scholarly journals Interleukin-1β May Mediate Insulin Resistance in Liver-Derived Cells in Response to Adipocyte Inflammation

Endocrinology ◽  
2010 ◽  
Vol 151 (9) ◽  
pp. 4247-4256 ◽  
Author(s):  
Ori Nov ◽  
Ayelet Kohl ◽  
Eli C. Lewis ◽  
Nava Bashan ◽  
Irit Dvir ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Receptor ◽  
Receptor Antagonist ◽  
Glycogen Synthase ◽  
Liver Cells ◽  
Hepatic Insulin Resistance ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation

Central obesity is frequently associated with adipose tissue inflammation and hepatic insulin resistance. To identify potential individual mediators in this process, we used in vitro systems and assessed if insulin resistance in liver cells could be induced by secreted products from adipocytes preexposed to an inflammatory stimulus. Conditioned medium from 3T3-L1 adipocytes pretreated without (CM) or with TNFα (CM-TNFα) was used to treat Fao hepatoma cells. ELISAs were used to assess the concentration of several inflammatory mediators in CM-TNFα. CM-TNFα-treated Fao cells exhibited about 45% diminution in insulin-stimulated phosphorylation of insulin receptor, insulin receptor substrate proteins, protein kinase B, and glycogen synthase kinase-3 as compared with CM-treated cells, without changes in the total abundance of these protein. Insulin increased glycogenesis by 2-fold in CM-treated Fao cells but not in cells exposed to CM-TNFα. Expression of IL-1β mRNA was elevated 3-fold in TNFα-treated adipocytes, and CM-TNFα had 10-fold higher concentrations of IL-1β but not TNFα or IL-1α. IL-1β directly induced insulin resistance in Fao, HepG2, and in primary rat hepatocytes. Moreover, when TNFα-induced secretion/production of IL-1β from adipocytes was inhibited by the IL-1 converting enzyme (ICE-1) inhibitor II (Ac-YVAD-CMK), insulin resistance was prevented. Furthermore, liver-derived cells treated with IL-1 receptor antagonist were protected against insulin resistance induced by CM-TNFα. Finally, IL-1β secretion from human omental fat explants correlated with body mass index (R2 = 0.639, P < 0.01), and the resulting CM induced insulin resistance in HepG2 cells, inhibitable by IL-1 receptor antagonist. Our results suggest that adipocyte-derived IL-1β may constitute a mediator in the perturbed cross talk between adipocytes and liver cells in response to adipose tissue inflammation.

scholarly journals Loss of Oncostatin M Signaling in Adipocytes Induces Insulin Resistance and Adipose Tissue Inflammation in Vivo

2016 ◽  
Vol 291 (33) ◽  
pp. 17066-17076 ◽  
Author(s):  
Carrie M. Elks ◽  
Peng Zhao ◽  
Ryan W. Grant ◽  
Hardy Hang ◽  
Jennifer L. Bailey ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Cell Types ◽  
Oncostatin M ◽  
Adipose Tissue Inflammation ◽  
High Fat ◽  
Tissue Inflammation ◽  
Fat Feeding

Oncostatin M (OSM) is a multifunctional gp130 cytokine. Although OSM is produced in adipose tissue, it is not produced by adipocytes. OSM expression is significantly induced in adipose tissue from obese mice and humans. The OSM-specific receptor, OSM receptor β (OSMR), is expressed in adipocytes, but its function remains largely unknown. To better understand the effects of OSM in adipose tissue, we knocked down Osmr expression in adipocytes in vitro using siRNA. In vivo, we generated a mouse line lacking Osmr in adiponectin-expressing cells (OSMRFKO mice). The effects of OSM on gene expression were also assessed in vitro and in vivo. OSM exerts proinflammatory effects on cultured adipocytes that are partially rescued by Osmr knockdown. Osm expression is significantly increased in adipose tissue T cells of high fat-fed mice. In addition, adipocyte Osmr expression is increased following high fat feeding. OSMRFKO mice exhibit increased insulin resistance and adipose tissue inflammation and have increased lean mass, femoral length, and bone volume. Also, OSMRFKO mice exhibit increased expression of Osm, the T cell markers Cd4 and Cd8, and the macrophage markers F4/80 and Cd11c. Interestingly, the same proinflammatory genes induced by OSM in adipocytes are induced in the adipose tissue of the OSMRFKO mouse, suggesting that increased expression of proinflammatory genes in adipose tissue arises both from adipocytes and other cell types. These findings suggest that adipocyte OSMR signaling is involved in the regulation of adipose tissue homeostasis and that, in obesity, OSMR ablation may exacerbate insulin resistance by promoting adipose tissue inflammation.

