Is essential fatty acid interconversion an important source of PUFA in humans?

The Concentration of Docosahexaenoic Acid (DHA) and Arachidonic Acid (AA) in Human Milk Is Associated With the Size of Maternal Social Network

INTRODUCTION

Social factors, such as kin and non-kin support in helping the mother of a newborn baby, impact the duration of lactation and may affect human milk composition. Recent studies suggest that maternal stress negatively affects the level of polyunsaturated fatty acids in human milk, which are crucial for infant vision and brain development. We suggest that social support may have the potential to attenuate a negative effect of stress on the composition of human milk fatty acids.

METHODS

We studied 129 exclusively breastfeeding mothers and their healthy, term infants to explore the relationship between support from significant others (structural and functional) and the concentration of docosahexaenoic acid (DHA, N = 49) and arachidonic acid (AA, N = 129) in human milk. We also examined whether maternal stress reactivity (log Cort. AUC) may be related to these fatty acids. Gas chromatography was used to analyze the concentration of DHA and AA in human milk samples.

RESULTS

Analyses revealed a positive association between the number of helpers (structural support) and the concentration of DHA and AA. Maternal stress reactivity was not a statistically significant predictor of DHA and AA contents in milk and was unrelated to the number of helpers.

CONCLUSION

Our results show for the first time that human milk composition, particularly DHA and AA concentrations, may be associated with the size of mothers' immediate social network of kin and non-kin helpers. This result is consistent with evolutionary studies that emphasize the role of cooperative breeding in human reproduction.

Paternal trans fatty acid and vitamin E diet affect the expression pattern of androgen signaling pathway genes in the testis of rat offspring

Numerous studies have shown that an improper diet in parents has a negative impact on offspring's health. Furthermore, the negative effects of trans fatty acids (TFA) in maternal diets on fertility and health and their impact on future generations have been documented. However, there is limited research on the negative effects of TFA in paternal diets on male children. The current work used qRT-PCR to investigate the effects of trans fatty acids and vitamin E in the paternal diet on the expression pattern of androgen signaling pathway genes such as STAR, CYP11a1, HSD3B, SRD5a2, and SCARB1 in offspring testes. In this experiment, parental rats were randomly separated into four groups, each with ten father rats, and were fed for eight weeks (60 days) as follows. 1: Standard diet group plus liquid sunflower oil (control). 2: Standard diet group containing trans fatty acids (CTH). 3: The regular diet group received 2.5 times the recommended quantity of vitamin E supplement. 4: Standard diet group with vitamin E and trans fatty acid supplementation (ETH). The testis tissue samples from 35 offspring were then used. Following RNA extraction from tissues and cDNA synthesis, quantitative real-time PCR was used to evaluate the expression levels of androgen signaling pathway genes such as STAR, CYP11A1, HSD3B, SCARB1, and SRD5A2. Our findings showed that the expression of CYP11A1 was considerably reduced in the progeny of paternal rats given ETH compared to the CTH group. The expression levels of the STAR gene were significantly lower in the progeny of paternal rats administered TFA, ETH, and vitamin E compared to the controls. Although the CTH group had lower SCARB1 expression than the other groups, the difference was not statistically significant. Paternal vitamin E consumption substantially affected SRD5A2 expression when compared to offspring of paternal rats fed vitamin E + trans fatty acid or those fed a conventional diet containing trans fatty acid. Furthermore, the vitamin E group showed a statistically significant increase in HSD3B expression compared to the other groups. Bioinformatics analyses, such as protein-protein interaction networks and gene ontology term enrichment, revealed that these genes play roles in lipid biosynthesis, hormone metabolism, male sex differentiation, reproductive development, and steroid biosynthesis. Our data indicate that paternal trans fatty acid consumption influences the expression of particular androgen signaling pathway genes in offspring testis, with vitamin E potentially mitigating some of these effects.

The Cardioprotective Effects of Polyunsaturated Fatty Acids Depends on the Balance Between Their Anti- and Pro-Oxidative Properties

Polyunsaturated fatty acids (PUFAs) are not only structural components of membrane phospholipids and energy storage molecules in cells. PUFAs are important factors that regulate various biological functions, including inflammation, oxidation, and immunity. Both n-3 and n-6 PUFAs from cell membranes can be metabolized into pro-inflammatory and anti-inflammatory metabolites that, in turn, influence cardiovascular health in humans. The role that PUFAs play in organisms depends primarily on their structure, quantity, and the availability of enzymes responsible for their metabolism. n-3 PUFAs, such as eicosapentaenoic (EPA) and docosahexaenoic (DHA), are generally known for anti-inflammatory and atheroprotective properties. On the other hand, n-6 FAs, such as arachidonic acid (AA), are precursors of lipid mediators that display mostly pro-inflammatory properties and may attenuate the efficacy of n-3 by competition for the same enzymes. However, a completely different light on the role of PUFAs was shed due to studies on the influence of PUFAs on new-onset atrial fibrillation. This review analyzes the role of PUFAs and PUFA derivatives in health-related effects, considering both confirmed benefits and newly arising controversies.

