Effects Of Different Fatty Acids Research Articles

Comparative study on the transcriptional activities of grass carp (Ctenopharyngodon idellus) peroxisome proliferator-activated receptors induced by different fatty acids

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that are part of the nuclear hormone receptor family, playing a crucial role in gene expression regulation. They serve as a connection between lipid metabolism disorders and innate immunity by being activated by fatty acids and their derivatives, facilitating signal transduction between the cell surface and nucleus. However, the specific transcriptional effects of different fatty acids (FAs) in fish are not yet fully understood. In our research, we identified and characterized PPARs in grass carp (Ctenopharyngodon idellus). The complete coding sequences of pparαa, pparαb, pparγ, pparδa, and pparδb were 1443 bp, 1404 bp, 1569 bp, 1551 bp, and 1560 bp in length, respectively. Pparα showed the highest expression in the liver, pparγ was mainly expressed in abdominal adipose tissue, and pparδ exhibited increased expression in the heart compared to other tissues. Gene localization analysis revealed that only pparδa was present in both the nucleus and cytoplasm, while the other four genes were exclusively located in the nucleus. Furthermore, our study explored the influence of various fatty acids (docosahexaenoic acid, palmitic acid, lauric acid and oleic acid at concentrations of 0, 50, 100, and 200 μM) on the transcriptional activities of different PPARs, demonstrating the diverse effects of fatty acid ligands on PPAR transcriptional activity. These results have significant implications for understanding the regulation of PPARs transcriptional activity.

Abstract 5411: Effect of different fatty acids on ccRCC behavior and metabolism

Abstract Introduction: Clear Cell Renal Cell Carcinoma (ccRCC) is the most common type of kidney cancer, presenting with defining characteristics of increased lipid droplets formation, loss of the VHL tumor suppressor, and low levels of fatty acid oxidation (FAO). Obesity is associated with an increase in ccRCC incidence, although obese patients respond better to different therapies, a phenomenon called as obesity paradox. The consumption of diets rich in lipids and leading to obesity has been increasing, but how the dietary composition affects ccRCC progression, or could be modulated in combination with other therapies for better responses is still unclear. In the present study, we aimed to evaluate how different fatty acids (FAs) affect ccRCC behavior and metabolism. Methods: We used 786-O and 769-P ccRCC cell lines. Palmitic acid (PA), oleic acid (OA), and linoleic acid (LA), which are saturated, monounsaturated, and polyunsaturated fatty acids, respectively were used as stimuli for the cells at 50 or 200µM. All stimuli were diluted in culture media with 5% FBS. Lipid droplets were evaluated by Oil Red O staining; viability was assessed by MTT; protein expression was tested by Western Blotting; Oxygen Consumption rate (OCR) by Seahorse; survival was quantified by clonogenic assay; and mRNA was measured by RT-qPCR. Results: All FAs increased the amount of lipid droplets compared to the control, but OA was the most potent. PA impaired the growth rate for cells compared to control, and other FAs in both cell lines, and did not increase the expression of cleaved caspase-3. PA, even in a lower concentration [50µM], impaired the formation of colonies for both cell lines compared to control and other FAs. LA impaired colony formation only in the higher concentration [200µM], while OA only induced a difference for 769-P cells at the smaller concentration, increasing the number of colonies. OA, and mainly PA, decreased 769-P cells migration, at the time of 6 and 12 h, while only PA decreased migration for 786-O cells, at the time of 12 h. LA, and mainly PA, increased CPT1a mRNA levels in 786-O cells but did not induce a significant difference to 769-P, and all FAs decreased FASN in both cell lines. Conclusion: It was demonstrated that OA was a potent inducer of lipid droplet formation, which can be protective in avoiding lipid peroxidation. On the other hand, PA and LA induced fewer lipid droplets probably because they are going to FAO, as we observed increased mRNA CPT1a levels, which is the rate-limiting enzyme in FAO. PA impaired potentially the formation of colonies and growth rate, and it is important to highlight that it was without inducing caspase 3-dependent programmed cell death. Taken together our data suggest that PA could be a target therapy for ccRCC, but it is still necessary for more studies in vitro and in vivo to evaluate how PA and enriched lipid diet can impact a better outcome for patients. Citation Format: Isadora Ramos de Andrade, Dazhi Wang, Scott Welford. Effect of different fatty acids on ccRCC behavior and metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5411.

