scholarly journals Effects of three different conjugated linoleic acid preparations on insulin signalling, fat oxidation and mitochondrial function in rats fed a high-fat diet

2007 ◽  
Vol 98 (2) ◽  
pp. 264-275 ◽  
Author(s):  
Joo Sun Choi ◽  
In-Uk Koh ◽  
Myeong Ho Jung ◽  
Jihyun Song
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Mitochondrial Function ◽  
High Fat Diet ◽  
Insulin Signalling ◽  
Fat Oxidation ◽  
Acid Oxidation ◽  
High Fat ◽  
Cla Isomers

To investigate the effects of three different conjugated linoleic acid (CLA) preparations containing different ratios of CLA isomers on insulin signalling, fatty acid oxidation and mitochondrial function, Sprague–Dawley rats were fed a high-fat diet either unsupplemented or supplemented with one of three CLA preparations at 1 % of the diet for 8 weeks. The first CLA preparation contained approximately 30 % cis-9, trans-11 (c9, t11)-CLA isomer and 40 % trans-10, cis-12 (t10, c12)-CLA isomer (CLA-mix). The other two preparations were an 80:20 mix (c9, t11-CLA-mix) or a 10:90 mix of two CLA isomers (t10, c12-CLA-mix). Insulin resistance was decreased in all three supplemented groups based on the results of homeostasis model assessment and the revised quantitative insulin-sensitivity check index. The phosphorylation of insulin receptor substrate-1 on serine decreased in the livers of all three supplemented groups, while subsequent Akt phosphorylation increased only in the t10, c12-CLA-mix group. Both the c9, t11-CLA-mix and the t10, c12-CLA-mix increased the expression of hepatic adiponectin receptors R1 and 2, which are thought to enhance insulin sensitivity and fat oxidation. The c9, t11-CLA-mix increased protein and mRNA levels of PPARα, acyl-CoA oxidase and uncoupling protein, which are involved in fatty acid oxidation and energy dissipation. The c9, t11-CLA-mix enhanced mitochondrial function and protection against oxidative stress by increasing the activities of cytochrome c oxidase, manganese-superoxide dismutase, glutathione peroxidase, and glutathione reductase and the level of GSH. In conclusion, all three CLA preparations reduced insulin resistance. Among them, the c9, t11-CLA-mix was the most effective based on the parameters reflecting insulin resistance and fat oxidation, and mitochondrial antioxidative enzyme activity in the liver.

scholarly journals Tumor Necrosis Factor Alpha Knockout Promotes Adipose Fatty Acid Oxidation and Attenuates Insulin Resistance and Hepatic Steatosis in High Fat Diet-Fed Mice

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1705-1705
Author(s):  
Seok-Yeong Yu ◽  
Jinchao Li ◽  
Zhenhua Liu ◽  
Young-Cheul Kim
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
High Fat Diet ◽  
Tumor Necrosis ◽  
Acid Metabolism ◽  
Acid Oxidation ◽  
High Fat ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Necrosis Factor

Abstract Objectives Substantial evidence indicates that adipose tissue (AT) dysfunction and lipid spillover in obesity promote insulin resistance and non-alcoholic fatty liver disease. Tumor necrosis factor alpha (TNFα) is one of the pro-inflammatory cytokines overexpressed in obesity and its knockout (KO) attenuates diet-induced adiposity, lipid deposition in the liver and insulin resistance. However, the potential roles played by TNFα in fatty acid metabolism in AT have been incompletely understood. The objective of this study was to investigate the role of TNFα in obesity-induced insulin resistance with the goal of providing a potential target for therapeutics. Methods Three groups of wild type (WT) or TNFα KO male mice on the same B6 genetic background were fed designated diets for 16 weeks; WT fed a low-fat diet (LFD-WT), WT fed a high-fat diet (HFD-WT), and TNFα KO fed a HFD (HFD-TNFα KO). Blood concentrations of glucose and insulin and hepatic triacylglycerol (TG) levels were measured. The expression of genes involved in fatty acid and TG synthesis and fatty acid oxidation (FAO) was measured in epididymal white AT (eWAT). Results Compared to the LFD-fed mice, HFD-WT group had a significantly higher levels of blood glucose and insulin, and hepatic TG (P < 0.05). TNFα KO mice significantly improved HFD-induced hyperglycemia, hyperinsulinemia and hepatic TG accumulation (P < 0.05). In eWAT, TNFα ablation did not affect the expression of de novo fatty-acid synthesis-related genes, but significantly increased the expression of TG synthesis-related genes (p < 0.05). Moreover, TNFα KO presented a significantly increased expression of the FAO-related gene, CPT1, with a concomitant increase in the expression of glucose transporter 4 (GLUT4) and oxidative phosphorylation-related genes (CS and mt-CO1) (P < 0.05). Further evidence of the inhibition of fatty acid metabolism by TNFα includes a significant suppression of CPT1 as well as TG synthesis-related genes (P < 0.05) in 3T3-L1 adipocytes treated with TNFα. Conclusions These data indicate that antagonizing TNFα may mitigate diet-induced insulin resistance and hepatic steatosis by promoting FAO in obese AT. Funding Sources N/A.