Essential Fatty Acids along the Women’s Life Cycle and Promotion of a Well-balanced Metabolism

Abstract:

Linoleic acid (ω-6 LA) and α-linolenic acid (ω-3 ALA) are essential fatty acids (EFA) for human beings. They must be consumed through diet and then extensively metabolized, a process that plays a fundamental role in health and eventually in disease prevention. Given the numerous changes depending on age and sex, EFA metabolic adaptations require further investigations along the women’s life cycle, from onset to decline of the reproductive age. Thus, this review explains women’s life cycle stages and their involvement in diet intake, digestion and absorption, the role of microbiota, metabolism, bioavailability, and EFA fate and major metabolites. This knowledge is crucial to promoting lipid homeostasis according to female physiology through well-directed health strategies. Concerning this, the promotion of breastfeeding, nutrition, and physical activity is cardinal to counteract ALA deficiency, LA/ALA imbalance, and the release of unhealthy derivatives. These perturbations arise after menopause that compromise both lipogenic and lipolytic pathways. The close interplay of diet, age, female organism, and microbiota also plays a central role in regulating lipid metabolism. Consequently, future studies are encouraged to propose efficient interventions for each stage of women's cycle. In this sense, plant-derived foods and products are promising to be included in women’s nutrition to improve EFA metabolism.

Role of ACSBG1 in Brain Lipid Metabolism and X-Linked Adrenoleukodystrophy Pathogenesis: Insights from a Knockout Mouse Model

"Bubblegum" acyl-CoA synthetase (ACSBG1) is a pivotal player in lipid metabolism during mouse brain development, facilitating the activation of long-chain fatty acids (LCFA) and their incorporation into lipid species that are crucial for brain function. ACSBG1 converts LCFA into acyl-CoA derivatives, supporting vital metabolic processes. Fruit fly mutants lacking ACSBG1 exhibited neurodegeneration and had elevated levels of very long-chain fatty acids (VLCFA), characteristics of human X-linked adrenoleukodystrophy (XALD). To explore ACSBG1's function and potential as a therapeutic target in XALD, we created an ACSBG1 knockout (Acsbg1-/-) mouse and examined the effects on brain FA metabolism during development. Phenotypically, Acsbg1-/- mice resembled wild type (w.t.) mice. ACSBG1 expression was found mainly in tissue affected pathologically in XALD, namely the brain, adrenal gland and testis. ACSBG1 depletion did not significantly reduce the total ACS enzyme activity in these tissue types. In adult mouse brain, ACSBG1 expression was highest in the cerebellum; the low levels detected during the first week of life dramatically increased thereafter. Unexpectedly, lower, rather than higher, saturated VLCFA levels were found in cerebella from Acsbg1-/- vs. w.t. mice, especially after one week of age. Developmental changes in monounsaturated ω9 FA and polyunsaturated ω3 FA levels also differed between w.t. and Acsbg1-/- mice. ACSBG1 deficiency impacted the developmental expression of several cerebellar FA metabolism enzymes, including those required for the synthesis of ω3 polyunsaturated FA, precursors of bioactive signaling molecules like eicosanoids and docosanoids. These changes in membrane lipid FA composition likely affect membrane fluidity and may thus influence the body's response to inflammation. We conclude that, despite compelling circumstantial evidence, it is unlikely that ACSBG1 directly contributes to the pathology of XALD, decreasing its potential as a therapeutic target. Instead, the effects of ACSBG1 knockout on processes regulated by eicosanoids and/or docosanoids should be further investigated.

Docosahexaenoic acid supplementation during porcine oocyte in vitro maturation improves oocyte quality and embryonic development by enhancing the homeostasis of energy metabolism

Although supplementation with docosahexaenoic acid (DHA) during porcine oocyte IVM is well-established, the available data are limited due to the lack of consistency. Moreover, to our knowledge, the anti-oxidant effects of DHA on porcine oocytes have not been reported. Hence, this study aimed to examine the effects of DHA supplementation on the regulation of energy metabolism during porcine oocyte maturation to improve oocyte maturation and embryonic development. By supplementing the IVM medium with various DHA concentrations, 25 μM DHA was identified as the optimal concentration which improved intraoocyte glutathione content and enhanced embryonic development after parthenogenesis. Compared to embryos derived from the control group, those derived from SCNT or IVF showed significantly improved blastocyst formation upon DHA supplementation during IVM. In addition, various transcription factors associated with oocyte development and apoptosis in mature oocytes were beneficially regulated in the DHA-treated oocytes. Moreover, DHA improved the AMP-activated protein kinase (AMPK)-regulatory ability of porcine oocytes and ameliorated nuclear maturation and embryonic development, which were decreased by artificially downregulating AMPK. To our knowledge, this is the first study to examine the effects of DHA as an AMPK regulator on oocyte maturation and embryo development in pigs. Furthermore, DHA addition to the IVM medium upregulated the relative expression of genes associated with mitochondrial potential and lipid metabolism. Therefore, the membrane potential of mitochondria (evaluated based on the JC-1 aggregate/JC-1 monomer ratio) and the levels of fatty acids and lipid droplets in matured oocytes increased, resulting in increased ATP synthesis. In conclusion, the DHA treatment of porcine oocytes with 25 μM DHA during IVM enhances the homeostasis of energy metabolism by improving mitochondrial function and lipid metabolism, leading to improved quality of matured oocytes and enhanced embryonic developmental potential of in vitro produced (IVP) embryos. Thus, 25 μM DHA supplementation could serve as a tool for improving the quality of IVP embryos. The study findings provide a basis for further research on improving the production efficiency of cloned animals by securing high-quality matured oocytes and enhancing energy metabolism in mammalian oocytes, including those of pigs.