The effects of different fatty acids on nesfatin-1, omentin-1, adropin, leptin and ghrelin levels

There are many studies on nesfatin-1, omentin, adropin, leptin, and ghrelin. However, data on the effects of long, medium, and short chain fatty acids on serum/tissue concentrations of nesfatin-1, omentin, adropin, leptin, and ghrelin are scarce. This study aims to investigate the effects of butyric acid, caprylic acid, and oleic acid alone or in combination on nesfatin-1, omentin, adropin, leptin, and ghrelin secretion. In the study, 49 male Wistar rats were used. The rats were randomly divided into 7 groups as control (CONT), butyric acid (BA), caprylic acid (CA), oleic acid (OA), butyric acid+caprylic acid (BA+CA), butyric acid+oleic acid (BA+OA) and caprylic acid+oleic acid (CA+OA) groups. The rats were orally administered fatty acids for twenty-one days. At the end of the study, the levels of nesfatin-1, omentin, adropin, leptin, and ghrelin were determined by the ELISA method. When the groups were compared in terms of nesfatin-1, omentin, adropin, leptin, and ghrelin levels, the butyric acid group had higher nesfatin-1, omentin, adropin, leptin, and ghrelin levels than the other groups (p<0.05). No statistically significant difference was found in the other groups (p>0.05). In conclusion, it was observed that butyric acid use caused an increase in serum nesfatin-1, omentin, adropin, leptin, and ghrelin levels.

Effects of Different Fatty Acids as Surfactants on the Rheological Properties of Kerosene-Based Magnetic Fluids

Three types of surfactants (oleic acid, linoleic acid, and a mixture of oleic acid and linoleic acid) were coated on ferromagnetic particles, which were dispersed in kerosene to prepare magnetic fluids, to study the effect of different fatty acids as surfactants on the rheological properties of magnetic fluids. The particles were analyzed by XRD, TEM, FT-IR, and VSM. Furthermore, a rheometer was used to examine the rheological properties of kerosene-based magnetic fluids dispersed with various surfactants. The yield stress at different magnetic fields was calculated by fitting the Herschel–Bulkley model. The fitted curve and the observed values of mixed fatty acids are identical. The graphs of viscosity increase with the shear rate for each magnetic fluid were measured at constant magnetic field strengths. At constant shear rates, the curves of viscosity increase with magnetic field intensity were measured. In the absence of a magnetic field, the relative change in viscosity from 40°C to 0°C was observed. The rheological measurements of the mixed fatty acid-dispersed ferrofluid with a rising magnetic field at a constant shear rate are smoother than the single-fatty-acid-dispersed ferrofluid, indicating that it is more stable. As the temperature is dropped, the viscosity–temperature curve evidence that mixed fatty acids as surfactants can lower the proportion of magnetic fluid viscosity rise.

New insights in the understanding of TREK-1 channel activation by fatty acids

Among the two-pore domain K+ channels (K2P), TREK-1 channel is one of the most studied K2P channel members due to its involvement in cardio- and neuroprotection but it suffers from a poor specific pharmacological profile. TREK-1 channel is polymodulated by voltage, pH changes, membrane stretch and polyunsaturated fatty acids (PUFAs) and generates an outwardly rectifying current. The PUFAs-mediated activation is supposedly correlated to the length of the carbon chain suggesting a link between FAs membrane insertion and a stretch effect through an increase of membrane tension. The aim of this study is to test the effects of different fatty acids, especially polyunsaturated fatty acids, to delineate a possible mechanism of action to explain the activation of ITREK-1. In this study, using the patch-clamp technique in ruptured whole-cell configuration, we compared the effects of FAs, from stearic acid (C18:0, 18 carbons; 0 double bound) to docosahexaenoic acid (C22:6, 22 carbons; 6 double bounds) on ITREK-1 in a HEK293 cell line overexpressing the human TREK-1 channel. C18:0 and C18:3 failed to activate ITREK-1. Surprisingly, it was the shortest PUFA, linoleic acid (LA C18:2) that produced the largest activated ITREK-1. At 0 mV, ITREK-1 was increased 32.4 ± 5.4 folds by LA (C18:2); DHA(C22:6): 29.7 ± 4.1 and AA(C20:4): 14.7 ± 1.9. Since the activation kinetic was fast (in the range of 1.5 min) and the reversibility immediate when FA solution was washed, we supposed that FAs interact directly with TREK-1 rather than FAs membrane insertion changing membrane tension. Some FAs linearized the current-voltage relationship with a calculated linearization index (LI) greater than 0.9, for C18:2, C22:5w6, C22:6, while the rectifier current was maintained for C20:5, C20:4, C20:5, C22:5w3 FAs (LI < 0.75). We propose that the observed linearization results from an activation process involving a K + -flux gating mechanism. Taken together, all these data suggest that the activation of TREK-1 by PUFAs is not a consequence of change in membrane tension but rather more complex than previously assumed. A better understanding of the TREK-1 channels activation mechanisms will help to develop more efficient activators in the perspective of a use to protect the heart following an infarction.

