scholarly journals Genetic Correction of IL-10RB Deficiency Reconstitutes Anti-Inflammatory Regulation in iPSC-Derived Macrophages

2021 ◽  
Vol 11 (3) ◽  
pp. 221
Author(s):  
Dirk Hoffmann ◽  
Johanna Sens ◽  
Sebastian Brennig ◽  
Daniel Brand ◽  
Friederike Philipp ◽  
...  
Keyword(s):  
Disease Modeling ◽  
Integration Site ◽  
Cytokine Secretion ◽  
Cytokine Signaling ◽  
Stat3 Phosphorylation ◽  
Tnf Α ◽  
Socs3 Expression ◽  
Healthy Control ◽  
Anti Inflammatory ◽  
Inflammatory Regulation

Patient material from rare diseases such as very early-onset inflammatory bowel disease (VEO-IBD) is often limited. The use of patient-derived induced pluripotent stem cells (iPSCs) for disease modeling is a promising approach to investigate disease pathomechanisms and therapeutic strategies. We successfully developed VEO-IBD patient-derived iPSC lines harboring a mutation in the IL-10 receptor β-chain (IL-10RB) associated with defective IL-10 signaling. To characterize the disease phenotype, healthy control and VEO-IBD iPSCs were differentiated into macrophages. IL-10 stimulation induced characteristic signal transducer and activator of transcription 3 (STAT3) and suppressor of cytokine signaling 3 (SOCS3) downstream signaling and anti-inflammatory regulation of lipopolysaccharide (LPS)-mediated cytokine secretion in healthy control iPSC-derived macrophages. In contrast, IL-10 stimulation of macrophages derived from patient iPSCs did not result in STAT3 phosphorylation and subsequent SOCS3 expression, recapitulating the phenotype of cells from patients with IL-10RB deficiency. In line with this, LPS-induced cytokine secretion (e.g., IL-6 and tumor necrosis factor-α (TNF-α)) could not be downregulated by exogenous IL-10 stimulation in VEO-IBD iPSC-derived macrophages. Correction of the IL-10RB defect via lentiviral gene therapy or genome editing in the adeno-associated virus integration site 1 (AAVS1) safe harbor locus led to reconstitution of the anti-inflammatory response. Corrected cells showed IL-10RB expression, IL-10-inducible phosphorylation of STAT3, and subsequent SOCS3 expression. Furthermore, LPS-mediated TNF-α secretion could be modulated by IL-10 stimulation in gene-edited VEO-IBD iPSC-derived macrophages. Our established disease models provide the opportunity to identify and validate new curative molecular therapies and to investigate phenotypes and consequences of additional individual IL-10 signaling pathway-dependent VEO-IBD mutations.

IFNγ-dependent SOCS3 expression inhibits IL-6-induced STAT3 phosphorylation and differentially affects IL-6 mediated transcriptional responses in endothelial cells

2010 ◽  
Vol 299 (2) ◽  
pp. C354-C362 ◽  
Author(s):  
Hans A. R. Bluyssen ◽  
M. Mehdi Rastmanesh ◽  
Chantal Tilburgs ◽  
Kim Jie ◽  
Sebastiaan Wesseling ◽  
...  
Keyword(s):  
Target Genes ◽  
Interferon Γ ◽  
Cytokine Signaling ◽  
Transcriptional Responses ◽  
Stat3 Phosphorylation ◽  
Socs3 Expression ◽  
Protective Genes ◽  
Inflammatory Phenotype ◽  
Anti Inflammatory ◽  
Interfering Rna

