scholarly journals The Effect of a High-Fat Diet on the Fatty Acid Composition in the Hearts of Mice

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 824 ◽  
Author(s):  
Alicja Pakiet ◽  
Agnieszka Jakubiak ◽  
Paulina Mierzejewska ◽  
Agata Zwara ◽  
Ivan Liakh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Cardiac Function ◽  
High Fat Diet ◽  
Heart Function ◽  
Membrane Properties ◽  
Heart Cells ◽  
Standard Diet ◽  
High Fat ◽  
Fa Composition

The Western diet can lead to alterations in cardiac function and increase cardiovascular risk, which can be reproduced in animal models by implementing a high-fat diet (HFD). However, the mechanism of these alterations is not fully understood and may be dependent on alterations in heart lipid composition. The aim of this study was to evaluate the effect of an HFD on the fatty acid (FA) composition of total lipids, as well as of various lipid fractions in the heart, and on heart function. C57BL/6 mice were fed an HFD or standard laboratory diet. The FA composition of chow, serum, heart and skeletal muscle tissues was measured by gas chromatography–mass spectrometry. Cardiac function was evaluated by ultrasonography. Our results showed an unexpected increase in polyunsaturated FAs (PUFAs) and a significant decrease in monounsaturated FAs (MUFAs) in the heart tissue of mice fed the HFD. For comparison, no such effects were observed in skeletal muscle or serum samples. Furthermore, we found that the largest increase in PUFAs was in the sphingolipid fraction, whereas the largest decrease in MUFAs was in the phospholipid and sphingomyelin fractions. The hearts of mice fed an HFD had an increased content of triacylglycerols. Moreover, the HFD treatment altered aortic flow pattern. We did not find significant changes in heart mass or oxidative stress markers between mice fed the HFD and standard diet. The above results suggest that alterations in FA composition in the heart may contribute to deterioration of heart function. A possible mechanism of this phenomenon is the alteration of sphingolipids and phospholipids in the fatty acid profile, which may change the physical properties of these lipids. Since phospho- and sphingolipids are the major components of cell membranes, alterations in their structures in heart cells can result in changes in cell membrane properties.

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.

scholarly journals Shift in metabolic fuel in acylation-stimulating protein-deficient mice following a high-fat diet

2008 ◽  
Vol 294 (6) ◽  
pp. E1051-E1059 ◽  
Author(s):  
Christian Roy ◽  
Sabina Paglialunga ◽  
Alexandre Fisette ◽  
Patrick Schrauwen ◽  
Esther Moonen-Kornips ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Energy Expenditure ◽  
High Fat Diet ◽  
Ex Vivo ◽  
Direct Result ◽  
Acid Oxidation ◽  
High Fat ◽  
Metabolic Potential ◽  
Deficient Mice

ASP-deficient mice (C3 KO) have delayed postprandial TG clearance, are hyperphagic, and display increased energy expenditure. Markers of carbohydrate and fatty acid metabolism in the skeletal muscle and heart were examined to evaluate the mechanism. On a high-fat diet, compared with wild-type mice, C3 KO mice have increased energy expenditure, decreased RQ, lower ex vivo glucose oxidation (−39%, P = 0.018), and higher ex vivo fatty acid oxidation (+68%, P = 0.019). They have lower muscle glycogen content (−25%, P < 0.05) and lower activities for the glycolytic enzymes glycogen phosphorylase (−31%, P = 0.005), hexokinase (−43%, P = 0.007), phosphofructokinase (−51%, P < 0.0001), and GAPDH (−15%, P = 0.04). Analysis of mitochondrial enzyme activities revealed that hydroxyacyl-coenzyme A dehydrogenase was higher (+25%, P = 0.004) in C3 KO mice. Furthermore, Western blot analysis of muscle revealed significantly higher fatty acid transporter CD36 (+40%, P = 0.006) and cytochrome c (a marker of mitochondrial content; +69%, P = 0.034) levels in C3 KO mice, whereas the activity of AMP kinase was lower (−48%, P = 0.003). Overall, these results demonstrate a shift in the metabolic potential of skeletal muscle toward increased fatty acid utilization. Whether this is 1) a consequence of decreased adipose tissue storage with repartitioning toward muscle or 2) a direct result of the absence of ASP interaction with the receptor C5L2 in muscle remains to be determined. However, these in vivo data suggest that ASP inhibition could be a potentially viable approach in correcting muscle metabolic dysfunction in obesity.