Effect of different fatty acids on the proliferation and cytokine production of dairy cow peripheral blood mononuclear cells

During the transition period, dairy cows often experience negative energy balance, which induces metabolic and immunological disturbances. Our previous work has shown a relationship between the inhibition of immune functions and increased blood nonesterified fatty acid (NEFA) levels. In this study, we evaluated the effect of 11 fatty acids (palmitoleic, myristic, palmitic, stearic, oleic, linoleic, docosahexaenoic, conjugated linoleic, lauric, eicosapentaenoic, and linolenic acids) as well as a mix that represented the NEFA profile observed during the transition period at different concentrations (0, 50, 100, and 250 µM) on proliferation and cytokines secretion of lymphocytes. To assess lymphoproliferation, peripheral blood mononuclear cell (PBMC) from 5 healthy cows (166-189 d in milk) were isolated, stimulated with the mitogenic lectin concanavalin A (ConA), incubated for 72 h with or without fatty acids, and subjected to flow cytometry analysis. Our results showed that all fatty acids, except lauric acid, significantly reduced proliferation of PBMC in a dose-dependent manner. The most detrimental effect was observed with conjugated linoleic and stearic acids, where proliferation of PBMC was already inhibited at the lowest dose (50 µM). For cytokine secretion, we found that levels of IL-4 in culture supernatant of ConA-stimulated PBMC were reduced after a 24-h exposure to the lowest dose (50 µM) of oleic and palmitoleic acids. A dose of 100 µM of eicosapentaenoic acid, NEFA mixture, and myristic acid was necessary to observe a reduction in IL-4 levels. The PBMC also showed a decrease in the secretion of IFN-γ in response to lauric, linolenic, palmitoleic, and stearic acids at 50 µM and myristic acid at 100 µM. Overall, polyunsaturated fatty acids were more potent inhibitors of cytokine secretions than saturated fatty acids. In addition, we detected an inverse relationship between the melting points of fatty acids and their ability to inhibit IL-4 and IFN-γ secretions, as evidenced by greater inhibition with low-melting point fatty acids. Overall, our study confirmed that NEFA have a negative effect on some lymphocyte functions, and that their inhibitory effect on cytokine secretions increases with the degree of unsaturation.

Label-free Raman mapping of saturated and unsaturated fatty acid uptake, storage, and return toward baseline levels in macrophages.

Macrophage uptake and metabolism of fatty acids is involved in a large number of important biological pathways including immune activation and regulation of macrophages, as well as pathological conditions including obesity, atherosclerosis, and others lifestyle diseases. There are few methods available to directly probe both the uptake and later redistribution/metabolism of fatty acids within living cells as well as the potential changes induced within the cells themselves. We use Raman imaging and analysis to evaluate the effects of different fatty acids following their uptake in macrophages. The label-free nature of the methods means that we can evaluate the fatty acid dynamics without modifying endogenous cellular behavior and metabolism.

Effects of different fatty acids on BRL3A rat liver cell damage.