IL-6 has pro- and anti-inflammatory effects and is involved in endothelial cell (EC) dysfunction. The anti-inflammatory effects of IL-6 are mediated by signal transducer and activator of transcription-3 (STAT3), which is importantly controlled by suppressor of cytokine signaling 3 (SOCS3). Therefore, cytokines that modulate SOCS3 expression might inhibit the anti-inflammatory effects of IL-6. We hypothesized that in EC, interferon-γ (IFNγ)-induced SOCS3 expression leads to inhibition of IL-6-induced STAT3 activation and IL-6-dependent expression of anti-, but not pro-inflammatory, target genes. IFNγ activated STAT1 and STAT3 and increased SOCS3 expression in EC. IL-6 only activated STAT3 and induced SOCS3 expression. IFNγ pretreatment of EC inhibited IL-6-induced STAT3 activation accompanied by increased SOCS3 protein. Inhibition of SOCS3 expression, using costimulation, Act-D, and small interfering RNA (siRNA), subsequently implicated the importance of IFNγ-induced SOCS3 in this phenomenon. Pretreatment of EC with IFNγ also affected the transcriptional program induced by IL-6. We identified 1) IL-6 anti-inflammatory target genes that were inhibited by IFNγ, 2) IFNγ-target genes of pro-inflammatory nature that were increased in response to IL-6 in the presence of IFNγ, and 3) a set of target genes that were increased upon IL-6 or IFNγ alone, or combined IFNγ and IL-6. In summary, by increasing SOCS3 expression in EC, IFNγ can selectively inhibit STAT3-dependent IL-6 signaling. This in turn leads to decreased expression of some EC protective genes. In contrast, other genes of pro-inflammatory nature are not inhibited or even increased. This IFNγ-induced shift in IL-6 signaling to a pro-inflammatory phenotype could represent a novel mechanism involved in EC dysfunction.

scholarly journals Evaluation of Antioxidant, Anti-Inflammatory and Cytoprotective Properties of Ethanolic Mint Extracts from Algeria on 7-Ketocholesterol-Treated Murine RAW 264.7 Macrophages

Antioxidants ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 184 ◽  
Author(s):  
Fatiha Brahmi ◽  
Thomas Nury ◽  
Meryam Debbabi ◽  
Samia Hadj-Ahmed ◽  
Amira Zarrouk ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Cytokine Secretion ◽  
Total Phenolic ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Raw 264.7 Macrophages ◽  
Tnf Α ◽  
Anti Inflammatory

The present study consisted in evaluating the antioxidant, anti-inflammatory and cytoprotective properties of ethanolic extracts from three mint species (Mentha spicata L. (MS), Mentha pulegium L. (MP) and Mentha rotundifolia (L.) Huds (MR)) with biochemical methods on murine RAW 264.7 macrophages (a transformed macrophage cell line isolated from ascites of BALB/c mice infected by the Abelson leukemia virus). The total phenolic, flavonoid and carotenoid contents were determined with spectrophotometric methods. The antioxidant activities were quantified with the Kit Radicaux Libres (KRLTM), the ferric reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The MS extract showed the highest total phenolic content, and the highest antioxidant capacity, while the MR extract showed the lowest total phenolic content and the lowest antioxidant capacity. The cytoprotective and anti-inflammatory activities of the extracts were quantified on murine RAW 264.7 macrophages treated with 7-ketocholesterol (7KC; 20 µg/mL: 50 µM) associated or not for 24 h and 48 h with ethanolic mint extracts used at different concentrations (25, 50, 100, 200 and 400 µg/mL). Under treatment with 7KC, an important inhibition of cell growth was revealed with the crystal violet test. This side effect was strongly attenuated in a dose dependent manner with the different ethanolic mint extracts, mainly at 48 h. The most important cytoprotective effect was observed with the MS extract. In addition, the effects of ethanolic mint extracts on cytokine secretion (Interleukin (IL)-6, IL-10, Monocyte Chemoattractant Protein (MCP)-1, Interferon (IFN)-ϒ, Tumor necrosis factor (TNF)-α) were determined at 24 h on lipopolysaccharide (LPS, 0.2 µg/mL)-, 7KC (20 µg/mL)- and (7KC + LPS)-treated RAW 264.7 cells. Complex effects of mint extracts were observed on cytokine secretion. However, comparatively to LPS-treated cells, all the extracts strongly reduce IL-6 secretion and two of them (MP and MR) also decrease MCP-1 and TNF-α secretion. However, no anti-inflammatory effects were observed on 7KC- and (7KC + LPS)-treated cells. Altogether, these data bring new evidences on the potential benefits (especially antioxidant and cytoprotective properties) of Algerian mint on human health.

