Δ6 Desaturase Research Articles

N-3 Polyunsaturated Fatty Acid Dehydrogenase Fat-1 Regulates Mitochondrial Energy Metabolism by Altering DNA Methylation in Isolated Cells of Transgenic Cattle.

The fatty acid dehydrogenase fat-1 gene, derived from Caenorhabditis elegans, encodes n-3 polyunsaturated fatty acid dehydrogenase (Δ15 desaturase) and catalyzes the 18–20-carbon n-6 polyunsaturated fatty acids (n-6 PUFA) to generate corresponding n-3 polyunsaturated fatty acids (n-3 PUFA). Subsequently, fat-1 can influence the n-6: n-3 PUFA ratio in fat-1 transgenic cells. This study aimed to explore which processes of energy metabolism are affected exogenous fat-1 transgene and the relationship between these effects and DNA methylation. Compared with the wild-type group, the n-3 PUFA content in fat-1 transgenic bovine fetal fibroblasts was significantly increased, and the n-6 PUFA content and the n-6: n-3 PUFA ratio decreased. In the context of energy metabolism, the increase of exogenous fat-1 transgene decreased ATP synthesis by 39% and reduced the activity and expression of key rate-limiting enzymes in glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation, thus weakening the cells’ capacity for ATP production. DNA methylation sequencing indicated that this inhibition of gene expression may be due to altered DNA methylation that regulates cell energy metabolism. Exogenous fat-1 transgenic cells showed changes in the degree of methylation in the promoter region of genes related to energy metabolism rate-limiting enzymes. We suggest that alters the balance of n-6/n-3 PUFA could regulate altered DNA methylation that affect mitochondrial energy metabolism.

Quantitative Lipidomics and Spatial MS-Imaging Uncovered Neurological and Systemic Lipid Metabolic Pathways Underlying Troglomorphic Adaptations in Cave-Dwelling Fish

Sinocyclocheilus represents a rare, freshwater teleost genus endemic to China that comprises the river-dwelling surface fish and the cave-dwelling cavefish. Using a combinatorial approach of quantitative lipidomics and mass-spectrometry imaging (MSI), we demonstrated that neural compartmentalization of lipid distribution and lipid metabolism is associated with the evolution of troglomorphic traits in Sinocyclocheilus. Attenuated docosahexaenoic acid (DHA) biosynthesis via the Δ4 desaturase pathway led to reductions in DHA-phospholipids in cavefish cerebellum. Instead, cavefish accumulates arachidonic acid-phospholipids that may disfavor retinotectal arbor growth. Importantly, MSI of sulfatides coupled with immunostaining of myelin basic protein and transmission electron microscopy images of hindbrain axons revealed demyelination in cavefish raphe serotonergic neurons. Demyelination in cavefish parallels the loss of neuroplasticity governing social behavior such as aggressive dominance. Outside the brain, quantitative lipidomics and qRT-PCR revealed systemic reductions in membrane esterified DHAs in the liver, attributed to suppression of genes along the Sprecher pathway (elovl2, elovl5, and acox1). Development of fatty livers was observed in cavefish; likely mediated by an impeded mobilization of storage lipids, as evident in the diminished expressions of pnpla2, lipea, lipeb, dagla, and mgll; and suppressed β-oxidation of fatty acyls via both mitochondria and peroxisomes as reflected in the reduced expressions of cpt1ab, hadhaa, cpt2, decr1, and acox1. These neurological and systemic metabolic adaptations serve to reduce energy expenditure, forming the basis of recessive evolution that eliminates nonessential morphological and behavioral traits and giving cavefish a selective advantage to thrive in caves where proper resource allocation becomes a major determinant of survival.

A Fat-Promoting Botanical Extract From Artemisia scoparia Exerts Geroprotective Effects on Caenorhabditis elegans Life Span and Stress Resistance.

