scholarly journals Functional Comparison of High and Low Molecular Weight Chitosan on Lipid Metabolism and Signals in High-Fat Diet-Fed Rats

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 251 ◽  
Author(s):  
Shing-Hwa Liu ◽  
Chen-Yuan Chiu ◽  
Ching-Ming Shi ◽  
Meng-Tsan Chiang
Keyword(s):  
Molecular Weight ◽  
Lipid Metabolism ◽  
Regulatory Element ◽  
Lipid Absorption ◽  
Liver Fat ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Protein Expressions

The present study examined and compared the effects of low- and high-molecular weight (MW) chitosan, a nutraceutical, on lipid metabolism in the intestine and liver of high-fat (HF) diet-fed rats. High-MW chitosan as well as low-MW chitosan decreased liver weight, elongated the small intestine, improved the dysregulation of blood lipids and liver fat accumulation, and increased fecal lipid excretion in rats fed with HF diets. Supplementation of both high- and low-MW chitosan markedly inhibited the suppressed phosphorylated adenosine monophosphate (AMP)-activated protein kinase-α (AMPKα) and peroxisome proliferator-activated receptor-α (PPARα) protein expressions, and the increased lipogenesis/cholesterogenesis-associated protein expressions [peroxisome proliferator-activated receptor-γ (PPARγ), sterol regulatory element binding protein-1c and -2 (SREBP1c and SREBP2)] and the suppressed apolipoprotein E (ApoE) and microsomal triglyceride transfer protein (MTTP) protein expressions in the livers of rats fed with HF diets. Supplementation with both a low- and high-MW chitosan could also suppress the increased MTTP protein expression and the decreased angiopoietin-like protein-4 (Angptl4) expression in the intestines of rats fed with HF diets. In comparison between low- and high-MW chitosan, high-MW chitosan exhibits a higher efficiency than low-MW chitosan on the inhibition of intestinal lipid absorption and an increase of hepatic fatty acid oxidation, which can improve liver lipid biosynthesis and accumulation.

scholarly journals Functional Comparison of High and Low Molecular Weight Chitosan on Lipid Metabolism and Signals in High-Fat Diet-Fed Rats

2018 ◽  
Author(s):  
Shing-Hwa Liu ◽  
Chen-Yuan Chiu ◽  
Ching-Ming Shi ◽  
Meng-Tsan Chiang
Keyword(s):  
Molecular Weight ◽  
Lipid Metabolism ◽  
Protein Expression ◽  
High Fat Diet ◽  
Liver Lipid ◽  
Lipid Absorption ◽  
Low Molecular Weight ◽  
High Fat ◽  
Apo E ◽  
Protein Expressions

The present study examined and compared the effects of high- and low-molecular weight (MW) chitosan, a nutraceutical, on intestinal and liver lipid metabolism in rats fed with high-fat diet. Both high- and low-MW chitosan decreased liver weight, elongated small intestine, improved the dysregulation of blood lipids and liver fat accumulation, and increased fecal lipid excretion in high-fat diet-fed rats. Supplementation of both high- and low-MW chitosan significantly inhibited the decreased phosphorylated AMP-activated protein kinase (AMPK)α and peroxisome proliferator-activated receptor (PPAR)α protein expressions and the increased lipogenesis/cholesterogenesis-associated protein expressions (sterol regulatory element binding protein (SREBP)1c, SREBP2, and PPARγ) and the decreased apolipoprotein (Apo)E and microsomal triglyceride transfer protein (MTTP) protein expressions in the livers of high-fat diet-fed rats. Both high and low-MW chitosan supplementation could also suppress the increased MTTP protein expression and the decreased angiopoietin-like protein (Angptl)4 protein expression in the intestines of high-fat diet-fed rats. Comparison between high and low-MW chitosan, high-MW chitosan has a higher efficiency than low-MW chitosan on the inhibition of intestinal lipid absorption and the increase of hepatic fatty acid oxidation, which can improve liver lipid biosynthesis and accumulation.

