Decrease In Monounsaturated Fatty Acids Research Articles

Simultaneous ocean acidification and warming do not alter the lipid-associated biochemistry but induce enzyme activities in an asterinid starfish

Ocean acidification and warming affect marine ecosystems from the molecular scale in organismal physiology to broad alterations of ecosystem functions. However, knowledge of their combined effects on tropical-subtropical intertidal species remains limited. Pushing the environmental range of marine species away from the optimum initiates stress impacting biochemical metabolic characteristics, with consequences on lipid-associated and enzyme biochemistry. This study investigates lipid-associated fatty acids (FAs) and enzyme activities involved in biomineralization of the tropical-subtropical starfish Aquilonastra yairi in response to projected near-future global change. The starfish were acclimatized to two temperature levels (27 °C, 32 °C) crossed with three pCO2 concentrations (455 μatm, 1052 μatm, 2066 μatm). Total lipid (ΣLC) and FAs composition were unaffected by combined elevated temperature and pCO2, but at elevated temperature, there was an increase in ΣLC, SFAs (saturated FAs) and PUFAs (polyunsaturated FAs), and a decrease in MUFAs (monounsaturated FAs). However, temperature was the sole factor to significantly alter SFAs composition. Positive parabolic responses of Ca-ATPase and Mg-ATPase enzyme activities were detected at 27 °C with elevated pCO2, while stable enzyme activities were observed at 32 °C with elevated pCO2. Our results indicate that the lipid-associated biochemistry of A. yairi is resilient and capable of coping with near-future ocean acidification and warming. However, the calcification-related enzymes Ca-ATPase and Mg-ATPase activity appear to be more sensitive to pCO2/pH changes, leading to vulnerability concerning the skeletal structure.

Influence of genetic and interannual factors on the fatty acids profile of virgin olive oil.

Among olive oil nutritional benefits, it is worth mentioning its fatty acids composition with predominance of monounsaturated fatty acids (MUFAs). We have evaluated the influence of the cultivar and interannual factors on the fatty acids profile of virgin olive oil samples obtained from 45 and 71 cultivars along three and two consecutive crop seasons, respectively. The cultivars were classified in two groups according to the fatty acids composition: (1) high content in MUFAs and moderate content in saturated and polyunsaturated fatty acids (SFAs and PUFAs, respectively) and (2) moderate content in MUFAs and high content in SFAs/PUFAs. We also observed variations in the fatty acids content with the climate conditions, which can significantly alter the saturated and unsaturated profiles. Thus, a significant decrease in MUFAs and an increase in SFAs/PUFAs concentrations was found when the precipitation accumulated within the June-October period was reduced.

Expression of fatty acid related gene promotes astaxanthin heterologous production in Chlamydomonas reinhardtii.

Natural astaxanthin is a high-value ketone carotenoid mainly derived from Haematococcus pluvialis, which is an excellent antioxidant for human consumption. To study the role of lipids in accumulation of astaxanthin, the H. pluvialis-derived astaxanthin synthesis pathway genes (β-carotene ketolase gene, BKT and β-carotene hydroxylase gene, BCH) and fatty acid elongation gene (mitochondrial trans-2-enoyl-coa reductase gene, MECR) were heterologously co-expressed in C. reinhardtii. Zeaxanthin, the precursor of astaxanthin synthesis, was significantly increased after BKT and BCH were expressed. In contrast, the α-carotene that competes with astaxanthin synthesis for lycopene decreased significantly. This redistribution of carbon flow was conducive to the synthesis of astaxanthin. In addition, the transformant only expressed astaxanthin metabolism related genes (BKT, BCH) would lead to an increase in total lipid, a decrease in monounsaturated fatty acids and an increase in polyunsaturated fatty acids. On this basis, the expression of MECR gene further increased the total lipid, and the relative content of different fatty acids also changed. The astaxanthin content of algal strains transformed with BKT and BCH genes was nearly 50% higher than that of the wild type. On this basis, the astaxanthin content of transformants expressing MECR gene related to long-chain fatty acid synthesis was increased by 227.5%. In this study, an astaxanthin production model similar to H. pluvialis by combining carotenoid metabolism and fatty acid metabolism was constructed in C. reinhardtii. The results suggest that the increase in astaxanthin is indeed linked to the regulation of fatty acid metabolism, and this link may involve the type of fatty acids and the dynamics of astaxanthin ester in cells. The strategy of promoting the synthesis of fatty acids has potential to achieve efficient production of astaxanthin in C. reinhardtii.

