Expression Of acyl-CoA Oxidase Research Articles

Rhapontigenin Improves Non-alcoholic Fatty Liver Disease by Inducing Lipophagy Through the ACOX1 and mTOR/ULK1 Pathways

Background Non-alcoholic fatty liver disease (NAFLD) is severely affecting the quality of people’s life. Rhapontigenin (RA) is a stilbene compound isolated from Rhubarb L., which has been reported to have an effect on cholesterol diet-induced hyperlipidemia in rats. This study aims to explore the pharmacodynamics and the mechanism of RA obtained from Rheum franzenbachii Munt. against NAFLD. RA was extracted from the roots of the Rheum L. (Polygonaceae) plant Rheum franzenbachii Munt. Materials and Methods RA was extracted by Sephadex-gel column and identified by high-performance liquid chromatography (HPLC)-UV and HR-ESI-MS. The pharmacodynamic indexes of L-02 cells and mice treated with RA were determined by histological staining and ELISA, while the expression of autophagy-related proteins was analyzed by Western blot. Results The results in vivo showed that the liver structure of RA-treatment mice was normal, and the organ coefficient was significantly decreased. It also showed that RA could significantly reduce the expression of reactive oxygen species (ROS) in the liver as well as inhibit oxidative stress and inflammatory response. Interestingly, the autophagy inhibitor 3-methyladenine (3-MA) could reverse the effect of RA on NAFLD, which further confirmed that RA plays an anti-NAFLD role through activating lipophagy. Conclusion It suggested that RA has an effect on NAFLD by down-regulating the expression of Acyl-CoA oxidase 1 (ACOX1), p-mTOR, and p-Unc-51-like kinase 1 (ULK1), then inhibiting Acetyl-CoA (A-CoA) production, and up-regulating the expression of autophagy protein 5 (Atg5) to promote the lipophagy of lipocytes.

Effects of supplemental mixed bile acids on growth performance, body composition, digestive enzyme activities, skin color, and flesh quality of juvenile large yellow croaker (Larimichthys crocea) in soybean oil based diet

Now the replacement of fish oil (FO) with vegetable oils (VOs) has been broadly applied in aquatic feed, but studies reported that there were negative effects on growth, skin color, flavor and muscle texture. A 10-week feeding trial was conducted to investigate the effects of dietary mixed bile acids (BA) on growth performance, body composition, digestive enzyme activities, skin color and flesh quality of juvenile large yellow croaker (initial weight, 13.10 ± 0.18 g). Four iso-nitrogenous and iso-lipidic experimental diets were formulated and designated as soybean oil (SO), SO supplemented with 300 (BA300), 600 (BA600), and 1200 (BA1200) mg/kg bile acids. Two hundred and forty fish were randomly allocated into 12 floating net cages (1 m × 1 m × 1.5 m) that were located at marine fishing rafts. Each diet was randomly distributed in triplicate (three replicates per treatment, 20 fish per replicate). Fish were hand-fed to apparent satiation twice daily (05:30 and 17:30) for 10 weeks. Results showed that specific growth rate presented quadratic pattern with supplemental bile acids level, peaking at BA600 group. Meanwhile, feed conversion rate of cultured fish was significantly improved in BA600 group (P < 0.05). The redness (a*) of dorsal and lateral line skin and the yellowness (b*) of abdominal skin showed significantly quadratic pattern with the increase of supplemental BA level (P < 0.05), peaking at BA600 group. In terms of dorsal muscle texture, springiness showed a decreasing trend in significantly linear pattern with the increase of supplemental BA level, bottoming at BA600 group. However, cohesiveness and gumminess were significantly linear increased with the increase of supplemental BA level (P < 0.05). No significant differences were observed in lipase, amylase, and trypsin activities (P > 0.05). Total proportion of muscle n-3LCPUFA showed a linearly increasing trend with the increase of supplemental BA level. Muscle TG content was linearly increased with the increase of supplemental BA level (P < 0.05), and significant differences occurred as compared to fish fed diets with SO when supplemental BA level were reached 600 mg/kg and 1200 mg/kg (P < 0.05). The gene expression of acyl-CoA oxidase (aco) was significantly decreased in fish fed diets supplemented with 600 mg/kg bile acids compared with 300 mg/kg other than those fed diets with SO. In conclusion, these results suggested that mixed bile acids supplemented to SO-based diets could improve feed conversion ratio, skin color and flesh quality to some extent.

Effects of peroxisome proliferator activated receptor-α agonist on growth performance, blood profiles, gene expression related to liver fat metabolism in broilers fed diets containing corn naturally contaminated with mycotoxins.