Like other biological processes, aging is not random but subject to molecular control. Natural products that modify core metabolic parameters, including fat content, may provide entry points to extend animal life span and promote healthy aging. Here, we show that a botanical extract from Artemisia scoparia (SCO), which promotes fat storage and metabolic resiliency in mice, extends the life span of the nematode Caenorhabditis elegans by up to 40%. Notably, this life-span extension depends significantly on SCO's effects on fat; SCO-treated worms exhibit heightened levels of unsaturated fat, and inhibition of Δ9 desaturases, which oversee biosynthesis of monounsaturated fatty acids, prevents SCO-dependent fat accumulation and life-span extension. At an upstream signaling level, SCO prompts changes to C. elegans fat regulation by stimulating nuclear translocation of transcription factor DAF-16/FOXO, an event that requires AMP-activated protein kinase under this condition. Importantly, animals treated with SCO are not only long-lived but also show improved stress resistance in late adulthood, suggesting that this fat-promoting intervention may enhance some aspects of physiological health in older age. These findings identify SCO as a natural product that can modify fat regulation for longevity benefit and add to growing evidence indicating that elevated fat can be prolongevity in some circumstances.

Understanding desaturation/hydroxylation activity of castor stearoyl Δ9-Desaturase through rational mutagenesis

A recently proposed reaction mechanism of soluble Δ9 desaturase (Δ9D) allowed us to identify auxiliary residues His203, Asp101, Thr206 and Cys222 localized near the di-iron active site that are supposedly involved in the proton transfer (PT) to and from the active site. The PT, along with the electron transfer (ET), seems to be crucial for efficient desaturation. Thus, perturbing the major PT chains is expected to impair the native reaction and (potentially) amplify minor reaction channels, such as the substrate hydroxylation. To verify this hypothesis, we mutated the four residues mentioned above into their counterparts present in a soluble methane monooxygenase (sMMO), and determined the reaction products of mutants. We found that the mutations significantly promote residual monohydroxylation activities on stearoyl-CoA, often at the expense of native desaturation activity. The favored hydroxylation positions are C9, followed by C10 and C11. Reactions with unsaturated substrate, oleoyl-CoA, yield erythro-9,10-diol, cis-9,10-epoxide and a mixture of allylic alcohols. Additionally, using 9- and 11-hydroxystearoyl-CoA, we showed that the desaturation reaction can proceed only with the hydroxyl group at position C11, whereas the hydroxylation reaction is possible in both cases, i.e. with hydroxyl at position C9 or C11. Despite the fact that the overall outcome of hydroxylation is rather modest and that it is mostly the desaturation/hydroxylation ratio that is affected, our results broaden understanding of the origin of chemo- and stereoselectivity of the Δ9D and provide further insight into the catalytic action of the NHFe2 enzymes.

A fat-promoting plant extract from Artemisia scoparia exerts geroprotective effects on C. elegans health & lifespan

Only 5-10% of Parkinson’s Disease (PD) cases have a direct genetic origin; however, exposure to herbicides, pesticides, and interactions with soil are potential risk factors. PD is characterized by the loss of dopaminergic (DA) neurons and the formation of protein inclusions that contain α-synuclein (α-syn). Conversely, a soil bacterium, Streptomyces venezuelae (S. ven), produces a secondary metabolite that causes age- and dose- dependent DA neurodegeneration in C. elegans; it also exacerbates α-syn-induced DA neurodegeneration. Previous studies from our lab determined that exposure to the S. ven metabolite caused oxidative stress, mitochondrial fragmentation and enhanced reactive oxygen species (ROS). Here we report that exposure to S. ven metabolite causes a hormetic effect on C. elegans lifespan, where low concentrations (5X) extend lifespan in N2 animals, but at higher concentrations (20X) lifespan is decreased. To further examine this hormetic response, we examined daf-16 mutants in this assay. daf-16 mutants displayed no significant differences between solvent and metabolite at both high and low concentrations, suggesting the hormetic response is daf-16 dependent. We also studied S. ven metabolite on C. elegans aging mutants. We investigated mutants in the AMPK signaling pathway and found when exposed to the 20X concentration of S. ven metabolite, aak-2 mutants displayed no significant difference between solvent and metabolite over lifespan. However, when aak-2 mutants were exposed to solvent control and the 5X concentration, mutants displayed a decreased lifespan. This suggests that functional aak-2 might be important for increased lifespan when combating toxicants following chronic exposure.