P023 Immune-metabolic profiles of creeping fat in relation to degree of severity in Crohn’s disease postsurgical recurrence.

Abstract Background Crohn’s disease (CD) is an inflammatory bowel disease (IBD) of complex etiology that normally requires bowel resection. However, many patients suffer from post-operative recurrence (POR) within one year. Here, the inflammatory and bacterial influence of the affected intestine transforms the neighboring mesenteric tissue to creeping fat (CrF). The main objective has been to characterize the immune-metabolic profile of CrF according to the POR severity and compare them with mesenteric tissues from IBD-free controls (colorectal cancer and severe obesity). Methods POR severity was classified using the Rutgeerts index: non-recurrents (i0+i1, n=18; NR), mild-recurrents (i2, n=14; MR) and severe-recurrents (i3+i4, n=10; SR). The CrF were gathered from intestinal resections, and IBD-free mesenteric tissues were collected from intestinal resections for colorectal cancer (n=10) and bariatric surgery for severe obese patients (n=11). The total DNA was quantified using DABA assay, 105 cytokines were semiquantified by immune blotting and the fatty acid (FA) profile was quantified by GC-MS. Results The DNA analyses in the CrF showed a major cellularity demonstrating the hyperplasia. When compared to the control groups and to SR, the NR patients showed an increment of infection pro-resolutive cytokines (IFN-γ, MIF, BAFF), and, specially, an increase in both Th1 and Th2 cytokines (IL-18, IL-33). Here, there was also an increase in molecules related to angiogenesis (endoglin) and cellular adhesion (ICAM-1 and VCAM-1). On the other hand, the SR showed a higher level of pro-fibrotic PAI-1 and of the leukocyte homing inducer CCL5. Going into the FA, in comparison to the control groups, there was an increase in the saturated in front of a decrease in mono-unsaturated FA in all the CD groups. Regarding the polyunsaturated FAs, the CrF and the obese mesentery showed a general increase of the omega 6/omega 3 FA ratio when compared to colorectal cancer controls. Finally, both obese and NR CD patients had less short-chain FAs, specifically acetate and propionate, than the colorectal controls. Unexpectedly, the butyrate levels were very low in all the mesenteric tissues. Conclusion The CrF from NR CD patients show an infection resolutive profile regarding the controls and the SR. Instead, these lasts showed signs of chronic inflammation and a fibrotic profile. In general, CrF FA proportions suggests changes in cell signaling due to loss of cell membrane fluidity. In addition, the greater presence of omega-6 than omega-3 FA in the CrF and mesentery of obese patients could be related to the generation of potent proinflammatory lipid mediators. In contrast, the propionate and acetate decrease detected in NR CD patients could be protective against POR.

SCD2-mediated cooperative activation of IRF3-IRF9 regulatory circuit controls type I interferon transcriptome in CD4+ T cells

Type I interferons (type I-IFN) are critical for the host defense to viral infection, and at the same time, the dysregulation of type I-IFN responses leads to autoinflammation or autoimmunity. Recently, we reported that the decrease in monounsaturated fatty acid caused by the genetic deletion of Scd2 is essential for the activation of type I-IFN signaling in CD4+ Th1 cells. Although interferon regulatory factor (IRF) is a family of homologous proteins that control the transcription of type I-IFN and interferon stimulated genes (ISGs), the member of the IRF family that is responsible for the type I-IFN responses induced by targeting of SCD2 remains unclear. Here, we report that the deletion of Scd2 triggered IRF3 activation for type I-IFN production, resulting in the nuclear translocation of IRF9 to induce ISG transcriptome in Th1 cells. These data led us to hypothesize that IRF9 plays an essential role in the transcriptional regulation of ISGs in Scd2-deleted (sgScd2) Th1 cells. By employing ChIP-seq analyses, we found a substantial percentage of the IRF9 target genes were shared by sgScd2 and IFNβ-treated Th1 cells. Importantly, our detailed analyses identify a unique feature of IRF9 binding in sgScd2 Th1 cells that were not observed in IFNβ-treated Th1 cells. In addition, our combined analyses of transcriptome and IRF9 ChIP-seq revealed that the autoimmunity related genes, which increase in patient with SLE, were selectively increased in sgScd2 Th1 cells. Thus, our findings provide novel mechanistic insights into the process of fatty acid metabolism that is essential for the type I-IFN response and the activation of the IRF family in CD4+ T cells.

