scholarly journals Deficiency of the Purinergic Receptor 2X7 Attenuates Nonalcoholic Steatohepatitis Induced by High-Fat Diet: Possible Role of the NLRP3 Inflammasome

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Claudia Blasetti Fantauzzi ◽  
Stefano Menini ◽  
Carla Iacobini ◽  
Chiara Rossi ◽  
Eleonora Santini ◽  
...  
Keyword(s):  
Nonalcoholic Steatohepatitis ◽  
Nlrp3 Inflammasome ◽  
High Fat Diet ◽  
Molecular Mechanisms ◽  
Purinergic Receptor ◽  
High Fat ◽  
Liver Sinusoidal Endothelial Cells ◽  
Nonalcoholic Fatty Liver ◽  
Markers Of Inflammation

Molecular mechanisms driving transition from simple steatosis to nonalcoholic steatohepatitis (NASH), a critical step in the progression of nonalcoholic fatty liver disease (NAFLD) to cirrhosis, are poorly defined. This study aimed at investigating the role of the purinergic receptor 2X7 (PR2X7), through the NLRP3 inflammasome, in the development of NASH. To this end, mice knockout for the Pr2x7 gene (Pr2x7−/−) and coeval wild-type (WT) mice were fed a high-fat diet (HFD) or normal-fat diet for 16 weeks. NAFLD grade and stage were lower in Pr2x7−/− than WT mice, and only 1/7 Pr2x7−/− animals showed evidence of NASH, as compared with 4/7 WT mice. Molecular markers of inflammation, oxidative stress, and fibrosis were markedly increased in WT-HFD mice, whereas no or significantly reduced increments were detected in Pr2x7−/− animals, which showed also decreased modulation of genes of lipid metabolism. Deletion of Pr2x7 gene was associated with blunted or abolished activation of NLRP3 inflammasome and expression of its components, which were induced in liver sinusoidal endothelial cells challenged with appropriate stimuli. These data show that Pr2x7 gene deletion protects mice from HFD-induced NASH, possibly through blunted activation of NLRP3 inflammasome, suggesting that PR2X7 and NLRP3 may represent novel therapeutic targets.

scholarly journals RANKL Is Involved in Runx2-Triggered Hepatic Infiltration of Macrophages in Mice with NAFLD Induced by a High-Fat Diet

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Li Zhong ◽  
Jianghan Yuan ◽  
Lu Huang ◽  
Shan Li ◽  
Liang Deng
Keyword(s):  
High Fat Diet ◽  
Macrophage Infiltration ◽  
Macrophage Migration ◽  
High Fat ◽  
Transwell Assay ◽  
Nonalcoholic Fatty Liver ◽  
Related Transcription Factor

Background. Receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL) is significant in the activation of inflammation. Runt-related transcription factor 2 (Runx2) promotes the hepatic infiltration of macrophages in nonalcoholic fatty liver disease (NAFLD). We studied how RANKL affects Runx2-triggered macrophage infiltration in NAFLD. Method. 30 male C57BL/6J mice at 4 weeks of age were utilized in this study, 20 mice received a high-fat diet (HFD), and 10 mice received standard rodent chow over 8 months. The histopathologic features of the liver were identified by H&E, Oil red O, and Masson staining. Runx2, RANKL, and F4/80 were analyzed by western blot, real-time PCR, and immunohistochemistry in vivo, respectively. Lentivirus or siRNA was utilized for transwell assay to investigate the role of RANKL in Runx2-induced macrophage migration in vitro. Results. Compared to controls, during NAFLD development, HFD increased Runx2 and RANKL in vivo in NASH (P<0.01). Meanwhile, a correlation between the expression of Runx2 and RANKL (P<0.05) was evident. In addition, the hepatic infiltration of macrophages was increased upon HFD feeding, and analysis showed that the macrophage infiltration was correlated with the expression of Runx2 or RANKL (P<0.05). In vitro, we found that overexpression or deficiency of Runx2 increased or decreased the production of RANKL in mHSCs. Then, transwell assay revealed that RANKL was involved in Runx2-induced macrophage migration. Conclusions. Overall, RANKL is involved in Runx2-triggered macrophage migration during NAFLD pathogenesis, which may provide an underlying therapeutic target for NAFLD.

scholarly journals Sijunzi, Lizhong, and Fuzilizhong Decoction Alleviate Nonalcoholic Fatty Liver Disease through Activation of PPAR Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jiayao Yang ◽  
Dongqing Tao ◽  
Wei Ma ◽  
Song Liu ◽  
Yan Liao ◽  
...  
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
High Fat Diet ◽  
Fatty Liver Disease ◽  
Molecular Mechanisms ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Nonalcoholic Fatty Liver ◽  
Chinese Herbal

