Mechanisms of regulation of gene expression by fatty acids

Feeding sows milk biofortified with n-6 and n-3 modulates immune status of sows and drives positive transgenerational effects

The risk of chronic diseases such as cardiovascular disease, cancer, inflammation, obesity, and autoimmune disease is linked to the quality of dietary fats, with lower intake of saturated and higher intake of n-6 and n-3 polyunsaturated fatty acids (PUFA) considered beneficial to health. This study investigated the effect of supplementing sows' diets with cow's milk biofortified with n-6 or n-3 PUFA, at varying n-6/n-3 ratios (8.26, 7.92, and 2.72) during their growing phase and throughout gestation and lactation on their reproductive performance and immune-inflammatory status. Specifically, we analyzed circulating cholesterol and fatty acid profiles of serum, colostrum and milk, sow body weight, and neonate colostrum intake, Apgar scores, muscle composition, and embryo viability. Analysis of circulating immunoglobulins (Ig), interleukins, and eicosanoids and complement system hemolytic activity were used to evaluate inflammatory and immune responses of sows and piglets. Expression of lipolysis and lipogenic genes in the liver were investigated in sows and piglets, with additional investigation of hypothalamus genes regulating appetite in sows. Feeding sows milk biofortified with n-6 and n-3 PUFA altered serum fatty acid profiles, reduced triglycerides (TG), increased embryo total number, increased early gestation backfat, and reduced colostrum IgG. Piglets of biofortified sow had higher circulating IgA, IgM and TNF-α, and lower IL-10. Sows fed n-3 biofortified milk had higher very low-density lipoproteins (VLDL) and TNF-α in circulation. Offspring from sows fed n-6 versus n-3 biofortified milk had lower IL-10 and expression levels of SREBP-1. N-3 versus n-6 also lowered arachidonic acid (ARA) levels in sow's milk and piglet viability 1. Findings offer insights into the potential health benefits of dietary supplementation with biofortified milk in swine, which serve as good model of diet-nutrition studies of humans, and therefore can potentially be considered in dietary recommendations both human and animal populations.

Efficiency of the fatty acids extracted from the microalga Parachlorella kessleri in wound-healing

Wound healing is a physiological process that results in the reconstruction and restoration of granulation tissue, followed by scar formation. We explored the impact of fatty acids in the form of oils on wound healing since they are part of membrane phospholipids and participate in the inflammatory response. This work investigated the efficiency of fatty acids extracted from microalga Parachlorella kessleri in treating excisional wounds and burns and evaluated their antioxidant activity. The rationale behind this investigation lies in the integral role fatty acids play in membrane phospholipids and their involvement in the inflammatory response. Among different nitrogen sources, glycine showed the highest biomass and lipid productivity (0.08 g L-1 d-1 and 58.37 μgml-1 day-1, respectively). Based on the percentage of polyunsaturated fatty acids that increased by 50.38 % in the Glycine culture of P. kessleri, both total antioxidant capacity and DPPH radical scavenging activity were higher in the Glycine culture than control culture. In 30 anaesthetized male mice divided into 6 groups, using either a burn or an excision, two identical paravertebral full-thickness skin lesions were created. Either oils of P. kessleri (extracted from control and glycine culture) ointments or the vehicle (placebo cream) were applied twice daily to the excisional wounds of mice, while mebo cream was used for burn wounds as well as P. kessleri oil. P. kessleri oils (control or glycine culture) showed a significant effect on the reduction of excisional wounds and burns. Histopathological analysis showed that angiogenesis, collagen fiber formation, and epidermis creation were some of the healing indicators that improved. The key elements for this healing property are omega -3 fatty acids, and both P. kessleri oils extracted from control and glycine culture have significant wound-healing effects. Oil of glycine culture of P. kessleri, however, displayed superior results in this regard.

Large-Scale Population-Based Studies of Blood Metabolome and Brain Health

Metabolomics technologies enable the quantification of multiple metabolomic measures simultaneously, which provides novel insights into molecular aspects of human health and disease. In large-scale, population-based studies, blood is often the preferred biospecimen. Circulating metabolome may relate to brain health either by affecting or reflecting brain metabolism. Peripheral metabolites may act at or cross the blood-brain barrier and, subsequently, influence brain metabolism, or they may reflect brain metabolism if similar pathways are engaged. Peripheral metabolites may also include those penetrating the circulation from the brain, indicating, for example, brain damage. Most brain health-related metabolomics studies have been conducted in the context of neurodegenerative disorders and cognition, but some studies have also focused on neuroimaging markers of these disorders. Moreover, several metabolomics studies of neurodevelopmental disorders have been performed. Here, we provide a brief background on the types of blood metabolites commonly assessed, and we review the literature describing the relationships between human blood metabolome (n > 50 metabolites) and brain health reported in large-scale studies (n > 500 individuals).

Regulation of omega-3 fatty acids production by different genes in freshwater fish species: a review

The present study aims to compare the gene expression of three different fish species (common carp, tilapia, and trout) with varying levels of fatty acids (FA). Based on transcriptome analysis and RNA sequencing, various genes and their associated metabolic pathways are identified. Pathways are categorized based on the genes they encode. Genes that were differentially expressed and their promoter's methylation patterns were revealed by RNA-seq analysis in common carp. Furthermore, fatty acid-enriched pathways, such as ARA4 and adipocytokine signaling, were also identified. Many genes and pathways may influence tilapia's growth and omega-3 content. Using the mTOR pathway, trout with differential expression were discovered to be involved in producing omega-3 fatty acids. This study revealed major pathways in fish species to produce omega-3 fatty acids.

Changes to PUFA-PPAR pathway during mesaconitine induced myocardial coagulative necrosis

Coagulation necrosis is characterized by the denaturation of structural proteins and lysosomal enzymes; its occurrence in myocardium can lead to heart failure. Current studies on myocardial injury primarily focus on inflammation, hypertrophy, and hemorrhage, while those on myocardial coagulation necrosis are still limited. Mesaconitine (MA), a C₁₉ diester diterpenoid alkaloid derived from Aconitum carmichaelii Debx, has strong cardiotoxicity. During this study, the myocardial cells of SD rats showed significant coagulative necrosis after 6 days of oral administration of MA at a dose of 1.2 mg/kg/day. Investigations of its biological mechanism showed abnormal levels of polyunsaturated fatty acids (PUFAs) and Peroxisome proliferator activated receptors Alpha (PPARα) pathway related protein. Moreover, MA affected the PPARα signaling pathway through interactions with proteins such as POR, TFAM and GPD1, indirectly indicating that these above proteins are important targets for blocking myocardial coagulative necrosis. This study thus discusses the effects of the use of cardiotoxic compound, MA, to initiate myocardial coagulative necrosis and its associated toxic mechanisms.

Optimization of the Sulfo-Phospho-Vanillin Assay for Total Lipid Normalization in Untargeted Quantitative Lipidomic LC-MS/MS Applications

Liquid chromatography (LC)-mass spectrometry (MS)/MS lipidomic normalization is generally performed by equalizing pre-extraction sample materials or via DNA or protein pre-quantitation methods, which have known measurement inaccuracies. We propose the use of the sulfo-phospho-vanillin assay (SPVA), a total lipid colorimetric analysis, as a pre-quantitation method to normalize lipids in lipidomic LC-MS/MS applications. The assay has been applied to a 300 μL well volume in a 96-well plate and tested using Avanti total lipid standards of porcine brain and E. coli. Assay parameters for lipid sample volume, sulfuric acid, vanillin/phosphoric acid, post-reaction incubation time, and wavelength are optimized for robust application to biologically sourced lipid samples. Standard test samples were prepared using three concentrations covering approximately 100 μg/mL range. The optimized assay yielded test sample errors less than 10%, indicating a precise and accurate assay performance. The test samples were then analyzed by LC-MS/MS and normalized using SPVA pre-quantitation and pseudo-mass normalization. The detected lipids showed smaller standard deviations and greater relative concentration differences compared to the pseudo-mass normalized lipids, showing promise as a normalization method.

