scholarly journals Amorphous Silica Nanoparticles Obtained by Laser Ablation Induce Inflammatory Response in Human Lung Fibroblasts

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1026 ◽  
Author(s):  
Sorina Voicu ◽  
Mihaela Balas ◽  
Miruna Stan ◽  
Bogdan Trică ◽  
Andreea Serban ◽  
...  

Silica nanoparticles (SiO2 NPs) represent environmentally born nanomaterials that are used in multiple biomedical applications. Our aim was to study the amorphous SiO2 NP-induced inflammatory response in MRC-5 human lung fibroblasts up to 72 hours of exposure. The intracellular distribution of SiO2 NPs was measured by transmission electron microscopy (TEM). The lactate dehydrogenase (LDH) test was used for cellular viability evaluation. We have also investigated the lysosomes formation, protein expression of interleukins (IL-1β, IL-2, IL-6, IL-8, and IL-18), COX-2, Nrf2, TNF-α, and nitric oxide (NO) production. Our results showed that the level of lysosomes increased in time after exposure to the SiO2 NPs. The expressions of interleukins and COX-2 were upregulated, whereas the expressions and activities of MMP-2 and MMP-9 decreased in a time-dependent manner. Our findings demonstrated that the exposure of MRC-5 cells to 62.5 µg/mL of SiO2 NPs induced an inflammatory response.

2016 ◽  
Vol 311 (5) ◽  
pp. L855-L867 ◽  
Author(s):  
Shannon H. Lacy ◽  
Collynn F. Woeller ◽  
Thomas H. Thatcher ◽  
Krishna Rao Maddipati ◽  
Kenneth V. Honn ◽  
...  

Human lung fibroblasts (HLFs) act as innate immune sentinel cells that amplify the inflammatory response to injurious stimuli. Here, we use targeted lipidomics to explore the hypothesis that HLFs also play an active role in the resolution of inflammation. We detected cyclooxygenase-2 (COX-2)-dependent production of both proinflammatory and proresolving prostaglandins (PGs) in conditioned culture medium from HLFs treated with a proinflammatory stimulus, IL-1β. Among the proresolving PGs in the HLF lipidome were several known ligands for peroxisome proliferator-activated receptor-γ (PPARγ), a transcription factor whose activation in the lung yields potent anti-inflammatory, antifibrotic, and proresolving effects. Next, we used a cell-based luciferase reporter to confirm the ability of HLF supernatants to activate PPARγ, demonstrating, for the first time, that primary HLFs activated with proinflammatory IL-1β or cigarette smoke extract produce functional PPARγ ligands; this phenomenon is temporally regulated, COX-2- and lipocalin-type PGD synthase-dependent, and enhanced by arachidonic acid supplementation. Finally, we used luciferase reporter assays to show that several of the PGs in the lipidome of activated HLFs independently activate PPARγ and/or inhibit NFκB. These results indicate that HLFs, as immune sentinels, regulate both proinflammatory and proresolving responses to injurious stimuli. This novel endogenous resolution pathway represents a new therapeutic target for globally important inflammatory diseases such as chronic obstructive pulmonary disease.


Author(s):  
Arnab Datta ◽  
Chris J. Scotton ◽  
Alejandro Ortiz-Stern ◽  
Robin J. McAnulty ◽  
Rachel C. Chambers

2012 ◽  
Vol 47 (5) ◽  
pp. 614-627 ◽  
Author(s):  
Malgorzata Wygrecka ◽  
Dariusz Zakrzewicz ◽  
Brigitte Taborski ◽  
Miroslava Didiasova ◽  
Grazyna Kwapiszewska ◽  
...  

2013 ◽  
Vol 304 (11) ◽  
pp. L774-L781 ◽  
Author(s):  
David H. McMillan ◽  
Collynn F. Woeller ◽  
Thomas H. Thatcher ◽  
Sherry L. Spinelli ◽  
Sanjay B. Maggirwar ◽  
...  