Regioselectivity mechanism of the Thunbergia alata Δ6-16:0-acyl carrier protein desaturase

Abstract Plant plastidial acyl–acyl carrier protein (ACP) desaturases are a soluble class of diiron-containing enzymes that are distinct from the diiron-containing integral membrane desaturases found in plants and other organisms. The archetype of this class is the stearoyl-ACP desaturase which converts stearoyl-ACP into oleoyl (18:1Δ9cis)-ACP. Several variants expressing distinct regioselectivity have been described including a Δ6-16:0-ACP desaturase from black-eyed Susan vine (Thunbergia alata). We solved a crystal structure of the T. alata desaturase at 2.05 Å resolution. Using molecular dynamics (MD) simulations, we identified a low-energy complex between 16:0-ACP and the desaturase that would position C6 and C7 of the acyl chain adjacent to the diiron active site. The model complex was used to identify mutant variants that could convert the T. alata Δ6 desaturase to Δ9 regioselectivity. Additional modeling between ACP and the mutant variants confirmed the predicted regioselectivity. To validate the in-silico predictions, we synthesized two variants of the T. alata desaturase and analyzed their reaction products using gas chromatography-coupled mass spectrometry. Assay results confirmed that mutants designed to convert T. alata Δ6 to Δ9 selectivity exhibited the predicted changes. In complementary experiments, variants of the castor desaturase designed to convert Δ9 to Δ6 selectivity lost some of their Δ9 desaturation ability and gained the ability to desaturate at the Δ6 position. The computational workflow for revealing the mechanistic understanding of regioselectivity presented herein lays a foundation for designing acyl-ACP desaturases with novel selectivities to increase the diversity of monoenes available for bioproduct applications.

Cloning and characterisation of a Δ9 fatty acyl desaturase-like gene from the red claw crayfish (Cherax quadricarinatus) and its expression analysis under cold stress.

Desaturase is one of the key enzymes in the unsaturated fatty acid synthesis pathway. Δ9 desaturase catalyzes the synthesis of oleic acid from stearic acid by introducing double bonds in the 9th and 10th carbon chains, thereby increasing the content of MUFAs in the body. In order to explore the main function of the Δ9 desaturase gene under low temperature stress, RACE-PCR technology was used in this study to clone the full-length sequence of the CqFAD9-like from the hepatopancreas of red claw crayfish, Cherax quadricarinatus. The full length of the sequence is 1236 bp, and the open reading frame is 1041 bp, encoding 346amino acid residues. The 5 'UTR is 116 bp, the 3' UTR is 79 bp, and the 3 'UTR contains a PloyA tail. The predicted theoretical isoelectric point and molecular weight are 8.68 and 40.28kDa, respectively. Homology analysis showed that the sequence had the highest similarity with FAD9 from crustaceans. The results of real-time PCR showed that the expression level of this gene was highest in the hepatopancreas, which was significantly higher than other tissues, followed by the ovaries, brain ganglion and stomach. At the same time, the expression of the CqFAD9-like in hepatopancreas of crayfish cultured at 25, 20, 15 and 9°C for four weeks was detected. The results showed that expression of the FAD9 gene increased gradually with decreasing temperature, indicating that metabolic desaturation might play a regulatory role during cold stress.

Effects of plasma fatty acids and desaturase activity on metabolic syndrome in a general population

Abstract Background Altered plasma fatty acid (FA) profile and desaturase activities have been associated with several metabolic disease, including MetS. However, their relations have rarely been studied among general population, and no study have included the FA profile in plasma phospholipids (PL) and triglycerides (TG) separately. We investigated the relationship of the FA profile and desaturase activities in plasma PL and TG with MetS, and investigated if there were new characteristics of altered FA profile that could be related to MetS status in a general population. Methods Baseline characteristic data from 850 participants (Male: 50.2%) aged 38-68 years who were recruited in the Lifelines Cohort study in the Netherlands were obtained. Individual FA profile was determined in fasting plasma PL and TG, and desaturase activities were estimated from product/precursor ratios. MetS was defined according to International Diabetes Federation in 2006. Logistic regression and odds ratios (OR) were used to examine these relations with the prevalence of MetS, and possible moderation effect of gender in these relation was also investigated. Results There was 102 people (12%) who had MetS. After adjustment for several confounders, higher tertiles of PL C18:3 n-6, C18:0, C20:3 n-6, Δ6 desaturase (D6D), and TG C14:0, C16:0, C20:0 were associated with an increasing prevalence of MetS, while higher tertiles of PL C18:1 n-7, C24:1 n-9, C20:0, C24:0, Δ5 desaturase (D5D), stearoyl-CoA desaturase (SCD-18), and TG C24:0, C18:2 n-6, C20:4 n-6, C24:1 n-9, C20:5 n-3, C22:5 n-3, C22:6 n-3, D5D were inversely associated with MetS. Meanwhile, men seemed to be more vulnerable to MetS when having an altered or unfavorable FA profile in both plasma PL and TG. Conclusions It is important to increase w-3 and w-6 essential fatty acids intake and decrease saturated fatty acids intake, and monitoring the D5D, D6D, and SCD-18 desaturases as additional fatty acids biomarkers is of equal importance. Key messages This study have added the evidence that an altered fatty acids profile was associated with metabolic syndrome (MetS) in a general population. The altered fatty acids profile that was associated with metabolic syndrome differed in plasma PL and TG, which requires further study.