Lipid profiling differentiates the effect of ambient microenriched copper on a coral as an advanced tool for biomonitoring

Copper can be beneficial or harmful to coral at environmentally relevant levels, making environmental monitoring a challenging. Membrane lipids make the cell a dynamic environment according to the circumstances; thus, the lipid profile should be indicative of an environmental/physiological state. To gain more insight into the copper effect on coral health and be a basis of biomonitoring, glycerophosphocholine profiling of coral exposed to microenriched copper levels was conducted in this study. The copper microenrichments resulted in a diacritical effect of decreasing carbonic anhydrase activity, following a supplementation effect, on coral lipid metabolism. Microdifferences in copper levels are critical to determine the coral metabolic state and were therefore included in this study. In addition, an excellent quantitative model correlating the coral lipid variation with the exposed copper levels or the induced physiological effect was obtained to demonstrate its performance for biomonitoring.

Enhancement of sperm quality and fertility-related parameters in Hubbard grandparent rooster fed diets supplemented with soybean lecithin and vitamin E

The purpose of this study was to investigate the effect of dietary supplementation of different levels of soybean lecithin and vitamin E on semen quality parameters and some reproductive hormones in Hubbard grandparent roosters. The experiment was conducted in a 3 × 2 factorial arrangement with 3 levels of soybean lecithin (0, 1, and 2%) and 2 levels of vitamin E (0 and 300 mg/kg). Semen samples were collected on d 0, 20, 40 and 60 of the experiment and analyzed. Adding 1% soybean lecithin and vitamin E into the diet increased semen volume and sperm concentration, membrane integrity and viability (P < 0.05). Supplementing diets with 1 or 2% lecithin in addition to vitamin E significantly improved total motility and progressive motility (P < 0.05). Vitamin E significantly increased the amplitude of lateral head displacement (ALH) of sperm (P < 0.05). Although there was no effect on LH and FSH when diets were supplemented with vitamin E and 1 or 2% lecithin, testosterone concentration was increased (P < 0.05). Malondialdehyde (MDA) concentration was significantly lower in all 3 treatments containing vitamin E (P < 0.05). It can be concluded that supplementation of rooster diets with vitamin E and 1% lecithin can improve fertility related parameters in Hubbard grandparent roosters.

Supplementation of Enriched Polyunsaturated Fatty Acids and CLA Cheese on High Fat Diet: Effects on Lipid Metabolism and Fat Profile

Epidemiological studies have demonstrated a positive relationship between dietary fat intake and the onset of several metabolic diseases. This association is particularly evident in a diet rich in saturated fatty acids, typical of animal foods, such as dairy products. However, these foods are the main source of fatty acids with a proven nutraceutical effect, such as the ω-3 fatty acid α-linolenic acid (ALA) and the conjugated linoleic acid (CLA), which have demonstrated important roles in the prevention of various diseases. In the present study, the effect of a supplementation with cheese enriched with ω-3 fatty acids and CLA on the metabolism and lipid profiles of C57bl/6 mice was evaluated. In particular, the analyses were conducted on different tissues, such as liver, muscle, adipose tissue and brain, known for their susceptibility to the effects of dietary fats. Supplementing cheese enriched in CLA and ω-3 fats reduced the level of saturated fat and increased the content of CLA and ALA in all tissues considered, except for the brain. Furthermore, the consumption of this cheese resulted in a tissue-specific response in the expression levels of genes involved in lipid and mitochondrial metabolism. As regards genes involved in the inflammatory response, the consumption of enriched cheese resulted in a reduction in the expression of inflammatory genes in all tissues analyzed. Considering the effects that chronic inflammation associated with a high-calorie and high-fat diet (meta-inflammation) or aging (inflammaging) has on the onset of chronic degenerative diseases, these data could be of great interest as they indicate the feasibility of modulating inflammation (thus avoiding/delaying these pathologies) with a nutritional and non-pharmacological intervention.

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 346 amino 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 40.28 kDa, 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 GLP-1RA and SGLT2i, Alone or in Combination, on Mouse Models of Type 2 Diabetes Representing Different Disease Stages

Glucagon-like peptide-1 receptor agonist (GLP-1RA) and sodium-dependent glucose transporter 2 inhibitor (SGLT2i), in addition to lowering glucose, have pleiotropic effects on the heart, kidneys, and liver. These drugs have thus come into widespread use for treating type 2 diabetes (T2DM). However, mechanistic comparisons and effects of combining these drugs have not been adequately studied. Employing diet-induced obese (DIO) mice and db/db mice as models of the early and advanced stages of T2DM, we evaluated effects of single or combined use of liraglutide (a GLP-1RA) and ipragliflozin (a SGLT2i). Treatments with liraglutide and/or ipragliflozin for 28 days improved glycemic control and reduced hepatic lipid accumulation similarly in DIO mice. In contrast, in db/db mice, despite similar favorable effects on fatty liver, liraglutide exerted no beneficial effects on glycemic control. Improved glycemic control in db/db mice treated with ipragliflozin was accompanied by increased pancreatic β-cell area and insulin content, both of which tended to rise further when ipragliflozin was combined with liraglutide. Our data suggest that liraglutide is more efficient at an earlier stage and ipragliflozin can be effective in both stages. In addition, their combined use is a potential option for treating advanced stage diabetes with fatty liver disease.

Genome wide effects of oleic acid on cultured bovine granulosa cells: evidence for the activation of pathways favoring folliculo-luteal transition

BACKGROUND

Metabolic stress, as negative energy balance on one hand or obesity on the other hand can lead to increased levels of free fatty acids in the plasma and follicular fluid of animals and humans. In an earlier study, we showed that increased oleic acid (OA) concentrations affected the function of cultured bovine granulosa cells (GCs). Here, we focus on genome wide effects of increased OA concentrations.

RESULTS

Our data showed that 413 genes were affected, of which 197 were down- and 216 up-regulated. Specifically, the expression of FSH-regulated functional key genes, CCND2, LHCGR, INHA and CYP19A1 and 17-β-estradiol (E2) production were reduced by OA treatment, whereas the expression of the fatty acid transporter CD36 was increased and the morphology of the cells was changed due to lipid droplet accumulation. Bioinformatic analysis revealed that associated pathways of the putative upstream regulators "FSH" and "Cg (choriogonadotropin)" were inhibited and activated, respectively. Down-regulated genes are over-represented in GO terms "reproductive structure/system development", "ovulation cycle process", and "(positive) regulation of gonadotropin secretion", whereas up-regulated genes are involved in "circulatory system development", "vasculature development", "angiogenesis" or "extracellular matrix/structure organization".

CONCLUSIONS

From these data we conclude that besides inhibiting GC functionality, increased OA levels seemingly promote angiogenesis and tissue remodelling, thus suggestively initiating a premature fulliculo-luteal transition. In vivo this may lead to impeded folliculogenesis and ovulation, and cause sub-fertility.

