 and FA4) with Ser-342, Arg-348, Arg-485, Arg-410, and Tyr-411. NBD-C12 FA has the unique structural properties, compared to short-, medium-, and long-chain saturated and unsaturated natural free fatty acids, of interacting with well-defined structures with amino acids of both the internal and external polar anchor sites in Sudlow's binding site I and with amino acids in both FA3 and FA4 in Sudlow's binding site II. The NBD-C12 FA, therefore, interacts with novel structural characteristics in the drug binding sites I and II and can be regarded as a prototype molecule for drug development.

Revealing the synergy mechanisms of organic components anaerobic co-digestion from the prevailing tendency of endogenous inhibitors

The anaerobic co-digestion (AcoD) test among three organic components (model compounds) under high feeding load was carried out in this study, then the dynamic change of intermediate metabolic inhibitors was detected and analyzed to identify the interaction mechanism among organic components from the prevailing tendency of endogenous inhibitors. Carbohydrate and protein show significant two-way synergistic effects for methane production. The addition of protein can supplement additional alkalinity to alleviate the sharp drop of pH (from 4.56 to 6.73) and avoid the acidification caused by high concentration of carbohydrate. Additionally, volatile fatty acids (VFAs) produced by carbohydrate can transform free ammonia to ammonium ion with the largest drop of 54%, thus reducing ammonia toxicity. Carbohydrate and lipid show one-way synergistic effects, namely, lipid can reduce VFAs accumulation by 49% through long chain fatty acids (LCFAs) inhibiting action, and then avoid complete rancidity of carbohydrate fermentation at high concentration. However, protein and lipid show serious two-way antagonistic effects, especially under high load digestion. On one hand, LCFAs would weaken ammonia volatilization and thus aggravate ammonia inhibition; On the other hand, protein would not only accelerate the formation of LCFAs inhibition by promoting lipid hydrolysis, but also transform the degradation pathway of oleic acid (unsaturated LCFAs) and then increase the proportion of stearic acid from 5.17% to 40.33%, which is of higher toxicity than palmitic acid.

Stabilization of Hydroxy-α-Sanshool by Antioxidants Present in the Genus Zanthoxylum.

Japanese pepper (sansho, Zanthoxylum piperitum) contains several types of sanshools belonging to N-alkylamides. Because of the long-chain unsaturated fatty acids present in their structure, sanshools are prone to oxidative deterioration, which poses problems in processing. In this paper, we evaluated the effects of antioxidants from the genus Zanthoxylum in preventing sanshool degradation using accelerated tests. An ethanolic extract of segment membranes of the sansho fruit pericarp was incubated at 70 °C for 7 days with different antioxidants to determine the residual amount of hydroxy-α-sanshool (HαS) in the extract. α-Tocopherol (α-Toc) showed excellent HαS-stabilizing activity at low concentrations. Among phenolic acids, we noted that the HαS-stabilizing activity increased with the number of hydroxy groups per molecule. For example, gallic acid and its derivatives exhibited excellent sanshool-stabilizing activity. Quercetin was found to be a superior HαS stabilizer compared with hesperetin and naringenin. However, the effective concentration was much higher for phenolic compounds than for α-Toc. These substances are believed to play a role in preventing the decomposition of sanshools in the pericarp of sansho. These sanshool stabilizers should be useful in the development of new beverages, foods, cosmetics, and pharmaceuticals that take advantage of the taste and flavor of sansho.

Effect of fat contents of buttermilk on fatty acid composition, lipolysis, vitamins and sensory properties of cheddar-type cheese.

