scholarly journals Targeting a ceramide double bond improves insulin resistance and hepatic steatosis

Science ◽  
2019 ◽  
Vol 365 (6451) ◽  
pp. 386-392 ◽  
Author(s):  
Bhagirath Chaurasia ◽  
Trevor S. Tippetts ◽  
Rafael Mayoral Monibas ◽  
Jinqi Liu ◽  
Ying Li ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Double Bond ◽  
Hepatic Steatosis ◽  
Metabolic Disorders ◽  
Glucose Utilization ◽  
Lipid Uptake ◽  
Dihydroceramide Desaturase ◽  
Dihydroceramide Desaturase 1 ◽  
And Storage ◽  
Specific Deletion

Ceramides contribute to the lipotoxicity that underlies diabetes, hepatic steatosis, and heart disease. By genetically engineering mice, we deleted the enzyme dihydroceramide desaturase 1 (DES1), which normally inserts a conserved double bond into the backbone of ceramides and other predominant sphingolipids. Ablation of DES1 from whole animals or tissue-specific deletion in the liver and/or adipose tissue resolved hepatic steatosis and insulin resistance in mice caused by leptin deficiency or obesogenic diets. Mechanistic studies revealed ceramide actions that promoted lipid uptake and storage and impaired glucose utilization, none of which could be recapitulated by (dihydro)ceramides that lacked the critical double bond. These studies suggest that inhibition of DES1 may provide a means of treating hepatic steatosis and metabolic disorders.

Edible Red Seaweed Campylaephora Hypnaeoides J. Agardh Alleviates Obesity and Related Metabolic Disorders in Mice by Suppressing Oxidative Stress and Inflammatory Response

2021 ◽  
Author(s):  
Shigeru Murakami ◽  
Chihiro Hirazawa ◽  
Rina Yoshikawa ◽  
Toshiki Mizutani ◽  
Takuma Ohya ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
White Adipose Tissue ◽  
Metabolic Disorders ◽  
Public Health Problem ◽  
Serum Levels ◽  
Diet Group ◽  
Raw264.7 Cells ◽  
Edible Seaweed

Abstract Background: The obesity epidemic has become a serious public health problem in many countries worldwide. Seaweed has few calories and is rich in active nutritional components necessary for health promotion and disease prevention. The aim of this study was to investigate the effects of the Campylaephora hypnaeoides J. Agardh (C. hypnaeoides), an edible seaweed traditionally eaten in Japan, on high-fat (HF) diet-induced obesity and related metabolic diseases in mice.Methods: Male C57BL/6J mice were randomly divided into the following groups: normal diet group, HF diet group, HF diet supplemented with 2% C. hypnaeoides, and HF diet supplemented with 6% C. hypnaeoides. After 13 weeks of treatment, the weight of the white adipose tissue and liver, and the serum levels of glucose, insulin, adipokines, and lipids were measured. Hepatic levels of adipokines, oxidant markers, and antioxidant markers were also determined. Insulin resistance was assessed by a glucose tolerance test. Polysaccharides of C. hypnaeoides were purified and their molecular weight was determined by high-performance seize exclusion chromatography. The anti-inflammatory effects of purified polysaccharides were evaluated in RAW264.7 cells. Results: Treatment of HF diet-induced obese mice with C. hypnaeoides for 13 weeks suppressed the increase in body weight and white adipose tissue weight. It also ameliorated insulin resistance, diabetes, hepatic steatosis, and hypercholesterolemia. The ingestion of an HF diet increased serum levels of malondialdehyde (MDA), tumor necrosis factor a (TNF-a), and monocyte chemoattractant protein-1 (MCP-1), while it decreased serum adiponectin levels. In the liver, an HF diet markedly increased the MDA, TNF-a, and interleukin-6 (IL-6) levels, while it decreased glutathione (GSH) and superoxide dismutase (SOD). These metabolic changes induced by HF diet feeding were ameliorated by dietary C. hypnaeoides. Purified polysaccharides and ethanol extract from C. hypnaeoides inhibited the lipopolysaccharide-induced overproduction of nitric oxide and TNF-a in macrophage RAW264.7 cells. Conclusions: The present results indicated that C. hypnaeoides was able to alleviate HF diet-induced metabolic disorders, including obesity, diabetes, hepatic steatosis, and hypercholesterolemia by attenuating inflammation and improving the antioxidant capacity in mice. Polysaccharides and polyphenols may be involved in these beneficial effects of C. hypnaeoides.

scholarly journals Effect of the Hepatocyte-Specific Deletion of SND1 in Mice on the Liver Insulin Resistance and Acute Liver Failure