Structural and molecular indices in common carp (Cyprinus carpio L.) fed n-3 PUFA enriched diet

Sustainable freshwater aquaculture has been recently gaining attention owing to the potential of nourishing the world. The study aimed to evaluate the influence of finishing diets on the activity of 21 genes involved in hepatic lipid metabolism and intestinal homeostasis, liver and intestine histology, and the level of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in common carp fillets. We compared two experimental diets: control diet mimicking a commercial feed (CTRL) and a test diet (CB) fortified with EPA and DHA retrieved from salmon by-products. An additional control (eCTRL) from extensively cultured carps was investigated. The study revealed that the expression of seven hepatic genes, e.g., lipoprotein lipase and fatty acid synthase, and six intestinal genes e.g., claudin-3c and γ-glutamyl transpeptidase, was influenced specifically by the experimental diets and farming type. Fish from the eCTRL group had the smallest hepatocytes and the largest nuclei compared with CTRL and CB. No pathological signs were found in intestine samples. Additionally, the levels of EPA and DHA in fillets were significantly higher in fish receiving CB compared with CTRL and eCTRL. The use of fortified diets is a promising solution to produce freshwater species with enhanced nutritional value without compromising the safety of fillets.

Fatty Acid Desaturase 1 Influences Hepatic Lipid Homeostasis by Modulating the PPARα-FGF21 Axis

The fatty acid desaturase 1 (FADS1), also known as delta-5 desaturase (D5D), is one of the rate-limiting enzymes involved in the desaturation and elongation cascade of polyunsaturated fatty acids (PUFAs) to generate long-chain PUFAs (LC-PUFAs). Reduced function of D5D and decreased hepatic FADS1 expression, as well as low levels of LC-PUFAs, were associated with nonalcoholic fatty liver disease. However, the causal role of D5D in hepatic lipid homeostasis remains unclear. In this study, we hypothesized that down-regulation of FADS1 increases susceptibility to hepatic lipid accumulation. We used in vitro and in vivo models to test this hypothesis and to delineate the molecular mechanisms mediating the effect of reduced FADS1 function. Our study demonstrated that FADS1 knockdown significantly reduced cellular levels of LC-PUFAs and increased lipid accumulation and lipid droplet formation in HepG2 cells. The lipid accumulation was associated with significant alterations in multiple pathways involved in lipid homeostasis, especially fatty acid oxidation. These effects were demonstrated to be mediated by the reduced function of the peroxisome proliferator-activated receptor alpha (PPARα)-fibroblast growth factor 21 (FGF21) axis, which can be reversed by treatment with docosahexaenoic acid, PPARα agonist, or FGF21. In vivo, FADS1-knockout mice fed with high-fat diet developed increased hepatic steatosis as compared with their wild-type littermates. Molecular analyses of the mouse liver tissue largely corroborated the observations in vitro, especially along with reduced protein expression of PPARα and FGF21. Conclusion: Collectively, these results suggest that dysregulation in FADS1 alters liver lipid homeostasis in the liver by down-regulating the PPARα-FGF21 signaling axis.

The role of oxidative stress in the development of obesity and obesity-related metabolic disorders

Obesity is a serious medical condition, defined as excessive accumulation of fat. Abdominal fat is recognized as the major risk for obesity related diseases such as: hypertension, dyslipidemia, type 2 diabetes mellitus, coronary heart disease, stroke, non-alcoholic fatty liver disease etc. Fat accumulation is also related to pro-oxidant and pro-inflammatory states. Recently published articles suggest that oxidative stress may be a link between obesity and related complications. Adiposity leads to increased oxidative stress via several multiple biochemical processes such as superoxide generation through the action of NADPH oxidase, glyceraldehyde auto-oxidation, oxidative phosphorylation, protein kinase C (PKC) activation, and polyol and hexosamine pathways. On the other hand, oxidative stress plays a causative role in the development of obesity, by stimulating the deposition of adipose tissue, including preadipocyte proliferation, adipocyte differentiation and growth. Exercise-induced weight loss can improve the redox state by modulating both oxidative stress and antioxidant promoters, which reduce endothelial dysfunction and inflammation.

Loss of the seipin gene perturbs eggshell formation in Caenorhabditiselegans

Seipin, an evolutionary conserved protein, plays pivotal roles during lipid droplet (LD) biogenesis and is associated with various human diseases with unclear mechanisms. Here, we analyzed Caenorhabditis elegans mutants deleted of the sole SEIPIN gene, seip-1 Homozygous seip-1 mutants displayed penetrant embryonic lethality, which is caused by the disruption of the lipid-rich permeability barrier, the innermost layer of the C. elegans embryonic eggshell. In C. elegans oocytes and embryos, SEIP-1 is associated with LDs and is crucial for controlling LD size and lipid homeostasis. The seip-1 deletion mutants reduced the ratio of polyunsaturated fatty acids (PUFAs) in their embryonic fatty acid pool. Interestingly, dietary supplementation of selected n-6 PUFAs rescued the embryonic lethality and defective permeability barrier. Accordingly, we propose that SEIP-1 may maternally regulate LD biogenesis and lipid homeostasis to orchestrate the formation of the permeability barrier for eggshell synthesis during embryogenesis. A lipodystrophy allele of seip-1 resulted in embryonic lethality as well and could be rescued by PUFA supplementation. These experiments support a great potential for using C. elegans to model SEIPIN-associated human diseases.

Peroxisome proliferator-activated receptors (PPARs) as a mediator of dietary fatty acids affects reproductive performance in broiler breeder roosters

This study analyzed the effects of dietary sources of omega-3 and omega-6 fatty acids on semen parameters and fertility potential in broiler breeder roosters. The mRNA and protein profiles of peroxisome proliferator-activated receptors-γ (PPAR-γ) expression in sperm as potential mediator of FAs were considered. Roosters were categorized into three groups and received their diets for 24 weeks as follows: 1) control diet received a basal diet (CTRL); 2) Fish oil based diet (FO) received the basal diet supplemented with 15 g/kg of diet fish oil; and 3) sunflower oil based diet (SO) received the basal diet supplemented with 15 g/kg of diet sunflower oil. While the different diets had significant effects on semen parameters, the effect of sampling time was not significant. The effect of the diets on sperm parameters were significantly higher in the SO and FO groups in total motility, progressive motility, amplitude of lateral head displacement, linearity, straightness, wobble and viability (P ≤ 0.05). Fertility rate was significantly improved in the FO and SO groups (P = 0001). The highest value for PPAR-γ mRNA was observed in the SO group compared to other groups (P ≤ 0.05). Moreover, supplementation of the roosters' diets with FO and SO increased PPAR-γ protein expression compared to the control. It seems that PPAR-γ could be a strong potential mediator of the underlying mechanism of improvement in semen parameters and reproductive performance of roosters under the effects of both dietary omega-3 and omega-6 polyunsaturated fatty acids.

The impact of PUFA on cell responses: Caution should be exercised when selecting PUFA concentrations in cell culture

Polyunsaturated fatty acids (PUFA) are important components of cellular membranes, serving both structural and signaling functions. Investigation of the functional responses of cells to various PUFA often involves cell culture experiments, which can then inform or guide subsequent in vivo and clinical investigations. In this study, human carcinoma and leukemia cell lines (MCF-7, HepG2, THP-1, Jurkat) were incubated for 3 days in the presence of up to 150 μM of exogenous arachidonic or eicosapentaenoic acids. At concentrations up to 20 μM these PUFA were enriched in cellular phospholipids, but at concentrations of 20 μM or higher cells accumulated large quantities of these PUFA and their elongation products into triglycerides. This coincided with decreased cell proliferation and enhanced apoptosis. Inhibition of DGAT1 but not DGAT2 enhanced the cytotoxic effect of exogenous PUFA suggesting a protective role of PUFA sequestration into TGs. Lower (10 μM) and higher (50 μM) exogenous PUFA concentrations also had different impacts on the expression of PUFA metabolizing enzymes. Overall, these results indicate that caution must be exercised when planning in vitro experiments since elevated concentrations of PUFA can lead to dysfunctional cellular responses that are not predictive of in vivo responses to dietary PUFA.

