scholarly journals Angiopoietin-like protein 4 improves glucose tolerance and insulin resistance but induces liver steatosis in high-fat-diet mice

2016 ◽  
Vol 14 (4) ◽  
pp. 3293-3300 ◽  
Author(s):  
Yi Wang ◽  
Li-Ming Liu ◽  
Li Wei ◽  
Wei-Wei Ye ◽  
Xiang-Ying Meng ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Tolerance ◽  
High Fat Diet ◽  
Liver Steatosis ◽  
High Fat

Black rice anthocyanins alleviate hyperlipidemia, liver steatosis and insulin resistance by regulating lipid metabolism and gut microbiota in obese mice

2021 ◽  
Author(s):  
Haizhao Song ◽  
Xinchun Shen ◽  
Yang Zhou ◽  
Xiaodong Zheng
Keyword(s):  
Insulin Resistance ◽  
Lipid Metabolism ◽  
Gut Microbiota ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Liver Steatosis ◽  
Obese Mice ◽  
Black Rice ◽  
High Fat ◽  
Diet Induced Obesity

Supplementation of black rice anthocyanins (BRAN) alleviated high fat diet-induced obesity, insulin resistance and hepatic steatosis by improvement of lipid metabolism and modification of the gut microbiota.

scholarly journals Hypoglycemic effects and mechanisms of electroacupuncture on insulin resistance

2014 ◽  
Vol 307 (3) ◽  
pp. R332-R339 ◽  
Author(s):  
Jieyun Yin ◽  
Jian Kuang ◽  
Manisha Chandalia ◽  
Demidmaa Tuvdendorj ◽  
Batbayar Tumurbaatar ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Blood Glucose ◽  
Insulin Sensitivity ◽  
Free Fatty Acid ◽  
Glucose Tolerance ◽  
High Fat Diet ◽  
Postprandial Glucose ◽  
Tolerance Test ◽  
High Fat

The aim of this study was to investigate effects and mechanisms of electroacupuncture (EA) on blood glucose and insulin sensitivity in mice fed a high-fat diet. Both wild-type (WT) and adipose ectonucleotide pyrophosphate phosphodiesterase (ENPP1) transgenic (TG) mice were fed a high-fat diet for 12 wk; for each mouse, an intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) were performed with or without EA at abdomen or auricular areas. A high-fat diet-induced insulin resistance in both WT and TG mice. In the WT mice, EA at 3 Hz and 15 Hz, but not at 1 Hz or 100 Hz, via CV4+CV12 significantly reduced postprandial glucose levels; EA at 3 Hz was most potent. The glucose level was reduced by 61.7% at 60 min and 74.5% at 120 min with EA at 3 Hz (all P < 0.001 vs. control). Similar hypoglycemic effect was noted in the TG mice. On the contrary, EA at auricular points increased postprandial glucose level ( P < 0.03). 4). EA at 3 Hz via CV4+CV12 significantly enhanced the decrease of blood glucose after insulin injection, suggesting improvement of insulin sensitivity. Plasma free fatty acid was significantly suppressed by 42.5% at 15 min and 50.8% at 30 min with EA ( P < 0.01) in both WT and TG mice. EA improves glucose tolerance in both WT and TG mice fed a high-fat diet, and the effect is associated with stimulation parameters and acupoints and is probably attributed to the reduction of free fatty acid.

scholarly journals Melatonin Improves Glucose Homeostasis and Endothelial Vascular Function in High-Fat Diet-Fed Insulin-Resistant Mice

Endocrinology ◽  
2009 ◽  
Vol 150 (12) ◽  
pp. 5311-5317 ◽  
Author(s):  
Claudio Sartori ◽  
Pierre Dessen ◽  
Caroline Mathieu ◽  
Anita Monney ◽  
Jonathan Bloch ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Signal Transduction ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
High Fat Diet ◽  
High Fat ◽  
Insulin Resistant ◽  
Normal Chow ◽  
Underlying Mechanisms

Abstract Obesity and insulin resistance represent a problem of utmost clinical significance worldwide. Insulin-resistant states are characterized by the inability of insulin to induce proper signal transduction leading to defective glucose uptake in skeletal muscle tissue and impaired insulin-induced vasodilation. In various pathophysiological models, melatonin interacts with crucial molecules of the insulin signaling pathway, but its effects on glucose homeostasis are not known. In a diet-induced mouse model of insulin resistance and normal chow-fed control mice, we sought to assess the effects of an 8-wk oral treatment with melatonin on insulin and glucose tolerance and to understand underlying mechanisms. In high-fat diet-fed mice, but not in normal chow-fed control mice, melatonin significantly improved insulin sensitivity and glucose tolerance, as evidenced by a higher rate of glucose infusion to maintain euglycemia during hyperinsulinemic clamp studies and an attenuated hyperglycemic response to an ip glucose challenge. Regarding underlying mechanisms, we found that melatonin restored insulin-induced vasodilation to skeletal muscle, a major site of glucose utilization. This was due, at least in part, to the improvement of insulin signal transduction in the vasculature, as evidenced by increased insulin-induced phosphorylation of Akt and endoethelial nitric oxide synthase in aortas harvested from melatonin-treated high-fat diet-fed mice. In contrast, melatonin had no effect on the ability of insulin to promote glucose uptake in skeletal muscle tissue in vitro. These data demonstrate for the first time that in a diet-induced rodent model of insulin resistance, melatonin improves glucose homeostasis by restoring the vascular action of insulin.

