RAGE signaling by alveolar macrophages influences tobacco smoke-induced inflammation

2012 ◽  
Vol 302 (11) ◽  
pp. L1192-L1199 ◽  
Author(s):  
Adam B. Robinson ◽  
KacyAnn D. Johnson ◽  
Brock G. Bennion ◽  
Paul R. Reynolds
Keyword(s):  
Alveolar Macrophages ◽  
Intracellular Signaling ◽  
Small Gtpase ◽  
Wild Type ◽  
Surface Receptors ◽  
Ras Activation ◽  
Tnf Α ◽  
Glycation End Products ◽  
Rage Expression

Receptors for advanced glycation end-products (RAGE) are multiligand cell surface receptors of the immunoglobin family expressed by epithelium and macrophages, and expression increases following exposure to cigarette smoke extract (CSE). The present study sought to characterize the proinflammatory contributions of RAGE expressed by alveolar macrophages (AMs) following CSE exposure. Acute exposure of mice to CSE via nasal instillation revealed diminished bronchoalveolar lavage (BAL) cellularity and fewer AMs in RAGE knockout (KO) mice compared with controls. Primary AMs were obtained from BAL, exposed to CSE in vitro, and analyzed. CSE significantly increased RAGE expression by wild-type AMs. Employing ELISAs, wild-type AMs exposed to CSE had increased levels of active Ras, a small GTPase that perpetuates proinflammatory signaling. Conversely, RAGE KO AMs had less Ras activation compared with wild-type AMs after exposure to CSE. In RAGE KO AMs, assessment of p38 MAPK and NF-κB, important intracellular signaling intermediates induced during an inflammatory response, revealed that CSE-induced inflammation may occur in part via RAGE signaling. Lastly, quantitative RT-PCR revealed that the expression of proinflammatory cytokines including TNF-α and IL-1β were detectably decreased in RAGE KO AMs exposed to CSE compared with CSE-exposed wild-type AMs. These results reveal that primary AMs orchestrate CSE-induced inflammation, at least in part, via RAGE-mediated mechanisms.

Impaired functional activity of alveolar macrophages from GM-CSF-deficient mice

2001 ◽  
Vol 281 (5) ◽  
pp. L1210-L1218 ◽  
Author(s):  
Robert Paine ◽  
Susan B. Morris ◽  
Hong Jin ◽  
Steven E. Wilcoxen ◽  
Susan M. Phare ◽  
...  
Keyword(s):  
Host Defense ◽  
Alveolar Macrophages ◽  
Phagocytic Activity ◽  
Wild Type ◽  
Specific Expression ◽  
Gm Csf ◽  
Functional Capabilities ◽  
Tnf Α

We hypothesized that pulmonary granulocyte-macrophage colony-stimulating factor (GM-CSF) is critically involved in determining the functional capabilities of alveolar macrophages (AM) for host defense. To test this hypothesis, cells were collected by lung lavage from GM-CSF mutant mice [GM(−/−)] and C57BL/6 wild-type mice. GM(−/−) mice yielded almost 4-fold more AM than wild-type mice. The percentage of cells positive for the β2-integrins CD11a and CD11c was reduced significantly in GM(−/−) AM compared with wild-type cells, whereas expression of CD11b was similar in the two groups. The phagocytic activity of GM(−/−) AM for FITC-labeled microspheres was impaired significantly compared with that of wild-type AM both in vitro and in vivo (after intratracheal inoculation with FITC-labeled beads). Stimulated secretion of tumor necrosis factor-α (TNF-α) and leukotrienes by AM from the GM(−/−) mice was greatly reduced compared with wild-type AM, whereas secretion of monocyte chemoattractant protein-1 was increased. Transgenic expression of GM-CSF exclusively in the lungs of GM(−/−) mice resulted in AM with normal or supranormal expression of CD11a and CD11c, phagocytic activity, and TNF-α secretion. Thus, in the absence of GM-CSF, AM functional capabilities for host defense were significantly impaired but were restored by lung-specific expression of GM-CSF.

scholarly journals Scavenger Receptor A Dampens Induction of Inflammation in Response to the Fungal Pathogen Pneumocystis carinii

2007 ◽  
Vol 75 (8) ◽  
pp. 3999-4005 ◽  
Author(s):  
Melissa Hollifield ◽  
Elsa Bou Ghanem ◽  
Willem J. S. de Villiers ◽  
Beth A. Garvy
Keyword(s):  
Alveolar Macrophages ◽  
Pneumocystis Carinii ◽  
Scavenger Receptor ◽  
Interleukin 12 ◽  
Wild Type ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Scavenger Receptor A