scholarly journals L-Carnitine Is Involved in Hyperbaric Oxygen-Mediated Therapeutic Effects in High Fat Diet-Induced Lipid Metabolism Dysfunction

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 176 ◽  
Author(s):  
Junhua Yuan ◽  
Qixiao Jiang ◽  
Limin Song ◽  
Yuan Liu ◽  
Manwen Li ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Hyperbaric Oxygen ◽  
High Fat Diet ◽  
Therapeutic Effects ◽  
Human Beings ◽  
High Fat ◽  
Adipose Tissues ◽  
Expression Levels

Lipid metabolism dysfunction and obesity are serious health issues to human beings. The current study investigated the effects of hyperbaric oxygen (HBO) against high fat diet (HFD)-induced lipid metabolism dysfunction and the roles of L-carnitine. C57/B6 mice were fed with HFD or normal chew diet, with or without HBO treatment. Histopathological methods were used to assess the adipose tissues, serum free fatty acid (FFA) levels were assessed with enzymatic methods, and the endogenous circulation and skeletal muscle L-carnitine levels were assessed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Additionally, western blotting was used to assess the expression levels of PPARα, CPT1b, pHSL/HSL, and UCP1. HFD treatment increased body/adipose tissue weight, serum FFA levels, circulation L-carnitines and decreased skeletal muscle L-carnitine levels, while HBO treatment alleviated such changes. Moreover, HFD treatment increased fatty acid deposition in adipose tissues and decreased the expression of HSL, while HBO treatment alleviated such changes. Additionally, HFD treatment decreased the expression levels of PPARα and increased those of CPT1b in skeletal muscle, while HBO treatment effectively reverted such changes as well. In brown adipose tissues, HFD increased the expression of UCP1 and the phosphorylation of HSL, which was abolished by HBO treatment as well. In summary, HBO treatment may alleviate HFD-induced fatty acid metabolism dysfunction in C57/B6 mice, which seems to be associated with circulation and skeletal muscle L-carnitine levels and PPARα expression.

scholarly journals Effects Of Dietary Supplementation With A Mixture Of Buckwheat Leaf And Flower On Fatty Acid Composition Of Rat Brain Phospholipids

2015 ◽  
Vol 65 (3) ◽  
pp. 390-403 ◽  
Author(s):  
Petrović Snježana ◽  
Arsić Aleksandra ◽  
Debeljak-Martačić Jasmina ◽  
Đurendić-Brenesel Maja ◽  
Pilija Vladimir ◽  
...  
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
High Fat Diet ◽  
Standard Diet ◽  
High Fat ◽  
Beneficial Effects ◽  
Partial Period ◽  
Brain Phospholipids ◽  
Full Period

AbstractThe aim of our study was to stablish the possible alternations in fatty acid composition of brain phospholipids in rats on a standard and high-fat diet supplemented with buckwheat leaf and flower mixture (BLF) and subsequent possible beneficial effects of BLF. Four months old male Wistar rats were randomly divided into five experimental groups fed a standard diet, standard diet supplemented with 5% BLF, high-fat diet, high-fat diet with full-period (13 weeks) of 5% BLF supplementation and high-fat diet with partial-period (7 weeks) of 5% BLF supplementation. Gas-liquid chromatography was performed to analyze the fatty acids in hexane lipid extracts of whole rat brains.Supplementation with BLF did not induce significant changes in fatty acid composition of whole brain phospholipids in rats fed the standard diet. In rats on high-fat diet concomitant (full-period) BLF supplementation increased eicosapentaenoic acid (20:5n-3, EPA), total n-6 and n-6/n-3 ratio, and decreased the percentage of oleic acid (18:1n-9) and estimated activity of Δ-9 desaturase. When BLF application was postponed (partial-period) in the case of developed hyperlipidemia, a decrease of stearic acid (18:0) accompanied with an increased estimated Δ-9 desaturase activity was observed. Regardless of BLF supplementation all high-fat diet-fed groups showed an elevated percentage of linoleic acid (18:2n-6, LA) and a reduced estimated Δ-6 desaturase activity.BLF contributes to the maintenance of stable fatty acid composition of brain phospholipids and supports normal brain function in high-fat diet rats, with more positive effects when BLF was applied before hyperlipidemia developed. This could be the mode of buckwheat health beneficial effects on the brain.

