scholarly journals Loss of Ron receptor signaling leads to reduced obesity, diabetic phenotypes and hepatic steatosis in response to high-fat diet in mice

2015 ◽  
Vol 308 (7) ◽  
pp. E562-E572 ◽  
Author(s):  
William D. Stuart ◽  
Nicholas E. Brown ◽  
Andrew M. Paluch ◽  
Susan E. Waltz
Keyword(s):  
Tyrosine Kinase ◽  
High Fat Diet ◽  
Inflammatory Responses ◽  
Standard Diet ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ron Receptor ◽  
Membrane Spanning

The Ron receptor tyrosine kinase is a heterodimeric, membrane-spanning glycoprotein that participates in divergent processes, including proliferation, motility, and modulation of inflammatory responses. We observed male C57BL/6 mice with a global deletion of the Ron tyrosine kinase signaling domain (TK−/−) to be leaner compared with control (TK+/+) mice under a standard diet. When fed a high-fat diet (HFD), TK−/− mice gained 50% less weight and were more insulin sensitive and glucose tolerant than controls. Livers from HFD TK−/− mice were considerably less steatotic and weighed significantly less than TK+/+ livers. Serum cytokine levels of HFD TK−/− mice were also significantly altered compared with TK+/+ mice. Fewer and smaller adipocytes were present in the TK−/− mice on both control and HFD and were accompanied by diminished adiponectin and peroxisome proliferator-activated receptor-γ expression. In vitro adipogenesis experiments suggested reduced differentiation in TK−/− embryonic fibroblasts (MEFs) that was rescued by Ron reconstitution. Likewise, signal transducer and activator of transcription (STAT)-3 phosphorylation was diminished in TK−/− MEFs but was increased after Ron reconstitution. The adipogenic inhibitors, preadipocyte factor 1 and Sox9, were elevated in TK−/− MEFs and increased in both groups after STAT3 silencing. In total, these studies document a previously unknown function for the Ron receptor in mediating HFD-induced obesity and metabolic dysregulation.

scholarly journals Curcumin improves glycolipid metabolism through regulating peroxisome proliferator activated receptor γ signalling pathway in high-fat diet-induced obese mice and 3T3-L1 adipocytes

2017 ◽  
Vol 4 (11) ◽  
pp. 170917 ◽  
Author(s):  
Yanyun Pan ◽  
Dandan Zhao ◽  
Na Yu ◽  
Tian An ◽  
Jianan Miao ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Fasting Blood Glucose ◽  
Signalling Pathway ◽  
Peroxisome Proliferator ◽  
Obese Mice ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Glycolipid Metabolism

Curcumin is an active component derived from Curcuma longa L. which is a traditional Chinese medicine that is widely used for treating metabolic diseases through regulating different molecular pathways. Here, in this study, we aimed to comprehensively investigate the effects of curcumin on glycolipid metabolism in vivo and in vitro and then determine the underlying mechanism. Male C57BL/6 J obese mice and 3T3-L1 adipocytes were used for in vivo and in vitro study, respectively. Our results demonstrated that treatment with curcumin for eight weeks decreased body weight, fat mass and serum lipid profiles. Meanwhile, it lowered fasting blood glucose and increased the insulin sensitivity in high-fat diet-induced obese mice. In addition, curcumin stimulated lipolysis and improved glycolipid metabolism through upregulating the expressions of adipose triglyceride lipase and hormone-sensitive lipase, peroxisome proliferator activated receptor γ/α (PPARγ/α) and CCAAT/enhancer binding proteinα (C/EBPα) in adipose tissue of the mice. In differentiated 3T3-L1 cells, curcumin reduced glycerol release and increased glucose uptake via upregulating PPARγ and C/EBPα. We concluded that curcumin has the potential to improve glycolipid metabolism disorders caused by obesity through regulating PPARγ signalling pathway.

scholarly journals 8-Hydroxyeicosapentaenoic Acid Decreases Plasma and Hepatic Triglycerides via Activation of Peroxisome Proliferator-Activated Receptor Alpha in High-Fat Diet-Induced Obese Mice

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hidetoshi Yamada ◽  
Sayaka Kikuchi ◽  
Mayuka Hakozaki ◽  
Kaori Motodate ◽  
Nozomi Nagahora ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Expression Of Genes ◽  
Ppar Ligand ◽  
Obesity In Mice ◽  
Ligand Activity