Clostridium difficile caused changes in fatty acids profile and resolvin D1 content in plasma of infected patients

OBJECTIVES

Clostridium difficile infection (CDI) is an acute gastrointestinal infection caused by anaerobic, toxin-producing bacteria. During the course of CDI, there is a general inflammatory state. In order to gain a deeper understanding of the role of fatty acids (FAs) in the pathogenesis of acute infection we analyzed their plasma content in both patients with CDI and controls.

METHODS

The study groups included 40 patients with CDI and 40 healthy volunteers. Plasma FA content was analyzed by gas chromatography, resolvin D1 (RvD1) level using ELISA assay, and we assessed the white blood cell (WBC) count, neutrophil count and C-reactive protein (CRP) level.

RESULTS

Patients with CDI were characterized by significantly higher values of WBC, neutrophils, platelets and CRP compared with the control group. The saturated FA index was statistically higher and total n-3 FA was significantly decreased in the plasma of CDI patients as compared with the control group. RvD1 content was significantly higher in the control group as compared with patients with CDI.

CONCLUSION

In patients with good outcomes, we probably observed the effective resolution of inflammation, as reflected in n-3 FA metabolism and their significant decrease in plasma. This may indicate the therapeutic role of n-3 FA in CDI infection.

Nutrition and Nonalcoholic Fatty Liver Disease: Current Perspectives

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis are diseases in their own right as well as modifiable risk factors for cardiovascular disease and type 2 diabetes. With expanding knowledge on NAFLD pathogenesis, insights have been gleaned into molecular targets for pharmacologic and nonpharmacologic approaches. Lifestyle modifications constitute a cornerstone of NAFLD management. This article reviews roles of key dietary macronutrients and micronutrients in NAFLD pathogenesis and their effects on molecular targets shared with established or emerging pharmacotherapies. Based on current evidence, a recommendation for a dietary framework as part of the comprehensive management strategy for NAFLD is provided.

Short-Term Responses to Fatty Acids on Lipid Metabolism and Adipogenesis in Rainbow Trout (Oncorhynchus mykiss)

Fish are rich in n-3 long-chain polyunsaturated fatty acids (LC-PUFA) such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Due to the increasing use of vegetable oils (VO), their proportion in diets has lowered, affecting lipid metabolism and fillet composition. Rainbow trout cultured preadipocytes were treated with representative FA found in fish oils (EPA and DHA) or VO (linoleic, LA and alpha-linolenic, ALA acids), while EPA and LA were also orally administered, to evaluate their effects on adipogenesis and lipid metabolism. In vitro, all FA increased lipid internalization, with ALA producing the highest effect, together with upregulating the FA transporter fatp1. In vivo, EPA or LA increased peroxisome proliferator-activated receptors ppara and pparb transcripts abundance in adipose tissue, suggesting elevated β-oxidation, contrary to the results obtained in liver. Furthermore, the increased expression of FA synthase (fas) and the FA translocase/cluster of differentiation (cd36) in adipose tissue indicated an enhanced uptake of lipids and lipogenesis de novo, whereas stable or low hepatic expression of genes involved in lipid transport and turnover was found. Thus, fish showed a similar tissue metabolic response to the short-term availability of EPA or LA in vivo, while in vitro VO-derived FA demonstrated greater potential inducing fat accumulation.

Fast and Quantitative Phospholipidomic Analysis of SH-SY5Y Neuroblastoma Cell Cultures Using Liquid Chromatography-Tandem Mass Spectrometry and 31P Nuclear Magnetic Resonance

Global lipid analysis still lags behind proteomics with respect to the availability of databases, experimental protocols, and specialized software. Determining the lipidome of cellular model systems in common use is of particular importance, especially when research questions involve lipids directly. In Parkinson's disease research, there is a growing awareness for the role of the biological membrane, where individual lipids may contribute to provoking α-synuclein oligomerisation and fibrillation. We present an analysis of the whole cell and plasma membrane lipid isolates of a neuroblastoma cell line, SH-SY5Y, a commonly used model system for research on this and other neurodegenerative diseases. We have used two complementary lipidomics methods. The relative quantities of PC, PE, SMs, CL, PI, PG, and PS were determined by ³¹P NMR. Fatty acid chain composition and their relative abundances within each phospholipid group were evaluated by liquid chromatography-tandem mass spectrometry. For this part of the analysis, we have developed and made available a set of Matlab scripts, LipMat. Our approach allowed us to observe several deviations of lipid abundances when compared to published reports regarding phospholipid analysis of cell cultures or brain matter. The most striking was the high abundance of PC (54.7 ± 1.9%) and low abundance of PE (17.8 ± 4.8%) and SMs (2.7 ± 1.2%). In addition, the observed abundance of PS was smaller than expected (4.7 ± 2.7%), similar to the observed abundance of PG (4.5 ± 1.8%). The observed fatty acid chain distribution was similar to the whole brain content with some notable differences: a higher abundance of 16:1 PC FA (17.4 ± 3.4% in PC whole cell content), lower abundance of 22:6 PE FA (15.9 ± 2.2% in plasma membrane fraction), and a complete lack of 22:6 PS FA.

Dietary DHA/EPA supplementation ameliorates diabetic nephropathy by protecting from distal tubular cell damage

The aim was to explore the influence of experimental diabetes mellitus type 1 (DM1) and potential protective/deleterious effects of different dietary n-6/n-3 PUFA ratios on renal phospholipid composition and pathological changes caused by DM1. Male Wistar rats were injected with 55 mg/kg streptozotocin or citrate buffer (control group). Control (C) and diabetic groups (STZ) were fed with n-6/n-3 ratio of ≈ 7, STZ + N6 with n-6/n-3 ratio ≈ 60 and STZ + DHA with n-6/n-3 ratio of ≈ 1 containing 16% EPA and 19% DHA. Tissues were harvested 30 days after DM1 induction. Blood and kidneys were collected and analysed for phospholipid fatty acid composition, pathohystological changes, ectopic lipid accumulation and expression of VEGF, NF-kB and special AT-rich sequence-binding protein-1 (SATB1). Pathological changes were studied also by using transmission electron microscopy, after immunostaining for VEGF. Substantial changes in renal phospholipid fatty acid composition resulted from DM1 and dietary PUFA manipulation. Extensive vacuolization of distal tubular cells (DTCs) was found in DM1, but it was attenuated in the STZ + DHA group, in which the highest renal NF-kB expression was observed. The ectopic lipid accumulation was observed in proximal tubular cells (PTCs) of all diabetic animals, but it was worsened in the STZ + N6 group. In DM1, we found disturbance of VEGF-transporting vesicular PTCs system, which was substantially worsened in STZ + DHA and STZ + N6. Results have shown that the early phase of DN is characterized with extent damage and vacuolization of DTCs, which could be attenuated by DHA/EPA supplementation. We concluded that dietary fatty acid composition can strongly influence the outcomes of DN.