Genetically increasing flux through β-oxidation in skeletal muscle increases mitochondrial reductive stress and glucose intolerance

2021 ◽  
Author(s):  
Cody D. Smith ◽  
Chein-Te Lin ◽  
Shawna L. McMillin ◽  
Luke A. Weyrauch ◽  
Cameron Alan Schmidt ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Glucose Tolerance ◽  
Glucose Intolerance ◽  
High Fat Diet ◽  
Whole Body ◽  
Acid Oxidation ◽  
Wild Type ◽  
High Fat ◽  
Redox Environment

Elevated mitochondrial H2O2 emission and an oxidative shift in cytosolic redox environment have been linked to high fat diet-induced insulin resistance in skeletal muscle. To test specifically whether increased flux through mitochondrial fatty acid oxidation, in the absence of elevated energy demand, directly alters mitochondrial function and redox state in muscle, two genetic models characterized by increased muscle β-oxidation flux were studied. In mice overexpressing peroxisome proliferator activated receptor-α in muscle (MCK-PPARα), lipid supported mitochondrial respiration, membrane potential (ΔΨm) and H2O2 production rate (JH2O2) were increased, which coincided with a more oxidized cytosolic redox environment, reduced muscle glucose uptake, and whole-body glucose intolerance despite an increased rate of energy expenditure. Similar results were observed in lipin-1 deficient, fatty-liver dystrophic mice, another model characterized by increased β-oxidation flux and glucose intolerance. Crossing MCAT (mitochondrial-targeted catalase) with MCK-PPARα mice normalized JH2O2 production, redox environment and glucose tolerance, but surprisingly both basal and absolute insulin-stimulated rates of glucose uptake in muscle remained depressed. Also surprising, when placed on a high fat diet MCK-PPARα mice were characterized by much lower whole body, fat and lean mass as well as improved glucose tolerance relative to wild-type mice, providing additional evidence that overexpression of PPARα in muscle imposes more extensive metabolic stress than experienced by wild-type mice on a high fat diet. Overall, the findings suggest that driving an increase in skeletal muscle fatty acid oxidation in the absence of metabolic demand imposes mitochondrial reductive stress and elicits multiple counterbalance metabolic responses in attempt to restore bioenergetic homeostasis.

scholarly journals Effects of different intensities of physical exercise on insulin sensitivity and protein kinase B/Akt activity in skeletal muscle of obese mice

2014 ◽  
Vol 12 (1) ◽  
pp. 82-89 ◽  
Author(s):  
Rodolfo Marinho ◽  
Leandro Pereira de Moura ◽  
Bárbara de Almeida Rodrigues ◽  
Luciana Santos Souza Pauli ◽  
Adelino Sanchez Ramos da Silva ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Protein Kinase ◽  
High Fat Diet ◽  
Protein Kinase B ◽  
Whole Body ◽  
Control Group ◽  
Standard Diet ◽  
Obese Mice ◽  
High Fat

Objective : To investigate the effects of different intensities of acute exercise on insulin sensitivity and protein kinase B/Akt activity in skeletal muscle of obese mice. Methods : Swiss mice were randomly divided into four groups, and fed either a standard diet (control group) or high fat diet (obese sedentary group and obese exercise group 1 and 2) for 12 weeks. Two different exercise protocols were used: swimming for 1 hour with or without an overload of 5% body weight. The insulin tolerance test was performed to estimate whole-body sensitivity. Western blot technique was used to determine protein levels of protein kinase B/Akt and phosphorylation by protein Kinase B/Akt in mice skeletal muscle. Results : A single bout of exercise inhibited the high fat diet-induced insulin resistance. There was increase in phosphorylation by protein kinase B/Akt serine, improve in insulin signaling and reduce of fasting glucose in mice that swam for 1 hour without overload and mice that swan for 1 hour with overload of 5%. However, no significant differences were seen between exercised groups. Conclusion : Regardless of intensity, aerobic exercise was able to improve insulin sensitivity and phosphorylation by protein kinase B/Ak, and proved to be a good form of treatment and prevention of type 2 diabetes.

