scholarly journals Inhibition of Prostaglandin F2α Receptors Exaggerates HCl-Induced Lung Inflammation in Mice

2021 ◽  
Vol 22 (23) ◽  
pp. 12843
Author(s):  
Toko Maehara ◽  
Ko Fujimori

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe respiratory disorders that are caused by aspiration, sepsis, trauma, and pneumonia. A clinical feature of ALI/ARDS is the acute onset of severe hypoxemia, and the mortality rate, which is estimated at 38–50%, remains high. Although prostaglandins (PGs) are detected in the bronchoalveolar lavage fluid of patients with ALI/ARDS, the role of PGF2α in ALI remains unclear. We aimed to clarify the role of PGF2α/PGF2α receptor (FP) signaling in acid-induced ALI using an FP receptor antagonist, AL8810. Intratracheal injection of hydrochloric acid (HCl) increased neutrophil migration into the lungs, leading to respiratory dysfunction. Pre-administration of AL8810 further increased these features. Moreover, pre-treatment with AL8810 enhanced the HCl-induced expression of pro-inflammatory cytokines and neutrophil migratory factors in the lungs. Administration of HCl decreased the gene expression of lung surfactant proteins, which was further reduced by co-administration of AL8810. Administration of AL8810 also increased lung edema and reduced mRNA expression of epithelial sodium channel in the lungs, indicating that AL8810 reduced fluid clearance. Furthermore, AL8810 also increased lipopolysaccharide-induced expression of adhesion molecules such as intracellular adhesion molecule-1 and E-selectin in human umbilical vein endothelial cells. These results indicate that inhibition of FP receptors by AL8810 exacerbated HCl-induced ALI.

1983 ◽  
Vol 54 (4) ◽  
pp. 984-988 ◽  
Author(s):  
M. M. Tarpey ◽  
H. M. O'Brodovich ◽  
S. L. Young

To study the role of lung lymphatics in the removal of surfactant lipid from the sheep lung, we injected [1–14C]palmitate intravenously into six animals previously fitted with a cannula draining the caudal mediastinal lymph node. Lung lymph was collected for 100 h after injection of radiolabel. We obtained alveolar lavage material through a tracheostomy in four other animals after intravenous injection of [9,10–3H]palmitate. We measured radioactivity at several time points in lipid extracts from lymph, lavage fluid, and lung tissue. Alveolar lavage disaturated phosphatidylcholine (DSPC) specific activity peaked at about 40 h and was reduced to 30% of this value by 82 h. About 2% of the injected radiolabel was incorporated into lung tissue lipids. Only 4% of the level of labeling achieved in lung tissue lipids was found in lung lymph lipid during 100 h of lymph collection. Sixty-three percent of radiolabel in lymph lipid was recovered in phospholipids, and 29% of phospholipid radiolabel was found in DSPC. The distribution of phosphorus and palmitate radiolabel in lung lymph phospholipid did not closely resemble that of surfactant lipid. No rise in lung lymph DSPC specific activity was observed following the peak in lavage specific activity. If surfactant lipid is removed from the alveolar compartment without extensive recycling, then we conclude that the lung lymphatics do not play a major role in the clearance of surfactant lipid from the alveolar surface.


2003 ◽  
Vol 285 (4) ◽  
pp. L879-L888 ◽  
Author(s):  
Evan S. Ong ◽  
Xiao-Pei Gao ◽  
Ning Xu ◽  
Dan Predescu ◽  
Arshad Rahman ◽  
...  

