Houttuynia cordata Attenuates Lipid Accumulation via Activation of AMP-Activated Protein Kinase Signaling Pathway in HepG2 Cells

2014 ◽  
Vol 42 (03) ◽  
pp. 651-664 ◽  
Author(s):  
Hyun Kang ◽  
Sushruta Koppula
Keyword(s):  
Protein Kinase ◽  
High Glucose ◽  
Lipid Accumulation ◽  
Hepg2 Cells ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
Regulatory Element ◽  
Adenosine Monophosphate ◽  
Perennial Herb ◽  
Houttuynia Cordata

Houttuynia cordata (H. cordata) from the family Saururaceae is a perennial herb native to Southeast Asia. It possesses a range of medicinal properties to treat several disease symptoms including allergic inflammation and anaphylaxis. In the present investigation, we provided the molecular mechanisms underlying the role of H. cordata extract (HCE) in the prevention of high glucose-induced lipid accumulation in human HepG2 hepatocytes. HepG2 cells were pre-treated with various concentrations of HCE (0, 10, 20, 40, and 80 μg/mL) and treated with serum-free medium with normal glucose (5 mM) for 1 h, followed by exposure to high glucose (25 mM D-glucose) for 24 h. HCE significantly and dose-dependently attenuated lipid accumulation in human HepG2 hepatocytes when exposed to high glucose (25 mM D-glucose) (p < 0.05, p < 0.01 and p < 0.001 at 20, 40, and 80 μg/mL concentrations, respectively). Further, HCE attenuated the expression of fatty acid synthase (FAS), sterol regulatory element-binding protein-1 and glycerol 3-phosphate acyltransferases (GPATs). The adenosine monophosphate-activated protein kinase (AMPK) was also activated by HCE treatment when exposed to high glucose (25 mM D-glucose) in human HepG2 hepatocytes. This study suggests the hypolipidemic effects of HCE by the inhibition of lipid biosynthesis mediated through AMPK signaling, which may play an active role and can be developed as an anti-obesity agent.

scholarly journals Nobiletin Inhibits Hepatic Lipogenesis via Activation of AMP-Activated Protein Kinase

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Taewon Yuk ◽  
Younghwa Kim ◽  
Jinwoo Yang ◽  
Jeehye Sung ◽  
Heon Sang Jeong ◽  
...  
Keyword(s):  
Protein Kinase ◽  
High Glucose ◽  
Lipid Accumulation ◽  
Hepg2 Cells ◽  
Fatty Acid Synthase ◽  
Regulatory Element ◽  
Hepatic Lipogenesis ◽  
Nonalcoholic Fatty Liver ◽  
Compound C ◽  
Amp Activated Protein Kinase

We aimed to investigate the effects of nobiletin on hepatic lipogenesis in high glucose-induced lipid accumulation in HepG2 cells. Nobiletin, a citrus polymethoxyflavonoid with six methoxy groups, is present abundantly in the peels of citrus fruits. HepG2 cells were incubated in Dulbecco’s modified Eagle’s medium containing high glucose (25 mM) and subsequently treated with nobiletin at different concentrations (5, 25, and 50 μM). Results showed that nobiletin markedly inhibited high glucose-induced hepatic lipid accumulation in HepG2 cells. In addition, it reduced the protein expression of lipogenic factors, including sterol regulatory element-binding protein 1c (SREBP-1c) and fatty acid synthase (FAS). Nobiletin significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. Pretreatment with compound C, an AMPK inhibitor, abolished the inhibitory effects of nobiletin on SREBP-1c and FAS expression. These results suggested that nobiletin might attenuate high glucose-induced lipid accumulation in HepG2 hepatocytes via modulation of AMPK signaling pathway. Therefore, nobiletin might be useful for the prevention and treatment of nonalcoholic fatty liver diseases.

scholarly journals Phloretin ameliorates hepatic steatosis through regulation of lipogenesis and Sirt1/AMPK signaling in obese mice

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chian-Jiun Liou ◽  
Shu-Ju Wu ◽  
Szu-Chuan Shen ◽  
Li-Chen Chen ◽  
Ya-Ling Chen ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Hepatic Steatosis ◽  
Lipid Accumulation ◽  
Hepg2 Cells ◽  
Fatty Acid Synthase ◽  
Regulatory Element ◽  
Liver Lipid ◽  
Obese Mice ◽  
Alcoholic Fatty Liver