This study was conducted to determine the subclinical symptom of broilers exposure to mycotxoins from corn naturally contaminated, and the preventive effect with peroxisome proliferator activated receptor-α (PPARα) agonist (Wy-14643) supplementation. A total of 360 one-day -old male Arbor Acres broilers were randomly distributed into 4 treatments with 9 replicates of 10 birds. Dietary treatments included: treatment 1, normal corn diets group, treatment 2, normal corn + Wy-14643 diets group, treatment 3, mycotoxin-contaminated corn diets group, treatment 4, mycotoxin-contaminated corn + Wy-14643 diets group. The supplementation of Wy-14643 was added at the expense of 1 and 2 mg/kg in starter and grower diets, respectively. Birds fed mycotoxin diets had lower (P < 0.05) final body weight (BW), Body weight gain (BWG), feed intake (FI), and had higher (P < 0.05) feed conversion ratio (FCR). Feeding mycotoxin diets reduced (P < 0.05) the levels of serum superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT), total antioxidative capacity (T-AOC) and high-density lipoprotein cholesterol (HDL-C), but higher malondialdehyde (MDA), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and fatty acid synthetase (FAS). The supplementation of Wy-14643 increased (P < 0.05) the level of serum T-AOC, but reduced (P < 0.05) TG and LDL-C. Interactive effect was not observed (P > 0.05) in growth performance and blood profiles. The relative expression of PPARα mRNA and 3-Hydroxy-3-MethylGlutaryl-CO enzyme A (HMGCoA) mRNA was higher (P < 0.05) in treatment 3 and treatment 4 than treatment 1 and treatment 2, and there was significant difference (P <0.05) between treatment 3 and treatment 4. There was significant difference (P < 0.05) between groups of the relative expression of recombinant carnitine palmitoyl transferase 1 (CPT1) mRNA. The relative expression of acyl CoA oxidase (ACO) mRNA was higher (P < 0.05) in treatment 1 and treatment 4 than treatment 2 and treatment 3, and there was significant difference (P < 0.05) between treatment 1 and treatment 4. The relative expression of apolipoprotein A (APO-A) mRNA was higher (P < 0.05) in treatment 1 and treatment 4 than treatment 2 and treatment 3. The relative expression of sterol regulatory element binding protein (SREBP) mRNA was lower (P < 0.05) in treatment 2, treatment 3 and treatment 4 than treatment 1, and there was significant difference (P < 0.05) between treatment 3 and treatment 4. Overall, feeding naturally contaminated mycotoxin diets caused negative effects on growth performance and blood profiles, while diet supplementation with Wy-14643 alleviate the detrimental effects on gene and expression related to liver fat metabolism in broilers.

Lipid metabolism disorders effects of 6:2 chlorinated polyfluorinated ether sulfonate through Hsa-miRNA-532–3p/Acyl-CoA oxidase 1(ACOX1) pathway

6:2 Chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA), an alternative product of perfluorooctane sulfonate (PFOS), has been frequently detected in various environmental, wildlife, and human samples. A few studies revealed the hepatotoxicity of 6:2 Cl-PFESA in animals, but the underlying toxicity mechanisms remain largely unknown. In this study, we investigated the lipid metabolism disorders of 6:2 Cl-PFESA through miRNA-gene interaction mode in Huh-7 cells. Our results showed that 6:2 Cl-PFESA significantly promoted cellular lipid accumulation and increased the expression of Acyl-CoA oxidase 1 (ACOX1), with the lowest effective concentrations (LOECs) of 3 μM. In silico analysis showed that hsa-miR-532–3p is a potential miRNA molecule targeting ACOX1. Fluorescent-based RNA electrophoretic mobility shift assay (FREMSA) and ACOX1-mediated luciferase reporter gene assays showed that hsa-miR-532–3p could directly bind to ACOX1 and inhibit its transcription activity. Besides, 6:2 Cl-PFESA decreased the expression of hsa-miR-532–3p in the PPARα-independent manner. Overexpression of hsa-miR-532–3p promoted 6:2 Cl-PFESA-induced cellular lipid accumulation and decreased the ACOX1 production in Huh-7 cells. Taken together, at human exposure relevant concentrations, 6:2 Cl-PFESA might upregulate the expression levels of ACOX1 through downregulating hsa-miR-532–3p, and disturbed lipid homeostasis in Huh-7 cells, which revealed a novel epigenetic mechanism of 6:2 Cl-PFESA-induced hepatic lipid toxic effects.

Increased expression of acyl-CoA oxidase 2 in the kidney with plasma phytanic acid and altered gut microbiota in spontaneously hypertensive rats.