To evaluate the effects of fatty acids on endoplasmic reticulum (ER) stress, oxidative stress, and lipid damage. We treated BRL3A rat liver cells with, linoleic (LA), linolenic, oleic (OA), palmitic (PA), palmitoleic (POA), or stearic (SA) acid for 12 hr. The characteristics of cell lipid deposition, oxidative stress indexes, ER stress markers, nuclear factor κB p65 (NF-κB p65), lipid synthesis and transport regulators, and cholesterol metabolism regulators were analyzed. Endoplasmic chaperones like glucose-regulated protein 78, CCAAT-enhancer-binding protein, NF-κB p65, hydrogen peroxide, and malonaldehyde in PA- and SA-treated cells were significantly higher than in other treated cells. Deposition of fatty acids especially LA and POA were significantly increased than in other treated cells. De novo lipogenesis regulators sterol regulatory element-binding protein 1c, fatty acid synthase, and acetyl-coenzyme A carboxylase 1 (ACC1) expression were significantly increased in all fatty acid stimulation groups, and PA- and SA-treated cells showed lower p-ACC1 expression and higher scd1 expression than other fatty acid groups. Very low-density lipoprotein synthesis and apolipoprotein B100 expression in free fatty acids treated cells were significantly lower than control. PA, SA, OA, and POA had shownsignificantly increased cholesterol synthesis than other treated cells. PA and SA showed the lower synthesis of cytochrome P7A1 and total bile acids than other fatty acids treated cells. Excess of saturated fatty acids led to severe ER and oxidative stress. Excess unsaturated fatty acids led to increased lipid deposition in cultured hepatocytes. A balanced fatty acid intake is needed to maintain lipid homeostasis.

The association of plasma fatty acids levels with hand and knee osteoarthritis

Purpose: Obesity is one of the most important risk factors for osteoarthritis (OA). In addition to increased mechanical loading, systemic factors also likely play a role. Nutrient excess leading to obesity may result in lipotoxicity, with increased levels of circulating fatty acids. However, our knowledge about the effect of different fatty acids on OA is sparse. Therefore, we aimed to investigate the association of plasma saturated fatty acids (SFAs), monounsaturated fatty acid (MUFAs), polyunsaturated fatty acids (PUFAs), omega (n-)3 and n-6 PUFAs on clinically defined hand and knee OA. Since we are in a postprandial state most of the day, both fasting and postprandial samples after a standardized mixed meal were used for the association analyses. Methods: In the population-based Netherlands Epidemiology of Obesity (NEO) study, a total of 6,671 middle-aged participants were recruited from the greater area of Leiden. Clinical hand and knee OA were defined by the ACR clinical classification criteria. Blood samples were obtained after an overnight fast and 150 minutes after consumption of a standardized liquid mixed meal containing 600kCal, with 16% of energy (En%) derived from protein, 50 En% from carbohydrates and 34 En% from fat. EDTA-plasma samples were used for a high-throughput proton nuclear magnetic resonance (NMR) metabolomics platform (Nightingale Health Ltd., Helsinki, Finland) to quantify 159 lipid and metabolite measures. For the present analyses the concentrations of fasting and postprandial total fatty acids, SFAs, MUFAs, PUFAs, n-6 PUFAs and n-3 PUFAs in mmol/l were used. We excluded participants who reported to have inflammatory rheumatic disease or fibromyalgia, with missing physical examination, who were non-fasting at baseline, or reported using lipid-lowering medication. Logistic regression analyses were used to investigate the association between fatty acids and clinical OA phenotypes. All analyses were stratified by sex and corrected for age, education, ethnicity and total body fat percentage. Data are presented as odds ratios (OR) with 95% confidence intervals (CI). Results: In the current analysis 5,328 NEO participants were included, with a mean age of 56 years and 58% were women. Hand OA, knee OA and concurrent hand and knee OA were defined in 8%, 10% and 4%, respectively. After correction for possible confounders, SFA, total PUFA and omega-3 PUFA levels were positively associated with clinical hand OA in men, with OR (95% CI) of 1.26 (1.00 - 1.57), 1.35 (1.00 - 1.82) and 5.27 (1.07 - 25.96) respectively. In women, these associations were not found; however, although not significant, the OR of omega-3 PUFAs and hand OA was 2.49 (0.45 - 13.72). None of the postprandial fatty acid subtypes were statistically significantly associated with knee or concurrent hand and knee OA in both men and women. In comparison, although not significant, results from the analyses with fasting fatty acids showed similar albeit slightly dampened effect estimates. Conclusions: Quantitively measured plasma postprandial SFA and omega-3 PUFA levels were significantly associated with hand OA in men. In women no significant associations were found, however the estimated effect was comparable to the results in men. Intriguingly, although SFA and omega-3 PUFAs are deemed to have opposing effects on inflammation, both were positively associated with hand OA. No significant associations were found between fatty acids and knee and concurrent hand and knee OA. Future research is warranted to replicate the association and determine whether there is a causal role for plasma fatty acid levels in hand OA.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Tea Seed Oil Prevents Obesity, Reduces Physical Fatigue, and Improves Exercise Performance in High-Fat-Diet-Induced Obese Ovariectomized Mice.

