scholarly journals Palmitate induces fat accumulation via repressing FoxO1-mediated ATGL-dependent lipolysis in HepG2 hepatocytes

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0243938
Author(s):  
Naiqian Zhao ◽  
Huiwen Tan ◽  
Li Wang ◽  
Le Han ◽  
Yanli Cheng ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Target Gene ◽  
Elevated Serum ◽  
Peroxisome Proliferator ◽  
Alcoholic Fatty Liver ◽  
Fat Accumulation ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation ◽  
Forkhead Box

Obesity is closely associated with non-alcoholic fatty liver disease (NAFLD), and elevated serum palmitate is the link between obesity and excessive hepatic lipid accumulation. Forkhead box O-1 (FoxO1) is one of the FoxO family members of transcription factors and can stimulate adipose triglyceride lipase (ATGL) and suppress its inhibitor G0/G1 switch gene 2 (G0S2) expression in the liver. However, previous researches have also shown conflicting results regarding the role of FoxO1 in hepatic lipid accumulation. We therefore examined the role of FoxO1 as a downstream suppressor to palmitate-stimulated hepatic steatosis. Palmitate significantly promoted lipid accumulation but inhibited lipid decomposition in human HepG2 hepatoma cells. Palmitate also significantly reduced FoxO1, ATGL and its activator comparative gene identification-58 (CGI-58) expression but increased peroxisome proliferator-activated receptorγ (PPARγ) and its target gene G0S2 expression. FoxO1 overexpression significantly increased palmitate-inhibited ATGL and CGI-58 expression but reduced palmitate-stimulated PPARγ and its target gene G0S2 expression. FoxO1 overexpression also inhibited lipid accumulation and promoted lipolysis in palmitate-treated hepatocytes. Overall, these results indicate that FoxO1-mediated ATGL-dependent lipolysis may be an effective molecular mechanism in protecting hepatocytes from palmitate-induced fat accumulation.

scholarly journals Hepatoprotective Effects of MHY3200 on High-Fat, Diet-Induced, Non-Alcoholic Fatty Liver Disease in Rats

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2057 ◽  
Author(s):  
Min Jo Kim ◽  
Chan Hum Park ◽  
Dae Hyun Kim ◽  
Min Hi Park ◽  
Kyung Chul Park ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
High Fat Diet ◽  
Serum Triglyceride ◽  
Serine Phosphorylation ◽  
Luciferase Assay ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Alcoholic Fatty Liver ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation

This study investigated the effects of 2-(4-(5-chlorobenzo[d]thiazol-2-yl)phenoxy)-2,2-difluoroacetic acid (MHY3200) on high-fat diet (HFD)-induced hepatic lipid accumulation and inflammation. The measurement of peroxisome proliferator-activated receptor (PPAR)α activity by using a luciferase assay indicated that MHY3200 was more potent than a known PPARα agonist, WY14643, in AC2F cells. Six-month-old male SD rats were fed chow or HFD for 1 month, and after, with or without added MHY3200 (1 or 2 mg/kg/day) for 4 weeks. The oral administration of MHY3200 caused a significant decrease in serum triglyceride (TG), glucose, alanine aminotransferase, and insulin, as well as a slight decrease in the level of free fatty acid and aspartate transaminase. No weight gain was detected when compared with HFD rats, and hepatic TG content was also attenuated by the administration of MHY3200. Furthermore, phosphorylation of the ER stress marker, inositol-requiring kinase 1 and its downstream gene, c-Jun N-terminal kinase, in addition to serine phosphorylation of insulin receptor substrate 1 were suppressed by MHY3200. Consistent with these results, MHY3200 administration reduced the levels of activation of protein-1, cyclooxygenase-2, and inducible nitric oxide synthase. Our results suggested that MHY3200 ameliorated HFD-induced hepatic lipid accumulation and inflammation, and improved insulin resistance through PPARα activation.

Uridine attenuates obesity, ameliorates hepatic lipid accumulation and modifies the gut microbiota composition in mice fed with a high-fat diet

2021 ◽  
Author(s):  
Yilin Liu ◽  
Chunyan Xie ◽  
Zhenya Zhai ◽  
Ze-yuan Deng ◽  
Hugo R. De Jonge ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Lipid Accumulation ◽  
High Fat Diet ◽  
Microbiota Composition ◽  
High Fat ◽  
Fat Accumulation ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation ◽  
Gut Microbiota Composition

This study aimed to investigate the effect of uridine on obesity, fat accumulation in liver, and gut microbiota composition in high-fat diet-fed mice.