We performed a DNA microarray analysis of the renal medulla and cortex from spontaneously hypertensive rats (SHRs), stroke-prone SHRs (SHRSPs), and Wistar-Kyoto (WKY) rats to identify pivotal molecules in the kidney associated with the onset of hypertension and found increased expression of acyl-CoA oxidase 2 (Acox2) mRNA. Real-time polymerase chain reaction revealed that Acox2 mRNA expression in the renal medulla and cortex of SHRs and SHRSPs was increased in comparison to WKY rats. These findings indicate that increased renal ACOX2 (an enzyme that induces the β-oxidation of fatty acids) is associated with the onset of hypertension. Immunostaining of ACOX2 in the distal tubules from SHRs was stronger than that in the distal tubules from WKY rats. Western blot analysis showed increased expression of ACOX2 protein in renal medulla from SHRs. Regarding the overexpression of ACOX2, plasma levels of phytanic acid in SHRs were significantly higher than those in WKY rats. There were no differences in other short-chain fatty acids. Plasma phytanic acid was affected by the gut microbiota through the conversion from phytol by yeast in the intestinal tract. We compared the gut microbiota profile in three strains of 5-week-old rats by the terminal-restriction fragment length polymorphism method. The gut microbiota profile and ratio of Firmicutes/Bacteroides differed between SHRs and WKY rats. These findings suggest that the increased expression of ACOX2 in the kidney along with increases in plasma phytanic acid and the altered gut microbiota may be involved in the oxidation in the kidney and the pathogenesis of hypertension.

Histological changes, lipid metabolism, and oxidative and endoplasmic reticulum stress in the liver of laying hens exposed to cadmium concentrations

The objective of this study was to determine the effects of cadmium (Cd) on histological changes, lipid metabolism, and oxidative and endoplasmic reticulum (ER) stress in the liver of layers. A total of 480 hens at 38 wk of age were randomly assigned in 5 groups that were fed a basal diet or basal diet supplemented with CdCl2 2.5H2O at 7.5, 15, 30, and 60 mg Cd/kg feed for 9 wk. The results showed that accumulation of Cd was the greatest in the kidney, followed by the liver, pancreas, and lung. Diet contaminated with 30 mg Cd/kg induced antioxidant defenses accompanied by the increase of the activities of antioxidant enzymes in the liver, while dietary supplementation with 60 mg Cd/kg decreased the antioxidant levels significantly (P < 0.05). Immunofluorescence assay showed Cd induced reactive oxygen species production and endoplasmic reticulum stress in hepatocytes. Exposure to 60 mg Cd/kg significantly upregulated the expression of cytochrome C, caspase 3, caspase 9, caspase 7, Grp78, and Chop (P < 0.05). Histopathology and quantitative real-time PCR results presented periportal fibrosis, bile duct hyperplasia, and periportal inflammatory cell infiltration in the liver accompanied by upregulating the expression of tumor necrosis factor-α, IL-6 and IL-10 in the 30- or 60-mg Cd/kg groups. Oil Red O staining and RT-qPCR results showed dietary supplementation with 7.5, 15, and 30 mg Cd/kg promoted the synthesis of lipid droplets and upregulated the expression of fatty acid synthase, while dietary supplementation with 60 mg Cd/kg attenuated the synthesis of lipid droplets and downregulated the expression of acyl-CoA oxidase 1, carnitine palmitoyltransferase-1, and perixisome proliferation-activated receptor α (P < 0.05). Besides, the expression of vitellogenin (VTG) II and microsomal triglyceride transfer protein were upregulated in the 7.5-mg Cd/kg group, and the expressions of apolipoprotein B, vitellogenin II, and apolipoprotein very-low-density lipoprotein-II were downregulated in the 30- and/or 60-mg Cd/kg groups (P < 0.05). Conclusively, although low-dose Cd exposure promoted the synthesis of lipids and lipoproteins in the liver, the increase of Cd exposure could trigger liver injury through inducing oxidative and endoplasmic reticulum stress and negatively affect lipid metabolism and yolk formation in laying hens.

Hepatocyte‐specific depletion of augmenter of liver regeneration (ALR) protein alters miRNA signature linked to lipid homeostasis leading to excessive steatosis

