Macrophage-specific metalloelastase (MMP-12) truncates and inactivates ELR+ CXC chemokines and generates CCL2, -7, -8, and -13 antagonists: potential role of the macrophage in terminating polymorphonuclear leukocyte influx

Blood ◽  
2008 ◽  
Vol 112 (8) ◽  
pp. 3455-3464 ◽  
Author(s):  
Richard A. Dean ◽  
Jennifer H. Cox ◽  
Caroline L. Bellac ◽  
Alain Doucet ◽  
Amanda E. Starr ◽  
...  

AbstractThrough the activity of macrophage-specific matrix metalloproteinase-12 (MMP-12), we found that macrophages dampen the lipopolysaccharide (LPS)-induced influx of polymorphonuclear leukocytes (PMNs)—thus providing a new mechanism for the termination of PMN recruitment in acute inflammation. MMP-12 specifically cleaves human ELR+ CXC chemokines (CXCL1, -2, -3, -5, and -8) at E-LR, the critical receptor-binding motif or, for CXCL6, carboxyl-terminal to it. Murine (m) MMP-12 also cleaves mCXCL1, -2, and -3 at E-LR. MMP-12-cleaved mCXCL2 (macrophage-inflammatory protein-2 [MIP-2]) and mCXCL3 (dendritic cell inflammatory protein-1 [DCIP-1]) lost chemotactic activity. Furthermore, MMP-12 processed and inactivated monocyte chemotactic proteins CCL2, -7, -8, and -13 at position 4-5 generating CCR antagonists. Indeed, PMNs and macrophages in bronchoalveolar lavage fluid were significantly increased 72 hours after intranasal instillation of LPS in Mmp12−/− mice compared with wild type. Specificity occurred at 2 levels. Macrophage MMP-1 and MMP-9 did not cleave in the ELR motif. Second, unlike human ELR+CXC chemokines, mCXCL5 (LPS-induced CXC chemokine [LIX]) was not inactivated. Rather, mMMP-12 cleavage at Ser4-Val5 activated the chemokine, promoting enhanced PMN early infiltration in wild-type mice compared with Mmp12−/− mice 8 hours after LPS challenge in air pouches. We propose that the macrophage, specifically through MMP-12, assists in orchestrating the regulation of acute inflammatory responses by precise proteolysis of ELR+CXC and CC chemokines.

2003 ◽  
Vol 71 (4) ◽  
pp. 1630-1634 ◽  
Author(s):  
Marc J. Schultz ◽  
Sylvia Knapp ◽  
Sandrine Florquin ◽  
Jennie Pater ◽  
Kiyoshi Takeda ◽  
...  

ABSTRACT Interleukin-18 (IL-18) is a potent cytokine with many different proinflammatory activities. To study the role of IL-18 in the pathogenesis of Pseudomonas pneumonia, IL-18-deficient (IL-18 −/−) and wild-type mice were intranasally inoculated with Pseudomonas aeruginosa. IL-18 deficiency was associated with reduced outgrowth of Pseudomonas in the lungs and diminished dissemination of the infection. In addition, pulmonary inflammation (histopathology) and levels of tumor necrosis factor alpha, IL-6, and macrophage inflammatory protein-2 in lungs and plasma were lower in IL-18 −/− mice. Consistent with results obtained for IL-18 −/− mice, treatment of wild-type mice with a neutralizing IL-18 binding protein-immunoglobulin G Fc fusion construct also attenuated outgrowth of Pseudomonas compared with that for mice treated with a control protein. These results demonstrate that the presence of endogenous IL-18 activity facilitates inflammatory responses in the lung during Pseudomonas pneumonia, concurrently impairing bacterial clearance.


2005 ◽  
Vol 289 (1) ◽  
pp. L144-L152 ◽  
Author(s):  
Cliona M. Stapleton ◽  
Maisa Jaradat ◽  
Darlene Dixon ◽  
Hong Soon Kang ◽  
Seong-Chul Kim ◽  
...  