Menopause is associated with changes in body composition (a decline in lean body mass and an increase in total fat mass), leading to an increased risk of metabolic syndrome, nonalcoholic fatty liver disease, and heart disease. A healthy diet to control body weight is an effective strategy for preventing and treating menopause-related metabolic syndromes. In the present study, we investigated the effect of long-term feeding of edible oils (soybean oil (SO), tea seed oil (TO), and lard oil (LO)) on female ovariectomized (OVX) mice. SO, TO, and LO comprise mainly polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), and saturated fatty acids (SFA), respectively. However, there have been quite limited studies to investigate the effects of different fatty acids (PUFA, MUFA, and SFA) on physiological adaption and metabolic homeostasis in a menopausal population. In this study, 7-week-old female Institute of Cancer Research (ICR) mice underwent either bilateral laparotomy (sham group, n = 8) or bilateral oophorectomy (OVX groups, n = 24). The OVX mice given a high-fat diet (HFD) were randomly divided into three groups: OVX+SO, OVX+TO, and OVX+LO. An HFD rich in SO, TO, or LO was given to the OVX mice for 12 weeks. Our findings revealed that the body weight and relative tissues of UFP (uterus fatty peripheral) and total fat (TF) were significantly decreased in the OVX+TO group compared with those in the OVX+SO and OVX+LO groups. However, no significant difference in body weight or in the relative tissues of UFP and TF was noted among the OVX+SO and OVX+LO groups. Furthermore, mice given an HFD rich in TO exhibited significantly decreased accumulation of liver lipid droplets and adipocyte sizes of UFP and brown adipose tissue (BAT) compared with those given an HFD rich in SO or LO. Moreover, replacing SO or LO with TO significantly increased oral glucose tolerance. Additionally, TO improved endurance performance and exhibited antifatigue activity by lowering ammonia, blood urea nitrogen, and creatine kinase levels. Thus, tea seed oil (TO) rich in MUFA could prevent obesity, reduce physical fatigue, and improve exercise performance compared with either SO (PUFA)- or LO(SFA)-rich diets in this HFD-induced obese OVX mice model.

Enzymatic epoxidation of soybean oil in the presence of perbutyric acid

Enzymatic epoxidation of vegetable oils using a long chain fatty acid as an active oxygen carrier could produce a desirable epoxy oxygen group content (EOC); however, the acid value (AV) of final epoxidized oil is too high. The present study was to investigate the effect of different fatty acids with varying length of carbon chain on EOC and AV of the final epoxidized soybean oil (ESO); finding butyric acid was the choice of active oxygen carrier when hydrogen peroxide was used as an oxygen donor in the presence of lipase Novozyme 435. And in situ IR was used to monitor the epoxidation process, which revealed that the formation of perbutyric acid was the key step in the whole reaction. The epoxidation process was optimized as follows: molar ratio of butyric acid/C=C bonds of 0.19:1, 8% of immobilized lipase Novozyme 435 load (relative to the weight of soybean oil) and molar ratio of H2O2/C=C bonds of 3.5:1, reaction time of 4 h and reaction temperature of 45 °C. Under these conditions, ESO with a high EOC (7.62 ± 0.20%) and a lower AV value (8.53 ± 0.18 mgKOH/g) was obtained. The oxriane conversion degree was up to 97.94%.

