α-linolenic acid and long-chain n-3 polyunsaturated fatty acids modulate colitis operating with a different gene set
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ABSTRACT: Adult Wistar rats were fed diet enriched with either α-linolenic acid (ALA) or fish oil for 8 (n=10) weeks. Colitis was induced in rats using 5% dextran sulfate sodium for 7 days. The rats were dissected and RNA was isolated from the colon tissues of rats, the samples from 6 rats were pooled and used for the microarray experiments. Global gene expression analysis was done in duplicates in each group and the results were compared to n-6 fatty acid group. α-linolenic acid (ALA) and fish oil rich in eicosapentaenoic acid and docosahexaenoic acid significantly attenuated the symptoms of colitis, compared to n-6 fatty acid group. Gene expression analysis has revealed that there is no common gene signature in the two groups.
Project description:Novel DHA-enriched oils with high α-linolenic acid (ALA) content will be available in the near future as an alternative for dietary fish oil replacement in aquafeeds. As preliminary validation, we 1) assessed the ability of a diet containing a formulated oil blend (tuna oil + flaxseed oil, TOFX) with high DHA and ALA content to achieve fish oil-like omega-3 long-chain (≥C20) polyunsaturated fatty acids (n-3 LC-PUFA) tissue composition in Atlantic salmon smolts, and 2) applied liver proteomics as exploratory approach to understand the consequent nutritional changes. Comparisons were made on fish fed a fish oil-based diet (FO) and a commercial-like oil blend diet (fish oil + poultry oil, FOPO) over 89 days. Growth and feed efficiency ratio were lower on the TOFX diet. Fish tissue concentration of n-3 LC-PUFA and the n-3:n-6 ratio were significantly higher for TOFX than for FOPO, but not higher than for FO, while tissue retention efficiency of n-3 LC-PUFA was promoted by TOFX relative to FO. Proteomics analysis revealed an unexpected oxidative stress response as the main adaptive physiological mechanism in TOFX fish. While specific dietary fatty acid concentrations and balances and antioxidant supplementation may need further attention, the use of an oil with a high content of DHA and ALA can enhance tissue deposition of n-3 LC-PUFA in relation to a commercially used blend oil.
Project description:Two rapeseed germplasms named YH25005 and R8Q10 that contain 15% to 21% α-linolenic acid (ALA) in the seed fatty acids was developed and high linolenic acid trait is a new goal to improve the nutritional quality. In order to identify the important biological pathways underpinning high/low linolenic acid trait, the transcriptome profiles of the 24-days-old embryos of YH25005 and R8Q10 was compared to that of two low linolenic acid inbred lines named A28 and SW, by using Illumina RNA-seq. We identified 6140, 8830, 9868, and 11846 differential expression genes in pairewise transcriptomic comparison of R8Q10 vs A28, YH25005 vs A28, R8Q10 vs SW, and YH5005 vs SW, respectively. It was found that some key genes related to fatty acid biosynthesis process, including LEC1, TT8, TT12, FAB1, KASII, FUS3, LEC2, FaTA, FATB, FAD7, ABI3, FAD3, KASI, SUA, Lox1 and Lox2, were significantly altered in YH25005 and R8Q10.
Project description:Omega-3 and omega-6 polyunsaturated fatty acids (PUFA) have important signalling roles in the body. The goal of this study was to investigate the impact of linoleic acid (LA, omega-6) and alpha-linolenic (ALA, omega-3) on global skeletal muscle gene expression. We were also interested to study the impact of these fatty acids on myokine expression. To differentiate the roles of essential dietary PUFA on skeletal muscle function, we fed male rats a control diet (AIN-93G) or diets containing 10% safflower oil or flaxseed oil. Skeletal muscle gene expression was investigated by microrray.
Project description:Lipid metabolic disarray in young and adult mice offspring's liver is induced by saturated fatty acids (SFA) but prevented by alpha linolenic acid (ALA, 18:3 ω3) in the maternal diet during pregnancy and lactation. The aim of the present study was to analyse the impact of maternal dietary ALA on the liver gene expression in the new-born offspring in comparison to a SFA diet. Methods: C57Bl6/J dams were fed with diets normal in calories but rich in ALA or SFA before mating and during pregnancy. Pups were sacrificed at birth and liver parameters were assessed. Gene expression was characterized by microarray analysis and validated by real time qPCR. Results: ALA compared to SFA in maternal diets during pregnancy, increased polyunsaturated fatty acids while differentially modified fatty acid desaturase activities in offspring liver. Overall, 474 and 662 genes from born pups’ liver, were differentially regulated by ALA and SFA compared to control diet (p<0.05; Fold change 2), respectively. Notably, Per3 was up-regulated by ALA whereas down-regulated by SFA, compared to control diet. Conclusions: ALA and SFA enriched diets differentially affect gene expression pattern in the offspring’s liver. ALA in particular, upregulates genes associated to low adiposity.