Cheddar-type cheese produced from buttermilk had softer texture than standard cheddar cheese due to lower fat content of buttermilk. Fat is extremely important for the functional characteristics and optimum textural attributes of cheese. The effect of different fat contents of buttermilk on chemical characteristics of cheddar-type cheese is not previously investigated. This investigation was conducted to know the effect of different fat contents of buttermilk on fatty acids composition, organic acids, vitamins, lipolysis and sensory characteristics of cheddar-type cheese. Cheddar-type cheese was produced from buttermilk having 1, 1.75, 2.50 and 3.25% fat contents (control, T1, T2 and T3). Fat content of control, T1, T2 and T3 were 9.81, 16.34, 25.17 and 31.19%. Fatty acids profile was determined on GC-MS, organic acids and vitamin A and E were determined on HPLC. Free fatty acids, peroxide value and cholesterol were determined. Cheddar-style cheese produced from buttermilk (1% fat) showed that it had softer texture and lacking typical cheese flavor. Gas chromatography-mass spectrometry (GC-MS) analysis showed that long-chain unsaturated fatty acids in control, T1, T2 and T3 samples were 45.88, 45.78, 45.90 and 46.19 mg/100 g. High Performance Liquid Chromatography (HPLC) analysis showed that lactic acid, propionic acid, citric acid and acetic acid gradually and steadily increased during the storage interval of 90 days. At the age of 90 days, lactic acid in control, T1, T2 and T3 was 4,789, 5,487, 6,571 and 8,049 ppm, respectively. At the end of ripening duration of 90 days, free fatty acids in control, T1, T2 and T3 were 0.29, 0.31, 0.35 and 0.42% with no difference in peroxide value. Stability of vitamin A after 90 days storage control, T1, T2 and T3 was 87.0, 80.0, 94.0 and 91.0%. Flavor score of cheddar-type cheese produced from butter milk having 1.0, 2.5 and 3.25% fat content was 81, 89 and 91% of total score (9). Hence, it is concluded that cheddar-type cheese can be produced from buttermilk having 2.5 and 3.25% fat contents with acceptable sensory attributes. Application of buttermilk for the production of other cheese varieties should be studied.

Impact of fatty acid composition on markers of exocrine pancreatic stimulation in dogs.

Chronic pancreatitis in dogs is typically managed with a low-fat diet. Human research suggests that consumption of medium-chain triglycerides (MCT) may lessen pancreatic enzyme release compared to consumption of long-chain fatty acids (LCFA). Twelve healthy adult colony dogs were fed a meal of cod and rice with either 3% metabolizable energy (ME) fat (control), high MCT (25% ME MCT oil, 25% ME butter), high saturated LCFA (50% ME butter), or high unsaturated LCFA (50% ME canola oil) in a 4-period by 4-treatment crossover design. Serum concentrations of canine pancreatic lipase immunoreactivity, gastrin, cholesterol, triglycerides, and serum activities of amylase and DGGR lipase (1,2-o-dilauryl-rac-glycero-3-glutaric acid-(69-methylresorufin) ester lipase) were measured at times 0 (fasted), 30, 120 and 180 minutes post-prandially. Following a 3-or 4-day wash-out period, each dog was assigned a new diet and the process was repeated for all treatments. Data were analyzed as a repeated-measures mixed model ANOVA. Post-hoc pairwise comparisons were run using Tukey-Kramer adjusted p-values. Shapiro-Wilk tests were used to evaluate residual normality. All statistical assumptions were sufficiently met. Statistical significance was defined as P<0.05. Of the markers tested, only serum triglyceride concentrations were affected by treatment, with consumption of high MCT resulting in lower triglycerides than both LCFA groups at times 120 and 180 minutes (P<0.0001). As expected, the high MCT group had higher triglycerides compared to the control group (P<0.0001). The type of dietary fat consumed had little acute impact on most markers of exocrine pancreatic stimulation in healthy dogs.

Unsaturated Long-Chain Fatty Acids Activate Resident Macrophages and Stem Cells in a Human Skeletal Muscle Tissue Model.

