Intraperitoneal Administration of Short-Chain Fatty Acids Improves Lipid Metabolism of Long–Evans Rats in a Sex-Specific Manner

Short-chain fatty acids (SCFAs) are microbial metabolites, mainly generated by the action of gut microbiota on dietary fibers. Acetate, propionate, and butyrate are the three main SCFAs produced typically in a 60:20:20 molar ratio in the colon. Acetate, propionate, and butyrate, when given individually as supplements, have shown a protective role in obesity and hyperglycemia; however, the sex-specific effects of a mixture of SCFAs, when given in 60:20:20 ratio, on the regulation of lipid metabolism and lipid profile are not known. Male and female Long–Evans rats were given a mixture of SCFAs (acetate, propionate, and butyrate; molar ratio 60:20:20) each day for seven days intraperitoneally; plasma and hepatic lipids, gene expression, and lipidomics profile were analyzed. SCFAs significantly decreased plasma and hepatic triglycerides and cholesterol in males, whereas the fatty acyl composition of cholesteryl esters, triglycerides, and phospholipids was modulated in females. SCFAs decreased the mRNA expression of hepatic acetyl-CoA carboxylase-1 in both males and females. Our findings demonstrate for the first time that SCFAs (60:20:20) improved plasma and hepatic lipid levels and fatty acyl composition in a manner that may provide cardio-protective and anti-inflammatory effects in both sexes, via independent mechanisms

An Interaction of the Pre- and Post-Weaning Diets Rich in Omega-6 Polyunsaturated Fats Alters Plasma Lipids, Hepatic Gene Expression and Aortic Vascular Reactivity in Adult 057Bl/6 Mice

Aim To investigate the effects of diets rich in n-6 polyunsaturated fats (PUFA) fed during pre- and post-weaning time periods on the lipid metabolism and vascular reactivity in adult C57Bl/6 mice, in order to assess the impact of maternal nutrition and its interaction with the offspring diet on the metabolism of adult offspring. Methods Female C57Bl/6 mice were fed a high-fat diet enriched with n-6 PUFA (P) or control diet (C) for 2-weeks before, during mating, gestation and lactation, while their pups received either P or C for 8-weeks post-weaning. Results A significant interaction between the maternal and post-weaning diets was observed for the offspring body weight, food-, caloric-intake, plasma lipids, hepatic mRNA expression of lecithin cholesterol acyltransferase, aortic contractile and relaxation responses ( P < 0.05). Conclusion The overall metabolic and physiological outcome in the offspring is dependent upon the interaction between the pre- and post-weaning dietary environments

Novel regulatory roles of omega-3 fatty acids in metabolic pathways: a proteomics approach

Background: Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been shown to alleviate the symptoms of metabolic disorders, such as heart disease, diabetes, obesity and insulin resistance. Several putative mechanisms by which n-3 PUFA elicit beneficial health effects have been proposed; however, there is still a shortage of knowledge on the proteins and pathways that are regulated by n-3 PUFA. Methods: Using two dimensional polyacrylamide gel electrophoresis (2D-PAGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, we investigated the effects of diets high or low in n-3 PUFA on hepatic proteomic profile of C57BL/6 mice. Results: The findings show for the first time that high dietary n-3 PUFA reduced the expression of regucalcin, adenosine kinase and aldehyde dehydrogenase. On the other hand, diets high in n-3 PUFA increased the expression of apolipoprotein A-I, S-adenosylmethionine synthase, fructose-1, 6-bisphosphatase, ketohexokinase, malate dehydrogenase, GTP-specific succinyl CoA synthase, ornithine aminotransferase and protein disulfide isomerase-A3. Conclusions: Our findings revealed for the first time that n-3 PUFA causes alterations in several novel functional proteins involved in regulating lipid, carbohydrate, one-carbon, citric acid cycle and protein metabolism, suggesting integrated regulation of metabolic pathways. These novel proteins are potential targets to develop therapeutic strategies against metabolic disorders

Modification of gene expression in rat cardiomyocytes by linoleic and docosahexaenoic acid

