Prostacyclin analogs stimulate VEGF production from human lung fibroblasts in culture

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.

1993 ◽  
Vol 264 (3) ◽  
pp. L253-L260 ◽  
Author(s):  
R. J. Zitnik ◽  
T. Zheng ◽  
J. A. Elias

We characterized the effects of agents that alter intracellular adenosine 3',5'-cyclic monophosphate (cAMP) on the interleukin (IL)-6 production of human lung fibroblasts. Unstimulated fibroblasts did not produce significant amounts of IL-6. Recombinant (r) tumor necrosis factor (TNF) weakly stimulated, recombinant interleukin-1-alpha (rIL-1 alpha) strongly stimulated, and rIL-1 alpha and rTNF in combination synergistically augmented fibroblast IL-6 production. Prostaglandin (PG)E1, forskolin, dibutyryl cAMP (DBcAMP), 3-isobutyl-1-methylxanthine (IBMX), and cholera toxin did not cause a detectable alteration in the IL-6 production of unstimulated fibroblasts. However, these agents inhibited the IL-6 production of rIL-1 and rIL-1 plus rTNF-stimulated cells. These effects were dose dependent with a concentration of 2 x 10(-9) M PGE1, 5 x 10(-6) M forskolin, 5 x 10(-4) M DBcAMP, and 1 x 10(-3) M IBMX decreasing rIL-1 alpha (2.5 ng/ml)-induced IL-6 production by approximately 50%. The inhibitory effects of these agents, correlated with their ability to induce fibroblast cAMP accumulation, could not be explained by alterations in cell number or viability and were appreciable even when cAMP modifiers were added to fibroblast culture, 1 h after rIL-1. They were also at least partly specific for rIL-1, since these agents increased the IL-6 production of rTNF-stimulated cells. These cAMP-induced alterations in IL-6 production were associated with corresponding alterations in IL-6 mRNA accumulation. Nuclear run-on analysis demonstrated that the inhibitory effects of PGE1 were associated with a comparable decrease in IL-6 transcription. Agents that increase the levels of intracellular cAMP inhibit rIL-1-induced IL-6 by human lung fibroblasts.


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 ◽  
...  

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.


2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Maria A Navarro Olmo ◽  
Dong Xu ◽  
Mo Rezaiekhaligh ◽  
Sherry Mabry ◽  
Ricardo E Perez ◽  
...  

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.


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.


1998 ◽  
Vol 275 (2) ◽  
pp. L223-L230 ◽  
Author(s):  
Sekiya Koyama ◽  
Etsuro Sato ◽  
Tsuyoshi Masubuchi ◽  
Akemi Takamizawa ◽  
Hiroshi Nomura ◽  
...  

We determined whether human lung fibroblasts (HLFs) might release mediators that are responsible for monocyte chemokinetic activity (MCA) constitutively. HLF supernatant fluids showed MCA in a time-dependent manner ( P < 0.001). Checkerboard analysis of 24- and 72-h supernatant fluids showed that the activity was chemokinetic. Partial characterization of 24- and 72-h supernatant fluids revealed that the mediators released after 24 h were predominantly composed of lipid-soluble activity, and MCA was blocked by lipoxygenase inhibitors. The mediators released after 72 h were predominantly trypsin sensitive and blocked by cycloheximide. Molecular-sieve column chromatography identified four peaks of MCA. A polyclonal antibody to monocyte chemoattractant protein-1 (MCP-1) inhibited MCA by 20% after 24 h and by 40% after 72 h. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor-β (TGF-β) antibodies attenuated MCA released after 72 h by 30 and 10%, respectively. These antibodies inhibited corresponding molecular-weight peaks separated by molecular-sieve column. The concentrations of MCP-1, GM-CSF, and TGF-β were 4,698 ± 242, 26.8 ± 3.8, and 550 ± 15 pg/ml, respectively. A leukotriene B4(LTB4)-receptor antagonist attenuated the total MCA and the lowest molecular weight peak of MCA. The concentrations of LTB4were 153.4 ± 12.4 (24 h) and 212 ± 16.6 (72 h) pg/ml. These findings suggest that HLFs may modulate the recruitment of monocytes into the lung by releasing MCP-1, GM-CSF, TGF-β, and LTB4constitutively.