Abstract Background Phloretin is isolated from apple trees and could increase lipolysis in 3T3-L1 adipocytes. Previous studies have found that phloretin could prevent obesity in mice. In this study, we investigated whether phloretin ameliorates non-alcoholic fatty liver disease (NAFLD) in high-fat diet (HFD)-induced obese mice, and evaluated the regulation of lipid metabolism in hepatocytes. Methods HepG2 cells were treated with 0.5 mM oleic acid to induce lipid accumulation, and then treated with phloretin to evaluate the molecular mechanism of lipogenesis. In another experiment, male C57BL/6 mice were fed normal diet or HFD (60% fat, w/w) for 16 weeks. After the fourth week, mice were treated with or without phloretin by intraperitoneal injection for 12 weeks. Results Phloretin significantly reduced excessive lipid accumulation and decreased sterol regulatory element-binding protein 1c, blocking the expression of fatty acid synthase in oleic acid-induced HepG2 cells. Phloretin increased Sirt1, and phosphorylation of AMP activated protein kinase to suppress acetyl-CoA carboxylase expression, reducing fatty acid synthesis in hepatocytes. Phloretin also reduced body weight and fat weight compared to untreated HFD-fed mice. Phloretin also reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis in obese mice. In liver tissue from obese mice, phloretin suppressed transcription factors of lipogenesis and fatty acid synthase, and increased lipolysis and fatty acid β-oxidation. Furthermore, phloretin regulated serum leptin, adiponectin, triglyceride, low-density lipoprotein, and free fatty acid levels in obese mice. Conclusions These findings suggest that phloretin improves hepatic steatosis by regulating lipogenesis and the Sirt-1/AMPK pathway in the liver.

PPARγ2 regulates lipogenesis and lipid accumulation in steatotic hepatocytes

2005 ◽  
Vol 288 (6) ◽  
pp. E1195-E1205 ◽  
Author(s):  
Susan E. Schadinger ◽  
Nancy L. R. Bucher ◽  
Barbara M. Schreiber ◽  
Stephen R. Farmer
Keyword(s):  
Fatty Acid ◽  
Cell Line ◽  
Lipid Accumulation ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Binding Protein ◽  
Regulatory Element ◽  
Fatty Acid Binding ◽  
Triacylglycerol Synthesis

Peroxisome proliferator-activated receptor-γ (PPARγ) is considered to be one of the master regulators of adipocyte differentiation. PPARγ2 is abundantly expressed in mature adipocytes and is elevated in the livers of animals that develop fatty livers. The aim of this study was to determine the ability of PPARγ2 to induce lipid accumulation in hepatocytes and to delineate molecular mechanisms driving this process. The hepatic cell line AML-12 was used to generate a cell line stably expressing PPARγ2. Oil Red O staining revealed that PPARγ2 induces lipid accumulation in hepatocytes. This phenotype is accompanied by a selective upregulation of several adipogenic and lipogenic genes including adipose differentiation-related protein (ADRP), adipocyte fatty acid-binding protein 4, sterol regulatory element-binding protein-1 (SREBP-1), fatty acid synthase (FAS), and acetyl-CoA carboxylase, genes whose expression levels are known to increase in steatotic livers of ob/ob mice. Furthermore, the PPARγ2-regulated induction of both SREBP-1 and FAS parallels an increase in de novo triacylglycerol synthesis in hepatocytes. Triacylglycerol synthesis and lipid accumulation are further enhanced by culturing hepatocytes with troglitazone in the absence of exogenous lipids. These results correspond with an increase in the lipid droplet protein, ADRP, and the data demonstrate that ADRP functions to coat lipid droplets in hepatocytes as observed by confocal microscopy. Taken together, these observations propose a role for PPARγ2 as an inducer of steatosis in hepatocytes and suggest that this phenomenon occurs through an induction of pathways regulating de novo lipid synthesis.

scholarly journals Flavonones from Penthorum chinense Ameliorate Hepatic Steatosis by Activating the SIRT1/AMPK Pathway in HepG2 Cells