Project description:Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFA) have important signalling roles in the hypothalamus, a region of the brain that regulates whole-body energy homeostasis. While evidence suggests that high PUFA intake can impact hypothalamic activity, the underlying molecular mechanisms regulated by essential dietary PUFA (i.e., linoleic acid and alpha-linolenic acid) remain poorly described in this brain region. To differentiate the roles of essential dietary PUFA on hypothalamic function, we fed male rats high-fat diets (35% kcal/d) containing either safflower (linoleic acid) or flaxseed (alpha-linolenic acid) oil for 2 months. Control rats were fed a low-fat (16% kcal/d) diet containing soybean oil. Hypothalmic gene expression was investigated by microrray.
Project description:Tree peony (Paeonia ostii section Moutan DC.) is known for its excellent ornamental and medicinal values. In 2011, seeds from P. ostii have been identified as novel resource of alpha-linolenic acid (ALA) for seed oil production and development in China. However, the molecular mechanism on biosynthesis of unsaturated fatty acids in tree peony seeds remains unknown. Therefore, transcriptome data is needed to better understand the underlying mechanisms. In this study, lipids accumulation contents were measured using GC-MS methods across developing tree peony seeds, which exhibited an extraordinary ALA content (49.3%) in P. ostii mature seeds. Transcriptome analysis was performed using Illumina sequencing platform. A total of 144 million 100-bp paired-end reads were generated from six libraries, which identified 175,874 contigs. In the KEGG Orthology enrichment of differentially expressed genes, lipid metabolism pathways were highly represented categories. Using this data we identified 388 unigenes that may be involved in de novo fatty acid and triacylglycerol biosynthesis. In particular, three unigenes (SAD, FAD2 and FAD8) encoding fatty acid desaturase with high expression levels in the fast oil accumulation stage compared with the initial stage of seed development were identified.
Project description:This experiment was designed to test the effect of alpha-linolenic acid (ALA) and insulin on liver slices prepared from Atlantic salmon. Liver slices were incubated with increasing concentrations of ALA and insulin from 20µM to 100µM and 10nM to 100nM, respectively. RNA was subsequently sequenced and response was evaluated and compared to the expected response from Atlantic salmon feeding trials. The purpose of this was to evaluate liver slice culture as a cell culture system for studying lipid metabolism in Atlantic salmon.
Project description:As representatives of n-6 and n-3 fatty acids, many studies have analyzed the use of soybean oil and linseed oil rich in linoleic acid (18:2n-6, LA) and α-linolenic acid (18:3n-3, LNA) as better substitutes for fish oil. In aquatic animals, different dietary ratios of LA and LNA could have significant effects on growth, lipid metabolism, immune response, and reproduction. To assess the nutritive value of these two fatty acids for the Chinese mitten crab (Eriocheir sinensis), we performed transcriptome analysis and proteomic analysis using label-free quantification of the hepatopancreas of mitten crabs fed with LA or LNA diet. Our results provide new insights for further investigation into the replacement of fish oil from mitten crabs with vegetable oils and enable us to better understand the different roles and nutrition value of LA and LNA in mitten crabs.
Project description:The beneficial effects of dietary long-chain (LC) n-3 polyunsaturated fatty acids (PUFA) in the prevention and/or treatment of some metabolic disorders result largely from their capacity to regulate the transcription level of many genes involved in metabolic and physiological homeostasis, especially in the liver. In this respect, they are known to bind and activate the Peroxisome Proliferator-Activated Receptor alpha (PPARalpha). The precursor of LC-PUFA, a-linoleic acid (ALA, C18:3 n-3) share some beneficial metabolic effects with its LC derivatives, however its role in gene regulation is poorly documented. Here, we analysed the hepatic transcriptome of mice fed for 5 weeks diets rich in either saturated FA from palm oil (PALM group) or ALA from linseed oil (LIN group). This modification of dietary fatty acid composition in a context of a high fat diet had a subtle but significant effect on the hepatic transcriptome. We identified mainly a group of genes that were upregulated in the LIN vs the PALM group and that include several well-known PPARalpha target genes involved in lipid and xenobiotic metabolism. Liver gene expression was measured in male C57BL/6J mice fed during 5 weeks a high fat diet (51% energy from fat) containing palm oil, rich in saturated fatty acids (n=10) or linseed oil, rich in 18:3 n-3 (n=8)
Project description:The goal of this study was to investigate the individual and combined effects of alpha-linolenic acid (the essential omega-3 fatty acid) and an inhibitor of the delta-6 desaturse (SC-26196) during adipocye differentiation.