Decreased liver triglyceride content in adult rats exposed to protein restriction during gestation and lactation: roles of hepatic lipogenesis and lipid utilization in muscle and adipose tissue

Protein restriction throughout pregnancy and lactation reduces liver triglyceride (TG) content in adult male rat offspring. The study determined the contribution of hepatic lipogenesis to the reduction in liver TG content. Rats received either control or protein-restricted diets throughout pregnancy and lactation. Offspring were sacrificed on day 65. Hepatic fatty acid uptake and de novo fatty acid and TG biosynthesis were similar between control and low-protein (LP) offspring. These results indicate that hepatic lipogenesis cannot mediate the decrease in liver TG content in LP offspring. We then determined whether increased lipid utilization in adipose tissue and muscle was responsible for the decrease in liver TG content. There was suggestive evidence of increased sympathetic nervous system tone in epididymal adipose tissue of LP offspring that increased fatty acid uptake, TG lipolysis, and utilization of fatty acids in mitochondrial thermogenesis. Measurement of similar parameters demonstrated that such alterations do not occur in gastrocnemius muscle, another major lipid-utilizing tissue. Our results suggest that the decrease in liver TG content in LP offspring is likely due to increased diversion of fatty acids to white and brown adipose tissue depots and their enhanced utilization to fuel mitochondrial thermogenesis.

Quercetin and its derivative Q2 modulate chromatin dynamics in adipogenesis and Q2 prevents obesity and metabolic disorders in rats

Recently the attention of the scientific community has focused on the ability of polyphenols to counteract adverse epigenetic regulation involved in the development of complex conditions such as obesity. The aim of this study was to investigate the epigenetic mechanisms underlying the anti-adiposity effect of Quercetin (3,3',4',5,7-pentahydroxyflavone) and of one of its derivatives, Q2 in which the OH groups have been replaced by acetyl groups. In 3 T3-L1 preadipocytes, Quercetin and Q2 treatment induce chromatin remodeling and histone modifications at the 5' regulatory region of the two main adipogenic genes, c/EBPα and PPARγ. Chromatin immunoprecipitation assays revealed a concomitant increase of histone H3 di-methylation at Lys9, a typical mark of repressed gene promoters, and a decrease of histone H3 di-methylation at Lys 4, a mark of active transcription. At the same time, both compounds inhibited histone demethylase LSD1 recruitment to the 5' region of c/EBPα and PPARγ genes, a necessary step for adipogenesis. The final effect is a significant reduction in c/EBPα and PPARγ gene expression and attenuated adipogenesis. Q2 supplementation in rats reduced the gain in body weight and in white adipose tissue, as well as the increase in adipocyte size determined by high fat diet. Moreover, Q2 improved dyslipidemia, glucose tolerance and decreased the hepatic lipid accumulation by activating the expression of beta-oxidation related genes. Our data suggest that Q2, as well as Quercetin, has the potential to revert the unfavorable epigenomic profiles associated with obesity onset. This opens the possibility to use these compounds in targeted prevention strategies against obesity.

Transcriptome Analysis Identified Genes for Growth and Omega-3/-6 Ratio in Saline Tilapia

Growth and omega-3/-6 ratio are important traits in aquaculture. The mechanisms underlying quick growth and high omega-3/-6 ratio in fish are not fully understood. The consumption of the meat of tilapia suffers a bad reputation due to its low omega-3/-6 ratio. To facilitate the improvement of these traits and to understand more about the mechanisms underlying quick growth and high omega-3/-6 ratio, we conducted transcriptome analysis in the muscle and liver of fast- and slow-growing hybrid saline tilapia generated by crossing Mozambique tilapia and red tilapia. A transcriptome with an average length of 963 bp was generated by using 486.65 million clean 100 bp paired-end reads. A total of 42,699 annotated unique sequences with an average length of 3.4 kb were obtained. Differentially expressed genes (DEGs) in the muscle and liver were identified between fast- and slow-growing tilapia. Pathway analysis classified these genes into many pathways. Ten genes, including foxK1, sparc, smad3, usp38, crot, fadps, sqlea, cyp7b1, impa1, and gss, from the DEGs were located within QTL for growth and omega-3, which were previously detected content in tilapia, suggesting that these ten genes could be important candidate genes for growth and omega-3 fatty acid content. Analysis of SNPs in introns 1 and 2 of foxK1 revealed that the SNPs were significantly associated with growth and omega-3/-6 ratio. This study lays the groundwork for further investigation of the molecular mechanisms underlying the phenotypic variation of these two traits and provides SNPs for selecting these traits at fingerling stage.

Skeletal Muscle Interleukin-6 Regulates Hepatic Cytochrome P450 Expression: Effects of 16-Week High-Fat Diet and Exercise

High-fat diet (HFD) induces several changes to the pathways regulating energy homeostasis and changes the expression of the hepatic cytochrome p450 (Cyp) enzyme-system. Despite these pervious findings, it is still unclear how the effects of HFD and especially HFD in combination with treadmill running affect hepatic Cyp expression. In this study, we investigated the mRNA and protein expression of selected Cyp's in mice subjected to 16 weeks of HFD and treadmill running. To understand the regulatory mechanisms behind the exercise-induced reversion of the HFD-induced changes in Cyp expression, we used a model in which the exercise-induced myokine and known regulator of hepatic Cyp's, interleukin-6 (IL-6), were knocked out specifically in skeletal muscle. We found that HFD increased the mRNA expression of Cyp1a1 and Cyp4a10, and decreased the expression of Cyp2a4, Cyp2b10, Cyp2e1, and Cyp3a11. HFD in combination with treadmill running reversed the HFD increase in Cyp4a10 mRNA expression. In addition, we observed increased Cyp1a and Cyp3a protein expression as an effect of exercise, whereas Cyp2b expression was lowered as an effect of HFD. IL-6 effected the response in Cyp3a11 and Cyp1a expression. We observed no changes in the content of the aryl hydrocarbon receptor, constitutive androstane receptor, pregnane X receptor, or peroxisome proliferation activator receptor alpha. In conclusion, we show that both HFD and exercise in HFD-fed animals can regulate hepatic Cyp expression and that changes in Cyp3a in response to HFD and exercise are dependent on skeletal muscular IL-6.

Nutrients in Alzheimer’s Disease: The Interaction of Diet, Drugs and Disease

In recent decades, clinical trials in Alzheimer’s disease (AD) have failed at an unprecedented rate. The etiology of AD has since come under renewed scrutiny, both to elucidate the underlying pathologies and to identify novel therapeutic strategies. Here, diet has emerged as a potential causative/protective agent. A variety of nutrients, including lipids, minerals, vitamins, antioxidants and sugars as well as broader dietary patterns and microbiotal interactions have demonstrated associations with AD. Although clinical trials have yet to definitively implicate any singular dietary element as therapeutic or causative, it is apparent that dietary preferences, likely in complex synergies, may influence the risk, onset and course of AD. This review catalogs the impact of major dietary elements on AD. It further examines an unexplored reciprocal association where AD may modulate diet, as well as how potential therapeutics may complicate these interactions. In doing so, we observe diet may have profound effects on the outcome of a clinical trial, either as a confounder of a drug/disease interaction or as a generally disruptive covariate. We therefore conclude that future clinical trials in AD should endeavor to control for diet, either in study design or subsequent analyses.