Insect (black soldier fly larvae) oil as a potential substitute for fish or soy oil in the fish meal-based diet of juvenile rainbow trout (Oncorhynchus mykiss).

Alternative sources of fish oil (FO) are one of the major problems in aquaculture; therefore, the goal of the present study was to examine insect (black soldier fly larvae) oil (BSLO) as a potential replacer of fish/soy oil in juvenile rainbow trout (initial average weight of 32 ± 0.15 g) feed. Four diets were formulated wherein FO (control diet) was completely replaced with either soybean oil (SO) or BSLO, and an additional BSLO-based diet supplemented with 1.5% bile acid (BSLO + BA) were fed to the fish for 10 weeks. Growth performance of the BSLO fed group was similar (P > 0.05) to that of the FO and SO fed groups, however, the fish fed BSLO + BA diet registered the lowest growth (P < 0.05). Oil sources did not (P > 0.05) affect the major nutrient content of whole-body, however, the fatty acid composition of the muscle and liver was influenced (P < 0.05), with the highest 14:0, 16:0, and total saturated fatty acid detected in BSLO or BSLO + BA fed trout compared to the others (P < 0.001). No significant differences were observed in eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) or total n-3 polyunsaturated fatty acid (PUFA) content in muscle among the groups, whereas, the highest EPA:DHA and n-3:n-6 ratios were detected in the FO group. Gene expression for fatty acid binding protein (fabp), fatty acid synthase (fas), and Δ5 desaturase in the liver was lower in FO (P < 0.05), while BSLO + BA registered the highest Δ6 expression (P = 0.006). Supplementation of BA in the BSLO diet increased superoxide dismutase (SOD) and catalase (CAT) activities compared to the other groups (P < 0.05). In conclusion, BSLO could serve as a substitute for FO and SO in rainbow trout diet without negatively impacting growth performance, whole-body composition and nutrient retention, and modulate the expression of fatty acid metabolism-related genes in rainbow trout.

Insect meal inclusion as a novel feed ingredient in soy-based diets improves performance of rainbow trout (Oncorhynchus mykiss)