2015 ◽  
Vol 309 (11) ◽  
pp. L1305-L1312 ◽  
Author(s):  
Robert Matthew Kottmann ◽  
Emma Trawick ◽  
Jennifer L. Judge ◽  
Lindsay A. Wahl ◽  
Amali P. Epa ◽  
...  

Myofibroblasts are one of the primary cell types responsible for the accumulation of extracellular matrix in fibrosing diseases, and targeting myofibroblast differentiation is an important therapeutic strategy for the treatment of pulmonary fibrosis. Transforming growth factor-β (TGF-β) has been shown to be an important inducer of myofibroblast differentiation. We previously demonstrated that lactate dehydrogenase and its metabolic product lactic acid are important mediators of myofibroblast differentiation, via acid-induced activation of latent TGF-β. Here we explore whether pharmacologic inhibition of LDH activity can prevent TGF-β-induced myofibroblast differentiation. Primary human lung fibroblasts from healthy patients and those with pulmonary fibrosis were treated with TGF-β and or gossypol, an LDH inhibitor. Protein and RNA were analyzed for markers of myofibroblast differentiation and extracellular matrix generation. Gossypol inhibited TGF-β-induced expression of the myofibroblast marker α-smooth muscle actin (α-SMA) in a dose-dependent manner in both healthy and fibrotic human lung fibroblasts. Gossypol also inhibited expression of collagen 1, collagen 3, and fibronectin. Gossypol inhibited LDH activity, the generation of extracellular lactic acid, and the rate of extracellular acidification in a dose-dependent manner. Furthermore, gossypol inhibited TGF-β bioactivity in a dose-dependent manner. Concurrent treatment with an LDH siRNA increased the ability of gossypol to inhibit TGF-β-induced myofibroblast differentiation. Gossypol inhibits TGF-β-induced myofibroblast differentiation through inhibition of LDH, inhibition of extracellular accumulation of lactic acid, and inhibition of TGF-β bioactivity. These data support the hypothesis that pharmacologic inhibition of LDH may play an important role in the treatment of pulmonary fibrosis.


2020 ◽  
Vol 21 (11) ◽  
pp. 4008 ◽  
Author(s):  
Katarzyna Wójcik-Pszczoła ◽  
Grażyna Chłoń-Rzepa ◽  
Agnieszka Jankowska ◽  
Marietta Ślusarczyk ◽  
Paweł E Ferdek ◽  
...  

Phosphodiesterase (PDE) inhibitors are currently a widespread and extensively studied group of anti-inflammatory and anti-fibrotic compounds which may find use in the treatment of numerous lung diseases, including asthma and chronic obstructive pulmonary disease. Several PDE inhibitors are currently in clinical development, and some of them, e.g., roflumilast, are already recommended for clinical use. Due to numerous reports indicating that elevated intracellular cAMP levels may contribute to the alleviation of inflammation and airway fibrosis, new and effective PDE inhibitors are constantly being sought. Recently, a group of 7,8-disubstituted purine-2,6-dione derivatives, representing a novel and prominent pan-PDE inhibitors has been synthesized. Some of them were reported to modulate transient receptor potential ankyrin 1 (TRPA1) ion channels as well. In this study, we investigated the effect of selected derivatives (832—a pan-PDE inhibitor, 869—a TRPA1 modulator, and 145—a pan-PDE inhibitor and a weak TRPA1 modulator) on cellular responses related to airway remodeling using MRC-5 human lung fibroblasts. Compound 145 exerted the most considerable effect in limiting fibroblast to myofibroblasts transition (FMT) as well as proliferation, migration, and contraction. The effect of this compound appeared to depend mainly on its strong PDE inhibitory properties, and not on its effects on TRPA1 modulation. The strong anti-remodeling effects of 145 required activation of the cAMP/protein kinase A (PKA)/cAMP response element-binding protein (CREB) pathway leading to inhibition of transforming growth factor type β1 (TGF-β1) and Smad-dependent signaling in MRC-5 cells. These data suggest that the TGF-β pathway is a major target for PDE inhibitors leading to inhibitory effects on cell responses involved in airway remodeling. These potent, pan-PDE inhibitors from the group of 7,8-disubstituted purine-2,6-dione derivatives, thus represent promising anti-remodeling drug candidates for further research.


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