The retinoid-related orphan receptor α (RORα), a member of the ROR subfamily of nuclear receptors, has been implicated in the control of a number of physiological processes, including the regulation of several immune functions. To study the potential role of RORα in the regulation of innate immune responses in vivo, we analyzed the induction of airway inflammation in response to lipopolysaccharide (LPS) challenge in wild-type and staggerer (RORαsg/sg) mice, a natural mutant strain lacking RORα expression. Examination of hematoxylin and eosin-stained lung sections showed that RORαsg/sg mice displayed a higher degree of LPS-induced inflammation than wild-type mice. Bronchoalveolar lavage (BAL) was performed at 3, 16, and 24 h after LPS exposure to monitor the increase in inflammatory cells and the level of several cytokines/chemokines. The increased susceptibility of RORαsg/sg mice to LPS-induced airway inflammation correlated with a higher number of total cells and neutrophils in BAL fluids from LPS-treated RORαsg/sg mice compared with those from LPS-treated wild-type mice. In addition, IL-1β, IL-6, and macrophage inflammatory protein-2 were appreciably more elevated in BAL fluids from LPS-treated RORαsg/sg mice compared with those from LPS-treated wild-type mice. The enhanced susceptibility of RORαsg/sg mice appeared not to be due to a repression of IκBα expression. Our observations indicate that RORαsg/sg mice are more susceptible to LPS-induced airway inflammation and are in agreement with the hypothesis that RORα functions as a negative regulator of LPS-induced inflammatory responses.


Endocrinology ◽  
2008 ◽  
Vol 149 (8) ◽  
pp. 4080-4085 ◽  
Author(s):  
Maria Pini ◽  
Melissa E. Gove ◽  
Joseph A. Sennello ◽  
Jantine W. P. M. van Baal ◽  
Lawrence Chan ◽  
...  

Adipokines, cytokines mainly produced by adipocytes, are active participants in the regulation of inflammation. Administration of zymosan (ZY) was used to investigate the regulation and role of adipokines during peritonitis in mice. Injection of ZY led to a significant increase in leptin levels in both serum and peritoneal lavage fluid, whereas a differential trend in local vs. systemic levels was observed for both resistin and adiponectin. The role of leptin in ZY-induced peritonitis was investigated using leptin-deficient ob/ob mice, with and without reconstitution with exogenous leptin. Leptin deficiency was associated with delayed resolution of peritoneal inflammation induced by ZY, because ob/ob mice had a more pronounced cellular infiltrate in the peritoneum as well as higher and prolonged local and systemic levels of IL-6, TNFα, IL-10, and chemokine (C-X-C motif) ligand 2 compared with wild-type mice. Reconstitution with exogenous leptin exacerbated the inflammatory infiltrate and systemic IL-6 levels in ob/ob mice while inhibiting production of TNFα, IL-10, and chemokine (C-X-C motif) ligand 2. In contrast with the important role of leptin in regulating each aspect of ZY-induced peritonitis, adiponectin deficiency was associated only with a decreased inflammatory infiltrate, without affecting cytokine levels. These findings point to a complex role for adipokines in ZY-induced peritonitis and further emphasize the interplay between obesity and inflammation.


2006 ◽  
Vol 130 (4) ◽  
pp. 440-446
Author(s):  
Jaime Chavez ◽  
Hays W. J. Young ◽  
David B. Corry ◽  
Michael W. Lieberman

Abstract Context.—During an asthmatic episode, leukotriene C4 (LTC4) and interleukin 13 (IL-13) are released into the airways and are thought to be central mediators of the asthmatic response. However, little is known about how these molecules interact or affect each other's signaling pathway. Objective.—To determine if the LTC4 and IL-13 signaling pathways interact with each other's pathways. Design.—We examined airway responsiveness, cysteinyl LTs (Cys-LTs), and Cys-LT and IL-13 receptor transcript levels in wild-type mice and in mice that were deficient in γ-glutamyl leukotrienase (an enzyme that converts LTC4 to LTD4), STAT6 (signal transducer and activator of transcription 6 [a critical molecule in IL-13 signaling]), and IL-4Rα (a subunit of the IL-13 receptor). Results.—Wild-type (C57BL/129SvEv) and γ-glutamyl leukotrienase–deficient mice showed increased airway responsiveness after intranasal instillation of IL-13; similar results were observed after intranasal instillation of IL-13 or LTC4 in a second wild-type strain (BALB/c). Interleukin 13 treatment reduced levels of Cys-LTs in bronchoalveolar lavage fluid. This change was unaccompanied by changes in other arachidonic acid metabolites or in RNA transcript levels of enzymes associated with Cys-LT synthesis. Interleukin 13 treatment also increased transcript levels of the Cys-LT 1 and Cys-LT 2 receptors, while LTC4 increased transcript levels of the α1 chain of the IL-13 receptor. Furthermore, IL-4Rα–deficient mice had increased airway responsiveness to LTC4 but not to IL-13, whereas STAT6-deficient mice failed to respond to either agonist. Conclusions.—These findings indicate that LTC4 and IL-13 are dependent on or signal through STAT6 to increase airway responsiveness and that both agonists regulate expression of each other's receptors.


