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 IL-1 family members in the pathogenesis and treatment of metabolic disease: Focus on adipose tissue inflammation and insulin resistance

Cytokine ◽  
2015 ◽  
Vol 75 (2) ◽  
pp. 280-290 ◽  
Author(s):  
Dov B. Ballak ◽  
Rinke Stienstra ◽  
Cees J. Tack ◽  
Charles A. Dinarello ◽  
Janna A. van Diepen
Keyword(s):  
Metabolic Disease ◽  
Insulin Resistance ◽  
Adipose Tissue ◽  
Family Members ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Disease Focus

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.

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 Treatment with atrial natriuretic peptide induces adipose tissue browning and exerts thermogenic actions in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haruka Kimura ◽  
Tomohisa Nagoshi ◽  
Yuhei Oi ◽  
Akira Yoshii ◽  
Yoshiro Tanaka ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
Cold Exposure ◽  
Lipid Droplets ◽  
Adipose Tissues ◽  
Brown Adipose ◽  
Ucp1 Expression ◽  
Tissue Browning

AbstractIncreasing evidence suggests natriuretic peptides (NPs) coordinate inter-organ metabolic crosstalk with adipose tissues and play a critical role in energy metabolism. We recently reported A-type NP (ANP) raises intracellular temperature in cultured adipocytes in a low-temperature-sensitive manner. We herein investigated whether exogenous ANP-treatment exerts a significant impact on adipose tissues in vivo. Mice fed a high-fat-diet (HFD) or normal-fat-diet (NFD) for 13 weeks were treated with or without ANP infusion subcutaneously for another 3 weeks. ANP-treatment significantly ameliorated HFD-induced insulin resistance. HFD increased brown adipose tissue (BAT) cell size with the accumulation of lipid droplets (whitening), which was suppressed by ANP-treatment (re-browning). Furthermore, HFD induced enlarged lipid droplets in inguinal white adipose tissue (iWAT), crown-like structures in epididymal WAT, and hepatic steatosis, all of which were substantially attenuated by ANP-treatment. Likewise, ANP-treatment markedly increased UCP1 expression, a specific marker of BAT, in iWAT (browning). ANP also further increased UCP1 expression in BAT with NFD. Accordingly, cold tolerance test demonstrated ANP-treated mice were tolerant to cold exposure. In summary, exogenous ANP administration ameliorates HFD-induced insulin resistance by attenuating hepatic steatosis and by inducing adipose tissue browning (activation of the adipose tissue thermogenic program), leading to in vivo thermogenesis during cold exposure.

scholarly journals Peripancreatic adipose tissue protects against high-fat-diet-induced hepatic steatosis and insulin resistance in mice

2020 ◽  
Vol 44 (11) ◽  
pp. 2323-2334
Author(s):  
Belén Chanclón ◽  
Yanling Wu ◽  
Milica Vujičić ◽  
Marco Bauzá-Thorbrügge ◽  
Elin Banke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Obese Mice ◽  
High Fat ◽  
Insulin Levels ◽  
Fat Depots ◽  
Fat Depot

Abstract Background/objectives Visceral adiposity is associated with increased diabetes risk, while expansion of subcutaneous adipose tissue may be protective. However, the visceral compartment contains different fat depots. Peripancreatic adipose tissue (PAT) is an understudied visceral fat depot. Here, we aimed to define PAT functionality in lean and high-fat-diet (HFD)-induced obese mice. Subjects/methods Four adipose tissue depots (inguinal, mesenteric, gonadal, and peripancreatic adipose tissue) from chow- and HFD-fed male mice were compared with respect to adipocyte size (n = 4–5/group), cellular composition (FACS analysis, n = 5–6/group), lipogenesis and lipolysis (n = 3/group), and gene expression (n = 6–10/group). Radioactive tracers were used to compare lipid and glucose metabolism between these four fat depots in vivo (n = 5–11/group). To determine the role of PAT in obesity-associated metabolic disturbances, PAT was surgically removed prior to challenging the mice with HFD. PAT-ectomized mice were compared to sham controls with respect to glucose tolerance, basal and glucose-stimulated insulin levels, hepatic and pancreatic steatosis, and gene expression (n = 8–10/group). Results We found that PAT is a tiny fat depot (~0.2% of the total fat mass) containing relatively small adipocytes and many “non-adipocytes” such as leukocytes and fibroblasts. PAT was distinguished from the other fat depots by increased glucose uptake and increased fatty acid oxidation in both lean and obese mice. Moreover, PAT was the only fat depot where the tissue weight correlated positively with liver weight in obese mice (R = 0.65; p = 0.009). Surgical removal of PAT followed by 16-week HFD feeding was associated with aggravated hepatic steatosis (p = 0.008) and higher basal (p < 0.05) and glucose-stimulated insulin levels (p < 0.01). PAT removal also led to enlarged pancreatic islets and increased pancreatic expression of markers of glucose-stimulated insulin secretion and islet development (p < 0.05). Conclusions PAT is a small metabolically highly active fat depot that plays a previously unrecognized role in the pathogenesis of hepatic steatosis and insulin resistance in advanced obesity.