scholarly journals Vinegar-Baked Radix Bupleuri Regulates Lipid Disorders via a Pathway Dependent on Peroxisome-Proliferator-Activated Receptor-αin High-Fat-Diet-Induced Obese Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Thing-Fong Tzeng ◽  
Hung-Jen Lu ◽  
Shorong-Shii Liou ◽  
Chia Ju Chang ◽  
I-Min Liu
Keyword(s):  
High Fat Diet ◽  
Regulatory Element ◽  
Plasma Lipid ◽  
Cholesterol Content ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Obese Rats ◽  
Radix Bupleuri

The aim of this study was to investigate the antiobesity and antihyperlipidemic effects of vinegar-baked Radix Bupleuri (VBRB) on high-fat diet- (HFD-) induced obese rats. After being fed HFD for two weeks, rats were dosed orally with VBRB or fenofibrate, once daily for further twelve weeks. VBRB (1.0 g kg−1per day) produced effects similar to fenofibrate (100 mg kg−1) in reducing body weight (BW) gain, visceral fat-pad weights, plasma lipid levels, as well as hepatic TG and cholesterol content of HFD-fed rats. VBRB also lowered hepatic lipid droplet accumulation and the size of epididymal adipocytes in HFD-fed rats. VBRB and fenofibrate reversed the HFD-induced downregulation of hepatic peroxisome proliferator-activated receptor (PPAR)α. HFD-induced reductions in the hepatic levels of acyl-CoA oxidase (ACO) and cytochrome P450 isoform 4A1 (CYP4A1) proteins were reversed by VBRB and fenofibrate. The elevated expression of hepatic sterol regulatory element binding proteins (SREBPs) in HFD-fed rats was lowered by VBRB and fenofibrate. The results of this study show that VBRB suppresses BW gain and body fat accumulation by increasing fatty acid oxidation, an effect which is likely mediated via upregulation of PPARα and downregulation of SREBP expression in the liver of HFD-fed rats.

scholarly journals Myricetin Increases Hepatic Peroxisome Proliferator-Activated ReceptorαProtein Expression and Decreases Plasma Lipids and Adiposity in Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Chia Ju Chang ◽  
Thing-Fong Tzeng ◽  
Shorong-Shii Liou ◽  
Yuan-Shiun Chang ◽  
I-Min Liu
Keyword(s):  
Plasma Lipids ◽  
Regulatory Element ◽  
Plasma Lipid ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Down Regulation ◽  
Peroxisome Proliferator Activated Receptor ◽  
Once Daily ◽  
Sterol Regulatory Element ◽  
Lowered Body

The aim of this study was to investigate the antiobesity and antihyperlipidaemic effects of myricetin. Myricetin exhibited a significant concentration-dependent decrease in the intracellular accumulation of triglyceride in 3T3-L1 adipocytes. The high-fat diet (HFD)-fed rats were dosed orally with myricetin or fenofibrate, once daily for eight weeks. Myricetin (300 mg kg−1per day) displayed similar characteristics to fenofibrate (100 mg kg−1per day) in reducing lowered body weight (BW) gain, visceral fat-pad weights and plasma lipid levels of HFD-fed rats. Myricetin also reduced the hepatic triglyceride and cholesterol contents, as well as lowered hepatic lipid droplets accumulation and epididymal adipocyte size in HFD-fed rats. Myricetin and fenofibrate reversed the HFD-induced down-regulation of the hepatic peroxisome proliferator activated receptor (PPAR)α. HFD-induced decreases of the hepatic protein level of acyl-CoA oxidase and cytochrome P450 isoform 4A1 were up-regulated by myricetin and fenofibrate. The elevated expressions of hepatic sterol regulatory element binding proteins (SREBPs) of HFD-fed rats were lowered by myricetin and fenofibrate. These results suggest that myricetin suppressed BW gain and body fat accumulation by increasing the fatty acid oxidation, which was likely mediated via up-regulation of PPARαand down-regulation of SREBP expressions in the liver of HFD-fed rats.

scholarly journals Comparative Effects and Mechanisms of Chitosan and Its Derivatives on Hypercholesterolemia in High-Fat Diet-Fed Rats