2012 ◽  
Vol 113 (9) ◽  
pp. 1476-1485 ◽  
Author(s):  
Ming Zhu ◽  
Alison S. Williams ◽  
Lucas Chen ◽  
Allison P. Wurmbrand ◽  
Erin S. Williams ◽  
...  

The purpose of this study was to examine the role of tumor necrosis factor receptor 1 (TNFR1) in the airway hyperresponsiveness characteristic of obese mice. Airway responsiveness to intravenous methacholine was measured using the forced oscillation technique in obese Cpe fat mice that were either sufficient or genetically deficient in TNFR1 ( Cpe fat and Cpe fat/TNFR1−/− mice) and in lean mice that were either sufficient or genetically deficient in TNFR1 [wild-type (WT) and TNFR1−/− mice]. Compared with lean WT mice, Cpe fat mice exhibited airway hyperresponsiveness. Airway hyperresponsives was also greater in Cpe fat/TNFR1−/− than in Cpe fat mice. Compared with WT mice, Cpe fat mice had increases in bronchoalveolar lavage fluid concentrations of several inflammatory moieties including eotaxin, IL-9, IP-10, KC, MIG, and VEGF. These factors were also significantly elevated in Cpe fat/TNFR1−/− vs. TNFR1−/− mice. Additional moieties including IL-13 were also elevated in Cpe fat/TNFR1−/− vs. TNFR1−/− mice but not in Cpe fat vs. WT mice. IL-17A mRNA expression was greater in Cpe fat/TNFR1−/− vs. Cpe fat mice and in TNFR1−/− vs. WT mice. Analysis of serum indicated that obesity resulted in systemic as well as pulmonary inflammation, but TNFR1 deficiency had little effect on this systemic inflammation. Our results indicate that TNFR1 is protective against the airway hyperresponsiveness associated with obesity and suggest that effects on pulmonary inflammation may be contributing to this protection.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Taeyeop Park ◽  
Huazhen Chen ◽  
Hee-Yong Kim