Identification of genomic regions associated with fatty acid metabolism across blood, liver, backfat and muscle in pigs

BACKGROUND

The composition and distribution of fatty acids (FA) are important factors determining the quality, flavor, and nutrient value of meat. In addition, FAs synthesized in the body participate in energy metabolism and are involved in different regulatory pathways in the form of signaling molecules or by acting as agonist or antagonist ligands of different nuclear receptors. Finally, synthesis and catabolism of FAs affect adaptive immunity by regulating lymphocyte metabolism. The present study performed genome-wide association studies using FA profiles of blood, liver, backfat and muscle from 432 commercial Duroc pigs.

RESULTS

Twenty-five genomic regions located on 15 Sus scrofa chromosomes (SSC) were detected. Annotation of the quantitative trait locus (QTL) regions identified 49 lipid metabolism-related candidate genes. Among these QTLs, four were identified in more than one tissue. The ratio of C20:4n-6/C20:3n-6 was associated with the region on SSC2 at 7.56-14.26 Mb for backfat, liver, and muscle. Members of the fatty acid desaturase gene cluster (FADS1, FADS2, and FADS3) are the most promising candidate genes in this region. Two QTL regions on SSC14 (103.81-115.64 Mb and 100.91-128.14 Mb) were identified for FA desaturation in backfat and muscle. In addition, two separate regions on SSC9 at 0 - 14.55 Mb and on SSC12 at 0-1.91 Mb were both associated with the same multiple FA traits for backfat, with candidate genes involved in de novo FA synthesis and triacylglycerol (TAG) metabolism, such as DGAT2 and FASN. The ratio C20:0/C18:0 was associated with the region on SSC5 at 64.84-78.32 Mb for backfat. Furthermore, the association of the C16:0 content with the region at 118.92-123.95 Mb on SSC4 was blood specific. Finally, candidate genes involved in de novo lipogenesis regulate T cell differentiation and promote the generation of palmitoleate, an adipokine that alleviates inflammation.

CONCLUSIONS

Several SNPs and candidate genes were associated with lipid metabolism in blood, liver, backfat, and muscle. These results contribute to elucidating the molecular mechanisms implicated in the determination of the FA profile in different pig tissues and can be useful in selection programs that aim to improve health and energy metabolism in pigs.

Effects and Mechanisms of Polyunsaturated Fatty Acids on Age-Related Musculoskeletal Diseases: Sarcopenia, Osteoporosis, and Osteoarthritis-A Narrative Review

Background: The process of the globally aging population has been accelerating, leading to an increasing social burden. As people age, the musculoskeletal system will gradually go through a series of degenerative and loss of function and eventually develop age-related musculoskeletal diseases, like sarcopenia, osteoporosis, and osteoarthritis. On the other hand, several studies have shown that polyunsaturated fatty acids (PUFAs) possess various important physiological functions on the health of muscles, bones, and joints. Objective: This narrative review paper provides a summary of the literature about the effects and mechanisms of PUFAs on age-related musculoskeletal diseases for the prevention and management of these diseases. Methods: Web of Science, PubMed, Science Direct, and Scopus databases have been searched to select the relevant literature on epidemiological, cellular, and animal experiments and clinical evidence in recent decades with keywords "polyunsaturated fatty acids", "PUFAs", "omega-3", "omega-6", "musculoskeletal diseases", "sarcopenia", "osteoporosis", "osteoarthritis", and so on. Results: PUFAs could prevent and treat age-related musculoskeletal diseases (sarcopenia, osteoporosis, and osteoarthritis) by reducing oxidative stress and inflammation and controlling the growth, differentiation, apoptosis, and autophagy of cells. This review paper provides comprehensive evidence of PUFAs on age-related musculoskeletal diseases, which will be helpful for exploitation into functional foods and drugs for their prevention and treatment. Conclusions: PUFAs could play an important role in the prevention and treatment of sarcopenia, osteoporosis, and osteoarthritis.

Role of ACSBG1 in brain lipid metabolism and X-linked adrenoleukodystrophy pathogenesis: Insights from a knockout mouse model