Critical assessment of metabolism and related growth and quality traits in trout fed spirulina-supplemented plant-based diets

Nowadays in aquaculture, the nutrition of carnivorous fish species requires the development of sustainable plant-based diets. Supplementation with microorganisms such as spirulina could offer an alternative to full plant-based diets that are inappropriate for carnivorous species such as rainbow trout. However, the benefits and drawbacks of spirulina supplementation on fish performance and metabolism need to be assessed to substantiate spirulina as an appropriate ingredient. The objective of this work was to determine the metabolic utilization of a plant-based diet supplemented with two levels of spirulina (5% and 15%) and to compare it to a full plant-based (PB) and a commercial-like (COM) diet for trout. Spirulina supplementation induced both a decrease in feed intake and an increase in feed efficiency while maintaining growth and a putative reorientation of lipid deposition from viscera to muscle. Fatty acid changes, including an increase in saturated fatty acids, a decrease in monounsaturated fatty acids, and color changes with an increase in b* index (yellow), suggested a slight alteration of the nutritional and visual quality of fish fed a spirulina diet. 1H NMR metabolomics profiling was used to measure metabolites in experimental feeds and in fish plasma, liver, and muscle. Two specific compounds of the spirulina ingredient were identified and determined to have opposed metabolic fates: i) a quinone-like compound was found to accumulate in liver and ii) β-hydroxybutyrate was found to be completely metabolized. The main metabolites modulated by spirulina in plasma and tissues were involved in energy and amino acid metabolisms. Spirulina supplementation almost suppressed the accumulation of glucose and essential amino acids in fish plasma and muscle induced by the PB diet. However, these compounds, as well as betaine, were found to accumulate in the liver of fish fed spirulina-supplemented diets. An alteration of liver metabolism due to the specific fatty acid profile and quinone-like compound of spirulina is suspected. A correlative approach of fish performance, quality traits, and metabolomic data in plasma and liver suggests that the maintenance of growth rate and feed efficiency using spirulina supplementation of a PB diet requires not only the supply of a well-balanced protein but also the redirection of lipid metabolism. However, observed changes in fatty acid composition and color suggest further alterations of the phospholipid metabolism. This work thus provides a contrasted fate of spirulina supplementation of a PB diet with both expected positive effects and unexpected negative effects that must be investigated further.

SCD2-mediated monounsaturated fatty acid metabolism regulates cGAS-STING-dependent type I IFN responses in CD4+ T cells

Host lipid metabolism and viral responses are intimately connected. However, the process by which the acquired immune systems adapts lipid metabolism to meet demands, and whether or not the metabolic rewiring confers a selective advantage to host immunity, remains unclear. Here we show that viral infection attenuates the expression of genes related to lipid metabolism in murine CD4+ T cells, which in turn increases the expression of antiviral genes. Inhibition of the fatty acid synthesis pathway substantially increases the basal expression of antiviral genes via the spontaneous production of type I interferon (IFN). Using a combination of CRISPR/Cas9-mediated genome editing technology and a global lipidomics analysis, we found that the decrease in monounsaturated fatty acid caused by genetic deletion of Scd2 in mice was crucial for the induction of an antiviral response through activation of the cGAS-STING pathway. These findings demonstrate the important relationship between fatty acid biosynthesis and type I IFN responses that enhances the antiviral response.

Neutral Ceramidase Mediates Nonalcoholic Steatohepatitis by Regulating Monounsaturated Fatty Acids and Gut IgA+ B Cells.

