scholarly journals Induction of Heme Oxygenase-1 with Hemin Reduces Obesity-Induced Adipose Tissue Inflammation via Adipose Macrophage Phenotype Switching

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Thai Hien Tu ◽  
Yeonsoo Joe ◽  
Hye-Seon Choi ◽  
Hun Taeg Chung ◽  
Rina Yu
Keyword(s):  
Heme Oxygenase ◽  
Marker Genes ◽  
Heme Oxygenase 1 ◽  
M2 Macrophage ◽  
Macrophage Phenotype ◽  
M1 Macrophage ◽  
Phenotype Switching ◽  
Anti Inflammatory ◽  
Adipose Inflammation ◽  
M2 Phenotype

Adipose macrophages with the anti-inflammatory M2 phenotype protect against obesity-induced inflammation and insulin resistance. Heme oxygenase-1 (HO-1), which elicits antioxidant and anti-inflammatory activity, modulates macrophage phenotypes and thus is implicated in various inflammatory diseases. Here, we demonstrate that the HO-1 inducer, hemin, protects against obesity-induced adipose inflammation by inducing macrophages to switch to the M2 phenotype. HO-1 induction by hemin reduced the production of proinflammatory cytokines (TNF-αand IL-6) from cocultured adipocytes and macrophages by inhibiting the activation of inflammatory signaling molecules (JNK and NF-κB) in both cell types. Hemin enhanced transcript levels of M2 macrophage marker genes (IL-4, Mrc1, and Clec10a) in the cocultures, while reducing transcripts of M1 macrophage markers (CD274 and TNF-α). The protective effects of hemin on adipose inflammation and macrophage phenotype switching were confirmed in mice fed a high-fat diet, and these were associated with PPARγupregulation and STAT6 activation. These findings suggest that induction of HO-1 with hemin protects against obesity-induced adipose inflammation through M2 macrophage phenotype switching, which is induced by the PPARγand STAT6 pathway. HO-1 inducers such as hemin may be useful for preventing obesity-induced adipose inflammation.

scholarly journals MiR-98-5p expression inhibits polarization of macrophages to an M2 phenotype by targeting Trib1 in inflammatory bowel disease

2020 ◽  
Author(s):  
Yunhua Peng ◽  
Qingyuan Wang ◽  
Wei Yang ◽  
Qiqi Yang ◽  
Ynani Pei ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Macrophage Polarization ◽  
Luciferase Reporter ◽  
Marker Genes ◽  
M2 Macrophage ◽  
M1 Macrophage ◽  
Inflammatory Bowel ◽  
M2 Macrophage Polarization ◽  
M2 Phenotype

Herein, we unfolded miR-98-5p mechanism in inflammatory bowel disease (IBD). IBD mouse model was established. The severity of colitis was assessed daily using the disease activity index (DAI). Murine peritoneal macrophages were stimulated by lipopolysaccharide (LPS). MiR-98-5p, tribbles homolog 1 (Trib1), M1 and M2 macrophage marker genes mRNA expression was analyzed. The relationship between miR-98-5p and Trib1 was explored using a luciferase reporter assay. The strategy of loss-of-function was used to explore the mechanism of miR-98-5p in macrophage polarization, inflammation and IBD. The results revealed that IBD mice had higher DAI index and miR-98-5p expression when compared to the Sham group. MiR-98-5p and Trib1 displayed a targeted regulation relationship. Knockdown of miR-98-5p transformed LPS-induced M1 macrophage polarization into M2 macrophage polarization and inhibited inflammation via up-regulating Trib1. However, shTrib1 reversed the effects. In vivo experiment, silencing of miR-98-5p, diminished the DAI and promoted M2 macrophage polarization. In conclusion, knockdown of miR-98-5p changed macrophage polarization to the M2 phenotype by increasing Trib1 expression, thereby alleviating IBD symptoms.

scholarly journals Heme Oxygenase-1 Contributes to an Alternative Macrophage Activation Profile Induced by Apoptotic Cell Supernatants

2009 ◽  
Vol 20 (5) ◽  
pp. 1280-1288 ◽  
Author(s):  
Nicole Weis ◽  
Andreas Weigert ◽  
Andreas von Knethen ◽  
Bernhard Brüne
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Heme Oxygenase ◽  
Apoptotic Cell ◽  
Macrophage Polarization ◽  
Heme Oxygenase 1 ◽  
M2 Macrophage ◽  
Vascular Endothelial ◽  
Anti Inflammatory ◽  
Endothelial Growth Factor