Objective. Sijunzi, Lizhong, and Fuzilizhong decoction were traditional Chinese classic formulations, which are widely used in clinical treatment, and the underlying mechanism is unclear. In this study, we aim to investigate the molecular mechanisms underlying the protective effects of Sijunzi, Lizhong, and Fuzilizhong on nonalcoholic fatty liver disease (NAFLD). Methods. Male Wistar rats were fed a high-fat diet for four weeks to induce NAFLD and were thereafter administered Sijunzi (8 g/kg/d), Lizhong (10 g/kg/d), or Fuzilizhong (10 g/kg/d) by gavage for four weeks. Hepatic damage, lipid accumulation, inflammation, autophagy, and peroxisome proliferator-activated receptor-α signaling were evaluated. Results. The high-fat diet-fed rats showed typical symptoms of NAFLD, including elevated levels of hepatic damage indicators, increased hepatic lipid deposition and fibrosis, severe liver inflammation, and prominent autophagy. Upon administration of Sijunzi, Lizhong, and Fuzilizhong, liver health was improved remarkably, along with ameliorated symptoms of NAFLD. In addition, NAFLD-suppressed peroxisome proliferator-activated receptor-α signaling was reactivated after treatment with the three types of decoctions. Conclusions. The results collectively signify the effective therapeutic and protective functions of Sijunzi, Lizhong, and Fuzilizhong against NAFLD and demonstrate the potential of Chinese herbal medication in mitigating the symptoms of liver diseases. Novelty of the Work. Traditional Chinese herbal medicine has been used for centuries to treat various diseases, but the molecular mechanisms of individual ingredients have rarely been studied. The novelty of our work lies in elucidating the specific signaling pathways involved in the control of NAFLD using three common Chinese herbal decoctions. We suggest that natural herbal formulations can be effective therapeutic agents to combat against NAFLD.

scholarly journals Hepatocyte high-mobility group box 1 protects against steatosis and cellular stress during high fat diet feeding

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Minjie Lin ◽  
Jungke Long ◽  
Wenbo Li ◽  
Chenxuan Yang ◽  
Patricia Loughran ◽  
...  
Keyword(s):  
Er Stress ◽  
High Fat Diet ◽  
High Mobility ◽  
High Mobility Group ◽  
High Fat ◽  
Rapid Weight Gain ◽  
Nonalcoholic Fatty Liver ◽  
Primary Mouse

Abstract Background Circulating high-mobility group box 1 (HMGB1) plays important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Intracellular HMGB1 is critical for the biology of hepatocytes. However, the intracellular role of HMGB1 in hepatocellular steatosis is unknown. Therefore, we aimed to investigate the role of hepatocyte-specific HMGB1 (HC-HMGB1) in development of hepatic steatosis. Methods Wild type (WT) C57BL/6 and HC-HMGB1−/− mice were fed high-fat diet (HFD) or low-fat diet (LFD) for up to 16 weeks. Results As expected, HMGB1 translocated from nuclear into cytoplasm and released into circulation after HFD treatment. HC-HMGB1 deficiency significantly reduced circulating HMGB1, suggesting that hepatocyte is a major source of circulating HMGB1 during NAFLD. Unexpectedly, HC-HMGB1 deficiency promoted rapid weight gain with enhanced hepatic fat deposition compared with WT at as early as 4 weeks after HFD treatment. Furthermore, there was no difference between WT and HC-HMGB1−/− mice in glucose tolerance, energy expenditure, liver damage or systemic inflammation. Interestingly, hepatic gene expression related to free fatty acid (FFA) β-oxidation was significantly down-regulated in HC-HMGB1−/− mice compared with WT, and endoplasmic reticulum (ER) stress markers were significantly higher in livers of HC-HMGB1−/− mice. In vitro experiments using primary mouse hepatocytes showed absence of HMGB1 increased FFA-induced intracellular lipid accumulation, accompanied by increased ER-stress, significant downregulation of FFA β-oxidation, and reduced oxidative phosphorylation. Conclusions Our findings suggest that hepatocyte HMGB1 protects against dysregulated lipid metabolism via maintenance of β-oxidation and prevention of ER stress. This represents a novel mechanism for HMGB1-regulation of hepatocellular steatosis, and suggests that stabilizing HMGB1 in hepatocytes may be effective strategies for prevention and treatment of NAFLD.