2019 ◽  
Vol 21 (1) ◽  
pp. 92 ◽  
Author(s):  
Chen-Yuan Chiu ◽  
Tsai-En Yen ◽  
Shing-Hwa Liu ◽  
Meng-Tsan Chiang
Keyword(s):  
Molecular Weight ◽  
Protein Expression ◽  
Density Lipoprotein ◽  
Cholesterol Homeostasis ◽  
Chitosan Oligosaccharide ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Gene Expressions ◽  
Necrosis Factor Alpha ◽  
Peroxisome Proliferator Activated Receptor

The present study investigated and compared the effects of different molecular weights of chitosan (high molecular weight chitosan (HC) and low molecular weight chitosan (LC)) and its derivatives (chitosan oligosaccharide (CO)) on cholesterol regulation in high-fat (HF) diet-fed rats. A diet supplementation of 5% HC, 5% LC, or 5% CO for 8 weeks showed hypocholesterolemic potential in HF diet-fed rats. Unexpectedly, a 5% CO-supplemented diet exerted hepatic damage, producing increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor-alpha (TNF-α). The supplementation of HC and LC, unlike CO, significantly decreased the hepatic total cholesterol (TC) levels and increased the fecal TC levels in HF diet-fed rats. The hepatic protein expression of the peroxisome proliferator-activated receptor-α (PPARα) in the HF diet-fed rats was markedly decreased, which could be significantly reversed by both HC and LC, but not CO, supplementation. Unlike the supplementation of CO, both HC and LC supplementation could effectively reverse the HF-inhibited/induced gene expressions of the low-density lipoprotein receptor (LDLR) and cholesterol 7α-hydroxylase (CYP7A1), respectively. The upregulated intestinal acyl-CoA cholesterol acyltransferase 2 (ACAT2) protein expression in HF diet-fed rats could be reversed by HC and LC, but not CO, supplementation. Taken together, a supplementation of 5% CO in HF diet-fed rats may exert liver damage via a higher hepatic cholesterol accumulation and a higher intestinal cholesterol uptake. Both HC and LC effectively ameliorated the hypercholesterolemia and regulated cholesterol homeostasis via the activation and inhibition of hepatic (AMPKα and PPARα) and intestinal (ACAT2) cholesterol-modulators, respectively, as well as the modulation of downstream signals (LDLR and CYP7A1).

Human skeletal muscle PPARα expression correlates with fat metabolism gene expression but not BMI or insulin sensitivity

2004 ◽  
Vol 286 (2) ◽  
pp. E168-E175 ◽  
Author(s):  
Junlong Zhang ◽  
D. I. W. Phillips ◽  
Chunli Wang ◽  
Christopher D. Byrne
Keyword(s):  
Skeletal Muscle ◽  
Lipid Metabolism ◽  
Insulin Sensitivity ◽  
Uncoupling Protein ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Peroxisome Proliferator Activated Receptor ◽  
Few Data

Peroxisome proliferator-activated receptor-α (PPARα) is a key regulator of fatty acid oxidation in skeletal muscle, but few data exist from humans in vivo. To investigate whether insulin sensitivity in skeletal muscle and body mass index (BMI) were associated with skeletal muscle expression of PPARα and with important genes regulating lipid metabolism in humans in vivo, we undertook hyperinsulinemic-euglycemic clamps and measured PPARα mRNA levels and mRNA levels of lipid regulating PPARα response genes in skeletal muscle biopsies. mRNA levels were measured in 16 men, using a novel highly sensitive and specific medium throughput quantitative competitive PCR that allows reproducible measurement of multiple candidate mRNAs simultaneously. mRNA levels of PPARα were positively correlated with mRNA levels of CD36 ( r = 0.77, P = 0.001), lipoprotein lipase ( r = 0.54, P = 0.024), muscle-type carnitine palmitoyltransferase-I ( r = 0.54, P = 0.024), uncoupling protein-2 ( r = 0.63, P = 0.008), and uncoupling protein-3 ( r = 0.53, P = 0.026), but not with measures of insulin sensitivity, BMI, or GLUT4, which plays an important role in insulin-mediated glucose uptake. Thus our data suggest that in humans skeletal muscle PPARα expression and genes regulating lipid metabolism are tightly linked, but there was no association between both insulin sensitivity and BMI with PPARα expression in skeletal muscle.

