scholarly journals Exercise and Omega-3 Polyunsaturated Fatty Acid Supplementation for the Treatment of Hepatic Steatosis in Hyperphagic OLETF Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Sarah J. Borengasser ◽  
R. Scott Rector ◽  
Grace M. Uptergrove ◽  
E. Matthew Morris ◽  
James W. Perfield ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Insulin Sensitivity ◽  
Hepatic Steatosis ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Omega 3 ◽  
Oletf Rats ◽  
Hepatic Fatty Acid

Background and Aims.This study examined if exercise and omega-3 fatty acid (n3PUFA) supplementation is an effective treatment for hepatic steatosis in obese, hyperphagic Otsuka Long-Evans Tokushima Fatty (OLETF) rats.Methods.Male OLETF rats were divided into 4 groups (n=8/group): (1) remained sedentary (SED), (2) access to running wheels; (EX) (3) a diet supplemented with 3% of energy from fish oil (n3PUFA-SED); and (4) n3PUFA supplementation plus EX (n3PUFA+EX). The 8 week treatments began at 13 weeks, when hepatic steatosis is present in OLETF-SED rats.Results.EX alone lowered hepatic triglyceride (TAG) while, in contrast, n3PUFAs failed to lower hepatic TAG and blunted the ability of EX to decrease hepatic TAG levels in n3PUFAs+EX. Insulin sensitivity was improved in EX animals, to a lesser extent in n3PUFA+EX rats, and did not differ between n3PUFA-SED and SED rats. Only the EX group displayed higher complete hepatic fatty acid oxidation (FAO) to CO2and carnitine palmitoyl transferase-1 activity. EX also lowered hepatic fatty acid synthase protein while both EX and n3PUFA+EX decreased stearoyl CoA desaturase-1 protein.Conclusions.Exercise lowers hepatic steatosis through increased complete hepatic FAO, insulin sensitivity, and reduced expression ofde novofatty acid synthesis proteins while n3PUFAs had no effect.

scholarly journals Acetyl-CoA carboxylase inhibition by ND-630 reduces hepatic steatosis, improves insulin sensitivity, and modulates dyslipidemia in rats

2016 ◽  
Vol 113 (13) ◽  
pp. E1796-E1805 ◽  
Author(s):  
Geraldine Harriman ◽  
Jeremy Greenwood ◽  
Sathesh Bhat ◽  
Xinyi Huang ◽  
Ruiying Wang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Liver Disease ◽  
Insulin Sensitivity ◽  
Fatty Liver ◽  
Hepatic Steatosis ◽  
Fatty Acid Synthesis ◽  
Fatty Liver Disease ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Acetyl Coa Carboxylase

Simultaneous inhibition of the acetyl-CoA carboxylase (ACC) isozymes ACC1 and ACC2 results in concomitant inhibition of fatty acid synthesis and stimulation of fatty acid oxidation and may favorably affect the morbidity and mortality associated with obesity, diabetes, and fatty liver disease. Using structure-based drug design, we have identified a series of potent allosteric protein–protein interaction inhibitors, exemplified by ND-630, that interact within the ACC phosphopeptide acceptor and dimerization site to prevent dimerization and inhibit the enzymatic activity of both ACC isozymes, reduce fatty acid synthesis and stimulate fatty acid oxidation in cultured cells and in animals, and exhibit favorable drug-like properties. When administered chronically to rats with diet-induced obesity, ND-630 reduces hepatic steatosis, improves insulin sensitivity, reduces weight gain without affecting food intake, and favorably affects dyslipidemia. When administered chronically to Zucker diabetic fatty rats, ND-630 reduces hepatic steatosis, improves glucose-stimulated insulin secretion, and reduces hemoglobin A1c (0.9% reduction). Together, these data suggest that ACC inhibition by representatives of this series may be useful in treating a variety of metabolic disorders, including metabolic syndrome, type 2 diabetes mellitus, and fatty liver disease.