Phenotypically heterogeneous populations of tissue-resident macrophages and stem cells play important roles in the regeneration of the skeletal muscle tissue. Previous studies using animal and cell culture models implied a beneficial effect of fatty acid (FA) species on tissue regeneration. Here, we applied a human experimental model using excised muscle tissues from reconstructive surgeries to study the effects of FAs on resident macrophages and stem cells in the natural environment of human skeletal muscle tissue. Muscle tissue samples from 20 donors were included in this study. The expression of 34 cytokines/chemokines was determined, using multiplex protein analysis. The phenotypes of macrophages and stem cells were determined immunohistochemically. The numbers of CD80+ macrophages correlated with the expression levels of IL-1α, IL-1RA, IL-8, IL-17A, and MCP-1, while the PAX7+ and MyoD+ stem cell counts were positively correlated with the expression level of CXCL12α, a recognized chemoattractant for muscle stem cells. Treatment of additional tissue sections with FAs revealed that CD80+ or MARCO+ macrophages- and PAX7+ or MyoD+ stem cells were simultaneously increased by unsaturated long-chain FAs. Taken together, this is the first experimental demonstration of a coordinated activation of macrophages and stem cells in human skeletal muscle tissue.

Decoding the role of triacylglycerol composition in the milk fat crystallisation behaviour: A study using buffalo milk fat fractions

The role of triacylglycerols (TAGs) composition in milk fat crystallisation is evaluated from a new perspective by correlating the crystal structures and their predicted TAG contributors. Four different TAG groups, defined by their fatty acid (FA) chain length and saturation are proposed to explain the crystallisation behaviour of different milk fat samples, namely TAGs containing (i) fully saturated long chain FAs, (ii) single unsaturated long-chain FA and (iii) multi unsaturated long-chain FAs, as well as (iv) short-chain FAs. Samples containing different TAGs proportions were obtained from two-step dry fractionation of buffalo milk fat. Liquid chromatography and mass spectrometry (LCMS) was employed to determine the TAGs composition. The crystallisation characteristics were evaluated using small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC) and polarised light microscopy. The results confirm that fully saturated long chain TAGs are responsible for the formation of high melting point 2L-crystals (d-spacing: 44.1–49.7 Å), whilst the low melting point 3L-crystals (64.4–72.8 Å) are mainly contributed by long chain TAGs containing unsaturated fatty acids. Further, the crystallisation inhibiting effect of asymmetrical TAGs, containing short chain fatty acid (C4-6) is evident. As a final point, effects of the four TAG groups, each given with a specific composition, were examined closely also with respect to their influence on the nucleation and polymorphic transformation kinetics of milk fat crystals.

Fatty acid composition in Ocotea caudata (Nees) Mez (Lauraceae) fruits from Colombia

The genus Ocotea of the Lauraceae family has species whose wood is employed in construction and for other purposes including as biofuel, for disinfection, cosmetics, and in the treatment of various diseases. Studies regarding Ocotea caudata’s phytochemical and pharmacognostic uses are scarce, thus, this work is the first to study its fruits. O. caudata (Nees) Mez fruits from Colombia were investigated for their oil content. Heptane extraction from O. caudata fruit oil yielded 54.9 % of total lipids, where the fatty acid composition was determined. The oil analysis by gas chromatography with flame ionization detection (GC-FID) demonstrated that lauric acid was the most abundant fatty acid (51.7 %, C12:0). In addition to lauric acid, oleic acid (23.6 %, C18:1) and palmitic acid (16.6 %, C16:0) were found. The fatty acid composition was confirmed by gas chromatography-mass spectrometry (GC-MS). O. caudata can be considered as a species that accumulates medium-chain saturated fatty acids (C12) and long-chain unsaturated fatty acids (C18). In conclusion, many of its health benefits may be due to its high content of lauric acid. Therefore, this oil is highly regarded for its nutritional and health properties.

Fatty Acids Reverse the Supramolecular Chirality of Insulin Fibrils.