Nonalcoholic steatohepatitis (NASH) is associated with obesity and an increased risk for liver cirrhosis and cancer. Neutral ceramidase (NcDase), which is highly expressed in the intestinal brush border of the small intestine, plays a critical role in digesting dietary sphingolipids (ceramide) to regulate the balance of sphingosine and free fatty acids. It remains unresolved whether obesity-associated alteration of NcDase contributes to the manifestation of NASH. Here, we revealed that NcDase deficiency in murine models of NASH prevents hepatic inflammation and fibrosis but not steatosis. NcDase-/- mice display reduced stearoyl-CoA desaturase (SCD) 1 expression with a compositional decrease of monounsaturated fatty acids (MUFAs) under the different dietary conditions. We further found that NcDase is a functional regulator of intestinal B cells and influences the abundance and quality of the secretory IgA response toward commensal bacteria. Analysis of composition of the gut microbiota found that Clostridiales colonization was increased in NcDase-/- mice. The colonization of germ-free mice with gut microbiota from NcDase-/- mice resulted in a greater decrease in the expression of SCD1 and the level of MUFAs in the liver relative to gut microbiota from wild-type littermates, which are associated with the alternation of IgA-bound bacteria, including increase of Ruminococcaceae and reduction of Desulfovibrio. Mechanistically, NcDase is a crucial link that controls the expression of SCD1 and MUFA-mediated activation of the Wnt/β-catenin. Very importantly, our experiments further demonstrated that Wnt3a stimulation can enhance the activity of NcDase in hepatocytes. Thus, the NcDase-SCD1-Wnt feedback loop promotes the diet-induced steatohepatitis and fibrosis through the regulation of intestinal IgA+ immune cells.

NF-κB pathway play a role in SCD1 deficiency-induced ceramide de novo synthesis

ABSTRACT Stearoyl-CoA-desaturase 1 (SCD1) deficiency mediates apoptosis in colorectal cancer cells by promoting ceramide de novo synthesis. The mechanisms underlying the cross-talk between SCD1 and ceramide synthesis have not been explored. We treated colorectal cancer cells with an SCD1 inhibitor and examined the effects on gene expression, cell growth, and cellular lipid contents. The main effect of SCD1 inhibition on the fatty acid contents of colorectal cancer cells was a decrease in monounsaturated fatty acids (MUFAs). RNA sequencing (RNA-seq) showed that the most intense alteration of gene expression after SCD1 inhibition occurred in the NF-κB signaling pathway. Further experiments revealed that SCD1 inhibition resulted in increased levels of phosphorylated NF-κB p65 and increased nuclear translocation of NF-κB p65. Treatment with an NF-κB inhibitor eliminated several effects of SCD1 inhibition, mainly including overexpression of serine palmitoyltransferase1 (SPT1), elevation of dihydroceramide contents, and suppression of cell growth. Furthermore, treatment with supplemental oleate counteracted the SCD1-induced NF-κB activation and downstream effects. In summary, our data demonstrate that the NF-κB pathway plays a role in SCD1 deficiency-induced ceramide de novo synthesis in colorectal cancer cells, and that reduced MUFA levels contribute to the course.

Modeling the effect of heat treatment on fatty acid composition in home-made olive oil preparations.

The aim of this study was to simulate olive oil use and to monitor changes in the profile of fatty acids in home-made preparations using olive oil, which involve repeated heat treatment cycles. The material used in the experiment consisted of extra virgin and refined olive oil samples. Fatty acid profiles of olive oil samples were monitored after each heating cycle (10 min). The outcomes showed that cycles of heat treatment cause significant (p < 0.05) differences in the fatty acid profile of olive oil. A similar trend of differences (p < 0.05) was found between fatty acid profiles in extra virgin and refined olive oils. As expected, the main differences occurred in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). Cross-correlation analysis also showed differences between the fatty acid profiles. The most prolific changes were observed between the control samples and the heated (at 180°C) samples of refined olive oil in PUFAs, though a heating temperature of 220°C resulted in similar decrease in MUFAs and PUFAs, in both extra virgin and refined olive oil samples. The study showed differences in fatty acid profiles that can occur during the culinary heating of olive oil. Furthermore, the study indicated that culinary heating of extra virgin olive oil produced results similar to those of the refined olive oil heating at a lower temperature below 180°C.

The Effect of a High-Fat Diet on the Fatty Acid Composition in the Hearts of Mice.

