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.

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.

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 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.

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.

scholarly journals Hepatic Lipid Accumulation Induced by a High-fat Diet Is Regulated by Nrf2 Through Multiple Pathways

2021 ◽  
Author(s):  
sheng Qiu ◽  
Zerong Liang ◽  
Qinan Wu ◽  
Miao Wang ◽  
Mengliu Yang ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Lipid Accumulation ◽  
High Fat Diet ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
High Fat ◽  
Hepatic Lipid ◽  
Hepatic Lipid Accumulation

Abstract BackgroundNuclear factor erythroid 2-related factor 2 (Nrf2) is reportedly involved in hepatic lipid metabolism, but the results are contradictory and the underlying mechanism thus remains unclear. Herein we focused on elucidating the effects of Nrf2 on hepatic adipogenesis and on determining the possible underlying mechanism. We established a metabolic associated fatty liver disease (MAFLD) model in high fat diet (HFD) fed Nrf2 knockout (Nrf2 KO) mice; further, a cell model of lipid accumulation was established using mouse primary hepatocytes (MPHs) treated with free fatty acids (FAs). Using these models, we investigated the relationship between Nrf2 and autophagy and its role in the development of MAFLD.ResultsWe observed that Nrf2 expression levels were up-regulated in patients with MAFLD and diet-induced obese mice. Nrf2 deficiency led to hepatic lipid accumulation in vivo and in vitro, in addition to, promoting lipogenesis mainly by increasing SREBP-1 activity. Moreover, Nrf2 deficiency attenuated autophagic flux and inhibited the fusion of autophagosomes and lysosomes in vivo and in vitro. Weakened autophagy caused reduced lipolysis in the liver. Importantly, Chromatin immunoprecipitation-qPCR (ChIP-qPCR) and dual-luciferase assay results proved that Nrf2 bound to LAMP1 promoter and regulated its transcriptional activity. We accordingly report that Nrf2-LAMP1 interaction has an indispensable role in Nrf2-regulated hepatosteatosis. ConclusionsThese data collectively confirm that Nrf2 deficiency promotes hepatosteatosis by enhancing SREBP-1 activity and attenuating autophagy. To conclude, our data reveal a novel multi-pathway effect of Nrf2 on lipid metabolism in the liver, and we believe that multi-target intervention of Nrf2 signaling is a promising new strategy for the prevention and treatment of MAFLD.

scholarly journals High-Fat Diet Induced Gut Microbiota Alterations Associating With Ghrelin/Jak2/Stat3 Up-Regulation to Promote Benign Prostatic Hyperplasia Development

2021 ◽  
Vol 9 ◽  
Author(s):  
Meng Gu ◽  
Chong Liu ◽  
TianYe Yang ◽  
Ming Zhan ◽  
Zhikang Cai ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Benign Prostatic Hyperplasia ◽  
Gut Microbiota ◽  
High Fat Diet ◽  
Prostatic Hyperplasia ◽  
Prostate Tissue ◽  
High Fat ◽  
Ghrelin Receptor

The role of high-fat diet (HFD) induced gut microbiota alteration and Ghrelin as well as their correlation in benign prostatic hyperplasia (BPH) were explored in our study. The gut microbiota was analyzed by 16s rRNA sequencing. Ghrelin levels in serum, along with Ghrelin and Ghrelin receptor in prostate tissue of mice and patients with BPH were measured. The effect of Ghrelin on cell proliferation, apoptosis, and induction of BPH in mice was explored. Our results indicated that BPH mice have the highest ratio of Firmicutes and Bacteroidetes induced by HFD, as well as Ghrelin level in serum and prostate tissue was significantly increased compared with control. Elevated Ghrelin content in the serum and prostate tissue of BPH patients was also observed. Ghrelin promotes cell proliferation while inhibiting cell apoptosis of prostate cells. The effect of Ghrelin on enlargement of the prostate was found almost equivalent to that of testosterone propionate (TP) which may be attenuated by Ghrelin receptor antagonist YIL-781. Ghrelin could up-regulate Jak2/pJak2/Stat3/pStat3 expression in vitro and in vivo. Our results suggested that Gut microbiota may associate with Ghrelin which plays an important role in activation of Jak2/Stat3 in BPH development. Gut microbiota and Ghrelin might be pathogenic factors for BPH and could be used as a target for mediation.

In Vitro Experimental Investigation of the Integrity of the Stem–Cement Interface

2013 ◽  
Vol 647 ◽  
pp. 53-56
Author(s):  
Hong Yu Zhang ◽  
Leigh Fleming ◽  
Liam Blunt
Keyword(s):  
Experimental Investigation ◽  
Fluid Flow ◽  
Hip Replacement ◽  
Hip Prosthesis ◽  
Vitro Experiment ◽  
Cement Interface ◽  
In Vitro Experiment ◽  
Mechanical Bonding

The rationale behind failure of cemented total hip replacement is still far from being well understood in a mechanical and molecular perspective. In the present study, the integrity of the stem–cement interface was investigated through an in vitro experiment monitoring fluid flow along this interface. The results indicated that a good mechanical bonding formed at the stem–cement interface before debonding of this interface was induced by physiological loadings during the in vivo service of the hip prosthesis.

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.

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