scholarly journals Acorus gramineusand and Euodia ruticarpa Steam Distilled Essential Oils Exert Anti-Inflammatory Effects Through Decreasing Th1/Th2 and Pro-/Anti-Inflammatory Cytokine Secretion Ratios In Vitro

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 338 ◽  
Author(s):  
Tzu-He Yeh ◽  
Jin-Yuarn Lin
Keyword(s):  
Essential Oils ◽  
Immune Cells ◽  
Cytokine Secretion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Total Flavonoids ◽  
Immune Functions ◽  
Immune Balance ◽  
Tnf Α ◽  
Th2 Polarization ◽  
Anti Inflammatory

To clarify the effects of steam distilled essential oils (SDEO) from herbs used in traditional Chinese medicine on immune functions, two potential herbs, Acorus gramineusand (AG) and Euodia ruticarpa (ER) cultivated in Taiwan, were selected to assess their immunomodulatory effects using mouse primary splenocytes and peritoneal macrophages. T helper type 1 lymphocytes (Th1) (IL-2), Th2 (IL-5), pro-inflammatory (TNF-α) and anti-inflammatory (IL-10) cytokines secreted by correspondent immune cells treated with SDEO samples were determined using enzyme-linked immunosorbent assay. The total amounts of potential phytochemicals, including total flavonoids, polyphenols and saponins, in these two selected SDEOs were measured and correlated with cytokine levels secreted by immune cells. Our results evidenced that ER SDEO is rich in total flavonoids, polyphenols and saponins. Treatments with AG and ER SDEO significantly (p < 0.05) increased IL-5/IL-2 (Th2/Th1) cytokine secretion ratios by splenocytes, suggesting that both AG and ER SDEO have the Th2-polarization property and anti-inflammatory potential. In addition, AG and ER SDEO, particularly ER SDEO, markedly decreased TNF-α/IL-10 secretion ratios by macrophages in the absence or presence of lipopolysaccharide (LPS), exhibiting substantial effects on spontaneous and LPS-induced inflammation. Significant correlations were found between the total polyphenols, flavonoids or saponins content in the two selected SDEOs and Th1/Th2 immune balance or anti-inflammatory ability in linear, non-linear or biphasic manners, respectively. In conclusion, our results suggest that AG and ER, particularly ER, SDEO have immunomodulatory potential in shifting the Th1/Th2 balance toward Th2 polarization in splenocytes and inhibiting inflammation in macrophages in the absence or presence of LPS.

Immunomodulatory consequences of oral administration of Lactobacillus rhamnosus strain GG in healthy volunteers

2003 ◽  
Vol 70 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Michael Schultz ◽  
Hans-Jörg Linde ◽  
Norbert Lehn ◽  
Kurt Zimmermann ◽  
Johannes Grossmann ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Oral Administration ◽  
Healthy Volunteers ◽  
Intestinal Flora ◽  
Lactobacillus Rhamnosus ◽  
Cytokine Secretion ◽  
Tnf Α ◽  
Ifn Γ ◽  
Anti Inflammatory ◽  
Cellular Immune

Probiotic microorganisms, especially lactic acid bacteria, are effective in the treatment of infectious diarrhoeal diseases and experimental colitis. Although the mechanisms by which these organisms exert their anti-inflammatory effects are largely unknown, immunomodulating effects are suggested. The objective of this study was to examine the effect of a 5-week oral administration of Lactobacillus rhamnosus subspecies GG (Lb. GG) on the cellular immune response to intestinal microorganisms in ten healthy volunteers. Peripheral blood cells (PB) were stimulated with either ‘self’ or ‘non-self’ preparations of faecal samples and isolated Bacteroides fragilis group-organisms (Bfg) or Escherichia coli (Esch. coli), and pro- and anti-inflammatory cytokines (IL-10, IL-4, IL-6, IFN-γ, TNF-α) were measured in the culture supernatant. CD4+ T-lymphocyte activation was determined by measurement of intracellular ATP following lysis of the cells. The activational response of CD4+ T-lymphocytes towards isolated and heat-inactivated intestinal organisms was increased after the probiotic treatment. Additionally, TNF-α, IL-6 and in part IFN-γ cytokine secretion by PB cells following stimulation with whole stool preparations and single members of the flora was significantly decreased, whereas the IL-10 and in part IL-4 cytokine secretion was increased at the end of the study. In contrast, the activational response of CD4+ T-lymphocytes following stimulation with whole ‘non-self’ intestinal flora was higher than by ‘self’ intestinal flora, but both responses showed a trend towards a reduction at the end of the study. This study documents a direct effect by Lb. GG on the cellular immune system of healthy volunteers and offers a promising tool to investigate systemic immunomodulation due to oral administration of probiotic microorganisms.