The Effects of Gymnema sylvestre in High-Fat Diet-Induced Metabolic Disorders

2017 ◽  
Vol 45 (04) ◽  
pp. 813-832 ◽  
Author(s):  
Hyeon-Jeong Kim ◽  
Sanghwa Kim ◽  
Ah Young Lee ◽  
Yoonjeong Jang ◽  
Orkhonselenge Davaadamdin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Weight ◽  
Adipose Tissue ◽  
Dietary Supplement ◽  
High Fat Diet ◽  
Liver Steatosis ◽  
Integrated Approach ◽  
Serum Levels ◽  
Gymnema Sylvestre ◽  
High Fat

This study used an integrated approach to investigate the effects of Gymnema sylvestre (GS) extract as a functional dietary supplement with a high-fat diet. This approach examined insulin resistance, the dysfunction of adipose tissue, and liver steatosis. Male C57BL/6J mice were fed a normal chow or high-fat diet (HFD) for the acute and chronic study, in addition to GS in different doses (100, 250 and 500[Formula: see text]mg/kg body weight). Their body composition changes, serum lipid and glucose parameters, adipose and liver tissue histology, and gene expression were measured. It was found that GS significantly suppressed the increase of body weight, serum levels of lipid, insulin and leptin, and adipose tissue, and liver inflammation. GS also demonstrated hypoglycemic effects due to the amylase inhibition activity. Our results support the existence of a relationship between the HFD induced insulin resistance, adipose dysfunction and liver steatosis. In conclusion, GS works as a functional dietary supplement with preventative effects against metabolic disorder.

scholarly journals Role of Hepatic Glucocorticoid Receptor in Metabolism in Models of 5αR1 Deficiency in Male Mice

Endocrinology ◽  
2019 ◽  
Vol 160 (9) ◽  
pp. 2061-2073 ◽  
Author(s):  
Tracy C S Mak ◽  
Dawn E W Livingstone ◽  
Mark Nixon ◽  
Brian R Walker ◽  
Ruth Andrew
Keyword(s):  
Insulin Resistance ◽  
Glucocorticoid Receptor ◽  
High Fat Diet ◽  
Liver Steatosis ◽  
Area Under The Curve ◽  
High Fat ◽  
Glucose Challenge ◽  
Glucocorticoid Metabolism ◽  
Challenge Area

Abstract Inhibition of 5α-reductases impairs androgen and glucocorticoid metabolism and induces insulin resistance in humans and rodents. The contribution of hepatic glucocorticoids to these adverse metabolic changes was assessed using a liver-selective glucocorticoid receptor (GR) antagonist, A-348441. Mice lacking 5α-reductase 1 (5αR1-KO) and their littermate controls were studied during consumption of a high-fat diet, with or without A-348441(120 mg/kg/d). Male C57BL/6 mice (age, 12 weeks) receiving dutasteride (1.8 mg/kg/d)) or vehicle with consumption of a high-fat diet, with or without A-348441, were also studied. In the 5αR1-KO mice, hepatic GR antagonism improved diet-induced insulin resistance but not more than that of the controls. Liver steatosis was not affected by hepatic GR antagonism in either 5αR1KO mice or littermate controls. In a second model of 5α-reductase inhibition using dutasteride and hepatic GR antagonism with A-348441 attenuated the excess weight gain resulting from dutasteride (mean ± SEM, 7.03 ± 0.5 vs 2.13 ± 0.4 g; dutasteride vs dutasteride plus A-348441; P &lt; 0.05) and normalized the associated hyperinsulinemia after glucose challenge (area under the curve, 235.9 ± 17 vs 329.3 ± 16 vs 198.4 ± 25 ng/mL/min; high fat vs high fat plus dutasteride vs high fat plus dutasteride plus A-348441, respectively; P &lt; 0.05). However, A-348441 again did not reverse dutasteride-induced liver steatosis. Thus, overall hepatic GR antagonism improved the insulin resistance but not the steatosis induced by a high-fat diet. Moreover, it attenuated the excessive insulin resistance caused by pharmacological inhibition of 5α-reductases but not genetic disruption of 5αR1. The use of dutasteride might increase the risk of type 2 diabetes mellitus and reduced exposure to glucocorticoids might be beneficial.