2020 ◽  
Author(s):  
Chunyan Zhao ◽  
Xiaoteng Cui ◽  
Baoxin Qian ◽  
Nan Zhang ◽  
Lingbiao Xin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Failure ◽  
Acute Liver Failure ◽  
Cholesterol Level ◽  
Hepatic Steatosis ◽  
Glucose Homeostasis ◽  
Hepatic Failure ◽  
High Fat Diet ◽  
High Fat ◽  
Specific Deletion

Abstract Background: The multifunctional protein SND1 was reported to be involved in a variety of biological processes, such as cell cycle, proliferation or lipogenesis. We previously proposed that global-expressed SND1 in vivo is likely to be a key regulator for ameliorating HFD-induced hepatic steatosis and systemic insulin resistance. Herein, we are very interested in investigating further whether the hepatocyte-specific deletion of SND1 affects the insulin resistance or acute liver failure (ALF) of mice.Methods: By using Cre-loxP technique, we constructed conditional knockout (LKO) mice of SND1 driven by albumin in hepatocytes and analyze the changes of glucose homeostasis, cholesterol level, hepatic steatosis and hepatic failure under the treatment of high-fat diet (HFD) or upon the simulation of Lipopolysaccharide/galactosamine (LPS/GalN).Results: No difference for the body weight, liver weight, and cholesterol level was detected. Furthermore, we did not observe the alteration of glucose homeostasis in SND1 hepatic knockout mice on either chow diet or high-fat diet. Besides, hepatocyte-specific deletion of SND1 failed to influence the hepatic failure of mice induced by LPS/GalN.Conclusions: These findings suggest that hepatic SND1, independently, is insufficient for changing glucose homeostasis, hepatic lipid accumulation and inflammation. The synergistic action of multiple organs may contribute to the role of SND1 in insulin sensitivity or inflammatory response.

scholarly journals Hepatic glucose utilization in hepatic steatosis and obesity

2016 ◽  
Vol 36 (6) ◽  
Author(s):  
Georgia Keramida ◽  
James Hunter ◽  
Adrien Michael Peters
Keyword(s):  
Insulin Resistance ◽  
Hepatic Steatosis ◽  
Glucose Utilization ◽  
Graphical Analysis ◽  
Whole Body ◽  
Utilization Rate ◽  
Obese Patients ◽  
Pet Ct ◽  
Significant Difference ◽  
Hepatic Glucose

Hepatic steatosis is associated with obesity and insulin resistance. Whether hepatic glucose utilization rate (glucose phosphorylation rate; MRglu) is increased in steatosis and/or obesity is uncertain. Our aim was to determine the separate relationships of steatosis and obesity with MRglu. Sixty patients referred for routine PET/CT had dynamic PET imaging over the abdomen for 30 min post-injection of F-18-fluorodeoxyglucose (FDG), followed by Patlak–Rutland graphical analysis of the liver using abdominal aorta for arterial input signal. The plot gradient was divided by the intercept to give hepatic FDG clearance normalized to hepatic FDG distribution volume (ml/min per 100 ml) and multiplied by blood glucose to give hepatic MRglu (μmol/min per 100 ml). Hepatic steatosis was defined as CT density of ≤40 HU measured from the 60 min whole body routine PET/CT and obesity as body mass index of ≥30 kg/m2. Hepatic MRglu was higher in patients with steatosis (3.3±1.3 μmol/min per 100 ml) than those without (1.7±1.2 μmol/min per 100 ml; P<0.001) but there was no significant difference between obese (2.5±1.6 μmol/min per 100 ml) and non-obese patients (2.1±1.3 μmol/min per 100 ml). MRglu was increased in obese patients only if they had steatosis. Non-obese patients with steatosis still had increased MRglu. There was no association between MRglu and chemotherapy history. We conclude that MRglu is increased in hepatic steatosis probably through insulin resistance, hyperinsulinaemia and up-regulation of hepatic hexokinase, irrespective of obesity.