scholarly journals Inflammation, obesity, and thrombosis

Blood ◽  
2013 ◽  
Vol 122 (20) ◽  
pp. 3415-3422 ◽  
Author(s):  
Fahumiya Samad ◽  
Wolfram Ruf
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
Plasminogen Activator Inhibitor ◽  
Epidemiological Studies ◽  
Clinical Markers ◽  
Plasminogen Activator Inhibitor 1 ◽  
Protease Activated Receptors ◽  
The Metabolic Syndrome

Abstract Clinical and epidemiological studies support a connection between obesity and thrombosis, involving elevated expression of the prothrombotic molecules plasminogen activator inhibitor-1 and tissue factor (TF) and increased platelet activation. Cardiovascular diseases and metabolic syndrome–associated disorders, including obesity, insulin resistance, type 2 diabetes, and hepatic steatosis, involve inflammation elicited by infiltration and activation of immune cells, particularly macrophages, into adipose tissue. Although TF has been clearly linked to a procoagulant state in obesity, emerging genetic and pharmacologic evidence indicate that TF signaling via G protein-coupled protease-activated receptors (PAR2, PAR1) additionally drives multiple aspects of the metabolic syndrome. TF–PAR2 signaling in adipocytes contributes to diet-induced obesity by decreasing metabolism and energy expenditure, whereas TF–PAR2 signaling in hematopoietic and myeloid cells drives adipose tissue inflammation, hepatic steatosis, and insulin resistance. TF-initiated coagulation leading to thrombin–PAR1 signaling also contributes to diet-induced hepatic steatosis and inflammation in certain models. Thus, in obese patients, clinical markers of a prothrombotic state may indicate a risk for the development of complications of the metabolic syndrome. Furthermore, TF-induced signaling could provide new therapeutic targets for drug development at the intersection between obesity, inflammation, and thrombosis.

scholarly journals Increased Subcutaneous and Epicardial Adipose Tissue Production of Proinflammatory Cytokines in Cardiac Surgery Patients: Possible Role in Postoperative Insulin Resistance

2006 ◽  
Vol 91 (11) ◽  
pp. 4620-4627 ◽  
Author(s):  
Jaromir Kremen ◽  
Marketa Dolinkova ◽  
Jana Krajickova ◽  
Jan Blaha ◽  
Katerina Anderlova ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Cardiac Surgery ◽  
Mrna Expression ◽  
Proinflammatory Cytokines ◽  
Epicardial Adipose Tissue ◽  
Monocyte Chemoattractant Protein 1 ◽  
Elective Cardiac Surgery ◽  
Tnf Α ◽  
History Of

Abstract Context: Hyperglycemia and insulin resistance frequently occur in critically ill patients even without a history of diabetes. Objective: Our objective was to study the role of adipose tissue hormonal production in the development of insulin resistance in cardiac surgery patients. Participants, Interventions, and Settings: Fifteen patients with elective cardiac surgery underwent blood sampling before, at the end, and 6, 12, 24, 48, and 120 h after the end of their operation. Epicardial and sc adipose tissue sampling was done at the beginning and at the end of surgery in the Department of Cardiac Surgery. Main Outcome Measures: We measured serum concentrations and sc and epicardial adipose tissue mRNA expression of IL-6, monocyte chemoattractant protein-1 (MCP-1), TNF-α, leptin, resistin, and adiponectin and sc and epicardial adipose tissue mRNA expression of CD14, CD45, and CD68. Results: The rate of insulin infusion required to maintain euglycemia increased up to 7-fold 12 h after the operation, suggesting the development of insulin resistance. Serum IL-6 levels increased 43-fold 12 h after surgery. MCP-1 peaked 6-fold at the end of surgery. Smaller peaks of TNF-α and leptin appeared 6 and 12 h after surgery, respectively. Resistin levels peaked 4-fold 24 h after surgery, but adiponectin levels were not significantly affected. TNF-α and CD45 mRNA expression increased markedly during the operation in sc adipose tissue. IL-6, resistin, and MCP-1 mRNA expression increased in both sc and epicardial adipose tissue. Leptin, adiponectin, CD14, and CD68 mRNA expression did not change significantly. Conclusions: Both sc and epicardial adipose tissue is a source of proinflammatory cytokines in cardiac surgery patients and may contribute to the development of postoperative insulin resistance.