ABSTRACT Alveolar macrophages are the effector cells largely responsible for clearance of Pneumocystis carinii from the lungs. Binding of organisms to β-glucan and mannose receptors has been shown to stimulate phagocytosis of the organisms. To further define the mechanisms used by alveolar macrophages for clearance of P. carinii, mice deficient in the expression of scavenger receptor A (SRA) were infected with P. carinii, and clearance of organisms was monitored over time. SRA-deficient (SRAKO) mice consistently cleared P. carinii faster than did wild-type control mice. Expedited clearance corresponded to elevated numbers of activated CD4+ T cells in the alveolar spaces of SRAKO mice compared to wild-type mice. Alveolar macrophages from SRAKO mice had increased expression of CD11b on their surfaces, consistent with an activated phenotype. However, they were not more phagocytic than macrophages expressing SRA, as measured by an in vivo phagocytosis assay. SRAKO alveolar macrophages produced significantly more tumor necrosis factor alpha (TNF-α) than wild-type macrophages when stimulated with lipopolysaccharide in vitro but less TNF-α in response to P. carinii in vitro. However, upon in vivo stimulation, SRAKO mice produced significantly more TNF-α, interleukin 12 (IL-12), and IL-18 in response to P. carinii infection than did wild-type mice. Together, these data indicate that SRA controls inflammatory cytokines produced by alveolar macrophages in the context of P. carinii infection.

Role of clathrin-mediated endocytosis of surfactant protein A by alveolar macrophages in intracellular signaling

2009 ◽  
Vol 296 (3) ◽  
pp. L430-L441 ◽  
Author(s):  
Christina Moulakakis ◽  
Cordula Stamme
Keyword(s):  
Alveolar Macrophages ◽  
Intracellular Signaling ◽  
Protein A ◽  
Surfactant Protein ◽  
Kinase Assay ◽  
Coated Vesicle ◽  
Dependent Manner ◽  
Tnf Α

We recently provided evidence that anti-inflammatory macrophage activation, i.e., the inhibition of constitutive and signal-induced NF-κB activity by the pulmonary collectin surfactant protein (SP)-A, critically involves a promoted stabilization of IκB-α, the predominant inhibitor of NF-κB, via posttranscriptional mechanisms comprising the activation of atypical (a)PKCζ. SP-A uptake and degradation by alveolar macrophages (AMφ) occur in a receptor-mediated, clathrin-dependent manner. However, a mutual link between endocytosis of and signaling by SP-A remains elusive. The aim of this study was to investigate whether clathrin-mediated endocytosis (CME) of SP-A by AMφ is a prerequisite for its modulation of the IκB-α/NF-κB pathway. The inhibition of clathrin-coated pit (CCP) formation and clathrin-coated vesicle (CCV) formation/budding abrogates SP-A-mediated IκB-α stabilization and SP-A-mediated inhibition of LPS-induced NF-κB activation in freshly isolated rat AMφ, as determined by Western analysis, fluorescence-activated cell sorting, confocal microscopy, and EMSA. Actin depolymerization and inhibition of CCP formation further abolished SP-A-mediated inhibition of LPS-induced TNF-α release, as determined by ELISA. In addition, SP-A-induced atypical PKCζ activation was abolished by pretreatment of AMφ with CCV inhibitors as determined by in vitro immunocomplex kinase assay. Although CME is classically considered as a means to terminate signaling, our results demonstrate that SP-A uptake via CME by AMφ has to precede the initiation of SP-A signaling.

scholarly journals PSIII-38 Butyric acid and derivatives: In vitro anti-inflammatory effects tested in porcine alveolar macrophages

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 370-370
Author(s):  
Lauren L Kovanda ◽  
Monika Hejna ◽  
Yanhong Liu
Keyword(s):  
Organic Acid ◽  
Butyric Acid ◽  
Sodium Butyrate ◽  
Alveolar Macrophages ◽  
Block Design ◽  
Lps Challenge ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Challenge Group

Abstract The aim of this experiment was to examine the anti-inflammatory effects of butyric acid, sodium butyrate, monobutyrin and tributyrin using porcine alveolar macrophages (PAMs). PAMs were isolated from the bronchial lavage of 6 piglets at 6 weeks of age, and then seeded at 106 cells/mL in 24-well plates. After 24 h incubation, cells were treated with different treatments in a randomized complete block design with 10 replicates. The treatments were in a factorial arrangement with 2 doses of lipopolysaccharide (LPS, 0 or 1 μg/mL) and 5 levels of organic acid (0, 0.5, 1, 2, 4 mM for butyric acid and tributyrin and 0, 1, 2, 4, 8 mM for sodium butyrate and monobutyrin). Supernatants were collected after another 24 h incubation and analyzed for tumor necrosis factor alpha (TNF-α). Cell viability was also tested by the MTT assay. Data were analyzed using the MIXED procedure of SAS. No cytotoxic effect was observed in LPS challenge and each organic acid with the percentage of live cells was more than 76% in comparison to the sham control. Sodium butyrate at 2 and 4 mM dose exhibited (P < 0.01) a stimulatory effect on cell proliferation. LPS challenge remarkably stimulated (P < 0.0001) TNF-α secretion from PAMs. In the non-challenge group, butyric acid, monobutyrin, and tributyrin linearly reduced TNF-α production from PAMs, whereas 2 mM sodium butyrate tended to increase (P = 0.056) TNF-α secretion from PAMs. In the LPS challenge group, all tested organic acid dose-dependently reduced (P < 0.001) TNF-α production from LPS-challenged PAMs, with the strongest inhibiting effect observed at the highest dose. Results indicated that butyric acid and its derivatives that were tested in the current experiment all had strong anti-inflammatory activities in vitro.