Hepatocyte-specific deletion of LASS2 protects against diet-induced hepatic steatosis and insulin resistance

2018 ◽  
Vol 120 ◽  
pp. 330-341 ◽  
Author(s):  
Shaohua Fan ◽  
Yanyan Wang ◽  
Cun Wang ◽  
Haojie Jin ◽  
Zheng Wu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Hepatic Steatosis ◽  
Specific Deletion

scholarly journals Disrupting phosphatase SHP2 in macrophages protects mice from high-fat diet-induced hepatic steatosis and insulin resistance by elevating IL-18 levels

2020 ◽  
Vol 295 (31) ◽  
pp. 10842-10856 ◽  
Author(s):  
Wen Liu ◽  
Ye Yin ◽  
Meijing Wang ◽  
Ting Fan ◽  
Yuyu Zhu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Metabolic Disorders ◽  
Metabolic Diseases ◽  
Low Grade ◽  
High Fat ◽  
Caspase 1

Chronic low-grade inflammation plays an important role in the pathogenesis of type 2 diabetes. Src homology 2 domain-containing tyrosine phosphatase-2 (SHP2) has been reported to play diverse roles in different tissues during the development of metabolic disorders. We previously reported that SHP2 inhibition in macrophages results in increased cytokine production. Here, we investigated the association between SHP2 inhibition in macrophages and the development of metabolic diseases. Unexpectedly, we found that mice with a conditional SHP2 knockout in macrophages (cSHP2-KO) have ameliorated metabolic disorders. cSHP2-KO mice fed a high-fat diet (HFD) gained less body weight and exhibited decreased hepatic steatosis, as well as improved glucose intolerance and insulin sensitivity, compared with HFD-fed WT littermates. Further experiments revealed that SHP2 deficiency leads to hyperactivation of caspase-1 and subsequent elevation of interleukin 18 (IL-18) levels, both in vivo and in vitro. Of note, IL-18 neutralization and caspase-1 knockout reversed the amelioration of hepatic steatosis and insulin resistance observed in the cSHP2-KO mice. Administration of two specific SHP2 inhibitors, SHP099 and Phps1, improved HFD-induced hepatic steatosis and insulin resistance. Our findings provide detailed insights into the role of macrophagic SHP2 in metabolic disorders. We conclude that pharmacological inhibition of SHP2 may represent a therapeutic strategy for the management of type 2 diabetes.

scholarly journals Myeloid cell TRAF3 promotes metabolic inflammation, insulin resistance, and hepatic steatosis in obesity

2015 ◽  
Vol 308 (6) ◽  
pp. E460-E469 ◽  
Author(s):  
Zheng Chen ◽  
Hong Shen ◽  
Chengxin Sun ◽  
Lei Yin ◽  
Fei Tang ◽  
...  
Keyword(s):  
Metabolic Disease ◽  
Insulin Resistance ◽  
Adipose Tissue ◽  
Disease Progression ◽  
Hepatic Steatosis ◽  
Proinflammatory Cytokines ◽  
Myeloid Cell ◽  
Metabolic Inflammation ◽  
Molecular Patterns ◽  
Specific Deletion

Myeloid cells, particularly macrophages, mediate metabolic inflammation, thus promoting insulin resistance and metabolic disease progression in obesity. Numerous cytokines, toxic metabolites, damage-associated molecular patterns, and pathogen-associated molecular patterns are involved in activating macrophages via their cognate receptors in obesity. TRAF3 (TNF receptor-associated factor 3) is a common signaling molecule for these ligands/receptors and negatively regulates the proinflammatory NF-κB and MAPK pathways, but its metabolic activity is unknown. We here show that myeloid cell TRAF3 is required for metabolic inflammation and metabolic disease progression in obesity. Myeloid cell-specific deletion of TRAF3 significantly attenuated insulin resistance, hyperglycemia, hyperinsulinemia, glucose intolerance, and hepatic steatosis in mice with either genetic ( ob/ob) or high-fat diet (HFD)-induced obesity. Myeloid cell-specific deletion of TRAF3 had the opposite effects on metabolic inflammation between obese and lean mice. It decreased the expression of proinflammatory cytokines in the liver and adipose tissue of obese mice and largely prevented HFD-induced inflammation in these metabolic tissues; by contrast, in lean mice, it increased the expression of proinflammatory cytokines in the liver and adipose tissue. These data suggest that, in obesity progression, myeloid TRAF3 functionally switches its activity from anti-inflammatory to proinflammatory modes, thereby coupling overnutrition to metabolic inflammation, insulin resistance, and metabolic disease.

scholarly journals Effects of vitamin D deficiency on the improvement of metabolic disorders in obese mice after vertical sleeve gastrectomy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Zhang ◽  
Min Feng ◽  
Lisha Pan ◽  
Feng Wang ◽  
Pengfei Wu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vitamin D ◽  
Weight Loss ◽  
Sleeve Gastrectomy ◽  
Vitamin D Deficiency ◽  
Hepatic Steatosis ◽  
Metabolic Disorders ◽  
Obese Mice ◽  
Vertical Sleeve Gastrectomy ◽  
Obesity And Diabetes

