Phytol stimulates the browning of white adipocytes through the activation of AMP-activated protein kinase (AMPK) α in mice fed high-fat diet

2018 ◽  
Vol 9 (4) ◽  
pp. 2043-2050 ◽  
Author(s):  
Fenglin Zhang ◽  
Wei Ai ◽  
Xiaoquan Hu ◽  
Yingying Meng ◽  
Cong Yuan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signaling Pathway ◽  
High Fat Diet ◽  
High Fat ◽  
White Adipocytes ◽  
Amp Activated Protein Kinase

In vivo and in vitro studies show that phytol stimulates the browning of mice iWAT and formation of brown-like adipocytes in the differentiated 3T3-L1 through the activation of the AMPKα signaling pathway.

scholarly journals Influence ofOreocnide integrifolia(Gaud.) Miq on IRS-1, Akt and Glut-4 in Fat-Fed C57BL/6J Type 2 Diabetes Mouse Model

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ansarullah ◽  
Selvaraj Jayaraman ◽  
Anandwardhan A. Hardikar ◽  
A. V. Ramachandran
Keyword(s):  
Signaling Pathway ◽  
Insulin Signaling ◽  
High Fat Diet ◽  
Therapeutic Potential ◽  
Insulin Signaling Pathway ◽  
High Fat ◽  
Isolated Pancreatic Islets ◽  
Glut 4

Oreocnide integrifolia(OI) leaves are used as folklore medicine by the people of northeast India to alleviate diabetic symptoms. Preliminary studies revealed hypoglycemic and hypolipidemic potentials of the aqueous leaf extract. The present study was carried out to evaluate whether the OI extract induces insulin secretionin vivoandin vitroand also whether it is mediated through the insulin-signaling pathway. The experimental set-up consisted of three groups of C57BL/6J mice strain: (i) control animals fed with standard laboratory diet, (ii) diabetic animals fed with a high-fat diet for 24 weeks and (iii) extract-supplemented animals fed with 3% OI extract along with high-fat diet for 24 weeks. OI-extract supplementation lowered adiposity and plasma glucose and insulin levels. Immunoblot analysis of IRS-1, Akt and Glut-4 protein expressions in muscles of extract-supplemented animals revealed that glucoregulation was mediated through the insulin-signaling pathway. Moreover, immunostaining of pancreas revealed increased insulin immunopositive cells in OI-extract-treated animals. In addition, the insulin secretogogue ability of the OI extract was demonstrated when challenged with high glucose concentration using isolated pancreatic isletsin vitro. Overall, the present study demonstrates the possible mechanism of glucoregulation of OI extract suggestive of its therapeutic potential for the management of diabetes mellitus.

1′-Acetoxychavicol Acetate Inhibits Adipogenesis in 3T3-L1 Adipocytes and in High Fat-Fed Rats

2012 ◽  
Vol 40 (06) ◽  
pp. 1189-1204 ◽  
Author(s):  
Rie Ohnishi ◽  
Isao Matsui-Yuasa ◽  
Yohei Deguchi ◽  
Keisuke Yaku ◽  
Masaki Tabuchi ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Metabolic Diseases ◽  
Regulation Of Transcription ◽  
High Fat ◽  
Preventive Activity ◽  
Cellular Lipid Accumulation ◽  
Amp Activated Protein Kinase ◽  
Dose Dependent

Alpinia galanga and Languas galanga, which are plants belonging to the ginger family, are frequently used for cooking, especially in Thai and Indonesian cuisine. The compound 1′-acetoxychavicol acetate (ACA), which is naturally obtained from the rhizomes and seeds of these gingers, has antioxidant and anti-inflammatory properties. We investigated the anti-obesity effects of ACA in 3T3-L1 adipocytes and in high fat diet (HFD)-induced rat models of obesity. ACA caused a significant decrease in the activity of GPDH in 3T3-L1 adipocytes without eliciting cell cytotoxicity, and it inhibited cellular lipid accumulation through the down-regulation of transcription factors such as PPARγ and C/EBPα. ACA also induced a dose-dependent phosphorylation of AMP-activated protein kinase (AMPK). In the animal model, rats fed an HFD containing 0.05% ACA gained less weight than rats fed an HFD alone. The visceral fat mass in rats fed an HFD containing 0.05% ACA tended to be lower than that in rats fed an HFD alone. Furthermore, a histological examination of livers from rats fed an HFD showed steatohepatitis. However, rats fed an HFD containing 0.05% ACA showed no histopathological changes in the liver tissue. Our results show that ACA exerts anti-obesity activities both in vitro and in vivo and suggests that ACA may have a novel preventive activity against obesity and possibly other metabolic diseases.