Augmenter of liver regeneration (ALR) is a fundamental life protein expressed in all mammalian organs. ALR's presence in mitochondria is essential for their function and survival. Depletion of ALR from liver (hepatocyte)‐specific ALRflox/flox/Alb‐Cre (ALR‐L‐KO) mice causes mitochondrial injury, robust lipid accumulation and apoptosis between 1 and 2 weeks post‐birth. Steatosis is regressed upon reappearance of ALR by 4 weeks but continued death of Cre‐expressing hepatocytes induces regeneration, inflammation and fibrosis. To delineate mechanisms of this pathological progression, we investigated whether ALR depletion alters expression of micro‐RNAs (miRNAs), which play important roles in numerous biological processes including lipid homeostasis. We performed miRNA‐seq analysis and profiled the hepatic miRNA expression in 1‐, 2‐, and 4‐week old mice. Of the 765 micro‐RNAs identified in WT and ALR‐L‐KO livers, 203 showed differential expression: 125, 106 and 141 miRNAs were up‐regulated and 70, 97 and 61 miRNAs down‐regulated at 1, 2 and 4 weeks respectively in ALR‐L‐KO compared to the WT mice. miR‐708‐3p, miR‐540‐3p and miR‐541‐5p, which have 3′UTR‐binding sites for peroxisome proliferator‐activated receptor (PPAR)α, carnitine palmitoyl transferase a (CPT1a) and mitochondrial transcription factor A (TFAM) (all down‐regulated at 2 weeks in ALR‐L‐KO mice), were all found to be up‐regulated at 2 weeks in ALR‐L‐KO compared to the WT mice. Increase in these miRNAs upon ALR depletion was also concurrent with increased expression of elongation of very long fatty acids 6 (ELOVl6) and steroyl CoA desaturase (SCD1) that are involved in de novo lipogenesis, and decreased expression of acyl CoA oxidase 1 (ACOX1) and CPT1 that promote β‐oxidation of fatty acids. The effect of ALR depletion on these miRNAs was recapitulated in vitro in cultured hepatocytes. Likewise, hepatic expression of miRNAs implicated in inflammation and fibrosis (miR‐199a‐1‐5p, miR‐146b‐5p, miR‐194‐1‐5p, miR‐1843a, miR‐410‐3p and miR‐434‐3p) was also altered in a way to promote these pathologies. These findings suggest that ALR's regulation of miRNAs is critical to hepatic lipid homeostasis with potential implications in nonalcoholic fatty liver disease/steatohepatitis.Support or Funding InformationThis work was supported by DoD grant W81XWH‐14‐PRMRP‐IIRA and NIH R21 AA020846 to CRG.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

AMPK activation by pterostilbene contributes to suppression of hepatic gluconeogenic gene expression and glucose production in H4IIE cells

Pterostilbene, a bioactive component of blueberries and grapes, shows structural similarity to resveratrol, and exhibits antioxidant, anti-inflammatory, anti-cancer, hypoglycemic, and cholesterol lowering effects. Recent evidence indicates that pterostilbene is an agonist of the nuclear receptor, peroxisome proliferator-activated receptor-alpha (PPAR-α). Since PPAR-α agonists induce peroxisomal proliferation and fatty acid oxidation, we examined gene expression of acyl CoA oxidase (ACO) and carnitine palmitoyl transferase-1 (CPT-1). Pterostilbene treatment, at concentrations that demonstrated over 75% cell viability (20 μM, 50 μM), significantly increased gene expression of ACO, CPT-1, and PPAR-α. Pterostilbene treatment (50 μM) also demonstrated potent activation of AMP-activated kinase (AMPK), compared to AICAR (0.5 mM) or metformin (2 mM), consistent with upregulation in fatty acid oxidation gene expression. Since AMPK activators mimic the actions of insulin by repressing hepatic gluconeogenesis, we examined pterostilbene's effects on hepatic gluconeogenic gene expression. Pterostilbene treatment significantly repressed dexamethasone-induced phosphoenol pyruvate carboxykinase (PEPCK) and glucose6-phosphatase (G6Pase) gene expression, and decreased glucose production in H4IIE cells. Taken together, our studies demonstrate that pterostilbene, a natural compound and PPAR-α agonist, modulate several AMPK-dependent metabolic functions. The results of the present study suggest that pterostilbene may have beneficial effects in the prevention and management of type 2 diabetes and related disorders. In this study, we found that pterostilbene activated AMP-activated kinase (AMPK) and increased the expression of fatty acid oxidation genes, including acyl CoA oxidase and carnitine palmitoyl transferase-1.

A Combination of Flaxseed Oil and Astaxanthin Improves Hepatic Lipid Accumulation and Reduces Oxidative Stress in High Fat-Diet Fed Rats.

Hepatic lipid accumulation and oxidative stress are crucial pathophysiological mechanisms for non-alcoholic fatty liver disease (NAFLD). Thus, we examined the effect of a combination of flaxseed oil (FO) and astaxanthin (ASX) on hepatic lipid accumulation and oxidative stress in rats fed a high-fat diet. ASX was dissolved in flaxseed oil (1 g/kg; FO + ASX). Animals were fed diets containing 20% fat, where the source was lard, or 75% lard and 25% FO + ASX, or 50% lard and 50% FO + ASX, or FO + ASX, for 10 weeks. Substitution of lard with FO + ASX reduced steatosis and reduced hepatic triacylglycerol and cholesterol. The combination of FO and ASX significantly decreased hepatic sterol regulatory element-binding transcription factor 1 and 3-hydroxy-3-methylglutaryl-CoA reductase but increased peroxisome proliferator activated receptor expression. FO + ASX significantly suppressed fatty acid synthase and acetyl CoA carboxylase but induced carnitine palmitoyl transferase-1 and acyl CoA oxidase expression. FO + ASX also significantly elevated hepatic SOD, CAT and GPx activity and GSH, and markedly reduced hepatic lipid peroxidation. Thus, FO and ASX may reduce NAFLD by reversing hepatic steatosis and reducing lipid accumulation and oxidative stress.