Long-chain unsaturated and polyunsaturated fatty acids (LCUFAs and LCPUFAs, respectively) are the essential components of phospholipids and sphingolipids, major building blocks of plasma and organelle membranes. These molecules are also involved in cell signaling and energy metabolism. Hence, both LCUFAs and LCPUFAs are broadly used as food supplements. However, the role of these fatty acids (FAs) in the self-assembly of misfolded proteins remains unclear. In this study, we investigated the effect of LCUFAs and LCPUFAs, as well as their saturated analogue, on insulin aggregation. Using vibrational circular dichroism, we found that all analyzed FAs reversed the supramolecular chirality of insulin fibrils. Molecular dynamics simulations showed that strong hydrophobic interactions were formed between the long aliphatic tails of FAs and hydrophobic amino acid residues of insulin. We infer that such insulin:FA complexes had different self-assembly mechanisms compared to that of insulin alone, which resulted in the observed reversal of the supramolecular chirality of the amyloid fibrils.

Effects of Endurance Exercise and Vitamin D Supplementation on Insulin Resistance and Plasma Lipidome in Middle-Aged Adults with Type 2 Diabetes.

(1) Background: We investigated the effects of a 12-week exercise intervention with or without vitamin D supplementation on insulin resistance and the plasma lipidome of participants with type 2 diabetes. We further explored whether the effects of the intervention on glycemic parameters could be associated with the baseline lipidome. (2) Methods: Sixty-one participants were randomly allocated to control (Con), exercise (EX), vitamin D (VD), and EX + VD groups. Multiple glycemic and anthropometric parameters were evaluated before and after intervention. The homeostasis model assessment of insulin resistance (HOMA-IR) was the primary outcome. The plasma lipidome was analyzed before, after, and at an additional 12-week follow-up. Machine learning was applied to establish prediction models for responsiveness of glycemic control. (3) Results: Our interventions failed to improve the HOMA-IR index while fasting glucose was reduced in the EX + VD group (change%, -11.9%; effect size, 0.65; p < 0.05). Both EX and VD interventions altered the plasma lipidome, with EX + VD intervention considerably affecting levels of lyso-phosphatidylcholines and triglycerols containing long-chain unsaturated fatty acids. Such effects could last until 12 weeks after intervention. Notably, there was high inter-individual variability in glycemic parameters including HOMA-IR in response to the interventions, which could be predicted with great accuracy using an optimal panel of baseline lipid predictors alone or in combination with clinical indices, as assessed by an area under the receiver operating characteristic curve value of over 0.9. (4) Conclusions: Although substantial alterations were observed in the plasma lipidome related to glycemic control, our intervention failed to improve HOMA-IR scores, which may have been predominately due to the large inter-individual variability in responses. Basal plasma lipid levels could potentially predict an individual's response to intervention, highlighting the necessity of personalized nutrition.

The impact of glycerol monostearate's similarity to fats and fatty acid composition of fats on fat crystallization, destabilization, and texture properties of ice cream.

Fat significantly affects the properties of ice cream. Prior studies have investigated the correlation between fat crystallization, fat destabilization, and ice cream quality. However, the role of fatty acid composition, the similarity between fat and emulsifier in these characteristics, and their impact on final product quality remains unclear. To investigate the influence of the fatty acid composition of fats, as well as their similarity to glycerol monostearate (GMS), on fat crystallization and destabilization during the aging and freezing stages, ice creams were formulated using a combination of two types of fats (coconut oil and palm olein) in five different ratios. In oil phases, decreased saturation of fatty acids (from 93.38% to 46.69%) and increased similarity to GMS (from 11.96% to 46.01%) caused a reduction in the maximum solid fat content. Moreover, the rise in unsaturated long-chain fatty acids (from 34.61% to 99.57%) and similarity to GMS enhanced the formation of rare and coarse fat crystals, leading to a sparse crystalline network. This, in turn, reduced the crystallization rate and the stiffness of the fat in emulsions. Assuming consistent overrun across all ice creams, the enhanced interactions between fat globules in ice cream improved its hardness, melting properties, and shrinkage. The crystalline properties of fat in emulsions were influenced by oil phases, impacting fat destabilization and ultimately enhancing the quality of ice cream. The present study offers valuable insights for the optimization of fat and monoglyceride fatty acid ester selection, with the potential to improve ice cream quality. © 2023 Society of Chemical Industry.