Adiponectin promotes VEGF-C-dependent lymphangiogenesis by inhibiting miR-27b through a CaMKII/AMPK/p38 signaling pathway in human chondrosarcoma cells

2016 ◽  
Vol 130 (17) ◽  
pp. 1523-1533 ◽  
Author(s):  
Chun-Yin Huang ◽  
An-Chen Chang ◽  
Hsien-Te Chen ◽  
Shih-Wei Wang ◽  
Yuan-Shun Lo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signaling Pathway ◽  
Tube Formation ◽  
Human Chondrosarcoma ◽  
Dependent Protein ◽  
And Migration ◽  
Factor C ◽  
Amp Activated Protein Kinase

Chondrosarcoma is the second most frequently occurring type of bone malignancy characterized by distant metastatic propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumour lymphangiogenesis and lymphatic metastasis. Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes. In recent years, adiponectin has also been indicated as facilitating tumorigenesis, angiogenesis and metastasis. However, the effect of adiponectin on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has remained largely a mystery. In the present study, we have shown a clinical correlation between adiponectin and VEGF-C, as well as tumour stage, in human chondrosarcoma tissues. We further demonstrated that adiponectin promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium from adiponectin-treated cells significantly induced tube formation and migration of human lymphatic endothelial cells. In addition, adiponectin knock down inhibited lymphangiogenesis in vitro and in vivo. We also found that adiponectin-induced VEGF-C is mediated by the calmodulin-dependent protein kinase II (CaMKII), AMP-activated protein kinase (AMPK) and p38 signaling pathway. Furthermore, the expression of miR-27b was negatively regulated by adiponectin via the CaMKII, AMPK and p38 cascade. The present study is the first to describe the mechanism of adiponectin-promoted lymphangiogenesis by up-regulating VEGF-C expression in chondrosarcomas. Thus, adiponectin could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis.

scholarly journals Formononetin, an isoflavone, activates AMP-activated protein kinase/β-catenin signalling to inhibit adipogenesis and rescues C57BL/6 mice from high-fat diet-induced obesity and bone loss

2017 ◽  
Vol 117 (5) ◽  
pp. 645-661 ◽  
Author(s):  
Jyoti Gautam ◽  
Vikram Khedgikar ◽  
Priyanka Kushwaha ◽  
Dharmendra Choudhary ◽  
Geet Kumar Nagar ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Bone Loss ◽  
High Fat Diet ◽  
Body Weight Gain ◽  
Binding Protein ◽  
Regulatory Element ◽  
Adipogenic Differentiation ◽  
High Fat ◽  
Amp Activated Protein Kinase

AbstractBalance between adipocyte and osteoblast differentiation is the key link of disease progression in obesity and osteoporosis. We have previously reported that formononetin (FNT), an isoflavone extracted from Butea monosperma, stimulates osteoblast formation and protects against postmenopausal bone loss. The inverse relationship between osteoblasts and adipocytes prompted us to analyse the effect of FNT on adipogenesis and in vivo bone loss, triggered by high-fat diet (HFD)-induced obesity. The anti-obesity effect and mechanism of action of FNT was determined in 3T3-L1 cells and HFD-induced obese male mice. Our findings show that FNT suppresses the adipogenic differentiation of 3T3-L1 fibroblasts, through down-regulation of key adipogenic markers such as PPARγ, CCAAT/enhancer-binding protein alpha (C/EBPα) and sterol regulatory element-binding protein (SREBP) and inhibits intracellular TAG accumulation. Increased intracellular reactive oxygen species levels and AMP-activated protein kinase (AMPK) activation accompanied by stabilisation of β-catenin were attributed to the anti-adipogenic action of FNT. In vivo, 12 weeks of FNT treatment inhibited the development of obesity in mice by attenuating HFD-induced body weight gain and visceral fat accumulation. The anti-obesity effect of FNT results from increased energy expenditure. FNT also protects against HFD-induced dyslipidaemia and rescues deterioration of trabecular bone volume by increasing bone formation and decreasing bone resorbtion caused by HFD. FNT’s rescuing action against obesity-induced osteoporosis commenced at the level of progenitors, as bone marrow progenitor cells, obtained from the HFD mice group supplemented with FNT, showed increased osteogenic and decreased adipogenic potentials. Our findings suggest that FNT inhibits adipogenesis through AMPK/β-catenin signal transduction pathways and protects against HFD-induced obesity and bone loss.

scholarly journals Cholesterol Enhances Colorectal Cancer Progression via ROS Elevation and MAPK Signaling Pathway Activation