scholarly journals Increase in fat oxidation on a high-fat diet is accompanied by an increase in triglyceride-derived fatty acid oxidation

Diabetes ◽  
2000 ◽  
Vol 49 (4) ◽  
pp. 640-646 ◽  
Author(s):  
P. Schrauwen ◽  
A. J. Wagenmakers ◽  
W. D. van Marken Lichtenbelt ◽  
W. H. Saris ◽  
K. R. Westerterp
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Fat Oxidation ◽  
Acid Oxidation ◽  
High Fat

scholarly journals Consumption of a Mango Fruit Powder Protects Mice from High-Fat Induced Insulin Resistance and Hepatic Fat Accumulation

2017 ◽  
Vol 42 (2) ◽  
pp. 564-578 ◽  
Author(s):  
Agustín G. Sabater ◽  
Joan Ribot ◽  
Teresa Priego ◽  
Itxaso Vazquez ◽  
Sonja Frank ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Insulin Sensitivity ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Acid Oxidation ◽  
High Fat ◽  
Food Ingredient ◽  
Mango Fruit ◽  
Fruit Powder

Background/Aims: The aim of this study was to gain more insight into the beneficial effects of mango fruit powder on the early metabolic adverse effects of a high-fat diet. Methods: The progressive dose-response effects of mango fruit powder on body composition, circulating parameters, and the expression of genes related to fatty acid oxidation and insulin sensitivity in key tissues were studied in mice fed a moderate (45%) high-fat diet. Results: Findings suggest that mango fruit powder exerts physiological protective effects in the initial steps of insulin resistance and hepatic lipid accumulation induced by a high-fat diet in mice. Moreover, AMPK and SIRT1 appear as key regulators of the observed improvement in fatty acid oxidation capacity, as well as of the improved insulin sensitivity and the increased glucose uptake and metabolism through the glycolytic pathway capacity in liver and skeletal muscle. Conclusion: In summary, this study provides evidence that the functional food ingredient (CarelessTM) from mango fruit prevents early metabolic alterations caused by a high-fat diet in the initial stages of the metabolic syndrome.

scholarly journals PO-193 Exercise training decreased lipid accumulation in murine skeletal muscle through Sestrin2-mediated SHIP2-JNK signaling pathway

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Tianyi Wang ◽  
Song Huang ◽  
Xiao Han ◽  
Sujuan Liu ◽  
Yanmei Niu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Exercise Training ◽  
High Fat Diet ◽  
De Novo ◽  
Underlying Mechanism ◽  
Wild Type ◽  
High Fat