The Western diet can lead to alterations in cardiac function and increase cardiovascular risk, which can be reproduced in animal models by implementing a high-fat diet (HFD). However, the mechanism of these alterations is not fully understood and may be dependent on alterations in heart lipid composition. The aim of this study was to evaluate the effect of an HFD on the fatty acid (FA) composition of total lipids, as well as of various lipid fractions in the heart, and on heart function. C57BL/6 mice were fed an HFD or standard laboratory diet. The FA composition of chow, serum, heart and skeletal muscle tissues was measured by gas chromatography–mass spectrometry. Cardiac function was evaluated by ultrasonography. Our results showed an unexpected increase in polyunsaturated FAs (PUFAs) and a significant decrease in monounsaturated FAs (MUFAs) in the heart tissue of mice fed the HFD. For comparison, no such effects were observed in skeletal muscle or serum samples. Furthermore, we found that the largest increase in PUFAs was in the sphingolipid fraction, whereas the largest decrease in MUFAs was in the phospholipid and sphingomyelin fractions. The hearts of mice fed an HFD had an increased content of triacylglycerols. Moreover, the HFD treatment altered aortic flow pattern. We did not find significant changes in heart mass or oxidative stress markers between mice fed the HFD and standard diet. The above results suggest that alterations in FA composition in the heart may contribute to deterioration of heart function. A possible mechanism of this phenomenon is the alteration of sphingolipids and phospholipids in the fatty acid profile, which may change the physical properties of these lipids. Since phospho- and sphingolipids are the major components of cell membranes, alterations in their structures in heart cells can result in changes in cell membrane properties.

Probing the effects of hexavalent chromium exposure on histology and fatty acid metabolism in liver of Bufo gargarizans tadpoles.

Hexavalent chromium is one of the major detrimental heavy metal pollutants. B.gargarizans tadpoles were treated with different concentrations of Cr6+ (0, 13, 52, 104, 208, and 416μg Cr6+ L-1) from Gs 2 to Gs 42. The effect of Cr6+ on histopathological alterations and transcript levels of fatty acid metabolism-related genes as well as fatty acids composition and content in liver were examined. Histopathological changes were observed in liver at 52, 104, 208, and 416μg Cr6+ L-1. Moreover, RT-qPCR analyses showed the downregulated mRNA levels of the genes related to fatty acid synthesis (SCD, MECR, TECR and ELOVL1) and fatty acid β-oxidation (ACOT1, PPT1, HADH and ACAA2) at 416μg Cr6+ L-1. However, the mRNA expression of fatty acid β-oxidation-related genes (ECHS1, HADHA and ACAA1) were significantly upregulated at 13, 52, 104, 208 and 416μg Cr6+ L-1. In situ hybridization revealed BSEP was expressed in hepatocyte nucleus and plasma membrane, and HSD17B12 was abundantly expressed in the plasma membrane. The HSD17B12 mRNA levels were significantly upregulated in tadpoles exposed to all Cr6+ treatment groups, while the BSEP mRNA levels were downregulated at 104, 208 and 416μg Cr6+ L-1 groups compared to control. In addition, an increase in polyunsaturated fatty acids and a decrease in monounsaturated fatty acids were found in 52, 104 and 416μg Cr6+ L-1 groups. Overall, chronic exposure to Cr6+ may suppress fatty acid synthesis, disturb fatty acid β-oxidation, aggravate disorders of hepatic function and induce hepatic impairment in B.gargarizans tadpoles.

Effect of Conjugated Linoleic Acid on Memory and Reflex Maturation in Rats Treated During Early Life.