scholarly journals Effects of Caffeine and Chlorogenic Acid on Nonalcoholic Steatohepatitis in Mice Induced by Choline-Deficient, L-Amino Acid-Defined, High-Fat Diet

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3886
Author(s):  
Erdenetsogt Dungubat ◽  
Shiori Watabe ◽  
Arisa Togashi-Kumagai ◽  
Masato Watanabe ◽  
Yasuyuki Kobayashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chlorogenic Acid ◽  
Nonalcoholic Steatohepatitis ◽  
High Fat Diet ◽  
Cell Injury ◽  
Control Diet ◽  
Experimental Studies ◽  
High Fat ◽  
Nonalcoholic Fatty Liver ◽  
Hepatic Expression

Several recent experimental studies have investigated the effects of caffeine and chlorogenic acid (CGA), representative ingredients of coffee, on nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). However, the results are conflicting, and their effects are yet to be clarified. In the present study, we examined the effects of caffeine and CGA on choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD)-fed mice, relatively new model mice of NASH. Seven-week-old male C57BL/6J mice were divided into the following groups: Control diet (control), CDAHFD (CDAHFD), CDAHFD supplemented with 0.05% (w/w) caffeine (caffeine), and CDAHFD supplemented with 0.1% (w/w) CGA (CGA). After seven weeks, the mice were killed and serum biochemical, histopathological, and molecular analyses were performed. Serum alanine aminotransferase (ALT) levels were significantly higher in the caffeine and CGA groups than in the CDAHFD group. On image analysis, the prevalence of Oil red O-positive areas (reflecting steatosis) was significantly higher in the caffeine group than in the CDAHFD group, and that of CD45R-positive areas (reflecting lymphocytic infiltration) in the hepatic lobule was significantly higher in the caffeine and CGA groups than in the CDAHFD group. Hepatic expression of interleukin (IL)-6 mRNA was higher in the caffeine and CGA groups than in the CDAHFD group, and the difference was statistically significant for the caffeine group. In conclusion, in the present study, caffeine and CGA significantly worsened the markers of liver cell injury, inflammation, and/or steatosis in NASH lesions in mice.

The purinergic 2X7receptor participates in renal inflammation and injury induced by high-fat diet: possible role of NLRP3 inflammasome activation

2013 ◽  
Vol 231 (3) ◽  
pp. 342-353 ◽  
Author(s):  
Anna Solini ◽  
Stefano Menini ◽  
Chiara Rossi ◽  
Carlo Ricci ◽  
Eleonora Santini ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Fat Diet ◽  
Inflammasome Activation ◽  
High Fat ◽  
Renal Inflammation ◽  
Nlrp3 Inflammasome Activation

scholarly journals Triclosan leads to dysregulation of the metabolic regulator FGF21 exacerbating high fat diet-induced nonalcoholic fatty liver disease

2020 ◽  
Vol 117 (49) ◽  
pp. 31259-31266
Author(s):  
Mei-Fei Yueh ◽  
Feng He ◽  
Chen Chen ◽  
Catherine Vu ◽  
Anupriya Tripathi ◽  
...  
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
High Fat Diet ◽  
Molecular Mechanisms ◽  
Consumer Products ◽  
Fibroblast Growth Factor 21 ◽  
High Fat ◽  
Aberrant Expression ◽  
Nonalcoholic Fatty Liver ◽  
Hepatic Expression

Triclosan (TCS), employed as an antiseptic and disinfectant, comes into direct contact with humans through a plethora of consumer products and its rising environmental release. We have demonstrated that TCS promotes liver tumorigenesis in mice, yet the biological and molecular mechanisms by which TCS exerts its toxicity, especially in early stages of liver disease, are largely unexplored. When mice were fed a high-fat diet (HFD), we found that fatty liver and dyslipidemia are prominent early signs of liver abnormality induced by TCS. The presumably protective HFD-induced hepatic expression of the metabolic regulator fibroblast growth factor 21 (FGF21) was blunted by TCS. TCS-alteredFgf21expression aligned with aberrant expression of genes encoding metabolic enzymes manifested as profound systemic metabolic changes that disturb homeostasis of amino acids, fatty acids, and glucose. Using a type 1 diabetic animal model, TCS potentiates and accelerates the development of steatohepatitis and fibrosis, accompanied by increased levels of hepatic lipid droplets and oxidative stress. Analysis of fecal samples revealed that HFD-fed mice exhibited a reduction in fecal species richness, and that TCS further diminished microbial diversity and shifted the bacterial community toward lower Bacteriodetes and higher Firmicutes, resembling changes in microbiota composition in nonalcoholic steatohepatitis (NASH) patients. Using reverse-genetic approaches, we demonstrate that, along with HFD, TCS induces hepatic steatosis and steatohepatitis jointly regulated by the transcription factor ATF4 and the nuclear receptor PPARα, which participate in the transcriptional regulation of theFgf21gene. This study provides evidence linking nutritional imbalance and exposure to TCS with the progression of NASH.