scholarly journals Interleukin-6 Depletion Selectively Improves Hepatic Insulin Action in Obesity

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3417-3427 ◽  
Author(s):  
Peter J. Klover ◽  
Alicia H. Clementi ◽  
Robert A. Mooney
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Receptor ◽  
Endogenous Glucose Production ◽  
Hepatic Insulin Resistance ◽  
Stat3 Phosphorylation ◽  
Insulin Dependent ◽  
Significant Change

Abstract Obesity and insulin resistance are considered chronic inflammatory states, in part because circulating IL-6 is elevated. Exogenous IL-6 can induce hepatic insulin resistance in vitro and in vivo. The importance of endogenous IL-6, however, to insulin resistance of obesity is unresolved. To test the hypothesis that IL-6 contributes to the inflammation and insulin resistance of obesity, IL-6 was depleted in Lepob mice by injection of IL-6-neutralizing antibody. In untreated Lepob mice, signal transducer and activator of transcription-3 (STAT3) activation was increased compared with that in lean controls, consistent with an inflammatory state. With IL-6 depletion, activation of STAT3 in liver and adipose tissue and expression of haptoglobin were reduced. Expression of the IL-6-dependent, hepatic acute phase protein fibrinogen was also decreased. Using the hyperinsulinemic-euglycemic clamp technique, insulin-dependent suppression of endogenous glucose production was 89% in IL-6-depleted Lepob mice, in contrast to only 32% in Lepob controls, indicating a marked increase in hepatic insulin sensitivity. A significant change in glucose uptake in skeletal muscle after IL-6 neutralization was not observed. In a direct comparison of hepatic insulin signaling in Lepob mice treated with anti-IL-6 vs. IgG-treated controls, insulin-dependent insulin receptor autophosphorylation and activation of Akt (pSer473) were increased by nearly 50% with IL-6 depletion. In adipose tissue, insulin receptor signaling showed no significant change despite major reductions in STAT3 phosphorylation and haptoglobin expression. In diet-induced obese mice, depletion of IL-6 improved insulin responsiveness in 2-h insulin tolerance tests. In conclusion, these results indicate that IL-6 plays an important and selective role in hepatic insulin resistance of obesity.

scholarly journals 4261 Insulin Sensitizing Effects of Vitamin D Mediated through Reduced Adipose Tissue Inflammation and Fibrosis: Evidence from a Human Randomized Trial and Mice Studies

2020 ◽  
Vol 4 (s1) ◽  
pp. 97-98
Author(s):  
Eric Lontchi Yimagou ◽  
Sona Kang ◽  
Kehao Zhang ◽  
Akankasha Goyal ◽  
Jee Young You ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vitamin D ◽  
Adipose Tissue ◽  
Tissue Expression ◽  
Hepatic Insulin Resistance ◽  
Adipose Tissue Inflammation ◽  
Collagen Vi ◽  
Tissue Inflammation ◽  
Tnf Α ◽  
Tgf Β1