Apoptotic cells (AC) are rapidly engulfed by professional phagocytes such as macrophages to avoid secondary necrosis and thus inflammation. Recognition of AC polarizes macrophages toward an anti-inflammatory phenotype, which shows homology to an alternatively activated M2 macrophage. However, mechanistic details provoking these phenotype alterations are incompletely understood. Here, we demonstrate a biphasic up-regulation of heme oxygenase-1 (HO-1), a protein that bears an antiapoptotic as well as an anti-inflammatory potential, in primary human macrophages, which were exposed to the supernatant of AC. Although the first phase of HO-1 induction at 6 h was accomplished by AC-derived sphingosine-1-phosphate (S1P) acting via S1P receptor 1, the second wave of HO-1 induction at 24 h was attributed to autocrine signaling of vascular endothelial growth factor A (VEGFA), whose expression and release were facilitated by S1P. Whereas VEGFA release from macrophages was signal transducer and activator of transcription (STAT) 1-dependent, vascular endothelial growth factor itself triggered STAT1/STAT3 heterodimer formation, which bound to and activated the HO-1 promoter. Knockdown of HO-1 proved its relevance in facilitating enhanced expression of the antiapoptotic proteins Bcl-2 and Bcl-XL, as well as the anti-inflammatory adenosine receptor A2A. These findings suggest that HO-1, which is induced by AC-derived S1P, is critically involved in macrophage polarization toward an M2 phenotype.

Heme oxygenase-1 mediates the anti-inflammatory effect of mushroom Phellinus linteus in LPS-stimulated RAW264.7 macrophages

2006 ◽  
Vol 106 (3) ◽  
pp. 364-371 ◽  
Author(s):  
Byung-Chul Kim ◽  
Joung-Woo Choi ◽  
Hye-Young Hong ◽  
Sin-Ae Lee ◽  
Suntaek Hong ◽  
...  
Keyword(s):  
Heme Oxygenase ◽  
Heme Oxygenase 1 ◽  
Phellinus Linteus ◽  
Raw264.7 Macrophages ◽  
Anti Inflammatory ◽  
Inflammatory Effect

Abstract 1727: Apolipoprotein E (ApoE) Induces an Anti-inflammatory Phenotype in Macrophages

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Daniel Baitsch ◽  
Ralph Telgmann ◽  
Georg Varga ◽  
Carsten Muller-Tidow ◽  
Martine Bot ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Apolipoprotein E ◽  
Kinase Inhibitor ◽  
Plasma Cholesterol ◽  
Macrophage Phenotype ◽  
Anti Inflammatory ◽  
M2 Phenotype ◽  
Functional Phenotype ◽  
Expression And Activity ◽  
Phenotype Expression

Apolipoprotein E (apoE) exerts anti-atherogenic effects by promoting cholesterol efflux and hepatic lipoprotein clearance. However, apoE retains protective effects even under experimental settings, in which its influence on plasma cholesterol is negligible suggesting that this lipoprotein inhibits atherosclerosis independently from cholesterol transport. To gain further insight into mechanisms underlying apoE-mediated atheroprotection, we investigated its effect on the functional phenotype of RAW 264.7 macrophages overexpressing either of two apoE receptors: ApoER2/LRP8 or VLDL-R. Incubation of ApoER2/LRP8- or VLDL-R-expressing macrophages with apoE downregulated markers of pro-inflammatory M1 functional phenotype (expression and activity of iNOS, production of IL-12), whereas markers of anti-inflammatory M2 phenotype (expression and activity of arginase-I, production of IL-1RA) were upregulated. In addition, macrophage responses typical for M1 phenotype (migration, generation of reactive oxygen species, antibody-dependent cell cytotoxicity) were suppressed in ApoER2/LRP8- or VLDL-R-expressing cells in the presence of apoE. Finally, apoE prevented LPS- and IFN-γ-induced activation of ApoER2/LRP8- or VLDL-R-expressing macrophages as documented by reduced production of IL-12, TNF-α and MCP-1, reduced expression and activity of iNOS and COX2, and reduced activation and/or phosphorylation of NF-κB, IκB and STAT1. The modulatory effects of apoE on macrophage phenotype were inhibited by SB220025, a p38MAP kinase inhibitor, and PP1A, a tyrosine kinase inhibitor. Accordingly, apoE induced tyrosine kinase-dependent activation of p38MAP kinase in ApoER2/LRP8- or VLDL-R-expressing macrophages. Under in vivo conditions, apoE −/− mice transplanted with apoE-producing wild-type bone marrow presented with increased plasma IL-1RA levels. In addition, peritoneal macrophages from transplanted animals demonstrated enhanced M2 phenotype (increased IL-1RA production and CD206 expression). We conclude that apoE signalling over ApoER2/LRP8 or VLDL-R promotes macrophage conversion from pro-inflammatory M1 to anti-inflammatory M2 phenotype. This effect may represent a novel anti-atherogenic activity of apoE.

