Circulating pro fibrotic protein promotes fibrosis in liver

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Hsiao ◽  
I Shimizu ◽  
Y Yoshida ◽  
R Ikegami ◽  
Y Hayashi ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
High Fat Diet ◽  
In Vitro Studies ◽  
High Fat ◽  
Brown Adipocytes ◽  
Adipose Tissues ◽  
Nash Model ◽  
Brown Adipose

Abstract Background/Introduction Non-alcoholic steatohepatitis (NASH), driven by the obesity epidemic, has become the most common form of liver disease. Inflamed visceral adipose tissue secretes pro-inflammatory adipokines that are causal for systemic metabolic disorders. Role of adipokines in NASH, especially those from brown adipose tissues (BATokine) remain unclear. Purpose To show the pathogenic role of BATokine in NASH. Methods To identify and characterize the pathological roles of pro-fibrotic BATokine, we generated a murine obese NASH model by imposing a high fat diet in C57BL6/NCr mice, and murine systemic or BAT specific knockout (KO) models. We also conducted functional in-vitro studies with differentiated brown adipocytes. Results Analyzing two sets of DNA micro array data with bioinformatics, we identified a secreted form pro-fibrotic protein (sPFP) expressed in dysfunctional brown adipose tissues (BAT) in mice. Testing our biobank samples, we found this protein increased in plasma of NASH patients. We generated a murine obese NASH model by imposing a high fat diet in C57BL6/NCr mice for 9–10 months since 4 weeks of age, and found that sPFP is produced predominantly by BAT. In this model, we also found that sPFP increased in plasma. We generated a murine systemic or BAT specific sPFP knockout (KO) models and found that liver fibrosis ameliorated in these models. We also suppressed circulating sPFP with a peptide vaccine targeting this molecule, and found that sPFP vaccination therapy inhibited liver fibrosis. Next, we generated sPFP gain of function (GOF) model by the administration of plasmid encoding sPFP into skeletal muscle. Liver fibrosis augmented in sPFP-GOF model, and these results suggested that sPFP has causal role for the progression of fibrotic response in liver. In vitro studies with differentiated brown adipocytes showed that metabolic stress increased c-Fos in nuclear, and this was causal for an increase in sPFP level. Conclusions Our results suggest that one of the BATokines, sPFP, contributes for the progression of fibrotic responses in obese-NASH model. Inhibition of sPFP may become a therapy for NASH or obesity related fibrotic disorders. Funding Acknowledgement Type of funding source: None

scholarly journals ASKA technology-based pull-down method reveals a suppressive effect of ASK1 on the inflammatory NOD-RIPK2 pathway in brown adipocytes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saki Takayanagi ◽  
Kengo Watanabe ◽  
Takeshi Maruyama ◽  
Motoyuki Ogawa ◽  
Kazuhiro Morishita ◽  
...  
Keyword(s):  
Uncoupling Protein ◽  
Biological Significance ◽  
Suppressive Effect ◽  
Brown Adipocyte ◽  
Brown Adipocytes ◽  
Adipose Tissues ◽  
Signaling Complex ◽  
Brown Adipose ◽  
Immune Pathway

AbstractRecent studies have shown that adipose tissue is an immunological organ. While inflammation in energy-storing white adipose tissues has been the focus of intense research, the regulatory mechanisms of inflammation in heat-producing brown adipose tissues remain largely unknown. We previously identified apoptosis signal-regulating kinase 1 (ASK1) as a critical regulator of brown adipocyte maturation; the PKA-ASK1-p38 axis facilitates uncoupling protein 1 (UCP1) induction cell-autonomously. Here, we show that ASK1 suppresses an innate immune pathway and contributes to maintenance of brown adipocytes. We report a novel chemical pull-down method for endogenous kinases using analog sensitive kinase allele (ASKA) technology and identify an ASK1 interactor in brown adipocytes, receptor-interacting serine/threonine-protein kinase 2 (RIPK2). ASK1 disrupts the RIPK2 signaling complex and inhibits the NOD-RIPK2 pathway to downregulate the production of inflammatory cytokines. As a potential biological significance, an in vitro model for intercellular regulation suggests that ASK1 facilitates the expression of UCP1 through the suppression of inflammatory cytokine production. In parallel to our previous report on the PKA-ASK1-p38 axis, our work raises the possibility of an auxiliary role of ASK1 in brown adipocyte maintenance through neutralizing the thermogenesis-suppressive effect of the NOD-RIPK2 pathway.