2017 ◽  
Vol 42 (2) ◽  
pp. 729-742 ◽  
Author(s):  
Caihua Wang ◽  
Peiwei Li ◽  
Junmei Xuan ◽  
Chunpeng Zhu ◽  
Jingjing Liu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Growth ◽  
Signaling Pathway ◽  
High Fat Diet ◽  
Ldl Receptor ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
High Fat

Background/Aims: Elevated serum cholesterol levels were linked to a higher risk of colorectal adenoma and colorectal cancer (CRC), while the effect of cholesterol on CRC metastasis has not been widely studied. Methods: CRC patients were enrolled to evaluate the association between low-density lipoprotein cholesterol (LDL) and CRC metastases, and LDL receptor (LDLR) level of the CRC tissue was assessed by immunohistochemistry. The effects of LDL on cell proliferation, migration and stemness were assessed in CRC cells in vitro, and the effects of high fat diet (HFD) on tumor growth and intestinal tumorigenicity were investigated in vivo. ROS assays, gene expression array analysis and western blot were used to explore the mechanisms of LDL in CRC progression. Results: The level of LDL was positively correlated with liver metastases, and a higher level of LDL receptor (LDLR) expression was associated with advanced N and M stages of CRC. In vitro, LDL promoted the migration and sphere formation of CRC cells and induced upregulated expression of “stemness” genes including Sox2, Oct4, Nanog and Bmi 1. High-fat diet (HFD) significantly enhanced tumor growth in vivo, and was associated with a shorter intestinal length in azoxymethane/dextran sodium sulfate (AOM/DSS)-treated mice. Furthermore, LDL significantly elevated reactive oxygen species (ROS) levels and Whole Human Genome Microarray found 87 differentially expressed genes between LDL-treated CRC cells and controls, which were largely clustered in the MAP kinase (MAPK) signaling pathway. Conclusions: LDL enhances intestinal inflammation and CRC progression via activation of ROS and signaling pathways including the MAPK pathway. Inflammation is strongly associated with cancer initiation, and the role of LDL in intestinal tumorigenicity should be further explored.

scholarly journals Exogenous IGF-1 improves tau pathology and neuronal pyroptosis in high-fat diet mice with cognitive impairment

2021 ◽  
Author(s):  
Guanghong Sui ◽  
Lu Wang ◽  
Caixia Yang ◽  
Mengtian Guo ◽  
Xiangyang Xiong ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cognitive Impairment ◽  
Signaling Pathway ◽  
High Fat Diet ◽  
Tau Pathology ◽  
High Fat ◽  
Vitro Experiment ◽  
In Vitro Experiment

Abstract Background Insulin-like growth factor-1 (IGF-1) improves obesity-induced cognitive impairment, but its mechanism is not fully clarified. The aim of the study was to reveal whether IGF-1 treated cognitive impairment by improving tau pathology and neuronal pyroptosis in high-fat diet mice, and to further explore its molecular mechanisms involved.Methods During in vitro experiment, C57BL/6J mice were fed with high-fat diet, and were treated with PEG-IGF-1, IGF-1 receptor blocker AXL1717, HO-1 blocker Znpp IX or their combinations. Cognitive function was evaluated using Morris water maze. Expression of Nrf-2, HO-1, p-tau, NLRP3, Caspase-1 and IL-1β in hippocampus was determined using western blotting. Pyroptosis rate in hippocampus was measured using flow cytometry. During in vivo experiment, HN-h cells were treated with palmic acid, pyroptosis blocker nonecrosulfonamide or their combinations. The expression of the proteins and pyroptosis rate were also measured using western blotting and flow cytometry.Results During in vitro experiment, high-fat diet mice showed cognitive impairment, hyperphospharylation of tau protein and significant neuronal pyroptosis in hippocampus compared with the sham mice. After exogenous IGF-1 treatment, these abnormalities were reversed, and Nrf-2/HO-1 signaling pathway was activated. Inhibition of such signaling pathway using IGF-1 receptor blocker or HO-1 blocker re-deteriorated cognitive function, neuronal pyroptosis and tau pathology in hippocampus. During in vivo experiment, inhibition of pyroptosis using its blocker improved tau pathology in palmic acid-treated HN-h cells. Conclusion Exogenous IGF-1 improved cognitive impairment, tau pathology and neuronal pyroptosis induced by high-fat diet through activation of Nrf-2/HO-1 signaling pathway.