In the critical period of neurodevelopment (gestation and lactation), maternal consumption of essential fatty acids (FAs) can alter the offspring cognitive function permanently causing damage. Lipids can regulate neurotrophin and compose brain tissue. However, the effects of maternal consumption of a mixture of conjugated linoleic acid (CLA) on an offspring nervous system are not completely clear. We aimed to investigate the impacts of different CLA concentrations mixed into the maternal diet during early life on neonatal reflex maturation and cognitive functions of the offspring. Three groups were formed: control (CG): receiving a standard diet; CLA1: receiving a diet containing 1% of CLA, and CLA3: receiving a diet containing 3% of CLA, offered during gestation and lactation. After birth, the reflex responses of the offspring were observed from the 1st to the 21st day. After weaning, the animals’ anxiety and memory were assessed using open field (OF) and novel object recognition tests. Fatty acids in the breast milk and the offspring’s brain were also quantified. The data were analyzed using one-way ANOVA and the Kruskal–Wallis test. CLA1 presented accelerated palmar grasp disappearance versus CLA3 and negative-geotaxis versus CG; and the CLA3 presented increases for most reflexes (cliff-avoidance, vibrissa-placing, negative-geotaxis, and auditory-startle response), and decrease in reflexes palmar grasp and free-fall righting versus CG (p < 0.05). CLA3 group explored less of the OF in the second exposure. CLA1 and CLA3 presented an increased exploration ratio for new objects, which indicates memory improvement. The milk tested from CLA3 demonstrated an increase in polyunsaturated fatty acids (PUFAs), and a decrease in monounsaturated fatty acids. The amount of CLA in milk was greater in CLA1 and CLA3 and in the brain offspring both presented moderated amounts of CLA. Maternal treatment with the CLA mixture induced anticipated reflex maturation and improved memory in the offspring. Even though CLA was detected in the brains in only trace amounts, offspring’s brain PUFA and SFA levels were increased. Further studies aimed to delineate the effect of maternal CLA supplementation on offspring’s brain lipid metabolism and long-term neurologic outcome are needed to confirm these findings.

Aurantiochytriumsp. meal as DHA source in Nile tilapia diet, part II: Body fatty acid retention and muscle fatty acid profile

Nile tilapia juveniles (8.35 ± 0.80 g) were fed on four levels (0.0%; 0.5%; 1.0%; 2.0%, 4.0%) of Aurantiochytrium sp. meal (ALL-G-RICH™), a source of docosahexaenoic acid (DHA). The 1% Aurantiochytrium sp. meal diet was compared to a control diet, which contained the same amount of DHA as cod liver oil (CLO) at 1.7% diet. Groups of 25 fish were stocked in 100 L tanks and fed twice daily until apparent satiation, for 57 days, at 28°C. Increasing dietary Aurantiochytrium sp. meal reduced the body retention of DHA and n-3 polyunsaturated fatty acids (n-3 PUFA) but increased the body retention of alpha-linolenic (α-LNA), linoleic (LOA) and n-6 polyunsaturated fatty acids (n-6 PUFA). Fatty acid profile in tilapia muscle was affected by increasing dietary inclusions of Aurantiochytrium sp. meal, with an increase in DHA, α-LNA, n-3 PUFA and n-3 long chain-polyunsaturated fatty acids (n-3 LC-PUFA) but a decrease in monounsaturated fatty acids (MUFA), n-6 PUFA and n-6 long-chain polyunsaturated fatty acids (n-6 LC-PUFA). There was a larger body retention of DHA, α-LNA, LOA, n-3 PUFA and n-6 PUFA fatty acids and a higher percentage of DHA, n-3 PUFA and n-3 LC-PUFA in muscle fatty acid profile in fish fed on CLO diets than in those fed on 1% Aurantiochytrium sp. Therefore, Aurantiochytrium sp. meal is an alternative source of DHA for Nile tilapia diets.

Fatty acid influence onProchilodus lineatus(Characiformes, Prochilodontidae) embryo cryopreservation parameters.

This study aimed to evaluate the vitellogenic transference and incorporation of long-chain polyunsaturated fatty acids (LC-PUFA) into the membranes of Prochilodus lineatus embryos, aiming to increase the permeability to cryoprotectants and resistance to electric fields. One hundred thirty broodstock of P. lineatus were fed with control (C) or fish oil-supplemented diets (FO) for 12 months. The fatty acid (FA) profle was determined using gas chromatography. For the neutral fraction, the FO group had a decrease in monounsaturated fatty acids (MUFA) and an increase in n3PUFA and, n6PUFA. To test for cryoprotectant toxicity, embryos were exposed for 20 min to a cryoprotectant solution of 1,2-Propanediol (Prop) at a concentration of 5 or 6 molar (M). For FO, a reduction in survival of 33.1% was observed in 5 M, and no survival was observed at 6 M. Embryo samples were exposed the six polarized electric fields (3.4–51.6 joules), and with 11.2 J of energy, the control group exhibited reduced survival in 98.3% of the fish, whereas the FO presented superior resistance, exhibiting a survival similar to that of the OJ up to 40.2 J. We conclude that FA were transferred between P. lineatus broodstock to the embryos, with an increase in LC-PUFA resulting in lower survival rates in the cryoprotectant test in the FO group and a greater physical plasticity of FO embryos to electrical field tests.