scholarly journals LPS-induced expression of CD14 in the TRIF pathway is epigenetically regulated by sulforaphane in porcine pulmonary alveolar macrophages

2016 ◽  
Vol 22 (8) ◽  
pp. 682-695 ◽  
Author(s):  
Qin Yang ◽  
Maren J Pröll ◽  
Dessie Salilew-Wondim ◽  
Rui Zhang ◽  
Dawit Tesfaye ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alveolar Macrophages ◽  
Methylation Status ◽  
Gene Body ◽  
Gene Body Methylation ◽  
Tnf Α ◽  
Pulmonary Alveolar Macrophages ◽  
Cluster Of Differentiation ◽  
Cd14 Gene

Pulmonary alveolar macrophages (AMs) are important in defense against bacterial lung inflammation. Cluster of differentiation 14 (CD14) is involved in recognizing bacterial lipopolysaccharide (LPS) through MyD88-dependent and TRIF pathways of innate immunity. Sulforaphane (SFN) shows anti-inflammatory activity and suppresses DNA methylation. To identify CD14 epigenetic changes by SFN in the LPS-induced TRIF pathway, an AMs model was investigated in vitro. CD14 gene expression was induced by 5 µg/ml LPS at the time point of 12 h and suppressed by 5 µM SFN. After 12 h of LPS stimulation, gene expression was significantly up-regulated, including TRIF, TRAF6, NF-κB, TRAF3, IRF7, TNF-α, IL-1β, IL-6, and IFN-β. LPS-induced TRAM, TRIF, RIPK1, TRAF3, TNF-α, IL-1β and IFN-β were suppressed by 5 µM SFN. Similarly, DNMT3a expression was increased by LPS but significantly down-regulated by 5 µM SFN. It showed positive correlation of CD14 gene body methylation with in LPS-stimulated AMs, and this methylation status was inhibited by SFN. This study suggests that SFN suppresses CD14 activation in bacterial inflammation through epigenetic regulation of CD14 gene body methylation associated with DNMT3a. The results provide insights into SFN-mediated epigenetic down-regulation of CD14 in LPS-induced TRIF pathway inflammation and may lead to new methods for controlling LPS-induced inflammation in pigs.

Geranylgeranyl transferase regulates CXC chemokine formation in alveolar macrophages and neutrophil recruitment in septic lung injury

2013 ◽  
Vol 304 (4) ◽  
pp. L221-L229 ◽  
Author(s):  
Zirak Hasan ◽  
Milladur Rahman ◽  
Karzan Palani ◽  
Ingvar Syk ◽  
Bengt Jeppsson ◽  
...  
Keyword(s):  
Lung Injury ◽  
Alveolar Macrophages ◽  
Neutrophil Infiltration ◽  
Abdominal Sepsis ◽  
Neutrophil Recruitment ◽  
Chemokine Production ◽  
Tnf Α ◽  
Cxc Chemokine ◽  
Geranylgeranyl Transferase

Overwhelming accumulation of neutrophils is a significant component in septic lung damage, although the signaling mechanisms behind neutrophil infiltration in the lung remain elusive. In the present study, we hypothesized that geranylgeranylation might regulate the inflammatory response in abdominal sepsis. Male C57BL/6 mice received the geranylgeranyl transferase inhibitor, GGTI-2133, before cecal ligation and puncture (CLP). Bronchoalveolar lavage fluid and lung tissue were harvested for analysis of neutrophil infiltration, as well as edema and CXC chemokine formation. Blood was collected for analysis of Mac-1 on neutrophils and CD40L on platelets. Gene expression of CXC chemokines, tumor necrosis factor-α (TNF-α), and CCL2 chemokine was determined by quantitative RT-PCR in isolated alveolar macrophages. Administration of GGTI-2133 markedly decreased CLP-induced infiltration of neutrophils, edema, and tissue injury in the lung. CLP triggered clear-cut upregulation of Mac-1 on neutrophils. Inhibition of geranylgeranyl transferase reduced CLP-evoked upregulation of Mac-1 on neutrophils in vivo but had no effect on chemokine-induced expression of Mac-1 on isolated neutrophils in vitro. Notably, GGTI-2133 abolished CLP-induced formation of CXC chemokines, TNF-α, and CCL2 in alveolar macrophages in the lung. Geranylgeranyl transferase inhibition had no effect on sepsis-induced platelet shedding of CD40L. In addition, inhibition of geranylgeranyl transferase markedly decreased CXC chemokine-triggered neutrophil chemotaxis in vitro. Taken together, our findings suggest that geranylgeranyl transferase is an important regulator of CXC chemokine production and neutrophil recruitment in the lung. We conclude that inhibition of geranylgeranyl transferase might be a potent way to attenuate acute lung injury in abdominal sepsis.