Dietary raffinose ameliorates hepatic lipid accumulation induced by cholic acid via modulation of enterohepatic bile acid circulation in rats

2021 ◽  
pp. 1-26
Author(s):  
Kenta Maegawa ◽  
Haruka Koyama ◽  
Satoru Fukiya ◽  
Atsushi Yokota ◽  
Koichiro Ueda ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Bile Acid ◽  
Cholic Acid ◽  
Lipid Accumulation ◽  
Enterohepatic Circulation ◽  
Control Diet ◽  
Hepatic Triglyceride ◽  
Alcoholic Fatty Liver ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation

Abstract Enterohepatic circulation of 12α-hydroxylated (12αOH) bile acid (BA) is enhanced depending on the energy intake in high-fat diet-fed rats. Such BA metabolism can be reproduced using a diet supplemented with cholic acid (CA), which also induces simple steatosis, without inflammation and fibrosis, accompanied by some other symptoms that are frequently observed in the condition of non-alcoholic fatty liver in rats. We investigated whether supplementation of the diet with raffinose (Raf) improves hepatic lipid accumulation induced by the CA-fed condition in rats. After acclimation to the AIN-93-based control diet, male Wistar rats were fed diets supplemented with a combination of Raf (30 g/kg diet) and/or CA (0.5 g/kg diet) for 4 weeks. Dietary Raf normalised hepatic triglyceride levels (two-way ANOVA P<0.001 for CA, P=0.02 for Raf, and P=0.004 for interaction) in the CA-supplemented diet-fed rats. Dietary Raf supplementation reduced hepatic 12αOH BA concentration (two-way ANOVA P<0.001 for CA, P=0.003 for Raf, and P=0.03 for interaction). The concentration of 12αOH BA was reduced in the aortic and portal plasma. Raf supplementation increased acetic acid concentration in the caecal contents (two-way ANOVA P=0.001 as a main effect). Multiple regression analysis revealed that concentrations of aortic 12αOH BA and caecal acetic acid could serve as predictors of hepatic triglyceride concentration (R2=0.55, P<0.001). However, Raf did not decrease the secondary 12αOH BA concentration in the caecal contents as well as the transaminase activity in the CA diet-fed rats. These results imply that dietary Raf normalises hepatic lipid accumulation via suppression of enterohepatic 12αOH BA circulation.

scholarly journals N-Acetyl Cysteine Targets Hepatic Lipid Accumulation to Curb Oxidative Stress and Inflammation in NAFLD: A Comprehensive Analysis of the Literature

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1283
Author(s):  
Phiwayinkosi V. Dludla ◽  
Bongani B. Nkambule ◽  
Sithandiwe E. Mazibuko-Mbeje ◽  
Tawanda M. Nyambuya ◽  
Fabio Marcheggiani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Accumulation ◽  
Randomized Clinical Trials ◽  
Therapeutic Potential ◽  
Therapeutic Effects ◽  
Metabolic Complications ◽  
Alcoholic Fatty Liver ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation ◽  
Acetyl Cysteine

Impaired adipose tissue function and insulin resistance remain instrumental in promoting hepatic lipid accumulation in conditions of metabolic syndrome. In fact, enhanced lipid accumulation together with oxidative stress and an abnormal inflammatory response underpin the development and severity of non-alcoholic fatty liver disease (NAFLD). There are currently no specific protective drugs against NAFLD, and effective interventions involving regular exercise and healthy diets have proved difficult to achieve and maintain. Alternatively, due to its antioxidant and anti-inflammatory properties, there has been growing interest in understanding the therapeutic effects of N-acetyl cysteine (NAC) against metabolic complications, including NAFLD. Here, reviewed evidence suggests that NAC blocks hepatic lipid accumulation in preclinical models of NAFLD. This is in part through the effective regulation of a fatty acid scavenger molecule (CD36) and transcriptional factors such as sterol regulatory element-binding protein (SREBP)-1c/-2 and peroxisome proliferator-activated receptor gamma (PPARγ). Importantly, NAC appears effective in improving liver function by reducing pro-inflammatory markers such as interleukin (IL)-6 IL-1β, tumour necrosis factor alpha (TNF-α) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). This was primarily through the attenuation of lipid peroxidation and enhancements in intracellular response antioxidants, particularly glutathione. Very few clinical studies support the beneficial effects of NAC against NAFLD-related complications, thus well-organized randomized clinical trials are still necessary to confirm its therapeutic potential.

scholarly journals The lncRNA Gm15622 stimulates SREBP-1c expression and hepatic lipid accumulation by sponging the miR-742-3p in mice

2020 ◽  
Vol 61 (7) ◽  
pp. 1052-1064 ◽  
Author(s):  
Minjuan Ma ◽  
Rui Duan ◽  
Lulu Shen ◽  
Mengting Liu ◽  
Yaya Ji ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Lipid Deposition ◽  
In Vivo Models ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation ◽  
Regulatory Circuit ◽  
Murine Liver