Effect of n-3 long-chain polyunsaturated fatty acids on wound healing using animal models – a review

The present review summarizes results of experiments, mostly performed on rodents, regarding the effects of fish oil (FO) and its biologically active constituents, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the healing of cutaneous wounds, but also of selected other types of injury. Structure, metabolism and functions of EPA/DHA in an organism are briefly mentioned, with an emphasis on the ability of these long-chain polyunsaturated fatty acids to modulate inflammation. Wound healing as a complex programmed sequence of cellular and molecular processes including inflammation, cell migration, angiogenesis, synthesis of provisional matrix, collagen deposition and reepithelialisation is briefly described. Markers for evaluation of the healing process include planimetry indices, tensile strength, quantification of collagen synthesis including hydroxyproline determination, histopathology/immunohistochemistry and genomic/proteomic markers. As far as effects on wound healing are concerned, the main emphasis is put on the outcomes of experiments using a dietary FO/DHA/EPA administration, but the results of experiments with a parenteral application are also mentioned, together with selected relevantin vitrostudies. An important conclusion from the above-mentioned studies is an inconsistency of FO/DHA/EPA effects on wound healing: decreased/increased collagen deposition; lower/higher counts of the inflammatory cells in the healing tissue; increased/decreased concentration of both pro- and anti-inflammatory cytokines; DHA accelerated/delayed wound healing process. Some experiments indicate superiority of DHA over EPA regarding wound healing.

Polyunsaturated fatty acid elongation and desaturation in activated human T-cells: ELOVL5 is the key elongase

PUFAs are important constituents of membrane glycerophospholipids. However, changes in the capacities to incorporate and metabolize PUFAs when cells enter the cell cycle have not been thoroughly studied. In this study, differences in the incorporation and metabolism of exogenous PUFAs in resting and proliferating primary human T-cells and in the Jurkat cell line were measured. Overall, proliferating T-cells and Jurkat cells had a greater capacity to incorporate and elongate exogenous 18- and 20-carbon PUFAs compared with resting T-cells. Proliferating T-cells and Jurkat cells also showed a greater capacity to desaturate 18-carbon PUFA substrates. Consistent with these observations, a significant increase in the expression of fatty acid desaturase (FADS) 1, FADS2, and elongation of very long chain fatty acids protein (ELOVL) 5 was measured in proliferating T-cells compared with resting T-cells. No quantifiable ELOVL2 was measured. Knockdown of ELOVL5 in T-cells and Jurkat cells significantly affected cellular monounsaturated and PUFA profiles and strongly impaired the elongation of 18- and 20-carbon PUFAs. In conclusion, the induction of proliferation in human T-cells is associated with a significant increase in the capacity to take up and metabolize exogenous PUFAs, and ELOVL5 is responsible for the elongation of 18- and 20-carbon PUFAs in these cells.

Fish oil feeding reverses hepatomegaly and disrupted hepatic function due to the lack of FXR signaling

Mice lacking farnesoid X receptor (FXR) are used as a model for nonalcoholic fatty liver disease because their livers exhibit hepatomegaly, hepatic steatosis, and hepatic inflammation. The influence of fish oil feeding on hepatomegaly and disrupted hepatic function was investigated using female Fxr-null mice and wild-type mice fed a fish oil diet (2% fish oil and 2% corn oil) or a control diet (4% corn oil) for 4 weeks. Hepatic n-3 polyunsaturated fatty acid (PUFA) levels, including 22:6 n-3 docosahexaenoic acid (DHA) and 20:5 n-3 eicosapentaenoic acid (EPA) were significantly higher in the fish oil group than those in the control group of Fxr-null mice and wild-type mice. Fxr-null mouse livers of the control group showed a whitish brown coloration, whereas Fxr-null mouse livers of the fish oil group showed a dark brown coloration similar to that of wild-type mice. The liver in Fxr-null mice of the fish oil group was smaller than that of the control group. There was a significant decrease in the levels of hepatic damage-associated diagnostic markers, hepatic and serum bile acids, triglycerides, free fatty acids, and total cholesterol levels in Fxr-null mice because of fish oil feeding. It also reversed elevated mRNA levels of oxidative stress-related genes (Hmox1, Gsta1, and Gsta2) and reduced mRNA levels of transcriptional factors (Pparα and Shp) in Fxr-null mice. These results suggest that fish oil feeding reverses hepatomegaly and disrupted hepatic function due to the lack of FXR signaling.

Food restriction increase the expression of mTORC1 complex genes in the skeletal muscle of juvenile pacu (Piaractus mesopotamicus)

Skeletal muscle is capable of phenotypic adaptation to environmental factors, such as nutrient availability, by altering the balance between muscle catabolism and anabolism that in turn coordinates muscle growth. Small noncoding RNAs, known as microRNAs (miRNAs), repress the expression of target mRNAs, and many studies have demonstrated that miRNAs regulate the mRNAs of catabolic and anabolic genes. We evaluated muscle morphology, gene expression of components involved in catabolism, anabolism and energetic metabolism and miRNAs expression in both the fast and slow muscle of juvenile pacu (Piaractus mesopotamicus) during food restriction and refeeding. Our analysis revealed that short periods of food restriction followed by refeeding predominantly affected fast muscle, with changes in muscle fiber diameter and miRNAs expression. There was an increase in the mRNA levels of catabolic pathways components (FBXO25, ATG12, BCL2) and energetic metabolism-related genes (PGC1α and SDHA), together with a decrease in PPARβ/δ mRNA levels. Interestingly, an increase in mRNA levels of anabolic genes (PI3K and mTORC1 complex: mTOR, mLST8 and RAPTOR) was also observed during food restriction. After refeeding, muscle morphology showed similar patterns of the control group; the majority of genes were slightly up- or down-regulated in fast and slow muscle, respectively; the levels of all miRNAs increased in fast muscle and some of them decreased in slow muscle. Our findings demonstrated that a short period of food restriction in juvenile pacu had a considerable impact on fast muscle, increasing the expression of anabolic (PI3K and mTORC1 complex: mTOR, mLST8 and RAPTOR) and energetic metabolism genes. The miRNAs (miR-1, miR-206, miR-199 and miR-23a) were more expressed during refeeding and while their target genes (IGF-1, mTOR, PGC1α and MAFbx), presented a decreased expression. The alterations in mTORC1 complex observed during fasting may have influenced the rates of protein synthesis by using amino acids from protein degradation as an alternative mechanism to preserve muscle phenotype and metabolic demand maintenance.

Predictive significance of HMGCS2 for prognosis in resected Chinese esophageal squamous cell carcinoma patients

Despite a series of attempts during the last decades, the prognosis of esophageal squamous cell carcinoma (ESCC) remains poor. Different responses of individual tumors encouraged us to look for valuable prognostic markers. As a key regulator controlling the anabolic ketogenic pathway, 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) has been reported to play a crucial role in colorectal cancer and prostate cancer. However, its importance to ESCC has not been verified. Therefore, a large cohort retrospective study was planned, to investigate the relationship between HMGCS2 expression and ESCC prognosis. By adopting real-time polymerase chain reaction (PCR) and immunohistochemical (IHC) staining, HMGCS2 expression was examined in tissues of 300 ESCC patients with complete resection. Besides, the association between HMGCS2 protein expression and survival time was evaluated through chi-square test and Kaplan–Meier analysis. With the use of Cox-proportional hazards model, the prognostic impact of clinicopathologic variables and biomarker expression was evaluated. Compared with their non-tumor counterparts, HMGCS2 downregulation occurred in 65.5% and 37.6% of primary ESCCs on the mRNA and protein levels (P<0.001), respectively. On the protein level, HMGCS2 expression was associated with tumor cell differentiation (P=0.003), pT status (P=0.006), and TNM stage (P=0.010). In the down-HMGCS2 expression group, the 5-year overall survival (OS) and relapse-free survival (RFS) are poorer than those in the normal expression group (19 months vs 24 months, P=0.002; 13 months vs 17 months, P=0.007, respectively). According to the TNM stage, stratified analysis revealed that its discernibility on RFS was only pronounced in patients with advanced clinical stage (P=0.001). In addition, multivariate Cox regression analysis showed that HMGCS2 expression was an independent risk factor for RFS (P=0.032) instead of OS (P=0.099). The findings of this study provided the evidence that HMGSC2 represented a potential novel prognostic biomarker for ESCC patients.