The additive effects of insect meal supplementation to diets containing a high soy protein inclusion were evaluated for growth performance, antioxidant potential and fillet nutritional quality of juvenile rainbow trout (Oncorhynchus mykiss). A basal diet (Soy) with a high-level soy protein (21% soybean meal, SBM plus 4–5.5% soy protein concentrate, SPC) was compared to similarly formulated soy-based diets supplemented with low (8%) and high levels (16%) of insect meal for diet groups Soy + IM Low and Soy + IM High, respectively. A high-level fishmeal (24%) based positive control diet (Fish meal) was also produced. All diets were iso‑nitrogenous (44%) and isolipidic (20%) and were fed to triplicate groups of rainbow trout juveniles (initial weight 32 ± 0.0 g) over the course of a 10-week trial. Fish fed the positive control diet showed significantly higher final weight, % weight gain (%WG) and specific growth rate (SGR) compared to the Soy + IM High and Soy diet groups, but these parameters were not significantly different from the Soy + IM Low diet group. The Soy and Soy + IM High diet groups showed significantly lower final weight, % WG and SGR. Feed efficiency and protein efficiency ratio was numerically higher in fish fed the Fish meal positive control diet followed by the Soy + IM Low and Soy and Soy + IM High diet groups, respectively. Among somatic indices, condition factor (CF) was significantly influenced by IM supplementation and the Soy + IM High diet group showed significantly lower CF compared to other dietary groups. Addition of insect meal significantly increased whole body amino acids viz., arginine, histidine, valine and threonine content. Insect meal supplementation significantly increased muscle α-linolenic acid content. However, α-linolenic acid content in fish fed the Soy + IM High diet was not significantly different from fish fed the Fishmeal positive control diet. Insect meal supplementation did not significantly influence EPA + DHA, total n-3 PUFA and monounsaturated fatty acid content in the muscle, whereas the significantly highest EPA/DHA and total monounsaturated fatty acids were detected in the fishmeal based positive control diet compared to other dietary treatment. The liver gene expression pattern for Δ5 desaturase was significantly higher in the Soy + IM Low diet fish, while Δ6 desaturase and fatty acid synthase (FAS) were significantly higher in Soy (basal) and Soy + IM Low diet fed fish. Elongase and fatty acid binding protein (FABP) were not significantly influenced by insect meal supplementation. Regarding the antioxidant potential, Soy diet group showed significantly higher superoxide dismutase (SOD) activity compared to insect meal included groups and positive control diet group. Glutathione peroxidase (GPX) activity was significantly reduced in Soy + IM High diet compared to other dietary groups. Finally, we conclude that insect meal inclusion at a low level (8%) is beneficial for increased growth and select fatty acid restoration for rainbow trout fed soy-based feeds.

Oleic Acid Protects Caenorhabditis Mothers From Mating-Induced Death and the Cost of Reproduction.

Reproduction comes at a cost, including accelerated death. Previous studies of the interconnections between reproduction, lifespan, and fat metabolism in C. elegans were predominantly performed in low-reproduction conditions. To understand how increased reproduction affects lifespan and fat metabolism, we examined mated worms; we find that a Δ9 desaturase, FAT-7, is significantly up-regulated. Dietary supplementation of oleic acid (OA), the immediate downstream product of FAT-7 activity, restores fat storage and completely rescues mating-induced death, while other fatty acids cannot. OA-mediated lifespan restoration is also observed in C. elegans mutants suffering increased death from short-term mating, and in mated C. remanei females, indicating a conserved role of oleic acid in post-mating lifespan regulation. Our results suggest that increased reproduction can be uncoupled from the costs of reproduction from somatic longevity regulation if provided with the limiting lipid, oleic acid.

Screening the rate-limiting genes in the ω6 polyunsaturated fatty acid biosynthesis pathway in Nannochloropsis oceanica

The enrichment of polyunsaturated fatty acids has made Nannochloropsis sp. a promising candidate for the production of polyunsaturated fatty acids. Although most of the genes involved in polyunsaturated fatty acid biosynthesis have been cloned, the regulatory mechanism at the molecular level has not been elucidated. To target the rate-limiting genes in the ω6 polyunsaturated fatty acid biosynthesis pathway in Nannochloropsis oceanica, we performed the following experiments. The function of the Δ9 fatty acid desaturase gene of N. oceanica was verified in Saccharomyces cerevisiae with a substrate preference for stearic acid. With gas chromatography–mass spectrometry (GC–MS) analysis, the fatty acid profiles in N. oceanica under different stress conditions (high nitrogen, low nitrogen, high temperature, and low temperature) were measured. The results showed that high nitrogen and low temperature stresses played significant roles in promoting polyunsaturated fatty acid biosynthesis. In contrast, low nitrogen and high temperature stresses were beneficial for the accumulation of monounsaturated fatty acids. We further measured the transcriptional abundances of all six genes in the ω6 polyunsaturated fatty acid biosynthesis pathway in N. oceanica and found that the Δ6 fatty acid elongase and the Δ12, Δ5, and Δ17 fatty acid desaturase genes were more sensitive to the stresses set in this study. Pearson correlation analysis showed that the Δ9 fatty acid desaturase was significantly associated with monounsaturated fatty acid biosynthesis, while Δ12, Δ5, and Δ17 fatty acid desaturases were proposed to be the rate-limiting enzymes in polyunsaturated fatty acid biosynthesis. This study helps to thoroughly elucidate the responses of N. oceanica to nitrogen and temperature stresses and optimize cultivation for high yield and quality of polyunsaturated fatty acids. More importantly, the selected rate-limiting genes may benefit further genetic engineering in N. oceanica.