The "bubblegum" acyl-CoA synthetase (ACSBG1) is a pivotal player in lipid metabolism during the development of the mouse brain, facilitating the activation of long-chain fatty acids (LCFAs) and their integration into essential lipid species crucial for brain function. Through its enzymatic activity, ACSBG1 converts LCFAs into acyl-CoA derivatives, supporting vital processes like membrane formation, myelination, and energy production. Its regulatory role significantly influences neuronal growth, synaptic plasticity, and overall brain development, highlighting its importance in maintaining lipid homeostasis and proper brain function. Originally discovered in the fruit fly brain, ACSBG1 attracted attention for its potential implication in X-linked adrenoleukodystrophy (XALD) pathogenesis. Studies using Drosophila melanogaster lacking the ACSBG1 homolog, bubblegum, revealed adult neurodegeneration with elevated levels of very long-chain fatty acids (VLCFA). To explore ACSBG1's role in fatty acid (FA) metabolism and its relevance to XALD, we created an ACSBG1 knockout (Acsbg1-/-) mouse model and examined its impact on lipid metabolism during mouse brain development. Phenotypically, Acsbg1-/- mice resembled wild type (w.t.) mice. Despite its primary expression in tissues affected by XALD, brain, adrenal gland and testis, ACSBG1 depletion did not significantly reduce total ACS enzyme activity in these tissues when using LCFA or VLCFA as substrates. However, analysis unveiled intriguing developmental and compositional changes in FA levels associated with ACSBG1 deficiency. In the adult mouse brain, ACSBG1 expression peaked in the cerebellum, with lower levels observed in other brain regions. Developmentally, ACSBG1 expression in the cerebellum was initially low during the first week of life but increased dramatically thereafter. Cerebellar FA levels were assessed in both w.t. and Acsbg1-/- mouse brains throughout development, revealing notable differences. While saturated VLCFA levels were typically high in XALD tissues and in fruit flies lacking ACSBG1, cerebella from Acsbg1-/- mice displayed lower saturated VLCFA levels, especially after about 8 days of age. Additionally, monounsaturated ω9 FA levels exhibited a similar trend as saturated VLCFA, while ω3 polyunsaturated FA levels were elevated in Acsbg1-/- mice. Further analysis of specific FA levels provided additional insights into potential roles for ACSBG1. Notably, the decreased VLCFA levels in Acsbg1-/- mice primarily stemmed from changes in C24:0 and C26:0, while reduced ω9 FA levels were mainly observed in C18:1 and C24:1. ACSBG1 depletion had minimal effects on saturated long-chain FA or ω6 polyunsaturated FA levels but led to significant increases in specific ω3 FA, such as C20:5 and C22:5. Moreover, the impact of ACSBG1 deficiency on the developmental expression of several cerebellar FA metabolism enzymes, including those required for synthesis of ω3 polyunsaturated FA, was assessed; these FA can potentially be converted into bioactive signaling molecules like eicosanoids and docosanoids. In conclusion, despite compelling circumstantial evidence, it is unlikely that ACSBG1 directly contributes to the pathology of XALD. Instead, the effects of ACSBG1 knockout on processes regulated by eicosanoids and/or docosanoids should be further investigated.

FgFAD12 Regulates Vegetative Growth, Pathogenicity and Linoleic Acid Biosynthesis in Fusarium graminearum

Polyunsaturated fatty acids (PUFAs), as important components of lipids, play indispensable roles in the development of all organisms. ∆12 fatty acid desaturase (FAD12) is a speed-determining step in the biosynthesis of PUFAs. Here, we report the characterization of FAD12 in Fusarium graminearum, which is the prevalent agent of Fusarium head blight, a destructive plant disease worldwide. The results demonstrated that deletion of the FgFAD12 gene resulted in defects in vegetative growth, conidial germination and plant pathogenesis but not sexual reproduction. A fatty acid analysis further proved that the deletion of FgFAD12 restrained the reaction of oleic acid to linoleic acid, and a large amount of oleic acid was detected in the cells. Moreover, the ∆Fgfad12 mutant showed increased resistance to osmotic stress and reduced tolerance to oxidative stress. The expression of FgFAD12 did show a temperature-dependent manner, which was not affected at a low temperature of 10 °C when compared to 25 °C. RNA-seq analysis further demonstrated that most genes enriched in fatty acid metabolism, the biosynthesis of unsaturated fatty acids, fatty acid biosynthesis, fatty acid degradation, steroid biosynthesis and fatty acid elongation pathways were significantly up-regulated in the ∆Fgfad12 mutants. Overall, our results indicate that FgFAD12 is essential for linoleic acid biosynthesis and plays an important role in the infection process of F. graminearum.

Germinated Brown rice enhanced n-3 PUFA metabolism in type 2 diabetes patients: A randomized controlled trial

BACKGROUND

Brown rice (BR) has been considered as a potential strategy in improving T2DM. However, there are a lack of population-based trials on the association of Germinated brown rice (GBR) and diabetes.

AIMS

We aimed to explore the influence of GBR diet in T2DM patients for 3 months and whether this effect relates to serum fatty acids.

METHODS

Two hundred and twenty T2DM patients have been enrolled and eligible subjects (n = 112, 61 female, 51 male) were randomly divided into GBR intervention group (n = 56) and control group (n = 56). Except those who lost follow-up and withdrew, final GBR group and control group consisted of 42 and 43 patients, respectively. Participants in GBR group were asked to consume 100 g/d GBR instead of equal refined grain (RG) for 3 months, while control group maintain their usual eating habits. A structured questionnaire was used for demographic information at baseline, and basic indicators were measured both at the beginning and end of the trail to evaluate plasma glucose and lipids levels.

RESULTS

In GBR group, mean dietary inflammation index (DII) decreased, indicating GBR intervention retarded patient inflammation. Besides, glycolipid related parameters, including FBG, HbA1c, TC and HDL, were all significantly lower than those in control group. Excitingly, fatty acid composition was changed by intake of GBR, especially n-3 PUFA and n-3/n-6 PUFA rate were significantly increased. Moreover, subjects in GBR group had higher levels of n-3 metabolites, such as RVE, MaR1 and PD1, reducing inflammatory effect. In contrast, n-6 metabolites, like LTB4 and PGE2 which could promote inflammatory effect, were lower in GBR group.

CONCLUSION

We confirmed that diet with 100 g/d GBR for 3 months could really improve T2DM to some extent. This beneficial effect may be related to n-3 metabolites, namely inflammation changes.

TRIAL REGISTRATION

ChiCRT-IOR-17013999, www.chictr.org.cn.