260. Effects of diet-induced obesity on ovarian function and female fertility

2005 ◽  
Vol 17 (9) ◽  
pp. 105 ◽  
Author(s):  
C. E. Minge ◽  
B. D. Bennett ◽  
V. Tsagareli ◽  
R. J. Norman ◽  
M. Lane ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Tolerance ◽  
High Fat Diet ◽  
Ovarian Function ◽  
Control Diet ◽  
Female Fertility ◽  
Ovulation Rate ◽  
High Fat ◽  
Blastocyst Development ◽  
Diet Induced Obesity

Obesity and its related complications (metabolic syndrome, Type II diabetes and polycystic ovary syndrome) are increasingly associated with female infertility. Our research is focused on understanding how diet-induced obesity, which triggers insulin resistance and symptoms of chronic inflammation, directly impacts ovarian function and female fertility. Female mice were maintained on a “Western style” diet (22% fat, 0.15% cholesterol) or a matched control diet. Body weights were monitored weekly and after 16 weeks fasting insulin levels and glucose tolerance were assessed. Mice were then paired with males and tissues collected on day 1 on pregnancy. Blood samples were taken to determine levels of progesterone, metabolites (glucose, HDL/LDL) and inflammatory cytokines. Tissue weights (fat pads, liver, kidney, spleen, pancreas, ovary and uterus) were recorded and the reproductive tissues were fixed for analysis of histology and gene expression. Zygotes were isolated from the oviduct, cultured in vitro and scored for on-time development and differentially stained to assess blastocyst quality. Indices of ovarian function, including ovulation rate, steroid production and oocyte quality/blastocyst development will then be correlated with degrees of insulin resistance, dyslipidemia and inflammation. Five strains of mice were tested (CBA, Balb/c, C57, SV129 and Swiss) and showed significant differences in susceptibility to diet-induced obesity and insulin resistance. In CBA mice, the first group to be completed, the high fat diet significantly increased body weight, but did not result in overtly impaired glucose tolerance. The number of days to mating was slightly extended compared to mice on the control diet. Interestingly, the high fat diet did not affect ovulation rate but resulted in dramatically impaired blastocyst development. The results of this study will reveal how ovarian folliculogenesis, oocyte competence and ovulation are affected by obesity-induced metabolic changes, which are increasingly affecting women of reproductive age.

MiR-425-5p Regulates Glucagon-like Peptide-1 Production and Affects Blood Glucose Levels in High-fat Diet-fed Mice

2021 ◽  
Author(s):  
Lirui Wei ◽  
Xuenan Zhao ◽  
Feng Guo ◽  
Fengjiao Huang ◽  
Yanyan Zhao ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Tolerance ◽  
Protein Level ◽  
High Fat Diet ◽  
Molecular Mechanisms ◽  
Tolerance Test ◽  
Control Group ◽  
High Fat ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Abstract BackgroundIn modern society, obesity has become a global problem with resulting in metabolic disorders and poses high risk for type 2 diabetes mellitus (T2DM). The glucagon-like peptide-1 (GLP-1) has been taken as an effective drug for the therapy of T2DM and obesity. In the present study, the regulatory roles and molecular mechanisms of miR-425-5p in GLP-1 secretion in high-fat diet (HFD)-induced diabetic mice were explored. MethodsOral glucose tolerance test and insulin tolerance test were performed to assess glucose metabolism and GLP-1 and LPS levels. Quantitative real time polymerase chain reaction (qRT-PCR) was employed to detect the expression of LPS, GLP-1, GLP-1 receptors, miR-425-5p, phosphatase and tensin homology (PTEN), proglucagon, p65 and β-catenin. Western blot was performed to determine the expression of proglucagon, p65, β-catenin and PTEN. ResultsThe results showed that plasma GLP-1 level was negatively correlated with plasma LPS level in HFD-fed mice, and miR-425-5p expression and LPS level were up-regulated in the ileal fluid compared with control groups. LPS injection boosted miR-425-5p expression in ileum. MiR-425-5p ameliorated glucose intolerance and insulin resistance in HFD-fed mice by increasing GLP-1 secretion. Furthermore, p65 protein level in the cytoplasmic and nuclear in the ileum of HFD-fed mice was increased compared with the control group. MiR-425-5p agomir elevated nuclear β-catenin protein level, but reduced PTEN protein level in HFD-fed mice compared with HFD-fed mice treated with the miR-425-5p antagomir. ConclusionsOur results suggest that miR-425-5p promotes GLP-1 secretion and improves glucose tolerance and insulin resistance in high-fat diet-fed mice.