OBJECTIVES/GOALS: Vitamin D [25(OH)D], known to have anti-inflammatory and anti-fibrotic effects in other tissues, may also impact adipose tissue. We designed parallel studies in humans and rodents to define the effects of vitamin D on adipose tissue inflammation and fibrosis, and on systemic insulin resistance. METHODS/STUDY POPULATION: We performed a randomized, double-blinded placebo-controlled trial to examine the effects of repleting vitamin D at to two levels (to >30 ng/ml and to > 50 ng/ml) in 25(OH)D-deficient (<20 ng/ml), insulin resistant, overweight-to-obese humans (n = 19). A comprehensive study of whole-body insulin action was undertaken with euglycemic stepped hyperinsulinemic clamp studies, both before (1st visit) and after administration of vitamin D or placebo (2nd visit and 3rd visit). Adipose tissue fibrosis and inflammation were quantified by ‘real-time’ rt-PCR and immunofluorescence. To determine whether vitamin D’s effects are mediated through adipocytes, we performed hyperinsulinemic clamp studies and adipose tissue analysis in an adipocyte-specific vitamin D receptor knockout (VDR KO) mouse model. RESULTS/ANTICIPATED RESULTS: 25(OH)D repletion (to >30 ng/ml) was associated with reductions in adipose tissue expression of inflammatory (0.6-0.7-fold decreased expression of TNF-α, IL-6, iNOS and PAI-1) and pro-fibrotic (0.4-0.8-fold decreased expression of TGF-β1, HiF1α, Collagen I, V, VI and MMP7) factors, decreased collagen VI immunofluorescence (p = 0.02) and improved hepatic insulin sensitivity in humans, with suppression of endogenous glucose production (EGP) (1.28 ± 0.20 vs 0.88 ± 0.18 mg/kg/min, p = 0.03). Compared to wild type (WT), VDR KO mice exhibited increased adipose tissue expression of several pro-inflammatory (Tnf-α, iNos, Pai-1, Mcp-1 and F4/80; 4-10 fold) and pro-fibrotic genes (Tgf-β1, Collagen VI, and Tsp1; 2-4 fold), in concert with hepatic insulin resistance (EGP 10 ± 3 vs 3 ± 2 mg/kg/min in WT, p = 0.021). DISCUSSION/SIGNIFICANCE OF IMPACT: Collectively, these complementary human and rodent studies establish a beneficial role of vitamin D to improve hepatic insulin resistance, likely by restraining adipose tissue inflammation and fibrosis. Thus, normalizing 25(OH)D levels could have metabolic benefits in targeted individuals. CONFLICT OF INTEREST DESCRIPTION: N/A

Adipose tissue inflammation contributes to short-term high-fat diet-induced hepatic insulin resistance

2013 ◽  
Vol 305 (3) ◽  
pp. E388-E395 ◽  
Author(s):  
Michael S. F. Wiedemann ◽  
Stephan Wueest ◽  
Flurin Item ◽  
Eugen J. Schoenle ◽  
Daniel Konrad
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
High Fat Diet ◽  
Hepatic Insulin Resistance ◽  
Adipose Tissue Inflammation ◽  
High Fat ◽  
Hepatic Insulin Sensitivity ◽  
Tissue Inflammation

High-fat feeding for 3–4 days impairs glucose tolerance and hepatic insulin sensitivity. However, it remains unclear whether the evolving hepatic insulin resistance is due to acute lipid overload or the result of induced adipose tissue inflammation and consequent dysfunctional adipose tissue-liver cross-talk. In the present study, feeding C57Bl6/J mice a fat-enriched diet [high-fat diet (HFD)] for 4 days induced glucose intolerance, hepatic insulin resistance (as assessed by hyperinsulinemic euglycemic clamp studies), and hepatic steatosis as well as adipose tissue inflammation (i.e., TNFα expression) compared with standard chow-fed mice. Adipocyte-specific depletion of the antiapoptotic/anti-inflammatory factor Fas (CD95) attenuated adipose tissue inflammation and improved glucose tolerance as well as hepatic insulin sensitivity without altering the level of hepatic steatosis induced by HFD. In summary, our results identify adipose tissue inflammation and resulting dysfunctional adipose tissue-liver cross-talk as an early event in the development of HFD-induced hepatic insulin resistance.

scholarly journals Hepatic Acetyl CoA Links Adipose Tissue Inflammation to Hepatic Insulin Resistance and Type 2 Diabetes

Cell ◽  
2015 ◽  
Vol 160 (4) ◽  
pp. 745-758 ◽  
Author(s):  
Rachel J. Perry ◽  
João-Paulo G. Camporez ◽  
Romy Kursawe ◽  
Paul M. Titchenell ◽  
Dongyan Zhang ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Hepatic Insulin Resistance ◽  
Adipose Tissue Inflammation ◽  
Acetyl Coa ◽  
Tissue Inflammation

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

scholarly journals Adipose tissue inflammation and metabolic dysfunction: a clinical perspective

2013 ◽  
Vol 15 (1) ◽  
Author(s):  
Charmaine S. Tam ◽  
Leanne M. Redman
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Metabolic Dysfunction ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Proinflammatory Mediators ◽  
Low Grade Inflammation

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).

scholarly journals Glucose-6-Phosphate Dehydrogenase Deficiency Improves Insulin Resistance With Reduced Adipose Tissue Inflammation in Obesity

Diabetes ◽  
2016 ◽  
Vol 65 (9) ◽  
pp. 2624-2638 ◽  
Author(s):  
Mira Ham ◽  
Sung Sik Choe ◽  
Kyung Cheul Shin ◽  
Goun Choi ◽  
Ji-Won Kim ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Dehydrogenase Deficiency ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Glucose 6 Phosphate Dehydrogenase
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