Freshwater Microalgae as Promising Food Sources: Nutritional and Functional Properties

A number of researchers have predicted that the current food crisis is predicted to worsen in 2050. The prediction of this crisis is aligned with climate change causing increases in some basic foodstuff prices. Therefore, everyone should prepare to consume alternative foods at an early stage. Alternative foods have been widely developed, one of which involves microalgae. However, the type of microalgae produced by some countries on a large scale consists of only oceanic/seawater microalgae. This will have an impact on and hinder development in countries that do not have these resources. Therefore, it is necessary to explore the use of microalgae derived from freshwater. Unfortunately, freshwater microalgae are still rarely investigated for use as alternative foods. However, there is considerable potential to utilize freshwater microalgae, and these algae are very abundant and diverse. In terms of nutritional properties, compared to oceanic / seawater microalgae, freshwater microalgae contain nearly the same protein and amino acids, lipids and fatty acids, carbohydrates, and vitamins. There are even more species whose composition is similar to those currently consumed foods, such as beef, chicken, beans, eggs, and corn. In addition to dietary properties, freshwater microalgae also have functional properties, due to the presence of pigments, sterols, fatty acids, and polyphenols. Given the potential of freshwater microalgae, these aquatic resources need to be developed for potential use as future food resources.

Molecular Regulation of Biosynthesis of Long Chain Polyunsaturated Fatty Acids in Atlantic Salmon

Salmon is a rich source of health-promoting omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA), such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). The LC-PUFA biosynthetic pathway in Atlantic salmon is one of the most studied compared to other teleosts. This has largely been due to the massive replacement of LC-PUFA-rich ingredients in aquafeeds with terrestrial plant oils devoid of these essential fatty acids (EFA) which ultimately pushed dietary content towards the minimal requirement of EFA. The practice would also reduce tissue content of n-3 LC-PUFA compromising the nutritional value of salmon to the human consumer. These necessitated detailed studies of endogenous biosynthetic capability as a contributor to these EFA. This review seeks to provide a comprehensive and concise overview of the current knowledge about the molecular genetics of PUFA biosynthesis in Atlantic salmon, highlighting the enzymology and nutritional regulation as well as transcriptional control networks. Furthermore, we discuss the impact of genome duplication on the complexity of salmon LC-PUFA pathway and highlight probable implications on endogenous biosynthetic capabilities. Finally, we have also compiled and made available a large RNAseq dataset from 316 salmon liver samples together with an R-script visualization resource to aid in explorative and hypothesis-driven research into salmon lipid metabolism.

α-linolenic acid interconversion is sufficient as a source of longer chain ω-3 polyunsaturated fatty acids in humans: An opinion

α-linolenic acid (αLNA) conversion into the functionally important ω-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), has been regarded as inadequate for meeting nutritional requirements for these PUFA. This view is based on findings of small αLNA supplementation trials and stable isotope tracer studies that have been interpreted as indicating human capacity for EPA and, in particular, DHA synthesis is limited. The purpose of this review is to re-evaluate this interpretation. Markedly differing study designs, inconsistent findings and lack of trial replication preclude robust consensus regarding the nutritional adequacy of αLNA as a source of EPC and DHA. The conclusion that αLNA conversion in humans is constrained is inaccurate because it presupposes the existence of an unspecified, higher level of metabolic activity. Since capacity for EPA and DHA synthesis is the product of evolution it may be argued that the levels of EPA and DHA it maintains are nutritionally appropriate. Dietary and supra-dietary EPA plus DHA intakes confer health benefits. Paradoxically, such health benefits are also found amongst vegetarians who do not consume EPA and DHA, and for whom αLNA conversion is the primary source of ω-3 PUFA. Since there are no reported adverse effects on health or cognitive development of diets that exclude EPA and DHA, their synthesis from αLNA appears to be nutritionally adequate. This is consistent with the dietary essentiality of αLNA and has implications for developing sustainable nutritional recommendations for ω-3 PUFA.

The g.4290 C>G Polymorphism in the FADS2 Gene Modifies the Fatty Acid Profile of the Pectoralis Superficialis Muscle of Ross 308 Broiler Chickens

The effect of the g.4290 C>G substitution in the FADS2 gene and g.285 C>T in the FABP4 gene on carcass quality, meat quality, and fatty acid profile of the pectoralis superficialis muscle of 238 male broiler chickens reared up to 45 days of age was analyzed. A significant influence of g.4290 C>G in the FADS2 gene on the pectoralis superficialis muscle fatty acid profile was demonstrated. Chickens with the GG genotype were characterized by the highest content of conjugated linoleic acid, amino acids, eicosapentaenoic acids, docosapentaenoic acid, docosahexaenoic acids. and the lowest value of the linoleic acid/alpha-linolenic acid ratio. The FABP4 polymorphism determined only the content of C18:1n-9, C18:2n-6 and docosahexaenoic acid. There was no effect of the studied genotypes on final body weight, carcass quality traits, or quality of broiler pectoral muscles.

FADS1 overexpression promotes fatty acid synthesis and triacylglycerol accumulation via inhibiting the AMPK/SREBP1 pathway in goat mammary epithelial cells

Delta-5 desaturase (D5D), encoded by the fatty acid desaturase 1 (FADS1) gene, is a rate-limiting enzyme in polyunsaturated fatty acid (PUFA) synthesis that influences the PUFA levels in milk fat. However, the function and molecular mechanism of FADS1 in milk fat metabolism remain largely unknown. The FADS1 overexpression increased the triglyceride content, lipid droplet size, and expression of genes related to fatty acid de novo synthesis (SREBP1 and ACC), intracellular fatty acid transporters (FABP3 and FABP4) and triacylglycerol synthesis gene (DGAT2). It also significantly promoted the SREBP1 nuclear translocation by inhibiting the AMPK activation. In addition, FADS1 overexpression inhibited cell proliferation and arrested cell cycle at the G1 phase. These findings reveal a novel FADS1-AMPK-SREBP1 pathway regulating milk fat production in the goat mammary gland.