The role of 5-HT7 receptors on isoproterenol-induced myocardial infarction in rats with high-fat diet exacerbated coronary endothelial dysfunction

2020 ◽  
Vol 39 (8) ◽  
pp. 1005-1018 ◽  
Author(s):  
I Cinar ◽  
Z Halici ◽  
B Dincer ◽  
B Sirin ◽  
E Cadirci
Keyword(s):  
Myocardial Infarction ◽  
Endothelial Dysfunction ◽  
High Fat Diet ◽  
Density Lipoprotein ◽  
Heart Tissue ◽  
High Fat ◽  
Inflammatory Status

The presence of 5-HT7r’s in both human and rat cardiovascular and immune tissues and their contribution to inflammatory conditions prompted us to hypothesize that these receptors contribute in acute myocardial infarction (MI) with underlying chronic endothelial dysfunction. We investigated the role of 5-HT7 receptors on heart tissue that damaged by isoproterenol (ISO)-induced MI in rats with high-fat diet (HFD). In vitro and in vivo effects of 5-HT7r agonist (LP44) and antagonist (SB269970) have been investigated on the H9C2 cell line and rats, respectively. For in vivo analyses, rats were fed with HFD for 8 weeks and after this period ISO-induced MI model has been applied to rat. To investigate the role of 5-HT7r’s, two different doses of LP44 and SB269970 were evaluated and compared with standard hypolipidemic agent, atorvastatin. In vitro studies showed that LP44 has protective and proliferative effects on rat cardiomyocytes. Also in in vivo studies stimulating 5-HT7r’s by LP44 improved blood lipid profile (decreased total cholesterol, low-density lipoprotein-C, and triglyceride, increased high-density lipoprotein), decreased cardiac damage markers (creatine kinase and troponin-I), and corrected inflammatory status (tumor necrosis factor-α, interleukin-6). Our results showed significant improvement in LP44 administered rats in terms of histopathologic analyses. In damaged tissues, 5-HT7 mRNA expression increased and agonist administration decreased this elevation significantly. We determined for the first time that 5-HT7r’s are overexpressed in ISO-induced MI of rats with underlying HFD-induced endothelial dysfunction. Restoration of this overexpression by LP44, a 5-HT7r agonist, ameliorated heart tissue in physiopathologic, enzymatic, and molecular level, showing the cardiac role of these receptors and suggesting them as future potential 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 Anti-Obesity Effects of Grateloupia elliptica, a Red Seaweed, in Mice with High-Fat Diet-Induced Obesity via Suppression of Adipogenic Factors in White Adipose Tissue and Increased Thermogenic Factors in Brown Adipose Tissue

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 308 ◽  
Author(s):  
Hyo-Geun Lee ◽  
Yu An Lu ◽  
Xining Li ◽  
Ji-Min Hyun ◽  
Hyun-Soo Kim ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
White Adipose Tissue ◽  
High Fat Diet ◽  
Red Seaweed ◽  
High Fat ◽  
Adipose Tissues ◽  
Ppar Γ ◽  
Brown Adipose ◽  
Treatment Of Obesity

Obesity is a serious metabolic syndrome characterized by high levels of cholesterol, lipids in the blood, and intracellular fat accumulation in adipose tissues. It is known that the suppression of adipogenic protein expression is an effective approach for the treatment of obesity, and regulates fatty acid storage and transportation in adipose tissues. The 60% ethanol extract of Grateloupia elliptica (GEE), a red seaweed from Jeju Island in Korea, was shown to exert anti-adipogenic activity in 3T3-L1 cells and in mice with high-fat diet (HFD)-induced obesity. GEE inhibited intracellular lipid accumulation in 3T3-L1 cells, and significantly reduced expression of adipogenic proteins. In vivo experiments indicated a significant reduction in body weight, as well as white adipose tissue (WAT) weight, including fatty liver, serum triglycerides, total cholesterol, and leptin contents. The expression of the adipogenic proteins, SREBP-1 and PPAR-γ, was significantly decreased by GEE, and the expression of the metabolic regulator protein was increased in WAT. The potential of GEE was shown in WAT, with the downregulation of PPAR-γ and C/EBP-α mRNA; in contrast, in brown adipose tissue (BAT), the thermogenic proteins were increased. Collectively, these research findings suggest the potential of GEE as an effective candidate for the treatment of obesity-related issues via functional foods or pharmaceutical agents.

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.