scholarly journals Maternal Overweight Programs Insulin and Adiponectin Signaling in the Offspring

Endocrinology ◽  
2010 ◽  
Vol 151 (6) ◽  
pp. 2577-2589 ◽  
Author(s):  
Kartik Shankar ◽  
Ping Kang ◽  
Amanda Harrell ◽  
Ying Zhong ◽  
John C. Marecki ◽  
...  
Keyword(s):  
Fatty Acid Synthase ◽  
Regulatory Element ◽  
Peroxisome Proliferator ◽  
Amp Kinase ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Gestational Exposure ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Maternal Overweight

Gestational exposure to maternal overweight (OW) influences the risk of obesity in adult life. Male offspring from OW dams gain greater body weight and fat mass and develop insulin resistance when fed high-fat diets (45% fat). In this report, we identify molecular targets of maternal OW-induced programming at postnatal d 21 before challenge with the high-fat diet. We conducted global transcriptome profiling, gene/protein expression analyses, and characterization of downstream signaling of insulin and adiponectin pathways in conjunction with endocrine and biochemical characterization. Offspring born to OW dams displayed increased serum insulin, leptin, and resistin levels (P < 0.05) at postnatal d 21 preceding changes in body composition. A lipogenic transcriptome signature in the liver, before development of obesity, was evident in OW-dam offspring. A coordinated locus of 20 sterol regulatory element-binding protein-1-regulated target genes was induced by maternal OW. Increased nuclear levels of sterol regulatory element-binding protein-1 and recruitment to the fatty acid synthase promoter were confirmed via ELISA and chromatin immunoprecipitation analyses, respectively. Higher fatty acid synthase and acetyl coenzyme A carboxylase protein and pAKT (Thr308) and phospho-insulin receptor-β were confirmed via immunoblotting. Maternal OW also attenuated AMP kinase/peroxisome proliferator-activated receptor-α signaling in the offspring liver, including transcriptional down-regulation of several peroxisome proliferator-activated receptor-α-regulated genes. Hepatic mRNA and circulating fibroblast growth factor-21 levels were significantly lower in OW-dam offspring. Furthermore, serum levels of high-molecular-weight adiponectin (P < 0.05) were decreased in OW-dam offspring. Phosphorylation of hepatic AMP-kinase (Thr172) was significantly decreased in OW-dam offspring, along with lower AdipoR1 mRNA. Our results strongly suggest that gestational exposure to maternal obesity programs multiple aspects of energy-balance regulation in the offspring.

scholarly journals Resveratrol Attenuates High-Fat Diet Induced Hepatic Lipid Homeostasis Disorder and Decreases m6A RNA Methylation

2020 ◽  
Vol 11 ◽  
Author(s):  
Jiamin Wu ◽  
Yi Li ◽  
Jiayao Yu ◽  
Zhending Gan ◽  
Wenyao Wei ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
High Fat Diet ◽  
Peroxisome Proliferator ◽  
Domain Family ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Rna Methylation ◽  
Low Fat Diet ◽  
Mrna Methylation ◽  
Yth Domain