scholarly journals Resolution phase agonists &bone remodeling

2016 ◽  
Author(s):  
Ευάγγελος Παπαθανασίου
Keyword(s):  
Bone Loss ◽  
Alveolar Bone ◽  
Peritoneal Macrophages ◽  
Alveolar Bone Loss ◽  
Cytokine Signaling ◽  
Periodontal Inflammation ◽  
Oral Inoculation ◽  
Tnf Α ◽  
Socs Proteins ◽  
Anti Inflammatory

Periodontitis is the 6th most prevalent disease in the world and the primary cause for tooth loss in adults. The host immune response plays a key role in bacteria-induced alveolar bone resorption. Endogenous control of the magnitude and duration of inflammatory signaling is considered an important determinant of the extent of periodontal pathology. Suppressor of cytokine signaling (SOCS) proteins are inhibitors of cytokine signaling pathways and may play a role in controlling periodontal inflammation. SOCS proteins are also considered crucial intracellular mediators of the anti-inflammatory actions of lipid mediator agonists including resolvins such as RvE1. We hypothesized that SOCS-3 regulates inflammatory cytokine signaling and alveolar bone loss in experimental periodontitis and that the anti-inflammatory actions of RvE1 are SOCS-3 dependent. Periodontal bone loss was induced in myeloid-specific SOCS-3-knockout (KO) and SOCS-3-wild-type (WT) C57Bl6-B.129 mice by oral inoculation with 1×109 colony-forming units (CFU) P. gingivalis A7436 using an oral gavage model for periodontitis. Sham controls for both types of mice received vehicle without bacteria. The mice were euthanized 6 weeks after the last oral inoculation. Morphometric, histomorphometric, and µCT analyses were performed to assess alveolar bone loss. Peritoneal macrophages were elicited with 4% thioglycolate broth and isolated from myeloid SOCS-3-KO and SOCS-3-WT mice by differential centrifugation. Macrophages were cultured at a concentration of 1.5×106 cells/ml in 6-well plates. After 2 hours, non-adherent cells were discarded and the remaining adherent cells were treated with either culture medium alone (control) or with 100 ng/ml P. gingivalis A7436 LPS or with culture medium and 100nM RvE1 or with 100 ng/ml P. gingivalis A7436 LPS and RvE1 100nM (n≥3 wells per group). Supernatants and cells were collected after 12 hours. Cytokine levels were assessed using Luminex multiplex bead immunoassay and RNA was extracted by Trizol and processed for qRT-PCR. Increased bone loss was demonstrated in P. gingivalis-infected SOCS-3- KO mice compared to P. gingivalis-infected WT mice by direct morphological measurements, µCT analyses and quantitative histology. Loss of SOCS-3 function resulted in increased number of alveolar bone osteoclasts and increased RANKL expression after P. gingivalis infection. SOCS-3 deficiency in myeloid cells also promoted a higher P. gingivalis LPS-induced inflammatory response by inducing a higher secretion of IL-1β, IL-6, TNF-α and KC (IL-8) by peritoneal macrophages from SOCS-3-KO mice. 100nM RvE1 resulted in a significant decrease in P. gingivalis LPS-induced secretion of IL-6, TNF-α and IL-8 by increasing mRNA expression of SOCS-3 and ERV1 in macrophages from SOCS-3-WT mice compared to macrophages from myeloid SOCS-3-KO ones. Our data implicate SOCS-3 as a critical negative regulator of alveolar bone loss in experimental periodontitis and P. gingivalis LPS-induced inflammatory response. SOCS-3 regulates the anti-inflammatory actions of RvE1 on P. gingivalis LPS-induced inflammatory cytokines in macrophages. Understanding further the role of SOCS proteins in regulating periodontal inflammation may provide novel pathways of host susceptibility to periodontitis and new therapeutic targets for modulating the immune response to achieve successful resolution of periodontal inflammation.