Influence of Dietary Lipids and Environmental Salinity on the n-3 Long-Chain Polyunsaturated Fatty Acids Biosynthesis Capacity of the Marine Teleost Solea senegalensis

Fish vary in their ability to biosynthesise long-chain polyunsaturated fatty acids (LC-PUFA) depending upon the complement and function of key enzymes commonly known as fatty acyl desaturases and elongases. It has been reported in Solea senegalensis the existence of a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid (DHA) from eicosapentaenoic acid (EPA), which can be modulated by the diet. The present study aims to evaluate the combined effects of the partial replacement of fish oil (FO) with vegetable oils and reduced environmental salinity in the fatty acid composition of relevant body compartments (muscle, hepatocytes and enterocytes), the enzymatic activity over α-linolenic acid (ALA) to form n-3 LC-PUFA through the incubation of isolated hepatocytes and enterocytes with [1-14C] 18:3 n-3, and the regulation of the S. senegalensis fads2 and elovl5 in the liver and intestine. The presence of radiolabelled products, including 18:4n-3, 20:4n-3 and EPA, provided compelling evidence that a complete pathway enabling the biosynthesis of EPA from ALA, establishing S. senegalensis, has at least one Fads2 with ∆6 activity. Dietary composition prevailed over salinity in regulating the expression of fads2, while salinity did so over dietary composition for elovl5. FO replacement enhanced the proportion of DHA in S. senegalensis muscle and the combination with 20 ppt salinity increased the amount of n-3 LC-PUFA in hepatocytes.

Reduction of litter size during lactation in rats greatly influences fatty acid profiles in dams.

This study aimed to determine in lactating rats how fatty acid profiles are affected by litter size. On day 2 after parturition, litters of lactating rats were adjusted to a normal litter size of 9 pups/dam (NL) or to a small litter of 4 pups/dam (SL), and dams were studied at day 21 of lactation. Plasma glucose, insulin, and docosahexaenoic acid (DHA) concentrations were higher in SL than in NL dams, whereas the concentrations of most other fatty acids, triacylglycerols (TAG), and non-esterified fatty acids were lower in the SL dams. In the liver, the concentration of TAG was lower in SL than in NL dams as was the concentration of most fatty acids, with the exception of stearic acid (STA), arachidonic acid (ARA), and DHA concentrations that were higher in SL. Both plasma and liver Δ9 desaturase indices were lower in SL than in NL dams, whereas both Δ5 and Δ6 desaturase indices were higher in SL dams. In the liver, the expression of acetyl CoA carboxylase was lower in SL than in NL dams, and among the different adipose tissue depots, only mesenteric adipose tissue showed a higher concentration of most fatty acids in SL than in NL dams. It is proposed that reduction of litter size during lactation decreases liver lipogenesis de novo, although the synthesis of long-chain polyunsaturated fatty acids from their corresponding precursors increases, and lipolytic activity in mesenteric adipose tissue decreases probably as result of increased insulin responsiveness.

Metabolomic Profiling of Lipids and Fatty Acids: 3 Years Postoperative Laparoscopic Sleeve Gastrectomy.