Lung inflammation can result from exposure to multiple types of inflammatory stimuli. Fibroblasts, key structural cells in the lung that are integral to inflammation and wound healing, produce inflammatory mediators after exposure to stimuli such as IL-1β. We and others have shown that the NF-κB member RelB has anti-inflammatory properties in mice. Little is known, however, about the anti-inflammatory role of RelB in human cells and how it functions. MicroRNAs (miRNAs), a novel class of small, noncoding RNAs, can mediate inflammatory signaling pathways, including NF-κB, through regulation of target gene expression. Our goal was to analyze the anti-inflammatory properties of RelB in human lung fibroblasts. We hypothesized that RelB regulates inflammatory mediator production in lung fibroblasts in part through a mechanism involving miRNAs. To accomplish this, we transfected human lung fibroblasts with a plasmid encoding RelB and small interfering (si)RNA targeting RelB mRNA to overexpress and downregulate RelB, respectively. IL-1β, a powerful proinflammatory stimulus, was used to induce NF-κB-driven inflammatory responses. RelB overexpression reduced IL-1β-induced cyclooxygenase (Cox)-2, PGE2, and cytokine production, and RelB downregulation increased Cox-2 expression and PGE2 production. Furthermore, RelB overexpression increased IL-1β-induced expression of miRNA-146a, an NF-κB-dependent miRNA with anti-inflammatory properties, whereas RelB downregulation reduced miRNA-146a. miR-146a overexpression ablated the effects of RelB downregulation on IL-1β-induced Cox-2, PGE2, and IL-6 production, suggesting that RelB mediates IL-1β-induced inflammatory mediator production in lung fibroblasts through miRNA-146a. RelB and miRNA-146a may therefore be new therapeutic targets in the treatment of lung inflammation caused by various agents and conditions.


1996 ◽  
Vol 184 (1) ◽  
pp. 191-201 ◽  
Author(s):  
M Roth ◽  
M Nauck ◽  
S Yousefi ◽  
M Tamm ◽  
K Blaser ◽  
...  

Platelet-activating factor (PAF) is a potent proinflammatory phospholipid mediator of the lung. In this study, we demonstrate that PAF receptor mRNA and protein is expressed by human lung fibroblasts. Interaction of PAF with its specific receptor resulted in increases of tyrosine phosphorylation of several intracellular proteins, indicating that the PAF-receptor might be functionally active. PAF-induced transcription of protooncogenes c-fos and c-jun as well as of interleukin (IL)-6 and IL-8 genes in human fibroblasts. Transcription of the interleukins was followed by secretion of the respective proteins. Moreover, PAF enhanced proliferation of fibroblasts in a concentration-dependent manner. Using signaling inhibitors, we demonstrate that PAF-induced transcription of the c-fos, IL-6, and IL-8 genes, as well as proliferation, require activation of pertussis toxin-sensitive G proteins, tyrosine kinases, and protein kinase C (PKC). In contrast, transcription of c-jun was blocked by pertussis toxin, but not by inhibitors for tyrosine kinases or PKC. These data suggest that PAF stimulates distinct signaling pathways in human lung fibroblasts. In addition, the activation of human fibroblasts by PAF leads to enhanced proliferation and to the expression of proinflammatory cytokines, which may contribute to the pathophysiological changes in pulmonary inflammation.


2000 ◽  
Vol 9 (3-4) ◽  
pp. 155-160 ◽  
Author(s):  
Masahiro Sasaki ◽  
Masayuki Kashima ◽  
Takefumi Ito ◽  
Akiko Watanabe ◽  
Noriko Izumiyama ◽  
...  

Fibroblast migration, proliferation, extracellular matrix protein synthesis and degradation,all of which play important roles in inflammation, are them selves induced by various growth factors and cytokines. Less is known about the interaction of these substances on lung fibroblast function in pulmonary fibrosis.The goal of this study was to investigate the effects of PDGF alone and in combination with IL–1β and TNF–α on the production of human lung fibroblast matrix metalloproteinases, proliferation, and the chemotactic response. The assay for MMPs activity against FITC labeled type I and IV collagen was based on the specificity of the enzyme cleavage of collagen. Caseinolytis and gelatinolytic activities of secreted proteinases were analyzed by zymography. Fibronectin in conditioned media was measured using human lung fibronectin enzyme immunoassay. Cell proliferation was measured by 3H-Thymidine incorporation assay. Cell culture supernatants were tested for PGE2 content by ELISA. Chemotactic activity was measured using the modified Boyden chamber.Matrix metalloproteinase assay indicated that IL–1β, TNF–α and PDGF induced intestitial collagenase (MMP-1) production. MMP assay also indicated that IL–1β and TNF–α had inhibitory effects on MMP-2,9(gelatinaseA,B) production. Casein zymography confirmed that IL–1β stimulated stromlysin (matrix metalloproteinase 3; MMP–3) and gelatin zymography demonstrated that TNF–α induced MMP–9 production in human lung fibroblast, whereas PDGF alone did not. PDGF in combination with IL–1β and TNF–α induced MMP–3 and MMP–9 activity, as demonstrated by zymography. PDGF stimulated lung fibroblast proliferation in a concentration-dependent manner, whereas IL–1β and TNF–α alone had no effect. In contrast, the proliferation of human lung fibroblasts by PDGF was inhibited in the presence of IL–1β and TNF–α, and this inhibition was not a consequence of any elevation of PGE2. PDGF stimulated fibroblast chemotaxis in a concentrationdependent manner, and this stimulation was augmented by combining PDGF with IL–1β and TNF–α.These findings suggested that PDGF differentially regulated MMPs production in combination with cytokines, and further that MMP assay and zymography had differential sensitivity for detecting MMPs. The presence of cytokines with PDGF appears to modulate the proliferation and chemotaxis of human lung fibroblasts.