PPARs regulate the expression of genes involved in lipid homeostasis. PPARs serve as molecular sensors of fatty acids, and their activation can act against obesity and metabolic syndromes. 8-Hydroxyeicosapentaenoic acid (8-HEPE) acts as a PPAR ligand and has higher activity than EPA. However, to date, the PPAR ligand activity of 8-HEPE has only been demonstratedin vitro. Here, we investigated its ligand activityin vivoby examining the effect of 8-HEPE treatment on high fat diet-induced obesity in mice. After the 4-week treatment period, the levels of plasma and hepatic triglycerides in the 8-HEPE-fed mice were significantly lower than those in the HFD-fed mice. The expression of genes regulated by PPARαwas significantly increased in 8-HEPE-fed mice compared to those that received only HFD. Additionally, the level of hepatic palmitic acid in 8-HEPE-fed mice was significantly lower than in HFD-fed mice. These results suggested that intake of 8-HEPE induced PPARαactivation and increased catabolism of lipids in the liver. We found no significant differences between EPA-fed mice and HFD-fed mice. We demonstrated that 8-HEPE has a larger positive effect on metabolic syndrome than EPA and that 8-HEPE acts by inducing PPARαactivation in the liver.

scholarly journals Effect ofLactobacillus plantarumStrain K21 on High-Fat Diet-Fed Obese Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Chien-Chen Wu ◽  
Wei-Lien Weng ◽  
Wen-Lin Lai ◽  
Hui-Ping Tsai ◽  
Wei-Hsien Liu ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Body Weight Gain ◽  
Normal Diet ◽  
Peroxisome Proliferator ◽  
Bacterial Strains ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Hepatic Expression ◽  
Beneficial Effects

Recent studies have demonstrated beneficial effects of specific probiotics on alleviating obesity-related disorders. Here we aimed to identify probiotics with potential antiobesity activity among 88 lactic acid bacterial strains viain vitroscreening assays, and aLactobacillus plantarumstrain K21 was found to harbor abilities required for hydrolyzing bile salt, reducing cholesterol, and inhibiting the accumulation of lipid in 3T3-L1 preadipocytes. Furthermore, effects of K21 on diet-induced obese (DIO) mice were examined. Male C57Bl/6J mice received a normal diet, high-fat diet (HFD), or HFD with K21 administration (109 CFU in 0.2 mL PBS/day) for eight weeks. Supplementation of K21, but not placebo, appeared to alleviate body weight gain and epididymal fat mass accumulation, reduce plasma leptin levels, decrease cholesterol and triglyceride levels, and mitigate liver damage in DIO mice. Moreover, the hepatic expression of peroxisome proliferator-activated receptor-γ(PPAR-γ) related to adipogenesis was significantly downregulated in DIO mice by K21 intervention. We also found that K21 supplementation strengthens intestinal permeability and modulates the amount ofLactobacillusspp.,Bifidobacteriumspp., andClostridium perfringensin the cecal contents of DIO mice. In conclusion, our results suggest that dietary intake of K21 protects against the onset of HFD-induced obesity through multiple mechanisms of action.

scholarly journals Differential organ-specific inflammatory response to progranulin in high-fat diet-fed mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maki Murakoshi ◽  
Tomohito Gohda ◽  
Eri Adachi ◽  
Saki Ichikawa ◽  
Shinji Hagiwara ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
High Fat Diet ◽  
Kidney Injury ◽  
Proximal Tubules ◽  
Tubular Damage ◽  
Standard Diet ◽  
Mrna Levels ◽  
High Fat ◽  
Organ Specific

AbstractProgranulin (PGRN) has been reported to bind tumor necrosis factor (TNF) receptor and to inhibit TNFα signaling. We evaluated the effect of augmentation of TNFα signaling by PGRN deficiency on the progression of kidney injury. Eight-week-old PGRN knockout (KO) and wild-type (WT) mice were fed a standard diet or high-fat diet (HFD) for 12 weeks. Albuminuria, markers of tubular damage, and renal mRNA levels of inflammatory cytokines were higher in HFD-fed KO (KO-HFD) mice than in HFD-fed WT (WT-HFD) mice. Body weight, vacuolization in proximal tubules, and systemic and adipose tissue inflammatory markers were lower in the KO-HFD mice than in the WT-HFD mice. The renal megalin expression was lower in the KO mice than in the WT mice regardless of the diet type. The megalin expression was also reduced in mouse proximal tubule epithelial cells stimulated with TNFα and in those with PGRN knockdown by small interfering RNA in vitro. PGRN deficiency was associated with both exacerbated renal inflammation and decreased systemic inflammation, including that in the adipose tissue of mice with HFD-induced obesity. Improved tubular vacuolization in the KO-HFD mice might partially be explained by the decreased expression of megalin in proximal tubules.