Regulation of cardiac fatty acid metabolism is central to the development of cardiac hypertrophy and heart failure. We investigated the effects of some specific fatty acids on the expression of genes involved in immediate early as well as inflammatory and hypertrophic responses in adult rat cardiomyocytes. Cardiac remodeling begins with upregulation of immediate early genes c-fos and c-jun, followed by upregulation of inflammatory genes such as NF-kB and NFAT. At later stages, genes involved in the hypertrophic responses such as atrial natriuretic peptide (ANP) and brain natriuretic factor (BNF) are upregulated. Adult rat cardiomyocytes were treated with saturated fatty acid palmitic acid, monounsaturated fatty acid oleic acid, polyunsaturated fatty acids (PUFA) belonging to the n-6 class, linoleic acid and n-3 PUFA docosahexaenoic acid. Linoleic acid produced a greater increase in the mRNA expression of c-fos, c-jun, NF-ÎşB, NFAT3, ANP and BNP, in comparison to palmitic acid and oleic acid. In contrast, docosahexaenoic acid caused a decrease in the expression of genes involved in cardiac hypertrophy. Our findings suggest that linoleic acid is a potent inducer of cardiac hypertrophy, whereas docosahexaenoic acid exerts protective effects for heart health benefits.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Diets Enriched in Fish-Oil or Seal-Oil have Distinct Effects on Lipid Levels and Peroxidation in BioF1B Hamsters

Aim Fish-oil omega-3 polyunsaturated fatty acids (n-3 PUFAs) are mostly esterified to the sn -2 position of triglycerides, while in seal-oil triglycerides, these are mostly esterified to the sn -1 and −3 positions. We investigated whether fish-oil and seal-oil feeding has a different effect on the regulation of lipid metabolism and oxidative stress in BioF 1 B hamsters. Methods BioF 1 B hamsters were fed high fat diets rich in fish-oil or seal-oil for 4 weeks, and fasted for 14 hours prior to blood and tissue collection. Results Plasma and hepatic lipids and lipid peroxidation levels were significantly lower in seal-oil-fed hamsters as compared to those fed fish-oil. There was a selective hindrance of clearance of lipids in fish-oil-fed hamsters as reflected by higher levels of plasma apoB48. Conclusion Differences in the fatty acid composition and positional distribution of n-3 PUFAs in triglycerides of fish-oil and seal-oil are suggested to trigger metabolic differences

Omega-3 fatty acids accelerate fledging in an avian marine predator: a potential role of cognition

Consuming omega-3 fatty acids (n-3 LCPUFAs) during development improves cognition in mammals, but the effect remains untested in other taxa. In aquatic ecosystems, n-3 LCPUFAs are produced by phytoplankton and bioaccumulate in the food web. Alarmingly, the warming and acidification of aquatic systems caused by climate change impair n-3 LCPUFA production, with an anticipated decrease of 80% by the year 2100. We tested whether n-3 LCPUFA consumption affects the physiology, morphology, behaviour and cognition of the chicks of a top marine predator, the ring-billed gull. Using a colony with little access to n-3 LCPUFAs, we supplemented siblings from 22 fenced nests with contrasting treatments from hatching until fledging; one sibling received n-3 LCPUFA-rich fish oil and the other, a control sucrose solution without n-3 LCPUFAs. Halfway through the nestling period, half the chicks receiving fish oil were switched to the sucrose solution to test whether n-3 LCPUFA intake remains crucial past the main growth phase (chronic versus transient treatments). Upon fledging, n-3 LCPUFAs were elevated in the blood and brains of chicks receiving the chronic treatment, but were comparable to control levels among those receiving the transient treatment. Across the entire sample, chicks with elevated n-3 LCPUFAs in their tissues fledged earlier despite their morphology and activity levels being unrelated to fledging age. Fledging required chicks to escape fences encircling their nest. We therefore interpret fledging age as a possible indicator of cognition, with chicks with improved cognition fledging earlier. These results provide insight into whether declining dietary n-3 LCPUFAs will compromise top predators' problem-solving skills, and thus their ability to survive in a rapidly changing world