scholarly journals Immunomodulatory Effects of Inactivated Parapoxvirus Ovis (Orf Virus) on Human Peripheral Immune Cells: Induction of Cytokine Secretion in Monocytes and Th1-Like Cells

2004 ◽  
Vol 78 (17) ◽  
pp. 9400-9411 ◽  
Author(s):  
Astrid Friebe ◽  
Angela Siegling ◽  
Sonja Friederichs ◽  
Hans-Dieter Volk ◽  
Olaf Weber
Keyword(s):  
Immune Cells ◽  
Cytokine Secretion ◽  
Orf Virus ◽  
Proinflammatory Response ◽  
Necrosis Factor Alpha ◽  
Virus Particles ◽  
Tnf Α ◽  
Ifn Γ ◽  
Anti Inflammatory ◽  
Parapoxvirus Ovis

ABSTRACT Inactivated parapoxvirus ovis (Orf virus; PPVO) recently displayed strong immunostimulating and modulating capacities in several animal models for acute and chronic virus infections through the induction of gamma interferon (IFN-γ) as a key mediator of antiviral activity. The data presented in this work demonstrate that inactivated PPVO has strong effects on cytokine secretion by human immune cells, including the upregulation of inflammatory and Th1-related cytokines (IFN-γ, tumor necrosis factor alpha [TNF-α], interleukin 6 [IL-6], IL-8, IL-12, and IL-18) as well as anti-inflammatory and Th2-related cytokines (IL-4, IL-10, and IL-1 receptor antagonist [IL-1ra]). Studies on the mechanism of action revealed virus particles to be the effective components of the preparation. The virus particles activate monocytes or other antigen-presenting cells (APC), e.g., plasmacytoid dendritic cells, through signaling over CD14 and a Toll-like receptor and the intracellular presence of certain PPVO-specific components. The activation of monocytes or APC is followed by the release of early proinflammatory cytokines (TNF-α, IL-6, and IL-8) as well as the Th1-related cytokines IL-12 and IL-18. Both IL-18 and IL-12 are involved in PPVO-mediated IFN-γ release by T cells and/or NK cells. The proinflammatory response is accompanied by the induction of anti-inflammatory and Th2-related cytokines (IL-4, IL-10, and IL-1ra), which exert a limiting efffect on the inflammatory response induced by PPVO. We conclude that the induction of a natural immune response with physiologically significant amounts of different cytokines and with antiviral potential might provide advantages over existing antiviral immunotherapies.

scholarly journals Distinct mechanisms of induction of hepatic growth hormone resistance by endogenous IL-6, TNF-α, and IL-1β

2014 ◽  
Vol 307 (2) ◽  
pp. E186-E198 ◽  
Author(s):  
Yueshui Zhao ◽  
Xiaoqiu Xiao ◽  
Stuart J. Frank ◽  
Herbert Y. Lin ◽  
Yin Xia
Keyword(s):  
Growth Hormone ◽  
Target Gene ◽  
Cytokine Signaling ◽  
Suppressor Of Cytokine Signaling ◽  
Gh Receptor ◽  
Tnf Α ◽  
Igf I ◽  
Socs3 Expression ◽  
Gh Resistance