Targeting of gallbladder megalin receptors with DHA-conjugated limonene albumin nanoparticles

Gallbladder stones are a major pathogenic factor leading to cholecystitis, and it is increasingly important to explore innovative drug delivery methods for gallstones. In the present study, docosahexaenoic acid-coupled limonene bovine serum albumin nanoparticles (LIM-DHA-BSA-NPs) were constructed. The LIM-DHA-BSA-NPs are spherical structures, and the distribution was relatively uniform, and, more importantly, it has low cytotoxicity and good safety. The LIM-DHA-BSA-NPs solution shows higher uptake rates by RAW264.7 cells when compared with free limonene (LIM). The fluorescence intensity of FITC-modified BSA NPs was significantly higher than that of free FITC, which further indicated that the uptake of DHA-conjugated BSA NPs by RAW264.7 cells was stronger than that of the free drugs. Moreover, the in vivo distribution experiment showed that the enrichment of DiD-loaded BSA NPs in the gallbladder was significantly enhanced when compared with that of free DiD. The semi-quantitative fluorescence intensity results showed that the uptake of DiD-DHA-BSA-NPs was 4.5 times higher when compared with the free DiD. It is preliminarily shown that the DHA-conjugated BSA NPs that were constructed, have an ability to target the gallbladder. Furthermore, the Pearson colocalization coefficient Rcoloc from in vivo colocalization results indicates that the DHA-BSA-NPs had a good colocalization effect on the gallbladder epithelial cells (GBECs). In addition, the LIM-DHA-BSA-NPs solution not only significantly reduced the concentration of nitric oxide (NO) secreted by inflammatory model cells and the number of peripheral blood leukocytes in guinea pigs with cholecystitis, but also significantly decreased the activities of the aspartate transaminase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), glutamyl endopeptidase (GGT), total bile acid (TBA), and total bilirubin (TBIL) enzymes. Collectively, the LIM-DHA-BSA-NPs could be used as an effective anti-inflammatory agent at the cellular and animal levels. This experiment, for the first time, showed that DHA-conjugated BSA NPs could be absorbed into GBECs by megalin receptor-mediated endocytosis and then they exert an anti-cholecystitis effect because of the LIM. The active uptake of DHA-conjugated BSA NPs by the megalin receptors of the GBECs is expected to become an effective therapeutic strategy for cholecystolithiasis.

The Partitioning of Newly Assimilated Linoleic and α-Linolenic Acids Between Synthesis of Longer-Chain Polyunsaturated Fatty Acids and Hydroxyoctadecaenoic Acids Is a Putative Branch Point in T-Cell Essential Fatty Acid Metabolism

Longer-chain polyunsaturated fatty acids (LCPUFAs) ≥20 carbons long are required for leukocyte function. These can be obtained from the diet, but there is some evidence that leukocytes can convert essential fatty acids (EFAs) into LCPUFAs. We used stable isotope tracers to investigate LCPUFA biosynthesis and the effect of different EFA substrate ratios in human T lymphocytes. CD3⁺ T cells were incubated for up to 48 h with or without concanavalin A in media containing a 18:2n-6:18:3n-3 (EFA) ratio of either 5:1 or 8:1 and [¹³C]18:3n-3 plus [d₅]18:2n-6. Mitogen stimulation increased the amounts of 16:1n-7, 18:1n-9, 18:2n-6, 20:3n-6, 20:4n-6, 18:3n-3, and 20:5n-3 in T cells. Expression of the activation marker CD69 preceded increased FADS2 and FADS1 mRNA expression and increased amounts of [d₅]20:2n-6 and [¹³C]20:3n-3 at 48 h. In addition, 22-carbon n-6 or n-3 LCPUFA synthesis was not detected, consistent with the absence of ELOVL2 expression. An EFA ratio of 8:1 reduced 18:3n-3 conversion and enhanced 20:2n-6 synthesis compared to a 5:1 ratio. Here, [d₅]9- and [d₅]-13-hydroxyoctadecadienoic (HODE) and [¹³C]9- and [¹³C]13-hydroxyoctadecatrienoic acids (HOTrE) were the major labelled oxylipins in culture supernatants; labelled oxylipins ≥20 carbons were not detected. An EFA ratio of 8:1 suppressed 9- and 13-HOTrE synthesis, but there was no significant effect on 9- and 13-HODE synthesis. These findings suggest that partitioning of newly assimilated EFA between LCPUFA synthesis and hydroxyoctadecaenoic acid may be a metabolic branch point in T-cell EFA metabolism that has implications for understanding the effects of dietary fats on T lymphocyte function.