Purpose:N6-methyladenosine (m6A) mRNA methylation is affected by dietary factors and associated with lipid metabolism; however, whether the regulatory role of resveratrol in lipid metabolism is involved in m6A mRNA methylation remains unknown. Here, the objective of this study was to investigate the effect of resveratrol on hepatic lipid metabolism and m6A RNA methylation in the liver of mice.Methods: A total of 24 male mice were randomly allocated to LFD (low-fat diet), LFDR (low-fat diet + resveratrol), HFD (high-fat diet), and HFDR (high-fat diet + resveratrol) groups for 12 weeks (n = 6/group). Final body weight of mice was measured before sacrificing. Perirhemtric fat, abdominal and epididymal fat, liver tissues, and serum were collected at sacrifice and analyzed. Briefly, mice phenotype, lipid metabolic index, and m6A modification in the liver were assessed.Results: Compared to the HFD group, dietary resveratrol supplementation reduced the body weight and relative abdominal, epididymal, and perirhemtric fat weight in high-fat-exposed mice; however, resveratrol significantly increased average daily feed intake in mice given HFD. The amounts of serum low-density lipoprotein cholesterol (LDL), liver total cholesterol (TC), and triacylglycerol (TAG) were significantly decreased by resveratrol supplementation. In addition, resveratrol significantly enhanced the levels of peroxisome proliferator-activated receptor alpha (PPARα), peroxisome proliferator-activated receptor beta/delta (PPARβ/δ), cytochrome P450, family 4, subfamily a, polypeptide 10/14 (CYP4A10/14), acyl-CoA oxidase 1 (ACOX1), and fatty acid-binding protein 4 (FABP4) mRNA and inhibited acyl-CoA carboxylase (ACC) mRNA levels in the liver. Furthermore, the resveratrol in HFD increased the transcript levels of methyltransferase like 3 (METTL3), alkB homolog 5 (ALKBH5), fat mass and obesity associated protein (FTO), and YTH domain family 2 (YTHDF2), whereas it decreased the level of YTH domain family 3 (YTHDF3) and m6A abundance in mice liver.Conclusion: The beneficial effect of resveratrol on lipid metabolism disorder under HFD may be due to decrease of m6A RNA methylation and increase of PPARα mRNA, providing mechanistic insights into the function of resveratrol in alleviating the disturbance of lipid metabolism in mice.

scholarly journals Elucidation of SIRT-1/PGC-1α-associated mitochondrial dysfunction and autophagy in nonalcoholic fatty liver disease

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yan Jiang ◽  
Duankai Chen ◽  
Qiming Gong ◽  
Qunqing Xu ◽  
Dong Pan ◽  
...  
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Sirtuin 1 ◽  
Liver Fat ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Nonalcoholic Fatty Liver

Abstract Background Nonalcoholic fatty liver disease (NAFLD) can lead to chronic liver diseases associated with mitochondrial damages. However, the exact mechanisms involved in the etiology of the disease are not clear. Methods To gain new insights, the changes affecting sirtuin 1 (SIRT-1) during liver fat accumulation was investigated in a NAFLD mouse model. In addition, the in vitro research investigated the regulation operated by SIRT-1 on mitochondrial structures, biogenesis, functions, and autophagy. Results In mice NAFLD, high-fat-diet (HFD) increased body weight gain, upregulated serum total cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, blood glucose, insulin levels, and liver malondialdehyde, and decreased liver superoxide dismutase activity. In liver, the levels of SIRT-1 and peroxisome proliferator-activated receptor-gamma coactivator -1α (PGC-1α) decreased. The expression of peroxisome proliferator-activated receptor-α and Beclin-1 proteins was also reduced, while p62/SQSTM1 expression increased. These results demonstrated SIRT-1 impairment in mouse NAFLD. In a well-established NAFLD cell model, exposure of the HepG2 hepatocyte cell line to oleic acid (OA) for 48 h caused viability reduction, apoptosis, lipid accumulation, and reactive oxygen species production. Disturbance of SIRT-1 expression affected mitochondria. Pre-treatment with Tenovin-6, a SIRT-1 inhibitor, aggravated the effect of OA on hepG2, while this effect was reversed by CAY10602, a SIRT-1 activator. Further investigation demonstrated that SIRT-1 activity was involved in mitochondrial biogenesis through PGC-1α and participated to the balance of autophagy regulatory proteins. Conclusion In conclusion, in high-fat conditions, SIRT-1 regulates multiple cellular properties by influencing on mitochondrial physiology and lipid autophagy via the PGC-1α pathway. The SIRT-1/PGC-1α pathway could be targeted to develop new NAFLD therapeutic strategies.

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