2018 ◽  
Vol 19 (9) ◽  
pp. 2555 ◽  
Author(s):  
Wei-Wei Guo ◽  
Xing Wang ◽  
Xiao-Qing Chen ◽  
Yin-Ying Ba ◽  
Nan Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Hepatic Steatosis ◽  
Hepg2 Cells ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
Regulatory Element ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ampk Pathway ◽  
Penthorum Chinense

Pinocembrin-7-O-β-d-glucoside (PCBG), pinocembrin (PCB), and 5-methoxy-pinocembrin-7-O-β-d-glucoside (MPG) are three flavonones isolated from Penthorum chinense Pursh (P. chinense). The effects of the three flavonones on hepatic steatosis and their molecular mechanisms in HepG2 cells were investigated in this study for the first time. A model of hepatic steatosis in HepG2 cells was induced by free fatty acid (FFA), and co-treated with the three flavonones as mentioned. Intracellular lipid droplets were detected by Oil Red O staining. PCB, PCBG, and MPG suppressed oxidative stress by decreasing malondialdehyde (MDA) levels and increasing superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were ameliorated. Moreover, these flavonones enhanced the phosphorylation of AMP-activated protein kinase (AMPK) and the expression of silent mating type information regulation 2 homolog 1 (SIRT1) and peroxisome proliferator-activated receptor α (PPARα), and reduced the expression of sterol regulatory element binding protein-1c (SREBP1c) and the downstream targets fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and stearoyl-CoA desaturase 1 (SCD1). Molecular docking was used to predict the interaction and combination patterns between the three flavonones and the enzymes above. The results revealed that the SIRT1/AMPK pathway is involved in the functions of the three flavonones, and the most effective flavonone against hepatic steatosis might be PCBG, followed by MPG and PCB. Therefore, the three flavonones from P. chinense were found to exert preventive effects against hepatic steatosis by regulating the SIRT1/AMPK pathway.

scholarly journals Catalpol Attenuates Hepatic Steatosis by Regulating Lipid Metabolism via AMP-Activated Protein Kinase Activation

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Xiang Tian ◽  
Qin Ru ◽  
Qi Xiong ◽  
Ruojian Wen ◽  
Yong Chen
Keyword(s):  
Fatty Acid ◽  
Protein Kinase ◽  
Hepatic Steatosis ◽  
Lipid Accumulation ◽  
Hepg2 Cells ◽  
Fatty Acid Synthase ◽  
Target Genes ◽  
Dependent Manner ◽  
Compound C ◽  
Amp Activated Protein Kinase

The increased prevalence of nonalcoholic fatty liver disease (NAFLD), which develops from hepatic steatosis, represents a public health challenge. Catalpol, a natural component extracted from the roots of Radix Rehmanniae, has several pharmacological activities. The present study is aimed at examining whether catalpol prevents hepatic steatosis in cell and animal experiments and elucidating the possible mechanisms. HepG2 cells were treated with 300 μM palmitate (PA) and/or catalpol for 24 h in vitro, and male C57BL/6J mice fed a high-fat diet (HFD) were administered catalpol for 18 weeks in vivo. The results revealed that catalpol significantly decreased lipid accumulation in PA-treated HepG2 cells. Moreover, catalpol drastically reduced body weight and lipid accumulation in the liver, whereas it ameliorated hepatocyte steatosis in HFD-fed mice. Notably, catalpol remarkably promoted the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. Subsequently, catalpol repressed the expressions of lipogenesis-associated genes such as sterol regulatory element-binding protein 1c and fatty acid synthase but promoted the expressions of genes associated with fatty acid β-oxidation such as peroxisome proliferator-activated receptor α together with its target genes carnitine palmitoyltransferase 1 and acyl-CoA oxidase 1 (ACOX1). However, the preincubation of the HepG2 cells with compound C (10 μM), an AMPK inhibitor, prevented catalpol-mediated beneficial effects. These findings suggest that catalpol ameliorates hepatic steatosis by suppressing lipogenesis and enhancing fatty acid β-oxidation in an AMPK-dependent manner. Therefore, catalpol has potential as a novel agent in the treatment of NAFLD.