Beneficial effect of long-chain n-3 polyunsaturated fatty acid supplementation on tuberculosis in mice

Intakes of the omega-3 essential fatty acids (n-3 EFAs) are low in the general adult population, with high n-6/n-3 polyunsaturated fatty acid (PUFA) ratios and the accompanying suboptimal n-3 PUFA status. Eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) have antibacterial and inflammation-resolving effects in tuberculosis (TB). However, whether switching to a diet with optimum n-3 EFA intake after the infection has comparable benefits has not been investigated. We aimed to compare the effects of a diet with sufficient n-3 EFA content in an acceptable n-6/n-3 PUFA ratio for rodents ((n-3)eFAS group) with those on the same diet supplemented with EPA and DHA (EPA/DHA group) in Mycobacterium tuberculosis (Mtb)-infected C3HeB/FeJ mice with a low n-3 PUFA status. Mice were conditioned on an n-3 PUFA-deficient diet with a high n-6/n-3 PUFA ratio for 6 weeks before Mtb infection and randomized to either (n-3)eFAS or EPA/DHA diets 1 week post-infection for 3 weeks. At endpoint, EPA and DHA compositions were higher and arachidonic acid, osbond acid, and total n-6 LCPUFAs lower in all lipid pools measured in the EPA/DHA group (all P < 0.001). Percentage body weight gain was higher (P = 0.017) and lung bacterial load lower (P < 0.001) in the EPA/DHA group. Additionally, the EPA/DHA group had a more pro-resolving lung lipid mediator profile and lower lung in IL-1α and IL-1β concentrations (P = 0.023, P = 0.049). Inverse correlations were found between the lung and peripheral blood mononuclear cell EPA and DHA and selected pro-inflammatory cytokines. These are the first findings that indicate that EPA/DHA supplementation provides benefits superior to a diet with sufficient n-3 EFAs concerning bacterial killing, weight gain and lung inflammation resolution in Mtb-infected mice with a low n-3 PUFA status. Therefore, EPA and DHA may be worth considering as adjunct TB treatment.

Fractionated free fatty acids and their relation to diabetes status after Roux-en-Y gastric bypass: A cohort study

Bariatric surgery is associated with near-immediate remission of type 2 diabetes and recently suggested as a treatment for type 2 diabetes. Specifically, Roux-en-Y gastric bypass has been a focus of much research, but still, the mechanisms of action are only partly elucidated. We aim to investigate whether some mechanisms might be mediated by free fatty acids (FFAs). We measured eight fractionated FFAs before and up to 2 years after Roux-en-Y gastric bypass surgery in 207 patients, divided into three groups. One non-diabetic group, one diabetic group with post-operative remission and one diabetic group with persistent diabetes after surgery. Pre- and postoperative levels of fractionated FFAs were compared within and between groups. The sum of the measured FFAs were lower in the group with persistent diabetes, compared to the other groups. The pre-surgery level of linoleic acid in the group with persistent diabetes was significantly lower compared to the other two groups. The levels of fractionated FFAs decreased from pre-surgery to three months after surgery, except for oleic acid and arachidonic acid and for Docosahexaenoic acid (DHA) in the non-diabetic group. The FFAs with decreasing levels from pre-surgery to three months post-surgery are all precursors to oleic acid, arachidonic acid, and DHA, respectively, which may imply a drift, indicating that they need to be sustained at an acceptable level for optimal metabolic function. The fact that the sum of the measured FFAs is lower in the group with persistent diabetes may suggest that this group and the group with diabetes remission represent two distinct types of type 2 diabetes. It is proposed that linoleic acid could be used as a biomarker to determine the plausibility for type 2 diabetes remission after Roux-en-Y gastric bypass surgery.

Plasma Phospholipid n-3/n-6 Polyunsaturated Fatty Acids and Desaturase Activities in Relation to Moderate-to-Vigorous Physical Activity through Pregnancy: A Longitudinal Study within the NICHD Fetal Growth Studies

Maternal plasma phospholipid polyunsaturated fatty acids (PUFAs) play critical roles in maternal health and fetal development. Beyond dietary factors, maternal moderate-to-vigorous physical activity (MVPA) has been linked to multiple health benefits for both the mother and offspring, but studies investigating the influence of maternal MVPA on maternal PUFA profile are scarce. The objective of present study was to examine the time-specific and prospective associations of MVPA with plasma PUFA profile among pregnant women. This study included 321 participants from the National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies–Singletons cohort. Maternal plasma phospholipid PUFAs and MPVA were measured at four visits during pregnancy (10–14, 15–26, 23–31, and 33–39 gestational weeks (GW)). Associations of maternal MVPA with individual plasma PUFAs and desaturase activity were examined using generalized linear models. Maternal MVPA was associated inversely with plasma phospholipid linoleic acid, gamma-linolenic acid, and Δ6-desaturase in late pregnancy (23–31 or 33–39 GW), independent of maternal age, race, education, parity, pre-pregnancy body mass index, and dietary factors. Findings from this longitudinal study indicate that maternal habitual MVPA may play a role on PUFAs metabolism, particular by alerting plasma n-6 subclass and desaturase activity in late pregnancy. These associations are novel and merit confirmation in future studies.

Potential Food Application of a Biosurfactant Produced by Saccharomyces cerevisiae URM 6670