scholarly journals Adipose Triglyceride Lipase-Null Mice Are Resistant to High-Fat Diet–Induced Insulin Resistance Despite Reduced Energy Expenditure and Ectopic Lipid Accumulation

Endocrinology ◽  
2011 ◽  
Vol 152 (1) ◽  
pp. 48-58 ◽  
Author(s):  
Andrew J. Hoy ◽  
Clinton R. Bruce ◽  
Sarah M. Turpin ◽  
Alexander J. Morris ◽  
Mark A. Febbraio ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Insulin Sensitivity ◽  
Energy Expenditure ◽  
Glucose Tolerance ◽  
Lipid Accumulation ◽  
High Fat Diet ◽  
Adipose Triglyceride Lipase ◽  
Wild Type ◽  
High Fat

Abstract Adipose triglyceride lipase (ATGL) null (−/−) mice store vast amounts of triacylglycerol in key glucoregulatory tissues yet exhibit enhanced insulin sensitivity and glucose tolerance. The mechanisms underpinning these divergent observations are unknown but may relate to the reduced availability of circulating fatty acids. The aim of this study was to determine whether the enhancements in insulin stimulated glucose metabolism in ATGL−/− mice persist when challenged with a high-fat diet. ATGL−/− mice fed a low-fat diet exhibit improved whole-body insulin sensitivity and glucose tolerance compared with wild-type mice. Wild-type mice became hyperlipidemic and insulin-resistant when challenged with a high-fat diet (HFD, 60% fat) for 4 wk. ATGL−/− mice fed a HFD had elevated circulating fatty acids but had reduced fasting glycemia compared to pre–high-fat diet levels and were refractory to glucose intolerance and insulin resistance. This protection from high-fat diet–induced metabolic perturbations was associated with a preference for fatty acid utilization but reduced energy expenditure and no change in markers of mitochondrial capacity or density. The protection from high-fat diet–induced insulin resistance in ATGL−/− mice was due to increased cardiac and liver insulin-stimulated glucose clearance despite increased lipid content in these tissues. Additionally, there was no difference in skeletal muscle insulin-stimulated glucose disposal, but there was a reduction observed in brown adipose tissue. Overall, these results show that ATGL−/− mice are protected from HFD-induced insulin resistance and reveal a tissue specific disparity between lipid accumulation and insulin sensitivity.

scholarly journals TLR4/AP-1-Targeted Anti-Inflammatory Intervention Attenuates Insulin Sensitivity and Liver Steatosis

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Xiang Hu ◽  
Jing Zhou ◽  
Sha-sha Song ◽  
Wen Kong ◽  
Yan-Chuan Shi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Signaling Pathway ◽  
High Fat Diet ◽  
Macrophage Polarization ◽  
Liver Steatosis ◽  
Lipid Deposition ◽  
Sirna Transfection ◽  
High Fat ◽  
Metabolic Inflammation

Insulin resistance has been shown to be the common pathogenesis of many metabolic diseases. Metainflammation is one of the important characteristics of insulin resistance. Macrophage polarization mediates the production and development of metainflammation. Toll-like receptor 4 (TLR4) mediates macrophage activity and is probably the intersection of immunity and metabolism, but the detailed mechanism is probably not fully understood. Activated protein 1 (AP1) signaling pathway is very important in macrophage activation-mediated inflammation. However, it is unclear whether AP1 signaling pathway mediates metabolic inflammation in the liver. We aimed to investigate the effects of macrophage TLR4-AP1 signaling pathway on hepatocyte metabolic inflammation, insulin sensitivity, and lipid deposition, as well as to explore the potential of TLR4-AP1 as new intervention targets of insulin resistance and liver steatosis. TLR4 and AP1 were silenced in the RAW264.7 cells by lentiviral siRNA transfection. In vivo transduction of lentivirus was administered in mice fed with high-fat diet. Insulin sensitivity and inflammation were evaluated in the treated cells or animals. Our results indicated that TLR4/AP-1 siRNA transfection alleviated high-fat diet-induced systemic and hepatic inflammation, obesity, and insulin resistance in mice. Additionally, TLR4/AP-1 siRNA transfection mitigated palmitic acid- (PA-) induced inflammation in RAW264.7 cells and metabolic abnormalities in cocultured AML hepatocytes. Herein, we propose that TLR4-AP1 signaling pathway activation plays a crucial role in high fat- or PA-induced metabolic inflammation and insulin resistance in hepatocytes. Intervention of the TLR4 expression regulates macrophage polarization and metabolic inflammation and further alleviates insulin resistance and lipid deposition in hepatocytes.

Sign in / Sign up

Export Citation Format

Share Document