ONO-2506 alleviates lipopolysaccharide-induced hippocampal neuroinflammation and apoptosis

2019 ◽  
Author(s):  
Jian-yu Liu ◽  
Wei Fang ◽  
Shi-xia Cai ◽  
Ming-ying Dai ◽  
Bo Yao
Keyword(s):  
S100 Protein ◽  
Brain Cell ◽  
Potential Treatment ◽  
Advanced Glycation ◽  
High Concentration ◽  
Tnf Α ◽  
Glycation End Products ◽  
End Products ◽  
Neurotoxic Effects ◽  
Rage Expression

Abstract Background Sepsis associated encephalopathy has high mortality rate, but there is no targeted therapy to reduce brain damage in septic patients. In our previous study, we found that S100β concentration was higher in patients with SAE. At high concentration, S100β exerts neurotoxic effects through receptor for advanced glycation end products (RAGE). RAGE-activated signalling could induce the inflammatory response. And neuroinflammation is an important mechanism of SAE. So inhibiting S100β expression may be a potential treatment of SAE. ONO-2506 can inhibit the production and release of S100 protein from astrocytes. In this study, we administered ONO-2506 to mice in order to evaluate its effectiveness on neuroinflammation and apoptosis in hippocampus induced by lipopolysaccharides. Results We found administration with lipopolysaccharides increased the levels of S100β, RAGE, IL-β, TNF-α and the TUNEL positive brain cells in hippocampus tissue. The ONO-2506 30mg/kg and 90mg/kg could reduce the levels of neuroinflammation (IL-β and TNF-α), and alleviate the apoptosis in hippocampus. Conclusions ONO-2506 could reduce the neuroinflammation and alleviate brain cell apoptosis in hippocampus of LPS mice models. Moreover, the RAGE expression was inhibited after ONO-2506 treatment.

scholarly journals MGL1 Receptor Plays a Key Role in the Control of T. cruzi Infection by Increasing Macrophage Activation through Modulation of ERK1/2, c-Jun, NF-κB and NLRP3 Pathways

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 108
Author(s):  
Tonathiu Rodriguez ◽  
Thalia Pacheco-Fernández ◽  
Alicia Vázquez-Mendoza ◽  
Oscar Nieto-Yañez ◽  
Imelda Juárez-Avelar ◽  
...  
Keyword(s):  
Immune Responses ◽  
Macrophage Activation ◽  
Cell Activation ◽  
Wild Type ◽  
Mhc Ii ◽  
Adaptive Immune ◽  
Splenic Cell ◽  
Tnf Α ◽  
Cruzi Infection

Macrophage galactose-C type lectin (MGL)1 receptor is involved in the recognition of Trypanosoma cruzi (T. cruzi) parasites and is important for the modulation of the innate and adaptive immune responses. However, the mechanism by which MGL1 promotes resistance to T. cruzi remains unclear. Here, we show that MGL1 knockout macrophages (MGL1−/− Mφ) infected in vitro with T. cruzi were heavily parasitized and showed decreased levels of reactive oxygen species (ROS), nitric oxide (NO), IL-12 and TNF-α compared to wild-type macrophages (WT Mφ). MGL1−/− Mφ stimulated in vitro with T. cruzi antigen (TcAg) showed low expression of TLR-2, TLR-4 and MHC-II, which resulted in deficient splenic cell activation compared with similar co-cultured WT Mφ. Importantly, the activation of p-ERK1/2, p-c-Jun and p-NF-κB p65 were significantly reduced in MGL1−/− Mφ exposed to TcAg. Similarly, procaspase 1, caspase 1 and NLRP3 inflammasome also displayed a reduced expression that was associated with low IL-β production. Our data reveal a previously unappreciated role for MGL1 in Mφ activation through the modulation of ERK1/2, c-Jun, NF-κB and NLRP3 signaling pathways, and to the development of protective innate immunity against experimental T. cruzi infection.

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