Tu1818 The Chemical Chaperon 4-Phenylbutyrate Inhibits Liver Fibrosis and Tumorgenesis in High-Fat Diet With N-Acetyl-ß-D-Glucosaminedase Inhibitor-Induced NASH Model Mice

2012 ◽  
Vol 142 (5) ◽  
pp. S-1024-S-1025
Author(s):  
Kazuyoshi Kon ◽  
Kenichi Ikejima ◽  
Takashi Miyaji ◽  
Satoko Hosoya ◽  
Kumiko Arai ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
High Fat Diet ◽  
High Fat ◽  
Nash Model

Ventromedial hypothalamic knife-cut lesions in rats resistant to dietary obesity

1984 ◽  
Vol 246 (6) ◽  
pp. R943-R948 ◽  
Author(s):  
J. Oku ◽  
G. A. Bray ◽  
J. S. Fisler ◽  
R. Schemmel
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Food Intake ◽  
High Fat Diet ◽  
Corn Oil ◽  
High Fat ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Dietary Obesity

The effects of ventromedial hypothalamic (VMH) knife-cut lesions on food intake and body weight of S 5B/Pl rats, which are normally resistant to obesity when eating a high-fat diet, were examined in two experiments. In the first experiment body weight increased only slightly after VMH knife-cut lesions when animals were fed pelleted laboratory chow or a 10% corn oil diet. When eating the 30% corn oil diet, however, body weight increased in the VMH knife-cut rats. In the second experiment VMH knife-cut lesions produced a small weight gain in rats fed the 10% fat diet; this manipulation also increased food intake and disrupted the normal diurnal feeding pattern. Changes in the weight of the liver, interscapular brown adipose tissue, and white adipose tissue paralleled the changes in body weight. Plasma insulin increased in the rats eating the 30% corn oil diet ad libitum but not in the VMH-lesioned animals pair fed to the sham-operated rats. Incorporation of 3H from 3H2O into lipid was significantly increased in white fat of animals with VMH knife cuts. Similar results were obtained from incubation of adipose tissue in vitro with insulin and radioactively labeled glucose. These studies show that hypothalamic knife-cut lesions can remove the resistance of the S 5B/Pl rats to obesity when they are fed a high-fat diet.

Role of brown adipose tissue in modulating adipose tissue inflammation and insulin resistance in high-fat diet fed mice

2019 ◽  
Vol 854 ◽  
pp. 354-364 ◽  
Author(s):  
Kripa Shankar ◽  
Durgesh Kumar ◽  
Sanchita Gupta ◽  
Salil Varshney ◽  
Sujith Rajan ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
High Fat Diet ◽  
Adipose Tissue Inflammation ◽  
High Fat ◽  
Tissue Inflammation ◽  
Brown Adipose

scholarly journals Crude Extracts fromLycium barbarumSuppress SREBP-1c Expression and Prevent Diet-Induced Fatty Liver through AMPK Activation

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Wang Li ◽  
Yan Li ◽  
Qing Wang ◽  
Yi Yang
Keyword(s):  
Fatty Liver ◽  
High Fat Diet ◽  
Uncoupling Protein ◽  
Expression Profiles ◽  
Liver Steatosis ◽  
High Fat ◽  
Lycium Barbarum ◽  
Brown Adipose

Lycium barbarumpolysaccharide (LBP) is well known in traditional Chinese herbal medicine that, has beneficial effects. Previous study reported that LBP reduced blood glucose and serum lipids. However, the underlying LBP-regulating mechanisms remain largely unknown. The main purpose of this study was to investigate whether LBP prevented fatty liver through activation of adenosine monophosphate-activated protein kinase (AMPK) and suppression of sterol regulatory element-binding protein-1c (SREBP-1c). Male C57BL/6J mice were fed a low-fat diet, high-fat diet, or 100 mg/kg LBP-treatment diet for 24 weeks. HepG2 cells were treated with LBP in the presence of palmitic acid. In our study, LBP can improve body compositions and lipid metabolic profiles in high-fat diet-fed mice. Oil Red O stainingin vivoandin vitroshowed that LBP significantly reduced hepatic intracellular triacylglycerol accumulation. H&E staining also showed that LBP can attenuate liver steatosis. Hepatic genes expression profiles demonstrated that LBP can activate the phosphorylation of AMPK, suppress nuclear expression of SREBP-1c, and decrease protein and mRNA expression of lipogenic genesin vivoorin vitro. Moreover, LBP significantly elevated uncoupling protein-1 (UCP1) and peroxisome proliferator-activated receptor-γcoactivator-1α(PGC-1α) expression of brown adipose tissue. In summary, LBP possesses a potential novel treatment in preventing diet-induced fatty liver.

scholarly journals High-Fat Diet Alters Serum Fatty Acid Profiles in Obesity Prone Rats: Implications for In Vitro Studies

Lipids ◽  
2015 ◽  
Vol 50 (10) ◽  
pp. 997-1008 ◽  
Author(s):  
Tzu-Wen Liu ◽  
Timothy D. Heden ◽  
E. Matthew Morris ◽  
Kevin L. Fritsche ◽  
Victoria J. Vieira-Potter ◽  
...  
Keyword(s):  
Fatty Acid ◽  
High Fat Diet ◽  
In Vitro Studies ◽  
Fatty Acid Profiles ◽  
High Fat ◽  
Serum Fatty Acid
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