Hepatitis B virus X protein induces lipogenic transcription factor SREBP1 and fatty acid synthase through the activation of nuclear receptor LXRα

2008 ◽  
Vol 416 (2) ◽  
pp. 219-230 ◽  
Author(s):  
KyeongJin Kim ◽  
Kook Hwan Kim ◽  
Hyeong Hoe Kim ◽  
JaeHun Cheong
Keyword(s):  
Fatty Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Lipid Accumulation ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
Regulatory Element ◽  
Liver Lipid ◽  
Hepatic Cells ◽  
B Virus

HBV (hepatitis B virus) is a primary cause of chronic liver disease, which frequently results in hepatitis, cirrhosis and ultimately HCC (hepatocellular carcinoma). Recently, we showed that HBx (HBV protein X) expression induces lipid accumulation in hepatic cells mediated by the induction of SREBP1 (sterol-regulatory-element-binding protein 1), a key regulator of lipogenic genes in the liver. However, the molecular mechanisms by which HBx increases SREBP1 expression and transactivation remain to be clearly elucidated. In the present study, we demonstrated that HBx interacts with LXRα (liver X receptor α) and enhances the binding of LXRα to LXRE (LXR-response element), thereby resulting in the up-regulation of SREBP1 and FAS (fatty acid synthase) in the presence or absence of the LXR agonist T0901317 in the hepatic cells and HBx-transgenic mice. Furthermore, HBx also augments the ability to recruit ASC2 (activating signal co-integrator 2), a transcriptional co-activator that controls liver lipid metabolic pathways, to the LXRE with LXRα. These studies place LXRα in a key position within the HBx-induced lipogenic pathways, and suggest a molecular mechanism through which HBV infection can stimulate the SREBP1-mediated control of hepatic lipid accumulation.

scholarly journals Aqueous Extract of Pepino (Solanum muriactum Ait) Leaves Ameliorate Lipid Accumulation and Oxidative Stress in Alcoholic Fatty Liver Disease

Nutrients ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 931 ◽  
Author(s):  
Jen-Ying Hsu ◽  
Hui-Hsuan Lin ◽  
Cheng-Chin Hsu ◽  
Bing-Chen Chen ◽  
Jing-Hsien Chen
Keyword(s):  
Oxidative Stress ◽  
Fatty Liver ◽  
Aqueous Extract ◽  
Lipid Accumulation ◽  
Fatty Acid Synthase ◽  
Regulatory Element ◽  
Adenosine Monophosphate ◽  
Peroxisome Proliferator ◽  
Alcoholic Fatty Liver ◽  
Anti Inflammatory

Chronic alcohol intake leads to alcoholic fatty liver. The pathogenesis of alcoholic fatty liver is related to abnormal lipid accumulation, oxidative stress, endotoxins, and cytokines. Solanum muricatum Ait. (Pepino) is a plant food commonly cultivated in the Penghu island, Taiwan. Previous studies indicated that the aqueous extract of pepino was able to attenuate diabetic progression via its antioxidative and anti-inflammatory effects. However, the mechanisms of the antioxidative and anti-inflammatory effects of pepino leaf in preventing alcoholic fatty liver remain unknown. In this study, Lieber–DeCarli ethanol-containing liquid diet was used to induce alcoholic hepatic injury in C57BL/6 mice. The hepatoprotective effects and the related mechanisms of aqueous extract of pepino leaf (AEPL) were examined. Our results showed that 2% AEPL treatments protected the liver from ethanol-induced injury through reducing serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC) and triglyceride (TG) (all p < 0.05). AEPL had the effects in improving the ethanol-induced lipid accumulation in mice under histological examination. Molecular data indicated that the anti-lipid accumulation effect of AEPL might be mediated via inducing hepatic levels of phospho-adenosine monophosphate-activated kinase (p-AMPK) and peroxisome proliferator-activated receptor (PPAR)-α, and reducing the expressions of hepatic lipogenic enzymes, including sterol regulatory element-binding protein (SREBP)-1c, acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) (all p < 0.05). AEPL also decreased hepatic levels of thiobarbituric acid relative substances (TBARS), tumor necrosis factor (TNF)-α, and interleukin (IL)-6, as well as the expression of nuclear factor kappa B (NF-κB) (all p < 0.05). Moreover, AEPL significantly elevated the activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx), and glutathione (GSH) content compared to the ethanol-fed group (all p < 0.05). Our present study suggests that AEPL could protect the liver against ethanol-induced oxidative injury and lipid accumulation.