Biosurfactants have aroused considerable interest due to the possibility of acquiring useful products that are tolerant to processing techniques used in industries. Some yeasts synthesize biosurfactants that offer antioxidant activity and thermal resistance and have no risk of toxicity or pathogenicity, demonstrating potential use in food formulations. The aim of the present study was to assess the use of a biosurfactant produced by Saccharomyces cerevisiae URM 6670 to replace egg yolk in a cookie formulation. The yeast was grown in a medium containing 1% waste soybean oil and 1% corn steep liquor. The biosurfactant was isolated using a novel method and was structurally characterized using FT-IR, NMR, and GC/FID. Thermal stability was determined using thermogravimetry (TG)/differential scanning calorimetry (DSC) and antioxidant activity was investigated using three methods. Cytotoxicity tests were performed using the MTT assay with mouse fibroblast and macrophage lines. In the final step, the biosurfactant was incorporated into the formulation of a cookie dough replacing egg yolk. The physical properties and texture profile were analyzed before and after baking. The surface and interfacial tensions of the culture medium after the production process were 26.64 ± 0.06 and 9.12 ± 0.04 mN/m, respectively, and the biosurfactant concentration was 5.84 ± 0.17 g/L after isolation. In the structural characterization by NMR and FT-IR, the biosurfactant from S. cerevisiae exhibited a glycolipid structure, with the fatty acid profile revealing a high percentage of linoleic acid (50.58%). The thermal analysis demonstrated stability at the industrial application temperature, with the negligible loss of mass at temperatures of up to 200°C. The biosurfactant was non-toxic to the fibroblast and macrophage cell lines, with cell inhibition less than 15%. The incorporation of the biosurfactant into the cookie dough did not alter the physical or physicochemical properties of the product after baking. In the analysis of the texture profile before baking, the substitution of egg yolk with the biosurfactant did not alter the properties of firmness, cohesiveness, or elasticity compared to the standard formulation. Therefore, the biosurfactant produced by S. cerevisiae URM 6670 has potential applications in the food industry as a replacement for egg yolk.

Biological Role of Unsaturated Fatty Acid Desaturases in Health and Disease

Polyunsaturated fatty acids (PUFAs) are considered one of the most important components of cells that influence normal development and function of many organisms, both eukaryotes and prokaryotes. Unsaturated fatty acid desaturases play a crucial role in the synthesis of PUFAs, inserting additional unsaturated bonds into the acyl chain. The level of expression and activity of different types of desaturases determines profiles of PUFAs. It is well recognized that qualitative and quantitative changes in the PUFA profile, resulting from alterations in the expression and activity of fatty acid desaturases, are associated with many pathological conditions. Understanding of underlying mechanisms of fatty acid desaturase activity and their functional modification will facilitate the development of novel therapeutic strategies in diseases associated with qualitative and quantitative disorders of PUFA.

Adipose tissue content of alpha-linolenic acid and development of peripheral artery disease: a Danish case-cohort study

PURPOSE

The aim of this study was to investigate the association between adipose tissue content of the plant-derived n-3 fatty acid, alpha-linolenic acid, and the rate of incident peripheral artery disease (PAD).

METHODS

We conducted a case-cohort study nested within the Danish Diet, Cancer and Health cohort (n = 57,053), which was established between 1993 and 1997. Potential PAD cases were identified using linkage with The Danish National Patient Register and all potential cases were validated. Adipose tissue samples from the buttock were collected at baseline and fatty acid composition was determined in cases and in a random sample (n = 3500) from the cohort by gas chromatography. Statistical analyses were performed using weighted Cox regression allowing for different baseline hazards among sexes.

RESULTS

During a median of 13.5 years of follow-up, we identified 863 PAD cases with complete information. The median adipose tissue content of ALA in the sub-cohort (n = 3197) was 0.84% (interquartile range 0.73-0.94%) of total fatty acids. In multivariate analyses including adjustment for established risk factors, we observed a U-shaped association between ALA in adipose tissue and rate of PAD, but the association was not statistically significant (P = 0.131). Similar pattern of associations were observed between ALA content in adipose tissue and the rate of PAD among men and women.

CONCLUSIONS

We found indications of a U-shaped association between adipose tissue content of ALA and the rate of PAD, but the association was not statistically significant.

Long-chain Omega-3 Polyunsaturated Fatty Acids in Natural Ecosystems and the Human Diet: Assumptions and Challenges

Over the past three decades, studies of essential biomolecules, long-chain polyunsaturated fatty acids of the omega-3 family (LC-PUFAs), namely eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have made considerable progress, resulting in several important assumptions. However, new data, which continue to appear, challenge these assumptions. Based on the current literature, an attempt is made to reconsider the following assumptions: 1. There are algal classes of high and low nutritive quality. 2. EPA and DHA decrease with increasing eutrophication in aquatic ecosystems. 3. Animals need EPA and DHA. 4. Fish are the main food source of EPA and DHA for humans. 5. Culinary treatment decreases EPA and DHA in products. As demonstrated, some of the above assumptions need to be substantially specified and changed.

Polyunsaturated Fatty Acids and Risk of Ischemic Stroke

Ischemic stroke is a major cause of death and morbidity worldwide. It has been suggested that polyunsaturated fatty acids (PUFAs) may be associated with a lower risk ischemic stroke, but this has been far less studied than their role for coronary heart disease. In this paper, we summarize the main findings from previous follow-up studies investigating associations between intake or biomarkers of the major PUFAs including alpha-linolenic acid (ALA), marine n-3 PUFAs and linoleic acid (LA) and the development of ischemic stroke. Several follow-up studies have suggested that marine n-3 PUFAs may be associated with a lower risk of ischemic stroke although results have not been consistent and limited knowledge exist on the individual marine n-3 PUFAs and ischemic stroke and its subtypes. The role of ALA is less clear, but most studies have not supported that ALA is appreciably associated with ischemic stroke risk. Some studies have supported that LA might be associated with a lower risk of total ischemic stroke, while limited evidence exist on PUFAs and ischemic stroke subtypes. The associations may depend on the macronutrients that PUFAs replace and this substitution aspect together with focus on dietary patterns represent interesting areas for future research.