We examined the relationship between neutrophil [polymorphonuclear leukocyte (PMN)] influx and lung vascular injury in response to Escherichia coli pneumonia. We assessed lung tissue PMN uptake by measuring myeloperoxidase and transvascular PMN migration by determining PMN counts in lung interstitium and bronchoalveolar lavage fluid (BALF) in mice challenged intratracheally with E. coli. Lung vascular injury was quantified by determining microvessel filtration coefficient ( Kf,c), a measure of vascular permeability. We addressed the role of CD18 integrin in the mechanism of PMN migration and lung vascular injury by inducing the expression of neutrophil inhibitory factor, a CD11/CD18 antagonist. In control animals, we observed a time-dependent sixfold increase in PMN uptake, a fivefold increase in airway PMN migration, and a 20-fold increase in interstitial PMN uptake at 6 h after challenge. Interestingly, Kf,cincreased minimally during this period of PMN extravasation. CD11/CD18 blockade reduced lung tissue PMN uptake consistent with the role of CD18 in mediating PMN adhesion to the endothelium but failed to alter PMN migration in the tissue. Moreover, CD11/CD18 blockade did not affect Kf,c. Analysis of BALF leukocytes demonstrated diminished oxidative burst compared with leukocytes from bacteremic mice, suggesting a basis for lack of vascular injury. The massive CD11/CD18-independent airway PMN influx occurring in the absence of lung vascular injury is indicative of an efficient host-defense response elicited by E. coli pneumonia.


1991 ◽  
Vol 71 (2) ◽  
pp. 657-665 ◽  
Author(s):  
A. J. Ghio ◽  
T. P. Kennedy ◽  
G. E. Hatch ◽  
J. S. Tepper

Phosgene inhalation causes a severe noncardiogenic pulmonary edema characterized by an influx of neutrophils into the lung. To study the role of neutrophils in lung injury and mortality after phosgene, we investigated the effects of leukocyte depletion with cyclophosphamide, inhibiting the generation of the chemotaxin leukotriene B4 with the 5-lipoxygenase inhibitor AA861 and impairing neutrophil migration with the microtubular poison colchicine. Cyclophosphamide, AA861, and colchicine injected before exposure significantly reduced percent neutrophils, protein, and thiobarbituric acid-reactive products in bronchoalveolar lavage fluid of rats exposed to phosgene (0.5 ppm X 60 min). Cyclophosphamide, AA861, and colchicine also significantly decreased mortality from phosgene (2.0 ppm X 90 min) in mice. Colchicine significantly reduced neutrophil influx, lung injury, and mortality even when given 30 min after phosgene exposure. We conclude that lung injury and mortality after phosgene exposure are associated with an influx of neutrophils into the lung. Prevention of neutrophil migration with colchicine may hold therapeutic potential in phosgene poisoning.


Author(s):  
Amreek Singh ◽  
Judith M. McLaren ◽  
Onkar S. Atwal ◽  
Peter Eyre

Introduction3-methylindole (MI), a rumen metabolite of the amino acid L-tryptophan, has been shown to produce bovine pulmonary edema and emphysema. The airways contain free and exfoliated cells. A morphologic analysis of these cells may complement the understanding of the mechanism of lung edema. Ultrastructure of the bronchopulmonary lavage (BL) cells 24 h following MI oral administration to calves is described in this experiment. The 12 hours post-treatment results were described earlier.Materials and MethodsTwo Holstein-Friesian calves were each administered an oral dose of 0.2 g MI/Kg body weight and another two calves served as controls. The animals were euthanized with sodium pentabarbitol 24 h after receiving the compound. The lungs and trachea were removed and 0.1 M sodium phosphate buffered saline was infused into the lungs through the trachea. Glutaraldehyde fixative was added to the recovered BL fluid so as to form a 1% solution. The fluid was centrifuged and the resulting cell pellet was suspended in the buffer. The procedures were repeated on the suspension; the pellet was post-fixed in osmium tetroxide and was processed by conventional methods of section preparations for TEM examination. Lung samples from caudal lobes were fixed in 1.5% glutaraldehyde to obtain tissue sections for TEM.Results and DiscussionPulmonary alveolar macrophages (AM), neutrophils, ciliated epithelial cells, globule leukocytes and plasma cells were recovered from the BL fluid of the control and Mi-administered calves. Ciliated cells and globule leukocytes could not be harvested from the controls. The AM obtained from the treated calves (Fig. 1) in comparison with similar cells from the controls were larger, and contained large membrane-limited inclusions (phagolysosomes). There was a remarkable similarity between the lavaged AM and the AM studied in thin sections of lung (cf. Fig. 1 and Fig. 2). The neutrophil was the second most abundant cell type retrieved from the lavage fluid from the calves of control or treated group. Except for scanty pseudopodia in the neutrophils obtained from the Mi-receiving calves, the cells appeared unaltered (Fig. 3). Ciliated cells were abundant in the BL fluid of Mi-ingesting calves. A heterogeneous collection of vesicles filled the ciliated cell cytoplasm (Fig. 3). Globule leukocytes were commonly observed among BL cells of treated calves. The globule leukocytes were ca. 15 μm in diameter and contained round or elliptical nuclei with conspicuous nucleoli. The cytoplasmic granules, which are a prominent feature of globule leukocytes, were electron-opaque and had a variable diameter (0.5-3.0 μm). A one-line account of globule leukocytes in the bronchi of steers administered MI has appeared. Plasma cells were rare. Ultrastructure of BL cells is compatible with their response to chemical insult by MI.