Prediction of milk fatty acid content with mid-infrared spectroscopy in Canadian dairy cattle using differently distributed model development sets

The fatty acid profile of milk is a prevailing issue due to the potential negative or positive effects of different fatty acids to human health and nutrition. Mid-infrared spectroscopy can be used to obtain predictions of otherwise costly fatty acid phenotypes in a widespread and rapid manner. The objective of this study was to evaluate the prediction of fatty acid content for the Canadian dairy cattle population from mid-infrared spectral data and to compare the results produced by altering the partial least squares (PLS) model development set used. The PLS model development sets used to develop the predictions were reference fatty acids expressed as (1) grams per 100 g of fatty acid, (2) grams per 100 g of milk, (3) the natural logarithmic transform of grams per 100 g of milk, and (4) subsets of samples randomly selected by removing excess records around the mean to present a more uniform distribution, repeated 10 times. Gas chromatography measured fatty acid concentration and spectral data for 2,023 milk samples of 373 cows from 4 breeds and 44 herds were used in the model development. The coefficient of determination of cross-validation (Rcv2) increased when fatty acids were expressed on a per 100 g of milk basis compared with on a per 100 g of fat basis for all examined fatty acids. The logarithmic transformation used to create a more Gaussian distribution in the development set had little effect on the prediction accuracy. The individual fatty acids C12:0, C14:0, C16:0, C18:0, C18:1n-9 cis, and saturated, monounsaturated, unsaturated, short-chain, medium-chain, and long-chain fatty acid groups had (Rcv2) greater than 0.70. When model development was performed with subsets of the original samples, slight increases in (Rcv2) values were observed for the majority of fatty acids. The difference in (Rcv2) between the top- and bottom-performing prediction equation across the different subsets for a single predicted fatty acid was on average 0.055 depending on which samples were randomly selected to be used in the PLS model development set. Predictions for fatty acids with high accuracies can be used to monitor fatty acid contents for cows in milk recording programs and possibly for genetic evaluation.

The pro-/anti-inflammatory effects of different fatty acids on visceral adipocytes are partially mediated by GPR120

This study examines whether G-protein coupled receptor 120 (GPR120) is involved in the pro-/anti-inflammatory effects of different types of fatty acids (FAs) in human visceral adipocytes, and whether these effects may be altered in obesity, a state with a chronic inflammation. Pro-/anti-inflammatory effects of palmitic, oleic, linoleic and docosahexaenoic acids on human visceral adipocytes were tested in mature adipocytes from non-obese and morbidly obese (MO) subjects. Also, the effects of these FAs were tested when the GPR120 gene was silenced. In adipocytes from non-obese subjects, palmitic and linoleic acids increased TNF-α and IL-6 mRNA expression (p<0.05), and decreased IL-10 and adiponectin expression (p<0.05). However, oleic and docosahexaenoic acids (DHA) produced the opposite effect (p<0.05). In adipocytes from MO subjects, all FAs used increased TNF-α and IL-6 expression (p<0.05). Palmitic and linoleic acids decreased IL-10 and adiponectin expression (p<0.05), but oleic acid and DHA did not have significant effects. Only oleic acid increased adiponectin expression (p<0.05). The effects of FAs on TNF-α, IL-6, IL-10 and adiponectin expression in non-obese and MO subjects were significantly annulled when the GPR120 gene was silenced in visceral adipocytes differentiated from human mesenchymal stem cells. FAs are capable of directly acting on visceral adipocytes to modulate differently TNF-α, IL-6, IL-10 and adiponectin expression, with a different and greater effect in MO subjects. These effects are largely annulled when GPR120 expression was silenced, which suggests that they could be mediated by GPR120.

Fatty acids increase adiponectin secretion through both classical and exosome pathways

Little is known about the effects of fatty acids on adiponectin oligomer assembly and trafficking. The aim of this study was to examine the effects of different fatty acids on adiponectin transport and secretion in differentiated 3T3-L1 adipocytes. Subcellular fractionation and immunofluorescence microscopy revealed that the majority of cellular adiponectin was located in the endoplasmic reticulum (ER). Adiponectin secretion was increased by treatment with fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and several fatty acids changed the cellular localization of adiponectin. Adiponectin secretion has been shown to be altered by ER stress and interactions with ER chaperone proteins. However these mechanisms were not influenced by fatty acids, suggesting that alternative mechanisms must be responsible for the increased secretion of adiponectin observed with fatty acid treatment. Secretion of adiponectin was blocked by Brefeldin A, but we identified a minor pool of adiponectin that could be secreted from beyond the Brefeldin A block. Exosomes appeared to contribute to a minor amount of adiponectin secreted from the cell, and exosome release was increased by treatment with DHA. These data suggest that the ER is an important site of adiponectin accumulation and that treatment with long chain omega-3 fatty acids increases adiponectin release. Furthermore, the secretory pathway of adiponectin is complex, involving both the classical ER–Golgi pathway as well as unconventional secretory mechanisms such as an exosome-mediated pathway.