Daily exercise increases hepatic fatty acid oxidation and prevents steatosis in Otsuka Long-Evans Tokushima Fatty rats

2008 ◽  
Vol 294 (3) ◽  
pp. G619-G626 ◽  
Author(s):  
R. Scott Rector ◽  
John P. Thyfault ◽  
R. Tyler Morris ◽  
Matthew J. Laye ◽  
Sarah J. Borengasser ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Exercise Training ◽  
Hepatic Steatosis ◽  
Fatty Acid Oxidation ◽  
Wheel Running ◽  
Acid Oxidation ◽  
Oletf Rats ◽  
Hepatic Fatty Acid ◽  
Long Evans ◽  
Hepatic Fatty Acid Oxidation

Exercise training is commonly prescribed for treatment of nonalcoholic fatty liver disease (NAFLD). We sought to determine whether exercise training prevents the development of NAFLD in Otsuka Long-Evans Tokushima Fatty (OLETF) rats and to elucidate the molecular mechanisms underlying the effects of exercise on hepatic steatosis. Four-week-old OLETF rats were randomly assigned to either a sedentary control group (Sed) or a group given access to voluntary running wheels for 16 wk (Ex). Wheels were locked 2 days before euthanasia in the Ex animals, and both groups were euthanized at 20 wk old. Voluntary wheel running attenuated weight gain and reduced serum glucose, insulin, free fatty acids, and triglycerides in Ex animals compared with Sed ( P < 0.001). Ex animals exhibited significantly reduced hepatic triglyceride levels and displayed fewer lipid droplets (Oil Red O staining) and reduced lipid droplet size compared with Sed. Wheel running increased by threefold the percent of palmitate oxidized completely to CO2 in the Ex animals but did not alter AMP-activated protein kinase-α (AMPKα) or AMPK phosphorylation status. However, fatty acid synthase and acetyl-coenzyme A carboxylase (ACC) content were significantly reduced (∼70 and ∼35%, respectively), and ACC phosphorylation and cytochrome c content were significantly elevated (∼35 and ∼30%, respectively) in the Ex animals. These results unequivocally demonstrate that daily physical activity attenuates hepatic steatosis and NAFLD in an obese rodent model and suggest that this effect is likely mediated, in part, through enhancement of hepatic fatty acid oxidation and reductions in key protein intermediates of fatty acid synthesis.

scholarly journals High glucose levels reduce fatty acid oxidation and increase triglyceride accumulation in human placenta

2013 ◽  
Vol 305 (2) ◽  
pp. E205-E212 ◽  
Author(s):  
Francisco Visiedo ◽  
Fernando Bugatto ◽  
Viviana Sánchez ◽  
Irene Cózar-Castellano ◽  
Jose L. Bartha ◽  
...  
Keyword(s):  
Fatty Acid ◽  
High Glucose ◽  
De Novo ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Glucose Levels ◽  
Triglyceride Accumulation ◽  
Triglyceride Content ◽  
Low Glucose ◽  
Cpt I

Placentas of women with gestational diabetes mellitus (GDM) exhibit an altered lipid metabolism. The mechanism by which GDM is linked to alterations in placental lipid metabolism remains obscure. We hypothesized that high glucose levels reduce mitochondrial fatty acid oxidation (FAO) and increase triglyceride accumulation in human placenta. To test this hypothesis, we measured FAO, fatty acid esterification, de novo fatty acid synthesis, triglyceride levels, and carnitine palmitoyltransferase activities (CPT) in placental explants of women with GDM or no pregnancy complication. In women with GDM, FAO was reduced by ∼30% without change in mitochondrial content, and triglyceride content was threefold higher than in the control group. Likewise, in placental explants of women with no complications, high glucose levels reduced FAO by ∼20%, and esterification increased linearly with increasing fatty acid concentrations. However, de novo fatty acid synthesis remained unchanged between high and low glucose levels. In addition, high glucose levels increased triglyceride content approximately twofold compared with low glucose levels. Furthermore, etomoxir-mediated inhibition of FAO enhanced esterification capacity by ∼40% and elevated triglyceride content 1.5-fold in placental explants of women, with no complications. Finally, high glucose levels reduced CPT I activity by ∼70% and phosphorylation levels of acetyl-CoA carboxylase by ∼25% in placental explants of women, with no complications. We reveal an unrecognized regulatory mechanism on placental fatty acid metabolism by which high glucose levels reduce mitochondrial FAO through inhibition of CPT I, shifting flux of fatty acids away from oxidation toward the esterification pathway, leading to accumulation of placental triglycerides.