1989 ◽  
Vol 61 (03) ◽  
pp. 485-489 ◽  
Author(s):  
Eva Bastida ◽  
Lourdes Almirall ◽  
Antonio Ordinas

SummaryBlood platelets are thought to be involved in certain aspects of malignant dissemination. To study the role of platelets in tumor cell adherence to vascular endothelium we performed studies under static and flow conditions, measuring tumor cell adhesion in the absence or presence of platelets. We used highly metastatic human adenocarcinoma cells of the lung, cultured human umbilical vein endothelial cells (ECs) and extracellular matrices (ECM) prepared from confluent EC monolayers. Our results indicated that under static conditions platelets do not significantly increase tumor cell adhesion to either intact ECs or to exposed ECM. Conversely, the studies performed under flow conditions using the flat chamber perfusion system indicated that the presence of 2 × 105 pl/μl in the perfusate significantly increased the number of tumor cells adhered to ECM, and that this effect was shear rate dependent. The maximal values of tumor cell adhesion were obtained, in presence of platelets, at a shear rate of 1,300 sec-1. Furthermore, our results with ASA-treated platelets suggest that the role of platelets in enhancing tumor cell adhesion to ECM is independent of the activation of the platelet cyclooxygenase pathway.


1997 ◽  
Vol 77 (03) ◽  
pp. 577-584 ◽  
Author(s):  
Mehrdad Baghestanian ◽  
Roland Hofbauer ◽  
Hans G Kress ◽  
Johann Wojta ◽  
Astrid Fabry ◽  
...  

SummaryRecent data suggest that auricular thrombosis is associated with accumulation of mast cells (MC) in the upper endocardium (where usually no MC reside) and local expression of MGF (mast cell growth factor) (25). In this study, the role of vascular cells, thrombin-activation and MGF, in MC-migration was analyzed. For this purpose, cultured human auricular endocardial cells (HAUEC), umbilical vein endothelial cells (HUVEC) and uterine-(HUTMEC) and skin-derived (HSMEC) microvascular endothelial cells were exposed to thrombin or control medium, and the migration of primary tissue MC (lung, n = 6) and HMC-1 cells (human MC-line) against vascular cells (supernatants) measured. Supernatants (24 h) of unstimulated vascular cells (monolayers of endocardium or endothelium) as well as recombinant (rh) MGF induced a significant migratory response in HMC-1 (control: 3025 ± 344 cells [100 ± 11.4%] vs. MGF, 100 ng/ml: 8806 ± 1019 [291 ± 34%] vs. HAUEC: 9703 ± 1506 [320.8 ± 49.8%] vs. HUTMEC: 8950 ± 1857 [295.9 ± 61.4%] vs. HSMEC: 9965 ± 2018 [329.4 ± 66.7%] vs. HUVEC: 9487 ± 1402 [313.6 ± 46.4%], p <0.05) as well as in primary lung MC. Thrombin-activation (5 U/ml, 12 h) of vascular cells led to an augmentation of the directed migration of MC as well as to a hirudin-sensitive increase in MGF synthesis and release. Moreover, a blocking anti-MGF antibody was found to inhibit MC-migration induced by unstimulated or thrombin-activated vascular cells. Together, these data show that endocardial and other vascular cells can induce migration of human MC. This MC-chemotactic signal of the vasculature is associated with expression and release of MGF, augmentable by thrombin, and may play a role in the pathophysiology of (auricular) thrombosis.


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