Modulation of adrenocorticotrophin hormone (ACTH)-induced expression of stress-related genes by PUFA in inter-renal cells from European sea bass (Dicentrarchus labrax).

Dietary fatty acids have been shown to exert a clear effect on the stress response, modulating the release of cortisol. The role of fatty acids on the expression of steroidogenic genes has been described in mammals, but little is known in fish. The effect of different fatty acids on the release of cortisol and expression of stress-related genes of European sea bass (Dicentrarchus labrax) head kidney, induced by a pulse of adenocorticotrophin hormone (ACTH), was studied. Tissue was maintained in superfusion with 60 min of incubation with EPA, DHA, arachidonic acid (ARA), linoleic acid or α-linolenic acid (ALA) during 490 min. Cortisol was measured by RIA. The quantification of stress-related genes transcripts was conducted by One-Step TaqMan real-time RT-PCR. There was an effect of the type of fatty acid on the ACTH-induced release of cortisol, values from ALA treatment being elevated within all of the experimental period. The expression of some steroidogenic genes, such as the steroidogenic acute regulatory protein (StAR) and c-fos, were affected by fatty acids, ALA increasing the expression of StAR after 1 h of ACTH stimulation whereas DHA, ARA and ALA increased the expression of c-fos after 20 min. ARA increased expression of the 11β-hydroxylase gene. Expression of heat shock protein 70 (HSP70) was increased in all the experimental treatments except for ARA. Results corroborate previous studies of the effect of different fatty acids on the release of cortisol in marine fish and demonstrate that those effects are mediated by alteration of the expression of steroidogenic genes.

The Bodysmart Detective Agency—Engaging young children in lifestyle education and behaviour change theory

of different fatty acid containing meals on appetite parameters. Methods: Nine normoglycaemic overweight or obese individuals (BMI 32± 1.2 kg/m2) randomly completed 4 weekly, single-blinded, fasting breakfast challenges. Meals consisted of toasted bread, jam and varying oils, resulting in control, and high lauric, oleic and linoleic acid meals. All meals provided 30% of EER. Appetite parameters were assessed immediately before consumption and 2 h postprandially with visual analogue scale questionnaires. Results: All meals resulted in decreased hunger and increased fullness, though appetite responses did not differ between meals. The lauric and linoleic acid meals decreased postprandial desire to eat. The linoleic and oleic acid meals did not decrease postprandial prospective food intake, whereas the control and lauric acid meals did. Discussion: Each lauric acid meal contained on average 14 g of lauric acid, which has been found to dose-dependently decrease gastric emptying, a likely cause of the postprandial increase in perception of fullness, and decrease in perception of hunger, desire to eat, and prospective food intake. This effect on appetite has been found to be greater than that of oleic acid at the same loading, in line with the findings of this study. Oleic acid may not have affected postprandial desire to eat and prospective food intake possibly due to its decreased ability to modulate appetite in the obese state. Current Australian diets are rich in highlinoleic acid plant-derived fats. Intriguingly, the high linoleic acid meal did not decrease postprandial prospective food intake, which may increase energy consumption at the subsequent meal, influencing obesity risk. The effect of different fatty acids on appetite in obese individuals requires further investigation.

Effects of different fat mixtures on milk fatty acid composition and oxidative stability of milk fat