scholarly journals d-allulose Ameliorates Metabolic Dysfunction in C57BL/KsJ-db/db Mice

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3656
Author(s):  
Dayoun Lee ◽  
Youngji Han ◽  
Eun-Young Kwon ◽  
Myung-Sook Choi
Keyword(s):  
Fatty Acid ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Fatty Acid Synthase ◽  
Glucose Transporter ◽  
Inflammatory Responses ◽  
Normal Diet ◽  
Acid Oxidation ◽  
Transferase Activity ◽  
Model Assessment ◽  
Hepatic Fatty Acid

d-allulose is an uncommon sugar that provides almost no calories when consumed. Its sweetness is 70% that of sucrose. d-allulose is a metabolic regulator of glucose and lipid metabolism. However, few reports concerning its effect on diabetes and related metabolic disturbances in db/db mice are available. In this study, we evaluated d-allulose’s effect on hyperglycemia, hyperinsulinemia, diabetes and inflammatory responses in C57BL/KsJ-db/db mice. Mice were divided into normal diet, erythritol supplemented (5% w/w), and d-allulose supplemented (5% w/w) groups. Blood glucose and plasma glucagon levels and homeostatic model assessment (HOMA-IR) were significantly lower in the d-allulose group than in the normal diet group, and plasma insulin level was significantly increased. Further, d-allulose supplement significantly increased hepatic glucokinase activity and decreased hepatic phosphoenolpyruvate carboxykinase and glucose-6-phosphatase activity. Expression of glucose transporter 4, insulin receptor substrate 1, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha and AKT serine/threonine kinase 2 were also upregulated by d-allulose supplement in adipocyte and muscle. Finally, d-allulose effectively lowered plasma and hepatic triglyceride and free fatty acid levels, and simultaneously reduced hepatic fatty acid oxidation and carnitine palmitoyl transferase activity. These changes are likely attributable to suppression of hepatic fatty acid synthase and glucose-6-phosphate dehydrogenase activity. Notably, d-allulose also reduced pro-inflammatory adipokine and cytokine levels in plasma. Our results indicate that d-allulose is an effective sugar substitute for improving lipid and glucose metabolism.

scholarly journals Identification of a Novel Mycobacterial 3-Hydroxyacyl-Thioester Dehydratase, HtdZ (Rv0130), by Functional Complementation in Yeast

2008 ◽  
Vol 190 (11) ◽  
pp. 4088-4090 ◽  
Author(s):  
Aner Gurvitz ◽  
J. Kalervo Hiltunen ◽  
Alexander J. Kastaniotis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mycobacterium Tuberculosis ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Acid Synthesis ◽  
Functional Complementation ◽  
Type Ii ◽  
Mutant Cells ◽  
Dehydratase Activity

ABSTRACT We report on the identification of Mycobacterium tuberculosis HtdZ (Rv0130), representing a novel 3-hydroxyacyl-thioester dehydratase. HtdZ was picked up by the functional complementation of Saccharomyces cerevisiae htd2Δ cells lacking the dehydratase of mitochondrial type II fatty acid synthase. Mutant cells expressing HtdZ contained dehydratase activity, recovered their respiratory ability, and partially restored de novo lipoic acid synthesis.

scholarly journals Role of adiponectin in the metabolic effects of cannabinoid type 1 receptor blockade in mice with diet-induced obesity

2014 ◽  
Vol 306 (4) ◽  
pp. E457-E468 ◽  
Author(s):  
Joseph Tam ◽  
Grzegorz Godlewski ◽  
Brian J. Earley ◽  
Liang Zhou ◽  
Tony Jourdan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Insulin Sensitivity ◽  
Hepatic Steatosis ◽  
Metabolic Effects ◽  
Acid Oxidation ◽  
Receptor Blockade ◽  
Wild Type Littermate ◽  
Cannabinoid Type 1 Receptor ◽  
Hepatocellular Damage