AbstractVertical sleeve gastrectomy (VSG) is one of the most commonly performed clinical bariatric surgeries for the remission of obesity and diabetes. Its effects include weight loss, improved insulin resistance, and the improvement of hepatic steatosis. Epidemiologic studies demonstrated that vitamin D deficiency (VDD) is associated with many diseases, including obesity. To explore the role of vitamin D in metabolic disorders for patients with obesity after VSG. We established a murine model of diet-induced obesity + VDD, and we performed VSGs to investigate VDD's effects on the improvement of metabolic disorders present in post-VSG obese mice. We observed that in HFD mice, the concentration of VitD3 is four fold of HFD + VDD one. In the post-VSG obese mice, VDD attenuated the improvements of hepatic steatosis, insulin resistance, intestinal inflammation and permeability, the maintenance of weight loss, the reduction of fat loss, and the restoration of intestinal flora that were weakened. Our results suggest that in post-VSG obese mice, maintaining a normal level of vitamin D plays an important role in maintaining the improvement of metabolic disorders.

scholarly journals Glycoursodeoxycholic Acid Ameliorates Diet-induced Metabolic Disorders with Inhibiting Endoplasmic Reticulum Stress

2021 ◽  
Author(s):  
Lele Cheng ◽  
Tao Chen ◽  
Manyun Guo ◽  
Peining Liu ◽  
Xiangrui Qiao ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Endoplasmic Reticulum ◽  
Bile Acid ◽  
Er Stress ◽  
Hepatic Steatosis ◽  
Metabolic Disorders ◽  
Stool Samples ◽  
Glycoursodeoxycholic Acid

Recent studies reveal that bile acid metabolite composition and its metabolism are changed in metabolic disorders, such as obesity, type 2 diabetes and metabolic associated fatty liver disease (MAFLD), yet its role and the mechanism remain largely unknown. In the present study, metabolomic analysis of 163 serum and stool samples of our metabolic disease cohort was performed and we identified glycoursodeoxycholic acid (GUDCA), glycine-conjugated bile acid produced from intestinal bacteria, were decreased in both serum and stool samples from patients with hyperglycemia. RNA-sequencing and quantitative PCR results indicated that GUDCA alleviated endoplasmic reticulum (ER) stress in livers of high fat diet (HFD)-fed mice without alteration of liver metabolism. In vitro, GUDCA reduced palmitic acid induced-ER stress and -apoptosis, as well as stabilized calcium homeostasis. In vivo, GUDCA exerted effects on amelioration of HFD-induced insulin resistance and hepatic steatosis. In parallel, ER stress and apoptosis were decreased in GUDCA-treated mice as compared to vehicle-treated mice in liver. These findings demonstrate that reduced GUDCA is an indicator of hyperglycemia. Supplementation of GUDCA could be an option for the treatment of diet-induced metabolic disorders, including insulin resistance and hepatic steatosis, with inhibiting ER stress.

scholarly journals Phenylmethimazole abrogates diet-induced inflammation, glucose intolerance and NAFLD

2018 ◽  
Vol 237 (3) ◽  
pp. 337-351 ◽  
Author(s):  
Ashley Patton ◽  
Tyler Church ◽  
Caroline Wilson ◽  
Jean Thuma ◽  
Douglas J Goetz ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Hepatic Steatosis ◽  
Glucose Intolerance ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Mrna Levels ◽  
Toll Like Receptor 4 ◽  
Nonalcoholic Fatty Liver ◽  
And Storage

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of both metabolic and inflammatory diseases and has become the leading chronic liver disease worldwide. High-fat (HF) diets promote an increased uptake and storage of free fatty acids (FFAs) and triglycerides (TGs) in hepatocytes, which initiates steatosis and induces lipotoxicity, inflammation and insulin resistance. Activation and signaling of Toll-like receptor 4 (TLR4) by FFAs induces inflammation evident in NAFLD and insulin resistance. Currently, there are no effective treatments to specifically target inflammation associated with this disease. We have established the efficacy of phenylmethimazole (C10) to prevent lipopolysaccharide and palmitate-induced TLR4 signaling. Because TLR4 is a key mediator in pro-inflammatory responses, it is a potential therapeutic target for NAFLD. Here, we show that treatment with C10 inhibits HF diet-induced inflammation in both liver and mesenteric adipose tissue measured by a decrease in mRNA levels of pro-inflammatory cytokines. Additionally, C10 treatment improves glucose tolerance and hepatic steatosis despite the development of obesity due to HF diet feeding. Administration of C10 after 16 weeks of HF diet feeding reversed glucose intolerance, hepatic inflammation, and improved hepatic steatosis. Thus, our findings establish C10 as a potential therapeutic for the treatment of NAFLD.

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