Objective Obesity is becoming increasingly prevalent and is an important contributor to the worldwide burden of diseases. It is widely accepted that exercise training is beneficial for the prevention and treatment of obesity. However, the underlying mechanism by which exercise training improving skeletal muscle lipid metabolism is still not fully described. Sestrins (Sestrin1-3) are highly conserved stress-inducible protein. Concomitant ablation of Sestrin2 and Sestrin3 has been reported to provoke hepatic mTORC1/S6K1 activation and insulin resistance even without nutritional overload and obesity, implicating that Sestrin2 and Sestrin3 have an important homeostatic function in the control of mammalian glucose and lipid metabolism. Our previous results demonstrated that physical exercise increased Sestrin2 expression in murine skeletal muscle, while the role of Sestrin2 in regulating lipid metabolism remains unknown.  SH2 domain containing inositol 5-phosphatase (SHIP2) acts as a negative regulator of the insulin signaling both in vitro and in vivo. An increased expression of SHIP2 inhibits the insulin-induced Akt activation, glucose uptake, and glycogen synthesis in 3T3-L1 adipocytes, L6 myotubes and tissues of animal models. Alterations of SHIP2 expression and/or enzymatic function appear to have a profound impact on the development of insulin resistance. However, the regulatory function of SHIP2 in lipid metabolism after exercise remains unclear. It has been reported that SHIP2 modulated lipid metabolism through regulating the activity of c-Jun N-terminal kinase (JNK) and Sterol regulatory element-binding protein-1 (SREBP-1). JNK is a subclass of mitogen-activated protein kinase (MAPK) signaling pathway in mammalian cells and plays a crucial role in metabolic changes and inflammation associated with a high-fat diet. Inhibition of JNK reduces lipid deposition and proteins level of fatty acid de novo synthesis in liver cells. It has been reported that Sestrin2 regulated the phosphorylation of JNK, however the underlying mechanism remains unclear. SREBP-1 is important in regulating cholesterol biosynthesis and uptake and fatty acid biosynthesis, and SREBP-1 expression produces two different isoforms, SREBP-1a and SREBP-1c. SREBP-1c is responsible for regulating the genes required for de novo lipogenesis and its expression is regulated by insulin. SREBP-1a regulates genes related to lipid and cholesterol production and its activity is regulated by sterol levels in the cell. Altogether, the purpose of this study was to explore the effect and underlying mechanism of Sestrin2 on lipid accumulation after exercise training. Methods Male wild type and SESN2−/− mice were divided into normal chow (NC) and high-fat diet (HFD) groups to create insulin resistance mice model. After 8 weeks the IR model group was then divided into HFD sedentary control and HFD exercise groups (HE). Mice in HE group underwent 6-week treadmill exercise to reveal the effect of exercise training on lipid metabolism in insulin resistance model induced by HFD. We explored the mechanism through which Sestrin2 regulated lipid metabolism in vitro by supplying palmitate, overexpressing or inhibiting SESNs, SHIP2 and JNK in myotubes. Results We found that 6-week exercise training decreased body weight, BMI and fat mass in wild type and SESN2-/- mice after high-fat diet (HFD) feeding. And exercise training decreased the level of plasma glucose, serum insulin, triglycerides and free fatty acids in wild type but not in Sestrin2-/- mice. Lipid droplet in skeletal muscle was also decreased in wild type but did not in Sestrin2-/- mice. Moreover, exercise training increased the proteins expression involved in fatty acid oxidation and decreased the proteins which related to fatty acid de novo synthesis. The results of oil red staining and the change of proteins related to fatty acid de novo synthesis and beta oxidation in myotubes treated with palmitate, Ad-SESN2 and siRNA-Sestrin2 were consisted with the results in vivo, which suggested that Sestrin2 was a key regulator in lipid metabolism. Exercise training increased Sestrin2 expression and reversed up-regulation of SHIP2 and pJNK induced by HFD in wild type mice but not in Sestrin2-/- mice. In parallel, overexpression of Sestrin2 decreased the level of SHIP2 and pJNK induced by palmitate while Sestrin2 knock down by siRNA-Sestrin2 treatment did not change the expression of SHIP2 and pJNK, which suggested that Sestrin2 modulated SHIP2 and JNK in the state of abnormal lipid metabolism. Inhibition of SHIP2 reduced the activity of JNK, increased lipid accumulation and the proteins of fatty acid synthesis after palmitate treatment and over expression of Sestrin2, which suggest that Sestrin2 modulated lipid metabolism through SHIP2/JNK pathway. Conclusions Sestrin2 plays an important role in improving lipid metabolism after exercise training, and Sestrin2 regulates lipid metabolism by SHIP2-JNK pathway in skeletal muscle.

Abstract 437: Increasing Cardiac Fatty Acid Oxidation Protects Against High Fat Diet Induced Cardiomyopathy in Mice

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Dan Shao ◽  
Nathan Roe ◽  
Loreta D Tomasi ◽  
Alyssa N Braun ◽  
Ana Mattos ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Cardiac Dysfunction ◽  
High Fat Diet ◽  
Heart Weight ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
High Fat ◽  
Diet Induced Obesity ◽  
Cardiac Lipotoxicity