During inflammation, the liver becomes resistant to growth hormone (GH) actions, leading to downregulation of the GH target gene IGF-I and activation of catabolism. Proinflammatory cytokines IL-6, TNF-α, and IL-1β are critically involved in the pathogenesis of hepatic GH resistance. However, the mechanisms used by endogenous IL-6, TNF-α, and IL-1β to inhibit the hepatic GH-IGF-I pathway during inflammation are not fully understood. Here, we show that TNF-α and IL-1β inhibited GH receptor (GHR) expression but had minor effects on the downstream suppressor of cytokine signaling (SOCS)3, while IL-6 induced SOCS3 expression but had no effect on GHR expression in Huh-7 cells. Consistent with the in vitro observations, neutralization of TNF-α and IL-1β in mouse models of inflammation did not significantly alter SOCS3 expression stimulated by inflammation but restored GHR and IGF-I expression suppressed by inflammation. Neutralization of IL-6 did not alter inflammation-suppressed GHR expression but drastically reduced the inflammation-stimulated SOCS3 expression and restored IGF-I expression. Interestingly, when the GH-IGF-I pathway was turned off by maximal inhibition of GHR expression, IL-6 and SOCS3 were no longer able to regulate IGF-I expression. Taken together, our results suggest that TNF-α/IL-1β and IL-6 use distinct mechanisms to induce hepatic GH resistance, with TNF-α and IL-1β acting primarily on GHR and IL-6 acting primarily on SOCS3. IL-6 action may be superseded by factors such as TNF-α and IL-1β that inhibit GHR expression.

Effect of IL-6 on the insulin sensitivity in patients with type 2 diabetes

2014 ◽  
Vol 306 (7) ◽  
pp. E769-E778 ◽  
Author(s):  
N. M. Harder-Lauridsen ◽  
R. Krogh-Madsen ◽  
J. J. Holst ◽  
P. Plomgaard ◽  
L. Leick ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Whole Body ◽  
Cytokine Signaling ◽  
Contributing Factors ◽  
Stat3 Phosphorylation ◽  
Socs3 Expression ◽  
Body Energy

Elevated interleukin-6 (IL-6) levels are associated with type 2 diabetes, but its role in glucose metabolism is controversial. We investigated the effect of IL-6 on insulin-stimulated glucose metabolism in type 2 diabetes patients and hypothesized that an acute, moderate IL-6 elevation would increase the insulin-mediated glucose uptake. Men with type 2 diabetes not treated with insulin [ n = 9, age 54.9 ± 9.7 (mean ± SD) yr, body mass index 34.8 ± 6.1 kg/m2, HbA1c7.0 ± 1.0%] received continuous intravenous infusion with either recombinant human IL-6 (rhIL-6) or placebo. After 1 h with placebo or rhIL-6, a 3-h hyperinsulinemic-isoglycemic clamp was initiated. Whole body glucose metabolism was measured using stable isotope-labeled tracers. Signal transducer and activator of transcription 3 (STAT3) phosphorylation and suppressor of cytokine signaling 3 (SOCS3) expression were measured in muscle biopsies. Whole body energy expenditure was measured using indirect calorimetry. In response to the infusion of rhIL-6, circulating levels of IL-6 ( P < 0.001), neutrophils ( P < 0.001), and cortisol ( P < 0.001) increased while lymphocytes decreased ( P < 0.01). However, IL-6 infusion did not change glucose infusion rate, rate of appearance, or rate of disappearance during the clamp. While IL-6 enhanced phosphorylation of STAT3 in skeletal muscle ( P = 0.041), the expression of SOCS3 remained unchanged. Whole body oxygen uptake ( P < 0.01) and expired carbon dioxide ( P < 0.01) increased during rhIL-6 infusion. In summary, although IL-6 induced local and systemic responses, the insulin-stimulated glucose uptake was not affected. While different contributing factors may be involved, our results are in contrast to our hypothesis and previous findings in young, healthy men.

MyD88 plays a key role in LPS-induced Stat3 activation in the hypothalamus

2010 ◽  
Vol 298 (2) ◽  
pp. R403-R410 ◽  
Author(s):  
Yosuke Yamawaki ◽  
Hitomi Kimura ◽  
Toru Hosoi ◽  
Koichiro Ozawa
Keyword(s):  
Time Course ◽  
Molecular Mechanisms ◽  
Intraperitoneal Administration ◽  
Primary Response ◽  
Janus Kinase ◽  
Negative Regulator ◽  
Cytokine Signaling ◽  
Stat3 Phosphorylation ◽  
Socs3 Expression ◽  
Hypothalamic Function