Abstract Background Neuroinflammation is a widely accepted underlying condition for various pathological processes in the brain. In a recent study, synaptamide, an endogenous metabolite derived from docosahexaenoic acid (DHA, 22:6n-3), was identified as a specific ligand to orphan adhesion G-protein-coupled receptor 110 (GPR110, ADGRF1). Synaptamide has been shown to suppress lipopolysaccharide (LPS)-induced neuroinflammation in mice, but involvement of GPR110 in this process has not been established. In this study, we investigated the possible immune regulatory role of GPR110 in mediating the anti-neuroinflammatory effects of synaptamide under a systemic inflammatory condition. Methods For in vitro studies, we assessed the role of GPR110 in synaptamide effects on LPS-induced inflammatory responses in adult primary mouse microglia, immortalized murine microglial cells (BV2), primary neutrophil, and peritoneal macrophage by using quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA) as well as neutrophil migration and ROS production assays. To evaluate in vivo effects, wild-type (WT) and GPR110 knock-out (KO) mice were injected with LPS intraperitoneally (i.p.) or TNF intravenously (i.v.) followed by synaptamide (i.p.), and expression of proinflammatory mediators was measured by qPCR, ELISA, and western blot analysis. Activated microglia in the brain and NF-kB activation in cells were examined microscopically after immunostaining for Iba-1 and RelA, respectively. Results Intraperitoneal (i.p.) administration of LPS increased TNF and IL-1β in the blood and induced pro-inflammatory cytokine expression in the brain. Subsequent i.p. injection of the GPR110 ligand synaptamide significantly reduced LPS-induced inflammatory responses in wild-type (WT) but not in GPR110 knock-out (KO) mice. In cultured microglia, synaptamide increased cAMP and inhibited LPS-induced proinflammatory cytokine expression by inhibiting the translocation of NF-κB subunit RelA into the nucleus. These effects were abolished by blocking synaptamide binding to GPR110 using an N-terminal targeting antibody. GPR110 expression was found to be high in neutrophils and macrophages where synaptamide also caused a GPR110-dependent increase in cAMP and inhibition of LPS-induced pro-inflammatory mediator expression. Intravenous injection of TNF, a pro-inflammatory cytokine that increases in the circulation after LPS treatment, elicited inflammatory responses in the brain which were dampened by the subsequent injection (i.p.) of synaptamide in a GPR110-dependent manner. Conclusion Our study demonstrates the immune-regulatory function of GPR110 in both brain and periphery, collectively contributing to the anti-neuroinflammatory effects of synaptamide under a systemic inflammatory condition. We suggest GPR110 activation as a novel therapeutic strategy to ameliorate inflammation in the brain as well as periphery.


2005 ◽  
Vol 288 (2) ◽  
pp. L390-L397 ◽  
Author(s):  
Richard A. Johnston ◽  
Igor N. Schwartzman ◽  
Lesley Flynt ◽  
Stephanie A. Shore

This study sought to examine the role of interleukin-6 (IL-6) in ozone (O3)-induced airway injury, inflammation, and hyperresponsiveness (AHR). Subacute (72 h) exposure to 0.3 ppm O3significantly elevated bronchoalveolar lavage fluid (BALF) protein, neutrophils, and soluble TNF receptors (sTNFR1 and sTNFR2) in wild-type C57BL/6 (IL-6+/+) mice; however, all four outcome indicators were significantly reduced in IL-6-deficient (IL-6−/−) compared with IL-6+/+mice. Acute O3exposure (2 ppm for 3 h) increased BALF protein, KC, macrophage inflammatory protein(MIP)-2, eotaxin, sTNFR1, and sTNFR2 in IL-6+/+mice. However, MIP-2 and sTNFR2 were not significantly increased following O3exposure in IL-6−/−mice. Increases in BALF neutrophils induced by O3(2 ppm for 3 h) were also significantly reduced in IL-6−/−vs. IL-6+/+mice. Airway responsiveness to methacholine was measured by whole body plethysmography before and following acute (3 h) or subacute (72 h) exposure to 0.3 ppm O3. Acute O3exposure caused AHR in both groups of mice, but there was no genotype-related difference in the magnitude of O3-induced AHR. AHR was absent in mice of either genotype exposed for 72 h. Our results indicate that IL-6 deficiency reduces airway neutrophilia, as well as the levels of BALF sTNFR1 and sTNFR2 following acute high dose and/or subacute low-dose O3exposure, but has no effect on O3-induced AHR.


2014 ◽  
Vol 307 (3) ◽  
pp. G338-G346 ◽  
Author(s):  
Courtney C. Kurtz ◽  
Ioannis Drygiannakis ◽  
Makoto Naganuma ◽  
Sanford Feldman ◽  
Vasileios Bekiaris ◽  
...  