scholarly journals URAT1-selective inhibition ameliorates insulin resistance by attenuating diet-induced hepatic steatosis and BAT whitening in mice

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
Y Tanaka ◽  
T Nagoshi ◽  
A Yoshii ◽  
Y Oi ◽  
H Takahashi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
Critical Role ◽  
Selective Inhibition ◽  
Selective Inhibitor ◽  
Obese Mice ◽  
Alcoholic Fatty Liver ◽  
Brown Adipose

Abstract Background Accumulating evidence suggests that high uric acid is strongly associated with obesity and metabolic syndrome and drives the development of non-alcoholic fatty liver disease (NAFLD) and insulin resistance. Although urate transporter-1 (URAT1), which is primarily expressed in the kidney, plays a critical role in the development of hyperuricemia, its pathophysiological implication in NAFLD and insulin resistance remains unclear. Objectives We hypothesizes that URAT1 plays an important role in obesity-induced metabolic disorders, and URAT1-selective inhibitor treatment ameliorates systemic insulin resistance, NAFLD and adipose tissue dysfunction using diet-induced obese mice. Methods Mice fed a high-fat diet (HFD) for 16 to 18 weeks or a normal-fat diet (NFD) were treated with or without a novel oral URAT1-selective inhibitor (dotinurad [50 mg/kg/day]) for another 4 weeks. Results Dotinurad administration significantly ameliorated HFD-induced obesity and insulin resistance. We found that URAT1 was also expressed in the liver and brown adipose tissue (BAT) other than kidney. HFD markedly induced NAFLD, which was characterized by severe hepatic steatosis, as well as the elevation of serum ALT activity and tissue inflammatory cytokine genes (Ccl2 and TNFα), all of which were attenuated by dotinurad. Likewise, HFD significantly increased URAT1 expression in BAT, resulting in the lipid accumulation (whitening of BAT) and increased production of tissue reactive oxygen species, which were reduced by dotinurad via UCP1 activation. Conclusions A novel URAT1-selective inhibitor, dotinurad, ameliorates insulin resistance by attenuating hepatic steatosis and promoting rebrowning of lipid-rich BAT in HFD-induced obese mice. URAT1 serves as a key regulator of the pathophysiology of metabolic syndrome, and may be a new therapeutic target for insulin-resistant individuals, particularly those with concomitant NAFLD. FUNDunding Acknowledgement Type of funding sources: None.

scholarly journals Beneficial Metabolic Effects of TREM2 in Obesity are Uncoupled from its Expression on Macrophages

2021 ◽  
Author(s):  
Omar Sharif ◽  
Julia Stefanie Brunner ◽  
Ana Korosec ◽  
Rui Martins ◽  
Alexander Jais ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
Immune Cell ◽  
Metabolic Effects ◽  
Sphingolipid Metabolism ◽  
Protective Effects ◽  
Tissue Macrophage ◽  
Insulin Tolerance ◽  
Ceramide Synthesis

Obesity-induced white adipose tissue (WAT) hypertrophy is associated with elevated adipose tissue macrophage (ATM) content. Overexpression of the triggering receptor expressed on myeloid cells 2 (TREM2) reportedly increases adiposity, worsening health. Paradoxically, using insulin resistance, elevated fat mass and hypercholesterolemia as hallmarks of unhealthy obesity, a recent report demonstrated ATM-expressed TREM2 promoted health. Here, we identified that in mice TREM2 deficiency aggravated diet-induced insulin resistance and hepatic steatosis independently of fat and cholesterol levels. Metabolomics linked TREM2 deficiency with elevated obesity-instigated serum ceramides that correlated with impaired insulin sensitivity. Remarkably, while inhibiting ceramide synthesis exerted no influences on TREM2-dependent ATM remodeling, inflammation or lipid load, it restored insulin tolerance, reversing adipose hypertrophy and secondary hepatic steatosis of TREM2-deficient animals. Bone marrow transplantation experiments revealed unremarkable influences of immune cell-expressed TREM2 on health instead demonstrating that WAT-intrinsic mechanisms impinging on sphingolipid metabolism dominate in TREM2’s systemic protective effects on metabolic health.

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