Lipidomic Impacts of an Obesogenic Diet Upon Lewis Lung Carcinoma in Mice.

Metabolic reprogramming of lipid metabolism is a hallmark of cancer. Consumption of a high-fat obesogenic diet enhances spontaneous metastasis using a Lewis lung carcinoma (LLC) model. In order to gain further insights into the mechanisms by which dietary fats impact cancer progression, we conducted a lipidomic analysis of primary tumors originated from LLC from mice fed with a standard AIN93G diet or a soybean oil-based high-fat diet (HFD). Hierarchical clustering heatmap analysis of phosphatidylcholine (PC) lipids and phosphatidylethanolamine (PE) lipids demonstrated an increase in polyunsaturated fatty acids (PUFA)-containing phospholipids and a decrease in monounsaturated fatty acids (MUFA)-containing lipids in tumors from mice fed the HFD. The quantities of 51 PC and 24 PE lipids differed in primary tumors of LLC from mice fed the control diet and the HFD. Analysis of triacylglycerol (TAG) lipids identified differences in 32 TAG (by brutto structure) between the two groups; TAG analysis by neutral loss identified 46 PUFA-containing TAG species that were higher in mice fed with the HFD than in the controls. Intake of the HFD did not alter the expression of the de novo lipogenesis enzymes (fatty acid synthase, acetyl-CoA carboxylase-1, and stearoyl-CoA desaturase-1). Our results demonstrate that the dietary fatty acid composition of the HFD is reflected in the higher order lipidomic composition of primary tumors. Subsequent studies are needed to investigate how these lipidomic changes may be used for targeted dietary intervention to reduce tumor growth and malignant progression.

Heat shock influences the fatty acid composition of the muscle of the Antarctic fish Trematomus bernacchii

In the Ross Sea region (average temperature of −1.87 °C), shelf water warming up to +0.8-+1.4 °C is predicted by 2200, so there is an urgent need to understand how organisms can respond to rising temperatures. In this study, we analyzed the effect of a heat shock on the fatty acid (FAs) composition of muscle of the Antarctic teleost Trematomus bernacchii, caught in Terra Nova Bay (Ross Sea), and held in fish tanks at 0, +1 or +2 °C, for 1, 5 and 10 days. In general, heat shock produced, beyond a reduction in total lipid content correlated to the temperature, an increase in the percentage of saturated FAs, and a decrease in mono-unsaturated FAs; however, the level of poly-unsaturated FAs did not seem to directly correlate with temperature. Principal component analysis indicated that both temperature and exposure time affect the composition of FAs in the muscle probably through an alteration of the metabolic pathways of FAs. In this study, we demonstrated that T. bernacchii was capable to rapidly acclimatize to a heat shock. This study contributes to increasing knowledge on the effect of temperature on the lipid composition of T. bernacchii and is complementary to previous studies on the gene expression and biochemistry of this species face multiple stressors.

Gas chromatography–mass spectrometry analysis on effects of thermal shock on the fatty acid composition of the gills of the Antarctic teleost, Trematomus bernacchii