Optimized Rapeseed Oils Rich in Endogenous Micronutrients Protect High Fat Diet Fed Rats from Hepatic Lipid Accumulation and Oxidative Stress.

Micronutrients in rapeseed exert a potential benefit to hepatoprotection, but most of them are lost during the conventional refining processing. Thus some processing technologies have been optimized to improve micronutrient retention in oil. The aim of this study is to assess whether optimized rapeseed oils (OROs) have positive effects on hepatic lipid accumulation and oxidative stress induced by a high-fat diet. Methods: Rats received experiment diets containing 20% fat and refined rapeseed oil or OROs obtained with various processing technologies as lipid source. After 10 weeks of treatment, liver was assayed for lipid accumulation and oxidative stress. Results: All OROs reduced hepatic triglyceride contents. Microwave pretreatment-cold pressing oil (MPCPO) which had the highest micronutrients contents also reduced hepatic cholesterol level. MPCPO significantly decreased hepatic sterol regulatory element-binding transcription factor 1 (SREBP1) but increased peroxisome proliferator activated receptor α (PPARα) expressions, and as a result, MPCPO significantly suppressed acetyl CoA carboxylase and induced carnitine palmitoyl transferase-1 and acyl CoA oxidase expression. Hepatic catalase (CAT) and glutathione peroxidase (GPx) activities as well as reduced glutathione (GSH) contents remarkably increased and lipid peroxidation levels decreased in parallel with the increase of micronutrients. Conclusion: OROs had the ability to reduce excessive hepatic fat accumulation and oxidative stress, which indicated that OROs might contribute to ameliorating nonalcoholic fatty liver induced by high-fat diet.

Inhibitory Effects of Bojungchiseub-tang on Adipocyte Differentiation and Adipogenesis in 3T3-L1 Preadipocytes

Bojungchiseub-tang (BJCST) has been used in symptoms and signs of edema, dampness-phlegm, kidney failure, and so on. BJCST is also expected to have strong anti-obesity activities. However, little is known about the mechanisms of its inhibitory effects on adipocyte differentiation and adipogenesis. In the present study, we examined the effects and mechanism of BJCST on transcription factors and adipogenic genes of 3T3-L1 preadipocytes to understand its inhibitory effects on adipocyte differentiation and adipogenesis. Our results showed that BJCST significantly inhibited differentiation and adipogenesis of 3T3-L1 preadipocytes in a dose-dependent manner. To elucidate the mechanism of the effects of BJCST on lowering lipid content in 3T3-L1 adipocytes, we examined whether BJCST modulate the expressions of transcription factors to induce adipogenesis and adipogenic genes related to regulate accumulation of lipids. As a result, the expression of steroid regulatory element-binding protein (SREBP)1, cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins α (C/EBPα), C/EBPβ, C/EBPδ, and peroxisome proliferator-activated receptor γ (PPARγ) genes, which induce the adipose differentiation, liver X receptor (LXR)α and fatty acid synthase (FAS) genes, which induce lipogenesis and adipose-specific aP2, Adipsin, lipoprotein lipase (LPL), CD36, TGF-β, leptin and adiponectin genes, which compose fat formation were decreased. BJCST also reduced the expression of acyl CoA oxidase (ACO) and uncoupling protein (UCP) genes related to lipid oxidation. In conclusion, BJCST could regulate transcript factor related to induction of adipose differentiation and inhibited the accumulation of lipids and expression of adipogenic genes.

Increased expression of oxidative enzymes in adipose tissue following PPARα-activation

ObjectiveEvaluate the effect of fenofibrate treatment on the expression of PPARα and oxidative enzymes in adipose tissue. Materials/methodsWistar male rats were fed a balanced diet supplemented with 100mg.Kg-1 bw.day-1 fenofibrate (Sigma) during nine days. Plasma glucose, free fatty acids (FFA) leptin and insulin were determined. PPARα, ACO and CPT-1 mRNA expression and amount of PPARα and PPARγ protein were assessed in epididymal adipose tissue. Oral glucose tolerance test was evaluated into overnight fasted rats. Glucose uptake was measured in adipocytes isolated from epididymal fat pads in the presence or absence of insulin (25ng/mL). ResultsFenofibrate treatment increased PPARα and PPARγ protein abundance in adipose tissue. In addition to it well- known effect on oxidative enzymes in liver, fenofibrate treatment also induces a high expression of Acyl CoA Oxidase (ACO) and Carnitine palmitoyltransferase 1 (CPT-1) in adipose tissue. Furthermore, we have shown that the fenofibrate treatment improves the glucose tolerance and enhance the glucose uptake by adipocytes. ConclusionAltogether, the data suggest that fenofibrate have a direct effect in adipose tissue contributing to the low adiposity and improvement of glucose homeostasis.