Lipid metabolism-related gene expression pattern of Atlantic bluefin tuna (Thunnus thynnus L.) larvae fed on live prey

The present study is the first to evaluate lipid metabolism in first-feeding Atlantic bluefin tuna (ABT; Thunnus thynnus L.) larvae fed different live prey including enriched rotifers Brachionus plicatilis and Acartia sp. copepod nauplii from 2 days after hatch. Understanding the molecular basis of lipid metabolism and regulation in ABT will provide insights to optimize diet formulations for this high-value species new to aquaculture. To this end, we investigated the effect of dietary lipid on whole larvae lipid class and fatty acid compositions and the expression of key genes involved in lipid metabolism in first feeding ABT larvae fed different live prey. Additionally, the expression of lipid metabolism genes in tissues of adult broodstock ABT was evaluated. Growth and survival data indicated that copepods were the best live prey for first feeding ABT and that differences in growth performance and lipid metabolism observed between larvae from different year classes could be a consequence of broodstock nutrition. In addition, expression patterns of lipid metabolic genes observed in ABT larvae in the trials could reflect differences in lipid class and fatty acid compositions of the live prey. The lipid nutritional requirements, including essential fatty acid requirements of larval ABT during the early feeding stages, are unknown, and the present study represents a first step in addressing these highly relevant issues. However, further studies are required to determine nutritional requirements and understand lipid metabolism during development of ABT larvae and to apply the knowledge to the commercial culture of this iconic species.

Molecular cloning, mRNA expression and nutritional regulation of a Δ6 fatty acyl desaturase-like gene of mud crab, Scylla paramamosain

Fatty acyl desaturases (Fads) are critical enzymes in the pathways for the biosynthesis of the highly unsaturated fatty acids (HUFA). Here we report on the molecular cloning, tissue expression and nutritional regulation of a Δ6 fatty acyl desaturase-like (Δ6 Fad-like) gene from mud crab, Scylla paramamosain. The full-length cDNA was 1973bp, with a 201bp of 5'-UTR, a 443bp of 3'-UTR, and an ORF of 1329bp that encoded a protein of 442 amino acids. Bioinformatics analysis showed that the deduced peptide sequence possessed the typical features of the microsomal Fads, including N-terminal cytochrome b₅ domain containing the heme-binding motif (H-P-G-G), three histidine-rich boxes and three membrane-spanning regions. Sequence comparison revealed that the predicted protein had a high percentage identity (>53%) with Δ6 Fads from other crustacean species. The tissue distribution of mud crab Δ6 Fad-like mRNA was found predominantly in hepatopancreas, with lower expression levels in all other tissues. Quantitative real-time PCR showed that the Δ6 Fad-like transcriptional levels in hepatopancreas gradually increased with the increased replacement of dietary fish oil (FO) by soybean oil (SO). The replacement ratio of FO by SO up to 60%, 80%, and 100% were significantly up-regulated by about 2.40-fold, 2.99-fold and 3.02-fold compared with that in the control group (100% FO) respectively (P<0.05). These results may contribute to better understanding the HUFA biosynthetic pathway and regulation mechanism in this species.

A Moderate Zinc Deficiency Does Not Alter Lipid and Fatty Acid Composition in the Liver of Weanling Rats Fed Diets Rich in Cocoa Butter or Safflower Oil

The aim of the study was to examine whether a moderate zinc deficiency alters hepatic lipid composition. Male weanling rats, assigned to five groups (8 animals each), were fed low-carbohydrate high-fat diets supplemented with 7 or 50 mg Zn/kg (LZ or HZ) and 22% cocoa butter (CB) or 22% safflower oil (SF) for four weeks. One group each had free access to the LZ-CB and LZ-SF diets, one group each was restrictedly fed the HZ-CB and HZ-SF diets in matching amounts, and one group had free access to the HZ-SF diet (ad libitum control). The rats fed the LZ diets had significantly lower energy intakes and final body weights than the ad libitum control group, and lower plasma and femur Zn concentrations than the animals consuming the HZ diets. Hepatic cholesterol, triacylglycerol and phospholipid concentrations, and fatty acid composition of hepatic triacylglycerols and phospholipids did not significantly differ between the LZ and their respective HZ groups, but were greatly affected by dietary fat source. In conclusion, the moderate Zn deficiency did not significantly alter liver lipid concentrations and fatty acid composition.

Metabolic profiling of fatty liver in young and middle-aged adults: Cross-sectional and prospective analyses of the Young Finns Study

Nonalcoholic fatty liver is associated with obesity-related metabolic disturbances, but little is known about the metabolic perturbations preceding fatty liver disease. We performed comprehensive metabolic profiling to assess how circulating metabolites, such as lipoprotein lipids, fatty acids, amino acids, and glycolysis-related metabolites, reflect the presence of and future risk for fatty liver in young adults. Sixty-eight lipids and metabolites were quantified by nuclear magnetic resonance metabolomics in the population-based Young Finns Study from serum collected in 2001 (n = 1,575), 2007 (n = 1,509), and 2011 (n = 2,002). Fatty liver was diagnosed by ultrasound in 2011 when participants were aged 34-49 years (19% prevalence). Cross-sectional associations as well as 4-year and 10-year risks for fatty liver were assessed by logistic regression. Metabolites across multiple pathways were strongly associated with the presence of fatty liver (P < 0.0007 for 60 measures in age-adjusted and sex-adjusted cross-sectional analyses). The strongest direct associations were observed for extremely large very-low-density lipoprotein triglycerides (odds ratio [OR] = 4.86 per 1 standard deviation, 95% confidence interval 3.48-6.78), other very-low-density lipoprotein measures, and branched-chain amino acids (e.g., leucine OR = 2.94, 2.51-3.44). Strong inverse associations were observed for high-density lipoprotein measures, e.g., high-density lipoprotein size (OR = 0.36, 0.30-0.42) and several fatty acids including omega-6 (OR = 0.37, 0.32-0.42). The metabolic associations were attenuated but remained significant after adjusting for waist, physical activity, alcohol consumption, and smoking (P < 0.0007). Similar aberrations in the metabolic profile were observed already 10 years before fatty liver diagnosis.

CONCLUSION

Circulating lipids, fatty acids, and amino acids reflect fatty liver independently of routine metabolic risk factors; these metabolic aberrations appear to precede the development of fatty liver in young adults. (Hepatology 2017;65:491-500).

Peroxisome proliferator-activated receptor α (PPARα) contributes to control of melanogenesis in B16 F10 melanoma cells

Recent studies revealed the cooperation between peroxisome proliferator-activated receptor gamma (PPARγ) and α-MSH signaling, which results in enhanced melanogenesis in melanocytes and melanoma cells. However, the agonists of PPARα, such as fenofibrate, exert depigmenting effect. Therefore, we aimed to check how the PPARα expression level affects the antimelanogenic activity of fenofibrate and whether PPARα modulates melanogenesis independently of its agonist. To answer these questions, we used three B16 F10-derived cell lines, which varied in the PPARα expression level and were developed by stable transfection with plasmids driving shRNA-based PPARα silencing or overexpression of PPARα-emerald GFP fusion protein. Melanin contents were assessed with electron paramagnetic resonance spectroscopy along with color component image analysis-a novel approach to pigment content characteristics in melanoma cells. B16 F10 wt and Ctrl shRNA lines showed intermediate pigmentation, whereas the pigmentation of the B16 F10-derived cell lines was inversely correlated with the PPARα expression level. We observed that cells overexpressing PPARα were almost amelanotic and cells with reduced PPARα protein level were heavily melanized. Furthermore, fenofibrate down-regulated the melanogenic apparatus (MITF, tyrosinase, and tyrosinase-related proteins) in the cells with the regular PPARα expression level resulting in their visibly lower total melanin content in all the cell lines. From these observations, we conclude that fenofibrate works as a strong depigmenting agent, which acts independently of PPARα, but in an additive fashion. Our results also indicate that alterations in PGC-1a acetylation and expression level might contribute to the regulation of melanogenesis by PPARα and fenofibrate.