Simple SummaryLaparoscopic Sleeve Gastrectomy (LSG) is one of the most effective type of bariatric surgery for weight loss that enables reduction in the size of stomach and associated comorbidities arises from obesity. LSG is well-accepted and safe surgical procedure, but it may lead to malabsorption of nutrients. However, long-term impact of LSG on other risk factors, including blood lipid and fatty acid (FA) profiles, largely remains unknown. The present study aimed to investigate the lipid and plasma FA profiles in patients who underwent LSG in reference to control group with obesity. We determine the markers of inflammation and metabolic risk in these groups by measuring different saturated, monounsaturated, polyunsaturated, and medium-chain FAs. We also estimated the activity of enzymes involved in synthesis of endogenous FA using the product precursor ratios of individual FAs as markers of global metabolic risk. Our study findings showed that patient’s 3-yrs post LSG developed a favorable lipid profile than control with similar metabolic profile in both groups, as determined by the blood FA profile and FA ratios. Our findings showed that LSG offers extended positive effect on the lipid profile in obese population. Though, lifestyle interventions following strict regular follow-up to maintain general health and well-being.Visceral obesity is common in the United Arab Emirates and worldwide. Although laparoscopic sleeve gastrectomy (LSG) leads to effective and sustainable weight loss, its long-term beneficial impact on other risk factors, including blood lipid and fatty acid (FA) profiles, remains unknown. These two profiles were assessed in patients 3 years after undergoing LSG and in LSG candidates (controls). Lipid profiles were measured using the Cobas e411 modular analyzer, and 35 FAs were identified. The age and body mass index were 36.55 ± 8.65 years and 31.49 ± 6.43 kg/m2 in the LSG group and 35.44 ± 9.51 years and 32.29 ± 5.38 kg/m2 in the control group, respectively. The overall lipid profile was more favorable in the LSG group than in the control group. Total saturated, monounsaturated, and polyunsaturated FAs were similar between the groups, but total medium-chain FAs were more abundant in the LSG group. In endogenous FA synthesis, the estimated activity of C16Δ9 desaturase and Δ5 desaturase decreased, whereas that of elongase increased in the LSG group compared with that in the control group. The benefits of LSG on blood lipid and FA profiles in patients with 3-year LSG may be limited. Hence, lifestyle interventions combined with a long-term and strict regular follow-up regime may be warranted for patients undergoing LSG.

A complete enzymatic capacity for biosynthesis of docosahexaenoic acid (DHA, 22 : 6n-3) exists in the marine Harpacticoida copepod Tigriopus californicus.

The long-standing paradigm establishing that global production of Omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA) derived almost exclusively from marine single-cell organisms, was recently challenged by the discovery that multiple invertebrates possess methyl-end (or ωx) desaturases, critical enzymes enabling the biosynthesis of n-3 LC-PUFA. However, the question of whether animals with ωx desaturases have complete n-3 LC-PUFA biosynthetic pathways and hence can contribute to the production of these compounds in marine ecosystems remained unanswered. In the present study, we investigated the complete enzymatic complement involved in the n-3 LC-PUFA biosynthesis in Tigriopus californicus, an intertidal harpacticoid copepod. A total of two ωx desaturases, five front-end desaturases and six fatty acyl elongases were successfully isolated and functionally characterized. The T. californicus ωx desaturases enable the de novo biosynthesis of C18 PUFA such as linoleic and α-linolenic acids, as well as several n-3 LC-PUFA from n-6 substrates. Functions demonstrated in front-end desaturases and fatty acyl elongases unveiled various routes through which T. californicus can biosynthesize the physiologically important arachidonic and eicosapentaenoic acids. Moreover, T. californicus possess a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid via the 'Δ4 pathway'. In conclusion, harpacticoid copepods such as T. californicus have complete n-3 LC-PUFA biosynthetic pathways and such capacity illustrates major roles of these invertebrates in the provision of essential fatty acids to upper trophic levels.

Serum Fatty Acid Latent Classes Are Associated With Suicide in a Large Military Personnel Sample.

Fatty acids (FAs) are involved in the functioning of biological systems previously associated with suicidal behavior (eg, monoamine signaling and the immune system). We sought to determine (1) whether observed FA levels in a sample of military suicide decedents and living matched controls were consistent with latent classes having distinctive FA profiles and (2) whether those latent classes were associated with suicide and mental health diagnoses. Serum samples from 800 US military suicide decedents who died between 2002 and 2008 and 800 demographically matched living controls were selected at random from a large military serum repository and assayed for 22 different FAs. A latent class cluster analysis was performed using values of 6 FAs previously individually associated with suicide. Once the latent classes were identified, they were compared in terms of suicide decedent proportion, demographic variables, estimated FA enzyme activity, diagnoses, and mental health care usage. A 6-latent class solution best characterized the dataset. Suicide decedents were less likely to belong to 2 of the classes and more likely to belong to 3 of the classes. The low-decedent classes differed from the high-decedent classes on 9 FAs and on estimated indices of activity for 3 FA enzymes: 14:0, 24:0, 18:1 n-9, 24:1 n-9, 22:5 n-3, 22:6 n-3, 20:2 n-6, 20:4 n-6, 22:5 n-6, elongation of very long chain fatty acids protein 1 (ELOVL1), ELOVL6, and Δ9 desaturase. The FA profiles of the latent classes were consistent with biological abnormalities previously associated with suicidal behavior. This study suggests the utility of methods that simultaneously examine multiple FAs when trying to understand their relationship with suicide and psychiatric illness.