Infection causes the production of proinflammatory cytokines, which act on the central nervous system (CNS) and can result in fever, sleep disorders, depression-like behavior, and even anorexia, although precisely how cytokines regulate the functions of the CNS remain unclear. In the present study, we investigated the regulatory-molecular mechanisms by which cytokines affect hypothalamic function in a state of infection. The intraperitoneal administration of lipopolysaccharide (LPS), a ligand of Toll-like receptor 4 (TLR4), time-dependently (2–24 h) increased signal transducer and activator of transcription 3 (STAT3) phosphorylation in the hypothalamus and liver, which corresponded with anorexia observed within 24 h. Interestingly, the pattern of phosphorylation in response to LPS differed between the hypothalamus and liver. In the hypothalamus, LPS increased STAT3 phosphorylation from 2 h, with a peak at 4 h and a decline thereafter, whereas, in the liver, the peak activation of STAT3 persisted from 2 to 8 h. The time course of the LPS-induced expression of suppressor of cytokine signaling 3 (SOCS3), a STAT3-induced negative regulator of the Janus kinase-STAT pathway, was similar to that of STAT3 phosphorylation. Using mice deficient in myeloid differentiation primary-response protein 88 (MyD88), an adapter protein of TLR4, we found that LPS-induced STAT3 phosphorylation and SOCS3 expression in the hypothalamus and liver were predominantly mediated through MyD88. Moreover, we observed that MyD88-deficient mice were resistant to LPS-induced anorexia. Taken together, our findings reveal a novel mechanism, i.e., MyD88 plays a key role in mediating STAT3 phosphorylation and anorexia in the CNS in a state of infection and inflammation.

Abstract 130: Il-10 Regulates the Immunoregulatory Response in the Regression of Atherosclerosis

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Cathal McCarthy ◽  
Michelle Duffy ◽  
Declan Mooney ◽  
William James ◽  
Desmond J Fitzgerald ◽  
...  
Keyword(s):  
Inflammatory Cytokine ◽  
Immune Cell ◽  
Receptor Expression ◽  
Cytokine Signaling ◽  
Aortic Tissue ◽  
Cholesterol Diet ◽  
Stat3 Phosphorylation ◽  
Anti Inflammatory ◽  
Anti Inflammatory Cytokine ◽  
M2 Phenotype

We have previously shown that dietary administration of conjugated linoleic acid (CLA) induces regression of pre-established atherosclerosis in the apoE -/- mouse, via modification of inflammatory cell function. However, the exact mechanism through which this occurs has not been elucidated. Here we describe a functional role for signaling of the anti-inflammatory cytokine, IL-10, in atherosclerosis regression and investigate the consequence of enhanced IL-10 generation on the immune cell population in vivo . Our initial aim was todelineate the atheroprotective mechanisms modulated by CLA. Transcriptomic analysis of aortic tissue in the CLA-induced regression model identified an enrichment of the IL-10 signaling pathway. Further analysis of the network identified increased IL-10 receptor expression (localized to the macrophage cells) and STAT3 phosphorylation; and increased expression of downstream target genes such as the anti-inflammatory cytokine IL-1Ra (by 3.45 ± 0.83 p<0.05 fold) and suppressor of cytokine signaling (SOCS3) (by 2.24± 0.44 p<0.01 fold). Moreover, there was increased circulating IL-10 serum levels in apoE -/- mice fed a CLA supplemented 1% cholesterol diet compared with apoE -/- mice fed a 1% cholesterol diet alone (41.9 ± 8.9 vs 79.8 pg/ml ± 22.4 p<0.01). Interestingly, both IL-10 production and STAT3 phosphorylation was significantly increased in bone marrow derived macrophages from CLA fed mice. We next employed flow cytometry to delineate the phenotype of single cell suspensions of aortae. CLA supplementation regulated immune cell infiltration of the aorta with increased number of the anti-inflammatory Ly6C lo monocytes evident during regression (29±8 vs 77±14cells/mg aorta p<0.05). In addition, CLA-induced regression was associated with increased polarization towards an anti-inflammatory M2 phenotype, confirmed by an enrichment of M2 genes in the aorta, which occurred as a consequence of increased aortic IL-10 production. In summary CLA mediated induction of IL-10 signaling alters the immunoinflammatory response to atherosclerosis, with increased volume of Ly6C lo monocytes infiltrating the regressing lesions and directed polarization of macrophages towards an M2 phenotype in the plaque microenvironment.

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