In the obese and diabetic heart, an imbalance between fatty acid uptake and fatty acid oxidation (FAO) promotes the development of cardiac lipotoxicity. We previously showed that cardiac specific deletion of acetyl CoA carboxylase 2 (ACC2) was effective in increasing myocardial FAO while maintaining normal cardiac function and energetics. In this study, we tested the hypothesis that ACC2 deletion in an adult heart would prevent the cardiac lipotoxic phenotype in a mouse model of diet-induced obesity. ACC2 flox/flox (CON) and ACC2 flox/flox-MerCreMer+ (iKO) after tamoxifen injection were subjected to a high fat diet (HFD) for 24 weeks. HFD induced similar body weight gain and glucose intolerance in CON and iKO. In isolated Langendorff-perfused heart experiments, HFD feeding increased FAO 1.6-fold in CON mice which was increased to 2.5-fold in iKO mice compared with CON on chow diet. Fractional shortening was significantly decreased in CON-HFD (32.8±2.8% vs. 39.2±3.2%, p< 0.05, n=5-6), but preserved in iKO-HFD mice (42.8±2.3%, vs. 38.5±1.4%, n=6), compared to respective chow fed controls. Diastolic function, assessed by E’/A’ ratio using tissue Doppler imaging, was significantly decreased in CON-HFD mice (1.11±0.08 vs. 0.91±0.09, p<0.05 n=5-6), while no difference was observed in iKO-HFD compared to iKO-chow (1.10±0.03 vs. 1.09±0.04, n=6). Heart weight /Tibia length ratio was significantly higher in CON than iKO mice after HFD feeding (7.19±0.22 vs. 6.47±0.28, p<0.05, n=6). Furthermore, HFD induced mitochondria super complex II, III and V instability, which was attenuated in iKO-HFD mice. These data indicate that elevated myocardial FAO per se does not cause the development of cardiac dysfunction in obese animals. In fact, enhancing FAO via ACC2 deletion prevents HFD induced cardiac dysfunction and attenuates pathological hypertrophy. These effects may be mediated, in part, by maintenance of mitochondrial integrity. Taken together, our findings suggest that promoting cardiac FAO is an effective strategy to resist the development of cardiac lipotoxicity during diet-induced obesity.

scholarly journals Proteomics study of the effect of high-fat diet on rat liver

2019 ◽  
Vol 122 (9) ◽  
pp. 1062-1072 ◽  
Author(s):  
Jian Sang ◽  
Hengxian Qu ◽  
Ruixia Gu ◽  
Dawei Chen ◽  
Xia Chen ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Rat Liver ◽  
High Fat Diet ◽  
Acid Synthesis ◽  
High Energy ◽  
The Body ◽  
Acid Oxidation ◽  
High Fat ◽  
Bioinformatics Analyses ◽  
Fat Diets

AbstractExcessive intake of high-energy diets is an important cause of most obesity. The intervention of rats with high-fat diet can replicate the ideal animal model for studying the occurrence of human nutritional obesity. Proteomics and bioinformatics analyses can help us to systematically and comprehensively study the effect of high-fat diet on rat liver. In the present study, 4056 proteins were identified in rat liver by using tandem mass tag. A total of 198 proteins were significantly changed, of which 103 were significantly up-regulated and ninety-five were significantly down-regulated. These significant differentially expressed proteins are primarily involved in lipid metabolism and glucose metabolism processes. The intake of a high-fat diet forces the body to maintain physiological balance by regulating these key protein spots to inhibit fatty acid synthesis, promote fatty acid oxidation and accelerate fatty acid degradation. The present study enriches our understanding of metabolic disorders induced by high-fat diets at the protein level.

scholarly journals Omega-3 Phospholipids from Krill Oil Enhance Intestinal Fatty Acid Oxidation More Effectively than Omega-3 Triacylglycerols in High-Fat Diet-Fed Obese Mice

Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2037 ◽  
Author(s):  
Petra Kroupova ◽  
Evert M. van Schothorst ◽  
Jaap Keijer ◽  
Annelies Bunschoten ◽  
Martin Vodicka ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
High Fat Diet ◽  
Body Weight Gain ◽  
Acid Oxidation ◽  
Obese Mice ◽  
Krill Oil ◽  
Omega 3 ◽  
High Fat ◽  
Lower Body Weight

Antisteatotic effects of omega-3 fatty acids (Omega-3) in obese rodents seem to vary depending on the lipid form of their administration. Whether these effects could reflect changes in intestinal metabolism is unknown. Here, we compare Omega-3-containing phospholipids (krill oil; ω3PL-H) and triacylglycerols (ω3TG) in terms of their effects on morphology, gene expression and fatty acid (FA) oxidation in the small intestine. Male C57BL/6N mice were fed for 8 weeks with a high-fat diet (HFD) alone or supplemented with 30 mg/g diet of ω3TG or ω3PL-H. Omega-3 index, reflecting the bioavailability of Omega-3, reached 12.5% and 7.5% in the ω3PL-H and ω3TG groups, respectively. Compared to HFD mice, ω3PL-H but not ω3TG animals had lower body weight gain (−40%), mesenteric adipose tissue (−43%), and hepatic lipid content (−64%). The highest number and expression level of regulated intestinal genes was observed in ω3PL-H mice. The expression of FA ω-oxidation genes was enhanced in both Omega-3-supplemented groups, but gene expression within the FA β-oxidation pathway and functional palmitate oxidation in the proximal ileum was significantly increased only in ω3PL-H mice. In conclusion, enhanced intestinal FA oxidation could contribute to the strong antisteatotic effects of Omega-3 when administered as phospholipids to dietary obese mice.

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