scholarly journals Neochlorogenic Acid Attenuates Hepatic Lipid Accumulation and Inflammation via Regulating miR-34a In Vitro

2021 ◽  
Vol 22 (23) ◽  
pp. 13163
Author(s):  
Meng-Hsun Yu ◽  
Tung-Wei Hung ◽  
Chi-Chih Wang ◽  
Sheng-Wen Wu ◽  
Tzu-Wei Yang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Accumulation ◽  
Fatty Acid Synthase ◽  
Regulatory Element ◽  
Adenosine Monophosphate ◽  
Acid Synthesis ◽  
Sirtuin 1 ◽  
Nonalcoholic Fatty Liver ◽  
Neochlorogenic Acid

Neochlorogenic acid (5-Caffeoylquinic acid; 5-CQA), a major phenolic compound isolated from mulberry leaves, possesses anti-oxidative and anti-inflammatory effects. Although it modulates lipid metabolism, the molecular mechanism is unknown. Using an in-vitro model of nonalcoholic fatty liver disease (NAFLD) in which oleic acid (OA) induced lipid accumulation in HepG2 cells, we evaluated the alleviation effect of 5-CQA. We observed that 5-CQA improved OA-induced intracellular lipid accumulation by downregulating sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FASN) expression, which regulates the fatty acid synthesis, as well as SREBP2 and HMG-CoA reductases (HMG-CoR) expressions, which regulate cholesterol synthesis. Treatment with 5-CQA also increased the expression of fatty acid β-oxidation enzymes. Remarkably, 5-CQA attenuated OA-induced miR-34a expression. A transfection assay with an miR-34a mimic or miR-34a inhibitor revealed that miR-34a suppressed Moreover, Sirtuin 1 (SIRT1) expression and inactivated 5’ adenosine monophosphate-activated protein kinase (AMPK). Our results suggest that 5-CQA alleviates lipid accumulation by downregulating miR-34a, leading to activation of the SIRT1/AMPK pathway.

scholarly journals Role of Long Non-Coding RNAs and the Molecular Mechanisms Involved in Insulin Resistance

2021 ◽  
Vol 22 (14) ◽  
pp. 7256
Author(s):  
Vianet Argelia Tello-Flores ◽  
Fredy Omar Beltrán-Anaya ◽  
Marco Antonio Ramírez-Vargas ◽  
Brenda Ely Esteban-Casales ◽  
Napoleón Navarro-Tito ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Biological Species ◽  
Necrosis Factor Alpha ◽  
Polypyrimidine Tract Binding Protein ◽  
Non Coding Rnas

Long non-coding RNAs (lncRNAs) are single-stranded RNA biomolecules with a length of >200 nt, and they are currently considered to be master regulators of many pathological processes. Recent publications have shown that lncRNAs play important roles in the pathogenesis and progression of insulin resistance (IR) and glucose homeostasis by regulating inflammatory and lipogenic processes. lncRNAs regulate gene expression by binding to other non-coding RNAs, mRNAs, proteins, and DNA. In recent years, several mechanisms have been reported to explain the key roles of lncRNAs in the development of IR, including metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), imprinted maternal-ly expressed transcript (H19), maternally expressed gene 3 (MEG3), myocardial infarction-associated transcript (MIAT), and steroid receptor RNA activator (SRA), HOX transcript antisense RNA (HOTAIR), and downregulated Expression-Related Hexose/Glucose Transport Enhancer (DREH). LncRNAs participate in the regulation of lipid and carbohydrate metabolism, the inflammatory process, and oxidative stress through different pathways, such as cyclic adenosine monophosphate/protein kinase A (cAMP/PKA), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT), polypyrimidine tract-binding protein 1/element-binding transcription factor 1c (PTBP1/SREBP-1c), AKT/nitric oxide synthase (eNOS), AKT/forkhead box O1 (FoxO1), and tumor necrosis factor-alpha (TNF-α)/c-Jun-N-terminal kinases (JNK). On the other hand, the mechanisms linked to the molecular, cellular, and biochemical actions of lncRNAs vary according to the tissue, biological species, and the severity of IR. Therefore, it is essential to elucidate the role of lncRNAs in the insulin signaling pathway and glucose and lipid metabolism. This review analyzes the function and molecular mechanisms of lncRNAs involved in the development of IR.

Sign in / Sign up

Export Citation Format

Share Document