Short-Term Consumption of Pomegranate Juice Alleviates Some Metabolic Disturbances in Overweight Patients with Dyslipidemia.

Pomegranate juice (PJ) has potential positive effects in patients with metabolic disturbances due to a high content of polyphenols. The objective of this study was to evaluate effects of a 2-week consumption of dietary doses of PJ on blood pressure, lipid metabolism, and oxidative stress markers in overweight patients with dyslipidemia. Twenty-four patients, 8 males and 16 females, 40-60 years of age, with established overweight and dyslipidemia were randomly assigned into intervention group, who consumed 300 mL of PJ daily for 2 weeks, or control group. After 2 weeks of juice intake, intervention group had significantly lower diastolic blood pressure, low-density lipoprotein cholesterol, aminotransferase, and activity of glutathione peroxidase. Furthermore, patients who consumed PJ had reduced percentage of docosahexaenoic acid (22:6n-3, DHA) in plasma phospholipids and increased estimated activity of stearoyl-CoA desaturase. In erythrocytes, we found a significant increase in the levels of dihomo-γ- linolenic acid (20:3n-6, DGLA) and DHA, as well as in estimated activity of Δ6 desaturase, and a decrease in estimated activity of Δ5 desaturase. These results show that even a short-term consumption of dietary doses of PJ exerts beneficial effects and affects lipid metabolism in overweight patients with dyslipidemia.

Pasture feeding strategy and milk fatty acid profile in small-scale dairy systems

The effect of the pasture feeding strategy on the milk fatty acid profile of lactating cows in small-scale dairy farms was evaluated. Ten farms participated in the study, five farms grazed pastures a minimum of 8.0 h/d, and five were fed cut herbage. Supplementary feeds were similar. Results were analysed with Student “t” test. There were no statistical differences when fatty acids were grouped by chain length, or in the proportion of saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA), but there were differences for polyunsaturated fatty acids (PUFA). Alpha-Linolenic acid (C18:3 n-3) was significantly higher in milk of grazing cows than in cows fed cut herbage. There were no differences in atherogenicity index nor in the Δ9 desaturase activity between pasture management strategies. In conclusion, grazing pastures results in milk with a more beneficial lipid profile for human health.

Associations of umbilical cord fatty acid profiles and desaturase enzyme indices with birth weight for gestational age in Japanese infants

Long-chain polyunsaturated fatty acids (LCPUFAs) required for infant development are produced by Δ6 desaturase (D6D) and Δ5 desaturase (D5D). The D6D index and D5D index are calculated based on their respective precursor/product ratios. The D5D and D6D indices are related to obesity and lifestyle-related diseases. The aim of the present study was to examine the associations of umbilical cord fatty acid profiles, D6D index, and D5D index in appropriate for gestational age (AGA), small for gestational age (SGA), and large for gestational age (LGA) infants. This was a nested case-control study, and the relationship between case and control maternal blood and umbilical cord blood fatty acid compositions was examined. Cases were small for gestational age (SGA; n = 55) and large for gestational age (LGA; n = 149) infants, whereas controls were appropriate for gestational age (AGA; n = 204) infants. Fatty acid profiles in maternal blood and umbilical cord plasma were analyzed by gas-liquid chromatography. The D6D index was calculated as dihomo-γ-linolenic acid (DGLA 20: 3 n-6) / linoleic acid (18: 2 n - 6), and the D5D index was calculated as arachidonic acid (20: 4 n - 6) / DGLA (20: 3 n - 6). Statistical analysis of umbilical cord blood fatty acids was performed with multiple comparisons. SGA infants showed high umbilical cord values for α-linolenic acid and DHA and lower values for DGLA compared to AGA infants. SGA infants showed a higher D5D index but a lower D6D index than AGA infants. LGA infants showed high values for α-linolenic acid and DGLA and lower values for arachidonic acid than AGA infants. LGA infants showed a high D6D index and a low D5D index relative to AGA infants. No significant differences in maternal blood fatty acid profiles, the D6D index, and D5D index desaturase activities were found among the three groups. There were differences in umbilical cord fatty acid profiles and D6D and D5D indices among AGA, SGA, and LGA infants, but further study is needed.