Dietary Fat Content and Fiber Type Modulate Hind Gut Microbial Community and Metabolic Markers in the Pig

Obesity leads to changes in the gut microbial community which contribute to the metabolic dysregulation in obesity. Dietary fat and fiber affect the caloric density of foods. The impact of dietary fat content and fiber type on the microbial community in the hind gut is unknown. Effect of dietary fat level and fiber type on hindgut microbiota and volatile fatty acid (VFA) profiles was investigated. Expression of metabolic marker genes in the gut, adipose tissue and liver was determined. A 2×2 experiment was conducted in pigs fed at two dietary fat levels (5% or 17.5% swine grease) and two fiber types (4% inulin, fermentable fructo-oligosaccharide or 4% solka floc, non-fermentable cellulose). High fat diets (HFD) resulted in a higher (P<0.05) total body weight gain, feed efficiency and back fat accumulation than the low fat diet. Feeding of inulin, but not solka floc, attenuated (P<0.05) the HFD-induced higher body weight gain and fat mass accumulation. Inulin feeding tended to lead to higher total VFA production in the cecum and resulted in a higher (P<0.05) expression of acyl coA oxidase (ACO), a marker of peroxisomal β-oxidation. Inulin feeding also resulted in lower expression of sterol regulatory element binding protein 1c (SREBP-1c), a marker of lipid anabolism. Bacteria community structure characterized by DGGE analysis of PCR amplified 16S rRNA gene fragments showed that inulin feeding resulted in greater bacterial population richness than solka floc feeding. Cluster analysis of pairwise Dice similarity comparisons of the DGGE profiles showed grouping by fiber type but not the level of dietary fat. Canonical correspondence analysis (CCA) of PCR- DGGE profiles showed that inulin feeding negatively correlated with back fat thickness. This study suggests a strong interplay between dietary fat level and fiber type in determining susceptibility to obesity.

Effects of conjugated linoleic acid on growth, non-specific immunity, antioxidant capacity, lipid deposition and related gene expression in juvenile large yellow croaker (Larmichthys crocea) fed soyabean oil-based diets

The effects of conjugated linoleic acid (CLA) on growth performance, non-specific immunity, antioxidant capacity, lipid deposition and related gene expression were investigated in the large yellow croaker (Larmichthys crocea). Fish (7·56 (SEM 0·60) g) were fed soyabean oil-based diets with graded levels of CLA (0, 0·42, 0·83, 1·70%) for 70 d. Quantitative PCR was used to assess the effects of CLA on the transcription of inflammation- and fatty acid oxidation-related genes. Growth in fish fed the diet with 0·42% CLA was significantly higher. Also, phagocytic index and respiratory burst activity were significantly higher in fish fed the diets containing 0·42 and 0·83% CLA, respectively. Hepatic total antioxidative capacity and catalase activities increased significantly when CLA increased from 0 to 0·83%, and then decreased with further increase of CLA. However, hepatic malondialdehyde content decreased significantly as dietary CLA increased. Lipid concentration in the whole body and muscle increased significantly with increasing dietary CLA. Transcription of genes related to inflammation (cyclo-oxygenase-2 and IL-b) in the liver and kidney and fatty acid oxidation (carnitine palmitoyl transferase I and acyl CoA oxidase) in the kidney decreased significantly as dietary CLA increased. PPAR alpha and acyl CoA oxidase expression in the liver decreased significantly as CLA increased from 0·42 to 1·70%. These results strongly suggest that dietary CLA could significantly affect growth performance, non-specific immunity, antioxidant capacity, lipid deposition and transcription of inflammation- and fatty acid oxidation-related genes of the large yellow croaker. This may contribute to our understanding of the mechanisms related to the physiological effects of dietary CLA in fish.