2008 ◽  
Vol 294 (6) ◽  
pp. L1226-L1232 ◽  
Author(s):  
Koichiro Kamio ◽  
Tadashi Sato ◽  
Xiangde Liu ◽  
Hisatoshi Sugiura ◽  
Shinsaku Togo ◽  
...  

Prostacyclin is a short-lived metabolite of arachidonic acid that is produced by several cells in the lung and prominently by endothelial cells. It increases intracellular cAMP levels activating downstream signaling thus regulating vascular mesenchymal cell functions. The alveolar wall contains a rich capillary network as well as a population of mesenchymal cells, i.e., fibroblasts. The current study evaluated the hypothesis that prostacyclin may mediate signaling between endothelial and mesenchymal cells in the alveolar wall by assessing the ability of prostacyclin analogs to modulate fibroblast release of VEGF. To accomplish this study, human lung fibroblasts were cultured in routine culture on plastic support and in three-dimensional collagen gels with or without three prostacyclin analogs, carbaprostacyclin, iloprost, and beraprost, and the production of VEGF was evaluated by ELISA and quantitative real-time PCR. Iloprost and beraprost significantly stimulated VEGF mRNA levels and protein release in a concentration-dependent manner. These effects were blocked by the adenylate cyclase inhibitor SQ-22536 and by the protein kinase A (PKA) inhibitor KT-5720 and were reproduced by a direct PKA activator but not by an activator of exchange protein directly activated by cAMP (Epac), indicating that cAMP-activated PKA signaling mediated the effect. Since VEGF serves to maintain the pulmonary microvasculature, the current study suggests that prostacyclin is part of a bidirectional signaling network between the mesenchymal and vascular cells of the alveolar wall. Prostacyclin analogs, therefore, have the potential to modulate the maintenance of the pulmonary microcirculation by driving the production of VEGF from lung fibroblasts.


2009 ◽  
Vol 8 (1) ◽  
pp. 129-143 ◽  
Author(s):  
P.K. Mishra ◽  
A. Bhargava ◽  
G.V. Raghuram ◽  
S. Gupta ◽  
S. Tiwari ◽  
...  

2004 ◽  
Vol 287 (5) ◽  
pp. L981-L991 ◽  
Author(s):  
Christine A. Martey ◽  
Stephen J. Pollock ◽  
Chantal K. Turner ◽  
Katherine M. A. O'Reilly ◽  
Carolyn J. Baglole ◽  
...  

Cigarette smoking can lead to many human pathologies including cardiovascular and respiratory disease. Recent studies have defined a role for fibroblasts in the development of colon cancer. Moreover, fibroblasts are now thought of as key “sentinel” cells that initiate inflammation by releasing proinflammatory mediators including prostaglandins (PGs). Pathological overexpression of cyclooxygenase-2 (COX-2) and excess eicosanoid production are found in the early stages of carcinogenesis. By promoting chronic inflammation, COX-2 and eicosanoid production may actually cause a predisposition to malignancy. Furthermore, the associated inflammation induced by production of these mediators is central to the pathogenesis of chronic obstructive pulmonary disease. Little is known of the responses of normal lung fibroblasts to cigarette smoke, despite their abundance. We report herein that normal human lung fibroblasts, when exposed to cigarette smoke extract, induce COX-2 with concurrent synthesis of prostaglandin E2 (PGE2). The mechanisms by which cigarette-derived toxicants lead to increased COX-2 levels and PGE2 synthesis include increases in steady-state COX-2 mRNA levels (approximately four- to fivefold), phosphorylation of ERK1/2, and nuclear translocation of the p50 and p65 subunits of the transcription factor NF-κB, which are important elements in COX-2 expression. Furthermore, there was a dramatic 25-fold increase in microsomal prostaglandin E synthase, the key enzyme involved in the production of PGE2. We propose that normal human lung fibroblasts, when exposed to cigarette smoke constituents, elicit COX-2 expression with consequent prostaglandin synthesis, thus creating a proinflammatory environment. This chronic inflammatory state may act as one of the first steps towards epithelial transformation.


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