Hepatic IL-1 signaling in NAFLD is a driver of whole-body insulin resistance and adipose tissue inflammation.

2020 ◽  
Author(s):  
N Gehrke ◽  
BK Straub ◽  
A Waisman ◽  
D Schuppan ◽  
MA Wörns ◽  
...  
Endocrinology ◽  
2010 ◽  
Vol 151 (3) ◽  
pp. 971-979 ◽  
Author(s):  
Sanshiro Tateya ◽  
Yoshikazu Tamori ◽  
Takayuki Kawaguchi ◽  
Hajime Kanda ◽  
Masato Kasuga

Chronic inflammation in adipose tissue is thought to be important for the development of insulin resistance in obesity. Furthermore, the level of monocyte chemoattractant protein-1 (MCP-1) is increased not only in adipose tissue but also in the circulation in association with obesity. However, it has remained unclear to what extent the increased circulating level of MCP-1 contributes to insulin resistance. We have now examined the relevance of circulating MCP-1 to the development of insulin resistance in mice. The plasma concentration of MCP-1 was increased chronically or acutely in mice to the level observed in obese animals by chronic subcutaneous infusion of recombinant MCP-1 with an osmotic pump or by acute intravenous infusion of MCP-1 with an infusion pump, respectively. Whole-body metabolic parameters as well as inflammatory changes in adipose tissue were examined. A chronic increase in the circulating level of MCP-1 induced insulin resistance, macrophage infiltration into adipose tissue, and an increase in hepatic triacylglycerol content. An acute increase in the circulating MCP-1 concentration also induced insulin resistance but not macrophage infiltration into adipose tissue. In addition, inhibition of signaling by MCP-1 and its receptor CCR2 by administration of a novel CCR2 antagonist ameliorated insulin resistance in mice fed a high-fat diet without affecting macrophage infiltration into adipose tissue. These data indicate that an increase in the concentration of MCP-1 in the circulation is sufficient to induce systemic insulin resistance irrespective of adipose tissue inflammation.


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

Author(s):  
Charmaine S. Tam ◽  
Leanne M. Redman

AbstractObesity is characterized by a state of chronic low-grade inflammation due to increased immune cells, specifically infiltrated macrophages into adipose tissue, which in turn secrete a range of proinflammatory mediators. This nonselective low-grade inflammation of adipose tissue is systemic in nature and can impair insulin signaling pathways, thus, increasing the risk of developing insulin resistance and type 2 diabetes. The aim of this review is to provide an update on clinical studies examining the role of adipose tissue in the development of obesity-associated complications in humans. We will discuss adipose tissue inflammation during different scenarios of energy imbalance and metabolic dysfunction including obesity and overfeeding, weight loss by calorie restriction or bariatric surgery, and conditions of insulin resistance (diabetes, polycystic ovarian syndrome).


Diabetes ◽  
2016 ◽  
Vol 65 (9) ◽  
pp. 2624-2638 ◽  
Author(s):  
Mira Ham ◽  
Sung Sik Choe ◽  
Kyung Cheul Shin ◽  
Goun Choi ◽  
Ji-Won Kim ◽  
...  

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Kyung Cheul Shin ◽  
Injae Hwang ◽  
Sung Sik Choe ◽  
Jeu Park ◽  
Yul Ji ◽  
...  

2020 ◽  
Vol 295 (51) ◽  
pp. 17535-17548
Author(s):  
Xanthe A. M. H. van Dierendonck ◽  
Tiphaine Sancerni ◽  
Marie-Clotilde Alves-Guerra ◽  
Rinke Stienstra

The development of a chronic, low-grade inflammation originating from adipose tissue in obese subjects is widely recognized to induce insulin resistance, leading to the development of type 2 diabetes. The adipose tissue microenvironment drives specific metabolic reprogramming of adipose tissue macrophages, contributing to the induction of tissue inflammation. Uncoupling protein 2 (UCP2), a mitochondrial anion carrier, is thought to separately modulate inflammatory and metabolic processes in macrophages and is up-regulated in macrophages in the context of obesity and diabetes. Here, we investigate the role of UCP2 in macrophage activation in the context of obesity-induced adipose tissue inflammation and insulin resistance. Using a myeloid-specific knockout of UCP2 (Ucp2ΔLysM), we found that UCP2 deficiency significantly increases glycolysis and oxidative respiration, both unstimulated and after inflammatory conditions. Strikingly, fatty acid loading abolished the metabolic differences between Ucp2ΔLysM macrophages and their floxed controls. Furthermore, Ucp2ΔLysM macrophages show attenuated pro-inflammatory responses toward Toll-like receptor-2 and -4 stimulation. To test the relevance of macrophage-specific Ucp2 deletion in vivo, Ucp2ΔLysM and Ucp2fl/fl mice were rendered obese and insulin resistant through high-fat feeding. Although no differences in adipose tissue inflammation or insulin resistance was found between the two genotypes, adipose tissue macrophages isolated from diet-induced obese Ucp2ΔLysM mice showed decreased TNFα secretion after ex vivo lipopolysaccharide stimulation compared with their Ucp2fl/fl littermates. Together, these results demonstrate that although UCP2 regulates both metabolism and the inflammatory response of macrophages, its activity is not crucial in shaping macrophage activation in the adipose tissue during obesity-induced insulin resistance.


2007 ◽  
Vol 292 (5) ◽  
pp. E1433-E1440 ◽  
Author(s):  
Jinhui Zhang ◽  
Wendy Wright ◽  
David A. Bernlohr ◽  
Samuel W. Cushman ◽  
Xiaoli Chen

Adipose tissue inflammation has recently been linked to the pathogenesis of obesity and insulin resistance. C1 complex comprising three distinct proteins, C1q, C1r, and C1s, involves the key initial activation of the classic pathway of complement and plays an important role in the initiation of inflammatory process. In this study, we investigated adipose expression and regulation of C1 complement subcomponents and C1 activation regulator decorin in obesity and insulin resistance. Expression of C1q in epididymal adipose tissue was increased consistently in ob/ob mice, Zucker obese rats, and high fat-diet-induced obese (HF-DIO) mice. Decorin was found to increase in expression in Zucker obese rats and HF-DIO mice but decrease in ob/ob mice. After TZD administration, C1q and decorin expression was reversed in Zucker obese rats and HF-DIO mice. Increased expression of C1 complement and decorin was observed in both primary adipose and stromal vascular cells isolated from Zucker obese rats. Upregulation of C1r and C1s expression was also perceived in adipose cells from insulin-resistant humans. Furthermore, expression of C1 complement and decorin is dysregulated in TNF-α-induced insulin resistance in 3T3-L1 adipocytes and cultured rat adipose cells as they become insulin resistant after 24-h culture. These data suggests that both adipose and immune cells are the sources for abnormal adipose tissue production of C1 complement and decorin in obesity. Our findings also demonstrate that excessive activation of the classic pathway of complement commonly occurs in obesity, suggesting its possible role in adipose tissue inflammation and insulin resistance.


Metabolism ◽  
2020 ◽  
Vol 106 ◽  
pp. 154194 ◽  
Author(s):  
Joseph Skurski ◽  
Christie M. Penniman ◽  
Ramasatyaveni Geesala ◽  
Garima Dixit ◽  
Priyanjali Pulipati ◽  
...  

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