Effect of dietary n-3 fatty acids supplementation on fatty acid metabolism in atorvastatin-administered SHR.Cg-Leprcp/NDmcr rats, a metabolic syndrome model

The effects of cholesterol-lowering statins, which substantially benefit future cardiovascular events, on fatty acid metabolism have remained largely obscured. In this study, we investigated the effects of atorvastatin on fatty acid metabolism together with the effects of TAK-085 containing highly purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ethyl ester on atorvastatin-induced n-3 polyunsaturated fatty acid lowering in SHR.Cg-Lepr^cp/NDmcr (SHRcp) rats, as a metabolic syndrome model. Supplementation with 10mg/kg body weight/day of atorvastatin for 17 weeks significantly decreased plasma total cholesterol and very low density lipoprotein cholesterol. Atorvastatin alone caused a subtle change in fatty acid composition particularly of EPA and DHA in the plasma, liver or erythrocyte membranes. However, the TAK-085 consistently increased both the levels of EPA and DHA in the plasma, liver and erythrocyte membranes. After confirming the reduction of plasma total cholesterol, 300mg/kg body weight/day of TAK-085 was continuously administered for another 6 weeks. Supplementation with TAK-085 did not decrease plasma total cholesterol but significantly increased the EPA and DHA levels in both the plasma and liver compared with rats administered atorvastatin only. Supplementation with atorvastatin alone significantly decreased sterol regulatory element-binding protein-1c, Δ5- and Δ6-desaturases, elongase-5, and stearoyl-coenzyme A (CoA) desaturase-2 levels and increased 3-hydroxy-3-methylglutaryl-CoA reductase mRNA expression in the liver compared with control rats. TAK-085 supplementation significantly increased stearoyl-CoA desaturase-2 mRNA expression. These results suggest that long-term supplementation with atorvastatin decreases the EPA and DHA levels by inhibiting the desaturation and elongation of n-3 fatty acid metabolism, while TAK-085 supplementation effectively replenishes this effect in SHRcp rat liver.

The Influence of Probiotic Lactobacilli and Flaxseed on the Health of Weaned Piglets and Metabolism of Polyunsaturated Fatty Acids (PUFAs)

This study investigated for 14 days post-weaning, the influence of dietary supplementation of synbiotics in the form of probiotic cheeses containing cultures of L. plantarum and L. fermentum and crushed flaxseed (source of ω-3 polyunsaturated fatty acids — PUFAs and fibre) on 36 commercial piglets originating from an infected herd (Coronavirus and E. coli) during the critical period of weaning. We focused on the health and metabolism of PUFAs in this critical period of a piglet’s life. The dietary supplementation positively affected: the overall health state of weaners, reduced diarrhoea by 29 % by 14 days post-weaning and significantly increased the counts of lactic acid bacteria, bifidobacteria and the production of volatile fatty acids. The PUFA concentrations in the m. biceps femoris of the piglets were analysed by gas chromatography. High levels of ω-3 alpha-linolenic acid (ALA) in flaxseed increased significantly the level of ALA, eicosapentaenic acid (EPA) and docosahexaenic acid (DHA) in the pig muscles on days 7 and 14 post-weaning. The levels of ω-6 linolenic acid (LA) were less affected by the diet, but were increased on day 14 post-weaning, while the conversion products of LA, and arachidonic acid (AA), were decreased on days 7 and 14. The increased level of dietary ALA favoured the activity of Δ-6-desaturase for the conversion of ALA to EPA and DHA, at the expense of AA synthesis from LA. The ability of synbiotics to incorporate high levels of DHA in the pig muscles appear prospective for improving the nutritional properties of pork and reducing the occurrence of civilization diseases in consumers of this product of animal origin.

Hypoxia is associated with a lower expression of genes involved in lipogenesis in visceral adipose tissue

Background

A key role for HIF-1α in the promotion and maintenance of dietary obesity has been proposed. We analyzed the association between hypoxia and de novo lipogenesis in human adipose tissue.

Methods

We studied HIF-1α mRNA and protein expression in fasting status in visceral adipose tissue (VAT) from non-obese and morbidly obese subjects, and in VAT from wild-type and ob/ob C57BL6J mice in both fasting and feeding status. We also analyzed the effect of hypoxia on the VAT mRNA expression of genes involved in lipogenesis.

Results

HIF-1α was increased in VAT from morbidly obese subjects. In fasting status, C57BL6J ob/ob mice had a higher VAT HIF-1α mRNA expression than C57BL6J wild-type mice. In feeding status, VAT HIF-1α mRNA expression significantly increased in C57BL6J wild-type, but not in C57BL6J ob/ob mice. In humans, HIF-1α mRNA expression correlated positively with body mass index and insulin resistance. VAT HIF-1α mRNA expression correlated negatively with ACC1, PDHB and SIRT3 mRNA expression, and positively with PPAR-γ. VAT explants incubated in hypoxia showed reduced SIRT3 and increased PPAR-γ, SREBP-1c, ACLY, ACC1 and FASN mRNA expression.

Conclusions

Morbidly obese subjects have a higher level of VAT HIF-1α. Postprandial status is associated with an increase in HIF-1α mRNA expression in C57BL6J wild-type mice. Hypoxia alters the mRNA expression of genes involved in de novo lipogenesis in human VAT.

Differential Ratios of Omega Fatty Acids (AA/EPA+DHA) Modulate Growth, Lipid Peroxidation and Expression of Tumor Regulatory MARBPs in Breast Cancer Cell Lines MCF7 and MDA-MB-231

Omega 3 (n3) and Omega 6 (n6) polyunsaturated fatty acids (PUFAs) have been reported to exhibit opposing roles in cancer progression. Our objective was to determine whether different ratios of n6/n3 (AA/EPA+DHA) FAs could modulate the cell viability, lipid peroxidation, total cellular fatty acid composition and expression of tumor regulatory Matrix Attachment Region binding proteins (MARBPs) in breast cancer cell lines and in non-cancerous, MCF10A cells. Low ratios of n6/n3 (1:2.5, 1:4, 1:5, 1:10) FA decreased the viability and growth of MDA-MB-231 and MCF7 significantly compared to the non-cancerous cells (MCF10A). Contrarily, higher n6/n3 FA (2.5:1, 4:1, 5:1, 10:1) decreased the survival of both the cancerous and non-cancerous cell types. Lower ratios of n6/n3 selectively induced LPO in the breast cancer cells whereas the higher ratios induced in both cancerous and non-cancerous cell types. Interestingly, compared to higher n6/n3 FA ratios, lower ratios increased the expression of tumor suppressor MARBP, SMAR1 and decreased the expression of tumor activator Cux/CDP in both breast cancer and non-cancerous, MCF10A cells. Low n6/n3 FAs significantly increased SMAR1 expression which resulted into activation of p21^WAF1/CIP1 in MDA-MB-231 and MCF7, the increase being ratio dependent in MDA-MB-231. These results suggest that increased intake of n3 fatty acids in our diet could help both in the prevention as well as management of breast cancer.