Environmental contextGlobal warming is an important problem for life on Earth, and there is an increasing need to understand how organisms respond to rising temperatures. We show that an Antarctic fish, the emerald rockcod, can acclimate to thermal shock by modifying the fatty acid composition and total lipid content in its gills. This study contributes to our understanding of how the physiology of Antarctic life could be influenced by climate change. AbstractAs a result of rising temperatures in the Antarctic seawater, there is an increasing interest to investigate the capacities for inducing a temperature acclimation response in Antarctic organisms. We analysed the effect of a thermal shock on the fatty acid (FA) composition of gills of the Antarctic notothenioid Trematomus bernacchii. To perform the quantification of fatty acids in gills, we applied an analytical method based on a fast microwave-assisted extraction (MAE) of lipids from a lyophilised sample, a base-catalysed trans-esterification of lipid extract to obtain fatty acid methyl esters (FAMEs), and their separation and identification by gas chromatography–mass spectrometry. The percentage of lipids extracted with MAE preceded by sample lyophilisation, 0.6 ± 0.3 % ww (wet weight), was consistent with the lipids obtained by the official Bligh and Dyer method, 0.8 ± 0.3 % ww. These data are among the first ever published for T. bernacchii. Specimens, caught in Terra Nova Bay (Ross Sea), were held in different tanks at 0, +1 and +2 °C, for 1, 5 and 10 days. In general, thermal shock produced an alteration in total lipid content, an increase in the percentage of saturated FAs, a decrease in mono-unsaturated FAs, and a variable response of poly-unsaturated FAs (an increase in specimens exposed to 0 and +1 °C, a decrease in those exposed to +2 °C). A chemometric approach based on principal component analysis indicated that temperature and exposure time influenced the composition of FAs in the gills, probably through an alteration of the metabolic pathways of FAs. This is the first study ever published on the FA composition of total lipids in gills of T. bernacchii exposed to high temperatures. This study demonstrates that T. bernacchii is capable of rapidly acclimating to a thermal shock, and contributes to increasing the knowledge on the effect of temperature on Antarctic notothenioids.

Effect of dietary kapok oil supplementation on growth performance, carcass traits, meat quality and sensory traits of pork in finishing-pigs.

Kapok seed and oil from the tropical zone are widely used as pig feed to harden porcine fat in Japan. This study evaluated the effect of dietary kapok oil supplementation on pork quality and sensory traits. Five Duroc pigs each were assigned to an experimental group supplemented with kapok oil and a control group. Dietary kapok oil supplementation had no effect on growth performance and intramuscular fat content in the Longissimus dorsi muscle (LM). Supplemental kapok oil increased saturated fatty acid contents in subcutaneous and intramuscular fat and decreased monounsaturated fatty acid levels (P<0.05). Off-flavor detection by a trained panel was higher in the experimental than the control group (P<0.05), but tenderness, juiciness, texture and flavor intensity of LM chops were similar in both groups. The overall palatability of pork as judged by a consumer panel decreased with kapok oil supplementation (P<0.01). These results indicate that while growth performance, intramuscular fat contents and carcass characteristics were unchanged, while dietary kapok oil supplementation makes firm fat to prevent inferior soft fat in pork, it can lower the palatability of pork due to a decrease in monounsaturated fatty acids.

Fatty Acid Profiles and Volatile Compounds Formation During Processing and Ripening of a Traditional Salted Dry Fish Product

The present research aimed to investigate the chemical changes and volatiles formation during processing and ripening of a traditional dry salted fish product prepared from landlocked shad (Alosa fallax lacustris). Proximate and fatty acid composition, thiobarbituric acid reactive substances (TBARS) values, color measurements and volatile compounds were determined in fresh fish and salted samples at 9, 40, 70 and 100 days of maturation. The fatty acid composition changed during ripening, with significant increase of saturated fatty acids and decrease of monounsaturated fatty acids. The total concentration of volatile compounds increased rapidly from fresh fish to dried product, with a maximum peak in correspondence to the drying step. The TBARS values increased from 0.76 μg/g in fresh fish to 10.95 μg/g in dry fish. Lipolytic and proteolytic reactions occurring in salted product, exacerbated by the presence of high amount of salt and ambient ripening temperature, contributed to the development of typical flavors. Practical Applications In Europe there is a growing interest in traditional fish products derived from local species and prepared with ancient recipes. Shad is one of the major species harvested in subalpine lakes and most of captured fish are traditionally subjected to an artisanal processing procedure, to give a dried fish product that is commercialized with the historic name of missoltino. This study describes the quality changes of prepared shad during processing and ripening. The appropriate combination of salt, drying and ripening conditions allows to obtain a product with optimal chemical and sensory properties. This study aims to provide the fish producers with improved criterions to traditional practices, in order to standardize the process and to obtain higher quality product for consumers. Moreover, these results represent a basis for product valorization and could contribute to a better consideration of the product on the market.