Impact of Cadmium Exposure during Pregnancy on Hepatic Glucocorticoid Receptor Methylation and Expression in Rat Fetus

Adverse fetal environment due to maternal undernutrition or exposure to environmental chemicals alters glucocorticoid (GC) metabolism increasing the risk of metabolic disorders in adulthood. In this study, we investigated the effects of maternal exposure to cadmium (Cd, 50 ppm) during pregnancy in the methylation of fetal hepatic glucocorticoid receptor promoter (GR) and the correlation with its expression and that of the DNA methyltransferases (DNMT1a and 3a). We also studied the expression of liver phosphoenolpyruvate carboxykinase (PEPCK) and acyl-CoA oxidase (AOX), two enzymes involved in the metabolism of carbohydrates and lipids respectively. The methylation of the rat GR gene exon 110 (GR110) in nucleotides -2536 to -2361 was analyzed by pyrosequencing. Quantitative real time PCR was used to assess hepatic GR, PEPCK and AOX mRNA, and their protein levels using Western blotting analysis. Differential methylation was noted across groups at all CpG sites in the GR exon 110 in a sex-dependent manner. In males, CpG were more methylated than the controls (185±21%, p<0.001) but only CpG sites 1,6,7 and 9 showed a significantly different extent of methylation. In addition, a lower expression of GR (mRNA and protein) was found. On the contrary, in females, CpG were less methylated than the controls (62±11%, p<0.05) and overexpressed, affecting PEPCK and AOX expression, which did not change in males. The GR methylation profile correlates with DNMT3a expression which may explain epigenetic sex-dependent changes on GR110 promoter induced by Cd treatment. In conclusion, Cd exposure during pregnancy affects fetal liver DNMT3a resulting in sex-dependent changes in methylation and expression of GR110. Although these effects do not seem to be directly involved in the low birth weight and height, they may have relevant implications for long-term health.

(−)-Secoisolariciresinol attenuates high-fat diet-induced obesity in C57BL/6 mice

Flaxseed lignan, secoisolariciresinol has been reported to possess health benefits. We previously synthesized each stereoisomer of secoisolariciresinol and found that (-)-secoisolariciresinol reduces lipid accumulation and induces adiponectin production in 3T3-L1 adipocytes. Here we show the effects of (-)-secoisolariciresinol on high-fat diet-induced obesity in C57BL/6 male mice. Oral administration of (-)-secoisolariciresinol for 28 consecutive days significantly suppressed the gain of body weight. Increased serum adiponectin level and decreased gene expression of fatty acid synthase and sterol regulatory element-binding protein-1c in liver, which are related to fatty acid synthesis, were observed in the mice orally administered with (-)-secoisolariciresinol. In addition, subcutaneous injection of (-)-secoisolariciresinol also significantly suppressed the gain of body weight. Serum leptin levels were significantly increased by treating with (-)-secoisolariciresinol or (-)-enterolactone. Subcutaneous injection of (-)-secoisolariciresinol, (-)-enterolactone, or (-)-enterodiol promoted gene expression of acyl-CoA oxidase, carnitine palmitoyl transferase-1, and peroxisome proliferator-activated receptor α, which are related to β-oxidation. Overall results suggest that (-)-secoisolariciresinol exerts a suppressive effect on the gain of body weight of mice fed a high-fat diet by inducing gene expression of adiponectin, resulting in the altered expression of various genes related to the synthesis and β-oxidation of fatty acids.

Inhibition of stearoyl-CoA desaturase1 activates AMPK and exhibits beneficial lipid metabolic effects in vitro

Stearoyl-CoA desaturase1 (SCD1) whole body deficiency protects mice from diet-induced obesity. However the specific mechanism of how SCD1 deficiency protects mice from obesity is not clear yet. To understand the tissue-specific role of SCD1 in energy homeostasis, we investigated the responses of adipocytes, hepatocytes and myotubes to SCD1 inhibition. 3T3-L1 adipocytes treated with a SCD1 inhibitor had decreased expression of lipogenic genes including fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and sterol-regulatory element binding protein 1c (SREBP1c) while the expression of fatty acid oxidative genes including carnitine palmitoyltransferase 1 (CPT1), uncoupling protein 2 (UCP2), and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1-α) remained unaltered. In mouse primary hepatocytes, treatment with the inhibitor reduced the expression of FAS, ACC, and SREBP1c but increased the expression of fatty acid oxidative genes including acyl-CoA oxidase (AOX), CPT1, and PGC1-α. In addition, inhibitor-treated C2C12 myotubes showed decrease in ACC and FAS expression and increase in expression of CPT1, AOX and PGC1-α. AMP-activated protein kinase (AMPK) is known to regulate cellular metabolism in response to available energy and AMPK activation is associated with enhancement of fatty acid oxidation and suppression of lipogenesis. In all tested cell models, AMPK phosphorylation was increased significantly when SCD1 was inhibited. Taken together, our results indicate that inhibition of SCD1 activity has beneficial lipid metabolic effects of decreased lipogenesis and/or increased fatty acid oxidation, which is at least in part due to an increase of AMPK activation.