scholarly journals Maternal Fat-1 Transgene Protects Offspring from Excess Weight Gain, Oxidative Stress, and Reduced Fatty Acid Oxidation in Response to High-Fat Diet

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 767 ◽  
Author(s):  
Kristen E. Boyle ◽  
Margaret J. Magill-Collins ◽  
Sean A. Newsom ◽  
Rachel C. Janssen ◽  
Jacob E. Friedman
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Fatty Acid ◽  
Weight Gain ◽  
Fatty Acid Oxidation ◽  
High Fat Diet ◽  
Overweight And Obesity ◽  
Acid Oxidation ◽  
High Fat ◽  
Mitochondrial Fatty Acid

Overweight and obesity accompanies up to 70% of pregnancies and is a strong risk factor for offspring metabolic disease. Maternal obesity-associated inflammation and lipid profile are hypothesized as important contributors to excess offspring liver and skeletal muscle lipid deposition and oxidative stress. Here, we tested whether dams expressing the fat-1 transgene, which endogenously converts omega-6 (n-6) to omega-3 (n-3) polyunsaturated fatty acid, could protect wild-type (WT) offspring against high-fat diet induced weight gain, oxidative stress, and disrupted mitochondrial fatty acid oxidation. Despite similar body mass at weaning, offspring from fat-1 high-fat-fed dams gained less weight compared with offspring from WT high-fat-fed dams. In particular, WT males from fat-1 high-fat-fed dams were protected from post-weaning high-fat diet induced weight gain, reduced fatty acid oxidation, or excess oxidative stress compared with offspring of WT high-fat-fed dams. Adult offspring of WT high-fat-fed dams exhibited greater skeletal muscle triglycerides and reduced skeletal muscle antioxidant defense and redox balance compared with offspring of WT dams on control diet. Fat-1 offspring were protected from the reduced fatty acid oxidation and excess oxidative stress observed in offspring of WT high-fat-fed dams. These results indicate that a maternal fat-1 transgene has protective effects against offspring liver and skeletal muscle lipotoxicity resulting from a maternal high-fat diet, particularly in males. Altering maternal fatty acid composition, without changing maternal dietary composition or weight gain with high-fat feeding, may highlight important strategies for n-3-based prevention of developmental programming of obesity and its complications.

AMPK-α2 is involved in exercise training-induced adaptations in insulin-stimulated metabolism in skeletal muscle following high-fat diet

2014 ◽  
Vol 117 (8) ◽  
pp. 869-879 ◽  
Author(s):  
Marcia J. Abbott ◽  
Lorraine P. Turcotte
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Exercise Training ◽  
High Fat Diet ◽  
Citrate Synthase ◽  
Wheel Running ◽  
Dominant Negative ◽  
Standard Diet ◽  
High Fat ◽  
Palmitate Uptake

AMP-activated protein kinase (AMPK) has been studied extensively and postulated to be a target for the treatment and/or prevention of metabolic disorders such as insulin resistance. Exercise training has been deemed a beneficial treatment for obesity and insulin resistance. Furthermore, exercise is a feasible method to combat high-fat diet (HFD)-induced alterations in insulin sensitivity. The purpose of this study was to determine whether AMPK-α2 activity is required to gain beneficial effects of exercise training with high-fat feeding. Wild-type (WT) and AMPK-α2 dominant-negative (DN) male mice were fed standard diet (SD), underwent voluntary wheel running (TR), fed HFD, or trained with HFD (TR + HFD). By week 6, TR, irrespective of genotype, decreased blood glucose and increased citrate synthase activity in both diet groups and decreased insulin levels in HFD groups. Hindlimb perfusions were performed, and, in WT mice with SD, TR increased insulin-mediated palmitate uptake (76.7%) and oxidation (>2-fold). These training-induced changes were not observed in the DN mice. With HFD, TR decreased palmitate oxidation (61–64%) in both WT and DN and increased palmitate uptake (112%) in the WT with no effects on palmitate uptake in the DN. With SD, TR increased ERK1/2 and JNK1/2 phosphorylation, regardless of genotype. With HFD, TR reduced JNK1/2 phosphorylation, regardless of genotype, carnitine palmitoyltransferase 1 expression in WT, and CD36 expression in both DN and WT. These data suggest that low AMPK-α2 signaling disrupts, in part, the exercise training-induced adaptations in insulin-stimulated metabolism in skeletal muscle following HFD.

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