The adipocyte-derived hormone adiponectin promotes fatty acid oxidation and improves insulin sensitivity and thus plays a key role in the regulation of lipid and glucose metabolism and energy homeostasis. Chronic cannabinoid type 1 (CB1) receptor blockade also increases lipid oxidation and improves insulin sensitivity in obese individuals or animals, resulting in reduced cardiometabolic risk. Chronic CB1 blockade reverses the obesity-related decline in serum adiponectin levels, which has been proposed to account for the metabolic effects of CB1 antagonists. Here, we investigated the metabolic actions of the CB1 inverse agonist rimonabant in high-fat diet (HFD)-induced obese adiponectin knockout (Adipo−/−) mice and their wild-type littermate controls (Adipo+/+). HFD-induced obesity and its hormonal/metabolic consequences were indistinguishable in the two strains. Daily treatment of obese mice with rimonabant for 7 days resulted in significant and comparable reductions in body weight, serum leptin, free fatty acid, cholesterol, and triglyceride levels in the two strains. Rimonabant treatment improved glucose homeostasis and insulin sensitivity to the same extent in Adipo+/+ and Adipo−/− mice, whereas it reversed the HFD-induced hepatic steatosis, fibrosis, and hepatocellular damage only in the former. The adiponectin-dependent, antisteatotic effect of rimonabant was mediated by reduced uptake and increased β-oxidation of fatty acids in the liver. We conclude that reversal of the HFD-induced hepatic steatosis and fibrosis by chronic CB1 blockade, but not the parallel reduction in adiposity and improved glycemic control, is mediated by adiponectin.

Fatty Acid Synthesis by Rat Liver after Chronic Ethanol Feeding with a Low-Fat Diet

1994 ◽  
Vol 87 (4) ◽  
pp. 441-446 ◽  
Author(s):  
K. J. Simpson ◽  
S. Venkatesan ◽  
T. J. Peters
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthase ◽  
Plasma Lipids ◽  
Fold Increase ◽  
Acid Synthesis ◽  
Low Fat ◽  
Hepatic Fatty Acid ◽  
Low Fat Diet

1. Chronic alcohol feeding with a low-fat diet (4.4% total calories) produced a two- to three-fold increase in hepatic triacylglycerol and esterified cholesterol compared with pair-fed low-fat diet controls. Plasma lipids were similar in both groups. 2. Hepatic fatty acid synthesis rates measured in vivo with 3H2O were significantly lower in the alcohol-fed animals than in controls. Activities of hepatic fatty acid synthase (EC 2.3.1.85) and acetyl-CoA carboxylase (EC 6.4.1.2) were reduced in the alcohol-fed rats. 3. These results indicate that enhanced hepatic fatty acid synthesis does not occur in rats fed alcohol and a low-fat diet for 4 weeks, and is thus not implicated in the pathogenesis of alcohol-induced fatty liver.

scholarly journals Expression in Escherichia coli, purification and characterization of two mammalian thioesterases involved in fatty acid synthesis

1991 ◽  
Vol 273 (3) ◽  
pp. 787-790 ◽  
Author(s):  
J Naggert ◽  
A Witkowski ◽  
B Wessa ◽  
S Smith
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Acid Synthesis ◽  
Temperature Sensitive ◽  
Lambda Repressor ◽  
Thioesterase Ii ◽  
Chain Lengths

Thioesterase I, a constituent domain of the multifunctional fatty acid synthase, and thioesterase II, an independent monofunctional protein, catalyse the chain-terminating reaction in fatty acid synthesis de novo at long and medium chain lengths respectively. The enzymes have been cloned and expressed in Escherichia coli under the control of the temperature-sensitive lambda repressor. The recombinant proteins are full-length catalytically competent thioesterases with specificities indistinguishable from those of the natural enzymes.