scholarly journals Glial A2B Adenosine Receptors Modulate Abnormal Tachykininergic Responses and Prevent Enteric Inflammation Associated with High Fat Diet-Induced Obesity

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1245 ◽  
Author(s):  
Vanessa D’Antongiovanni ◽  
Laura Benvenuti ◽  
Matteo Fornai ◽  
Carolina Pellegrini ◽  
Renè van den Wijngaard ◽  
...  
Keyword(s):  
Glial Cell ◽  
High Fat Diet ◽  
Enzyme Linked Immunosorbent Assay ◽  
Standard Diet ◽  
Tlr4 Expression ◽  
High Fat ◽  
Toll Like Receptor 4 ◽  
Diet Induced Obesity ◽  
Adenosine A2b

The role played by adenosine A2B receptors (A2BRs) in the regulation of enteric glial cell (EGC) functions remains unclear. This study was aimed at investigating the involvement of A2BRs in the control of EGC functions in a model of obesity. C57BL/6 mice were fed with standard diet (SD) or high fat diet (HFD) for eight weeks. Colonic tachykininergic contractions were recorded in the presence of BAY60-6583 (A2BRs agonist), MRS1754 (A2BRs antagonist), and the gliotoxin fluorocitrate. Immunofluorescence distribution of HuC/D, S100β, and A2BRs was assessed in whole mount preparations of colonic myenteric plexus. To mimic HFD, EGCs were incubated in vitro with palmitate (PA) and lipopolysaccharide (LPS), in the absence or in the presence of A2BR ligands. Toll-like receptor 4 (TLR4) expression was assessed by Western blot analysis. Interleukin-1β (IL-1β), substance P (SP), and glial cell derived neurotrophic factor (GDNF) release were determined by enzyme-linked immunosorbent assay (ELISA) assays. MRS1754 enhanced electrically evoked tachykininergic contractions of colonic preparations from HFD mice. BAY60-6583 decreased the evoked tachykininergic contractions, with higher efficacy in HFD mice. Such effects were blunted upon incubation with fluorocitrate. In in vitro experiments on EGCs, PA and LPS increased TLR4 expression as well as IL-1β, GDNF, and SP release. Incubation with BAY60-6583 reduced TLR4 expression as well as IL-1β, GDNF, and SP release. Such effects were blunted by MRS1754. The present results suggest that A2BRs, expressed on EGCs, participate in the modulation of enteric inflammation and altered tachykininergic responses associated with obesity, thus representing a potential therapeutic target.

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 CD36-Mediated Lipid Accumulation and Activation of NLRP3 Inflammasome Lead to Podocyte Injury in Obesity-Related Glomerulopathy

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Jing Zhao ◽  
Hong-liang Rui ◽  
Min Yang ◽  
Li-jun Sun ◽  
Hong-rui Dong ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Lipid Accumulation ◽  
Inflammatory Responses ◽  
Regulatory Element ◽  
Animal Experiments ◽  
Receptor Protein ◽  
Peroxisome Proliferator ◽  
Podocyte Injury ◽  
Peroxisome Proliferator Activated Receptor

Podocyte injury critically contributes to the pathogenesis of obesity-related glomerulopathy (ORG). Recently, lipid accumulation and inflammatory responses have been found to be involved in podocyte injury. This study is to explore their role and relationship in podocyte injury of ORG. In animal experiments, the ORG mice developed proteinuria, podocyte injury, and hypertriglyceridemia, accompanied with deregulated lipid metabolism, renal ectopic lipid deposition, activation of NOD-like receptor protein 3 (NLRP3) inflammasome, and secretion of IL-1β of the kidney. The expression of adipose differentiation-related protein (ADRP), CD36, sterol regulatory element-binding protein 1 (SREBP-1), and peroxisome proliferator-activated receptor α (PPARα) in renal tissue were increased. In in vitro cell experiments, after cultured podocytes were stimulated with leptin, similar to ORG mice, we found aggravated podocyte injury, formatted lipid droplet, increased expression of ADRP and CD36, activated NLRP3 inflammasome, and released IL-1β. In addition, after blocking CD36 with inhibitor sulfo-N-succinimidyl oleate (SSO) or CD36 siRNA, activation of NLRP3 inflammasome and release of IL-1β are downregulated, and podocyte injury was alleviated. However, after blocking NLRP3 with MCC950, although podocyte injury was alleviated and release of IL-1β was decreased, there was no change in the expression of CD36, ADRP, and intracellular lipid droplets. Taken together, our study suggests that CD36-mediated lipid accumulation and activation of NLRP3 inflammasome may be one of the potential pathogeneses of ORG podocyte injury.

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