Excessive lipid deposition is a hallmark of NAFLD. Although much has been learned about the enzymes and metabolites involved in NAFLD, few studies have focused on the role of long noncoding RNAs (lncRNAs) in hepatic lipid accumulation. Here, using in vitro and in vivo models of NAFLD, we found that the lncRNA Gm15622 is highly expressed in the liver of obese mice fed a HFD and in murine liver (AML-12) cells treated with free fatty acids. Investigating the molecular mechanism in the liver-enriched expression of Gm15622 and its effects on lipid accumulation in hepatocytes and on NAFLD pathogenesis, we found that Gm15622 acts as a sponge for the microRNA miR-742-3p. This sponging activity increased the expression of the transcriptional regulator SREBP-1c and promoted lipid accumulation in the liver of the HFD mice and AML-12 cells. Moreover, further results indicated that metformin suppresses Gm15622 and alleviates NAFLD-associated lipid deposition in mice. In conclusion, we have identified an lncRNA Gm15622/miR-742-3p/SREBP-1c regulatory circuit associated with NAFLD in mice, a finding that significantly advances our insight into how lipid metabolism and accumulation are altered in this metabolic disorder. Our results also suggest that Gm15622 may be a potential therapeutic target for managing NAFLD.

scholarly journals Understanding the Role of Exercise in Nonalcoholic Fatty Liver Disease: ERS-Linked Molecular Pathways

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yong Zou ◽  
Zhengtang Qi
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Lipid Accumulation ◽  
Fatty Liver Disease ◽  
Molecular Pathways ◽  
Nonalcoholic Fatty Liver ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation

Nonalcoholic fatty liver disease (NAFLD) is globally prevalent and characterized by abnormal lipid accumulation in the liver, frequently accompanied by insulin resistance (IR), enhanced hepatic inflammation, and apoptosis. Recent studies showed that endoplasmic reticulum stress (ERS) at the subcellular level underlies these featured pathologies in the development of NAFLD. As an effective treatment, exercise significantly reduces hepatic lipid accumulation and thus alleviates NAFLD. Confusingly, these benefits of exercise are associated with increased or decreased ERS in the liver. Further, the interaction between diet, medication, exercise types, and intensity in ERS regulation is more confusing, though most studies have confirmed the benefits of exercise. In this review, we focus on understanding the role of exercise-modulated ERS in NAFLD and ERS-linked molecular pathways. Moderate ERS is an essential signaling for hepatic lipid homeostasis. Higher ERS may lead to increased inflammation and apoptosis in the liver, while lower ERS may lead to the accumulation of misfolded proteins. Therefore, exercise acts like an igniter or extinguisher to keep ERS at an appropriate level by turning it up or down, which depends on diet, medications, exercise intensity, etc. Exercise not only enhances hepatic tolerance to ERS but also prevents the malignant development of steatosis due to excessive ERS.

scholarly journals Role of β-adrenergic receptors in regulation of hepatic fat accumulation during aging

2012 ◽  
Vol 213 (3) ◽  
pp. 251-261 ◽  
Author(s):  
Paramita M Ghosh ◽  
Zhen-Ju Shu ◽  
Bing Zhu ◽  
Zhongding Lu ◽  
Yuji Ikeno ◽  
...  
Keyword(s):  
Adenylyl Cyclase ◽  
Hepatic Steatosis ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Adenylyl Cyclase Activity ◽  
Fat Accumulation ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation ◽  
Hepatic Fat

Excessive fat accumulation in liver (hepatic steatosis) predisposes to hepatic functional and structural impairment and overall metabolic risk. Previous studies noted an association between hepatic steatosis and age in humans and rodents. However, the mechanisms leading to age-associated hepatic fat accumulation remain unknown. Earlier work from our group showed that β-adrenergic receptor (β-AR) levels and β-AR-stimulated adenylyl cyclase activity increase in rat liver during aging. Here we investigated whether age-associated increases in β-AR signaling play a role in augmenting hepatic lipid accumulation. We demonstrate an increase in hepatic lipid content during senescence and a significant correlation between hepatic fat content and stimulation of adenylyl cyclase activity by the β-AR agonist isoproterenol in rat liver. Isoproterenol administration to young and old rodents in vivo increased hepatic lipid accumulation. Furthermore, in vitro overexpression of β1- and β2-AR subtypes in hepatocytes from young rodents increased cellular lipid content, whereas inhibition of β-ARs by receptor subtype-specific inhibitors reduced lipid levels in hepatocytes from senescent animals. Isoproterenol-induced hepatic lipid accumulation in vivo was prevented by the β-AR nonselective blocker propranolol, suggesting a novel therapeutic effect of this class of drugs in hepatic steatosis. Acipimox, which inhibits adipose tissue lipolysis, did not alter isoproterenol-mediated hepatic fat accumulation; thus β-AR responsive hepatic lipid accumulation does not appear to be related primarily to altered lipolysis. These findings suggest that augmented hepatic β-AR signaling during aging may increase lipid accumulation in liver and advocate a possible role for β-adrenergic blockers in preventing or retarding the development of hepatic steatosis.

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