scholarly journals Fatty Acid Synthase: Association with Insulin Resistance, Type 2 Diabetes, and Cancer

2009 ◽  
Vol 55 (3) ◽  
pp. 425-438 ◽  
Author(s):  
Javier A Menendez ◽  
Alejandro Vazquez-Martin ◽  
Francisco Jose Ortega ◽  
Jose Manuel Fernandez-Real
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Fatty Acid ◽  
Insulin Sensitivity ◽  
Fatty Acid Synthase ◽  
Metabolic Diseases ◽  
De Novo ◽  
Genetic Alterations ◽  
Insulin Resistant

Abstract Background: An emerging paradigm supports the notion that deregulation of fatty acid synthase (FASN)-catalyzed de novo FA biogenesis could play a central role in the pathogenesis of metabolic diseases sharing the hallmark of insulin-resistance. Content: We reviewed pharmacological and genetic alterations of FASN activity that have been shown to significantly influence energy expenditure rates, fat mass, insulin sensitivity, and cancer risk. This new paradigm proposes that insulin-resistant conditions such as obesity, type 2 diabetes, and cancer arise from a common FASN-driven “lipogenic state”. An important question then is whether the development or the progression of insulin-related metabolic disorders can be prevented or reversed by the modulation of FASN status. If we accept the paradigm of FASN dysfunction as a previously unrecognized link between insulin resistance, type 2 diabetes, and cancer, the use of insulin sensitizers in parallel with forthcoming FASN inhibitors should be a valuable therapeutic approach that, in association with lifestyle interventions, would concurrently improve energy-flux status, ameliorate insulin sensitivity, and alleviate the risk of lipogenic carcinomas. Conclusions: Although the picture is currently incomplete and researchers in the field have plenty of work ahead, the latest clinical and experimental evidence that we discuss illuminates a functional and drug-modifiable link that connects FASN-driven endogenous FA biosynthesis, insulin action, and glucose homeostasis in the natural history of insulin-resistant pathologies.

scholarly journals Interrelated effects of dihomo-γ-linolenic and arachidonic acids, and sesamin on hepatic fatty acid synthesis and oxidation in rats

2012 ◽  
Vol 108 (11) ◽  
pp. 1980-1993 ◽  
Author(s):  
Takashi Ide ◽  
Yoshiko Ono ◽  
Hiroshi Kawashima ◽  
Yoshinobu Kiso
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Dietary Fat ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Mrna Levels ◽  
Lipogenic Enzymes ◽  
Hepatic Fatty Acid ◽  
Hepatic Fatty Acid Oxidation ◽  
Maize Oil

Interrelated effects of dihomo-γ-linolenic acid (DGLA) and arachidonic acid (ARA), and sesamin, a sesame lignan, on hepatic fatty acid synthesis and oxidation were examined in rats. Rats were fed experimental diets supplemented with 0 or 2 g/kg sesamin (1:1 mixture of sesamin and episesamin), containing 100 g/kg of maize oil or fungal oil rich in DGLA or ARA for 16 d. Among the groups fed sesamin-free diets, oils rich in DGLA or ARA, especially the latter, compared with maize oil strongly reduced the activity and mRNA levels of various lipogenic enzymes. Sesamin, irrespective of the type of fat, reduced the parameters of lipogenic enzymes except for malic enzyme. The type of dietary fat was rather irrelevant in affecting hepatic fatty acid oxidation among rats fed the sesamin-free diets. Sesamin increased the activities of enzymes involved in fatty acid oxidation in all groups of rats given different fats. The extent of the increase depended on the dietary fat type, and the values became much higher with a diet containing sesamin and oil rich in ARA in combination than with a diet containing lignan and maize oil. Analyses of mRNA levels revealed that the combination of sesamin and oil rich in ARA compared with the combination of lignan and maize oil markedly increased the gene expression of various peroxisomal fatty acid oxidation enzymes but not mitochondrial enzymes. The enhancement of sesamin action on hepatic fatty acid oxidation was also confirmed with oil rich in DGLA but to a lesser extent.

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