The experiment was carried out to determine effects of different fatty acids (FA) mixtures on milk FA composition and milk fat oxidation change. Thirty-six dairy cows were used in a completed design experiment for 8 weeks. Cows were fed one of three lipid supplements (1) short- and medium-chain fatty acids (SMCFA), (2) butterfat, and (3) long-chain fatty acids (LCFA). Data were analyzed using MIXED procedure of SAS. Daily dry matter intake (DMI), milk yield, and milk protein, total solids (TS), lactose, free fatty acids (FFA) content were unaffected among 3 treatments, whereas milk fat concentration was decreased (P<0.05) as carbon chain length increased in supplement lipid. Relative to SMCFA, 12:0, 14:0 and 16:0 concentrations in milk fat from cows on butterfat and LCFA treatment were decreased (P<0.05). Proportions of cis9-18:1, trans9-C18:1, and cis9, trans11-conjugated linoleic acid (CLA) were increased by 15.5, 74.3, and 20.3% (P<0.05) in milk fat from cows on LCFA compared with cows on SMCFA. Similar increases in trans9-18:1, trans11-18:1, cis9, trans11-CLA, 18:2n-6 and 18:3n-3 were 34.2, 31.5, 21.4, 11.0, and 15.4% (P<0.05) in butterfat treatments, respectively. Furthermore, activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were decreased (P<0.05) when increased long-chain FA in diets, while concentration of malondialdehyde (MDA) was increased (P<0.01) in bovine milk. Our results indicated that long-chain FA exhibit positive effects on milk FA composition, but may decrease oxidative stability of milk fat.

Effects of different fatty acids on cell differentiation and lipid accumulation in preadipocytes of warm water fish cobia (Rachycentron canadumLinnaeus, 1766)

This study investigates the effects of four predominant constituent fatty acids of fish oils, including palmitic acid (16:0, PAM), oleic acid (18:1n-9, OLA), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), on cell differentiation and lipid accumulation in the primary culture of cobia preadipocytes. Time-serial (0–20 days) comparisons of the changes in the expression of relevant genes and late-stage (Day 20) adiposity including lipid droplet size and lipid accumulation of the differentiating preadipocytes were also studied. Lipid accumulation was significantly higher when adipocytes were incubated with OLA compared to EPA and DHA and with DHA compared to EPA. Although the expressions of transcription factors C/EBPβ and PPARγ were significantly higher when treated with EPA than with DHA in the early stage (Day 4), the lipogenic genes FABP1, FATP2 and LPL were equally upregulated. The upregulation by EPA was greater than that by DHA in the late stage (Day 20). Among the fatty acids studied, OLA, which is also abundant in plant oils such as olive or canola oil, was most adipogenic. Although both EPA and DHA were antiadipogenic, EPA was more adipogenic than DHA.

Exocrine pancreas ER stress differentially induced by different fatty acids

Exocrine pancreas ER stress differentially induced by different fatty acids

Identification of UAS domain as a motif polymerizing upon interaction with unsaturated fatty acids

In cells fatty acids(FAs) are required for the synthesis of membrane phospholipid components and energy generation. However, overaccumulation of FAs is toxic. Accumulation of FAs prevents their further synthesis by stabilization of Insulin‐induced gene 1(Insig‐1) that inhibits proteolytic activation of sterol regulatory element binding protein‐1(SREBP‐1) that activates all genes required for FA synthesis. This stabilization is achieved through disrupting the interaction between Insig‐1 and UBX domain‐containing protein 8(Ubxd8). Here, we identified Ubxd8, a protein that does not contain any previously recognized domains that bind FAs, as a sensor for unsaturated FAs. In cultured cells, we demonstrated that unsaturated FAs but not saturated FAs stimulated polymerization of Ubxd8 through bimolecular fluorescence complementation assays. In vitro, unsaturated but not saturated FAs also stimulated polymerization of purified recombinant Ubxd8. The effect of different FAs and their derivatives on polymerization of Ubxd8 in vitro correlated with their effect on stabilization of Insig‐1 in cultured cells. Ubxd8 contains 3 domains, namely UBX, UBA and UAS domain. Deletion analysis showed that UAS domain was necessary and sufficient for polymerization of the protein in response to unsaturated FAs. Point mutations in UAS domain that disrupted its interaction with unsaturated FAs in vitro also impaired the ability of full length Ubxd8 to stabilize Insig‐1 in response to unsaturated FAs in cultured cells. In addition to Ubxd8, the only other protein expressed in mammalian cells that contains a UAS domain similar to that of Ubxd8 is Fas‐associated factor 1(FAF1). We showed that unsaturated FAs also specifically induced polymerization of FAF1, and this polymerization was mediated by the UAS domain. The identification of UAS domain as a motif polymerizing upon interaction with unsaturated FAs should provide more insights into cellular responses to FAs. [the National Institute of Health (HL‐20948/Jin Ye)]