Kaempferol Regulates the Lipid-Profile in High-Fat Diet-Fed Rats through an Increase in Hepatic PPARαLevels

The aim of this study was to investigate the antiobesity and antihyperlipidemic effects of the flavonoid kaempferol (3,5,7,4'-tetrahydroxyflavone). After being fed a high-fat diet (HFD) for two weeks, rats were dosed orally with kaempferol (75, 150, or 300 mg/kg) or fenofibrate (100 mg/kg) once daily for eight weeks. Fenofibrate is an antilipemic agent that exerts its therapeutic effects through activation of peroxisome proliferator-activated receptor α (PPAR α). Kaempferol (300 mg/kg/day) produced effects similar to fenofibrate in reducing body weight gain, visceral fat-pad weights, plasma lipid levels, as well as the coronary artery risk and atherogenic indices of HFD-fed rats. Kaempferol also caused dose-related reductions in hepatic triglyceride and cholesterol content and lowered hepatic lipid droplet accumulation and the size of epididymal adipocytes in HFD-fed rats. Kaempferol and fenofibrate reversed the HFD-induced downregulation of hepatic PPAR α. HFD-induced reductions in the hepatic levels of acyl-CoA oxidase (ACO), and cytochrome P450 isoform 4A1 (CYP4A1) proteins were reversed by kaempferol and fenofibrate. The elevated expression of hepatic sterol regulatory element binding proteins (SREBPs) in HFD-fed rats were lowered by kaempferol and fenofibrate. These results suggest that kaempferol reduced the accumulation of visceral fat and improved hyperlipidemia in HFD-fed obese rats by increasing lipid metabolism through the downregulation of SREBPs and promoting the hepatic expression of ACO and CYP4A1, secondary to a direct upregulation hepatic PPAR α expression.

Regulation of Obesity and Lipid Disorders by Extracts from Angelica acutiloba Root in High‐fat Diet‐induced Obese Rats

The aim of this study was to investigate the antiobesity and antihyperlipidemic effects of Angelica acutiloba root (Japanese Dong Quai). High-fat diet (HFD)-induced obese rats were treated orally with the polyphenolic-rich extract of Angelica acutiloba root (AARE) once daily for 8 weeks. The AARE (300 mg/kg per day) supplementation significantly lowered body weight gain, visceral fat-pad weights and plasma lipid levels, as well as the coronary artery risk index and the atherogenic index of HFD-fed rats. The AARE caused dose related reductions in the hepatic triglyceride and cholesterol contents, as well as lowered hepatic lipid droplet accumulation and epididymal adipocyte size in the HFD-fed rats. The AARE reversed the HFD-induced down-regulation of the hepatic peroxisome proliferator activated receptor-α (PPARα). The HFD-induced decreases of the hepatic protein level of acyl-CoA oxidase (ACO), and the cytochrome P450 isoform 4A1 (CYP4A1) was up-regulated by AARE. The elevated expressions of hepatic sterol regulatory element binding proteins (SREBPs) of HFD-fed rats were lowered by AARE. These results suggest that AARE attenuated visceral fat accumulation and improved hyperlipidemia in HFD-induced obesity by increasing lipid metabolism through the down-regulation of SREBPs and enhanced the expression of ACO and CYP4A1 in the liver, which was likely mediated by up-regulation of the expression of hepatic PPARα.

Effects of bezafibrate in nonalcoholic steatohepatitis model mice with monosodium glutamate-induced metabolic syndrome

Recently, we reported that monosodium glutamate-treated mice (MSG mice) developed severe hyperlipidemia and diabetes mellitus and several complications of obesity. MSG mice acquired fatty livers and subsequently underwent changes that are characteristic of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). In the present study, the effects of bezafibrate on obesity, diabetes mellitus, and NAFLD/NASH were examined in MSG mice. A single dose of MSG (4mg/g) was administered subcutaneously to neonatal male mice within 24h of birth. Bezafibrate was mixed into the normal feed for 8weeks. The weight and body mass index of MSG mice increased significantly despite the unchanged intake of food. Triglyceride and total cholesterol levels in blood, visceral adipose tissue, and interscapular adipose tissue rose significantly. In the livers of MSG mice, moderate centrilobular microvesicular steatosis, ballooning degeneration with Mallory bodies, and scattered infiltration of neutrophils and lymphocytes were observed. Centrilobular hepatocytes were 4-hydroxynonenal-positive in MSG mice. Bezafibrate ameliorated the severity of diabetes mellitus, hyperinsulinemia, and hyperlipidemia. Adiponectin and leptin concentrations in blood improved, and the accumulation of visceral fat was inhibited. The expression of acyl-CoA oxidase, a beta-oxidation gene, and carnitine palmitoyl transferase, which regulates lipid metabolism, increased markedly on administration of bezafibrate. The liver pathology in MSG mice also improved with bezafibrate; specifically, macro- and microvesicles in hepatocytes nearly disappeared, and NAFLD activity score improved. It is concluded that bezafibrate inhibits the accumulation of visceral fat, following amelioration of hyperlipidemia, in MSG-induced obese mice, due to improvements in diabetes mellitus, fatty liver, and NAFLD.