CircRNA-02191 regulating unsaturated fatty acid synthesis by adsorbing miR-145 to enhance CD36 expression in bovine mammary gland

CD36 functions as a receptor for long-chain fatty acids, promoting the absorption and transport of long-chain unsaturated fatty acids. However, the regulatory influence of upstream circRNAs or miRNAs on its expression in cow mammary gland remains unclear. Herein, we performed high-throughput sequencing to screen for differentially expressed miRNAs and mRNAs in bovine mammary tissue during the late-lactation and the dry period to screen and conducted bioinformatics analysis to identify 420 miRNA/mRNA pairs, including miR-145/CD36. Experimental results indicate that miR-145 can directly target CD36 and inhibit its expression. Additionally, the circRNA-02191 sequence is predicted to contain a miR-145 binding site. As shown by dual luciferase reporter system detection, circRNA-02191 bound to miR-145 and its overexpression significantly reduced the expression of miR-145. Furthermore, the overexpression of miR-145 inhibited triglyceride accumulation, while circRNA-02191 enhanced the expression of the miR-145 target gene CD36. The above results indicate that circRNA-02191 can regulate triglyceride and fatty acid components by binding miR-145 and subsequently alleviating the inhibitory effect of miR-145 on the expression of CD36. Taken together, these findings present a novel approach to improve milk quality by analyzing the regulatory effect and mechanism regulating the circ02191/miR-145/CD36 pathway on fatty acid synthesis in the mammary gland of dairy cows.

Lipid Membrane Remodeling by the Micellar Aggregation of Long-Chain Unsaturated Fatty Acids for Sustainable Antimicrobial Strategies.

Antimicrobial fatty acids derived from natural sources and renewable feedstocks are promising surface-active substances with a wide range of applications. Their ability to target bacterial membrane in multiple mechanisms offers a promising antimicrobial approach for combating bacterial infections and preventing the development of drug-resistant strains, and it provides a sustainable strategy that aligns with growing environmental awareness compared to their synthetic counterparts. However, the interaction and destabilization of bacterial cell membranes by these amphiphilic compounds are not yet fully understood. Here, we investigated the concentration-dependent and time-dependent membrane interaction between long-chain unsaturated fatty acids-linolenic acid (LNA, C18:3), linoleic (LLA, C18:2), and oleic acid (OA, C18:1)-and the supported lipid bilayers (SLBs) using quartz crystal microbalance-dissipation (QCM-D) and fluorescence microscopy. We first determined the critical micelle concentration (CMC) of each compound using a fluorescence spectrophotometer and monitored the membrane interaction in real time following fatty acid treatment, whereby all micellar fatty acids elicited membrane-active behavior primarily above their respective CMC values. Specifically, LNA and LLA, which have higher degrees of unsaturation and CMC values of 160 µM and 60 µM, respectively, caused significant changes in the membrane with net |Δf| shifts of 23.2 ± 0.8 Hz and 21.4 ± 0.6 Hz and ΔD shifts of 5.2 ± 0.5 × 10-6 and 7.4 ± 0.5 × 10-6. On the other hand, OA, with the lowest unsaturation degree and CMC value of 20 µM, produced relatively less membrane change with a net |Δf| shift of 14.6 ± 2.2 Hz and ΔD shift of 8.8 ± 0.2 × 10-6. Both LNA and LLA required higher concentrations than OA to initiate membrane remodeling as their CMC values increased with the degree of unsaturation. Upon incubating with fluorescence-labeled model membranes, the fatty acids induced tubular morphological changes at concentrations above CMC. Taken together, our findings highlight the critical role of self-aggregation properties and the degree of unsaturated bonds in unsaturated long-chain fatty acids upon modulating membrane destabilization, suggesting potential applications in developing sustainable and effective antimicrobial strategies.