Sequoyitol ameliorates diabetic nephropathy in diabetic rats induced with a high-fat diet and a low dose of streptozotocin

2014 ◽  
Vol 92 (5) ◽  
pp. 405-417 ◽  
Author(s):  
Xian-Wei Li ◽  
Yan Liu ◽  
Wei Hao ◽  
Jie-Ren Yang
Keyword(s):  
Diabetic Nephropathy ◽  
Blood Glucose ◽  
High Fat Diet ◽  
Low Dose ◽  
Serum Insulin ◽  
Fasting Blood Glucose ◽  
Diabetic Rats ◽  
High Fat

Sequoyitol decreases blood glucose, improves glucose intolerance, and enhances insulin signaling in ob/ob mice. The aim of this study was to investigate the effects of sequoyitol on diabetic nephropathy in rats with type 2 diabetes mellitus and the mechanism of action. Diabetic rats, induced with a high-fat diet and a low dose of streptozotocin, and were administered sequoyitol (12.5, 25.0, and 50.0 mg·(kg body mass)−1·d−1) for 6 weeks. The levels of fasting blood glucose (FBG), serum insulin, blood urea nitrogen (BUN), and serum creatinine (SCr) were measured. The expression levels of p22phox, p47phox, NF-κB, and TGF-β1 were measured using immunohistochemisty, real-time PCR, and (or) Western blot. The total antioxidative capacity (T-AOC), as well as the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were also determined. The results showed that sequoyitol significantly decreased FBG, BUN, and SCr levels, and increased the insulin levels in diabetic rats. The level of T-AOC was significantly increased, while ROS and MDA levels and the expression of p22phox, p47phox, NF-κB, and TGF-β1 were decreased with sequoyitol treatment both in vivo and in vitro. These results suggested that sequoyitol ameliorates the progression of diabetic nephropathy in rats, as induced by a high-fat diet and a low dose of streptozotocin, through its glucose-lowering effects, antioxidant activity, and regulation of TGF-β1 expression.

scholarly journals Aloe-Emodin Relieves High-Fat Diet Induced QT Prolongation via MiR-1 Inhibition and IK1 Up-Regulation in Rats

2017 ◽  
Vol 43 (5) ◽  
pp. 1961-1973 ◽  
Author(s):  
Yan Bai ◽  
Zhenli Su ◽  
Hanqi Sun ◽  
Wei Zhao ◽  
Xue Chen ◽  
...  
Keyword(s):  
Action Potential ◽  
Protein Expression ◽  
High Fat Diet ◽  
Qt Prolongation ◽  
Electrical Remodeling ◽  
High Fat ◽  
Treatment Groups ◽  
Aloe Emodin

Background/Aims: High-fat diet (HFD) causes cardiac electrical remodeling and increases the risk of ventricular arrhythmias. Aloe-emodin (AE) is an anthraquinone component isolated from rhubarb and has a similar chemical structure with emodin. The protective effect of emodin against cardiac diseases has been reported in the literature. However, the cardioprotective property of AE is still unknown. The present study investigated the effect of AE on HFD-induced QT prolongation in rats. Methods: Adult male Wistar rats were randomly divided into three groups: control, HFD, and AE-treatment groups. Normal diet was given to rats in the control group, high-fat diet was given to rats in HFD and AE-treatment groups for a total of 10 weeks. First, HFD rats and AE-treatment rats were fed with high-fat diet for 4 weeks to establish the HFD model. Serum total cholesterol and triglyceride levels were measured to validate the HFD model. Afterward, AE-treatment rats were intragastrically administered with 100 mg/kg AE each day for 6 weeks. Electrocardiogram monitoring and whole-cell patch-clamp technique were applied to examine cardiac electrical activity, action potential and inward rectifier K+ current (IK1), respectively. Neonatal rat ventricular myocytes (NRVMs) were subjected to cholesterol and/or AE. Protein expression of Kir2.1 was detected by Western blot and miR-1 level was examined by real-time PCR in vivo and in vitro, respectively. Results: In vivo, AE significantly shortened the QT interval, action potential duration at 90% repolarization (APD90) and resting membrane potential (RMP), which were markedly elongated by HFD. AE increased IK1 current and Kir2.1 protein expression which were reduced in HFD rats. Furthermore, AE significantly inhibited pro-arrhythmic miR-1 in the hearts of HFD rats. In vitro, AE decreased miR-1 expression levels resulting in an increase of Kir2.1 protein levels in cholesterol-enriched NRVMs. Conclusions: AE prevents HFD-induced QT prolongation by repressing miR-1 and upregulating its target Kir2.1. These findings suggest a novel pharmacological role of AE in HFD-induced cardiac electrical remodeling.

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