miR-182-5p Attenuates High-Fat -Diet-Induced Nonalcoholic Steatohepatitis in Mice

2018 ◽  
Vol 17 (5) ◽  
pp. 0-10
Author(s):  
Qionghe Liang ◽  
Huan Chen ◽  
Xiaoqun Xu ◽  
Weiwei Jiang
Keyword(s):  
Nonalcoholic Steatohepatitis ◽  
High Fat Diet ◽  
Hepg2 Cells ◽  
Treated Group ◽  
High Fat ◽  
Protein Levels ◽  
Tlr4 Mrna ◽  
Increased Risk

Introduction and Aim: Patients with NASH have increased risk for sepsis or cardiovascular disease after Liver transplantation. An important role of Toll-like receptor (TLR) 4 in the pathogenesis of nonalcoholic steatohepatitis (NASH) was demonstrated. Here, we study the role of miR-182-5p in TLR4 expression and high-fat-diet (HFD)-induced NASH in vitro and in vivo. Methods: Following transfection with a miR-182-5p mimic, the effect of miR-182-5p on TLR4 in RAW264.7 and HepG2 cells was investigated. Following administration of the miR-182-5p mimic into the livers of HFD-induced NASH mice, we determined the in vivo expression of TLR4, TNFα, and IL-6 and assessed the histologic features of the livers. Results: Following lipopolysaccharide (LPS) treatment of RAW264.7 cells, real-time RT-PCR and western blot results indicated decreases levels of TLR4 mRNA and protein in the miR-182-5p group as compared with levels observed in controls, with similar trends were observed in TNFα and IL-6 protein levels. Following oleic acid (OA) treatment of HepG2 cells, TLR4, TNFα, and IL-6 levels were significantly decreased in the miR-182-5p group as compared with levels observed in controls. Following miR-182-5p administration, TLR4 mRNA and protein levels decreased along with those of TNFα and IL-6 proteins, and the liver weight/body weight ratio of treated mice was less than that observed in controls. Furthermore, hematoxylin and eosin staining showed that the miR-182-5p-treated group exhibited low adipose-cell cross-sectional areas, and Oil Red O staining showed decreases in the size of lipid droplets in the miR-182-5p-treated group. Conclusions: miR-182-5p ameliorated HFD-induced NASH by suppressing TLR4.

scholarly journals P2X7 Receptor as a Key Player in Oxidative Stress-Driven Cell Fate in Nonalcoholic Steatohepatitis

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Saurabh Chatterjee ◽  
Suvarthi Das
Keyword(s):  
Oxidative Stress ◽  
Nonalcoholic Steatohepatitis ◽  
Purinergic Receptors ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Purinergic Receptor ◽  
Leptin Resistance ◽  
Hepatocellular Injury ◽  
Cardiometabolic Disorders

Incidences of nonalcoholic fatty liver disease parallels increase in the global obesity epidemic. NAFLD has been shown to be associated with risks of cardiometabolic disorders and kidney disturbances. It is accompanied by insulin and leptin resistance that complicate the diagnosis and treatment of this public health menace. Though significant research is underway for understanding the molecular mechanisms of NAFLD and its subsequent inflammatory and fibrotic manifestations like nonalcoholic steatohepatitis, the role of purinergic receptors has been unclear. It is increasingly being recognized that damage associated molecular patterns like NAD and ATP that are released from injured cells via hepatocellular injury either by oxidative stress or lipotoxicity from steatosis activate the purinergic receptor. Based on evidence from inflammatory responses in the airways and vasculature and autoimmune complications in humans and rodents, it is beyond doubt that hepatocellular inflammation such as that seen in NASH can result from the activation of purinergic receptors. This event can result in the formation of inflammasomes and can be an important pathway for the progression of NASH. The present review evaluates the current knowledge of the role of oxidative stress and its signaling via P2X7 receptors in hepatocellular injury that might contribute to the NASH pathophysiology.

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