scholarly journals Role of nuclear factor-κ B and heme oxygenase-1 in the mechanism of action of an anti-inflammatory chalcone derivative in RAW 264.7 cells

2004 ◽  
Vol 142 (7) ◽  
pp. 1191-1199 ◽  
Author(s):  
María José Alcaraz ◽  
Ana María Vicente ◽  
Amparo Araico ◽  
José N Dominguez ◽  
María Carmen Terencio ◽  
...  
Keyword(s):  
Heme Oxygenase ◽  
Mechanism Of Action ◽  
Raw 264.7 Cells ◽  
Heme Oxygenase 1 ◽  
Raw 264.7 ◽  
Nuclear Factor ◽  
Chalcone Derivative ◽  
Anti Inflammatory ◽  
Nuclear Factor Κ B

scholarly journals Eplerenone prevented obesity-induced inflammasome activation and glucose intolerance

2017 ◽  
Vol 235 (3) ◽  
pp. 179-191 ◽  
Author(s):  
Tsutomu Wada ◽  
Akari Ishikawa ◽  
Eri Watanabe ◽  
Yuto Nakamura ◽  
Yusuke Aruga ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Glucose Intolerance ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
M2 Macrophage ◽  
Expression Levels ◽  
Nlrp3 Inflammasome Activation ◽  
M1 Macrophage ◽  
Anti Inflammatory

Obesity-associated activation of the renin-angiotensin-aldosterone system is implicated in the pathogenesis of insulin resistance; however, influences of mineralocorticoid receptor (MR) inhibition remain unclear. Therefore, we aimed to clarify the anti-inflammatory mechanisms of MR inhibition using eplerenone, a selective MR antagonist, in C57BL/6 mice fed a high-fat diet (HFD) for 12 weeks. Eplerenone prevented excessive body weight gain and fat accumulation, ameliorated glucose intolerance and insulin resistance and enhanced energy metabolism. In the epididymal white adipose tissue (eWAT), eplerenone prevented obesity-induced accumulation of F4/80+CD11c+CD206−-M1-adipose tissue macrophage (ATM) and reduction of F4/80+CD11c−CD206+-M2-ATM. Interestingly, M1-macrophage exhibited lower expression levels of MR, compared with M2-macrophage, in the ATM of eWAT and in vitro-polarized bone marrow-derived macrophages (BMDM). Importantly, eplerenone and MR knockdown attenuated the increase in the expression levels of proIl1b, Il6 and Tnfa, in the eWAT and liver of HFD-fed mice and LPS-stimulated BMDM. Moreover, eplerenone suppressed IL1b secretion from eWAT of HFD-fed mice. To reveal the anti-inflammatory mechanism, we investigated the involvement of NLRP3-inflammasome activation, a key process of IL1b overproduction. Eplerenone suppressed the expression of the inflammasome components, Nlrp3 and Caspase1, in the eWAT and liver. Concerning the second triggering factors, ROS production and ATP- and nigericin-induced IL1b secretion were suppressed by eplerenone in the LPS-primed BMDM. These results indicate that eplerenone inhibited both the priming and triggering signals that promote NLRP3-inflammasome activation. Therefore, we consider MR to be a crucial target to prevent metabolic disorders by suppressing inflammasome-mediated chronic inflammation in the adipose tissue and liver under obese conditions.

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