Analysis of the Effective Components of Cocos nucifera L. Oil on Atopic Dermatitis Skin Disease and Staphylococcus Aureus Bacteria

The major objective of the research was to investigate the in vitro antibacterial susceptibility to particular fatty acids contained in coconut oil on a collection of clinical isolates. especially, the chronic skin condition Atopic dermatitis (Atopic eczema). caused by gram-positive bacteria (Staphylococcus aureus). Clinical isolates were collected from Shar Hospitals, and the organisms went through a typical biochemical examination evolution. While coconut oil was obtained using the centrifuge method to extract coconut oil (CE VCO). The sensitivity evaluation was conducted using the disc diffusion method. Lastly, used a measuring tool to estimate the inhibitory zones' diameter. In another hand, after analysis of the oil by GC-MASS, Coconut oil contained numerous chemical components and the highest amount was Oleic acid 54.62%, while the smallest amount was N-Hexadecanoic acid, N-Hexadecanoic acid, (Myristic acid), % 3.34. Sequentially, Heneicosane, 9-Octadecenoic acid (Z)- % 13.78, with 9,12-Octadecadienoic acid 11.23%, and Nonadecane and his isomers 5.77% percent. Coconut oil doesn't show any sensitivity and a high potential for antibacterial activity due to the high contents of medium and long-chain saturated and unsaturated fatty acids so This study recommends further studies should be done on the oil and its derivative both in vitro and in vivo for showing its mechanisms of actions.

Fatty Acids Abolish Shigella Virulence by Inhibiting Its Master Regulator, VirF.

The pathogenicity of Shigella, the intracellular pathogen responsible for human bacillary dysentery, depends on a coordinated and tightly regulated expression of its virulence determinants. This is the result of a cascade organization of its positive regulators, with VirF, a transcriptional activator belonging to the AraC-XylS family, in a pivotal position. VirF itself is submitted to several well-known regulations at the transcriptional level. In this work, we present evidence for a novel posttranslational regulatory mechanism of VirF mediated by the inhibitory interaction with specific fatty acids. By homology modeling and molecular docking analyses, we identify a jelly roll motif in the structure of ViF capable of interacting with medium-chain saturated and long-chain unsaturated fatty acids. In vitro and in vivo assays show that capric, lauric, myristoleic, palmitoleic, and sapienic acids interact effectively with the VirF protein, abolishing its transcription-promoting activity. This silences the virulence system of Shigella, leading to a drastic reduction in its ability to invade epithelial cells and proliferate in their cytoplasm. IMPORTANCE In the absence of a valid vaccine, the main therapeutic approach currently used to treat shigellosis is based on the use of antibiotics. The emergence of antibiotic resistance jeopardizes the future effectiveness of this approach. The importance of the present work resides both in the identification of a new level of posttranslational regulation of the Shigella virulence system and in the characterization of a mechanism offering new opportunities for the design of antivirulence compounds, which may change the treatment paradigm of Shigella infections by limiting the emergence of antibiotic-resistant bacteria.

The Zooxanthellate Jellyfish Holobiont Cassiopea andromeda, a Source of Soluble Bioactive Compounds.

Cassiopea andromeda (Forsskål, 1775), commonly found across the Indo-Pacific Ocean, the Red Sea, and now also in the warmest areas of the Mediterranean Sea, is a scyphozoan jellyfish that hosts autotrophic dinoflagellate symbionts (family Symbiodiniaceae). Besides supplying photosynthates to their host, these microalgae are known to produce bioactive compounds as long-chain unsaturated fatty acids, polyphenols, and pigments, including carotenoids, with antioxidant properties and other beneficial biological activities. By the present study, a fractionation method was applied on the hydroalcoholic extract from two main body parts (oral arms and umbrella) of the jellyfish holobiont to obtain an improved biochemical characterization of the obtained fractions from the two body parts. The composition of each fraction (i.e., proteins, phenols, fatty acids, and pigments) as well as the associated antioxidant activity were analyzed. The oral arms proved richer in zooxanthellae and pigments than the umbrella. The applied fractionation method was effective in separating pigments and fatty acids into a lipophilic fraction from proteins and pigment-protein complexes. Therefore, the C. andromeda-dinoflagellate holobiont might be considered as a promising natural source of multiple bioactive compounds produced through mixotrophic metabolism, which are of interest for a wide range of biotechnological applications.