Adenosine is a purine metabolite that can mediate anti-inflammatory responses in the digestive tract through the A2A adenosine receptor (A2AAR). We examined the role of this receptor in the control of inflammation in the adoptive transfer model of colitis. Infection of A2AAR−/− mice with Helicobacter hepaticus increased colonic inflammation scores compared with uninfected A2AAR controls. Comparison of T cell subsets in wild-type and A2AAR−/− mice revealed differences in markers associated with activated helper T (Th) cells and regulatory T (Treg) cells. Previous studies showed that expression of A2AAR on CD45RBHI and CD45RBLO Th cells is essential for the proper regulation of colonic inflammation. Adoptive transfer of CD45RBHI with CD45RBLO from wild-type mice into RAG1−/−/A2AAR−/− mice induced severe disease within 3 wk, although transfer of the same subsets into RAG1−/− mice does not induce colitis. This suggests that the presence of A2AAR on recipient cells is also important for controlling colitis. To investigate the role of A2AAR in myeloid cells, chimeric recipients were generated by injection of bone marrow from RAG1−/− or RAG1−/−/A2AAR−/− mice into irradiated RAG1−/− mice. After adoptive transfer, these recipients did not develop colitis, regardless of A2AAR expression by the donor. Together, our results suggest that the control of inflammation in vivo is dependent on A2AAR signaling through multiple cell types that collaborate in the regulation of colitis by responding to extracellular adenosine.


2008 ◽  
Vol 77 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Hemanth Ramaprakash ◽  
Toshihiro Ito ◽  
Theodore J. Standiford ◽  
Steven L. Kunkel ◽  
Cory M. Hogaboam

ABSTRACT The role of Toll-like receptor 9 (TLR9) in antifungal responses in the immunodeficient and allergic host is unclear. We investigated the role of TLR9 in murine models of invasive aspergillosis and fungal asthma. Neutrophil-depleted TLR9 wild-type (TLR9+/+) and TLR9-deficient (TLR9−/−) mice were challenged with resting or swollen Aspergillus fumigatus conidia and monitored for survival and lung inflammatory responses. The absence of TLR9 delayed, but did not prevent, mortality in immunodeficient mice challenged with resting or swollen conidia compared to TLR9+/+ mice. In a fungal asthma model, TLR9+/+ and TLR9−/− mice were sensitized to soluble A. fumigatus antigens and challenged with resting or swollen A. fumigatus conidia, and both groups of mice were analyzed prior to and at days 7, 14, and 28 after the conidium challenge. When challenged with resting conidia, TLR9−/− mice exhibited significantly lower airway hyper-responsiveness compared to the TLR9+/+ groups. In contrast, A. fumigatus-sensitized TLR9−/− mice exhibited pulmonary fungal growth at days 14 and 28 after challenge with swollen conidia, a finding never observed in their allergic wild-type counterparts. Increased fungal growth in allergic TLR9−/− mice correlated with markedly decreased dectin-1 expression in whole lung samples and isolated dendritic cell populations. Further, whole lung levels of interleukin-17 were lower in allergic TLR9−/− mice compared to similar TLR9+/+ mice. Together, these data suggest that TLR9 modulates pulmonary antifungal immune responses to swollen conidia, possibly through the regulation of dectin-1 expression.


2001 ◽  
Vol 69 (10) ◽  
pp. 5991-5996 ◽  
Author(s):  
M. Audrey Koay ◽  
John W. Christman ◽  
Brahm H. Segal ◽  
Annapurna Venkatakrishnan ◽  
Thomas R. Blackwell ◽  
...  

ABSTRACT Reactive oxygen species (ROS) are thought to be involved in intracellular signaling, including activation of the transcription factor NF-κB. We investigated the role of NADPH oxidase in the NF-κB activation pathway by utilizing knockout mice (p47phox−/−) lacking the p47phox component of NADPH oxidase. Wild-type (WT) controls and p47phox−/−mice were treated with intraperitoneal (i.p.) Escherichia coli lipopolysaccharide (LPS) (5 or 20 μg/g of body weight). LPS-induced NF-κB binding activity and accumulation of RelA in nuclear protein extracts of lung tissue were markedly increased in WT compared to p47phox−/− mice 90 min after treatment with 20 but not 5 μg of i.p. LPS per g. In another model of lung inflammation, RelA nuclear translocation was reduced in p47phox−/− mice compared to WT mice following treatment with aerosolized LPS. In contrast to NF-κB activation in p47phox−/− mice, LPS-induced production of macrophage inflammatory protein 2 in the lungs and neutrophilic lung inflammation were not diminished in these mice compared to WT mice. We conclude that LPS-induced NF-κB activation is deficient in the lungs of p47phox−/− mice compared to WT mice, but this abnormality does not result in overt alteration in the acute inflammatory response.


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